卫星激光通信光束控制中的迟滞建模与补偿

为保证卫星激光通信的链路稳定,需要将接收的光束始终控制在通信中心点.由于压电陶瓷驱动的快速倾斜镜具有高刚度和快速响应等特点,作为执行机构广泛应用于卫星激光通信的精跟踪系统.但是压电陶瓷本身具有迟滞特性,给精跟踪系统的闭环控制带来了难题.传统的处理方法是在精跟踪系统内部增加一层闭环控制使快速倾斜镜达到线性化的目的,但这会极大地降低精跟踪系统的带宽.通过对快速倾斜镜结构进行分析,我们发现可以利用对称迟滞模型对其迟滞特性进行建模,进一步提出了一种基于Madelung规则的对称迟滞建模与补偿方法,能够精确地描述和补偿快速倾斜镜的迟滞特性,有效地提升光束控制带宽,从而提高通信链路的稳定性.理论仿真和实验结果验证了所提出方法的有效性.

Hysteresis modeling and compensation in beam control of satellite laser communication

In order to ensure the link stability of satellite laser communication,ongoing control of the received beam at the communication center is imperative.Due to the characteristics of high stiffness and fast response,the fast steering mirror driven by piezoelectric ceramics is widely used as an actuator in the fine tracking system of the satellite laser communication.However,it raises challenges to the closed-loop control of the fine tracking system.The traditional method adds a closed-loop control inside the fine tracking system to linearize the fast steering mirror,that in turn reduces the bandwidth of the fine tracking system considerably.Analyzing the structure of the fast steering mirror reveals that the symmetric hysteresis model could be employed to describe its hysteresis behavior.This study introduces a symmetric hysteresis modeling and compensation method based on Madelung’s rules,which can accurately describe and compensate the hysteresis characteristics of the fast steering mirror,and effectively improve the beam control bandwidth,along with the stability of the communication link.The theoretical simulation and experimental results show the effectiveness of the proposed method.