Observer-Based Proportional-Type Controller for Two-Wheeled Mobile Robots via Simple Coordinate Transformation Technique

This article briefs on an advanced observer-based proportional-type control scheme that stabilizes the attitude and regulates the position of two-wheeled mobile balancing robots. The robot parameter and load uncertainties are under consideration. There are three main differences from previous results: (a) the development of coordinate transformation for securing the applicability of the proposed nonlinear controller design technique, (b) the pole-zero cancellation parameter-independent observers for estimating the wheel and yaw angular velocities, and (c) the guarantees of performance recovery and offset-free properties through the replacement of integrators via observer-based disturbance observers. The practical merits of the closed-loop analysis are confirmed by performing experiments with a LEGO Mindstorms EV3 operated by MATLAB/Simulink.