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.

Hubble Tension Explanation from This Cosmological Model AΛΩ (Slow Bang Model, SB)

In this article we present a model of Hubble-Lemaître law using the notions of a transmitter (galaxy) and a receiver (MW) coupled to a model of the universe (Slow Bang Model, SB), based on a quantum approach of the evolution of space-time as well as an equation of state that retains all the infinitesimal terms. We find an explanation of the Hubble tension H0. Indeed, we have seen that this constant depends on the transceiver pair which can vary from the lowest observable value, from photons of the CMB (theoretical [km/s/Mpc]) to increasingly higher values depending on the earlier origin of the formation of the observed galaxy or cluster (ETG ~0.3 [Gy], ~74 [km/s/Mpc]). We have produced a theoretical table of the values of the constant according to the possible pairs of transmitter/receiver in the case where these galaxies follow the Hubble flow without large disturbance. The calculated theoretical values of the constant are in the order of magnitude of all values mentioned in past studies. Subsequently, we applied the models to 9 galaxies and COMA cluster and found that the models predict acceptable values of their distances and Hubble constant since these galaxies mainly follow the Hubble flow rather than the effects of a galaxy cluster or a group of clusters. In conclusion, we affirm that this Hubble tension does not really exist and it is rather the understanding of the meaning of this constant that is questioned.

Introducing a 2nd Universal Space-Time Constant Can Explain the Observed Age of the Universe and Dark Energy

The purpose of this paper is to introduce new theoretical concepts as opposed to accepting the existence of dark entities, such as dark energy. This research sought to introduce a 2nd universal space-time constant, besides having a finite speed constant (speed of light in vacuum c). A finite universal age constant b is introduced. Namely, this paper shows that the changes in the Earth’s anomalistic year duration over time support the hypothesis of the age of the universe correlating with a maximum number of orbital revolutions constant. Neglecting the gravitational influence of other cosmological entities in the proximity of the Earth, the constant maximum number of revolutions is herewith determined solely by the Earth’s orbital revolutions around the Sun. The value of the universal age constant b is calculated to be around 13.8 billion orbital revolutions, derived out of an equation related to the changes in the Earth’s anomalistic year duration over time and the so-called Hubble tension. The above-mentioned calculated value b correlates well with the best fit to measured data of the cosmic microwave background radiation (CMBR) by the Planck spacecraft, the age of the observed universe is measured to be approximately 13.787 ± 0.020 billion years (2018 final data release). Developing a theory with this 2nd universal space-time constant b, being covariant with respect to the Lorentz transformations when time spans are large, gives results such as: A confirmation of the measured CMBR value of 13.787 ± 0.020 billion years. Correlating well with the observed expansion rate of the universe (dark energy). The universe’s expansion accelerating over the last four to five billion years.

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.

Fatigue Properties of Plain Concrete under Triaxial Constant-Amplitude Tension-Compression Cyclic Loading

Fatigue tests were conducted on tapered plain concrete prism specimens under tri axial constant-amplitude tension-compression cyclic loading. The low stress of the cyclic loading was taken as 0.2f c and the upper stress ranged from 0. 20f t to 0.65f t. Three constant lateral pressures were 0.1f c, 0.2f c and 0.3f c respec tively. Based on the results, the th ree-stage evolution rule of the fatigue stiffness, maximum(minimum) longitudina l strain and damage were analyzed, and a unified S-N curve to calculate fati gue strength factors was worked out. The results show that the fatigue strength and fa tigue life under triaxial constant-amplitude tension-compression cyclic loadin g are smaller than those under uniaxial fatigue condition. Moreover, the secondary strain creep rate is related to the fatigue life, a formula for describing thei r relation was derived. The investigation of this paper can provide information for the fatigue design of concrete structures.

