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Viewing 1 to 30 of 3990
Technical Paper
2014-05-09
Nikolina Samardzic
Values of the speech intelligibility index (SII) were found to be different for the same speech intelligibility performance measured in an acoustic perception jury test with 35 human subjects and different background noise spectra. Using a novel method for in-vehicle speech intelligibility evaluation, the human subjects were tested using the hearing-in-noise-test (HINT) in a simulated driving environment. A variety of driving and listening conditions were used to obtain 50% speech intelligibility score at the sentence Speech Reception Threshold (sSRT). In previous studies, the band importance function for ‘average speech’ was used for SII calculations since the band importance function for the HINT is unavailable in the SII ANSI S3.5-1997 standard. In this study, the HINT jury test measurements from a variety of background noise spectra and listening configurations of talker and listener are used in an effort to obtain a band importance function for the HINT, to potentially correlate the calculated SII scores with the measured speech intelligibility scores.
Technical Paper
2014-04-01
Michael Flannagan, Mitsuhiro Uchida, John Michael Sullivan, Mary Lynn Buonarosa
This study was designed to investigate how the spectral power distribution (SPD) of LED headlamps (including correlated color temperature, CCT) affects both objective driving performance and subjective responses of drivers. The results of this study are not intended to be the only considerations used in choosing SPD, but rather to be used along with results on how SPD affects other considerations, including visibility and glare. Twenty-five subjects each drove 5 different headlamps on each of 5 experimental vehicles. Subjects included both males and females, in older (64 to 85) and younger (20 to 32) groups. The 5 headlamps included current tungsten-halogen (TH) and high-intensity discharge (HID) lamps, along with three experimental LED lamps, with CCTs of approximately 4500, 5500, and 6500 K. Driving was done at night on public roads, over a 21.5-km route that was selected to include a variety of road types. Vehicle instrumentation was used to derive the measures of objective driving performance.
Technical Paper
2014-04-01
Mark William Arndt
Abstract The current certification requirements under CFR 49, Part 567 state that GVWR of a motor vehicle shall not be less than the sum of the unloaded vehicle weight, rated cargo weight and 150 pounds times the number of designated seating positions. Actual occupant weight distributions versus certified weight per occupant seat causes a potential conflict between a vehicle's in-use weights versus its certified GVWR. Population weight distributions were developed based upon The Center for Disease Control's (CDC) publication of 2007 - 2010 anthropometric reference data and publically available weights of a special population from high school football teams. For five buses from small (18-seat) to large (55-seat), key parameters were measured. The weight distributions and bus parametric data were combined in a probabilistic analysis to explore the probability that passengers and rated cargo would result in weight distributions that exceeded tire load capability, Gross Axle Weight Rating (GAWR), or Gross vehicle Weight Rating (GVWR).
Technical Paper
2014-04-01
Mitsuru Enomoto, Michiko Kakinuma, Nobuhito Kato, Haruo Ishikawa, Yuichiro Hirose
Abstract Design work for truck suspension systems requires multi-objective optimization using a large number of parameters that cannot be solved in a simple way. This paper proposes a process-based systematization concept for ride comfort design using a set-based design method. A truck was modeled with a minimum of 13 degrees of freedom, and suspension performance under various vehicle speeds, road surface conditions, and load amounts was calculated. The range of design parameters for the suspension, the range of performance requirements, and the optimal values within these ranges were defined based on the knowledge and know-how of experienced design engineers. The final design of the suspension was installed in a prototype truck and evaluated. The performance of the truck satisfied all the objectives and the effectiveness of the set-based design approach was confirmed.
