Overview

This page presents some highlights of current and recent projects. See the Research page for a broader overview of my research activities.

WIAMan: A New ATD for Soldier Protection Assessment

rear seat safety

My colleagues in the Biosciences Group and I are heavily involved with other researchers across the country in a program to develop a new anthropomorphic test device (ATD or dummy) for underbody blast testing. The Army currently uses the Hybrid-III ATD, which was developed for frontal crash testing in automobiles. Our group is conducting vertical impact testing using our droptower to develop the basic biomechanical performance targets for the ATD. We have also had primary responsibility for developing the anthropometric specifications for the ATD. The image to the right is an early prototype concept originally developed by Humanetics and brought to fruition by DTS. Among our contributions to this design are the design of the overall body shape and joint locations, head contour, pelvis shape, design posture, and foot contour. This is the first ATD in which the anthropometric specification is based on a statistical analysis of whole-body shape data. It follows a long tradition at UMTRI of the development of anthropomorphic human surrogates for safety applications.

Stapp 2015

rear seat safety

My colleagues and I attended the Stapp Car Crash Conference in New Orleans this month. During the sessions, we received an award for the best paper at the previous years' conference. Dr. Lauren Zaseck was the lead author on the paper, which was the first to look closely at the side-impact response and tolerance of older and female PMHS. Because these populations are greater risk of serious injury, test procedures, ATDs, and injury criteria need to take their needs into account.

ZF TRW Collaboration

rear seat safety

AutoBeatDaily has a nice piece on recent work we did with ZF TRW aimed at improving occupant protection in rear seats. My colleagues Jingwen Hu, Steve Peterson and I were interviewed about the collaboration between ZF TRW and UMTRI on this NHTSA-funded project. The overall goal of the effort was to develop optimized restraint systems for occupants of various sizes in second-row, outboard seating positions. The best-performing system included a unique, self-configuring airbag design that provides good head protection for occupants with a wide range of body size. Future work will consider the effects of alternative and adaptable belt and seat geometries.

BBC Coverage on our Soldier Protection Research

soldier safety

The BBC did a great piece on our work over the past few years to improve accommodation and safety for soldiers in vehicles. This work was funded by TARDEC through the Automotive Research Center. This effort has involved a large number of U-M and TARDEC collaborators. The dataset from the Seated Soldier Study is now the primary information the Army uses in determining the posture, shape, and space claim for soldiers in vehicles. This work for the Army is part of wide ranging research program in the Biosciences group to quantify how people sit in vehicles, as well as how they get in and out and move around in them. We have pioneered the use of 3D human surface measurement and modeling in this domain and are increasingly using markerless technology, such as Microsoft Kinect, to measure motion as well as posture.

IRCOBI 2015

lower abdomen contour

I presented a short communication at the IRCOBI annual conference in Lyon, France. A substantial part of our current research focuses on measuring and modeling body shape. Many of our applications relate to automobile crash safety. Using whole body scan data, we analyzed the contour of the lower abdomen in the area where the lap portion of a three-point belt is routed. We found that the length of this contour is strongly associated with body mass index (BMI), which is a useful surrogate for adiposity. Age had a small effect, but gender was unimportant. This research is consistent with our previously published work showing that high BMI is associated with relatively poor lap belt fit. That is, high-BMI individuals tend to place the belt higher and more forward relative to the pelvis. The current study confirms that the effect can be largely accounted for by lower abdomen protrusion, a finding that is not unexpected, but is now quantitatively demonstrated. We have previously published human simulation studies demonstrating the consequences of high BMI for drivers, which are consistent with our analysis of field crash data. We are currently underway with studies to evaluate the effectiveness of advanced belt systems and other countermeasures to improve restraint performance for the 1/3 of U.S. adults who are obese.

International Ergonomics Association 2015

landmarks on scan

Locating body surface landmarks on whole-body scan data is usually a time-consuming manual process. Manual digitizing is the "gold standard", producing higher accuracy and precision than automated methods, but for some applications a rapid, fully automated procedure is desireable, even if accuracy is lower. I presented a brief paper at the IEA conference in Melbourne, Australia, this month examining the precision of a purely statistical method for predicting landmark and joint locations. The method is based on a statistical body shape model that incorporates landmarks and joints. The results showed that the predictions for torso joints are surprisingly precise when scan data is fitted using a rapid optimization process. The most important near-term application is the estimation of a kinematic linkage for avatars created from Kinect scan data.

