空间相机调偏流机构的设计与控制

Design and control of drift adjusting mechanism in space camera

为了减小像移对空间相机成像质量的影响,提高相机分辨率,对空间相机像移补偿方法进行了研究。分析了偏流角产生的原因及调整原理,根据本相机自身特点,设计了高精密像移补偿机构。系统采用正弦机构作为传动形式,以80C31作为偏流角控制器,以步进电机为执行元件,以绝对式编码器作为偏流角测量元件,实现了偏流角位置的闭环控制。由于偏流角调整范围在-4°～+4°之间,以-4°、-2°、0°、+2°、+4°作为假想偏流角期望值,用编码器测得了10组偏流角调整实际数据。实验结果表明:偏流角控制系统精度可达到2′,满足系统对控制系统精度<3′的要求,可以实现高精度的像移补偿。

In order to reduce the effect of image motion on the image quality of space camera and to improve the resolution of camera, a compensation method of image motion to space camera is researched. The producing reason of drift angle and its adjusting principle are analyzed. Based on the characteristics of the camera, a fine compensation mechanism for motion image is designed. By taking a 80C31 as controller of drift angle,a step motor as actuating mechanism, and an absolute encoder as measuring component,the system realizes the closed-loop control of the drift angle position using transmissing form of sine agencies. Because the adjusting range of drift angle is between -4°＋4°, this paper measures and obtains ten groups of practical data by absolute encoder in choosing -4°, -2°,0°,＋2°, ＋4° as the expectation values of drift angle. Experimental results indicate that the drift adjusting mechanism can implement the accurate image motion compensation, and the accuracy of the drift angle can reach 2′ ,which can meet the accuracy requirement less than 3′ for control system .