Technical Paper
2014-04-01
Jan-Mou Li, David Smith
Abstract Driver is a key component in vehicle simulation. An ideal driver model simulates driving patterns a human driver may perform to negotiate road profiles. There are simulation packages having the capability to simulate driver behavior. However, it is rarely documented how they work with road profiles. This paper proposes a new truck driver model for vehicle simulation to imitate actual driving behavior in negotiating road grade and curvature. The proposed model is developed based upon Gipps' car-following model. Road grade and curvature were not considered in the original Gipps' model although it is based directly on driver behavior and expectancy for vehicles in a stream of traffic. New parameters are introduced to capture drivers' choice of desired speeds that they intend to use in order to negotiating road grade and curvature simultaneously. With the new parameters, the proposed model can emulate behaviors like uphill preparation for different truck drivers. Speed variation while cruising can be explained by the empirical model and therefore facilitating a better estimation of performance in vehicle simulation.
Technical Paper
2014-04-01
Rama Subbu, Baskar Anthony Samy, Piyush mani Sharma
Abstract Fierce competition in India's motorcycle industry has led to constant product innovation among manufacturers. This has resulted in the reduction of the lifecycle of the vehicle and has driven the manufacturers to alter the product design philosophies and design tools. One of the performance factors that have continued to challenge motorcycle designers is ride comfort in vertical and longitudinal direction. An essential tool in the motorcycle development process is the ability to quantify and grade the ride comfort behavior. This is performed either through subjective or objective tests. Subjective tests have the disadvantage that numerous factors influence test drivers' opinion while objective measures have the advantage of repeatability. However, objective methods provide only an approximate grading of vehicles and it is difficult to get consistent results that we can rely upon It is proposed that consistent result could be achieved if the motorcycle is run over the pave track in similar repeated cycles.
Technical Paper
2014-04-01
Masashi Tsushima, Eiichi Kitahara, Taichi Shiiba, Takumi Motosugi
The adoption of the electronic controlled steering systems with new technologies has been extended in recent years. They have interactions with other complex vehicle subsystems and it is a hard task for the vehicle developer to find the best solution from huge number of the combination of parameter settings with track tests. In order to improve the efficiency of the steering system development, the authors had developed a steering bench test method for steering system using a Hardware-In-the-Loop Simulation (HILS). In the steering HILS system, vehicle dynamics simulation and the tie rod axial force calculation are required at the same time in the real-time simulation environment. The accuracy of the tie rod axial force calculation is one of the key factors to reproduce the vehicle driving condition. But the calculation cannot be realized by a commercial software for the vehicle dynamics simulation. A multibody kinematics model of strut suspension was developed for the tie rod axial force calculation.
Technical Paper
2014-04-01
Lee Carr, Dan Barnes, Jennifer Crimeni
Abstract Prior to the widespread implementation of ABS brake technology in light vehicles, driver training often included instruction to “pump the brakes” to avoid locking the wheels. Many driver education programs now recommend maintaining high brake pedal force and relying on ABS. It is sometimes asserted that drivers desiring to stop a vehicle quickly still “pump the brakes”. Investigators sought to understand whether drivers desiring to decelerate quickly pump the brakes, especially in a way that may deplete the vacuum stored in a vehicle's brake booster if so equipped, or whether they apply the brakes in a manner corresponding to their desired deceleration. The National Highway Traffic Safety Administration (NHTSA) conducted a testing program to examine driver braking behavior in crash avoidance maneuvers. The data for those 245 test runs were reanalyzed, assessing patterns of brake pedal force application to determine whether pedal force variation was sufficient in magnitude and duration to reflect driver intent.
Technical Paper
2014-04-01
Ibrahim A. Badiru
The automotive industry is one of the most competitive enterprises in the world. Customers face an ever-expanding number of entries in each market segment vying for their business. Sales price, brand image, marketing, etc. all play a role in purchase decisions, but the factor distinguishing products that consistently perform in the market place is the ability to satisfy the customer. Steering character plays a critical role in the customer driving experience and can be one of the most heavily debated topics during a new vehicle program. The proliferation of EPS steering systems now allows engineers to calibrate steering feel to almost any desired specification. This raises a key question: What subjective & objective characteristics satisfy customers in a particular market segment? Answering this question requires continued research to develop objective metrics correlated to subjective steering attributes and increased understanding of customer preferences for objective performance parameters.
