Anthropometric Evaluation for Ergonomic Design

<div class="htmlview paragraph">Several research institutions and universities have taken on the challenge of providing solutions for accessible and universally designed workplace accommodations with a focus on people with disabilities. Accessible Design is a subset of what is termed Universal Design. Where Universal Design covers the design of products, systems and environments for all people and encompasses all design principles, Accessible Design focuses on principles that extend the standard design process to those people with some type of performance limitation. In order for individuals with disabiltities to gain better access to the work environments and the products that facilitate independence, health, safety, and social participation a multi-disciplined approach to the research is needed to identify needs and challenges of the targeted population.</div> <div class="htmlview paragraph">Georgia Institute of Technology and its Center for Assistive Technology and Environmental Access (CATEA) were participants in CAESAR the surface anthropometric data collection project. Data from both the CAESAR study and research generated from the Anthropometry for the Disabled project from SUNY Buffalo as well as principle of Universal Design developed at the University of North Carolina will be utilized to supplement activities for a recent grant received by CATEA to assist people with disabilities in the workplace. In keeping with President Bush's New Freedom Initiative to promote full access to community life for all Americans, Karen Milchus principle investigator for the Workplace Accommodations research grant says, (qtd. In Georgia Tech's “The Whistle”)</div> <div class="htmlview paragraph"> <div class="quote"> <div class="htmlview paragraph">“The primary objective of the research is to identify, design and develop new assistive devices and universally designed technologies that will enable all individuals, particularly those with disabilties, to achieve the greatest degree of independence and integration in the workplace.”</div> </div> </div> <div class="htmlview paragraph">The Center provides the expertise and information needed to assess and understand the requirements for people with disabiltities in the workplace. The evaluation of existing workplace products and services and archival studies of successful or unsucessful employment outcomes are a small sampling of the research being implemented in the project. Another area of focus will be showing designers how accessible features can be incorporated into their mainstream workplace products so that all emplyees can benefit from them while improving their productivity. Improving the effectiveness of the research through the use of new tools is key to the project. Some of the initial projects include the use of computer human modeling and anthropometry which offers significant benefits through analyses of the workplace accomodations for people with disabiltities. In the creation of DHM manikins for those with disabilties certain adaptations and new developments that incorporate characteristics and attributes of users with disabilities will be outlined in this research. Current off the shelf DHM tools are being evaluated for effectiveness in meeting the needs of a project of this scope. Moreover, this project will help to identify needs and features of DHM tools that are designed to address issues involving disability. Assessing human performance and evaluating tasks through simulations will be a critical component and advantage through the use DHM software tools. It is important to discuss the limitations of current off the shelf DHM software tools in addressing the needs of the disabled. The Workplace Accommodations project is ongoing and will be for the next five years. The recommendations and resulting developments will generate new bodies of research, products and tools to address the Universal Design of Workplace Accommodations. Using DELMIA's Human Modeling Solution V5R9, NexGen, Anthropos, and Surface Scan data in preliminary evaluations confirms the contributions that DHM plays in meeting the goals of this project. I will discuss establishing a methodology needed to understand issues of those with physical limitations while focusing on needs and adaptations of DHM manikins that are based on anthropometrics data gathered from a pool of subjects with varying attributes and characteristics representative of those with disabilities.</div>

