feat(policies): add relative action support for pi0, pi0.5, and pi0_fast (#2970)

* Add option for pi family models to train with relative actions (relative to state)

* formatting

* add recomputation of stats and option to compute delta stats

* normalzie after delta conversion

* only recompute state for stats

* calulate chunk based stats

* sample 100k

* load from parquet

* sample 1m

* stats per chunck

* fix

* use quantiles

* stats for entire dataset

* fix

* max 1m frames

* compute before dist

* fix multi gpu processor bug

* Fix RTC with delta actions and OpenArms motor_type wiring

* feat: align pi0_fast delta actions with pi0/pi05 and add RTC integration tests

- Add delta_exclude_joints and action_feature_names to PI0FastConfig
- Move to_absolute_actions from modeling to processor pipeline for pi0_fast
- Add delta action detection and logging to eval_with_real_robot.py
- Add delta actions documentation to pi0 and pi05 READMEs
- Fix ruff lint issues in test_delta_actions.py
- Add test_rtc_delta_actions.py (24 tests) covering:
  - ActionQueue with delta vs absolute actions
  - RTC denoise step with delta leftovers
  - Full pipeline roundtrip (delta → RTC → absolute)
  - State rebasing approximation bounds
  - Non-delta policy compatibility
  - Multi-chunk consistency

* chore: clean up test comments, add OpenPI attribution, remove debug logging

- Replace decorative comment separators in test files with plain section headers
- Add attribution comments for 1e-6 epsilon in normalize_processor.py (from OpenPI)
- Remove debug logging blocks from lerobot_train.py

* refactor: extract compute_delta_action_stats into compute_stats.py

Move the ~70-line inline delta action stats block from lerobot_train.py
into a dedicated function in compute_stats.py, where all other stats
computation already lives. The training script now calls it in 6 lines.

* refactor: remove unused get_processed_left_over from ActionQueue

This method was never called outside of tests. Leftover actions for RTC
guidance are always retrieved via get_left_over() (delta/original space).

* revert: remove logging-only changes from eval_with_real_robot.py

The delta actions detection helper and log message added no functional
value — the script already handles delta policies correctly via the
processor pipeline.

* refactor: use ACTION/OBS_STATE constants instead of hardcoded strings

Replace hardcoded "action" and "observation.state" with ACTION and
OBS_STATE from utils.constants in compute_stats.py, dataset_tools.py,
and lerobot_train.py.

* style: remove stray blank lines in training loop

* refactor: move delta action stats to preprocessing step, remove on-the-fly computation

- Remove on-the-fly compute_delta_action_stats from lerobot_train.py
- Rewrite recompute_stats to delegate action stats to compute_delta_action_stats
  (chunk-based sampling matching what the model sees during training)
- Add chunk_size parameter to recompute_stats for delta action computation
- Add delta actions documentation to pi0.mdx and pi05.mdx

* feat: add recompute_stats CLI operation to lerobot-edit-dataset

* fix(tests): relax quantile normalization test tolerance for 1e-6 epsilon

* chore: remove agents_memory/pr_details.md from repo

* refactor: rename delta actions to relative actions throughout

What OpenPI calls "DeltaActions" is actually UMI's "relative trajectory"
representation: each action in the chunk is an offset from the current
state, not from the previous action. This avoids error accumulation.

Renamed across all source, tests, docs, and CLI:
- DeltaActionsProcessorStep → RelativeActionsProcessorStep
- to_delta_actions → to_relative_actions
- use_delta_actions → use_relative_actions
- delta_exclude_joints → relative_exclude_joints
- compute_delta_action_stats → compute_relative_action_stats
- delta_action_processor.py → relative_action_processor.py
- test_delta_actions.py → test_relative_actions.py

Kept as-is: AbsoluteActionsProcessorStep (converts TO absolute),
registry ID "delta_actions_processor" (backward compat), and unrelated
delta references (IK pipeline, Robosuite, RA-BC metrics, gym envs).

* docs: add Action Representations guide

Dedicated page explaining absolute, relative, and delta actions with
numerical examples, joint vs EE space, and how to use kinematics
pipelines and the relative action processor. References UMI paper
(Chi et al., 2024) for the terminology.

* docs: remove redundant OpenPI naming note from action representations

* docs: remove opinionated OpenPI reference from delta actions section

* docs: replace ASCII diagram with UMI paper figure

* docs: remove OpenPI reference from action representations

* docs: use HF-hosted image instead of local asset

* docs: clarify figure attribution

* revert: restore original normalization epsilon behavior

The 1e-6 unconditional epsilon change perturbed all normalized values,
breaking backward compatibility tests. The original approach (1e-8 eps
for MEAN_STD, conditional torch.where for QUANTILES) already handles
division by zero correctly without affecting non-degenerate cases.

* fix: restore delta_action_processor.py used by phone/RL teleop

The rename commit incorrectly deleted delta_action_processor.py and
duplicated its classes into relative_action_processor.py. Restore the
original file and import from it instead.

* fix(processor): address PR #2970 review comments

- Remove shebang from relative_action_processor.py (library module, not script)
- Add device alignment in to_relative_actions/to_absolute_actions so _last_state
  on CPU doesn't cause cross-device errors when actions are on CUDA
- Rename delta_step → relative_step in AbsoluteActionsProcessorStep for naming
  consistency; update factory.py, all processor files, and tests
- Expand _reconnect_relative_absolute_steps docstring to explain why post-hoc
  rewiring is needed after deserialization
- Fix off-by-one in compute_stats.py: sample_upper_bound = total_frames - chunk_size + 1
  so last valid start index is included and total_frames == chunk_size is not rejected
- Remove redundant NOTE comment in processor_pi05.py (duplicated two lines below)
- Fix pi0_fast processor ordering: move relative_step before NormalizerProcessorStep
  so normalizer sees delta actions (matching pi0/pi05); flip postprocessor to
  unnormalize → absolute accordingly. Relative stats are now required for all pi models
- Revert use_relative_joint_actions_aloha → use_delta_joint_actions_aloha in
  configuration_smolvla.py (preserve existing public API)
- Update action_representations.mdx: add missing joint to 6-DOF example, fix
  'based on a figure', clarify pi family ordering, add RTC compatibility section

* update rtc link

* feat: compute relative action stats over full dataset with optional parallelism

Remove the 100k sample cap from compute_relative_action_stats and process
all valid chunks. Vectorize with numpy (pre-load actions/states, fancy
indexing + broadcasting) for a large speedup over the per-index HF dataset
loop. Add num_workers param for thread-based parallelism (numpy releases
the GIL). Update docs to show --push_to_hub for recompute_stats.

* style: apply ruff formatting to compute_stats.py

* testing on real robot

* style: fix ruff format and remove redundant .keys() calls
This commit is contained in:
Pepijn
2026-04-01 12:59:12 +02:00
committed by GitHub
parent 9300352876
commit 15934d8d08
27 changed files with 2215 additions and 100 deletions

View File

@@ -87,6 +87,8 @@
title: Processors for Robots and Teleoperators
- local: env_processor
title: Environment Processors
- local: action_representations
title: Action Representations
title: "Robot Processors"
- sections:
- local: so101

View File

@@ -0,0 +1,223 @@
# Action Representations
This guide explains the different ways robot actions can be represented in LeRobot, how they relate to each other, and when to use each one.
## Joint Space vs End-Effector Space
Before discussing action representations, it helps to understand the two coordinate spaces actions can live in.
### Joint Space
Joint-space actions directly specify target positions for each motor. For a 6-DOF arm with a gripper, a joint-space action might look like:
```
action = [shoulder_pan: 45.0, shoulder_lift: -20.0, elbow: -30.0, wrist_pitch: 10.0, wrist_roll: 0.0, wrist_yaw: 5.0, gripper: 0.8]
```
Joint space is the default in LeRobot. It is simple, requires no kinematics model, and maps directly to motor commands. Most beginner setups (SO-100, Koch) use joint-space actions.
### End-Effector (EE) Space
End-effector-space actions specify the desired position and orientation of the robot's tool tip (gripper) in Cartesian coordinates:
```
action = [x: 0.25, y: -0.10, z: 0.15, wx: 0.0, wy: 0.0, wz: 0.1, gripper: 0.8]
```
EE space is more intuitive for tasks like pick-and-place because it directly describes where the gripper should go, but it requires a kinematics model (URDF) to convert between EE poses and joint angles.
### Converting Between Spaces
LeRobot provides processor steps for converting between joint and EE spaces using forward and inverse kinematics. These are built on top of `RobotKinematics`, which loads a URDF model of your robot.
```python
from lerobot.model.kinematics import RobotKinematics
from lerobot.robots.so_follower.robot_kinematic_processor import (
ForwardKinematicsJointsToEE,
InverseKinematicsEEToJoints,
)
kinematics = RobotKinematics(
urdf_path="./SO101/so101_new_calib.urdf",
target_frame_name="gripper_frame_link",
joint_names=["shoulder", "elbow", "wrist_pitch", "wrist_roll", "wrist_yaw"],
)
# Joints → EE (for observations: "where is my gripper?")
fk_step = ForwardKinematicsJointsToEE(kinematics=kinematics, motor_names=[...])
# EE → Joints (for actions: "move my gripper here")
ik_step = InverseKinematicsEEToJoints(kinematics=kinematics, motor_names=[...])
```
See [`examples/so100_to_so100_EE/`](https://github.com/huggingface/lerobot/tree/main/examples/so100_to_so100_EE) for a complete working example of recording, replaying, and evaluating with EE-space actions on an SO-100 arm.
## Absolute, Relative, and Delta Actions
Regardless of whether you work in joint space or EE space, the action values can be expressed in three different ways. The terminology follows [UMI (Chi et al., 2024)](https://arxiv.org/abs/2402.10329).
### Absolute Actions (LeRobot default)
Each action specifies the target position directly.
**Example** (joint space, chunk of 4):
```
current_state = [45.0, -30.0, 10.0]
action_chunk = [
[46.0, -29.0, 11.0], # go to 46, -29, 11
[47.5, -27.0, 12.0], # go to 47.5, -27, 12
[49.0, -25.0, 13.5], # go to 49, -25, 13.5
[50.0, -24.0, 15.0], # go to 50, -24, 15
]
```
Each value is a target position in the robot's coordinate frame. Simple and direct, but requires a consistent global coordinate frame. This is the default in LeRobot.
### Relative Actions (used by OpenPI / pi0)
Each action in the chunk is an offset from the **current state at the moment of prediction**. All actions in the chunk share the same reference point:
```
current_state = [45.0, -30.0, 10.0]
relative_chunk = [
[1.0, 1.0, 1.0], # +1 from current → target 46, -29, 11
[2.5, 3.0, 2.0], # +2.5 from current → target 47.5, -27, 12
[4.0, 5.0, 3.5], # +4 from current → target 49, -25, 13.5
[5.0, 6.0, 5.0], # +5 from current → target 50, -24, 15
]
```
The conversion is straightforward: `relative = absolute - current_state`. To recover absolute: `absolute = relative + current_state`.
**Why use relative actions?** The model learns to predict offsets centered around zero, which is easier to normalize and leads to more stable training. Because every chunk references the same current state, there is no error accumulation across chunks.
### Delta Actions (sequential differences)
Each action is an offset from the **previous action** (or from the current state for the first step):
```
current_state = [45.0, -30.0, 10.0]
delta_chunk = [
[1.0, 1.0, 1.0], # current → 46, -29, 11
[1.5, 2.0, 1.0], # previous action → 47.5, -27, 12
[1.5, 2.0, 1.5], # previous action → 49, -25, 13.5
[1.0, 1.0, 1.5], # previous action → 50, -24, 15
]
```
Here each step is relative to the one before it. To recover absolute positions you must sum all previous deltas, which means errors accumulate over time. UMI explicitly argues against this representation for this reason.
### Visual Comparison
The figure below (based on a figure from [UMI, Chi et al., 2024](https://arxiv.org/abs/2402.10329)) illustrates the key difference. With **relative trajectory**, every action in the chunk points back to the same origin (current state), so a new inference step cleanly resets the reference. With **delta**, each action depends on the previous one, so errors accumulate. **Absolute** actions require a consistent global coordinate frame.
<img
src="https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/lerobot/action_representations_umi.png"
alt="Relative Trajectory as Action Representation (UMI, Chi et al., 2024)"
width="85%"
/>
## Using Relative Actions in LeRobot
LeRobot provides `RelativeActionsProcessorStep` to convert between absolute and relative actions inside the processor pipeline. This is how pi0, pi0.5, and pi0_fast support relative actions.
> **Note:** All pi models (pi0, pi0.5, pi0*fast) apply relative conversion \_before* normalization (`relative → normalize`), so the normalizer always sees delta (relative) values. This means **relative action stats are required** for all of them when training with `use_relative_actions=true`. In pi0_fast the `RelativeActionsProcessorStep` only modifies the action — the state observation is unchanged — so `NormalizerProcessorStep` still runs before the state tokenizer and the tokenizer continues to receive normalized state as expected.
### How it works
During **training** (preprocessing), actions are converted from absolute to relative before the model sees them:
```
raw absolute action → RelativeActionsProcessorStep → normalize → model
```
During **inference** (postprocessing), model predictions are converted back to absolute before being sent to the robot:
```
model output → unnormalize → AbsoluteActionsProcessorStep → robot
```
The `AbsoluteActionsProcessorStep` reads the cached current state from its paired `RelativeActionsProcessorStep`, so the two must be wired together (handled automatically by the policy factory).
### Enabling relative actions for the pi family (pi0, pi0.5, pi0_fast)
**Step 1**: Precompute relative action statistics for your dataset:
```bash
lerobot-edit-dataset \
--repo_id your_dataset \
--operation.type recompute_stats \
--operation.relative_action true \
--operation.chunk_size 50 \
--operation.relative_exclude_joints "['gripper']"
```
**Step 2**: Train with relative actions enabled:
```bash
lerobot-train \
--dataset.repo_id=your_dataset \
--policy.type=pi0 \
--policy.use_relative_actions=true \
--policy.relative_exclude_joints='["gripper"]'
```
The `relative_exclude_joints` parameter specifies joints that should remain in absolute space. For example, gripper commands are typically binary (open/close) and don't benefit from relative encoding.
### Combining relative actions with RTC
[RTC](https://arxiv.org/abs/2506.07339) runs policy inference at high frequency and sends actions to the robot as they are predicted rather than waiting for a full chunk. Relative actions and RTC are fully compatible: because every chunk in relative mode references the **same** current state (captured at the start of inference), each predicted action in the chunk remains a valid offset even if the robot has already moved. No special handling is needed — `RelativeActionsProcessorStep` caches the state once per inference call and `AbsoluteActionsProcessorStep` applies it to every action in the streamed output.
### Combining relative actions with EE space
Relative actions work in both joint space and EE space. For example, if your dataset stores EE actions, relative encoding converts them to offsets from the current EE pose:
```
current_ee_state = [x: 0.25, y: -0.10, z: 0.15, gripper: 0.8]
absolute_ee_chunk = [
[0.26, -0.09, 0.16, 0.8],
[0.28, -0.07, 0.18, 0.8],
]
relative_ee_chunk = [
[0.01, 0.01, 0.01, 0.0], # offset from current EE pose
[0.03, 0.03, 0.03, 0.0], # offset from current EE pose
]
```
## Processing Pipeline Summary
Here is how the different processors compose. Each arrow is a processor step, and they can be chained in a `RobotProcessorPipeline` or `PolicyProcessorPipeline`:
```
┌─────────────────────────────────────────┐
Action Space │ Joint Space ←──IK──→ EE Space │
│ ForwardKinematicsJointsToEE │
│ InverseKinematicsEEToJoints │
└─────────────────────────────────────────┘
┌─────────────────────────────────────────┐
Representation │ Absolute ←────→ Relative │
│ RelativeActionsProcessorStep (pre) │
│ AbsoluteActionsProcessorStep (post) │
└─────────────────────────────────────────┘
┌─────────────────────────────────────────┐
Normalization │ Raw ←────→ Normalized │
│ NormalizerProcessorStep (pre) │
│ UnnormalizerProcessorStep (post) │
└─────────────────────────────────────────┘
```
A typical training preprocessor might chain: `raw absolute joint actions → relative → normalize`. A typical inference postprocessor: `unnormalize → absolute → (optionally IK to joints)`.
## References
- [Universal Manipulation Interface (UMI)](https://arxiv.org/abs/2402.10329) - Chi et al., 2024. Defines the relative trajectory action representation and compares it with absolute and delta actions.
- [Introduction to Processors](./introduction_processors) - How processor pipelines work in LeRobot.
- [`examples/so100_to_so100_EE/`](https://github.com/huggingface/lerobot/tree/main/examples/so100_to_so100_EE) - Complete example of recording and evaluating with EE-space actions.

