Browse Topic: Crash research

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An Uncertainty Propagation Approach to Collective Bounce Rotorcraft-Pilot Couplings AnalysisF-0080-2024-13215/7/2024
In the context of Rotorcraft Pilot Couplings, the biomechanics of the pilot body play a fundamental role in determining the stability of the pilot-vehicle closed loop system. The response of the pilot body is, in turn, inherently stochastic, being a function of pilot biometrics and muscular activation. Coupling the statistical distribution of pilot biomechanical behavior determined in specialized experimental campaign with linear models of the helicopter heave dynamics, an uncertainty propagation procedure is developed, with the aim of estimating the statistical distribution of the stability margins of the closed loop pilot-vehicle system. Results obtained varying the collective lever characteristics, as well as the helicopter model parameters, align well with results obtained previously in deterministic settings. However, the new scheme allows to define quantitative robustness indices.
Zanoni, Andrea, Masarati, Pierangelo, Colombo, Francesca, Zilletti, Michele, Marchesoli, Davide, Talamo, Carmen, Cassoni, Gianni
Pilot Biomechanics for the Definition of a Rotorcraft-Pilot Interaction ExperimentF-0078-2022-175205/10/2022
ABSTRACT
Colombo, Francesca, Kemp, Sarah, Fosco, Ermanno, Zanoni, Andrea, Cocco,  Alessandro, Marchesoli,  Davide, Masarati,  Pierangelo, Talamo, Carmen
Development of a Subhuman Primate Brain Finite Element Model to Investigate Brain Injury Thresholds Induced by Head Rotation2019-22-00033/31/2020
An anatomically detailed rhesus monkey brain FE model was developed to simulate in vivo responses of the brain of sub-human primates subjected to rotational accelerations resulting in diffuse axonal injury (DAI). The material properties used in the monkey model are those in the GHBMC 50th percentile male head model (Global Human Body Model Consortium). The angular loading simulations consisted of coronal, oblique and sagittal plane rotations with the center of rotation in neck to duplicate experimental conditions. Maximum principal strain (MPS) and Cumulative strain damage measure (CSDM) were analyzed for various white matter structures such as the cerebrum subcortical white matter, corpus callosum and brainstem. The MPS in coronal rotation were 45% to 54% higher in the brainstem, 8% to 48% higher in the corpus callosum, 13% to 22% higher in the white matter when compared to those in oblique and sagittal rotations, suggesting that more severe DAI was expected from coronal and oblique rotations as compared to that from sagittal rotation. The level 1+ DAI was associated with 1.3 to 1.42 MPS and 50% CSDM (0.5) responses in the brainstem, corpus callosum and cerebral white matter. The mass scaling method, sometimes referred to as Holbourn's inverse 2/3 power law, used for development of human brain injury criterion was evaluated to understand the effect of geometrical and anatomical differences between human and animal head. Based on simulations conducted with the animal and human models in three different planes - sagittal, coronal and horizontal - the scaling from animal to human models are not supported due to lack of geometrical similitude between the animal and human brains. Thus, the scaling method used in the development of brain injury criterion for rotational acceleration/velocity is unreliable.
Arora, Tushar, Zhang, Liying, Prasad, Priya
Optimization of Braking Strategy for Automatic Emergency Braking System in Vehicle-Pedestrian Accidents07-12-02-00093/23/2020
Braking strategy is the core of the automatic emergency braking (AEB) system. How to make the braking strategy of the AEB system more suitable for real traffic conditions and more acceptable to drivers is a very important research. This article carries out the braking strategy optimization for the AEB system. From the vehicle-pedestrian accidents collected by the National Automobile Accident In-depth Investigation System (NAIS) of Songjiang Station, this article selects typical cases equipped with event data recorder (EDR) and then analyzes the EDR data. On this basis, the strategy for the optimization of the AEB system is formed. The optimized strategy is simulated in the test scenario specified in the European New Car Assessment Programme (Euro-NCAP) and compared with the real vehicle test results. The result illustrates that the optimized braking strategy is more effective to avoid or mitigate collisions.
Qian, Yubin, Yang, Xueyan, Xiao, Lingyun, Zhu, Yican
Bio-Inspired Mechanics to Make Robots More EffectiveTBMG-361913/1/2020
In an effort to make robots more effective and versatile teammates for soldiers in combat, researchers are looking to understand the value of the molecular living functionality of muscle and the fundamental mechanics that would need to be replicated in order to artificially achieve the capabilities arising from the proteins responsible for muscle contraction.
Influence Analysis of AEB Two-Wheeler on Passenger Car Impact Two-Wheeler Traffic Accidents in China2020-01-50232/24/2020
AEB two-wheeler system is an active safety technology which developed for avoiding two-wheeler accidents. With a large number of two wheelers, China needs to conduct research and analysis of this system. In this paper, real traffic accident data in China are used to analyze the possible influence of AEB two-wheeler system on traffic accidents. The paper chooses real passenger car impact two wheeler accidents happen in China, and gets the characteristics of data analysis. Then the paper analysis the influence of AEB system using position data when TTC=3s. According to the analysis, the detection range of 90 meters and the detection angle of 45 degrees can improve the recognition rate of day crossing accident by 17.7%, night crossing accident by 21.5% and longitudinal accident by 38.8%. The paper provides effective support for the development and test of AEB two-wheeler system in China. Car-to-two-wheeler accident AEB two-wheeler system Influence of the accident
Xudong, Li, Xiaowei, Lian, Xingchang, Wang
Pedestrian Collision Avoidance System for Autonomous Vehicles12-02-04-002112/18/2019
Advanced driver assistance systems (ADAS) are state of the art in modern vehicles (SAE level 1-2). They support the driver and improve thereby the vehicle safety during manual driving. In critical situations, collision avoidance systems warn the driver or trigger an autonomous emergency braking maneuver to mitigate or avoid a collision. Also, automated driving vehicles (SAE level 3+) must be able to avoid critical situations and must be more capable than currently available systems. During automated driving, the vehicle is responsible for the driving task instead of the driver. Therefore, safe automated driving requires robust algorithms to avoid collisions with other traffic participants in every situation, especially in critical situations with pedestrians and a limited perception ability. In this work, we investigate how automated driving vehicles can handle critical situations with pedestrians on multilane roads with an emergency braking or evasion maneuver. We focus in detail on very critical situations, where pedestrians are crossing behind an occluded area, e.g. from behind a parked car on the side of the road. In these critical situations, a collision avoidance system is not enough anymore because of the limited time-to-react. It is not acceptable that an automated driving vehicle passes obstacles very slowly. Therefore, a collision avoidance system is combined with a situation awareness planner to optimize the driving velocity. The situation awareness planner considers the sensor’s visibility and the capability of the collision avoidance system to provide a set of collision-free trajectories. This combination has the advantage that the vehicle does not need to pass objects on the side very conservative. We evaluate the approach rigorously on a set of well-defined scenarios from the Euro NCAP test protocol.
Schratter, Markus, Hartmann, Michael, Watzenig, Daniel
Harvesting Energy from the Human KneeTBMG-350979/1/2019
An energy harvester attached to the wearer’s knee can generate 1.6 μW of power while the wearer walks without any increase in effort. The energy is enough to power small electronics like health monitoring equipment.
Wearable Liquid Unit Harvests EnergyTBMG-349338/1/2019
Researchers have created wearable technology to convert mechanical energy into electrical energy. It presents a step toward the practical realization of self-powered, human-integrated technologies.
Flight Simulator Testing to Enhance Comprehension and Modeling of Rotorcraft Pilot CouplingsF-0075-2019-146435/13/2019
This work presents the results of a piloted flight simulator campaign aimed at measuring biomechanical performance indicators -- upper limbs motion and electromiography of main muscle bundles -- of pilots performing complex, realistic tasks. Ship deck landings performed by a single pilot, flying several helicopter configurations with sea conditions of increasing intensity have been considered. The analysis of the results shows an increase in muscular activity in relation with the increase in task difficulty, in agreement with subjective ratings (Bedford workload scale). The study provided useful indications to improve the corresponding biomechanical simulations, as well as to characterize pilot performance during specific tasks.
