Research On The Measurement Of Coal’s Dynamic Volume On The Conveyor Based On Binocular Stereo Vision

Coal volume is an important index to measure economic benefit of the coal mines, power plants and other enterprises, it is difficult to reach high precision, high efficiency and low cost requirements for the limited messuring method in the traditional statical way for the larger pile coal. To tackle this problem,this paper proposed the dynamic volume measurement based on binocular stereo vision to gauge the coal on the conveyor.Binocular stereo vision is an important branch in the computer vision field, it simulates the human’s eye’s depth perception capability of scenes, which can use two cameras to obtain three-dimensional images of the scene, then to find the corresponding points in two images. Geometric information can be obtained via the corresponding points’ 3D coordinates, which can be caculated by binocular imaging principle. Reconstruction of scenes, distance measurement, position detection can be achived by utizing those informations. Binocular stereo vision have been used more and more widely in the industry detection, robot navigation, medical imaging, machine control and detection of pose as well as in military and aviation mapping fields after years of development.Firstly, this paper establishes the pinhole camera model and non-linear camera model, which discusses the general camera calibration method and Zhang Zhengyou calibration method for pinhole camera and analyzes the method for correction of distorted image under nonlinear camera model.Secondly,binocular vision model is established under the monocular camera model,commonly used methods are summarized for calculating the 3D coordinates of binocular stereo vision, what’s more,a new optimization algorithm of calculating the 3D coordinates is given in another objective function, which employs matrix singular value decomposition(SVD) method while calculating the coordinate values, in order to avoid the matrix inversion, besides,the principle of polar geometry and three-dimensional correction is introduced. Finally, according to the characteristics of coal, two dynamic volume measurement methods of coal is given based on passive vision and active vision measuring method, the volume measurement method of active vision adopts particular structure light which shed on to the conveyor belt, and stereo matching was achieved by using the method of morphology, comparing with the coal volume dynamic measurement based on passive vision, it has obvious advantages in the measurement precision and efficiency.