共查询到19条相似文献,搜索用时 250 毫秒
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经编机编织过程中首先要实现控制经纱在1个横列内不同角度区域张力值的变化,才能达成纱线的动态张力补偿控制。为解决当前系统控制经轴送经量出现的纱线张力波动大,且无法精确到控制1个横列内不同角度纱线张力等缺陷,设计了一种基于模型预测的经编送经动态张力补偿系统。通过结合经编机成圈机构运动规律进行分析,设计出系统的硬件和软件平台,优化张力传感器选型,设计了电子凸轮规划曲线算法和模型预测控制算法,实现了纱线动态张力补偿控制。通过理论分析和实验测试,从反馈的纱线动态张力值曲线分析验证了该模型预测控制算法能够使纱线张力峰值降低至少56%以上。 相似文献
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纱线卷绕系统具有不确定性及时变性、纱线卷绕张力值小的特点,导致纱线卷绕张力波动大,控制精度不高等问题。为此,提出了一种卷绕系统恒张力模糊控制策略,理论推导了系统的控制模型,设计了模糊自适应控制器,并最后进行了仿真与实验。结果表明:模糊自适应PD控制器具有良好的鲁棒性,突发干扰信号下,调节时间大约为15ms;在目标张力值8cN时,实际张力测试误差变化范围为-0.2~0.3cN,误差小,达到了较理想的控制效果。 相似文献
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李正 《国外纺织技术(纺织针织服装化纤染整)》1993,(11)
对于任何成功的织造工艺来说,纱线张力是最重要的因素之一。在织造过程中,纱线张力应尽可能保持恒定。现在纱线张力的控制技术已得到了很大的发展,并研制出了能确保经纱 相似文献
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在纺纱过程中,纱线张力的大小直接影响到筒纱的成形、纱线的质量和织机的生产效率。本文通过对络筒过程中纱线张力的产生原理、影响纱线张力波动的因素进行分析,设计了一种基于DSP的闭环式恒张力喂送纱线的系统。该系统以美国TI公司生产的电机专用芯片DSP28035为主控芯片,实时采集纱线张力传感器传送的纱线张力,利用智能PID控制方法,实现对一个超低惯量高动态性能伺服电机转速的全数字化控制,以达到纱线恒张力喂送的目的。该系统不但具有张力设定、过电流保护、错误报警等功能,还具有结构简单、成本低、实时性好、控制精度高等特点。 相似文献
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因不同的编织锭子放线速度将对纱线张力造成波动影响继而改变编织件品质,针对编织锭子放线速度影响纱线张力值的问题,通过研究高速绳带类编织机的工作路径,获取编织锭子放线速度范围;然后分析曲折式纱线补偿类锭子的工作原理,建立相应的纱线张力模型;再根据纱线张力模型进行Mat Lab仿真计算;最后对比仿真结果,总结此类锭子在放线过程中对纱线张力的调控规律。同时,对编织锭子的工作进行阶段性动态计算,并在不同放线速度下分析纱线张力仿真结果。研究结果表明:锭子快速放线将缩短纱线张力波动周期,缩小纱线张力波动范围,且令纱线筒持续放线。 相似文献
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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。 相似文献
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In order to control yarn vibration and improve carpet quality, it is essential to research the fluctuation of yarn tension and its influences during tufting process. Assuming the polypropylene yarn has linear elasticity with a circular cross-section, we take the dynamic tension as the output and the friction acted on yarn by Jacquard roller as the input. At the moment of clutch operation and release, the tension fluctuation of polypropylene yarn during transmission from pulling roller to Jacquard roller was theoretically analyzed. A mathematical model describing yarn tension fluctuation was derived based on the moment of momentum theorem and mass conservation. The dynamic tension was obtained by applying Laplace’s transformation, providing the input-breaking moment as a step response. The result shows that tension fluctuation has an important influence on the carpet quality; therefore, it is necessary to carefully design the Jacquard roller and the control friction plate of clutch. Moreover, the effects of the yarn length between Jacquard rollers and pulling rollers on natural frequency and damping coefficient of yarn tension fluctuation were analyzed. 相似文献
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This article proposes a method for simulating plain woven fabric appearance based on photographs taken by still camera of actual yarns along their lengths. The survey mathematically models the transformation of yarns from a straight circular cylinder to a flattened and crimped form in the fabric structure. The simulation is performed by yarn images that are obtained by image processing techniques and resized according to mathematical models developed by means of the software prepared. Transforming circular yarn cross-section to elliptical one for simulating yarn flattening and modelling the crimped shape of yarn by an elastica curve are both convenient and realistic. The simulation of plain woven fabric can be performed by a method based on raster graphics. This article provides a model for yarn shape in fabric structure as well as a method for simulating plain woven fabric appearance. This method may be used in textile industry for design and quality control. 相似文献
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The carriers are moved along the eight-shaped orbit during braiding, which makes the length of dynamic catenary fluctuate in a certain range. With changing the release speed of carriers, the yarn tension is difficult to maintain stability. The varying tension affects the structure and mechanical properties of the products. In this paper, the calculation of geometrical dimension is carried out for common carriers. The aim is to analyze the influence of the pulleys wrapping angle, the spool rotation speed and tension control during braiding. For the same processing task, the kinematics and dynamics models of the radial-direction and axial-direction braiding are established using the Newton–Raphson iterative method. Comparing the simulation results, the fluctuant range and the changing rules of the yarn tension are analyzed, which will provide the theoretical basis for braiding carriers design in the future. 相似文献
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簇绒地毯织机纱线张力是影响提花质量的关键因素,为对其进行有效控制,本文研究了步进电机输入对簇绒提花装置区间绕过纱线张力的动态变化情况。首先建立提花装置的步进电机的负载模型,并分析其角频率输入对输出电磁转矩的对应关系;然后,根据米纳科夫定理的原理,建立纱线段绕过提花罗拉前后纱线动态张力模型。同时,进一步分析步进电机的输入与提花装置绕纱的输出动态张力之间的数学模型,在选定提花罗拉半径r、中心距 、纱线包角 等初始条件下,利用迭代-欧拉法分析其数值变化情况,得出角频率输入与纱线张力输出之间的定量关系,并探究不同包角对纱线动态张力的影响机制,为不同绒高的簇绒地毯甚至满幅簇绒提花地毯的制造和研究提供参考。 相似文献
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为解决因配色复杂多变,数码纱外观难以直观预测的问题,提出基于纤维单元的模拟方法,用于实现数码纱外观的仿真。依据纤维原料颜色数值,构建纤维级别的纹理模型;根据纺纱工艺参数计算数码纱上的区域色块参数,构建色块排列模型;利用不同组分纤维间渐变规律,同时结合光照模型仿真亮度信息构建颜色渐变模型;采集真实数码纱的直径数据,仿真纱线的直径形态。实验中分别保持颜色和组分不变,模拟出不同组分和颜色的数码纱。结果证明所提出的纱线仿真方法可较快地模拟出数码纱的外观,并且与实际数码纱的外观视觉十分接近,为数码纱的设计开发以及织物仿真奠定了基础。 相似文献