Zanoni, Andrea, Maisano, Giorgio, Frigerio, Lorenzo, Murawa, Michal, Zago, Matteo, Paolini, Rita, Quaranta, Giuseppe, Masarati, Pierangelo, Galli, Manuela
Investigation of Structural Coupling Problems in Tiltrotor AircraftF-0075-2019-145835/13/2019
The paper investigates structural coupling problems in tiltrotor aircraft. A detailed tiltrotor model, representative of the Bell XV-15, has been built. The airframe model has been modified with a thinner wing to better reveal structural coupling proneness. A linearized FCS has been introduced to analyze the overall stability on an extended frequency band, ranging from the flight mechanics up to the aeroelastic modes. In addition to the FCS, biomechanical models of the pilot, acting on the power-lever and on the center stick, are included in feedback loop. Overall stability analyses demonstrate that the FCS improves handling qualities although several structural coupling mechanisms arise, in combination with the involuntary pilot's response, reducing flutter clearance. A modified version of the XV-15, using differential collective pitch for yaw control in airplane mode, has been also investigated. This configuration reduces costs and weights although the FCS destabilizes the antisymmetric wing chord mode at low speed flight, severely limiting the flight envelope. Means of prevention, based on notch filters, are implemented and discussed.
Muscarello, Vincenzo
Analysis of Rear Seat Sled Tests with the 5th Female Hybrid III: Incorrect Conclusions in Bidez et al. SAE 2005-01-17082019-01-06184/2/2019
Objective: Sled test video and data were independently analyzed to assess the validity of statements and conclusions reported in Bidez et al. SAE paper 2005-01-1708 [7]. Method: An independent review and analysis of the test data and video was conducted for 9 sled tests at 35 km/h (21.5 mph). The 5th female Hybrid III was lap-shoulder belted in the 2nd or 3rd row seat of a SUV buck. For one series, the angle was varied from 0, 15, 30, 45 and 60 deg PDOF. The second series involved shoulder belt pretensioning and other belt modifications. Results: Bidez et al. [7] claimed “The lap belts moved up and over the pelvis of the small female dummy for all impact angles tested.” We found that there was no submarining in any of the tests with the production lap-shoulder belts. Bidez et al. [7] claimed “H3-5F dummies began to roll out of their shoulder belt at… 30 degrees. Complete loss of torso support was seen at 45 degrees without significant kinetic energy dissipation.” We found that the shoulder belt remained in place and restrained the upper torso in the 0, 15 and 30 deg sled tests. At 45 and 60 deg, significant restraint was provided before the belt slipped off the shoulder. It remained in contact with the arm and chest providing restraint. Bidez et al. [7] claimed “The results indicated kinematic movement of the dummies, which were predictive of injury in all sled runs.” We found that the kinematic control was good and the biomechanical responses were well below IARVs for the 5th female Hybrid III. Bidez et al. [7] claimed “a retractor pretensioner (7 ms fire time) eliminated both submarining and torso rollout in the H3-5F in the conditions tested.” We found that the pretensioner firing pulled the lap belt up onto the abdomen inducing submarining and causing abdominal loading in two out of four tests. Conclusion: The independent review of the videos and data shows that Bidez et al. [7] misstated the results, misrepresented the findings and reached incorrect conclusions on the testing.
Viano, David, Parenteau, Chantal
Residual Injury Situation and Accident Characteristics of Severe Motorcycle Accidents2019-01-06384/2/2019
The total number of persons severely and fatally injured in road traffic accidents has reduced considerably in recent decades. However, the number of motorcyclists involved in accidents has not reduced to the same extent, and some countries have even recorded an increase. The aim of this study is to analyse the circumstances of motorcycle accidents in Germany involving vehicles with a cubic capacity of over 125 cm3 with particular reference to severely or fatally injured riders. An analysis is to be made of the characteristics and patterns of injuries suffered by the most severely injured motorcyclists and proposals developed for injury prevention. The study included accident data from 464 motorcycle accidents collected in Hanover and Dresden between 2010 and 2015 by an academic research team in the course of the GIDAS project (German In-Depth Accident Study). This data represents a statistically representative sample from real accidents occurring in Germany. The analysis of the current injury situation shows that motorcyclists are often severely injured, i.e. suffered injuries of grade MAIS 3+ (so called serious injuries) in 16.9% of cases and thus around 9 times more frequently than car occupants. Motorcyclists wearing helmets suffered head injuries in approx. 20 % of cases. The serious injuries sustained were in particular skull fractures, including base of the skull and traumatic brain injuries are rare. Severe thoracic injuries included in particular rib and shoulder/clavicle fractures, often accompanied by injuries to internal organs. In terms of spinal injuries, the most common serious injuries were fractures of the thoracic spine, followed by fractures of the lumbar spine and cervical spine. In the abdominal area there were often severe injuries in the form of fractures in the pelvic area and accompanying injuries to internal organs. Arm injuries included, besides minor injuries (grazes, bruises, etc.), most commonly fractures of the hands/fingers and forearms, followed by elbow and upper arm fractures. Leg injuries seen in particular were femoral fractures as well as injuries to the muscles and tendons around the knee, also fractures of the shin and calf bones. Around the feet there were many fractures and dislocations of the wrist and ankle joints, as well as toes. The causes of the injuries, which were recorded in detail in the study for the various regions of the body and individual injuries, were most often caused by impact with the road and collision with objects and solid vehicle structural elements of cars and trucks. Serious injuries are linked with high energy respectively high relative impact speed.
Otte, Dietmar
Thoracic Spine Extension Injuries in Occupants with Pre-Existing Conditions during Rear-End Collisions2019-01-12224/2/2019
Certain ankylosing spondyloarthropathies such as ankylosing spondylitis (AS) or diffuse idiopathic skeletal hyperostosis (DISH) can substantially alter clinicopathologic spine biomechanics as well as injury mechanisms in rear-end motor vehicle collisions. AS is an inflammatory disease which can lead to structural impairments of the spine secondary to flowing ossification along the spinal column, including ossification across the spinal discs, facet joints, and ligaments, and it has also been associated with diffuse osteoporosis of the spine. DISH is characterized by excess bone formation along the spinal column, encompassing the annulus and forming the thickest and strongest bridging osteophytes over adjacent vertebral bodies at the level of the disc space. In both conditions the spine is mechanically stiffened and generally more kyphotic than a healthy spine. This paper presents a series of case studies in which a front-seat occupant with ankylosing spondyloarthropathy experienced a moderate- or high-speed rear-end collision and sustained a thoracic spine fracture/dislocation, often with spinal cord injuries. Forward acceleration of the occupant by the seat back in each case resulted in straightening of the kyphotic thoracic spine and consequent extension fractures of the pathologically stiff and brittle thoracic spine. This paper illustrates the predisposition of thoracic fracture for this segment of the population with spinal pathologies such as DISH and AS in rear impacts and notes the role that seat back stiffness could play in injury mechanism for these individuals.
Davis, Mathieu, Isaacs, Jessica, Graber, Martin, Fisher, Jacob
Development of Subject-Specific Elderly Female Finite Element Models for Vehicle Safety2019-01-12244/2/2019
Previous study suggested that female, thin, obese, and older occupants had a higher risk of death and serious injury in motor vehicle crashes. Human body finite element models were a valuable tool in the study of injury biomechanics. The mesh deformation method based on radial basis function(RBF) was an attractive alternative for morphing baseline model to target models. Generally, when a complex model contained many elements and nodes, it was impossible to use all surface nodes as landmarks in RBF interpolation process, due to its prohibitive computational cost. To improve the efficiency, the current technique was to averagely select a set of nodes as landmarks from all surface nodes. In fact, the location and the number of selected landmarks had an important effect on the accuracy of mesh deformation. Hence, how to select important nodes as landmarks was a significant issue. In the paper, an efficient peak point-selection RBF mesh deformation method was used to select landmarks. The multiple peak points were selected to expand landmarks set, so as to improve the morphing quality compared with the traditional point-selection method. A human head model morphing example was used to verify the effectiveness and stability of the proposed method. Furthermore, the proposed mesh deformation methodology was also applied in a full subject-specific elderly female occupant modeling. The findings of this study demonstrated the feasibility of the proposed mesh deformation method to rapidly develop subject-specific human models in advancing occupant safety.
