Automobile Assembly Research Articles

Multi-objective optimization of greening scheduling problems of part feeding for mixed model assembly lines based on the robotic mobile fulfillment system

Since greening scheduling problems are drawing increasing attention from researchers and modern manufacturing enterprises, and the energy consumption is a substantial problem regarding the greening and sustainability, the aim of this paper is to construct an energy-saving scheduling scheme to carry out the part feeding tasks of mobile robots in the automobile mixed model assembly lines. The objective of minimizing the total energy consumption of mobile robots is jointly incorporated with the operational criterions when implementing part feeding tasks. Due to the NP-hardness nature of the proposed greening problem, a multi-objective disturbance and repair strategy enhanced cohort intelligence (MDRCI) algorithm is established to deal with the multi-objective problem. Computational results indicate that the enhanced strategies are of great significance to the MDRCI algorithm and it outperforms the other benchmark algorithms on both global search capability and search depth. In addition, the energy-saving strategy and disturbance and repair strategy are validated by comparison experiments. Furthermore, managerial insights are illustrated to make trade-offs between the total line-side inventory level and the energy consumption, jointly making it helpful in the greening scheduling process of the practical production. The achievements acquired in this paper may be inspiring for further researches on the energy-related production scheduling problem.

Visual effects creation to improve user performance in fully immersive virtual environment of automobile engine assembly

Virtual reality (VR) technologies and computer-generated technologies are very useful for many industries, such as medical, education, gaming, mining, engineering, and other sectors. In engineering sector specifically for assembly department, the major problem they are facing was that traditional components of automotive engine are complex and very difficult to assemble using current method which use paper manual. The goal of this project is to create an interactive VR application such that users can quickly integrate and perform the work easily. In this work, the authors designed and developed an immersive VR application with several stages, such as 3D model creation, visual effects creation and gaming scene building. The application was built using Unreal and HTC vive headset. As this is an on-going project work, further functionality will be added to render the application immensely for users and assist the sense of pedagogy in terms of the digital method of learning.

Design of Automobile Rapid Maintenance Based on Digital Maintenance Assistant System

In recent years, with the rapid growth of China’s automobile ownership, the profit proportion of automobile aftermarket in the automobile industry is increasing day by day, and the automobile service industry is gradually growing in the development of China’s national economy. The current automobile maintenance management software is not good and bad, most of these management software in order to meet the common possible user needs and lead to the same software function, lack of consideration for the management system of small and medium-sized enterprises, and there are certain defects in generality. At the recent 2020 China Automobile Supply Chain Conference, Wu Wei, director of the Machinery Department of the Industrial Development Department of the national development and Reform Commission, said that the production and sales volume of the automobile market had achieved a year-on-year growth for six consecutive months. If this momentum can continue in the fourth quarter, the total production and sales volume by the end of this year is expected to be close to the level of last year. Automobile fast repair refers to the activities of automobile maintenance and minor repair, but not vehicle repair, automobile assembly repair and secondary maintenance. The service scope is locked in 120 fast repair and maintenance items that can be completed within 2 hours. At present, the total number of motor vehicles in our country is huge, and the number of maintenance enterprises can not meet the demand of maintenance, so the potential of automobile fast repair market is unlimited. As the main business of fast repair industry, automobile fast repair is paid more and more attention by people. The application of digital management mode and maintenance cases creates good conditions for the development of fast repair enterprises, and makes it possible for fast repair enterprises to adopt reasonable maintenance methods. This paper focuses on the chaos in maintenance management, On the basis of the research and analysis of automobile maintenance management system and digital management concept, taking customer demand as the starting point, this paper designs a digital automobile maintenance auxiliary system specially for automobile fast repair enterprises to assist managers in maintenance management, so as to achieve the purpose of standardized management business “fast and reasonable” maintenance, and improve customer satisfaction.

