Matt Reed, Ergonomics and Safety Research

Matthew P. Reed, Ph.D.

I'm the Don B. Chaffin Collegiate Research Professor and Head of the Biosciences Group of the University of Michigan Transportation Research Institute. I conduct research in a variety of areas relating to anthropometry and biomechanics, including vehicle ergonomics and vehicle occupant crash protection. I'm also a Research Professor in the Center for Ergonomics in Industrial and Operations Engineering, where I lead the Human Motion Simulation Laboratory. The HUMOSIM Lab develops movement simulation algorithms and ergonomics analysis tools for use with digital human modeling software. I am also a Research Professor in the Integrative Systems+Design program in the College of Engineering, where I serve as Acting Director of the Design Science program.

Follow the links at the right for more information about my research and see these highlights of recent projects.

Google Scholar Profile

Scopus Public Profile (ID: 7401800235)

ORCID ID: 0000-0001-6650-0727

University of Michigan Researchers

Other affiliations:

Associate Editor, Traffic Injury Prevention

Associate Editor, SAE International Journal of Transportation Safety

Associate Editor, International Journal of the Digital Human

International Research Council on the Biomechanics of Injury

Update: 2017-07 cervical spine model

The cervical spine is of considerable interest in biomechanics research due to its complexity and its importance as a site of both low-severity and high-severity injury (e.g., whiplash-associated disorders and fractures with spinal cord injury). My colleague Dr. Monica Jones and I recently published a technical report describing new two- and three-dimensional parametric models of cervical spine geometry and posture. The data for the 2d model were drawn from a Snyder et al. x-ray study conducted at UMTRI in the 1970s. Using the same methods we've previously applied to model body shape, we created a parametric model that generates sagittal spine geometry as a function of sex, stature, age, and head-to-thorax posture. This is the only parametric model of its kind for unsupported head postures typical of seated environments, such as vehicles. In addition, we linked this 2d model to 3d geometry provided by collaborators at Johns Hopkins University Applied Physics Lab (APL). Using 3D spine geometry data extracted by APL from medical imaging (CT) studies, we created a parametric model that predicts 3d bone geometry from 2d shape. One unexpected observation is that lateral dimensions of cervical vertebrae are essentially uncorrelated with sagittal dimensions. The resulting 3d model can be used as input for finite-element models used to examine the influence of posture and spine shape on injury risk in a wide range of exposures.

Update: 2017-07 error distribution

My colleague Dr. Daniel Park and I recently completed a research project for the U.S. Army that tackled an array of cutting-edge problems relating to human body measurement and modeling. The report on this work is now available online. From the abstract: "Two metrics were devised for comparing two body shapes represented by surface meshes. The distance from the nodes of one mesh to the polygonal surface of another was defined as mesh error. Six torso dimensions computed between mesh nodes that are analogous to standard anthropometric measures were compared to compute mesh error. Analyses were performed using three datasets: 236 male Soldiers, 200 Air Crew, and 73 civilian women. Statistical body shape models (SBSM) were developed using methods developed and adapted in previous UMTRI research. A standardized template was fit to each scan to enable the analysis. Mesh error was found to diminish smoothly with the number of PCs used for reconstruction, with minimal improvement after 100 PCs. When conducting regression predictions, retaining more than 80 PCs provided minimal improvement in mesh or dimension error metrics. A simulation study demonstrated that improvements in regression model performance when using more than 50 subjects were small. Errors in predicting Air Crew torso mesh dimensions using 10 standard anthropometric variables averaged less than 10 mm. A novel method was developed to predict seated body shape from standing body shape, and a new inscribed fitting method enabled generation of accurate avatars from scans of individuals wearing clothing and gear. A pilot test demonstrated the potential for scanning prone individuals using a transparent table to obtain good coverage." Whew! Lots of good stuff in there. Contact me if you'd like details or would like to use these models or methods.

