PhysicalAI Bimanual SO-101 Plugin

Third-party bimanual SO-101 robot arm plugin for PhysicalAI, the Python library and runtime for robot control, transport, and CLI workflows. It registers with Physical AI Studio, the application that discovers catalog plugins and provides robot setup, teleoperation, and workflow experiences. Part of the physicalai-plugins monorepo.

Features

• Composes two SO-101 arms (left + right) behind a single Robot protocol
• Follower and leader (read-only) roles for teleoperation
• Bundled dual-arm URDF for kinematics and visualization

Hardware

Screenshots

Placeholder images — replace them with real screenshots.

Installation

uv add physicalai-bimanual-so101-plugin

feetech-servo-sdk is included as a core dependency.

Calibration examples

Bundled SO-101 calibration files (LeRobot format) live under examples/calibration/:

Pass them as the calibration path when constructing a SO101:

from physicalai.robot.so101 import SO101, SO101Calibration

cal = SO101Calibration.from_path("examples/calibration/follower.json")
arm = SO101(port="/dev/ttyACM0", calibration=cal, role="follower")

The bundled runtime config (examples/runtime/teleop.yaml) references these files already.

Quick start

Calibrated follower

import numpy as np
from physicalai.robot import connect
from physicalai_bimanual_so101_plugin import BimanualSO101

# Build left and right arms manually
from physicalai.robot.so101 import SO101, SO101Calibration

left_cal = SO101Calibration.from_path("left_calibration.json")
right_cal = SO101Calibration.from_path("right_calibration.json")

left = SO101(port="/dev/ttyACM0", calibration=left_cal, role="follower")
right = SO101(port="/dev/ttyACM1", calibration=right_cal, role="follower")

robot = BimanualSO101(left=left, right=right)

with connect(robot) as arm:
    obs = arm.get_observation()     # shape (12,)
    action = obs.joint_positions.copy()
    arm.send_action(action)

Uncalibrated bringup mode

from physicalai.robot import connect
from physicalai_bimanual_so101_plugin import BimanualSO101
from physicalai.robot.so101 import SO101

left = SO101.uncalibrated(port="/dev/ttyACM0", role="follower")
right = SO101.uncalibrated(port="/dev/ttyACM1", role="follower")

robot = BimanualSO101(left=left, right=right)

Leader (read-only teleoperation)

from physicalai.robot import connect
from physicalai.robot.so101 import SO101
from physicalai_bimanual_so101_plugin import BimanualSO101

left = SO101.uncalibrated(port="/dev/ttyACM0", role="leader")
right = SO101.uncalibrated(port="/dev/ttyACM1", role="leader")

robot = BimanualSO101(left=left, right=right)

with connect(robot) as arm:
    while True:
        obs = arm.get_observation()
        print(obs.joint_positions)

Teleoperation

Because BimanualSO101 satisfies the Robot protocol, it can be driven by the built-in physicalai.runtime.TeleopSource with a leader BimanualSO101 (both arms in role="leader"), e.g. via physicalai run --config or directly in Python:

from physicalai.robot.so101 import SO101
from physicalai.runtime import RobotRuntime, TeleopSource
from physicalai_bimanual_so101_plugin import BimanualSO101

follower = BimanualSO101(
    left=SO101.uncalibrated(port="/dev/ttyACM0", role="follower"),
    right=SO101.uncalibrated(port="/dev/ttyACM1", role="follower"),
)
leader = BimanualSO101(
    left=SO101.uncalibrated(port="/dev/ttyUSB0", role="leader"),
    right=SO101.uncalibrated(port="/dev/ttyUSB1", role="leader"),
)

runtime = RobotRuntime(fps=30, robot=follower, action_source=TeleopSource(leader=leader))
with runtime:
    runtime.run()

The same teleoperation can be run from a config with the PhysicalAI CLI:

uv run physicalai run --config packages/physicalai-bimanual-so101-plugin/examples/runtime/teleop.yaml

Press Ctrl+C to stop.

URDF Model

from physicalai_bimanual_so101_plugin import get_urdf_path

urdf_path = get_urdf_path()

Two arms mounted 0.4 m apart: left at +0.2 m (Y), right at -0.2 m (Y).

Joint Order

Left arm (indices 0-5): left_shoulder_pan, left_shoulder_lift, left_elbow_flex, left_wrist_flex, left_wrist_roll, left_gripper

Right arm (indices 6-11): right_shoulder_pan, right_shoulder_lift, right_elbow_flex, right_wrist_flex, right_wrist_roll, right_gripper

Development

uv sync
uv run pytest packages/physicalai-bimanual-so101-plugin/tests/

Acknowledgments

URDF model generated from Onshape via onshape-to-robot. SO-101 arm by LeRobot.