Assembly Part Positioning on Transformable Pin Array Fixture by Active Pin Maximization and Joining Point Alignment

Designing and installing jigs and fixtures for new products are very costly tasks. In order to rapidly respond to frequent product changes in a manufacturing system, we developed a transformable pin array fixture system including reconfiguration planning software that finds the optimal position for mounting an assembly part and automatically generates a pin height control code. We first classified main fixturing quality factors such as type of contact, distance between a pin and a joining point, and part shape. We then formulate the part positioning problem as an alignment problem between the joining point set and the pin point set in the xy plane in consideration of the fixturing quality factors. A car door trim assembly module was used to verify the proposed method. Finite-element analysis results showed that in a car door trim assembly process such as ultrasonic welding and screwing, relocating an assembly part at the optimal position reduces its deformation.

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.

Finger Clamping Unit: A Clamping Device with a Large Clamping Range

Finger Clamping Unit (FCU) is a small-sized single-point clamp developed to clamp thin object of various thicknesses. It has a six-bar linkage with one compliant link, uses an electric motor as an actuator and induces toggle-lock motion by singular configuration. The main purpose of the FCU is to clamp car bodies in car assembly lines, while adapting to various thicknesses of car body. Unlike other clamping devices in the industry, it has a large clamping range (defined as the thickness range that the FCU can clamp). In this paper, the overall process of FCU development is presented. The six-bar linkage was chosen in type synthesis, and compliance was added for toggle-lock motion. Static analysis of the compliant FCU was completed, and results were plotted in a three-dimensional (3D) plot which expresses the behavior of the FCU. The lengths of each link were optimized in dimension synthesis. An FCU was constructed to reinforce the simulated results. The unique design of both the six-bar linkage FCU and the compliant link were presented. Simulated and experimental 3D plots were compared and analyzed. An appropriate friction model that best fits the experiment data was found. The advantage of the FCU—its clamping range—was proved by experiment.

Production scheduling problem of automobile mixed model assembly line

Nowadays, the mode of production has changed from mass production to multi variety and small batch production, and mixed model assembly line has emerged. Mixed model assembly is widely used in automobile enterprises. This paper summarizes the theory and method of automobile mixed model assembly line scheduling, analyzes its characteristics and difficulties, summarizes the related optimization objectives, and introduces the related algorithms, so as to make the scheduling problem of mixed model assembly line more clear.

Black Carbon Exposure Characteristics in Diesel Engine Vehicle-related Jobs

ABSTRACT We aimed to characterize the black carbon (BC) exposure from eight types of jobs involving diesel engine vehicles—namely, machinery operation, forklift operation, automobile assembly, garbage collection, garbage truck driving, delivery, toll operation, and crane operation—across seven industries. The workers chosen for this study (N = 106) measured their exposure every minute using an AE51 microAethalometer affixed to a microcyclone and also recorded their time-activity patterns and whereabouts in detail during working hours. We then categorized and analyzed 71,987 of these 1-min observations based on four potential exposure determinants: the operation of a diesel engine vehicle (yes or no), proximity to the source of BC (near or far), location of the workplace (indoor or outdoor), and type of work (moving or stationary). Among the participants, the geometric mean (GM) exposure was highest for forklift operators in indoor environments (9.5 µg m–3), followed by toll operators (GM = 7.4 µg m–3), machinery operators (GM = 7.4 µg m–3), and garbage collectors (GM = 5.5 µg m–3). After accounting for the random effects of the individual workers and working dates (evaluated per occupation) as well as the fixed effects of the determinants and their pairwise interaction terms (p < 0.001), we found that all four of the determinants significantly differed in their associated levels of BC exposure. In particular, working near instead of far from diesel engine equipment doubled the average level of exposure. Additionally, upon investigating different combinations of the determinants, we identified proximity to diesel exhaust sources and indoor working conditions as the main factors of BC exposure. Thus, installing diesel particulate filters on diesel engine vehicles effectively reduces exposure. Our findings potentially contribute to the development of a model that predicts the level of exposure for various types of jobs.