Update: 2017-06 boundary manikins

My colleagues Dr. Monica Jones and Dr. Daniel Park represented our group at the International Digital Human Modeling Symposium in Bonn, Germany this month. Dr. Jones presented methods and preliminary results from our work on occupant dynamics during abrupt vehicle maneuvers. The goal of this work is to understand how occupant posture and position many change due to automatic crash avoidance systems so that restraint systems can be designed appropriately to protect occupants when a crash does occur. Dr. Park presented an investigation into the development of boundary manikins. Principal component methods are widely used for developing small families of 3d manikins for use in ergonomics analysis. However, little has been published regarding the effects of the many decisions that are necessary when using the typical methods based on standard anthropometric dimensions. In this paper, we compared manikins generated using traditional methods with those created from direct analysis of body shape. Boundary manikin analyses do not achieve quantifiable accommodation assessments; statistical population accomodation models or virtual fit testing are necessary. However, boundary manikins are useful for representing range of extreme body dimensions while incorporating covariance. This paper provides some guidance for thinking about the various decisions to be made in generating a boundary manikin family.

Update: 2017-06

frontal_atd

Several faculty from the Biosciences Group participated in the Enhanced Safety of Vehicles (ESV) conference in Detroit this month.

Hu, J., Klinich, K., Manary, M.A., Flannagan, C.A.C., Narayanaswamy, P., Reed, M.P., Andreen, M., Neal, M., and Lin, C-H. (2017). Does Unbelted Safety Requirement Affect Protection for Belted Occupants? This article has been accepted for publication in Traffic Injury Prevention.

My colleague Dr. Jingwen Hu gave an overview of a large-scale study funded by NHTSA and conducted collaboratively with General Motors. Under FMVSS 208, automakers are required to certify their vehicles based in part on a frontal crash test with unbelted dummies. Several automakers have petitioned NHTSA to permit them to skip the unbelted test if they have belt assurance systems that can be expected to produce near 100% belt use. In this study, we conducted a large number of simulations to optimize the restraint system with and without the belted test. The major change in the restraint system in the absence of the unbelted test is to remove the knee bolster, which changes load sharing between the remaining components of the frontal protection system (seat, seat belt, steering column, and steering wheel airbag).

Jones, M.L.H., Ebert, S.M., Hu, J., Park, B-K D., and Reed, M.P. (2017). Proximity to the steering wheel for obese drivers. Proc. 25th ESV. Detroit, MI.

steering wheel clearance

Dr. Monica Jones presented the first study to examine the spatial relationship between the steering wheel and torso for individuals with high body mass index (BMI). Her study demonstrated that none of a cohort of 52 obese drivers sat with the recommended 250 mm of clearance to the steering wheel, and some, particularly those with short stature, sat with essentially a contact condition at the lower wheel rim. These findings may have important implications for crash safety, because the restraint systems are tuned for frontal impact conditions in which the airbag is able to deploy fully prior to contacting the occupant. We are conducting simulations studies using morphed parametric human body models of obese occupants to understand how to optimize restraints for these individuals.

Hu, J., Zhang, K., Fanta, A., Hwang, E., and Reed M.P. (2017). Effects of male stature and body shape on thoracic impact response using parametric finite element human modeling. Proc. 25th ESV. Detroit, MI.

morphed models

Over the past several years, our group has developed automated methods for rapidly modifying the size and shape of FE models used for occupant simulations in crashes. This study was the first to morph both widely used detailed models of midsize male occupants, from the THUMS and GHBMC families. The results demonstrate the utility of being able to separate true anatomical effects from the differences between models.

Update: 2017-05

childshape.org

A new paper on our work modeling child body shape has appeared in Traffic Injury Prevention. My colleague Dr. Daniel Park led the development of the first-ever statistical body shape model of seated children. The model, which is available online for interactive use, predicts body shape for children ages 3 to 11 years as a function of stature, body weight (expressed as body mass index), and the ratio of sitting height to stature. The posture of the predicted body shape can also be varied with respect to recline angle and lumbar spine flexion. Whole-body laser scans from 135 children in up to 4 postures were used to create the model. Applications include the development of new physical human surrogates for safety system design (e.g., crash test dummies) and parametric human body models. The downloadable body shapes are also approprite for use in the development of child restraint systems. The new model joins other body shape models for adults and children available online at humanshape.org.

Update: 2017-04

The Biosciences Group was well represented at the SAE Congress this month. My colleagues presented three papers on a range of topics.

