Thoughts on features that an electric drive train might make easy

[flar]

I was thinking today and wondering how much electric motors and the associated drive control systems could make day to day tasks and maintenance easier. Most of my thoughts started with "I wonder if they could" and probably never recovered from the universe of wishful thinking, but I thought I'd throw some ideas out in case anyone had any ideas about how feasible they could be at some point down the road.

1. Cruise control.  How much is this system "drive by wire" in terms of the throttle, and couldn't that translate into an easy cruise control feature entirely built in software in the drive controller?  If it has full control over power delivery, knows if you've pulled the brake, speed is electronic (and likely being recorded in the log), then what other variables would the computer need to maintain speed on its own?  (Usually the clutch is also sensed in MT cars so it can disable cruise control - that would probably have to be inferred from overrevving conditions unless it has a physical sensor in it.)

2. Chain slack.  Are there any/enough sensors in the drive train or motor that could detect the changing conditions that accompany stretch on a chain?  I'm guessing with a transmission it is harder to detect how much is due to the transmission and how much is due to chain tension, but perhaps the drive train slop is a fairly constant amount and so with a precise enough sensor on when the power requirements indicate that the drive train is fully tight and delivering power to the rear wheel, an estimate could be made of whether or not the chain slack is out of spec.

2a. Chain slack detection during maintenance.  If it isn't easy to infer chain tension from on-the-road conditions, could the computer perform some maintenance diagnostics while stopped to detect chain slack?  Does a controlled condition make the idea from #2 more feasible?

3. Creep mode for chain maintenance.  "Creep" is probably a very apropos term for this idea that probably should have died a young death, but here's the thought.  It's not all that hard to spin the rear wheel on a stand, but it is hard to get a nice even speed with a hand moving back and forth.  With precise control over the power delivery it could potentially be possible to deliver just enough power to get the chain moving at a constant slow speed, but with so little power that any additional drag (say a finger getting caught in the sprocket) would stop it.  This seems doubtful because of the amount of torque required just to move the motor + transmission + chain + wheel/tire would probably be in the range of not really noticing a finger arriving at the wrong place, but I thought I'd throw this in for discussion (or straw man ridicule) purposes.  (I think this also wins the "lawyers would never allow it" award.)

OK, someone who actually knows something about any of this please feel free to share some other ideas that might actually work...

[FreepZ]

Chain slack could be pretty trivial to determine.

It could work something like this:
1. Keep the brake locked on, so the bike doesn't move.
2. The motor spins slowly one way, and then back, and then forward again.

For this to work, I'm assuming that:
- the electric motor can turn both ways.
- the electric motor can determine the position of the motor.

There's going to be some play due to the transmission, and some play due to the normal chain slack, but the computer can compare the play of some baseline with the play on the current chain. With that information, it's very easy to determine if the chain has too much or too little slack. I.e. if the motor is able to move further that the baseline, then the chain is too slack. Not as far; too tight.

Notes:
- It might be necessary to reset the baseline whenever the chain is replaced.
- Although this could be added to part of the start up sequence, it would delay getting going, so I think it would be batter as a maintenance mode feature.