Technical Paper
2014-04-01
Sooncheol Park, Wonwook Jung, Chunwoo Shin, Jaewung Jung
Abstract Customer vehicle usage monitoring is one of the most fundamental elements to consider in the process of developing a durable vehicle. The extant method to research customer vehicle usage takes considerable time and effort because it requires attaching a series of sensors to the vehicle-gyroscope, accelerometer, microphone, and GPS-to gather information through data logs and then to analyze data in a computer where designated analyzing software has been installed. To solve the problem, this paper introduces a new concept of integrated system developed to examine customer vehicle usage that can analyze data by collecting it from a variety of sensors installed on a smartphone.
Technical Paper
2014-04-01
Raunak Santosh, Vijayakumar Chekuri
Abstract Rapid growth in the Indian economy has led to new market trends for commercial vehicles. Customers now expect high levels of comfort from all tactile points in a truck cabin; the gear lever knob is frequently used and its reactions greatly influence how a driver perceives Gear Shift Quality (GSQ) and thereby vehicle quality. The subjectivity of human perception is difficult to measure objectively; therefore this paper represents an objective methodology to correlate customer feedback of gearshift reactions. For the attribute evaluation of a set of intermediate commercial vehicles; detailed subjective appraisals were conducted by expert level assessors for GSQ sub-attributes, and a consecutive objective measurement was performed to investigate and substantiate these vehicle assessments. Dynamic and Static testing techniques were used to measure GSQ parameters like efforts during gear shift/select, feel of different phases of gear engagement /selection, gate definitions and lever travels; this helped in formulating objective metrics that can be used to create a definition of GSQ in a vehicle segment and an objective methodology to assess the same.
Technical Paper
2014-04-01
Maki Kawakoshi, Takanobu Kaneko, Toru Nameki
Abstract Controllability (C) is the parameter that determines the Automotive Safety Integrity Level (ASIL) of each hazardous event based on an international standard of electrical and/or electronic systems within road vehicles (ISO 26262). C is classified qualitatively in ISO 26262. However, no specific method for classifying C is described. It is useful for C classification to define a specific classification based on objective data. This study assumed that C was classified using the percentage of drivers who could reduce Severity (S) in one or more classes compared with the S class in which the driver did not react to a hazardous event. An experiment simulated a situation with increased risk of collision with a leading vehicle due to insufficient brake force because of brake-assist failure when the experiment vehicle decelerated from 50 km/h on a straight road. First, the relationship between the S class and the difference of speed at the moment of collision obtained in the experiment was classified according to ISO/DIS 26262 Part 3 Annex B.
Technical Paper
2014-04-01
Hongjie Ma, Hui Xie, Shuangxi Chen, Ying Yan, DengGao Huang
Abstract Approximately 50% energy is consumed during the acceleration of a city bus. Fuel consumption during acceleration is significantly affected by driving behavior. In this study, 13 characteristic parameters were selected to describe driving style based on analysis of how driving influences fuel consumption during acceleration. The 100,000 km real-world vehicle running data of six drivers on three city buses in a particular bus line in Tianjin, China were sampled using a vehicle-on-line data logger. Based on the selected characteristic parameters and collected driving data, an evaluation model of the fuel consumption level of a driver was established by adopting the method of decision tree C4.5. For two-level classification, the model has over 85% prediction accuracy. The model also has the advantages of having a few training samples and strong generalization. As an example of the model application, the fuel-saving potential of a driver under optimal operations was analyzed. Thus, the model can be used to train and evaluate drivers employed by bus companies.
