Yarn Tension Sensor Research Articles

Research on nonlinear compensation scheme of yarn tension sensor using SAW devices based on SSA–SVR model

The detection accuracy of a yarn tension sensor using surface acoustic wave devices has become increasingly important. We investigate a nonlinear compensation scheme based on sparrow search algorithm (SSA) and support vector regression (SVR) models to improve its detection accuracy, and the principle of SSA–SVR model and training method are also explored. We take the output frequency of the two sensors as input, the yarn tension applied to the working sensor as output, train an SSA–SVR model and use it for nonlinear compensation. We analyze and calculate the linearity, compensation accuracy and robustness of the SSA-SVR model, and compared it with the multiple regression model and BP neural network. The comparison results show that the SSA–SVR model has the best linearity, the highest compensation accuracy and the most robust. Finally, a novel nonlinear compensation scheme is proposed.

Enhanced Frequency Stability of SAW Yarn Tension Sensor by Using the Dual Differential Channel Surface Acoustic Wave Oscillator.

This paper presents a 60 MHz surface acoustic wave (SAW) yarn tension sensor incorporating a novel SAW oscillator with high-frequency stability. A SAW delay line was fabricated on ST-X quartz substrate using the unbalanced-split electrode and bi-directional engraving slots. The dual differential channel delay linear acoustic surface wave oscillator is designed and implemented to test yarn tension, which can effectively remove the interference of temperature, humidity, and other peripheral factors through differential design. The yarn tension sensor using the surface acoustic wave has high-precision characteristics, and the SAW delay line oscillator is designed to ensure the test system’s stable operation. The effect of time and tension on oscillator frequency stability is studied in detail, and the single oscillator and the dual differential channel system were tested, respectively. After using the dual differential channel system, the short-term frequency stability from is reduced from 1.0163 ppm to 0.17726 ppm, the frequency accuracy of the tension sensor is improved from 134 Hz to 27 Hz, and the max frequency jump steady is reduced from 2.2395 ppm to 0.45123 ppm.

Study on the Practical Application of Surface Acoustic Wave Yarn Tension Sensor

Nowadays, the commonly used yarn tension sensors cannot meet the requirement well in the textile manufacturing process. So surface acoustic wave (SAW) yarn tension sensor is a good selection to adapt to today's textile manufacturing and improve the production efficiency. First, two key problems of SAW yarn tension sensor in practical application are proposed in this article, one is the construction of the sensor measurement system, the other is the temperature compensation. Then, the integrated design of measurement circuit and measurement structure is implemented and introduced in this article, which improves the accuracy, reliability, and sensitivity of SAW yarn tension sensor. Finally, binary regression analysis method and least squares support vector machine (LSSVM) algorithm optimized by particle swarm optimization (PSO-LSSVM) method are applied to the temperature compensation of SAW yarn tension sensor, which both achieve satisfactory compensation effect. By comparison, PSO-LSSVM method is more convenient and flexible, and still has a large space for improvement. Through those research contents, it can be concluded that the design and implementation of the measurement system lay a foundation for the practical application of SAW yarn tension sensor, the research of temperature compensation is of great significance to the wide application of the sensor.

Sensitivity Optimization of Surface Acoustic Wave Yarn Tension Sensor Based on Elastic Beam Theory

The measurement of yarn tension has a direct impact on the product quality and production efficiency in the textile manufacturing process, and the surface acoustic wave (SAW) yarn tension sensor is a good option for detecting the yarn tension. For SAW yarn tension sensors, sensitivity is an important indicator to assess their performance. In this paper, a new type of SAW yarn tension sensor based on a simply supported beam structure is studied to improve the sensitivity of the fixed beam SAW yarn tension sensor. The sensitivity analysis method based on elastic beam theory is proposed to illustrate the sensitivity optimization. According to the analysis results, the sensitivity of the SAW yarn tension sensor can be greatly improved by using a simply supported beam structure compared to the s fixed beam structure. Moreover, from the calibration experiment, the sensitivity of the simply supported beam SAW yarn tension sensor is 2.5 times higher than that of the fixed beam sensor.