Crash Protection for Soldiers

Pelvis_calculations

The Biosciences Group is conducting a broad range of research for the U.S. Army, including a large-scale study focused on improving protection for soldiers in vehicle crash and rollover events. At the 2015 GVSETS meeting, my colleague Dr. Jingwen Hu presented an overview of outcomes from a sled-test series comparing the performance of alternative belt restraint systems in frontal impact. This is the first study to examine the influence of restraint system configuration across a range of body size, taking into account the effects of body armor and body borne gear. This work was recognized with a "best paper" award, one of only 2 out of 53 peer-reviewed papers to receive this honor.

Estimating Pelvis Position in Seated Postures

Pelvis_calculations

My colleagues Dr. Daniel Park and Dr. Jangwoon Park presented some recent work at the Applied Human Factors and Ergonomics (AHFE) annual meeting in Las Vegas. Dr. J. Park presented a new method for estimating pelvis position and orientation in automobile seats. This perennially challenging problem is more difficult in individuals with high BMI, and the new methods enable adjustments to account for larger flesh margins. Dr. Daniel Park presented methods for mapping a statistical body shape model generated on one manikin mesh to another mesh. This method allows us to apply our model outcomes much more broadly. In particular, we can rapidly generate a CATIA manikin automatically from Kinect scan data.

Effects of Obesity on Crash Protection

ASME_Article

Analyses of crash data in the field have shown that obese occupants are at higher risk in frontal crashes than occupants of normal weight. Improving protection for obese occupants requires an understanding of how these occupants interact with restraint systems. At the 2015 ESV Conference in Gothenberg, Sweden, my colleague Jingwen Hu presented a simulation study aimed at understanding how obese occupants interact with belts in frontal impact. This work is based on a new paradigm in parametric human modeling that allows rapid, accurate morphing of complex finite element models to represent individuals with a wide range of size and shape. This study validated a set of obese occupant models using post-mortem human subject data from testing conducted at the University of Virginia.

Wang et al. (2015), A Simulation Study on the Efficacy of Advanced Belt Restraints to Mitigate the Effects of Obesity for Rear-Seat Occupant Protection in Frontal Crashes Traffic Injury Prevention, 16:S75-S83, doi:10.1080/15389588.2015.1010722

First Parametric Body Shape Model of Children -- Available Online

ASME_Article

Daniel Park and I have just published the first parametric body shape model for children. The model is based on laser scans of 137 children ages 3-11 in a standing posture. We used a custom template fitting approach followed by standard PCA+regression methods to create a statistical body shape model parameterized by stature, BMI, and the ratio of sitting height to stature. This model is now available online at childshape.org. As far as we know, this is the first data-based body shape model to be made available for free online. The online versions allows for downloads of a mesh surface (STL) file along with body landmark and joint locations and a set of standard anthropometric dimensions. We expect to be putting many more models online in the next year as we published more of our body shape studies. Please contact me if you have questions about using the model in your research.

Park and Reed (2015), "Parametric Body Shape Model of Standing Children Ages 3 to 11 Years." Ergonomics, doi:10.1080/00140139.2015.1033480

ASME Publication on Parametric Human Body Modeling

ASME_Article

The UMTRI Biosciences Group was featured in an article in Mechanical Engineering, the monthly magazine of ASME. The work of my colleague Dr. Jingwen Hu and his students on parametric human body modeling for restraint system optimization was highlighted. The article touches on a range of activities now underway in our greoup, including whole-body scanning and body shape modeling, finite-element modeling of highly detailed human anatomy, and restraint system optimization.

Updated Anthropometry for US Children

Soldier Scan

My collaborator Matt Parkinson, his student Brian Pagano, and I have just published the first updated assessment of U.S. child anthroometry in a generation. During the 1970s, UMTRI researchers led by Jerry Snyder conducted two large-scale studies of child body dimensions, measuring thousands of children across the country. Since that time, children in the U.S. at each age have gotten considerably heavier, with greater differences at older ages. Dr. Parkinson and I have previously published statistical methods for adjusting a detailed dataset to match a population for which only overall body dimensions, such as stature and weight, are known. We applied a similar methodology to update the detailed dimensions in the Snyder 1977 study based on recent stature and body weight data from the U.S. National Health and Nutrition Examination Survey. This update will be valuable for anyone who creates products or environments for children in the U.S. including child restraints, furniture, and clothing. Ultimately, a new, comprehensive study of U.S. child anthropometry is needed. Contact me for an article reprint.

