Title of Invention

A SYSTEM FOR DETECTION AND ELIMINATION OF FOREIGN BODIES FROM TEXTILE FIBRES

Abstract

A system for detection and removal of foreign bodies from textile fibres involving an imaging system comprising CCD camera means for obtaining images of moving fibre webs, means for analyzing the said images of the fibre web and detecting the presence of foreign materials, if any, and means for removal for detecting foreign materials from said fibre web. The system, therefore, provides for detection and removal of foreign material from textile fibres which would avoid the problems in quality and processing off yarn having such foreign bodies. Also the system would be simple to manufacture and extremely reliable and can even provide for selective removal of foreign material of only selected sizes avoiding any unwanted wastage of fibres. To The Controller of Patents The Patent Office

Full Text

The present invention relates to a system for detection and removal or roreign ouui^b from textile fibres. Usually, foreign materials are found to be present in textile fibres such as in raw cotton. Foreign material present in the raw cotton are of two types, one which consists of parts of the cotton plant namely seed coat fragments, leaf particles and other portions of the cotton plant which are likely to remain along with the cotton even after the process of harvesting cotton, and the other which consists of impurities like jute threads, cloth fragments, paper, polythene, hairs etc which get introduced during the process of harvesting or in the process of transporting the material from one place to the other. The presence of these foreign material greatly affects the quality of the yarn produced in the textile mill. During the process in a textile-mill some of these foreign material get removed but it is not possible to remove them once they are broken into small fragments in the later stages of the textile process. These foreign material ultimately shows up in the yarn and result in poor quality of the fabric. It is thus essential to remove these foreign matter from the cotton in the initial stages of the textile process where the relative size of the matter is reasonably higher. US Pat. 5692622 dated 2nd December 1997 and 5626237 dated 6th May 1997, discloses devices which are used for removal of such foreian material from textile fibres. However, such known devices suffer from many disadvantages : 1) the system is complex in construction and further complicated by the use of an array of simple colour sensors. 2) Systems are not able to move the material at a uniform speed thus resulting in frequent blow outs as a result of distortion in the images captured thereby reducing the production efficiency of the system. Moreover, the use of colour sensors in such known devices on the other hand also 1. by using colour sensors the system construction becomes bulky as many sensors are required to be placed to cover the entire width of the system. 2. It becomes difficult to precisely determine the size of the object. 3. The performance of the system deteriorates with the colour variations of the cotton and the background. 4. Calibration of the system is a rather tedious process and has to be repeated every time the material is changed. 5. The system necessitates the requirement of special lighting devises. It is thus the basic objective of the present invention to provide a system for detection and removal of foreign material from textile fibres which would avoid the aforesaid disadvantages of presently known devices. Another object of the present invention is to provide a system for detection and removal of foreign material from textile fibres which would be simple to manufacture and at the same time will be extremely reliable. Yet further object of the present invention is directed to provide for a system for detection and removal of foreign material which would provide for selective removal of foreign material of only selected sizes. Yet another object of the present invention is directed to provide for a system for detection and removal of foreign material from textile fibres which would provide for selective removal of foreign material and avoid accompanying wastage of fibres. Thus according to the present invention there is provided a system for detection and elimination of foreign bodies from textile fibres comprising : means to transport uniform fibre web at predetermined and selected uniform speed for presenting to an imaging system ; said imaging system comprising CCD camera means for obtaining images of the moving fibre web ; means for analyzing the said images of the fibre web and detecting the presence of foreign material if any ; means for removal of the detected foreign material from said fibre web. The system described herein before of the invention is a simple to operate but highly reliable in as far as effective removal of foreign material is concerned. The system uses a belt to transport the fibre flocks at a unirorm speea Dy creaung a unirorm weu of fibre flock in the process and presenting this web to an imaging system consisting of a special CCD camera which captures the images of the moving fibre flock. The images obtained are further processed to analyse and detect the presence of the foreign material. Once the system detects a foreign matter, the portion of the fibre containing the foreign material is removed from the main stream and prevented from going to the further processing stages. The system of the invention utilizes a simple but reliable transport mechanism where the textile material such as cotton material is formed into a uniform web and is positively conveyed using a conveyer belt and utilizes a CCD camera to capture images of the cotton web and processing the images in a high speed computer to detect the presence of foreign material. Further the system is able to cope up with the minor changes in the speed of the material by triggering the camera at a constant pace relative to the speed of the conveyor belt. Such a system ensures the foreign material of only the selected size is removed from the process. Another important feature of the device is that only a small portion of the material containing the foreign material is removed, this is made possible with the array of air nozzles provided and