Papers by Keyword: Assembly

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Authors: Yan Cao, Dan Yang, Yu Bai
Abstract: Based on Group Technology, a machine tool fixture library management system based on assembly knowledge description is put forward to maximize the reuse of fixture design knowledge and experience. According to GT classification results, fixture parts are divided into standard ones and non-standard ones. To support parametric assembly, a reuse library is used for parametric standard part design. For the non-standard parts, second development technology is used to realize their parametric design based on 3D model templates. Parametric assembly design is achieved based on assembly relation description. SolidWorks platform, VB programming language and Access database are used to develop the system that includes feature-based parameter-driven parts and assemblies for machine tool fixtures.
Authors: Marcin Zemczak, Damian Krenczyk
Abstract: The paper presents the task scheduling issue, which main aim is to establish a proper sequence of tasks, that would maximize the utilization of companys production capacity. According to the literature sources, the presented sequencing problem, denoted as CSP (Car Sequencing Problem) belongs to the NP-hard class, as has been proven by simple reduction from Hamiltonians Path problem. Optimal method of solution has not yet been found, only approximate solutions have been offered, especially from the range of evolutionary algorithms. Regardless of specific production system, while considering reception of new tasks into the system, current review of the state of the system is required in order to decide whether and when a new order can be accepted for execution. In this paper, the problem of task scheduling is limited to the specific existing mixed-model production system. The main goal is to determine the effective method of creation of task sequence. Through the use of computational algorithms, and automatic analysis of the resulting sequence, rates of production are able to be checked in a real time, and so improvements can be proposed and implemented.
Authors: Yi Ming Zhu, Xiao Hong Wang, Yan An Zhou
Abstract: A novel assembly method for a micro direct methanol fuel cell (μDMFC) using multi-layer bonding is developed. The anode and cathode plates of the μDMFC are fabricated by using MEMS technologies. PDMS gaskets are introduced to fill the gap between the silicon plate and the membrane electrode assembly (MEA) to prevent fuel or oxidant leaking. To assemble a μDMFC, adhesive tapes and oxygen plasma treatment of the PDMS gasket for surface activation are introduced. In this method, the PDMS gasket with adhesive tapes is bonded to the silicon plate then bonded to the MEA, which fixes the movable components of the μDMFC to simplify the assembly operation. The novel assembly method shows good maneuverability and reliability. The μDMFC shows great performance due to the low internal resistance attributing to this novel assembly method. With thermal insulated holders, the μDMFC generates a power density of 20.29mW/cm2. This assembly method is applicable for the assembly of the μDMFC stack.
Authors: Xiao Jun Tian, Yue Chao Wang, Zai Li Dong
Abstract: Nowadays research on nano-electronic device based on carbon nanotube (CNT) raises much interest among researchers, but in the fabrication process, crucial problems exist in making and improving the electrical contact between CNT and microelectrode. Here pulse gas alignment method, combined with nanomanipulation technology based on atomic force microscope (AFM) if necessary, is proposed for the first time to assemble and make electrical contact between CNT and microelectrode. After the assembly, a processing technique of applying sweeping voltages is performed for producing electrical current induced local Joule heat, which will decompose and remove the sodium dodecyl sulfate (SDS) molecules adsorbed on the CNT and at the interface region, or even have some annealing effect, to reduce the contact resistance between CNT and microelectrode and thus to improve the electrical contact. Experiments of assembly and improvement of electrical contact between multi-wall carbon nanotube and microelectrode are performed to verify the effectiveness of the proposed methods
Authors: Yu Lieh Wu, Yu Dai Shiue, Kuo Hsiang Chien, Chiu Li Wang
Abstract: To avoid continuous damage of ozone layer and deterioration of global warming, many countries have devoted to the development and application of natural refrigerant. Although CO2, an alternative refrigerant in the area of air conditioning is not the best all-temperature refrigerant, it has the lowest operating risk as compared to hydrocarbon (HCs) and ammonia.Traditional drinking fountain provides heat source through secondary energy source - electric heating; however, the heating effect is limited. Since heat pump has a high performance, this study used a carbon dioxide heat pump, which has energy-saving effect and high efficiency, to provide heat source to drinking fountains. It further assembled the drinking fountain system with carbon dioxide heat pump and analyzed its performance.
