Assembly Work Research Articles

JAČANJE METODA RADA KAO MOGUĆNOST ZAUSTAVLJANJA MARGINALIZACIJE GENERALNE SKUPŠTINE UJEDINJENIH NACIJA

The paper analyses improving the United Nations General Assembly’s working methods as one of the possibilities of ending its marginalization. The General Assembly is facing numerous difficulties, including an overburdened agenda, repetitive agenda items, the need for better working organization and non-implementation of resolutions by the member states. Among the UN member states there is consent to improve the General Assembly’s working methods, but also disagreements on mechanisms it can be achieved. In order to strengthen the role and competencies of the General Assembly, an ad hoc working group on the revitalization of the work of the General Assembly (the AHWG) was established in 1991. So far, the AHWG group had made some contributions in improving the General Assembly’s working methods. The paper aims to show that efforts of the AHWG, although significant, are not sufficient to solve all problems of working methods of the General Assembly. The author concludes that the only effective way in solving the working methods of the General Assembly is the UN Charter revision.

Optimizing task scheduling in human-robot collaboration with deep multi-agent reinforcement learning

Human-Robot Collaboration (HRC) presents an opportunity to improve the efficiency of manufacturing processes. However, the existing task planning approaches for HRC are still limited in many ways, e.g., co-robot encoding must rely on experts’ knowledge and the real-time task scheduling is applicable within small state-action spaces or simplified problem settings. In this paper, the HRC assembly working process is formatted into a novel chessboard setting, in which the selection of chess piece move is used to analogize to the decision making by both humans and robots in the HRC assembly working process. To optimize the completion time, a Markov game model is considered, which takes the task structure and the agent status as the state input and the overall completion time as the reward. Without experts’ knowledge, this game model is capable of seeking for correlated equilibrium policy among agents with convergency in making real-time decisions facing a dynamic environment. To improve the efficiency in finding an optimal policy of the task scheduling, a deep-Q-network (DQN) based multi-agent reinforcement learning (MARL) method is applied and compared with the Nash-Q learning, dynamic programming and the DQN-based single-agent reinforcement learning method. A height-adjustable desk assembly is used as a case study to demonstrate the effectiveness of the proposed algorithm with different number of tasks and agents.

Ergonomic Design of Manual Assembly Workstation Using Digital Human Modeling.

Background:Manual assembly workers are exposed to risk factors of musculoskeletal disorders. The most important risk factor among the workers is static and awkward posture. This study aimed to the ergonomic design of manual assembly workstation using Digital Human Modeling (DHM).Methods:This cross-sectional study was conducted among manual assembly workers. Data was gathered via 1) demographic/occupational questionnaire, 2) The Persian version of the Nordic General Questionnaire (P-NMQ), 3) Rapid Upper Limb Assessment (RULA) using Kinect sensor, 4) Hierarchical Task Analysis (HTA), 5) Idea Rating Sheet (IRS), 6) Anthropometric data of the participants, 7) CATIA software and RULA technique.Results:The results of the evaluations showed that in the design of most workstations of assemblers in Shiraz electronics industries, complete ergonomic principles were not observed, and the implementation of targeted ergonomic interventions in them is necessary.Conclusion:The prevalence of musculoskeletal symptoms is high among manual assembly workers. The RULA technique showed that the designed manual assembly workstation using DHM effectively could improve the subjects’ awkward postures.

Carrier type induced magnetoresistance upending in assembly of sulfur doped Sb2Se3 nanotubes

Materials showing low field induced switch over in magnetoresistance is investigated heavily nowadays for promising power electronics and phase change memory applications. In this work, morphological, topographical, magnetoresistance (MR) and thermoelectric properties of nanobulk assembly of sulfur doped Sb2Se3nanotubes synthesized by novel microwave assisted solvothermal process is investigated and reported. Structural properties indicate that the sample crystallizes in orthorhombic phase while morphology study confirms the formation of nanotubes of length 1–5 μm and diameter 100–150 nm. Electrical resistivity measurements indicates 2D variable range hopping at low temperature (2–50 K), nearest neighbor hopping at intermediate temperature (50–200 K) and thermal activation behavior with activation energy of 2.3 meV from 200 K to 300 K. Interestingly the positive magnetoresistance observed in low magnetic field and at constant low temperatures makes a transition to negative magnetoresistance above 20 K. Bipolaron model along with wave function shrinkage models were invoked to understand the MR measurements while low temperature thermoelectric measurement univocally elucidates that the carrier type switching at 13 K dictates the conduction mechanism as demonstrated by the complex crossover in magnetoresistance.

