MPG Cruise Control Algorithm

[GasSavers_maximilian]

Redid the algorithm. A lot of the complexity is hidden in the "compute speed for maximum efficiency" statement. A look up table could get the system close and then a control system examining the instantaneous mpg could refine it. I considered a maximum speed case, but since braking is under the control of the driver and also that a steep grade would lead to coasting anyway, I don't think it will be needed. This differs slightly from what I do now in that I do a limited form of pulse and glide when already coasting anyway: I just let my speed go down really far. That behaviour seems less appropriate in a cruise control so I left it out. Once I have my new car computer and get some other testing done I will drive this algorithm to gauge its efficiency. Now I can think about how a GPS equipped algorithm could work. That gives a lot more possibilities!

Repeat {

if( grade <= MIN_GRADE_FOR_COASTING) {

// on steep downhill
coast;

} else if( speed <= MIN_SPEED ) {

// very steep uphill, economy is not the concern
adjust throttle as needed to maintain MIN_SPEED;

} else {

// slight uphill, level, or slight downhill
compute speed for maximum efficiency;
// for a level, this will be a cruise speed of around 50-55
// for slight uphill, this will be slower than the cruise speed
// for slight downhill, this will be faster than the cruise speed

}

}