<div class="htmlview paragraph">The major goal of Space Human Factors program is to provide the technology which will enable safe and productive human performance throughout and after long duration space flights and planetary/lunar missions. The Human Factors element has three major sub-goals:</div> <div class="htmlview paragraph"> <ol class="list nostyle"> <li class="list-item"> <span class="li-label">1.</span> <div class="htmlview paragraph">Human Performance Models, Data and Tools - provide the basic understanding of human's activities in the physical, mental, and perceptual domains and to identify important lessons learned about human activities from prior space and lunar missions. To this end, Johnson Space Center is using a laser-based human body mapping system to measure different anthropometric sizes and shapes for incorporation into a large database. This database is employed, along with a spatial computer image graphics system, to analyze human motion in zero gravity conditions as the hypothetical, human bodysized figure performs a variety of new procedures in Space Station Freedom or in the Shuttle orbiter. At Ames Research Center, human performance models for computer-aided engineering, a program initially developed for aeronautical applications, are being modified for space applications. The value of the dynamic human performance models lies in the versatility in which various management decisions can be evaluated as to their impact on mission effectiveness, personnel skill and knowledge allocation, workload, workstation and cockpit design, and overall system design.</div> </li> <li class="list-item"> <span class="li-label">2.</span> <div class="htmlview paragraph">Crew Support and Enhancement - address the development of technology and its applications for the evaluation of the crew's living and working activities in the spacecraft and planetary/lunar habitat and on planetary/lunar surfaces. During the year, a number of projects were completed. At Johnson Space Center, new computer graphics were developed, particularly new methods for portraying procedures which reduce human error. Also, advances in information management methods for application to Shuttle maintenance operations were developed at Ames Research Center. Data from Kennedy Space Center operations is being used as a testbed for managing the information processing in maintenance.</div> </li> <li class="list-item"> <span class="li-label">3.</span> <div class="htmlview paragraph">Human-Automation-Robotic Systems - determine the means by which humans and automated or semi-autonomous systems can effectively work together. A major project at Ames Research Center is the development of the Virtual Workstation as a user interface device for exploring lunar or planetary surfaces. The effort this year has been to obtain a Mar-like data base and begin to employ it in simulated missions. At Johnson Space Center, effort was directed toward identifying the best location of visual sensors for teleoperations.</div> </li> </ol> </div>

<div class="htmlview paragraph">Since product development cycles are continuously rationalized, the usage of human models in product design becomes more and more necessary and popular. In particular, they enable designers to evaluate criteria related to anthropometry, such as accessibility and sight conditions, at an early design stage.</div> <div class="htmlview paragraph">Usually, it is the designer′s task to design satisfactory accommodation for an entire population or at least a certain subset thereof rather than for single individuals. In practice, most situations preclude covering the entire population at reasonable cost. Consequently, tools are required which provide discrete samples representing the anthropometrics of the target population with respect to design requirements. These samples should be as small as possible in order to limit the evaluation efforts.</div> <div class="htmlview paragraph">From the nineties on the human model RAMSIS has been applied in the design process of the automotive industry. Taking into account the automotive customer target population worldwide, RAMSIS provides anthropometrical databases from several nations.</div> <div class="htmlview paragraph">This paper presents multi dimensional statistical functions of the digital human model RAMSIS which generate optimal test samples according to specific design and population requirements. They make use of the multi percentile approach and a specific physique typology clustering. These approaches are discussed and compared with the well-known boundary manikin concept. The functions use anthropometrical databases. Several applications and solutions are given, ranging from one-/two-sided problems, where anthropometrics are directly correlated with the design, to complex design problems, where this correlation does not apply anymore.</div>

<div class="section abstract"><div class="htmlview paragraph">The paper contributes to the field of vehicle safety technology by the virtual approach using biomechanical virtual human body models. The goal of the paper is to exploit the previously developed scaling algorithm to create several virtual human models of a given age and body proportions and to assess the impact analysis using the sensitivity approach.</div><div class="htmlview paragraph">Based on a validated reference model, the previously developed scaling algorithm develops virtual human body models for given height, mass, age and gender. Particular body segments are scaled based on the anthropometrical database concerning the body dimensions taking also percentiles into account. The body stiffness is driven by age dependent flexindex.</div><div class="htmlview paragraph">Several virtual models of human bodies representing particular cadavers were generated via the automatic scaling algorithm. The frontal sled test response of three models was successfully compared to the available experimental data previously. Since all the sled tests concerned different seat and loading conditions, the models were further compared by running the same standard sled test. The particular model anthropometry dependent response was compared for the different body statures.</div></div>

<div class="section abstract"><div class="htmlview paragraph">Statistical Energy Analysis (SEA) is the standard analytical tool for predicting vehicle acoustic and vibration responses at high frequencies. SEA is commonly used to obtain the interior Sound Pressure Level (SPL) due to each individual noise or vibration source and to determine the contribution to the interior noise through each dominant transfer path. This supports cascading vehicle noise and vibration targets and early evaluation of the vehicle design to effectively meet NVH targets with optimized cost and weight.</div><div class="htmlview paragraph">A common misconception is that SEA is only capable of predicting a general average interior SPL for the entire vehicle cabin and that the differences between different locations such as driver's ear, rear passenger's ear, lower interior points, etc., in the vehicle cannot be analytically determined by an SEA model. However, because the interior acoustic energy distribution varies due to absorption and distance effects that can be modeled, an SEA model is capable of predicting the SPL at different interior locations with good accuracy at high frequencies.</div><div class="htmlview paragraph">This paper discusses the SEA modeling assumptions used to generate a typical model of a vehicle cabin interior and surrounding structure. The distribution of acoustic absorption and its effect on the local interior SPL responses are addressed. Measurements of transfer functions to various points of the vehicle interior from exterior and interior acoustic sources and structureborne sources for a typical vehicle are presented and compared to SEA model predictions. Observations and recommendations about typical interior transfer function correlation, modeling limitations, and use of the SEA model as a design tool are given.</div></div>

