Study On Spatial Target Visual Simulator Technology

With the rapid development of the aerospace industry, the rendezvous anddocking technology are increasingly important.The rendezvous and dockingtechnology is an important technical basis of building a space station. Televisioncameras has become widely accepted in space rendezvous and dockingtechnology.Television cameras and the target plays an irreplaceable role in the manualcontrol rendezvous and docking mission, due to the high precision of measurementand auto-adjusting in large irradiance range.Due to the particularity of the spaceexperiment, the camera can't be tested in space, it is necessary to simulate thereal-time space targets imaging and optical conditions on the ground to test thetelevision cameras, as well as the rendezvous and docking technology.The specific technical difficulties of the space target visual simulator is: thebrightness of the space target is required up to38866cd/m~2, and if using the physicalsimulation technology, it needs300000W solar simulator, meanwhile the spaceenvironment simulation of the black background also need to be achieved; if using thetarget projection simulation, you will need1.1million lumens projector. these aredifficult to achieve objectively. In this thesis, a program using a few watts ofillumination light source has been proposed, that can effectively solve the problemthat target imaging can't be simulated in the light environments of space on theground.In this program, using micro-display LCD as visual generator of spatial targetsand using LED as an light source, both the image of the targets and the brightnesswith them is coupled to the tested camera through a special optical system, and thenthe visual simulation of the spatial targets can be achieved. Base on this program, thechanges of the brightness of spatial targets and their light environments must beanalyzed; the non-imaging optical system of illumination and the imaging optical system also must be designed.In order to achieve the goal of miniaturization of the simulator, design theillumination optical system based on white LED, and optimize simulate and analysisthe illumination uniformity at the light valve, less than10%.Introduce the methodincluding using attenuators and controlling LED current To simulate the wide rangeof brightness variations.In allusion to characteristic of the camera, need designing two optical system: bigfield of view and narrow field of view optical system.Every system has been designedto the secondary imaging telecentric optical system, optimize the system,finally imagequality meet the requirement of imaging optical system of spatial target visualsimulator. Model the combination of the spatial camera and simulator, tracke opticalrays and analysis of the image plane illuminance, the illuminance in the focal plane ofthe spatial camera achieve a very good uniformity. In the end, a prototype of thenarrow field of view simulator has been completed and its'performance has beentested.it meets the requirements of design.The main innovation points of this thesis are:(1)"The method of combininghighlighted LCD with optical imaging" is proposed to achieve the simulation of thespatial targets. This method can fundamentally solve the technical problems which theconventional simulation programs can't achieve.(2)The correspondence between thebrightness of the objectives and black background has been analyzed, and for solvingthe problem of the black background simulation, it also be proposed that the CCDdynamic range determines the selection of micro-display contrast.(3)The dynamicchanges of luminous flux of the micro-display have been utilized to solve the problemthat the micro-display grayscale range is difficult to cover the range of brightnessvariations, and the simulation of the big dynamic range for targets' brightness has alsobeen achieved.