Assembly Line Process Research Articles

Learning from demonstration for 7-DOF anthropomorphic manipulators without offset via analytical inverse kinematics

Learning from demonstration (LfD) has been widely studied as a convenient method for robot learning. In the LfD paradigm for redundant manipulators, the reproduced trajectories ought to be similar to human demonstrations in both task and joint space. Despite many advancements achieved in the context of learning in task space, the solutions for generating similar reproductions in joint space are still largely open. In this paper, a novel non-parametric LfD framework for 7-DOF anthropomorphic manipulators with high computational efficiency is proposed. The proposed method leverages redundancy resolution and kernel-based approaches to formulate an efficient model characterized by a limited set of open parameters. Experiments were conducted to evaluate the performance of the proposed method and compare it with the commonly used ‘LfD+IK’ solution. The results indicated that the proposed method behaves much better in terms of the similarity between the demonstration and reproduction with high computing efficiency. As the proposed method can learn from human demonstrations effectively in both task and joint space, it has the potential to significantly enhance human–robot collaboration, streamline assembly line processes, or improving robot learning. An important future challenge will be extending the proposed method for general-purpose redundant manipulators and considering task constraints to perform complex tasks.

A deep learning approach for balance optimisation of patch panel assembly line

This paper introduces an integrated methodology to enhance the efficiency of patch panel assembly lines by harnessing advanced artificial intelligence (AI) techniques. The primary objective is to minimise the total completion time of patch panels, a pivotal metric for manufacturing efficiency. The study employs the Assembly Line Production Optimisation (ALPO) model to analyze and enhance the production capacity of the bottleneck station. Existing challenges related to patch panel assembly line task distribution, process content, and tooling layout are scrutinised against production process standards for operational measurements. To achieve improvement, Deep Neural Network (DNN) and Recurrent Neural Network (RNN) models are employed in hidden layers, supplemented by deep feed-forward (DFF) layers for output, in adherence to engineering design principles. The bottleneck station's load rate is successfully reduced to below 80%, contributing to an overall balance rate increase from 73% to 88%. These outcomes signify a notable enhancement in production efficiency and employee satisfaction. The research utilises a dataset derived from the Microsoft Azure AI-based PdM dataset. The paper illustrates how AI techniques offer a comprehensive solution to address the inherent complexities in patch panel assembly line optimisation.

How smart is a ‘smart factory’?: an organizational view

Abstract This paper investigates the game-changing paradigm in modern manufacturing, known as the “smart factory,” from an organizational perspective. Factories get smarter—or smartized—by becoming more data-intensive and more tightly integrating operations with management. We design a unique survey to measure this intangible organizational capital accumulation process for 939 Korean manufacturing plants. Observing heterogeneous levels of smartization across factories, we explore their relationship with three performance dimensions: productivity, cost efficiency, and product variety. The drivers of smartization are also identified. Our analysis uncovers a strong association between smartization and heightened productivity, with varying interactions with other performance metrics based on the specific manufacturing process (e.g., lower defect rate only in assembly line process). Importantly, we find that investments in digital technologies drive smartization only when complemented by structured incentive management and proper chief executive officer (CEO) leadership.

Pharmacy Workplace Wellbeing and Resilience: Themes Identified from a Hermeneutic Phenomenological Analysis with Future Recommendations.

