On 02/20/2014 11:47 PM, Jon Elson wrote: > On 02/20/2014 12:01 PM, Charles Steinkuehler wrote: >> Peter's solution will work. I was going to add a dead-band to the PID >> control internal to the HAL component that talks to the PRU, but Peter's >> suggestion of pushing the PID outside the PRU driver and into HAL makes >> a lot more sense. > I might mention that I have to use deadband with the Pico > universal > stepper controller, as it uses the traditional PID and the > step generator > is velocity only. This allows the board to be used with > either open- > or closed-loop stepper setups with minimal change. > > I meant to add, the reason is that otherwise there are positions that can be commanded in the G-code that are between discrete step positions, and the PID will endlessly hunt back and forth between the surrounding step positions if you don't give it a deadband. So, a deadband of slightly more than the step resolution seems to solve it.
Jon ------------------------------------------------------------------------------ Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
