有效消除多视拼接累计误差的大曲面测量方法

Large Surface Measurement Method of Effectively Eliminating Multi-view Stitching Accumulative Error

为了提高大尺寸曲面测量精度,综合利用精密机械、光电技术、CAD/CAM/CAT和自动控制等科学技术,将高精度测量设备与数控加工设备相结合,实现了大尺寸曲面在线检测加工一体化。在详细分析影响多视序列子轮廓拼接精度原因的基础上,为了减小多视拼接累计误差的影响,提出了基于互为基准的轮廓拼接策略和基于整体误差补偿的拼接方法,按照轮廓的封闭连续拼接误差最终为零的原则,实现累计误差的二次分配,减少序列轮廓数据连续拼接累计误差。实验结果表明:系统测量精度优于20μm。

For the purpose of improving the accuracy of measuring large-sized curved surfaces, precision machines, photoelectric technology, CAD/CAM/CAT and automatic control technology are employed comprehensively, and high- precision measuring equipment and numerically controlled processing equipment are combined to realize the integration of on-line inspection and processing of large-sized curved surfaces. According to a detailed analysis of factors that affect the precision of splicing sub-contours of a multi-view sequence, both a contour splicing strategy based on mutual reference and a splicing method based on integral error compensation are proposed to diminish the effect of accumulative errors resulting from multi-view splicing. Subsequently, quadratic assignment of accumulative errors is achieved in line with the principle that the closed continuous splicing error of contours is zero in the end, thus reducing the accumulative errors resulting from continuous splicing of sequential contour data. The results show that the accuracy of this system is higher than 20 μm.