Messages in this thread | | | Date | Sat, 17 Jun 2006 10:04:07 -0700 | From | Andrew Morton <> | Subject | Re: clocksource |
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On Thu, 15 Jun 2006 20:21:24 -0700 john stultz <johnstul@us.ibm.com> wrote:
> The method I came up with is really just P-D (proportional-derivative) > control, but that should be ok since the adjustments are all linear so I > don't think the integral control is necessary (control theorists can > pipe in here).
Boy, that takes me back. If you don't feed back the integral you'll end up with an output which has a steady-state offset error against the control point (unless the forward gain is infinite, and it never is). I don't know if that matters here, but it cannot be good.
If you feed back the integral of the error then it introduces the possibility of instability. Probably in this application you can just overdamp the thing to avoid that. It'll make it slower to respond to changes in the setpoint. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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