Patent Application
20220282416
The invention relates to a sensing system for monitoring the tension and breakage of yarn on a textile machine.
A number of textile improvements have sought to monitor tension and breakage in textile machines, however for the most part these monitoring devices have been mechanical. There has been some use of optical sensors, frequently in combination with mechanical members, to indicate breakage. Tension, however, is more difficult to monitor optically and has been primarily indicated through mechanical members.
The sensors most commonly used in monitoring devices are piezoelectric sensors which are less accurate and more prone to effects environmental conditions, such as humidity. Additionally, typical monitoring systems cannot measure tension without the use of mechanical members which are prone to error and breakage. Although the detection of breakage is critical, stopping the machine before the yarn breaks saves a great deal of time in the production process.
A system using sensors transmitting data to software for the monitoring of tension and breakage of yarn in a textile machine is disclosed. A sensor bar contains multiple eyelets to receive the yarn, each of the multiple eyelets containing at least one sensor, preferably optical. The sensors can be reflective or transmissive with equal accuracy. The microprocessor, housed in a controller, contains software that is in constant communication with each of the sensors to receive and analyze the raw signals created by the yarn motion. The sensors register the motion of the yarn, both wiggle and speed, with the signals being received and analyzed by the software within the microprocessor in milliseconds. The microprocessor is also in two-way communication with the textile machine.
To initiate the system the user enters a user defined broken yarn set point that defines how long a raw signal can stay below the broken yarn control limit, thereby establishing that the yarn is broken. Also entered is a user defined tight end set point to define how many times the raw signal average can drop below the tight end control limit, thereby establishing that the yarn is over-tensioned.
Once the machine is started empirical values inherent in the software algorithm are initiated. The empirical values include tight end control limit, broken yarn control limit, factors for averaging of yarn motion, and features and characteristics of yarn types and textile machine types. The tight end control limit defines the lowest reading permitted for the yarn, and after a number of drops below this limit as defined by the tight end set point, the algorithm determines that the yarn is too tight. The broken yarn control limit determines the lowest reading permitted for the yarn, and after a period of time below this limit as defined by the broken yarn set point, the algorithm determines that the yarn is broken.
Once the values are loaded the system scans each of the sensors, receiving and analyzing the raw signals to generate raw signal data. As they are received the raw signals are compared to the empirical control limit for a broken end. If the raw signals are above the empirical control limit for a broken end, the raw signals are added to an existing running data average, or raw signal average, thus constantly creating an updated running data average. The updated running data average is compared to the predefined empirical control limit for a tight end. If the updated running data average is above the predefined empirical control limit for a tight end, the system loops back to scanning the sensors.
When the raw signals fall below the control limit for a broken end for the time defined by the broken end set point, a broken yarn command is sent by the system to shut down operation of the machine. The system isolates the sensor with the broken yarn and once repaired, the machine is restarted.
These and other objects, features, advantages, and aspects of the present invention can be better understood with reference to the following detailed description of the preferred embodiments when read in conjunction with the appended drawing figures.
As used herein the term “sensing bar” shall refer to a collection of sensors that mounts on a textile machine, each sensor having a single yarn for monitoring.
As used herein the term “yarn” or “thread” shall refer to multiple strands of filament for use in textile machines.
As used herein the term “data point” and “data points” shall refer to a voltage reading somewhere between +Voltage (+V) and ground (GND). This point is determined by the condition (presence, tension, or absence) of the yarn as read by the sensors.
As used herein the term “eyelet” shall refer to a receiving and guide aperture for yarn in accordance with the invention.
As used herein the term “sensor” shall refer to the combination of emitter and detector elements of a sensor, whether these are a single physical element or two physical elements.
As used herein the term “yarn motion” shall refer to any motion of the yarn as it moves past the sensor, including but not limited to wiggle, and vertical movement.
As used herein the term “wiggle” shall refer to the side-to-side motion made by the yarn as it passes past a sensor. Unless over tight, and ready to break, yarn has some degree of horizontal movement along its length.
As used herein the term “raw signal” shall refer to the signal created by the sensor and communicated to the controller.
As used herein the term “raw signal data” shall refer to the raw signal data points received from the sensor by the controller.