Technical Paper
2014-04-01
Chuqi Su, Zhengzhong Chu
Driving comfort is one of the most important indexes for automobile comfort. Driving posture comfort is closely related to the drivers' joint angles and joint torques. In present research, a new method is proposed to identify the most comfortable driving posture based on studying the relation between drivers' joint angles and joint torques. In order to truly reflect a driving situation, the accurate human driving model of 50 percent of the size of Chinese male is established according to the human body database of RAMSIS firstly. Biomechanical model based on accurate human driving model is also developed to analyze and obtain dynamic equations of human driving model by employing Kane method. The joint torque-angle curves of drivers' upper and lower limbs during holding wheel or pedal operation can be obtained through dynamic simulation in the MATLAB. Through curve-fitting analysis, the minimum joint torque of a driver' limb and the optimal joint angel can be found. As an important reference, these parameters can be used to optimize driving seat structure and offer an important support for the optimization of cab package.
Technical Paper
2014-04-01
Alessandro Naddeo, Nicola Cappetti, Orlando Ippolito
Abstract General comfort may be defined as the “level of well-being” perceived by humans in a working environment. The state-of-the-art about evaluation of comfort/discomfort shows the need for an objective method to evaluate the “effect in the internal body” and “perceived effects” in main systems of comfort perception. In the early phases of automotive design, the seating and dashboard command can be virtually prototyped, and, using Digital Human Modeling (DHM) software, several kinds of interactions can me modeled to evaluate the ergonomics and comfort of designed solutions. Several studies demonstrated that DHM approaches are favorable in virtual reachability and usability tests as well as in macro-ergonomics evaluations, but they appear insufficient in terms of evaluating comfort. Comfort level is extremely difficult to detect and measure; in fact, it is affected by individual perceptions and always depends on the biomechanical, physiological, and psychological state of the tester during task execution.
Technical Paper
2014-04-01
Helen S. Loeb, Thomas Seacrist, Catherine McDonald, Flaura Winston
Abstract Driving simulators provide a safe, highly reproducible environment in which to assess driver behavior. Nevertheless, data reduction to standardized metrics can be time-consuming and cumbersome. Further, the validity of the results is challenged by inconsistent definitions of metrics, precluding comparison across studies and integration of data. No established tool has yet been made available and kept current for the systematic reduction of literature-derived safety metrics. The long term goal of this work is to develop DriveLab, a set of widely applicable routines for reducing simulator data to expert-approved metrics. Since Matlab™ is so widely used in the research community, it was chosen as a suitable environment. This paper aims to serve as a case study of data reduction techniques and programming choices that were made for simulator analysis of a specific research project, the Simulated Driving Assessment. The initial set of Matlab™ routines was successfully tested by analyzing recognized metrics, such as Distance Headway, Time Headway, Time-To-Collision, and Reaction Time.
Technical Paper
2014-04-01
Tobias Karlsson, Magdalena Lindman, Jordanka Kovaceva, Bo Svanberg, Henrik Wiberg, Lotta Jakobsson
Abstract Different types of driver workload are suggested to impact driving performance. Operating a vehicle in a situation where the driver feel uneasy is one example of driver workload. In this study, passenger car driving data collected with Naturalistic Driving Study (NDS) data acquisition equipment was analyzed, aiming to identify situations corresponding to a high driver's subjective rating of ‘unease’. Data from an experimental study with subjects driving a passenger car in normal traffic was used. Situations were rated by the subjects according to experienced ‘unease’, and the Controller Area Network (CAN) data from the vehicle was used to describe the driving conditions and identify driving patterns corresponding to the situations rated as ‘uneasy’. These driving patterns were matched with the data in a NDS database and the method was validated using video data. Two data mining approaches were applied. The first was based on an ensemble classifier on general variables derived from the CAN-data to predict the subjective rating of segments of the data.
Technical Paper
2014-04-01
Clive D'Souza
The purpose of this paper is to demonstrate the impact of low- floor bus seating configuration, passenger load factor (PLF) and passenger characteristics on individual boarding and disembarking (B-D) times -a key component of vehicle dwell time and overall transit system performance. A laboratory study was conducted using a static full-scale mock-up of a low-floor bus. Users of wheeled mobility devices (n=48) and walking aids (n=22), and visually impaired (n=17) and able-bodied (n=17) users evaluated three bus layout configurations at two PLF levels yielding information on B-D performance. Statistical regression models of B-D times helped quantify relative contributions of layout, PLF, and user characteristics viz., impairment type, power grip strength, and speed of ambulation or wheelchair propulsion. Wheeled mobility device users, and individuals with lower grip strength and slower speed were impacted greater by vehicle design resulting in increased dwell time. To ensure safe, efficient and equitable access to the diverse spectrum of transit riders, transit system design needs approaches that transcend existing minimum federal accessibility design standards.
