Method and monitoring system for monitoring the tension of pile yarn in a tufting machine

Abstract

A method and associated monitoring system for monitoring the tension of pile yarn (3) in a tufting machine (1) equipped with multiple tufting needles (12) that periodically take on continuous machine positions during various machine cycles, wherein the pile yarn (3) is incorporated into the fabric (7) during each machine cycle (M) by tufting needles (12) positioned at various needle positions at different distances from the fabric (7) by positioning the tufting machine (1) at the machine position in each machine cycle (M), and a measurement signal (D) which serves as an indicator of pile yarn consumption of the pile yarn (3) is measured using motion sensors (16, 17). v ) generate and machine position data (D) that serve as indicators of one or more machine positions for each machine cycle (M). m ) and machine position data (D m ) based on the measurement signal (D v A method and associated monitoring system for evaluating ) ).

Description

[Technical Field]

[0001] The present invention relates to a method for monitoring the tension of pile yarn in a tufting machine equipped with multiple tufting needles and taking periodically consecutive machine positions during various machine cycles, wherein the pile yarn is incorporated into the fabric during each machine cycle by tufting needles positioned at various needle positions at different distances from the fabric, by positioning the tufting machine at the machine position in each machine cycle, and the method includes using motion sensors to generate a measurement signal that serves as an indicator of pile yarn consumption. In addition, the present invention relates to a monitoring system for monitoring the tension of pile yarn. [Background technology]

[0002] In each machine cycle, tufting needles may or may not be inserted into the fabric (backing or base material) for the purpose of forming a pile using pile yarn. A tufting machine is equipped with multiple tufting needles, and multiple corresponding pile yarns are supplied to the tufting machine to form a tufted fabric. For this purpose, the tufting needles are usually positioned on a needle bar, which moves up and down during such a machine cycle. In this case, the tufting needles may be individually selected to follow the movement of the needle bar or not (individual needle selection), resulting in the tufting needles being inserted into the fabric or not.

[0003] During a machine cycle, a specific position of the tufting needle, resulting from the vertical movement of the needle bar at a certain distance from the fabric, is called the needle position. In one machine cycle, the tufting needle passes through all needle positions between its upper and lower positions a total of two times: once during the upward movement and once during the downward movement.

[0004] If the tufting needle is selected such that it does not follow the movement of the needle bar during the machine cycle, the needle position of this tufting needle remains unchanged during this machine cycle because it does not follow the up-and-down movement of the needle bar.

[0005] A machine cycle is a periodic sequence of machine positions.

[0006] Conventionally, the machine cycle is divided into 360 degrees and is similar to the angular position of the shaft used to drive the tufting machine. Alternatively, it is also possible to select another division between predetermined limit values.

[0007] A system and method for monitoring the tension of the pile yarn aims to enable the tufting machine to stop as quickly as possible when the tension increases and / or when the pile yarn breaks in this case. When the tension increases, it is desirable to be able to stop the tufting machine before the pile yarn breaks. In addition, the tension of the pile yarn to be monitored has a great influence on the quality of the fabric tufted using the pile yarn, such as a tufted carpet.

[0008] WO 2017 / 006226 describes a detection system and related method for monitoring the tension of pile yarn in a fiber processing machine, such as a tufting machine, using individual actuators provided respectively to supply the corresponding pile yarn. However, in the monitoring system described therein, intervention is possible only when the tension deviates after a considerable number of machine cycles have been executed. Therefore, in a tufting machine equipped with a motor for supplying different pile yarns simultaneously, the solution described in WO 2017 / 006226 cannot be used.

[0009] British Patent Application Publication No. 2113404 describes a detection system and related method for monitoring yarn tension in a textile processing machine, more specifically a tufting machine, using sensors that generate measurements that measure the tension of yarn, more specifically pile yarn. At least one signal is generated for each machine cycle. The measurements for at least one machine cycle thus determined are compared to the same reference values ​​(such as a high reference value and a low reference value), and an error signal is generated if the difference between these measurements and the reference values ​​deviates from a certain value. The error signal is usually generated only after several machine cycles.

[0010] European Patent Application Publication No. 3165490 describes a detection system and related method for monitoring thread tension in a sewing machine using a piezoelectric sensor in the form of a rectangular plate that also generates a measurement that serves as a measure of thread tension. This system may be used with a tufting machine, but in practice it is a rather laborious process. Tufting machines require a very large number of pile threads. The system is not compact, takes up considerable space, and requires various components to operate. Ultimately, the thread tension is converted into a mechanical force on an object (e.g., a cylinder), which further transmits the mechanical force to a force-receiving component, which then generates tension at the piezoelectric sensor.

[0011] Eltex, the applicant of European Patent Application Publication No. 3165490, has introduced to the market the Eltex Eye detection system, which uses a different type of piezoelectric sensor to detect movement, specifically adapted for tufting machines. In this case as well, it can only operate after a considerable number of machine cycles. In addition, sensor control is initiated only when the machine is at operating speed. Therefore, it does not detect movement while the machine is accelerating or decelerating.

[0012] U.S. Patent Application Publication No. 2020 / 0087103 describes a detection system and related method for monitoring yarn tension in a textile processing machine, such as a tufting machine, using an optical sensor that measures yarn speed. Here again, the machine stops only when the sensor indicates that there has been no yarn movement for a sufficiently long time. Here again, sensor control is initiated only when the machine is at operating speed.

[0013] In the current system, the machine does not stop every time the pile yarn comes off the tufting needle. The yarn feeding system still supplies the pile yarn at a precise speed, so the sensor located above the needle still detects the movement of the yarn. Because this pile yarn passes through the sensor, error detection is not fast enough. [Overview of the Initiative] [Problems that the invention aims to solve]

[0014] Therefore, there is a need for an improved detection system for tufting machines that can be used with different types of tufting machines and that can act more quickly when an error is detected. [Means for solving the problem]

[0015] The object of the invention is, firstly, achieved by providing a method for monitoring the tension of pile yarn in a tufting machine equipped with multiple tufting needles and taking periodically consecutive machine positions, wherein the pile yarn is incorporated into the fabric during the machine cycle by tufting needles positioned at various needle positions at different distances from the fabric, by positioning the tufting machine in the machine position in each machine cycle, and the method is, - Using a motion sensor, generate a measurement signal that serves as an indicator of pile yarn consumption, - Determine one or more machine position data points that serve as indicators of machine position for each machine cycle, - Evaluating the measurement signal based on machine position data, Includes.

[0016] The fact that the measurement signal is compared to the corresponding machine position makes it possible to analyze the behavior of yarn movement within a single machine cycle, thereby enabling faster analysis of any yarn errors. In this way, for example, it becomes possible to quickly detect whether a pile yarn has come off the tufting needle. In existing systems, the delay before a problem is detected is so long that multiple machine cycles are performed without notification.

[0017] This makes it possible to detect errors and deviations even while the tufting machine is accelerating or decelerating.

