CERES :: Browsing by Author "Fletcher, Sarah R."

Browsing by Author "Fletcher, Sarah R."

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Open Access
Adaptive automation assembly: Identifying system requirements for technical efficiency and worker satisfaction
(Elsevier, 2019-03-23) Fletcher, Sarah R.; Johnson, Teegan L.; Adlon, Tobias; Larreina, Jon; Casla, Patricia; Parigot, Laure; Alfaro, Pedro J.; Del Mar Otero, María
Manual assembly work systems bring high flexibility but low productivity in comparison to fully automated systems. To increase productivity but maintain flexibility, future systems need to incorporate greater levels of automation which complement or augment the capabilities of the human operators who provide the manual work. Future systems should be designed for social and economic sustainability within fluctuating conditions and for adaptive utilisation of operators’ individual capabilities to maintain levels of productivity and personal satisfaction. To successfully create such systems with greater adaptivity and interactivity between people and technology a comprehensive understanding of design requirements is needed; the current problem is that there is no standard valid framework. The work described in this paper employed a three-component investigation to identify the various key requirements that are needed to form such a design framework for future human-automation assembly systems. This involves separate activities with different methodologies involving literature reviews, surveys and business case analysis to define use case scenarios and requirements for creating adaptive automation assembly system demonstrators. The different methodological approaches and results for all of the three component studies are described, along with conclusions and implications for further research work and for industry in general.
Open Access
Automating human skills : preliminary development of a human factors methodology to capture tacit cognitive skills
(Cranfield University Press, 2013-09-19) Caird-Daley, Antoinette; Fletcher, Sarah R.; Baker, William
Despite technological advances in intelligent automation, it remains difficult for engineers to discern which manual tasks, or task components, would be most suitable for transfer to automated alternatives. This research aimed to develop an accurate methodology for the measurement of both observable and unobservable physical and cognitive activities used in manual tasks for the capture of tacit skill. Experienced operators were observed and interviewed in detail, following which, hierarchical task analysis and task decomposition methods were used to systematically explore and classify the qualitative data. Results showed that a task analysis / decomposition methodology identified different types of skill (e.g. procedural or declarative) and knowledge (explicit or tacit) indicating this methodology could be used for further human skill capture studies. The benefit of this research will be to provide a methodology to capture human skill so that complex manual tasks can be more efficiently transferred into automated processes.
Open Access
The case for the development of novel human skills capture methodologies
(Taylor & Francis, 2015-04-13) Everitt, Jamie; Fletcher, Sarah R.
As the capabilities of industrial automation are growing, so is the ability to supplement or replace the more tacit, cognitive skills of manual operators. Whilst models have been published within the human factors literature regarding automation implementation, they neglect to discuss the initial capture of the task and automation experts currently lack a formal tool to assess feasibility. The definition of what is meant by "human skill" is discussed and three crucial theoretical underpinnings are proposed for a novel, automation-specific skill capture methodology: emphasis upon procedural rules, emphasis upon action-facilitating factors and taxonomy of skills
Open Access
The development of a Human Factors Readiness Level tool for implementing industrial human-robot collaboration
(Springer, 2017-01-06) Charalambous, George; Fletcher, Sarah R.; Webb, Philip
The concept of industrial human-robot collaboration (HRC) is becoming increasingly attractive as a means for enhancing manufacturing productivity and product. However, due to traditional preventive health and safety standards, there have been few operational examples of true HRC, so it has not been possible to explore the organisational human factors that need to be considered by manufacturing organisations to realise the benefits of industrial HRC until recently. Charalambous, Fletcher and Webb (2015) made the first attempt to identify the key organisational human factors for the successful implementation of industrial HRC through an industrial exploratory case study. This work enabled (i) development of a theoretical framework of key organisational human factors relevant to industrial HRC and (ii) identification of these factors as enablers or barriers. Although identifying the key organisational human factors (HF) was an important step, it presented a crucial question: when should practitioners involved in HRC design and implementation consider these factors? New industrial processes are typically designed and implemented using a maturity or readiness evaluation system, but these do not incorporate of or link to any formal considerations of HF. The aim of this paper is to expand on the previous findings and link the key human factors in the theoretical framework directly to a recognised industrial maturity readiness level system to develop a new Human Factors Readiness Level (HFRL) tool for system design practitioners to optimise successful implementation of industrial HRC.
