基于同心圆光栅的远心三维测量系统

针对条纹投影术对简化系统模型、降低运算量并有效抑制误差扩散等要求，提出并构造了一种基于同心圆光栅的广义远心三维测量系统。该系统利用菲涅尔透镜与投影仪产生平行光线建立线性投影模型，降低运算复杂度，利用傅里叶变换得到经物体高度调制的初始相位信息，同时结合同心圆光栅标定技术的并行运算，通过逐点计算获取真实相位。全过程只需对一个系统参数进行标定，并且摆脱解相过程，有效抑制了误差扩散。对最大高度20 mm的物体进行形貌测量，最大误差0.23 mm，相对误差仅为1.15%。

Concentric circles grating-based telecentric 3D profile measurement system

A concentric circles grating-based telecentric 3D profile measurement system was proposed to satisfy the needs for simplification of system models, removal of system constraints and increase of calculation speed. The method utilized a Fresnel lens and a projector to generate paralleled structured light so as to establish a linear projecting model and reduce the calculating complexity. Wrapped phase information was obtained by using Fourier transform method and through concentric circles grating-based calibrating method, unwrapping phase was obtained point by point at the same time. The whole process got rid of traditional phase unwrapping procedure and effectively repressed the diffusion of errors. When a tested object with 20mm maximal height was measured, the maximal error was 0.23mm and the relative error was 1.15%. The validity was verified by experiments and 3D information of an object could be obtained accurately and rapidly.