Development of PLC-based Tension Control System

Fiber winding tension is an important factor in the molding techniques of composite material which influences the quality of winding product directly, and the tension control is a key technique in fiber winding techniques. This paper introduces a closed-loop tension control system with the programmable logic controller （PLC） with function modules as its control kernel, the alternating current （AC） servo motor as execute element and the radius-following device to accomplish the real-time radius compensation. The mechanism of the tension control system is analyzed and the numerical model is set up. The compensation technique of the radius of the scroll is analyzed. Experimental results show that the system is well qualified with high control precision and high reaction speed.

Design and Analysis of a Novel Tension Control Method for Winding Machine

Filament winding has emerged as the main process for carbon fiber reinforced plastic(CFRP) fabrication, and tension control plays a key role in enhancing the quality of the winding products. With the continuous improvement of prod?uct quality and e ciency, the precision of the tension control system is constantly improving. In this paper, a novel tension control method is proposed, which can regulate the fiber tension and transport speed of the winding process by governing the outputs of three di erent driven rollers(the torque of the unwind roll, the torque of the magnetic powder brake roller, and the speed of the master speed roller) in three levels. The mechanical structures and dynamic models of the driven rollers and idle rollers are established by considering the time?varying features of the roller radius and inertia. Moreover, the influence of parameters and speed variation on fiber tension is investigated using the increment model. Subsequently, the control method is proposed by applying fiber tension in three levels accord?ing to the features of the three driven rollers. An adaptive fuzzy controller is designed for tuning the PID parameters online to control the speed of the master speed roller. Simulation is conducted for verifying the performance and sta?bility of the proposed tension control method by comparing with those of the conventional PID control method. The result reveals that the proposed method outperforms the conventional method. Finally, an experimental platform is constructed, and the proposed system is applied to a winding machine. The performance and stability of the tension control system are demonstrated via a series of experiments using carbon fiber under di erent reference speeds and tensions. This paper proposes a novel tension control method to regulate the fiber tension and transport speed.

Variable Tension Control for Discontinuous Tape Winding of Composites Based on Constant Extension Ratio

Discontinuous tape winding, which has obvious advantages in large extension ratio winding, is widely used in the molding of composites. Therefore, the research on technological parameters becomes the focus of many scholars. However, how to accomplish the variable tension control is usually not fully considered. Accordingly, the constant extension ratio and the smoothness of winding process cannot be ensured. Aiming at the problem of tension control, this paper first gives a comparatively deep research on the control method and the interaction mechanism of tension, extension ratio, automatic lap and automatic rectification. Then, according to the winding process features, the mechanical device and the mathematical model of tension control system are established respectively. With regard to the characteristics of PID controller and fuzzy controller, the fuzzy self-tuning PID controller is designed. As a result, the variable tension control is realized during the winding and lapping process, and the constant extension ratio is guaranteed. Finally, a sample application is presented for demonstration. By presenting the variable tension control techniques for discontinuous tape winding, the constant extension ratio of tapes is achieved, the consecution and the automation degree of winding process is improved as well. Thus, the quality of wound products is guaranteed.

Precision Tension Control System Using Magnetic Particle Clutch

The control of the stability of the filament tension is one of the crucial techniques ensuring the component quality of the composite materials. The open-loop tension control system, with industrial control computer as the core, magnetic particle clutch as the actuator, equipped with compensation technique is researched and manufactured. It can assure the tension control stability of the yarn in filament winding process and increase the control precision of the whole system.

A compensating technique for precise tension control

The Paper presents the mathematical model which has been Proved to be right and tha compensating tech-nique for the Precise tension control system on a nuznerical controlled winding machine. Which has been proved to bereasonable and feasible to Pereisely coned the tension of fihannt.

