Research On Ship Emergency Rescue Path Planning In Offshore Wind Farm Environment

With the rapid development of Chinese offshore wind power industry,the traffic flow in the waters of offshore wind farms has increased sharply,and the navigation safety situation is becoming more and more serious.Due to the dense structures,complex navigation environment and magnetic field interference in the water area of offshore wind farm,the timeliness is low and the effect of path planning is not ideal when using the traditional algorithm to plan the rescue path.From the perspective of path planning algorithm,this paper scientifically studies and analyzes the ship emergency rescue path planning in the environment of offshore wind farm.Aiming at the data of rescue time and rescue voyage distance,this paper designs a ship emergency rescue path planning algorithm suitable for the environment of offshore wind farm.The main research contents of this paper are as follows:Firstly,based on the characteristics of emergency rescue in offshore wind farm waters,by comparing the existing path planning methods,this paper analyzes the basic concept and general planning process of path planning,introduces the global path planning algorithm and local path planning algorithm suitable for offshore wind farm environment,and puts forward the emergency rescue path planning framework in offshore wind farm environment,which lays a solid foundation for subsequent research.Secondly,based on the emergency rescue path planning framework under the environment of offshore wind farm,the paper designs the overall emergency rescue path planning process.The simulation environment model is constructed by grid graph method.According to the characteristics of the environment,the model and the boundary of obstacles are optimized to simplify the model and improve the calculation speed of the algorithm and the safety of the planned path.In order to solve the problem of low planning accuracy and easy to fall into local optimization of traditional A* algorithm,this paper improves the A* algorithm and proposes a twoway 24 neighborhood A* algorithm.Before the implementation of the improved algorithm,Dijkstra algorithm is used to obtain the initial path point information in the simulation environment,so as to speed up the convergence speed of the improved algorithm and improve the accuracy of the solution;After the implementation of the improved algorithm,the adaptive arc optimization algorithm is used to smooth multiple grid turning points in a wide range,reduce the adverse impact of the grid environment on the effect of path planning,enhance the practicability of the algorithm,and enable the rescue ship to sail to the target position safely and at high speed.Thirdly,based on the emergency rescue path planning framework under the environment of offshore wind farm,this paper designs the local emergency rescue path planning process.Referring to the 《 International Regulations for Prevention Collision at Sea》,formulate the restraint rules for local collision avoidance behavior of ships,establish the ship motion restraint model under the influence of environmental forces,analyze the law of ship motion,improve the traditional Artificial Potential Field algorithm and D* algorithm,and propose D* Lite EAPF algorithm,which solves the problems that the traditional algorithm is prone to oscillation,falling into local optimization,too many path corners and too close to obstacles.Finally,according to the environmental characteristics of offshore wind farm and the requirements of emergency rescue planning,taking the H1#100MW offshore wind farm in Binhai north area as an example,the improved algorithm is used to carry out the global emergency rescue path planning and local emergency rescue path planning in the environment of offshore wind farm.The experimental results show that the improved algorithm has stronger timeliness,shorter rescue distance,less path angle,higher safety factor and better overall performance than the traditional algorithm,which can provide some reference for maritime authorities to carry out emergency rescue work in the environment of offshore wind farm.