Vision reconstruction based on planar laser with nonrestrictive installation position and posture relative to 2D reference.

Abstract

The active-vision-based reconstruction is an advanced approach to characterize the spatial object. In the active vision, the planar laser is a kind of the moderate structured light for the robustness and adaptivity in the complicated illumination environment. However, as the planar laser is determined by 3 unknown degrees of freedom, the laser sensor should be calibrated in the immovable coordinate frame of reference (CFR), or be pre-calibrated in the coordinate frame of the camera (CFC) and moved with CFC. In the study, as the main improvement, the laser plane is attached to the simple 2D reference without strict constraints of the relative installation position and posture. The laser plane is desired to be flexibly moved and registered in CFC. The calibration is modeled by the closed loop of the camera, the cylindrical object, the planar laser and the 2D reference, in which the camera is twice considered as the bridge between the cylindrical object and the 2D reference. The calibration contributes the planar laser that is determined as a constant vector in CFR. Furthermore, the reconstruction is performed by the calibrated laser plane and refined by the optimization method. The method errors of 1.263, 1.517, 1.633, and 1.803 mm are evaluated by the experiments, which indicate the flexibility of the method and applicable prospects in the spatial reconstruction field.