The Power of Assembly

The Power of Assembly

Pipeline design in SolidWorks

It is shown that is the program SolidWorks and what it is intended for, taking into account also that SolidWorks is a network standard for tree- dimensional solid state design. There are also tree basic system configurations, which are used depending on the class and complexity of the tasks.
 Application in practice of design of SolidWorks provides automatic reception of the license for use of technologies of tree- dimensional designing which allow to design and bring to the market modern innovative production.
 Respect for those that the SolidWorks program functions on the Windows platform has been transferred to the Russian language and on- demands DSTU and ESKD.
 The use of SolidWorks can significantly reduce labor costs when performing assembly work. The risibility of tree- dimensional design is fundamentally different from the usual project and allows workers to perform assembly work without contact consultation and ongoing control by engineering personnel. SolidWorks can be used for the design in various branches of mechanical engineering, construction, as well as for installation work on water supply and sewerage pipe systems. There tasks are solved using the SolidWorks Routing module, which is included in the configuration of the SolidWorks Premium and is specially designed to facilitate the design of prefabricated and bent pipelines, as well as flexible hoses. When designing plumbing equipment in pumping stations there is a task to complete the individual components and nodes of the project to obtain a tree- dimensional model in a complete form.
 The inclusion of pipeline equipment in a tree- dimensional model of a object allows solving many problems already at the design stage and avoiding situations when at the installation stage it is revealed, that the pipes are incorrectly bent and interfere with the operation of other system nodes, or there is little free space in the created structure for saying all the necessary communications.
 Using the SolidWorks Routing program makes it possible to optimally and compactly place water and sewer pipes indoors, prevent them from crossing and quickly get accurate data on the needs for materials and components. Indicates additional modules, which can also be used witch the SolidWorks program to facilitate the design work on the boring and bent pipelines, flexible lines and communications.

Balancing and Simulation Algorithm For Manual Assembly Line Operations.(Dept.M)

This work consists of a model which is based on a computerized algorithm and consists of two main parts namely balancing and simulation routines. This model was used to determine the buffer in-process units required between work stations along manual assembly lines. Since the task durations and deviations vary from assembly of one product to another and frum one task to another for the same product; this model was developed to handle different cases of wide and narrow Work variability according tu the type or assembly work. The model is capable of banding two different assembly line problem cases. Firstly in case of an assembly line production without balancing, the balancing routine is invited first to produce a balancing solution for the problem and then the simulation routine is Invited to determine the number of in-process units needed for each individual work station. Secondly in case of balanced assembly line production, the simulation routine is invited to simulate the work performance in each work station along the line and to determine the number of buffer in-process units needed for each individual work station. An assembly line problem consisting of fourteen tasks was used to test the balancing and simulation capability of the model. The problem was prepared to produce a perfect balancing solution of three work stations. The resultant balanced problem data was then used to Investigate the relationship between task variance, buffer in-process units between work stations and confidence level.

User‐centered development of a worker guidance system for a flexible production line

AbstractWorker guidance systems are digital assistance systems in production, which provide work‐related information and, thus, guide employees through production processes. This article describes the user‐centered development of such a worker guidance system for a flexible production line in a metrology company. Usage context analysis and requirements analysis illustrate the need for a simple and independent system that can be used voluntarily by employees. After two iterations of the human‐centered design process, an interactive software prototype was created and implemented on a tablet personal computer. In this prototype, all essential process and assembly information in the flexible production line is available to the employees in the form of text descriptions and pictures as step‐by‐step instructions, which can be selected via two‐step navigation. The final evaluation was conducted as a user study with N = 10 assembly workers in the flexible production line under realistic conditions and was also intended to find out at which level of detail the information should be displayed in the system. The system scored well on the system usability scale (between 65.8 and 70.8) and concerning acceptance. Using the worker guidance system, no assembly faults occurred during the user study. Due to the significantly shorter assembly time, but no further significant differences, it was decided to set up the less detailed assembly information as a standard in the system. However, employees can call up more detailed information, if necessary. This system will be used by the company in the future.

