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2014-09-30
Technical Paper
2014-01-2383
Takahiko Yoshino, Hiromichi Nozaki
Abstract In recent years, the conversion of vehicles to electric power has been accelerating, and if a full conversion to electric power is achieved, further advancements in vehicle kinematic control technology are expected. Therefore, it is thought that kinematic performance in the critical cornering range could be further improved by significantly controlling not only the steering angle but also the camber angle of the tires through the use of electromagnetic actuators. This research focused on a method of ground negative camber angle control that is proportional to the steering angle as a technique to improve maneuverability and stability to support the new era of electric vehicles, and the effectiveness thereof was clarified. As a result, it was found that in the critical cornering range as well, camber angle control can control both the yaw moment and lateral acceleration at the turning limit. It was also confirmed that both stability and the steering effect in the critical cornering range are improved by implementing ground negative camber angle control that is proportional to the steering angle using actuators.
2014-09-30
Technical Paper
2014-01-2405
Jiaqi Xu, Bradley Thompson, Hwan-Sik Yoon
Abstract Hydraulic excavators perform numerous tasks in the construction and mining industry. Although ground grading is a common task, proper grading cannot easily be achieved. Grading requires an experienced operator to control the boom, arm, and bucket cylinders in a rapid and coordinated manner. Due to this reason, automated grade control is being considered as an effective alternative to conventional human-operated ground grading. In this paper, a path-planning method based on a 2D kinematic model and inverse kinematics is used to determine the desired trajectory of an excavator's boom, arm, and bucket cylinders. Then, the developed path planning method and PI control algorithms for the three cylinders are verified by a simple excavator model developed in Simulink®. The simulation results show that the automated grade control algorithm can grade level or with reduced operation time and error.
2014-04-01
Technical Paper
2014-01-0522
Chinmoy Pal, Tomosaburo Okabe, Kulothungan Vimalathithan, Jeyabharath Manoharan, Muthukumar Muthanandam, Satheesh Narayanan
Abstract A logistic regression analysis of accident cases in the NASS-PCDS (National Automotive Sampling System-Pedestrian Crash Data Study) database clearly shows that pedestrian pelvis injuries tend to be complex and depend on various factors such as the impact speed, the ratio of the pedestrian height to that of the bonnet leading edge (BLE) of the striking vehicle, and the gender and age of the pedestrian. Adult female models (50th %ile female AF50: 161 cm and 61 kg; 5th %ile female AF05: 154 cm and 50 kg) were developed by morphing the JAMA 50th %ile male AM50 and substituting the pelvis of the GHBMC AM50 model. The fine-meshed pelvis model thus obtained is capable of predicting pelvis fractures. Simulations conducted with these models indicate that the characteristics of pelvis injury patterns in male and female pedestrians are influenced by the hip/BLE height ratio and to some extent by the pelvis bone shape. A previously developed six-year-old (6YO) child pedestrian model and the newly developed models were used to estimate the head impact time (HIT) for a typical SUV fitted with an active pop-up hood system.
2014-04-01
Technical Paper
2014-01-0493
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.
2014-04-01
Technical Paper
2014-01-0527
William N. Newberry, Stacy Imler, Michael Carhart, Alan Dibb, Karen Balavich, Jeffrey Croteau, Eddie Cooper
Abstract It is well known from field accident studies and crash testing that seatbelts provide considerable benefit to occupants in rollover crashes; however, a small fraction of belted occupants still sustain serious and severe neck injuries. The mechanism of these neck injuries is generated by torso augmentation (diving), where the head becomes constrained while the torso continues to move toward the constrained head causing injurious compressive neck loading. This type of neck loading can occur in belted occupants when the head is in contact with, or in close proximity to, the roof interior when the inverted vehicle impacts the ground. Consequently, understanding the nature and extent of head excursion has long been an objective of researchers studying the behavior of occupants in rollovers. In evaluating rollover occupant protection system performance, various studies have recognized and demonstrated the upward and outward excursion of belted occupants that occurs during the airborne phase of a rollover, as well as excursion from vehicle-to-ground impacts.
