大尺寸复杂曲面高效高精度轮廓测量关键问题研究

High efficiency conflicts with high precision. The project aims to resolve the conflict in getting profile with large scale and complicated contour with high efficiency and high precision. The structure light encoded by color measurement with non-scanning is a good technology to get high efficiency and relatively high precision. Yet the precision is not enough due to the technology bottle-necks, including worse calibration precision in large field, large error brought by getting information from the color codes and the high-light problem etc. To deal with these problems, the project proposed new ways, including a new self-suitable calibration method with high precision, a new self-suitable method of time-space encoding of colored stripe based on frequency information and a series steps to eliminate the high light. The project research will have such achievements as the self-suitable calibration model with high precision, the theory of error correction, the new encoding theory and realization of time-space encoding of colored stripe based on frequency information, the calculation theory of angles and the technology of removing the high light in the multi-angle high light elimination method. The goal of this project is to realize the measurement of large scale object with high precision and high efficiency which will be proved by getting a contour of a long blade of a nuclear turbine .

高效率与高精度是测量中的一对矛盾体，本课题主要针对大尺寸复杂曲面轮廓测量技术中高效与高精度的问题展开研究。结构光彩色编码全场测量技术是解决高效测量问题的较好方法，但测量精度还不能满足要求，主要影响因素有：标定精度不高、彩色编码信息提取误差大、高光问题等。针对这些关键问题本课题提出了一种大视场高精度、自适应的标定方法，提出了一种自适应并基于多频彩色信息的时空编码新方法，建立被测物体的高光预测模型，提出进一步消除高光的频域滤波法、网格投影法。本课题拟解决的科学问题包括：高精度自适应标定的模型建立和误差修正理论、彩色编码测量中自适应多频彩色时空编码理论与实现、多角度高光消除方法中角度计算理论与高光消除技术。最终将以核电汽轮机长叶片为验证对象，实现大尺寸复杂曲面高效高精度的轮廓测量。

本课题主要针对大尺寸复杂曲面轮廓测量技术中高效与高精度的问题展开研究。结构光彩色编码全场测量技术是解决高效测量问题的较好方法，但测量精度还不能满足要求，主要影响因素有：大视场标定精度不高、彩色编码信息提取误差大、高光问题等。本课题针对上述问题开展精度保证技术研究。在标定精度保障方面，从标定模型修正技术、基于神经网络技术、双目结构光技术三方面展开研究，分别提出了一种基于有理函数式畸变修正的三维测量标定模型、基于神经网络技术的标定思想、基于多视角的双目结构光三系统标定方法，理论分析和实验结果都证明了上述研究结果对系统标定精度都有不同程度的改善；在彩色编码信息提取精度保障方面，提出了一种多频彩色时空编码消除色差的方法，在此基础上进一步滤除串色，并通过改进Steger条纹中心提取方法，从而提高了彩色编码条纹信息提取的整体精度；对于结构光测量中的高光问题，提出基于多曝光及区域投影的高光消除方法，针对高光非溢出部分，通过条纹增强算法解决由饱和及反射率突变引起的条纹变形问题，针对高光溢出部分，通过区域投影方法消除高光，该方法全面有效地解决了测量中产生的高光问题。其次，从表面反射机理出发，研究投影光源波长对测量精度的影响，表明蓝光光源对一般金属表面具有降低高光影响的作用。