A LOCAL CONTROLLER BASED CONSTANT TENSION CONTROL SYSTEM

This paper is mainly about a local controller whose main function is to achieve the constant tension of the thin denier filament in the high speed winding process. A mathematic model of the induction motor while controlling its stator frequency and voltage is given. A new kind of variable parameter, real time constant tension control system is presented. The paper uses the microprocessor -INTEL 8097 as the CPU of the local controller. A standard serial communication interface-RS232 is used to communicate with the main computer. Computer simulation and experiment test show that this system has good control characteristics.

Research on Anti-Fluctuation Control of Winding Tension System Based on Feedforward Compensation

In the fiber winding process,strong disturbance,uncertainty,strong coupling,and fiber friction complicate the winding constant tension control.In order to effectively reduce the influence of these problems on the tension output,this paper proposed a tension fluctuation rejection strategy based on feedforward compensation.In addition to the bias harmonic curve of the unknown state,the tension fluctuation also contains the influence of bounded noise.A tension fluctuation observer(TFO)is designed to cancel the uncertain periodic signal,in which the frequency generator is used to estimate the critical parameter information.Then,the fluctuation signal is reconstructed by a third-order auxiliary filter.The estimated signal feedforward compensates for the actual tension fluctuation.Furthermore,a time-varying parameters fractional-order PID controller(TPFOPID)is realized to attenuate the bounded noise in the fluctuation.Finally,TPFOPID is enhanced by TFO and applied to control a tension control system considering multi-source disturbances.The stability of the method is analyzed by using the Lyapunov theorem.Finally,numerical simulations verify that the proposed scheme improves the tracking ability and robustness of the system in response to tension fluctuations.

Adaptive RISE Control of Winding Tension with Active Disturbance Rejection

A winding system is a time-varying system that considers complex nonlinear characteristics,and how to control the stability of the winding tension during the winding process is the primary problem that has hindered development in this field in recent years.Many nonlinear factors affect the tension in the winding process,such as friction,structured uncertainties,unstructured uncertainties,and external interference.These terms severely restrict the tension tracking performance.Existing tension control strategies are mainly based on the composite control of the tension and speed loops,and previous studies involve complex decoupling operations.Owing to the large number of calculations required for this method,it is inconvenient for practical engineering applications.To simplify the tension generation mechanism and the influence of the nonlinear characteristics of the winding system,a simpler nonlinear dynamic model of the winding tension was established.An adaptive method was applied to update the feedback gain of the continuous robust integral of the sign of the error(RISE).Furthermore,an extended state observer was used to estimate modeling errors and external disturbances.The model disturbance term can be compensated for in the designed RISE controller.The asymptotic stability of the system was proven according to the Lyapunov stability theory.Finally,a comparative analysis of the proposed nonlinear controller and several other controllers was performed.The results indicated that the control of the winding tension was significantly enhanced.

Modeling and Analysis of Interstand Tension Control in 6-high Tandem Cold Rolling Mill

The interstand tension control is one of the most important ways to meet tight tolerances for strip product quality during tandem cold rolling process. Using coordinate analysis and parabolic approximation for the mass flow balance principle, the strip velocities eliminating the use of forward slips and backward slips were calculated. In order to reduce the effect of roll eccentricity on the tension measurement, a filter based on bilinear transformation was de- signed. Applying a first-order Taylor series approximation, the transfer function matrix model of interstand tension stress was derived. The actual measurements on-site and the final calculation results showed that the established model had high calculation accuracy and was beneficial for interstand tension control of random cold rolling process.

ELECTRO-HYDRAULIC COMPOUND CONTROL METHOD AND CHARACTERISTIC OF CONTROL FOR TENSION SYSTEM WITH HIGH INERTIA LOADS

Based on the pressure regulation circuit adopting electro-hydraulic proportional relief valve to control tension, a new type of electro-hydraulic compound control circuit with throttle control unit is presented, which can obtain optimal dynamic damping ratio through real-time altering pressure-flow gain of the throttle control unit, improve the dynamic characteristic of tension follow-up control for the tension system with high inertia loads. Moreover, the characteristic when the cable linear velocity variation causes change of tension is investigated, and a compound control strategy is proposed. The theoretical analysis and experimental results show that the electro-hydraulic compound control circuit is effective and the characteristic of the compound control strategy is satisfactory.

