Conclusion
This has been a successful project that combines physical concepts and computer science. A programmed robotic arm was able to keep control of an unstable inverted pendulum using a PID algorithm for 20 minutes before human intervention was needed. The PID constants were found by using just the proportional value to bring the pendulum into oscillations, and the other PID values were found by comparing reduction in error as the constants were adjusted. This robotic arm could withstand taps to the pendulum bob, and if the mechanism were to be made mobile, it could maintain control of the pendulum on an inclined plane for up to a (6.60 ± 0.20)° incline. For the proof that the critical angle of an inclined plane is independent of the length of the pendulum, the confidence interval of 0.21 was acceptable. We were unsuccessful at comparing the success of PID constants for a known impulse force. Future groups should investigate further how to control the initial velocity and position of the pendulum so the PID response to an impulse force can be measured. Overall, this experiment is a great example of how a PID controller can bring an unstable system into equilibrium.
To see the control arm in action, click the link below: