The settings in EMC's ini will not make much difference because EMC has no feedback about real position. Step-and-direction is out only and assumes that the systems out there are able to follow accurately.
The Rutex PID loop tunes like nothing else I've used. You will need to increase P, but that's not all. Increasing P will narrow the resting position of the motor. Think of this as a dial indicator or caliper sitting so that commanded position is in the center of the space between jaws. P then is the distance between the jaws. Make the jaws closer together and you will have less error in final resting position. The problem here is that you've got to increase D along with P in order to get the Rutex to respond. Then with more D you need more I to calm it. This is a very dynamic process. Hint. Make only one change at a time and write each change down with a "better, same, worse" evaluation for both accuracy and palsey. You'll have to run P to where the motor will not settle down at all and then increase I and D. If you have a way to hand crank the axis while the motor is running it will help you feel the stiffness of the system. Rayh On Mon, 2007-01-08 at 10:05 +0200, Anders Wallin wrote: > > It appears that I have a velocity dependent situation. I honestly have > > little background in PID tuning, is this a drive tuning issue or is this > > an EMC config issue? I am using the sample_inch.ini config and have > > only changed the steps per inch, reduced the max acceleration, and max > > velocity to reflect my machine. > > most likely this is a tuning issue within the Rutex drive. > > If I understand correctly you are driving the rutex with step/dir > signals from the parallell port. EMC will have no idea of where your > machine is, it relies on the drive to close the loop. > > So, your following error setting should be in the rutex drive. If the > following error limit is set too high the behavior you describe would be > allowed. > Try reducing the allowed following error in the rutex drive and then > maybe re-tuning it. > > AW ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