<div class="htmlview paragraph">This study investigates the relevance of certain parameters for virtual testing of the driver's side OOP problem and attempts to answer the following questions: Which level of detail is needed in the airbag models to assess occupants' injury values for OOP scenarios? What is the influence of the airbag cover on the occupant response for OOP situations and how to accurately model the airbag cover? Are current dummy models suitable to assess the localized human injuries and/or is it beneficial to include human models for injury assessment?</div> <div class="htmlview paragraph">The combined multibody-FE code MADYMO was used. A virtual set-up of a folded driver airbag including cover, steering wheel and a simple seat forms the base model. Occupants were positioned according to the two OOP driver positions defined in FMVSS 208, i.e. chin on module to maximize neck injury risk and chest on module to maximize chest injury risk. The 5<sup>th</sup> percentile Hybrid III dummy model as well as the 5<sup>th</sup> percentile human model were used and different airbag inflation and cover modeling techniques were investigated. Attention was focussed on analyses of the injury values obtained from the simulations of the different situations (with / without cover, use of gasflow, human / dummy model).</div> <div class="htmlview paragraph">From this study, it is concluded that it is important to take into account the geometrical effects of the airbag cover on airbag deployment and hence injury generation in OOP simulations. Adding a gasflow description to the airbag deployment simulation resulted in differences in the early deployment phase. If the dummy's injuries are determined in this phase (dependent of scenario), gasflow contributes to improved airbag modeling at the cost of higher CPU times. From the human model simulations, it is concluded that for this specific scenario, using dummy models could lead to underestimation of human injuries in the chest region, in contrast to overestimation of the head acceleration and the neck loads in the rebound phase. Therefore, human models could provide additional value compared to dummy models.</div>

<div class="section abstract"><div class="htmlview paragraph">As congestion increases and commute times lengthen with the growing urbanization, many customers will look for effective mobility solutions. Two-wheeler are one of the solutions to deal with these issues, in particular if equipped with electrified powertrains for minimized local noise and air pollutant emissions.</div><div class="htmlview paragraph">Scooters powertrain technology is predominantly based on Spark Ignition Engine (ICE) associated with a Continuously Variable Transmissions (CVT) and a Centrifugal Clutch. Nevertheless, even though CVT gives satisfaction in simplicity, fun to drive, cost effectiveness and vehicle dynamics, its efficiency is an undeniable drawback. Indeed, a conventional CVT is wasting more than 50% of ICE effective power in customer driving conditions. Consequently, those vehicles have high fuel consumption relative to their size, and are equipped with overpowered and heavy internal combustion engines, allowing a large area for further improvements.</div><div class="htmlview paragraph">Therefore, IFP Energies nouvelles (IFPEN) has developed a physically based simulation tools for scooters powertrain analysis, design and control. ICE model is based on an analytical calculation for indicated efficiency and frictions. CVT and centrifugal clutch are modeled using existing LMS Amesim components and a specifically developed physical transfer function. The final model is in a good agreement with real figures, such as fuel consumption and dynamics behavior of each system. Therefore, these methods and tools have proven to be relevant and time effective to study the impact of powertrain innovations on those two-wheeler performances.</div><div class="htmlview paragraph">By using these methodological apparatus, IFPEN evaluates the benefit of powertrain evolution such as innovative transmission or hybridization. Taking into account ICE operation limits, and comparable fun to drive behavior with respect to scooters equipped with a CVT, IFPEN estimates a huge impact of a modification of the transmission on fuel consumption (reduction of around 1L/100km on WMTC), proving the benefit of a new concept proposed by IFPEN (not described in this paper). Moreover, the simulator also evaluates the electrification benefits, particularly in urban conditions.</div><div class="htmlview paragraph">Finally, the modeling approach through detailed simulation platform and an energy optimization tool developed in this paper aims at helping the design of an innovative concept providing equivalent drivability with a better fuel consumption, both on certification cycle and in real use conditions, taking into account the next powertrain evolutions for sustainable and energy effective individual mobility.</div></div>

