International Journal of Human Factors Modelling and Simulation (13 papers in press)
Pedestrian Simulators for Traffic Research: State of the Art and Future of a Motion Lab
by Ilja Feldstein, Christian Lehsing, Andre Dietrich, Klaus Bengler
Abstract: While classical driving simulators have for decades been a valuable tool for the investigation of human behavior and validation of advanced driver assistance systems (ADAS), the development of pedestrian simulators is still in its beginning stages. However, with an increasing complexity of ADAS, it is not sufficient anymore to evaluate those uniquely from the perspective of a driver using driving simulators. Mainly based on motion tracking and virtual reality (VR) technology, pedestrian simulators are used to investigate human behavior from the pedestrian perspective especially in urban traffic scenarios in a reproducible, safe, and cost-efficient way. They enable research on pedestrian behavior in potentially hazardous traffic situations (e.g., crossing scenarios). Becoming an increasingly valuable tool for car manufacturers and original equipment manufacturers (OEMs) in the development process of ADAS, e.g., pedestrian detection and avoidance, the importance of these simulators will grow given the emergence of autonomous and silent cars (e.g., electric vehicles) in the near future.
This paper will help researchers starting off in this research field to get a general idea and also some primary technological input. It explains the potential and possible areas of application of this particular simulator paradigm and gives a detailed overview of some of the technologically most advanced virtual reality simulators used by various research institutes for pedestrian investigations. More specifically, the technology used in the pedestrian simulator developed at the Technical University of Munich is thoroughly described, and components such as head-mounted display, motion capture system, and simulation software are discussed.
Finally, the approach of linking a driving simulator to a pedestrian simulator so that both participants can meet simultaneously in the same virtual environment is introduced. This promising approach facilitates social interaction regarding mutual behavior adaption in the virtual environment of a driving simulation. Experimental evaluations that use this multiple simulator setup can address a broader variety of research questions in traffic-related areas where the interaction between different classes of road users can be assessed as opposed to the reaction to programmed agents used in conventional driving simulators. Regarding data validity, especially in urban scenarios where interaction plays a significant role, the approach of two human beings encountering each other in a safe and reproducible traffic environment shows its potential.
Keywords: pedestrian simulator; virtual reality (VR); head-mounted display (HMD); motion capture; road crossing investigation; linked simulation; social interaction in traffic.
The Effect of Task Characteristics on the Choice to Lean, Upper Body Postures and Joint Loading During Simulated Automotive Manufacturing Tasks with One-Handed, Submaximal Exertions
by Kayla M. Fewster, James R. Potvin
Abstract: The purpose of this study was to investigate the preferred leaning postures, while giving participants the choice to lean when completing tasks with constrained reaches. Twenty female participants completed a variety of different exertions with and without a leaning surface available. The frequency of choice to lean changed with task hand location. The long reaching task hand locations resulted in the most frequent choice to lean, and this decreased trunk and task arm shoulder loading, while allowing the participant to get closer to the task. These findings will be of use to industry in validating future leaning posture prediction software to help guide leaning posture estimates during proactive risk assessments.
Keywords: Leaning; Proactive Ergonomics; Constrained Posture; Automotive Manufacturing.
Examination of robotic manipulability indices to evaluate upper limb manipulability in digital human models
by Hiroshi Endo
Abstract: Robotic manipulability indices (RMIs) quantitatively evaluate kinematic factors regarding manipulability and can be applied to manipulability evaluations in digital human models (DHMs). However, in the kinematics of human motion based on Eulers angles, the rotational transformation order around three orthogonal coordinate axes is arbitrary, meaning that the coordinate transformation at a shoulder joint is not unique. Because RMIs are calculated from the coordinate transformation matrix, the RMIs of an upper limb may be influenced by this arbitrariness. This study examined the effects of the rotation order of the coordinate transformation at a shoulder joint on the manipulability evaluation of an upper limb. The results indicate that RMIs depend on rotation order. Thus, a modified method that eliminates the influence of rotation order was subsequently proposed. Experimental results indicate that RMIs calculated via this proposed modified method are rotation order independent, verifying that it contributes to manipulability evaluation in DHMs.
