Created: October 16th, 2023.

Set Base Acceleration

Overview

Linear axis in the horizontal (slides) and vertical direction (lifts) are sometimes used to move the robot. If the control system senses an unexpected acceleration of the robot joints, a protective stop might result.

The set_base_acceleration function can be used to inform the control system that the robot base is moving, and so prevent unwanted protective stops in this situation.

set_base_acceleration(a)

Sets the acceleration of the robot base. This function is used when the robot is attached to a moving base such a linear rail or vertical lift.

Parameters

a: a 3D vector, describing the base acceleration, relative to the base coordinate system of the robot

High Holding Torque Disable/Enable

Overview

UR Robots are designed to go into a high-torque hold mode when stationary. This feature is used in applications such as screw driving, where the robot is expected to maintain its stationary position without issuing a protective stop.

In some situations, this is not the desirable behavior. If the robot base is moving, but the robot joints are stationary, we still may want a protective stop issued if the robot collides with an object. For example, moving the robot using a horizontal linear rail (slide) or vertical lift, we may want the robot to stop in a collision situation.

This function has been introduced for the purpose of turning off the default high torque hold mode.

high_holding_torque_disable()

Disable automatically applying high hold torque when the robot is stationary.

UR controller automatically applies high holding torque when

• the program state is PROGRAM_STATE_RUNNING
• all actual joint movement <= 0.01 rad/s
• all target joint velocities == 0

This function script disables that behavior. Note that the default is restored to enabled after restarting the controller.

high_holding_torque_enable()

Enable automatically applying high hold torque when the robot is stationary.

See also high_holding_torque_disable().

Note: If the base of the robot collides with an object while moving, the protective stop may not be issued. Adequate saftey precautions should be put in place to guard against this situation.

With High Holding Torque OFF, the robot may issue a protective stop when colliding with an object.