I must thank you all for the excellent input to my dillemma. It has been very helpful, and amusing. I have experimented some more with just the VTR24F1 retro-reflective opto-sensor, and the results are excellent for short range (4-8 inches). Which I may then use as a downward looking sensor for path correction. As for a reliable frontal object detection with greater range; I will do some more R&D and experiment with some of Sharps' modulated IR devices. This seems to be a popular and proven method, used by many robots. Proximity detection and path prediction of the object being sensed will come a bit later. I speculate that a variety of IR sensing methods will be used to determine as much valuable information of whats up ahead as possible. Maybe three different sensing methods. Long, medium, and short range tracking. Such a combination, with added redundancy might prove to be accurate and reliable (hopefully fast too, 50+ Hz). The economics of such a solution might be high ($100+ for full setup), but worth it if the results are good. Thanks. Sebastian >-----Original Message----- >From: Dan Creagan [SMTP:dcreagan@SCHOLARS.BELLEVUE.EDU] >Sent: Thursday, August 26, 1999 5:17 PM >To: PICLIST@MITVMA.MIT.EDU >Subject: Re: Signal filtering through code > >We are now aiming for the Rube Goldberg award. However, I >think this is weird enough to almost work. If some method of >getting the resolution down to, say, the width of a chair >leg (chair legs are not nice - office chairs with those five >different arms that trap unsuspecting 'bots are EVIL) then >it would be a hoot to make one. > >Dan > >-----Original Message----- >From: Anne Ogborn >To: PICLIST@MITVMA.MIT.EDU >Date: Thursday, August 26, 1999 11:03 AM >Subject: Re: Signal filtering through code > > >>OK - my sickest range finder yet. >> >>I take the issue is to get some overall sense of the >proximity of >>an obstructing object, with information about it's >proximity >>(more than one bit). >> >>(And, I raise the question, do you need more than one bit? >If >>it's collision detection, probably not). >> >>Put a fan on the front of the robot. Off to the sides mount >>small aluminum foil "flags" on a low - friction bearing >(say >>a length of fine thread) and photodetectors to sense the >>position of the foil. >> >>When the robot approaches an obstruction, the wind will be >>reflected back and move the foil flags. >> >>::Annie is seen dragging a roll of chicken wire down the >>hall, cackling with glee:: >> >> >> >>-- >>Anniepoo >>Need loco motors? >>http://www.idiom.com/~anniepoo/depot/motors.html