基于干扰观测器的航空成像系统的扰动抑制

Disturbance rejection for aerial imaging system based on disturbance observer

针对反射式长焦斜视相机减振器组件固有频率带来的低频扰动,提出了一种基于干扰观测器的加速度反馈控制方法,实现了镜筒系统对扰动的抑制。首先,分析了扰动对相机成像质量的影响。然后,对镜筒光纤陀螺进行参数标定并构造镜筒控制系统的干扰观测器,实现对镜筒角加速度及外界扰动的估计。最后,提出带干扰观测器的加速度反馈控制策略并应用到镜筒控制系统中。实验结果表明,相比于超前-滞后校正方法,基于干扰观测器的加速度反馈控制方法能够提高系统的闭环带宽,将减振器固有频率带来的低频扰动幅值降低50%,改善相机成像质量,在实际工程中具有较高的应用价值。

Aiming at the low frequency disturbance resulted from the shock absorber inherent frequency of long focal length oblique CCD camera in reflection type optical system, this paper presents an acceleration feedback control method based on disturbance observer. The disturbance restraint for the lens barrel system is realized. Firstly,the in- fluence of the disturbance on camera imaging quality is analyzed. Then, the parameters of the lens barrel optical fiber gyro are calibrated and the disturbance observer of the lens barrel control system is constructed ;and the estimation of the lens barrel angular acceleration and external disturbance is realized. Finally, the acceleration feedback control strategy with disturbance observer is proposed and applied to the lens barrel control system. The experiment results show that compared with lead-lag correction method, the acceleration feedback control method based on disturbance observer can enhance the system closed-loop bandwidth and reduce the low frequency disturbance amplitude brought by shock absorber inherent frequency by 50%. The proposed method can improve the camera imaging quality and has high application value in practical engineering.