Methods of solving in‐band ripples and out‐of‐band suppression for yarn tension sensor based on surface acoustic wave

The two key problems of the in-band ripples and out-of-band suppression are proposed in the design of the SAW yarn tension sensor and the methods of decreasing them are achieved. The unbalanced split-electrode interdigital transducers (IDT) are designed so that the total phase of the regenerated reflection wave and mass load feedback is close to 180°, leading to an effective reduction of the in-band ripples effect characterised by the sensor frequency response. The engraved bi-directional slots on the back of the substrate can block the propagation path of the bulk acoustic wave (BAW) to a certain extent, reducing the influence of BAW propagation and suppressing the out-of-band suppression of the frequency response. The experimental results show that the SAW yarn tension sensor with the unbalanced split-electrode IDT can reduce the in-band ripples from 23.34 to 0.93 dB, and the engraved bi-directional slots can suppress the out-of-band suppression from 28.03 to 7.71 dB.

Fitting analysis and research of measured data of SAW yarn tension sensor based on PSO–SVR model

With the rapid growth of the SAW (Surface Acoustic Wave) yarn tension sensor, the requirement for its measurement accuracy is higher and higher. However, little research has been conducted in this field. Thus, this paper studies this field and provides a solution. This paper firstly investigates the principle and training of PSO–SVR model. On this basis, this paper also studies the association of output frequency difference data with the matching yarn tension exerted on the SAW yarn tension sensor. After that, employing the frequency difference data as input and corresponding tension as output, the PSO–SVR model is trained and employed to predict output tension of the sensor. Finally, the error with actually applied tension was calculated, the same in the least-squares approach and the BP neural network. By multiple comparisons of the same sample data set in the overall, as well as the local accuracy of the forecasted results, it is easy to confirm that the output error forecast by PSO–SVR model is much smaller relative to the least-squares approach and BP neural network. As a result, a new way for the data analysis of the SAW yarn tension sensor is provided.

Effect of IDT position parameters on SAW yarn tension sensor sensitivity

In this paper, the effect of the interdigital transducer (IDT) position parameters on the surface acoustic wave (SAW) yarn tension sensor sensitivity is investigated. The stress–strain characteristic of substrate was studied by the combination of finite element simulation and regression analysis method. According to this characteristic, the function relationship between the SAW yarn tension sensor sensitivity and the IDT position parameters was built using the regression analysis method. The monotonicity of the regression function was also given. On this basis, a novel sensitivity optimal scheme was proposed and solved by the quadratic programming method. Its solution demonstrates that the optimum sensitivity can be obtained when the IDT is 8.9 mm to the left side of the substrate and the IDT is 0.3 mm to the top edge of the substrate within a domain of the IDT position parameters. The SAW yarn tension sensor with corresponding IDT position parameters was fabricated to validate the correctness of the sensitivity optimal scheme. The measured results indicate that the SAW yarn tension sensor sensitivity can reach 813.69 Hz/g, which confirms that the novel scheme is effective.

EXPERIMENTAL INVESTIGATION OF THE PERFORMANCE OF A FEEDBACK TENSION CONTROL SYSTEM DESIGNED FOR WARPING MACHINES

This paper presents a research work which investigates experimentally the performance of a tension control system realized by a controlled disc brake. An experimental set-up was established by using a creel with step motor controlled disc brake, laser distance sensor, yarn tension sensor and a 2-unit winding machine. A software was developed in C programming language to read yarn tension and bobbin diameter data and then to control the disc brake by step motor drive. Experimental investigation was carried out with three different cotton yarn counts and unwinding speeds. It was shown that yarn tension changed from full to empty bobbin at a significant amount depending mainly on yarn number and unwinding speed. The feedback tension control system based on adjusting level of braking responded well to short, medium and long term tension variations and enabled unwinding tension control mostly within ±1 cN deviation from the adjusted value.

In situ measurement of the dynamic yarn path in a turbo ring spinning process based on the superconducting magnetic bearing twisting system

The yarn tension and balloon form are the most important physical process parameters to characterize the dynamic yarn path in ring spinning. The present research work focuses on the in situ measurement of yarn tension in different regions of the yarn path in a developed turbo ring spinning tester with a friction-free superconducting magnetic bearing (SMB) twisting system and at an angular spindle speed of up to 50,000 rpm. The influence of different parameters, such as angular spindle speeds (15,000–50,000 rpm), yarn counts (15–40 tex) and balloon control ring (one or multiple), were evaluated to identify the influence of acting forces, for example, centrifugal forces. The effects of these process parameters were analyzed statistically using an analysis of variance. The yarn tension between the delivery rollers and the yarn guide was measured using a modified one-roller tensile yarn tension sensor. The yarn tension between the yarn guide and the SMB system was determined with an already existing optical approach at a higher angular spindle speed. As the highest yarn tension theoretically occurs between the SMB system and the cop, it was estimated in this region by measuring the coefficient of friction between the yarn and the yarn guide using the friction module of the constant tension tester equipment. The maximum balloon diameter was determined from the recorded balloon form between the yarn guide and the SMB system with respect to different angular spindle speeds. The results provide valuable information about the highest possible spinnable speed and enable a better understanding of the dynamic yarn path in the SMB spinning system.