This study applied a hermeneutic phenomenological approach to better understand pharmacy workplace wellbeing and resilience using respondents' written comments along with a blend of the researchers' understanding of the phenomenon and the published literature. Our goal was to apply this understanding to recommendations for the pharmacy workforce and corresponding future research. Data were obtained from the 2021 APhA/NASPA National State-Based Pharmacy Workplace Survey, launched in the United States in April 2021. Promotion of the online survey to pharmacy personnel was accomplished through social media, email, and online periodicals. Responses continued to be received through the end of 2021. A data file containing 6973 responses was downloaded on 7 January 2022 for analysis. Usable responses were from those who wrote an in-depth comment detailing stories and experiences related to pharmacy workplace and resilience. There were 614 respondents who wrote such comments. The findings revealed that business models driven by mechanized assembly line processes, business metrics that supersede patient outcomes, and reduction of pharmacy personnel's professional judgement have contributed to the decline in the experience of providing patient care in today's health systems. The portrait of respondents' lived experiences regarding pharmacy workplace wellbeing and resilience was beyond the individual level and revealed the need for systems change. We propose several areas for expanded inquiry in this domain: (1) shared trauma, (2) professional responsibility and autonomy, (3) learned subjection, (4) moral injury and moral distress, (5) sociocultural effects, and (6) health systems change.

Electrochemical On-Site Switching of the Directional Liquid Transport on a Conical Fiber.

Directional liquid transport (DLT), especially that proceeding on a conical fiber (DLT-CF), is an important mass-transfer process widely used both by natural organisms and in practical applications. However, on-site switching of the DLT-CF remains a challenge due to the nontunable driving force imparted by the structural gradient, which greatly limits its application. Here, unprecedently, a facile electrochemical strategy is developed for reaching the on-site switchable DLT-CF, featuring in situ control and fast response. Depending on the poised electric potential, the droplet can either move directionally or be pinned at any position for a tunable duration time, exhibiting completely different moving characteristics from the traditional DLT-CF with no control. It is proposed that the surface hysteresis resistance, closely related to both the surface hydrogen-bonding network and the droplet topology on the fiber, can be largely altered electrochemically. The tunable hysteresis resistance works synergistically with the conical-structure-induced Laplace pressure to on-site tune the forces acting on the droplet, leading to various controllable DLTs-CF, including those with tunable distance and direction, array manipulation, and assembly line processing of droplets. The strategy is applicable for versatile liquids, offering a general approach for controllable liquid transport in fibrous systems.

Wearable shear and normal force sensing glove development for real-time feedback on assembly line processes

This research aims to develop a force sensing glove worn by workers in manual assembly to measure both shear and normal forces and motion data to evaluate the connections completed and provide real-time feedback to the operator. Many tasks in production assembly are still completed manually due to the intuition needed, complex automation steps, or time constraints. This is largely seen in automotive assembly environments which also creates a greater possibility for error because they consist of predominately human completed operations. These processes include hose and electrical connections which can loosen over time after passing initial quality testing, resulting in costly, time-consuming rework and a diminished brand image. Operator forces and motion data are selected for measurement to ensure processes are completed with the correct approach and ample forces applied while also verifying that all necessary tasks within the takt are completed. Multiple forms of measurement will assist with adapting to operator variability while offering operator accountability and process verification. It was found that operator forces and motion could successfully be captured and analyzed through the developed sensor glove and that the glove offers a robust, durable format that is adequately equipped for use on the physically demanding assembly line.

EFFORTS TO REDUCE THE RISK OF DEFECTS OF MINICAB PRODUCTS TYPE MSM 2230 IN ASSEMBLING PROCESS WITH FAILURE MODE EFFECT AND ANALYSIS METHOD


 Indospring Tbk, is a spring producer company of two types, namely leaf springs and coil springs. Based on the results of the data obtained from the assembling process at PT. Indospring, Tbk that there are still high defects or product incompatibility, especially Minicab type MSM 2230 with 290 types of defects for 3 months (January 2021 - March 2021) with a percentage of 18.59%. The purpose of this research is to find out the types of Minicab MSM 2230 defects in the assembly line process, to find out the factors that cause defects problems, to provide benefits as knowledge and considerations to improve quality by correcting the causes of product defects. In finding the cause of product defects and their impact using the Failure Mode Effect and Analysis (FMEA) method. During the period from January to March 2021, before repairing the average defect, koba defects 17.33, scratch 20, eye forming defects 4.33, half span NG 15.33, eccentricity out spec 2, taper NG 11.66, pieces NG, 18 .66, EF gap narrowed 0.66, crack 6.66. Based on Failure Mode Effect Analysis, scratch has the highest Risk Priority Number value, which is 324 with a value of 9 on severity, 6 on occurrence and 6 on detection. The results of brainstorming factors that cause defect scratch, namely the product testing process is often dragged down due to speeding up the production flow, during the after tempering process the operator is wrong in the arrangement on the rack / pallet, and it can also be that the material from the supplier is already scratched. So that the highest defect will be the main priority for immediate repairs.
 