Jones, M.L.H., Park, J., Ebert, S., Kim, K.H., and Reed, M.P. (2017). Effects of Seat and Sitter Dimensions on Pressure Distribution in Automotive Seats. SAE Technical Paper 2017-01-1390. sipt

My colleague Dr. Monica Jones presented work investigating the associations between sitter and seat characteristics and the pressure distribution at the seat-sitter interface. A study was conducted using 12 production driver seats from passenger vehicles and light trucks. Thirty-eight men and women sat in each seat in a vehicle mockup and seat surface pressure distribution was measured on the seatback and cushion. Anthropometric dimensions were recorded for each participant and standardized dimensions based on SAE J2732 were acquired for each test seat. Regression models were effective in predicting characteristics of pressure distribution from the anthropometric variables and SAE J2732 dimensions.

Park, B-K.D. and Reed, M.P. (2017). Characterizing Vehicle Occupant Body Dimensions and Postures Using a Statistical Body Shape Model. SAE Technical Paper 2017-01-0497. sipt

My colleague Dr. Daniel Park presented a novel method for quantifying vehicle occupant postures and body shapes. The methodology was demonstrated using children and a single Microsoft Kinect sensor. The challenge posed by the noisy and incomplete data was addressed by fitting the data using a statistical body shape model (SBSM). The SBSM used in this work was developed using laser scan data gathered from 147 children with stature ranging from 100 to 160 cm and BMI from 12 to 27 kg/m2 in various sitting postures. A principal component (PC) analysis was conducted based on these scans along with the manually-measured body landmarks, and 100 PC scores were retained to account for 99% of variance in the body shape and sitting postures. A PC-based fast fitting method was applied to estimate the occupant characteristics by fitting the SBSM to an incomplete depth image of a subject. The results demonstrate that a fast, inexpensive system can be used to produce useful estimates of occupant characteristics that could be applied to improve personalization of component adjustments, restraint systems, and infotainment systems.

Hu, J., Orton, N., Gruber, R., Hoover, R., Tribbett, K., Rupp, J.D., Clark, D., Scherer, R., and Reed, M.P. (2017). Development of A New Dynamic Rollover Test Methodology for Heavy Vehicles. SAE Technical Paper 2017-01-1457.

The SAE J2114 dolly rollover test is the most widely used vehicle rollover test procedure. However, it requires the test vehicle to be seated on a dolly with a 23° initial angle, which makes it difficult to test a vehicle over 5,000 kg without a dolly design change, and repeatability is often a concern. My colleague Dr. Jingwen Hu presented a new dynamic rollover test methodology that can be used for evaluating crashworthiness and occupant protection without requiring an initial vehicle angle. A custom cart was designed to carry the test vehicle laterally down a track. The cart incorporates two ramps under the testing vehicle's trailing-side tires. In a test, the cart with the vehicle travels at the desired test speed and is stopped by a track-mounted curb. While the cart is being stopped by two honeycomb blocks, the vehicle slides laterally from the cart with the far-side wheels sliding up the ramps, which generates the desired lateral roll rate. The vehicle near-side wheels slide onto a high-friction surface, which generates an additional strong roll moment around the vehicle center of gravity. Three physical tests using three armored military vehicles were conducted using the procedure. All tests resulted in the desired 5 to 8 quarter-turns of the vehicle, and the instrumented tests showed repeatable initial roll rates. The tests demonstrated that the newly-designed rollover procedure is suitable for vehicles that are generally too large/heavy for other dynamic rollover methods, and may also be useful for lighter vehicles when a well-controlled, directly lateral roll is desired.

sipt

 

Update: 2017-03

shapcoder

We recently completed an interesting study looking at upper-extremity activities in driving. We coded nearly 10k snapshots from videos of over 100 drivers who participated in a naturalistic driving study. The activities of the left and right hand and forearm were documented, including contacts (e.g., steering wheel or armrest) and whether they were holding an object. Drivers had left, right, and both hands on the steering wheel in 64%, 46%, and 28%, respectively, of frames in which the hand placements could be determined. The driver’s left elbow was in contact with the door or armrest in 18% of frames, and the driver’s right elbow was contacting the center console armrest in 29% of frames. Women were more likely to have a phone in their right hands than men, and women were twice as likely as men to be wearing sunglasses during trips taken in daylight hours. For more information, see the report, now available online.

Update: 2017-02

shapcoder

I gave a brief presentation at the Midwest meeting of the American Society of Biomechanics this month. Held at Grand Valley State University in beautiful downtown Grand Rapids, the two-day conference featured keynote speakers and a dual track of primarily student presentations covering a wide range of topics in biomechanics. My talk covered some of our recent work in human body modeling, with a particular emphasis on using Microsoft Kinect to create subject-specific avatars. Software developed by my colleague Dr. Daniel Park fits a statistical body shape model to data from a single Kinect sensor, rapidly generating an accurate representation of body shape even for a clothed scan.