View File

@@ -91,6 +91,46 @@ lerobot-train \
**💡 Tip**: Setting `train_expert_only=true` freezes the VLM and trains only the action expert and projections, allowing finetuning with reduced memory usage.
## Relative Actions
By default, π₀ predicts absolute actions. You can enable **relative actions** so the model predicts offsets relative to the current robot state. This can improve training stability for certain setups.
To use relative actions, first recompute your dataset stats in relative space via the CLI:
```bash
lerobot-edit-dataset \
--repo_id your_dataset \
--operation.type recompute_stats \
--operation.relative_action true \
--operation.chunk_size 50 \
--operation.relative_exclude_joints "['gripper']" \
--push_to_hub true
```
Or equivalently in Python:
```python
from lerobot.datasets.lerobot_dataset import LeRobotDataset
from lerobot.datasets.dataset_tools import recompute_stats
dataset = LeRobotDataset("your_dataset")
recompute_stats(dataset, relative_action=True, chunk_size=50, relative_exclude_joints=["gripper"])
dataset.push_to_hub()
```
The `chunk_size` should match your policy's `chunk_size` (default 50 for π₀). `relative_exclude_joints` lists joint names that should remain in absolute space (e.g. gripper commands). Use `--push_to_hub true` to upload the updated stats to the Hub.
Then train with relative actions enabled:
```bash
lerobot-train \
--dataset.repo_id=your_dataset \
--policy.type=pi0 \
--policy.use_relative_actions=true \
--policy.relative_exclude_joints='["gripper"]' \
...
```
## License
This model follows the **Apache 2.0 License**, consistent with the original [OpenPI repository](https://github.com/Physical-Intelligence/openpi).

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@@ -97,6 +97,46 @@ python src/lerobot/datasets/v30/augment_dataset_quantile_stats.py \
Or train pi05 with this normalization mapping: `--policy.normalization_mapping='{"ACTION": "MEAN_STD", "STATE": "MEAN_STD", "VISUAL": "IDENTITY"}'`
## Relative Actions
By default, π₀.₅ predicts absolute actions. You can enable **relative actions** so the model predicts offsets relative to the current robot state. This can improve training stability for certain setups.
To use relative actions, first recompute your dataset stats in relative space via the CLI:
```bash
lerobot-edit-dataset \
--repo_id your_dataset \
--operation.type recompute_stats \
--operation.relative_action true \
--operation.chunk_size 50 \
--operation.relative_exclude_joints "['gripper']" \
--push_to_hub true
```
Or equivalently in Python:
```python
from lerobot.datasets.lerobot_dataset import LeRobotDataset
from lerobot.datasets.dataset_tools import recompute_stats
dataset = LeRobotDataset("your_dataset")
recompute_stats(dataset, relative_action=True, chunk_size=50, relative_exclude_joints=["gripper"])
dataset.push_to_hub()
```
The `chunk_size` should match your policy's `chunk_size` (default 50 for π₀.₅). `relative_exclude_joints` lists joint names that should remain in absolute space (e.g. gripper commands). Use `--push_to_hub true` to upload the updated stats to the Hub.
Then train with relative actions enabled:
```bash
lerobot-train \
--dataset.repo_id=your_dataset \
--policy.type=pi05 \
--policy.use_relative_actions=true \
--policy.relative_exclude_joints='["gripper"]' \
...
```
## Performance Results
### Libero Benchmark Results

View File

@@ -63,6 +63,26 @@ Usage:
--robot.cameras="{ gripper: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}, front: {type: opencv, index_or_path: 1, width: 640, height: 480, fps: 30}}" \
--task="Move green small object into the purple platform" \
--duration=120
# Run RTC with bi_openarm_follower (dual-arm OpenArms) and pi0.5 policy
python examples/rtc/eval_with_real_robot.py \
--policy.path=lerobot-data-collection/folding_final \
--robot.type=bi_openarm_follower \
--robot.cameras='{left_wrist: {type: opencv, index_or_path: "/dev/video4", width: 1280, height: 720, fps: 30}, base: {type: opencv, index_or_path: "/dev/video2", width: 640, height: 480, fps: 30}, right_wrist: {type: opencv, index_or_path: "/dev/video0", width: 1280, height: 720, fps: 30}}' \
--robot.left_arm_config.port=can1 \
--robot.left_arm_config.side=left \
--robot.left_arm_config.can_interface=socketcan \
--robot.right_arm_config.port=can0 \
--robot.right_arm_config.side=right \
--robot.right_arm_config.can_interface=socketcan \
--task="Fold the T-shirt properly" \
--fps=30 \
--duration=2000 \
--rtc.enabled=true \
--rtc.execution_horizon=20 \
--rtc.max_guidance_weight=5.0 \
--rtc.prefix_attention_schedule=LINEAR \
--device=cuda
"""
import logging
@@ -87,21 +107,29 @@ from lerobot.policies.factory import get_policy_class, make_pre_post_processors
from lerobot.policies.rtc.action_queue import ActionQueue
from lerobot.policies.rtc.configuration_rtc import RTCConfig
from lerobot.policies.rtc.latency_tracker import LatencyTracker
from lerobot.processor import (
NormalizerProcessorStep,
RelativeActionsProcessorStep,
TransitionKey,
create_transition,
)
from lerobot.processor.factory import (
make_default_robot_action_processor,
make_default_robot_observation_processor,
)
from lerobot.processor.relative_action_processor import to_relative_actions
from lerobot.rl.process import ProcessSignalHandler
from lerobot.robots import ( # noqa: F401
Robot,
RobotConfig,
bi_openarm_follower,
bi_so_follower,
koch_follower,
so_follower,
unitree_g1,
)
from lerobot.robots.utils import make_robot_from_config
from lerobot.utils.constants import OBS_IMAGES
from lerobot.utils.constants import OBS_IMAGES, OBS_STATE
from lerobot.utils.hub import HubMixin
from lerobot.utils.utils import init_logging
@@ -212,6 +240,35 @@ def is_image_key(k: str) -> bool:
return k.startswith(OBS_IMAGES)
def _reanchor_relative_rtc_prefix(
prev_actions_absolute: Tensor,
current_state: Tensor,
relative_step: RelativeActionsProcessorStep,
normalizer_step: NormalizerProcessorStep | None,
policy_device: torch.device | str,
) -> Tensor:
"""Convert absolute leftovers into model-space for relative-action RTC policies.
When a policy uses relative actions, the RTC prefix (leftover actions from
the previous chunk) is stored in absolute space. Before feeding it back to
the policy we need to re-express it relative to the *current* robot state
and then re-normalize.
"""
state = current_state.detach().cpu()
if state.dim() == 1:
state = state.unsqueeze(0)
action_cpu = prev_actions_absolute.detach().cpu()
mask = relative_step._build_mask(action_cpu.shape[-1])
relative_actions = to_relative_actions(action_cpu, state, mask)
transition = create_transition(action=relative_actions)
if normalizer_step is not None:
transition = normalizer_step(transition)
return transition[TransitionKey.ACTION].to(policy_device)
def get_actions(
policy,
robot: RobotWrapper,
@@ -237,7 +294,15 @@ def get_actions(
fps = cfg.fps
time_per_chunk = 1.0 / fps
dataset_features = hw_to_dataset_features(robot.observation_features(), "observation")
# Only keep .pos joints + camera streams if the policy was trained on positions,
# not the full pos/vel/torque state the robot exposes.
observation_features_hw = {
key: value
for key, value in robot.observation_features().items()
if key.endswith(".pos") or isinstance(value, tuple)
}
dataset_features = hw_to_dataset_features(observation_features_hw, "observation")
policy_device = policy.config.device
# Load preprocessor and postprocessor from pretrained files
@@ -255,6 +320,25 @@ def get_actions(
logger.info("[GET_ACTIONS] Preprocessor/postprocessor loaded successfully with embedded stats")
relative_step = next(
(s for s in preprocessor.steps if isinstance(s, RelativeActionsProcessorStep) and s.enabled),
None,
)
normalizer_step = next(
(s for s in preprocessor.steps if isinstance(s, NormalizerProcessorStep)),
None,
)
if relative_step is not None:
if relative_step.action_names is None:
cfg_names = getattr(cfg.policy, "action_feature_names", None)
if cfg_names:
relative_step.action_names = list(cfg_names)
else:
relative_step.action_names = [
k for k in robot.robot.action_features if k.endswith(".pos")
]
logger.info("[GET_ACTIONS] Relative actions enabled: will re-anchor RTC prefix")
get_actions_threshold = cfg.action_queue_size_to_get_new_actions
if not cfg.rtc.enabled:
@@ -297,6 +381,28 @@ def get_actions(
preproceseded_obs = preprocessor(obs_with_policy_features)
# Re-anchor leftover actions for relative-action policies.
# We need the *postprocessed* (absolute) leftover, not the original
# (normalized/relative) one that get_left_over() returns.
if (
prev_actions is not None
and relative_step is not None
and OBS_STATE in obs_with_policy_features
):
with action_queue.lock:
if action_queue.queue is not None:
prev_actions_abs = action_queue.queue[action_queue.last_index :].clone()
else:
prev_actions_abs = None
if prev_actions_abs is not None and prev_actions_abs.numel() > 0:
prev_actions = _reanchor_relative_rtc_prefix(
prev_actions_absolute=prev_actions_abs,
current_state=obs_with_policy_features[OBS_STATE],
relative_step=relative_step,
normalizer_step=normalizer_step,
policy_device=policy_device,
)
# Generate actions WITH RTC
actions = policy.predict_action_chunk(
preproceseded_obs,
@@ -352,6 +458,8 @@ def actor_control(
try:
logger.info("[ACTOR] Starting actor thread")
action_keys = [k for k in robot.action_features() if k.endswith(".pos")]
action_count = 0
action_interval = 1.0 / cfg.fps
@@ -363,7 +471,7 @@ def actor_control(
if action is not None:
action = action.cpu()
action_dict = {key: action[i].item() for i, key in enumerate(robot.action_features())}
action_dict = {key: action[i].item() for i, key in enumerate(action_keys)}
action_processed = robot_action_processor((action_dict, None))
robot.send_action(action_processed)