H_∞ Control of Looper-Tension Control Systems Based on a Discrete-Time Model

High control performances cannot be obtained by most of the existing looper-tension control approaches through only considering controller designs based on continuous time models, which cannot meet the requirements of modern computer control systems with high control accuracy. In order to solve the above problems, a state feedback H∞ control method based on a discrete-time model for looper-tension control systems in hot rolling mills is presen- ted. The considered system is approximated by a discrete-time loope∞tension control system model. Based on a Lya- punov functional method, a state feedback H∞ control law is developed which makes the closed-loop system asymp totically stable with guaranteed H∞ performance. The controller gains are obtained by solving a set of linear matrix inequalities （LMIs）. In contrast to the existing results, the proposed approach can obtain good H∞ performance and effectively reduce external disturbances. The strip tension is also less affected by the change of looper angel, so good control performances can be obtained. Moreover, this control scheme is easy to implement, and can be applied to other linear systems. A simulation example with practical parameters is provided to illustrate the effectiveness of the developed method.

A Study on a Wire Tension Adaptive Control System of a Multi-wire Saw in Computer Simulation

Based on the analysis of the mechanism of wire tension control by using torque motors in the multi-wire saw machining process, some mathematical models of a tension control system are studied, and an adaptive algo- rithm is designed for controlling the wire tension. In this algorithm of tension control, the rotation speeds and waving angle of motors are measured and fed back to the controller, and the NLMS（ normalized least mean squares） algorithm is used to calculate the adaptive correction value and control the wire tension accurately. The computer simulation results in Matlab software validate the high accuracy for controlling the system of the wire tension with the NLMS algorithm in the multi-wire saw machining process.

基于滑模变结构的精密涂布机放卷系统张力控制策略研究

张力稳定是涂布工艺的一个基础条件,如何提高放卷系统的张力控制精度是精密涂布机张力控制面临的难点问题。本研究针对精密涂布机放卷系统张力稳定性控制需求,提出了一种基于滑模变结构控制策略的放卷系统张力控制方法。首先,根据精密涂布机放卷系统的工作原理,建立了放卷系统的参数时变、非线性动力学模型,分析了张力波动的主要原因;然后,在放卷系统张力模型的基础上,设计了一个放卷张力系统滑模变结构控制器,并利用李雅普诺夫(Lyapunov)定理进行了系统稳定性分析;最后,通过仿真试验对所设计的滑模变结构控制器进行了性能验证。仿真结果表明,相比于传统PID控制,本研究所设计的滑模变结构控制器对放卷张力系统具有更好的控制鲁棒性。

On the Mechanical Analysis and Control for the Tension System of the Cylindrical Filament Winding

The constant winding tension can make the filament arranged in order. The stress distribution between the filament balance fully gives play to the enhancement of filament, and increases the intensive workload of the composite winding material. This paper conducts the mechanical analysis for the unwinding roller and tension measuring roller of the cylindrical winding machine so that gets the mechanical model, gives error compensation formula caused by the radius change of the yarn group in the unwinding side, designs the closed-loop control system and utilizes the dynamical- integral PID control strategy to achieve the tension control during the process of the cylindrical winding.

Taxol Production in Suspension Cultures of Taxus chinensis as Affected by the Combination of Nutrient Feed with Dissolved Oxygen Control

Influence of the combination of nutrient feed with dissolved oxygen control on taxol production in suspension cultures of Taxus chinensis (Pilg.) Rehd. was investigated in bioreactors. Addition of feeding medium with 20 g/L sucrose on day 16 enhanced both the biomass and taxol production in 5-L bioreactors. Further investigation of the fed-batch cultures in a 20-L bioreactor showed that cultivation under a low dissolved oxygen tension (DOT) of 20% for the entire culture resulted in the highest taxol content of 0.98 mg/g DW, while the taxol production was lower than that with 40% and 60% DOT. Moreover, taxol accumulation was remarkably improved by the cultivation of cells initially under DOT of 60% for 20 d followed by changing the DOT to 20% for another 12 d. By combining the use of these two strategies, a maximum taxol content of 18.7 mg/L was obtained in a 20-L bioreactor.