Update: 2017-01

shapcoder

My colleagues Dr. Lauren Zaseck and Dr, Jingwen Hu have led the publication of recent work aimed at improving crash protection for soldiers. Vehicle crashes and rollovers, sometimes secondary to IED blasts, are a leading cause of injury. In this project, funded by the US Army TARDEC through the Automotive Research Center, we conducted a series of sled tests to assess the performance of various restraint systems. Hybrid-III ATDs were used along with a range of body armor and body borne gear configurations. The results demonstrated that advanced belt system features such as pretensioners and load limiters substantially improve restraint performance. The data also showed that achieving good belt or harness restraint performance with soldiers in body armor and wearing gear is challenging.

Update: 2016-12

shapcoder

A broad collaboration at U-M several years in the making has produced an innovative tool for visual assessment of child body shape. The lead researchers on the effort are Dr. Julie Lumeng and Dr. Daniel Park. The first validation article on ShapeCoder appeared this month in Pediatric Obesity. The underlying body shape model was developed at UMTRI by Daniel Park and colleagues based on whole-body laser scan data from 147 children. The parametric model used in ShapeCoder allows a rater to select images on screen that best match the body shape of particular child. This tool has value for both estimating the body mass index of children for which measured stature and weight data are not available and for investigating misperception of child body size. An online version of the tool is available. We welcome further collaboration in this domain. Our growing library of body shape models can be used to accurately represent individuals from age 12 months through elderly adults. Please contact me if you have interest in collaborating on further research in this area or applying body shape models.

Update: 2016-11

PTHUMS

Dr. Eunjoo Hwang, who recently completed a post-doc fellowship in our group at UMTRI, presented a paper at the Stapp Car Crash Conference this month. This is the most in-depth effort to date to validate parametric finite-element human body models (HBM) by subject-specific comparisons to data from impact tests with post-mortem human subjects (PMHS). Previously, the responses of HBMs have been compared to corridors developed for physical crash test dummies. These corridors have been developed by scaling of PMHS responses (and some low-speed human volunteer test data) to target specific body sizes. But parametric HBM can generate a wide range of body shapes and sizes. Validating this methodology requires comparison to individual subject tests, with the model configured to match the specimen geometry as closely as possible. Although much more work remains to be done in this domain, the results showed clearly that subject-specific models match test data better than naively scaled models.

Update: 2016-11

Don Chaffin

I gave two presentations at the NHTSA-hosted biomechanics workshop preceding the Stapp Car Crash Conference.

Developing Anthropometric Targets for ATDs Using Statistical Body Shape Modeling

In this talk, I gave an overview of the methodology we used to develop the anthropometric vargets for the Warrior Injury Assessment Manikin midsize-male ATD. This is the first ATD for which the shape and posture targets were developed through 3D statistical modeling of data from a diverse population.

Responses of Minimally-aware Passengers to Abrupt Braking and Steering Maneuvers

I reported on a pilot study of the motions of front-seat passengers who experienced a surprise vehicle manuever, either a hard braking event or a sharp turn followed by hard braking. For this study, we developed a camera-based method for tracking the upper-body posture and motion during the event, as well as capturing vehicle kinematics. We plan to follow this pilot work with data collection on up to 60 volunteers with a wide range of body size and age.

Update: 2016-10

Obese Passenger

In early October an had the opportunity to visit Chalmers University and SAFER in Gothenburg, Sweden to participate in a dissertation defense. While there I gave a talk on our recent progress on parametric human body modeling. The abstract:

People Are Not Dummies: Modeling Human Variability for Vehicle Restraint System Optimization

Over the past 50 years, crash test dummies (also known as anthropomorphic test devices, or ATDs) have been critical tools for advancing vehicle occupant protection. ATDs allow vehicle manufacturers to design their seat belts, airbags, and other components so that they protect vehicle occupants in a wide range of crash scenarios. However, ATDs are only rough approximations of humans: they have unrealistic body shapes and the need for durability is sometimes achieved at the expense of realism.