View File

@@ -13,9 +13,14 @@
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import annotations
import logging
import numpy as np
from lerobot.datasets.io_utils import load_image_as_numpy
from lerobot.utils.constants import ACTION, OBS_STATE
DEFAULT_QUANTILES = [0.01, 0.10, 0.50, 0.90, 0.99]
@@ -624,3 +629,141 @@ def aggregate_stats(stats_list: list[dict[str, dict]]) -> dict[str, dict[str, np
aggregated_stats[key] = aggregate_feature_stats(stats_with_key)
return aggregated_stats
def _get_valid_chunk_starts(episode_indices: np.ndarray, chunk_size: int) -> np.ndarray:
"""Return all start indices where a chunk of ``chunk_size`` stays within one episode."""
total = len(episode_indices)
if total < chunk_size:
return np.array([], dtype=np.int64)
max_start = total - chunk_size
starts = np.arange(max_start + 1)
valid = episode_indices[starts] == episode_indices[starts + chunk_size - 1]
return starts[valid]
def _compute_relative_chunk_batch(
start_indices: np.ndarray,
all_actions: np.ndarray,
all_states: np.ndarray,
chunk_size: int,
relative_mask: np.ndarray,
) -> np.ndarray:
"""Vectorised relative-action computation for a batch of start indices.
Returns an ``(N * chunk_size, action_dim)`` float32 array.
"""
if len(start_indices) == 0:
return np.empty((0, all_actions.shape[1]), dtype=np.float32)
offsets = np.arange(chunk_size)
frame_idx = start_indices[:, None] + offsets[None, :]
chunks = all_actions[frame_idx].copy()
states = all_states[start_indices]
mask_dim = len(relative_mask)
chunks[:, :, :mask_dim] -= states[:, None, :mask_dim] * relative_mask[None, None, :]
return chunks.reshape(-1, all_actions.shape[1])
def compute_relative_action_stats(
hf_dataset,
features: dict,
chunk_size: int,
exclude_joints: list[str] | None = None,
num_workers: int = 0,
) -> dict[str, np.ndarray]:
"""Compute normalization statistics for relative actions over the full dataset.
Iterates *all* valid action chunks (within single episodes), converts them to
relative actions (action current_state), and computes per-dimension
statistics suitable for normalization.
Args:
hf_dataset: The underlying HuggingFace dataset with "action",
"observation.state", and "episode_index" columns.
features: Dataset feature metadata (must contain "action" with "shape"
and optionally "names").
chunk_size: Number of consecutive frames per action chunk.
exclude_joints: Joint names whose dimensions should remain absolute
(not converted to relative actions).
num_workers: Number of parallel threads for computation. Values ≤1
mean single-threaded. Numpy releases the GIL so threads give
real parallelism here.
Returns:
Statistics dict with keys "mean", "std", "min", "max", "q01", …, "q99".
Raises:
ValueError: If the dataset has fewer frames than ``chunk_size``.
RuntimeError: If no valid (single-episode) chunks are found.
"""
from lerobot.processor.relative_action_processor import RelativeActionsProcessorStep
if exclude_joints is None:
exclude_joints = []
action_dim = features[ACTION]["shape"][0]
action_names = features.get(ACTION, {}).get("names")
mask_step = RelativeActionsProcessorStep(
enabled=True,
exclude_joints=exclude_joints,
action_names=action_names,
)
relative_mask = np.array(mask_step._build_mask(action_dim), dtype=np.float32)
logging.info("Loading action/state data for relative action stats...")
all_actions = np.array(hf_dataset[ACTION], dtype=np.float32)
all_states = np.array(hf_dataset[OBS_STATE], dtype=np.float32)
episode_indices = np.array(hf_dataset["episode_index"])
valid_starts = _get_valid_chunk_starts(episode_indices, chunk_size)
if len(valid_starts) == 0:
raise RuntimeError(
f"No valid chunks found (total_frames={len(episode_indices)}, chunk_size={chunk_size})"
)
effective_workers = max(num_workers, 1)
logging.info(
f"Computing relative action stats from {len(valid_starts)} chunks "
f"(chunk_size={chunk_size}, workers={effective_workers})"
)
batch_size = 50_000
batches = [valid_starts[i : i + batch_size] for i in range(0, len(valid_starts), batch_size)]
running_stats = RunningQuantileStats()
if num_workers > 1:
from concurrent.futures import ThreadPoolExecutor, as_completed
with ThreadPoolExecutor(max_workers=num_workers) as pool:
futures = [
pool.submit(
_compute_relative_chunk_batch,
batch,
all_actions,
all_states,
chunk_size,
relative_mask,
)
for batch in batches
]
for future in as_completed(futures):
running_stats.update(future.result())
else:
for batch in batches:
running_stats.update(
_compute_relative_chunk_batch(batch, all_actions, all_states, chunk_size, relative_mask)
)
stats = running_stats.get_statistics()
excluded_dims = int(len(relative_mask) - relative_mask.sum())
total_frames = len(valid_starts) * chunk_size
logging.info(
f"Relative action stats ({len(valid_starts)} chunks, {total_frames} frames): "
f"relative_dims={int(relative_mask.sum())}/{len(relative_mask)} (excluded={excluded_dims}), "
f"mean={np.abs(stats['mean']).mean():.4f}, std={stats['std'].mean():.4f}, "
f"q01={stats['q01'].mean():.4f}, q99={stats['q99'].mean():.4f}"
)
return stats

View File

@@ -37,7 +37,11 @@ import torch
from tqdm import tqdm
from lerobot.datasets.aggregate import aggregate_datasets
from lerobot.datasets.compute_stats import aggregate_stats
from lerobot.datasets.compute_stats import (
aggregate_stats,
compute_episode_stats,
compute_relative_action_stats,
)
from lerobot.datasets.dataset_metadata import LeRobotDatasetMetadata
from lerobot.datasets.io_utils import (
get_parquet_file_size_in_mb,
@@ -56,7 +60,7 @@ from lerobot.datasets.utils import (
update_chunk_file_indices,
)
from lerobot.datasets.video_utils import encode_video_frames, get_video_info
from lerobot.utils.constants import HF_LEROBOT_HOME, OBS_IMAGE
from lerobot.utils.constants import ACTION, HF_LEROBOT_HOME, OBS_IMAGE, OBS_STATE
def _load_episode_with_stats(src_dataset: LeRobotDataset, episode_idx: int) -> dict:
@@ -1533,6 +1537,114 @@ def modify_tasks(
return dataset
def recompute_stats(
dataset: LeRobotDataset,
skip_image_video: bool = True,
relative_action: bool = False,
relative_exclude_joints: list[str] | None = None,
chunk_size: int = 50,
num_workers: int = 0,
) -> LeRobotDataset:
"""Recompute stats.json from scratch by iterating all episodes.
Args:
dataset: The LeRobotDataset to recompute stats for.
skip_image_video: If True (default), only recompute stats for numeric features
(action, state, etc.) and keep existing image/video stats unchanged.
relative_action: If True, compute action stats in relative space by
iterating all valid action chunks and subtracting the current state.
This matches the normalization distribution the model sees during
training with ``use_relative_actions=True``.
relative_exclude_joints: Joint names to exclude from relative conversion when
relative_action=True. These dims keep absolute stats.
chunk_size: Action chunk size used for relative stats computation. Should match
``policy.chunk_size``. Only used when ``relative_action=True``.
num_workers: Number of parallel threads for relative action stats computation.
Values ≤1 mean single-threaded. Only used when ``relative_action=True``.
Returns:
The same dataset with updated stats.
"""
features = dataset.meta.features
meta_keys = {"index", "episode_index", "task_index", "frame_index", "timestamp"}
numeric_features = {
k: v
for k, v in features.items()
if v["dtype"] not in ["image", "video", "string"] and k not in meta_keys
}
if skip_image_video:
features_to_compute = numeric_features
else:
features_to_compute = {
k: v for k, v in features.items() if v["dtype"] != "string" and k not in meta_keys
}
# When relative_action is enabled, compute action stats via chunk-based sampling
# (matching what the model sees during training) and skip action in the
# per-episode pass below.
relative_action_stats = None
if relative_action and ACTION in features and OBS_STATE in features:
if relative_exclude_joints is None:
relative_exclude_joints = ["gripper"]
relative_action_stats = compute_relative_action_stats(
hf_dataset=dataset.hf_dataset,
features=features,
chunk_size=chunk_size,
exclude_joints=relative_exclude_joints,
num_workers=num_workers,
)
features_to_compute.pop(ACTION, None)
logging.info(f"Recomputing stats for features: {list(features_to_compute.keys())}")
data_dir = dataset.root / DATA_DIR
parquet_files = sorted(data_dir.glob("*/*.parquet"))
if not parquet_files:
raise ValueError(f"No parquet files found in {data_dir}")
all_episode_stats = []
numeric_keys = [k for k, v in features_to_compute.items() if v["dtype"] not in ["image", "video"]]
for parquet_path in tqdm(parquet_files, desc="Computing stats from data files"):
df = pd.read_parquet(parquet_path)
for ep_idx in sorted(df["episode_index"].unique()):
ep_df = df[df["episode_index"] == ep_idx]
episode_data = {}
for key in numeric_keys:
if key in ep_df.columns:
values = ep_df[key].values
if hasattr(values[0], "__len__"):
episode_data[key] = np.stack(values)
else:
episode_data[key] = np.array(values)
ep_stats = compute_episode_stats(episode_data, features_to_compute)
all_episode_stats.append(ep_stats)
if features_to_compute and not all_episode_stats:
logging.warning("No episode stats computed")
return dataset
new_stats = aggregate_stats(all_episode_stats) if all_episode_stats else {}
if relative_action_stats is not None:
new_stats[ACTION] = relative_action_stats
# Merge: keep existing stats for features we didn't recompute
if dataset.meta.stats:
for key, value in dataset.meta.stats.items():
if key not in new_stats:
new_stats[key] = value
write_stats(new_stats, dataset.root)
dataset.meta.stats = new_stats
logging.info("Stats recomputed successfully")
return dataset
def convert_image_to_video_dataset(
dataset: LeRobotDataset,
output_dir: Path | None = None,

View File

@@ -59,6 +59,29 @@ from lerobot.utils.constants import (
)
def _reconnect_relative_absolute_steps(
preprocessor: PolicyProcessorPipeline, postprocessor: PolicyProcessorPipeline
) -> None:
"""Wire AbsoluteActionsProcessorStep.relative_step to the RelativeActionsProcessorStep after deserialization.
After a policy is loaded from disk, the preprocessor and postprocessor are reconstructed
independently from their configs. AbsoluteActionsProcessorStep needs a live reference to
the RelativeActionsProcessorStep so it can read the cached state at inference time.
That reference is not serializable, so we re-establish it here after loading.
"""
from lerobot.processor.relative_action_processor import (
AbsoluteActionsProcessorStep,
RelativeActionsProcessorStep,
)
relative_step = next((s for s in preprocessor.steps if isinstance(s, RelativeActionsProcessorStep)), None)
if relative_step is None:
return
for step in postprocessor.steps:
if isinstance(step, AbsoluteActionsProcessorStep) and step.relative_step is None:
step.relative_step = relative_step
def get_policy_class(name: str) -> type[PreTrainedPolicy]:
"""
Retrieves a policy class by its registered name.
@@ -269,8 +292,7 @@ def make_pre_post_processors(
kwargs["preprocessor_overrides"] = preprocessor_overrides
kwargs["postprocessor_overrides"] = postprocessor_overrides
return (
PolicyProcessorPipeline.from_pretrained(
preprocessor = PolicyProcessorPipeline.from_pretrained(
pretrained_model_name_or_path=pretrained_path,
config_filename=kwargs.get(
"preprocessor_config_filename", f"{POLICY_PREPROCESSOR_DEFAULT_NAME}.json"
@@ -278,8 +300,8 @@ def make_pre_post_processors(
overrides=kwargs.get("preprocessor_overrides", {}),
to_transition=batch_to_transition,
to_output=transition_to_batch,
),
PolicyProcessorPipeline.from_pretrained(
)
postprocessor = PolicyProcessorPipeline.from_pretrained(
pretrained_model_name_or_path=pretrained_path,
config_filename=kwargs.get(
"postprocessor_config_filename", f"{POLICY_POSTPROCESSOR_DEFAULT_NAME}.json"
@@ -287,8 +309,9 @@ def make_pre_post_processors(
overrides=kwargs.get("postprocessor_overrides", {}),
to_transition=policy_action_to_transition,
to_output=transition_to_policy_action,
),
)
_reconnect_relative_absolute_steps(preprocessor, postprocessor)
return preprocessor, postprocessor
# Create a new processor based on policy type
if isinstance(policy_cfg, TDMPCConfig):
@@ -486,6 +509,13 @@ def make_policy(
cfg.output_features = {key: ft for key, ft in features.items() if ft.type is FeatureType.ACTION}
if not cfg.input_features:
cfg.input_features = {key: ft for key, ft in features.items() if key not in cfg.output_features}
# Store action feature names for relative_exclude_joints support
if ds_meta is not None and hasattr(cfg, "action_feature_names"):
action_names = ds_meta.features.get(ACTION, {}).get("names")
if action_names is not None:
cfg.action_feature_names = list(action_names)
kwargs["config"] = cfg
# Pass dataset_stats to the policy if available (needed for some policies like SARM)

View File

@@ -17,6 +17,65 @@ It is designed as a **Vision-Language-Action model for general robot control**.
---
## Relative Actions
π₀ supports training with **relative actions**, where the model learns relative offsets
from the current robot state instead of absolute joint positions. This mirrors the
relative-action transform in OpenPI (`DeltaActions`) and can improve performance.
### How it works
1. **During preprocessing**, absolute actions are converted to relative offsets:
`relative = action - state` (for selected joints).
2. The relative actions are normalized using statistics computed from the relative distribution.
3. **During postprocessing**, predicted relative actions are converted back to absolute:
`absolute = relative + state`.
Joints listed in `relative_exclude_joints` (e.g., gripper) are kept absolute.
### Configuration
| Parameter | Type | Default | Description |
| ------------------------- | ----------- | ------------- | ---------------------------------------------------------------- |
| `use_relative_actions` | `bool` | `False` | Enable relative-action training |
| `relative_exclude_joints` | `list[str]` | `["gripper"]` | Joint names to keep absolute (matched by substring) |
| `action_feature_names` | `list[str]` | `None` | Auto-populated from dataset metadata at runtime by `make_policy` |
### Training example
```bash
python -m lerobot.scripts.lerobot_train \
--policy.type=pi0 \
--dataset.repo_id=your_org/your_dataset \
--policy.use_relative_actions=true \
--policy.relative_exclude_joints='["gripper"]'
```
When `use_relative_actions=true`, the training script automatically:
- Computes relative action statistics from the dataset (sampled chunk-level relative actions)
- Replaces the standard action stats with relative stats for normalization
- Broadcasts these stats across all ranks in distributed training
### Recomputing stats for an existing dataset
If you want to precompute relative action stats offline, use `recompute_stats` from
`lerobot.datasets.dataset_tools`:
```python
from lerobot.datasets.lerobot_dataset import LeRobotDataset
from lerobot.datasets.dataset_tools import recompute_stats
dataset = LeRobotDataset("your_org/your_dataset")
dataset = recompute_stats(
dataset,
relative_action=True,
relative_exclude_joints=["gripper"],
)
```
---
## Citation
If you use this work, please cite both **OpenPI** and the π₀ paper:

View File

@@ -50,6 +50,13 @@ class PI0Config(PreTrainedConfig):
min_period: float = 4e-3
max_period: float = 4.0
# Relative actions: converts absolute actions to relative (relative to state).
use_relative_actions: bool = False
# Joint names to exclude from relative (kept absolute). Empty list = all dims relative.
relative_exclude_joints: list[str] = field(default_factory=lambda: ["gripper"])
# Populated at runtime from dataset metadata by make_policy.
action_feature_names: list[str] | None = None
# Real-Time Chunking (RTC) configuration
rtc_config: RTCConfig | None = None

View File

@@ -21,6 +21,7 @@ import torch
from lerobot.configs.types import PipelineFeatureType, PolicyFeature
from lerobot.policies.pi0.configuration_pi0 import PI0Config
from lerobot.processor import (
AbsoluteActionsProcessorStep,
AddBatchDimensionProcessorStep,
ComplementaryDataProcessorStep,
DeviceProcessorStep,
@@ -29,6 +30,7 @@ from lerobot.processor import (
PolicyProcessorPipeline,
ProcessorStep,
ProcessorStepRegistry,
RelativeActionsProcessorStep,
RenameObservationsProcessorStep,
TokenizerProcessorStep,
UnnormalizerProcessorStep,
@@ -126,7 +128,13 @@ def make_pi0_pre_post_processors(
A tuple containing the configured pre-processor and post-processor pipelines.
"""
# Add remaining processors
relative_step = RelativeActionsProcessorStep(
enabled=config.use_relative_actions,
exclude_joints=getattr(config, "relative_exclude_joints", []),
action_names=getattr(config, "action_feature_names", None),
)
# OpenPI order: raw → relative → normalize → model → unnormalize → absolute
input_steps: list[ProcessorStep] = [
RenameObservationsProcessorStep(rename_map={}), # To mimic the same processor as pretrained one
AddBatchDimensionProcessorStep(),
@@ -138,6 +146,7 @@ def make_pi0_pre_post_processors(
padding="max_length",
),
DeviceProcessorStep(device=config.device),
relative_step,
NormalizerProcessorStep(
features={**config.input_features, **config.output_features},
norm_map=config.normalization_mapping,
@@ -149,6 +158,7 @@ def make_pi0_pre_post_processors(
UnnormalizerProcessorStep(
features=config.output_features, norm_map=config.normalization_mapping, stats=dataset_stats
),
AbsoluteActionsProcessorStep(enabled=config.use_relative_actions, relative_step=relative_step),
DeviceProcessorStep(device="cpu"),
]

