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Numerical and Experimental Investigation of Rheodrop Technology 流变滴技术的数值与实验研究
Pub Date : 2022-10-30 DOI: 10.1115/imece2022-94952
K. Alqosaibi, Mohammed Alemmrani, Ahmed Almalki, A. Duhduh, J. Coulter
A novel invention to advanced hot runner-based injection molding called Rheodrop technology is introduced. The technology allows control over the melt rheology inside the hot drops during/between injection molding cycles. The concept is to rotate the valve pin inside the hot drop to apply a controlled shear rate to the polymer melt. Doing so eliminated the incomplete filling defects associated with molding thin-walled parts and allowed processing at a lower melt temperature. The applied shear stress by Rheodrop technology was investigated utilizing ANSYS fluent software. The maximum shear stress that the polymer gets exposed to during the injection molding cycle was specified using Moldflow software. The results showed that the Rheodrop applies less shear stress than what the polymer gets exposed to during the injection molding cycle. Thus, utilizing Rheodrop does not cause additional damage to the polymer melt. Rheometric analyses were performed to investigate the polymer degradation for ABS. The reduction rate of viscosity was the same for samples that were injection molded conventionally and samples that were molded using Rheodrop technology.
介绍了一种先进的热流道注射成型技术——流变滴技术。该技术允许在注射成型周期期间/之间控制热滴内部的熔体流变。其原理是旋转热滴内部的阀销,以控制聚合物熔体的剪切速率。这样做消除了与薄壁件成型相关的不完全填充缺陷,并允许在较低的熔体温度下进行加工。利用ANSYS fluent软件对流变降技术施加的剪切应力进行了研究。聚合物在注射成型周期中暴露的最大剪切应力是使用Moldflow软件指定的。结果表明,流变滴施加的剪切应力小于聚合物在注射成型周期中暴露的剪切应力。因此,使用流变液不会对聚合物熔体造成额外的损害。通过流变学分析,研究了ABS的聚合物降解情况。常规注射成型和使用Rheodrop技术成型的样品的粘度降低率是相同的。
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引用次数: 0
Assembly Automation Using an Industrial Robot 用工业机器人实现装配自动化
Pub Date : 2022-10-30 DOI: 10.1115/imece2022-94986
Timofey Dragun, Seth Mascaro, J. Blanchard, Vedang Chauhan
Industrial automation is a prominent process that has been around for many years and is continuing to evolve. An important aspect of automation is industrial robots. This paper focuses on an automated circuit board assembly process. Components of the assembly are described and identified, as well as a completed assembly is shown with 3D printed components. Important camera setup steps are documented and discussed in addition to the iRVision Geometric Pattern Matching (GPM) tool which is used to teach the camera how to find parts. The process was first developed using ROBOGUIDE simulation software, once validated the program was implemented on a physical FANUC LR Mate 200iD/4s robot. Trial runs were completed with both the physical robot and the ROBOGUIDE simulation, with the data being analyzed to determine the system performance. Comparing the physical robot to the ROBOGUIDE simulation has revealed that the physical robot can perform as well as the simulation in terms of part detection, but suffers when it comes to speed. Simulation in the virtual software is a quick and easy way to visualize and analyze the robotic work cell before investing money into implementing it in the real world.
