基于三次拟合方程畸变校正的光电测量系统

在大视场光电测量系统中,光学系统产生的畸变使目标在线阵CCD上的成像偏离了理论成像点,导致系统产生测量误差.为了减小该误差,提高系统的测量精度,根据畸变产生机理,设计了由11个等距目标点组成的畸变检测装置.根据检测得到的系统实际畸变变化情况,需要拟合出系统测量时目标点在线阵CCD上成像位置的补偿方程.以检测装置测量拟合得到的三次补偿方程作为畸变校正的数学模型编写了测量校正程序,对光电测量系统进行了实验检测.测量结果表明,当目标物物高为200.115mm时,按照拟合的补偿方程进行计算补偿,可将畸变误差从校正前的-2.08mm提高到校正后的0.05mm,并使系统整体检测精度从1.039%提高到0.025%.

Distortion Correction for the Photoelectricity Measuring System Based on the Cubic Fitting Equation

In the 70° big visual field photoelectrictity measuring system,distortion produced by optical system makes the image of object in linear CCD deviate from the theoretical point and lead to the system measuring error. In order to improve measuring precision for the goal point in the measuring system,a set of device made up of eleven equidistance goal points for detecting optical distortion is designed on the basis of distortion theory. According to the change condition of systematic distortion,the compensation equation need fitting to join point location imagined by object point on linear CCD in real time measure. By the cubic equation fitting based on the data detected in measurement system as math model,the compensation program is compiled to carry out distortion correction in experiment program. The experiment result in actual detection shows that the device can reduce error obviously from -2.08 mm to 0.05 mm according to the compensation equation when the height is 200.115 mm,and raise the whole systematic detection precision from 1.039% to 0.025%.