Method and adjustment system for adjusting the sensor sensitivity of a motion sensor for detecting the movement of pile yarn in a tufting machine

Abstract

A method and associated adjustment system (24) for adjusting the sensor sensitivity of motion sensors (16, 17) for detecting the movement of pile yarn (3) in a tufting machine (1) provided with a plurality of tufting needles (12), wherein the pile yarn (3) is incorporated into a fabric (7), the method and associated adjustment system comprising: determining current process data; providing reference data for the sensor sensitivity of motion sensors (16, 17), the reference data consisting of one or more sets, each set including a reference sensor sensitivity value and corresponding process data; determining a relationship between the current process data and the process data of the provided reference data; determining a sensor sensitivity value to be adjusted based on this relationship and one or more reference sensor sensitivity values ​​of the provided reference data; and adjusting the sensor sensitivity value to be adjusted in the motion sensors (16, 17).

Description

[Technical Field]

[0001] The present invention relates to a method for adjusting the sensor sensitivity of a motion sensor for detecting the movement of pile yarn in a tufting machine equipped with a plurality of tufting needles, wherein the pile yarn is incorporated into a fabric. The present invention also relates to a method for monitoring the tension of pile yarn in a tufting machine equipped with a plurality of tufting needles, wherein the pile yarn is incorporated into a fabric, and the method includes generating a measurement signal by the motion sensor which is an indicator of the pile consumption of the pile yarn, determining a moving average of the measurement signal over a specific period of time, and determining whether the moving average exceeds a first limit and / or falls below a second limit.

[0002] In addition, the present invention relates to an adjustment system for adjusting the sensor sensitivity of a motion sensor for detecting the movement of pile yarns in a tufting machine, and a monitoring system for monitoring the tension of pile yarns. [Background technology]

[0003] In a tufting machine, pile yarns may or may not be inserted into the fabric (backing or base material) by tufting needles during various machine cycles, for the purpose of forming a pile using the pile yarns. Such 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 machine cycles. 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.

[0004] The system and method for monitoring pile yarn tension are intended to allow the tufting machine to be stopped as quickly as possible if the tension increases and / or if the pile yarn breaks. Ideally, the tufting machine should be stopped before the pile yarn breaks if the tension increases. In addition, the tension of the pile yarn being monitored has a significant impact on the quality of tufted fabrics, such as tufted carpets.

[0005] International Publication No. 2017 / 006226 describes a detection system and related method for monitoring the tension of pile yarns in a textile processing machine, such as a tufting machine, using separate actuators provided for supplying the corresponding pile yarns. However, the monitoring system described therein only allows intervention if the tension deviates after a considerable number of machine cycles have been performed. Therefore, the solution described in International Publication No. 2017 / 006226 cannot be used in a tufting machine equipped with motors for supplying different pile yarns simultaneously.

[0006] 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.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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 the correct speed, so the sensor located in front of the tufting needle during the yarn feeding process still detects the movement of the yarn. Since this pile yarn passes through the sensor, no error is detected as a result. [Overview of the project] [Problems that the invention aims to solve]

[0011] 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]

[0012] This object of the invention is achieved, on the one hand, by providing a method for adjusting the sensor sensitivity of a motion sensor for detecting the movement of pile yarn in a tufting machine equipped with a plurality of tufting needles, the pile yarn being incorporated into a fabric, and the method comprises the following steps: a) determining current process data; b) providing reference data for the sensor sensitivity of a motion sensor, the reference data consisting of one or more sets, each set including a reference sensor sensitivity value and corresponding process data; c) determining a relationship between the current process data and the process data of the provided reference data; d) determining a sensor sensitivity value to be adjusted based on this relationship and one or more reference sensor sensitivity values ​​of the provided reference data; and e) adjusting the sensor sensitivity value to be adjusted in the motion sensor.

[0013] Since motion sensors generate measurement signals with specific sensor sensitivities, the resulting measurement signals are affected by boundary conditions such as machine speed or the type of pile yarn used, resulting in relevant measurement signals. 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, similar relevant measurement signals can be obtained in both cases, accurately indicating whether or not there is yarn movement. In this way, the generated measurement signals are clear and unambiguous indicators of pile yarn consumption and can be evaluated without considering the effects of boundary conditions and ambient effects.

[0014] The sensor sensitivity serves as an indicator of the degree to which the motion sensor responds to movement. Therefore, the 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, which serves as an indicator of the pile consumption of the pile yarn.

[0015] Consequently, the sensor sensitivity is a scale factor by which the raw data measured by the sensor is multiplied, resulting in a measurement signal that can be evaluated without considering the influence of ambient effects such as boundary conditions and vibrations.