2014-04-01
Technical Paper
2014-01-0514
Hiroyuki Asanuma, Yukou Takahashi, Miwako Ikeda, Toshiyuki Yanaoka
Abstract Japanese accident statistics show that despite the decreasing trend of the overall traffic fatalities, more than 1,000 pedestrians are still killed annually in Japan. One way to develop further understanding of real-world pedestrian accidents is to reconstruct a variety of accident scenarios dynamically using computational models. Some of the past studies done by the authors' group have used a simplified vehicle model to investigate pedestrian lower limb injuries. However, loadings to the upper body also need to be reproduced to predict damage to the full body of a pedestrian. As a step toward this goal, this study aimed to develop a simplified vehicle model capable of reproducing pedestrian full-body kinematics and pelvis and lower limb injury measures. The simplified vehicle model was comprised of four parts: windshield, hood, bumper and lower part of the bumper. Several different models were developed using different combinations of geometric and stiffness representation. A unique model called a multi-layer model developed in this study represented each of the hood and the windshield with a stack of the panel representing the entire area of these components, while applying localized stiffness characteristics and contact definition with a particular pedestrian body region that contacts with the layer represented by the stiffness characteristics.
2014-04-01
Technical Paper
2014-01-0484
Bryan Randles, Daniel Voss, Isaac Ikram, Christopher Furbish, Judson Welcher, Thomas Szabo
Determination of vehicle speed at the time of impact is frequently an important factor in accident reconstruction. In many cases some evidence may indicate that the brake pedal of a striking vehicle was disengaged, and the vehicle was permitted to idle forward prior to impacting the target vehicle. This study was undertaken to analyze the kinematic response of various vehicles equipped with automatic transmissions while idling, with the transmissions in drive and the brake pedals disengaged. An array of sedans, SUV's and pickup trucks were tested under 3 roadway conditions (flat, medium slope and high slope). The vehicle responses are reported and mathematical relationships were developed to model the idle velocity profiles for flat and sloped roadway surfaces.
2014-04-01
Technical Paper
2014-01-0086
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.
2013-12-20
Technical Paper
2013-01-9003
Gaurav Bindal, Sparsh Sharma, Frank Janser, Eugen Neu
Body motions of flying animals can be very complex, especially when the body parts are greatly flexible and they interact with the surrounding fluid. The wing kinematics of an animal flight is governed by a large number of variables and thus the measurement of complete flapping flight is not so simple, making it very complex to understand the contribution of each parameter to the performance and hence, to decide the important parameters for constructing the kinematic model of a bat is nearly impossible. In this paper, the influence of each parameter is uncovered and the variables that a specified reconstruction of bat flight should include in order to maximally reconstruct actual dimensional complexity, have been presented in detail. The effects of the different kinematic parameters on the lift coefficient are being resulted. The computation analysis of the lift coefficient for different camber thicknesses and various wing areas is done by unsteady thin airfoil theory and vortex lattice method, respectively.
2013-04-08
Technical Paper
2013-01-1242
Yasuhiro Dokko, Toshiyuki Yanaoka, Kazuki Ohashi
Corresponding to the increasing need for the protection of elderly people from traffic accidents, the authors have been developing age-specific human FE models capable of predicting body kinematics and skeletal injuries for younger adult (35y.o.) and the elderly (75y.o.). The models have been developed and validated part by part referring to the literature and then integrated into whole bodies. Validation had been conducted in order of single bones, components and whole body. Whole body kinematics in frontal impact had been validated against the PMHS frontal belt restrained sled tests series, resulting in good biofidelity scores. In this study, the models were validated for lateral impact. The models were validated against several impact tests of body regions from ISO-TR9790 and against recently published full scale lateral sled tests for whole body kinematics. In most cases, the results showed good biofidelity of the models. Capability of the rib fracture prediction was also discussed.
2013-04-08
Technical Paper
2013-01-0215
Yoshiko Kawabe, Chinmoy Pal, Hiroyuki Okuyama, Tomosaburo Okabe
The Flexible Pedestrian Legform Impactor (Flex-PLI) was developed to evaluate the risk of pedestrian lower extremity injuries. However, it has been pointed out that the post-crash kinematics of the Flex-PLI differs from those of a human body when it is hit by high-bumper vehicles. This paper describes the feasibility of applying the Flex-PLI to a wide range of vehicle types by adding a supplemental weight. The following aspects are discussed in this regard: A human body finite element (FE) model analysis shows that the upper body of the Flex-PLI is not involved in tibia and knee ligament injury indexes in the first contact with a high-bumper vehicle. A rigid bar model is introduced and its rotational energy ratio is formulated. The rotational energy ratio is employed to evaluate the post-crash kinematics of the Flex-PLI and a human leg model. The feasibility of adding a supplemental weight to the Flex-PLI with regard to the bumper height is discussed.