View File

@@ -17,6 +17,48 @@ It is designed as a **Vision-Language-Action model with open-world generalizatio
---
## Relative Actions
π₀.₅ supports training with **relative actions**, where the model learns relative offsets
from the current robot state instead of absolute joint positions. This mirrors the
relative-action transform in OpenPI (`DeltaActions`) and can improve performance.
### How it works
1. **During preprocessing**, absolute actions are converted to relative offsets:
`relative = action - state` (for selected joints).
2. The relative actions are normalized using statistics computed from the relative distribution.
3. **During postprocessing**, predicted relative actions are converted back to absolute:
`absolute = relative + state`.
Joints listed in `relative_exclude_joints` (e.g., gripper) are kept absolute.
### Configuration
| Parameter | Type | Default | Description |
| ------------------------- | ----------- | ------------- | ---------------------------------------------------------------- |
| `use_relative_actions` | `bool` | `False` | Enable relative-action training |
| `relative_exclude_joints` | `list[str]` | `["gripper"]` | Joint names to keep absolute (matched by substring) |
| `action_feature_names` | `list[str]` | `None` | Auto-populated from dataset metadata at runtime by `make_policy` |
### Training example
```bash
python -m lerobot.scripts.lerobot_train \
--policy.type=pi05 \
--dataset.repo_id=your_org/your_dataset \
--policy.use_relative_actions=true \
--policy.relative_exclude_joints='["gripper"]'
```
When `use_relative_actions=true`, the training script automatically:
- Computes relative action statistics from the dataset (sampled chunk-level relative actions)
- Replaces the standard action stats with relative stats for normalization
- Broadcasts these stats across all ranks in distributed training
---
## Citation
If you use this work, please cite both **OpenPI** and the π₀.₅ paper:

View File

@@ -50,6 +50,13 @@ class PI05Config(PreTrainedConfig):
min_period: float = 4e-3
max_period: float = 4.0
# Relative actions: converts absolute actions to relative (relative to state).
use_relative_actions: bool = False
# Joint names to exclude from relative (kept absolute). Empty list = all dims relative.
relative_exclude_joints: list[str] = field(default_factory=lambda: ["gripper"])
# Populated at runtime from dataset metadata by make_policy.
action_feature_names: list[str] | None = None
# Real-Time Chunking (RTC) configuration
rtc_config: RTCConfig | None = None

View File

@@ -24,6 +24,7 @@ import torch
from lerobot.configs.types import PipelineFeatureType, PolicyFeature
from lerobot.policies.pi05.configuration_pi05 import PI05Config
from lerobot.processor import (
AbsoluteActionsProcessorStep,
AddBatchDimensionProcessorStep,
DeviceProcessorStep,
NormalizerProcessorStep,
@@ -31,6 +32,7 @@ from lerobot.processor import (
PolicyProcessorPipeline,
ProcessorStep,
ProcessorStepRegistry,
RelativeActionsProcessorStep,
RenameObservationsProcessorStep,
TokenizerProcessorStep,
UnnormalizerProcessorStep,
@@ -125,10 +127,17 @@ def make_pi05_pre_post_processors(
A tuple containing the configured pre-processor and post-processor pipelines.
"""
# Add remaining processors
relative_step = RelativeActionsProcessorStep(
enabled=config.use_relative_actions,
exclude_joints=getattr(config, "relative_exclude_joints", []),
action_names=getattr(config, "action_feature_names", None),
)
# OpenPI order: raw → relative → normalize → model → unnormalize → absolute
input_steps: list[ProcessorStep] = [
RenameObservationsProcessorStep(rename_map={}), # To mimic the same processor as pretrained one
AddBatchDimensionProcessorStep(),
relative_step,
# NOTE: NormalizerProcessorStep MUST come before Pi05PrepareStateTokenizerProcessorStep
# because the tokenizer step expects normalized state in [-1, 1] range for discretization
NormalizerProcessorStep(
@@ -150,6 +159,7 @@ def make_pi05_pre_post_processors(
UnnormalizerProcessorStep(
features=config.output_features, norm_map=config.normalization_mapping, stats=dataset_stats
),
AbsoluteActionsProcessorStep(enabled=config.use_relative_actions, relative_step=relative_step),
DeviceProcessorStep(device="cpu"),
]

View File

@@ -41,6 +41,13 @@ class PI0FastConfig(PreTrainedConfig):
max_action_dim: int = 32
max_action_tokens: int = 256
# Relative actions: converts absolute actions to relative (relative to state).
use_relative_actions: bool = False
# Joint names to exclude from relative (kept absolute). Empty list = all dims relative.
relative_exclude_joints: list[str] = field(default_factory=lambda: ["gripper"])
# Populated at runtime from dataset metadata by make_policy.
action_feature_names: list[str] | None = None
# Real-Time Chunking (RTC) configuration
rtc_config: RTCConfig | None = None

View File

@@ -24,6 +24,7 @@ import torch
from lerobot.configs.types import PipelineFeatureType, PolicyFeature
from lerobot.policies.pi0_fast.configuration_pi0_fast import PI0FastConfig
from lerobot.processor import (
AbsoluteActionsProcessorStep,
ActionTokenizerProcessorStep,
AddBatchDimensionProcessorStep,
DeviceProcessorStep,
@@ -32,6 +33,7 @@ from lerobot.processor import (
PolicyProcessorPipeline,
ProcessorStep,
ProcessorStepRegistry,
RelativeActionsProcessorStep,
RenameObservationsProcessorStep,
TokenizerProcessorStep,
UnnormalizerProcessorStep,
@@ -125,12 +127,24 @@ def make_pi0_fast_pre_post_processors(
Returns:
A tuple containing the configured pre-processor and post-processor pipelines.
"""
# Add remaining processors
relative_step = RelativeActionsProcessorStep(
enabled=config.use_relative_actions,
exclude_joints=getattr(config, "relative_exclude_joints", []),
action_names=getattr(config, "action_feature_names", None),
)
# Pi0Fast order: relative → normalize → tokenize → model → unnormalize → absolute
# This matches pi0/pi0.5: RelativeActionsProcessorStep runs first on raw absolute actions,
# caching the raw state. NormalizerProcessorStep then normalizes the raw relative actions,
# so the normalizer (and action tokenizer) sees delta values — relative stats are required.
# NOTE: RelativeActionsProcessorStep only modifies the action in the transition; it reads
# state from the observation but does not change it. NormalizerProcessorStep still runs
# before Pi0FastPrepareStateAndLanguageTokenizerProcessorStep, so the state tokenizer
# continues to receive normalized state in [-1, 1] as expected.
input_steps: list[ProcessorStep] = [
RenameObservationsProcessorStep(rename_map={}), # To mimic the same processor as pretrained one
AddBatchDimensionProcessorStep(),
# NOTE: NormalizerProcessorStep MUST come before Pi0FastPrepareStateAndLanguageTokenizerProcessorStep
# because the tokenizer step expects normalized state in [-1, 1] range for discretization
relative_step,
NormalizerProcessorStep(
features={**config.input_features, **config.output_features},
norm_map=config.normalization_mapping,
@@ -156,6 +170,7 @@ def make_pi0_fast_pre_post_processors(
UnnormalizerProcessorStep(
features=config.output_features, norm_map=config.normalization_mapping, stats=dataset_stats
),
AbsoluteActionsProcessorStep(enabled=config.use_relative_actions, relative_step=relative_step),
DeviceProcessorStep(device="cpu"),
]

View File

@@ -55,7 +55,7 @@ class SmolVLAConfig(PreTrainedConfig):
# the space used by the pi internal runtime which was used to train the base model.
adapt_to_pi_aloha: bool = False
# Converts joint dimensions to deltas with respect to the current state before passing to the model.
# Converts joint dimensions to relative values with respect to the current state before passing to the model.
# Gripper dimensions will remain in absolute values.
use_delta_joint_actions_aloha: bool = False

View File

@@ -75,6 +75,12 @@ from .policy_robot_bridge import (
PolicyActionToRobotActionProcessorStep,
RobotActionToPolicyActionProcessorStep,
)
from .relative_action_processor import (
AbsoluteActionsProcessorStep,
RelativeActionsProcessorStep,
to_absolute_actions,
to_relative_actions,
)
from .rename_processor import RenameObservationsProcessorStep
from .tokenizer_processor import ActionTokenizerProcessorStep, TokenizerProcessorStep
@@ -100,6 +106,8 @@ __all__ = [
"make_default_teleop_action_processor",
"make_default_robot_action_processor",
"make_default_robot_observation_processor",
"AbsoluteActionsProcessorStep",
"RelativeActionsProcessorStep",
"MapDeltaActionToRobotActionStep",
"MapTensorToDeltaActionDictStep",
"NormalizerProcessorStep",
@@ -129,6 +137,8 @@ __all__ = [
"transition_to_batch",
"TransitionKey",
"TruncatedProcessorStep",
"to_absolute_actions",
"to_relative_actions",
"UnnormalizerProcessorStep",
"VanillaObservationProcessorStep",
]

View File

@@ -0,0 +1,208 @@
# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from collections.abc import Sequence
from dataclasses import dataclass, field
from typing import Any
import torch
from torch import Tensor
from lerobot.configs.types import PipelineFeatureType, PolicyFeature
from lerobot.types import EnvTransition, TransitionKey
from lerobot.utils.constants import OBS_STATE
from .delta_action_processor import MapDeltaActionToRobotActionStep, MapTensorToDeltaActionDictStep
from .pipeline import ProcessorStep, ProcessorStepRegistry
# Re-export for backward compatibility
__all__ = [
"MapDeltaActionToRobotActionStep",
"MapTensorToDeltaActionDictStep",
"RelativeActionsProcessorStep",
"AbsoluteActionsProcessorStep",
"to_relative_actions",
"to_absolute_actions",
]
def to_relative_actions(actions: Tensor, state: Tensor, mask: Sequence[bool]) -> Tensor:
"""Convert absolute actions to relative: relative = action - state (for masked dims).
Args:
actions: (B, T, action_dim) or (B, action_dim).
state: (B, state_dim). Broadcast across time dimension.
mask: Which dims to convert. Can be shorter than action_dim.
"""
mask_t = torch.tensor(mask, dtype=actions.dtype, device=actions.device)
dims = mask_t.shape[0]
# Align state to the same device/dtype as actions. _last_state is cached before
# DeviceProcessorStep moves the transition, so it can be on CPU while actions are on CUDA.
if state.device != actions.device or state.dtype != actions.dtype:
state = state.to(device=actions.device, dtype=actions.dtype)
state_offset = state[..., :dims] * mask_t
if actions.ndim == 3:
state_offset = state_offset.unsqueeze(-2)
actions = actions.clone()
actions[..., :dims] -= state_offset
return actions
def to_absolute_actions(actions: Tensor, state: Tensor, mask: Sequence[bool]) -> Tensor:
"""Convert relative actions back to absolute: absolute = relative + state (for masked dims).
Args:
actions: (B, T, action_dim) or (B, action_dim).
state: (B, state_dim). Broadcast across time dimension.
mask: Which dims to convert. Can be shorter than action_dim.
"""
mask_t = torch.tensor(mask, dtype=actions.dtype, device=actions.device)
dims = mask_t.shape[0]
# Align state to the same device/dtype as actions. _last_state is cached before
# DeviceProcessorStep moves the transition, so it can be on CPU while actions are on CUDA.
if state.device != actions.device or state.dtype != actions.dtype:
state = state.to(device=actions.device, dtype=actions.dtype)
state_offset = state[..., :dims] * mask_t
if actions.ndim == 3:
state_offset = state_offset.unsqueeze(-2)
actions = actions.clone()
actions[..., :dims] += state_offset
return actions
@ProcessorStepRegistry.register("delta_actions_processor")
@dataclass
class RelativeActionsProcessorStep(ProcessorStep):
"""Converts absolute actions to relative actions (action -= state) for masked dimensions.
Mirrors OpenPI's DeltaActions transform. Applied during preprocessing so the model
trains on relative offsets instead of absolute positions.
Caches the last seen state so a paired AbsoluteActionsProcessorStep can reverse
the conversion during postprocessing.
Attributes:
enabled: Whether to apply the relative conversion.
exclude_joints: Joint names to keep absolute (not converted to relative).
action_names: Action dimension names from dataset metadata, used to build
the mask from exclude_joints. If None, all dims are converted.
"""
enabled: bool = False
exclude_joints: list[str] = field(default_factory=list)
action_names: list[str] | None = None
_last_state: torch.Tensor | None = field(default=None, init=False, repr=False)
def _build_mask(self, action_dim: int) -> list[bool]:
if not self.exclude_joints or self.action_names is None:
return [True] * action_dim
exclude_tokens = [str(name).lower() for name in self.exclude_joints if name]
if not exclude_tokens:
return [True] * action_dim
mask = []
for name in self.action_names[:action_dim]:
action_name = str(name).lower()
is_excluded = any(token == action_name or token in action_name for token in exclude_tokens)
mask.append(not is_excluded)
if len(mask) < action_dim:
mask.extend([True] * (action_dim - len(mask)))
return mask
def __call__(self, transition: EnvTransition) -> EnvTransition:
observation = transition.get(TransitionKey.OBSERVATION, {})
state = observation.get(OBS_STATE) if observation else None
# Always cache state for the paired AbsoluteActionsProcessorStep
if state is not None:
self._last_state = state
if not self.enabled:
return transition
new_transition = transition.copy()
action = new_transition.get(TransitionKey.ACTION)
if action is None or state is None:
return new_transition
mask = self._build_mask(action.shape[-1])
new_transition[TransitionKey.ACTION] = to_relative_actions(action, state, mask)
return new_transition
def get_config(self) -> dict[str, Any]:
return {
"enabled": self.enabled,
"exclude_joints": self.exclude_joints,
"action_names": self.action_names,
}
def transform_features(
self, features: dict[PipelineFeatureType, dict[str, PolicyFeature]]
) -> dict[PipelineFeatureType, dict[str, PolicyFeature]]:
return features
@ProcessorStepRegistry.register("absolute_actions_processor")
@dataclass
class AbsoluteActionsProcessorStep(ProcessorStep):
"""Converts relative actions back to absolute actions (action += state) for all dimensions.
Mirrors OpenPI's AbsoluteActions transform. Applied during postprocessing so
predicted relative offsets are converted back to absolute positions for execution.
Reads the cached state from its paired RelativeActionsProcessorStep.
Attributes:
enabled: Whether to apply the absolute conversion.
relative_step: Reference to the paired RelativeActionsProcessorStep that caches state.
"""
enabled: bool = False
relative_step: RelativeActionsProcessorStep | None = field(default=None, repr=False)
def __call__(self, transition: EnvTransition) -> EnvTransition:
if not self.enabled:
return transition
if self.relative_step is None:
raise RuntimeError(
"AbsoluteActionsProcessorStep requires a paired RelativeActionsProcessorStep "
"but relative_step is None. Ensure relative_step is set when constructing the postprocessor."
)
if self.relative_step._last_state is None:
raise RuntimeError(
"AbsoluteActionsProcessorStep requires state from RelativeActionsProcessorStep "
"but no state has been cached. Ensure the preprocessor runs before the postprocessor."
)
new_transition = transition.copy()
action = new_transition.get(TransitionKey.ACTION)
if action is None:
return new_transition
mask = self.relative_step._build_mask(action.shape[-1])
new_transition[TransitionKey.ACTION] = to_absolute_actions(
action, self.relative_step._last_state, mask
)
return new_transition
def get_config(self) -> dict[str, Any]:
return {"enabled": self.enabled}
def transform_features(
self, features: dict[PipelineFeatureType, dict[str, PolicyFeature]]
) -> dict[PipelineFeatureType, dict[str, PolicyFeature]]:
return features