[0016] This sensor sensitivity can be adjusted individually for each motion sensor.

[0017] In the prior art, the sensor sensitivity may be adjustable, but this applies to either all motion sensors used in a tufting machine for monitoring the tension of the pile yarn or a group of motion sensors used in a specific area of the tufting machine. In existing systems, when there are too many false detections, such as when two significantly different pile yarns are incorporated adjacent to each other in a fabric, visual inspection by a person is required to complement the detection.

[0018] In existing tufting machines, adjusting the sensor sensitivity is also a laborious process and can take a significant amount of time when starting up the tufting machine. During that procedure, important measurement signals from as many motion sensors as possible are desired.

[0019] Here, by making the sensor sensitivity adjustable individually for each motion sensor, it becomes possible to individually consider the influence of boundary conditions and ambient effects for each motion sensor. As a result, for example, it is also possible to adjust the sensor sensitivity in the case of motion sensors used to detect the movement of significantly different pile yarns.

[0020] Reference data is provided to enable easy and rapid adjustment of sensor sensitivity. By adjusting the sensor sensitivity, it becomes possible to start from the given reference data and quickly respond to changing boundary conditions and ambient effects for each motion sensor.

[0021] The reference data consists of one or more sets, each set containing the reference sensor sensitivity value and corresponding process data.

[0022] Process data includes one or more characteristic properties or characteristics in the process of incorporating pile yarn into a fabric.

[0023] By determining the relationship between the current process data and the process data of one or more sets of reference data, and by determining the value of the sensor sensitivity that should be adjusted based on the reference sensitivity of one or more sets of reference datasets based on this relationship, it becomes possible to adjust the sensor sensitivity value in the motion sensor to the most optimal setting possible.

[0024] The amount of pile yarn movement per unit time detected by the motion sensor is proportional to the machine speed of the tufting machine. When the machine speed is halved, the movement of the detected pile yarn is also halved. It is preferable that the process data includes this machine speed.

[0025] In addition, process data may also include one or more other parameters that affect the amount of movement detected by the motion sensor. Thus, these parameters may include one or more characteristic properties of the yarn, such as, among other things, the type or thickness of the yarn, the type of tufting machine, the machine acceleration (which may also include deceleration) of the tufting machine, the type of detection, or pattern information of the fabric being produced. The expressed pattern information is intended to mean not only the desired pile height of the tufted pile, but also the needle selection data of the tufting machine, the needle bar position data to account for the lateral position of the needle, and the yarn feeding speed of the yarn feeding device for the pile yarn. The measurement signal generated by the motion sensor may also be used to monitor the tension of the pile yarn. The expressed form of detection means, for example, detecting a condition in which the tension of the pile yarn is too low (BED or "Broken End Detection") or a condition in which the tension of the pile yarn is too high (TED or "Tight End Detection").

[0026] Preferably, one or more sets of reference data define the relationship between the reference sensor sensitivity value and the corresponding expressed process data using a lookup table and / or a mathematical function.

[0027] After determining the relationship between the current process data and the provided reference data, the sensor sensitivity to be set can be easily calculated by applying a mathematical function and / or by interpolation or extrapolation of the reference sensor sensitivity.

[0028] More specifically, the method further features that in step b), specific reference data is determined based on the current process data from reference data provided for the sensor sensitivity of the motion sensor. In this way, only the most relevant set of reference data can be selected, and the process data of these selected reference data are as similar as possible to the current process data. For example, it is possible to consider only reference datasets where the machine type in the process data is the same as the machine type in the current process data, or where the machine speed is close to the machine speed in the current process data. Then, in step c), a mathematical relationship is determined between the process data of the specific reference data and the current process data, thereby determining the relationship between the two. This can be done, for example, by interpolation or extrapolation. Next, in step d), the sensor sensitivity is determined by applying the mathematical relationship to the reference sensor sensitivity value of the specific reference data.

[0029] In a preferred method according to the present invention, providing reference data for the sensor sensitivity of a motion sensor in step b) includes determining a set of reference data in a learning cycle, which consists of a reference sensor sensitivity value and corresponding process data, the learning cycle comprising the following steps: determining an expected percentage detection value per unit time; setting a starting value for the sensor sensitivity of the motion sensor; detecting a movement per unit time by the motion sensor; comparing this amount with a specific expected percentage detection value per unit time; adjusting the sensor sensitivity set on the motion sensor until the detected movement per unit time matches the specific expected percentage detection value per unit time; and, when the detected movement per unit time matches the specific expected percentage detection value per unit time, adding a set of sensor sensitivity values ​​set on the motion sensor to the reference data as the reference sensor sensitivity value and current process data.

