Browse Topic: Restraint systems

Items (1,433)
The Crashworthy and Escape Systems Branch at NAWCAD has been developing an integrated restraint harness concept for several years, with the intent of developing a novel method of providing improved occupant protection in a crash scenario. A series of tests was conducted on the Horizontal Accelerator at NAS Patuxent River to evaluate the performance of the prototype integrated-restraint system under MIL-STD-58095 conditions with the 50th percentile male Hybrid III Anthropomorphic Test Device (ATD). While occupant flail was the primary metric being analyzed in this effort, ATD instrumentation was also captured, showing that the integrated restraint system demonstrated a significant reduction in head flail compared to five-point restraints while maintaining injury criteria within acceptable levels.
Anderson, EricMinnich, Shannon
ABSTRACT
Richards, Marv
This document applies to webbing used on occupant restraint systems in service on 14 CFR/CS part 23, part 25, part 27, and part 29 aircraft applications. The guidelines presented within this document are intended to be supplemental to the requirements supplied by the OEM in the CMM, ICA, or like document. In cases of conflict between this ARP and the OEM’s requirements, the requirements of the OEM shall be followed. The objective of this document is to establish practical guidelines to help operators in the determining if restraint webbing has reached the end of its service life. The recommendations contained herein are based on test data from in service restraint systems and the continued airworthiness guidelines recommended by restraint system OEMs.
Aircraft SEAT Committee
This glossary was written to provide a consistent and uniform definition of terms used in describing an automatic belt tensioner as it applies to an automotive accessory drive system.
Belt Drive (Automotive) Systems Committee
This SAE Recommended Practice establishes minimum performance and test requirements for combination pelvic and upper torso occupant restraint systems provided for off-road self-propelled work machines.
HFTC4, Operator Seating and Ride
This SAE Recommended Practice describes the test procedures for conducting simulated dynamic lateral rollover restraint system tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
Truck Crashworthiness Committee
This SAE Recommended Practice provides a standardized test procedure for heavy-duty truck sleeper berth restraints to determine whether they meet the FMCSR 393.76(h) requirements.
Truck Crashworthiness Committee
ITIS Phrase Lists (International Traveler Information Systems)J2540/2_202012 (Current)12/6/2020
This standard provides a table of textual messages meeting the requirements for expressing International Traveler Information Systems (ITIS) phrases commonly used in the ITS industry. The tables provided herein follow the rules of SAE J2540 and therefore allow a local representation in various different languages, media expressions, etc., to allow true international use of these phrases. The phrases are predominantly intended for use in the description of traffic-related events of interest to travelers and other traffic practitioners. Other phrases exist for other specific specialty areas of ITS, and all such phrases follow a set of encoding and decoding rules outlined in SAE J2540 to ensure that the use of these phrases in messages remain interoperable between disparate types of user equipment. Implementers are cautioned to obtain the most recent set of tables by means of the ITS data registry, a process which involves SAE and other standards-setting organizations, and which is intended to maintain and enhance the level of harmonization among ITS standards set by each of the organizations. This standard defines the normative index values to be used to provide phrases needed by ITS practitioners. This standard provides non-normative textual phrases which MAY be used by implementers to ensure intelligible results. This standard follows the formats and rules established in SAE J2540 in the expressions, manipulations, and use of such tables. It should be pointed out that within the rules established by this standard, a variety of final tables are all considered “conformant” with the standard, and may vary as fits the needs of implementers.
V2X Core Technical Committee
This SAE Recommended Practice describes the test procedures for conducting frontal impact restraint tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
Truck Crashworthiness Committee
Assessment of Collision Markings on Non-Used Vehicle Seat Belt Restraint Systems2020-01-09754/14/2020
Forensic investigators of automobile collisions are commonly tasked with determining whether physical evidence observed on restraint systems is consistent with the occupant’s use or non-use of the seat belt restraint. The characteristics of collision-induced markings generated on seat belt systems are not solely dependent on the belted status of the occupant, but also the technological features incorporated in the seat belt assembly. As the state-of-the-art for seat belt assemblies has changed over time, so has the constellation of physical evidence typically created on seat belt restraint systems. Pretensioner deployment can leave physical evidence on restraint system hardware in the absence of occupant loading. This study presents examples of physical evidence collected from seat belt systems involved in real-world collisions, which were initially alleged to affirm proper belt use, but were ultimately proven to be evidence of non-use. Several laboratory demonstrations were conducted to investigate physical evidence created on restraint system hardware as a result of pretensioner deployments of non-used seat belts in a variety of incompletely stowed conditions. The demonstrations show the initial positions of the seat belt assemblies necessary to produce the distinct physical evidence documented in the real-world samples. The physical evidence observed on the real-world restraint systems were consistent with the markings produced in the laboratory demonstrations. The presence of physical evidence on restraint system hardware and webbing is inadequate to conclude that a seat belt restraint was in use. Careful consideration of restraint system physical evidence combined with restraint system geometry and incorporated technological features can distinguish physical evidence related to seat belt use or non-use during a collision event. These examples will be useful to investigators for the assessment of physical evidence and diagnosis of seat belt use.
