激光半主动定位系统的性能提高研究

发布时间：2018-07-23 11:15

【摘要】：激光半主动定位系统是一种接收目标散射激光回波,解算目标方位信息,实现目标定位和跟踪功能的系统。该系统采用直接探测激光回波能量的方法,目前存在远距离探测时系统信噪比严重下降;低信噪比引起的系统测角精度严重下降等急需解决的问题。本论文通过理论分析和推导、仿真和试验研究等手段,改善了激光半主动定位系统的信噪比,提高了测角精度,实现了激光半主动定位系统在月牙形光斑情况下正确解算目标方位信息的功能。本文分析了激光半主动定位系统偏振探测提高系统信噪比和Kalman滤波提高定位系统精度的国内外研究现状。目前,针对该系统的性能提高研究,已报道出的国外研究进展相对较少,且国内外的研究主要集中在提高系统测角精度的研究,对系统信噪比和月牙形光斑的研究没有报道。首先,针对激光半主动定位系统远距离探测时,系统信噪比严重降低的问题,本文提出基于偏振检测直接探测激光半主动定位系统的方案,利用范数理论确定了偏振检测结构的参数,推导得到了偏振探测激光半主动定位系统的信号光和天空背景光的模型,给出了偏振探测模式下的目标方位信息解算算法。搭建了偏振探测激光半主动定位系统试验室验证试验系统,进行了信噪比试验和目标方位信息解算验证试验。试验结果表明,偏振探测可将激光半主动定位系统信号光与背景光强度比值SBR提高1.2倍左右,偏振探测模式下目标方位信息解算试验结果也近似与理论仿真曲线吻合。然后,针对低信噪比导致直接探测激光半主动定位系统的测角误差增大,测角精度降低的问题,本文分析了该系统测角精度的影响因素及其统计特性。推导了激光半主动定位系统在恒定弹目偏差角和非恒定弹目偏差角两种工作模式下的状态空间描述,根据测角精度近似正态分布的特性选择Kalman滤波提高该系统的测角精度。仿真研究了恒定弹目偏差角和非恒定弹目偏差角两种工作模式下的测角精度,仿真结果表明,对于非恒定弹目偏差角工作状态,Kalman滤波可以将测角精度从0.50°提升至0.21°。对于恒定弹目偏差角工作状态,Kalman滤波可以将测角精度从0.50°提升至0.19°。搭建了直接探测激光半主动定位系统试验室测角精度测量试验系统,进行了Kalman滤波提高该系统测角精度试验,试验结果表明,对于非恒定弹目偏差角工作状态,Kalman滤波可以将测角精度从1.24°提升至0.50°,对于恒定弹目偏差角工作状态,Kalman滤波可以将测角精度从0.12°提升至0.01°。最后,针对直接探测激光半主动定位系统在工作时,由于弹体阻挡目标散射回波而在探测器光敏面上出现的月牙形光斑,本文分析了月牙形光斑的形成机理,给出了此种情况下的目标方位信息解算算法。进行了月牙形光斑目标方位信息解算试验,试验结果曲线与仿真结果曲线近似吻合,有效将激光半主动定位系统的视场角由±2.5°增大至±3.5°,提升了该系统的探测能力。
[Abstract]:The laser semi-active positioning system is a system that receives the target's azimuth information and realizes the target positioning and tracking function. The system uses the method of direct detection of the laser echo energy. The system has a serious decline in the signal to noise ratio of the system and the accuracy of the system angle measurement caused by the low signal to noise ratio is seriously reduced. By means of theoretical analysis and deduction, simulation and experimental research, this paper improves the signal to noise ratio of the laser semi-active positioning system, improves the accuracy of the angle measurement, and realizes the function of the correct solution of the target orientation information in the laser semi active positioning system in the case of the crescent light spot. Positioning system polarization detection improves the research status of system signal to noise ratio and Kalman filtering to improve the precision of positioning system. At present, in view of the performance improvement of the system, the reported foreign research progress is relatively small, and the research at home and abroad is mainly focused on improving the study of the system angle measurement accuracy and the system signal-to-noise ratio and crescent shape. The research of light spot is not reported. Firstly, in view of the problem that the signal to noise ratio of the system is seriously reduced when the laser semi-active positioning system is long distance detection, this paper proposes a scheme for the direct detection of the laser semi-active positioning system based on polarization detection. The polarization detection node is determined by the norm theory, and the polarization detection laser half master is derived. The signal light of the dynamic positioning system and the model of the sky background light are used to calculate the orientation information of the target in the polarization detection mode. A test system for the test room of the polarization detection laser semi-active positioning system is built, and the signal to noise ratio test and the target azimuth information solution test are carried out. The results show that the polarization detection can be excited. The ratio of the signal light to the background light intensity of the optical semi-active positioning system is increased by about 1.2 times. The results of the target azimuth calculation test under polarization detection mode are similar to that of the theoretical simulation curve. Then, the angle error of the direct detection laser semi-active positioning system is increased and the angle measurement precision is reduced by the low signal to noise ratio, which is caused by the low signal to noise ratio. The influence factors and the statistical characteristics of the angle measurement accuracy of the system are analyzed. The state space description of the laser semi-active positioning system under two operating modes of constant projectile deviation angle and unsteady projectile deviation angle is derived. According to the characteristic of the approximate normal distribution of the angle measurement accuracy, the Kalman filter is selected to improve the angle measurement accuracy of the system. The angle measurement accuracy under the two operating modes of constant projectile deviation angle and unsteady projectile deviation angle is investigated. The simulation results show that the Kalman filter can increase the angle measurement accuracy from 0.50 to 0.21 degrees for the working state of the unsteady projectile deviation angle. For the working state of the constant projectile deviation angle, the Kalman filter can improve the angle measurement accuracy from 0.50 degrees. To 0.19 degrees, a test system for measuring angle accuracy of the direct detection laser semi-active positioning system is built. The angle measurement accuracy test of the system is improved by Kalman filtering. The experimental results show that the Kalman filter can increase the angle measurement precision from 1.24 to 0.50, and to the constant projectile deviation. In the angle working state, the Kalman filter can improve the angle measurement accuracy from 0.12 to 0.01 degrees. Finally, this paper analyzes the formation mechanism of the moon shaped light spot for the direct detection of the laser semi active positioning system when the projectile blocks the target scattering echo on the detector's photosensitive surface. The target azimuth information solution algorithm is used to calculate the orientation information of the crescent spot target. The test result curve is approximately consistent with the simulation result curve, and the field angle of the laser semi-active positioning system is effectively increased from 2.5 to 3.5 degrees, and the detection ability of the system is improved.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN24

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