What is P.I.D.?

[Alan Anderson]

Originally Posted by GeeTwo

If your desired target has a tolerance that is wider than a couple of clicks of the encoder, and your system has enough drag (or a brake) to hold position with no actuator input, it can work. When either of these assumptions is not met, an encoder system will be jittery at best.

I don't agree with your general point. An encoder will give you a change from one count to another at a specific, precise position. If that's where your target is, that's where your position will be driven to. It's going to have exactly the same effect as any quantized position or velocity feedback measurement, encoder or otherwise. It seems to me that your objection is based on assuming coarse measurement resolution. That's an issue whether you're using encoders or potentiomenters or Hall effect magnetic sensors.