Key Role of Some Specific Occupied Molecular Orbitals of Short Chain n-Alkanes in Their Surface Tension and Reaction Rate Constants with Hydroxyl Radicals: DFT Study

Basing on the DFT calculations we propose the new theoretical model which describes both the surface tension σ of the short chain n-alkanes at their normal boiling points and their reaction rate constants with hydroxyl radicals OH• (at 297 ± 2 K) on the basis of their molecular orbital electronic characteristics. It has been shown that intermolecular dispersion attraction within the surface liquid monolayer of these compounds, as well as their reaction rate constants k with OH• radicals are determined by the energies Eorb of the specific occupied molecular orbitals which are the same in the determination of both the above physico-chemical characteristics of the studied n-alkanes. The received regression equations confirm the theoretically found dependences between the quantities of σ and k and the module |Eorb|. For the compounds under study this fact indicates the key role of their electronic structure particularities in determination of both the physical (surface tension) and the chemical (reaction rate constants) properties.

基于自抗扰控制的圆纬机恒张力输纱控制系统设计

针对当前圆纬机积极式送纱方式中存在的纱线张力及输送速度不可任意调节、纱线张力波动大等问题,提出了一种可为圆纬机输送恒定张力纱线的输纱控制系统。构建了以无刷直流电动机速度环为内环、以纱线张力为外环的纱线恒张力双闭环反馈控制系统,通过自抗扰控制技术获取纱线实时动态指标,并对无刷直流电动机目标转速进行调整,最后通过磁场定向控制技术驱动无刷直流电动机。详细阐述了纱线张力的形成机制、纱线恒张力输送控制方案、系统硬件设计及控制算法。输纱测试表明,该控制系统可实现多种类型纱线的恒定张力输送。其中,棉纱张力波动标准差为1.5 cN(300 m/min测试条件),氨纶包芯纱的张力波动标准差为0.33 cN(240 m/min测试条件)。输纱速度的调节范围为0~600 m/min,纱线张力的控制范围为2.0~50.0 cN。

基于准零刚度机构与间接力控制的恒拉力系统设计与分析

现有的悬吊式微低重力模拟恒拉力系统常采用力传感器数值作为反馈直接控制系统,但实际情况下力作为反馈信号常会产生突变,影响系统控制精度。为了改进刚性控制策略下系统稳定性差与大冲击条件下力误差大的状况,文中设计了包含准零刚度机构的恒拉力系统,通过控制准零刚度机构长度间接对恒拉力系统输出拉力进行控制。对准零刚度机构进行受力分析,明确影响准零刚度机构性能的关键指标和准零刚度机构的工作行程区间,建立恒拉力系统动力学模型,设计控制系统。为了验证系统控制精度与系统抗干扰性能,进行了动力学联合仿真对设计进行验证,仿真结果表明:该恒拉力系统拉力的控制误差可控制在2%以内,且具有较好的鲁棒性。

A New Physics Would Explain What Looks Like an Irreconcilable Tension between the Values of Hubble Constants and Allows <i>H₀</i>to Be Calculated Theoretically Several Ways

Observing galaxies receding from each other, Hubble found the universe’s expansion in 1929. His law that gives the receding speed as a function of distance implies a factor called Hubble constant H0. We want to validate our theoretical value of H0 ≈ 72.09548580(32) km⋅s-1⋅MParsec-1 with a new cosmological model found in 2019. This model predicts what may look like two possible values of H0. According to this model, the correct equation of the apparent age of the universe gives ~ 14.14 billion years. In approximation, we get the well-known equation 1/H0 ≈ 13.56 billion years. When we force these ages to fit the 1/H0 formula, it gives two different Hubble constant values of ~69.2 and 72.1 km⋅s-1⋅sdot;MParsec-1. When we apply a theoretical correction factor of η ≈ 1.042516951 on the first value, both target the second one. We found 42 equations of H0 linking different physics constants. Some are used to measure H0 as a function of the average temperature T of the Cosmological Microwave Background and the universal gravitational constant G: H0 ≈ 72.06(90) km⋅s-1⋅MParsec-1 from T by Cobra probe & Equation (16) H0 ≈ 71.95(50) km⋅s-1⋅MParsec-1 from T by Partridge & Equation (16) H0 ≈ 72.086(36) km⋅s-1⋅MParsec-1 from G & Equation (34) H0 ≈ 72.105(36) km⋅s-1⋅MParsec-1 from G & Equations (74), (75), or (76). With 508 published values, H0 ≈ 72.0957 ± 0.33 km⋅s-1⋅MParsec-1 seems to be the “ideal” statistical result. It validates our model and our theoretical H0 value which are useful to find various interactions with the different constants. Our model also explains the ambiguity between the different universe’s age measurements and seems to unlock a tension between two H0 values.