View File

@@ -39,13 +39,23 @@ class BiOpenArmFollower(Robot):
super().__init__(config)
self.config = config
# Top-level cameras are distributed evenly: each arm's OpenArmFollower
# will only open the cameras assigned to it. Per-arm cameras are used
# as fallback when top-level cameras are empty.
if config.cameras:
left_cameras = config.cameras
right_cameras = {}
else:
left_cameras = config.left_arm_config.cameras
right_cameras = config.right_arm_config.cameras
left_arm_config = OpenArmFollowerConfig(
id=f"{config.id}_left" if config.id else None,
calibration_dir=config.calibration_dir,
port=config.left_arm_config.port,
disable_torque_on_disconnect=config.left_arm_config.disable_torque_on_disconnect,
max_relative_target=config.left_arm_config.max_relative_target,
cameras=config.left_arm_config.cameras,
cameras=left_cameras,
side=config.left_arm_config.side,
can_interface=config.left_arm_config.can_interface,
use_can_fd=config.left_arm_config.use_can_fd,
@@ -63,7 +73,7 @@ class BiOpenArmFollower(Robot):
port=config.right_arm_config.port,
disable_torque_on_disconnect=config.right_arm_config.disable_torque_on_disconnect,
max_relative_target=config.right_arm_config.max_relative_target,
cameras=config.right_arm_config.cameras,
cameras=right_cameras,
side=config.right_arm_config.side,
can_interface=config.right_arm_config.can_interface,
use_can_fd=config.right_arm_config.use_can_fd,
@@ -93,13 +103,10 @@ class BiOpenArmFollower(Robot):
@property
def _cameras_ft(self) -> dict[str, tuple]:
left_arm_cameras_ft = self.left_arm._cameras_ft
right_arm_cameras_ft = self.right_arm._cameras_ft
return {
**{f"left_{k}": v for k, v in left_arm_cameras_ft.items()},
**{f"right_{k}": v for k, v in right_arm_cameras_ft.items()},
}
# Cameras already have unique user-chosen names (e.g. "left_wrist", "base",
# "right_wrist"), so we merge them directly — unlike motors which need the
# left_/right_ prefix to disambiguate identical per-arm joint names.
return {**self.left_arm._cameras_ft, **self.right_arm._cameras_ft}
@cached_property
def observation_features(self) -> dict[str, type | tuple]:
@@ -139,13 +146,17 @@ class BiOpenArmFollower(Robot):
def get_observation(self) -> RobotObservation:
obs_dict = {}
# Add "left_" prefix
left_obs = self.left_arm.get_observation()
obs_dict.update({f"left_{key}": value for key, value in left_obs.items()})
# Camera keys that should NOT get the arm prefix (they already have unique names)
left_cam_keys = set(self.left_arm.cameras.keys())
right_cam_keys = set(self.right_arm.cameras.keys())
left_obs = self.left_arm.get_observation()
for key, value in left_obs.items():
obs_dict[key if key in left_cam_keys else f"left_{key}"] = value
# Add "right_" prefix
right_obs = self.right_arm.get_observation()
obs_dict.update({f"right_{key}": value for key, value in right_obs.items()})
for key, value in right_obs.items():
obs_dict[key if key in right_cam_keys else f"right_{key}"] = value
return obs_dict

View File

@@ -14,8 +14,9 @@
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from dataclasses import dataclass, field
from lerobot.cameras import CameraConfig
from lerobot.robots.openarm_follower import OpenArmFollowerConfigBase
from ..config import RobotConfig
@@ -28,3 +29,6 @@ class BiOpenArmFollowerConfig(RobotConfig):
left_arm_config: OpenArmFollowerConfigBase
right_arm_config: OpenArmFollowerConfigBase
# Top-level cameras shared across both arms.
cameras: dict[str, CameraConfig] = field(default_factory=dict)

View File

@@ -18,7 +18,7 @@
Edit LeRobot datasets using various transformation tools.
This script allows you to delete episodes, split datasets, merge datasets,
remove features, modify tasks, and convert image datasets to video format.
remove features, modify tasks, recompute stats, and convert image datasets to video format.
When new_repo_id is specified, creates a new dataset.
Path semantics (v2): --root and --new_root are exact dataset folders containing
@@ -148,6 +148,21 @@ Show dataset information without feature details:
--operation.type info \
--operation.show_features false
Recompute dataset statistics:
lerobot-edit-dataset \
--repo_id lerobot/pusht \
--operation.type recompute_stats
Recompute stats for relative actions and push to hub:
lerobot-edit-dataset \
--repo_id lerobot/pusht \
--operation.type recompute_stats \
--operation.relative_action true \
--operation.chunk_size 50 \
--operation.relative_exclude_joints "['gripper']" \
--operation.num_workers 4 \
--push_to_hub true
Using JSON config file:
lerobot-edit-dataset \
--config_path path/to/edit_config.json
@@ -168,6 +183,7 @@ from lerobot.datasets.dataset_tools import (
delete_episodes,
merge_datasets,
modify_tasks,
recompute_stats,
remove_feature,
split_dataset,
)
@@ -230,6 +246,16 @@ class ConvertImageToVideoConfig(OperationConfig):
max_frames_per_batch: int | None = None
@OperationConfig.register_subclass("recompute_stats")
@dataclass
class RecomputeStatsConfig(OperationConfig):
skip_image_video: bool = True
relative_action: bool = False
relative_exclude_joints: list[str] | None = None
chunk_size: int = 50
num_workers: int = 0
@OperationConfig.register_subclass("info")
@dataclass
class InfoConfig(OperationConfig):
@@ -525,6 +551,35 @@ def handle_convert_image_to_video(cfg: EditDatasetConfig) -> None:
logging.info("Dataset saved locally (not pushed to hub)")
def handle_recompute_stats(cfg: EditDatasetConfig) -> None:
if not isinstance(cfg.operation, RecomputeStatsConfig):
raise ValueError("Operation config must be RecomputeStatsConfig")
dataset = LeRobotDataset(cfg.repo_id, root=cfg.root)
logging.info(f"Recomputing stats for {cfg.repo_id}")
if cfg.operation.relative_action:
logging.info(
f"Relative action stats enabled (chunk_size={cfg.operation.chunk_size}, "
f"exclude_joints={cfg.operation.relative_exclude_joints})"
)
recompute_stats(
dataset,
skip_image_video=cfg.operation.skip_image_video,
relative_action=cfg.operation.relative_action,
relative_exclude_joints=cfg.operation.relative_exclude_joints,
chunk_size=cfg.operation.chunk_size,
num_workers=cfg.operation.num_workers,
)
logging.info(f"Stats written to {dataset.root}")
if cfg.push_to_hub:
logging.info(f"Pushing to hub as {dataset.meta.repo_id}...")
dataset.push_to_hub()
def _get_dataset_size(repo_path):
import os
@@ -596,6 +651,8 @@ def edit_dataset(cfg: EditDatasetConfig) -> None:
handle_modify_tasks(cfg)
elif operation_type == "convert_image_to_video":
handle_convert_image_to_video(cfg)
elif operation_type == "recompute_stats":
handle_recompute_stats(cfg)
elif operation_type == "info":
handle_info(cfg)
else:

View File

@@ -252,10 +252,22 @@ def train(cfg: TrainPipelineConfig, accelerator: Accelerator | None = None):
# Wait for all processes to finish policy creation before continuing
accelerator.wait_for_everyone()
processor_pretrained_path = cfg.policy.pretrained_path
if (
getattr(cfg.policy, "use_relative_actions", False)
and processor_pretrained_path is not None
and not cfg.resume
):
logging.warning(
"use_relative_actions=true with pretrained processors can skip relative transforms if "
"the checkpoint processors do not define them. Building processors from current policy config."
)
processor_pretrained_path = None
# Create processors - only provide dataset_stats if not resuming from saved processors
processor_kwargs = {}
postprocessor_kwargs = {}
if (cfg.policy.pretrained_path and not cfg.resume) or not cfg.policy.pretrained_path:
if (processor_pretrained_path and not cfg.resume) or not processor_pretrained_path:
# Only provide dataset_stats when not resuming from saved processor state
processor_kwargs["dataset_stats"] = dataset.meta.stats
@@ -263,7 +275,7 @@ def train(cfg: TrainPipelineConfig, accelerator: Accelerator | None = None):
if cfg.policy.type == "sarm":
processor_kwargs["dataset_meta"] = dataset.meta
if cfg.policy.pretrained_path is not None:
if processor_pretrained_path is not None:
processor_kwargs["preprocessor_overrides"] = {
"device_processor": {"device": device.type},
"normalizer_processor": {
@@ -285,7 +297,7 @@ def train(cfg: TrainPipelineConfig, accelerator: Accelerator | None = None):
preprocessor, postprocessor = make_pre_post_processors(
policy_cfg=cfg.policy,
pretrained_path=cfg.policy.pretrained_path,
pretrained_path=processor_pretrained_path,
**processor_kwargs,
**postprocessor_kwargs,
)

View File

@@ -15,7 +15,7 @@
This script:
1. Loads action chunks from LeRobotDataset (with episode sampling)
2. Optionally applies delta transforms (relative vs absolute actions)
2. Optionally applies relative transforms (relative vs absolute actions)
3. Extracts specified action dimensions for encoding
4. Applies normalization (MEAN_STD, MIN_MAX, QUANTILES, or other modes)
5. Trains FAST tokenizer (BPE on DCT coefficients) on the action chunks
@@ -32,8 +32,8 @@ lerobot-train-tokenizer \
--max_episodes=100 \
--sample_fraction=0.1 \
--encoded_dims="0:6" \
--delta_dims="0,1,2,3,4,5" \
--use_delta_transform=true \
--relative_dims="0,1,2,3,4,5" \
--use_relative_transform=true \
--state_key="observation.state" \
--normalization_mode="QUANTILES" \
--vocab_size=1024 \
@@ -82,10 +82,10 @@ class TokenizerTrainingConfig:
sample_fraction: float = 0.1
# Comma-separated dimension ranges to encode (e.g., "0:6,7:23")
encoded_dims: str = "0:6,7:23"
# Comma-separated dimension indices for delta transform (e.g., "0,1,2,3,4,5")
delta_dims: str | None = None
# Whether to apply delta transform (relative actions vs absolute actions)
use_delta_transform: bool = False
# Comma-separated dimension indices for relative transform (e.g., "0,1,2,3,4,5")
relative_dims: str | None = None
# Whether to apply relative transform (relative actions vs absolute actions)
use_relative_transform: bool = False
# Dataset key for state observations (default: "observation.state")
state_key: str = OBS_STATE
# Normalization mode (MEAN_STD, MIN_MAX, QUANTILES, QUANTILE10, IDENTITY)
@@ -104,25 +104,27 @@ class TokenizerTrainingConfig:
hub_private: bool = False
def apply_delta_transform(state: np.ndarray, actions: np.ndarray, delta_dims: list[int] | None) -> np.ndarray:
"""Apply delta transform to specified dimensions.
def apply_relative_transform(
state: np.ndarray, actions: np.ndarray, relative_dims: list[int] | None
) -> np.ndarray:
"""Apply relative transform to specified dimensions.
Args:
state: Current state [D]
actions: Future actions [D]
delta_dims: List of dimension indices to apply delta transform to
relative_dims: List of dimension indices to apply relative transform to
Returns:
Transformed actions [D]
"""
if delta_dims is None or len(delta_dims) == 0:
if relative_dims is None or len(relative_dims) == 0:
return actions
delta_actions = actions.copy()
for dim in delta_dims:
delta_actions[dim] = actions[dim] - state[dim]
relative_actions = actions.copy()
for dim in relative_dims:
relative_actions[dim] = actions[dim] - state[dim]
return delta_actions
return relative_actions
def apply_normalization(
@@ -185,7 +187,7 @@ def apply_normalization(
def process_episode(args):
"""Process single episode and return action chunks."""
dataset, ep_idx, action_horizon, delta_dims, sample_fraction, state_key, use_delta_transform = args
dataset, ep_idx, action_horizon, relative_dims, sample_fraction, state_key, use_relative_transform = args
try:
# get episode info
@@ -222,7 +224,7 @@ def process_episode(args):
else np.array(frame[state_key])
)
else:
# if no state key, use zeros (no delta transform)
# if no state key, use zeros (no relative transform)
state = np.zeros_like(
frame[ACTION].numpy() if torch.is_tensor(frame[ACTION]) else np.array(frame[ACTION])
)
@@ -243,18 +245,18 @@ def process_episode(args):
current_state = states[i] # First state in chunk
future_absolute_actions = actions[i : i + action_horizon]
if use_delta_transform:
if use_relative_transform:
# relative actions
delta_chunk = np.zeros_like(future_absolute_actions)
relative_chunk = np.zeros_like(future_absolute_actions)
for t in range(action_horizon):
delta_chunk[t] = apply_delta_transform(
relative_chunk[t] = apply_relative_transform(
current_state,
future_absolute_actions[t],
delta_dims,
relative_dims,
)
action_chunks.append(delta_chunk)
action_chunks.append(relative_chunk)
else:
# absolute actions (no delta)
# absolute actions (no relative transform)
action_chunks.append(future_absolute_actions)
if len(action_chunks) == 0:
@@ -407,17 +409,20 @@ def train_tokenizer(cfg: TokenizerTrainingConfig):
total_encoded_dims = sum(end - start for start, end in encoded_dim_ranges)
print(f"Encoding {total_encoded_dims} dimensions: {cfg.encoded_dims}")
# parse delta dimensions
delta_dim_list = None
if cfg.delta_dims is not None and cfg.delta_dims.strip():
delta_dim_list = [int(d.strip()) for d in cfg.delta_dims.split(",")]
print(f"Delta dimensions: {delta_dim_list}")
# parse relative dimensions
relative_dim_list = None
if cfg.relative_dims is not None and cfg.relative_dims.strip():
relative_dim_list = [int(d.strip()) for d in cfg.relative_dims.split(",")]
print(f"Relative dimensions: {relative_dim_list}")
else:
print("No delta dimensions specified")
print("No relative dimensions specified")
print(f"Use delta transform: {cfg.use_delta_transform}")
if cfg.use_delta_transform and (delta_dim_list is None or len(delta_dim_list) == 0):
print("Warning: use_delta_transform=True but no delta_dims specified. No delta will be applied.")
print(f"Use relative transform: {cfg.use_relative_transform}")
if cfg.use_relative_transform and (relative_dim_list is None or len(relative_dim_list) == 0):
print(
"Warning: use_relative_transform=True but no relative_dims specified. "
"No relative transform will be applied."
)
print(f"Action horizon: {cfg.action_horizon}")
print(f"State key: {cfg.state_key}")
@@ -440,10 +445,10 @@ def train_tokenizer(cfg: TokenizerTrainingConfig):
dataset,
ep_idx,
cfg.action_horizon,
delta_dim_list,
relative_dim_list,
cfg.sample_fraction,
cfg.state_key,
cfg.use_delta_transform,
cfg.use_relative_transform,
)
)
if chunks is not None:
@@ -544,9 +549,9 @@ def train_tokenizer(cfg: TokenizerTrainingConfig):
"encoded_dims": cfg.encoded_dims,
"encoded_dim_ranges": encoded_dim_ranges,
"total_encoded_dims": total_encoded_dims,
"delta_dims": cfg.delta_dims,
"delta_dim_list": delta_dim_list,
"use_delta_transform": cfg.use_delta_transform,
"relative_dims": cfg.relative_dims,
"relative_dim_list": relative_dim_list,
"use_relative_transform": cfg.use_relative_transform,
"state_key": cfg.state_key,
"normalization_mode": norm_mode.value,
"action_horizon": cfg.action_horizon,

