载机平台光电转塔目标定位的仿真算法

目标定位是光电转塔典型功能和任务之一,对其定位精度的考量也是转塔作战技术指标之一,针对该问题,从理论和仿真角度进行了分析。分析目标定位中用到的坐标系及其相互转换关系,给出光电转塔视轴反演、有源目标定位、无源目标定位的算法流程,通过仿真实验加以验证,考虑了定位过程中可能的随机误差来源,并分析是否采用均值滤波及其对定位结果的影响,最后通过Monte-Carlo分析计算了定位精度。分析结果表明:1）有源定位比无源定位的精度高,在仿真假设条件下,精度约提高1倍;2）均值滤波后,定位精度有较大提升（约提高15倍）;3）18 km距离时典型无源定位精度在80%置信度条件下约为39.4 m;4）统计直方图反映出80%置信度CEP半径及最大误差距离随载机位置、姿态、转塔视轴等（体现在目标载机距离上）不同参数的变化结果。     

基于粒子滤波的运动目标光电定位仿真研究

运动目标的光电定位不能像静止目标那样简单做均值滤波,鉴于此,引入粒子滤波算法,它不仅可以应用于线性系统,而且还适用于非线性系统。结合光电定位需求,详细推导了计算公式及初值和参数选取公式,对只含测量噪声以及含有测量和运动噪声等的海面运动目标光电无源定位算法进行了仿真计算,验证了算法的有效性,讨论了噪声强度对滤波效果的影响,滤波参数选择对滤波效果的影响,目标运动方式对滤波跟随性的影响,重采样算法对滤波效果的影响等。所得结论为:粒子滤波可用于运动目标光电定位过程,可有效降低定位误差;粒子滤波算法具有较强鲁棒性,适用于噪声较大、目标运动形态变化大等情况。     

两轴转台位置伺服系统自适应鲁棒控制

针对某两轴随动转台运行时负载与参数变化大、轴间耦合干扰作用强的特点,将自适应鲁棒控制策略应用到其位置伺服系统控制器设计中,并证明了稳定性;由于控制律中含有采集信号的高阶微分项,为避免采集噪声对控制精度的影响,采用微分观测器,以减小其影响;仿真结果表明,相对于PID及传统自适应鲁棒控制器,使用该控制方法后,系统跟踪精度明显提高,且控制输入更加平滑,具有较好的瞬态与稳态性能。     

Quantitative Bulk and Trace Element X-Ray Mapping Using Multiple Detectors

X-ray mapping using energy dispersive spectroscopy or wavelength dispersive spectroscopy is a very popular characterisation tool for determining the elemental distribution in materials. Furthermore, quantitative X-ray mapping has become a very powerful technique enabling reliable quantitative results that can be an order of magnitude better than traditional analysis. Quantitative X-ray mapping is also far superior to regions of interest X-ray maps where low levels of an element or elemental overlaps are present. The one major drawback with X-ray mapping is the time required to obtain a high resolution X-ray map with good statistics at low levels of concentration. The use of multi-detectors, and just developed dual turret detectors for X-ray mapping, allows improvement in performance at low levels without compromising quantification quality and precision of traces, even in the presence of overlaps. However, for quantitative X-ray mapping to work properly, the characteristics of each detector must be accurately determined so that the final quantification of the individual detectors can be summed. To accomplish this effectively, the full spectrum at each pixel for each energy dispersive detector should be saved. As a final check for consistency between detectors, a technique was developed that involves assigning a different red-green-blue colour for each detector for the same element. By doing this, when we combine the three maps of the same element, we should obtain a grey scale map that indicates total correlation between the three detectors at the most critical final stage of quantification. To reduce contrast noise and further improve the quality of quantitative X-ray mapping images, a filter referred to as a “speckle filter” has been developed that allows the eye to see a more correct elemental concentration relationship.     

航空摄影陀螺稳定平台的嵌入式计算机控制系统

针对航空摄影陀螺稳定平台的特殊要求，论证了嵌入式控制模型，采用数据流程图对系统软件进行了分析，设计了应用于陀螺稳定平台的计算机控制系统。系统试验和飞行试用结果表明：该计算机控制系统具有功能强，可靠性高的特点。陀螺稳定平台已成功地应用于航空摄影领域。     

直升机机载光电吊舱的发展现状及对策

介绍了直升机机载光电吊舱的应用背景、基本组成和工作原理,主要以警用机载吊舱为对象,分析了该系统的国内外发展现状及未来的发展趋势,并有针对性地提出了进行相关研究的具体思路和方案。