[0018] In some tufting machines, pile yarn consumption varies depending on the operating principle, and this can differ from one machine cycle to the next. The method according to the present invention now makes it possible to detect individual pile points in these tufting machines, thereby completely eliminating the absence of pile. Such detection is impossible in existing systems because there is no analysis of each machine cycle that takes into account the specific machine position associated with the generated measurement signal. As a result, abrupt changes in desired pile yarn consumption resulting from variations in individual needle selection or pile yarn supply are difficult to detect in existing systems.

[0019] The method according to the present invention also makes it possible to quickly and accurately detect yarn breakage (BED or "Broken End Detection"). BED includes not only the detection of actually broken pile yarns, but also the detection of a state in which the tension of the pile yarn is significantly low. An increase in pile yarn tension (TED or "Tight End Detection") can be detected even before yarn breakage occurs. By detecting undesirable changes in yarn tension in a timely manner, it is also possible to ensure a more uniform quality of tufted fabrics.

[0020] Depending on the type of error or deviation detected, an alarm may be triggered, or the tufting machine may be stopped.

[0021] Machine position data can be determined in various ways.

[0022] Therefore, it is possible to determine machine position data for evaluating the measurement signal quasi-continuously with limited interpolation or without interpolation. Alternatively, for example, it is possible to determine the machine position using one pulse per machine cycle, or using different discrete pulses per machine cycle, and then interpolate other machine positions based on that.

[0023] The method according to the present invention is preferably used for each individual pile yarn incorporated using a corresponding tufting needle in a tufting machine. A separate motion sensor is provided for each individual pile yarn.

[0024] When pile yarn is incorporated into a fabric according to a predetermined desired pile pattern, by a particular method according to the present invention, this pile pattern can be transferred to various components of the tufting machine that use the pile pattern at at least one fixed point in time per machine cycle in the tufting machine. In this case, the pile pattern may also be transferred to motion sensors and / or units for determining machine position data, which form, for example, part of a control unit. The machine position data can then be determined at least partially by the point in time when the pile pattern was transferred.

[0025] More specifically, based on the pile pattern of each machine cycle, it becomes possible to determine at what pile height the pile yarn will be incorporated into the fabric. Then, the measurement signal can be evaluated based on this pile height. In this way, it becomes possible to consider not only whether pile is expected during detection, but also how much pile yarn should be supplied for this purpose. The detected pile yarn consumption can be compared more accurately with the expected pile yarn consumption, thereby enabling error detection.

[0026] In tufting machines, variations in pile yarn consumption occur when producing tufted fabrics with different pile heights. Examples include the following:

[0027] - A tufting machine comprising a system having multiple pile feed rollers having different yarns and / or yarn colors, or each rotating at different and / or varying speeds to produce different (separate) pile heights, wherein the yarns and colors are visually visible or invisible in the carpet to form a pattern (design). For example, a multi-roll attachment (MRA) is known in the market.

[0028] - Tufting machines with individual pile feeders (e.g., Myriad, Infinity, iTuft individual tuft). Depending on the machine, in this case, it is possible to form unlimited pile heights from multiple piles.

[0029] Fluctuations in pile yarn consumption also occur in the following cases in particular:

[0030] - Tufting machines with individual needle selection (e.g., Colortec). In this type of machine, the tufting needle can be optionally selected to follow the movement of the needle bar. If no tufting needle is selected, only the minimum pile yarn consumption of the corresponding pile yarn remains.

[0031] - If the carpet strips are designed not to have pile.

[0032] Determining whether the pile is formed with a consistent pile yarn during a machine cycle and taking this into account when evaluating the measurement signal is possible based on the pile pattern and / or knowledge of whether the corresponding tufting needle has been selected, i.e., corresponding needle selection data.

[0033] If it is possible to selectively position the tufting needle in each machine cycle to various needle positions according to various machine positions, then needle selection data can be determined in a specific manner according to the present invention, and this data indicates whether the tufting needle was selected to be positioned to various needle positions according to various machine positions for each machine cycle. Then, the measurement signal can be evaluated based on this needle selection data.

[0034] Thread breakage (BED) detection should not produce a false error message when pile yarn consumption is minimal. Such false error messages can be minimized by taking needle selection data and / or pile pattern into consideration.

[0035] For example, as is common when manufacturing different types of artificial turf, if the pile height is fixed across the entire width of the tufting machine, the selected pile height can be determined, for example, by the speed value of the pile feed roller that supplies all the pile yarns together in the tufting machine.

[0036] In a particular embodiment of the method according to the present invention, the measurement signal in each machine cycle is evaluated based on machine position data in both a first and a second mode. If necessary, the measurement signal may be evaluated in three or more modes for each machine cycle. In this way, it is possible to detect various problems in a single machine cycle, depending on what you want to detect. This makes it possible, for example, to detect both an undesirable increase in pile yarn tension (TED) and pile yarn breakage (BED) in a single machine cycle. These detections may be performed in a specific area of ​​the machine position.

[0037] In a further embodiment of the method according to the present invention, the statistical distribution of measurement signals for each machine position is determined based on these measurement signals over multiple machine cycles.

[0038] This statistical distribution allows the needle cycle of a tufting needle with a specific pile yarn to be precisely determined by a measurement signal using a corresponding motion sensor. The probability that the motion sensor determines the yarn movement usually closely matches the typical needle movement.

[0039] This provides information about the presence of pile yarns in this motion sensor. If the measurement signal indicates no movement of pile yarns, i.e., no pile yarn consumption, it is possible to determine whether or not these pile yarns should be moving. In areas where carpet tufting is not performed, the motion sensor can be used to detect whether pile yarn consumption is suddenly occurring in undesirable locations.

[0040] In the method according to the present invention, the motion sensor can take various forms. For example, it is possible to select an optical sensor as the motion sensor, similar to U.S. Patent Application Publication No. 2020 / 0087103. Alternatively, it is possible to select a piezoelectric sensor as the motion sensor, similar to Eltex Eye, for example.

[0041] The measurement signal is generated with a specific sensor sensitivity, and consequently, the resulting measurement signal is affected by boundary conditions such as machine speed or the type of pile yarn used, yielding a relevant measurement signal. For example, in a relatively slow machine, the movement of yarn detected by the motion sensor will be less than in a relatively fast machine over the same time interval. By using different sensor sensitivities in both situations, a similar relevant measurement signal can be obtained in both cases, accurately indicating whether or not there is yarn movement. In this way, the generated measurement signal is a clear and unambiguous indicator of pile yarn consumption and can be evaluated without considering the influence of boundary conditions or ambient influences.

[0042] Sensor sensitivity is an indicator of how well a motion sensor responds to movement. Therefore, sensor sensitivity determines how suitable the measurement signal generated by the sensor is for use in indicating movement (or pile yarn consumption). The movement to be detected is the movement of the pile yarn following the known movement of the needles in the tufting machine. Consequently, adjusting sensor sensitivity is also used to obtain a measurement signal that detects the expected movement of the needles, regardless of boundary conditions and ambient influences such as vibration.

[0043] Sensor sensitivity is, consequently, a scaling factor multiplied by the raw data measured by the sensor, resulting in a measurement signal that can be evaluated without considering boundary conditions and ambient influences.

[0044] Therefore, it is preferable that the sensor sensitivity is adjustable.