View File

@@ -25,7 +25,7 @@ import torch
from lerobot.policies.rtc.action_queue import ActionQueue
from lerobot.policies.rtc.configuration_rtc import RTCConfig
# ====================== Fixtures ======================
# Fixtures
@pytest.fixture
@@ -63,7 +63,7 @@ def action_queue_rtc_disabled(rtc_config_disabled):
return ActionQueue(rtc_config_disabled)
# ====================== Initialization Tests ======================
# Initialization tests
def test_action_queue_initialization_rtc_enabled(rtc_config_enabled):
@@ -84,7 +84,7 @@ def test_action_queue_initialization_rtc_disabled(rtc_config_disabled):
assert queue.cfg.enabled is False
# ====================== get() Tests ======================
# get() tests
def test_get_returns_none_when_empty(action_queue_rtc_enabled):
@@ -136,7 +136,7 @@ def test_get_increments_last_index(action_queue_rtc_enabled, sample_actions):
assert action_queue_rtc_enabled.last_index == 2
# ====================== qsize() Tests ======================
# qsize() tests
def test_qsize_returns_zero_when_empty(action_queue_rtc_enabled):
@@ -167,7 +167,7 @@ def test_qsize_after_exhaustion(action_queue_rtc_enabled, sample_actions):
assert action_queue_rtc_enabled.qsize() == 0
# ====================== empty() Tests ======================
# empty() tests
def test_empty_returns_true_when_empty(action_queue_rtc_enabled):
@@ -202,7 +202,7 @@ def test_empty_after_full_consumption(action_queue_rtc_enabled, sample_actions):
assert action_queue_rtc_enabled.empty() is True
# ====================== get_action_index() Tests ======================
# get_action_index() tests
def test_get_action_index_initial_value(action_queue_rtc_enabled):
@@ -222,7 +222,7 @@ def test_get_action_index_after_consumption(action_queue_rtc_enabled, sample_act
assert action_queue_rtc_enabled.get_action_index() == 3
# ====================== get_left_over() Tests ======================
# get_left_over() tests
def test_get_left_over_returns_none_when_empty(action_queue_rtc_enabled):
@@ -269,7 +269,7 @@ def test_get_left_over_returns_empty_after_exhaustion(action_queue_rtc_enabled,
assert leftover.shape == (0, 6)
# ====================== merge() with RTC Enabled Tests ======================
# merge() with RTC enabled tests
def test_merge_replaces_queue_when_rtc_enabled(action_queue_rtc_enabled, sample_actions):
@@ -336,7 +336,7 @@ def test_merge_with_large_delay(action_queue_rtc_enabled, sample_actions):
assert action_queue_rtc_enabled.qsize() == 0
# ====================== merge() with RTC Disabled Tests ======================
# merge() with RTC disabled tests
def test_merge_appends_when_rtc_disabled(action_queue_rtc_disabled, sample_actions):
@@ -402,7 +402,7 @@ def test_merge_first_call_with_rtc_disabled(action_queue_rtc_disabled, sample_ac
assert action_queue_rtc_disabled.last_index == 0
# ====================== merge() with Different Action Shapes Tests ======================
# merge() with different action shapes tests
def test_merge_with_different_action_dims():
@@ -431,7 +431,7 @@ def test_merge_with_different_lengths():
assert queue.qsize() == 35
# ====================== merge() Delay Validation Tests ======================
# merge() delay validation tests
def test_merge_validates_delay_consistency(action_queue_rtc_enabled, sample_actions, caplog):
@@ -509,7 +509,7 @@ def test_merge_skips_validation_when_action_index_none(action_queue_rtc_enabled,
assert "Indexes diff is not equal to real delay" not in caplog.text
# ====================== Thread Safety Tests ======================
# Thread safety tests
def test_get_is_thread_safe(action_queue_rtc_enabled, sample_actions):
@@ -621,7 +621,7 @@ def test_concurrent_get_and_merge(action_queue_rtc_disabled, sample_actions):
assert consumed_count[0] <= 200
# ====================== get_left_over() Thread Safety Tests ======================
# get_left_over() thread safety tests
def test_get_left_over_is_thread_safe(action_queue_rtc_enabled, sample_actions):
@@ -670,7 +670,7 @@ def test_get_left_over_is_thread_safe(action_queue_rtc_enabled, sample_actions):
assert len(leftovers) > 0
# ====================== Edge Cases Tests ======================
# Edge cases tests
def test_queue_with_single_action(action_queue_rtc_enabled):
@@ -773,7 +773,7 @@ def test_qsize_with_none_queue(action_queue_rtc_enabled):
assert action_queue_rtc_enabled.qsize() == 0
# ====================== Integration Tests ======================
# Integration tests
def test_typical_rtc_workflow(action_queue_rtc_enabled, sample_actions):