Gregg, Richard H.Petroskey, Karla J.
Experimental Investigation of Axial Cutting of AA6061 Extrusions under a Tension Deformation Mode2020-01-02064/14/2020
A plethora of applications in the transportation industry for both vehicular and roadside safety hardware, especially seatbelts, harnesses and restraints, rely on tensile loading to dissipate energy and minimize injury. There are disadvantages to the current state-of-the-art for these tensile energy absorbers, including erratic force-displacement responses and low tensile force efficiencies (TFE). Axial cutting was extensively demonstrated by researchers at the University of Windsor to maintain a stable reaction force, although exclusively under compressive loading. A novel apparatus was investigated in this study which utilized axial cutting under a tensile loading condition to absorb energy. A parametric scope was chosen to include circular AA6061 extrusions in both T4 and T6 temper conditions with an outer diameter of 63.5 mm and wall thickness of 3.18 mm. The experiments were performed quasi-statically utilizing a custom, hydraulically powered long stroke tension/compression testing machine with a maximum capacity of 300kN. Strain-gauge based load cells and non-contact displacement transducers were implemented to measure the cutting force and displacement response of the setup. The results demonstrated highly stable force responses, with cutting force efficiencies typically in the vicinity of 90%. The experimental force-displacement responses exhibited a high degree of repeatability and correlation to the analytical model. Critical performance metrics, including the mean load and total energy absorption, were predicted to within 5 %. Additionally, the complete force-displacement response was predicted utilizing an analytical modeling approach with an average validation metric of approximately 0.92.
Gudisey, AnthonyAltenhof, WilliamMagliaro, John
Evaluation of General Motors Event Data Recorder Performance in Semi-Trailer Rear Underride Collisions2020-01-13284/14/2020
The objective of this study was to analyze the validity of airbag control module data in semi-trailer rear underride collisions. These impacts involve unusual collision dynamics, including long crash pulses and minimal bumper engagement [1]. For this study, publicly available data from 16 semi-trailer underride guard crash tests performed by the Insurance Institute for Highway Safety (IIHS) were used to form conclusions about the accuracy of General Motors airbag control module (ACM) delta-V (ΔV) data in a semi-trailer rear underride scenario. These tests all utilized a 2009 or 2010 Chevrolet Malibu impacting a stationary 48’ or 53’ semi-trailer at a speed of 35 mph. Nine tests were fully overlapped collisions, six were 30% overlapped, and one was 50% overlapped [2]. The IIHS test vehicles were equipped with calibrated 10000 Hz accelerometer units. Event Data Recorder (EDR) data imaged post-accident from the test vehicles were compared to the reference IIHS data. For each test, root mean square error (RMSE), the percent error over time, and the difference between the EDR ΔV and the IIHS ΔV, was quantified, plotted, and related to crash pulse. This analysis revealed a general trend of decreasing EDR ΔV parity with an increasing crash pulse duration, although overall differences remained low for most tests. Eleven tests, all with airbag deployments, converged towards an average of 3.3% error at the end of the crash pulse, which were 150-270 ms. EDR recorded ΔVs were in the range of 29.8-39.9 mph. Five tests, three of which were non-deployments, diverged to higher percentage error averaging 12.7% at an EDR ΔV of 31.8-40.0 mph. All higher error tests were 30% overlapped and had the highest crash pulse durations of 240-300 ms. One fully overlapped test generated highly unusual EDR data due to failure of the rear underride guard mounting bolts and plates.
Famiglietti, NicholasHoang, RyanFatzinger, EdwardLanderville, Jon
Innovative Active Head Restraint System in a Car: Safety Assessment with Virtual Human Body Model2020-01-09794/14/2020
The aim of this study is to use numerical simulations for safety assessment of an innovative active head restraint system. This system was developed to protect the head and neck of an occupant in a car without a head airbag during a side impact. Its FE model is created and embedded it in a model of a small car with a side airbag. The dynamics of the head restraint activation are also taken into account. The virtual human body model Virthuman is used to represent occupants. The model is scaled for pre-selected human individuals to cover large numbers of occupants of different sizes. It extends conventional virtual evaluation of new safety designs via existing pre-defined mono-purpose side dummies and their FE models. The benefit of the head restraint system is evaluated in side impact scenarios inspired by the pole tests performed by EuroNCAP. Transversal impacts to a pole at 29 and 32 km/h are considered at 90° and 75° angles from driver and the opposite side. Also, the far side impact prescribed with an acceleration pulse according to EuroNCAP is considered. Various initial driver sizes in standard seated positions are tested. To extend the study beyond standard testing protocols, out-of-position of driver is also considered, leading to more than 100 simulations of impact scenarios in total. The effect of the innovative head restraint system is assessed from the point of view of driver injury risk.
