基于PLC的地毯自动上胶控制系统的开发

介绍了旋转式织毯上胶复合一体机的一个子系统——基于PLC的地毯自动上胶控制系统。该系统通过旋转编码器采集地毯圆机的织毯信息,然后PLC据此控制上胶系统的各个执行元件的动作,达到上胶与织毯同步进行的目的。     

Assessing performance and uncertainty in developing carpet reverse logistics systems

The US carpet industry is striving to reach a 40% diversion rate from landfills by 2012, according to a memorandum of understanding signed by industry and government officials in 2002. As a result, they are interested in methods of setting up a reverse logistics (RL) system which will allow them to manage the highly variable return flows. In this paper, we simulate such a carpet RL supply chain and use a designed experiment to analyze the impact of the system design factors as well as environmental factors impacting the operational performance of the RL system. First, we identify the relative importance of various network design parameters. We then show that even with the design of an efficient RL system, the use of better recycling technologies, and optimistic growth in recycling rates, the return flows cannot meet demand for nearly a decade. We conclude by discussing possible management options for the carpet industry to address this problem, including legal responses to require return flows and the use of market incentives for recycling.     

Musculoskeletal disorders among female carpet weavers in Iran

The aim of this study was to determine factors associated with self-reported upper extremity musculoskeletal disorders (UEMSDs) among female carpet weavers. Data on demographic characteristics and workplace factors were collected from 626 female carpet weavers. Type of carpet weaving looms, weaving style (Persian vs. Turkish), daily working hours and work experience as well as personal factors including age and marital status were significantly and independently associated with self-reported UEMSDs (p < 0.05), while education, handedness and weight of weaving comb were not. A major finding of this study was the significant association between weaving style and UEMSDs. Better measures of the biomechanical requirements of carpet weaving tasks in Persian and Turkish weaving types are required to understand better their influences on the health of weavers and on UEMSDs in particular. Poor workstation design, in particular, design inappropriate for the anthropometric dimensions of weavers, was a major risk factor for musculoskeletal symptoms in carpet weaving. Therefore, this industry should develop equipment adapted to women's sizes and shapes. PRACTITIONER SUMMARY: This article provides an insight into the risk factors associated with self-reported UEMSDs among female carpet weavers, identifying major factors associated with upper extremity musculoskeletal symptoms and exploring guidelines for designing weaving workstations.     

基于嵌入式Linux的簇绒机控制系统上位机设计

根据簇绒机工作原理,设计了簇绒机控制系统。在分析控制系统需求的基础上,设计了基于嵌入式Linux的簇绒机控制系统上位机,详细介绍了地毯图片处理和串行通信模块设计,最后给出了簇绒机控制系统上住机开发实例。     

A facility location allocation model for reusing carpet materials

Re-using the huge quantities of carpet waste that are yearly generated has become a must. A facility location–allocation model for the collection, preprocessing and redistribution of carpet waste is presented. This model differs from other mathematical models for supporting the design of the logistic structure of reuse networks among others in a completely free choice of the locations for preprocessing and in explicitly taking into account depreciation costs. Two applications of the model, one in Europe and one in the United States of America, are described.     

剑麻地毯定长包装控制器的设计

应用单片机设计剑麻地毯定长包装控制器,改进传统的剑麻地毯定长包装控制方法中不良之处。并详细介绍了系统设计、仿真及调试方法。该控制器人机界面友善,操作简单方便,并能提高测量精度,现场运行稳定可靠。     

Modelling of a carpet installer knee-kicker

A model of a carpet installer's knee-kicker is presented. A “knee-kicker” is a tool used by a carpet installer in stretching a carpet. It consists of a rod with a knee pad on one end and barbs on the other end. During use, the tool is placed on the carpet and it is then impacted on the knee pad by the suprapatellar region of the knee of the carpet installer. The tool is modelled by a viscoelastic solid representing the knee pad and an elastic column representing the rod. The behavior of this system during a kicking cycle can be described by a pair of differential equations. Solutions to these equations are also presented. The results are compared with experimental data and with results from a biodynamic model of the carpet installer. It is found that the typical knee-kicker pad does little to attenuate the impulse of the kick stroke. Recommendations for improving the pads are suggested.     

Computer-aided design of textiles

This paper, extracted from a SRC project report, is concerned with aspects of the computer-aided design of textiles. It chronicles technological innovation in a number of industnal textile areas including weft and warp knitting, carpet and clothing manufacture and printing. Historical, current and future aspects of machinery and data processing development for textiles are reviewed as well as wider issues concerning the introduction of c.a.d. into production and design environments.     