2013-04-08
Technical Paper
2013-01-0216
Bingbing Nie, Yong Xia, Qing Zhou, Jun Huang, Bing Deng, Mark Neal
This study concerns the generation of response surfaces for kinematics and injury prediction in pedestrian impact simulations using human body model. A 1000-case DOE (Design of Experiments) study with a Latin Hypercube sampling scheme is conducted using a finite element pedestrian human body model and a simplified parametric vehicle front-end model. The Kriging method is taken as the approach to construct global approximations to system behavior based on results calculated at various points in the design space. Using the response surface models, human lower limb kinematics and injuries, including impact posture, lateral bending angle, ligament elongation and bone fractures, can be quickly assessed when either the structural dimensions or the structural behavior of the vehicle front-end design change. This will aid in vehicle front-end design to enhance protection of pedestrian lower limbs.
2013-04-08
Technical Paper
2013-01-0599
Kazuya Iwata, Kaoru Tatsu, Hidetsugu Saeki, Tomosaburo Okabe
A new highly biofidelic side impact dummy, the WorldSID 50th percentile male, has been developed under the supervision of the International Organization for Standardization in order to harmonize a number of existing side impact dummies in one single dummy. Momentum is growing for using the WorldSID in safety tests in the EU and the US. In the present study, two Euro-NCAP pole side impact tests were conducted to compare ES-2 and WorldSID responses in a mid-size SUV with respective seating positions as stipulated in the Euro-NCAP test conditions and fitted with the same side airbag. It was found that, compared with ES-2, the chest, abdomen and pelvis accelerations of WorldSID are more sensitive to variation in the applied external load transmitted by the deployed side airbag and door intrusion.
2013-04-08
Technical Paper
2013-01-0683
Scott Zagorski, Dennis A. Guenther, Gary J. Heydinger
This paper presents a feedback linearization control technique as applied to a Roll Simulator. The purpose of the Roll Simulator is to reproduce in-field rollovers of ROVs and study occupant kinematics in a laboratory setting. For a system with known parameters, non-linear dynamics and trajectories, the feedback linearization algorithm cancels out the non-linearities such that the closed-loop dynamics behave in a linear fashion. The control inputs are computed values that are needed to attain certain desired motions. The computed values are a form of inverse dynamics or feed-forward calculation. With increasing system eigenvalue, the controller exhibits greater response time. This, however, puts a greater demand on the translational actuator. The controller also demonstrates that it is able to compensate for and reject a disturbance in force level. The feedback linearization controller demonstrates that with the limitation of the current actuators and track length removed, the simulator could reproduce the motions for an entire rollover maneuver.
2012-10-05
Standard
J1574/1_201210
The parameters measured according to this SAE Recommended Practice will generally be used in simulating directional control performance in the linear range. (The “linear range” is the steady-state lateral acceleration below which steering wheel angle can generally be considered to be linearly related to lateral acceleration.) But they may be used for certain other simulations (such as primary ride motions), vehicle and suspension characterization and comparison, suspension development and optimization, and processing of road test data. This document is intended to apply to passenger cars, light trucks, and on-highway recreational and commercial vehicles, both non-articulated and articulated. Measurement techniques are intended to apply to these vehicles, with alterations primarily in the scale of facilities required. But some differences do exist between passenger cars and trucks, especially heavy trucks, such as differences in body/frame flexibility, suspension stiffness, and suspension friction.
2012-05-11
Standard
J1460/1_201205
This series of reports provides response characteristics of the head, face, neck, shoulder, thorax, lumbar spine, abdomen, pelvis, and lower extremities. In each report, the descriptions of human impact response are based on data judged by the subcommittee to provide the most appropriate information for the development of human surrogates.
2012-04-16
Technical Paper
2012-01-0570
Mark S. Erickson
Dynamic simulation is routinely used to analyze the occupant response to motor vehicle impact. That said, while commercially-available models have been subjected to numerous high-severity level validation studies, little attention has been given to lower severity crashes. While high severity crashes typically result in more severe injury, the vast numbers of lower severity “fender bender” type crashes and the ensuing high medical costs warrant study related to biomechanics and vehicle design. The scope of this study is directed at addressing the validity of these models for analyzing occupant response to collinear rear impact involving delta-V less than 5 mph. As part of this study, a series of five vehicle-to-vehicle collisions with instrumented volunteer occupants were performed with closing speeds of 1.1, 1.9, 2.9, 4.0 and 5.1 mph. These impacts produced delta-V, for the target vehicle, of 0.6, 1.8, 2.5, 3.1 and 3.2 mph, respectively. The measured response of the volunteer kinematics was compared with GATB simulation.