Vychytil, JanHlucha, JanaKovar, LudekKostikova, MartinaMoravcova, PavlinaBucsuhazy, Katerina
Determination of Seatbelt Use Following a Crash2020-01-06434/14/2020
When investigating a vehicle crash, the issue of seatbelt usage is frequently part of the information needed to perform an occupant kinematics or injury analysis. A physical inspection of the vehicle is the preferred method to investigate seatbelt usage. However, if the vehicle is no longer available, or the condition has changed since the time of the crash, preventing analysis of seatbelt usage by an occupant, the investigators must rely on other available evidence to assess occupant seatbelt usage. This would typically include a review of the police report, scene or early photographs of the vehicle, physical marks on the occupant in medical records and statements from witnesses. More recently, event data recorders (EDR) can provide data regarding seatbelt status for front seat occupants, and occasionally, rear seat occupants. However, the EDR data must have been previously recovered or the vehicle must be available. In cases where the available data is limited or includes only subjective data such as a police report or statements of occupants, some investigators have used the post-crash seatbelt position to determine seatbelt usage at the time of the impact. The theory is if the seatbelt is retracted or stowed post-crash, it was not in use at the time of the collision. The validity of this theory was investigated using EDR data from the NHTSA Crash Investigation Sampling System (CISS) as well as EDR files collected during in-house crash investigations. Photographic documentation of the post-crash seatbelt position was compared to EDR reported seatbelt use to determine if post-crash seatbelt position is reliable in determining seatbelt usage at the time of impact. Additionally, EDR seatbelt usage was compared to police reported seatbelt usage. The analysis of the data in this study found that in a third of the cases where the EDR data indicated the occupant was seatbelted, the seatbelt was found in the stowed or retracted position. Therefore, finding a stowed or retracted seatbelt following a crash is not a reliable means of determining seatbelt use by the occupant at the time of the crash. Additionally, a comparison of EDR data to police reported seatbelt usage revealed that 13 to 25 percent of the occupants reported by the police as seatbelted did not have the seatbelt fastened based on EDR data.
Yannaccone, John R.
The Effects of Small Seat Swiveling Angles on Occupant Responses during a Frontal Impact2020-01-05714/14/2020
In highly automated vehicles (HAVs), new seat configurations may be desirable to allow occupants to perform new activities. One of the current HAV concepts is the swiveled seat layout, which might facilitate communication between occupants. The main objective of this study was to investigate the effects of seat swiveling angles on occupant kinematics and injury risk predicted by a Human Body Model (HBM) during a frontal impact. A detailed 50th percentile male HBM (GHBMC M50-O) was subjected to two frontal crash pulses in a sled setup. The model was positioned on a semi-rigid seat and restrained using a pre-inflated airbag and a three-point seatbelt. Simulations included four seat swiveling angles (0, -10, -20, and -30 degrees), three occupant positions (Sedan driver, large VAN driver or Laptop user), two airbag initial locations (nominal or matching the head Y location), and the inclusion of lateral supports on the seat pan. The effects of the seat swiveling angle were similar for all occupant positions. With the airbag in the nominal location, higher seat swiveling angles led to a higher head lateral displacement and a higher risk of head injury, especially for the BrIC criterion. The Sedan driver position had higher BrIC and a larger head lateral excursion than the other two positions. This could be mitigated by aligning the airbag location with the head. Pelvic fractures were also predicted for the configurations with the highest swiveling angles. These fractures were limited by the use of seat pan lateral supports. Overall, the model responses were sensitive to both seating configurations and occupant postures, and the results suggest that swiveled seating may increase the injury risk, especially for the head and pelvis. However, simple countermeasures, such as adapted airbag location or adding lateral seat pan supports, seemed possible to mitigate the risk.
Grébonval, CyrilleTrosseille, XavierPetit, PhilippeWang, XuguangBeillas, Philippe
Load Distribution Optimization of Seatbelt Using Validated Finite Element Approach2019-28-257511/21/2019
The seat belt system is one of most important component of the safety instrument family in a vehicle. The main purpose of seat belt is to minimize the injuries by preventing the occupant from impacting hard on interior parts of the vehicle and also the passenger from being thrown-out from the vehicle in case of rollover accidents. The standard three-point belt is mounted in the vehicle at three locations namely Anchor, D-ring and Buckle. The position of anchorages is very important to distribute the impact load evenly to the occupants. Very high load in any of these locations could cause breakage of the mountings and also concentrated loading on the occupant chest of pelvis. Current study mainly focuses on the seatbelt assembly performance improvement against UNECE-R16 sled test. The sled test was carried out first using 28g peak acceleration pulse and measurement of forces at shoulder and anchor position was measured using the load cell. FE (Finite Element) model of the complete seatbelt assembly was developed including Buckle, Retractor and Anchor plate. The simulation was carried out using TNO-10 R-16 dummy with the given position of D-ring, Buckle and Anchor plate. First correlation was established between the forces at shoulder location, Anchor plate location. Further correlation was established in the pelvis and thorax displacement. Multiple iterations were performed with the different position of anchorages in a given range in the validated model of seatbelt. The results showed significant effect of the Buckle and Anchor position in the force distribution on the dummy.
