[Robotgroup] Control systems

[Acy Stapp]

Hey guys. I'm working on getting my Bioloid up and following a line of
electrical tape. The robot is wheels on legs with an articulated neck and
head and moves by rolling. The legs form a ridiculously overcomplicated
active suspension.

I have put the "eye" (an IR rangefinder) on a head with a pan/tilt so I can
scan left and right and hopefully track the edges of the tape by scanning
the eye over it. Does anyone have any advice on these issues:
* Separating the reflectance component from the distance component. The
reported value seems to be proportional to emitterBrightness * albedo / d^2.
I've tried tracking the largest negative and positive derivatives as the
edges of the tape but there is a lot of sensor noise. Any ideas?
* PID control. I will probably just start with an error term between the
center of the tape and the center of the robot and just use proportional
control. Later I'd like to implement the I and D terms if necessary. Does
anyone have any references about or in particular relation to tuning control
systems?

Happy roboting,

-- 
Acy Stapp

"When I'm working on a problem, I never think about beauty. I think only how
to solve the problem. But when I have finished, if the solution is not
beautiful, I know it is wrong." -- R. Buckminster Fuller (1895 - 1983)