3-D Shape Measurement for Complex Reflective Surface Based on UAOM Device

Fringe projection profilometry (FPP) is widely used in the field of 3-D shape measurement with the advantages of noncontact, high speed, and nondestructive. However, measuring the complex reflective surface is a severe challenge for the FPP system. In this article, an active optimization method based on the reflection characteristics of the surface is proposed. We first design an ultrasonic atomization optimization measurement (UAOM) device. It is capable of uniformly and stably covering the measured surface with a microscopic water mist layer. The water mist layer is used to change the reflection characteristics, thereby reducing the impact of overexposure and underexposure on the measurement results. Apart from that, a bidirectional reflectance distribution function (BRDF) model and projector-object–camera radiation transfer model are established, which could be used to quantitatively describe the changes in reflection characteristics caused by the microscopic water mist layer. Comparative experimental results demonstrate that the proposed method yields improved measurements of complex reflective surfaces without the need for intricate algorithms. The final 3-D result of the points cloud based on our method is more complete and accurate, which improves the efficiency and versatility of 3-D measurement.