In recent years, improvements in computational power and modeling techniques have enabled the creation of highly detailed computer models of human anatomy that can be used to augment ATDs in vehicle design. Currently, most computational models represent people who are the same size as the physical crash test dummies, but our research group has developed methods that allow the existing models to be rapidly morphed to represent a wide range of body sizes and shapes. I'll discuss the rich data we have gathered to characterize the occupant population, the methods and outcomes of model morphing, and the opportunities that we now have to improve protection for the full range of vehicle occupants.

Update: 2016-09

Don Chaffin

My colleagues Dr. Monica Jones and Dr. Daniel Park participated in the Human Factors and Ergonomics Society annual meeting in Washington, DC this month. Dr. Park participated in a panel discussion on new markerless motion techniques for ergonomics analysis. These methods have great potential for gathering data on worker motions in realistic scenarios without time-consuming and intrusive interventions. Dr. Park's contribution was based on innovative work he's doing using Kinect in concert with our new articulated, rapidly generated subject-specific avatars. Dr. Jones presented work on a new database of body shapes and postures of individuals with high body mass index. Around 5% of US adults have a BMI greater than 40 kg/m^2, and these individuals often experience difficult with the fit and performance of consumer products, vehicles, medical devices, and other products and environments that are too frequently designed for the average. Integrating studies like these with earlier work on body shape modeling, we aim to produce tools that enable the design of products that work well for a wider range of the population.

Update: 2016-09

Don Chaffin

My colleagues Kathy Klinich and Lauren Zaseck and I participated this month in the annual conference of the International Research Council on the Biomechanics of Injury (IRCOBI) held this year in beautiful Málaga, Spain. We presented and co-authored several papers this year.

Zaseck, L.W., Chen, C., Hu, J., Reed, M.P., and Rupp, M.P (2016). The Influence of Pre-Existing Rib Fractures on GHBMC Thorax Response in Lateral Impact. Proc. 2016 IRCOBI Conference. Malaga, Spain.

Dr. Zaseck presented this innovative simulation study examining the consequence of rib fractures on thorax response. PMHS often have rib fractures due to CPR. Typically such specimens are rejected for biomechanics testing involving the thorax due to concerns that the response would be strongly affected. This simulation study suggests that a small number of rib fractures is unlikely to have a large effect, which also opens the door to more efficient use of PMHS through multiple impacts.

Don ChaffinMartínez, L., Reed M.P., Garcia, A., de Loma-Ossorio, M., Torres, C., and Bueno, A. (2016). Crash Impact dummies adapted to People Affected by Osteogenesis Imperfecta. Proc. 2016 IRCOBI Conference. Malaga, Spain.

My colleague Dr. Martínez from INSIA in Madrid presented the results of assembling components from range of crash test dummies to better represent the size and mass distribution of individuals with OI. This work is an important step toward developing improved occupant protection systems for this population.

Don ChaffinPark, J., Ebert, S.M., Reed, M.P., and Hallman, J.J. (2016). Effects of Occupant and Vehicle Factors on Three-Point Belt Fit in Rear Seats. Proc. 2016 IRCOBI Conference. Malaga, Spain.

I presented this work by my post-doc Dr. Jangwoon Park, the latest in a long series of papers on belt fit in vehicle seats for occupants with a wide range of characteristics. The results were similar to those presented previously for drivers, showing a strong effect of BMI on belt fit. Individuals with high BMI tend to have markedly worse lap belt fit than those with normal BMI, potentially reducing safety in frontal and other collisions. The findings confirm the need to look for new ways of improve belt fit and belt performance for all occupants, particularly those who are not shaped like crash test dummies.

Don ChaffinKlinich, K.D., Flannagan, C.A.C., Hu, J., and Reed, M.P. (2016). Potential Safety Effects of Low-Mass Vehicles with Comprehensive Crash Avoidance Technology. Proc. 2016 IRCOBI Conference. Malaga, Spain.

My colleague Dr. Klinich presented this innovative study looking at the potential consequences of advanced crash avoidance systems and vehicle lightweighting. Even if a vehicle cannot cause a crash, other vehicles will still collide with it and cause risks to the occupants. Our analysis of current crash data suggests that side impacts will become increasingly important as frontal impacts are reduced and mitigated. This effect is accentuated by vehicle lightweighting, which exposes the occupants to higher accelerations.