Open Access
Development of a human factors roadmap for the successful implementation of industrial human-robot collaboration
(Springer, 2016-07-10) Fletcher, Sarah R.; Webb, Philip; Charalambous, George
The concept of industrial human-robot collaboration (HRC) is becoming increasingly integrated into manufacturing production lines as a means for enhancing productivity and product quality. However, developments have focused primarily on the technology and, until recently, little research has been geared to understand the key human factors (HF) that need to be considered to enable successful implementation of industrial HRC. Recent work by the authors has led to the identification of key organisational and individual level HF. The purpose of this paper is to draw together the evidence from their studies and propose a HF roadmap for the successful implementation of industrial HRC. The roadmap will have profound implications as it enables automation specialists and manufacturing system engineers to understand the key HF that need to be considered optimise the efficiency and productivity of the collaboration between humans and industrial robots.
Open Access
The development of a human factors tool for the successful implementation of industrial human-robot collaboration
(Cranfield University, 2014-11) Charalambous, George; Fletcher, Sarah R.
Manufacturing organisations have placed significant attention to the potential of industrial human-robot collaboration (HRC) as a means for enhancing productivity and product quality. This concept has predominantly been seen from an engineering and safety aspect, while the human related issues tend to be disregarded. As the key human factors relevant to industrial HRC have not yet been fully investigated, the research presented in this thesis sought to develop a human factors tool to enable the successful implementation of industrial HRC. First, a theoretical framework was developed which collected the key organisational and individual level human factors by reviewing comparable contexts to HRC. The human factors at each level were investigated separately. To identify whether the organisational human factors outlined in the theoretical framework were enablers or barriers, an industrial exploratory case study was conducted where traditional manual work was being automated. The implications provided an initial roadmap of the key organisational human factors that need to be considered as well as the critical inter-relations between them. From the list of individual level human factors identified in the theoretical framework, the focus was given on exploring the development of trust between human workers and industrial robots. A psychometric scale that measures trust specifically in industrial HRC was developed. The scale offers the opportunity to system designers to identify the key system aspects that can be manipulated to optimise trust in industrial HRC. Finally, the results were gathered together to address the overall aim of the research. A human factors guidance tool was developed which provides practitioners propositions to enable successful implementation of industrial HRC.
Open Access
Do speed and proximity affect human-robot collaboration with an industrial robot arm?
(Springer, 2022-01-07) Story, Matthew; Webb, Phil; Fletcher, Sarah R.; Tang, Gilbert; Jaksic, Cyril; Carberry, Jon
Current guidelines for Human-Robot Collaboration (HRC) allow a person to be within the working area of an industrial robot arm whilst maintaining their physical safety. However, research into increasing automation and social robotics have shown that attributes in the robot, such as speed and proximity setting, can influence a person’s workload and trust. Despite this, studies into how an industrial robot arm’s attributes affect a person during HRC are limited and require further development. Therefore, a study was proposed to assess the impact of robot’s speed and proximity setting on a person’s workload and trust during an HRC task. Eighty-three participants from Cranfield University and the ASK Centre, BAE Systems Samlesbury, completed a task in collaboration with a UR5 industrial robot arm running at different speeds and proximity settings, workload and trust were measured after each run. Workload was found to be positively related to speed but not significantly related to proximity setting. Significant interaction was not found for trust with speed or proximity setting. This study showed that even when operating within current safety guidelines, an industrial robot can affect a person’s workload. The lack of significant interaction with trust was attributed to the robot’s relatively small size and high success rate, and therefore may have an influence in larger industrial robots. As workload and trust can have a significant impact on a person’s performance and satisfaction, it is key to understand this relationship early in the development and design of collaborative work cells to ensure safe and high productivity.
