Camera Orientation Optimization in Stereo Vision Systems for Low Measurement Error
Xingjian Liu, Wen‐Yuan Chen, Harikrishnan Madhusudanan, Linghao Du, Yu Sun · IEEE/ASME Transactions on Mechatronics · 2020
Stereo vision (SV) is widely used for noncontact three-dimensional industrial measurement. In SV systems, camera orientation (the angles formed by the two cameras optical axes across the baseline) is among the factors that influence the measurement accuracy. Presently, there is a great divergence regarding the optimal value of camera orientation, i.e., existing theoretical analyses suggest that the optimal angle lies in 30°-50°; however, a camera orientation angle between 60°-80°is typically used in practical SV systems and commercial products. Unlike previous models that treated system parameters as uncorrelated, the proposed model introduces covariance to model the correlation between camera orientation and the accuracy of detecting corresponding points. The proposed model proves the optimal camera orientation angle lies in 60°-80°, which was verified experimentally via measurements with a circle center tracker (CCT), fringe projection profilometry (FPP), and stereo digital image correlation (DIC).