Dong, Wenxiang, Zhan, Zhenfei, Yin, Yunlei, Li, Junming, Wang, Qingmiao, Jin, Xin
Seat Performance and Occupant Moving Out of the Shoulder Belt in ABTS (All-Belts-to-Seat) in Rear Impacts2019-01-10314/2/2019
This study examined occupant and seat responses with ABTS (all-belts-to-seat) in rear end collisions. Some have claimed improved ABTS seat performance and retention in rear impacts than conventional seats. ABTS seats tend to have higher ultimate yield strengths than conventional yielding seats. Most ABTS seats have asymmetric seatback stiffness due to the need for additional structure on one side of the seat to support shoulder belt loads. Many designs use a single-side recliner and single stanchion that anchors the D-ring. This asymmetry results in twisting of the seatback in severe rear impacts. Seatback twist can allow the occupant to move away from the shoulder belt. Rearward pull tests on ABTS seats also demonstrates seatback twisting and in some cases large drops in load during the test. The added strength and stiffness of ABTS seats lead to designs that are vulnerable to sudden force drops from separated parts.
White, Samuel, Viano, David, Burnett, Roger
Video-Recorded “Looked-but-Failed-to-See” (LBFTS) Accidents in the Junctions of Hong Kong2018-01-50491/18/2019
To determine causation and contributory factors of “looked-but-failed-to-see” (LBFTS) junction accidents in which the driver stated that “I did not see the pedestrian,” in-depth studies of 22 such accidents which had taken place in Hong Kong were conducted. The studied crashes were all video recorded by closed-circuit television (CCTV) cameras and/or dashboard cameras. Using the video recordings, these junction accidents were reconstructed at the scenes to determine the drivers’ views of the pedestrians and the sequence of events leading up to each accident. The results of the reconstructions and the police investigations, as well as the testimony of the drivers, were analyzed to identify causation and contributing factors of each accident. Attention error/visual search strategy (41%) and misjudgments of drivers (18%) remain the dominant cause of LBFTS crashes. However, it was found that eight crashes (36%) were attributed to the physical obstructions caused by the A-pillars of the vehicles, with the obscuration of the pedestrians being the major contributory factor. This study shows that reconstructions based on video recordings can provide detailed accounts of junction accidents to determine causations and to understand the individual characteristics of each accident. It also reveals A-pillar obscuration to be a cause of such accidents, and this provides a basis for further research on the A-pillar “blind spot.”
Cheng, Yuk Ki, Tam, Cheok Ning, Tao, Chi Hang, Tsang, Cheuk Nam
Adhesive Failure Prediction in Crash Simulations2019-26-02971/9/2019
Structural adhesive is a good alternative to provide required strength at joinery of similar and dissimilar materials. Adhesive joinery plays a critical role to maintain structural integrity during vehicle crash scenario. Robust adhesive failure definitions are critical for accurate predictions of structural performance in crash Computer Aided Engineering (CAE) simulations. In this paper, structural adhesive material characterization challenges like comprehensive In-house testing and CAE correlation aspects are discussed. Considering the crash loading complexity, test plan is devised for identification of strength and failure characteristics at 0°, 45°, 75°, 90°, and Peel loading conditions. Coupon level test samples were prepared with high temperature curing of structural adhesive along with metal panels. Test fixtures were prepared to carryout testing using Instron VHS machine under quasi-static and dynamic loading. Various material models available in LSDYNA are studied and MAT169 (*MAT_ARUP_ADHESIVE) material model is selected for adhesive material characterization. Finite Element (FE) models inline to the test conditions were prepared. Sensitivity studies carried out to understand the significance of critical parameters in material model and modelling practices. Test and CAE correlation for all the test configurations are established considering quasi-static and dynamic scenarios. Methodology developed for adhesive material modelling and simulations are carried out at BIW and vehicle level using characterized adhesive material model.
Rao, Hrishikesh S., Tiwari, Sourabh, Koralla, Sivaprasad, Ghosh, Debabrata, Dey, Susanta
Predictive Estimation of Side Pole Impact Dummy Response Based on Linear Impactor SAB Performance2018-01-50186/18/2018
This article discusses steps to predictively estimate the responses of Anthropomorphic Test Device (ATD) in a side impact event, based on a Side Airbag (SAB) Force-Deformation (F-D) characteristics derived from the linear impactor test. A critical load management challenge that has been used to assess this predictive response process is the oblique pole impact test - part of the FMVSS 214 protocol. In this scenario, the ATD is assumed to have a free travel until it is stopped by the crushed and stacked up door against the rigid pole. Three critical energy management paths involved to manage the kinetic energy of the ATD at impact are assumed at the onset, namely, the door trim crush, ATD torso loading and most important efficient energy management of the SAB at a controlled force level. The SAB energy management is assumed critical and tied with the final response of the test ATD. In the study being reported, the amount of energy absorbed by the SAB and the reaction force of the SAB are used to predictively estimate the final responses of the test ATD. After robust vehicle components and systems designs for body structure, door trim, friendly interior and effective SAB to ATD coverage are achieved, results from this study show that the F-D response of the SAB is crucial and may be used to predictively estimate the final response of the test ATD. The ability to predictively estimate ATD responses via linear impactor derived SAB F-D at the component level will invariably greatly reduce SAB development time and overall side impact safety development cost. Examples of physical SAB linear impactor test results have been used to demonstrate the effectiveness of this predictive assessment tool in terms of SAB development time.
Uduma, Kalu, Purushothaman, Dipu, Wu, Jianping, Beaudet, Brian, Keshtkar, Hamid
Development of Component Level Transfer Equations of Simplified Human and ATD Occupant Models09-06-01-00056/5/2018
Safety systems have historically been evaluated with anthropomorphic test devices for research, development, or regulatory concerns. Human body models are another avenue for use in the investigation of occupant safety. In this study, transfer equations are developed to quantify the response of a human model (Global Human Body Models Consortium average male simplified model) and dummy model (Hybrid-III) in equivalent environments. Environments were selected based on certification test setups used for the Hybrid III ATD as well as a basic frontal sled environment. The tests include a head drop, neck flexion/extension, and chest and knee impacts. Furthermore, models were positioned within a simplified occupant interior for sled tests. In all, 30 matched pair simulations were run, 60 in total. Peak metrics between human and anthropomorphic test device models showed strong linear correlation in component testing however, as the complexity of the simulations increased, agreement tended to decrease. Kinematic data are also presented and they trend similarly between human and anthropomorphic test device models however they exhibit different timing and peaks. Within the range tested, the developed transfer equations can be used to estimate performance of one model if data from the other is available. Furthermore, the evaluation of risk for these equivalent impacts is provided for HIC-15, max chest deflections and femur forces aggregated across all tests. Over the range tested, equivalent impacts result in roughly equivalent risk levels with the exception of the femur, which resulted in higher forces in the Hybrid III and thus predicted higher risk.
