Servo Drive Move Stopped By Mechanical object

[BITS N BYTES 66]

Some ideas/advice please.

I have a 1S servo in my Sysmac project moving a belt driven linear slide.

During movement it is possible that an object can prevent completion of a move command.

What method should I use to monitor this problem Position Error, Over Torque etc. ?

Once detected what further action should me taken. MC_Stop, MC_ImmediateStop, dropout MC_Power etc.?

Any recommendations/suggestions most welcomed.

Thanks

 

Edited 17 Mar 2021 by BITS N BYTES

[photovoltaic 121]

If an object gets in the way with any move instruction it will trip the drive normally. The only way I can think to do this, and it may not be the only way, is to use MC_SetTorqueLimit to do your movements. This is not usually ideal as it negates any position control and just spins the motor as fast as it can as long as your torque is less than the torque set by the function block. I can confirm however that you can stall a motor and it won't trip the drive. You could detect the collision if your torque is at the setpoint limit, you're not at the end of the linear slide, and your position isn't changing. It's been a while since I've used it but I think you can enable a velocity override at the same time and this at least controls your speed. Parameter 3031.01 looks like this will control it as well. You would have to use position comparisons in logic under normal operation to detect if you're at the end of the slide and then stop the movement which may not be ideal and would take some tuning.

Like I said there may be another way that I'm not aware of.

Edited 18 Mar 2021 by photovoltaic

[photovoltaic 121]

Another way you could go is have the BufferMode of the movement instruction set to _mcAborting and keep an eye on the torque and position. When you see the torque pass a value and the position not equal to your target you might be able to execute an MC_ImmediateStop in time or even a relative movement in the opposite direction to relieve some strain on the system. You would have to test this and you might not have enough time before it trips.