Lean Companies Employed Assembly Workers Train with New Approches

LM has proven itself the production system that enhances shop floor efficiency. Furthermore, the current environment for production firms is accelerating the pace at which LM is implemented. The manufacture of lean is not easy to introduce. It is constant and complex activity. Assembly workers in production processes are the core of lean manufacturing activity. Training is known as vehicle to aid the implementation process. While the importance of training is known so far, there are only a few options for organizing effective training. The results of the survey of questions conducted inside UK manufacturing companies are examined. This article illustrates the definition of lean production and worker requirements in lean environment.

Parametrization of manual work in automotive assembly for wearable force sensing

This research aims to model manual assembly processes by parameterizing operator force readings, specifically for engine and coolant hose connections in an automotive manufacturing line. During automotive assembly, many processes are still performed manually by the human operator due to the complexity of automating the process or product with current technology. Processes include completing hose connections and subsequent “push–pull–push” verification testing. Manual work introduces an opportunity for human error because of natural variation when completing tasks; even a slight inconsistency in operation can lead to an incomplete or missed process. These incomplete processes can pass post-production checks, such as a pressure test, but later loosen and fail, causing rework or warranty issues. To minimize human error, operator force is parameterized to provide real-time feedback to the connection status. The operator force was chosen to classify connections and to verify testing quantitatively. The parametrization was completed by partitioning the shear and normal forces using custom fixtures, with shear being the primary force type required by the process. The varying finger and hand engagement for the different connector locations were factored into the parametrization to encompass a broader range of manually completed tasks. It was found that operator forces in finger engagement for manual assembly could be effectively represented by a limited set of measurable parameters.

Application of Automation Technology in Automobile Machinery Manufacturing

China’s science and technology have become increasingly mature in today’s society, and various fields of society will actively apply relevant advanced technologies to reshape the original operating model during the development process. In particular, the application range of automation technology has become more extensive, because automation technology itself has more advantages and cannot be replaced by many other traditional technologies. It can fundamentally improve the work efficiency of some manufacturing industries. Thanks to the application of high-precision automation technology, all work can be carried out continuously in accordance with established computer programs. In this way, the number of errors caused by human work is actually reduced, and the pass rate of the product can also take this opportunity to be significantly improved. When performing various tasks, workers in the mechanical manufacturing field will actively apply the most suitable automation technology according to their actual conditions, and organically integrate their valuable work experience with brand-new automation technology. This allows all work to be of higher quality in the implementation process. In the automobile production industry, since many parts are manufactured on the assembly line, if the advanced automation technology is actively applied, the production time of parts can be saved, and the assembly and processing work of the staff will be carried out in an orderly manner. In this way, the profits of the automobile manufacturing industry can be effectively improved and unnecessary cost input can be reduced.

An Empirical Study on Process Management System using YOLO-Based Parts Recognition

The process of assembling the engines used in medium and large ships appears to be a continuous production process, but it is not the process through which numerous workers perform work with automated equipment or simple assembly work, but rather a process through which skilled workers, who can effectively perform various tasks, perform multiple aspects of the assembly process. Due to this characteristic, it was difficult to assess the work process rate during the engine assembly process through real-time analysis of the process because it was difficult to shorten the lead time or improve the process, and most of stages of the process depend on manual reports or operators’ work data input. Therefore, in this study, we developed and applied a system capable of recognizing the current process rate by identifying specific engine parts using YOLO.

