Algodoo

PID-controlled rocker balancer v.1.2

changelog:
1.1: set integral coefficient to zero by default [thanks for a tip, Xray!]
1.2: limit suspension travel

controls:
left arrow: drive left
right arrow: drive right
down: brake
0: toggle PID controller on/off

if you're into control theory, try tuning the coefficients:
scene.my.k - overall multiplier (useful when changing the gear size)
scene.my.kp - proportional
scene.my.kd - derivative
scene.my.kd2 - second derivative (this balancer can't be stabilized using only 1st)
scene.my.ki - integral (not really needed in this case)