Inverted Pendulum Controls

Submitted by Evan Boldt on Sat, 04/12/2014 - 12:23

Balancing an inverted pendulum is the typical example when demonstrating a control system. A weight on an arm above the rotation pivot is an unstable system. It has one stable point when the weight is perfectly balanced. If the weight is slightly on either side of this point it will begin to move away from this stable point. On the other hand, a weight on an arm below the rotation pivot is a stable system. The weight is stable at the point exaclty below the pivot as well, but if it is moved slightly away from this point it will move back towards it.

I have built a simulation using web standards like JavaScript and HTML so you can observe the impact different PID controls have on an inverted pendulum. You can modify the gains of the proportional, integral, and derivative controls to test how each component works. The simulation is optimized to be used with Chrome and Firefox, but has a limited set of features available for Internet Explorer.

A screenshot of the simulation. Click to do your own simulations.