Speed sensorless vector control of semi-submersible ship dynamic positioning based on LSSUKF

Abstract

In this paper, a robust UKF algorithm based on least-square is proposed for the semi-submersible ship dynamic positioning speed sensorless control system, which lacks the ability to adapt itself to system state anomalies. The algorithm uses the least-square method to compute the suboptimal fading factor, it adjusts the filter estimation gain adaptively, and it realizes the strong tracking to the real state of the system. The algorithm is applied to the semi-submersible ship dynamic position sensorless control system and compared with the standard UKF. The results show that when the state of the dynamic positioning system is abnormal, the improved UKF algorithm based on the least-square for positioning control system has better control quality and response characteristics. The disturbance rejection ability and robustness of the system are improved, and its estimation ability to disturbance is enhanced obviously, which improves the positioning accuracy of the semi-submersible ship dynamic positioning system.