Open Access
Evaluating the use of human aware navigation in industrial robot arms
(Walter de Gruyter, 2021-08-27) Story, Matthew; Jaksic, Cyril; Fletcher, Sarah R.; Webb, Philip; Tang, Gilbert; Carberry, Jonathan
Although the principles followed by modern standards for interaction between humans and robots follow the First Law of Robotics popularized in science fiction in the 1960s, the current standards regulating the interaction between humans and robots emphasize the importance of physical safety. However, they are less developed in another key dimension: psychological safety. As sales of industrial robots have been increasing over recent years, so has the frequency of human–robot interaction (HRI). The present article looks at the current safety guidelines for HRI in an industrial setting and assesses their suitability. This article then presents a means to improve current standards utilizing lessons learned from studies into human aware navigation (HAN), which has seen increasing use in mobile robotics. This article highlights limitations in current research, where the relationships established in mobile robotics have not been carried over to industrial robot arms. To understand this, it is necessary to focus less on how a robot arm avoids humans and more on how humans react when a robot is within the same space. Currently, the safety guidelines are behind the technological advance, however, with further studies aimed at understanding HRI and applying it to newly developed path finding and obstacle avoidance methods, science fiction can become science fact.
Open Access
Gesture detection towards real-time ergonomic analysis for intelligent automation assistance
(Springer, 2016-07-10) Mgbemena, Chika Edith; Oyekan, John; Tiwari, Ashutosh; Xu, Yuchun; Fletcher, Sarah R.; Hutabarat, Windo; Prabhu, Vinayak Ashok
Manual handling involves transporting of load by hand through lifting or lowering and operators on the manufacturing shop floor are daily faced with constant lifting and lowering operations which leads to Work-Related Musculoskeletal Disorders. The trend in data collection on the Shop floor for ergonomic evaluation during manual handling activities has revealed a gap in gesture detection as gesture triggered data collection could facilitate more accurate ergonomic data capture and analysis. This paper presents an application developed to detect gestures towards triggering real-time human motion data capture on the shop floor for ergonomic evaluations and risk assessment using the Microsoft Kinect. The machine learning technology known as the discrete indicator—precisely the AdaBoost Trigger indicator was employed to train the gestures. Our results show that the Kinect can be trained to detect gestures towards real-time ergonomic analysis and possibly offering intelligent automation assistance during human posture detrimental tasks.
Open Access
How and why we need to capture tacit knowledge in manufacturing: Case studies of visual inspection
(Elsevier, 2018-08-03) Johnson, Teegan L.; Fletcher, Sarah R.; Baker, W; Charles, Rebecca
Human visual inspection skills remain superior for ensuring product quality and conformance to standards in the manufacturing industry. However, at present these skills cannot be formally shared with other workers or used to develop and implement new solutions or assistive technologies because they involve a high level of tacit knowledge which only exists in skilled operators' internal cognitions. Industry needs reliable methods for the capture and analysis of this tacit knowledge so that it can be shared and not lost but also so that it can be best utilised in the transfer of manual work to automated systems and introduction of new technologies and processes. This paper describes two UK manufacturing case studies that applied systematic task analysis methods to capture and scrutinise the tacit knowledge and skills being applied in the visual inspection of aerospace components. Results reveal that the method was effective in eliciting tacit knowledge, and showed that tacit skills are particularly needed when visual inspection standards lack specification or the task requires greater subjective interpretation. The implications of these findings for future research and for developments in the manufacturing industry are discussed.
Open Access
Human-automation collaboration in manufacturing: identifying key implementation factors
(Cranfield University Press, 2013-09-19) Charalambous, George; Fletcher, Sarah R.; Webb, Philip
Human-automation collaboration refers to the concept of human operators and intelligent automation working together interactively within the same workspace without conventional physical separation. This concept has commanded significant attention in manufacturing because of the potential applications, such as the installation of large sub-assemblies. However, the key human factors relevant to human-automation collaboration have not yet been fully investigated. To maximise effective implementation and reduce development costs for future projects these factors need to be examined. In this paper, a collection of human factors likely to influence human-automation collaboration are identified from current literature. To test the validity of these and explore further factors associated with implementation success, different types of production processes in terms of stage of maturity are being explored via industrial case studies from the project’s stakeholders. Data was collected through a series of semi-structured interviews with shop floor operators, engineers, system designers and management personnel.
