条纹投影测量系统标定方法研究

Research on calibration method of fringe projection measurement system

条纹投影测量方法具有无接触、测量精度较高、分辨率高等优点,是最可靠的三维测量方法技术之一。而系统标定的精度决定了测量数据的精度上限,是三维测量中至关重要的环节,所以本文分析比较了条纹投影测量系统已有的主要标定方法,包括有:反向投影法、三角关系建模法、隐式拟合法和神经网络法。从误差积累、系统搭建严格程度、操作复杂度、是否需要精密辅助装置、是否考虑镜头畸变以及测量精度等方面进行了对比分析,得出每种方法的优缺点及应用,并以精度相对较高的相位匹配标定法、多项式标定法和平面拟合标定法3种方法为例进行对比实验,综合方法特征与实验结果,得出标定方法选择依据:需要高精度测量应选择多项式拟合法,需要操作灵活应选择相位匹配法,同时对精度和灵活性有需求,应选择平面拟合标定法,对此类技术面向不同需求时选择适当的方法进行系统标定具有一定的应用价值。

Fringe projection measurement method is one of the most reliable three-dimensional measurement methods because of its non-contact,high measurement accuracy and high resolution.The system calibration directly determines the upper limit of measurement data accuracy,and is the most important step of 3D measurement.In this paper,the main calibration methods of fringe projection measurement system were summarized,including the back projection method,tri-angle relation modeling method,implicit fitting method and neural network method.The advantages or disadvantages of each method and its application were analyzed from the aspects of error accumulation,system construction rigor,opera-tion complexity,demand of precision auxiliary device,and measurement accuracy.The comparative experiments were carried out with three methods with high precision:phase matching calibration method with relatively high accuracy,polynomial calibration method and plane fitting calibration method,and the selection basis of calibration method was ob-tained based on the synthesis of method characteristics and experimental results:the polynomial fitting method could be selected for high-precision measurement,and the phase matching method could be selected for flexible operation,and the plane one for accuracy and flexibility.It has its application value to select the appropriate method for system calibra-tion of such technology when facing different needs.