As an assignment for the class Mechanical Engineering Lab, I led a team of four students to develop a setup to nullifying the damping of a pendulum by imparting lost energy through an electromagnet.

The setup consisted of a cylindrical iron bob attached to a steel rod. The rod was mounted on bearings through a shaft. An optical encoder was installed on the shaft for measuring the angle of the rod with time. Additionally, an Inertial Measurement Unit (IMU) containing an accelerometer and gyroscope was attached to the bob for measuring acceleration and angular velocity of the bob with time. A voltage controlled electromagnet was also installed just below the bob at the equilibrium position.

Using the behavior of the amplitude decay, we calculated the damping coefficients of the system. These coefficients were then used to find the required force/energy to overcome the damping. This force was then provided by the switching the electromagnet such that the magnet always attracts the bob in the direction of its motion. Further, a PID control loop was implemented on the voltage input of the electromagnet. At the end of the experimentation, we were successfully able to overcome the damping loses and maintain a constant amplitude and time period.