Research On Control And Hardware-in-the-loop Simulation Platform Development For Dynamic Positioning Of Ships

The dynamic positioning of ships allows a ship to maintain its position at a desired location or navigate along a predetermined trajectory exclusively by means of the ship's own thruster system to counteract environmental disturbances.The dynamic positioning system of ships has advantages including high positioning accuracy,working in the deep sea and high maneuverability.It has been widely used in the supply ship,pipe-laying ship and rescue ship,etc.Since the operating conditions and the ocean environment often change,there are obvious uncertainties of ship dynamics and environmental disturbances such that the dynamic positioning control of ships is the challenging control problem for a class of complex uncertain nonlinear system.In addition,before the ship dynamic positioning controller is applied to the actual ship experiment,it is necessary to develop a hardware-in-the-loop simulation platform for dynamic positioning control and perform hardware-in-the-loop simulation test,which will reduce the danger of the actual ship experiments and guarantee the safety of the ship's personnel.Therefore,it is of great theoretical significance and application value to carry out research on control and hardware-in-the-loop simulation platform development for dynamic positioning of ships.Firstly,the motion mathematical model of ship dynamic positioning and the mathematical model of ocean disturbances are established in this thesis.Then,under the condition of ship dynamic model parameters uncertainties and unknown time-varying disturbances,the adaptive laws are respectively designed by applying the adaptive technology to estimate the ship dynamic model parameters and the bounds of unknown time-varying disturbances.The ship dynamic positioning control law based on adaptive technology is designed employing the dynamic surface control method.Next,an extended state observer is constructed to estimate the total disturbances composed of the dynamic uncertainties of ship and unknown time-varying disturbances.The ship dynamic positioning control law based on active disturbance rejection control is designed employing the proportional-derivative control method to improve control accuracy and reduce the conservativeness.Furthermore,a finite time extended state observer is constructed,and the ship dynamic positioning finite time control law is designed employing the dynamic surface control method to improve the system response speed and ensure that the positioning error converges in a finite time.Taking a supply ship as an example,the numerical simulations of the above ship dynamic positioning control laws are carried out using the MATLAB/Simulink.The simulation results demonstrate that the designed ship dynamic positioning control laws are effective.Finally,the OP4510 real-time simulator,the signal conditioning box and PC are used to complete the hardware construction of hardware-in-the-loop simulation platform,and MATLAB,RT-LAB and LabVIEW are used to accomplish the software design.Based on this,a hardware-in-the-loop simulation platform for dynamic positioning control is developed.Taking the designed control law based on active disturbance rejection control as an example,it is implemented in a programmable logic controller and the hardware-in-the-loop simulation test of the controller is carried out using the hardware-in-loop simulation platform.The test results show the effectiveness of the designed hardware-in-loop simulation platform,and the performance test of the ship dynamic positioning controller under different sea conditions can be realized.