浅谈北京式地毯的发展史

北京式地毯是我国地毯的典型代表,它具有悠久的历史和深厚的文化底蕴,通过对北京式地毯的历史发展进行了深入的了解与研究。详细的探究了北京式地毯的由来,以及其初期、中期和现代的发展,并分析了影响其发展的因素,最后,结合当下地毯业的发展状况来分析北京式地毯未来应有的发展趋势。     

Evaluation of occupational knee-joint stress using liquid crystal thermography: a case study

This paper describes a method to detect knee stress using liquid crystal thermography and presents the results of a case study in which the system was applied to two carpet installers. The method involves placing heat-sensitive sheets of film on the knees of workers at various intervals during the work day. The thermographic sheets react to variations in heat by changing colour. The measurements are taken with the worker's knee positioned in an illuminated, enclosed box. Once the patch stabilizes, the exhibited colours are recorded with an 8 mm video camera. The colour pattern, ranging from brown to blue, provides a thermal record of what is believed to be knee stress resulting from installing carpet. The thermographic records are stored in computer memory for subsequent analysis using an AT&T TARGA 16 video board. Custom software allows computation of the area of each distinct colour pattern as a percentage of total patch size. These records provide a characterization of knee response (inflammation) resulting from the biomechanical load sustained by the knee during the carpet installation task.     

基于CAN总线的多绒高地毯簇绒机提花控制系统设计

在对地毯簇绒机多绒高提花控制要求的分析基础上,本文提出了一种基于CAN总线的提花控制总体方案,采用DSP技术实现对120个无刷直流电机进行控制,从而完成簇绒提花。并针对提花控制的具体要求,设计了提花控制节点。在MATLAB／SIMULINK中对提花控制系统进行了建模仿真,证实了方案的可行性。     

Continuous assessment of back and upper arm postures by long-term inclinometry in carpet weavers

Awkward back and shoulder postures have been suggested to be a cause of back and shoulder discomfort in carpet weavers. This study aimed at continuous assessment of the upper arm and back postures and estimation of biomechanical load subtasks using inclinometers during 4 h.Median of trunk flexion angle in weavers was 18° and 13° during knotting and compacting subtasks, respectively. The weavers worked with arms elevated greater than 45° for %4.5 of the work time. The average cumulative compression load for males and females were estimated at 22 MN-S and 13 MN-S, respectively.In addition to poor workstation design, constrained posture of the trunk and low elevation and velocity for both arms may be the main risk factors for developing fatigue and disorders in the back and shoulder regions among carpet weavers. Therefore, any ergonomic interventions should be focused on reducing trunk flexion and the constrained postures of weavers.     

Evolutionary optimization of Haferman carpet fractal patterned antenna array

This article investigates radiation characteristics of a new type of fractal shaped antenna array based on Haferman carpet geometry. An iterative feed matrix eases the complexity of array factor calculation that makes the array factor suitable for the application of any evolutionary optimization techniques. It is seen that Haferman carpet array produces peak side lobe level (PSLL) better than Sierpinski carpet that produces ?10 dB PSLL at every stage of growth. Optimization techniques have been applied for array element reduction and PSLL minimization at different stages of growth. Here, PSLL is minimized by turning off array elements and also by varying inter element spacing between the array elements. The optimized version of Haferman carpet array produces better characteristics (49.38% thinning with ?20.5 dB PSLL for stage‐2, 46.3% thinning with ?22 dB PSLL for stage‐3 and 42.3% thinning with ?21dB PSLL for stage‐4) than its original counterpart in terms of reduced element count and PSLL. Numerical results for obtaining optimized array performance exploit both DE as well as PSO. A comparative study on the performance is also presented. As a whole, Haferman carpet is seen to be more effective approach than Sierpinski carpet in fractal antenna paradigm. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:719–729, 2015.     

地域特色在新疆织毯装饰上的表现

织毯为人们的日常生活增添了一抹绚丽、浪漫的色彩。新疆拥有广阔的天然草地面积,畜牧业发达,因而产生了大量的优质毛料,为织毯的发展奠定了基础。同时众多少数民族、游牧民族聚居于此,不同的民俗、不同的宗教影响于织毯的装饰风格,使新疆地毯极具地域特点。随着社会的发展,织毯的社会功能逐渐高于它的使用功能。织毯除了满足人们生理需求与视觉享受之余,更多的是对其地域思想、地域文化的体现,并对其进行推广与传播。     

基于颜色量化和密度峰聚类的彩色图像分割

彩色图像分割是簇绒地毯数字化制造的关键技术,图像的分割质量直接影响到后续的图像处理。为解决地毯的彩色图像分割问题,针对人眼在RGB颜色空间中感知不均匀的特性,提出了一种基于颜色量化和密度峰聚类的彩色图像分割算法。基于Lab颜色空间进行颜色量化,在HVC颜色空间中用NBS距离来衡量人眼对颜色差异的感知程度,采用改进的密度峰聚类算法自动确定聚类中心,从而分割地毯图案。实验结果表明,该算法能在不影响人眼感知的前提下得到颜色种类少且边缘清晰的地毯分割图像。     

Perturbed Sierpinski carpet resonator and its usage in compact dual and triple band bandpass filters

In this paper, perturbed Sierpinski carpet fractal shaped resonator is characterized and applied in the design of multiband band pass filters (BPFs). The route to achieving compact multimode resonators starting from the Sierpinski carpet fractal shaped resonator is detailed. The proposed resonators are used to demonstrate two topologies of dual band bandpass filters with passband center frequencies at 3.5 GHz as well as 5.5 GHz, respectively. Both the designs exhibit nearly identical passband bandwidth. In the second design, it is observed that the second passband gets slightly shifted towards 5.85 GHz. However, with edge loading this shift is nullified. A scaled down version of the same resonator is designed and three such resonators are interdigitally coupled in conjunction with complementary split ring resonators to exhibit a novel technique of achieving compact triband bandpass filter. All designs have acceptable passband insertion loss in the respective bands. Accessories are used to improve passband selectivity in all designs and also a wide stop band till 10 GHz is obtained. Fabrication prototypes for all the variants are realized with simulated and measured results in good agreement. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:418–425, 2016.     