The Seated Soldier Study: Posture and Body Shape

Soldier Scan

The final report for the Seated Soldier Study conducted by UMTRI for the US Army TARDEC is now available. The report describes the methods and results from detailed measurements of 315 soldiers at three Army posts. A detailed posture analysis was conducted for both driver and squad seating conditions. Posture-prediction models based on UMTRI's Cascade methodology are presented for both environments. The models take into account the effects of body armor and body borne gear. Whole-body laser scanning was conducted to characterize body shape with and without PPE and gear. Analysis of this rich dataset will be underway for some time. Already, we are working on accommodation models for driver and squad condition, new vehicle packaging paradigms, and methods for optimizing seat design based on these findings and data. Three-dimensional body shape modeling using a subset of data from the Seated Soldier Study was used to develop anthropometric specifications for the midsize-male WIAMan ATD. If you have additional ideas on how these data could be used to improve the design of vehicles, seats, and protective equipment for soldiers, please contact me.

Fast Generation of Subject-Specific Models for Ergonomics Research

Kinect Jack

Building on recent work on body shape modeling and using Kinect as a body scanner, I presented a paper at the 2014 HFES conference in Chicago on work with Siemens on generating subject-specific Jack models. In May, we presented work at the 2014 DHM conference on the implementation in Jack of standing male and female statistical body shape models (SBSM). For some applications, it is useful to create a Jack manikin of a particular individual, for example, a subject in a laboratory study. Normally we would take a set of a dozen or so standard anthropometric measures and type them into Jack to scale a custom figure. That figure will have roughly the right size, but often the shape is quite unlike the individual. In the current work, we find the set of principal component scores in our male or female shape model that produces the body shape most closely matching the data from a snapshot taken with the Kinect sensor.We then pass those PC scores to Jack to obtain a figure with very similar size and shape. The paper shows quantitative comparisons for four women scanned with the Kinect system. In future work, we'll apply the new Kinect 2 sensor, which promises greater accuracy, and relax the current restrictions on scanning posture.

Knee Locations in Driving Postures

Knee Location

I presented a short communication at the 2014 IRCOBI conference in Berlin this month addressing driver knee locations. In modern vehicles, the underside of the instrument panel is designed to absorb energy in frontal impacts by exerting controlled force on the driver's knees. The knee bolster is an important component of the restraint system, sharing load with the steering wheel airbag and three-point belt. In recent work, we showed that the lap portion of the belt fits considerably more loosely for most people than for crash dummies. A loose belt means that the occupant will translate further forward before belt force builds up, potentially changing the load sharing between the belt and knee bolster. The starting knee location at the time of the crash is one critical determinant of load sharing. We used data from 100 men and women with a wide range of body size who sat in a laboratory vehicle mockup in 9 different vehicle configurations spanning the range from sports cars to SUVs. We used regression analysis to model the location of the forward-most margin of the patella (kneecap) as a function of vehicle and driver variables. As expected, the vehicle configuration had a strong effect, but we also found that taller drivers' knees are more rearward, on average. These results are useful for understanding the distribution of drivers' knee locations in any particular vehicle and could be used to conduct parametric studies of load sharing for a range of frontal impact conditions.

Virtual Seat Assessment Tools

Seat Fitting Results

I presented an update of our virtual seat fit assessment work at the 8th Annual Automotive Seating Innovators Summit in Detroit. This collaboration builds on work my colleague Jingwen Hu presented at the SAE Congress in 2013. The critical insight behind this work is that rigorous dimensional assessments of seats requires evaluation with hundreds or even thousands of people. Since it's not remotely practical to do that with physical prototypes, virtual seat fit evaluations with synthesized populations of sitters is the only way to conduct an accurate dimensional analysis considering all geometric aspects of the seat sitter interaction, rather than just a few standard anthropometric dimensions. The previous work used 3D body shape models based on CAESAR. The work now underway will apply body shape models based on UMTRI data gathered in a number of studies.

