An improved measurement method of large hot forgings based on laser-aided multi-view stereo vision

Abstract

It is difficult to obtain high-precision thermal geometric parameters of large hot forgings online because of the harsh measurement condition, the high-temperature and large-sized targets. To solve these problems, an online measurement method for thermal geometric parameters of hot forgings based on laser-aided multi-view stereo vision is proposed in this paper. The core content of the method is to use the shapes of the lasers projected onto the surfaces of forgings to represent the geometrical characteristics of the forgings. First, an image acquisition method for high-temperature components is proposed, which can successfully reduce the effect of radiation light. Then, an improved camera calibration method of multi-view stereo vision is proposed, which can realize rapid field calibration for the multi-view stereo vision camera. Finally, an extraction method for feature information based on the laser-aided feature lines is employed, which can effectively improve the extraction efficiency. Experiments in the laboratory show that the measurement error of multi-view stereo vision system less than 0.18%. The experimental results in the workshop indicate that the proposed method is effective for measuring the geometric parameters of large hot forgings.