[0045] More specifically, the sensor sensitivity may be configured to be automatically adjustable in this case, thereby eliminating the need to manually adjust the sensor sensitivity at all times.

[0046] In the following specific embodiments where the sensor sensitivity is adjusted, the sensor sensitivity can be adjusted either manually or automatically.

[0047] In conventional technology, sensor sensitivity may be adjustable, but this applies to either all motion sensors used in a tufting machine to monitor the tension of the pile yarns, or a group of motion sensors used in a specific area of ​​the tufting machine. In existing systems, there are too many false positives, such as when two significantly different pile yarns are incorporated into the fabric adjacent to each other, requiring detection to be supplemented by human visual inspection.

[0048] In the method according to the present invention, it is preferable that the sensor sensitivity is individually adjustable for each motion sensor, thereby increasing the reliability of the measurement signal for different types of pile yarn and under different conditions such as the presence or absence of pile formation, the needle bar position of a sliding needle bar, pile height, variable supply motor speed, variable machine speed, and acceleration or deceleration of the machine speed. Such individual adjustability is not only advantageous in the method according to the present invention, but can also provide significant advantages in known tufting machines, independently of the evaluation of the measurement signal based on machine position data.

[0049] More specifically, a statistical distribution of measurement signals at each machine position can be determined to determine the specific sensor sensitivity for the pile yarn used in the tufting machine. Over a learning cycle across various machine cycles, the sensor sensitivity can be adjusted until the specific statistical distribution closely matches the typical needle movement in the machine cycle. Typical needle movement means that little or no yarn movement is detected at TDC (top dead center - when the tufting needle is at its highest point) and BDC (bottom dead center - when the tufting needle (12) is at its lowest point), with the greatest movement occurring midway between TDC and BDC.

[0050] In this learning cycle, it is possible to (automatically) determine which sensor sensitivity is optimal for each individual pile yarn. During such a learning cycle, the sensor sensitivity can be easily adjusted individually for each pile yarn, depending on the type of yarn, and / or the machine speed, and / or the desired type of detection, such as BED or TED.

[0051] In a further specific embodiment, if, after a learning cycle, a particular statistical distribution deviates from the typical needle movement by exceeding a set upper limit or falling below a set lower limit, the particular sensor sensitivity can be adjusted as appropriate until the particular statistical distribution again closely matches the typical needle movement. Preferably, these upper and / or lower limits are determined as deviation percentages.

[0052] In the method according to the present invention, the sensor sensitivity can be configured to be adjustable based on one or more factors. Therefore, this sensor sensitivity can be configured to be adjustable based on the following: - Needle selection data, and / or - Needle bar position data determined when the tufting machine is equipped with a sliding needle bar, and / or - Pile height (a lower pile height results in higher sensitivity than a higher pile height), - A variable feed motor speed at which pile yarn is supplied within the tufting machine by a feed motor, and / or a variable feed motor speed that ensures adjustment based on pile delivery for each machine cycle. - Variable machine speeds that drive the tufting machine, and / or - Acceleration or deceleration of the machine speed by means of controlling the tufting machine, and / or -Type of pile yarn, -Type of detection.

[0053] When using a sliding needle bar, the angle of the pile yarn relative to the motion sensor differs depending on the position of the needle bar, and as a result, the sensor signal fluctuates according to the displacement of the tufting needle relative to the motion sensor. By adjusting the sensor sensitivity based on the needle bar position data, the sensor sensitivity is adjusted while taking into account the angle of the pile yarn relative to the motion sensor.

[0054] During the processing of pile yarn in each machine cycle, there are regions where there is little or no movement of pile yarn. In a further embodiment, the measurement signal in these regions can be evaluated, and an error signal may be generated if the measurement signal shows a constant pile yarn consumption during the monitoring time. In this case, it is preferable that the sensor sensitivity is also adjusted according to the region.

[0055] In this way, an increase in the tension of the pile yarn can be detected with the same precision as detecting yarn breakage. Before the pile yarn breaks, the quality of the tufted fabric has already deteriorated over a long period due to the increase in pile yarn tension. Therefore, low-quality carpets can be manufactured for a long time until the pile yarn actually breaks.

[0056] By using a piezoelectric sensor as a motion sensor, the measurement signal in this situation already provides an active signal over a wider range of machine positions. This range expands as the yarn tension increases due to increased friction of the pile yarns within the sensor. Ultimately, the motion sensor generates a signal at machine positions where movement is not expected due to the continuous friction of the pile yarns within the sensor.

[0057] Instead of generating an error signal when the measurement signal shows a constant pile yarn consumption during the monitoring time in areas where pile yarn movement is not expected, or in addition to that, an error signal may be generated when the measurement signal shows a constant pile yarn consumption during a monitoring time longer than the machine cycle. This is because movement over an area so wide that it can no longer be accommodated by repeated needle movements also indicates an undesirable increase in pile yarn tension.

[0058] If the motion sensor is an optical sensor, the detection of pile yarn movement will be reduced as a result of an undesirable increase in yarn tension. Ultimately, the motion sensor will show a significantly reduced movement in the area where movement is expected. This allows for the detection of such an undesirable increase in yarn tension (TED detection).

[0059] For the method of the present invention to be applied, it is preferable that the pile yarn consumption is measured by a motion sensor between the yarn supply device that supplies the pile yarn in the tufting machine and the tufting needle.

[0060] Alternatively, the pile yarn consumption of the pile yarn may be measured between the yarn storage system and the yarn feeding device that supplies the pile yarn from the yarn storage system within the tufting machine, but this is not preferable. At this location, fewer detections may be performed, or the accuracy of the detection may be reduced. However, due to space limitations, it is not always possible to install a motion sensor between the yarn feeding device and the tufting needle within the tufting machine. In such cases, it is still possible to perform more detections and / or more accurate detections by using the method according to the present invention, which has a motion sensor between the yarn storage system and the yarn feeding device, compared to conventional monitoring systems.

[0061] In further specific embodiments, a moving average of the measurement signal is determined over a certain number of machine cycles, and it is determined whether this moving average exceeds a first limit. An increase in the moving average is typically an indication of thread breakage. Additionally (or alternatively), it may be determined whether the moving average falls below a second limit.

[0062] In this case, the moving average may be a so-called simple moving average. Alternatively, this moving average may be, for example, a central (cumulative) moving average, a weighted moving average, or an exponential moving average.

[0063] In this case, it is preferable that this limit value be determined as a percentage deviation. Therefore, the first limit value may be, for example, a 10% deviation, in which case it is determined whether the moving average has increased by 10%. Using a percentage deviation makes it easier to consider differences such as differences in pile yarn. Alternatively, although less preferable, an absolute number may be selected as the limit value.

[0064] Preferably, this specific number of machine cycles is adjustable, and / or the limit value is also adjustable.

[0065] By comparing this moving average with the limit value, it becomes possible to identify excessively high tension conditions that carry the risk of thread breakage or quality degradation, as well as excessively low tension conditions that also carry the risk of quality degradation.

[0066] As the tension in the string increases, this moving average increases. As the tension in the string decreases, this moving average decreases.

