Automatic Transmission

[gnirts]

I know this has been discussed here, but it is still unclear (at least to me):

When you are attempting to choose the appropriate gear in software, what variables in the environment is the decision based on? It seems that in a manual car they are based on engine RPM (tachometer) vs. speed, as these are the two instruments that drivers are given. But others say it should be throttle (joystick values) vs. RPM. It seems weird to do it with RPM vs. speed because on robots they are linearly related (although that is probably true in cars, too). In each gear, speed = RPM * gear ratio (and the wheel circumference, which is always constant). Anyways, what are my independent and dependant variables going to be for my lookup table?

Also, when you up-shift, should you lower power to the motors enough to still be at your current speed with the new gear ratio? (eg. lower the PWM output for a given joystick input)

Additionally, in the Nothing But Dewaults whitepaper, they mention that

the PWM values for [the servo to engage] 1st, 2nd and 3rd [gears] should be adjusted in software to match the actual values. If shifted slowly, the transmissions will actually shift into "neutral" between each gear. This feature together with sensors on the wheels can be used to help the software provide smoother shifting via "software synchronization" but that is a topic for another whitepaper.

Any more info on that? Has that whitepaper been written?

Thanks in advance,
Robinson

BTW, yes I am going to have a manual override, and yes, I will have logic that prevent quickly changing gears when the 'bot is on the boundary of the curve.