Method for measuring coal bunker material level based on laser and binocular vision and device thereof

Abstract

The invention relates to a method for measuring coal bunker material level based on laser and binocular vision and a device thereof, belonging to the field of machine vision. The device comprises two CCD cameras with the same parameters, two lenses with consistent parameters, one or a plurality of lasers, a light source, a processing element and an explosion-proof case provided with a window. A rotating mechanism is also included when one laser is used. The method includes that the laser emits variable size laser beams, so as to form a light spot on coal surface, image parallax of the light spot between the two cameras is utilized to measure material level, and an image pair is acquired by the two cameras; corrosion expansion pre-treatment is carried out on the obtained images by utilizing an improved algorithm; for the two images after being pretreated, a new rapid stereoscopic vision algorithm is utilized to calculate a depth map; depth is obtained according to the depth map, and finally high efficiency, real time and accurate coal bunker material level measurement is realized. The device has two measuring modes, namely real-time detection mode and sensor detection mode.

Description

technical field [0001] The invention is a method and device for measuring coal bunker material level based on laser and binocular vision, belonging to the field of machine vision, stereoscopic measurement and automation, and used for quickly and correctly obtaining three-dimensional position information of coal bunker material level. Background technique [0002] Coal bunker material level detection is an important measure for coal mine safety production. As coal is continuously fed into the coal bunker, the distance between the coal surface and the top of the coal bunker is getting smaller and smaller. If coal feeding is not stopped in time, it may overflow. Coal accumulation will cause coal accumulation at the head of the belt conveyor and heavy-duty start-up of the belt conveyor, which will lead to a series of major accidents; The structure of the lower mouth is damaged by the impact, on the other hand, it can ensure the safety of the workers in the lower part. At the sa...

AI Technical Summary

Problems solved by technology

[0007] 1) The contact measurement method is easy to stick to the material and damage it because the probe contacts the material, and the measurement distance of most methods is relatively small. Most of the hammer-type material level sensors are mechanical, and the entire structure including the display part is very complicated and reliable. Poor performance, prone to failure

[0008] 2) Non-contact measurement method, once the measuring head is polluted, the measurement accuracy will be greatly reduced, and this type of method generally requires the shape of the coal surface to be regular, the inner surface smooth, and the measurement blind area is large, the measurement accuracy is unstable, and when the wave propagates , the humidity in the bunker also affects the measurement accuracy, and many methods have certain requirements on the ratio of the diameter to the depth of the coal bunker

[0009] 3) The ranging method based on a single camera, due to the existence of too many blind spots in imaging and the multi-resolution of images, such as Figure 7 The 2D images of 5 different objects in the real world are the same, and the measurement error is large;

[0010] 4) The precision is low. When the spatial three-dimensional scene object is projected onto the two-dimensional image, the images of the same scene are very different under different viewpoints, and due to the poor conditions in the coal bunker, the geometric shape and physical characteristics of the coal, noise interference, etc. combined in a single image grayscale

It is difficult to obtain high-precision and depth information from images containing so many unfavorable factors, which may cause large errors

[0011] 5) The initiative is poor; due to the high depth of the coal bunker, there is a large difference in the degree of dullness and coal particles, there is no obvious consistent feature, and the initiative is poor

[0012] 6) It is not easy to deploy. It is difficult to deploy in the limited position of the underground coal bunker. The PC-based vision system is difficult and it is difficult to realize the characteristics of safe production in coal mines.

Images