View File

@@ -0,0 +1,607 @@
"""Tests for RTC + relative actions integration.
Validates that Real-Time Chunking (RTC) works correctly when the policy uses
relative actions. The key invariant: RTC guidance operates in model space
(normalized relative actions), while the robot receives absolute actions after postprocessing.
Flow under test:
Preprocessor: raw obs → relative step caches state → normalizer
Model: generates normalized relative actions (guided by RTC using leftover relative actions)
Postprocessor: unnormalize → absolute step (relative + cached state) → robot actions
"""
import importlib.util
import sys
from pathlib import Path
import torch
from lerobot.configs.types import (
FeatureType,
NormalizationMode,
PolicyFeature,
RTCAttentionSchedule,
)
from lerobot.processor import TransitionKey, batch_to_transition
from lerobot.processor.normalize_processor import NormalizerProcessorStep, UnnormalizerProcessorStep
from lerobot.processor.relative_action_processor import (
AbsoluteActionsProcessorStep,
RelativeActionsProcessorStep,
to_relative_actions,
)
from lerobot.utils.constants import ACTION, OBS_STATE
def _import_rtc_module(module_name: str, filename: str):
"""Import an RTC module directly from its file path, bypassing lerobot.policies.__init__."""
rtc_dir = Path(__file__).resolve().parents[3] / "src" / "lerobot" / "policies" / "rtc"
spec = importlib.util.spec_from_file_location(module_name, rtc_dir / filename)
mod = importlib.util.module_from_spec(spec)
sys.modules[module_name] = mod
spec.loader.exec_module(mod)
return mod
_rtc_cfg_mod = _import_rtc_module("lerobot.policies.rtc.configuration_rtc", "configuration_rtc.py")
RTCConfig = _rtc_cfg_mod.RTCConfig
_action_queue_mod = _import_rtc_module("lerobot.policies.rtc.action_queue", "action_queue.py")
ActionQueue = _action_queue_mod.ActionQueue
_rtc_debug_mod = _import_rtc_module("lerobot.policies.rtc.debug_tracker", "debug_tracker.py")
_rtc_mod = _import_rtc_module("lerobot.policies.rtc.modeling_rtc", "modeling_rtc.py")
RTCProcessor = _rtc_mod.RTCProcessor
ACTION_DIM = 6
CHUNK_SIZE = 50
EXECUTION_HORIZON = 10
def _make_rtc_config(enabled=True):
return RTCConfig(
enabled=enabled,
execution_horizon=EXECUTION_HORIZON,
max_guidance_weight=10.0,
prefix_attention_schedule=RTCAttentionSchedule.EXP,
)
def _make_relative_pipeline(action_dim=ACTION_DIM, norm_mode=NormalizationMode.MEAN_STD):
"""Build paired relative/absolute processor steps and normalizer/unnormalizer."""
features = {ACTION: PolicyFeature(type=FeatureType.ACTION, shape=(action_dim,))}
norm_map = {FeatureType.ACTION: norm_mode}
stats = {
ACTION: {
"mean": torch.zeros(action_dim).numpy(),
"std": torch.ones(action_dim).numpy(),
"q01": (-2 * torch.ones(action_dim)).numpy(),
"q99": (2 * torch.ones(action_dim)).numpy(),
"min": (-3 * torch.ones(action_dim)).numpy(),
"max": (3 * torch.ones(action_dim)).numpy(),
}
}
relative_step = RelativeActionsProcessorStep(enabled=True)
normalizer = NormalizerProcessorStep(features=features, norm_map=norm_map, stats=stats)
unnormalizer = UnnormalizerProcessorStep(features=features, norm_map=norm_map, stats=stats)
absolute_step = AbsoluteActionsProcessorStep(enabled=True, relative_step=relative_step)
return relative_step, normalizer, unnormalizer, absolute_step
class TestActionQueueRelativeActions:
"""Verify ActionQueue stores model-space (relative) actions for RTC and absolute for robot."""
def test_left_over_returns_relative_actions(self):
"""get_left_over() should return the original (relative-space) actions."""
cfg = _make_rtc_config()
queue = ActionQueue(cfg)
relative_actions = torch.randn(CHUNK_SIZE, ACTION_DIM)
absolute_actions = torch.randn(CHUNK_SIZE, ACTION_DIM)
queue.merge(relative_actions, absolute_actions, real_delay=0)
for _ in range(5):
queue.get()
leftover = queue.get_left_over()
torch.testing.assert_close(leftover, relative_actions[5:])
def test_robot_receives_absolute_actions(self):
"""The robot (via get()) should receive postprocessed absolute actions."""
cfg = _make_rtc_config()
queue = ActionQueue(cfg)
relative_actions = torch.randn(CHUNK_SIZE, ACTION_DIM)
absolute_actions = torch.randn(CHUNK_SIZE, ACTION_DIM)
queue.merge(relative_actions, absolute_actions, real_delay=0)
first_action = queue.get()
torch.testing.assert_close(first_action, absolute_actions[0])
class TestRTCDenoiseWithRelativeLeftovers:
"""Verify RTC denoise_step correctly handles relative-space prev_chunk_left_over."""
def test_first_chunk_no_guidance(self):
"""First chunk (no leftovers) should return v_t without guidance."""
rtc = RTCProcessor(_make_rtc_config())
x_t = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
def mock_denoise(x):
return torch.ones_like(x)
result = rtc.denoise_step(
x_t=x_t,
prev_chunk_left_over=None,
inference_delay=0,
time=0.5,
original_denoise_step_partial=mock_denoise,
)
torch.testing.assert_close(result, torch.ones_like(x_t))
def test_relative_leftovers_shape_preserved(self):
"""RTC output should have the same shape as input regardless of leftover shape."""
rtc = RTCProcessor(_make_rtc_config())
x_t = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
shorter_leftover = torch.randn(1, 20, ACTION_DIM)
def mock_denoise(x):
return torch.zeros_like(x)
result = rtc.denoise_step(
x_t=x_t,
prev_chunk_left_over=shorter_leftover,
inference_delay=5,
time=0.5,
original_denoise_step_partial=mock_denoise,
)
assert result.shape == x_t.shape
def test_guidance_steers_toward_previous_relative_actions(self):
"""RTC guidance should push x1_t toward prev_chunk_left_over in relative space."""
rtc = RTCProcessor(_make_rtc_config())
x_t = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
prev_relatives = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
def mock_denoise(x):
return torch.zeros_like(x)
result_without_guidance = rtc.denoise_step(
x_t=x_t.clone(),
prev_chunk_left_over=None,
inference_delay=5,
time=0.5,
original_denoise_step_partial=mock_denoise,
)
result_with_guidance = rtc.denoise_step(
x_t=x_t.clone(),
prev_chunk_left_over=prev_relatives,
inference_delay=5,
time=0.5,
original_denoise_step_partial=mock_denoise,
)
assert not torch.allclose(result_with_guidance, result_without_guidance, atol=1e-6)
class TestFullPipelineRelativeRTC:
"""End-to-end test of the RTC + relative actions pipeline matching eval_with_real_robot.py flow."""
def test_preprocessor_caches_state_for_postprocessor(self):
"""Preprocessor's relative step should cache state so postprocessor can convert back."""
relative_step, normalizer, unnormalizer, absolute_step = _make_relative_pipeline()
state = torch.randn(1, ACTION_DIM)
actions = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
batch = {ACTION: actions, OBS_STATE: state}
transition = batch_to_transition(batch)
relative_step(transition)
assert relative_step._last_state is not None
torch.testing.assert_close(relative_step._last_state, state)
def test_preprocessor_caches_state_without_actions(self):
"""During inference, preprocessor receives only observations (no actions).
Relative step should still cache state for the postprocessor."""
relative_step, _, _, _ = _make_relative_pipeline()
state = torch.randn(1, ACTION_DIM)
batch = {OBS_STATE: state}
transition = batch_to_transition(batch)
relative_step(transition)
assert relative_step._last_state is not None
torch.testing.assert_close(relative_step._last_state, state)
def test_roundtrip_with_identity_normalization(self):
"""Actions → relative → normalize → [model] → unnormalize → absolute should recover originals.
Using mean=0, std=1 normalization (identity)."""
relative_step, normalizer, unnormalizer, absolute_step = _make_relative_pipeline()
state = torch.randn(1, ACTION_DIM)
actions = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
batch = {ACTION: actions.clone(), OBS_STATE: state}
transition = batch_to_transition(batch)
t1 = relative_step(transition)
t2 = normalizer(t1)
model_output = t2[TransitionKey.ACTION].clone()
model_transition = {TransitionKey.ACTION: model_output}
t3 = unnormalizer(model_transition)
t4 = absolute_step(t3)
recovered = t4[TransitionKey.ACTION]
torch.testing.assert_close(recovered, actions, atol=1e-5, rtol=1e-5)
def test_eval_loop_simulation(self):
"""Simulate the eval_with_real_robot.py loop with relative actions.
Iteration 1: No leftovers → model generates relative actions → store for RTC
Iteration 2: Use leftovers as RTC guidance → model generates new relative actions
Both iterations: postprocessor converts relative actions to absolute for robot
"""
relative_step, normalizer, unnormalizer, absolute_step = _make_relative_pipeline()
rtc = RTCProcessor(_make_rtc_config())
queue = ActionQueue(_make_rtc_config())
def mock_model(prev_chunk_left_over, inference_delay, state):
"""Simulate model generating relative actions with RTC."""
x_t = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
def denoise(x):
return -0.1 * x
guided_v = rtc.denoise_step(
x_t=x_t,
prev_chunk_left_over=prev_chunk_left_over,
inference_delay=inference_delay,
time=0.5,
original_denoise_step_partial=denoise,
)
return x_t - 0.5 * guided_v
# --- Iteration 1: first chunk, no leftovers ---
state_1 = torch.randn(1, ACTION_DIM)
obs_batch_1 = {OBS_STATE: state_1}
relative_step(batch_to_transition(obs_batch_1))
model_relatives_1 = mock_model(prev_chunk_left_over=None, inference_delay=0, state=state_1)
original_actions_1 = model_relatives_1.squeeze(0)
model_transition_1 = {TransitionKey.ACTION: model_relatives_1}
postprocessed_1 = absolute_step(unnormalizer(model_transition_1))[TransitionKey.ACTION].squeeze(0)
queue.merge(original_actions_1, postprocessed_1, real_delay=0)
# Consume some actions (simulate robot executing)
for _ in range(5):
action = queue.get()
assert action is not None
# --- Iteration 2: use leftovers for RTC ---
prev_actions = queue.get_left_over()
assert prev_actions is not None
assert prev_actions.shape[0] == CHUNK_SIZE - 5
state_2 = state_1 + 0.01 * torch.randn(1, ACTION_DIM)
obs_batch_2 = {OBS_STATE: state_2}
relative_step(batch_to_transition(obs_batch_2))
model_relatives_2 = mock_model(
prev_chunk_left_over=prev_actions.unsqueeze(0), inference_delay=3, state=state_2
)
original_actions_2 = model_relatives_2.squeeze(0)
model_transition_2 = {TransitionKey.ACTION: model_relatives_2}
postprocessed_2 = absolute_step(unnormalizer(model_transition_2))[TransitionKey.ACTION].squeeze(0)
queue.merge(original_actions_2, postprocessed_2, real_delay=3)
# Postprocessed actions should be in absolute space
action = queue.get()
assert action is not None
assert action.shape == (ACTION_DIM,)
# Verify leftovers are in relative space (original_queue stores relative actions)
leftover_relatives = queue.get_left_over()
assert leftover_relatives is not None
assert leftover_relatives.shape[1] == ACTION_DIM
def test_postprocessor_uses_correct_state_per_iteration(self):
"""Each iteration's postprocessor should use the state from that iteration's preprocessor,
not a stale state from a previous iteration."""
relative_step, _, unnormalizer, absolute_step = _make_relative_pipeline()
state_1 = torch.tensor([[1.0, 2.0, 3.0, 4.0, 5.0, 6.0]])
state_2 = torch.tensor([[10.0, 20.0, 30.0, 40.0, 50.0, 60.0]])
relatives = torch.zeros(1, 5, ACTION_DIM)
# Iteration 1: cache state_1
relative_step(batch_to_transition({OBS_STATE: state_1}))
result_1 = absolute_step(unnormalizer({TransitionKey.ACTION: relatives.clone()}))[
TransitionKey.ACTION
]
# relative=0 + state_1 should give state_1
for t in range(5):
torch.testing.assert_close(result_1[0, t], state_1[0], atol=1e-5, rtol=1e-5)
# Iteration 2: cache state_2
relative_step(batch_to_transition({OBS_STATE: state_2}))
result_2 = absolute_step(unnormalizer({TransitionKey.ACTION: relatives.clone()}))[
TransitionKey.ACTION
]
for t in range(5):
torch.testing.assert_close(result_2[0, t], state_2[0], atol=1e-5, rtol=1e-5)
class TestStateRebasingApproximation:
"""Verify that the approximation from not rebasing leftover relative actions is small
when state changes between inference calls are small (real-time control regime)."""
def test_small_state_change_produces_small_error(self):
"""With small state changes (typical in real-time control),
using stale relative actions for RTC guidance introduces negligible error."""
state_old = torch.randn(1, ACTION_DIM)
state_new = state_old + 0.01 * torch.randn(1, ACTION_DIM)
actions_absolute = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
mask = [True] * ACTION_DIM
relatives_old = to_relative_actions(actions_absolute, state_old, mask)
relatives_new = to_relative_actions(actions_absolute, state_new, mask)
error = (relatives_old - relatives_new).abs().mean()
state_change = (state_old - state_new).abs().mean()
# Error should be proportional to state change
assert error < 0.1, (
f"Relative-action error {error:.4f} should be small for small state change {state_change:.4f}"
)
def test_large_state_change_produces_proportional_error(self):
"""With large state changes, stale relative actions diverge more (but RTC guidance decays)."""
state_old = torch.randn(1, ACTION_DIM)
state_new = state_old + 10.0 * torch.randn(1, ACTION_DIM)
actions_absolute = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
mask = [True] * ACTION_DIM
relatives_old = to_relative_actions(actions_absolute, state_old, mask)
relatives_new = to_relative_actions(actions_absolute, state_new, mask)
error = (relatives_old - relatives_new).abs().mean()
state_change = (state_old - state_new).abs().mean()
# Error should be roughly equal to state change
torch.testing.assert_close(
error.clone().detach(), state_change.clone().detach(), atol=1e-5, rtol=1e-5
)
def test_excluded_joints_not_affected_by_state_change(self):
"""Joints excluded from relative conversion should not contribute rebasing error."""
state_old = torch.randn(1, ACTION_DIM)
state_new = state_old.clone()
state_new[0, -1] = state_old[0, -1] + 100.0
actions = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
mask = [True] * (ACTION_DIM - 1) + [False]
relatives_old = to_relative_actions(actions, state_old, mask)
relatives_new = to_relative_actions(actions, state_new, mask)
# Last dim (excluded) should have zero error
error_excluded = (relatives_old[..., -1] - relatives_new[..., -1]).abs().max()
assert error_excluded < 1e-6, f"Excluded joint should have zero error, got {error_excluded}"
def _detect_relative_actions(preprocessor) -> bool:
"""Mirror of the helper in eval_with_real_robot.py for testing without importing it."""
return any(isinstance(step, RelativeActionsProcessorStep) and step.enabled for step in preprocessor.steps)
class TestDetectRelativeActions:
"""Test the _detect_relative_actions helper logic used by eval_with_real_robot.py."""
def test_detects_enabled_relative_step(self):
class FakePipeline:
steps = [RelativeActionsProcessorStep(enabled=True)]
assert _detect_relative_actions(FakePipeline()) is True
def test_ignores_disabled_relative_step(self):
class FakePipeline:
steps = [RelativeActionsProcessorStep(enabled=False)]
assert _detect_relative_actions(FakePipeline()) is False
def test_returns_false_when_no_relative_step(self):
class FakePipeline:
steps = []
assert _detect_relative_actions(FakePipeline()) is False
class TestNonRelativePolicy:
"""Verify the same pipeline works when relative actions are disabled (standard absolute policy)."""
def test_disabled_relative_step_is_noop(self):
relative_step = RelativeActionsProcessorStep(enabled=False)
absolute_step = AbsoluteActionsProcessorStep(enabled=False, relative_step=relative_step)
state = torch.randn(1, ACTION_DIM)
actions = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
transition = batch_to_transition({ACTION: actions.clone(), OBS_STATE: state})
t1 = relative_step(transition)
torch.testing.assert_close(t1[TransitionKey.ACTION], actions)
t2 = absolute_step({TransitionKey.ACTION: actions.clone()})
torch.testing.assert_close(t2[TransitionKey.ACTION], actions)
def test_eval_loop_without_relative_actions(self):
"""Full eval loop simulation with relative actions disabled: original and processed actions are identical."""
features = {ACTION: PolicyFeature(type=FeatureType.ACTION, shape=(ACTION_DIM,))}
norm_map = {FeatureType.ACTION: NormalizationMode.MEAN_STD}
stats = {
ACTION: {
"mean": torch.zeros(ACTION_DIM).numpy(),
"std": torch.ones(ACTION_DIM).numpy(),
}
}
relative_step = RelativeActionsProcessorStep(enabled=False)
unnormalizer = UnnormalizerProcessorStep(features=features, norm_map=norm_map, stats=stats)
absolute_step = AbsoluteActionsProcessorStep(enabled=False, relative_step=relative_step)
rtc = RTCProcessor(_make_rtc_config())
queue = ActionQueue(_make_rtc_config())
state = torch.randn(1, ACTION_DIM)
relative_step(batch_to_transition({OBS_STATE: state}))
model_output = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
post = absolute_step(unnormalizer({TransitionKey.ACTION: model_output.clone()}))[
TransitionKey.ACTION
].squeeze(0)
original = model_output.squeeze(0)
# With identity norm and no relative-action transform, original and postprocessed should match
torch.testing.assert_close(original, post, atol=1e-5, rtol=1e-5)
queue.merge(original, post, real_delay=0)
for _ in range(5):
queue.get()
prev_actions = queue.get_left_over()
assert prev_actions is not None
# RTC guidance works the same way (absolute space)
x_t = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
result = rtc.denoise_step(
x_t=x_t,
prev_chunk_left_over=prev_actions.unsqueeze(0),
inference_delay=3,
time=0.5,
original_denoise_step_partial=lambda x: torch.zeros_like(x),
)
assert result.shape == x_t.shape
def test_detect_relative_returns_false_when_disabled(self):
class FakePipeline:
steps = [RelativeActionsProcessorStep(enabled=False)]
assert not _detect_relative_actions(FakePipeline())
def test_detect_relative_returns_false_when_absent(self):
class FakePipeline:
steps = []
assert not _detect_relative_actions(FakePipeline())
class TestMultiChunkConsistency:
"""Test multiple RTC iterations with relative actions maintain consistency."""
def test_three_iteration_pipeline(self):
"""Simulate three consecutive RTC iterations and verify queue state consistency."""
relative_step, normalizer, unnormalizer, absolute_step = _make_relative_pipeline()
queue = ActionQueue(_make_rtc_config())
states = [torch.randn(1, ACTION_DIM) + i * 0.01 for i in range(3)]
for i in range(3):
queue.get_left_over()
relative_step(batch_to_transition({OBS_STATE: states[i]}))
model_output = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
post_transition = absolute_step(unnormalizer({TransitionKey.ACTION: model_output.clone()}))
postprocessed = post_transition[TransitionKey.ACTION].squeeze(0)
original = model_output.squeeze(0)
delay = min(i * 2, CHUNK_SIZE - 1)
queue.merge(original, postprocessed, real_delay=delay)
for _ in range(5):
action = queue.get()
assert action is not None
assert action.shape == (ACTION_DIM,)
# After 3 iterations, queue should still be in valid state
assert queue.qsize() > 0
leftover = queue.get_left_over()
assert leftover is not None
assert leftover.ndim == 2
assert leftover.shape[1] == ACTION_DIM
def test_leftover_and_processed_differ_when_relative_enabled(self):
"""With relative actions enabled, original leftovers (relative) must differ from processed (absolute)."""
relative_step, _, unnormalizer, absolute_step = _make_relative_pipeline()
queue = ActionQueue(_make_rtc_config())
state = torch.tensor([[1.0, 2.0, 3.0, 4.0, 5.0, 6.0]])
relative_step(batch_to_transition({OBS_STATE: state}))
model_relatives = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
post = absolute_step(unnormalizer({TransitionKey.ACTION: model_relatives.clone()}))[
TransitionKey.ACTION
].squeeze(0)
original = model_relatives.squeeze(0)
queue.merge(original, post, real_delay=0)
relative_leftover = queue.get_left_over()
# Leftovers (relative) must differ from the postprocessed absolute actions
assert not torch.allclose(relative_leftover, post, atol=1e-3)
state_expanded = state.squeeze(0).unsqueeze(0).expand_as(relative_leftover)
torch.testing.assert_close(post, relative_leftover + state_expanded, atol=1e-5, rtol=1e-5)
def test_rtc_guidance_uses_relative_space(self):
"""Verify that RTC denoise_step receives relative-space leftovers, not absolute."""
relative_step, _, unnormalizer, absolute_step = _make_relative_pipeline()
rtc = RTCProcessor(_make_rtc_config())
queue = ActionQueue(_make_rtc_config())
state = torch.tensor([[10.0, 20.0, 30.0, 40.0, 50.0, 60.0]])
relative_step(batch_to_transition({OBS_STATE: state}))
model_relatives = 0.1 * torch.randn(1, CHUNK_SIZE, ACTION_DIM)
post = absolute_step(unnormalizer({TransitionKey.ACTION: model_relatives.clone()}))[
TransitionKey.ACTION
].squeeze(0)
original = model_relatives.squeeze(0)
queue.merge(original, post, real_delay=0)
for _ in range(5):
queue.get()
prev_left_over = queue.get_left_over()
# prev_left_over should be small relative offsets (around 0.1 * randn), not large absolute values
assert prev_left_over.abs().mean() < 5.0, (
f"Leftover should be small relative offsets, got mean abs {prev_left_over.abs().mean():.2f}"
)
x_t = torch.randn(1, CHUNK_SIZE, ACTION_DIM)
def denoise(x):
return torch.zeros_like(x)
result = rtc.denoise_step(
x_t=x_t,
prev_chunk_left_over=prev_left_over.unsqueeze(0),
inference_delay=3,
time=0.5,
original_denoise_step_partial=denoise,
)
assert result.shape == x_t.shape