[0030] For example, based on theoretical knowledge regarding the needle cycle of a tufting needle in a tufting machine, the expected amount of pile yarn movement in one needle cycle of the tufting needle can be determined for this purpose. When selecting a tufting needle, the needle cycle is equal to the machine cycle. From the combination of the expected amount of movement for each needle cycle, the machine speed of the tufting machine (number of machine cycles per unit time), and the pattern information of the fabric being tufted (ratio of needle cycles to machine cycles), it is possible to determine the expected detection rate per unit time relative to the amount of movement detected per unit time. Then, a starting value for the sensor sensitivity can be set for the motion sensor, which can be determined, for example, from reference data.

[0031] Subsequently, the amount of movement detected by the motion sensor can be compared to this expected detection rate value per unit time. If this amount of movement does not match the expected detection rate value per unit time, i.e., if it does not fall within a specific predetermined boundary of the detection rate value, for example, 20%, 10%, or 5% of the detection rate value, the sensor sensitivity set on the motion sensor can be adjusted until the detected amount of movement matches the expected detection rate value per unit time. Then, the sensor sensitivity value set on the motion sensor can be added to the reference data as a reference sensor sensitivity value, along with the current process data.

[0032] The object of the invention is, on the one hand, achieved by providing a method for monitoring the tension of pile yarn in a tufting machine equipped with multiple tufting needles, the pile yarn being incorporated into a fabric, and the method includes: generating a measurement signal by a motion sensor which is an indicator of pile consumption of the pile yarn; determining a moving average of the measurement signal over a specific period of time; and determining whether the moving average exceeds a first limit value, wherein the motion sensor is set to a sensor sensitivity set according to a method for adjusting the sensor sensitivity of the motion sensor according to the present invention. An increase in the moving average is usually a precursor to yarn breakage. Additionally (or alternatively), it is possible to determine whether the moving average falls below a second limit value.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] As the tension in the string increases, this moving average increases. As the tension in the string decreases, this moving average decreases.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] In addition, various possible limits may be set for various possible detections.

[0041] Such a method according to the present invention for monitoring pile yarn tension in a tufting machine not only enables rapid and accurate detection of broken yarn (BED), but also, in the solution according to the present invention, the term BED encompasses not only the detection of actually broken pile yarn, but also the detection of significantly low pile yarn tension. Increased pile yarn tension (TED) can also be detected before broken yarn occurs. By detecting undesirable changes in yarn tension in a timely manner, it is also possible to ensure more consistent quality of tufted fabrics.

[0042] It is preferable that the specific time is adjustable. If necessary, multiple specific time settings may be provided for various detection possibilities. For example, a first specific time setting may be provided for BED detection and a second specific time setting may be provided for TED detection, in which case the first moving average is determined for BED detection over the first specific period and the second moving average is determined for TED detection over the second specific period.

[0043] It is preferable that one or more limit values ​​are also adjustable.

[0044] In a preferred embodiment of the method according to the present invention, a motion sensor measures the pile yarn consumption between the yarn storage system and a yarn feeding device that supplies the pile yarn from the yarn storage system in the tufting machine. At this point, the tension has already begun to gradually increase before the yarn breaks.

[0045] Alternatively, the pile consumption of the pile yarn can also be measured by motion sensors between the yarn feeding device for supplying the pile yarn within the tufting machine and the tufting needles that incorporate the pile yarn into the fabric. In this case, it is preferable that the measurement data from the motion sensors incorporated into the tufting machine at this position be further evaluated based on machine position data, which is an index of one or more machine positions for each cycle.

[0046] A machine cycle is a periodic sequence of machine positions.

[0047] Traditionally, the machine cycle has been divided into 360 degrees, similar to the angular positions of the shafts used to drive the tufting machine. Alternatively, it is possible to select a different division between predetermined limit values.

[0048] 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.

[0049] To improve or enhance the set sensor sensitivity, the sensor sensitivity may be adjusted during the learning cycle to target a specific acceptable percentage detection value of motion. For this purpose, the acceptable percentage detection value is first determined, for example, as described above. Then, the motion sensor determines the amount of movement per unit time. Subsequently, the amount of movement detected per unit time is compared with the acceptable percentage detection value per unit time.

[0050] More specifically, it is possible to verify whether the amount of detected migration per unit time matches the allowable detection rate value per unit time; that is, in this case, a check is performed to determine whether it is within a specific predetermined limit of the detection rate value, for example, 25%, 20%, 15%, 10%, or 5% of the detection rate value.

[0051] If the amount of movement detected per unit time does not match the allowable detection rate value per unit time, the sensor sensitivity set on the motion sensor can be adjusted until the amount of movement detected matches the allowable detection rate value per unit time.

