Add bundled OpenArm URDF and meshes for UMI evaluation

- Copy openarm_bimanual_pybullet.urdf and all referenced STL/DAE meshes
  into src/lerobot/robots/openarms/urdf/
- Update openarms_follower.py to prefer the bundled URDF over the
  external ~/Documents/openarm_description path
- Includes visual and collision meshes for arm, body, and end-effector
- Force-add .stl and .urdf files past .gitignore

src/lerobot/robots/openarms/openarms_follower.py

@@ -96,16 +96,26 @@ class OpenArmsFollower(Robot):
         # Initialize Pinocchio robot model for dynamics (optional)
         self.pin_robot = None
         try:
-            # Load URDF - try external path first (with meshes), then repository
             import os
-            from os.path import expanduser, dirname
-            
-            # Try external URDF with meshes first
-            external_urdf_path = expanduser("~/Documents/openarm_description/openarm_bimanual_pybullet.urdf")
-            if os.path.exists(external_urdf_path):
+            from os.path import dirname
+
+            # Prefer the URDF bundled in the repository
+            repo_urdf_path = os.path.join(
+                dirname(__file__), "urdf", "openarm_bimanual_pybullet.urdf"
+            )
+            external_urdf_path = os.path.expanduser(
+                "~/Documents/openarm_description/openarm_bimanual_pybullet.urdf"
+            )
+
+            if os.path.exists(repo_urdf_path):
+                urdf_path = repo_urdf_path
+            elif os.path.exists(external_urdf_path):
                 urdf_path = external_urdf_path
+            else:
+                urdf_path = None
+
+            if urdf_path is not None:
                 urdf_dir = dirname(urdf_path)
-            
                 self.pin_robot = pin.RobotWrapper.BuildFromURDF(urdf_path, urdf_dir)
                 self.pin_robot.data = self.pin_robot.model.createData()
                 logger.info(f"Loaded OpenArms URDF for dynamics computation from {urdf_path}")

