Synergetic Workspace Tracking Control for 4-DOF Robot Manipulator

This paper presents a tracking control for robot manipulators based on synergetic control theory. The purpose is to design a smooth controller that is able to track the desired trajectories in the workspace quickly and precisely in a finite time. This control strategy consists of three main steps. First, a manifold is constructed based on a nonlinear exponential term and the tracking error to ensure a precise tracking in precise time. Second, a controller is designed to drive the tracking error to exponentially approach the manifold. Finally, the control law is derived by solving the evolution constraint equation. Using the Lyapunov function, the stability of the error dynamics is proved. The proposed synergetic controller is tested experimentally on a 4-DOF manipulator. All the experimental results demonstrate the effectiveness and feasibility of the proposed controller. Good tracking is obtained in both joint space and workspace.