[0052] If the amount of movement detected per unit time matches the allowable detection rate value per unit time, the sensor sensitivity set for the motion sensor can then be added to the reference data as a reference sensor sensitivity value, along with the current process data.

[0053] Alternatively, the target specific acceptable detection rate value can be adjusted.

[0054] This learning cycle makes it possible to (automatically) determine which sensor sensitivity is optimal for each individual pile yarn. Once such a learning cycle is completed, the sensor sensitivity can be quickly adjusted individually for each pile yarn, depending on the yarn type, and / or the machine speed, and / or the desired type of detection, such as BED or TED.

[0055] In the method according to the present invention, it is preferable that the tension of one or more additional pile yarns is similarly monitored by generating corresponding additional measurement signals using one or more corresponding additional motion sensors. Preferably, for each pile yarn being monitored, a moving average of the corresponding measurement signals 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. In this case, the first limit and / or the second limit may be selected to differ for each motion sensor or for each group of motion sensors, for example, to take into account different types of pile yarns incorporated into the same fabric, as necessary. As described above, it is also optionally possible to set multiple limits when the moving average increases and multiple limits when the moving average decreases. Similarly, necessary alarms may be generated and / or the tufting machine may be stopped.

[0056] An object of the present invention is also achieved by providing an adjustment system for adjusting the sensor sensitivity of a motion sensor for detecting the movement of pile yarn in a tufting machine equipped with a plurality of tufting needles, the pile yarn being incorporated into a fabric, the adjustment system comprising: a data unit for reading current process data; a storage unit for storing reference data relating to the sensor sensitivity of the motion sensor, the reference data consisting of one or more sets, each set including a reference sensor sensitivity value and corresponding process data; and a calculation unit for determining the relationship between the current process data and the process data of the provided reference data, and determining a sensor sensitivity value to be adjusted based on this relationship and one or more reference sensor sensitivity values ​​of the provided reference data, the adjustment system is provided for adjusting the sensor sensitivity value to be adjusted in the motion sensor.

[0057] More specifically, in this case, the adjustment system is preferably provided for adjusting the sensor sensitivity according to the method described above according to the present invention.

[0058] In addition, the object of the invention is also achieved by providing a monitoring system for monitoring the tension of pile yarn in a tufting machine, the pile yarn being incorporated into a fabric, the monitoring system comprising: a motion sensor for generating a measurement signal which is an indicator of pile consumption of the pile yarn; and an evaluation system for determining a moving average of the measurement signal over a specific period and determining whether the moving average exceeds a first limit and / or falls below a second limit, the monitoring system comprising such an adjustment system.

[0059] More specifically, the monitoring system is preferably provided in this case to monitor the tension of the pile yarn in the tufting machine in accordance with the method described above according to the present invention.

[0060] It is even more preferable that this monitoring system also includes adjustment units for adjusting specific time periods and / or limit values ​​and / or sensor sensitivity.

[0061] The object of the present invention is further achieved by providing a tufting machine equipped with an adjustment system according to the present invention. More specifically, this tufting machine may, in this case, be equipped with a monitoring system according to the present invention.

[0062] 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.

[0063] In this detailed explanation, reference numbers refer to the attached drawings. [Brief explanation of the drawing]

[0064] [Figure 1] A tufting machine according to the present invention is illustrated. [Figure 2] A monitoring system according to the present invention is illustrated. [Modes for carrying out the invention]

[0065] 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) provides a drive roller and a guide roller driven by an actuator for each pile yarn (3), and comprises, for example, a plurality of yarn feeding modules (5) with an individual supply section for each pile yarn (3). In addition, puller rolls (6) are also provided.

[0066] The pile yarn (3) is supplied to the corresponding tufting needle (12) by the yarn feeding module (5) and the puller roll (6).

[0067] 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.

[0068] 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).

[0069] 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.

[0070] 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 optionally forming cut piles.

[0071] 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).

[0072] 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.

[0073] 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 ).

[0074] 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.

[0075] 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. A control unit (19) is provided to control this monitoring system (20), and for this purpose, it includes, for example, a microprocessor.

[0076] Measurement signals (D) from each motion sensor (16, 17) v Moving average of (D ma ) is determined, and this moving average (D ma An evaluation system (22) is provided to determine whether the measurement signal (D) exceeds a first limit (or possibly exceeds one or more limits) and / or falls below a second limit (or possibly falls below one or more limits). The evaluation system (22) is typically distributed across various motion sensors (16, 17), and each motion sensor is individually or in groups (for example, groups of 2, 4, 8, and 16) and measures the measurement signal (D). v Moving average of (D ma ) is determined, and if necessary, this moving average (D maA local part of an evaluation system (22) for comparing [[ID=]] with one or more limit values is provided. In a housing having 16 motion sensors (16, 17), these motion sensors (16, 17) may be controlled simultaneously by a local control unit controlled by, for example, a control unit (19), or may be divided into various blocks (2, 4, 8, 16). In this case, the various motion sensors (16, 17) within one block may be scanned one by one in each case, and the obtained measurement signal (Dv) may be compared with the value on a comparator within the local part of the evaluation system (22). In this case, the sensor sensitivity corresponding to the motion sensors (16, 17) to be scanned (and, optionally, also corresponding to the detection area if there is a difference in sensitivity in two different detection areas of one machine cycle) may be input.

