Fourier Transform Profilometry Using Linear CCD Camera

Optical3-D measurement has been widely researched in industry and scientific research with all the characteristics in high speed, no-contact and high accuracy. With the advantage of recovering the height distribution by only one fringe frame, Fourier Transform Profilometry (FTP) is very suitable for the measurement of dynamic process.Given by the limitation of fast measurement of area CCD used in traditional FTP and the high cost of high speed area CCD, Fourier Transform Profilometry using linear CCD has been studied in this paper. This method combines the advantage of high speed of sampling frequency rate of linear CCD camera and fast processing speed of FTP. With the scanning or continued sampling, the height distribution of static object and dynamic process could be obtained.The main contribution can be summarized as follows.1. An optical3-D measurement method based on FTP using linear CCD has been researched and basic principles have been explained in terms of the characteristic in imaging1-D of linear CCD camera.2. The unwrapping algorithm suitable for FTP measurement using linear CCD is developed. The results of simulation in Matlab and experiments verified this method and algorithm.3. The principles of calibration are explained in details and the calibration result is obtained by calibrating along z direction.4. A3-D measurement system for static object based on FTP using linear CCD camera is presented and applied for obtaining profiles of three objects, triangular blocks, mask and rail by scanning.5. A3-D measurement system for vibration process based on FTP using linear CCD camera is presented and applied to obtain the forced sinusoidal vibration process.The FTP using linear CCD has been verified by the experimental results that the measurement accuracy for static object is0.25mm and the deviation frequency between measured frequency and actual frequency for vibration process is0.35Hz. These research results have certain practical values to fast measurement of object surface and have broad application prospect in measurement of rail surface, vibration process and other object surface.