Fine Line and Low Stress RDL Solition for Fan-Out Wafer Level & Panel Level Packaging

Abstract Process limitations faced during the construction and integration of current and next generation advanced packages require a new RDL (Redistribution Layer) approach to overcome fine L/S and stress constraints. If interactions between design, process and materials are not optimized or controlled, then yield loss and higher cost result. RDL is an integral part of a package and with greater design complexity the number of such layers also increase. This paper introduces a new RDL concept through HRDP® (High Resolution Debondable Panel) technology. It has received industry wide attention, especially for Fan-Out, Chip Last, Wafer Level & Panel Level package assemblies. The structure and materials for HRDP® are described. The applicable HRDP® carrier can be provided in various dimensions and thicknesses for round panels and for square/rectangular panels with glass or silicon to match customer requirements. This accommodates process simplification and improves interfacial stresses. The process steps using HRDP® are elaborated, which essentially use existing tools in RDL metal patterning (i.e., Lithography, Developer/Descum etc.) without disrupting the assembly line layout and process flow. HRDP® is compatible with existing dielectrics and photoresists. It has been demonstrated that based upon the capabilities of dielectrics and photoresists used for RDL in the bump fab, fine L/S geometries of 2/2 um and less have been achieved. Reliability data has been shared.

Virtual reality simulation of human-robot coexistence for an aircraft final assembly line: process evaluation and ergonomics assessment

ABSTRACT Aeronautics, in the context of industry 4.0, is continuously evolving to respond to the market dynamics and has incorporated automation to many stages of aircraft manufacturing. However, most of the final assembly line processes are still done manually and remain a challenge. Virtual Reality (VR) technologies can be leveraged to study the incorporation of automation systems involving Human-Robot Coexistence (HRC) in assembly processes before the physical system is available, which is beneficial for increasing the productivity and identifying issues beforehand, thus, preventing unexpected costs. In this context, a VR simulation environment was developed with two innovative factors: (1) The possibility to evaluate multiple new automated and semi-automated cabin and cargo processes and select the best one in terms of specific Key Performance Indicators (KPIs) for a future implementation in the physical system and (2) the capability to study the ergonomics of the human worker inside the narrow space of the fuselage while assembling the parts and coexisting with robots, without compromising the worker’s safety. The results show that most of the new proposed strategies improve the assembly time, worker cost, or ergonomics of the process, with an investment varying between 100 K and 200 K euros and ROI of 1–2 years.

Divide and Conquer: A Hygienic, Efficient, and Reliable Assembly Line for Housekeeping