Keywords: DHM; Digital human models; Manipulability evaluation; Manipulability ellipsoid; Workspace; Reaching; Upper limb movements; Shoulder joint; Kinematics; Rotation transformation of coordinate system; Euler’s angle; Ergonomics.
Ergonomic Assessment of a Physical Task Using Two Different Digital Human Modelling Systems: A case study
by Marisol Quintero-Duran, Gunther Paul
Abstract: The cost of occupational musculoskeletal disorders (MSDs) causes a significant burden on the health system, and lower back pain (LBP) is associated with a substantial portion of MSDs. Australia has a high prevalence of MSDs for health care workers, such as nurses. Two digital human models (DHMs) Siemens JACK and imk EMA were used to investigate if hospital bed pushing, a simple task and hazard that is commonly associated with LBP, can be validly simulated and ergonomically assessed in a virtual environment. While JACK and EMA have implemented a range of common physical work assessment methods, the simulation of a dynamic task such as bed pushing remains a challenge. This research highlights limitations in the DHMs studied, and the need for further research in this area. In particular, the implementation of legacy two dimensional, low resolution ergonomic methods in an analytic, high resolution three dimensional software system is critically reflected.
Keywords: Siemens JACK; imk EMA; workload assessment; hospital bed; health care; nursing; pushing task; musculoskeletal disorder; physical workload; Digital Human Model; virtual environment.
Simulation Based Discomfort Assessment of Two-Wheeler Riders
by Mohd Parvez, Abid Khan
Abstract: Ride discomfort apart from various other factors is caused due to transmission of vibrations to human body while driving. Road surface irregularities or road profile act as a major source of vibration generation to which a vehicle rider is exposed. In the present study, a 6DOF simulation model of two-wheeler coupled with rider was developed considering road profile as a major source of vibration generation. The model developed may be used to assess ride discomfort of rider caused due to WBV exposure for various type of roads classified as per ISO 8608:2016. The model was developed using LabVIEW graphical software Control Design and Simulation module. The model developed was validated for a two-wheeler named HERO SPLENDOR PRO on all the three types of road profile i.e. good, average and poor at a vehicle speed of 20km/h (since the distance of particular road was very short hence more data could be acquired for better validation at lower speed ). The weight of the vehicle rider was 85kg. Assessment of discomfort, according to ISO 2631-1:1997, was done for 85kg rider on Good road profile at 40km/h vehicle speed by calculating RMS acceleration at seat and it was found that the ride was uncomfortable (0.977756m/s2 RMS acceleration). Further to investigate the effect of road profile, vehicle speed, seat stiffness and seat damping on RMS acceleration (level of comfort) at seat, a full factorial experiment with three levels for each (34) was performed. It was found by performing ANOVA that there was significant effect of all these factors as well as their interactions on RMS acceleration. Also from full factorial results, minimum level of vibration (0.506m/s2 RMS acceleration) was found for Good road profile, 20km/h vehicle speed, 10000N/m seat stiffness and 300N-s/m seat stiffness which predicted that the comfortable ride can be achieved by driving two-wheeler on Good road profile at low speed with a seat of low stiffness and high damping values.
Keywords: Two-wheeler vibration; Random road profile; Ride comfort; Whole Body Vibration.
Special Issue on: Quantifying Human Factors Towards Analytical Human-in-the-Loop
Quantitative analysis and assessment of intrinsic and extrinsic factors in human-in-the-loop incidents and prevalent early failures
by David Verbitsky
Abstract: Comprehensive analyses of complex human-in-the-loop (HITL)-equipment incidents and early failures (EF) are critical for prevention of safety problems. Traditional methods often overestimate extrinsic late-life causes, overlook and/or misattribute prevalent EF causing high losses and missing vital opportunities. Instrumentation-based systemic early failure analysis (SEFA) methodology provides comprehensive assessments of human-technical-mixed root causes and interactions. It also sorts few fundamental intrinsic causes and numerous trivial extrinsic ones using physics- and subject-matter specifics (Juran-F10 principle). A typical industry-new EF of micro-wire-wound resistors supported by similar cross-industry errors illustrate the issues proving inherent deficiency of conventional approaches. These urge to restore enhanced modernized SEFA-centred closed feedback loop. The proposed SEFA-based semi-quantitative expert weight assessment better characterizes multifaceted HITL incidents-EF vs. the conventional qualitative common-special causes. SEFA has demonstrated concurrent multifaceted improvements and high customer satisfaction for all tiers of modern HITL electronics.
