UR3 and UR3e: Screw driving with the tool flange
This how to demonstrates how to rotate wrist 3 for a screwing application.
Examples are valid for:
CB3 Software version: 3.1.18024
e-Series Software version: All versions
Note that older or newer software versions may behave differently.
NOTE: This is only intended to be used on UR3/UR3e as it has infinity rotation of the last axes.
Basic functionality
This is a simple application suggestion for doing screw driving applications using the infinite rotation on UR3 tool. The robot uses force mode to push onto the screw, while rotating the end joint at desired speed. Force mode is set up as Simple type using Tool as feature. A desired force value can be manually given.
The SpeedJ script code takes 3 arguments; speed vector for each joint in rad/sec, acceleration and time. Thus a desired time and rotational speed can be given by operator or modified manually. Maximum speed is 360 deg/sec for size 0 joints.
After the process, the revolution counter is reset, so the tool does not have to rotate back to its origin.
Screwing can be done using the speedj() script code.
Alternatively, the Force function may be used.
Force settings:
Type: Frame
Feature: Tool
Set the robot force complaint in Z and RZ directions, and input a given force and torque for the robot to start screwing.
Desired maximum speeds can also be given, max. joint speed for wrist 3 is 360 °/sec.
Test the Force settings by pressing “Test” button on screen and pressing Freedrive button on back of TP.