硅锭线切割张力控制方法对比研究

为满足低成本、低切损、高精度、高稳定性的硅片切割要求,在分析常用的两种线切割张力控制方法优缺点的基础上,采用ADAMS软件进行了弹簧式张力控制原理的建模与动力学仿真,并基于Simulink与MFAC控制算法对电控式张力控制进行了ADAMS与MATLAB动力学联合仿真。结果表明,两种张力控制方法所得到的电极丝加速度变化曲线走势一致,电控式张力控制在快速性及精确性方面优于弹簧式张力控制,但平稳性较差。进而,提出弹簧与电控相结合的张力控制方法,并在ADAMS中完成建模与动力学仿真。结果表明,该装置可在一定程度上取长补短。

预绞丝成型工艺研究与设备开发

预绞丝是特高压架空线路上的连接金具,能传递机械载荷、电气负荷以及保护电缆。预绞丝制造难点是成型张力不恒定,影响预绞丝尺寸精度,导致金具与电缆配合度降低,加剧磨损与松动,影响电气性能。从预绞丝成型工艺出发,对成型张力进行研究,分析成型条件,设计张力控制机构和系统;运用模糊神经网络算法对张力进行控制,研发出新型预绞丝成型设备并进行试验。试验结果符合控制技术指标,设备性能满足生产需求。

一种电缆自动绕包机的设计与实现

针对输配电重要部件高压电缆在发生线芯断裂、绝缘层破损等故障时,人工绕包维修存在效率较低、易损伤电气性能等问题,文中提出了一种利用微控制器自动化调节齿轮做卷绕运动的电缆自动绕包机设计。电缆自动绕包机的机械结构利用步进电机与C型齿轮结构实现卷绕机械运动,其控制系统的硬件部分利用传感器、微控制器、串口电路、数模转换处理电路等实现高压电缆绕包过程的恒张力反馈系统,软件部分通过运行模式和调试模式满足绕包过程的实时性和交互性需求。利用绕包过程中常用的3种带材完成自动绕包的实际效果测试,测试结果表明,所提出的电缆自动绕包机在对3种材料进行的绕包过程中,可以保证张力的恒定,其结果满足铺设电缆所需要的性能,提升了绕包效率和质量。

钢帘线外绕捻股机床综合性能提升

提出了一种钢帘线外绕捻股机床综合性能提升改造方案,在原机床上增加双扭转检测装置(ATC)、电磁张力装置、永磁外绕头、虚捻器、恒张力收线等部件。其中重点是双ATC的使用,第一道ATC防呆纠错,在线检测并制止上道工序为了产量而牺牲质量;第二道ATC对钢帘线残余扭转实时调整,提高产品质量。改造后放线张力波动范围稳定在±5 N;钢帘线扭转可在显示屏上看到波动曲线图,对超差实时调整、纠错,标准扭转目标控制值-1.5~+0.5圈的比例达94%,比改造前提高了34%。减少了停车扭转检验工序,成品可直接装箱,人员生产效率提高17%~24%,经济效益明显。

