The Strategy Of Shipboard Helicopter Safe Path Planning

Nowadays,shipboard helicopters play an increasingly vital role in modern naval battles,searching and antisubmarine action.So the safety of carrier landing for shipboard helicopters is of great significantcet.In this thesis,the envelope and landing path of three different shipboard helicopters are studied,and on this basis,the safe landing strategy of several helicopters is studied preliminarily.Firstly,the envelope where helicopters hover was discussed in this thesis Quasi-steady and unsteady aerodynamics model were considered to calculate the aerodynamic forces and moments of the rotor.Then,the flight dynamics model of the helicopter was built by combining rotor,fuselage,empennage,and tail rotor model.With the operational limit of the helicopter,an envelope can be computed accompanied with the ship model and flow field model.The impact factors on envelopes were discussed for different helicopters.Secondly,this thesis studies the method of helicopter landing path planning.The traditional 2-D A* path planning algorithm was analyzed.A direction matrix was set up and could be used to show how a helicopter could move in 3-D condition,so the 3-D A* path planning algorithm could be obtained.Through simulation based on 3-D A* path planning on different situations,comparison and discussion were conducted on the factors which impacted path planning.Thirdly,summarization on the whole process of shipboard helicopter carrier landing was studied in this paper.By using the envelope model and path planning model obtained above,a simulation of whole carrier landing processes of three different types of shipboard helicopters was conducted.The impacts of different situations were discussed and the strategy of shipboard helicopter safe carrier landing was analyzed.Finally,the multi-helicopter carrier landing path planning algorithm is obtain based on sigle helicopter landing algorithm,after modifying the A* algorithm.Factors have great impact on path planning process are analyzed,in the meantime,the safe landing strategy of multi-helicpter carrier landing is obtained after a 3-D path planning simulation of several different conditions.