Research On Ground Target Positioning Technology Of Airborne Optoelectronic Payload

Airborne optoelectronic platforms are one of the important means of obtaining real-time information in modern warfare.Especially in several local wars in recent years,the optoelectronic payloads carried by UAVs have provided the army with services such as real-time reconnaissance,guidance and strikes,and the war situation development played a key role.The target positioning accuracy of the airborne electro-optical payload is an important indicator for its target reconnaissance.The accurate target positioning effect plays a vital role in battlefield situational awareness,target strike guidance,and even civilian treatment of wounded and forest fire prevention.Aiming at the problem of how to improve the accuracy of target positioning,this paper first introduces the background and significance of this research,and focuses on the methods and progress of related research at home and abroad.On this basis,the positioning model of the target is obtained,and each error source that affects the positioning results is introduced in detail.Further research found that most of the existing target positioning methods take the systematic error in the process of installation and debugging as a link in the error analysis,but rarely solve it and correct it.In this paper,the installation error is corrected based on the flight data.Firstly,according to the physical meaning,a target positioning equation including five error terms including the installation error of the integrated navigation system and the zero position error of the photoelectric load is established,and the error solving model based on the least square method is obtained by derivation.Then,the Monte Carlo method is used to analyze the method,and the feasibility of the method is proved.Finally,the flight experiment is organized,and the ground control points(including the error solving control point and the error correction result verification control point)are organized,and the system error The route is solved and the error correction results are used to verify the route.The results before and after error correction are analyzed and verified.The experimental results show the effectiveness of the method,and the experimental process and results are discussed.In order to solve the system error more conveniently,this paper proposes an installation error correction method based on ground test data.According to the rigid body dynamics theory,the target positioning equation with only the installation errors of the heading angle,pitch angle and roll angle is established,and the error solving model based on the least square method is deduced.Then,Monte Carlo simulation analysis and flight test analysis were carried out to verify the feasibility of the method.The method has the feasibility of solving the ground data and the flight data at the same time,so it can realize the solution and correction of the error on the ground,and can also be applied to the real-time target calibration task in the air.Aiming at the problem of the positioning error of the system caused by the time asynchrony of the sensors,this paper quantitatively analyzes the impact of the time asynchrony.This paper proposes a solution to this problem from two aspects of software and hardware,and uses linear interpolation and quadratic interpolation to solve the problem respectively.The processing method can effectively reduce the impact of the time asynchronous problem.Finally,in order to obtain the speed and direction of the moving target,the Kalman filtering method is used for the data after system error correction and time synchronization,and the target position observation is filtered to obtain the best estimate of the target position;then the distance baseline is introduced.The method is to perform quadratic fitting of the target trajectory to obtain the speed and direction of the moving target.In this paper,simulation analysis and flight experiment verification are carried out for this method.The experimental results show that for vehicles with no sharp turns,large acceleration and deceleration maneuvers,and the speed of highway driving is greater than 36km/h,good target positioning and speed measurement can be obtained.to the effect.Finally,this part of the content is extended to the extrapolation mode when the moving target is occluded for a short time,and a good tracking effect is obtained.To sum up,combined with the practical engineering problems in the process of airborne electro-optical payload target positioning,on the basis of the existing methods,the paper proposes a method of system error correction based on flight data,a method of system error correction based on ground test data,The methods for dealing with the problem of sensor time asynchrony,the speed and direction finding of moving targets,and the auxiliary tracking methods under the occlusion state can effectively improve the target positioning accuracy,and have certain significance for the research on the target positioning of airborne electro-optical payloads.