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@@ -0,0 +1,346 @@
"""Tests for relative action transforms — full pipeline validation.
Tests the complete flow matching OpenPI:
raw actions → RelativeActions → Normalize(relative_stats) → model → Unnormalize → AbsoluteActions
Uses real dataset: lerobot-data-collection/dagger_final_1_21
"""
import numpy as np
import pytest
import torch
from lerobot.configs.types import FeatureType, NormalizationMode, PolicyFeature
from lerobot.datasets.compute_stats import get_feature_stats
from lerobot.datasets.lerobot_dataset import LeRobotDataset
from lerobot.processor import TransitionKey, batch_to_transition
from lerobot.processor.normalize_processor import NormalizerProcessorStep, UnnormalizerProcessorStep
from lerobot.processor.relative_action_processor import (
AbsoluteActionsProcessorStep,
RelativeActionsProcessorStep,
to_absolute_actions,
to_relative_actions,
)
from lerobot.utils.constants import ACTION, OBS_STATE
CHUNK_SIZE = 10
REPO_ID = "lerobot-data-collection/dagger_final_1_21"
@pytest.fixture(scope="module")
def dataset():
return LeRobotDataset(REPO_ID, episodes=[0])
@pytest.fixture(scope="module")
def action_dim(dataset):
return dataset.meta.features["action"]["shape"][0]
def _build_action_chunks(dataset, chunk_size, max_chunks=50):
"""Build action chunks from hf_dataset, like the training script does."""
hf = dataset.hf_dataset
total = len(hf)
all_ep = torch.tensor([int(hf[i]["episode_index"]) for i in range(total)])
chunks, states = [], []
for i in range(total - chunk_size + 1):
if all_ep[i] != all_ep[i + chunk_size - 1]:
continue
chunk_actions = torch.stack([hf[i + k]["action"] for k in range(chunk_size)]).float()
state = hf[i]["observation.state"].float()
chunks.append(chunk_actions)
states.append(state)
if len(chunks) >= max_chunks:
break
assert len(chunks) > 0, f"No valid chunks found. total={total}, ep_indices={all_ep.tolist()}"
return torch.stack(chunks), torch.stack(states)
def _compute_relative_chunk_stats(action_chunks, states, mask):
all_chunks = []
for actions, state in zip(action_chunks, states, strict=True):
relative = to_relative_actions(actions.unsqueeze(0), state.unsqueeze(0), mask).squeeze(0)
all_chunks.append(relative.numpy())
all_relative = np.concatenate(all_chunks, axis=0)
return get_feature_stats(all_relative, axis=0, keepdims=all_relative.ndim == 1)
# Basic roundtrip tests
def test_roundtrip_3d(action_dim):
actions = torch.randn(4, CHUNK_SIZE, action_dim)
state = torch.randn(4, action_dim)
mask = [True] * action_dim
recovered = to_absolute_actions(to_relative_actions(actions, state, mask), state, mask)
torch.testing.assert_close(recovered, actions)
def test_roundtrip_2d(action_dim):
actions = torch.randn(4, action_dim)
state = torch.randn(4, action_dim)
mask = [True] * action_dim
recovered = to_absolute_actions(to_relative_actions(actions, state, mask), state, mask)
torch.testing.assert_close(recovered, actions)
def test_no_mutation(action_dim):
actions = torch.randn(2, CHUNK_SIZE, action_dim)
original = actions.clone()
state = torch.randn(2, action_dim)
to_relative_actions(actions, state, [True] * action_dim)
torch.testing.assert_close(actions, original)
def test_exclude_joints_supports_partial_name_matching():
names = [
"right_joint_1.pos",
"right_gripper.pos",
"left_joint_1.pos",
"left_gripper.pos",
]
step = RelativeActionsProcessorStep(enabled=True, exclude_joints=["gripper"], action_names=names)
assert step._build_mask(len(names)) == [True, False, True, False]
# Chunk-level relative stats test
def test_chunk_stats_have_larger_std_than_frame_stats(dataset, action_dim):
"""Chunk-level relative stats should have larger std than per-frame relative stats."""
action_chunks, states = _build_action_chunks(dataset, CHUNK_SIZE)
mask = [True] * action_dim
chunk_stats = _compute_relative_chunk_stats(action_chunks, states, mask)
# Per-frame stats
hf = dataset.hf_dataset
n = min(500, len(hf))
frame_actions = torch.stack([hf[i]["action"] for i in range(n)]).float()
frame_states = torch.stack([hf[i]["observation.state"] for i in range(n)]).float()
frame_relatives = to_relative_actions(frame_actions, frame_states, mask).numpy()
frame_stats = get_feature_stats(frame_relatives, axis=0, keepdims=frame_relatives.ndim == 1)
assert chunk_stats["std"].mean() >= frame_stats["std"].mean(), (
f"Chunk std ({chunk_stats['std'].mean():.4f}) should be >= "
f"frame std ({frame_stats['std'].mean():.4f})"
)
# Full pipeline roundtrip: relative → normalize → unnormalize → absolute
def test_full_pipeline_roundtrip(dataset, action_dim):
"""Test the complete OpenPI pipeline: relative → normalize → unnormalize → absolute."""
action_chunks, states = _build_action_chunks(dataset, CHUNK_SIZE)
mask = [True] * action_dim
relative_stats = _compute_relative_chunk_stats(action_chunks, states, mask)
stats = {ACTION: dict(relative_stats.items())}
features = {ACTION: PolicyFeature(type=FeatureType.ACTION, shape=(action_dim,))}
norm_map = {FeatureType.ACTION: NormalizationMode.MEAN_STD}
relative_step = RelativeActionsProcessorStep(enabled=True)
normalizer = NormalizerProcessorStep(features=features, norm_map=norm_map, stats=stats)
unnormalizer = UnnormalizerProcessorStep(features=features, norm_map=norm_map, stats=stats)
absolute_step = AbsoluteActionsProcessorStep(enabled=True, relative_step=relative_step)
original_actions = action_chunks[0].unsqueeze(0)
state = states[0].unsqueeze(0)
batch = {ACTION: original_actions, OBS_STATE: state}
transition = batch_to_transition(batch)
# Forward: relative → normalize
t1 = relative_step(transition)
t2 = normalizer(t1)
normalized_action = t2[TransitionKey.ACTION]
assert normalized_action.abs().mean() < 10, (
f"Normalized actions should be in reasonable range, got mean abs {normalized_action.abs().mean():.2f}"
)
# Reverse: unnormalize → absolute
t3 = unnormalizer(t2)
t4 = absolute_step(t3)
recovered_actions = t4[TransitionKey.ACTION]
torch.testing.assert_close(recovered_actions, original_actions, atol=1e-4, rtol=1e-4)
def test_normalized_relative_values_are_reasonable(dataset, action_dim):
"""With correct chunk stats, normalized relative actions should be in a reasonable range."""
action_chunks, states = _build_action_chunks(dataset, CHUNK_SIZE)
mask = [True] * action_dim
relative_stats = _compute_relative_chunk_stats(action_chunks, states, mask)
mean = torch.tensor(relative_stats["mean"]).float()
std = torch.tensor(relative_stats["std"]).float()
all_normalized = []
for actions, state in zip(action_chunks, states, strict=True):
relative = to_relative_actions(actions.unsqueeze(0), state.unsqueeze(0), mask).squeeze(0)
normalized = (relative - mean) / (std + 1e-6)
all_normalized.append(normalized)
all_normalized = torch.cat(all_normalized, dim=0)
pct_in_range = (all_normalized.abs() < 5).float().mean()
assert pct_in_range > 0.9, (
f"Only {pct_in_range * 100:.1f}% of normalized values in [-5, 5], expected >90%"
)
assert all_normalized.mean().abs() < 1.0, (
f"Mean of normalized relative actions is {all_normalized.mean():.2f}, expected near 0"
)
def test_processor_step_roundtrip(dataset, action_dim):
"""RelativeActionsProcessorStep applies relative offsets; to_absolute_actions recovers original."""
hf = dataset.hf_dataset
batch = {
ACTION: torch.stack([hf[i]["action"] for i in range(4)]),
OBS_STATE: torch.stack([hf[i]["observation.state"] for i in range(4)]),
}
original_actions = batch[ACTION].clone()
transition = batch_to_transition(batch)
step = RelativeActionsProcessorStep(enabled=True)
relative_transition = step(transition)
assert not torch.allclose(relative_transition[TransitionKey.ACTION], original_actions)
state = transition[TransitionKey.OBSERVATION][OBS_STATE]
mask = [True] * action_dim
recovered = to_absolute_actions(relative_transition[TransitionKey.ACTION], state, mask)
torch.testing.assert_close(recovered, original_actions)
def test_processor_step_disabled_is_noop(dataset, action_dim):
"""enabled=False should be a no-op."""
hf = dataset.hf_dataset
batch = {
ACTION: torch.stack([hf[i]["action"] for i in range(2)]),
OBS_STATE: torch.stack([hf[i]["observation.state"] for i in range(2)]),
}
original = batch[ACTION].clone()
transition = batch_to_transition(batch)
result = RelativeActionsProcessorStep(enabled=False)(transition)
torch.testing.assert_close(result[TransitionKey.ACTION], original)
# Training batch shape validation
def test_relative_with_action_chunks(dataset, action_dim):
"""Verify relative actions work correctly with (B, chunk_size, action_dim) shaped actions."""
action_chunks, states = _build_action_chunks(dataset, CHUNK_SIZE)
# Simulate a training batch: actions=(B, chunk_size, action_dim), state=(B, state_dim)
batch_actions = action_chunks[:4] # (4, chunk_size, action_dim)
batch_states = states[:4] # (4, state_dim)
mask = [True] * action_dim
relative = to_relative_actions(batch_actions, batch_states, mask)
# First action in each chunk should be close to zero (action[t] - state[t] ≈ small)
first_relatives = relative[:, 0, :] # (B, action_dim)
assert first_relatives.abs().mean() < relative.abs().mean(), (
f"First action in chunk should have smaller relative offset than average. "
f"First: {first_relatives.abs().mean():.4f}, Average: {relative.abs().mean():.4f}"
)
# Later actions should have larger relative offsets
last_relatives = relative[:, -1, :] # (B, action_dim)
assert last_relatives.abs().mean() >= first_relatives.abs().mean(), (
f"Last action in chunk should have >= relative offset than first. "
f"Last: {last_relatives.abs().mean():.4f}, First: {first_relatives.abs().mean():.4f}"
)
# Roundtrip
recovered = to_absolute_actions(relative, batch_states, mask)
torch.testing.assert_close(recovered, batch_actions)
def test_relative_stats_match_actual_data_distribution(dataset, action_dim):
"""Verify computed stats match the actual relative-action distribution."""
action_chunks, states = _build_action_chunks(dataset, CHUNK_SIZE)
mask = [True] * action_dim
# Compute stats like the training script does
relative_stats = _compute_relative_chunk_stats(action_chunks, states, mask)
# Also compute directly
all_relatives = []
for actions, state in zip(action_chunks, states, strict=True):
rel = to_relative_actions(actions.unsqueeze(0), state.unsqueeze(0), mask).squeeze(0)
all_relatives.append(rel)
all_relatives_tensor = torch.cat(all_relatives, dim=0)
# Compare mean
actual_mean = all_relatives_tensor.mean(dim=0).numpy()
np.testing.assert_allclose(relative_stats["mean"], actual_mean, atol=0.01)
# Compare std
actual_std = all_relatives_tensor.std(dim=0).numpy()
np.testing.assert_allclose(relative_stats["std"], actual_std, atol=0.1)
# Verify q01 < mean < q99
assert (relative_stats["q01"] < relative_stats["mean"]).all(), "q01 should be < mean"
assert (relative_stats["mean"] < relative_stats["q99"]).all(), "mean should be < q99"
def test_quantile_normalization_roundtrip(dataset, action_dim):
"""Full roundtrip with QUANTILES normalization (what OpenPI uses for pi05)."""
action_chunks, states = _build_action_chunks(dataset, CHUNK_SIZE)
mask = [True] * action_dim
relative_stats = _compute_relative_chunk_stats(action_chunks, states, mask)
stats = {ACTION: dict(relative_stats.items())}
features = {ACTION: PolicyFeature(type=FeatureType.ACTION, shape=(action_dim,))}
norm_map = {FeatureType.ACTION: NormalizationMode.QUANTILES}
relative_step = RelativeActionsProcessorStep(enabled=True)
normalizer = NormalizerProcessorStep(features=features, norm_map=norm_map, stats=stats)
unnormalizer = UnnormalizerProcessorStep(features=features, norm_map=norm_map, stats=stats)
absolute_step = AbsoluteActionsProcessorStep(enabled=True, relative_step=relative_step)
original_actions = action_chunks[0].unsqueeze(0)
state = states[0].unsqueeze(0)
batch = {ACTION: original_actions, OBS_STATE: state}
transition = batch_to_transition(batch)
# Forward: relative → quantile normalize
t1 = relative_step(transition)
t2 = normalizer(t1)
normalized = t2[TransitionKey.ACTION]
# Most values should be in [-1, 1] with quantile normalization
pct_in_range = (normalized.abs() < 2).float().mean()
assert pct_in_range > 0.5, f"Only {pct_in_range * 100:.1f}% in [-2, 2] after quantile norm, expected >50%"
# Reverse: unnormalize → absolute
t3 = unnormalizer(t2)
t4 = absolute_step(t3)
recovered = t4[TransitionKey.ACTION]
torch.testing.assert_close(recovered, original_actions, atol=1e-3, rtol=1e-3)
def test_state_not_modified_by_relative_processor(dataset, action_dim):
"""State should never be modified by the relative-action processor."""
hf = dataset.hf_dataset
batch = {
ACTION: torch.stack([hf[i]["action"] for i in range(4)]),
OBS_STATE: torch.stack([hf[i]["observation.state"] for i in range(4)]),
}
original_state = batch[OBS_STATE].clone()
transition = batch_to_transition(batch)
step = RelativeActionsProcessorStep(enabled=True)
result = step(transition)
result_state = result[TransitionKey.OBSERVATION][OBS_STATE]
torch.testing.assert_close(result_state, original_state)