Human-centred Manufacturing Systems Research Articles

Specifying task allocation in automotive wire harness assembly stations for Human-Robot Collaboration

Wire harness assembly is normally a manual assembly process that poses ergonomic challenges. As a consequence of the rapidly expanding electrification of vehicles and transportation systems, the demand for wire harnesses can be expected to grow radically, further increasing assembly operator challenges. Thus, automating this assembly process is highly prioritised by production engineers. The rapid development of industrial robot technology has enabled more human-robot collaboration possibilities, simplifying the automation of wire harness process tasks. However, successful automation applications involving humans require efficient and safe allocation of tasks between humans and technology. Unfortunately, present assembly system design methods may be obsolete and insufficient in light of the capabilities of emerging automation technologies such as collaborative robots. This paper presents a design and specification methodology for human-centred manufacturing systems and focuses on collaborative assembly operations in complex production systems. A case study on human-robot collaboration provides an application example from a wire-harness collaborative assembly process. The proposed design methodology combines hierarchical task analysis with assessments of cognitive and physical Levels of Automation (LoAc and LoAp). The assessments are then followed by evaluations of the Levels of human-robot Collaboration (LoC) and the Levels of operator Skill requirements (LoSr) respectively. A task allocation matrix supports the identification of possible combinations of automation and collaboration solutions for a human-centred and collaborative wire harness assembly process. System designers and integrators may utilise the design and specification methodology to identify the potential and extent of human-robot collaboration in collaborative manufacturing assembly operations.

Key human factors and their effects on human centered assembly performance

Today in the increasingly competitive market, consumers prefer to have a great variety of products to choose from; this preference is often coupled with demands for a relatively smaller lot size, shorter lead time, higher quality and lower cost. Consequently, manufacturing companies are being forced to consistently increase flexibility and responsiveness of their production systems in order to accommodate changes of the fluctuating market. Among various forms of production systems, human-centred manufacturing systems can offer such a capability in dealing with product variations and production volumes as human workers can always adapt themselves to perform multiple tasks after a learning process. However, human performance can also be unpredictable and it may alter due to varying psychological and physiological states, which are often overlooked by researchers when designing, implementing or evaluating a manufacturing system. This paper presents a study aiming to address these issues by exploring human factors and their interactions that may affect human performance on human-centred assembly systems. The study was carried out based on a literature review and an industrial survey. Critical system performance indicators, which are affected by human factors, were evaluated and the most significant human factors were identified using the fuzzy extent analysis method. The research findings show that experience is the most significant human factor that affects individual human performance, compared to age and general cognitive abilities in human-centred assembly. By contrast, both human reaction time and job satisfaction have the least effect on human performance. The significance of ageing on human performance was also studied and it was concluded that average assembly time of human workers rises by average 1% per year after the age of 38 years old.

A comparative study on computer-integrated set-ups to design human-centred manufacturing systems

Manufacturing ergonomics refers to the application of ergonomic principles and human factors analysis to the design of manufacturing tasks with the final aim to optimize the workers’ wellbeing and guarantee the expected process performance. Traditional design approaches are based on the observation of individual workers performing their jobs, the detection of unnatural postures (e.g., bending, twisting, overextending, rotating), and the definition of late corrective actions according to ergonomic guidelines. Recently, computer-integrated simulations based on virtual prototypes and digital human models (DHMs) can be used to assess manufacturing ergonomics on virtual manikins operating in digital workplaces. Such simulations allow validating different design alternatives and optimizing the workstation design before the creation, and pave the way to a new approach to manufacturing system design. The present paper aims at comparing different computer-integrated set-ups to support the design of human-centred manufacturing workstations. It defines a protocol analysis to support workstation design by analysing both physical and cognitive aspects, and applies the protocol within different digital set-ups. In particular, the study investigates a 2D desktop set-up using standardized DHMs and a 3D immersive mixed reality set-up based on motion capture of real workers’ acting into a mixed environment, comparing them with the traditional approach. An industrial case study focusing on design optimization of a manufacturing workstation in the energy industry is used to test the effectiveness of the two digital set-ups for the definition of re-design actions.

Human Factors and Their Effects on Human-Centred Assembly Systems – A Literature Review-Based Study

If a product has more than one component, then it must be assembled. Assembly of products relies on assembly systems or lines in which assembly of each product is often carried out manually by human workers following assembly sequences in various forms. It is widely understood that efficiency of assembling a product by reducing assembly times (therefore costs) is vital particularly for small and medium-sized manufacturing companies to survive in an increasingly competitive market. Ideally, it is helpful for pre-determining efficiency or productivity of a human-centred assembly system at the early design stage. To date, most research on performance of an assembly system using modelling simulation methods is focused on its “operational functions”. The term used in a narrow sense always indicates the performance of the “operational system”, which does not incorporate the effect of human factors that may also affect the system performance. This paper presents a research outcome of findings through a literature review-based study by identifying possible human factors that mostly affect the performance on human-centred manufacturing systems as part of the research project incorporating parameters of human factors into a DES (discrete event simulation) tool.

Towards Human Centred Manufacturing Systems in the Next Generation-A Proposal of Human Friendly Manufacturing Systems-

Nowadays agile market is in common, and the fundamental technology supporting next-generation production system requires further development of machine and information technologies to establish “human friendly technology" and a bridging of these technologies together. IMS-HUTOP project proposes a new product life cycle that respects the human nature of individuals, and establishes the elemental technologies necessary for acquiring, modelling and evaluating various human factors in an effort to achieve the HUTOP cycle. In this paper we propose a human centred and human friendly manufacturing system, which has been proposed in the IMS-HUTOP project.

IT tools to improve the performance of metalworking SMEs

The small manufacturing enterprise is typically recognized as a company that is heavily reliant on its human constituents, namely the skilled manufacturing operators who accept a high level of responsibility for the parts they produce, and also have a major influence on the existence of the company. The significant reduction in costs of IT technology and software tools over recent years has enabled the SME to use hardware and software systems that were previously only available to larger companies. This paper investigates the use of modern IT tools and their application within a metalworking SME. The work is based on a number of major research areas, namely the holonic manufacturing paradigm, distributed planning and control, and open controllers for CNC control. The major emphasis of the paper is the design of appropriate IT tools tailored for the requirements of 'human-centred manufacturing systems' based on holonic concepts to support an autonomous cooperative working environment.

Getting the most out of advanced manufacturing technology (AMT)-based systems. Part I: recognising and managing technology limitations

In Part 1 of this two-part paper, we examined several technological issues pertaining to automated AMT systems. We concluded that human presence in such systems is essential to compensate technological limitations, and the anthropocentric approach to designing AMT systems is the most appropriate manner in which we can obtain the most out of AMT systems in terms of productivity, reliability, economy and flexibility. In Part II, we focus on the limitations of the human component of an anthropocentric AMT system (human-centred manufacturing system). Specifically, we discuss the following issues that limit the effectiveness of human contributions to an automated AMT system: 1) stress management, 2) training issues, 3) sources and causes of errors, 4) information processing limitations, and 5) interface design issues.