<div class="htmlview paragraph">The problems that have until now prevented the practical application of a Finite-Element (FE) calculation in passenger vehicle acoustics are identified and their causes investigated.</div> <div class="htmlview paragraph">First of all, measurements of vibration scatter in "bodies in white" and complete vehicles provided tolerances for the FE-Model prediction accuracy.</div> <div class="htmlview paragraph">The investigations in the dynamic properties of the total vehicle's constituent parts and the subsequently based build up of the "body in white" FE-Model is seen to be decisive.</div> <div class="htmlview paragraph">Measurements of a "body in white" and a complete vehicle in a vacuum changer, to determine the effect of the air vibration on the structure vibration, led to important conclusions in the FE-Model conception which strongly differ from former representations. Based on these results the validity of an uncoupled air-cavity-model excited with measured structure vibration has been tested, from which clear indications were given at which points the structure model needs to be refined. In close connection with the problem of coupling between the structure and air cavity, physical causes were sought for the high damping of the air vibrations in the interior cavity model and if possible these to harmonize with the model assumptions</div>

<div class="section abstract"><div class="htmlview paragraph">The objective evaluation of occupant comfort is a complex task where numerous aspects such as posture, pressure distribution, internal tissue loads, handling of steering wheel or gear shift have to be taken into consideration. Currently the standard evaluation procedures are hardware tests with human subjects, who are sensitive to all these aspects. However, the reproducibility of subjective tests for the comparison of design variants is a questionable issue and the costs for each test cycle with new prototypes are very high.</div><div class="htmlview paragraph">As an alternative, numerical approaches using human body models such as AnyBody [<span class="xref">1</span>], CASIMIR [<span class="xref">2</span>] or RAMSIS [<span class="xref">3</span>] are applied. Here the issue of reproducibility does not exist and only little effort is required to investigate new setups. However, the disadvantage is that each approach focuses only on one specific aspect of occupant comfort, while in reality the emotions of the occupant are always a combination of all impressions. Furthermore, these kinds of numerical approaches can only provide mechanical quantities like seat pressure or joint angles. Defining the relation between these objective values and subjective rankings and defining optimization targets is a great challenge.</div><div class="htmlview paragraph">For a comprehensive virtual comfort evaluation, the interaction of the different numerical approaches is essential. This is the goal of the research project UDASim [<span class="xref">4</span>], funded by the German government. Here the transfer of the posture between the human body models was a first goal to ensure consistency between the investigated setups. A second step was an iterative simulation procedure. In this procedure, a CAD-based setup is combined with a mechanical setup, which allows the simultaneous assessment of packaging and seat design.</div></div>

<div class="htmlview paragraph">Rapidly developing application areas for human models in simulations are pre-crash, rollover, comfort and occupant sensing, which in general require longer simulation times than the short impact scenarios used so far. These applications require postural stability of the human model during the simulated time, which was incorporated in the spine of the MADYMO human model in this study.</div> <div class="htmlview paragraph">The model uses lumped active control elements with full-state feedback at each vertebra in flexion-extension and lateral bending. Control parameters were identified on the basis of impactor tests on human volunteers. As a result a stable and robust model was developed, yet only the parameter identification did not live up to the expectations, due to limitations in both test and human model.</div>