Experimental investigation of effect of balloon length on yarn tension during unwinding

PurposeYarns of different types are unwound from bobbins in different processes like warping, weaving, doubling and re-winding. It is required that yarn tension remains constant during unwinding in all these processes. Otherwise, it ends with product quality and process efficiency problems. The purpose of this paper is to investigate experimentally the effect of balloon length on yarn tension change with respect to bobbin diameter during unwinding in an attempt to obtain a minimum yarn tension variation.Design/methodology/approachAn experimental set up was built. Bobbin diameter was measured by a laser sensor and yarn tension was measured by a single yarn tension sensor. Both sensor outputs were interfaced to a PC via a DAQ cad. A software program was developed in C programming language to read and record the tension and bobbin diameter simultaneously. Experimental study was conducted with three different balloon lengths for both continuous filament and spun yarns of four different yarn numbers and five different unwinding speeds.FindingsResults showed that yarn tension change with bobbin diameter was affected in different ways with balloon length depending on yarn number, unwinding speed and yarn type.Originality/valueAvailable literature on the effect of balloon length on yarn tension bobbin diameter relation is limited and measurements were generally conducted for three different bobbin diameters. Yarn tension bobbin diameter relation is obtained in this research for at least eight different diameters and more for three different balloon lengths covering practical application ranges. The results obtained can be used in the design of tension control system for warping and winding machines as well as for setting these machines for optimum efficiency.

Study of the Doubly Clamped Beam Yarn Tension Sensor Based on the Surface Acoustic Wave

In this paper, a design method for the yarn tension sensor based on a surface acoustic wave is presented. When the yarn tension is applied to the sensor's doubly clamped beam (i.e., piezoelectric substrate), it is linearly related to the output frequency shift, which achieves the purpose of measuring the yarn tension. This paper deduces the functional relationship between the oscillation frequency shift of the sensor and the yarn tension. We put forward the choice of a piezoelectric substrate material, the choice of the piezoelectric die size, and the placement of interdigital transducers (IDTs) as the three key issues to be determined. By using the ANSYS software, we determined that the optimal piezoelectric substrate is quartz, and determined the optimal size of the die and the maximum strain area of the die. When IDTs are placed in the maximum strain area of the piezoelectric substrate, the sensor has the best sensitivity. We have designed and produced the sensor and also have tested the sensor. Experimental results: the range is 0–2 N, the linearity is 1.0112%, the hysteresis is 0.6153%, the repeatability is 1.1067%, the accuracy is 1.6205%, the maximum overload capacity is 200% (i.e., 4 N), and the fracture strength of the substrate is 5 N.

Temperature compensation of the SAW yarn tension sensor

The objective of this research was to investigate the possibility of the temperature compensation for the surface acoustic wave (SAW) yarn tension sensor. The motivation for this work was prompted by the oscillation frequency of the SAW yarn tension sensor varying with the temperature.In this paper, we deduce the functional relationship between the temperature variation and the oscillation frequency shift caused by the temperature. This functional relationship and the temperature sensor are used to get the oscillation frequency shift caused by the temperature, so that we can use the oscillation frequency shift caused by the temperature to implement the temperature compensation of the SAW yarn tension sensor. In this paper, we also get the relative error of the temperature compensation. The theoretical and experimental results confirm that this temperature compensation method can implement the temperature compensation of the SAW yarn tension sensor.

Optimization of Sensitivity Induced by Substrate Strain Rate for Surface Acoustic Wave Yarn Tension Sensor

In this paper, we propose a novel sensitivity optimization design scheme for the yarn tension sensor using surface acoustic wave (SAW) device by improving the strain rate of the SAW yarn tension sensor substrate. The yarn tension sensor, operating at 169.4 MHz, is designed as an oscillator fabricated on a 42° $Y{-}\!X$ quartz substrate. Based on regression analysis and finite-element analysis, two mathematical models are established and a linear programming model is built to obtain the best sensitivity. Moreover, the determination coefficients of the two mathematical models both are >0.99, which means that the regression models fit the experimental data exactly. The linear programming results show that the maximum sensitivity will be achieved when the SAW yarn tension sensor substrate length is 19 mm and its width is 3 mm within a fixed interval of the substrate size. The SAW yarn tension sensor with the size of $19~{\rm mm}\times 3$ mm was fabricated. Experimental results show that the actual optimal sensitivity 3.13 kHz/g was obtained, confirming that the sensitivity optimization design scheme is effective and applicable.

