Research On Dynamic Coal Weight Measurement Method Of Belt Conveyor Based On Ultrasonic Array

The dynamic detection technology of coal weight is the basis and key to energy-saving optimization such as multi-stage belt conveyor startup along coal flow and belt speed adjustment.Compared with the existing coal weight detection technology,which is greatly affected by belt conveyor vibration or underground visibility,low safety and high investment cost,a dynamic coal weight measurement of belt conveyor based on ultrasonic array which has low cost,high safety,high detection accuracy and real-time detection method is proposed.First of all,the overall design scheme of the detection system is determined based on the coal weight detection requirements of the belt conveyor for a specific belt conveyor,and the physical construction of the system is completed.The system includes a support device,an ultrasonic array device,and an electric control device.Several ultrasonic sensor array elements in the ultrasonic array device are arranged in a linear array,and each array element collects the coal height data corresponding to the detection point,and the electronic control device performs real-time processing,display,storage,and query on the coal weight data.Secondly,the corresponding dynamic coal quantity detection algorithm is proposed based on the array layout and relative dimensions of the ultrasonic array.The dynamic coal weight detection algorithm includes the coal volume algorithm,the real-time coal flow and coal total quantity algorithm,and the coal weight-band speed matching algorithm.The coal volume algorithm is the core of the whole dynamic coal weight algorithm.This paper proposes two coal volume algorithms-the sectioning method of coal cross-section and the method of tetrahedral partition.The sectioning method of coal cross-section takes the instantaneous coal cross section as the slice and takes the coal running distance within the single acquisition time of the ultrasonic sensor as the slice thickness,and divides the total amount of coal passing through the conveyor belt in unit time into coal amount micro-elements for volume calculation;the method of tetrahedral partition is to divide the coal block into several tetrahedra,build a three-dimensional point cloud,determine the coordinates of the boundary points,calculate the volume of each tetrahedron by the determinant method,and accumulate and sum to obtain irregular polyhedral coal blocks volume.Finally,the proposed coal weight detection scheme and algorithm are verified by experiments.The results show that the dynamic detection accuracy of the ultrasonic array is over 94%,which can basically realize the accurate real-time detection of dynamic coal weight and meet the coal weight detection requirements and the cost is lower.It can be used for speed regulation and energy-saving control of belt conveyors.At the same time,to a certain extent,it can meet the country’s strategic needs for coal weight data.