Assembly Area Research Articles

Performance measures to benchmark the grasping, manipulation, and assembly of deformable objects typical to manufacturing applications.

The National Institute of Standards and Technology is developing performance tests and associated artifacts to benchmark research in the area of robotic assembly. Sets of components consistent with mechanical assemblies including screws, gears, electrical connectors, wires, and belts are configured for assembly or disassembly using a task board concept. Test protocols accompany the task boards and are designed to mimic low-volume, high-mixture assembly challenges typical to small and medium sized manufacturers. In addition to the typical rigid components found in assembled products, the task boards include many non-rigid component operations representative of wire harness and belt drive assemblies to support research in the area of grasping and manipulation of deformable objects, an area still considered to be an emerging research problem in robotics. A set of four primary task boards as well as competition task boards are presented as benchmarks along with scoring metrics and a method to compare robot system assembly times with human performance. Competitions are used to raise awareness to these benchmarks. Tools to progress and compare research are described along with emphasis placed on system competition-based solutions to grasp and manipulate deformable task board components.

Assembly area risk assessment methodology for post-flood evacuation by integrated neutrosophic AHP-CODAS

Assembly area risk assessment methodology for post-flood evacuation by integrated neutrosophic AHP-CODAS

Development of Safety Briefing Kit for School of Health Sciences

Occupational safety and health (OSH) briefings for employees and other interested parties are crucial in ensuring the proper dissemination of minimal OSH requirements and information across the organization [1]. The implementation in Malaysia is based on OSH regulations as outlined by the Department of Safety and Health Malaysia. The challenge here is the requirement for OSH briefing shall be different depending on the facility and operations themselves. Adding up, it is crucial for OSH briefing to be delivered with the right content to everyone efficiently and simply but as accurately and easily understandable as possible [2]. Several studies have indicated the multiple types of hazards available in tertiary education settings (i.e., university, college, polytechnic, etc.) which include physical, chemical, biological, electrical, and even radiological [3–5]. As tertiary education settings have multiple types of occupancy ranging from students, academic staff, support staff, contractors, and visitors, the risk of injury to the occupants is feasible. Hence, the objective of this study was to identify the elements of OSH briefing content and develop an OSH briefing kit for tertiary education settings.
 
 Understanding and evaluating elements of OSH briefing require a systematic approach for reviewing documents, both printed and electronic materials, hence document analysis methods were utilized [6]. Reports, articles, books, standards, and guidelines with a keyword of safety briefing were used to filter the identified documents and every identified information on OSH briefing is categorized into larger elements. These produced the total elements needed in conducting an effective OSH briefing. An OSH briefing kit was developed for the School of Health Sciences, Universiti Sains Malaysia (USM) based on the identified elements. By utilizing the face validity method [7], the OSH was then discussed and verified by seven experts consisting of the school emergency team. Using an adopted four sections, thirteen questions of five points Likert scale questionnaire were used to assist experts in reviewing the OSH briefing kit. This study has been reviewed and approved by the USM Human Research Ethics Committee (USM/JEPeM/22020125).
 Through extensive literature, there were seven safety briefing elements identified for a good safety briefing [1–3,5,8] as summarized in Figure 1. The scope of the safety briefing served as the learning outcomes must be informed to the participant earlier during each safety briefing session. A specified facility background is necessary as different facilities might have different layouts and arrangements. General safety and security requirements should be stated clearly as each facility is unique and might have different risks. Basic personal protective equipment (PPE) is required to ensure that everyone entering the facility is minimally protected in preventing or minimizing injuries. Common hazards, which are typically identified by a comprehensive risk management process, will ensure that everyone understands the hazards located across the facility while reiterating the necessity of general safety and security regulations and basic PPE needs. An essential emergency procedure provides everyone with an understanding of basic response to the emergency which includes notification, communication, evacuation process, and route including assembly area and accountability process. Finally, the briefing time should be less than 15 minutes to ensure short and precise communications and to minimally disrupt the main activity or operations.
 
 The developed OSH briefing kit was tailored to the School of Health Sciences requirements and consisted of a presentation slide for a manual briefing by respective emergency team personnel as well as the three minutes and 40 seconds of pre-recorded OSH briefing multimedia depending on the availability of non-emergency team members. There were 13 slides in the presentation, each with pre-written text to make the briefing process simpler. School event organizers could have the option to use any of the two materials from the OSH briefing kit. The kit utilizes the elements of effective safety briefing identified earlier. Through the experts' validations process, it was agreed that the OSH briefing kit has good information quality with an average score of 4.26 indicating the accuracy of the content covered. The usefulness of the kit was also consented by experts at 4.52 average score indicating comprehensive general OSH requirement in the school. The OSH briefing kit scored 4.24 on average for usage characteristic and the overall satisfaction of the kit was at 4.29 average score.
 