Seated Reach with Body Armor

Kinect Fitting Results

The Automotive Research Center at the University of Michigan held its Annual Review this month, celebrating 20 years of research in modeling and simulation of ground vehicles. I presented an overview of some of our activities in Thrust Area II, Human-Centered Modeling in Simulation. Among other projects, we are studying the effects of body armor and body borne gear on seated reach difficulty and capability; developing new statistical tools for vehicle interior layout based on soldier posture data; and conducting sled tests and finite-element simulations to optimize belt restraints and airbags for tactical vehicles.

Body Scanning Using Kinect: Applications to Child Anthropometry

Kinect Fitting Results

My colleague Daniel Park presented a paper at the 3rd International Digital Human Modeling Symposium on our work with using Kinect sensors for body scanning.

Our technique uses only two Kinect sensors and requires only about 12 seconds to obtain a subject-specific avatar. The key innovation is a rapid application of a statistical body shape model based on body scan data. The method is demonstrated using children between ages 3 and 11.

Generating Subject-Specific Models for Ergonomics Analysis

Kinect Fitting Results

Prof. Matt Parkinson of The Pennsylvania State University presented some joint work on human modeling at the 3rd International Digital Human Modeling Symposium.

The paper reports a collaboration with Siemens to implement a statistical body shape model based on scan data in the Jack human modeling software. To our knowledge, this is the first time a widely used commercial ergonomics tool has included a high-resolution body shape model based on a statistical analysis of scan data.

This paper won an Applied Research Award at the conference.

West Point Guest Lecture on Soldier Protection Research

West Point Lecture

I was fortunate to have the opportunity to present an overview of our research on tactical vehicle occupant protection at the U.S. Military Academy at West Point. LTC Bruce Floersheim, Director of the Center for Innovation and Engineering, hosted my visit.

The research I presented was funded by TARDEC through the Automotive Research Center at the University of Michigan. The ARC is a U.S. Army Center of Excellence in modeling and simulation of ground vehicles.

Seated Soldier Study: Summary Briefing

Seated Soldier Final Presentation

I gave a briefing at the U.S. Army Tank-Automotive Research, Development, and Engineering Center this month on our Seated Soldier Study. In close collaboration with the Army, and with assistance from Anthrotech, we measured the seated postures and body shapes of over 300 soldiers. This study is the first we are aware of to document in detail the effects of body armor and body-borne gear on supported seated postures. Major outcomes of this work include new posture-prediction models for drivers and squad members in military vehicles. In addition to posture measurements, over 8200 whole-body surface scans were obtained using a laser scanner, documenting male and female body shape in up to 20 postures. Along with our related work on civilian vehicle occupants, this study provides the first large-scale data on body shapes in supported seated postures. We have used the data to generate statistical models of body shape for use in a wide range of engineering applications.

The Seated Soldier Study was funded by TARDEC through the Automotive Research Center at the University of Michigan. The ARC is a U.S. Army Center of Excellence in modeling and simulation of ground vehicles.

Presentation

Driver Belt Fit

Stapp Conference Talk

I gave a talk at the Stapp Car Crash Conference in Orlando this month. My paper examined the effects of driver characteristics on seat belt fit. We'd previously shown that obesity significantly worsens lap belt fit in passenger conditions. The latest study, based on data from 97 men and women with a wide range of age and body size, show that many drivers place their seat belts farther from their pelves than they should. Individuals with higher BMI had worse belt fit, on average. The results suggest a need to educate drivers about proper belt placement, but also indicate that improved belt designs might help. This research was funded by the Toyota Collaborative Safety Research Center.

Paper

IRCOBI 2013

SAFER Symposium

I gave a short talk at the IRCOBI conference in Gothenburg Sweden last month. My paper focused on our work measuring and modeling seated occupant body shapes for parametric human body modeling. We are continuing to improve the depth and breadth of our human modeling capability. We have a rich dataset that includes children ages 2 and up, young adults, elderly, and soldiers.

Paper

Child Occupant Protection Symposium

SAFER Symposium

I participated in an informative symposium hosted by SAFER in Gothenburg Sweden. With a focus on occupant protection for children 4-12 years old, the symposium noted the considerable progress made in the past decade while outlining the remaining challenges. The presentations are available at this website.

Presentations

Digital Human Modeling Symposium June 11-13, 2013

My colleague Matt Parkinson and I hosted a symposium on digital human modeling in Ann Arbor. We had over 140 participants from 12 countries with poster and podium sessions over three days. The program, proceedings, and other info are available at dhm2013.org. One highlight was a twitter scavenger hunt featuring our brand-new human modeling avatar, Diablos.