Don ChaffinKlein, K., Reed, M.P., and Rupp, J.D. (2016). Development of Geometric Specifications for the Pelvis of a Small Female Anthropomorphic Test Device. Proc. 2016 IRCOBI Conference. Malaga, Spain.

I presented this short communication presenting the development of a geometric target for the pelvis of a small-female crash test dummy. Current small-female ATDs have pelves developed by simple geometric scaling of midsize-male pelves. This analysis, which is based on Katelyn Klein's PhD work, demonstrates that linear scaling produces a distinctly unrealistic pelvis shape. We've made the results of this work available online.

Update: 2016-08

Don Chaffin

My colleages Gale Zielinkski and Frank Huston from the U.S. Army TARDEC presented some of our joint work at the annual Ground Vehicle Systems Engineering and Technology Symposium (GVSETS) in Novi, MI, this month. We have been collaborating for several years on the development of new methods and models for laying out and evaluating military vehicle interiors. The work is based on outcomes from the Seated Soldier Study, our landmark project to gather and analyze data on soldier postures in ground vehicle seats as drivers and squad. The 2016 GVSETS presentation was focused on the development of a CAD implementation of our suite of driver accomodation models for the fixed-heel-point scenarios typical of truck-like vehicles. The image at the right shows the graphical rendering of the models in the Creo parametric CAD system. Based on steering wheel location and the distribution of driver body dimensions, the models generate clearance contours for the head (with helmet), knees, and torso (with body armor and gear). A seat adjustment envelope is generated for a target accommodation level, and an eyellipse graphically illustrates the expected distribution of driver eye locations, which is useful for conducting analysis of driver vision to external and internal targets.

Update: 2016-08

Don Chaffin

I'm honored to have been named the Don B. Chaffin Collegiate Research Professor by approval of the U-M Board of Regents. The Collegiate Research Professorship is the highest honor awarded to research faculty at the University and is intended to recognize "exceptional scholarly achievement and impact on advancing knowledge." This professorship is named for my mentor Prof. Don Chaffin, a professor of Industrial and Operations Engineering and Biomedical Engineering who led the U-M Center for Ergonomics for many years. Don was a pioneer in the use of biomechanical modeling in ergonomics, leading the development of a human modeling tool for strength assessment that is still used around the world. Don also founded the Human Motion Simulation lab that I now lead. This award is a recognition of the tremendous contributions of my colleagues and students who have created and sustained a highly productive, engaging research enterprise both at UMTRI and in IOE that I am fortunate to be a part of.

Update: 2016-06

I joined my UMTRI colleagues Dr. Monica Jones and Dr. Daniel Park at the Digital Human Modeling Conference in Montreal. Our hosts at ÉTS did a terrific job organizing the conference. We presented work focused on three-dimensional anthropometry and computational simulation of vehicle occupants

Jones, M.L.H., Ebert, S.M., Hu, J., Park, B-K.D., and Reed, M.P. (2016). Quantifying body shape differences between supine and standing postures for adults with high body mass index. Proc. 4th International Digital Human Modeling Conference. Montreal, Canadaobese_spine

Dr. Jones presented a pilot study of the body shape of men and women with high body weight. People with body mass index >40 kg/m2 are almost completely absent from previous body scan study. Yet, such adults are about 5% of the U.S. adult population, and their attributes are critical to set design targets for many products, including vehicle seats and medical equipment. In this study, we also compared supine and standing postures. The goal is to create a linkage

Reed, M.P., Park, B-K. D., and Corner, B.D. (2016). Predicting seated body shape from standing body shape. Proc. 4th International Digital Human Modeling Conference. Montreal, Canada.seated from standing

As part of a collaborative project with the U.S. Army, we have been exploring many issues related to the measurement and modeling of body shapes. Most scan datasets have a large number of subjects in small number of postures, none of which are functional postures useful for vehicle and seat designs. However, our UMTRI studies typically measure participants in up to 25 postures, including supported seated postures. To make better use of other studies, we developed a statistical model that very accurately predicts seated body shape from a standing scan. We demonstrated the method with civilian female models, but we will be exending this to the male military population.