src/lerobot/robots/openarms/urdf/openarm_bimanual_pybullet.urdf

@@ -0,0 +1,618 @@
+<?xml version='1.0' encoding='utf-8'?>
+<robot name="openarm">
+  <link name="world" />
+  <joint name="openarm_body_world_joint" type="fixed">
+    <parent link="world" />
+    <child link="openarm_body_link0" />
+    <origin rpy="0 0 0" xyz="0 0 0" />
+  </joint>
+  <link name="openarm_body_link0">
+    <visual name="openarm_body_link0_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 0.0" />
+      <geometry>
+        <mesh filename="./meshes/body/v10/visual/body_link0.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_body_link0_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 0.0" />
+      <geometry>
+        <mesh filename="./meshes/body/v10/collision/body_link0_symp.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 0.0" />
+      <mass value="13.89" />
+      <inertia ixx="1.653" ixy="0.0" ixz="0.0" iyy="1.653" iyz="0.0" izz="0.051" />
+    </inertial>
+  </link>
+  <joint name="openarm_left_openarm_body_link0_joint" type="fixed">
+    <parent link="openarm_body_link0" />
+    <child link="openarm_left_link0" />
+    <origin rpy="-1.5708 0 0" xyz="0.0 0.031 0.698" />
+  </joint>
+  <link name="openarm_left_link0">
+    <visual name="openarm_left_link0_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 0.0" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link0.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_link0_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 0.0" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link0_symp.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0009483362816297526 -0.0001580207020448382 0.03076860287587199" />
+      <mass value="1.1432284943239561" />
+      <inertia ixx="0.001128" ixy="-4e-06" ixz="-3.3e-05" iyy="0.000962" iyz="-7e-06" izz="0.00147" />
+    </inertial>
+  </link>
+  <link name="openarm_left_link1">
+    <visual name="openarm_left_link1_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 0.0 -0.0625" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link1.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_link1_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 0.0 -0.0625" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link1_symp.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="0.0011467657911800769 -3.319987657026362e-05 0.05395284380736254" />
+      <mass value="1.1416684646202298" />
+      <inertia ixx="0.001567" ixy="-1e-06" ixz="-2.9e-05" iyy="0.001273" iyz="1e-06" izz="0.001016" />
+    </inertial>
+  </link>
+  <joint name="openarm_left_joint1" type="revolute">
+    <origin rpy="0 0 0" xyz="0.0 0.0 0.0625" />
+    <parent link="openarm_left_link0" />
+    <child link="openarm_left_link1" />
+    <axis xyz="0 0 1" />
+    <limit effort="40" lower="-3.490659" upper="1.3962629999999998" velocity="16.754666" />
+  </joint>
+  <link name="openarm_left_link2">
+    <visual name="openarm_left_link2_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0301 0.0 -0.1225" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link2.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_link2_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0301 0.0 -0.1225" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link2_symp.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="0.00839629182351943 2.0145102027597523e-08 0.03256649300522363" />
+      <mass value="0.2775092746011571" />
+      <inertia ixx="0.000359" ixy="1e-06" ixz="-0.000109" iyy="0.000376" iyz="1e-06" izz="0.000232" />
+    </inertial>
+  </link>
+  <joint name="openarm_left_joint2" type="revolute">
+    <origin rpy="-1.57079632679 0 0" xyz="-0.0301 0.0 0.06" />
+    <parent link="openarm_left_link1" />
+    <child link="openarm_left_link2" />
+    <axis xyz="-1 0 0" />
+    <limit effort="40" lower="-3.3161253267948965" upper="0.17453267320510335" velocity="16.754666" />
+  </joint>
+  <link name="openarm_left_link3">
+    <visual name="openarm_left_link3_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 -0.0 -0.18875" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link3.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_link3_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 -0.0 -0.18875" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link3_symp.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="-0.002104752099628911 -0.0005549085042607548 0.09047470545721961" />
+      <mass value="1.073863338202347" />
+      <inertia ixx="0.004372" ixy="1e-06" ixz="1.1e-05" iyy="0.004319" iyz="-3.6e-05" izz="0.000661" />
+    </inertial>
+  </link>
+  <joint name="openarm_left_joint3" type="revolute">
+    <origin rpy="0 0 0" xyz="0.0301 0.0 0.06625" />
+    <parent link="openarm_left_link2" />
