PID natural tracking control of a robot: application

An elementwise exponential natural tracking control algorithm is applied to a nonlinear robot model with rigid links; The natural trackability condition of the robot is used to formulate the natural tracking control. The natural tracking control is developed without the knowledge of the internal dynamics of the robot. The controller forces the Cartesian output space tracking error to zero even though the internal dynamics of the robot are unknown, the desired outputs are unknown a priori and time varying, and the tracking error is initially arbitrary (within kinematic constraints) and unknown. A two-degree-of-freedom nonlinear robot model is used in the simulation which demonstrates the effective use of natural tracking control. The controller, using almost unit positive internal feedback (high-gain natural tracking control,) is applied to a robot system exhibiting natural trackability and the controller forces the robot to exhibit elementwise, prespecified, exponential tracking.