Digital Human Modeling Symposium in Ann Arbor, June 11-13, 2013

 

Soldier Posture and Position

Soldier Scanning

My colleagues and I presented an update on our work on soldier posture, position, and body shape at the 19th annual meeting of the Automotive Research Center at the University of Michigan. The overall goal of this work is to develop modeling and simulation tools that will lead to safer and more efficient vehicle designs.

Presentation

 

 

 

Driver Steering Wheel Preference

Steering Wheel Position

Driver preference for fore-aft steering wheel position has not previously been addressed directly in the SAE literature. We analyzed data from a laboratory study to create a logistic regression model predicting subjective response as a function of H30, L6, and driver stature. The results compare favorably to a large set of vehicle benchmarking data.

Presentation

 

 

Virtual Seat Fit Testing

Seat Interaction Simulation

My colleague Jingwen Hu developed a new framework for conducting virtual seat fit testing using a parametric human body model. This work differs from previous simulation studies of human/seat interaction in using a human body model that can represent a large range of male and female body shapes and postures. Our ongoing body-shape modeling work includes the development of new, whole-body paramtric shape and posture models based on a wider range of postures than are found in the CAESAR database we used for this study.

Presentation

Seat Belt Anchorage Locations

Seat Interaction Simulation

We have measured the interior geometry of dozens of vehicles over the past few years for a wide range of safety and ergonomics applications. One important finding for safety is that the seat belt anchorage locations in second-row, outboard seats vary widely, with the lab belt anchorages spanning essentially the entire legal range. ATD and simulator studies show that the range of belt fit we document in our current paper can have important safety implications.

Presentation

WIAMan Anthropometry Specification

WIAMan ANthro

We've just completed development of anthropometric specifications for the Army's new WIAMan blast dummy. The new anthropomorphic test device (ATD) will lead to the development of safer vehicles, seats, and interiors. This work is an outgrowth of our Seated Soldier Study.

The U.S. Army's TARDEC organization recently featured our work in an internal publication. The data from this study will have broad applicability in the development of road vehicles, not just military vehicles. This study is the first to gather and model data on whole-body shape from a large, diverse sample of people in supported seated postures. Consistency in study protocol will allow the data from the 300 soldiers measured in this project to be merged with data from 200 adults measured in another current project.

Accelerate Modeling

Recent Updates

Older Occupant Posture, Body Shape and Belt Fit

Older Driver

Presentation from a special session at the Stapp Car Crash Conference in Savannah, Georgia.

Recent research, including studies by my colleagues at UMTRI, has shown that older drivers are at increased risk of injury in vehicle crashes. Some of that risk is due to frailty -- injury (particularly thoracic injury) occuring with less loading than is required to injury younger occupants. But the posture and belt fit of older drivers may also put them at greater risk. To addess this issue, we are conducting a laboratory study of older occupant posture, belt fit, and body shape. Supported by the Toyota Collaborative Safety Research Center, the study measured 200 men and women, including 120 over age 60. The participants sat in laboratory mockups that can be reconfigured to represent the driver and passenger package configurations of a wide range of vehicles, from sports cars to minivans. Posture and belt fit are recorded using a FARO Arm coordinate digitizer to measure body landmark locations. A whole-body laser scanner is used to record the participant's body shape in a range of postures. These data will be valuable for designing improved restraint systems that optimally protect occupants of all ages.

 

Recent Updates

Child Posture and Body Shape

Child Recline

At the 2012 Human Factors and Ergonomics Society Annual Meeting in Boston, I presented an overview of the methods for our recent large-scale child anthropometry study. We used a laser scanner to record the body shapes of 162 kids age 4 to 11 in a wide range of standing and seated postures. These data will be used to develop new anthropometric specifications for crash dummies, but also have application to a wide range of other products for children. We will be using the data to develop parametric finite-element models of children for use in crash simulation and restraint-system optimization.

Paper: A pilot study of three-dimensionsional child anthropometry for restraint system optimization.

Presentation: Three-dimensionsional child anthropometry for restraint system optimization.

Body Shape Modeling Research

Older Driver

Wired Autopia covered some of our recent work on body shape modeling. We're using a range of technologies to measure posture and body shape in automotive postures. Although the results have significant applications in ergonomics (for example, improved seat design for comfort) the primary applications of the data and resulting models will be in the development of improved physical and computational surrogates for crash simulations. These tools will allow improved optimization of restraint systems to proteect vehicle occupants with a wide range of physical characteristics. This presentation covers a some of our current activities.

