| ??? 03/13/07 14:35 Modified: 03/13/07 15:16 Read: times |
#134855 - Ideas on PID motor |
I'm trying to do a PID for motor control. Need some ideas here.
What i have coming into my micro-controller is the time it triggers (capturing PWM generated from motor), which is then converted to # of counts (ie: 1 count = 30ns). I know for my speed i would need 50000 counts. so every rising edge should result in 50000 counts (+- 5%) or 1.5ms. The important thing is what to do with this counts and how to control it. Only 2 things affect my speed, current or PWM (effectively shutting off the voltage to the motor). I could fixed the PWM to 100% and just play with the current or vice versa or both which would make it more complicated. I know with a PID, it talks about either - Slow response time if you don't increment your current fast enough or decrease it fast enough. (if a big load suddenly comes in i would need to increase the current immediately to maintain speed) - Fast response time where you have either increase/decrease it too much resulting in overshoot thus it never really settles to your desired speed resulting in some minor oscillation I tried doing simple increment/decrement by 1 until reaches speed but it doesn't seem to settle nicely. My current is controlled by DAC since it provides a ref voltage. Any ideas applying integral/derivative method Thanks |
| Topic | Author | Date |
| Ideas on PID motor | 01/01/70 00:00 | |
| clarify | 01/01/70 00:00 | |
| trigger on input capture | 01/01/70 00:00 | |
| p-I-d | 01/01/70 00:00 | |
| do you mean | 01/01/70 00:00 | |
It's a control theory thing ... | 01/01/70 00:00 | |
| sounds like noise to me | 01/01/70 00:00 | |
| capturing PWM waveform | 01/01/70 00:00 | |
| what is that PWM generated by???? | 01/01/70 00:00 | |
| by motor hall sensors | 01/01/70 00:00 | |
| put a scope on the hall sensor input, is it "spark | 01/01/70 00:00 | |
| looks clean, a little spark i suppose | 01/01/70 00:00 | |
| that depends | 01/01/70 00:00 |