BE1010234A3 - Recognition process of small streams in a foreign fiber fiber flakes. - Google Patents

Abstract

Method of recognizing small foreign fibers in the form of fibers in fiber flake streams. The fiber flow is examined by color detectors or cameras. The measurement results are processed by special evaluation methods so that knowledge of the length of the impurities present in the fiber stream determines their extraction.

Description

       

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  METHOD FOR RECOGNIZING SMALL FOREIGN FIBERS
IN A FLOW OF FIBER FLAKES
Methods and apparatuses are known which make it possible to recognize and extract fibrous foreign particles in fiber processing lines. A flow of fibers is led there into a well where it is examined by color detectors or cameras. If a detector or the camera's evaluation device detects a foreign particle of another color, these foreign particles are extracted. The sensitivity of monitoring systems can be changed. If you look at widely dispersed fibers, it is possible to recognize foreign bodies in the form of fibers, such as woolen threads or bands of colored synthetic material.

   However, the problem arises here that dark seed seeds, which can be removed in conventional cleaning machines, are also extracted. As a result, the fiber losses are very high.



   The object of the invention is to create an evaluation system which leaves seeds and seed hulls in the fiber stream and which extracts small foreign fibers.



   According to the invention, this is obtained by detecting the measurement values in fine grid, combined with a special evaluation of the data from the camera or the detector. The measurement points are collected there in grid units. The size of the units corresponds to the size of a seed or similar particle to be removed by a cleaning machine. If a foreign colored part is then detected by only one unit, it is kept.

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 vee. In the case of several detections of foreign particles in a measurement cycle, a special evaluation is required.



   For mathematical evaluation, the evaluation units are considered as a matrix (figure 1), in which the value one is given to the elements which indicate a detection. All other elements have the value zero. The difference between an element (i) to which the value one is applied to all the other elements (j) to which the value one is applied is determined by:
 EMI2.1
 n = number of elements of value un x, y: coordinate in the row and column of elements of value un i = l ... n; j = 1 ... n
If the distance a (i, j) is less than the distance of three neighboring units, an extraction must be carried out, because the foreign body (1) is not then a seed of seed (2). If during the analysis a greater distance is established, the extraction is not done and it is the distance a (i, j + 1) which is determined.

   This process is repeated for each element (i) and correspondingly for each measurement cycle.



   Another method of distinguishing between foreign fibers and seeds is the examination of each evaluation unit which indicates the detection of a foreign particle. If a neighboring unit also recognizes a foreign particle, the extraction is done.



   Using the two variants of the method, it is possible, despite the high accuracy of evaluation, to extract only foreign particles in the form of fibers and no seeds or seed hulls.


    

Claims (7)

Claims 1. Method for recognizing small foreign particles in the form of fibers in a stream of fiber flakes, in which seed seeds will not be taken into account, characterized in that the detection is distributed over a fine grid of optical detectors, and that an extraction is only undertaken under the control of a computer when, in accordance with the logic of the program, it is established that several neighboring points of the grid exhibit simultaneously, with respect to the standard flakes, a color anomaly which can be caused by a seed.  2. Method according to claim 1, characterized in that measurement points are collected in grid units which correspond to the size of the particles (seeds) to be kept in the fiber stream.  3. Method according to claim 1 or 2, characterized in that the detectors are arranged in the form of a matrix, so that the logic of the program detects the elongation X and the elongation Y of the foreign particles.  4. Method according to any one of claims 1 to 3, characterized in that, by mathematical routines, the length of the foreign particles is determined and therefore the nature of the impurities can be deduced.  5. Method according to any one of claims 1 to 4, characterized in that the length of the fibers is determined by means of a two-dimensional analysis by packets.  6. Method according to any one of claims 1 to 5, characterized in that the program logic deduces the length and therefore the nature of the impurities-  <Desc / Clms Page number 4>  ted by interrogating the units surrounding a unit detecting an impurity.  7. Method according to any one of claims 1 to 6, characterized in that the interrogation is carried out in a list of instructions, by AND and OR couplings.