Comparing the Efficiency of State-Feedback Controllers in Stabilizing Two-Wheeled Robot

Abstract

A two-wheeled robot is an intriguing example of a self-balancing robot that captivates the interest of many hobbyists and engineers. Due to its inherent nature, the mechanical structure alone can not achieve stability, necessitating the use of an appropriate controller. In this paper, we are comparing state-feedback controllers based on two methods: the Coefficient Diagram Method (CDM) and the Linear-Quadratic Regulator (LQR), with the goal of stabilizing the two-wheeled robot. The simulation results confirm that both controllers are capable of quickly stabilizing the pitching angle of the two-wheeled robot. Here, the LQR-based controller exhibits slightly faster responses compared to the CDM-based controller. The settling times are 0.1555 seconds and 0.1211 seconds, consecutively for CDM and LQR. It can be said that the difference is not significant. Despite the slower response time, the CDM-based controller proves to be more efficient in terms of control effort when compared to LQR. The results show that the CDM-based controller requires only 61 percent control effort used by the LQR-based controller for stabilizing the two-wheeled robot.