 It is concluded that in developing an effective OSH briefing, a total of seven (7) elements should be considered to ensure the comprehensiveness of the briefing, hence the novelty of this study. The elements are suitable to be used in developing an OSH briefing for tertiary education settings, but the content should be tailored based on the entity itself. Future studies will include the evaluation of the developed OSH briefing kit for the end-user in understanding the acceptability and understanding of the minimum OSH requirement in tertiary education settings.

Why Women Became the Enemy of Democracy in Poland? The Illiberal Regime’s Response to the Women’ Rights Movement

After the political transformation in Poland, abortion was first regulated by the Law of 7 January 1993, Protection of the Human Fetus and Conditions Permitting Pregnancy Termination. Since then, attempts have been made to change the existing regulation. However, it was in 2016 that there were nationwide protests against changes to abortion provisions, and then in 2020, when the constitutional court ruling limited the possibility of termination of pregnancy in Poland. These protests can be seen in the context of the process of neo-militant democracy rule implementation, that is, the taking over the characteristics of non-democratic regimes by existing democracies under the cover of the regime self-preservation. The aim of this article is to identify and explain the government’s attitude towards women as an enemy of democracy at the institutional level during the two waves of protests. The study shows that during the period considered, restrictions specific to neo-militant democracies in the area of assembly and association, speech and press and restrictions on religious freedom were imposed in order to limit the activity of protesters viewed as enemies of the democratic system.

장애인 고용기회 확대 및 적합 직업 추천에 관한 연구: 직무적성검사(JAT-P)를 중심으로

The purpose of this study was to collect data about the opinions of workers with disabilities in ways of expanding their employment opportunities, investigating their employment retention strategies, and recommending their proper occupational groups, utilizing the battery of Job Aptitude Test-Personal(JAT-P). To fulfill the purpose of this study, a total of 200 PWD participated in this study, taking the individual questionnaire and the online JAT-P. After the administration of the study tools, data was analyzed to compare the recommended job groups in terms of disability types and to see their employment strategies and their influencing employment retention factors, focusing on the exploration of their ability-interest and aptitude-interest results. The study indicated that over 50% of PWD have been working in the areas of assembly, office work, cleaning, and arrangement tasks, and they reported a ‘previous work experience’ as a critical factor in employment achievement, also reporting satisfaction with their current work conditions and self-reported work performance abilities. No significant differences were found between disability types and their occupations, but reasonable occupations in terms of the matching between ability-interest and aptitude-interest were recommended, along with the suggestions of required government policies and organizational co-works.

Methodology based on causes of accidents for forcasting the effects of falls from scaffoldings using the construction industry in poland as an example

Every year, there are several thousand occupational accidents on Polish construction sites. Many of them are related to the use of building scaffolding. Depending on the type of injury, accidents are classified as light, severe or fatal. This article presents a methodology, which is based on identified causes, for predicting the effects (severity) of falls from building scaffolding. The basis for the research was a set of 200 accidents that occurred on Polish construction sites in 2011. Information on the accidents was obtained from the archives of the National Labor Inspectorate. For each fall from scaffolding, the following were identified (in accordance with the Polish TOH methodology): technical (T), organizational (O) and human (H) causes of the accident, as well as its effects. The significance of the causes was assessed in each group using Pareto-Lorenz analysis and the ABC classification. Significant causes include those that were identified in over 80% of accidents. These causes were taken into account in the further analyzes. In order to define the relationship between the identified significant causes of an accident, and its effect, an original methodology of screening was proposed. It involved the assigning of the possible effects of accidents to each theoretical combination of accident causes. For this purpose, computational scripts in the Python programming language were developed. The test results allowed for the percentage determination of the probability of light, severe and fatal consequences of an accident for each of the combinations of significant causes. The conducted research is of great importance for science and engineering practice. The obtained test results can be used to estimate the occupational risk of work carried out on building scaffoldings. The developed computational models enable the consequences of accidents to be easily and quickly forecast, depending on the deficiencies and shortcomings identified “in situ” in the area of scaffolding assembly, work organization and human factors. Good identification of the factors influencing the severity of accidents allows high-risk factors to be distinguished and specific preventive measures to be developed.

