Document PID

[strichter]

While I have lots of software development experience, I am only doing robotics with EV3 for fun with my kids. And I have no idea what PID is and the quick google results did not give me the tight intro I was looking for.

(I am a chemist and physicist by training, so the Calculus explanation will do. ;-)

[laurensvalk]

so the Calculus explanation will do

In that case, this might get you started for now. Equation (1) has the basic idea. In speed control (run, run_time), the error e is the speed error. In position control (run_angle, run_target), e is the angle error.

A simplified version is intended to be eventually included on the "More about Motors" page.

[laurensvalk]

The implementation is very different though, avoiding almost all numerical differentiation and integration steps. On the other hand, this brings it closer to the theory than most numerical PID implementations :)

[strichter]

BTW, the link helped me to get the idea.

[laurensvalk]

Sounds good. I'm thinking I'll leave this issue open until we've documented it in the docs.