lerobotrobotrosetta

LeRobot Robot plugin for ROS2. Translates contract-defined topics into LeRobot's get_observation() / send_action() interface.

Usage

from lerobot_robot_rosetta import Rosetta, RosettaConfig

robot = Rosetta(RosettaConfig(config_path="contract.yaml"))
robot.connect()

# Get observations as dict
obs = robot.get_observation()
# {"shoulder.position": 0.1, "elbow.position": 0.2, "camera": array(...)}

# Send actions
robot.send_action({"shoulder.position": 0.5, "elbow.position": 0.3})

robot.disconnect()

Or with LeRobot CLI:

lerobot-record --robot.type=rosetta --robot.config_path=contract.yaml
lerobot-teleoperate --robot.type=rosetta --robot.config_path=contract.yaml

Installation

colcon build --packages-select lerobot_robot_rosetta
source install/setup.bash

The package follows LeRobot's lerobot_robot_* naming convention and is auto-discovered.

Configuration

All configuration comes from the contract YAML. See rosetta/README.md for the full schema.

robot_type: my_robot
fps: 30

observations:
  - key: observation.state
    topic: /joint_states
    type: sensor_msgs/msg/JointState
    selector: {names: [position.shoulder, position.elbow]}

actions:
  - key: action
    publish: {topic: /cmd, type: sensor_msgs/msg/JointState}
    selector: {names: [position.shoulder, position.elbow]}
    safety_behavior: hold  # what to publish if actions stop

LeRobot Interface

Implements the Robot base class:

Property/Method	Description
observation_features	Dict of feature names → types (callable before connect())
action_features	Dict of action names → types (callable before connect())
is_connected	True when lifecycle node is active
connect()	Configure and activate ROS2 subscriptions/publishers
disconnect()	Deactivate, send safety action, cleanup
get_observation()	Sample current observations from topic buffers
send_action(action)	Publish action to ROS2 topics

Behavior

Lifecycle: Uses ROS2 lifecycle nodes. connect() activates subscriptions and publishers. disconnect() triggers safety behavior then cleans up.

Missing data: If a topic has no data, zeros are returned and a warning is logged once.

Safety watchdog: If no action is sent within 2/fps seconds:

• none: stop publishing
• hold: repeat last action
• zeros: publish zeros

Timestamp alignment: Observations from multiple topics are aligned using StreamBuffers with configurable strategies (hold, asof, drop).

License

Apache-2.0