工业自动化是一个突出的过程,已经存在了很多年,并且还在继续发展。自动化的一个重要方面是工业机器人。本文主要研究电路板的自动化装配过程。组件的组件被描述和识别,以及一个完整的组件显示与3D打印组件。除了iRVision几何模式匹配(GPM)工具外,还记录和讨论了重要的相机设置步骤,该工具用于教相机如何查找零件。该流程首先使用ROBOGUIDE仿真软件进行开发,一旦验证,该程序将在FANUC LR Mate 200iD/4s物理机器人上实施。通过物理机器人和ROBOGUIDE模拟完成了试运行,并对数据进行了分析以确定系统性能。将物理机器人与ROBOGUIDE仿真进行比较,发现物理机器人在零件检测方面可以表现得与仿真一样好,但在速度方面则受到影响。在投入资金在现实世界中实现机器人工作单元之前,虚拟软件中的仿真是一种快速简便的方法来可视化和分析机器人工作单元。
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引用次数: 0
A Multi-Scale Model for Microstructure Evolution During a Multi-Material Additive Manufacturing Process 多材料增材制造过程微结构演变的多尺度模型
Pub Date : 2022-10-30 DOI: 10.1115/imece2022-92563
A. Abubakar, K. Al-Athel, S. S. Akhtar, Abdulazeez Abubakar
Powder-based additive manufacturing (AM) technologies are commonly used to fabricate intricate-shape three-dimensional (3D) composite parts. The present study provides further insights into powder melt pool behavior and microstructure evolution during additive manufacturing of Hastelloy(HX)/WC composite using sequentially coupled multi-scale models. At the macro-scale, the heat transfer model is used to predict the temperature distribution and melts pool geometry formed during laser heating of multi-material powder bed. At the mesoscale, the phase-field and heat transfer models are coupled to predict the evolution of grains during the solidification of the powder melt. The computational results are reasonably comparable to that of the experiments. It is found that an ellipsoidal melt pool shape is formed around the irradiated zone. The temperature, thermal gradient and cooling rate changes across the melt pool dimensions. Due to epitaxial growth, columnar (elongated) grains are developed near the solid-liquid interface. In contrast, equiaxed grains are formed near the top regions of the melt pool due to higher cooling rates. The elongated grains become split into equiaxed ones due to the presence of the WC particles. The presence of the larger WC particles enhances the cooling rate; thereby, resulted in grain refinement. Reducing the WC particle size still results in grain refinement due to the pinning effect on grain boundaries; however, the grain size becomes affected by the WC particle size. The inclusion of foreign particles could be used to inhibit anisotropic behavior in 3D printed parts.
粉末增材制造(AM)技术通常用于制造复杂形状的三维(3D)复合材料零件。本研究利用顺序耦合多尺度模型对哈氏合金/碳化钨复合材料增材制造过程中的粉末熔池行为和微观结构演变进行了进一步的研究。在宏观尺度上,利用传热模型对多材料粉末床激光加热过程中的温度分布和熔池几何形状进行了预测。在中尺度上,结合相场和传热模型对粉末熔体凝固过程中晶粒的演化进行了预测。计算结果与实验结果有较好的可比性。结果表明,辐照区周围形成椭球形熔池。温度、热梯度和冷却速率随熔池尺寸的变化而变化。由于外延生长,柱状(拉长)晶粒在固液界面附近发育。相反,由于较高的冷却速率,在熔池顶部区域附近形成等轴晶。由于WC颗粒的存在,拉长的晶粒分裂成等轴的晶粒。较大WC颗粒的存在提高了冷却速度;因此,导致晶粒细化。由于钉住晶界的作用,减小WC晶粒尺寸仍会导致晶粒细化;晶粒尺寸受WC粒度的影响。异物颗粒的加入可以用来抑制3D打印部件的各向异性行为。
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引用次数: 0
Data Augmentation Using Spectral Failure Deltas to Diagnose Bearing Failure 利用频谱故障增量进行数据增强诊断轴承故障
Pub Date : 2022-10-30 DOI: 10.1115/imece2022-93869
Ethan Wescoat, Matthew Krugh, L. Mears
Labeled training data are challenging to obtain in a manufacturing environment during production due to the time and cost constraints of the labelling process. Of the labeled training data that is collected, failure data comprises a small proportion or is non-existent in production datasets for condition monitoring. The small proportion can be related to failures occuring uxpectedly and parts are replaced quickly, meaning the failure state is rare and makes up a small portion of the run life and number of samples collected. The lack of labeled data and failure data leads to challenges in creating effective predictive systems, such as Digital Twins, to accurately determine equipment health state and remaining useful life. This work investigates training predictive algorithms using an augmented failure data set derived from laboratory systems with knowledge of real-world failures. Data are collected under different failure progressions and operating conditions to create variability for the variety of different production applications to apply these data augmentation methodologies. These same data are transformed by adding the variability measured through purposefully damaging the mechanical system to create the degraded and failed state data. This variability is extracted using a spectral augmentation technique on the surrogate system’s failure data under an artificial fatigue case. The fatigue case is created by incrementally damaging the bearing raceway and measuring the damaged surface area with respect to the total bearing raceway. The measured difference between these pre- and post-lab damage states is used as the damage state data set transformation function. The augmented and “true” data are then compared using class probability analysis and diagnosing particular failure instances. For future research, relatability analysis will be investigated to see how the effects change between bearings of different sizes.