As used herein the term “tight end” shall refer to the condition of over-tensioned yarn.
As used herein the term “tight end control limit” shall refer to the lowest reading permitted for the yarn, below which the algorithm determines that the yarn is too tight.
As used herein the term “broken yarn control limit” shall refer to the lowest reading permitted for the yarn, below which the algorithm determines that the yarn is broken after a user-entered number of raw signal readings are below this limit.
As used herein the term “operational zone” is the area above the control limit within which the yarn is progressing with normal motion.
As used herein the term “averaging” shall refer to the ongoing accumulation and analysis of raw signal data received by the controller from each of the sensors. The value obtained by averaging is a moving average defined by the yarn type and machine type being used in the system, the characteristics and features of which are known by the controller algorithm.
As used herein the term “raw signal average” is the value of the sensor readings determined by averaging raw signal data.
As used herein the term “broken yarn set point” shall refer to value entered by a user that indicates how long a raw signal can stay below the broken yarn control limit, thereby establishing that the yarn is broken.
As used herein the term “averaged set point” and “tight end set point” shall be used interchangeably and refer to the value entered by a user that indicates how long the raw signal average can stay below the tight end control limit, thereby establishing that the yarn is over-tensioned.
The pending application is a continuation-in-part of U.S. Ser. No. 16/553,664 filed Aug. 28, 2019, with a priority date of Aug. 28, 2018, and is incorporated herein as though recited in full.
Tension and breakage of yarn must be carefully monitored in order to produce viable products. Tension that is too great will cause uneven yarns, marring the finished product, and is generally a precursor to yarn breakage. It is therefore beneficial to the operation of a textile machine such as a tufting machine to catch the over-tensioning of yarn prior to either breakage or causing a flaw in the finished product. Conversely, under-tensioning can result in loose threads and thread loops. The present invention discloses a sensor system that improves yarn management by detecting tight, over-tensioned yarn as well as broken yarn. The disclosed sensor system monitors the tension and breakage of the yarn during the operation of a textile machine through the use of one or more optical sensors located in or adjacent to yarn eyelets. The sensors are in communication with a controller running an algorithm that can determine yarn motion based on the sensor readings. The operation of the textile machine can be controlled as needed depending on the detection of a broken or over-tensioned yarn. Each of the sensors in the sensor system has an ID, and the controller software knows the location of any sensor having issues and maintains the machine in shutdown until repaired. The optical sensors used in the disclosed system can be photoelectric sensors, using infrared, visible, or laser light. Although photoelectric infrared sensors are used as examples herein, any sensor that can provide the required data can be used. The disclosed sensor system can be retrofitted to current machines or incorporated into machines by the manufacturer.
A typical tufting machine of the above noted co-pending application is illustrated in
A block diagram of the sensor system 100 is illustrated in
In the example illustrated herein the circuit board 31 is positioned on the sides of the sensor bar 30 and data is fed into the controller 70 through wiring 82. Other configurations of the circuit board 31 within the sensor bar 30 can be used and the optimal positioning will be known to those skilled in the art. It is critical that the circuit board 31 does not block the movement of the yarn and that clear sensor readings are enabled.
The optical sensor signal is gathered by the circuit board 31, sent to the microprocessor within the controller 70, and, depending on the sensors being used, either converted from analog to digital or used directly. The microprocessor reads the signal voltage and compares the voltage received from all sensors to the preprogrammed voltage range.
The circuit board 31 within the sensor bar 30 carries the sensor electronics and is secured to the sensor bar 30 in any manner known in the art that will not obstruct the path of the yarn. The circuit board 31 is responsible for transmitting the signals received from the sensors 50, 60 to a microprocessor.
A top view of the sensor bar 30 is illustrated in
The disclosed system can also be applicable to using dual sensors as illustrated in
In
The averaging of the yarn, using either sensor 50 or 60, is based on the raw signal received in milliseconds, indicating the motion of the yarn. The raw signal average is part of a running average (next reading in and last reading dropped off). The algorithm analyzing the raw signal data has some basic knowledge of the yarn being used in the system and its inherent properties, including movement or lack thereof, thereby reducing the time required to form an acceptable average. The empirical values inherent within the algorithm are tight end control limit, broken yarn control limit, factors for averaging of yarn motion, and features and characteristics of yarn types and textile machine types. The tight end control limit and broken yarn control limit are determined by routine experimentation and testing of different yarn types and different textile machines. Control limit testing is focused on capturing behavior of different kinds of yarn in different machines such as raw signal highs and lows, raw signal averages based on different sizes of yarn, and different speed and wiggle responses based on yarn angle entering the sensors. These and other factors can also be tested as determined by one skilled in the art.
