Abstract
This paper presents a tracking control strategy for a non-holonomic mobile manipulator using a decentralised control strategy. The mobile manipulator is viewed as an interconnection of two subsystems - a non-holonomic mobile platform subsystem and a holonomic manipulator subsystem. First, a kinematic controller of the two-wheel driven mobile platform is developed to obtain a desired velocity. Second, a distributed control strategy is developed in order to track a desired trajectory in the joint space. This desired trajectory is obtained from the workspace trajectory using the inverse kinematics. The distributed control strategy consists of controlling the manipulator, starting from the last joint and going backwards until the first joint. Each joint is controlled while assuming that the remaining joints and the platform are stable and follow their desired trajectories. The stability of the system is proved using Lyapunov theory. These controllers are tested on a three degrees-of-freedom mobile manipulator and compared with the computed torque approach. The experimental and simulation results present a good tracking which shows the effectiveness of this control strategy.