Problem definition: This work focuses on the hotel housekeeping process. In a field study, a possible channel of disease transmission between consecutive guests in hotel rooms is revealed. In order to prevent the transmission, an innovative assembly-line housekeeping method is developed. Academic/practical relevance: The transmission of infectious diseases during hotel stays (e.g., by touching unclean towels or bed linens) has been reported globally. Under the current COVID-19 pandemic, having contact with saliva or mucus left by an infected person could cause infection. The standard housekeeping process used by the majority of hotels leaves a channel for new towels and bed linens in refreshed rooms to be contaminated by bacteria or viruses from used towels and bed linens. Eliminating the contamination channel and preventing disease transmission are crucial for protecting the health and safety of hotel guests, especially under a disease outbreak such as the current COVID-19 pandemic. Methodology: The research was conducted during a field study at a hotel. To design the assembly-line process, the service time distribution of each housekeeping operational step is characterized using data collected from the practice at hundreds of hotel rooms. An optimization model is proposed to optimize the operation. Through a pilot test, the performance of the assembly-line and the traditional housekeeping methods is compared. Results: The pilot test results show that the assembly-line housekeeping method has the potential to improve not only hygienic standards but also, labor efficiency and service quality (error rate). Managerial implications: The outbreak of the COVID-19 pandemic draws tremendous public attention on disease transmission and public hygiene. The principle of the assembly-line method (i.e., eliminating contamination channels through teamwork operational design) can be applied to not only hotel housekeeping practices but also, many other service settings. It leads to hygienic, efficient, and reliable operations, at no additional cost.

Malaria Pigment Crystals: The Achilles' Heel of the Malaria Parasite.

The biogenic formation of hemozoin crystals, a crucial process in heme detoxification by the malaria parasite, is reviewed as an antimalarial drug target. We first focus on the in‐vivo formation of hemozoin. A model is presented, based on native‐contrast 3D imaging obtained by X‐ray and electron microscopy, that hemozoin nucleates at the inner membrane leaflet of the parasitic digestive vacuole, and grows in the adjacent aqueous medium. Having observed quantities of hemoglobin and hemozoin in the digestive vacuole, we present a model that heme liberation from hemoglobin and hemozoin formation is an assembly‐line process. The crystallization is preceded by reaction between heme monomers yielding hematin dimers involving fewer types of isomers than in synthetic hemozoin; this is indicative of protein‐induced dimerization. Models of antimalarial drugs binding onto hemozoin surfaces are reviewed. This is followed by a description of bromoquine, a chloroquine drug analogue, capping a significant fraction of hemozoin surfaces within the digestive vacuole and accumulation of the drug, presumably a bromoquine–hematin complex, at the vacuole's membrane.

Evaluation Scheme of Voltage Sag Immunity in Sensitive Industrial Process

In order to enhance the effectiveness of voltage sag governance and the practicability of the process immunity assessment method, an immunity assessment method for the assembly line process is proposed, fully considering the relationship between logistics line and power line, and thoroughly portraying the relationship between equipment and its links in depth. Combined with the existing voltage tolerance curve test results, the power line immunity time is reasonably evaluated considering the response delay of each device. In addition, the fault probability is quantified considering the possibility of equipment failure and its link repairing. On this basis, the minimal cut-set method is adapted to standardize the constructed random network of logistics lines. The immunity of the whole manufacturing process is evaluated through series-parallel logical analysis. In the end, the paper mill is taken as a sample to illustrate the proposed method. The deviation between the average annual economic loss obtained from model evaluation and this typical producer’s survey loss is regarded as the basis for the measurement of the effectiveness of the method. The results show that the immunity of the process can be accurately evaluated for the deviation of the evaluation obtained by the proposed method is relatively small.

Mobilizing Communities to Sustainably Produce Face Masks: Public Health Practice in the Time of COVID-19

Background: Face mask shortages in health care and use recommendations and requirements in a variety of com-munity and professional contexts associated with the coronavirus disease 2019 (COVID-19) pandemic in the United States created initial and ongoing demand for face masks. In March 2020, the US Centers for Disease Control and Prevention (CDC) provided guidelines for use of cotton masks for individuals in health care settings and in public. Community volun-teers provide a potential workforce to rapidly and flexibly address critical needs in emergent circumstances.
 Methods: People Protecting Each-other Sustainably (PPEs) was developed to recruit and manage over 100 Northeast Ohio volunteers. People Protecting Each-other Sustainably used the social media platform Facebook to facilitate material donations, volunteer recruitment and training, and to function as an ongoing central communications hub. Leaders used an assembly line process with zero contact pick up and drop off at multiple stages of production to allow safe assembly and distribution of face masks.
 Results: A total of 7 695 handmade face masks were created to distribute to local frontline responders in 10 weeks. Use of upsourced and donated materials allowed this project to reduce potential landfill waste and made a zero cost project possible. Volunteers had positive responses to the project and reported benefits from their participation.
 Conclusion: This model has been successfully recreated by a smaller group in Geauga County, Ohio, with similarly successful results. Clearly this model of community mobilization has the potential to be replicated in other state of emer-gency crises and emergency response situations to produce lifesaving or necessary equipment when industry standard equipment is not readily available.

