Dynamic Response Characteristics of the Hydraulic Rotary System of an Azimuth Thruster for a Dynamic Positioning Vessel

Abstract

The composition characteristics and working principle of the hydraulic rotary system of the azimuth thruster were analyzed. The mathematical model of the rotary dynamic system of the pump-controlled hydraulic motor driving the gear reduction mechanism was established. Additionally, a fast tracking method for the azimuth angle of the azimuth thruster was proposed to analyze the rotary azimuth angle, angular velocity and dynamic response characteristics of the hydraulic system for different desired azimuth angles. The simulation results show that the established dynamic model can simulate the rotary motion response process of the real thruster, and can realize the rapid and accurate tracking of the azimuth angle. At the same time, the physical constraints of the rotary dynamic response were established. It provides an important reference for research on the motion control methods of dynamic positioning vessels.

Dynamic Positioning Control for Marine Crafts: A Survey and Recent Advances

“…The observer module consists of two unscented Kalman filters (UKFs) working simultaneously for estimating the current states of the vessel and disturbance forces. UKF, which preserves the nonlinear characteristics of the system, is reported as the method of choice for the improved and efficient state estimation [5], [6]. The approach is tightly coupled and the calculated vessel states are used for estimating the unknown loads.…”

“…Today, marine DP has become an indispensable key technique for deep-sea resource development and territorial sea protection. A marine DP system is a comprehensive system that covers almost all craft equipment, with subsystems including thruster systems, control systems, power systems, and power management systems [3,5]. The DP control system is the core of the entire system and the controller design is the important part of the control system, which utilizes sensor-detected external environmental and craft states information to coordinate and command the thrusters in cooperation with the power system and power management system, ultimately achieving DP functions.…”