A reaction wheel inverted pendulum

Abstract

Being the simplest among the various pendulum systems but at the same time nonlinear and underactuated, the Reaction Wheel Inverted Pendulum has several a ractive features both from a pedagogical standpoint and from a research standpoint. is thesis presents a complete solution for building a Reaction Wheel Pendulum system having a square shape of 17:5 cm 17:5 cm and an overall height of 6:8 cm. It consists in the design and implementation of both the physical system making up the pendulum setup, the electronic interface circuitry, system modelling and simulations, and the control algorithm. Instead of the conventional ways of using encoders this project used a combination of accelerometers and gyroscopes for obtaining the pendulum angle and angular velocity and Hall sensors to obtain the wheel angular velocity. A brushless DC motor controlled by a fully digital motor controller is used to actuate the wheel. e implementation of the system is done on a dSPACE DS1104 controller board using C-MEX S-functions. Cascade control is used for balancing the pendulum in its inverted position. e inner loop regulates the motor current by the use of a PI controller. e outer loop calculates the desired motor current in order to balance the pendulum by means of a linear quadratic regulator (LQR) designed on the linearized State Space model of the system. is dissertation also presents a set of experimental results demonstrating the e ectiveness of the complete implemented system and the ful lment of the control task.