Motion Axis Jog on 1756-M02AS

[Tinine]

Why feed forward on a, what, crane?

 

[Robb B]

Yes, it's a sort of crane. It's a hoist that picks up railway ties (up to 8 at a time) travels from 16 to 108 inches, then lowers the ties and releases them onto a tram. All hydraulic power. The encoder is 22bit with a resolution of 41.7 counts per inch.

 

[Tinine]

Another question: Has the hydraulic pressure changed since original calibration?

 

[Robb B]

Another question: Has the hydraulic pressure changed since original calibration?

I don't know the history of the pump running the hydraulics, other than it's more than 5 years old in it's current configuration. There may have been different pumps at the time it was commissioned (more than 30 yrs ago).

 

[Robb B]

Why feed forward on a, what, crane?

I don't know, I inherited the system as is. I've spent a lot of time looking into lots of areas of the programming and the operations, trying to get up to speed!

 

[Tinine]

I would say lose the FF and maybe drop the proportional to 0.4 and see which direction that takes us.

 

[Robb B]

I would say lose the FF and maybe drop the proportional to 0.4 and see which direction that takes us.

Remove the feedforward gains?

 

[Tinine]

Yeah...that alone might stabilise the jog. Then play with the proportional gain. Dropping it will soften the response but you still need enough to get within your tolerance window....if there is one

 

[Peter Nachtwey]

The control output is jumping too much. Something is wrong.