+    <child link="openarm_left_link3" />
+    <axis xyz="0 0 1" />
+    <limit effort="27" lower="-1.570796" upper="1.570796" velocity="5.445426" />
+  </joint>
+  <link name="openarm_left_link4">
+    <visual name="openarm_left_link4_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.0315 -0.3425" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link4.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_link4_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.0315 -0.3425" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link4_symp.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0029006831074562967 -0.03030575826634669 0.06339637422196209" />
+      <mass value="0.6348534566833373" />
+      <inertia ixx="0.000623" ixy="-1e-06" ixz="-1.9e-05" iyy="0.000511" iyz="3.8e-05" izz="0.000334" />
+    </inertial>
+  </link>
+  <joint name="openarm_left_joint4" type="revolute">
+    <origin rpy="0 0 0" xyz="-0.0 0.0315 0.15375" />
+    <parent link="openarm_left_link3" />
+    <child link="openarm_left_link4" />
+    <axis xyz="0 1 0" />
+    <limit effort="27" lower="0.0" upper="2.443461" velocity="5.445426" />
+  </joint>
+  <link name="openarm_left_link5">
+    <visual name="openarm_left_link5_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 -0.0 -0.438" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link5.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_link5_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 -0.0 -0.438" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link5_symp.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="-0.003049665024221911 -0.0008866902457326625 0.043079803024980934" />
+      <mass value="0.6156588026168502" />
+      <inertia ixx="0.000423" ixy="-8e-06" ixz="6e-06" iyy="0.000445" iyz="-6e-06" izz="0.000324" />
+    </inertial>
+  </link>
+  <joint name="openarm_left_joint5" type="revolute">
+    <origin rpy="0 0 0" xyz="0.0 -0.0315 0.0955" />
+    <parent link="openarm_left_link4" />
+    <child link="openarm_left_link5" />
+    <axis xyz="0 0 1" />
+    <limit effort="7" lower="-1.570796" upper="1.570796" velocity="20.943946" />
+  </joint>
+  <link name="openarm_left_link6">
+    <visual name="openarm_left_link6_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0375 -0.0 -0.5585" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link6.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_link6_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0375 -0.0 -0.5585" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link6_symp.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="-0.037136587005447405 -0.00033230528343419053 -9.498374522309838e-05" />
+      <mass value="0.475202773187987" />
+      <inertia ixx="0.000143" ixy="1e-06" ixz="1e-06" iyy="0.000157" iyz="1e-06" izz="0.000159" />
+    </inertial>
+  </link>
+  <joint name="openarm_left_joint6" type="revolute">
+    <origin rpy="0 0 0" xyz="0.0375 0.0 0.1205" />
+    <parent link="openarm_left_link5" />
+    <child link="openarm_left_link6" />
+    <axis xyz="1 0 0" />
+    <limit effort="7" lower="-0.785398" upper="0.785398" velocity="20.943946" />
+  </joint>
+  <link name="openarm_left_link7">
+    <visual name="openarm_left_link7_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.0 -0.5585" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link7.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_link7_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.0 -0.5585" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link7_symp.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="6.875510271106056e-05 -0.01266175250761268 0.06951945409987448" />
+      <mass value="0.4659771327380578" />
+      <inertia ixx="0.000639" ixy="1e-06" ixz="1e-06" iyy="0.000497" iyz="8.9e-05" izz="0.000342" />
+    </inertial>
+  </link>
+  <joint name="openarm_left_joint7" type="revolute">
+    <origin rpy="0 0 0" xyz="-0.0375 0.0 0.0" />
+    <parent link="openarm_left_link6" />
+    <child link="openarm_left_link7" />
+    <axis xyz="0 -1 0" />
+    <limit effort="7" lower="-1.570796" upper="1.570796" velocity="20.943946" />
+  </joint>
+  <joint name="openarm_right_openarm_body_link0_joint" type="fixed">
+    <parent link="openarm_body_link0" />
+    <child link="openarm_right_link0" />
+    <origin rpy="1.5708 0 0" xyz="0.0 -0.031 0.698" />
+  </joint>
+  <link name="openarm_right_link0">
+    <visual name="openarm_right_link0_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 0.0" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link0.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_link0_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 0.0" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link0_symp.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0009483362816297526 0.0001580207020448382 0.03076860287587199" />
