corection of position for servo motor

[pr2501]

All the code is attached at topic: On the attached picture i had insert : 398 AND X010 399 ADD K20 D40 D40 From default D40 is set indirectly (some others calculations) from C251. I have point A and B. And servo is moving between them (from A to B then from B to A). After (let say 1 our) servo moves out of range. Could correction be performed in this way? And actually way (while online) D40 don't change it value (i have made a test without X010)?

[pr2501]

This is temporally solution. (a know that mistake in time will increase) But until i figure out in mechanic what produces this mistake i need to make machine work.

[Veganic]

Anything that changes the output value will change the movement. Just out of interest: Is this a Mitsu servo? Is it always reciprocating to and from the same two points at the same speed and acceleration? Does it always go 'out' of sync in the same direction? How far is 'out of sync'?

[pr2501]

It is Melservo MR-C40A. Tomorrow i 'll give you answer for other question.

[Sergei Troizky]

Anything calculated from C251 is most probably 32-bit, in which case your calculations also should be such.

[P Daniil]

The position drift you describe is typically caused by: 1. Loose mechanical coupling, backlash etc, and 2. Encoder dither. Our white paper looks at the problem and may be of interest.

[FNMdeJong]

Like previous already mentioned, this could happen because of any backlash in the system. Specially when changing movement directions, like this pick and place movement. Use in case of this the backlash compensation parameter inside the amplifier. Another option is to check the mechanical settings. Are these correct. Also EMC can cause this behaviour.