由于标注过程的时间和成本限制,在生产环境中获得标注训练数据是具有挑战性的。在收集的标记训练数据中,故障数据只占很小的比例,或者不存在于用于状态监测的生产数据集中。这一小部分可能与意外发生的故障和零件的快速更换有关,这意味着故障状态很少,只占运行寿命和采集样品数量的一小部分。缺乏标记数据和故障数据导致在创建有效的预测系统(如Digital Twins)以准确确定设备健康状态和剩余使用寿命方面面临挑战。这项工作研究了使用来自实验室系统的增强故障数据集来训练预测算法,并了解了现实世界的故障。在不同的故障进展和操作条件下收集数据,为各种不同的生产应用创造可变性,以应用这些数据增强方法。这些相同的数据通过添加可变性进行转换,通过有目的地破坏机械系统来创建退化和失效状态数据。在人工疲劳情况下,利用谱增强技术对替代系统的失效数据进行提取。通过逐渐损坏轴承滚道并测量相对于整个轴承滚道的损坏表面积来创建疲劳情况。将实验前后损伤状态的测量差值作为损伤状态数据集的变换函数。然后使用类概率分析和诊断特定故障实例来比较增强和“真实”数据。对于未来的研究,将研究相关性分析,以了解不同尺寸的轴承之间的影响如何变化。
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引用次数: 0
Compostable, Full Biobased Foams Using Environmentally Benign Manufacturing 使用环保制造的可堆肥、全生物基泡沫
Pub Date : 2022-10-30 DOI: 10.1115/imece2022-95956
K. Oluwabunmi, N. D'Souza, Weihuan Zhao
With initiatives on carbon capture utilization, use of CO2 in the manufacture of foamed polymers is valuable. The low solubility and strong temperature/pressure correlation to utilization remains a limit. Here we explore two aspects of green manufacturing. Use of a biopolymer and CO2 to foam it. Microcellular foams were produced from amorphous polylactic acid (PLA) with 12% d-lactide content using the batch foaming method. The batch method produces foams that are affected by cell nucleation, growth and solidification. In the thermal soak method, CO2 was introduced into PLA above its Tg, depressurized resulting in solidification, followed by soaking in a hot water bath for trapped CO2 to be released. In a second method, CO2 injected above the Tg was held at a temperature above ambient to encourage cell growth followed by a quench. The results showed that foams made through the decompression technique at foaming temperature of 55 °C were rigid in nature and had a better mix of cellular architecture due to their well-defined bimodal cellular structure compared to the foams made at foaming temperature of 75° C. Excellent mechanical and good sound absorption properties were attributed to the bimodal distr. Thermal conductivity values of (0.031–0.063) W/mK obtained for the PLA foams made using the thermal soak and decompression techniques was equivalent to that of petroleum based extruded polystyrene (EPS) and expanded polystyrene (XPS) foams ∼ (0.03–0.06) W/mK valuable for building insulation.