Authors: Fu Yun Liu, Ni Ya Lu, Bing Kuang
Abstract: To improve the design efficiency of product, the variant design method of assembly is researched. Firstly, the identifying and extracting method of assembly constraints is researched, and an identifying and extracting method of assembly constraints based on the re-development technology of SolidWorks is presented. With the identifying and extracting method, assembly constraints are obtained and a relationship network of them is built. Secondly, a method for dimensions to transfer around the relationship network of assembly constraints is researched and a dimension transfer method is put forward. Then a dimension modify method of assembly based on the dimension transfer method is obtained. Lastly, a variant design method of assembly based on the dimension transfer and dimension modify method is presented and a variant design module integrated into SolidWorks is developed. As an example, all methods are applied to a coupling assembly, and the methods are verified.
Authors: Jun Gao, Xin Ye, Zhi Jing Zhang, Yong Long Tang, Xin Jin
Abstract: This paper proposes a vision detection algorithm to acquire LIGA part’s edges based on an in-house multi-DOF manipulator for LIGA part assembly. Feature recognition based on maximum information entropy is proposed to solve the problem that high precision edge recognition under backlight source. In order to further improve vision recognition accuracy, edge feature recognition algorithm based on symmetrical edge is proposed to recognize the center line of the symmetrical parts when the quality of the image is poor.
Authors: Yan Yan Liu, Li Bao An, Chao Ding
Abstract: As a new type of materials, carbon nanotubes (CNTs) have been intensively studied due to their outstanding properties. Dielectrophoresis (DEP) is an effective method to assemble CNTs across a pair of electrical conductors for various applications. In DEP, CNTs suspended in dielectric liquid medium suffer a force imbalance due to induced dipole moment when subject to an externally applied non-uniform electric field, and move towards and finally deposit onto the electrode region. As a model plays a critical role in the numerical study of the DEP process, this paper introduces the theoretical background of DEP and basic DEP models based on the effective dipole moment method which has been widely accepted in the study of DEP. Particularly, the DEP force calculation methods developed recently for improved precision using these basic models are presented and discussed. A DEP model with high computing accuracy helps precisely predict a DEP process.
Authors: Shao Hua Zhen, Li Bao An, Yan Yan Liu
Abstract: Study of the effect of dielectrophoresis (DEP) parameters is important in high-precision DEP assembly of carbon nanotubes (CNTs). The DEP parameters usually considered in the literature include the magnitude and frequency of the applied voltage, the assembly time, the concentration of the CNT suspension, and the geometry of the electrodes. This paper reviews the current progresses on both numerical and experimental study of the CNT assembly by DEP, especially the influence of the DEP parameters on the assembly process and results. The review shows that the magnitude of the applied voltage affects the DEP force and the number of deposited CNTs. The assembly time and CNT concentration influence the density of deposited CNTs. Different electrode geometries have an effect on the distribution of the electric field. The electrode spacing changes the field strength and the direction of the field gradient. The related discussion is presented as well.
Authors: Nina Vetríková, Michala Šimúnová
Abstract: In this contribution is presented application of evolution diagrams at the assembly process of at the intelligent manufacturing and assembly cell. At this assembly cell was designed new assembly configuration for next research to our department and institute. Intelligent manufacturing and assembly cell is situated at the Institute of Production Systems and Applied Mechanics. The complex design of assembly sequences at the intelligent manufacturing and assembly cell is realized on the basis of evolution diagrams and outgoing from knowledge about intelligent manufacturing and assembly systems. For intelligence increase of assembly process was this cell completed by additional sensors. This assembly process is possible to name intelligent assembly process.
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