This robotic plate can "catch" and balance a ball
by Andrea James from on (#55YDP)
Swiss student Johan Link created an instructable for making a Ball Balancing PID System, and he posted a very nice video demonstration.
Via his instructable:
This system holds a ball in balance on a plate. A webcam films the system and a python program analyzes the images to find the position of the ball. The python program calculates the tilting of the tray to prevent the ball from falling.
A proportional-integral-derivative (PID) regulator is used to compensate the movements of the ball. The position and speed of the ball are measured by the camera and these measurements are used by the PID regulator in the python program.
Image: YouTube / Johan Link