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lerobot-clone/src/lerobot/policies/rtc/action_queue.py
Eugene Mironov 7185a5350e Small fixes
2025-11-18 21:30:02 +07:00

220 lines
8.0 KiB
Python

#!/usr/bin/env python
# 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.
"""Action queue management for Real-Time Chunking (RTC).
This module provides ActionQueue, a thread-safe queue for managing action chunks
in real-time control scenarios. It supports both RTC-enabled and non-RTC modes,
handling action merging and leftover tracking.
"""
import logging
from threading import Lock
import torch
from torch import Tensor
from lerobot.policies.rtc.configuration_rtc import RTCConfig
logger = logging.getLogger(__name__)
class ActionQueue:
"""Thread-safe queue for managing action chunks in real-time control.
This queue handles two types of action sequences:
- Original actions: Used for RTC to compute leftovers from previous chunks
- Processed actions: Post-processed actions ready for robot execution
The queue operates in two modes:
1. RTC-enabled: Replaces the entire queue with new actions, accounting for inference delay
2. RTC-disabled: Appends new actions to the queue, maintaining continuity
Args:
cfg (RTCConfig): Configuration for Real-Time Chunking behavior.
Attributes:
queue (Tensor | None): Processed actions for robot rollout (time_steps, action_dim).
original_queue (Tensor | None): Original actions for RTC computation (time_steps, action_dim).
last_index (int): Current consumption index in the queue.
"""
def __init__(self, cfg: RTCConfig):
"""Initialize the action queue.
Args:
cfg: RTC configuration controlling queue behavior.
"""
self.queue = None # Processed actions for robot rollout
self.original_queue = None # Original actions for RTC
self.lock = Lock()
self.last_index = 0
self.cfg = cfg
def get(self) -> Tensor | None:
"""Get the next action from the queue.
Returns:
Tensor | None: The next action (action_dim,) or None if queue is empty.
Returns a clone to prevent external modifications.
"""
with self.lock:
if self.queue is None or self.last_index >= len(self.queue):
return None
action = self.queue[self.last_index]
self.last_index += 1
return action.clone()
def qsize(self) -> int:
"""Get the number of remaining actions in the queue.
Returns:
int: Number of unconsumed actions.
"""
if self.queue is None:
return 0
length = len(self.queue)
return length - self.last_index
def empty(self) -> bool:
"""Check if the queue is empty.
Returns:
bool: True if no actions remain, False otherwise.
"""
if self.queue is None:
return True
length = len(self.queue)
return length - self.last_index <= 0
def get_action_index(self) -> int:
"""Get the current action consumption index.
Returns:
int: Index of the next action to be consumed.
"""
return self.last_index
def get_left_over(self) -> Tensor | None:
"""Get leftover original actions for RTC prev_chunk_left_over.
These are the unconsumed actions from the current chunk, which will be
used by RTC to compute corrections for the next chunk.
Returns:
Tensor | None: Remaining original actions (remaining_steps, action_dim),
or None if no original queue exists.
"""
with self.lock:
if self.original_queue is None:
return None
return self.original_queue[self.last_index :]
def merge(
self,
original_actions: Tensor,
processed_actions: Tensor,
real_delay: int,
action_index_before_inference: int | None = 0,
):
"""Merge new actions into the queue.
This method operates differently based on RTC mode:
- RTC enabled: Replaces the queue, accounting for inference delay
- RTC disabled: Appends to the queue, maintaining continuity
Args:
original_actions: Unprocessed actions from policy (time_steps, action_dim).
processed_actions: Post-processed actions for robot (time_steps, action_dim).
real_delay: Number of time steps of inference delay.
action_index_before_inference: Index before inference started, for validation.
"""
with self.lock:
self._check_delays(real_delay, action_index_before_inference)
if self.cfg.enabled:
self._replace_actions_queue(original_actions, processed_actions, real_delay)
return
self._append_actions_queue(original_actions, processed_actions)
def _replace_actions_queue(self, original_actions: Tensor, processed_actions: Tensor, real_delay: int):
"""Replace the queue with new actions (RTC mode).
Discards the first `real_delay` actions since they correspond to the time
spent during inference, when the robot was executing previous actions.
Args:
original_actions: Unprocessed actions from policy.
processed_actions: Post-processed actions for robot.
real_delay: Number of time steps to skip due to inference delay.
"""
self.original_queue = original_actions[real_delay:].clone()
self.queue = processed_actions[real_delay:].clone()
logger.debug(f"original_actions shape: {self.original_queue.shape}")
logger.debug(f"processed_actions shape: {self.queue.shape}")
logger.debug(f"real_delay: {real_delay}")
self.last_index = 0
def _append_actions_queue(self, original_actions: Tensor, processed_actions: Tensor):
"""Append new actions to the queue (non-RTC mode).
Removes already-consumed actions and appends new ones, maintaining
queue continuity without replacement.
Args:
original_actions: Unprocessed actions from policy.
processed_actions: Post-processed actions for robot.
"""
if self.queue is None:
self.original_queue = original_actions.clone()
self.queue = processed_actions.clone()
return
self.original_queue = torch.cat([self.original_queue, original_actions.clone()])
self.original_queue = self.original_queue[self.last_index :]
self.queue = torch.cat([self.queue, processed_actions.clone()])
self.queue = self.queue[self.last_index :]
self.last_index = 0
def _check_delays(self, real_delay: int, action_index_before_inference: int | None = None):
"""Validate that computed delays match expectations.
Compares the delay computed from inference latency with the actual
number of actions consumed during inference.
Args:
real_delay: Delay computed from inference latency.
action_index_before_inference: Action index when inference started.
"""
if action_index_before_inference is None:
return
indexes_diff = self.last_index - action_index_before_inference
if indexes_diff != real_delay:
# Let's check that action index difference (real delay calculated based on action queue)
# is the same as delay calculated based on inference latency
logger.warning(
f"[ACTION_QUEUE] Indexes diff is not equal to real delay. "
f"Indexes diff: {indexes_diff}, real delay: {real_delay}"
)