Modelling and control of a nonholonomic mobile robot

Abstract

Mobile robots are becoming more common in today's fast growing environment. Its extensive study and research have become a major part in the mobile robot's rapid development. An effective method of development is via modelling tools and computerized simulations. In this project, kinematic and dynamic models of a nonholonomic two-wheeled mobile robot were simulated with its behaviour defined by a controller. The robot defined in this project has two actuated wheels while any other contact with the surface travelled is assumed to be frictionless. This project identifies two robot controllers, which are the proportionalintegral- derivative (PID) control and pole placement methods. These control methods are implemented via the MATLAB/Simulink software into the kinematic and dynamic models of the robot. Controllers were chosen according to its robot model that conforms to the standard robot designed in this project. The tracking control method of each controller was also studied to ensure stability of the model. In the simulation, the robot is given several predetermined paths. The robot does not know these paths and it has to be able to adapt and react to different paths. The controller is considered successful when it can follow the predetermined path accordingly and effectively. Through the simulations, these controllers are studied and compared.