Technical Paper
2014-04-01
Xingyu Liang, Kang Sun, Yuesen Wang, Gequn Shu, Lin Tang, Lei Ling, Xu Wang
Abstract Like outside scenery, the car interior noise and road condition will affect the driver's mental state when driving. In order to explore the influence of external visual and auditory factors on the driver's mood in the driving process based on research of traffic soundscape, this paper has selected four backbone roads of Tianjin city (China) to test and drive a gasoline passenger vehicle at different speeds. Near Acoustic Holographic was used to scan interior acoustic field distribution, while the tracking shot of the driver's location was recorded by a Sony camera. People with different characteristics were invited to watch the video and completed a self-designed survey questionnaire. The external factors affecting the driver's mood were explored by analyzing all these data. After the investigation, we found that the sound field distribution inside the car could be affected directly and significantly by the opening and closing the car window when driving; in the case of keeping the window closed, the acoustic characteristics of the car cabin was relatively stable; and the visual impact factor of the driver's mood is mainly related to the traffic congestion degree and the construction quality of road surface, whereas the road appearance and aesthetics, which people usually concern about have very little influence.
Technical Paper
2014-04-01
Nicholas P. Skinner, John D. Bullough
Abstract Rear automotive lighting systems employing dynamic features such as sweeping or flashing are not commonly used on vehicles in North America, in part because they are not clearly addressed in vehicle lighting regulations. Nor is there abundant evidence suggesting they have a substantial role to play in driver safety. The results of a human factors investigation of the potential impacts of dynamic rear lighting systems on driver responses are summarized and discussed in the context of safety, visual effectiveness and the present regulatory context.
Technical Paper
2014-04-01
Rudolf Mortimer, Errol Hoffmann, Aaron Kiefer
Abstract Relative velocity detection thresholds of drivers are one factor that determines their ability to avoid rear-end crashes. Laboratory, simulator and driving studies show that drivers could scale relative velocity when it exceeded the threshold of about 0.003 rad/sec. Studies using accident reconstruction have suggested that the threshold may be about ten times larger. This paper discusses this divergence and suggests reasons for it and concludes that the lower value should be used as a true measure of the psychological threshold for detection of relative velocity.
Technical Paper
2014-04-01
John D. Bullough
Abstract Present standards for vehicle forward lighting specify two headlamp beam patterns: a low beam when driving in the presence of other nearby vehicles, and a high beam when there is not a concern for producing glare to other drivers. Adaptive lighting technologies such as curve lighting systems with steerable headlamps may be related to increments in safety according to the Insurance Institute for Highway Safety, but isolating the effects of lighting is difficult. Recent analyses suggest that visibility improvements from adaptive curve lighting systems might reduce nighttime crashes along curves by 2%-3%. More advanced systems such as adaptive high-beam systems that reduce high-beam headlamp intensity toward oncoming drivers are not presently allowed in the U.S. The purpose of the present study is to analyze visual performance benefits and quantify potential safety benefits from adaptive high-beam headlamp systems. Before adaptive high-beam systems could be permitted on U.S. roadways, it is necessary to have data describing their potential for crash reductions.
