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.

The Tension Cosmology, Largest Cosmic Structures and Explosions of Supernovae from SST

Here, using the Scale-Symmetric Theory (SST) we explain the cosmological tension and the origin of the largest cosmic structures. We show that a change in value of strong coupling constant for cold baryonic matter leads to the disagreement in the galaxy clustering amplitude, quantified by the parameter S8. Within the same model we described the Hubble tension. We described also the mechanism that transforms the gravitational collapse into an explosion—it concerns the dynamics of virtual fields that lead to dark energy. Our calculations concern the Type Ia supernovae and the core-collapse supernovae. We calculated the quantized masses of the progenitors of supernovae, emitted total energy during explosion, and we calculated how much of the released energy was transferred to neutrinos. Value of the speed of sound in the strongly interacting matter measured at the LHC confirms that presented here model is correct. Our calculations show that the Universe is cyclic.

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.

农业自动卷管机设计与试验

为了解决农业喷灌作业过程中通过人工收放水管存在效率低下、劳动强度大的问题,设计了一种由导向机构、收放管机构、排管机构及控制系统组成的自走式农业自动卷管机,提出了基于步进电机的精密排管系统以及基于增量式PID的恒张力收放管控制方法,开发了自动卷管机实物样机。样机试验结果表明:自动卷管机的排管效果良好,能够适应多种管径的水管且水管排列整齐紧密;卷管机的恒张力控制性能良好,在4.0km/h小时车速工况下,水管张力的最大相对误差为7.7%;在(0~4.0)km/h速度阶变工况下水管张力的最大相对误差为15.3%,收放管的速度能够自适应车速变化,水管的张力始终处于合理范围内。

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.

基于改进鲸鱼算法的收卷张力PID控制的性能优化

PID控制器的参数决定张力控制系统的稳定性和速度,因此研究收卷张力控制中经典PID控制器参数整定优化问题具有重要意义。以卷绕张力系统为切入点,结合PID和改进的鲸鱼优化算法,设计了基于改进鲸鱼算法(L-WOA)的PID张力控制器;为了提高PID整定参数方法的收敛精度和速度,在进行整定时结合了改进鲸鱼算法;建立数学模型和动态转矩平衡方程,分析了线速度和卷径对卷材张力的影响;分别使用改进鲸鱼算法和其他多种算法进行了参数优化。仿真结果表明,采用改进鲸鱼算法优化PID的控制策略具有响应速度快、控制输出稳定、抗干扰能力强、鲁棒性好等优点。

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。

小艇收放装置波浪补偿功能的设计与应用

随着船舶航海任务需求的日益增加,对小艇收放装置吊放小艇的安全性提出了更高的要求。为在气象多变、海况恶劣的海洋环境下安全收放小艇,通过对小艇收放装置波浪补偿功能的设计、实现和应用,该波浪补偿功能可保障小艇收放装置在4级海况下安全收放小艇,有效降低了海浪对小艇的冲击,提高了人和艇的安全性。

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。