Jump to content
OMRON Forums

Gains for different position feedback encoders


kmonroe023
 Share

Recommended Posts

I have a question regarding how to update/change motor servo gains if the feedback device is changed.

 

The application is a rotary servo motor driving a vertical slide via a ball-screw.

 

There are two encoders in the system, a quadrature encoder that is built into the motor, and a BissC absolute encoder that is connected directly to the slide. The initial motor setup and tuning was performed using the quadrature encoder.

 

The existing gains work well with the slide & load attached and the quadrature encoder closing the position and velocity loops. I'd like to use the existing servo gains, but close the position loop using the absolute encoder; it's connected directly to the slide and has a much higher resolution than the quadrature encoder.

 

If I update pEnc and PosSf to use the absolute encoder, do I need to update the servo position gains to maintain the same bandwidth and performance I have with the quadrature encoder (See below for Motor.PosSf info)?

 

If I do need to update the position gains to use the absolute encoder, is there an easy way to scale the existing gains if I know the difference in resolution of the encoders?

 

// both encoder scaling factors setup to output millimeters
// absolute encoder, 1 nano-meter resolution (1 million counts per mm)
Motor[5].pEnc=EncTable[10].a
Motor[5].PosSf=1/1000000
// incremental encoder on ballscrew w/ 2mm pitch, 8192 counts per rev
Motor[5].pEnc=EncTable[5].a
Motor[5].PosSf=2/8192

Link to comment
Share on other sites

  • Replies 1
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Guest
This topic is now closed to further replies.
 Share


×
×
  • Create New...