+      <mass value="1.1432284943239561" />
+      <inertia ixx="0.001128" ixy="-4e-06" ixz="-3.3e-05" iyy="0.000962" iyz="-7e-06" izz="0.00147" />
+    </inertial>
+  </link>
+  <link name="openarm_right_link1">
+    <visual name="openarm_right_link1_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 0.0 -0.0625" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link1.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_link1_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 0.0 -0.0625" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link1_symp.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="0.0011467657911800769 3.319987657026362e-05 0.05395284380736254" />
+      <mass value="1.1416684646202298" />
+      <inertia ixx="0.001567" ixy="-1e-06" ixz="-2.9e-05" iyy="0.001273" iyz="1e-06" izz="0.001016" />
+    </inertial>
+  </link>
+  <joint name="openarm_right_joint1" type="revolute">
+    <origin rpy="0 0 0" xyz="0.0 0.0 0.0625" />
+    <parent link="openarm_right_link0" />
+    <child link="openarm_right_link1" />
+    <axis xyz="0 0 1" />
+    <limit effort="40" lower="-1.396263" upper="3.490659" velocity="16.754666" />
+  </joint>
+  <link name="openarm_right_link2">
+    <visual name="openarm_right_link2_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0301 0.0 -0.1225" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link2.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_link2_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0301 0.0 -0.1225" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link2_symp.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="0.00839629182351943 -2.0145102027597523e-08 0.03256649300522363" />
+      <mass value="0.2775092746011571" />
+      <inertia ixx="0.000359" ixy="1e-06" ixz="-0.000109" iyy="0.000376" iyz="1e-06" izz="0.000232" />
+    </inertial>
+  </link>
+  <joint name="openarm_right_joint2" type="revolute">
+    <origin rpy="1.57079632679 0 0" xyz="-0.0301 0.0 0.06" />
+    <parent link="openarm_right_link1" />
+    <child link="openarm_right_link2" />
+    <axis xyz="-1 0 0" />
+    <limit effort="40" lower="-0.17453267320510335" upper="3.3161253267948965" velocity="16.754666" />
+  </joint>
+  <link name="openarm_right_link3">
+    <visual name="openarm_right_link3_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 -0.0 -0.18875" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link3.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_link3_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 -0.0 -0.18875" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link3_symp.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="-0.002104752099628911 0.0005549085042607548 0.09047470545721961" />
+      <mass value="1.073863338202347" />
+      <inertia ixx="0.004372" ixy="1e-06" ixz="1.1e-05" iyy="0.004319" iyz="-3.6e-05" izz="0.000661" />
+    </inertial>
+  </link>
+  <joint name="openarm_right_joint3" type="revolute">
+    <origin rpy="0 0 0" xyz="0.0301 0.0 0.06625" />
+    <parent link="openarm_right_link2" />
+    <child link="openarm_right_link3" />
+    <axis xyz="0 0 1" />
+    <limit effort="27" lower="-1.570796" upper="1.570796" velocity="5.445426" />
+  </joint>
+  <link name="openarm_right_link4">
+    <visual name="openarm_right_link4_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.0315 -0.3425" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link4.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_link4_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.0315 -0.3425" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link4_symp.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0029006831074562967 -0.03030575826634669 0.06339637422196209" />
+      <mass value="0.6348534566833373" />
+      <inertia ixx="0.000623" ixy="-1e-06" ixz="-1.9e-05" iyy="0.000511" iyz="3.8e-05" izz="0.000334" />
+    </inertial>
+  </link>
+  <joint name="openarm_right_joint4" type="revolute">
+    <origin rpy="0 0 0" xyz="-0.0 0.0315 0.15375" />
+    <parent link="openarm_right_link3" />
+    <child link="openarm_right_link4" />
+    <axis xyz="0 1 0" />
+    <limit effort="27" lower="0.0" upper="2.443461" velocity="5.445426" />
+  </joint>
+  <link name="openarm_right_link5">
+    <visual name="openarm_right_link5_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 -0.0 -0.438" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link5.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_link5_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0 -0.0 -0.438" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link5_symp.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="-0.003049665024221911 0.0008866902457326625 0.043079803024980934" />
