I've looking to build an Arduino based cruise control for a home built piece of farm equipment. I have a large servo installed to control the throttle and tapped into the transmission for its output speed signal. There will be varying load as we drive across the field and varying set points. What kind of control system would you recommend?
I've been playing with the PID library by Brett Beauregard, inputting the speed signal as frequency and outputting to my servo. I can get a decent tune at a particular speed/load but if either of those change then I get oscillations. I am by no means an expert but I'm wondering if a pid controller is the correct system to use because it's not a very predictable plant/system.