提出了正弦脉宽调制和相位编码结合的一种三维形貌测量方法。这种方法离焦投影编码的两种条纹到被测对象上, 使用相移算法, 由正弦脉冲宽度调制条纹得到截断相位, 由相位编码条纹解码得到条纹级次, 从而恢复测量对象的三维形貌。实验结果证明了该方法有两个优点: (1) 轻度离焦滤除了谐波从而能降低测量误差; (2) 基于相位的编码方式能测量表面反射率不一物体。

A 3D shape measurement method combining sinusoidal pulse width modulation fringe with phase coding fringe was proposed. Two kinds of coding fringes were projected onto the object with defocus. Using a phase-shift algorithm, the wrapped phase was obtained by the sinusoidal pulse width modulation fringe, the fringe order was got by the phase coding fringe. Then, the three-dimensional shape of the measurement object can be restored. The experimental results demonstrate that the proposed method has two merits: (1) It can decrease the measurement error because of filtering the harmonics with slight defocus; (2) It can measure the different contrast object because it is based on phase code.