The Design of Gain Scheduling PID Controller of the USV Course Control System

Because the hydrodynamic coefficients of the unmanned surface vessel (USV) change with the speed during navigation, it is difficult to use a PID controller with constant parameters to control the course since of the model uncertainty. This paper proposes a method to design a gain scheduling PID controller to adapt to different speed navigation. It identifies the maneuvering model parameters in different speed at first. With the accurate model parameters, it designs the PID controller based on the pole placement method. In order to get smooth gain scheduling performance, it uses the interpolation algorithm to calculate the controller parameters between the definite pair of controller parameters. With the USV speed changing, the controller adjusts its parameters according to the design rule. The simulation results show that the gain scheduling PID controller has obvious advantages over the fixed parameter PID controller.