[0077] If necessary, a control unit (19) (designed as a microprocessor, for example) may additionally be provided with a central part of the evaluation system (implemented in the microprocessor), which, for example, when the control unit (19) further compares with one or more limit values based on the moving average (D ma ), or when the motion sensors (16, 17) generate different signals (S) for each exceedance of their respective limit values, and the control unit (19) determines whether an alarm should be generated based on this signal (S), which alarm should be generated, or whether the tufting machine (1) may be stopped. Or it is also possible to let the control unit (19) read the measurement signal (D v ), and the evaluation system (22) completely forms a part of the control unit (19).

[0078] By dispersing the evaluation system (22) over the local components of one or more motion sensors (16, 17), there is no need to transfer the measurement signal (D v ) itself to the control unit (19), so the information to be exchanged between these motion sensors (16, 17) and the control unit (19) (microprocessor) is limited. The measurement signal (Dv 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.

[0079] 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.

[0080] The monitoring system (20) further determines the limit value and / or moving average (D ma ) a specific period during which 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.

[0081] In addition, the monitoring system (20) may include a reading unit (23) for reading data from the tufting machine (1), such as the pile pattern and / or the machine speed at which the tufting machine (1) is driven. 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.

[0082] The adjustment unit (21) and / or reading unit (23) may form part of the control unit (19), for example, as shown in Figure 2.

[0083] 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 then 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).

[0084] Alternatively, this control unit (19) can be configured as a component of the monitoring system (20) according to the present invention, completely separated 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, this control unit (19) of the monitoring system (20) can be connected to a control unit already present in the existing tufting machine (1), for example, the machine speed (V m The control unit (19) of the monitoring system (20) may also be connected to an existing control unit already present in the existing tufting machine (1) to read other data by the reading unit (23), thereby adjusting the sensor sensitivity and / or the measurement signal (D v These data can be taken into consideration when evaluating ). Therefore, the former can take these machine position data (D m ) based on the measurement signal (D v To evaluate this, the pile pattern is read and machine position data (D m) may be configured to determine. Subsequently, motion sensors (16, 17) are installed on 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).

[0085] Measurement signal (D v ) is generated by one or more motion sensors (16, 17). The evaluation system (22) evaluates these measurement signals (D) over a specific period of time for each motion sensor (16, 17). v Moving average of (D ma ) is determined, and this moving average (D ma Determine whether ) exceeds the first limit and / or falls below the second limit.

[0086] Moving average (D ma If the number of limits increases, multiple limits may be set, and the moving average (D ma If the moving average (D) decreases, multiple limit values ​​may be set. This allows for, for example, setting a limit value for the moving average (D ma If the moving average (D) rises above a first limit, an alarm will be triggered, and if it exceeds a third limit that is higher than the first limit, the tufting machine will be stopped. Similarly, the moving average (D) ma If the value falls below a second limit, an alarm is triggered, and if it falls below a fourth limit, which is lower than the second limit, the tufting machine (1) can be stopped.

[0087] Furthermore, various possible limits may be set for various possible detections.

[0088] In this case, the limit value is adjustable by the adjustment unit (21). Any resulting alarms and / or stopping of the tufting machine (1) may also be provided via the adjustment unit (21) for adjustment.

[0089] The specific time is also adjustable by the adjustment unit (21). In this case, this specific time may be selected, for example, according to the desired detection. Thus, in BED detection, it is possible to select, for example, one machine cycle as the specific time, or several machine cycles as the specific time. More specifically, in this case, for example, about 10 machine cycles may be selected as the specific time. In TED detection, for example, a longer time or tens of cycles may be selected. More specifically, in this case, for example, about 100 machine cycles may be selected as the specific time.

[0090] At 2000 revolutions per minute, this means specific times, for example, 0.3 seconds for BED detection and 3 seconds for TED detection. At 1500 revolutions per minute, these are 0.4 seconds and 4 seconds respectively, and at 600 revolutions per minute, they are 1 second and 10 seconds respectively.

[0091] Measurement signal (D v The signal is generated at a specific sensor sensitivity. This sensor sensitivity is also adjustable by the adjustment unit (21).