Prior to initialization of the system, the user enters values, depending on yarn type and machine type, to the system that defines the actions that indicate a defect. These values would include the amount of time either a raw signal or an averaged signal can remain below the control limits, specifically:
When a yarn is in the operational zone above the control limits, the yarn experiences wiggle that yields an acceptable variety of changes in raw signal data and raw signal averages. When a yarn starts to get tight, it does not wiggle as much; therefore, the amount of change in the raw signal that the detector is seeing becomes more consistent with less wiggle. The algorithm recognizes the averaged reduction in wiggle, and after this reduction meets the user defined tight end set point and registers a defective yarn. If left without any action, the defective yarn will most likely break and fall below the broken yarn control limit, stopping the machine. How the system handles signals that fall below the broken yarn set point is based on user input.
In
The readings, whether reflective or transmissive, remain the same, thereby eliminating the need for any changes to the software. As there is no difference in the accuracy between the reflective and transmissive sensors the decision can be made on cost, thereby making the system more affordable.
As the emitter 52, 62 and detector 54, 64 are connected together the amplifier gain is automatically set so that the signal is always in the proper range. Any changes to this arrangement will require modifications as well known to those skilled in the art.
The software, or algorithm, analyzing the readings and sending instructions to the machine is part of the system along with the sensor bar and circuit board and therefore pre-programmed with the location and type of sensor being used. However, in some applications it can be advantageous to program the software to recognize the type of sensor and its location. Alternatively, individual programs can be contained with controller 70 and the user would select the applicable program to run.
The software within the controller 70 is in constant communication with the circuit board 31, monitoring the raw data received regarding yarn motion, while simultaneously and continuously analyzing the data. When the readings indicate that a yarn is either under unacceptable tension, or there is a lack of yarn, the software institutes a protocol, as noted below, and a signal is sent to stop the machine.
Due to the ability of the basic algorithm to compensate for any change in yarn type or resulting signal change, the system does not need to redefine a zero baseline before each start up. The algorithm contains a number of basic values that are specific to yarn and machine type and never change, eliminating an initial set up of the averaging control limits. These basic values are automatically loaded upon machine start up and do not require entry at each run.
An important feature of the present invention is that the disclosed system does not require a predefined learning period as the algorithm uses the raw signal data as read directly from the sensor 50, 60 to evaluate whether the yarn is below the tight end control limit. If the raw signal data reading from the yarn is above the tight end control limit, the raw signal data is added into the raw signal average which is a running average. The running average is examined to see if the new data has brought the running average below the predefined tight end control limit. If the reading is below the tight end control limit, it defines a tight end. The tight end set point entered by the user define the number of times the running average is below the tight end control limit. Reaching the tight end control limit is based on the raw signal average and is dependent on yarn type and machine type. As the raw signal average is a running average, it is a real-time, ongoing calculation. A tight end set point is established by the user indicating the number of times that the raw signal average can reach the control limit before a tight end defect is determined.
The broken yarn control limit is predefined by the system set up in the algorithm. The presence of a broken end is defined by the time below the broken yarn control limit which is entered by the user as the broken yarn set point.
The graph illustrated in
The flow chart 110 in
The raw signal data received from the sensors is analyzed 128 to ensure that the speed and yarn motion fall into the predetermined operational area as defined by being above the broken yarn control limit. When the raw signal is within the operational area, it is added to the current data average to the create an updated data average 123. The updated data average is then checked against the averaged tight end control limit to ensure that the averaged data remains in the operational area, above the tight end control limit. When the signals indicate that the yarn motion is above the averaged tight end control limits 124, the system loops back to scanning each sensor 122. This is a constant, ongoing process as the raw signal is read in milliseconds.