[0067] In this way, it becomes possible to detect increases or decreases in the tension of the pile yarn with the same precision as that required to detect yarn breakage.

[0068] If the moving average exceeds the first limit and / or falls below the second limit, an alarm may be triggered and / or the tufting machine may be stopped.

[0069] If necessary, multiple limits may be set when the moving average increases, and multiple limits may be set when the moving average decreases. This makes it possible, for example, to generate an alarm when the moving average rises above the first limit, and to stop the tufting machine when it exceeds a third limit that is higher than the first limit. Similarly, it makes it possible to generate an alarm when the moving average falls below the second limit, and to stop the tufting machine when it falls below a fourth limit that is lower than the second limit.

[0070] In addition, various possible limits may be set for various possible detections.

[0071] In yet another embodiment of the method according to the present invention, the tension of one or more additional pile yarns is monitored by generating corresponding additional measurement signals using one or more corresponding additional motion sensors and evaluating these additional measurement signals based on machine position data.

[0072] In this case, it is preferable to also determine the statistical distribution of the measurement signals from multiple motion sensors. The statistical distribution of the measurement signals from multiple motion sensors provides information about the movement of the entire needle bar. Based on this information, it is possible to confirm the precise adjustment of the needle movement. In addition, information about the profile and the timing of pile yarn consumption can also be obtained.

[0073] Preferably, for each pile yarn being monitored, a moving average of the corresponding measurement signal over a specific period is determined, and preferably, it is determined whether this moving average exceeds a first limit and / or falls below a second limit.

[0074] In this case, the first and / or second limit values ​​may be optionally selected to differ for each motion sensor or for each group of motion sensors, for example, to take into account the different types of pile yarns incorporated into the same fabric. Using the deviation percentage as the limit value makes it easier to account for the differences.

[0075] Adjustments are also easy. Users can define the maximum allowable deviation percentage for all yarns, but due to the fact that deviation is a deviation percentage, the actual limit values ​​may still differ for each pile yarn.

[0076] Similarly, it is optional to set multiple limits when the moving average increases, and to set multiple limits when the moving average decreases. Likewise, necessary alarms may be generated, and / or the tufting machine may be stopped.

[0077] In addition, the object of the present invention is also achieved by providing a monitoring system for monitoring the tension of pile yarn in a tufting machine equipped with multiple tufting needles and taking periodically consecutive machine positions during various machine cycles, wherein the pile yarn is incorporated into the fabric during each machine cycle by tufting needles positioned at various needle positions at different distances from the fabric, by positioning the tufting machine at the machine position in each machine cycle, and the monitoring system comprises a motion sensor for generating a measurement signal that serves as an indicator of pile yarn consumption, a unit for determining machine position data that serves as an indicator of one or more machine positions for each machine cycle, and an evaluation system for evaluating the measurement signal based on the machine position data.

[0078] The object of the present invention is further achieved by providing a tufting machine equipped with such a monitoring system.

[0079] The present invention will be described in more detail below by a detailed description relating to some embodiments of the tufting machine, monitoring system and method according to the present invention. The sole purpose of this specification is to provide exemplary embodiments and to illustrate further advantages and details of the present invention, and therefore should not be construed as limiting the scope of application of the present invention or the patent rights defined in the claims.

[0080] Reference numbers are used in this detailed description to refer to the attached drawings. [Brief explanation of the drawing]

[0081] [Figure 1] A tufting machine according to the present invention is illustrated. [Figure 2] A monitoring system according to the present invention is illustrated. [Figure 3] The graph, spanning various machine cycles (M), illustrates how some regions where pile is formed on the fabric (7) using pile yarn (3) alternate with other regions where pile is not formed. [Figure 4]On one side, the machine position (Dm) is plotted in degrees, and on the other side, as shown in Figure 3, a time-based graph is shown in which the measured signal (Dv) in units of V represents the pile yarn consumption of the pile yarn (3) in the tufting machine (1) where the pile is formed. [Figure 5] A graph spanning various machine cycles (M) illustrates how pile is formed on the fabric (7) by the pile yarn (3), with pile yarn consumption adjusted according to the pile height achieved in the process, resulting in a variable pile yarn consumption over a more limited number of machine cycles (M). [Figure 6] On one side, the machine position (Dm) is plotted in degrees, and on the other side, as shown in Figure 5, a time-based graph is shown in which the pile yarn consumption of the pile yarn (3) in the tufting machine (1) where the pile is formed is plotted, with the measured signal (Dv) in units of V. [Figure 7] The probabilities for each machine position are shown in two graphs, where motion sensors placed between the yarn feeding device and the tufting needle determine the movement of the yarn with different sensor sensitivity settings. [Figure 8] The probability at each machine position is illustrated in a graph, and a motion sensor placed between the yarn feeding device and the tufting needle determines the movement of the yarn under various conditions. [Figure 9] The moving average of the measurement signal (Dv) at each machine position is illustrated in the graph, and the motion sensor placed between the yarn storage system and the yarn feeding device determines the movement of the yarn under various conditions. [Figure 10] Both machine position data and supply motor speed are displayed graphically based on time. [Figure 11] The movement of the tufting needle during the mechanical cycle is shown graphically based on the needle position, and two detection regions are indicated. [Figure 12] The movement of the tufting needle during the mechanical cycle is shown graphically based on the needle position, and three detection regions are indicated. [Modes for carrying out the invention]

[0082] In the tufting machine (1) shown in Figure 1, pile yarns (3) are supplied to the tufting machine (1) from a yarn storage system (creel) (2) (not shown) by a yarn supply device (4). For this purpose, the yarn supply device (4) comprises a plurality of yarn feeding modules (5) each providing an individual supply section for each pile yarn (3), for example, by providing actuator-driven drive rollers and guide rollers for each pile yarn (3). In addition, puller rolls (6) are also provided.

[0083] The pile yarn (3) is supplied to the corresponding tufting needle (12) by the yarn feeding module (5) and the puller roll (6).

[0084] The puller rolls (6) consist of a pair of rods between the yarn feeding device (4) and the tufting needle (12), through which all the pile yarns (3) pass. These puller rolls (6) are positioned to lightly touch each of the pile yarns (3) in the tufting machine (1) so that the tension of the pile yarns (3) is equal, as the pile yarns (3) are supplied from different heights and at different speeds.

[0085] The tufting needle (12) is positioned on a needle bar (14) that is movable up and down within the tufting machine (1) by one or more connecting rods (13). By moving the tufting needle (12) up and down, the corresponding pile yarn (3) is introduced into the fabric (lining or base material) (7), thereby producing a tufted fabric (8).

[0086] For this purpose, the fabric (7) is passed from the unwinders (10) under the tufting needles (12) by the fabric feed rollers (9) and rewound onto the winders (11). For this purpose, one or more fabric feed rollers (9) are designed as drive rollers, and the other fabric feed rollers (9) are designed as guide rollers.

[0087] The fabric (7) is clamped at the position of the tufting needle (12) by a pressing foot (15). Furthermore, there is a bed plate mechanism (18) which may include a gripper for forming loop piles and a knife for selectively cutting the loop piles to form cut piles.