[0092] 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.

[0093] To determine the value of the sensor sensitivity to be adjusted, the monitoring system (20) may include an adjustment system (24) for adjusting the sensor sensitivity of the motion sensors (16, 17). This adjustment system (24) may, for example, form part of a control unit (19).

[0094] To read process data of the tufting machine (1), such as the machine speed of the tufting machine (1), machine acceleration, characteristic properties of the pile yarn (3), type of detection, or pattern information, the adjustment system (24) is equipped with a data unit (25). In this case, a conventional fieldbus or a separate position channel may be used as needed, or, less preferably, the data may be transmitted wirelessly.

[0095] More specifically, the reading unit (21) described above may also serve as the data unit (25).

[0096] The adjustment system (24) further includes a storage unit (26) that stores reference data relating to the sensor sensitivity of the motion sensors (16, 17), the reference data consisting of one or more sets, each set containing a reference sensor sensitivity value and corresponding process data. One or more sets of reference data define the relationship between the reference sensor sensitivity value and the corresponding process data. This relationship can be represented by a lookup table or a mathematical function.

[0097] The adjustment system (24) further includes a calculation unit (27) which determines the relationship between the current process data and the process data of the reference data, and determines the value of the sensor sensitivity to be adjusted based on this relationship and the reference sensor sensitivity value of the reference data.

[0098] The calculation unit (27) either retains all reference data, or, based on the current values ​​of the process data, retains the most relevant reference data. For example, it may select only sets of reference data that have the same machine type, or sets of reference data that have machine speeds at specific intervals.

[0099] Subsequently, the calculation unit (27) can determine the mathematical relationship between the current process data and the process data of the retained reference data, and by applying this relationship to the reference sensor sensitivity of the retained reference data, it can determine the value of the sensor sensitivity that should be adjusted.

[0100] By using reference data, it becomes possible to set the sensor sensitivity as accurately as possible based on the current process data.

[0101] An additional set of reference data, consisting of reference sensor sensitivity values ​​and corresponding process data, can be determined during the learning cycle. For this purpose, the expected detection rate value is determined first.

[0102] The detection rate value is the percentage of measurement signals indicating movement (D v )

[0103] 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 in each machine cycle. In each machine cycle, 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 these should be allowed to indicate movement. This percentage is preferably selected as a specific expected detection percentage value to aim for in the learning cycle.

[0104] For motion sensors (16, 17), a starting value for the sensor sensitivity is then set, which can be determined, for example, from existing reference data.

[0105] Subsequently, the amount of movement detected by the motion sensors (16, 17) can be compared with this expected detection rate value per unit time. If this amount of movement does not match the expected detection rate value per unit time, i.e., if it is not within a specific predetermined limit of the detection rate value, for example, 20%, 10%, or 5% of the detection rate value, the sensor sensitivity set on the motion sensors (16, 17) can be adjusted until the detected amount of movement matches the expected detection rate value per unit time. Then, the sensor sensitivity value set on the motion sensors (16, 17) can be added to the reference data as a reference sensor sensitivity value, along with the current process data.

[0106] In this way, a large amount of reference data can be determined, and as a result, the reference sensor sensitivity can be used for as many different process data as possible.

[0107] To further improve or refine the set sensor sensitivity value, an additional learning cycle may be completed while monitoring the tension of the pile yarn (3). In this case, the sensor sensitivity may be adjusted while aiming for a specific allowable detection rate value of movement. The allowable detection rate value can be determined in the same way as the expected detection rate value, and the expected detection rate value and the allowable detection rate value can have different predetermined limits that they must fall within for the detected amount of movement to match. This allowable detection rate value may also be provided in the adjustment unit (21) to be adjustable.

[0108] This percentage is preferably selected as a specific detection percentage value to be targeted in the learning cycle. This may be, for example, 30% as a specific acceptable detection percentage value. If, at the set sensor sensitivity, the detected detection percentage value deviates significantly from this specific acceptable detection percentage value—for example, if the specific acceptable detection percentage value is adjusted to 30% but the detected value is between 70% and 80%—it is clear that the sensor sensitivity is not properly adjusted. The sensor sensitivity is then adjusted in the learning cycle until the detected detection percentage value matches the specific acceptable detection percentage value.

[0109] Depending on the type of tufting machine (1) and / or the desired detection, such sensor sensitivity may be determined based 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.

[0110] The sensor sensitivity is preferably configured to be adjustable, and preferably adjustable individually for each motion sensor (16, 17).

[0111] The sensor sensitivity may be configured to be automatically adjustable based on desired detections, such as TED detection or BED detection.

