Parameter Identification Of Ship Model And Heading Control Design

The 21 st century is the century of ocean.The development and protection of the rich resources in the ocean have become a research hotspot all over the world.Ship equipment play a significant role for uncovering ocean,exploiting ocean and protecting ocean.Accurate identification of the ship maneuvering model is the precondition for the ship heading control.The research topic is chosen as “Parameter Identification of Ship Model and Heading Control Design”.The proposed algorithms are tested with the semi-physical simulation platform of the ship motion simulator.This paper firstly describes the ship’s six degree-of-freedom(DOF)motion coordinate system and kinetics equation.Then,ship maneuvering model is established by simplifying the ship six DOF nonlinear mathematical model,and the shaping filter is used to generate wave interference simulation signals of different frequencies and amplitudes.Furthermore,the multi-innovation recursive least squares algorithm is introduced to identify ship model parameters,while the forgetting factor least square method is used to estimate the disturbance in real time.Simulation results have been conducted to verify the effectiveness of multi-innovation recursive least squares algorithm and forgetting factor least squares algorithm.For the ship heading control problem,the comprehensive optimal control algorithm and model reference adaptive algorithm are designed based on the heading control accuracy and energy consumption performance index,innovatively adding damping indicators to performance indicators.Moreover,course changing and course keeping performance indices are established to evaluate the performance of proposed optimal and adaptive controller.By applying ship experiments data,the effects of different optimal control rate parameters on heading maintaining accuracy,rudder movement times,average rudder angle amplitude and other indicators are compared to verify the effectiveness of the optimal control algorithm.In addition,considering the impact of environmental disturbance on ship body,the adaptive disturbance compensation mechanism is introduced.Comparing the changes in the performance index of the course keeping and course changing process for different adaptive disturbance compensation mechanism,we can conclude that the adaptive mechanism can effectively suppress the disturbance.The main research work of this paper are summarized as follows:Secondly,based on the mathematical model of ship motion,and the multi-innovation least squares identification algorithm is used to identify the K-T parameters in the ship maneuvering model.By applying ship experiment and simulation data,the effectiveness of the identification algorithm is verified.Experiment results show that increasing innovation number speed up the convergence of the identified parameters and strengthening forgetting factor improves the disturbance estimation accuracy.Finally,the optimal control algorithm and the model reference adaptive algorithm are designed for course model,respectively.The effectiveness of the presented algorithm is verified through the hardware-in-the-loop simulation platform and simulation experiment.The experiment results show that adjusting the optimal control parameters can significantly reduce the number of rudder movement times.Adjusting the optimal control rate parameters can achieve the accuracy of heading control.Meanwhile,the adaptive disturbance compensation mechanism is introduced.Comparing the performance indexes of the heading maintenance and steering process for the optimal control law,the heading control error and steering process adjustment time can be reduced by introducing model reference adaptive disturbance compensation mechanism.