Fractional order ADRC algorithm to ship servo system

Abstract

When the measure ship berthing or sailing, it is vulnerable to waves, tidal currents and other complex disturbance. The measurement precision of servo system is related to error and the inertial force caused by measurement ship swing and displacement as well as subgrade. So it is necessary to improve the accuracy of the ship servo system. The active disturbance rejection control (ADRC) algorithm has higher control accuracy and better robustness than the traditional PID control algorithm. The control performance of ADRC is excessive reliance on extended state observer, so a fractional order controller is proposed as a feedback controller to eliminate the dependence on the extended state observer in this paper, and the extended state observer can also maintain the system's uncertainty to insensitive zone of the fractional order controller. Compared with traditional PID algorithm, the simulation results show that the fractional order ADRC controller can obviously improve the performance of servo system.