Compensated SAW Yarn Tension Sensor

The measurement and control of yarn tension is important in textile technology. This paper presents a two channel architecture surface acoustic wave yarn tension sensor, which is able to provide a sensitivity about two times bigger than the previous one. The design and the fabrication of the devices are also presented. A mathematical analysis shows that the output frequency of the sensor varies linearly with the yarn tension. To test the performance of the sensor, an experiment is carried out to obtain the output frequencies in different yarn tension. The results show that the sensor has a sensitivity of 8234 Hz/N (80.75 Hz/gf), and the sensor is capable of measuring a range of 0-0.196 N (20 gf) yarn tension with a relative error of 2% and a hysteresis error of 3%.

A novel optimal sensitivity design scheme for yarn tension sensor using surface acoustic wave device

In this paper, we propose a novel optimal sensitivity design scheme for the yarn tension sensor using surface acoustic wave (SAW) device. In order to obtain the best sensitivity, the regression model between the size of the SAW yarn tension sensor substrate and the sensitivity of the SAW yarn tension sensor was established using the least square method. The model was validated too. Through analyzing the correspondence between the regression function monotonicity and its partial derivative sign, the effect of the SAW yarn tension sensor substrate size on the sensitivity of the SAW yarn tension sensor was investigated. Based on the regression model, a linear programming model was established to gain the optimal sensitivity of the SAW yarn tension sensor. The linear programming result shows that the maximum sensitivity will be achieved when the SAW yarn tension sensor substrate length is equal to 15mm and its width is equal to 3mm within a fixed interval of the substrate size. An experiment of SAW yarn tension sensor about 15mm long and 3mm wide was presented. Experimental results show that the maximum sensitivity 1982.39Hz/g was accomplished, which confirms that the optimal sensitivity design scheme is useful and effective.

The Design of Yarn Constant Tension Feeder System

A novel constant tension yarn feed control system for automatic winder is presented in this paper which is based on analyzing the principle of the generation of yarn tension and the factors which make the tension fluctuate. DSP28035 made by TI (Texas Instruments) is adopted as the main control unit of the system to acquire the real-time yarn tension which is transmitted from a yarn tension sensor. Intelligent PID (proportional-integral-derivative) algorithm is also adopted to achieve a high-dynamic performance and an ultra-low inertia servo motor speed digital control to realize constant yarn tension feed. The system not only have the function of tension setting, over current protection, error detection and alarm, but also possess the features of simple structure, low cost, real-time control and high accuracy.

Solving Three Key Problems of the SAW Yarn Tension Sensor

In this brief, we propose to implement a new method of the yarn tension sensor with a surface acoustic wave (SAW) oscillator. When the yarn tension is subjected to the piezoelectric substrate of SAW oscillator, the oscillation frequency of SAW oscillator varies with yarn tension so that the goal of measuring yarn tension is reached. We present the temperature compensation of the SAW yarn tension sensor, establishment of the functional relationship between the yarn tension and the output frequency shift of the yarn tension sensor, and suppression of the sidelobes for the frequency characteristic curve of the SAW oscillator as the three key problems of the SAW yarn tension sensor. The solutions to these problems are achieved in this brief.

Wireless yarn tension measurement, and control in direct cabling process

An online yarn tension sensing and control device has been designed and developed. The system was specifically devised for use in a direct cabling machine, wherein yarn tension in the spindle or pot yarn is highly critical and dictates the uniformity of the cabled yarn. Since a balloon formed by the creel yarn always encompasses the pot yarn in a direct cabling machine, yarn tension measurement using a wired sensor is far-fetched. Accordingly, a wireless yarn tension sensor was developed to address this problem and perform online yarn tension measurement. The wireless sensor can be used as an active monitoring tool for measuring online yarn tension in both component yarns, while the closed loop control system replaces passive yarn brakes used in the current direct cabling machines and executes a control mechanism that can control yarn tension adaptively. The device uses Micro-Electro-Mechanical Systems (MEMS) technology with radio frequency (RF) transmission to effectively carry out dynamic online measurement. The control system in conjunction with the wireless sensor ensures equal tension in the component yarns, resulting in the formation of a uniform cabled yarn with equal lengths of both yarns.