Guleyupoglu, Berkan, Koya, Bharath, Gayzik, Francis Scott
A Comprehensive Aeroservoelastic Approach to Detect and Prevent Rotorcraft-Pilot Coupling Phenomena in TiltrotorsF-0074-2018-127535/14/2018
ABSTRACT This work investigates rotorcraft-pilot coupling phenomena in tiltrotors. A detailed tiltrotor model, representative of the Bell-Boeing XV-15, has been built. Biomechanical models of the pilot, acting on the power lever and on the centre stick, are included in feedback loop to define the Pilot-Vehicle System. Pilot-Assisted Oscillation phenomena are investigated on the overall conversion corridor using Nyquist's criterion. Pilot-in-the-loop analyses demonstrate that a critical parameter is detected in the vertical fins geometry. Due to an asymmetric flaperons deflection the wing's wake impacts on the vertical fins, producing a side force. The pulsating tail-side-force makes the fuselage to yaw and excites the asymmetric wing chord mode coupled with the lateral pilot's biomechanics, leading to a reduction, or even a loss, of stability. No unstable event is detected about the longitudinal direction. Conversely, a resonance between the pilot's biomechanics and the aircraft poorly damped symmetric wing bending mode is predicted about the vertical axis. The instability is found on the whole conversion corridor, although the source of excitation changes with reference to the nacelle angle. Means of prevention are implemented and discussed.
Colombo, Francesca, Muscarello, Vincenzo, Quaranta, Giuseppe, Masarati, Pierangelo
Considerations for ISO 26262 ASIL Hazard ClassificationJ2980_201804 (Historical)4/28/2018
This SAE Recommended Practice presents a method and example results for determining the Automotive Safety Integrity Level (ASIL) for automotive motion control electrical and electronic (E/E) systems. The ASIL determination activity is required by ISO 26262-3:2011 [1], and it is intended that the process and results herein are consistent with ISO 26262:2011 [1]. The technical focus of this document is on vehicle motion control systems. It is limited to passenger cars weighing up to 3.5 metric tons. Furthermore, the scope of this recommended practice is limited to collision-related hazards associated with motion control systems. The recommended practice focused on motion control systems since the hazards they can create generally have higher ASIL ratings, as compared to the hazards non-motion control systems can create. Because of this, the Functional Safety Committee decided to give motion control systems a higher priority and focus exclusively on them in the SAE J2980 recommended practice. ISO 26262:2011 [1] has a wider scope than SAE J2980, covering other functions and accidents (not just motion control or collisions as in SAE J2980).
Functional Safety Committee
Correlation of “Non-Zero” Speedometer Readings with EDR Data2018-01-05224/3/2018
Observations made during forensic automotive crash investigations have identified instances of non-zero, post-crash speedometer readings and created questions as to the validity of the indicated speed relative to the vehicle speed at impact. Previously published work has addressed many issues related to the reliability of non-zero, post-crash speedometer readings identified in vehicles as well as motorcycles. Much of this work established criteria that related the reliability of the post-crash needle position to the design of the stepper motor that controls the needle. Part of this criteria is related to the static torque associated with the speedometer needle shaft rotation due to outside (crash) forces. The published criteria were evaluated in staged crash tests which investigated the ability to maintain needle position under longitudinal and lateral forces after an electrical power loss. In an effort to extend the science, this paper compares non-zero, post-crash speedometer readings with event data recorder (EDR) data from twenty-one real-world crashes where both non-zero, post-crash speedometer readings and EDR data were available. Results from this study suggest a positive correlation between non-zero speedometer readings and vehicles experiencing both an electrical power loss and a single impact. However, this study also shows a negative correlation between non-zero speedometer readings and vehicles experiencing an electrical power loss and multiple impacts. Eighteen of the twenty-one vehicles had valid pre-crash EDR speeds. Of those eighteen vehicles, the speedometer position and EDR speed were within ±15% for fourteen of the vehicles. The current study also demonstrates that non-zero tachometer readings do not always improve confidence levels of non-zero speedometer readings. While the post-crash needle position may provide a good estimate of the travel speed of the vehicle at the time of power loss, there are numerous other factors which must be considered prior to accepting these readings.
Yannaccone, John R., Kinder, Robert
Estimation of Injury Risk of the Cervical Spine of Car Occupants after Emergency Braking2018-01-05414/3/2018
This study deals with the question whether or not a “braking with maximum deceleration” represents a specific physical load situation for the occupants of a car. For this purpose, a literature study was performed to determine the relevance of symptoms concerning whiplash-associated disorders (WAD) of car occupants who were involved in traffic accidents with low accident severity. Additionally, test drives with full braking cars were conducted to determine the load situation of the neck for human test persons. Dummies were used too, which were equipped with measuring components at the head and thorax to identify the effective acceleration/deceleration and to compare these values to scientific approved characteristic deceleration values and to the existing neck injury criteria. Finally, the likelihood of occurrence of symptoms in terms of a neck injury was evaluated from the medical and biomechanical point of view. The study shows that there is basically no risk for the occurrence of neck injuries and neck pain (whiplash disorders) for car occupants who experienced a full braking maneuver. This applies for the specific individual measured data of the test subjects compared to the known maximum load from the literature. But the authors of the study have to point out that special individual psychological and physiological frame conditions can lead to symptoms in terms of minor whiplash associated disorders like muscle tension symptoms.
Otte, Dietmar, Facius lng, Thorsten, Johannsen, Heiko, Hüfner, Tobias
Ground Landing Mechanisms in Vehicle-To-Pedestrian Impacts Based on Accident Video Records2018-01-10444/3/2018
Accident data have shown that the pedestrian injuries resulting from contact with the ground are serious and may even be worse than the injuries resulting from the primary contact with the vehicle. The landing mechanisms, including the pedestrian trajectory and subsequent sequential body region contacts to the ground, are the basis for understanding the ground impact injuries of pedestrians. However, the landing mechanisms of pedestrian are too complicated to be categorized via investigation of the collision information after an accident has occurred. Nowadays, pedestrian kinematics after vehicle impacts can be observed from the accident videos that have been recorded by road monitoring and driver recorders. This study was aimed at investigating the pedestrian landing mechanisms and analyzing the influencing factors. In the current study, 134 pedestrian cases (involving 136 pedestrians) were selected from the internet, and 13 types of landing mechanisms were classified according to the fall kinematics and landing posture. Our results show that pedestrians who were thrown forward and hit the ground without a clear rotational tendency (ground landing mechanism II) accounted for the highest frequency, 49.3% in all cases. The landing mechanisms of pedestrians were affected by impact velocities and kinematic trajectories during vehicle impacts. The results of this study can benefit the development of vehicle safety systems that reduce pedestrian ground impact injuries.
Li, Quan, Han, Yong, Mizuno, Koji
System and Method for Managing Autonomous Entities Through ApoptosisTBMG-287064/1/2018
This NASA innovation is a biologically inspired system management method designed to make sensor webs as well as other autonomous and autonomic systems more self-directing and self-managing. Based on the mechanisms of cell apoptosis, this method ensures safe and correct operation over time by enabling self-destruct, self-sleep, or standby actions in response to potentially harmful or compromising situations. The capabilities provided by this technology will benefit systems such as sensors, computer systems, and spacecraft.
Integrated Genomic and Proteomic Information Security ProtocolTBMG-287404/1/2018
The evolving nature of the Internet will require continual advances in authentication and confidentiality protocols. Nature provides some clues as to how this can be accomplished in a distributed manner through molecular biology. Cryptography and molecular biology share certain aspects and operations that allow for a set of unified principles to be applied to problems in either venue.
Malleable ‘Electronic Skin’ Self-Healable, RecyclableTBMG-287484/1/2018
CU Boulder researchers have developed a new type of malleable, self-healing and fully recyclable “electronic skin” that has applications ranging from robotics and prosthetic development to better biomedical devices.
OCE Aids Development of Therapies for Damaged Heart TissueTBMG-282871/24/2018
Researchers have developed a new way to capture the detailed biomechanical properties of heart tissue. The high-resolution optical technique fills an important technology gap necessary to develop and test therapies that might eventually be used to heal heart damage after a heart attack.
