tailieunhanh - Optimal parameters selection for 3D mechanical surface measuring equipment based on the structured light gray code

The paper proposes the selection of optimum parameters for the measurement system. Experimental results determine the optimum conditions for the system at the measuring range (w x h = 400 mm x 300 mm) to obtain the best z-resolution of mm. | Journal of Science & Technology 122 (2017) 022-027 Optimal Parameters Selection for 3D-Mechanical Surface Measuring Equipment Based on the Structured Light Gray Code Nguyen Thi Kim Cuc*, Nguyen Van Vinh, Nguyen Thanh Hung, Pham Xuan Khai Hanoi University of Science and Technology – No. 1, Dai Co Viet Str., Hai Ba Trung, Ha Noi, Viet Nam Received: June 16, 2017; Accepted: November 03, 2017 Abstract 3D reconstruction techniques of object by using the structured light are widely used in the industry and academia. This method gives some advantages like fast and accurate. The measurement precision of a certain system depends on the geometrical parameters of the system, the characteristics of the surface under test and the specification of devices. In this paper, the effect of some parameters on the resolution of the 3D surface measurement equipment based on Gray code technique, especially the position correlation between the camera and the projector is investigated. Thereby, the paper proposes the selection of optimum parameters for the measurement system. Experimental results determine the optimum conditions for the system at the measuring range (w x h = 400 mm x 300 mm) to obtain the best z-resolution of mm. Keyword: 3D measuring devices, coded patterns, structured light, computer vision. 1. Introduction 1 The binary coding method was first proposed by Posdamer and Altschuler [7] in the field of a formulation with sequential projection of n samples to encode into 2n still using binary coding. Each pattern on the final template has a unique binary code. In these techniques, only two illumination levels are commonly used, which are coded as 0 and 1. The symbol 0 corresponds to black intensity while 1 corresponds to full illuminate white. However, the pixels on the same strip have the same binary code, so that, to obtain coordinates of the measurement points it is necessary to determine the center of the fringes or boundary of the fringes on the object .