【作者】 郭立东；

【导师】 谈振藩；

【作者基本信息】 哈尔滨工程大学 ， 导航、制导与控制， 2011， 博士

【摘要】 舰载激光武器系统与一般的光电跟踪系统不同,它不仅要求能在规定的视场内快速稳定地跟踪目标,而且要求能将激光光束锁定在目标的某一点上,持续辐照一定时间,这就要求跟踪精度达到角秒级。舰载激光武器系统要克服舰船摇摆的影响,一般的单稳定平台结构由于摩擦力矩、机械谐振、大转动惯量等因素很难达到这样的跟踪精度。本文首先针对舰载激光武器高跟踪精度和存在舰船摇摆干扰的特点,提出了粗、精组合的双平台结构。粗平台为捷联式三轴常平架结构,通过控制器将舰船惯导系统提供的舰船姿态角经过坐标变换转变为粗平台三个轴上的等效运动,然后利用粗平台的稳定系统控制粗平台朝相反的方向转动,实现粗平台相对地理坐标系的稳定。精平台安装在粗平台上,粗平台为精平台提供一个相对稳定的基座。对于舰载激光武器系统来说,如果要以角秒级精度快速稳定地跟踪运动目标,首先要保证光电跟踪仪器瞄准线的稳定,即视轴的稳定。同时跟踪架承担了全部的跟踪、扫瞄设备,很难以灵敏的反应速度跟踪目标。因此,精平台设计成宏微复合控制结构。宏控制系统为方位、俯仰两轴常平架结构,实现快速粗跟踪,同时隔离粗平台的剩余摇摆误差,稳定光电系统的视轴。微控制系统为光路中的快速反射镜系统,以低惯量保证高精度跟踪。其次,根据粗平台的结构特点,建立了粗平台的状态空间模型。从粗平台的状态空间模型可以发现,该模型是严反馈的、状态可检测的。影响粗平台稳定精度的主要因素是系统的非线性摩擦力矩,而滑模控制可以很好地解决非线性问题,但是摩擦力矩干扰是不匹配的,无法直接进行滑模控制器设计。同时作为稳定平台驱动元件的电机,参数也不是一成不变的。为了克服这个缺点设计了基于PID滑模面的自适应滑模控制器,并给出了闭环系统的稳定性分析。然后,建立了宏控制系统的模型,该模型主要由内环视轴稳定回路和外环光电跟踪回路组成。由于光电跟踪回路的误差检测元件宏跟踪器存在20ms的脱靶量时滞,该时滞会造成系统相位裕度的降低,从而导致系统超调量的增加,甚至使系统振荡,最终导致系统的不稳定。针对宏控制系统脱靶量时滞和高精度跟踪问题,提出了基于Kalman预报的跟踪控制方法。基于Kalman预报的跟踪控制分为两部分：Kalman预报器的设计和视轴稳定控制系统的设计。为了解决脱靶量时滞对系统的影响,提出了Kalman预报器的预报滤波方法,提高了系统的预报精度。针对视轴稳定系统中的摩擦力矩干扰不匹配问题以及状态变量之间没有直接的微分关系的特点,提出了基于神经网络Backstepping控制方法,提高了视轴稳定系统的跟踪精度。最后,建立了微控制系统的数学模型,针对快速反射镜驱动器PZT的迟滞以及不匹配问题,将动态面控制方法应用于微控制系统,并进行了稳定性分析。同时给出了舰载激光武器稳定控制系统的仿真,结果表明,采用粗、精组合的稳定技术及精平台的宏微复合控制技术后,有效地隔离了舰船摇摆,达到了角秒级的跟踪精度。更多还原

【Abstract】 The shipborne laser weapon system is different from the normal optical tracking system, which requires not only to track the moving targets in the field of view steadily and quickly, but also to lock the beam on a certain point of the target for a certain period of time, which requires the tracking accuracy of angular second. The shipbore laser weapon system will swing with the ship. In this case, the single platform structure is difficlt to achieve such precision because of the friction torque, mechanical resonance and large inertia etc..For the features of high tracking accuracy and the ship swing disturbane of the shipbore laser weapons, the double platform structure of primary and precise was suggested. Primary platform is three-axis strapdown gimbal structure. The controller will transform the ship attitude angles, which provided by ship inertial navigation system, into a equivalent movement of three axes of the primary platform. Then the stabilized control system rotates the primary platform in the opposite direction to achieve a relatively stabilization in inertial space.The precise platform is installed on the primary platform, and primary platform provide a relatively stable base for precise platform. For shipborne laser weapon system, if tracking the moving targets in angle-second precision fast and stably is wanted, the stablilization of line-of-sight(LOS) optical tracker must be ensured. At the same time, the tracking frame is difficult to tracking the target with sensitive reaction-speed, because it bears all the equipment of tracking and scanning. Therefore, the the structure of precise platform is designed as compound macro-micro control. The macro-control system is used to achieve a fast tracking, while isolating the remaining swing error of primary platform and stabilizing the LOS optical tracker. The micro-control is a fast steering mirror system, which is used to ensure high-precision tracking.According to the structural features of the primary platform, a state space model is established. From the state space model it can be found that the model is strictly feedback and state could be detected. The main factor that affects the stabilization accuracy of the primary platform is the nonlinear friction torque, and the sliding mode control can solve the robust control problems under the matching condition. But the friction torque disturbance is mismatched, which can not be compensated by designing sliding mode controller directly. At the same time, the motor as a driver of the primary platform, its parameters are not static. To overcome this disadvantage, an adaptive sliding mode control with PID sliding surface is proposed, and the stability analysis of the closed-loop system is given.The model of macro control system is estibilished, and the model is formed by the LOS stabilization loop and the optical tracking loop. Because there is 20ms target-missing delay in the optical tracking loop, the delay limits system performance, such as reducing the phase margin of the system, increasing the overshoot of system, or making the system oscillation, even instability. Based on Kalman predictor, a tracking control is proposed for the high precision and the target-missing delay problems of macro control system. Tracking control can be divided into two parts:Kalman predictor design and LOS stability control system design. The Kalman predictor is proposed to solve the problem of the target-missing delay and improve the prediction accuracy of the system. A NN-based Backstepping control is designed to solve the mismatched friction torque disturbane problem of LOS stablilization system to improve the tracking accuracy.Finally, a mathematical model of micro-control system is estibilished. For the mismatched hysteresis problem of the driver PZT, a dynamic surface control method is applied to the micro-control system and the stability analysis is given. The simulations of shipborne laser weapons stablilized platform control system show that the primary and precise combination technology and the compound macro-micro control of precise platform isolate the ship swing effectively and the angular-second tracking accuracy has been achieved.更多还原