Keywords: Human-in-the-loop; quantitative assessment; early failure; root cause analysis; closed feedback loop; extrinsic-intrinsic; common-special; SEFA; FRACAS-EM.
Relevance of Air-Traffic Controllers Tacit Knowledge in Enhancing Air-Traffic Control and Safety in Ghanaian Airspace
by Mohammed-Aminu Sanda
Abstract: This study explored the cognitive and workload demands of air-traffic control activity and the tacit knowledge used by air-traffic controllers to cope with the stress associated with such demands in ensuring air-traffic safety in Ghana. Guided by the systemic structural theory of activity, it was found that the air-traffic control activity entailed several challenges, whereby variety of tasks demand significant cognitive efforts, requiring use of tacit knowledge by the air-traffic controllers to augment their operational performances in order to enhance air-traffic safety. It is concluded that the functional efficiency and effectiveness of human work in the air-traffic control activity can be enhanced by understanding and integrating air-traffic controllers tacit knowledge in the job design. By implication, this understanding can be incorporated in designing an operator-efficient and effective work system for air-traffic controllers in order enhance their management capacity of air-traffic safety in Ghana.
Keywords: Air-traffic control activity; Air-traffic controller; Tacit knowledge; Air-traffic safety; Ghana.
Bayesian Network for the Prediction of Situation Awareness Errors
by Jean-Marc Salotti
Abstract: A new method is proposed to predict situation awareness errors in training simulations. It is based on Endsleys model and the 8 situation awareness demons that she described. The predictions are determined thanks to a Bayesian network and Noisy-Or nodes. A maturity model is introduced to come up with the initialization problem. The NASA behavioural competency model is also used to take individual differences into account.
Keywords: Situation awareness; Bayesian network; noisy-or; behavioural competency.
Extracting Typical Incident Patterns from Text Data
by Toru Nakata
Abstract: To prevent industrial incidents, it is important to learn why and how past incidents occurred and escalated. Information regarding accidents is recorded primarily in natural language texts, which are not convenient for analysing incident progression. This paper proposes a method for recognising the typical flow of events in a large set of text reports. Our method transforms each sentence in reports about industrial incidents into a vector (bag-of-words) to facilitate the detection of similar contexts and stories. In this way, we can recognise the typical progression of accidents.
Keywords: incident analysis; text mining; bag of words; modelling; safetyrnengineering.
