Research On Electro-Hydraulic Control System Of Rotary Active Heave Compensation Based On Secondary Control

With the acceleration of human exploration of the ocean,the demand and performance requirement of marine engineering equipment are increasing day by day.As an piece of indispensable equipment in offshore operations,the heave compensation system plays a very important role in offshore oil drilling operations,deep sea exploration,and marine material transportation.Compared with developed countries,the research on heave compensation technology in China started late and the current level is relatively backward.It is urgent for experts and scholars to invest in this research.In this paper,the rotary winch compensation electro-hydraulic system is selected as the research object,mainly considering compensation accuracy,compensation stroke,system volume and energy consumption.According to the load characteristics and functional requirements of the ship crane,this paper designs a double closed-loop heave compensation electro-hydraulic control system,and studies it by combining the principle design,theoretical modeling and simulation analysis.The specific contents are as follows:Firstly,the research background and different types of heave compensation system and secondary control technology are introduced,as well as the research status at home and abroad for nearly ten years.The purpose of the research is expounded,the significance of the research is analyzed,and the main research contents of the subject are proposed.Secondly,the principle of secondary control is expounded,and four quadrant operation principle and mechanical characteristics of secondary unit are studied.The static speed regulation characteristics of secondary unit under gravity load are researched by combining the mechanical characteristic curve and the displacement speed curve.The motor/pump working condition switching can be realized by changing the inclination direction of the secondary unit swashplate,and the simulation verification is carried out.The parameter control principle of the secondary control is analyzed.Then,the principle of ship motion and heave compensation is analyzed,and the active heave compensation system of winch based on secondary control is designed.According to the requirements of working conditions,the selection calculation is carried out,the mathematical model of the system is established,and the system transfer function is obtained.The Bode plot is drawn,and the analysis determines that the system is stable.Finally,the mathematical models of double closed loop PID controller and Active Disturbance Rejection Control(ADRC)-PID controller are established.The model of the active heave compensation position control system based on secondary control winch is built on the AMESim-Simulink joint simulation platform.The step response and sinusoidal tracking performance simulation analysis of double closed loop PID control and ADRC-PID control are conducted,and the influence of related parameters is analysed.Using vessel motion as input,the secondary control winch heave compensation system's actual working compensation rate is calculated and analyzed.Based on analysis above,it comes to a conclusion that ADRC-PID controller's performance is superior to double closed loop PID control,which has certain guiding significance on secondary control winch heave compensation control strategy selection in practical application.