Association of Impact Velocity with Serious-Injury and Fatality Risks to Cyclists in Commercial Truck-Cyclist Accidents2017-22-001311/13/2017
This study aimed to clarify the relationship between truck–cyclist collision impact velocity and the serious-injury and fatality risks to cyclists, and to investigate the effects of road type and driving scenario on the frequency of cyclist fatalities due to collisions with vehicles. We used micro and macro truck–cyclist collision data from the Japanese Institute for Traffic Accident Research and Data Analysis (ITARDA) database. We classified vehicle type into five categories: heavy-duty trucks (gross vehicle weight [GVW] ≥11 × 103 kg [11 tons (t)], medium-duty trucks (5 × 103 kg [5 t] ≤ GVW < 11 × 103 kg [11 t]), light-duty trucks (GVW <5 × 103 kg [5 t]), box vans, and sedans. The fatality risk was ≤5% for light-duty trucks, box vans, and sedans at impact velocities ≤40 km/h and for medium-duty trucks at impact velocities ≤30 km/h. The fatality risk was 6% for heavy-duty trucks at impact velocities ≤10 km/h. Thus, the fatality risk appears strongly associated with vehicle class and impact velocity. The results revealed that a 10 km/h reduction in impact velocities could mitigate the severity of cyclist injuries at impact velocities ≥30 km/h for all five vehicle types. The frequency of cyclist fatalities at intersections with traffic signals involving heavy-duty trucks was significantly higher during daytime than that at nighttime. Fatalities involving vehicles making a left turn generally increased with vehicle weight. The frequency of cyclist fatalities involving vehicles making a left turn was the largest for heavy-duty trucks both during daytime (67.6%) and at nighttime (52.3%).
Matsui, Yasuhiro, Oikawa, Shoko, Sorimachi, Kazuhiro, Imanishi, Akira, Fujimura, Takeshi
Brazil's Option to Join iGLAD - International Harmonized In-Depth Accident Data2017-36-018311/7/2017
A strong local initiative in Campinas - Brazil is studying how to be more effective in the improvement of road safety in order to align to other worldwide initiatives with similar goals. This paper describes the Brazilian initiative’s approach to the challenge of being aligned with iGLAD (Initiative for the Global Harmonization of Accident Data, starting as a project in 2011 and collecting data since 2007) on the delivery of its first set of accident cases from 2016. The Brazilian source of data started as a pilot project collecting local data with the aim of extending it within the next years to a larger region. In fact, a consistent method for the development of strategies and measures to prevent accidents and mitigate injury severity comes from accident database analysis. Although databases such as national statistics are available for many countries for assessing accident situations, examining trends, or carrying out similar analysis; the identification of accident and injury causation and the evaluation of countermeasures require a higher level of detail. Comparison with other regions or countries in terms of that analysis has been an aim for many researchers. For this reason, several in-depth accident data collection projects have emerged worldwide in recent years. Unfortunately, comparative analysis of in-depth data from different countries is difficult or even impossible due to different standards for data collection and coding. For that purpose, Brazil needs to join the methods used in iGLAD, i.e. to process and merge the different data samples describing and overviewing the current status in terms of case counts, marginal distributions as is done by the countries participating from Europe, Asia, Australia and North and South America (currently only Brazil) providing data for iGLAD. As an application example, the iGLAD dataset from 2007 to 2015 was used to analyze the distributions of accident types, presence of safety systems, characteristics of collision deformation and injury severity for each country and to provide country comparisons. The status of Brazil can be assessed in that frame and also capabilities for pre-crash analysis can be assessed. Exemplary statistical assessment of injury probability and descriptive statistics for comparison between different countries were given as a result of the analysis and for the Brazilian sample will give the first trends. This paper gives an overview of the Brazilian data in the framework of the iGLAD initiative as a new field crash data set and shows its unique opportunities for road accident analysis in a global scope, which are not provided by any other accident data source and will give stronger support for efficient and consistent traffic policies. The analysis according to the harmonized data helps to address challenges of road safety on a global level, whether through the identification of country-specific issues and measures to address them or the harmonization of legislation and ratings.
Longton, Alejandro, Schulze, Oliver, Bakker, Jörg, Parera, Nuria, Leitao, Joel
Activation Timing of a Collision Avoidance System with V2V Communication2017-01-00393/28/2017
A vehicle-to-vehicle communication system (V2V) sends and receives vehicle information by wireless communication and assists safe driving. The present study investigated the activation timings of collision information support, collision caution support, and collision warning support provided by a V2V in an experiment using a driving simulator for four situations of (1) assistance in braking, (2) assistance in accelerating, (3) assistance in making a right turn, and (4) assistance in making a left turn at a blind intersection. The four situations are common scenarios of traffic accidents in Japan. Safety margins for collision information support and collision warning support were the time required for the driver to fully apply the brake pedal, while the safety margin for collision caution support was the time required for the driver to begin applying the brake pedal. The study investigated the effects of adding safety margins to standard activation timings. The standard activation timings referred to activation timings defined by V2V guidelines of the Japanese Ministry of Land, Infrastructure, Transport and Tourism. The effects of new activation timings were investigated in the experiment. Objective (based on the use of the accelerator and braking pedals) and subjective evaluations were made of the activation timings. As result, in the case of collision warning support, the appropriate activation timing of V2V is 2.0 s in all experimental conditions. The timing of 2.0 s means that the safety margin is added twice to the standard activation timing. The collision caution support has appropriate activation timing if the safety margin is added once to the standard activation timing under several experimental conditions. In the case of collision information support, the appropriate activation timing was the addition of one safety margin to the standard activation timing in all experimental conditions.
Hirose, Toshiya, Ohtsuka, Yasufumi, Gokan, Masato
Method to Optimize Key Parameters and Effectiveness Evaluation of the AEB System Based on Rear-End Collision Accidents2017-01-01123/28/2017
Rear-end accident is one of the most important collision modes in China, which often leads to severe accident consequences due to the high collision velocity. Autonomous Emergency Braking (AEB) system could perform emergency brake automatically in dangerous situation and mitigate the consequence. This study focused on the analysis of the rear-end accidents in China in order to discuss about the parameters of Time–to-Collision (TTC) and the comprehensive evaluation of typical AEB. A sample of 84 accidents was in-depth investigated and reconstructed, providing a comprehensive set of data describing the pre-crash matrix. Each accident in this sample is modeled numerically by the simulation tool PC-Crash. In parallel, a model representing the function of an AEB system has been established. This AEB system applies partial braking when the TTC ≤ TTC1 and full braking when the TTC ≤ TTC2. Lastly, the AEB system’s model is coupled to the kinematic of the vehicle in simulation for virtual trajectories preceding the collision point to evaluate the potential effectiveness of different combinations of TTC according to the collision velocity reduction effectiveness and the excessive avoidance performance. After the simulations of 4284 run with 51 combination of the parameters based on 84 accidents, the results show that among the four desirable combinations, TTC1 = 1.0 s and TTC2 = 0.6 s is suitable for collision avoidance while TTC1 = 0.9 s and TTC2 = 0.5 s has satisfactory excessive collision avoidance.
