Stop Joint Motion

SUMMARY

Stop Joint Motion decelerates the robot and brings any active joint-space motion to a complete stop.

This skill is the safe and controlled way to interrupt a joint move launched with asynchronous=True.

SUPPORTED ROBOTS

This skill is currently supported on Universal Robots only. Calling this method on other robot brands will raise a NotImplementedError.

The Skill

robot.stop_joint_motion(stopping_speed=0.5)

The Code

Example: Stop Joint Motion Mid-Move

Launch an asynchronous joint move, wait briefly, then stop the robot before it reaches the target.

import time
from loguru import logger
from telekinesis.synapse.robots.manipulators import universal_robots

robot_ip = "192.168.1.2"  # replace with your robot's IP

robot = universal_robots.UniversalRobotsUR10E()
# Connect
robot.connect(ip=robot_ip)

initial_joint_positions = robot.get_joint_positions()

target_joint_positions = initial_joint_positions[:]
target_joint_positions[0] += 20

robot.set_joint_positions(
    joint_positions=target_joint_positions,
    speed=60,
    acceleration=80,
    asynchronous=True,
)
time.sleep(0.3)
robot.stop_joint_motion(stopping_speed=30)
logger.info("Stopped joint motion.")

# Disconnect
robot.disconnect()

The Explanation of the Code

stop_joint_motion sends a deceleration command to the robot controller, smoothly bringing any ongoing joint-space move to a halt. stopping_speed is expressed in deg/s — lower values produce gentler, longer stops; higher values produce faster, shorter stops.

How to Tune the Parameters

Parameter	Type	Default	Description
stopping_speed	float	0.5	Deceleration target speed in deg/s.

Return Value

Type	Description
None	Returns after the stop command is sent.

Where to Use the Skill

• Interrupt asynchronous joint moves — Stop a set_joint_positions or set_cartesian_pose_in_joint_space call launched with asynchronous=True
• Safety-triggered halt — Stop joint motion immediately when a safety condition is detected

When Not to Use the Skill

Do not use Stop Joint Motion when:

• The active motion is Cartesian-linear — use Stop Cartesian Motion instead
• The motion is already synchronous — synchronous calls block until completion; there is no motion to interrupt