Lithium oxide loss of lithium niobate nanocrystals during high-energy ball-milling

Congruent lithium niobate (LiNbO 3 ) prepared by sintering was ground under wet conditions in a planetary mill in order to produce nanocrystals. By using gradually lower sizes of the balls in the mill, the final particle size of the crystals could be reduced to about 12–15 nm. The particle size achieved as well as the lithium oxide (Li 2 O) loss of the lithium niobate particles were followed as a function of the grinding time. Lithium oxide was found to be released throughout the entire milling procedure, even in the case when the particle size no longer changed upon the grinding with a particular ball size. About 12% and 20% Li 2 O loss was detected upon grinding with 3 mm and 0.5 mm balls, respectively. X-ray diffractometry revealed the formation of a lithium-deficient phase, LiNb 3 O 8 , the presence of which was confirmed by means of Raman spectroscopy. The LiNb 3 O 8 :LiNbO 3 volume ratio achieved for 70 nm particle size as calculated from both the diffractograms and the lithium oxide loss determined by coulometric titration was assessed to be 0.39 (± 0.03). Correlation was revealed between the composition change of the nanopowder and the total surface area of the particle assembly calculated from dynamic light scattering measurements. • Lithium niobate nanopowders were produced with the help of a planetary mill. • The loss of lithium oxide and formation of LiNb 3 O 8 were observed upon milling. • The lithium loss during the wet grinding process was quantitatively characterized. • Particle size determined by SEM and DLS were in good agreement. • The surface area increase of the particle assembly correlated with the Li 2 O release.

Cross-Regional Dynamic Transfer Characteristics of Liquid Oil Contamination Induced by Random Contact in Machining Workshops in Shanghai, China

In industrial sites, the movement and contact behaviors of workers are random, but their frequency and statistical characteristics can be determined. Particularly in machining workshops, metalworking fluids (MWFs) cause liquid oil contamination on the processed workpieces, and the contamination spreads to the entire workshop given the random contact of workers or the handling of workpieces. This study proposes a contact transmission model based on the Markov chain to quantify oil contamination transfer. First, the transfer efficiency between the glove and the workpiece, which is regarded as a key model parameter in this research, was determined through experiments. The model was used to characterize and predict the spread of oil contamination across different regions, including production and assembly areas. Specifically, the oil contamination concentrations on workbench surfaces in seven locations of a machining workshop in Shanghai GKN HUAYU Driveline Systems Co., Ltd. (SDS) were measured on-site. Findings showed that the model could feasibly depict the transfer process of oil contamination across different surfaces. Then, the variation law of oil contamination concentration on the workbench surfaces over time was analyzed, the oil contamination distribution map of the entire workshop plane was drawn, and the effectiveness of two cleaning measures to reduce oil contamination concentrations was compared. The proposed contact transmission model offers a basis for identifying highly polluted surfaces in machining workshops and controlling the spread of liquid oil contamination.

A Case Study of Ergonomics Prevention Program in a Machine Manufacture Industry

Musculoskeletal Disorders (MSDs) is the most potential risks in human production and economic systems. In this research, ergonomics guidelines and enacted relevant regulations announced by other countries to effectively facilitate ergonomics prevention programs were discussed. A machine manufacture industry as a case study has been ergonomically evaluated by Musculoskeletal Disorders Checklist (MSDs) and Nordic Musculoskeletal Questionnaire (NMQ), which was used to recognize the dominating risk factors. According to the result of observation and preliminary assessment, low back pain related to the high frequency of manual material handling tasks was the critical issue in this case study. The conclusion revealed that the proposed improvement such as engineering redesign, training, health management, and administration, would be implemented into the main axle assembly area, customer service department, and Z-axis assembly area. The further improvement interventions would help organization to carry out the ergonomics prevention program.

Data fusion of local and global sensors within a Global Reference System in aeroplane assembly

Abstract Currently, aeroplane assembly is carried out in rigid, aeroplane-specific assembly lines which causes high costs for reconfiguration. One approach to reduce the costs is to use automated lineless assembly systems. To enable automated reconfiguration of assembly processes, continuous availability of factory-wide position data is required. When providing these data, a challenge is the combination of large-volume, “global” measurement sensors and high-precision, “local” measurement sensors to a single easily interpretable indication. The aim of this research work is the fusion of local and global measurement data within a so-called Global Reference System (GRS). For data fusion, sensors are linked to a reference measurement system covering the entire assembly area. The relationships between the coordinate systems of the individual measurement systems are described using homogeneous transformations. Using Kalman filters, the transformed measurement data are fused into a vector containing information about the pose of aeroplane components. Furthermore, a GUM-compliant statement about the measurement uncertainty of the fused sensor data is made by specifying the covariance matrix. The method is validated using a demonstrator covering the essential aspects of the assembly process. The result is a validated procedure for data fusion and for the determination of the combined measurement uncertainty in a GRS.

