Backlash Compensation

CPRog can help to compensate backlash(=gear-play) in software. This might increase precision in some applications, in others it might not.

Prerequisites

• CPRog Version V902-10-016 from March 2018 or later

Configuration

Roboter Ini file with GearPlay Compensation

The backlash compensation can be configured in the robot ini file at c:\CPRog\Data\Robots\yourrobotinifile.xml Please use "." as decimal separator!

For each joint the tags "GearPlay" and "GearPlayInc" can be adapted:

• GearPlay: Enter the mechanical backlash in degree in this joint. Values from 0.0 to 3.0. Needs to be higher than 0.1 to activate the compensation.
• GearPlayInc: Enter the velocity in degrees per cycle of backlash compensation. Values from 0.0 to 0.5. Should be around 0.05.

Test

To test the compensation:

• Make the changes in the ini file, save the file and start CPRog. Changes take effect only after a new start of CPRog.
• Set the override to e.g. 3%. Now move joint 1 a little to the left and to the right. Results:
  • If it does not move, the "GearPlay" Parameter should be increased.
  • If it moves too much, then the "GearPlay" parameter is too high. The backlash is overcompensated.
  • It should move just a little, then it is ok.

Side Effects

• When moving the robot for the first time, there might be a small motion to align the software and hardware gear play side.
• Please test the compensation in combination with your referencing procedure. Verify the referencing precision from different starting positions.