Research On Sliding Mode Control Of Fishing Vessel Path Tracking

The number of fishery vessels in China is large and significant.Under the background of the renewal of the fishing industry,the requirements for the technical level of fishing vessels are constantly improving.Considering the actual operation process of the fishing vessel,the high-precision tracking research of the planned route during the navigation of the fishing vessel should be continued.In the case of completing the positioning of the fish area,if the fishing boat can sail according to the designed route according to the automatic navigation equipment,this will not only reduce the labor intensity of the fishing boat steering gear.At the same time,due to the improvement of the path tracking accuracy,unnecessary navigation waste is avoided,the fuel consumption during the navigation process is reduced,and the economy of the fishing boat is improved to some extent.Therefore,researching the path tracking control of fishing vessels to ensure efficient tracking of the path during the operation of fishing vessels has become the focus of this paper.The research on the path tracking problem of under-actuated ships is rapidly developing,but the application of path tracking on fishing vessels is less.Compared with merchant ships and engineering ships,the main scales of captains and draughts of fishing vessels are relatively small,and the rolling period is short.Therefore,the design of the path tracking has increased the difficulty of designing the controller.The main work of this thesis is to give the design method of fishing vessel path tracking guidance-control integration considering the actual navigation demand,and to establish the basic fishing boat mathematical model based on the structural characteristics of the fishing boat,and apply the research design control strategy to the fishing vessel to design A relatively high-performance path-tracking controller that performs complex control tasks with fewer drives.The research work mainly includes the following aspects:1?Establish a motion reference coordinate system for fishing shipsAccording to the Newton-Eulerian equation in the attached coordinate system,the six-degree-of-freedom ship model is simplified by using the mechanism model research method,considering the force of the hull,rudder and propeller,and the influence of coupling on the ship motion.The estimation formulas such as the uphole model and Zhou Shaoming's regression formula,combined with the actual main scale values of the “Longxing 801” fishing vessel,calculate the parameters of the fishing boat model and establish a three-degree-of-freedom mathematical model of the fishing boat.Finally,the mathematical simulation experiment is carried out,and the simulation results are compared with the actual fishing boat test results.The purpose is to verify whether the established fishing boat model is correct.2?Research on fishing path following guidance algorithmThe selection of guidance strategy is one of the main modules for implementing complex automatic navigation tasks in ship control system research.In the guidance algorithm of this paper,the virtual ship guidance algorithm is adopted,and the virtual ship is used to generate a smooth reference path,so that the fishing boat can track the virtual ship.However,when the distance between the fishing boat and the guiding ship is too large,the actuator will be burdened,and the paper is virtual.Based on the ship guidance and dynamic switching mechanism,the dynamic virtual ship guidance algorithm is further introduced to buffer the actuator.The algorithm provides a more reasonable guidance mechanism for the ship's automatic navigation.3?Research on fishing path following control algorithmIn order to overcome the computational burden caused by repeated derivation,a dynamic surface technique is introduced in the control algorithm to estimate the derivative term generated in the virtual control law to reduce the complexity explosion problem.Combining neural network technology and sliding mode control method,a new sliding mode robust controller is designed to estimate the external environment interference and model uncertainty,calculate and derive the actual control law,and realize the ship's expected route.Effective tracking.The feasibility of designing the controller is verified by simulation experiments.