[0088] This structure of the tufting machine (1) is known and can be constructed in various ways and in various modified forms, so it will not be described in further detail in the context of this patent application. For example, in the case of a tufting machine (1) with individual pile feeders, there is no puller roll (6).

[0089] According to the present invention, each pile yarn (3) of such a tufting machine (1) is provided with a corresponding motion sensor (16, 17). These motion sensors (16, 17) can be mounted at various positions along the moving line of the corresponding pile yarn (3). In the first illustrated position, motion sensor (16) is positioned between the yarn feeder (4) and the tufting needle (12). In the second illustrated position, motion sensor (17) is positioned between the yarn storage system (2) and the yarn feeder (4). Multiple such motion sensors (16, 17) may be mounted at each position within the same housing to facilitate group installation in the tufting machine (1). Thus, for example, a housing comprising 16 such sensors (16, 17) may be provided.

[0090] At the installation location within the tufting machine (1), a measurement signal (D) is used as an indicator of pile yarn consumption for each supplied pile yarn (3). v These motion sensors (16, 17) are provided to generate ).

[0091] For this purpose, various types of motion sensors (16, 17) may be considered, such as optical sensors similar to those described in U.S. Patent Application Publication No. 2020 / 0087103, or piezoelectric sensors similar to those used in Eltex Eye. In the specific embodiments described below, piezoelectric sensors were used. These examples can be applied to other types of motion sensors with necessary modifications.

[0092] The monitoring system (20) according to the present invention, shown in Figure 2, includes motion sensors (16, 17) for installation on a tufting machine (1) as shown in Figure 1.

[0093] A control unit (19) is provided for controlling this monitoring system (20).

[0094] This control unit (19) receives machine position data (D m It includes a unit (24) for determining these machine position data (D m ) can be determined in various ways.

[0095] Therefore, machine position data (D) for evaluating the measurement signal with limited interpolation or without interpolation. m It is possible to determine the machine position quasi-continuously. Alternatively, for example, one pulse per machine cycle (M), or various discrete pulses per machine cycle (M), can be used to determine the machine position, and other machine positions can be interpolated based on that.

[0096] In this case, machine position data (D m For example, the machine position can be indicated directly or indirectly by the point in time at which a change in a pattern, which also serves as an indicator of the corresponding machine position, is transmitted.

[0097] The evaluation system (22) uses machine position data (D m ) based on the measurement signal (D v It is established to evaluate the machine position data (D m) may be supplied to the evaluation system (22) via a separate position channel or may be integrated, for example, into the transferred fieldbus process data.

[0098] The evaluation system (22) is usually distributed over various motion sensors (16, 17), and for each motion sensor individually or for each group (for example, for each group of 2, 4, 8, 16), local parts of the evaluation system (22) for evaluating the measurement signal (D m ) based on the mechanical position data (D v ) are provided. In a housing having 16 motion sensors (16, 17), these motion sensors (16, 17) may be controlled simultaneously, for example, by a local control unit controlled by a control unit (19), or may be divided into various blocks (of 2, 4, 8, 16). In this case, the various motion sensors (16, 17) within one block may be scanned individually in each case, and the obtained measurement signal (D v ) may be compared with the values on a comparator in the local part of the evaluation system (22). In this case, the sensor sensitivity corresponding to the motion sensor (16, 17) to be scanned (and optionally also the detection area if there is a difference in sensitivity in two different detection areas of one machine cycle) may be input.

[0099] If necessary, a control unit (19) (designed, for example, as a microprocessor) may additionally be provided with a central part of the evaluation system (22) (implemented in the microprocessor), which, for example, generates an error signal (S) based on the deviation detected by the motion sensors (16, 17) during evaluation, and determines whether the control unit (19) should generate an alarm based on such an error signal (S), which alarm to generate, or whether the tufting machine (1) may be stopped, or when the control unit (19) performs a comparison with a pile pattern to evaluate the measurement signal (D v ) and so on. Or the measurement signal (D vThe data is then loaded into the control unit (19), and the evaluation system (22) can completely form a part of the control unit (19).

[0100] By distributing the evaluation system (22) across the local components of one or more motion sensors (16, 17), the measurement signal (D v Since there is no need to transfer the measurement signal (D) itself to the control unit (19), the information that needs to be exchanged between these motion sensors (16, 17) and the control unit (19) (microprocessor) is limited. v When the measurement signal (D) is transferred to the control unit (19), it becomes possible to perform a more complex evaluation in the central part of the evaluation system (22), or / or the measurement signal (D) is transferred to the control unit (19). v Further statistical processing of the data over a longer period, and / or measurement signals (D) from various motion sensors (16, 17) v This allows for further statistical analysis by comparing the data with each other.

[0101] Each of the motion sensors (16, 17) is assigned a separate identification signal, which is transmitted along with the information transmitted from these motion sensors (16, 17), making it possible to record where an error occurred.

[0102] The monitoring system (20) further determines a limit value and / or a specific period over which the moving average should be determined, and / or the measurement signal (D v The system includes an adjustment unit (21) (e.g., a touchscreen) for adjusting the sensor sensitivity for generating the signal, and / or the type of pile yarn, and / or the type of detection, etc.

[0103] In addition, the monitoring system (20) may include a reading unit (23) for reading data from the tufting machine (1), such as pile pattern and / or machine speed and / or needle bar position data that drives the tufting machine (1). Optionally, a conventional fieldbus or a separate position channel may be used to read the data. Optionally, but less preferably, the data may be transmitted wirelessly.

[0104] The adjustment unit (21) and / or reading unit (23) may form part of the control unit (19), for example, as shown in Figure 2.

[0105] In this case, the control unit (19) of the monitoring system (20) may be integrated into the existing control unit of the tufting machine (1) which is additionally configured to control the monitoring system (20) in both a completely new tufting machine (1) according to the present invention and any existing tufting machine (1) which has been modified to become a tufting machine (1) according to the present invention. Motion sensors (16, 17) are installed in such a tufting machine (1), and the control unit of the tufting machine (1) is connected to these motion sensors (16, 17) to control them and to read the signals generated by the motion sensors (16, 17).

[0106] Alternatively, the control unit (19) can be configured as a component of the monitoring system (20) according to the present invention, completely separate from the existing control unit of the tufting machine (1). This allows the monitoring system (20) according to the present invention to be provided as a separate unit, and as a result, the existing tufting machine (1) can be easily upgraded. In that case, for example, the control unit (19) of the monitoring system (20) can be connected to a control unit already present in the existing tufting machine (1), and data can be read using a reading unit (23), for example, the sensor sensitivity can be adjusted based on that data, or an alarm can be transmitted to stop the tufting machine (1) based on that data. Subsequently, motion sensors (16, 17) are installed in the tufting machine (1), and the control unit (19) of the monitoring system (20) is optionally connected to the control unit of the tufting machine (1).

[0107] Figures 3 to 6 show the measured signal (D v This diagram illustrates how the evaluation system (22) can take into account predictable movements based on the pile pattern when evaluating the pile pattern.

[0108] The TDC (Top Dead Center) in Figures 3 and 5 always indicates the point in time when the tufting needle (12) is at its highest point, and in this case, it is used as the reference for time (T). This point TDC is used to determine the machine position data (D) depending on when the pile pattern is transferred. m ) may be determined as such.