智能凹版印刷设备张力控制系统仿真分析

智能凹版印刷设备是一个多输入、多输出变量的非线性系统,传统的控制策略无法适应智能凹版印刷设备对张力控制的快速响应和高精度要求。该文以智能机组式电子无轴凹版印刷设备为研究对象展开分析,首先对收放卷进行受力分析,建立了智能凹版印刷设备张力控制模型;然后设计张力控制系统,分别采用数字PID控制器和模糊控制PID控制器实现对智能凹版印刷设备收放卷张力控制;最后通过MATLAB Simulink进行仿真实验;结果表明,模糊PID控制自适应能力明显优于普通PID控制,所研究内容对提高印刷产品质量具有一定意义。

安钢冷轧1550 mm连退炉内张力控制与分析

结合安钢冷轧连退机组实际工艺流程,以安钢冷轧1 550 mm连退机组退火炉为研究平台,分析与研究了其炉内带钢张力,这对于薄带钢高速运行低张控制优化具有一定指导意义,可实现冷轧连退薄带钢高效化生产。

往复式压缩机中间接筒与曲轴箱的连接螺栓断裂失效分析

针对某石化公司重整单元新氢往复压缩机2023年所发生的中间接筒与曲轴箱连接螺栓断裂问题,根据其外观形貌、螺栓材质、螺栓受力情况分析其可能的断裂原因,并从工艺操作、设备安装要求、螺栓紧固方式方面,提出解决方案,保障装置的安稳长满优运行。

悬臂拼装施工的预制节段箱梁桥预应力参数优化

为揭示预制节段箱梁桥预应力相关参数对悬臂拼装阶段和合龙阶段箱梁横截面应力及施工期线形的影响,选取某工程一联三跨预制节段箱梁桥,针对悬臂拼装阶段和合龙阶段不同预应力参数取值对桥梁受力状态及变形特征的影响进行数值模拟。研究结果表明:预制节段箱梁桥顶板钢束最优张拉控制应力为预应力钢束抗拉强度标准值的0.70~0.75倍,与此同时应控制预应力钢束截面积不低于0.000 98 m^(2)(7Ф15.2 mm)。顶板单侧钢束组预应力合力作用线与顶板中轴线之间的距离,即顶板预应力合力偏心距宜取箱梁宽度的0.22~0.26倍。合龙阶段采用先张拉底板、腹板通长钢束,再张拉中、边跨局部钢束的方式可使桥梁在不同张拉阶段之间的线形及横截面应力变化更加平缓,有利于施工期间结构的安全控制。

无粘结环锚预应力衬砌张拉工艺足尺模型试验研究

针对预应力衬砌张拉过程中易出现应力集中而导致张拉裂缝的现象,通过开展洞外地面足尺模型试验,提出了分级分步张拉顺序和质量控制指标。首先根据钢绞线摩阻测试计算出摩擦系数,随后应用上述张拉顺序和质量控制方法进行自动张拉,并采用磁通量传感器和混凝土应变计分别对钢绞线和内衬混凝土的应力变化开展实测。现场张拉试验结果表明:①钢绞线沿程预应力损失约16.3%,采用的双层钢绞线在实践中可保证较高的有效预应力;②对锚具槽进行分级分步张拉,可使内衬混凝土获得较均匀的封闭环向压应力环,平均压应力达-10.9 MPa;③提出的3项控制指标可进行量化管理,结合自动张拉技术可有效地保证张拉质量。