Anders Wallin wrote: <somebody> wrote : > >>3. What sample frequency are you using? with torque mode and straight PWM amps >> you will need a high sample rate than used with velocity mode servos. A >> a higher sample rate will allow higher P gains with these amps, improving >> performance. > > > This is the standard 1 ms servo-thread. I could try decreasing that a > bit. Will EMC2 report about real-time delays if I reduce the servo > period too much? Not necessarily, but it does increase CPU load, of course. If you have an adequate computer, you can go to 5 KHz, for instance. This moves the 1/freq sampling jitter up to 2.5 KHz, well outside the band of motor response. At the default 1 KHz rate, the 1/freq produces a lot of "noise" at 500 Hz, which can lead to exciting some instabilities in the mechanical system. I'm not sure this is really any panacea, but it does seem to help with whistling servos. It certainly is easy to try, though. Save your parameters first, they will all change at a different frequency.
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