Musculoskeletal problems in Iranian hand-woven carpet industry: guidelines for workstation design

Long hours of static work with awkward posture at traditionally designed looms can cause high prevalence of musculoskeletal disorders (MSDs) among carpet weavers. A comprehensive study was conducted in this industry with the objectives of determination of MSDs symptoms prevalence; identification of major factors associated with MSDs symptoms in carpet weaving occupation; and development of guidelines for weaving workstation design. In the present paper, this ergonomics study is presented. The study consisted of two phases. In the first phase, MSDs symptoms in nine Iranian provinces were surveyed by questionnaire among 1439 randomly selected weavers. Working posture and weaving workstations were ergonomically assessed as well. The results of this phase revealed that symptoms from the musculoskeletal system occurred in high rate among weavers with the prevalence significantly higher than that of the general Iranian population (P<0.001). It was found that the majority of ergonomics shortcomings originated from ill-designed weaving workstation. Based on the findings, some general guidelines for workstation design were presented. In the second phase, considering the general guidelines, an adjustable workstation was designed and constructed. To develop quantitative guidelines for optimizing workstation set-up, in the laboratory, nine sets of experimental conditions were tested, and working posture and weavers' perceptions were measured. The results of this lab work showed that working posture was acceptable for both the researchers and the weavers when the weaving height was adjusted 20 cm above the elbow height and a high seat with forward slope was used. By combining the results of the two phases, guidelines for weaving workstation design were presented. In this ergonomics-oriented workstation, loom is vertical. Seat, loom and weaving heights are adjustable. There is enough leg room under the loom. The seat with 10 degrees forward slope is adjusted 15 cm above the popliteal height of the weaver. Weaving height is set at 20 cm above the elbow height. It is believed that the recommended workstation improves working posture and results in reduced postural stress on weavers' bodies and, consequently, reduced prevalence of MSDs symptoms.     

Self-assembly of 4-sided fractals in the Two-Handed Tile Assembly Model

We consider the self-assembly of fractals in one of the most well-studied models of tile based self-assembling systems known as the Two-Handed Tile Assembly Model (2HAM). In particular, we focus our attention on a class of fractals called discrete self-similar fractals (a class of fractals that includes the discrete Sierpiński carpet). We present a 2HAM system that finitely self-assembles the discrete Sierpiński carpet with scale factor 1. Moreover, the 2HAM system that we give lends itself to being generalized and we describe how this system can be modified to obtain a 2HAM system that finitely self-assembles one of any fractal from an infinite set of fractals which we call 4-sided fractals. The 2HAM systems we give in this paper are the first examples of systems that finitely self-assemble discrete self-similar fractals at scale factor 1 in a purely growth model of self-assembly. Finally, we show that there exists a 3-sided fractal (which is not a tree fractal) that cannot be finitely self-assembled by any 2HAM system.

     

遗传算法在Sierpinski地毯Hausdorff测度计算中的研究与应用

遗传算法是一种高效的全局优化概率搜索算法,基于分形几何中测度难以计算的问题,本文提出了采用遗传算法来求解Sierpinski地毯近似最优Hausdorff测度的思想,并研究和分析了遗传算法在Sierpinski地毯Hausdorff测度计算中的具体实现。     

Traumatogenic factors affecting the knees of carpet installers

An ergonomics analysis of carpet installation tasks was performed. The purpose was to identify and quality potential sources of biomechanical trauma that may be responsible for the high rates of knee morbidity found by previous researchers among carpet layers. Nine carpet layers were studied either at an apartment building worksite or at a training school. Results from a job analysis indicated that workers spent approximatately 75% of their time in the kneeling position using a tool called a knee-kicker to stretch and install carpet. Awkward body postures were identified from films of workers installing carpets. At the moment of impact the knee is severely flexed, subtended angles were less than 60 degrees. To obtain measures of impact force on the knee, the kicker-tool was instrumented with a load cell. Workers who executed the hardest kicks with the tool produced impact peak forces that averaged 3019 newtons (N), which is equivalent to about four times body weight. Measures from an accelerometer attached to the worker's knee showed values in ecxess of 120 m/s², which are comparable to those found during vigorous running and jumping exercises. The results imply that repetitive impact of the knee joint from the use of the knee-kicker combined with knee flexion, kneeling and squatting may be responsible for the high level of occupational knee-morbidity found among carpet layers.