+      <mass value="0.6156588026168502" />
+      <inertia ixx="0.000423" ixy="-8e-06" ixz="6e-06" iyy="0.000445" iyz="-6e-06" izz="0.000324" />
+    </inertial>
+  </link>
+  <joint name="openarm_right_joint5" type="revolute">
+    <origin rpy="0 0 0" xyz="0.0 -0.0315 0.0955" />
+    <parent link="openarm_right_link4" />
+    <child link="openarm_right_link5" />
+    <axis xyz="0 0 1" />
+    <limit effort="7" lower="-1.570796" upper="1.570796" velocity="20.943946" />
+  </joint>
+  <link name="openarm_right_link6">
+    <visual name="openarm_right_link6_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0375 -0.0 -0.5585" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link6.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_link6_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="-0.0375 -0.0 -0.5585" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link6_symp.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="-0.037136587005447405 0.00033230528343419053 -9.498374522309838e-05" />
+      <mass value="0.475202773187987" />
+      <inertia ixx="0.000143" ixy="1e-06" ixz="1e-06" iyy="0.000157" iyz="1e-06" izz="0.000159" />
+    </inertial>
+  </link>
+  <joint name="openarm_right_joint6" type="revolute">
+    <origin rpy="0 0 0" xyz="0.0375 0.0 0.1205" />
+    <parent link="openarm_right_link5" />
+    <child link="openarm_right_link6" />
+    <axis xyz="1 0 0" />
+    <limit effort="7" lower="-0.785398" upper="0.785398" velocity="20.943946" />
+  </joint>
+  <link name="openarm_right_link7">
+    <visual name="openarm_right_link7_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.0 -0.5585" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/visual/link7.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_link7_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.0 -0.5585" />
+      <geometry>
+        <mesh filename="./meshes/arm/v10/collision/link7_symp.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0.0 0.0 0.0" xyz="6.875510271106056e-05 0.01266175250761268 0.06951945409987448" />
+      <mass value="0.4659771327380578" />
+      <inertia ixx="0.000639" ixy="1e-06" ixz="1e-06" iyy="0.000497" iyz="8.9e-05" izz="0.000342" />
+    </inertial>
+  </link>
+  <joint name="openarm_right_joint7" type="revolute">
+    <origin rpy="0 0 0" xyz="-0.0375 0.0 0.0" />
+    <parent link="openarm_right_link6" />
+    <child link="openarm_right_link7" />
+    <axis xyz="0 1 0" />
+    <limit effort="7" lower="-1.570796" upper="1.570796" velocity="20.943946" />
+  </joint>
+  <link name="openarm_left_hand">
+    <visual name="openarm_left_hand_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 -0.6585" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/visual/hand.dae" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_hand_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 -0.6585" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/collision/hand.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0 0 0" xyz="0.0 0.002 0.03" />
+      <mass value="0.35" />
+      <inertia ixx="0.0002473" ixy="1e-06" ixz="1e-06" iyy="1.763e-05" iyz="1e-06" izz="0.0002521" />
+    </inertial>
+  </link>
+  <joint name="left_openarm_hand_joint" type="fixed">
+    <parent link="openarm_left_link7" />
+    <child link="openarm_left_hand" />
+    <origin rpy="0 0 0" xyz="0 -0.0 0.1001" />
+  </joint>
+  <link name="openarm_left_hand_tcp">
+    <inertial>
+      <origin xyz="0 0 0" rpy="0 0 0" />
+      <mass value="0.001" />
+      <inertia ixx="0.000001" ixy="0.0" ixz="0.0" iyy="0.000001" iyz="0.0" izz="0.000001" />
+    </inertial>
+  </link>
+  <joint name="openarm_left_hand_tcp_joint" type="fixed">
+    <origin rpy="0 0 0" xyz="0 -0.0 0.08" />
+    <parent link="openarm_left_hand" />
+    <child link="openarm_left_hand_tcp" />
+  </joint>
+  <link name="openarm_left_left_finger">
+    <visual name="openarm_left_left_finger_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.05 -0.673001" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/visual/finger.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_left_finger_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.05 -0.673001" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/collision/finger.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0 0 0" xyz="0.0064528 0.01702 0.0219685" />
+      <mass value="0.03602545343277134" />
+      <inertia ixx="2.3749999999999997e-06" ixy="1e-06" ixz="1e-06" iyy="2.3749999999999997e-06" iyz="1e-06" izz="7.5e-07" />
+    </inertial>
+  </link>
+  <link name="openarm_left_right_finger">