随着碳捕获利用的倡议,在泡沫聚合物的制造中使用二氧化碳是有价值的。低溶解度和较强的温度/压力相关性仍然是限制。在这里,我们探讨绿色制造的两个方面。使用生物聚合物和二氧化碳使其发泡。以d-丙交酯含量为12%的无定形聚乳酸(PLA)为原料,采用间歇发泡法制备了微孔泡沫。间歇法产生的泡沫受细胞成核、生长和凝固的影响。在热浸泡法中,将高于Tg的CO2引入PLA中,减压使其凝固,然后将其浸泡在热水浴中以释放捕获的CO2。在第二种方法中,注入高于Tg的二氧化碳被保持在高于环境温度的温度下,以促进细胞生长,然后淬火。结果表明,在55℃的发泡温度下,减压技术制备的泡沫具有较好的刚性,并且与75℃的发泡温度下制备的泡沫相比,双峰发泡技术制备的泡沫具有较好的多孔结构,具有良好的力学性能和吸声性能减压技术与石油基挤压聚苯乙烯(EPS)和膨胀聚苯乙烯(XPS)泡沫相当,对建筑绝缘具有(0.03-0.06)W/mK的价值。
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引用次数: 0
An Integrated Task and Path Planning Approach for Mobile Robots in Smart Factory 智能工厂中移动机器人任务与路径集成规划方法
Pub Date : 2022-10-30 DOI: 10.1115/imece2022-95364
Shuo Liu, Bohan Feng, Dan Yu, Youyi Bi
Mobile robots are being widely used in smart manufacturing, and efficient task assignment and path planning for these robots is an area of high interest. In previous studies, task assignment and path planning are usually solved as separate problems, which can result in optimal solutions in their respective fields, but not necessarily optimal as an integrated problem. Meanwhile, precedence constraints exist between sequential processing operations and material delivery tasks in the manufacturing environment. Thus, those planning methods developed for warehousing and logistics may not simply apply to the environment of smart factories. In this paper, we propose an integrated task and path planning approach based on Looking-backward Search Strategy (LSS) and Regret-based Search Strategy (RSS). In the stage of task assignment, the real paths for mobile robots are identified based on the Cooperative A* (CA*) algorithm and the time and energy consumed by mobile robots and machining centers are calculated. Then a greedy strategy working with LSS or RSS is used to search reasonable task assignments in time-series, which can generate a joint optimal solution for both task assignment and path planning. We verify the validity of the proposed approach in a simulated smart factory and the results show that our approach can improve the operation efficiency of the smart factory and save the time and energy consumption effectively.
移动机器人在智能制造中得到了广泛的应用,高效的任务分配和路径规划是一个备受关注的领域。在以往的研究中,任务分配和路径规划通常是作为独立的问题来解决的,它们在各自的领域可以得到最优解,但作为一个综合问题并不一定是最优的。同时,在制造环境中,顺序加工操作和材料交付任务之间存在优先约束。因此,那些为仓储和物流开发的规划方法可能不仅仅适用于智能工厂的环境。本文提出了一种基于向后看搜索策略(LSS)和基于后悔的搜索策略(RSS)的集成任务和路径规划方法。在任务分配阶段,基于CA* (Cooperative A*)算法识别移动机器人的真实路径,计算移动机器人和加工中心消耗的时间和能量。然后利用贪心策略结合LSS或RSS在时间序列中搜索合理的任务分配,生成任务分配和路径规划的联合最优解。在一个模拟智能工厂中验证了该方法的有效性,结果表明,该方法可以有效地提高智能工厂的运行效率,节约时间和能源消耗。
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引用次数: 0
A Physics-Based Computational Model for the Cold Spray Deposition of Composite Coatings 复合材料涂层冷喷涂的物理计算模型
Pub Date : 2022-10-30 DOI: 10.1115/imece2022-92144
A. Abubakar, A. Arif, S. S. Akhtar, K. Al-Athel
Composite coatings with tailored properties can be effectively deposited with the cold spray process via careful control of deposition parameters. To avoid repetitive experiments, numerical models are commonly used to optimize the cold spray deposition process parameters. The present study proposes using a physics-based hybrid computational approach to model the cold spray deposition of Ni-Ti/Al2O3 composite coating used for wear applications. The method involves using point cloud (for the impacting particles) and finite elements (for the deformed splats structures and substrate) to simulate dissimilar particles impact and interactions, plastic deformation, and temperature rise. The approach is computationally efficient and adequately captures the thermo-mechanical deformation resulting from the interactions among dissimilar particles. The simulations are carried out for various combinations of material types, particles sizes and shapes, and impacting velocities. The results from the simulations are analyzed and validated by comparing them with that of previous works. The plastic deformation and temperature rise within the mating bodies increase with increasing particles’ kinetic energies. The Ni-Ti-Al2O3 powder particles lead to higher plastic deformation, temperature rise, and inter-particle bonding due to the presence of the hard Al2O3 particles. The temperature does not rise above melting; however, recrystallization of coating microstructure becomes possible even at a low deposition rate.