Unimodular Methylation by Adenylation–Thiolation Domains Containing an Embedded Methyltransferase

Nonribosomal peptides (NRPs) are natural products that are biosynthesized by large multi-enzyme assembly lines called nonribosomal peptide synthetases (NRPSs). We have previously discovered that backbone or side chain methylation of NRP residues is carried out by an interrupted adenylation (A) domain that contains an internal methyltransferase (M) domain, while maintaining a monolithic AMA fold of the bifunctional enzyme. A key question that has remained unanswered is at which step of the assembly line mechanism the methylation by these embedded M domains takes place. Does the M domain methylate an amino acid residue tethered to a thiolation (T) domain on same NRPS module (in cis), or does it methylate this residue on a nascent peptide tethered to a T domain on another module (in trans)? In this study, we investigated the kinetics of methylation by wild-type AMAT tridomains from two NRPSs involved in biosynthesis of anticancer depsipeptides thiocoraline and echinomycin, and by mutants of these domains, for which methylation can occur only in trans. The analysis of the methylation kinetics unequivocally demonstrated that the wild-type AMATs methylate overwhelmingly in cis, strongly suggesting that this is also the case in the context of the entire NRPS assembly line process. The mechanistic insight gained in this study will facilitate rational genetic engineering of NRPS to generate unnaturally methylated NRPs.

SIX SIGMA METHODOLOGY IMPLEMENTED IN AUTOMOTIVE INDUSTRY

In present era of competition, Six Sigma has been considered as a powerful business strategy that employs a well structured continuous improvement methodology to reduce rejections within the manufacturing pro- cesses using effective application of statistical tools and techniques. This paper presents the implementation of Six- sigma methodology for reducing rejection of automobile part in an industry. The DMAIC (Define, Measure, Analyze, Improve and Control) methodology has been used to achieve quality level. During this process, data for all possible causes were collected, analyzed and thereby conclusions were drawn. Implementation of Six Sigma resulted in reduction of rejection and improvement of process capability and process performance. Finally, implementation of Six-sigma methodology has resulted in increase in quality level of assembly line and pre-assembly process in automobile company.

Using requirement-functional-logical-physical models to support early assembly process planning for complex aircraft systems integration

The assembly line process planning connects product design and manufacturing through translating design information to assembly integration sequence. The assembly integration sequence defines the aircraft system components installation and test precedence of an assembly process. This activity is part of the complex systems integration and verification process from a systems engineering view. In this paper, the complexity of modern aircraft is defined by classifying aircraft system interactions in terms of energy flow, information data, control signals and physical connections. At the early conceptual design phase of assembly line planning, the priority task is to understand these product complexities, and generate the installation and test sequence that satisfies the designed system function and meet design requirements. This research proposes a novel method for initial assembly process planning that accounts for both physical and functional integrations. The method defines aircraft system interactions by using systems engineering concepts based on traceable RFLP (Requirement, Functional, Logical and Physical) models and generate the assembly integration sequence through a structured approach. The proposed method is implemented in an industrial software environment, and tested in a case study. The result shows the feasibility and potential benefits of the proposed method.