[0112] In existing tufting machines (1), the sensor sensitivity is optimized for the operating speed of the tufting machine (1). At other machine speeds, the sensor sensitivity is optimized for different operating speeds, resulting in less accurate measurements. By adjusting the sensor sensitivity based on the machine speed (revolutions per minute), more accurate detection at different machine speeds becomes 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.

[0113] 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.

[0114] Next, the optimally set sensor sensitivity can be added to the reference data as a reference sensor sensitivity, along with the current process data.

[0115] If the motion sensor (16) is positioned between the yarn feeder (4) and the tufting needle (12), the statistical distribution of these measurement signals can be determined for each machine position, thereby allowing the sensor sensitivity of the motion sensor (16) to be set based on the measurement signals of the motion sensor (16) over multiple machine cycles, as an alternative to an expected detection rate value or an acceptable detection rate value.

[0116] In a learning cycle spanning various mechanical cycles, the sensor sensitivity of this motion sensor (16) can then be adjusted until a particular statistical distribution substantially matches the typical up-and-down movement of a needle in a mechanical cycle, as described, for example, in Belgian Patent Application No. 2023 / 5287.

[0117] This statistical distribution allows the needle cycle of a tufting needle (12) to which a particular pile yarn (3) is placed to be specifically determined by a measurement signal using a corresponding motion sensor (16). The probability that the motion sensor (16) determines the movement of the yarn usually closely matches that of a typical needle movement. A typical needle movement means that little or no yarn movement is detected when the tufting needle (12) is at its highest point or at its lowest point, and the greatest movement is detected at the midpoint between the two points.

Claims

1. A method for adjusting the sensor sensitivity of motion sensors (16, 17) for detecting the movement of pile yarn (3) in a tufting machine (1) equipped with multiple tufting needles (12), This pile yarn (3) is incorporated into the fabric (7), This method involves the following steps: a) To determine the current process data, b) Providing reference data for the sensor sensitivity of the motion sensors (16, 17), wherein the reference data consists of one or more sets, each set including a reference sensor sensitivity value and corresponding process data. c) Determining the relationship between the current process data and the provided reference data and the process data, d) Determining the value of the sensor sensitivity to be adjusted based on this relationship and one or more values ​​of the reference sensor sensitivity of the provided reference data, e) Adjusting the value of the sensor sensitivity to be adjusted in the motion sensors (16, 17), A method characterized by including

2. The method according to claim 1, wherein the process data includes the machine speed of the tufting machine (1) for controlling the tufting machine (1).

3. The aforementioned process data has the following parameters: - Mechanical acceleration of the tufting machine (1) and - Pattern information of the fabric (7) to be manufactured, - The thickness of the pile yarn (3) and - The type of yarn of the pile yarn (3) and - The type of machine of the tufting machine (1) mentioned above, - Detection of the desired type, The method of claim 2, further comprising one or more of the following.

4. The method according to claim 2 or 3, wherein one or more sets of reference data define the relationship between the value of the reference sensor sensitivity and the corresponding expressed process data using a lookup table and / or a mathematical function.

5. - Step b) further comprises determining specific reference data from the provided reference data relating to the sensor sensitivity of the motion sensors (16, 17) based on the current process data, - In step c), the mathematical relationship between the process data and the current process data of the specific reference data is determined, thereby determining the relationship. - In step d), the sensor sensitivity is determined by applying the mathematical relationship to the value of the reference sensor sensitivity of the specific reference data. The method according to any one of claims 1 to 4.

6. In step b), providing reference data for the sensor sensitivity of the motion sensors (16, 17) includes determining a set of reference data in the learning cycle, which consists of reference sensor sensitivity values ​​and corresponding process data, the learning cycle comprising the following steps: - Determining the expected detection rate per unit time, - Setting a starting value for the sensor sensitivity of the motion sensors (16, 17), - The motion sensors (16, 17) detect the amount of movement per unit time, - This amount is compared with a specific expected detection rate value per unit time, - Adjust the sensor sensitivity set in the motion sensors (16, 17) until the detected movement amount per unit time matches a specific expected detection rate value per unit time, - When the detected movement amount per unit time matches a specific expected detection rate value per unit time, the set consisting of the sensor sensitivity values ​​set for the motion sensors (16, 17) is added to the reference data as the reference sensor sensitivity value and the current process data, The method according to any one of claims 1 to 5, including the method described in any one of claims 1 to 5.

7. A method for monitoring the tension of pile yarn (3) in a tufting machine (1) equipped with multiple tufting needles (12), wherein the pile yarn (3) is incorporated into a fabric (7), and the method is as follows: a. A measurement signal (D) which is an indicator of pile consumption of this pile yarn (3). ｖ ) is generated by motion sensors (16, 17), b. The measurement signal over a specific period (D ｖ Moving average of (D ｍａ ) to decide, c. This moving average (D ｍａ This involves determining whether ) exceeds the first limit value and / or falls below the second limit value, Includes, A method characterized in that the sensor sensitivity adjusted according to the method of any one of claims 1 to 6 is adjusted to the motion sensors (16, 17).