Function Block-Based Multimodal Control for Symbiotic Human–Robot Collaborative Assembly

AbstractIn human–robot collaborative assembly, robots are often required to dynamically change their preplanned tasks to collaborate with human operators in close proximity. One essential requirement of such an environment is enhanced flexibility and adaptability, as well as reduced effort on the conventional (re)programming of robots, especially for complex assembly tasks. However, the robots used today are controlled by rigid native codes that cannot support efficient human–robot collaboration. To solve such challenges, this article presents a novel function block-enabled multimodal control approach for symbiotic human–robot collaborative assembly. Within the context, event-driven function blocks as reusable functional modules embedded with smart algorithms are used for the encapsulation of assembly feature-based tasks/processes and control commands that are transferred to the controller of robots for execution. Then, multimodal control commands in the form of sensorless haptics, gestures, and voices serve as the inputs of the function blocks to trigger task execution and human-centered robot control within a safe human–robot collaborative environment. Finally, the performed processes of the method are experimentally validated by a case study in an assembly work cell on assisting the operator during the collaborative assembly. This unique combination facilitates programming-free robot control and the implementation of the multimodal symbiotic human–robot collaborative assembly with the enhanced adaptability and flexibility.

Improving the Quality of Agricultural Roads

The article considers the issues of improving the quality of construction and operation of agricultural roads. The main reasons for the need for the construction control of the quality of work are considered. The stages of the control of quality of pavement made of stone materials have been sequentially analyzed. The actual consequences of violation of the quality of construction and assembly works are given. The modeling of the work of the system «roadbed –pavement» in conditions of increased traffic load and watering of agricultural roads has been carried out. Recommendations for increasing the service life of agricultural roads using new building materials are presented and substantiated.

Approaches to reduction of dynamic loads arising in truck-mounted hydraulic lifts

The article addresses approaches to reduction of dynamic loads arising in truck-mounted hydraulic lifts. Lifts are widely used to perform assembly and painting work in the course of construction. Dynamic loads, arising in the process of their operation, reduce performance and operational safety of lifts. The co-authors focused their research efforts on hinge mechanisms installed in truck-mounted hydraulic lifts. Hydraulic lift booms have hydraulic drives that ensure a uniformly continuous pace of hydraulic cylinder rod extension, but rotation speeds of the booms do not coincide, thus, causing them to move up by fits. This phenomenon triggers dynamic loads that arise in booms and make workers feel uncomfortable when on the platform. The co-authors provide motion equations for upper and lower booms of a lift. Having solved these equations, the co-authors obtained rational values of loads applied to the booms. Dependencies between varying values of the force in a hydraulic cylinder rod and the boom swing angle, as well as between the boom swing angle and the boom lifting angle are to be identified to reduce dynamic loads. These dependencies enable the co-authors to tailor the pump output. The co-authors suggest a rational system of proportional hydraulic cylinder control over acceleration or the force. Dependencies, obtained by the co-authors, can be applied to fine-tune the proportional distributor to make booms move smoothly, to reduce dynamic loads and to ensure a comfortable working environment for workers on the platform.

Impact of the Construction Supplies Implementation on Road Safety in the City Center: A Case Study of the City of Szczecin

The development of modern cities is impossible without an increase in the number of construction projects implemented. However, in the conditions of limited spaces, local and national legal regulations, and logistic difficulties, their implementation is becoming a growing challenge. Construction supplies can pose a particular problem. Its planning, organization, and implementation have an impact not only on construction and assembly works, but also on the external environment of the construction site, of which traffic is an important element. The aim of the study was to analyze and answer the question of whether there is a connection between the implementation of construction supplies and the occurrence of road traffic hazards in cities on the example of Szczecin. In addition, the article aims to find solutions to reduce the number of road accidents and increase road safety. The conducted research also revealed the weak points of the system of collecting and analyzing data on road accidents. The research covered selected areas in the center of Szczecin, where construction projects have been implemented since 2016 and road accidents have occurred. The reference year is the year preceding the start of construction. The research on selected construction projects meeting the criteria, carried out in the article has shown that their implementation may have an impact on the level of safety in the areas adjacent to the construction site. However, the unequivocal statement of such relationship must be supported by extended research, covering a greater number of projects, additional consideration of the number of deliveries for supply purposes, and the characteristics of vehicles involved in road incidents.

