01/24/2016 04:37 PM, Dave Cole rašė: > Is the positioning ability adequate? I am impressed how strong it holds in position even when fed with DC current (freq = 0). I can't force it to rotate by hand, while it is very easy rotating while turned off.
I did not implement any ramp there yet, just step in PID command for angle. pid.maximumoutput limits frequency to 1 or 2 rps. It swings a bit and takes about two seconds to settle. I have an idea to use limit3 component in such way: pos-fb => lim3.in pos-cmd => lim3.min lim3.max prepositioning => lim3.load pos-cmd-limited lim3.out => pid-orient.command It should work as adaptive vel, acc limiter. Adaptive, as it adapts to real position, not theoretical / commanded one. > Most squirrel cage motors are really bad at positioning under load as > they rely on slip to generate armature flux. No slip -> no flux -> no > torque But you are just trying to position the tool for the changer, > right? Yes, positioning is for the toolchanger only. > The best I have seen for positioning with a load is basically a > coast/brake to a stop position and then a brake is applied at the stop > position. An option in general, but there is no mechanical brakes in this case. > Is there a reason why you did not use the hal component that Andy > pointed out? Or did you modify that? > > Dave I actually took several lines only from lengthy bldc component which calculates phases. I choose to program in C often while integrating LinuxCNC. Neither lots of standard HAL components with messy HAL config nor classicladder (lets face the truth - old, buggy and not convenient) seems elegant and free-to-implement-whatever-I-wish solution to me. I am an IT-engineer, a programmer and do like programming in C. This time I had to find a formula and be able to freely tune it, implement current limiting and other features. Not to mention CPU cycles which are counting in realtime config. Universal components are great and I use them a lot too, but when I have a special need - I start with new .comp file :) And I found this way much easier even for PLC-type tasks than trying to tell my story about the logic to cl (which I learned and integrated in several projects too) with lots of mouse clicks and words not worth saying out loud :) ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