Improvement of Manual Assembly Line Based on Value Stream Mapping (VSM) and Efectiveness Coefficient

Abstract In the paper the possibilities of process re-organizing in relation to simple principles for limiting waste in the production cycle have been presented. Based on value stream mapping and monitoring of performance indicators, the possibilities of changes identification of in the assembly line process have been presented. Furthermore, based on the availability, performance and quality values, it has been proved that relatively small changes can have a very positive effect on the assembly process. Based on the OEE coefficient, it has been found that the proposed changes improved the process's efficiency by more than 20%.

Production Rate Improvement for Assembly Line in Sheet Metal Stamping Industry

In today’s manufacturing industry, there is an increased focus to produce the right product at right time. This project is to study the process flow of Philips Fluorescents Lamp assembly line in sheet metal stamping company based on lines concept and factors influencing the production lines efficiency by analyzing the problem occurred in the process. The manual and automatic assembly has been analyzed for its influence on the assembly line. The transformation from manual to the automated assembly where the manual screwing and packing processes replaced by automated machines is studied. During factory visit, the average cycle time for manual and automated assembly process was taken in order to analyze it. The number of output of Fluorescents Lamp before and after the transformation was studied. Data collected used to simulate the current assembly line process using simulation software, DELMIA Quest. The layout where all process consists of manual assembly and after adding the machines have been designed and analyzed using this software. Based on the current layout analysis, a new layout was proposed in order to get a better process flow. The proposed layout shows an improvement of average production rate of at least 16% from the current assembly line.

Lean Built-Up Panel Assembly in a Newbuilding Shipyard

The main shipbuilding assembly processes greatly influence the flow of interim products in a newbuilding shipyard. The panel assembly line is a major process located upstream of all the other shipyard assembly processes. In a previous paper, the application of lean principles enabled a balanced and smaller takt time along the workstations and yielded significant savings in man-hours. Although a panel consists of butt-welded steel plates with multiple fillet-welded longitudinal stiffeners, a built-up panel is this same panel fitted with longitudinal and transverse steel elements. Since there are many internal structural elements, the man-hours along a traditional built-up panel assembly line are multiple times greater than that of panel assembly. Therefore, it is necessary to analyze and map built-up panel assembly in an actual newbuilding shipyard. Using value stream mapping along with kaizen principles of continual improvement to determine the transformative steps to make the traditional built-up panel assembly line leaner. This enables significant man-hour reductions of about 60%, which yields remarkable cost savings to the shipyard. 1. Introduction The built-up panel assembly line process is located downstream to the panel assembly process, and in most shipyards, half of all steel panels become built-up panels. It is very labor intensive since there are many steel elements that need to be joined in both longitudinal and transverse directions and there are both fillet and vertical welding jobs to be done. The joining of built-up panels to panels yields large three-dimensional blocks. Although in past papers (Kolich et al. 2017, 2015a) a lean value stream mapping methodology to transform panel assembly was developed, it makes sense to develop a methodology for the more complex and man-hour intensive built-up panel assembly process as well. The transformed built-up panel assembly process will further reduce bottlenecks in the shipyard and improve flow bringing down man-hours, which translates to critical savings for the shipyard.

Diversity oriented biosynthesis via accelerated evolution of modular gene clusters

Erythromycin, avermectin and rapamycin are clinically useful polyketide natural products produced on modular polyketide synthase multienzymes by an assembly-line process in which each module of enzymes in turn specifies attachment of a particular chemical unit. Although polyketide synthase encoding genes have been successfully engineered to produce novel analogues, the process can be relatively slow, inefficient, and frequently low-yielding. We now describe a method for rapidly recombining polyketide synthase gene clusters to replace, add or remove modules that, with high frequency, generates diverse and highly productive assembly lines. The method is exemplified in the rapamycin biosynthetic gene cluster where, in a single experiment, multiple strains were isolated producing new members of a rapamycin-related family of polyketides. The process mimics, but significantly accelerates, a plausible mechanism of natural evolution for modular polyketide synthases. Detailed sequence analysis of the recombinant genes provides unique insight into the design principles for constructing useful synthetic assembly-line multienzymes.