摘要：AbstractThis paper presents design and evaluation of a wavelet-based multi-resolution proportional integral derivative controller (MRPID) for dynamic positioning (DP) of vessels under noise and environmental disturbances. In the proposed MRPID controller, the errors with position and orientation are decomposed into different frequency components using discrete wavelet transform. The different scales of wavelet transform represent details such as external disturbances, process noise and measurement noise. A set of sub-PID controllers are assigned to selected error components and the commands generated by all controllers are added together to produce the control command for dynamic positioning of the vessel. Performance of the controller is evaluated in simulation and compared with the conventional PID controller with acceleration feedback. Nonlinear state estimation is performed by using an unscented Kalman filter assuming a typical sensor package for localization.