Single-Digit time: Toward a Quick Change-over Process with The SMED method using The Vision System

Increasing the speed of the product change-over process is critical by implementing the Single Minute Exchange of Dies (SMED) effectively. The smallest activity variation between operators, activity speed, and process accuracy are identified research targets. This research was developed in the electronic component industry, where the Define-Measure-Analyze-Improve-Control (DMAIC) and Hierarchy Task Analysis (HTA) methods can describe the most crucial and key activities. Therefore, it takes accuracy and reliability between operators to carry out this activity. This paper presents the acceleration of the product change-over process by developing an automated non-contact inspection method in the assembly area using a vision system. The results of the study illustrate that the change-over process can be carried out in single-digit minutes (7 minutes), or reduced by 81%, and the speed of change-over activities between operators is the same.

Integration of ITER diagnostic ports at the Budker institute

The paper presents results of the design development of the diagnostic equatorial and upper ports by RF DA (Russian Federation Domestic Agency) and results of the preparation of the production and assembly areas. The ports are being developed at the Budker Institute of Nuclear Physics of the Siberian Branch of the Russian Academy of Sciences (BINP) in good coordination with the ITER Central Team with the task of standardizing ports. Studies of boron carbide ceramics were conducted to prove that they meet the requirements of ITER. The preparation of port-plug production and the construction of the assembly hall at the BINP are described.

Effect of pre-twist in the spinning triangle on yarn strength

The spinning triangle is the morphologic transformed area of fiber assembly, which influences the yarn structure and appearance quality. In the spinning triangle, the pre-twist was formed due to the twisting torque, it changed part of fibers delivered path and thus the way of fibers arrangement in yarn body. In this paper, a model of spinning triangle with pre-twist was proposed to study the effects of pre-twist position and other spinning parameters on the fiber tension in the spinning triangle and yarn strength. Three representative cases were discussed respectively, namely the pre-twist region on the left side, middle position, and right side. The following results were obtained: (1) yarn strength shown a W-shape tendency with the pre-twist region moved from left to right; (2) the increase of inclination angle boosted yarn strength and the increase of height of spinning triangle made the decrease of yarn strength when fiber buckling was considered; (3) the increase of spinning tension promoted yarn strength, but did not change the influence of pre-twist on yarn strength.

Numerical Analysis of Bird Impact Over the Aircraft Windshield

Bird impact on aircraft is one of the most important foreign object damages, which result in the reduction in airworthiness. Most bird impacts are not fatal but bird impact can be deadly when the impact is at engine assembly, leading-edge and Frontal area of aircraft. This study focuses on bird impact on windshield and its effects on stress concentration and energy absorption. The strength and stiffness of the windshield play a vital role during foreign object damage. Laminated glass is used as a windshield, the reason to use interlayer is to avoid separation of other layers after impact which ultimately reduces risk to pilot. Laminate configurations glass/PMMA/glass and PMMA/Polycarbonate/PMMA are used for the windshield. Impact analysis has been carried out at velocities of 50m/s, 100m/s and 150m/s. Modeling and solving are done in LS-Pre post and LS-Dyna using a FE-SPH approach. Simulations are carried out impact against bird, stress and energy absorption as the output. Based on results, PMMA/Polycarbonate/PMMA laminate is most likely to sustain the bird strike impact without failure.

Broadening the horizon of crop research: a decade of advancements in plant molecular genetics to divulge phenotype governing genes.

Advancements in sequencing, genotyping, and computational technologies during the last decade (2011-2020) enabled new forward-genetic approaches, which subdue the impediments of precise gene mapping in varied crops. The modern crop improvement programs rely heavily on two major steps-trait-associated QTL/gene/marker's identification and molecular breeding. Thus, it is vital for basic and translational crop research to identify genomic regions that govern the phenotype of interest. Until the advent of next-generation sequencing, the forward-genetic techniques were laborious and time-consuming. Over the last 10 years, advancements in the area of genome assembly, genotyping, large-scale data analysis, and statistical algorithms have led faster identification of genomic variations regulating the complex agronomic traits and pathogen resistance. In this review, we describe the latest developments in genome sequencing and genotyping along with a comprehensive evaluation of the last 10-year headways in forward-genetic techniques that have shifted the focus of plant research from model plants to diverse crops. We have classified the available molecular genetic methods under bulk-segregant analysis-based (QTL-seq, GradedPool-Seq, QTG-Seq, Exome QTL-seq, and RapMap), target sequence enrichment-based (RenSeq, AgRenSeq, and TACCA), and mutation-based groups (MutMap, NIKS algorithm, MutRenSeq, MutChromSeq), alongside improvements in classical mapping and genome-wide association analyses. Newer methods for outcrossing, heterozygous, and polyploid plant genetics have also been discussed. The use of k-mers has enriched the nature of genetic variants which can be utilized to identify the phenotype-causing genes, independent of reference genomes. We envisage that the recent methods discussed herein will expand the repertoire of useful alleles and help in developing high-yielding and climate-resilient crops.

