yam_arms

Preliminary testing and control scripts for I2RT YAM robot arms.

Setup

conda create -n yam_arms python=3.11 -y
conda activate yam_arms

pip install -e robots_realtime/dependencies/i2rt

CAN Bus Setup

Bring up the CAN interface before running any arm commands:

sudo ip link set can0 up type can bitrate 1000000

To verify:

ip link show can0
# Should show state UP

If the adapter is unresponsive, reset it:

sudo bash robots_realtime/dependencies/i2rt/scripts/reset_all_can.sh

Testing the Arm

Read Joint Positions (no movement)

python robots_realtime/dependencies/i2rt/test_arm.py --channel can0 --read-only

Continuously prints all 7 joint positions (6 arm + 1 gripper). Ctrl+C to exit.

Full Arm Movement Test

python robots_realtime/dependencies/i2rt/test_arm.py --channel can0

Interactive step-by-step test that walks through each joint:

1. Shoulder pan (joint 0, +/-0.3 rad)
2. Shoulder pitch (joint 1, +0.3 rad)
3. Elbow (joint 2, +0.3 rad)
4. Wrist joints (joints 3-5, +/-0.3 rad each)
5. Gripper (close then open)

Each step waits for Enter before moving. Ctrl+C to abort at any time.

Zero-Gravity Mode

Arm goes compliant so you can move it by hand:

python robots_realtime/dependencies/i2rt/i2rt/robots/motor_chain_robot.py --channel can0

Gripper-Only Test

Opens and closes the gripper repeatedly:

python robots_realtime/dependencies/i2rt/i2rt/robots/motor_chain_robot.py --channel can0 --operation_mode test_gripper

Hold Current Position

Locks the arm at its current pose:

python robots_realtime/dependencies/i2rt/i2rt/robots/motor_chain_robot.py --channel can0 --operation_mode stay_current_qpos

Python API

from i2rt.robots.get_robot import get_yam_robot
import numpy as np

robot = get_yam_robot(channel="can0")

# Read joint positions (7D: 6 arm joints + 1 gripper)
pos = robot.get_joint_pos()

# Command a target position
robot.command_joint_pos(np.array([0.0, 0.5, 1.0, 0.0, 0.0, 0.0, 0.8]))

# Smooth move to a target over 2 seconds
robot.move_joints(np.array([0.0, 0.5, 1.0, 0.0, 0.0, 0.0, 0.8]), time_interval_s=2.0)

# Gripper: index 6, range 0.0 (closed) to 0.8 (open)

# Cleanup
robot.close()

Gripper Types

Type	Flag	Notes
linear_4310	--gripper_type linear_4310	Default. Standard linear gripper
linear_3507	--gripper_type linear_3507	Lightweight linear
crank_4310	--gripper_type crank_4310	Zero-linkage crank
no_gripper	--gripper_type no_gripper	Arm only, no gripper

Troubleshooting

• "No such device": CAN interface is not up. Run sudo ip link set can0 up type can bitrate 1000000.
• "No module named 'i2rt'": Run pip install -e robots_realtime/dependencies/i2rt.
• Joint limit violation on startup: Arm may need recalibration. Move it to the zero position and power cycle.
• Motors unresponsive: Run sudo bash robots_realtime/dependencies/i2rt/scripts/reset_all_can.sh to reset the CAN adapter.