Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: anandbabu on January 11, 2007, 07:40:13 AM

Title: need of automatic path finder scheme
Post by: anandbabu on January 11, 2007, 07:40:13 AM

hi, am interested in designing aumatic path finder(for example getting out of a maze which is having single entry and exit)  robots using IR sensor and atmel microcontroller series at89c51.. guide me with block diagram and programming, constructional requirements and arrangement

Title: Re: need of automatic path finder scheme
Post by: Admin on January 11, 2007, 08:22:19 AM

The simplest algorithm for going through a maze is called wall following.

For example, suppose you are in a maze. Close your eyes, and put your hand on the right wall. Keep walking with your hand on the wall. You are absolutely guaranteed to find your way out this maze.

So for your robot, program it so the IR sensor on the right side of it never strays far from the right wall.

ps - you could also choose left, instead

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guide me with block diagram and programming, constructional requirements and arrangement

IR sensors
http://www.societyofrobots.com/schematics_infraredemitdet.shtml
http://www.societyofrobots.com/sensors_sharpirrange.shtml

the motor control algorithm
http://www.societyofrobots.com/programming_differentialdrive.shtml

chassis construction
http://www.societyofrobots.com/mechanics_chassisconstruction.shtml

Title: Re: need of automatic path finder scheme
Post by: JesseWelling on January 12, 2007, 11:23:49 PM

just a side note that the right hand (or left hand) only solution will not always find the goal.

Title: Re: need of automatic path finder scheme
Post by: Admin on January 13, 2007, 09:23:36 AM

well, if the exit was not outside the maze, i.e. in the center of the maze, then yes, there is possibly no solution.  :P

but i wouldnt count on that happening . . .

Title: Re: need of automatic path finder scheme
Post by: Militoy on January 13, 2007, 10:46:57 AM

I've heard of of course of the "left-turn" or "right-turn" wall-following strategy of maze solving, but it occurs to me that if not stopped at the goal by a handler, or fitted with a sensor to detect that it has solved the problem, the robot will just re-enter the maze, and work it again. Also, the robot will always take the same course through the maze (never the optimum route), and never eliminate blind alleys from its route. Still - it's the easiest program that will solve the problem.

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just a side note that the right hand (or left hand) only solution will not always find the goal.

Jesse - Do you mean, as Admin suggested, when the goal is "buried" within the maze? Or ???

Title: Re: need of automatic path finder scheme
Post by: JesseWelling on January 13, 2007, 02:22:10 PM

I guess I was thinking more mouse->cheese or flame->putout. but yes you are correct that if there is a goal on the outside of the maze the robot will find it with the right hand or left hand rule...unless the robot is started in the middle of the maze, then finding the goal is still not ensured. :-\