2012-04-16
Technical Paper
2012-01-0565
Yuichi Ito, Yasuhiro Dokko, Yasuki Motozawa, Fumie Mori, Kazuki Ohashi
Recently, the global increase of elderly vehicle users has become an issue to be considered in the effort of enhancing safety performance of vehicle restraint system. It is thought that an evaluation tool for the system representing properties of age-specific human body will play a major role for that. In previous research, the authors had developed age-specific component finite element (FE) models for the lower limb, lumbar spine, and thorax representing the adult and elderly occupants. However, the models have not been validated in terms of full body kinematics. It is essential for such models to be validated in terms of full body kinematics in order to ensure validity of the results of the assessment of the safety performance of restraint systems. In the present research, the adult and elderly occupant full body FE models were developed by incorporating the lower limb, lumbar spine and thorax of the adult and elderly FE models established in previous research. To represent the kinematics of the shoulder of the adult occupant model, the shoulder girdle muscles were modeled and incorporated into the models.
2012-04-16
Technical Paper
2012-01-0080
Takashi Deguchi, Akira Yamaguchi, Kaoru Tatsu, Tomosaburo Okabe
Occupant protection performance in frontal crashes has been developed and assessed for mainly front seat occupants over many years, and in recent years protection of rear seat occupants has also been extensively discussed. Unlike the front seats, the rear seats are often occupied by children seated in rear- facing or forward - facing child restraint systems, or booster seats. In the European New Car Assessment Program (NCAP), child occupant protection assessments using 18-month-old and 3-year-old test dummies in the rear seat are already being conducted. In addition, studies are under way concerning the development and introduction of test dummies of 6-year-old (6YO) and 10.5-year-old children. In this study, we focused on 6-year-old children sitting in belt-positioning booster seats. Offset frontal crash tests were conducted using two types of test dummies, a Hybrid III 6YO and a 6YO Q-series dummy (Q6), positioned in the rear seat. The Hybrid III 6YO and Q6 were used to compare dummy kinematics in rear seating positions between (a) behind the driver's seat and (b) the front passenger's seat.
2012-04-16
Technical Paper
2012-01-0096
William Newberry, Michael Carhart, Robert Larson, Amanda Bridges, Graeme Fowler
Recently, side-by-side Recreational Off-Highway Vehicles (ROVs) have brought elements of the on-road vehicle occupant environment to the off-road trail-riding world. In general, ROV occupant protection during normal operation and in accident scenarios is provided predominately by a roll cage, seatbelts, contoured seats with seat backs, handholds, and other components. Typical occupant responses include both passive (inertial) and active (muscular) components. The objective of the current study was to evaluate and quantify these passive and active occupant responses during belted operation of an ROV on a closed course, as well as during 90-degree tip-over events. Passive occupant responses were evaluated using anthropomorphic test devices (ATDs) in 90-degree tip-overs simulated on a deceleration sled. Active occupant responses were evaluated using instrumented vehicles and volunteer occupants, wherein vehicle dynamics and gross occupant kinematics, muscle activity, occupant-to-vehicle pressure distributions and forces were quantified during riding on a closed course and during 90-degree tip-overs in a roll-spit fixture.
2012-04-16
Technical Paper
2012-01-0271
Yoshiko Kawabe, Toshiyuki Asai, Daisuke Murakami, Chinmoy Pal, Tomosaburo Okabe
Pedestrian crashes are the most frequent cause of traffic-related fatalities worldwide. The high number of pedestrian accidents justifies more active research work on passive and active safety technology intended to mitigate pedestrian injuries. Post-impact pedestrian kinematics is complex and depends on various factors such as impact speed, height of the pedestrian, front-end profile of the striking vehicle and pedestrian posture, among others. The aim of this study is to investigate the main factors that determine post-crash pedestrian kinematics. The injury mechanism is also discussed. A detailed study of NASS-PCDS (National Automotive Sampling System - Pedestrian Crash Data Study, US, 1994-1998), showed that the vehicle-pedestrian interaction in frontal crashes can be categorized into four types: “Thrown forward”, “Wrapped position”, “Slid to windshield” and “Passed over vehicle”. A Principal Component Analysis (PCA) was performed and 11 independent factors were identified for study from a set of 26 variables, as defined in NASS-PCDS.
2012-04-16
Technical Paper
2012-01-0277
Yukou Takahashi, Fumio Matsuoka, Hiroyuki Okuyama, Iwao Imaizumi
The goal of this study was to develop injury probability functions for the leg bending moment and MCL (Medial Collateral Ligament) elongation of the Flexible Pedestrian Legform Impactor (Flex-PLI) based on human response data available from the literature. Data for the leg bending moment at fracture in dynamic 3-point bending were geometrically scaled to an average male using the standard lengths obtained from the anthropometric study, based on which the dimensions of the Flex-PLI were determined. Both male and female data were included since there was no statistically significant difference in bone material property. Since the data included both right censored and uncensored data, the Weibull Survival Model was used to develop a human leg fracture probability function. As for the MCL failure, since one of the two data sources does not provide tabulated data, two MCL failure probability functions as a function of the knee bending angle developed using the Weibull Survival Model were averaged over the knee bending angle.
