相移量校准提高正交复合光三维测量的精度  

Shifted-phase calibration for improving the accuracy of orthogonal composite light 3-D measurement

作　　者：何宇航[1] 曹益平[1] 翟爱平[1] 

机构地区：[1]四川大学光电科学技术系,四川成都610065

出　　处：《光电子．激光》2011年第3期404-408,共5页Journal of Optoelectronics·Laser

基　　金：国家"863"计划资助项目(2007AA01Z333);国家重大专项资助项目(2009ZX02204-008);四川省科技攻关资助项目(2006Z01-028)

摘　　要：由于滤波过程的影响,从复合半纹像中解调出的各帧变形条纹间的相移量发生了改变,采用传统正交复合三维测量方法中的相位算法进行解相会导致较大的相位误差,提出一种对条纹间相移量进行校准以提高正交复合光三维测量精确度的标定方法。首先从参考平面的复合光栅像中解调获得各帧相移正弦条纹,通过频域滤波的方法获取条纹的基频分量,计算出各帧正弦条纹相对于第1帧正弦条纹的相移量;然后在实物测量时以此相移量对解调出的各帧变形条纹间的相移量进行校准,建立了新的三维测量的数学模型。实验数据表明,本文提出的方法有效抑制了滤波过程导致的解相误差,将系统的测量精确度提高了将近1倍。A method for improving the accuracy of orthogonal composite light 3-D measurement is presented based on the shifted-phase calibration between fringes.Due to the effect of filtering in spatial frequency domain,the shifted phase between the deformed fringes demodulated from the composite gating image is changed,which leads to large phase error if the traditional phase algorithm is used.In this paper,the phase-shifting sine fringes demodulated from the composite grating image captured on the reference plane were got,the first order spectrum of the sine fringes could be obtained by filtering in spatial frequency domain,and then the shifted-phase between the first frame of fringe and others could be calculated out.The obtained shifted-phase was used to calibrate the shifted-phase between carrier channels from different demodulated frames when an object was measured,and a new 3-D measurement model was set up.The experiments prove that the new method can effectively restrain the demodulated phase error caused by filtering,and can improve the measurement accuracy almost by one time.

关 键 词：提高精度 复合结构光 三维测量 正弦条纹 滤波 位相算法 

分 类 号：TN247[电子电信—物理电子学]