Zhao, Mingming, Wang, Hongyan, Chen, Junyi, Xu, Xiao, He, Yutong
NHTSA’s Proposed Frontal Oblique Impact Test Protocol: Analyses and Evaluation2017-01-14753/28/2017
On December 2015, The National Highway Traffic Safety Administration (NHTSA) published its proposal to implement U.S New Car Assessment Program (NCAP) changes covering three categories of crashworthiness, crash avoidance and pedestrian protection, beginning with the 2019 model year. The crashworthiness category included a new frontal oblique impact (OI) test protocol. The test compromises of a new Oblique Moving Deformable Barrier (OMDB), new THOR 50th percentile male (THOR-50M) anthropomorphic test device (ATD), and a new test configuration. An OMDB of 2,486 kg (5,480 lb) impacts a stationary target vehicle at a speed of 90 kph (56 mph) at an angle of 15 degrees with a 35% barrier overlap with the front end of the target vehicle. In vehicle-to-vehicle collisions, the lighter weight vehicle experience higher velocity change and higher acceleration levels, thereby, occupants in the lighter vehicle experience higher injury risk. This paper describes the analyses of a series of 31 OI tests conducted by NHTSA, in which the target vehicles used were of different sizes and weight distribution ranging between 1034 Kg (SMART)-2624 Kg (Silverado). Deformation Energy in the OMDB was calculated from the honeycomb deformation and its associated stiffness. Target vehicle Deformation Energy (DE) in each of the 31 OI tests was determined and compared to its 56 kph (35 mph) NCAP DE. This was shown in a diagram of DE versus mass ratio of the target vehicle to the OMDB. THOR M50 dummy responses for each test were plotted against target vehicle Velocity Change (Δv2),calculated from momentum equation and from test’s velocity time histories. Results indicated that target vehicles absorb more DE in the proposed OI compared to a 56 kph (35 mph) full frontal barrier impact. Lighter weight vehicles, in particular, have to manage approximately 50-60% more DE in the proposed OI. Larger vehicles that have similar weight to that of the OMDB manage approximately same DE as in the NCAP full frontal barrier impact. Therefore lighter vehicles will require significant structural reinforcing and stiffening to manage the crash energy in the OI. This may have a negative impact on attributes such as occupant safety, vehicle compatibility, and fuel economy. For example, it could result in a stiffer crash pulse in light vehicles which may lead to issues associated with occupant safety in all seating position, elderly occupants in particular. Injury risk associated with THOR-M50 dummy responses in NHTSA’s OI tests showed weak or no correlations with (Δv2).The proposed OI mode did not demonstrate the expected injury trend with velocity change which may be attributed to potential issues with the barrier mass, barrier stiffness, THOR dummy, and the test configuration. It is concluded that further research is needed to develop appropriate OI test parameters, OMDB, and dummy type and / or injury criteria.
Barbat, Saeed, Li, Xiaowei
Analysis of Non-Police Reported Accidents on Indian Highways2017-26-00051/10/2017
The official Indian accident statistics show that the number of road accidents and fatalities are one of the highest worldwide. These official statistics provide important facts about the current accident situation. It is suspected that for various reasons not all accidents are reported to the official statistic. This study estimates the degree of underreporting of traffic accidents with casualties in India. In order to get a national overview of the traffic accident situation it is necessary to improve the knowledge about underreported accidents. Therefore, the in-depth accident database of “Road Accident Sampling System India” (RASSI) was analyzed [1]. This project is organized by a consortium that has collected traffic accidents scientifically in four different regions since 2011 on the spot which have been reported either by police or by local hospitals and own patrol by RASSI engineers. Thus, the level of underreporting is researched by comparing data from hospital records and police records in order to estimate the number of accidents which are not documented in official statistics. Based on a number of around 1 635 accidents mainly in rural area it was found that 32% of all documented cases are not recorded by the national police. Based on these findings it is assumed that the national statistics cover only about two-third of all rural crashes in India. Various characteristics of accidents can influence the percentage of underreported cases. Accident scenarios - e.g. classified by Accident Type - have different shares of underreported cases. RASSI data shows that every 2nd single vehicle accident (including pedestrian cases) is not notified in the official statistics. In the study the accident data is analyzed in detail concerning: Accident scenarios Road user category Injury severity Road conditions Infrastructural details Result of this study is an overview of the accident situation in rural area and point out the frequency of underreported accidents depending of typical accident characteristics. This information can be used to identify main causes of this phenomen.
Joerg, Moennich, Kumaresh, Girikumar, Lich, Thomas, Georgi, Andreas
Association of Impact Velocity with Risks of Serious Injuries and Fatalities to Pedestrians in Commercial Truck-Pedestrian Accidents2016-22-000711/7/2016
This study aimed to clarify the relationship between truck-pedestrian crash impact velocity and the risks of serious injury and fatality to pedestrians. We used micro and macro truck-pedestrian accident data from the Japanese Institute for Traffic Accident Research and Data Analysis (ITARDA) database. We classified vehicle type into five categories: heavy-duty trucks (gross vehicle weight [GVW] ≥11 × 103 kg [11 tons (t)], medium-duty trucks (5 × 103 kg [5 t] ≤ GVW < 11 × 103 kg [11 t]), light-duty trucks (GVW <5 × 103 kg [5 t]), box vans, and sedans. The fatality risk was ≤5% for light-duty trucks, box vans, and sedans at impact velocities ≤ 30 km/h and for medium-duty trucks at impact velocities ≤20 km/h. The fatality risk was ≤10% for heavy-duty trucks at impact velocities ≤10 km/h. Thus, fatality risk appears strongly associated with vehicle class. The results also revealed that a 10 km/h reduction in impact velocities could mitigate the severity of pedestrian injuries at impact velocities ≥30 km/h for all five analyzed vehicle types. Therefore, serious injuries and fatalities to pedestrians could be decreased by the development and deployment of collision mitigation systems (CMSs) to all vehicles, including to commercial trucks, because CMSs can detect pedestrians in even severe conditions, such as when the drive’s view is obstructed, and can reduce the impact velocity. The present results indicate that CMS design specifications should differ between vehicle types because of the strong dependence of serious-injury and fatality risks on vehicle type.
Matsui, Yasuhiro, Oikawa, Shoko, Sorimachi, Kazuhiro, Imanishi, Akira, Fujimura, Takeshi
3D Textile EngineeringTBMG-2595011/1/2016
Secant Medical, Telford, PA, has developed 3D textile engineering technology by integrating traditional textile engineering with advanced biomaterials. By combining the spatial resolution capability with advanced bioresorbable polymers, the company uses its proprietary bioelastomer Regenerez® to assist in enhancing the biomechanical properties of these 3D structures. This technology transforms a simple, synthetic textile into an elastomeric scaffold, which provides for a broad range of bioresorbable polymers for the structural design. The company has begun development of an anatomical scaffold prototype based on the trachea. The 3D textile engineered trachea scaffold demonstrates the precision of creating 20 Cshaped rings stacked along the length of the prototype with narrow, flexible regions spaced in between to mimic the natural bioarchitecture of the trachea.
Adverse Aeroelastic Roll/Lateral Rotorcraft-Pilot Couplings AnalysisF-0072-2016-114425/17/2016
The paper investigates the basic mechanism of aeroservoelastic Pilot Assisted Oscillation phenomenon (PAO) about the roll axis due to the interaction with the pilot's arm biomechanics. The motivation stems from the observation that a rotor imbalance may occur as a consequence of rotor cyclic lead-lag modes excitation. The instability mechanism is analogous to the 'air resonance' phenomenon, in which the pilot's involuntary action plays the role of the AFCS. Using robust stability analysis, the paper demonstrates that, in particular, the introduction of a gain and a time-delay between the stick motion and the servoactuator displacements may reduce the gain and phase margins of the pilotvehicle system. The mechanism of instability proves that the pilot biodynamics is participating to the destabilization of the system by inputting energy directly into the flapping mode. This destabilizes the airframe roll motion which, in turn, causes lag motion imbalance. It is found that, depending on the value of the time delay involved in the lateral cyclic control, the body couples with rotor motion in a different way. In the presence of small or no time delays, body roll couples with the rotor through the lag degrees of freedom. The increase of the time delay to 140ms modifies this coupling: the body no longer couples with the rotor through lag but directly through flap motion.
