航空相机镜筒位置控制的扰动估计与补偿

在航空相机镜筒速度内环设计了自抗扰控制器,以减小镜筒内偏心凸轮机构的运动对镜筒的扰动.采用扩张状态观测器对扰动进行实时估计,并生成扰动补偿量抵消扰动的影响.首先,分析了凸轮机构的运动对镜筒扰动的特点.然后,建立了镜筒的数学模型,基于带宽的单参数化设计思想设计了扩张状态观测器及带扰动补偿的控制律,设计了镜筒位置控制器.最后,在镜筒上对控制器的抗扰动性能进行了验证,并与目前航空相机常用的一阶平方滞后超前校正法进行了比较.结果表明,采用自抗扰控制能将凸轮机构对镜筒的扰动偏差减小为传统方法的50％左右.在提高系统抗扰动性能的同时,控制器增益减小约2个数量级,大大降低了对控制器增益的要求,提高了系统的稳定性,对改善航空相机控制系统的抗扰动性能及降低控制器设计难度具有较高的实用价值.

Disturbance estimation and compensation of position control of lensbarrels in aerial cameras

An active disturbance rejection controller was designed in the lensbarrel of an aerial camera to reduce the disturbance caused by an eccentric cam of the lensbarrel.An extended state observer was designed to estimate the disturbance and then to generate control signals to compensate the disturbance influence.First,the disturbance characteristic of the cam was analyzed.And then,a mathematic model of lensbarrel was established and simplified.Based on bandwidth parameterization,the extended state observer and the control law with disturbance compensation were designed and a position controller was finished.Finally,an experiment on the lensbarrel was performed to test the disturbance rejection performance of the controller.As compared with the traditional first order square lag-lead compensation method used in aerial cameras,experiment results show that the active disturbance rejection controller can reduce the disturbance error about 50% with a lower controller gain about percentile.In conclusion,the disturbance rejection performance of the system is improved and the demand for controller gain is lowered at the same time.It is feasible and practical.