Technical Paper
2014-04-01
Renaud Deborne, Skárlet Khouri Silva, Andras Kemeny
Abstract By the action on the steering wheel, the driver has the capability to control the trajectory of its vehicle. Nevertheless, the steering wheel has also the role of information provider to the driver. In particular, the torque level at the steering wheel informs the driver about the interaction between the vehicle and the road. This information flow is natural due to the mechanical chain between the road and the steering wheel. Many studies have shown that steering wheel torque feedback is crucial to ensure the control of the vehicle. In the context of uncoupled steering (steer-by-wire vehicle or driving simulators), the torque rendering on the steering wheel is a major challenge. In addition, of the trajectory control, the quality of this torque is a key for the immersion of drivers in virtual environment such as in driving simulators. The torque-rendering loop is composed of different steps. At first, a vehicle dynamics model computes the torque level at the steering wheel regarding the vehicle state (steering wheel position, vehicle speed, etc.).
Technical Paper
2014-04-01
Flaura Winston, Catherine McDonald, Venk Kandadai, Zachary Winston, Thomas Seacrist
Abstract Driving simulators offer a safe alternative to on-road driving for the evaluation of performance. In addition, simulated drives allow for controlled manipulations of traffic situations producing a more consistent and objective assessment experience and outcome measure of crash risk. Yet, few simulator protocols have been validated for their ability to assess driving performance under conditions that result in actual collisions. This paper presents results from a new Simulated Driving Assessment (SDA), a 35- to-40-minute simulated assessment delivered on a Real-Time® simulator. The SDA was developed to represent typical scenarios in which teens crash, based on analyses from the National Motor Vehicle Crash Causation Survey (NMVCCS). A new metric, failure to brake, was calculated for the 7 potential rear-end scenarios included in the SDA and examined according two constructs: experience and skill. The study included an inexperienced group (n=21): 16-17 year olds with 90 days or fewer of provisional licensure, and an experienced group (n=17): 25-50 year olds with at least 5 years of PA licensure, at least 100 miles driven per week and no self-reported collisions in the previous 3 years.
Technical Paper
2014-04-01
Richard Young
This study reanalyzes the data from a recent experimental report from the University of Utah investigating the effect on driving performance of auditory-vocal secondary tasks (such as cell phone and passenger conversations, speech-to-text, and a complex artificial cognitive task). The current objective is to estimate the relative risk of crashes associated with such auditory-vocal tasks. Contrary to the Utah study's assumption of an increase in crash risk from the attentional effects of cognitive load, a deeper analysis of the Utah data shows that driver self-regulation provides an effective countermeasure that offsets possible increases in crash risk. For example, drivers self-regulated their following distances to compensate for the slight increases in brake response time while performing auditory-vocal tasks. This new finding is supported by naturalistic driving data showing that cell phone conversation does not increase crash risk above that of normal baseline driving. The Utah data are next compared to those from a larger study that included visual-manual as well as auditory-vocal tasks.
Technical Paper
2014-04-01
Yinghao Huang, Wenduo Wang, Chen Fang, Yi Murphey, Dev S. Kochhar
A transportable instrumentation package to collect driver, vehicle and environmental data is described. This system is an improvement on an earlier system and is called TIP-II [13]. Two new modules were designed and added to the original system: a new and improved physiological signal module (PH-M) replaced the original physiological signals module in TIP, and a new hand pressure on steering wheel module (HP-M) was added. This paper reports on exploratory tests with TIP-II. Driving data were collected from ten driver participants. Correlations between On-Board-Diagnostics (OBD), video data, physiological data and specific driver behavior such as lane departure and car following were investigated. Initial analysis suggested that hand pressure, skin conductance level, and respiration rate were key indicators of lane departure lateral displacement and velocity, immediately preceding lane departure; heart rate and inter-beat interval were affected during lane changes. Correlation analyses of car-following data are ongoing.