通过对沉积参数的严格控制,可以在冷喷涂工艺中有效地沉积出具有特定性能的复合涂层。为了避免重复实验,通常采用数值模型对冷喷涂工艺参数进行优化。本研究提出了一种基于物理的混合计算方法来模拟用于磨损应用的Ni-Ti/Al2O3复合涂层的冷喷涂沉积。该方法包括使用点云(用于冲击颗粒)和有限元(用于变形的板片结构和基底)来模拟不同颗粒的冲击和相互作用,塑性变形和温升。该方法计算效率高,并能充分捕获由不同粒子间相互作用引起的热-机械变形。对材料类型、颗粒大小和形状以及冲击速度的各种组合进行了模拟。对仿真结果进行了分析和验证,并与前人的研究结果进行了比较。配合体内的塑性变形和温升随粒子动能的增大而增大。Ni-Ti-Al2O3粉末颗粒由于存在坚硬的Al2O3颗粒,导致较高的塑性变形、温升和颗粒间结合。温度不会超过熔点;然而,即使在较低的沉积速率下,涂层微观组织也可能发生再结晶。
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引用次数: 0
Environmental Sustainability of Additive Manufacturing: A Case Study of Indian Manufacturing Industry 增材制造的环境可持续性:以印度制造业为例
Pub Date : 2022-10-30 DOI: 10.1115/imece2022-95349
Alok Yadav, A. Sachdeva, Rajeev Agrawal, R. K. Garg
Manufacturing industries across the globe are now adopting additive manufacturing (AM) practices over the traditional manufacturing process due to less waste generation and other economic and emissions benefits. Additive manufacturing can also be considered a key enabling technology for the high technology plan. However, the practices related to additive manufacturing in developing and developed economies are limited due to knowledge and technological advancements. Environmental impact assessment is an emerging research area highlighted in the last few years. At this point, research and industry attention is focused on determining where AM can replace or create new manufacturing systems. This study compares the environmental impact assessment of traditional and additive manufacturing processes by considering a case of pattern making. This paper also investigates how additive manufacturing technologies contribute to creating a sustainable environment in the manufacturing industry. A real-time case study is performed in SMEs of India, showing that additive manufacturing processes help lower the environmental impacts. The present study also highlighted the opportunities for additive manufacturing in sustainability. The gate-to-gate analysis is performed, and impact assessment is done by GABI software version 9 on Windows 10 operating system. In this report, a case study has been done to compare the traditional IC and AM processes using Aluminum alloy (Al-Si-Cu) in terms of environmental Sustainability. Results show that 28.77% reduction in GWP, 74.04% reduction in emission to Air, 36.30% reduction in AP and 45.62% reduction in HTP by using AM process. Overall, AM process is an environmentally sustainable process. This study would help researchers and the manufacturing industry determine the emissions associated with pattern making using the conventional IC process under Indian climatic conditions. It assists manufacturing industries in choosing the best available IC alternative regarding reduced environmental emissions.
全球各地的制造业现在都在采用增材制造(AM)实践,而不是传统的制造工艺,因为它产生的废物更少,而且具有其他经济和排放效益。增材制造也可以被认为是高科技计划的关键使能技术。然而,由于知识和技术的进步,与增材制造相关的实践在发展中国家和发达经济体受到限制。环境影响评价是近年来发展起来的一个新兴研究领域。在这一点上,研究和行业的注意力集中在确定增材制造可以取代或创建新的制造系统。本研究比较了传统和增材制造工艺的环境影响评估,考虑了一个案例的模式制作。本文还探讨了增材制造技术如何有助于在制造业中创造可持续发展的环境。对印度中小企业进行了实时案例研究,表明增材制造工艺有助于降低对环境的影响。本研究还强调了增材制造在可持续性方面的机会。在Windows 10操作系统上使用GABI软件版本9进行门对门分析和影响评估。在本报告中,对使用铝合金(Al-Si-Cu)的传统集成电路和AM工艺在环境可持续性方面进行了案例研究。结果表明:采用增材制造工艺,GWP降低28.77%,空气排放降低74.04%,AP降低36.30%,HTP降低45.62%。总的来说,AM工艺是一个环境可持续的过程。这项研究将帮助研究人员和制造业确定在印度气候条件下使用传统IC工艺制作图案的相关排放。它帮助制造业选择关于减少环境排放的最佳可用集成电路替代品。
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引用次数: 0
Monitoring and Diagnosis of Dimensional Deviation in Assembly Process Using Tensor Regression 装配过程中尺寸偏差的张量回归监测与诊断
Pub Date : 2022-10-30 DOI: 10.1115/imece2022-95014
Rui Sun, Sun Jin, Yinhua Liu
The monitoring and diagnosis of dimensional deviation is an important means for the continuous improvement of assembly capacity in manufacturing systems. As optical scanning measurements become more common, statistical models based on 3D point cloud data have gained widespread attention. This paper introduces a general tensor regression method that builds a linear regression model between input and output. First, voxel technology is used to transform the 3D point cloud with deviation information into tensor form. Secondly, a Tensor-on-Scalar regression model is established for quality monitoring, and a Tensor-on-Tensor regression model is established for fault diagnosis. Then, tensor decomposition is used to reduce the number of parameters to be estimated in the regression model. Finally, the learning of parameter values is achieved by combining alternating least squares and gradient descent or coordinate descent. A case study of the door inner panel assembly process evaluates the predictive performance of a tensor regression model. The results show that the proposed method outperforms most existing methods in terms of prediction accuracy. Hence, the tensor regression model can achieve high-performance quality monitoring and fault diagnosis.