8. This method further, a. Determine the permissible detection rate value per unit time, b. The motion sensors (16, 17) detect the amount of movement per unit time, c. Comparing the detected displacement amount with the allowable detection ratio value, The method according to claim 7, characterized by the above.

9. The method according to claim 8, further comprising adjusting the sensor sensitivity set in the motion sensors (16, 17) until the detected movement amount per unit time matches the allowable detection rate value per unit time.

10. The method according to claim 8 or 9, further characterized in that when the detected amount of movement matches the allowable detection ratio value, the set consisting of the sensor sensitivity set for the motion sensors (16, 17) is added to the reference data as the reference sensor sensitivity and the current process data.

11. The method according to any one of claims 8 to 10, characterized in that the allowable detection rate value is adjustable.

12. The method according to any one of claims 7 to 11, characterized in that the aforementioned specific time is adjustable.

13. The method according to any one of claims 7 to 12, characterized in that the limit value is adjustable.

14. The method according to any one of claims 7 to 13, characterized in that the pile consumption of the pile yarn (3) is measured by the motion sensor (17) between the yarn storage system (2) and the yarn supply device (4) that supplies the pile yarn (3) from the yarn storage system (2) to the tufting machine (1).

15. The measurement signal (D ｖ The method according to any one of claims 7 to 14, characterized in that the motion sensor (16, 17) is generated by an optical sensor.

16. The measurement signal (D ｖ The method according to any one of claims 7 to 14, characterized in that the above is generated by a piezoelectric sensor as the motion sensor (16, 17).

17. By generating corresponding additional measurement signals (D ｖ ) with one or more corresponding additional motion sensors (16, 17), the tension of one or more additional pile yarns (3) is monitored, and for each monitored pile yarn (3), the corresponding measurement signal (D ｖ ) over a specific period is determined, and it is determined whether this moving average (D ｍａ ) exceeds a first limit value and / or falls below a second limit value, the method according to any one of claims 7 to 16, characterized in that.​

18. An adjustment system (24) for adjusting the sensor sensitivity of motion sensors (16, 17) for detecting the movement of pile yarn (3) in a tufting machine (1) equipped with multiple tufting needles (12), wherein the pile yarn (3) is incorporated into a fabric (7), and this adjustment system (24) adjusts the sensor sensitivity of motion sensors (16, 17) for detecting the movement of pile yarn (3) in a tufting machine (1) equipped with multiple tufting needles (12), wherein the pile yarn (3) is incorporated into a fabric (7), and this adjustment system (24) adjusts the sensor sensitivity of motion sensors (16, 17) for detecting the movement of pile yarn (3) in a tufting machine (1), wherein the pile yarn (3) is incorporated a. A data unit (25) for reading the current process data, b. A storage unit (26) for storing reference data relating to the sensor sensitivity of the motion sensor, wherein the reference data consists of one or more sets, each set including a reference sensor sensitivity value and corresponding process data, c. Computation unit (27), - To determine the relationship between the current process data and the provided reference data and the process data, - Based on this relationship and one or more values ​​of the reference sensor sensitivity of the provided reference data, determine the value of the sensor sensitivity to be adjusted, A computing unit (27) for performing this task, It is characterized by having, The adjustment system (24) is provided for adjusting the value of the sensor sensitivity to be adjusted in the motion sensors (16, 17).

19. The adjustment system (24) according to claim 18, characterized in that it is provided for adjusting the sensor sensitivity in accordance with the method described in any one of claims 1 to 6.

20. A monitoring system (20) for monitoring the tension of pile yarn (3) in a tufting machine (1), wherein the pile yarn (3) is incorporated into a fabric (7), and the monitoring system (20) receives a measurement signal (D) which is an indicator of pile consumption of the pile yarn (3). ｖ Motion sensors (16, 17) for generating the measurement signal (D over a specific time period) ｖ Moving average of (D ｍａ ) is determined, and this moving average (D ｍａ A monitoring system (20) comprising an evaluation system (22) for determining whether ) exceeds a first limit value and / or falls below a second limit value, wherein the monitoring system (20) comprises an adjustment system (24) as described in claim 18 or 19.

21. The monitoring system (20) according to claim 20, further comprising an adjustment unit (21) for adjusting the specific time and / or the limit value.

22. A tufting machine (1) comprising an adjustment system (24) according to claim 18 or 19, or a monitoring system (20) according to claim 20 or 21.

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