DEVICE FOR OBSERVING AND CONTROLLING ONE OR MORE TEXTILE YARNS BY A SUCCESSION OF NUMERICAL PHOTOGRAPHS

Abstract: A detection device for one or more textile yarns includes at least one numerical electronic camera C having a field of vision SC defining a detection zone and an image processing microprocessor P.

Description: DEVICE FOR OBSERVING AND CONTROLLING ONE OR MORE TEXTILE YARNS BY A SUCCESSION OF NUMERICAL PHOTOGRAPHS The present invention allows to serve and to check, like with the human eye, one or more textile yarns in real time mode, on the basis of successions of numerical photographs taken by a camera and processed by a microprocessor By means of an internal analysis by the microprocessor comprised in the device, it allows i a to recognize the form and the colour of a yam or yarns, as well as to identify the number of yarns present or passing in front of the field of vision of the camera in the device In the prior art, devices for the detection of yarns are commonly mechanical, electrical or optical devices working with visible or infrared light These types of devices gain information about "all or nothing" (presence or absence of an object) and do not either allow the detection of several yarns at the same time at one single detection device The device according to this invention results in an automatic instrument or apparatus allowing to observe and to check in real time mode one or more yarns at the same time The device according to the invention is primarily characterized in that it comprises a numerical camera associated with an image processing microprocessor It is thereby able i a to detect the presence or absence of one or a plurality of yarns and to determine for each yarn in said plurality its movement, as well as its form, cross-section and/or colour The device according to the invention compasses at least a numerical camera of a type of CCD or CDD, an image processing microprocessor a communication microprocessor, a continuous and regulated power supply The numerical camera successively and permanently takes very high-speed photographs of the yarn or yarns present or moving in front of its field of vision. Said photographs are then processed by a microprocessor which determines in a logical way i.a. the presence of the yam or yarns, as well as various information about it or them, such as the form, cross-section, movement, if any, and colour or colours. The device according to the invention allows the observation, in real-time, of one or several yarns found in the field of vision of the numerical camera. Thanks to its microprocessor the device can store, check and follow the yarn or yarns in real-time mode. An advantage of this invention resulting from the use of a numerical camera is that this camera allows it to see, like with the human eye, what is found within its field of vision. By means of processing in the microprocessor each photograph taken by the numerical camera is transformed into a binary image. This image (N) is stored and then compared to a stored earlier image (N - 1) with respect to various information such as the number of yarns that are present, their form, thickness (yam count or titre), colour, etc. Thus, the same microprocessor can determine the number of yarns present in front of the camera and for each one of them find out the movement resp. non-movement, the speed, the form, the thickness, colour, etc. Said invention is able to determine: whether one or more yarns is or are present; whether one or more yarns move or do not move: whether one or more yarns is or are broken (or is or are missing); whether one or more yarns have defects, such as weak spots or portions, to small or too big thicknesses, undesired twists or intermingling of several yarns or yarn fibres, etc. Said invention can also determine the colour of the yarn or yams found in front of the field of vision of the camera. -> - By means of the numerical processing of the image or images the device according to the invention is able to give information about the number of yarns present in front of the camera, to find out if they move and in case they do with what speed, as well as to inform about the form of the yarn or yarns and colour or colours. Moreover, the device according to the invention is able to send out information of a detection of a fault (error). The information of a fault may be used to stop the machine for which the device is provided. In the following cases the information of the detection of a fault is given: one or more yarns is or are not present as expected in front of the numerical camera; one or more yarns does or do not move although it or they are supposed to; one or more yams does or do not move with the desired speed: one or more yarns does or do not have the right form but has or have imperfect spots or portions, e.g. so called weak spots (too small thickness), knots, too thick portions, etc.; one or more yarns has or have a colour which differs or differ from a desired colour or colours. Thanks to a communication processor the device according to the invention may transmit and receive information to resp. from one or more other information devices or systems (Fig. 4). By employing a laser as light source to emit a rectilinear beam of rays onto the numerical camera the device can measure with high precision the respective position of the yarn or yarns present between the numerical camera and the laser beam facing it. According to the invention two or more numerical cameras may be placed perpendicularly with respect to each other in order to observe the yarn or yarns in more than one dimension. The device according to the invention may also incorporate two numerical cameras as explained above, each associated with a laser emitting a rectilinear beam, the rays of which are completely parallel and directed towards the cameras. The device can recognize even very complex yarn or yarns in which the fibres of filaments e.g. are extremely high-twisted, or intermingled. Also, the device according to the invention can recognize other complex yarn or yarns in which the fibres or filaments have different colour, different thickness or comprise of different material. According to Fig. 1 of the annexed drawings, the device according to the invention is characterized by an illumination source S arranged to face a numerical camera C such that a yarn or yarns F being present in the field of vision SC are observed like with a human eye. According to Fig. 2, the numerical camera C which is illuminated by the light source S observes the yarn or yarns F. A microprocessor P comprised in the device is continuously taking successive photographs of the view seen by the camera C and stores them for further processing and comparing purposes. According to Fig. 3 the light source L may be a laser which illuminates the numerical camera C. The particular property of such a light source L is that the laser generates rectilinear rays which allow to achieve a constant, identical illumination of the entire vision surface of the numerical camera C. The yarn or yarns F which is or are present between the source L and the camera C are then observed and recognized with a very high degree of precision. This way of combining a laser and a numerical camera allows to derive the form of the yarn or yarns with very high precision but also to accurately measure the distance between them. Calculations of movements of the yarns as well as of the magnitudes of their displacements, if any, can also be determined very easily and reliably. The numerical camera continuously sees all that is found in its field of vision, the microprocessor takes an image thereof and digitizes said image into a digital or numerical photograph N at a point in time T, which the microprocessor then compares to an earlier taken and stored photograph N - 1. After complex calculations, said comparison allows to determine the number of yarns present, their movements, if any, their displacements, their speed, their quality, i.e. their form, thickness (yarn count or titre), imperfections, their colours, etc. The microprocessor is the heart or rather brain of the device which is able to recognize and analyze the yarn or yarns as well as to determine any faults or deficiencies which may occur. The microprocessor can send a stop signal to a machine served by the detection device but it can also transmit and receive information to resp. from one or several other microprocessor information units. Furthermore, it is possible to observe the photographic numerical image "at distance" by the microprocessor and the numerical camera in order to have all relevant information or parameters of this photograph in real time. The microprocessor takes several hundreds of photographs per second allowing to obtain a living sequence of the yarns on a real time basis. To summarize, the detection device according to the invention can be used to collect in real time desired or necessary information about the detected yarn or yarns, such as e.g. their presence, movement, quality, form, structure, imperfections, thickness (yarn count or titre), colour, any fault conditions, etc. The information gained by the observation in the detection device could e.g. be used in any field of yarn processing, e.g. in the weaving or knitting field, more closely for example in, upstream or downstream a yam feeding device supplying yarn to a weaving or knitting machine, e.g. in order to initiate a reaction on occurring faults, like a stop signal to the weaving or knitting machine and/or to the yarn feeding device, or to carry out an adaptive parameter setting of any devices or machines involved in the process of yarn or fabric production, and by means of the detected information to treat the yarn in an optimum way.