Quantifying the roles of human error (HE) and his/her state-of-health (SH): use of the double-exponential-probability-distribution-function (DEPDF)
by Ephraim Suhir
Abstract: The probabilistic predictive modeling (PPM) approach in human-in-the-loop (HITL) related aerospace problems enables one to predict, quantify, assure and even specify the probability of the outcome of an aerospace mission or a situation, when the performance of a never-perfect human, never-100%-reliable instrumentation (equipment), never absolutely predictable response of the object of control (aero- or spacecraft), uncertain and often harsh environment, as well as the interaction (interfaces) of these uncertainties, contribute jointly to the likelihood of such an outcome. As to the human factor (HF), it includes (but might not be limited to) two major aspects: possible human-error (HE) and his/her state-of-health (SH). While the reliability of the navigation instrumentation (equipment) could be evaluated using the well known suitable and more or less well established modeling means, the role of the HF could be considered, when quantification of the human role in the HITL effort is critical, by using the double-exponential-probability-distribution-function (DEPDF). In the previously published paper suggesting the use of such a distribution the role of the HE aspect of the HF was considered indirectly, through the level and the role of the human capacity factor (HCF). In this analysis the HE characteristic is introduced directly. This has been done assuming and suggesting that mean-time-to-failure (MTTF) of a human, when performing his/her professional duties, can be used as an adequate criterion of his/her failure-free performance: when this performance is error-free, the MTTF, although never zero, is infinitely long, and is very short in an opposite extreme case. The suggested DEPDF considers that both high MTTF and high HCF result in a higher probability of a failure-free human performance, but, unlike in the previously suggested DEPDF, enables one to separate the MTTF as the direct HF characteristic from other critical HCF features, such as, e.g., level of training, ability to operate under time pressure, mature thinking, etc. Similarly, the suggested state-of-health (SH) characteristic is separated in the suggested DRPDF formulation from the general mental workload (MWL) level to emphasize the importance of human SH that could affect his/her perception of the otherwise more or less objective MWL. In any event, the major objective of this paper is to generate thinking on how to advance the state-of-the-art in the todays aerospace human psychology, and, particularly, on how to quantify, by both modeling and experimentation, the HITL related effort, when the HF and equipment/instrumentation performance contribute jointly to the outcome (success and safety) of an aerospace mission or an extraordinary situation. Future work will be aimed predominantly at these efforts.
Keywords: human factor; reliability; aerospace engineering; avionics psychology; mission success and safety.
Morphological analysis in systemic-structural activity theory
by Gregory Bedny, Inna Bedny
Abstract: Currently the most common ergonomic experiments often don\'t have sufficient external validity. To overcome this negative factor it\'s important to develop formalized and analytical methods of studying human performance. In this work authors describe the morphological analysis of tasks offered by Systemic-Structural Activity Theory. Morphological analysis is a general method for non-quantified modeling of various objects. In Systemic-Structural Activity Theory it is a systemic qualitative description of the structure of designed and often not yet existing activity. Such morphological analysis facilitates farther quantitative analysis of the operators\' performance. It allows not just to optimize the methods of performance but also to improve equipment and HCI design.
Keywords: Systemic-Structural Activity Theory; experimental and analytical methods of study; qualitative systemic analysis; Morphological analysis;.
Human Performance Modelling for Image Analyst Decision Support Design
by Holly Zelnio, Mary Fendley
Abstract: The critical element in human in the loop military systems, image analysts must make decisions quickly. Improving analyst performance remains a priority of military leadership. This model, and previous findings of synthetic aperture radar (SAR) human in the loop experiments were used to design and test a decision support system (DSS) for analyzing electro-optical (EO) and SAR images. Cognitive task analysis was used to develop an operator function model of the analyst classification task. Findings indicate that a DSS increased decision confidence and time. Interestingly, analyst trust is higher when employed in the analysis of EO images, yet aided performance was more accurate on SAR images. As uncovered through human performance modelling, analyst accuracy, confidence and time aided by a trusted DSS is crucial to analyst performance. These results suggest while the developed DSS improved analyst confidence and accuracy, it did not do so while concurrently decreasing task time.
Keywords: human in the loop; decision support system; DSS; synthetic aperture radar; SAR; analyst classification; analyst performance; cognitive bias; operator function model; OFM; confidence; trust.
Towards a Framework for Reliability and Safety Analysis of Complex Space Missions
by John Evans, Frank Groen, Lui Wang, Shira Okon, Rebekah Austin, Arthur Witulski, Nagabhushan Mahadevan, Steven Cornford, Martin Feather, Nancy Lindsey
Abstract: Long duration and complex mission scenarios are characteristics of NASAs human exploration of Mars, and will provide unprecedented challenges. Systems reliability and safety will become increasingly demanding and management of uncertainty will be increasingly important. NASAs current pioneering strategy recognizes and relies upon assurance of crew and asset safety. In this regard, flexibility to develop and innovate in the emergence of new design environments and methodologies, encompassing modeling of complex systems, is essential to meet the challenges
Keywords: Model Based Mission Assurance; Model Based Systems Engineering; Assurance Case; Failure Modes and Effects Analysis; Fault Tree Analayis; Bayesian Nets; Reliability.