Cotton stream velocity on-line estimation method using video to measure speed in isomerism fibre sorting system

Abstract

The invention pertains to the industry testing technique field based on machine vision, which is characterized in that two linear array cameras with a setting distance are utilized to respectively extract images in which the cotton stream is partly superposed in the setting equal sampling period, according to cotton streams doing a speed changing rectilinear movement along the channel, and the image are divided into a plurality of cotton stream sub-graphs along a direction perpendicular to the cotton stream cross section direction; according to each sub-graph, the similarity between the sub-graph picked up by a linear array camera 1 and the linear array camera 2 with a different time delay delta t, thereby a similarity curve f(delta t) varying with delta t is obtained, and then calculating a time delay delta T corresponding to the maximum value f(delta T) of the curve f(delta t), namely the time delay of a same point on the cotton stream passing through two linear array cameras; and then based on the setting distance between the two linear array cameras, the cotton stream online speed distributed along the cotton stream transversal, under the condition that the cotton stream velocity will not abruptly change in the setting sampling time delay. the invention can be used to realize accurate sorting of isomerism fiber in the cotton stream.

Description

technical field [0001] The invention belongs to the technical field of industrial detection based on machine vision. Background technique: [0002] The so-called foreign fiber sorting mainly refers to the process of identifying and sorting foreign fibers (such as human and animal hair, polypropylene yarn, plastic, etc.) from a large amount of cotton. In the cotton spinning industry, foreign fiber sorting is a very important process. The foreign fiber sorting system based on the principle of machine vision is a main method currently used. The foreign fiber sorting system uses a high-speed camera (usually a line camera) to take online pictures of the cotton flow in the transparent channel, and sends the captured images to the computer, and uses special computer software to identify foreign fibers and determine their positions. Finally, the delay time is determined according to the cotton flow speed and the corresponding solenoid valve is driven to blow out the foreign fibers...

AI Technical Summary

Problems solved by technology

This cotton flow velocity estimation method is simple and easy to use, and is suitable for cotton flow velocity estimation when the wind speed is relatively stable. However, in actual industrial applications, the wind velocity in the pipeline is often unstable, and for different cotton varieties, it is used to estimate The empirical coefficients of cotton flow velocity are generally different, so it is difficult to obtain an accurate estimate of cotton flow velocity using traditional methods

[0003] Video speed measurement is a research hotspot in the field of "intelligent transportation" (Tong Jianjun, talk about video speed measurement, China Traffic Information Industry, 2006, No. 9, pp. 36-38). Although video traffic speed measurement has its advantages, there are some difficulties. limited practical application

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