The Structure Design And Optimization Of A Target For Airborne Fire Control Test

As an important part of the aircraft weapon system,the airborne fire control system is vital to the detection of its recognition capability.At present,the commonly used outfield detection method is to use air maneuvering targets such as airplanes and missiles to be tracked.The fire control system directly tracks such real targets for detection.This detection method requires a lot of manpower and material resources,so it is necessary to design a set of system for tracking and testing airborne fire control systems quickly and economically.The test system designed in this paper uses the virtual image simulated by the photoelectric target as the tested target,which greatly reduces the difficulty and cost of the tracking test.This article is responsible for completing the structural design and optimization of the target for the airborne fire control system test.In this paper,firstly,according to the target using environment and performance index requirements proposed by the equipment user,the target system plan is determined.It’s main components are the target body,the two-dimensional adjustment mechanism and the car body,and the function of each part is determined.This article will combine the finite element method and computational fluid dynamics to design and research the target.Based on the system scheme of the target,the two-dimensional adjustment mechanism and the structural design of the car body were completed,and the appropriate driving components were selected through related calculations,so that the target can achieve continuous changes in the pitch angle of-45°～45°,and the azimuth angle-60°～60°continuous change and linear reciprocating motion with acceleration more than 1m/s~2.Afterwards,based on the finite element method,the statics module and transient dynamics module in ANSYS Workbench were used to study the mechanical properties of the target under dead-weight load and horizontal inertial load.The research results show that the maximum displacement of the target under its own weight is only 0.55mm,and the horizontal inertial load has a small effect on the target,which proves that the target structure has good stability.In order to ensure that the target has good wind resistance on the roof of 25m high,the mechanical performance of the target under the action of wind load has been studied and analyzed in detail.Firstly,the resistance coefficient of the target is used as the evaluation standard,and Fluent is used to carry out a simulation experiment to study the change of the resistance coefficient of the target in different attitudes.Based on this,the aerodynamic characteristics of the target in multiple attitudes are proposed.Then combined with the aerodynamic characteristics of the target,the overturning moment received by the target under different attitudes was studied,and the overturning moment change law of the target under multiple attitudes was proposed,and it was proved that the target under the action of7-level cross wind Has good anti-overturning performance.Finally,based on the assumption that the pitch angle and the azimuth angle have independent effects on the overturning moment of the target,an empirical formula for the overturning moment of the target under the action of a 7-level crosswind is proposed,which can help the operator estimate the target’s overturning moment.The overturning moment received in different attitudes has good practicability.In order to achieve the lightweight and rigidity of the target,firstly refer to the mechanical analysis results of the target,determine the optimization plan of reducing the weight of the outer frame and increasing the rigidity of the box,and then combine sensitivity analysis,experimental design,and approximate model.Construction,a target optimization method based on the Kriging model and quadratic polynomial response surface is proposed.Through this method,the input and output approximate models of the outer frame and the box are constructed respectively,and then the outer frame and the box are obtained by genetic algorithm.In the Pareto optimal solution set of the cabinet,a set of points is selected as the best point to optimize the outer frame and the cabinet,and compared with the performance before optimization.The comparison shows that the quality of the optimized outer frame is reduced by 17.13%.The maximum deformation of the body is reduced by 29.29%,which proves the feasibility of this optimization method.Finally,in order to verify whether the functional parameters and anti-overturning performance of the target meet the design index requirements,the basic function of the target and the anti-overturning performance under the action of the wind field are verified through the method of real machine experiment,which proves the target structure The stability.