Khoshnam Shojaei

PhD Thesis Defense Session

Abstract:

In this thesis, the trajectory tracking problem of nonholonomic wheeled mobile robots (WMRs) in presence of both parametric and non-parametric uncertainties is addressed. A combination of adaptive and robust control is employed using input-output feedback linearization, backstepping control technique and Lyapunov-based control techniques of robotic manipulators in order to solve the trajectory tracking control of uncertain nonholonomic mobile robots. At first, an adaptive-robust backstepping-based controller is proposed to solve global tracking problem of all WMR states for every arbitrary initial condition. The complexity of the proposed backstepping-based controller motivates us to design a simpler unified tracking controller in chapter 5. Therefore, an adaptive-robust feedback linearizing controller is proposed to provide a unified tracking controller with minimum complexity and less design parameters for an integrated formulation of uncertain kinematics and, dynamics of WMRs and uncertain actuator dynamics. Simulation and experimental results are presented to evaluate the proposed tracking controller. Since most of commercial WMRs are not equipped with velocity sensors, an output feedback tracking controller is proposed in chapter 6. This controller only requires position measurements of WMRs. The controller design task is accomplished by using control techniques of robotic manipulators. For this reason, a new input-output model is proposed in this thesis which allows the designer to directly apply the control techniques of robotic manipulators to control nonholonomic WMRs. Simulation results are also presented to evaluate the controller performance.

Date: Wednesdayu 24 Agust 2011, Time: 10:00
Place: Electrical Engineering Department, Room 305.