Assessment of return and volatility spillover across sectors indices: evidence from Pakistan stock exchange

This paper examines the dynamics of return and volatility transmission between several sectors of Pakistan Stock Exchange (PSX). We employed GARCH(1,1) model and our results demonstrate that the most influential sector regarding the return spillover is power generation and distribution sector, and regarding volatility spillover, highly influential sector is automobile sector indicating that these sectors are the main drivers of spillover effect. Whereas, the most suggested sectors for investment are Automobile Assembler and Power generation and distribution sectors, as these are least influenced by other sectors' spillover. The investors and portfolio managers can use such findings as a guideline in making a healthy portfolio resulting in reduced risk to their investment. The well-informed decisions of the investors can, in turn, facilitate the growth of economy.

An improved optimization method for materials distribution based on spatiotemporal clustering in automobile assembly lines

The development of smart factories has put forward more flexible logistics needs for automobile assembly system, and efficient scheduling strategies to meet these requirements still demand prompt solution. Thus, this paper focuses on the problem of materials distribution with automated guided vehicles (AGVs) in automobile assembly lines. The mathematical model is established in the light of actual situation with mixed time windows and an improved genetic algorithm (GA) is developed. Considering the demand characteristics both in time and space, material demand points are clustered based on their spatiotemporal distance to generate the initial population. Then, selection, crossover and mutation operators of GA are also ameliorated as necessary to minimize the total travel cost. Finally, practical examples are carried out to demonstrate the effectiveness of this methodology.

Path planning for simulating human motions in manual assembly operations

Assembly operation simulation can e.g. be used for optimizing complex manual assembly processes in the automotive industry. However, realistic human motion modeling involves difficult tasks such as inserting objects that require constraint definitions and collision detection. In this work, a method that applies the concept of an optimized potential field is employed to generate a motion model unit for simulating human motion for the assembly of pedal cars. This motion model unit is implemented into the newly created MOSIM motion modeling interfaces that is currently being standardized. This approach may allow motion simulation without being tied to a specific 3D environment.

Automatic assembly quality inspection based on an unsupervised point cloud domain adaptation model

This paper proposes an end-to-end method for automatic assembly quality inspection based on a point cloud domain adaptation model. The method involves automatically generating labeled point clouds from various CAD models and training a model on those point clouds together with a limited number of unlabeled point clouds acquired by 3D cameras. The model can then classify newly captured point clouds from 3D cameras to execute assembly quality inspection with promising performance. The method has been evaluated in an industry case study of pedal car front-wheel assembly. By utilizing CAD data, the method is less time-consuming for implementation in production.

Retracted] Research on Automobile Assembly Line Optimization Based on Industrial Engineering Technology and Machine Learning Algorithm

Aiming at the lack of search depth of traditional genetic algorithm in automobile assembly line balance optimization, an improved genetic algorithm based on bagging integrated clustering is proposed for balance optimization. Through the integrated learning of several K‐means algorithm based learners through bagging, a population clustering analysis method based on bagging integrated clustering algorithm is established, and then, a dual objective automobile assembly line balance optimization model is established. The population clustering analysis method is used to improve the intersection link of genetic algorithm to improve the search depth. The effectiveness and search performance of the improved genetic algorithm in solving the double objective assembly line balance problem are verified in an example.

ПРОБЛЕМЫ И НАПРАВЛЕНИЯ РАЗВИТИЯ ЦИФРОВИЗАЦИИ СИСТЕМЫ МЕНЕДЖМЕНТА КАЧЕСТВА АВТОСБОРОЧНОГО ПРЕДПРИЯТИЯ

The article presents research on the problem of digitalization of the quality management system of an automobile assembly plant. The directions of development of the processes of informatization and digitalization of the quality management system in production are proposed.

The Assessment of the Whole-Body Vibration on Health Effects in Automobile Assembly Line Worker in South Korea

The Assessment of the Whole-Body Vibration on Health Effects in Automobile Assembly Line Worker in South Korea

Process Capability Studies in an Automated Flexible Assembly Process: A Case Study in an Automotive Industry

Statistical Process Control (SPC) methods can significantly increase organizational efficiency if appropriately used. The primary goal of process capability studies is to obtain critical information about processes to render them even more effective. This paper proposes a comprehensive framework for proper implementation of SPC studies, including the design of the sampling procedure and intervals as well as process capability indices. Some of the most essential process capability indices in the literature were reviewed to develop a methodology to utilize process capability indices within the SPC framework. The current study presents an efficiency-oriented criterion designed for measuring SPC implementation productivity. The framework is applied to the windshield installation process of an Iranian automobile assembly line. The process was sampled in various sessions. Results verify that the implemented SPC framework could successfully improve the process and that the proposed framework could significantly address bottleneck in the process and enhance the quality level of the process from satisfactory to excellent according to the reference values of process capability indices. Managerial insights are also drawn from results.