If an averaged signal is below the average tight end control limit 124, the system checks the averaged set point as determined by user input 119, as noted above, and compares the number of times that the signal is below the control limit 124 with the user input 119. If the signal returns to above the averaged tight end control limit 124 and continues to stay within the operational area the process continues with the scanning of each sensor unit 122.
If the averaged signal continues to drop below the control limit 124 for the user input number of times, the tight end yarn stop machine signal 125 is sent, and the location of the sensor identified 130. Once the sensor issue has been resolved, the system waits for machine restart 132.
When the raw signal is below the broken end control limit 128 the user entered broken yarn set point is checked. After the shutdown criteria is met, based on user set points 119, the software issues a stop machine command 126 and identifies the sensor containing the broken yarn 130. The system then waits for resolution and machine restart 132.
In this graph, the data average 230 has dipped below the tight end control limit 200 four (4) times but has always returned to the operational zone. On the fifth (5th) dip, the raw data 220 falls below the operational zone and stays beyond the user-established broken yarn set point, indicating a break. The dips below the control limit 200 are monitored and, even if the data average 230 returns to the operational zone, the number of the dips below the control limit 200 beyond the user-established by the averaged set point indicates a tight yarn.
In
In contrast to the graphs of
The use of the terms “a” and “an” and “the” and similar references in the context of this disclosure (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. AD methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., such as, preferred, preferably) provided herein, is intended merely to further illustrate the content of the disclosure, and does not pose a limitation on the scope of the claims. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the preset disclosure.
Multiple embodiments are described herein, including the best mode known to the inventors for practicing the claimed invention. Of these, variations of the disclosed embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing disclosure. The inventors expect skilled artisans to employ such variations as appropriate (e.g., altering or combining features or embodiments), and the inventors intend for the invention to be practiced otherwise than as specifically described herein,
Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
The use of individual numerical values are stated as approximations as though the values were preceded by the word “about”, “substantially”, or “approximately.” Similarly, the numerical values in the various ranges specified in this application, unless expressly indicated otherwise, are stated as approximations as though the minimum and maximum values within the stated ranges were both preceded by the word “about”, “substantially”, or “approximately,” In this manner, variations above and below the stated ranges can be used to achieve substantially the same results as values within the ranges. As used herein, the terms “about”, “substantially”, and “approximately” when referring to a numerical value shall have their plain and ordinary meanings to a person of ordinary skill in the art to which the disclosed subject matter is most closely related or the art relevant to the range or element at issue. The amount of broadening from the strict numerical boundary depends upon many factors. For example, some of the factors which may be considered include the criticality of the element and/or the effect a given amount of variation will have on the performance of the claimed subject matter, as well as other considerations known to those of skill in the art, As used herein, the use of differing amounts of significant digits for different numerical values is not meant to limit how the use of the words “about”, “substantially”, or “approximately” will serve to broaden a particular numerical value or range. Thus, as a general matter, “about”, “substantially”, or “approximately” broaden the numerical value. Also, the disclosure of ranges is intended as a continuous range including every value between the minimum and maximum values plus the broadening of the range afforded by the use of the term “about”, “substantially”, or “approximately”. Thus, recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. To the extent that determining a given amount of variation of some the factors, as well as other considerations known to those of skill in the art to which the disclosed subject matter is most closely related or the art relevant to the range or element at issue will have on the performance of the claimed subject matter, is not considered to be within the ability of one of ordinary skill in the art, or is not explicitly stated in the claims, then the terms “about”, “substantially”, and “approximately” should be understood to mean the numerical value, plus or minus 10%,
It is to be understood that any ranges, ratios, and ranges of ratios that can be formed by, or derived from, any of the data disclosed herein represent further embodiments of the present disclosure and are included as part of the disclosure as though they were explicitly set forth, This includes ranges that can be formed that do or do not include a finite upper and/or lower boundary. Accordingly, a person of ordinary skill in the art most closely related to a particular range, ratio or range of ratios will appreciate that such values are unambiguously derivable from the data presented.
| Number | Date | Country | |
|---|---|---|---|
| 62723547 | Aug 2018 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16553664 | Aug 2019 | US |
| Child | 17650368 | US |