Masarati, Pierangelo, Tod, Georges, Pavel, Marilena, Muscarello, Vincenzo, Quaranta, Giuseppe, Malburet, François
Integration Strategy of Safety Systems - Status and Outlook2016-01-14994/5/2016
On the way to automated driving, the installation rate of surround sensing systems will rapidly increase in the upcoming years. The respective technical progress in the areas of driver assistance and active safety leads to a numerous and valuable information and signals to be used prior to, during and even after an accident. Car makers and suppliers can make use of this new situation and develop integrated safety functions to further reduce the number of injured and even deaths in car accidents. Nevertheless, the base occupant safety remains the core of this integrated safety system in order to ensure at least a state-of-the-art protection even in vehicles including partial, high or full automation. Current networked safety systems comprehend a point-to-point connection between single components of active and safety systems. The optimal integration requires a much deeper and holistic approach. This paper and presentation describe current and future challenges and a clear strategy for the product management as well as for the development and validation of integrated safety systems. The starting points are: market and field requirements based on accident research data, components and technologies brought into the market through driver assistant and automated driving functions as well as design and validation methods to minimize development cost for the targeted performance. This paper will also include an overview of current and future integrated safety functions, the required functional and E/E architectures and the respective roadmap. Technical examples for pre-and in-crash functions will be described including a design overview, HW components and results.
Klier, Willy, Lich, Thomas, D’Addetta, Gian Antonio, Freienstein, Heiko, Koehler, Armin, Reckziegel, Bastian, Yu, Zerong
Study on Airbag Concept for Motorcycles Using Opposing Vehicle as Reaction Structure2015-32-081311/17/2015
An airbag system for motorcycle applications was developed and commercially released in 2006 based on many research results on that system. In the airbag system, the bag should be supported during the period in a collision. The previously developed system employed a configuration in which the airbag was supported by the structures of the motorcycle, such as the instrument panel and the surrounding structures. These structures receive the reaction force to hold the airbag during a crash to properly absorb the rider's kinetic energy. Meanwhile, the previous system requires a larger area for these reaction structures and is applicable only to the motorcycles that can provide the area. To overcome this limitation, we propose an airbag system employing another concept. In this concept, the airbag does not use its vehicle structures as reaction structures but uses the structures of an opposing vehicle, such as doors and/or pillars. For evaluations of the proposed system, full scale motorcycle-to-car crash tests using 125 cm3 scooter-type models with and without the airbag were conducted in the seven impact configurations specified in ISO13232. Through the crash tests, benefits of protective effects of the airbag system were confirmed in particular impact configurations, and no significant risk for the rider due to the airbag was observed in the all tested impact configurations. It was concluded that the proposed airbag system is feasible for reducing rider's severity of injuries in a collision of a motorcycle not having sufficient reaction structures.
Aikyo, Yutaka, Kobayashi, Yuki, Sato, Takashi, Akashi, Tomohiko, Ishiwatari, Makoto
Research on Method for Classifying Injury Severity Using Motorcycle Accident Data for ISO 262622015-32-071411/17/2015
ISO 26262 was established in 2011 as a functional safety standard for passenger cars. In this standard, ASILs (Automotive Safety Integrity Levels) representing safety levels for passenger cars are determined by evaluating the hazardous events associated with each item constituting an electrical and/or electronic safety-related system according to three evaluation criteria including injury severity. On the other hand, motorcycles will be included in the scope of application of ISO 26262 in the next revision. It is expected that a severity evaluation for motorcycles will be needed because motorcycles are clearly different from passenger cars in vehicle mass and structure. Therefore, this study focused on severity class evaluation for motorcycles. A method of classifying injury severity according to vehicle speed was developed on the basis of accident data. In addition, a severity table for motorcycles classifying injury severity according to vehicle speed for each accident type was produced using accident data involved with motorcycles in Japan.
Arai, Yuji, Hasegawa, Makoto, Harigae, Takeshi
Risks of Serious Injuries and Fatalities of Cyclists Associated with Impact Velocities of Cars in Car-Cyclist Accidents in Japan2015-22-001511/9/2015
The main purpose of this study is to define the relationship between the car impact velocity and serious injury risk or fatality risk of cyclists. The authors investigated the risks of serious injuries and fatalities of cyclists using vehicle-cyclist accident data from the database of the Institute for Traffic Accident Research and Data Analysis (ITARDA) in Japan. The vehicle types considered are sedans, mini vans, box vans, light passenger cars and light cargo vans. The results revealed that a 10-km/h decrease in the impact velocity could reduce the severe injury risk and fatality risk for impact velocities of 40 km/h or higher. Specifically, when the impact velocity was less than or equal to 30 km/h, the serious injury risks were less than 21% and the fatality risks were less than or equal to 1% for the above listed vehicle types. Therefore, if the Collision Damage Mitigation Braking System (CDMBS) equipped vehicles can perform its functions effectively so as to reduce the impact velocities, then cyclist injuries will likely be significantly reduced. Another purpose of this study is to assess the effect of wearing a helmet for protection of the cyclist’s head. Impact experiment results showed that the measured head injury criterion (HIC) with helmets are lower than that of head-form impactor without a helmet, reducing the HIC by 57%.
Matsui, Yasuhiro, Oikawa, Shoko
Considerations for ISO 26262 ASIL Hazard ClassificationJ2980_201505 (Historical)5/7/2015
This SAE Recommended Practice presents a method and example results for determining the Automotive Safety Integrity Level (ASIL) for automotive electrical and electronic (E/E) systems. This activity is required by ISO 26262-3:2011 [1], and it is intended that the process and results herein are consistent with ISO 26262:2011 [1]. The technical focus of this document is on vehicle motion control systems. It is limited to passenger cars weighing up to 3.5 metric tons. Furthermore, the scope of this recommended practice is limited to collision-related hazards. ISO 26262:2011 [1] has a wider scope than SAE J2980, covering other functions and accidents (not just motion control or collisions as in SAE J2980).
Functional Safety Committee
A Comprehensive Pilot Model for Voluntary/Involuntary Action in Rotorcraft-Pilot CouplingF-0071-2015-102155/5/2015
ABSTRACT This work proposes a helicopter pilot model identified from experimental results obtained in piloted simulation flight tests. The tests were originally designed to verify predicted unstable pilot-vehicle systems. The results have been further analyzed using methods for the detection of pilot induced oscillation that are available from the literature. The results show that a pilot-assisted oscillation event occurring in one configuration is characterized by a change of biomechanical properties of the pilot. It is conjectured that such change is triggered by a change in the task of the pilot induced by the specific maneuver that is requested of the pilots in the tests.
Jump, Michael, Marguerettaz, Paolo, Masarati, Pierangelo, Lu, Linghai, Guglieri, Giorgio, Muscarello, Vincenzo, Quaranta, Giuseppe
Wrap Around Distance WAD of Pedestrian and Bicyclists and Relevance as Influence Parameter for Head Injuries2015-01-14614/14/2015
During most pedestrian-vehicle crashes the car front impacts the pedestrian and the whole body wraps around the front shape of the car. This influences the head impact on the vehicle. Meanwhile the windscreen is a major impact point and tested in NCAP conditions. The severity of injuries is influenced by car impact speed; type of vehicle; stiffness and shape of the vehicle; nature of the front (such as the bumper height, bonnet height and length, windscreen frame); age and body height of the pedestrian; and standing position of the pedestrian relative to the vehicle front. The so called Wrap Around Distance WAD is one of the important measurements for the assessment of protection of pedestrians and of bicyclists as well because the kinematic of bicyclists is similar to that of pedestrians. For this study accidents of GIDAS were used to identify the importance of WAD for the resulting head injury severity of pedestrians and bicyclists. GIDAS (German In-Depth-Accident-Study) collects accidents as representative sample of the German accident situation based on in-depth-investigation. A total number of n=548 pedestrian and n=436 bicyclists suffered a head impact with the car collected within n=27,666 accidents with all kind of traffic participants and injured persons from the years 1999 to 2013 which are used for the study. Results: A significant influence respectively an increase of WAD by the driving speed of the bicycle cannot be found. The cumulative frequencies show, that WAD 1500 only covers about 8% of bicyclists but 18% of pedestrians. WAD 2100 covers about 51% of bicyclists and 74% of pedestrians. The WAD for pedestrian as measure of distance from the ground to the impact point of the head is dependent on the impact speed of the car. For lower speeds the front hood area is more often contacted and for higher speeds the windscreen. For Vans and off-road cars front hood impacts can only be seen in lower speed collisions. The WAD of bicyclists in general is higher than for pedestrians. The cumulative frequencies of body heights show that bicyclists are larger than pedestrians. The injury severity of the head (AIS head) is increasing with the age of the pedestrian or bicyclist. Only 6.9% of pedestrians and 3.3% of bicyclists in the age group of 16 to 25 years suffer head injuries of AIS 3+, in the age group over 55 years there are 19.7% of pedestrians and 16.1% of bicyclists. The WAD is not a significant influence parameter for the injury severity of the head. The WAD is only increasing slightly with higher injury severity of the head (AIS head). The WAD is a usable parameter for the correlating impact speed of the car. Age and impact speed of the car have highly significant influence (p<0.001) and body height has slightly significant influence on the injury severity of the head (p<0.05).
