Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!brutus.cs.uiuc.edu!apple!well!nagle From: nagle@well.sf.ca.us (John Nagle) Newsgroups: comp.robotics Subject: Re: CM Ambler Rover Message-ID: <18280@well.sf.ca.us> Date: 1 Jun 90 06:26:58 GMT References: <3708@jato.Jpl.Nasa.Gov> <95816@philabs.Philips.Com> <1990May30.182249.22352@watmath.waterloo.edu> Reply-To: nagle@well.sf.ca.us (John Nagle) Distribution: na Lines: 33 In article <1990May30.182249.22352@watmath.waterloo.edu> mwtilden@watmath.waterloo.edu (M.W.Tilden, Hardware) writes: >In article Benjamin Chase writes: >Brooks at MIT seems to have a reasonable solution. They've built a >6 legged walker which uses a simple Algorithmic State Machine network >as the control (simulated in a single 8bit 68HC11 processor). The >thing they built is the size of a cat but walks and thinks very >much the way any 6 legged bio-critter does. The last above is an assumption probably not justified by the facts. But see "A Biological Perspective on Autonomous Agent Design", by Beer, Cheil, and Sterling, at CWRU, Cleveland, OH. (which may have appeared in print by now; I have a copy I got at MIT.) These people have a six-legged walking simulator which is based on an explicitly biological neural model. The model Brooks uses isn't particularly representative of any specific biological model. Patty Maes has a technique by which Brooks' machine is made to learn to walk, but her approach isn't something one would expect from a biological system either. (It may be better; it learns to walk in a minute or so.) Actually, Brooks' machine uses multiple M68HC11 processors, connected by what the papers call "a token ring" implemented with the chip's Serial Peripheral Interface port. There's no central control, but everybody gets broadcast info on what everybody else is doing, so if you run the same control algorithm on each processor but use different outputs on each one, they all come into agreement. >Brooks is more interested in making small machines, not moon-stompers. >Anybody know why this work is not in the running for space exploration? Because he sees his machines as being much more useful than those one-of-a-kind space exploration machines. John Nagle