Optimal Design Of Airborne Missile Launcher And Extraction Of Physical Information Before Air-to-air Missile Ignition

The airborne missile pylon is a device that carries air-to-air missiles,and its design quality has a major impact on the missile launch performance.In order to improve the matching performance of the aircraft-missile and the control accuracy of the missile launch,an airborne missile pylon is designed in this paper.this article also focuses on its ejection mechanism and principle,the extraction of physical information when the missile is separated from the pylon and before the missile is ignited,research on multi-objective optimization algorithms,the optimization of the ejection mechanism and the resistance optimization of the main part.This paper firstly designs a kind of catapult missile pylon of double-arm,and focuses on the principle research of the ejection structure.The relationship between the initial posture of the separation of missile from the swing arms and the design parameters of the ejection structure such as the length of the swing arm is analyzed,which provides theoretical reference for the optimal design of missile pylon.The static analysis of the key components for the missile mounting is completed,which ensures the reliability of the strength.In order to extract the physical information of the missile when it is separated from the pylon,a research plan for extracting the initial physical information of the separation of missile from aircraft is formulated,and the mapping relationship between the physical information of the marking circles and the physical information of the missile is established.Taking advantage of the high fps of the high-speed camera and the predictable characteristics of the marking circles in adjacent frame,a dynamically regional RHT algorithm is proposed;the method is verified by simulation experiments,and the experiment proves that the prediction error does not exceed 1.5%,and the prediction error of relative distance of the search box does not exceed 5%.This method is also an effective research method in a complex background,and it reduces the time consumption by nearly 41.6%compared with traditional algorithms.Then the modules in the software of the developed verification system for missile ejection are analyzed,and the physical information extraction results are given.Finally,the real missile ejection experiment proves that the average error of the physical information extracted does not exceed 2.39%,which verifies the accuracy of this algorithm and solves the experimental method for further optimal design.In order to extract the physical information of the missile before ignition,this paper models the ejection trajectory of the missile after it is separated from the pylon,and analyzes the movement and forces of the missile to establish the dynamics and kinematics equations.Several common turbulence models and corresponding applications are analysed.The research provides the theoretical foundation for the extraction of physical information after the missile is separated from the pylon.Finally,the wing/pylon/missile model used for flow field analysis is meshed,and the simulation working conditions,simulation process and software parameter settings are determined.In order to more effectively optimize the ejection mechanism of the missile pylon,the multi-objective optimization algorithm is researched,and an improved multi-objective quantum genetic algorithm(CQGA)is proposed based on the quantum genetic algorithm.On the basis of retaining the original quantum chromosome characteristics,the operation of quantum revolving gate is dynamically modified:for multi-objective optimization problems,the selection strategy of the optimal solution is dynamically changed,and the rotation angle is dynamically modified to avoid falling into the local optimal solution;H-gate and full interference cross-mutation are used to enhance the diversity of the population;Through comparison with the classic multi-objective optimization algorithm NSGA2,the result shows IGD value of CQGA has dropped by about 21.6%,which proves that the algorithm has good diversified convergence characteristics.Finally,the pylon structure is optimized and the missile falling physical information is extracted.The ejection structure of the pylon is mainly optimized:the orthogonal test method is used to design the samples and the input information of the CFD simulation is obtained through the physical information extraction experiment of separation of the missile from the pylon.After the trajectory and physical information of the missile are obtained in the simulation results,the corresponding objective functions are designed by analyzing the results,and the optimal solution is obtained by RBF neural network fitting-CQGA multi-objective optimization.The optimized structural parameter l₁=742,l₂=708,?=0.185,which satisfies f₁+f₂<5 under the four flight conditions,and is significantly better than the existing results,which proves that the optimization is successful.Secondly,the curve of windward surface of the pylon head is optimized:with the high efficiency of two-dimensional fluid simulation,matlab-fluent co-simulation is used to optimize the resistance of the pylon body.Taking the fourth-order Bezier curve as the curve to be optimized,the independent variable parameters are determined and the corresponding samples are designed by the orthogonal experiment method,by using the RBF neural network fitting-QGA optimization,use matlab to iterate until the optimization standard is reached.The drag coefficient after optimization is 0.5621,which is 2.04%lower than before optimization.Finally,the optimized missile pylon is shown.