两轴稳定平台的过顶盲区问题

过顶盲区问题是目标在导弹的小离轴角附近区域运动时,由于框架角速率限制产生的稳定平台不能正常跟踪目标机动的一种现象.根据光电探测系统成像的几何关系,分别对直角坐标框架和极坐标框架稳定平台的目标成像关系进行了分析,进而给出极坐标框架稳定平台的过顶盲区的数学描述,并对这种盲区的成因进行了分析.结合三种情况的目标机动速度,在Matlab的Simulink环境下对极坐标框架稳定平台的过顶盲区现象进行了仿真.最后,基于分区域变参数的PID控制方法,给出了目标在过顶盲区内作垂直向上机动时的一种控制方案,并与普通PID控制进行了对比仿真研究.实际仿真结果表明,通过数学分析得到的极坐标框架稳定平台的过顶盲区模型与实际情况相符合,并且基于分区域变参数的PID控制方法能够改善极坐标框架稳定平台的跟踪特性. 

Zenith blind zone of two-axis stabilized platform

Zenith blind zone is a phenomenon which the line of sight can not track the target when the target maneuvers in the narrow offboresight of the missile.Utilizing the geometrical relation of photoelectric imaging guidance,the rectangular coordinates and polar coordinates stabilized platform were analyzed.Moreover,the models of zenith blind zone for polar coordinates stabilized platform were presented and the reason of this type of zenith blind zone was analyzed.Furthermore,the zenith blind zone for polar coordinates stabilized platform was simulated in three different rate conditions of target maneuver in Simulink environment of Matlab.Finally,a PID control approach based on variable parameters per different areas was proposed.Aiming at a vertical maneuver mode of target,this variable parameters based PID control method was simulated using Matlab in contrast to general PID control.The results show that the zenith blind zone models for polar coordinates stabilized platform conform to the actual situation and the variable parameter based PID control approach can improve the characters of the target tracking.