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Originally Posted by bennelson
I've noticed that there ARE times when I would like to have at least two different settings on the controller.
Just one example.... Last year, I had my car in the local Independence Day Parade.
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Exactly! and so, for me at least, there are normal every-day occurrences that are like parade mode - creeping up the driveway, pulling out of a parking space, picking up crap food in a drive through... It'd be nice to have optimized operation at those times AND during brisk acceleration.
Quote:
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Originally Posted by MPaulHolmes
Even have some sort of continuous function that has kp and ki as its outputs depending on various inputs like pwm duty and current feedback.
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this is kind of what i was thinking. it seems that all of the the times where a slower loop would be good occur when moving slowly (parking lot, driveway, etc) and only lightly pressing the pedal. thus it seems like throttle position might be good to use as the input. i don't think the other parameters are that indicative of moving slowly. oh, and i bet there's a lot of processing time available when the throttle position is processed.
maybe there could be 3 more settings. a different Kp and Ki value at low throttle positions and a value that represents the pedal position at which the settings change (could be 0-99 for percent throttle position).
i don't know if it's good to have a step change for Kp/Ki, so maybe the kp/ki values change linearly from the new values at zero throttle position to main values at the change-over value. above the change-over value, only the main kp/ki values are used.
then, the tuning process could be: tune the loop for low speeds using the main kp/ki settings and write them down. then, re-tune for brisk acceleration. lastly, set the low throttle kp/ki values from the values written down and play around with the changeover point.
thoughts?