Open Access
Industrial robot ethics: facing the challenges of human-robot collaboration in future manufacturing systems
(Springer, 2017-01-07) Fletcher, Sarah R.; Webb, Philip
As a result of significant advances in information and communications technology the manufacturing industry is facing revolutionary changes whereby production processes will become increasingly digitised and interconnected cyber-physical systems. A key component of these new complex systems will be intelligent automation and human-robot collaboration. Industrial robots have traditionally been segregated from people in manufacturing systems because of the dangers posed by their operational speeds and heavy payloads. However, advances in technology mean that we will soon see large-scale robots being deployed to work more closely and collaboratively with people in monitored manufacturing sytems and widespread introduction of small-scale robots and assistive robotic devices. This will not only transform the way people are expected to work and interact with automation but will also involve much more data provision and capture for performance monitoring. This paper discusses the background to these developments and the anticipated ethical issues that we now face as people and robots become able to work collaboratively in industry.
Open Access
Investigating the effects of signal light position on human workload and reaction time in human-robot collaboration tasks
(Springer, 2016-07-10) Johnson, Teegan L.; Fletcher, Sarah R.; Webb, Philip
Critical to a seamless working relationship in human-robot collaborative environments is effective and frequent communication. This study looked to assess whether placing a light source on a robot was more effective for informing the human operator of the status of the robot than conventional human-machine interfaces for industrial system signaling such as light towers. Participants completed an assembly task while monitoring a robot and changes to the light sources: either from one of two light towers or LED strip lights attached to the robot. Workload was assessed by measuring reaction times to light changes and by counting number of completed assemblies. Although both the ANOVA and Friedman tests returned none significant results, total misses per condition showed that the participants did not miss any of the robot lights, whereas signals were missed for the light towers.
Open Access
An Investigation of Production Workers’ Performance Variations and the Potential Impact of Attitudes
(Springer Verlag, 2008-02) Fletcher, Sarah R.; Baines, Tim S.; Harrison, D. K.
In most manufacturing systems the contribution of human labour remains a vital element that affects overall performance and output. Workers’ individual performance is known to be a product of personal attitudes towards work. However, in current system design processes, worker performance variability is assumed to be largely insignificant and the potential impact of worker attitudes is ignored. This paper describes a field study that investigated the extent to which workers’ production task cycle times vary and the degree to which such variations are associated with attitude differences. Results show that worker performance varies significantly, much more than is assumed by contemporary manufacturing system designers and that this appears to be due to production task characteristics. The findings of this research and their implications are discussed.
Open Access
The limitations of using only CAD and DHM in design relating to high value manufacturing
(CRC Press : Taylor and Francis Group, 2015-04-13) Johnson, Teegan L.; Fletcher, Sarah R.
The ergonomics suites available within computer aided design and digital human modelling programs are increasingly being used to predict and prevent ergonomic and human factors risk due to poor design. To further aid the reduction in poor design, it is of importance to understand the need for user input and the limitations of these software programs. These limitations include: the small number of available anthropometric population samples; and the disconnect between what a designer perceives as possible, and what is possible within a manufacturing environment. A method of mitigating these limitations is the use of user input using virtual reality suites, mock-ups and motion capture technology.
Open Access
Putting people and robots together in manufacturing: are we ready?
(Unknown, 2017-12-31) Fletcher, Sarah R.; Johnson, Teegan L.; Larreina, J.