2012-04-16
Technical Paper
2012-01-0575
Dale E. Halloway, Frank Pintar, James Saunders, Aida Barsan-Anelli
The purpose of the study was to distinguish the role of vehicle structure in frontal impacts in published coded National Automotive Sampling System (NASS-CDS) data. The criteria used: Collision Deformation Classification (CDC) coding rules, crush profile locator data and the projected location of longitudinal structural members in models of vehicle class sizes used by NASS-CDS. Two classifiers were developed to augment the CDC system. The Coincidence classifier indicates the relationship between the quadrant of the clock face the crash vector originates in and the aspect of the end plane the center of damage is located. It has three values: Linear (12 o'clock impacts) Consistent and Variant ("oblique" Principal Directions of Force or PDOFs). The second classifier indicates the number of longitudinal members engaged: 0, 1 or 2. NASS-CDS data for sample years 2005 to 2009 was filtered for occupants involved in impacts with the highest ranked speed change assigned to the front-end plane.
2011-11-07
Technical Paper
2011-22-0002
Yan Li, Liying Zhang, Srinivasu Kallakuri, Runzhou Zhou, John M. Cavanaugh
A modified Marmarou impact acceleration injury model was developed to study the kinematics of the rat head to quantify traumatic axonal injury (TAI) in the corpus callosum (CC) and brainstem pyramidal tract (Py), to determine injury predictors and to establish injury thresholds for severe TAI. Thirty-one anesthetized male Sprague-Dawley rats (392 ± 13 grams) were impacted using a modified impact acceleration injury device from 2.25 m and 1.25 m heights. Beta-amyloid precursor protein (β-APP) immunocytochemistry was used to assess and quantify axonal changes in CC and Py. Over 600 injury maps in CC and Py were constructed in the 31 impacted rats. TAI distribution along the rostro-caudal direction in CC and Py was determined. Linear and angular responses of the rat head were monitored and measured in vivo with an attached accelerometer and angular rate sensor, and were correlated to TAI data. Logistic regression analysis suggested that the occurrence of severe TAI in CC was best predicted by average linear acceleration, followed by power and time to surface righting.
2011-10-06
Technical Paper
2011-28-0113
Parveen Kumar Sharma, Ravi Kiran Cheni, B. Sriram
Estimation by World health organization reveals that by 2020, road traffic injuries may be the third leading contributor for the cause of death with significant proportion of pedestrian causalities [9]. Pedestrian safety was not considered essential for vehicle design for developing countries, due to the vehicle manufacturer's reluctance to invest in area not governed by legislation, unavailability of new car assessment programs. However, as regulatory norms are turning out to be more stringent with increased competition of NCAP star ratings, advancements in vehicle research, significant progress in this field of safety is being made without compromising on contradictory fields like vehicle low speed insurance, stiffness etc. This paper provides an insight into the recent findings at MARUTI SUZUKI INDIA'S R&D centre, aimed at improving the lower leg pedestrian performance in the new model design with special attention to NCAP ratings. Understanding of leg impact kinematics and Identification of the potential areas in the front fascia styling is the first step in reducing the vehicle aggressiveness to a pedestrian.
2011-04-12
Technical Paper
2011-01-0270
Leigh Berger, Lisa Fallon, Michael G. Carpenter
This study documents a method developed for dynamically measuring occupant pocketing during various low-speed rear impact, or “whiplash” sled tests. This dynamic pocketing measurement can then be related to the various test parameters used to establish the performance rating or compliance results. Consumer metric and regulatory tests discussed within this paper as potential applications of this technique include, but are not limited to, the Insurance Institute for Highway Safety (IIHS) Low Speed Rear Impact (LSRI) rating, Federal Motor Vehicle Safety Standard (FMVSS) 202a, and European New Car Assessment Program (EURO-NCAP) whiplash rating. Example metrics are also described which may be used to assist in establishing the design position of the head restraint and optimize the balance between low-speed rear impact performance and customer comfort. This paper builds upon the results of a Design for Six Sigma (DFSS) project optimizing seat parameters influencing low-speed rear impact performance using an application of Principle Component Analysis (PCA).
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