带高增益观测器的高精度镜筒定位系统

High precision lens barrel positioning system with high gain observer

以长焦距斜视相机俯角系统为研究对象,针对高动态下自准直检焦镜筒定位精度不高的问题,提出了一种基于高增益观测器的多环路控制策略。首先,根据俯角控制系统开环幅频特性曲线,建立了俯角位置控制系统的数学模型,从控制理论角度分析了所设计控制策略的可行性;然后,通过实际系统进一步验证了所设计控制策略的可靠性。实验表明,高增益观测器能够很好地估计镜筒在非惯性空间下的角速度和角加速度状态;相比于双闭环控制方法,本文提出的控制策略可将俯角位置控制扰动最大误差减少96.3%,保证了镜筒的检焦位置定位精度优于0.05°,因此具有较好的工程应用价值。

By taking a long focal length oblique CCD camera as an object of study, a multiple loop con- trol scheme based on the high gain observer was proposed to improve the position accuracy of auto-col- limating auto-focusing lens barrel in a high dynamic state. Firstly, a mathematical model was estab- lished according to the open-loop amplitude-frequency characteristic curve of a depression angle control system. The feasibility of control scheme was analyzed by the control theory and the simulation tests were adequately performed. Then the reliability of control scheme was further validated through the practice control system. The experimental results show that the high gain observer can estimate the angle speeds and angle acceleration well. As compared with the double closed loop control method, this proposed control scheme reduces the maximum position control disturbance error by 96.3% and ensures the requirement of lens barrel positioning precision within ±0.05° . Hence the new control method is valuable in practical engineering applications.