定长成型立体织物矩阵式自适应送经技术研究

以立体机织物成型工艺为基础,分析传统送经路径,提出直通式送经路径设计技术。通过经纱球面点阵布置,解决单根经纱间张力不均和开口不清晰等技术问题。采用经纱恒张力控制技术,通过送经装置的力学建模,推导出恒张力的力学方程,并使用MATLAB分析其运动规律。为织物成型过程中张力恒定提供一种理论方法,实现了立体机织物高效、稳定的制备,同时保证了批次织物产品质量的一致性。

基于参数化运动方程的电缆卷筒运动特性分析

在分析电缆卷筒设计基础上,建立一种电缆卷筒收缆过程参数化模型方程,并对计算结果进行图形化处理;在分别对恒张力约束条件下和恒力矩约束条件下的卷筒收缆工况进行分析基础上,获得不同工况下的力学特性曲线,提出一种变频式、力矩式和磁滞式电缆卷筒的选型设计方法。该方法效率高,适应性好,对电缆卷筒的设计选型具有指导意义。

恒定高应变率拉伸条件下泡沫金属力学性能

为了探究泡沫金属恒定应变率动态拉伸力学行为,基于3D Voronoi模型,采用双向拉伸加载方式和1.55倍等效胞孔直径高度的试件,实现了5000 s^(-1)恒定高应变率动态拉伸条件下泡沫金属力学性能测试数值模拟实验,模拟结果显示:动态拉伸过程满足应力均匀性和变形均匀性要求,且试件破坏位置合理;在恒定应变率(0.5~5000 s^(-1))动态拉伸时,泡沫金属的破坏应变基本不受应变率的影响;当应变率不超过500 s^(-1)时,破坏应力受应变率影响很小,当应变率在500~5000 s^(-1)时,破坏应力随着加载速率的增大而线性增大。

动态恒张力氨纶输送控制研究

针对针织生产过程中氨纶与导纱嘴摩擦力及编织成圈喂纱量变化导致氨纶输送张力不均匀的问题,深入分析摩擦机制及氨纶输送流程特性,提出了一种基于速度和张力双闭环方式的恒张力氨纶输送控制方案。分析了氨纶输送相关工艺,构建了氨纶张力模型和混合式步进电动机数学模型,提出了张力模糊PID控制策略,进行了Simulink仿真及Recurdyn/Colink机电联合仿真,阐述了恒张力氨纶输纱控制算法实现。仿真结果表明,采用该控制方案可提高氨纶纱线输送的抗扰动能力、抑制纱线的振动以及减小氨纶输送张力的波动,同时模糊PID进行氨纶张力控制拥有更好的性能,响应时间更快,抗干扰能力更强。实验验证了本控制策略的适应性和优越性,动态恒张力氨纶输送控制方案具有工程应用价值。

基于转矩控制的卷纸机收卷恒张力系统设计

卷绕系统是一种常用的控制系统,广泛应用于收卷、包装、印刷等生产过程中。卷纸机在收卷过程中为保证生产效率和收卷的质量,张力控制系统至关重要。本文针对卷纸机自动控制系统中为了取得卷纸张力控制及信号调节目的,采用以三菱32MT/ES和三菱伺服驱动器MR-JE-20A对系统的信号进行采集和控制,以实现卷纸机收卷的恒张力控制。

熔喷非织造布卷绕张力分析及优化

为了研究卷绕过程中布卷内部应力分布规律,以厚壁圆筒理论模型为基础,对布卷内部周向应力分布进行弹性力学推演。通过低应变拉伸试验确定熔喷非织造布允许的拉伸条件,并在此基础上,以恒张力卷绕、恒力矩卷绕和锥度张力卷绕为例,分析了不同卷绕条件下布卷内部周向应力的分布情况,提出恒内张力卷绕策略,并得到了其卷绕张力函数曲线。结果表明:不同卷材的力学特性对卷绕效果存在较大影响,锥度张力卷绕和恒内张力卷绕均可有效改善卷绕效果并增大卷径比,采用恒内张力卷绕可有效避免收卷后的卷材不均匀变形问题。