傅里叶变化轮廓术将结构光投影与傅里叶条纹分析相结合,只需一帧变形条纹就可以重建被测物体三维面形,是动态三维面形测量中的首选。选择最适用于傅里叶变换轮廓术测量系统的二值条纹编码方法,对二值化后的正弦条纹进行离焦投影,既克服了普通商用数字投影仪的刷新频率限制和非线性响应影响,又能充分利用光学成像系统的低通滤波特性获得很好的高速正弦光场。设计搭建了一套高速离焦投影条纹并同步采集的三维面形测量系统,利用该测量系统对高速旋转的散热器风扇进行测量,得到任意采样时刻风扇扇叶的三维面形信息,重建完整的风扇转动过程。能进一步分析散热器风扇扇叶在高速转动过程中的形变,为散热器风扇材料选择以及改善其性能提供可靠的测量技术方案与原始数据,有效地拓展了动态三维面形测量的应用。

Fourier transform profilometry (FTP), only one deformed fringe needed to reconstruct three-dimensional (3D) shape of a measured object, is a promising method of dynamic 3D shape measurement which combines structured light projection with Fourier analysis. In this paper, the most suitable binary fringe encoding method was chosen in FTP measuring system. The binary defocused fringe is used to create a perfect sinusoidal light field with the low-pass filter effect of the used imaging system, which can overcome the nonlinear effect and refresh frequency limitation of an ordinary commercial digital projector. A measurement system is built to synchronously acquire the deformation fringes on the surface of a high-speed rotating radiator fan, and reconstructed the 3D shape. The further deformation analysis of the measured radiator fan blade is helpful to improve the performance of the radiator, which effectively expand the application of dynamic 3D shape measurement.