Research On Image Projection Technology For Verifying Multi-target Recognition

As a space target detector,the tracking camera is mounted on a space target carrier to detect,identify and track other space targets and determine important characteristics such as their trajectory,attitude and shape.Due to the difficulty and high cost of implementing the tracking camera airborne function detection and verification,it is important to verify multitarget identification function of the tracking camera in the laboratory through a target simulator.As one of the core components of semi-physical simulation experiments,the target simulator is an economical,efficient and highly reliable calibration device that provides the required multi-target identification features for tracking cameras.In order to meet the technical requirements of projection imaging of simulated targets at a fixed distance,in this paper the overall design scheme of the target simulator based on image projection technology is proposed on the basis of the traditional target simulator.A target simulation optical system with Digital Micro-mirror Device(DMD)as the spatial light modulator and the target simulation software are designed,and the target simulator performance tests are completed.In order to meet the requirement of high uniformity of the target simulator,this paper designs an illumination optical system based on collimation system,compound eye lens array,relay system and total reflection prism.Combining the working principle of DMD and requirements for high imaging quality of the target simulator,a projection optical system with small distortion,long exit pupil distance and long working distance is designed based on the telecentric optical path structure in the image space,and the image quality is analyzed.The analysis result shows that the distortion is less than 0.05%,indicating good imaging quality.Through the simulation analysis of the uniformity of the target simulation optical system using Light Tools software,the simulation results show that the uniformity of the DMD illumination surface is 97.6% and the uniformity of the projection screen is94.29%,with good overall uniformity.In response to the need for verification of multi target recognition of the tracking camera,a design scheme of target simulation software based on formation flying is proposed.Using the Satellite Tool Kit(STK)and MATLAB to interconnect,each module of the software is designed.Through target simulation experiment,the real simulation of the trajectory,attitude,and shape of spatial targets is realized,which indicates that the design scheme is feasible.By building an experimental platform,the performance of the target simulator is tested.The simulation and display of space targets are realized by projection imaging with good projection imaging effect.The optical indicators of the target simulator are tested.The test results show that the overall uniformity of the target simulator is 93.64%,and the instability is ±4.01%,which meets the requirements of the indicators.This provides a theoretical and experimental basis for the verification of multi target recognition with tracking camera.