| Solar simulator is a kind of device to simulate solar radiation of outer space from earth, has been widely used in ground experiment, test and calibration precision of solar sensor.Solar simulator is an attitude sensor in the satellite control system. A kind of optical attitude sensor that determine the orientation of the sun vector in stellar coordinates through the orientation of sensitive sun vector and then obtain the sun azimuth information relative to spacecraft. Because of the particularity of the aerospace test, the precision test of solar sensor is frequently need to be finished on the ground, solar sensor calibration is the essential link to realize the accuracy of attitude measurement, so high precision calibration of solar sensor is an urgent thing in the aerospace field to be solved, as it will directly affect the accuracy of spacecraft in orbit.Nowadays, the solar simulator at home and broad just a few characteristics of solar radiation can be simulated, but not all can be.The reason to this phenomenon is the mutual restraint of system designing parameters, especially the contradiction between solar collimation angle and solar radiation intensity. The simulated solar collimation angle is1°-2°while the solar radiation intensity achieves a solar constant. Solar radiation is just0.1-0.3solar constant while the solar collimation angle is32’.Therefore, this paper is to improve the calibration accuracy and carry out the key technology of high-accuracy collimating solar simulator based on exploring the high-accuracy calibration and solutions of solar sensor. Break through the restrains while simulating the solar collimation angle and real solar radiation together, realize simulating the space solar characteristics veritably, that the characteristics of radiation beams should possess real radiation solar radiation the solar angle(collimation angle)、spectral distribution、radiation stability、uniformity and a sufficiently large beam caliber. Design a solar simulator with solar constant and32’solar angle, introduce the composition and overall structure of solar simulator in detail, the focus is design of optical system, including selection of light source、design of combined condenser、optical integrator and optimization design of collimator lens, optical simulation analysis of the entire system is also carried out. A further study on thermal control structure is undertaken and the mechanical systems are designed, including xenon lamp adjustment mechanism and thermal control structure、the combined condenser adjustment mechanism and its thermal control structure、steering plane mirror support mechanism and its thermal control structure、the integrator and diaphragm institution and its thermal control diaphragm structure.Designed solar simulator in this paper is not only can be used directly in simulation test、performance test and calibration accuracy of existing solar sensor, the more important thing is it can also be used in simulation test, performance test and calibration accuracy of other new solar sensor in the future. The research is of great significance to the solar sensor quality assessment, performance test and production.To improve energy utilization efficiency of the system, a combined condenser as condenser system of solar simulator is designed. Compared with traditional ellipsoid condenser, combined condenser can improve the light condensing efficiency and the utilization of integrator caliber. Propose an optical integrator optimization design method, combined with sequential and non-sequential serial of Zemax to finish the optimization design of integrator structure parameters. Considering the optimization design of integrator from imaging relationship, this will not only avoid ray tracing inefficient and long time working of non-sequential, but also provide a new optimization design method of the optical integrator, and achieve a good design results; in order to modeling xenon lamp more realistically, according to the xenon lamp light distribution curve, using nested arc lamp modeling ideas, divide the whole arc lamp into energy distribution core and non-core zone, each regional energy is allotted by angle of xenon lamp light distribution curve,overcome disadvantages that radiation energy gradient is not evident of tradition xenon lamp. Use optical simulation software to analyze the affect on uniformity of irradiated surface from xenon lamp defocus and projection lens defocus in detail, as a guiding role for the subsequent alignment of solar simulator.Aiming at the phenomenon of heat concentrated when solar simulator in work, it is necessary to design and analyze the thermal control structure reasonable, on the premise of ensuring mechanical support stiffness and easy adjustment. The entire simulator system uses forced air cooling method, for heat concentrated components, a special cooling mechanism is designed. Use Ansys software to assume thermal simulation analysis, ensure thermal control design is rationality and optimality. The combined condenser is key component of solar simulator, has great impact on irradiated surface radiance and irradiance uniformity, as the light source placed internal simulator, it is the most heat concentrated area, by laying annular fins up outer wall of condenser and digging vent at appropriate position to dissipate heat.Design adjustment ring to achieve adjust of the axial and radial directions; three positions to jack and three positions to pull to achieve the tilt angle adjustment, a locking structure exists. The integrator is the core component of simulator, the key to achieve all targets for simulator, because it is placed at the second focal point of the condenser, endure strong thermal load, a hollow cylindrical fin piece radiator is applied on integrator. To fulfillment high thermal efficiency and light quality requirements, heat dissipation as conditional function and quality as objective function to optimization design cylindrical fin radiator structure, the effect is better to ensure normal function of the integrator.In conclusion, this paper studies on solar simulator with a solar constant、32’solar angle, that can simulate solar irradiation characteristics actually, can be applied to high-precision solar sensor ground calibration and simulation test of satellite control system, solve problems of solar sensor high-precision calibration and lay a technical foundation for the development of high-precision solar sensor. |
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