Park, B-K.D., Corner, B.D., Kearney, M., and Reed, M.P. (2016). Estimating human body characteristics under clothing using a statistical body shape model. Proc. 4th International Digital Human Modeling Conference. Montreal, Canada.

body shape under clothingMost body scan surveys measure people minimally clad so that the data best characterize the surface shape. However, in many practical situations it is not feasible to measure people without clothing. Hence, methods for estimating body shape under clothing have great potential utility for building subject-specific avatars. My colleague Daniel Park developed a novel method for rapidly fitting a statistical body shape model to a clothed figure. He demonstrated that the method was surprisingly effective even with soldiers wearing body armor and gear.

Hu, J., Fanta, A., Neal, M.O., Reed, M.P., and Wang, J-T. (2016). Vehicle crash simulations with morphed GHBMC human models of different stature, BMI, and age. Proc. 4th International Digital Human Modeling Conference. Montreal, Canada.ghbmc morphed

Mark Neal from General Motors presented an overview of a collaboration between UMTRI and GM that is part of our effort to dramatically increase the utility of computational human models for restraint system optimization. Jingwen Hu has led the efforts at UMTRI to develop methods to rapidly morph complex FE models (2M elements) to any arbitrary body size and shape. In this project, the template model is the GHBMC midsize male. The 100 models developed in through this study extend the population represented by that single model through more than 90% of the U.S. adult population based on stature, age, and BMI.

Update: 2016-05

squad clearance models

My colleague Dr. Jingwen Hu led a case-study presentation at the annual review meeting of the Automotive Research Center, an Army funded center of excellence at the University of Michigan focused on modeling and simulation of ground vehicles. With our collaborators from TARDEC, Takata, and Oakland University, the presentation outlined a large-scale effort to improve occupant protection in tactical military vehicles, such as the HMMWV, involved in frontal and roll-over crashes. UMTRI's contributions included sled testing, the development of computational models of body armor and gear, restraint optimization, and fitting vehicles for physical testing.

Update: 2016-05

squad clearance models

We've completed another analysis of data from the Seated Soldier Study aimed at improving the accommodation of warfighters in military vehicles. This work applies methods that we've previously developed for passenger cars, light trucks, and commercial trucks to the layout of seats and vehicle interiors for the squad seating positions in mlitary vehicles. The seat is parameterized by seat height and seat back angle. The population is described by the distributions of stature, body weight, and erect sitting height, along with gender ratio. For our demonstrations, we use data from the latest U.S. Army Survey (ANSUR II). For squad seating, the models provide a helmet clearance contour, eyellipse, and knee clearance contour. The contours can be set to accommodate any target percentage of the population, such as 95, 98, 99%. These new models provide the first opportunity for the designers of military seat and vehicle interiors to use design tools based on realistic warfighter postures.

Update: 2016-04

The Biosciences Group had a big presence at the SAE Congress in Detroit this month. We presented research on a broad range of topics from seat shape modeling to restraint system optimization for military vehicles. Here are some highlights:

Reed, M.P. and Ebert, S.M. (2016). Evaluation of the seat index point tool for military seats. SAE Technical Paper 2016-01-0309. SAE International Journal of Commercial Vehicles. sipt

In the design of on-highway vehicles, the SAE J826 H-point machine is used globally to establish reference points and angles to define the seat position and orientation. However, the H-point machine doesn't work very well in many military vehicle seats. In this paper, we compared the performance of the ISO 5353 seat index point tool (SIPT) to the H-point machine and found that not only is it more stable, but it gives comparable results in many situations. Consequently we recommend that the U.S. Army immediately adopt the SIPT as the standard for measuring ground vehicle seats whenever the H-point machine cannot be used or is not available.

Drignei, D., Mourelatos, Z., Kosova, E., Hu, J., Reed, M.P., Rupp, J.D., Gruber, R., and Scherer, R. (2016). Uncertainty assessment in restraint system optimization for occupants of tactical vehicles. SAE Technical Paper 2016-01-0316. SAE International Journal of Materials and Manufacturing, 9: 436-443 sipt

We are in the final stages of a large-scale project developing optimized restraint systems for a Humvee-like vehicle to protect its occupants in frontal-crash and rollover events. We conducted sled testing of a variety of restraints with fully equipped soldiers, then performed a wide-ranging simulation study to identify optimal restraints, including airbags for frontal crash protection. One challenge in restraint system optimization is that the complexity of the computational models for simulating crashes means that we can't run as many physical or computational tests as we would like. This paper explores a method for estimating the uncertainy in outcomes given a small number of test results.

