Quote:
Originally Posted by Cal578
Quote:
Originally Posted by apples000
With a positional PID loop, when the setpoint is reached, the pid loop will output a zero command to the motor. ...
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No, that's not how PID works. If you set the constant for I (Integral) to an appropriate value, the PID output will be a good value to maintain the setpoint. A zero output is what would happen if you used a Proportional only control. |
No, that's not how positional P-only works. With P-only, there would still need to be an output of sufficient magnitude to maintain a position against any external forces. With P-only, this output comes from the steady-state positional error.
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Controlling speed and position aren't really different, once you get your units of measurement and conversion factors (converting motor input to desired output) right.
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Yes, they really are that different. If you are controlling position, then the plant is an integrating plant. If you are controlling speed, then the plant is not an integrating plant. They require different strategies.
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