Trajectory Tracking for Mobile Manipulators : A Comparison of Control Laws and Optimization of the Reachable Workspace

This report investigates how mobile manipulators can be controlled when an end-eector is required to follow some certain trajectory. The robot platform is of type (2,0) and is restricted to planar motion under nonholonomic constraints. The manipulator of the robot are modeled as a series of chains, connected by revolute joints. Mathematical theory is presented for both the maximum working range and the reachable workspace of the manipulator. Three dierent control laws; nonlinear kinematic control with linear and nonlinear feedback and input/output linearization are derived. The performance of these control laws are compared in simulations by analysis of their trajectory tracking errors and their stability. Finally, each control laws pros and cons are presented.