+    <visual name="openarm_left_right_finger_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.05 -0.673001" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/visual/finger.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_left_right_finger_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.05 -0.673001" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/collision/finger.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0 0 0" xyz="0.0064528 -0.01702 0.0219685" />
+      <mass value="0.03602545343277134" />
+      <inertia ixx="2.3749999999999997e-06" ixy="1e-06" ixz="1e-06" iyy="2.3749999999999997e-06" iyz="1e-06" izz="7.5e-07" />
+    </inertial>
+  </link>
+  <joint name="openarm_left_finger_joint1" type="prismatic">
+    <parent link="openarm_left_hand" />
+    <child link="openarm_left_right_finger" />
+    <origin rpy="0 0 0" xyz="0 -0.006 0.015" />
+    <axis xyz="0 -1 0" />
+    <limit effort="333" lower="0.0" upper="0.044" velocity="10.0" />
+  </joint>
+  <joint name="openarm_left_finger_joint2" type="prismatic">
+    <parent link="openarm_left_hand" />
+    <child link="openarm_left_left_finger" />
+    <origin rpy="0 0 0" xyz="0 0.006 0.015" />
+    <axis xyz="0 1 0" />
+    <limit effort="333" lower="0.0" upper="0.044" velocity="10.0" />
+    <mimic joint="openarm_left_finger_joint1" />
+  </joint>
+  <link name="openarm_right_hand">
+    <visual name="openarm_right_hand_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 -0.6585" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/visual/hand.dae" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_hand_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.0 -0.6585" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/collision/hand.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0 0 0" xyz="0.0 0.002 0.03" />
+      <mass value="0.35" />
+      <inertia ixx="0.0002473" ixy="1e-06" ixz="1e-06" iyy="1.763e-05" iyz="1e-06" izz="0.0002521" />
+    </inertial>
+  </link>
+  <joint name="right_openarm_hand_joint" type="fixed">
+    <parent link="openarm_right_link7" />
+    <child link="openarm_right_hand" />
+    <origin rpy="0 0 0" xyz="0 -0.0 0.1001" />
+  </joint>
+  <link name="openarm_right_hand_tcp">
+    <inertial>
+      <origin xyz="0 0 0" rpy="0 0 0" />
+      <mass value="0.001" />
+      <inertia ixx="0.000001" ixy="0.0" ixz="0.0" iyy="0.000001" iyz="0.0" izz="0.000001" />
+    </inertial>
+  </link>
+  <joint name="openarm_right_hand_tcp_joint" type="fixed">
+    <origin rpy="0 0 0" xyz="0 -0.0 0.08" />
+    <parent link="openarm_right_hand" />
+    <child link="openarm_right_hand_tcp" />
+  </joint>
+  <link name="openarm_right_left_finger">
+    <visual name="openarm_right_left_finger_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.05 -0.673001" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/visual/finger.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_left_finger_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 -0.05 -0.673001" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/collision/finger.stl" scale="0.001 0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0 0 0" xyz="0.0064528 0.01702 0.0219685" />
+      <mass value="0.03602545343277134" />
+      <inertia ixx="2.3749999999999997e-06" ixy="1e-06" ixz="1e-06" iyy="2.3749999999999997e-06" iyz="1e-06" izz="7.5e-07" />
+    </inertial>
+  </link>
+  <link name="openarm_right_right_finger">
+    <visual name="openarm_right_right_finger_visual">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.05 -0.673001" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/visual/finger.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </visual>
+    <collision name="openarm_right_right_finger_collision">
+      <origin rpy="0.0 0.0 0.0" xyz="0.0 0.05 -0.673001" />
+      <geometry>
+        <mesh filename="./meshes/ee/openarm_hand/collision/finger.stl" scale="0.001 -0.001 0.001" />
+      </geometry>
+    </collision>
+    <inertial>
+      <origin rpy="0 0 0" xyz="0.0064528 -0.01702 0.0219685" />
+      <mass value="0.03602545343277134" />
+      <inertia ixx="2.3749999999999997e-06" ixy="1e-06" ixz="1e-06" iyy="2.3749999999999997e-06" iyz="1e-06" izz="7.5e-07" />
+    </inertial>
+  </link>
+  <joint name="openarm_right_finger_joint1" type="prismatic">
+    <parent link="openarm_right_hand" />
+    <child link="openarm_right_right_finger" />
+    <origin rpy="0 0 0" xyz="0 -0.006 0.015" />
+    <axis xyz="0 -1 0" />
+    <limit effort="333" lower="0.0" upper="0.044" velocity="10.0" />
+  </joint>
+  <joint name="openarm_right_finger_joint2" type="prismatic">
+    <parent link="openarm_right_hand" />
+    <child link="openarm_right_left_finger" />
+    <origin rpy="0 0 0" xyz="0 0.006 0.015" />
+    <axis xyz="0 1 0" />
+    <limit effort="333" lower="0.0" upper="0.044" velocity="10.0" />
+    <mimic joint="openarm_right_finger_joint1" />
+  </joint>
+</robot>