[0109] Figure 3 illustrates how, in a fabric (7) in which several regions where pile is continuously formed using pile yarn (3) alternate with other regions where pile is not formed, pile yarn consumption may be detected during various machine cycles (M), while pile yarn consumption should not be detected during various machine cycles (M).

[0110] This is illustrated in Figure 5 using a fabric (7) in which pile is formed with a variable pile yarn consumption over a limited number of machine cycles (M), with the pile yarn consumption adjusted according to the pile height generated in the process. Based on the pile pattern, it is possible to determine both the fixed time points per machine cycle (M) in which pile may be formed, and which pile heights and associated corresponding pile yarn consumptions can be expected. Similarly, if the tufting needles (12) for each machine cycle are selectively chosen to be positioned at various needle positions according to various machine positions, then for each machine cycle (M), needle selection data can be determined indicating whether the tufting needles (12) were selected to be positioned at various needle positions as a result of various machine positions. In this way, it is possible to determine where and which pile yarn consumptions can be expected. In this case, for example, the corresponding measurement signal (D v The detection zone (DZ) in which the ) is evaluated can be intentionally determined.

[0111] Figures 4 and 6 show, on the one hand, the actual machine position (D) based on time (T). m ) is shown in degrees, and on the other hand, as shown in Figures 3 and 5 respectively, the pile yarn consumption of the pile yarn (3) in the tufting machine (1) where the pile is formed is shown as the actual measurement signal (D v ) indicates the machine position (D m ) can vary between 0° and 360° in this case. The resulting graph is zigzag-shaped. Measurement signal (D v The movement is measured by a piezoelectric sensor (16) positioned between the yarn feeder (4) and the tufting needle (12), which in this case produces a measurement of 0 or a measurement of 1, where 0 indicates that no movement was detected and 1 indicates that movement was detected. The resulting graph is a square wave.

[0112] Machine position (D m Based on this, for example, TDC or DZ, the measurement signal (D v ) can be used to determine one or more machine positions or machine position regions for evaluation.

[0113] In this case, whether there is pile yarn consumption in places where pile yarn consumption is not expected, and / or these measurement signals (D v A comparison is made to see how much the pile yarn consumption indicated by ) deviates from the pile yarn consumption that can be expected based on the pile pattern. Depending on the type of error or deviation detected, an alarm may be issued or the tufting machine (1) may be stopped. Based on the pile yarn consumption expected based on the pile pattern, a measurement signal (D) that serves as an indicator of the actual pile yarn consumption is used. v By evaluating this, for example, it is possible to prevent the output of an incorrect error message indicating yarn breakage when pile yarn consumption is minimal.

[0114] Figure 7 shows the machine position in degrees (D m Based on this, the averaged probability (D) across various machine cycles s The values ​​(from 0 to 1) are shown in two graphs, where a motion sensor (16) installed between the yarn feeding device (4) and the tufting needle (12) determines the movement of the yarn.

[0115] With properly calibrated sensor sensitivity, this distribution results in the typical reciprocating motion of the needle of a tufting machine (1), as seen in the lower of the two graphs.

[0116] If the sensor sensitivity is too high, movement will be detected even when the needle is stationary in the machine. If the sensitivity is too low, the probability of detecting movement at high needle speeds will be too low (e.g., less than 0.8). If the sensitivity is too high, such a piezoelectric sensor may miss pile thread shedding, and if the sensitivity is too low, the piezoelectric sensor may report false thread breakage.

[0117] To properly adjust the sensor sensitivity, a learning cycle may be completed. In this case, the first sensor sensitivity may be set first, and the sensor signals in a particular pile delivery are cumulatively arranged in a line over multiple machine cycles for each machine position. Although needle movement cannot be observed within a machine cycle, when a sufficient number of machine cycles are averaged, the distribution approaches needle movement. In this way, the measured signal (D) at each machine position v The statistical distribution of ) is determined over multiple machine cycles, as can be seen in the graph above.

[0118] If this statistical distribution, as shown in the graph above, still deviates significantly from the typical needle movement, this procedure is repeated. As in the graph below, this determined statistical distribution (D s The sensor sensitivity is adjusted until the movement of the needle closely matches the typical movement of the needle, and the corresponding statistical distribution (D s ) will be decided.

[0119] After the learning cycle, the statistical distribution (D s It is possible to further evaluate how closely the movement of the needle remains in agreement with a typical statistical distribution (D s If the movement of the needle deviates above the upper limit set from the typical needle movement, or below the lower limit set from the typical needle movement, a specific statistical distribution (D s The sensitivity of a particular sensor can be adjusted as needed until it again closely matches the typical movement of the needle.

[0120] Alternatively or additionally, the sensor sensitivity may be adjusted in an alternative learning cycle to optimize it to target a specific detection rate value for motion.

[0121] In this case, it is preferable that this specific target detection rate value is adjustable.

[0122] The detection rate value is the percentage of measurement signals indicating movement.

[0123] The purpose is to ensure that the motion sensors (16, 17) detect the movement of the yarn and do not mistakenly detect movement of anything other than the yarn. Based on the physical knowledge of the tufting process in which the pile yarn (3) is incorporated into the fabric (7), it is known how long the pile yarn (3) moves during each machine cycle (M). In every machine cycle (M), there is always a region where movement occurs and where it must be detected, and there is a region where no movement occurs and where it should naturally not be detected. Based on this, the measurement signal (D v It is also possible to determine what percentage of the detection rate should indicate movement (constant thread consumption). This percentage is preferably selected as a specific detection rate value to aim for in the learning cycle. This could be, for example, 30%. If, at the set sensor sensitivity, the detection rate value deviates significantly from this specific detection rate value—for example, if the specific detection rate value is adjusted to 30% but it is between 70% and 80%—it is clear that the sensor sensitivity is not properly adjusted. The sensor sensitivity in alternative learning cycles is then adjusted until the detected detection rate value matches the specific detection rate value.

[0124] Such sensor sensitivity can thus be determined based on the type of tufting machine (1) and / or desired detection, on various types of pile yarn (3) and / or various types of detection, and / or various pile feeds and / or pile heights, and / or needle selection data, etc. Several specific examples are described in more detail below. Further sensor sensitivity may be determined, for example, by interpolation and / or calculated more precisely using a self-learning system.

[0125] The sensor sensitivity is preferably configured to be adjustable, and preferably adjustable individually for each motion sensor (16, 17).

[0126] The sensor sensitivity may be configured to be automatically adjustable based on desired detections, such as TED detection or BED detection. In addition, this makes it possible to determine, for example, where in the mechanical cycle (M) each of these detections can be optimally performed based on known needle movement. Thus, the mechanical cycle (M) can also be divided into different detection regions in which different detections can be performed in each case, as shown in Figure 11, where thread breakage (BED) is detected in region A and an undesirable tension increase (TED) is detected in region B. In addition, the sensor sensitivity can be adjusted in either case to be as optimal as possible for these different detection regions. Thus, the measured signal (D v ) is machine position data (D m Based on this, each machine cycle (M) can be evaluated using both the first and second methods.

