Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: prolog on January 05, 2008, 12:22:16 AM

Title: line following robot to engage 360 degree turn
Post by: prolog on January 05, 2008, 12:22:16 AM

Currently, my robot is using PID algorithm to follow a black line quite smoothly..

The only problem is that the robot is unable to turn 360 degree when it reaches a dead-end.
I think the mechanics is the limiting factor..




What's the best structure to be able to execute 360 turns?
My robot is differential driven, RWD with a ball caster at the front..


(http://i21.photobucket.com/albums/b272/yusof_hardy/DSC00143.jpg)

(http://i21.photobucket.com/albums/b272/yusof_hardy/Image024-1.jpg)

(http://i21.photobucket.com/albums/b272/yusof_hardy/Image020.jpg)

(http://i21.photobucket.com/albums/b272/yusof_hardy/DSC00142.jpg)

Title: Re: line following robot to engage 360 degree turn
Post by: dunk on January 05, 2008, 08:11:18 AM

you mean the motors can't turn the bot when one motor is going forward while the other is going backwards?
make your wheel base shorter.
move the drive wheels and the caster closer towards the center of the robot and you should be good.
it's a balance between maneuverability and stability.

dunk.

Title: Re: line following robot to engage 360 degree turn
Post by: Admin on January 20, 2008, 05:28:34 PM

What happens is when your robot rotates, the sensors swing really fast - hence losing the line.

To reduce that swinging speed, you want the sensors as close to your center of rotation as possible (close to the wheels).

Title: Re: line following robot to engage 360 degree turn
Post by: Ro-Bot-X on January 24, 2008, 06:47:31 AM

You've received good advice, I've got nothing to add eccept: can you post the code?