src/lerobot/scripts/lerobot_train.py

@@ -49,8 +49,7 @@ from lerobot.utils.train_utils import (
 )
 from lerobot.utils.relative_actions import (
     convert_to_relative_actions,
-    compute_relative_action_stats,
-    PerTimestepNormalizer,
+    compute_global_relative_stats,
 )
 from lerobot.utils.utils import (
     format_big_number,
@@ -304,40 +303,60 @@ def train(cfg: TrainPipelineConfig, accelerator: Accelerator | None = None):
             device=device,
         )
 
-    # Compute per-timestep normalizer for relative actions
-    relative_normalizer = None
+    # Compute relative action/state stats and hotswap them into the normalizer
+    raw_state_key = None
     if cfg.use_relative_actions:
+        from lerobot.processor.normalize_processor import hotswap_stats
+
         mode = "actions + state" if cfg.use_relative_state else "actions only"
         cfg.output_dir.mkdir(parents=True, exist_ok=True)
         stats_path = cfg.output_dir / "relative_stats.pt"
-        
+
+        reverse_rename = {v: k for k, v in cfg.rename_map.items()} if cfg.rename_map else {}
+        raw_state_key = reverse_rename.get("observation.state", "observation.state")
+
         if is_main_process:
             logging.info(colored(f"Relative mode: {mode}", "cyan", attrs=["bold"]))
-            
+
             if stats_path.exists():
-                logging.info(f"Loading pre-computed stats from: {stats_path}")
+                logging.info(f"Loading pre-computed relative stats from: {stats_path}")
             else:
-                logging.info("Computing per-timestep stats (first 1000 batches)...")
-                logging.info("Using fresh dataset to avoid video decoder state issues...")
-                # Create separate dataset instance to avoid corrupting main dataset's video decoders
+                logging.info("Computing global relative stats (first 1000 batches)...")
                 stats_dataset = make_dataset(cfg)
                 temp_loader = torch.utils.data.DataLoader(
                     stats_dataset, batch_size=cfg.batch_size, shuffle=False, num_workers=0
                 )
-                mean, std = compute_relative_action_stats(temp_loader, num_batches=1000)
+                rel_stats = compute_global_relative_stats(
+                    temp_loader, state_key=raw_state_key,
+                    convert_state=cfg.use_relative_state, num_batches=1000,
+                )
                 del temp_loader, stats_dataset
                 gc.collect()
-                torch.save({"mean": mean, "std": std}, stats_path)
-                logging.info(f"Saved stats to: {stats_path}")
-        
-        # Poll for stats file instead of using NCCL barrier (avoids timeout during long computation)
+                torch.save(rel_stats, stats_path)
+                logging.info(f"Saved relative stats to: {stats_path}")
+
         if not is_main_process:
             while not stats_path.exists():
                 time.sleep(5)
-        
-        data = torch.load(stats_path, weights_only=True, map_location="cpu")
-        relative_normalizer = PerTimestepNormalizer(data["mean"], data["std"])
-        accelerator.wait_for_everyone()  # Sync after everyone has loaded
+
+        rel_stats = torch.load(stats_path, weights_only=True, map_location="cpu")
+
+        # Replace absolute stats with relative stats in the normalizer
+        updated_stats = dict(dataset.meta.stats)
+        updated_stats["action"] = {
+            **updated_stats["action"],
+            "mean": rel_stats["action_mean"].numpy(),
+            "std": rel_stats["action_std"].numpy(),
+        }
+        if cfg.use_relative_state and "state_mean" in rel_stats:
+            updated_stats[raw_state_key] = {
+                **updated_stats.get(raw_state_key, {}),
+                "mean": rel_stats["state_mean"].numpy(),
+                "std": rel_stats["state_std"].numpy(),
+            }
+        preprocessor = hotswap_stats(preprocessor, updated_stats)
+        logging.info("Hotswapped normalizer stats with relative stats")
+        accelerator.wait_for_everyone()
 
     step = 0  # number of policy updates (forward + backward + optim)
 
