Robin.
-- R.M.O'Leary <robin nospam at acm.org> +44 973 310035 P.O. Box 20, Swansea SA2 8YB, U.K.-- >From: onat nospam at turbine.kuee.kyoto-u.ac.jp (Onat Ahmet) >Re: A Way To Go Home > > In "Richard T. Vannoy II"'s opinion; > >: I want my robot to go "home" and drop off an object it picks up. >: I don't want a light that makes it obvious to observers what is going on, >: so I want to have an invisible homing beacon. >: >: Sounds like I need IR... Correct? Do humans interfere with IR? Is there >: a sensor or a frequency that works best as a homing beacon? >: -- >: Richard T. Vannoy II richardv nospam at abac.com >: PO Box 103 Computer Programmer >: La Mesa, CA 91944-0103 College Electronics Instructor > >Hi; > >You can always flood the area with IR. Use many IR diodes attached to >an easily seen position (ceiling?). > >IS Robotics (I think) have a precise homing system that uses one IR >emitter, and two ultrasonic transmitters. There is a semi-intelligent >controller at the base that blips the IR emitter, and pings one of the >ultrasonic transducers. The robot picks up both transmissions, and from >the delay of sound, computes one distance. The base then blips the IR and >pings the other ultrasonic, and the robot gets the other distance, to >calculate its position. I guess you can calculate the orientation >by taking two position readings, but moving on a straight line in between, >and then finding out the orientation vector... > >The system is sold for thousands of dollars, but a hobbyist can probably >do it cheaply. > >| Ahmet ONAT Kyoto Univ. Japan | >| E-mail : onat nospam at kuee.kyoto-u.ac.jp | >| WWW page : http://turbine.kuee.kyoto-u.ac.jp/staff/onat.html | >| My 6 leg walker, RC airplanes & more in home page |