Recent Updates

Soldier Anthropometry

Overlaid Scans

We collaborated with Anthrotech on a large-scale study of soldier anthropometry, focusing on seated postures and body shapes with a range of clothing and personal protective equipment. The goal of the research is to develop new quantitative models that can be used for the design of physical and computational surrogates used for designing and assessing military vehicles. One near-term application is the Warrior Injury Assessment Manikin (WIAMan), a new anthropomorphic test device (ATD) to be used for evaluating protection in underbody blast events. UMTRI will use the data from the seated soldier study to specify the posture and body shape for WIAMan. Other applications include the development of statistical models to predict posture for soldiers in both driver and crew workstations. These models will be used to position computational models of soldiers for both ergonomics analysis and blast simulations.

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Belt Fit for Obese Occupants

High-BMI Driver

The prevalence of obesity among US adults has plateaued over the past few years, but still remains at historical highs. Analysis of crash data has suggested that, after correcting for other factors, obesity increases the risk of certain types of injuries. One reason for that increased risk may be problems with seat belt fit. We conducted a laboratory study of belt fit among 54 adults, 48% of whom were obese. We found that obesity results in relatively poor lap belt fit, with the belt riding high and forward relative to the pelvis. Both lap belt and shoulder belt length were also increased for heavier individuals, a trend which also reduces belt effectiveness. These results indicate that load sharing among the components of restraint system (including the belt, airbag, and knee bolster) may differ substantially for obese adults and should be taken into account in restraint system design.

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Truck Ingress/Egress Safety

Truck driver ingress

We have added new content to trucksteps.org, our website devoted to safe ingress and egress for truck drivers. Browse on over and check it out!

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Child Body Shape Measurement and Modeling

CHild Scanning Postures

We are conducting a major study of child posture and body shape. This is the first study to gather three-dimensional data on child posture in automotive seated postures. We have measured 160 children spanning an age range from45 to 11 years seated in a rear seat from a sedan, with and without a belt positioning booster, and in up to 18 different postures in our 3D body scanner. The primary near-term application of thedata will be to improve the design of crash dummies and computational models of child occupants. But the data will also have broad application for the design of child restraints, protective equipment, clothing, and other products and environments that interact physically with children in this age range.

Child Scanning Potures Child Scanning Postures

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Human Grasp Modeling

Grasp Postures

Digital human modeling for ergonomics applications is the focus of my research in the Center for Ergonomics. The research I direct in the Human Motion Simulation Laboratory focuses on the development of algorithms and models for accurate prediction of human postures and motions in tasksituations relevant to product and workspace design. We emphasize algorithms that can be implemented in any human figure model, rather than limiting ourselves to the capabilities of one model. We are fortunate to have the developers of the two most popular software systems for industrial ergonomics (Dassault Systemes and Siemens PLM) engaged in our laboratory as technology partners. Among other topics, we're currently working on improving grasp simulation. The literature on grasp is vast, including contributions from motor control and robotics as well as ergonomics and human modeling. Yet, ergonomics using human models spend a large amount of time working to simulate grasp, often with poor results. As part of ongoing research in the Human Motion Simulation Lab, Ph.D. candidate Wei Zhou and I developed a data-based method for predicting grasp motions. The hand motions are parameterized on target size and grasp type, so that they're readily configurable for different objects. We integrated this kinematic prediction with collision sensing to enable automated grasp of objects with arbitrary geometry.

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3D Body Shape and Posture Modeling from Body Scan Data

MidsizeMaleSeatedPostureMorph

Three-dimensional anthropometry is a part of many of my current research projects. Using data from UMTRI's whole-body laser scanner, medical imaging data, or studies conducted elsewhere, we create statistical models of anatomical shapes. These models are used for a wide variety of design and analysis purposes, from creating anthropometric specifications for crash dummies to virtual seat assessments. One challenge in using 3D scan data is that each scan represents a single posture. For general applications, it's necessary to be able to alter the posture of the scan. This figure shows a statistical model of the seated torso that encompasses both anthropometric and postural variability. A single relaxed seated scan from each of 712 men and women was morphed to 15 different postures using a skeletal linkage. The resulting external body shapes were analyzed using a principal component analysis/regression (PCAR) approach to produce the model demonstrated in the figure. The model provides an efficient way of representing a wide range of seated body shapes driven by both structural anthropometry and posture.The model has applications from seat and chair design to the development of parametric finite-element models for crash safety analysis.

