像移补偿快速反射镜时频特性优化控制(英文)

Time-frequency characteristics optimal control of fast steering mirror for image motion compensation

为了进一步优化像移补偿快速反射镜的时域和频域特性,进而提高运动相机所拍摄照片的清晰度,设计了基于线性扩张状态观测器(LESO)、零相位误差跟踪控制器(ZPETC)和卡尔曼滤波器的控制系统。首先,建立了音圈电机驱动型快速反射镜的数学模型。然后,阐述了LESO、ZPETC和卡尔曼滤波器的原理。最后,对被控对象进行了实验研究。阶跃响应曲线显示,系统调节时间达到2.5 ms,与比例-积分-微分(PID)控制系统相比,系统相对误差在小于1%时能够以更快的速度收敛到零。伯德图显示,系统带宽达到369 Hz,是PID控制系统的1.5倍以上,同时减少了接近一半的相位滞后。在加入干扰后,系统平均相对误差达到0.028%,比PID控制系统减少了75%。相机拍摄的照片表明,该控制方法使得照片的主观视角效果和客观评价指标参数都有所提高。

In order to further optimize time and frequency domain characteristics of fast steering mirror(FSM) for image motion compensation and thus to increase the definition of picture taken by moving camera, a control system based on linear extended state observer(LESO), zero phase error tracking control(ZPETC) and Kalman filter was designed. First, mathematical model of FSM driven by voice coil motor(VCM) was established. Next, principles of LESO, ZPETC and Kalman filter were clarified. Finally,experimental research for controlled object was made. Step response curves demonstrate that the settling time reaches 2.5 ms. Besides, compared to proportional-integral-differential(PID) control system, relative error of output converges to zero faster when it is less than 1%. Bode diagram shows that the bandwidth attains 369 Hz, which is more than 1.5 times that of PID control system. Meanwhile, phase lag reduces nearly a half. When disturbance is added, average relative error of the designed system reaches 0.028%,reduced by 75% compared to that of PID control system. Pictures taken by camera illustrate that this control method makes both subjective visual effect and objective evaluation parameters of image improve further.