Hwang, E., Hallman, J., Klein, K., Rupp, J.D Reed, M.P. and Hu, J. (2016). Rapid development of diverse human body models for crash simulations through mesh morphing. SAE Technical Paper 2016-01-1491. SAE International, Warrendale, PA.

siptOur postdoc Eunjoo Hwang presented some of her work on parametric modeling of vehicle occupants. The work reported here was actually completed about 18 months ago and represented the first project we're aware of to successfully morph a high-fidelity human body model (THUMS4, in this case) to a wide range of body sizes. With leadership from Dr. Jingwen Hu, we have extended this broadly, generating over 100 anthropometricallly distinct versions of THUMS4.

 

Jones, M.L., Ebert, S.M., and Reed, M.P. (2016). A Pilot Study of Occupant Accommodation and seat belt fit for law enforcement officers. SAE Technical Paper 2016-01-1504. SAE International, Warrendale, PA. sipt

My colleague Dr. Monica Jones presented some interesting pilot work she conducted assessing the geometric fit of law-enforcement officers (LEO) in vehicles with a focus on seats and restraint systems. Car crashes are a leading cause of death for LEO in the U.S., with more officers killed in vehicles than by guns. Some officers report that they do not wear their safety belts because they do not fit well when they're wearing their duty belts, and lower-back and other musculoskeletal ailments due to poor vehicle ergonomics are a leading cause of lost work time for officers. In this study, Monica used 3D laser scanning to document the mismatch between LEO and their seats and vehicles. More work is needed in this area to improve vehicle designs for law enforcement.

Park, J., Ebert, S.M., Kim, K.H., Jones, M.L., Park, B-K, and Reed, M.P. (2016). Development of an automatic seat-dimension extraction system. SAE Technical Paper 2016-01-1429. SAE International, Warrendale, PA.

sipt Dr. Jangwoon Park, a post-doc in our lab, developed a novel automated software system for extracting seat dimensions. In the auto industry, seat benchmarking is a slow process. Extracting the dimensions defined by SAE J2732 can take hours. Dr. Park's system can compute dimensions in minutes from a 3D scan of the seat, assuming H-point data are available. We are exploring the potential of combining this system with the statistical shape modeling methodology described below to create a new, quantitative system for evaluating vehicle seating.

Kim, K.H., Ebert, S.M., and Reed, M.P. (2016). Statistical modeling of automotive seat shapes. SAE Technical Paper 2016-01-1436. SAE International, Warrendale, PA.

seat shape parameterization

My colleague Dr. Han Kim developed an interesting approach to analyzing seat shapes. Observing the organic contours typical of modern auto seats, he applied the same methods we've been using in recent years for modeling human body shape. He developed a semi-automated method for fitting a template to each seat so that the contours are amenable to a statistical analysis using principal component analysis and regression. The resulting parameterization can be used for a host of interesting applications, including seat shape clustering, interpolating among seats, finding the "nearest neighbor" of a seat, and designing completely new seat shapes. The potential of this new tool will begin to be realized after we are able to add perhaps 100 more seats to the database.

Update: 2016-02

rear seat safety

Thanks to the great work of my colleague Dr. Daniel Park, we have launched a beta version of our new web portal, HumanShape.org. HumanShape will provide interactive, online access to our many statistical body shape models. Already, this is the only online source of data on child body shape and seated adults. Much more will be coming in the next few months. Currently, the site hosts three child anthropometry models and one adult model. Users can input the overall body dimensions, such as stature and body weight, and download an STL file along with a range of body landmarks. We welcome feedback and suggestions on how we can make this tool useful for a wide range of applications.

Update: 2016-01

rear seat safety

Anthropometric data on children are scarce, and anthropometric data on toddlers and infants are even more rare. My colleagues and I just wrapped up a preliminary analysis of an unprecedented dataset of 3D whole-body laser scans of toddlers ages 12 to 36 months. Using methods we previously applied to children ages 3 to 11, we developed a statistical body shape model parameterized on torso length (erect sitting height for children who could assume that posture, recumbent length for the younger ones) and body mass. The resulting model was used to generate a set of boundary manikins based on increments of body weight. These tools will be useful for child restraint design, in particular for ensuring that harness strap heights accommodate nearly all children within the weight ranges by which restraints are specified.

 

 

©2017 Matthew P. Reed and The University of Michigan