Influence of the soldering paste type on optical and thermal parameters of LED modules

PurposeThis paper presents the results of the investigations of LED modules soldered with the use of different soldering pastes.Design/methodology/approachThe tested power LED modules are soldered using different solder pastes and soldering processes. Thermal parameters of the performed modules are tested using indirect electrical methods. The results of measurements obtained for different modules are compared and discussed.FindingsIt was shown that the soldering process visibly influences the results of measurements of optical and thermal parameters of LED modules. For example, values of thermal resistance of these modules and the efficiency of conversion of electrical energy into light differ between each other even by 15%.Practical implicationsThe obtained results of investigations can be usable for designers of the assembly process of power LED modules.Originality/valueThis paper shows the investigations results in the area of effective assembly of power LEDs to the metal core printed circuit board (MCPCB) using different soldering pastes (REL22, REL61, LMPA-Q6, OM-5100, OM-338-PT, M8, OM-340, CVP-390). It was shown that the best thermal and optical properties of these modules are obtained for the OM5100 paste by Alpha Assembly.

Human intention and workspace recognition for collaborative assembly

Human-Robot-Collaboration is being used more often nowadays in assembly processes that can not be fully automated in an optimal way. Skill-based task sharing showed to be a good alternative to manual labor mainly when tasks are either non ergonomic or require high precision. While collaborating with humans, robots are usually equipped with sensors to perceive the environment or the human when necessary. This paper presents a method for not only recognizing the product being assembled along with its components but also tracking the live motions of the human hands in the assembly area. This method can either be used as an input for the decision making module of the robot, or as a measure for quality insurance and human fault detection.

Study on a test bench of a vehicle rear axle fatigue behavior

This paper presents a study with finite elements of the rear axle of a car. The virtual model of the rear axle assembly of a vehicle is made. Based on this model we made a study of the state of stresses and strains that occur in the components of the rear suspension. When constructing the analysis model, we considered the bearing conditions, as well as the loads from the real operation of the assembly. The purpose of this finite element analysis is to determine the most requested areas of the rear axle assembly, as well as to compare the results obtained for specific deformations and stresses experimentally with those obtained by finite element analysis. Also, through the analysis with finite elements, we obtained and presented in the paper results regarding the fatigue behavior of the elements of the ensemble.

Competence Requirements in Manufacturing Companies in the Context of Lean 4.0

Traditional production systems today are often based on Lean Production. With the advent of Industry 4.0, new digital and networked solutions are emerging that offer new opportunities and challenges combined with Lean Management principles and methods. The successful implementation of Lean Management requires that the employees in the production environment have internalized the associated philosophy, integrated the methods into their daily work, and implemented the necessary competencies into their processes. The different emerging technologies through Industry 4.0 lead to new changes for both the company and the employees. In order to master the challenges of this comprehensive industrial change and to remain competitive on the global market, timely training and further education of production employees are indispensable. The employees contribute significantly to the success of a company and the implementation of Lean 4.0. The prerequisite for sufficient qualification of employees is identifying relevant competencies. This scientific contribution aims to present a structured and comprehensive approach to develop a Lean 4.0 competence model for manufacturing companies that depicts the requirements for employee competencies due to Lean 4.0 elements and job profiles. The focus will be on assembly and manufacturing areas as well as the production-related areas maintenance and internal logistics.

Proving the Applicability of Assembly Complexity Measures for Process Time Prediction of Customer-specific Production

The production of customized goods is becoming more and more important for industrial companies. The large number of variants resulting from this, up to batch size 1 production, requires a high degree of flexibility of the production systems and their scheduling. To meet these requirements, manual production processes are frequently still used. This is especially applicable to the area of assembly. In contrast to automated systems, the processes in manual assembly are more difficult to schedule. Today, methods for generating predetermined times are used in order to better calculate and schedule processes. However, for the assembly of a product that has not yet been produced, there are neither predetermined times nor historical data from production runs that have already been completed.This paper describes an approach to optimize the production planning of manual assembly systems for customized products by calculating more realistic lead times for new product variants on the basis of historical product data already acquired. Based on objective data acquisition, the existing data sets are classified in order to be able to derive conclusions on new product variants. The classification is based on the measure of assembly complexity. The model for calculating the lead times is validated using data from a real production system of the Chair of Production Systems.