Shoot the moon game

Ravi Agrawal and James Finley automated the game "Shoot the Moon" a.k.a. "Collusor"

In this coffee table game you manipulate the rods at one end to drive a metal ball uphill, until it falls through between the rods into the most distant planet possible.

There's no moon.

James and Ravi motorized the player's role.

A single motor drives both rod ends symetrically.

The rod ends are attached to the upper and lower side of a belt so that they move in opposite directions.

Linear potentiometers measure the position of the rod ends.

The position of the ball is measured by using the long rods themselves as a potentiometer, with the ball acting as the wiper. The green wire you see here is the electrical connection to one rod, which contacts the ball and communicates its potential to an x100 amplifier.

The end-to-end resistance of the other rod is about 10 milliohm, so a 1 amp current throught it produces a voltage of 0 to 10 mV on the ball, proportional to the ball's distance along the rod.

Most of the controls were programmed in Simulink, but the strategy is in an embedded matlab program.