Stop Cartesian Motion

SUMMARY

Stop Cartesian Motion decelerates the robot and brings any active Cartesian (TCP-linear) motion to a complete stop.

This skill is the safe and controlled way to interrupt a Cartesian move that was 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_cartesian_motion(stopping_speed=0.5)

The Code

Example: Stop Cartesian Motion Mid-Move

Launch an asynchronous Cartesian 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)

actual_pose = robot.get_cartesian_pose()

target_pose = actual_pose[:]
target_pose[2] += 0.15

robot.set_cartesian_pose(
    cartesian_pose=target_pose,
    speed=0.25,
    acceleration=0.5,
    asynchronous=True,
)
time.sleep(0.3)
robot.stop_cartesian_motion(stopping_speed=0.25)
logger.info("Stopped Cartesian motion.")

# Disconnect
robot.disconnect()

The Explanation of the Code

stop_cartesian_motion sends a deceleration command to the robot controller, which smoothly brings any ongoing Cartesian move to a halt. The stopping_speed parameter controls how aggressively the robot decelerates — lower values yield gentler stops; higher values yield faster stops.

How to Tune the Parameters

Parameter	Type	Default	Description
stopping_speed	float	0.5	Deceleration target speed in m/s. Lower values produce gentler stops.

Return Value

Type	Description
None	Returns after the stop command is sent.

Where to Use the Skill

• Interrupt asynchronous Cartesian moves — Stop a set_cartesian_pose or set_joint_position_in_cartesian_space call launched with asynchronous=True
• Emergency path abort — Halt TCP motion immediately when a sensor or vision system detects an obstacle

When Not to Use the Skill

Do not use Stop Cartesian Motion when:

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