Nonlinear control of wheeled mobile robots

The purpose of this project is to implement an autonomous navigation system using nonlinear control techniques to control a wheeled mobile robot (WMR) to follow a preplanned trajectory and track a path. Two other aspects of navigation are studied: path planning and obstacle avoidance. Those three aspects are integrated into a navigation strategy that manages navigation and prevents deadlocks. Two nonlinear control techniques for path tracking and trajectory following have been developed and implemented. In the first approach, a fuzzy logic controller is used to drive the robot through a set of waypoints leading to the destination. In another approach, a controller derived from a Lyapunov function is used to track a reference trajectory that is time dependent. For path planning, a novel optimization technique based on dynamic programming has been developed. The curvature velocity method has been used for obstacle avoidance. The testing was conducted on a P3-AT all-terrain mobile robot equipped with encoders, a gyroscope, and sonar sensors for localization and environment perception. The test results validate the effectiveness of the different approaches that have been developed