[0127] The learning cycle for determining the optimal sensor sensitivity, and the resulting individual adjustability of this sensor sensitivity, not only allows for the optimization of sensor sensitivity for each individual pile yarn, but also...

[0128] The determination of the needle cycle in the motion sensors (16, 17) also provides information about the presence of pile yarn (3) in each motion sensor (16, 17), as shown in Figures 8-9. In this way, the wiring of these motion sensors (16, 17) can also be detected.

[0129] Figure 8 shows the machine position in degrees (D m Regarding the probability (D s The values ​​shown are between 0 and 1 in a graph, where a motion sensor (16) positioned between the yarn feeding device (4) and the tufting needle (12) detects the movement of the yarn under various conditions.

[0130] In this case, the curve below represents the probability (D) when the thread is not threaded through the tufting needle (12). sThe curve in the middle shows the probability (D) that the thread is correctly threaded through the tufting needle (12). s The curve above shows the probability (D) of an error condition occurring. s ) indicates.

[0131] In this way, graphs can be generated for various values ​​of the sensor sensitivity of the motion sensor (16). In this case, the probability (D) at this sensor sensitivity that the motion sensor (16) detects the movement of the thread is s ) is plotted.

[0132] Figure 8 shows that a threshold (L) can be defined in this case, and the following relationship holds.

[0133] -If all values ​​in all the graphs calculated in this way fall below this threshold (L), the pile yarn (3) is not properly threaded through the tufting needle (12).

[0134] -If the threshold (L) is exceeded in one or more graphs, the tufting needle (12) is properly threaded.

[0135] -If the threshold (L) is exceeded in all graphs, there is an error condition, such as a malfunction of the motion sensor (16) or the pile yarn (3) being too thick for the sensor.

[0136] Figure 9 shows each machine position in degrees (D m Regarding the measurement signal (D v Moving average of (D ma The graph shows that a motion sensor (17) installed between the yarn storage system (2) and the yarn feeding device (4) detects the movement of the yarn under various conditions.

[0137] The curve below shows the measurement signal (D) when the needle (12) is not passed through. v Moving average of (D ma The curve in the middle shows the measurement signal (D) when the tufting needle (12) is properly threaded. v Moving average of (Dma The curve above shows the measurement signal (D) in the case of an error condition. v Moving average of (D ma ) indicates.

[0138] Here too, graphs can be generated for various values ​​of the sensor sensitivity of the motion sensor (16). In all cases, the measurement signal (D) is used in relation to this sensor sensitivity. v Moving average of (D ma ) is plotted.

[0139] Figure 9 shows the measured signal (D v Moving average of (D ma ), and we show that the maximum and minimum values ​​of this average across various sensor sensitivities can be calculated in this case. In this case, the following relationship holds:

[0140] -If the maximum and minimum values ​​are similar and close to 0, the pile yarn (3) is not properly threaded through the tufting needle (12).

[0141] -If the maximum and minimum values ​​deviate sufficiently, the tufting needle (12) is properly threaded.

[0142] -If the maximum and minimum values ​​are similar and close to 1, there is an error condition, such as a malfunction of the motion sensor (16) or the pile yarn (3) being too thick for the sensor.

[0143] The determination of this needle cycle for various motion sensors (16) positioned between the yarn feeder (4) and the tufting needles (12) also provides information for precise adjustment of the needle movement. Since all tufting needles (12) perform the same reciprocating motion, the measurement of the needle cycle can be enhanced in this case by combining data measured simultaneously from various tufting needles (12). For this purpose, the measurement signals (D) from multiple motion sensors (16) are used. v The statistical distribution of ) is thus generated.

[0144] In a tufting machine (1) using a sliding needle bar, the angle of the pile yarn (3) with respect to a motion sensor (16) positioned between the yarn feeder (4) and the tufting needle (12) varies depending on the position of the needle bar (14). For example, when the pile yarn (3) comes into contact with the motion sensor (16), the yarn friction at the motion sensor (16) changes based on the angle the pile yarn (3) makes with respect to the motion sensor (16). The sensor sensitivity is preferably adjusted based on needle bar position data to take into account the angle the pile yarn (3) makes with the motion sensor (16). This needle bar position data can be determined, for example, based on the pile pattern.

[0145] To adjust the sensor sensitivity of each motion sensor (16, 17) according to the pile delivery in the machine cycle (M), this sensor sensitivity is set, for example, by the feed motor speed (V) of the feed motor, which has a variable feed motor speed to supply each pile yarn (3) in the tufting machine (1). f ) can be adjusted based on the following. In this case, Figure 10 is 0 to 65535 or 2 16 Machine position (D) fluctuates in increments of -1 m In addition to the above, the yarn feeding motor speed (V) is determined based on time (T). f The changes in ) are shown in revolutions per minute, 2 16 The increment corresponds to 360°.

[0146] In existing tufting machines (1), the sensor sensitivity is optimized for the operating speed of the tufting machine (1). At other machine speeds, only a very limited number of detections are possible. By adjusting the sensor sensitivity based on the machine speed (revolutions per minute), more accurate detections at different machine speeds become possible. To adjust the sensor sensitivity based on this machine speed, the optimal sensor sensitivity for two or more machine speeds may be determined in the learning cycle described above. Then, interpolation can be used to determine the sensor sensitivity to be set for other machine speeds.

[0147] When the tufting machine (1) accelerates or decelerates, the sensor sensitivity in this case can also be adjusted based on this acceleration or deceleration of the machine speed. Thus, it is possible to detect errors as early as possible under all circumstances.

[0148] If there is an undesirable increase in the tension of the pile yarn (3), the corresponding motion sensor (16) positioned between the yarn feeding device (4) and the tufting needle (12) will indicate the machine position (D m The motion sensor (16) emits an active signal over a wider area. This area expands as the yarn tension increases due to increased friction of the pile yarns within the sensor. Ultimately, the motion sensor (16) detects the machine position (D) where movement is not expected due to the continuous friction of the pile yarns (3). m The sensor (16) emits a signal in the area where movement is not expected, thereby detecting such an undesirable increase in yarn tension (TED detection).

[0149] Therefore, for example, when processing the pile yarn (3) in each machine cycle (M), it becomes possible to determine if there is a region where the pile yarn (3) does not move. The measurement signal (D) in these regions v ) can be evaluated, and the measurement signal (D v An error signal can be generated if the system shows a certain level of pile yarn consumption during the monitoring period.

[0150] Instead of a piezoelectric sensor, an optical sensor is used, and when an undesirable increase in the tension of the pile yarn (3) occurs, a corresponding motion sensor (16) positioned between the yarn feeder (4) and the tufting needle (12) detects less movement. Ultimately, the motion sensor shows a significantly reduced movement in the area where movement is expected. As a result, such an undesirable increase in yarn tension can be detected (TED detection).

