直升机桨叶共锥度测量中圆形标记点高精度定位方法

A New Method of Accurate Location of Circular Marker in Taper Angle Measuring of Helicopter Rotor Blades

针对直升机桨叶共锥度测量中背景复杂、圆形标记点较小,易出现定位不准的问题,提出一种新的圆形标记点定位方法。首先,利用OTSU图像分割方法计算阈值;然后,以OTSU阈值为边界阈值,对图像进行多重分割;利用圆度特征和质心变化规律,对每一次分割后的连通域轮廓进行干扰排除,实现圆形标记点的粗定位;最后,采用最小二乘拟合法完成标记点的精确定位。通过圆形标记点定位实验,表明该方法在复杂场景下对较小的圆形标记点具有较高的定位精度,可用于提高大场景复杂环境下直升机桨叶共锥度测量精度。

An accurate method for circular marker location was proposed to solve the problem of inaccurate location due to the smaller circular marker and the complex background in the measurement of taper angle of helicopter rotor blades. Firstly, OTSU image segmentation method was used to calculate the threshold. Secondly, image was multi-thresholds segmented bY boundary threshold. Thirdly, circular degree and change rules of barycenter were used to eliminate interference in connect domain contours, which located the circular marker approximately. Finally, least square fitting method was used to locate the circular marker precisely. Test results show that compared with the original model, the location accuracy of the new method is promoted in complex background. It is concluded that the proposed method can improve the location accuracy of taper angle of helicopter rotor blades in large area and complicated surrounding.