Leader-Follower Teleoperation

A human moves a leader arm, and the robot's follower arm copies each joint angle in real time.

Leader-follower teleoperation is a common way to collect robot data: the leader arm is a hand-operated mechanical arm with the same kinematic structure as the robot's follower arm, or a scaled-down version of it, with encoders or servos at each joint. The operator moves the leader arm, and the system reads out each joint angle and sends it straight to the follower arm. Because it is a direct joint-to-joint mapping, there is no need to solve inverse kinematics (working backward from end-effector position to joint angles), so latency is low and the motion is intuitive, which suits collecting fine bimanual manipulation data. The trade-off is that each robot needs its own matching leader arm, and there is usually no force feedback. ALOHA uses a WidowX leader arm with a ViperX follower arm for bimanual teleoperation; Berkeley's GELLO uses 3D-printed parts and off-the-shelf motors, at a cost under $300.

ExampleIn LeRobot, teleoperate an SO-101 follower arm with an SO-101 leader arm, recording camera footage and joint angles as you go; once you've recorded 50 demonstrations, that's enough to train an ACT policy.

Also called

Leader-Follower Arms, Isomorphic Leader Arm

Related

Teleoperation · ALOHA · GELLO · Bilateral Teleoperation · Demonstration Data · SO-100 / SO-101 Arm

Sources

GELLO: A General, Low-Cost, and Intuitive Teleoperation Framework for Robot Manipulators
ALOHA: Learning Fine-Grained Bimanual Manipulation with Low-Cost Hardware
LeRobot Docs: Imitation Learning on Real-World Robots