Design and manufacture of automatic plastic valve welding machine

Plastic welding method is a widely used technology for the welding of pressure and vacuum bags using plastic valves. Conducting this process with traditional methods creates disadvantages in terms of production speed, product quality and economical aspects. Today, assembly costs make up the majority of total production costs, manufacturers pay more attention to assembly automation and work in this direction in order to reduce costs, speed up the production process and increase efficiency. In this study, it is aimed to design and manufacture a single Automatic Valve Welding Machine that can do all of these operations and integrated automation system instead of cutting, punching and plastic welding process that can be performed with multiple machines and workers. In this context, a new automated machine was designed in 3 D, and engineering analyzes were carried out to manufacture a prototype. In design, the machine has been made suitable for developing technology by using PLC (Programming Logic Controller) and pneumatic system. In addition, static analyzes of the machine were made. With the inclusion of a production-specific automatic controlled plastic welding machine, manufacturing can be done faster, with higher quality, lower costs and less wastage compared to the traditional manufacturing process.

An investigation of musculoskeletal disorders at multiple sites and related influencing factors among workers in an automobile assembly shop

Objective: To investigate the current status of work-related musculoskeletal disorders (WMSDs) in automobile assembly workers, as well as the distribution of WMSDs at multiple sites and related influencing factors. Methods: From March to July 2019, cluster sampling was performed to select 663 male automobile assembly workers as respondents, and the musculoskeletal injury questionnaire was used to investigate their general status and working condition. A multinomial logistic regression analysis was used to analyze the influencing factors for WMSDs at multiple sites. Results: The detection rate of WMSDs within the past 7 days was 37.9% (251/663) among the automobile assembly workers, and the detection rate of WMSDs within the past 1 year was 51.9% (344/663) . Of all workers, 13.6% (90/663) had WMSDs involving only 1 site, while 38.3% (254/663) had WMSDs involving 2 or more sites. The multinomial logistic regression analysis showed that frequent turns during work was a risk factor for WMSDs involving 1-3, 4-6, and 7-9 sites (odds ratio [OR]=1.65, 2.47, and 3.65, respectively) . Repeated action of lower extremities and ankles was a risk factor for WMSDs involving 4-6 and 7-9 sites (OR=2.15 and 2.98, respectively) . Working in an uncomfortable position was a risk factor for WMSDs involving 1-3, 4-6, and 7-9 sites (OR=1.95, 2.67, and 3.04, respectively) . Prolonged standing during work was a risk factor for WMSDs involving 1-3 and 4-6 sites (OR= 1.87 and 1.79, respectively) . Working overtime was a risk factor for WMSDs involving 7-9 sites (OR=5.48) . Adequate time for rest was a protective factor against WMSDs involving 1-3 and 4-6 sites (OR=0.50 and 0.31, respectively) . Conclusion: There is a high detection rate of WMSDs in automobile assembly workers, and WMSDs at multiple sites are more common than WMSDs at a single site. Poor position and organizational management factors are risk factors for occupational WMSDs at multiple sites.

Consideration of workforce differences in assembly line balancing and worker assignment problem

Abstract Workforce differences in terms of skill, age, gender and physical measures have a large impact on production systems performance. Moreover, the role of differences between workers can be particularly seen in assembly lines, where a vast range of tasks are performed manually, and workers are involved widely. In this work, we introduce a new assembly line balancing and worker assignment model with consideration of workers’ diversity in terms of both workers’ expertise and perceived physical effort to implement an age-inclusive workforce. Here, a new Worker Task Categorization Matrix is introduced to assure the complete involvement of the individual during the balancing process. Following, a bi-objective linear programming model is proposed and solved by using the ϵ -constraint approach. Finally, we test and validate the model through a real-case application.

Exploring the Learnability of Assembly Tasks Using Digital Work Instructions in a Smart Factory

The trend towards individualized products leads to increased product variants and on-demand manufacturing. Assembly workers have to cope with constantly changing work instructions without impacting production speed. This paper explores the learnability of assembly tasks. A user study with transfer and 24h delayed retention tests compares how effectively assembly tasks can be learned using 1) an assistance system with digital work instructions and 2) paper-based work instructions. The results help to derive better structured work instructions and general recommendations for the design of assistance systems in the context of manual assembly.