I have the same question. From their block diagram it looks like there's a PD and a PI component that get mixed together and there's a classic feedback loop wit

I have the same question. From their block diagram it looks like there's a PD and a PI component that get mixed together and there's a classic feedback loop with some filtering. I think the main difference is the non-linear nature of the coefficients, otherwise it has all the pieces of a traditional PID.