What is Overshoot Error?

[travis]

What does Overshoot Error mean?

Hello,
What is a "Overshoot Alarm" in easy to understand language? Can someone provide an explanation or definition of a Overshoot error message and its possible causes. I'm looking for tips on troubleshooting this type of fault from the perspective of an electrical maintenance tech. Thank you!

Also can be known as:

• Overshoot Fault
• Overshoot Alarm
• Overshoot Problem
• Overshoot Message

[Cheller]

What is an "overshoot error"?

I'll give you my take on overshoot. I can't say I've seen this much but I do know what overshoot is...

Definition of Overshoot: Pertaining to a motion control system, overshoot is the deviance of actual position beyond the commanded position.

For the maintenance technician, this means that following a move, the motor has gone too far and had to back up to attain the position it needs to be in. This is typically caused by instability in the motion control system that is directly related to the motor and drive tuning.

I don't see this as a common problem in a fully operable system that was in production. It would seem to be a problem that you would encounter on startup of a new system or after the replacement of a drive or servo motor.

Sometimes overshoot error can be associated to "under-damped" tuning meaning it is not responsive enough.

On the contrary, an over-damped system would be too responsive and the motor would actually seem over-cautious as it approached its desired position. An under-damped motor would approach its desired position almost like it will worry about where it needs to be after it gets there.

Overshoot is typically addressed in the tuning of the motor and drive combo. These procedures vary tremendously among manufacturers so if you encounter an overshoot error, you'll likely need to address the response of the motor with a tuning procedure from the service manual that goes with your particular drive.