Random servo motor behavior


#1

Hello, I’m experiencing some random moves and would like to know if this could be related to encoder (or encoder wiring).

My hardware:
-single Ioni Pro in IoniCube 4 axis
-Bosch AC servo with Biss C magnetic encoder
-drive firmware version 1.7.2, Granity 1.14.1

How it behaves:
Drive initializes and moves the shaft slowly and smoothly in both directions.

Enabling test stimulus in Testing tab produces random results - sometimes the shaft moves according to target setpoint, sometimes it moves once and stops, and when I grab the motor shaft, it starts to move again (according to test stimulus). Letting the shaft go stops the motion. What could be the problem?

Edit. Jogging also doesn’t seem to work properly. Hitting Increment by TPS1 works only once. No movement from subsequent presses.


#2

Hi Walter

This sound a bit like the encoder direction is inverted.

Please read the following wiki page and test the motor in torque mode:
https://granitedevices.com/wiki/Servo_motor_torque_mode_test

Also, please check that the position feedback value in Granity/Testing increases and decreases when you manually rotate the motor. For this, set the motor to torque mode with zero setpoint.

Kind regards,
Esa


#3

Thank you very much.