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Old 08-27-2011, 08:04 AM   #5 (permalink)
dcb
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I've thought about rev-matching EV's before. If you have a gate switch for each gear, a throttle position sensor (duh), and have a vehicle speed signal, and you program in all the gear ratios, then the controller should have enough information.

i.e. you are going 20mph in 2nd, you lift the throttle to slip it into neutral and move the stick towards 3rd, the gate switch tells the controller to synch, the controller figures out what rpm is appropriate for 3rd at 20mph (because it knows all the ratios), and drops the rpm accordingly. Ditto for going from 3rd to 2nd except the controller will have to increase the rpm.

It should only do it for a brief pulse when the gate switch is first closed, the gate switches need to close before the gear engages (some fudge there), and only if the throttle is at zero.

If you want to be extra safe, have the controller do the actual gear changes, and install a little h-gate on a joystick or some switch box affair, or just up/down pushbuttons (or???). Not trivial, per-se, but doable, then the controller can synchronize the unloading of the drivetrain, the slip into neutral, the rpm match and the snick into the appropriate gear, all with the push of a button and very little chance of making a mistake in the process (once calibrated). You basically need two strong servos to take control of the gearbox.
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Last edited by dcb; 08-27-2011 at 09:13 AM..
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