the fact that the material is transported with a positive contact with the belt there by leaving no chance for the material to move laterally, perpendicular to the movement of the belt. * * * The system of the invention is described hereunder in greater detail with reference to non-limiting exemplary embodiments with reference to the accompanying figures wherein : Fig. 1 is a schematic illustration of an embodiment of the system of the present invention. Fig. 2 is a schematic illustration of another embodiment of the present invention. Fig. 3 is a schematic illustration of yet another embodiment of the present invention. Reference is first invited to Figure 1 wherein 1 represents the Condenser unit, a standard equipment in a blow room line. The condenser unit helps in drawing the material from the previous stage, which is often a beater or a step cleaner, and drops the material into the Hood 2. The Hood consists of a pair of lattice 3 which is positively driven. The lattice helps in conveying the material at a uniform rate and to the entire width of the feed rollers 4. The system is so devised that the lattice and the feed rollers are driven by the same drive and functions only if a predetermined quantity of cotton is present in the Hood i.e. between the pair of lattice. The amount of cotton present in the hood is sensed by a sensor 16, which can a be a simple reflective sensor. The output of this sensor is used to directly control the feed motor. Further it is possible to vary the distance between the feed rollers and also its relative distance from the conveyer belt 6 so as to produce a uniform web of cotton. The cotton web so formed by the pair of feed rollers on the belt is further leveled by the leveler roller 5. This web is now presented under a CCD camera 11 which can be of type line scan or a frame scan. The web is illuminated by two pairs of flourescent tubes. The image of the web is reflected by the mirror 10 on to the camera. 7 represents the set of rollers used to move the belt at a fixed speed. The camera is interfaced to the PC 13 through a frame grabber 12. 14 represents an array of nozzles used to divert the contaminants away from the main stream. An encoder 8 is attached to one of the rollers 7 used to drive the belt. The output of the encoder is used to trigger the camera through the frame grabber. This ensures the camera is operated at a fixed speed relative to the speed of the belt. As described above the camera is triggered at a constant speed relative to the speed of the belt and since the relative distance of the camera from the ebject is fixed it is possible to calculate the horizontal and vertical resolution of the image. With this it #T'3 also possible to calculate the area represented by each pixel. Each frame of the image is first acquired by the frame grabber and then transferred to the PC memory sequentially. The image is first binarised by determining the threshold value for every individual frame. In this binarised by applying a process of blob detection the shape of the foreign matter is determined. The number of dark pixels in a blob multiplied by the area gives the size of the foreign matter. If this value is above a set limit the portion of the contaminant is removed by activating the corresponding nozzle aligned laterally along the width of the belt. Reference is now invited to Fig. 2 which shows the system as a different embodiment. In this embodiment the belt is of transparent type to help analyse the flocks of fibres m both top and ootom sides For this, another set of light sources 9 and camera 11 are provided under moving conveyor belt The system functions simitar to that as explained under embodiment 1 above The signals are analyzed suitably to exactly detect and eliminate foreign bodies. Reference is now invited to Fig, 3 which shows another embodiment of the system of the invention wherein there is provided means for analyzingflie fibre flocks on both the sides i.e. top and bottom Here, this is achieved by providing a reversal mechanism and allowing the fibres to fall on the reverse side on a separate conweyor belt where the fibres can be observed by means of an additional light source. In this arrangement the transport means provide for turning the fibre flock by 180°C and transported to another belt for repeat inspection as shown in Fig. 3. In the system of the invention the means for removal of the detected foreign material can comprise of the array of air nozzles or can be devised with different arrangements for removal of foreign materials after detection. One such arrangement causes removal by means of a mechanical arm which plucks the fibres out of the moving belt and disposes to a separate collecting apparatus or another suction mechanism. The removal mechanism can also solely comprise of a suction arrangement to arrest the detected foreign material. The'abovedisclos-d system of the invention thus provides for a simple but reliable system for removal of foreign material from fibre flock. The system is ea4sy tc5 obtain and also cost effective for varied applications in textile industry. We claim : 1. A system for detection and elimination of foreign bodies from textile fibres comprising : means to transport uniform fibre web at predetermined and selected uniform speed for presenting to an imaging system ; said imaging system comprising CCD camera means for obtaining images of the moving fibre web ; means for analyzing the said images of the fibre web and detecting the presence of foreign material if any ; means for removal of the detected foreign material from said fibre web. 2. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 1 wherein said means for transport of said fibre web comprise conveyor means. 3. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 or 2 wherein said conveyor means is horizontally travelling conveyor which is fed with said fibre material from a condenser unit. 4. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 3 wherein said fibre material is fed on to said conveyor means from said condenser unit which is positioned vertically above said conveyour means. 5. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 4 wherein said fibre material is fed onto said conveyor means from said condenser unit thought hood means. 6. