The Sept/Oct 2009 issue of Robot magazine has an article on a very fast VEX line following robot.
There’s a video of the robot at - YouTube It uses a PID control algorithm… The robot runs at almost two feet per second. It was programmed in ROBOTC; complete source code is included as one of the sample programs that come with a ROBOTC download.
[ magazine.Robot](- YouTube shows the same robot programmed with a basic “zig zag” algorithm. The maximum speed of this robot is about six inches per second before it is unable to follow the line.)
Great article,
I could definitely see many teams using a more complex line sensor this year to have a major advantage in Clean Sweep.
I hope VEX expands their product line to have sensor similar to pololu 8 array reflectance sensor (similar to what was used in the Mr. Swann’s article)
I remember building a 16 array line sensor in college but it was a pain to tune analog reflectance sensors back then so it did not work very well.
The robot in this video used five VEX line sensors in a row:
I didn’t write the algorithm, but I know it used a PID routine and the analog values from the line sensors. It DID not just use the line sensors as “on/off” threshold toggles. I wonder how well 575 would do without all the extra weight and size of the Elevation game elements? It will do about 3.6" per second in a straight line, but obviously won’t make the tight turns the much-smaller robot in the above video can do.
