dora-openarm-mujoco

MuJoCo simulation node for the OpenArm bimanual robot, designed to run inside a dora-rs dataflow.

It replaces the physical follower arms and cameras: it accepts joint-position commands and publishes arm observations and JPEG camera frames at the same interface as the real hardware.

Installation

uv sync

Quick start

A self-contained dummy dataflow is included for testing without real hardware. It wires a dummy leader node to the MuJoCo sim and records to disk.

uv run dora build dataflow-dummy.yaml --uv
uv run dora run dataflow-dummy.yaml

Dataflow configuration

Minimal (headless and position forwarding only no cameras)

- id: openarm-mujoco
  build: pip install -e .
  path: dora-openarm-mujoco
  inputs:
    position_right: leader/follower_position_right
    position_left:  leader/follower_position_left
  outputs:
    - status
    - arm_right_observation
    - arm_left_observation

Full (interactive viewer + all cameras, with contacts, can be used for vr teleoperation)

- id: openarm-mujoco
  build: pip install -e .
  path: dora-openarm-mujoco
  args: "--viewer --render --enable-collision --ctrl --keyframe home"
  inputs:
    position_right: leader/follower_position_right
    position_left:  leader/follower_position_left
  outputs:
    - status
    - arm_right_observation
    - arm_left_observation
    - camera_wrist_right
    - camera_wrist_left
    - camera_head_left
    - camera_head_right
    - camera_ceiling

Inputs

ID	Type	Description
position_right	float32[8]	Target joint positions for the right arm: joints 1–7 then the gripper. ~500 Hz.
position_left	float32[8]	Same layout for the left arm.
pose_right	float32[7]	VR controller pose [x, y, z, qw, qx, qy, qz]. Used only with --debug-frames.
pose_left	float32[7]	Same for the left controller.

Outputs

ID	Type	Description
arm_right_observation	float32[8]	Observed joint positions, published per incoming command.
arm_left_observation	float32[8]	Same for the left arm.
camera_wrist_right	uint8[N]	JPEG frame, ~30 Hz. Requires --render.
camera_wrist_left	uint8[N]	JPEG frame, ~30 Hz. Requires --render.
camera_head_left	uint8[N]	JPEG frame, ~30 Hz. Requires --render.
camera_head_right	uint8[N]	JPEG frame, ~30 Hz. Requires --render.
camera_ceiling	uint8[N]	JPEG frame, ~30 Hz. Requires --render.

Camera outputs carry metadata={"encoding": "jpeg"}.

Arguments

Pass these via the args: field in the dataflow YAML, or directly on the command line.

Argument	Default	Description
--xml PATH	unset	MJCF scene file to load. Overrides --scene when set.
--scene NAME	cell	Bundled scene to load when --xml is not set. Choices: cell, demo, pedestal, bimanual.
--keyframe NAME	home	Keyframe in the MJCF to reset to on startup.
--enable-collision	off	Enable contact/collision detection. Disabled by default to avoid unexpected joint-locking during teleoperation.
--ctrl	off	Write incoming positions to data.ctrl and step the physics (mj_step) to simulate actuator control. The default writes directly to data.qpos with mj_forward.
--viewer	off	Open the interactive MuJoCo viewer window. Requires a display.
--render	off	Enable offscreen camera rendering and publish JPEG frames. Leave off if cameras are not needed.
--debug-frames	off	Draw VR controller poses as coloured arrows in the viewer. Only visible with --viewer.