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Cab Design for Trucks, Buses, and Off-Highway Machines

Truck driver reach Truck driver operating pedals

The design of truck and off-highway equipment cabs (agriculture, construction, mining, and forestry) is becoming more complex due to the increase in the use of electronic controls and displays. In most cases, the new equipment is added to the customary manual controls, creating a need to optimize the layout for all tasks.

We conducted a study of seated operators to quantify reach and force-exertion capability as a function of task location relative to the driver and package. Licensed truck drivers reached for push-button targets located throughout the workspace, providing subjective ratings of difficulty for each target. The subjects also exerted force on a handle located in 13 discrete positions spanning the range of typical hand control locations.

The drivers also operated accelerator, brake, and clutch pedals, using both normal motion speed and "as fast as possible", simulating emergency operation. An optical motion-capture system was used to record whole-body kinematics.

The data from this study are being used to develop new design tools for assessing and laying out truck and heavy equipment cabs.

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Truck Ingress and Egress

Truck driver getting into cab

Truck driving is among the most dangerous occupations in the U.S. Crashes are not the main cause of injury, though: Most occupational injuries to truck drivers are due to slips and falls. With support from at R01 grant from the National Institute for Occupational Safety and Health, we are conducting a field and laboratory study of truck driver ingress and egress. Our work uses biomechanical analysis techniques to quantify ingress/egress behaviors. We have gathered field data on entry and exit techniques drivers use, interviewed drivers on their experiences, and conducted a detailed laboratory study. Using an optical motion capture system and an instrumented cab mockup, we recorded driver's movements and the forces they exerted with a wide range of step and handhold configurations.

The outcomes of this research will include new design guidelines for truck ingress/egress systems (steps and handholds), new biomechanical analysis methodologies that can be used to assess candidate systems, and a better understanding of the factors that influence the risk to drivers of both acute and chronic injury.

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Advanced Anthropometry for Child Crash Dummy Design

Hybrid-III Skeleton

The performance of belt-positioning booster seats used by children who are too small to achieve good belt fit with vehicle belts alone, and no longer riding in harness restraints, is assessed in U.S. regulatory tests using Hybrid-III dummies. Unfortunately, these dummies interact with belt restraints in unrealistic ways. The lap, shoulder, and chest areas where the belt contacts the dummy are of particular concern, because the dummy geometry in these areas is substantial different from the skeletal anatomy of similar-size children. We are working on developing improved components for the dummies, starting with the Hybrid-III six-year-old. We have developed new methods for extracting and analyzing the shapes of anatomical structures from medical imaging data. We've used these methods to create a statistical model of the child pelvis, thorax, and shoulder based on data from over 80 children from ages 4 to 12. The analysis allows us to create skeletal models for children in that age range as a function of age, stature, body weight, or other variables. We've used these model to create a geometric target for the 6YO pelvis and thorax. This figure compares the skeletal gometry of the Hybrid-III 6YO to the targets.

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Optimizing Head Restraint Geometry

Head Restraint Data

The National Highway Traffic Safety Administration (NHTSA) has amended Federal Motor Vehicle Safety Standard (FMVSS) 202 to require higher and more-forward head restraints (sometimes called head rests, but primarily intended to protect occupant's necks in rear collisions). The new regulation, called FMVSS 202a, requires that head restraints lie within 55 mm of a Head Restraint Measurement Device representing a midsize-male head shape when measured at a seat back angle of 25 degrees. When this rule was proposed, my colleagues and I published a report showing that most drivers sit with more-upright seatback angles. We concluded that designing to the 55-mm "backset" would cause the head restraint to interfere with the preferred head locations of a substantial number of drivers. This prediction has since been substantiated by other research and field reports from vehicles built to the new standard. Recently, my colleague Prof. Matt Parkinson, who heads the OPEN Design Laboratory at Pensylvania State University, conducted a simulation study of an alternative seat back design that optimizes the head restraint position across seat back angles. This approach reduces the likelihood of interference with the head restraint for smaller-stature drivers while ensuring that taller drivers, who tend to select more-reclined seat back angles, are equally well protected. More...

 

©2017 Matthew P. Reed and The University of Michigan