How to control stepper motor efficiently

[E2005]

I am using hayden can stack motor z20000 series, with a r controller from Trinamic. The software provides different control options like setting max velocity, acceleration, ramp divisor , pulse divider , micro stepping etc.
Is there a resource somewhere on how to best optimize these parameters. I hope its not a trial and error thing. I am also looking for information on acceleration/deceleration profiles for best stepper performance. Does anyone have any resources they can point me to. I have a basic understanding of how a servo works and have worked with them before but never needed to optimize them. My problem is how to run it cool at high speed and with sufficient torque. Thank you

 

[MikeHalloran]

You get torque with current.
To drive a stepper fast, you need to get the current up to the max coil current as soon as possible. Because of the coil's inductance, you have to do that with a shot of high voltage.
If a common stepper hasn't stepped within a msec or so of the current peaking, it isn't going to move, ever, so you can wait a little after the boost and then crank the voltage down to a level that won't overheat the coil.

Commercial stepper drivers mostly do something like that and take care of the housekeeping for you.

Did the controller's documentation point you to any references? That would be a good place to start.

If you want practical stepper advice, Google Al Leenhouts.

If you want theoretical stepper advice, including math up the wazoo, Google C.K.Taft.



Mike Halloran
Pembroke Pines, FL, USA

 

[E2005]

Hi Mike, Thanks. I don't have book by C.K.Taft. AI Leehouts name came up in patents. Not sure if you suggested at looking at that. Will continue to look for free info online specifically on acceleration/deacceleration profiles and how to vary pulse divider,ramp divider and stepping ( on the fly). I am trying to understand how they affect performance.
The load in my application is increases non-linearly with time. The motor has to match that.I have a reciprocating piston-cylinder motion. The stepper provider linear back/forth movement.The controller manufacturers dont provide useful/practical info on that.Thanks

 

[MikeHalloran]

Leenhouts sells a (good) book to fund his retirement.
Taft and Gauthier wrote scholarly papers on analysis of stepping motor dynamics.

Common stepper controllers provide trapezoidal velocity ramping. You seem to be asking for a haversine ramp... which may be available, I don't know.



Mike Halloran
Pembroke Pines, FL, USA