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Unread 15-01-2008, 23:59
Capt. Quirk Capt. Quirk is offline
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AKA: Bill Mazzacane
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Re: Why don't I ever see robots that steer like a car

Quote:
Originally Posted by petek View Post
One gotcha with this is your un-steered wheels need to compensate for the different driven path length around corners. A differential can lead to sitting still with one driven wheel spinning while drifting (sliding) a solid axle takes more finesse to drive and re-introduces frictional losses, so I'd opt for differential control of the motors driving the wheels (sync'ing them to the steering angle).

The easy way around that is to just let your inside wheels freewheel through the corners. The differential and "Steering Brakes" like JesseK suggested would turn wickedly fast. Programming for the turn angle or using a Go-Kart style chassis that lifts 1 wheel and with programming, could drive 3 wheels would be another option.


Nice pictures deshirider430, how did it work?. I was worried that using the window motors would limit how quickly the bot could change directions?


Quote:
Originally Posted by JesseK
What I'd like to see is a tractor-style turning mechanism. 3 CIMs on 1 transmission that drives 2 rear wheels from a differential. To turn, all you do is brake the side you want to turn to. Put unpowered omnis on the front and BAM there you go -- seems easy enough right?

A differential wouldn't be hard to make and I think multiple motors feeding a differential would be a great idea, Especially for the 6 wheel drive "tractor style" drive train. All it would take is steering brakes and then the outside bank would receive full power.