[0151] At the start of the machine cycle (M), the motion sensor (16) may be set to the same sensor sensitivity as the sensor sensitivity for detecting yarn breakage. Thus, any region where an increase in yarn tension is being monitored may be adjacent to or coincide with a region where the possibility of yarn breakage is being monitored, as can be seen in Figure 12, where region C is immediately before region A. Alternatively, a specific region may be determined at a later stage of the machine cycle (M) where only the possibility of an increase in yarn tension is being monitored. In Figure 12, this is region B. The sensor sensitivity in this specific region can then be set separately for this predetermined detection.

Claims

1. A method for monitoring the tension of pile yarn (3) in a tufting machine (1) equipped with multiple tufting needles (12) and taking periodically consecutive machine positions during various machine cycles, wherein the pile yarn (3) is incorporated into the fabric (7) during each machine cycle (M) by tufting needles (12) positioned at various needle positions at different distances from the fabric (7) by positioning the tufting machine (1) at the machine position during each machine cycle (M), and the method uses motion sensors (16, 17) to obtain a measurement signal (D) which serves as an indicator of pile yarn consumption of the pile yarn (3). ｖ This method includes generating machine position data (D) that serves as an index of one or more machine positions for each machine cycle (M). ｍ ) and the determination of the machine position data (D ｍ Based on the measurement signal (D ｖ A method characterized by including the evaluation of ).

2. The pile yarn (3) is incorporated into the fabric (7) according to the pile pattern, and this pile pattern is transferred at least one fixed time point per machine cycle (M) in the tufting machine (1), and the machine position data (D ｍ The method according to claim 1, wherein the pile pattern is at least partially determined by the time at which the pile pattern was transferred.

3. Based on the pile pattern, the pile height at which the pile yarn (3) is incorporated into the fabric (7) is determined, and the measurement signal (D ｖ The method according to claim 2, characterized in that the pile height is evaluated based on this pile height.

4. The tufting needle (12) in each machine cycle (M) can be arbitrarily selected to be positioned in various needle positions according to the various machine positions, and for each machine cycle, needle selection data is determined indicating whether the tufting needle (12) has been selected to be positioned in various needle positions according to the various machine positions, and the measurement signal (D ｖ The method according to any one of claims 1 to 3, characterized in that the needles are evaluated based on these needle selection data.

5. The measurement signal (D) in each machine cycle (M) ｖ ), in both the first mode and the second mode, is evaluated based on the machine position data (D ｍ ), a method according to any one of claims 1 to 4, characterized in that

6. Measurement signal for each machine position (D ｖ ) Statistical distribution (D ｓ These measurement signals (D) are transmitted over multiple machine cycles (M). ｖ The method according to any one of claims 1 to 5, characterized in that it is determined based on ).

7. The measurement signal (D ｖ The method according to any one of claims 1 to 6, characterized in that the above is generated by an optical sensor as the motion sensor (16, 17).

8. The measurement signal (D ｖ The method according to any one of claims 1 to 6, characterized in that the above is generated by a piezoelectric sensor as the motion sensor (16, 17).

9. The measurement signal (D ｖ The method according to any one of claims 1 to 8, characterized in that the signal is generated with a specific sensor sensitivity, and this sensor sensitivity is adjustable.

10. The tufting needle (12) in each machine cycle (M) is positioned at various machine positions according to typical needle movement, and a specific statistical distribution (D) is used to determine the specific sensor sensitivity. ｓ The method according to claims 6 and 9, wherein the sensor sensitivity is adjusted over a learning cycle across various mechanical cycles (M) until it substantially matches the movement of the typical needle.

11. After the learning cycle, the specific statistical distribution (D ｓ If the movement of the needle deviates from the typical needle movement by exceeding a first set limit or falling below a second set limit, the specific sensor sensitivity is affected by the specific statistical distribution (D ｓ The method according to claim 10, characterized in that the value is adjusted appropriately until it again substantially matches the typical movement of the needle.

12. The method according to any one of claims 4 and 9 to 11, characterized in that the sensor sensitivity is adjusted based on the needle selection data.

13. The method according to any one of claims 4 and 9 to 12, characterized in that the tufting machine (1) is equipped with a sliding needle bar (14), needle bar position data is determined, and the sensor sensitivity is adjusted based on the needle bar position data.

14. The method according to any one of claims 3 and 9 to 13, characterized in that the sensor sensitivity is adjusted based on the pile height.

15. The pile yarn (3) of the tufting machine (1) is fed by a variable yarn feeding motor speed (V ｆ The yarn is supplied by a yarn feeding motor equipped with the following: and the sensor sensitivity is determined by the speed of this yarn feeding motor (V ｆ The method according to any one of claims 3 and 9 to 14, characterized in that it is adjusted based on ).

16. The method according to any one of claims 9 to 15, characterized in that the tufting machine (1) is driven at a variable mechanical speed, and the sensor sensitivity is adjusted based on the mechanical speed.

17. The method according to claim 16, characterized in that the tufting machine (1) is controlled by accelerating or decelerating the machine speed, and the sensor sensitivity is adjusted based on the acceleration or deceleration of the machine speed.

18. During the processing of the pile yarn (3) in each machine cycle (M), there is at least one region of machine position where no pile yarn is consumed, and the measurement signal (D) in this region ｖ ) is evaluated, and the measurement signal (D ｖ The method according to any one of claims 1 to 17, characterized in that an error signal is generated when the device shows a certain amount of pile yarn consumption during the monitoring period.

19. The method according to claim 18, characterized in that the sensor sensitivity is adjusted according to the region.

20. The method according to any one of claims 1 to 19, characterized in that the pile yarn consumption of the pile yarn (3) is measured by the motion sensor (16) between the yarn supply device (4) that supplies the pile yarn (3) in the tufting machine (1) and the tufting needle (12).

21. The measurement signal (D ｖ Moving average of (D ｍａ ) is determined over a specific number of machine cycles (M), and this moving average (D ｍａ The method according to any one of claims 1 to 20, characterized in that it is determined whether the value exceeds a limit value.

22. Corresponding additional measurement signal (D ｖ ) generates machine position data (D ｍ Based on these additional measurement signals (D ｖ The method according to any one of claims 1 to 21, characterized in that the tension of one or more additional pile yarns (3) is monitored by one or more corresponding additional motion sensors (16, 17) in order to evaluate the

23. The measurement signals (D) from multiple motion sensors (16, 17) ｖ The method according to claims 6 and 22, characterized in that the statistical distribution of ) is determined.

24. A monitoring system for monitoring the tension of pile yarn (3) in a tufting machine (1) equipped with multiple tufting needles (12) that periodically take on consecutive machine positions during various machine cycles, wherein the pile yarn (3) is incorporated into the fabric (7) during each machine cycle (M) by the tufting needles (12) positioned at various needle positions at different distances from the fabric (7) by the tufting machine (1) being positioned at the machine position during each machine cycle (M), and the monitoring system provides one or more machine position data (D) that serve as indicators of the machine position for each machine cycle (M). ｍ A unit (24) for determining the pile yarn (3) and a measurement signal (D) which serves as an indicator of pile yarn consumption. ｖ Motion sensors (16, 17) for generating the machine position data (D ｍ Based on the measurement signal (D ｖ A monitoring system comprising an evaluation system (22) for evaluating ) and ).

25. A tufting machine (1) comprising the monitoring system (20) according to claim 24.

Images