Abstract
This webpage describes work on a system to balance a pendulum at its unstable equilibrium point. The system uses a rotating arm with the pendulum fixed at the end. Torque on the arm causes a torque on the pendulum, for which we try to adjust to balance the pendulum. A DAQ is used to measure the pendulum's position and send motion commands to the arm. Currently, a proportional integral method is used that appears to be a promising method, but finer tunings of the apparatus are needed. Included are preliminary results of our success with this. Simulations were also used to explore the behavior of the system. Other control methods may also be used including a neural network adaptive control model.
Apparatus
The apparatus is small enough for a tabletop, and built to be both lightweight and configurable. Pendulii can be interchanged from the pivot and the length of the arm is variable. The angle of the pendulum measured via the potentiometer (Bourns 6538S-1-502) in the pivot. Forces are applied by rotating the arm via the motor (VextaStep PK266M-E2.0A), underneath the central platform. Motor control and angle input were both interfaced through a DAQ card (National Instruments PCI-MIO-16E-10) which interfaced a computer running Windows NT and LabWindows software.