wli@fornax.UUCP (William Li) (01/19/91)
I'm doing some work on a mobile robot and have decided on using rubber-belted treads, much as on a tank, to propel the beast. What I was wondering was, does anyone know of any good books on tread/track or even wheel dynamics? I'm not so much concerned with rolling friction as with turning characteristics. I'd like to be able to predict where and how the vehicle will turn. (and yes, I know that if I apply reverse to one tread and forward to the other, I can "turn on a dime, just like the Abrams"!) The current system I am considering simply brakes and cuts power to one tread while running power to the other. In playing with a toy tank that does this, I noticed that the pivot point was about the most forward point of the stopped tread which contacted the ground -- roughly the mid-point of the tread, because of curvature in the tread bottom. This makes sense to me, intuitively and pseudo-mathematically with some free-body diagrams. However, my experience isn't particularly mechanical, and I'd like some mathematics to back this up. Particular things I'd like to find out are: o what are the conditions for the tank to rotate about a given point? o given that slippage is the only way by which a dual-treaded vehicle can turn, what what will be the effect of supplying power to both treads simultaneously? If anyone could send or post a book reference on wheel or tread characterization, I'd really appreciate it. Nothing on drive-*linkages*, though -- I've got material on linkages and gearing coming out of my ears. For some strange reason, though, there's a grand total of *two* books in the entire library dealing with rubber pneumatic tires, neither of which are particularly enlightening about treads. In fact, none of the robotics and automation or machine design sources I looked at seemed to even faintly *allude* to the most important part of the vehicle -- that which contacts the road! Thanks in advance. - William Li School of Engineering Science Simon Fraser University Burnaby, British Columbia V5A 1S6 (604) 291-4451