[Mr. Lim]

We did a fair amount of work with Method 2 today as proposed by Ether.

We obtained fairly stable results, and would argue that they are overall better than Method 1.

There appears to be a major weakness with Method 2 however.

The I-term appears to be capped. Theoretically, even a small I-term should cause the speed control loop to reach its setpoint eventually. It might take a long time, but it should reach the setpoint, given enough time.

It does not.

What we're seeing is the maximum speed we can achieve is directly proportional to the I constant.

This is unfortunate, because we have been able to find some I-constants which appear to work beautifully, however since the I-term is capped, we can never quite achieve our top speed.

Capping the I-term is usually a great way to ensure our PIDs don't wind up too much, however in this case, it's inhibiting us from ever getting to our top speed.