Otte, Dietmar
Cycling Characteristics of Bicycles at an Intersection2015-01-14654/14/2015
Although traffic accidents in Japan involving bicycles have been decreasing yearly, more than 120,000 per year still occur. Few data exist regarding the mechanisms underlying bicycle accidents occurring at intersections. Such dangerous situations form the backdrop of the warning and automatic braking systems being developed for motor vehicles. By clarifying cyclist behavioral characteristics at crucial times, it may be possible to introduce a similar warning system for cyclists as a countermeasure to reduce accidents. The objective of this study is to clarify the mechanism of accidents involving bicycles and to obtain useful data for the development of a warning system for cyclists. A video camera and software investigated and analyzed cyclists' speed and trajectory at an intersection where many accidents occur. Cyclists entering the intersection from one direction were recorded. The results showed that the intersection offered poor visibility to cyclists, many of whom maintained their previous speed without stopping. Given these data, an improved infrastructure and a warning system using vehicle to cycle communication is desirable. Therefore, with construction of a warning system in mind, in this study we speculated on a timely warning that will contribute to safe cycling without causing alarm to the cyclist. If the warning should take place 2 s before the cyclist crosses the intersection, it would be effective for about 80% of the cyclists in this study, so our data have potential to contribute to the development of a warning system.
Nikaido, Sho, Wada, Shota, Matsui, Yasuhiro, Oikawa, Shoko, Hirose, Toshiya
Survivability of Event Data Recorder Data in Exposure to High Temperature, Submersion, and Static Crush2015-01-14494/14/2015
Event data recorder (EDR) data are currently only required to survive the crash tests specified by Federal Motor Vehicle Safety Standard (FMVSS) 208 and FMVSS 214. Although these crash tests are severe, motor vehicles are also exposed to more severe crashes, fire, and submersion. Little is known about whether current EDR data are capable of surviving these events. The objective of this study was to determine the limits of survivability for EDR data for realistic car crash conditions involving heat, submersion, and static crush. Thirty-one (31) EDRs were assessed in this study: 4 in the pilot tests and 27 in the production tests. The production tests were conducted on model year (MY) 2011-2012 EDRs enclosed in plastic, metal, or a combination of both materials. Each enclosure type was exposed to 9 tests. The high temperature tests were divided into 3 oven testing conditions: 100°C, 150°C, and 200°C. In the submersion tests, EDRs were submerged to a depth of 3 meters in either distilled, tap, or salt water, and then placed in an oven to dry at 65°C. The static crush tests were divided into 3 conditions that varied by the location on the EDR that the load was applied: (1) parallel and (2) perpendicular to the mounting flange onto the main enclosure, as well as (3) parallel to the mounting flange on the electrical connector. In each case, a static crush force of 2,500 lbf was applied for 5 minutes. If the data survived, a second round of loading was applied with increasing force until significant yielding occurred. The data were considered to have survived the test if it was successfully downloaded afterward using the direct-to-module imaging method. In all 27 production test EDRs, the data were downloaded successfully. The high temperature limit of the modules was determined to be 200°C, as components began to desolder beyond this temperature. During submersion, the plastic modules required more extensive drying beyond the established protocol. In top- and connector-loading of the enclosures to significant yield, the data were still accessible. Side-loading until significant deformation, however, led to damage of internal components and unsuccessful data download.
Tsoi, Ada H., Hinch, John, Winterhalter, Michael, Gabler, H.
Analysis and optimization of All Terrain Wheelchair2015-01-13684/14/2015
An all-terrain wheelchair is a lever propelled wheelchair which enables an individual to drive on all terrains easily as the driving mechanism is efficient, ergonomic and fast. It also increases the reach capabilities and social boundaries of disabled. The paper is divided into two parts. In the first part, a comparative study of push rim wheelchair and All-terrain Wheelchair (lever propelled) has been done. In the second part, Optimization of this All-terrain Wheelchair has been done. The comparison is done on various parameters such as peak velocity, average velocity, acceleration, retardation, stroke frequency, reduction in effort, mechanical efficiency, obstacle climbing ability, turning radius, the distance travelled per stroke, Pressure cuts and burns caused during propelling the chair. Biomechanical testing is also done considering the heart rate and oxygen consumption level. This information was used to determine the energy demand, which is intrinsically connected to a wheelchair's mechanical efficiency. The optimization mainly focuses on ergonomics and efficiency of design. For this, the main emphasis was given on factors like the position of lever-drive system, configuration of wheel, seating, backrest, chassis, breaking and foot rest. this optimized design would make the chair more efficient and easy to use by enabling the person to drive, steer, and stop without even touching the wheels, thus, eliminating the risk of friction burns and protecting the wrists and shoulders from repetitive stresses. The analysis was done using commercial software ANSYS and CATIA and validation of results was conducted with the users and non-users of wheel chair.
Agarwal, Shikhar, Gautam, Saumya
Improved Seat Belt Restraint Geometry for Frontal, Frontal Oblique and Rollover Incidents2015-01-07404/14/2015
Throughout the first decade of the twenty first century, large improvements in occupant safety have been made in NASCAR®'s (National Association for Stock Car Auto Racing, Inc) race series. Enhancements to the occupant restraint system include the development and implementation of head and neck restraints, minimum performance requirements for belts and seats and the introduction of energy absorbing foam are a few highlights, among others. This paper discusses nineteen sled tests used to analyze hypothesized improvements to restraint system mounting geometry. The testing matrix included three sled acceleration profiles, three impact orientations, two Anthropomorphic Test Device (ATD) sizes as well as the restraint system design variables.
Patalak, John, Gideon, Thomas, Melvin, John W., Rains, Mike
Study of the Similarity between Small Overlap Impact (SOI) Crashworthiness Tests and Real SOI Accidents in Spain2014-36-04809/30/2014
Recent studies identified new trends in frontal accident configurations, i.e. small overlap. This emerging type of crash represents a higher injury risk for the occupants compared to other frontal crashes with longer overlap due to the small interaction of the structural energy absorption elements. In response to this new accident reality, IIHS introduced a new type of crash to evaluate crashworthiness: the Small Overlap Impact (SOI). The purpose of this study is to analyze the accident trend in Spain to study the changes in the overlap in frontal crashes and identify crashworthiness similarities between an SOI crash test and a real crash. This research focuses on real accident data from Spain gathered in IDIADA's accident database with a crash configuration similar to SOI. Through the analysis of structural damage in real accidents and analysis of SOI tests performed, several deformation patterns have been detected in SOI tests and also in real accidents. Increasing the test configurations for vehicle safety development can enable a higher standard of safety in vehicles. However, an increased number of test configurations is costly and not always cost effective. For this reason, further work is needed in this field to assess the suitability of the introduction of new testing configurations in Europe. The SOI test is of recent introduction and the crashworthiness of some of the structural elements is still not fully acknowledged. For this reason, further development in both testing and vehicle safety must be implemented.
Da Silva, Xavier, Ferrer, Adrià
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