The relationship between chronotypes and musculoskeletal problems in male automobile manufacturing workers.

BackgroundPrevious studies have shown that morning types are less sensitive to pain. This study aimed to examine the relationship between chronotypes and musculoskeletal problems in workers with musculoskeletal burdens at work.MethodsThis cross-sectional study included 119 male production workers from a large automobile manufacturing plant. All the participants worked 2 shifts and worked on the automobile assembly line. Data were obtained using structured questionnaires, including the reduced Morningness-Eveningness Questionnaire (rMEQ), and musculoskeletal symptom questionnaire. Participants with an rMEQ score of 18 points or more were defined as morning-type workers (MTWs). Participants whose scores were less than 18 points were defined as neither-type workers (NTWs).ResultsThe arithmetic mean age was 51.8 ± 5.3 years. MTWs and NTWs accounted for 35.3% and 64.7% of the total participants, respectively. Evening- and intermediate-type workers accounted form 6.7% and 58.0% of the participants, respectively. There was no significant difference in the health indicators when the MTW and NTW groups were compared. However, the musculoskeletal symptom questionnaire demonstrated a significant difference between the MTW and NTW groups. In the preceding year, the MTW group had significantly lower musculoskeletal pain and treatment ratios compared to the NTW group (35.7% vs. 62.3%, p = 0.005 and 14.3% vs. 32.5%, p = 0.031, respectively). After adjusting for variables, the odds ratio (OR) for musculoskeletal pain was significantly higher in the NTW group than in the MTW group (OR, 3.112; 95% confidence interval, 1.285–7.535; p = 0.012).ConclusionsIn this study, the musculoskeletal pain ratio was significantly lower for MTWs when compared to NTWs. Chronotypes could play an important role in work-related musculoskeletal disorders. Further, larger-scale, follow-up studies on chronotypes are required to assist in the prevention of musculoskeletal disorders in future.

Fatigue recognition in overhead assembly based on a soft robotic exosuit for worker assistance

Physical stress and overuse during assembly tasks is one of the main causes of musculoskeletal disorders of workers. Innovative body-worn robotic assist systems aim to reduce the physical stress in manual assembly and handling operations. A novel approach for automatic fatigue detection using machine learning techniques, combined with body-borne sensors, enables early detection and classification of fatigue. This article introduces the new method for an innovative soft robotic exosuit for physical worker assistance. The feasibility of the method is demonstrated in a case study for overhead car assembly.

КОМПЛЕКСНЫЕ ИНСТРУМЕНТАРИЙ ПОВЫШЕНИЯ ЭФФЕКТИВНОСТИ ПРОИЗВОДСТВЕННОЙ СИСТЕМЫ МАШИНОСТРОИТЕЛЬНОГО ПРЕДПРИЯТИЯ

The article presents the results of the development and implementation of comprehensive tools for increasing efficiency in modern production systems of car assembly plants.

Effective application of the APQP quality tool in Pull Back Car toy assembly processes

The current Mexican market for the production and assembly of toys (Pull back car) demands ever higher productivity, quality, cost and delivery rates, complying with defined production requirements, as the market is becoming larger and of course competitive. For their part, companies have the need to continually launch new models to stay competitive. The current procedure is based on project management through a recognized procedure in the sector, such as APQP (Advanced Product Quality Planning), based on the implementation of a series of key management tools for DNP. The research carried out characterized the current context of toys for the development of new parts in the local toy sector of the Meccano company, in the Huauchinango Puebla region. An operational model proposal is made for the Pull back car toy assemblers, in order to improve performance in the activities of the Meccano company.