Fast inspection for size-based analysis in aggregate processing

Abstract

As rocks are transported along the conveyor belt of a quarry, the maximum dimension of the rocks exiting the crushers should not exceed a size threshold specific to each crusher. If the rocks are too large then they can pose a threat to equipment, and lead to a large cost in repair and loss of production. A 2D vision system is presented, which is capable of estimating the size distribution of the rocks, and also monitoring for oversize rocks. Image segmentation is performed, which is followed by a process that classifies the segments as valid or invalid using a support vector machine. A novel split algorithm is presented, which attempts to split segments that have resulted in undersegmentation. This allows the system to constantly monitor for oversize rocks without stopping the conveyor belt. For the experiments presented in this paper, a set of images was taken of rocks on a moving conveyor. In testing, it was found that 81.31 % of the segments output by the system correctly found the maximum dimension of the rock that it represented.

Image-based Method for Measuring Pellet Size Distribution in the Stable Area of Disc Pelletizer

“…[1][2][3] Optical imaging is an efficient tool for measurement of particle size because it has advantages of simple hardware configuration and abundant choice of image processing algorithms. It has been used for size measurement of various types of particles, such as granules, 4,5) rocks, 6,7) bubbles [8][9][10] and coals. 11) In processing of particle images, the main difficulty lies in segmentation of overlapping particles.…”

“…11) In processing of particle images, the main difficulty lies in segmentation of overlapping particles. The watershed transform to the gradient or edge image is popularly applied in literatures [6][7][8][9] to achieve the segmentation of overlapping particles, but it easily leads to severe over-segmentation due to large numbers of local minima/maxima on gradient image or distance transform map. 12) Over-segmentation results in many particles being measured smaller than they are.…”

Case study: Performance analysis and development of robotized screwing application with integrated vision sensing system for automotive industry

“…Research in this area becomes popular in the last 10 years mainly for robot control. Other interesting application of MV is presented in article written by Christie et al, 27 where a vision alarm system for rock crusher is presented. Bozek 28 and his colleagues proposed a new method for analytic solution of trajectory calculation for precise robot control along the advanced trajectories.…”

Evaluating Angularity of Coarse Aggregates Using the Virtual Cutting Method Based on 3D Point Cloud Images

“…Currently, in a pavement management system, the measurement of aggregate angularity is mainly based on human operation and the operators' experience, which is criticized as tedious, time-consuming, and subjective [8,9]. With the development of the machine vision technique, image analysis has been used extensively to characterize the size and shape of aggregate or gravel particles on conveyor belts in the aggregate industry [10][11][12][13][14][15][16][17][18]. However, due to harsh industrial environments in the aggregates industry, such as poor light conditions and excessive dust in the air, the 2D or 3D imaging method (camera) may not capture high-quality images (e.g., shadows from objects).…”