<div class="htmlview paragraph">A novel design tool that produces solid model geometry from computer-generated sketches was developed to dramatically increase the speed of component development. An understanding of component part break-up and section shape early in the design process can lead to earlier part design releases. The concept provides for a method to create 3-dimensional (3D) solid models from 2-dimensional (2D) digital image sketches.</div> <div class="htmlview paragraph">The traditional method of creating 3-dimensional surface models from sketches or images involves creation of typical sections and math surfaces by referencing the image only. There is no real use of the sketch within the math environment.</div> <div class="htmlview paragraph">An interior instrument panel and steering wheel is described as an example. The engineer begins with a 2-dimensional concept sketch or digital image. The sketch is scaled first by determining at least three known feature diameters. For example, the diameters of a radio control knob, instrument cluster display, and steering wheel should be known. The steering wheel is framed and an ellipse of the wheel is created. A circle is then generated from the ellipse by using mathematical calculations. A scale factor is determined to properly size the image of the instrument panel to the steering wheel. Steering wheel centers are aligned between the sketch image and another math-based instrument panel of similar size. The sketch image is properly sized and then morphed using computer graphics into an orthographic view from a sketch perspective view.</div> <div class="htmlview paragraph">A future small vehicle instrument panel and steering wheel sketch image was morphed into an orthographic view using a similar instrument panel previously developed math model. The glove box and knee bolster surfaces were found to be not correctly located relative to the other math model. This information provided very early and quick feedback to the designer for correction. These components would have required full redesign if not found in the early stages.</div>

<div class="htmlview paragraph">The paper presents the thermohydraulic models for aquifer thermal energy storage developed by the Lund Group for Ground Heat. The basic assumption is that the aquifer is horizontally homogeneous and that the groundwater flow is two-dimensional without a vertical component. The groundwater flow field is then given by an analytical function, or conformal transformation, which is obtained from the positions of the well, the pumping rates, and the regional flow.</div> <div class="htmlview paragraph">The first set of PC models concerns the groundwater flow and the motion of thermal fronts for any set of wells and a regional flow. The flow field, with streamlines and stagnation points, is presented graphically on the screen. The motion of the thermal fronts is determined by particle tracking. These interactive models have proven to be very convenient and useful design tools.</div> <div class="htmlview paragraph">The complete three-dimensional thermal process is solved in the second set of PC models. The groundwater flow is again given by the explicit analytical formulas, while the thermal process is solved numerically. The coupled groundwater and the heat flow process in the aquifer is dealt with using a new entropy-conservation technique.</div> <div class="htmlview paragraph">The models are carefully documented and available on PC. They have been validated against a few field experiments and they are used extensively for design studies.</div>

<div class="htmlview paragraph">Each time a new vehicle is developed, engineers face the challenge to develop the ideal sound insulation package. The goal is to attenuate powertrain, wind and road/tire noise from entering the vehicle while complying with cost, weight and packaging constraints. The design process is greatly facilitated if the engineer has effective tools to rapidly quantify how various sound insulation components contribute to the overall NVH performance of the vehicle.</div> <div class="htmlview paragraph">This paper discusses how an interactive vehicle acoustical design tool can be developed that assists the designer in making rapid decisions as to how to balance the performance of the various sound package components. The acoustical design tool is unique for each vehicle, and must take into account design decisions such as type of powertrain, body style, and numerous other factors in order to correctly predict the performance of the total package. Any good modeling tool must also take into account inputs from a reasonable range of operating conditions.</div> <div class="htmlview paragraph">A very good model for the acoustical behavior of the vehicle can be developed using data from measurements made while operating a sample vehicle at the target operating conditions. The authors will present a method for utilizing measurements together with some simple equations to predict the result when components of different designs are exchanged. The process of generating the needed data for this method from experiments on a vehicle is admittedly time consuming, if all of the possible design variations are to be considered. An alternative that the authors present in this paper is for the case in which a correlated Statistical Energy Analysis (SEA) model exists for the vehicle being considered [<span class="xref">1</span>]<sup><span class="xref">1</span></sup>. A great time savings is realized when the same acoustical behavior information about the vehicle can be extracted by running analytical experiments in the SEA model. The authors assert that even if an SEA model must be developed from scratch and correlated, this approach is preferable over the experimental approach.</div> <div class="htmlview paragraph">Once developed, an interactive design tool of the type being discussed has ongoing benefit to product development engineers by giving them a handy way to asses future design changes. If sound insulation components are later sacrificed in the interest of reducing vehicle costs or weight, the model can accurately portray the implication of the changes on sound levels in the vehicle. A case study is presented that demonstrates the use of this tool and its accuracy.</div>

