Record & Replay Trajectory

Location: examples/record_replay_trajectory/

Record a manipulation trajectory through teleoperation (or gravity-comp hand-guiding) and replay it exactly — useful for dataset collection and validating robot configurations.

Hardware Required

• 1× YAM arm (follower or standalone)
• 1× CANable USB-CAN adapter
• Optional: leader arm + teaching handle for teleoperation recording

Overview

Record phase:
  Arm in gravity-comp mode  ──►  Guide by hand  ──►  Save joint trajectory

Replay phase:
  Load trajectory  ──►  Command arm via PD control  ──►  Arm replays motion

Video

🎬

Video — Coming Soon

Split screen: left side shows recording phase (operator guiding arm by hand through a pouring task), right side shows replay phase (arm autonomously repeating the motion). 60–90 seconds.

Running

python examples/record_replay_trajectory/record_replay_trajectory.py --channel can0 --gripper linear_4310

Controls

Key	Action
r	Start / stop recording
p	Play back recorded motion
s	Save trajectory to file
l	Load trajectory from file
q	Quit

Options

--channel can0          # CAN bus channel
--gripper linear_4310   # Gripper type (for gravity compensation)
--output file.npy       # Output filename
--load file.npy         # Load and replay a trajectory at startup

Workflow

1. Run the script — arm enters gravity-comp mode
2. Press r to start recording, guide the arm by hand, press r to stop
3. Press p to replay the captured motion
4. Press s to save, or l to load a previously saved trajectory

Output Format

Trajectories are saved as NumPy arrays:

import numpy as np

# Shape: (T, 6) — T timesteps, 6 joints
trajectory = np.load("trajectory.npy")
print(trajectory.shape)  # (500, 6)

See Also

• YAM Arm API
• Bimanual Teleoperation