@@ -425,13 +444,14 @@ def train(cfg: TrainPipelineConfig, accelerator: Accelerator | None = None):
     for _ in range(step, cfg.steps):
         start_time = time.perf_counter()
         batch = next(dl_iter)
-        batch = preprocessor(batch)
-        
-        # Convert to relative actions (and optionally state) if enabled
+
+        # Convert to relative on raw data BEFORE normalization
         if cfg.use_relative_actions:
-            batch = convert_to_relative_actions(batch, convert_state=cfg.use_relative_state)
-            if relative_normalizer is not None:
-                batch["action"] = relative_normalizer.normalize(batch["action"])
+            batch = convert_to_relative_actions(
+                batch, state_key=raw_state_key, convert_state=cfg.use_relative_state,
+            )
+
+        batch = preprocessor(batch)
         
         train_tracker.dataloading_s = time.perf_counter() - start_time
 
@@ -487,9 +507,6 @@ def train(cfg: TrainPipelineConfig, accelerator: Accelerator | None = None):
                     preprocessor=preprocessor,
                     postprocessor=postprocessor,
                 )
-                # Save relative action stats with checkpoint
-                if relative_normalizer is not None:
-                    relative_normalizer.save(checkpoint_dir / "relative_stats.pt")
                 update_last_checkpoint(checkpoint_dir)
                 if wandb_logger:
                     wandb_logger.log_policy(checkpoint_dir)

src/lerobot/utils/relative_actions.py

@@ -74,11 +74,53 @@ def compute_relative_action_stats(
         rel = action.clone()
         rel[..., :min_dim] -= current_pos[:, None, :min_dim]
         all_rel.append(rel)
-    
+
     all_rel = torch.cat(all_rel, dim=0)
     return all_rel.mean(dim=0), all_rel.std(dim=0).clamp(min=1e-6)
 
 
+def compute_global_relative_stats(
+    dataloader,
+    state_key: str = "observation.state",
+    convert_state: bool = True,
+    num_batches: int | None = None,
+) -> dict[str, torch.Tensor]:
+    """Compute global mean/std for relative actions (and state) across all timesteps.
+
+    Returns stats compatible with the standard MEAN_STD normalizer (shape = action_dim).
+    """
+    all_rel_actions = []
+    all_rel_states = []
+    for i, batch in enumerate(dataloader):
+        if num_batches is not None and i >= num_batches:
+            break
+        action, state = batch["action"], batch[state_key]
+        current_pos = state[:, -1, :] if state.dim() == 3 else state
+
+        min_dim = min(action.shape[-1], current_pos.shape[-1])
+        rel = action.clone()
+        rel[..., :min_dim] -= current_pos[:, None, :min_dim]
+        all_rel_actions.append(rel.reshape(-1, rel.shape[-1]))
+
+        if convert_state:
+            if state.dim() == 3:
+                rel_state = state - current_pos[:, None, :]
+            else:
+                rel_state = torch.zeros_like(state)
+            all_rel_states.append(rel_state.reshape(-1, rel_state.shape[-1]))
+
+    all_rel_actions = torch.cat(all_rel_actions, dim=0)
+    result = {
+        "action_mean": all_rel_actions.mean(dim=0),
+        "action_std": all_rel_actions.std(dim=0).clamp(min=1e-6),
+    }
+    if convert_state and all_rel_states:
+        all_rel_states = torch.cat(all_rel_states, dim=0)
+        result["state_mean"] = all_rel_states.mean(dim=0)
+        result["state_std"] = all_rel_states.std(dim=0).clamp(min=1e-6)
+    return result
+
+
 def convert_to_relative(
     batch: dict,
     state_key: str = "observation.state",