<div class="htmlview paragraph">The Columbus laboratory module, developed by Astrium Bremen as prime contractor and Alenia Spazio as co-prime, is the European contribution to the International Space Station (ISS) program and as such it will support, once in orbit, micro-gravity and space based research activities of the member states.</div> <div class="htmlview paragraph">Columbus Environmental Control System (ECS) employs an Environmental Control and Life Support System (ECLSS) providing atmosphere pressure, cabin ventilation and temperature humidity control inside the module in conjunction with an autonomous Active Thermal Control System (ATCS) that provides the heat collection capability. The ATCS, based on software controlled water loop, provides also the cooling capability for Payloads and Subsystem equipment. The ECS is completed with the Passive Thermal Control System based on software controlled shell heating system plus passive fixtures such as Multi-Layers Insulation (MLI) blankets.</div> <div class="htmlview paragraph">Generally, both, the Columbus ATCS as well as the ECLSS are qualified via simplified but representative tests and concluding analyses. Complete verification of the module thermal and environmental control design however, will be performed via analysis supported by ECS System Level Integrated Test as well as the predictions for flight.</div> <div class="htmlview paragraph">With respect to responsibility sharing, Alenia is responsible for all verification by test related to thermal/environmental aspects, i.e. Alenia will define the test requirements and cases to be performed via the establishment of a dedicated test specification. On the other side, definition and production of the test set-up as well as the performance of the test is assigned to the Columbus prime Astrium SI Bremen.</div> <div class="htmlview paragraph">In order to get confidence on the functional performance of the Columbus ECS and to validate the Integrated Overall Thermal Mathematical Model (IOTMM) on system level the module will be subjected to an Integrated System Test (IST).</div> <div class="htmlview paragraph">Purpose of the ECS IST is to provide the first verification of the thermal/environmental interrelation between the active cooling (ATCS) and environmental control system (ECLSS) hardware and software and to collect as much characteristic thermal data as possible for the validation of the flight configuration IOTMM. This test will represent the second and last test in series on the flight configuration of the Columbus module.</div> <div class="htmlview paragraph">Previous tests, for verification of the functional interfaces of the ATCS and ECLSS, have been performed already in the frame of the Electrical Test Model (ETM) utilization. However, this test did not provide information on environmental and thermal parameters of the system but rather on the functional interrelations of the relevant units of the subsystems. Presently, the subject test will be performed in the integration hall of Astrium SI Bremen (Class 100.000 clean room conditions) and the pressurized shell is planned to be covered by the flight multi-layer insulation only located beneath the meteoroid debris panels (MDPS) of the module. However, in order to get as much as possible characteristic data of the system not only the test cases have to be selected very carefully but also additional test supporting equipment (TSE) has to be evaluated.</div> <div class="htmlview paragraph">The present paper summarizes the efforts generated to establish the Environmental/Thermal test in the frame of the system level IST of the Columbus module, describes the interrelation aspects of the thermal/environmental subsystem verification by test and analysis and presents the derived methodologies and expected results.</div>

<div class="section abstract"><div class="htmlview paragraph">The ergonomic design of automobiles has changed over in the last years. It is increasingly being transferred from the usage of two-dimensional templates of the human shape to computer-aided manmodels. So far these models were mainly used for static anthropometric investigations on the drivers workplace. Dynamic questions can be answered only very insufficiently.</div><div class="htmlview paragraph">In the context of this work a methodology was developed to precalculate target directed human movements in a motor vehicle environment with the CAD-manmodel RAMSIS.</div><div class="htmlview paragraph">A new two-piece model was developed. In this model dynamic boundary conditions, so called dynamic restrictions, for any movement in a car are determined, concerning outside parameters. In the following, the entire bodyposture is determined by a statistical posture probability model, considering these dynamic restrictions.</div><div class="htmlview paragraph">A control theory of human movements was derived from the field of neurophysiology. It was adapted to the problems for the application in a manmodel. This theory is used, to generate the necessary dynamic restrictions.</div><div class="htmlview paragraph">For the first time, a statistical angle probability model is used to make the posture prognosis. The model was generated in a preceding work and its suitability to answer dynamic questions was validated within two test series.</div><div class="htmlview paragraph">Altogether 12 different experiments, with in each case 15 test subjects, were carried out within all fields of this work. More than 500 “dynamic “ postures were measured and analysed as well as more than 2500 movements.</div><div class="htmlview paragraph">Within this report the developed strategy, that enables a technical designer to precalculate movements of humans within the manmodel RAMSIS realistically, will be shown. This enables the designer to regard also dynamic questions for the ergonomic design of an automobile.</div></div>