基于双频彩色条纹投影的相位测量去包裹方法

为了提高测量速度,提出一种基于双频彩色条纹投影的相位测量去包裹方法,只需采集一帧图像,就能实现高速测量以及动态物体轮廓测量中的相位去包裹。论述了双频相位测量和变精度去包裹原理,并详细分析影响测量精度的因素。该方法采用计算机生成一帧双频双色正弦条纹图,用液晶数字投影仪投影,并用傅里叶变换的方法对两个单色条纹图进行分析,获得高低两种精度的被测物体高度信息,从而进行变精度去包裹处理。结果表明,利用该方法提高了测量速度,可得到较高的去包裹精度,其测量最大绝对误差为 1．413～-1．582 mm,标准差为0．363 mm。

Phase-Unwrapping Method Based on Dual-Frequency Colorful Fringe Projection

A phase-unwrapping method based on dual-frequency colorful fringe projection was proposed to improve measurement speed. Only one frame image was collected to realize phase-unwrapping in high-speed measurement and dynamic object contour measurement. The dual-frequency phase measurement and the principle of unwrapping with variational precision were discussed, and then factors affecting measurement precision were analysed in detail. A dual-frequency dual-color sinusoidal fringe pattern encoded by computer was projected by a liquid crystal digital projector. And two monochroic fringe patterns were analysed by Fourier transform to obtain height information of the measured object with high and low precisions and then carry out the unwrapping with variational precision. The results showed that the measurement speed and the unwrapping precision were improved. The maximal absolute error was +1.413～-1.582 mm, and the standard deviation was 0.363 mm.