Technical Paper
2014-04-01
Takahiro Adachi, Takashi Yonekawa, Yoshitaka Fuwamoto, Shoji Ito, Katsuhiko Iwazaki, Sueharu Nagiri
Abstract The driving simulator (DS) developed by Toyota Motor Corporation simulates acceleration using translational (XY direction) and tilting motions. However, the driver of the DS may perceive a feeling of rotation generated by the tilting motion, which is not generated in an actual vehicle. If the driver perceives rotation, a vestibulo-ocular reflex (VOR) is generated that results in an unnecessary correction in the driver's gaze. This generates a conflict between the vestibular and visual sensations of the driver and causes motion sickness. Although such motion sickness can be alleviated by reducing the tilting motion of the DS, this has the effect of increasing the amount of XY motion, which has a limited range. Therefore, it is desirable to limit the reduction in the tilting motion of the DS to the specific timing and amount required to alleviate motion sickness. However, the timing and extent of the VOR has yet to be accurately identified. This paper describes how the eye movement of the driver was used to measure the positional deviation between the gaze of the driver and images caused by unnecessary VOR.
Technical Paper
2014-04-01
William R. Bussone, Michael Prange
Abstract Few studies have investigated pediatric head injury mechanics with subjects below the age of 8 years. This paper presents non-injurious head accelerations during various activities for young children (2 to 7 years old). Eight males and five females aged 2-7 years old were equipped with a head sensor package and head kinematics were measured while performing a series of playground-type activities. The maximum peak resultant accelerations were 29.5 G and 2745 rad/s2. The range of peak accelerations was 2.7 G to 29.5 G. The range of peak angular velocities was 4.2 rad/s to 22.4 rad/s. The range of peak angular accelerations was 174 rad/s2 to 2745 rad/s2. Mean peak resultant values across all participants and activities were 13.8 G (range 2.4 G to 13.8 G), 12.8 rad/s (range 4.0 rad/s to 12.8 rad/s), and 1375 rad/s2 (range 105 rad/s2 to 1375 rad/s2) for linear acceleration, angular velocity, and angular acceleration, respectively. The peak accelerations measured in this study were similar to older children performing similar tasks.
Technical Paper
2014-04-01
Lisa P. Gwin, Herbert Guzman, Enrique Bonugli, William Scott, Mark Freund
Abstract There is a paucity of recent data quantifying the injury risk of forces and accelerations that act on the whole body in a back-to-front direction. The purpose of this study was to quantify the level of back-to-front accelerations that volunteers felt were tolerable and non-injurious. Instrumented volunteers were dropped supine onto a mattress, and their accelerations during the impact with the mattress were measured. Accelerometers were located on the head, upper thoracic and lower lumbar regions. Drop heights started at 0.6 m (2 ft) and progressed upward as high as 1.8 m (6 ft) based on the test subjects' consent. The test panel was comprised of male and female subjects whose ages ranged from 25 to 63 years of age and whose masses ranged from 62 to 130 kg (136 to 286 lb). Peak head, upper thoracic and lower lumbar accelerations of 25.9 g, 29.4 g and 39.6 g were measured. There was considerable restitution in the impacts with the mattress and the test subjects experienced changes in velocity (ΔVs) of 5.2-11.4 m/s (11.6-25.5 mph).
Technical Paper
2014-04-01
Chinmoy Pal, Tomosaburo Okabe, Kulothungan Vimalathithan, Muthukumar Muthanandam, Jeyabharath Manoharan, Satheesh Narayanan
Abstract A comprehensive analysis was performed to evaluate the effect of BMI on different body region injuries for side impact. The accident data for this study was taken from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS). It was found that the mean BMI values for driver and front passengers increases over the years in the US. To study the effect of BMI, the range was divided into three groups: Thin (BMI<21), Normal (BMI 24-27) and Obese (BMI>30). Other important variables considered for this study were model year (MY1995-99 for old vehicles & MY2000-08 for newer vehicles), impact location (side-front F, side-center P & side-distributed Y) and direction of force (8-10 o'clock for nearside & 2-4 o'clock for far-side). Accident cases involving older occupants above 60 years was omitted in order to minimize the bone strength depreciation effect. Results of the present study indicated that the Model Year has influence on lower extremity injuries. Occurrence of pelvis injury was found to be influenced by BMI and was validated with logistic regression analysis.
Viewing 1 to 30 of 3990