尺寸偏差的监测与诊断是制造系统装配能力持续提高的重要手段。随着光学扫描测量的日益普及,基于三维点云数据的统计模型得到了广泛的关注。本文介绍了一种通用的张量回归方法,在输入和输出之间建立线性回归模型。首先,利用体素技术将含有偏差信息的三维点云转化为张量形式;其次,建立了用于质量监测的张量-标量回归模型,以及用于故障诊断的张量-张量回归模型;然后,利用张量分解来减少回归模型中需要估计的参数数量。最后,采用交替最小二乘和梯度下降或坐标下降相结合的方法实现参数值的学习。以门内嵌板装配过程为例,评价了张量回归模型的预测性能。结果表明,该方法在预测精度方面优于大多数现有方法。因此,张量回归模型可以实现高性能的质量监测和故障诊断。
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引用次数: 0
Performance Evaluation of Conveyor-Less Matrix Assembly System Using Simulation and Mathematical Models 基于仿真和数学模型的无输送机矩阵装配系统性能评价
Pub Date : 2022-10-30 DOI: 10.1115/imece2022-94996
Min-Soo Kim, Seog-Chan Oh, Eun Hyo Chang, James W. Wells, J. Arinez, Y. Jang
The increasing demand for electric vehicles and the emergence of autonomous transport technologies within production like autonomous mobile robot or self-driving rolling chassis have raised the possibility of developing conveyor-less matrix assembly system. The conveyor-less matrix assembly system is characterized by high adaptability to demand changes with low-cost investments and asynchronous operations allowing high routing and process flexibilities where the sequence of assembly operations is only limited by the product-specific precedence orders. With high flexibility potentials, however, the system needs to face high complexity issues in modeling and control. The high complexity may reduce the system performance and thus, the performance evaluation is a key component in modeling and control of conveyor-less matrix systems. To study the evaluation methods for the conveyor-less matrix assembly, this paper introduces two models, a mixed-integer linear programming model as exact method and a simulation model as heuristic method, and then illustrates how two models are different but can work collaboratively in a hypothetical example drawn from automotive assembly trim area. Finally, this paper intends to provide insights on the business value calculation of conveyor-less matrix assembly system, for practitioners who are interested in building conveyor-less matrix assembly system in the future.
随着对电动汽车需求的不断增长,以及自动移动机器人或自动滚动底盘等自动运输技术在生产中的出现,开发无输送机矩阵装配系统的可能性增加。无输送机矩阵装配系统的特点是具有对需求变化的高适应性,具有低成本的投资和异步操作,允许高路由和过程灵活性,其中装配操作的顺序仅受产品特定优先顺序的限制。然而,该系统具有很高的柔性潜力,在建模和控制方面需要面对较高的复杂性问题。高复杂性会降低系统的性能,因此,性能评估是无输送机矩阵系统建模和控制的关键组成部分。为了研究无输送机矩阵装配的评估方法,本文引入了混合整数线性规划模型作为精确方法和仿真模型作为启发式方法,并以汽车装配装饰区域为例,说明了两种模型的不同但如何协同工作。最后,本文旨在对无输送机矩阵装配系统的商业价值计算提供一些见解,供未来对构建无输送机矩阵装配系统感兴趣的从业者参考。
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引用次数: 1
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