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 5 wherein said hood means comprise a pair of lattices which is positively driven to maintain uniform rate and width of the feed material. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 6 wherein said fibre material is fed on to said conveyor means along said pair of lattices and through a pair of feed rollers for uniform feeding of said fibre material on said conveyor means. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 7 wherein a leveler roller is provided for uniform leveling of the feed material on said conveyor means. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 8 wherein said imaging system comprise said CCD camera, a light source for illuminating the fibre web, said CCD camera operatively linked to said means for analyzing images and detecting foreign body. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 9 wherein said means for analyzing images and detecting foreign material comprise a personal computer. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 9 wherein said camera is interfaced to said personal computer through a frame grabber where in said frame grabber comprises means for acquiring frame by frame of the said fibre web images. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 10 wherein said personal computer is adapted to acquire said images sequentially from said frame grabber. 13. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 10 to 12 wherein said personal computer comprise means for binarising the images by determining threshold value for every individual frame for analyzing images. 14. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 10 to 13 wherein said personal computer further comprise means for detecting the shape of foreign material by applying the process of blob detection on said binarised image wherein the number of dark pixels in a blob multiplied by the area provide for the size of the foreign material. 15. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 10 to 14 wherein said personal computer further comprise means for activating the said means for removal of foreign material as and when the size of the foreign material exceeds a predetermined value. 16 A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 15 wherein said CCD camera is selected to be one of type line like scan and frame scan. 17 A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 16 wherein there is provided a sensor to h continuously sense the amount of fibre i€ said hood. 18. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 17 wherein said sensor is a reflective sensor. 19. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 17 or 18 wherein said sensor is operativeiy connected to the feed motor 20. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 7 to 19 wherein the distance between said feed rollers and the relative distance between the feed rollers to said conveyor means is adapted to be varied to provide the uniform web. 21. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 20 wherein said means for removing the foreign materials from said fibre web comprise means for diverting the flow of the foreign material from said flow of fibre web thereby removing the foreign material from said fibre web. 22. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 21 wherein said means for diverting the foreign material comprise atleast one nozzle means operatively connected to pressurized air supply means 23. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 9 to 22 wherein said light source comprise tube lights. 24 A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 23 wherein said means for removal of foreign material from said fibre web comprise suction means arrangement. 25. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 23 wherein said means for removal of foreign material from said fibre web comprise mechanical arms for catching and removing the foreign material upon detection. 26 A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 25 wherein said images of said fibre web are obtained by said CCD camera means via a reflective mirror. 27. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 26 wherein said means for removal of foreign material from said fibre bed comprise array of nozzles. 28. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 27 wherein there is provided set of rollers to drive the conveyor means at desired speed. 29. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 28 wherein there is provided encoder means attached to one of said rollers, for said conveyor means, the output of said encoder being adapted to trigger the said CCD camera through the frame grabber to thereby ensure operation of the camera at a fixed speed relative to the speed of the belt. 30. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 29 wherein the light source and CCD camera of said imaging system is provided on the top of said conveyor means. 31. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 30 wherein said conveyor means is transparent. 32. A system for detection and elimination of foreign bodies from textile fibres as claimed in claim 31 wherein the light source and CCD camera of said imaging system is provided both at the top and under the said transparent conveyor means to inspect the fibre web from both sides of said transparent conveyor. 33. A system for detection and elimination of foreign bodies from textile fibres as claimed in anyone of claims 1 to 32 wherein said means to transport comprise conveyor means adapted to turn the fibre web by 180° thereby allowing the fibres to be reversed and transported on to another conveyor means for further imaging and detection. 34 A system for detection and elimination of foreign bodies from textile fibres substantially as herein described and illustrated with reference to accompanying figures.

Documents:

1016-mas-1999 abstract-granded.pdf

1016-mas-1999 claims-granded.pdf

1016-mas-1999 description (complete)-granded.pdf

1016-mas-1999 drawings-granded.pdf

1016-mas-1999-abstract.pdf

1016-mas-1999-claims.pdf

1016-mas-1999-correspondence others.pdf

1016-mas-1999-correspondence po.pdf

1016-mas-1999-description complete.pdf

1016-mas-1999-drawings.pdf

1016-mas-1999-form 1.pdf

1016-mas-1999-form 19.pdf

1016-mas-1999-form 26.pdf

1016-mas-1999-form 3.pdf