Hi, Check the Xylotex hal file in the ARM/BeagleBone directory for an example of using PID to get rid of the hunting problem on the DIR line.
Jeff On Saturday, November 5, 2016 at 7:01:30 AM UTC-7, Charles Steinkuehler wrote: > > On 11/5/2016 8:11 AM, Johan Jensen wrote: > > > > _4. After completing the first jog command (+/- does not matter), the > DIR signal > > starts to oscillate between 0V and 4V continuously. __Not expected._ > > 5. If I use "disable motors" in Machinekit the DIR signal stops > oscillating and > > goes back to 0V. > > > > Any ideas on how to correct this would be greatly appreciated. Thanks. > > This is "hunting" where the PRU driven step/dir generator is > oscillating back and forth (by a fraction of a step) around the set > position point due to the two asynchronous timebases (ARM CPU core and > PRU stepgen) and the ARM interrupt latency/jitter. > > If this is causing you problems, you could add a deadband to the > hal_pru_generic stepgen driver (PR welcome!), or switch to using a > standard HAL PID control (with the PRU stepgen in velocity mode) > instead of the fairly simplistic PID loop found in the hpg driver. > There are some examples of configurations using the HAL PID + steppers > for hostmot2 (Mesa) hardware, and I think there have been some for the > BeagleBone if you dig through the group archives. > > A PR for an example BegleBone configuration using HAL pid components > would also be welcome! > > -- > Charles Steinkuehler > [email protected] <javascript:> > -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