Traditionally, industrial robots have been completely segregated from people in manufacturing systems to mitigate the dangers posed by their operational speeds and heavy payloads. Putting human operators together with large-scale industrial robots is now becoming increasingly possible with the development of integrated safety monitoring systems, and with smaller force-limited robotics that are now being produced with sufficient robustness for industry. However, with long-standing perceptions of robots as hazardous, we do not yet know how manufacturing workforces will accept collaborative systems with either large or small scale robotics and there is a need to identify and define new ethical and safety standard requirements for integrating people and robots to work collaboratively in industrial assembly tasks. To date there is little or no attention to ethical issues or psychological safety in the industrial safety standards that govern robotics and automated work systems. This paper describes the current situation and specific ways in which human-robot collaboration will significantly improve efficiency and flexibility, and outlines some early work that is being performed to identify the requirements that will be needed in order to facilitate this new way of bringing people and robots together in manufacturing. It presents a brief summary of initial findings that support the need for ethical issues to be considered as a candidate for new and / or revised safety standards.
Open Access
Search strategies in human visual inspection
(Taylor and Francis, 2015-04-08) Charles, Rebecca; Tailor, Mitul; Fletcher, Sarah R.
Visual inspection in high value manufacturing is a task currently undertaken by highly trained human operators. Human operators show variability in detection rates and strategies. Work has been carried out (within the centre?) to automate certain aspects of visual inspection using robots. This paper presents the results of a small study investigating human visual search patterns and their effect on defect detection rates. This paper will focus on the human aspect of visual search which can provide an insight into the most effective ways of detecting defects.
Open Access
A study to trial the use of inertial non-optical motion capture for ergonomic analysis of manufacturing work
(Sage, 2016-08-26) Fletcher, Sarah R.; Johnson, Teegan L.; Thrower, John
It is going to be increasingly important for manufacturing system designers to incorporate human activity data and ergonomic analysis with other performance data in digital design modelling and system monitoring. However, traditional methods of capturing human activity data are not sufficiently accurate to meet the needs of digitised data analysis; qualitative data are subject to bias and imprecision, and optically derived data are hindered by occlusions caused by structures or other people in a working environment. Therefore, to meet contemporary needs for more accurate and objective data, inertial non-optical methods of measurement appear to offer a solution. This article describes a case study conducted within the aerospace manufacturing industry, where data on the human activities involved in aircraft wing system installations was first collected via traditional ethnographic methods and found to have limited accuracy and suitability for digital modelling, but similar human activity data subsequently collected using an automatic non-optical motion capture system in a more controlled environment showed better suitability. Results demonstrate the potential benefits of applying not only the inertial non-optical method in future digital modelling and performance monitoring but also the value of continuing to include qualitative analysis for richer interpretation of important explanatory factors.
Open Access
Task analysis of discrete and continuous skills: a dual methodology approach to human skills capture for automation
(Taylor and Francis, 2015-04-11) Everitt, Jamie; Fletcher, Sarah R.; Caird-Daley, Antoinette
There is a growing requirement within the field of intelligent automation for a formal methodology to capture and classify explicit and tacit skills deployed by operators during complex task performance. This paper describes the development of a dual methodology approach which recognises the inherent differences between continuous tasks and discrete tasks and which proposes separate methodologies for each. Both methodologies emphasise capturing operators’ physical, perceptual, and cognitive skills, however, they fundamentally differ in their approach. The continuous task analysis recognises the non-arbitrary nature of operation ordering and that identifying suitable cues for subtask is a vital component of the skill. Discrete task analysis is a more traditional, chronologically ordered methodology and is intended to increase the resolution of skill classification and be practical for assessing complex tasks involving multiple unique subtasks through the use of taxonomy of generic actions for physical, perceptual, and cognitive actions.
Open Access
Towards a theoretical framework for human performance modelling within manufacturing systems design
(Elsevier, 2005-09) Baines, Tim S.; Asch, R.; Hadfield, Linda; Mason, J. P.; Fletcher, Sarah R.; Kay, John M.
The performance of direct workers has a significant impact on the competitiveness of many manufacturing systems. Unfortunately, system designers are ill equipped to assess this impact during the design process. An opportunity exists to assist designers by expanding the capabilities of popular simulation modelling tools, and using them as a vehicle to better consider human factors during the process of system design manufacture. To support this requirement, this paper reports on an extensive review of literature that develops a theoretical framework, which summarizes the principal factors and relationships that such a modelling tool should incorporate.