Paul & Sabrina's cheap DIY 144v motor controller

[Tango Charlie]

Originally Posted by MPaulHolmes

Isn't it weird! type something on the computer,

i = 2, oops I mean i = 20. and ben hurtles down the street, out of control! hahaha!

Sounds like a plot line for one of them Hollywood movies.

But I agree, let's not kill Ben.
Gosh, I would love to get up to WI when Ben gets the controller in the mail. I could hold the video camera while he installs it and then arms the drag chute...

[MazdaMatt]

Originally Posted by MPaulHolmes

Ben, you can keep the controller!

Fine form, Paul I hope you're somehow writing this off.
Congrats Ben, if you don't die, you have a free controller.

[Blue Bomber Man]

Seems to me that if you tracked RPM's for a motor, you could create an interface for each wheel in an all wheel drive or multiwheel drive that uses separate motors. Combine that with tracking your steering angle so you can calculate the various turning radii's for each wheel. Then have them all maintain tracking by making sure that the relationship of rpm speed to each motor is appropriate. If one wheel is over revving compared to the others you have the cut down the current.

Only thing I am unsure of is how you establish your baseline rpm speed. Perhaps determine which wheel requires the most current compared to RPM's which suggest that wheel had traction.

Have fun with all that coding

If it was something you are interested in trying, I could work on establishing all the logic and math involved so that it could be coded more easily. I do have a small amount of C++ background so I could attempt to lay out the logic in a similar format.

[MPaulHolmes]

Blue Bomber Man, that would be awesome! It sounds complicated! Controlling 4 motors? Go on with your bad self! hehe.

[Blue Bomber Man]

I think in principle it wouldn't be too complicated. It would only be designed to control as many motors as a person was using, so either 2 or 4 in most situations.

It effectively simulate traction control if done properly and would probably improve the efficiency of the system in wintery/slippery conditions. It would require one relatively minor change to your controller. It would need an input/output port that could communicate with the traction control system. The system would need date regarding the wheels rpms or ground speed; and would need to be able to handle a command from the traction control system which would tell the controller to ease off the power some.

The traction system controller could be low voltage so cost of building the unit would probably be low and could even work for a single drive system to avoid spinning the loan wheel. This would probably require an auxilary sensor on a different wheel to determine road speed to compare to the wheel with motor's speed.

[dcb]

I just wanted to chime in here and say, you don't have to worry too much about killing Ben

[MPaulHolmes]

Joe has dramatically improved his charger!!! I just read about it on the EV tech list! He'll post when he has the chance. ya! It's a good time to be working on the EV stuff! I still need to do the programming. I've been busy with finals. yuck!

[roflwaffle]

Originally Posted by Blue Bomber Man

I think in principle it wouldn't be too complicated. It would only be designed to control as many motors as a person was using, so either 2 or 4 in most situations.

It effectively simulate traction control if done properly and would probably improve the efficiency of the system in wintery/slippery conditions. It would require one relatively minor change to your controller. It would need an input/output port that could communicate with the traction control system. The system would need date regarding the wheels rpms or ground speed; and would need to be able to handle a command from the traction control system which would tell the controller to ease off the power some.

The traction system controller could be low voltage so cost of building the unit would probably be low and could even work for a single drive system to avoid spinning the loan wheel. This would probably require an auxilary sensor on a different wheel to determine road speed to compare to the wheel with motor's speed.

Great idea! Just have it reduce power proportionally to the increase in slip. A hall sensor on each wheel could tell the AWD controller what wheels were slipping, and the AWD controller would tell whatever motor controller to scale back power, maybe even at some rate proportional to the slip, until it stops slipping or until we reach some minimum in terms of power output. Naturally we should be able to turn it off for big smoky burnouts.

Oh, and the controller is freakin' sweat Paul! Mind-blowingly awesome.

[brihoo2k]

Hey wheres Ben? Ben Ben where are you? Have you seen Ben? He was here a little while ago.

[MazdaMatt]

re: awd system. Very simple IMO.

Current system - pedal produces 0-5v, controller generates enough current to match that voltage (relative) on the motor current sensor.

New System - pedal produces 0-5v to awd system. Awd system reads wheels speed of 4 wheels and determines "desired" wheel speed. Each motor controller then receives a 0-5v signal equal to: (pedal input)*(desired wheel speed)/(actual wheel speed)

Then a faster-moving wheel will have its power output reduced according to the speed differential. Alternatively, one could design it (and this would be much better, imo) to monitor wheel acceleration instead. As long as all the wheels are accelerating at the same pace as each-other, the controll sends the pedal voltage on un-adjusted. If one wheel's acceleration is double, its voltage is halved. Sounds easy-peasy to me.