Claims: Claims 1. Detection device for one or more textile yarns, characterized by at least one numerical electronic camera (C) having a field of vision (SC) defining a yarn detection zone, and by an image processing microprocessor (P). 2. Device as in claim 1 , characterized in that the numerical camera (C) is a CCD or CDD type camera, preferably a high speed type of such camera. 3. Device as in claim 1 , characterized in that it includes a communication microprocessor (P), preferably for uni-directional or bi-directional communication with interrelated information units or systems. 4. Device as in claim 1 , characterized in that it is adapted to send out information representing detected yarn faults or detected out of tolerance conditions. 5. Device as in claim 1 , characterized in that at least one illumination source (L) is provided and oriented into the detection zone or towards the vision surface of the numerical camera (C). 6. Device as in claim 5, characterized in that the illumination source (L) is a laser. 7. Device as in claim 1 , characterized in that two or more numerical cameras (C) are arranged at an angle relative to one another, preferably perpendicularly to one another, in order to observe the yarn or yams in the detection zone in more than one dimension. 8. Device as in claim 1 , characterized in that the numerical camera (C) and its microprocessor (P) are arranged to continuously take and store successive photographs of the view of the detection zone. 9. Device as in claim 1 , characterized in that the microprocessor (P) is designed to take an image seen by the numerical camera (C) and to digitize said image into a photograph (N) at a point in time and to compare photograph (N) to at least one further earlier taken and stored photograph (N - 1 ) by a calculation process. 10. Device as in claim 1 , characterized in that the microprocessor (P) is designed to transfer each photograph taken by the numerical camera (C) into a binary image which is stored and compared with at least one other earlier taken and stored binary image by a pre-determined calculation process. 11. Device as in claim 1 , characterized in that the numerical camera (C) and/or microprocessor (P) is/are designed to take high speed photographs, preferably several hundreds per second, in order to create a real-time living sequence of the yarn or yarns found in the detection zone. 12. Device as in claim 10, characterized in that each taken and stored binary image is defined by its information, i.a. about the expected number of yarns, the expected form of the yarns and their look, the expected thickness (yarn count or titre), the expected colour, the expected yarn movement, the expected speed, and the like.

Inventors: MUNOZ REGIS, MUNOZ, REGIS
Applicants: MUNOZ REGIS, MUNOZ, REGIS
Application year: 2000
Main classification: B65H63
IPC codes: B65H63, G01N33, G06M1