Satija, AnshulMishra, PriyanshuGaurav, RaviSingh, Virender
The Effects of Front-Mounted Accessories on Air Bag Sensors and CrashworthinessJ2431_201910 (Current)10/9/2019
Almost all light trucks now are being manufactured with at least a driver side air bag and all will have dual air bags by 1998. The driving forces behind this feature are occupant safety, federal regulations, and competition in the industry. Along with the booming popularity of pickups and SUVs, they are commonly accessorized with a wide variety of products. Many accessories for four-wheel drives in particular are mounted on the front of the vehicle. These products include grille/brush guards, winches, snow plows, replacement bumpers, bicycle carriers, etc. Concerns have arisen over the compatibility of these accessories with the vehicle’s air bag system. The vehicle manufacturers are concerned because of their huge investment in design and crash test verification of the complete vehicle system and keen awareness of the federal regulations. The crushability of the front bumper and supporting structure are key elements in the system, so alterations to that area become logical concerns. The accessory manufacturers, dealers, and installers are concerned because the very core of their business could be at risk. The unknowns can range from fear of setting off an airbag while working on the vehicle to liability issues in an injury accident situation. In some cases, the installation of the product is contrary to recommendations from the vehicle manufacturer and may void the warranty. The ultimate customers (end users) are in a unique situation and are not being well served in some situations. Their dilemma stems from the conflict between what a manufacturer is willing to certify for sale and what the customer needs and expectations are. Their needs in vehicle equipment can vary widely from making a living to recreational lifestyle issues to simplify the desire to individualize. The precedent for front-mounted accessories is well established. The customers for both the vehicle and the equipment are there, so finding ways for them to coexist safely is beneficial to all.
Motor Vehicle Council
A Framework for Vision-Based Lane Line Detection in Adverse Weather Conditions Using Vehicle-to-Infrastructure (V2I) Communication2019-01-06844/2/2019
Lane line detection is a very critical element for Advanced Driver Assistance Systems (ADAS). Although, there has been significant amount of research dedicated to the detection and localization of lane lines in the past decade, there is still a gap in the robustness of the implemented systems. A major challenge to the existing lane line detection algorithms stems from coping with bad weather conditions (e.g. rain, snow, fog, haze, etc.). Snow offers an especially challenging environment, where lane marks and road boundaries are completely covered by snow. In these scenarios, on-board sensors such as cameras, LiDAR, and radars are of very limited benefit. In this research, the focus is on solving the problem of improving robustness of lane line detection in adverse weather conditions, especially snow. A framework is proposed that relies on using Vehicle-to-Infrastructure (V2I) communication to access reference images stored in the cloud. These reference images were captured at approximately the same geographical location when visibility was clear and weather conditions were good. The reference images are used to detect and localize lane lines. The proposed framework then uses image registration techniques to align both the sensed image (adverse weather) and the reference image. Once the two images are aligned, the lane line information from the reference image is then superimposed on the local map built by the ADAS or Autonomous driving system. A real-world experiment is designed to evaluate the error in localizing the lane lines using the proposed framework in comparison to ground truth data. The measurements and evaluations are based on data gathered from a test vehicle. The vehicle is equipped with a monocular camera, forward looking radar, LiDAR, and GPS/IMU. The initial results show good potential for improving upon current state-of-the art approaches used in today’s automotive industry.
Horani, ModarRawashdeh, Osamah
Passenger Vehicle Response and Damage Characteristics of Front and Rear Structures during Low- to Moderate-Speed Impacts2019-01-04154/2/2019
A significant number of vehicle-to-vehicle collisions involve front-to-rear impacts at low- to moderate-speeds. While a variety of studies have been conducted since the 1990s involving fore-aft collisions, those discussing the response of late model passenger vehicles during progressively more severe impacts are limited. In this study, four inline, front-rear tests were conducted using two midsize sedans of the same make, model, and year. An instrumented Hybrid III 50th percentile-male Anthropomorphic Test Device (ATD) was located in the driver seat of each sedan and was restrained using the standard three-point seat belt system. Instrumentation on the vehicles included tri-axis accelerometers and seat belt load cells. For each test, the centerlines of the vehicles were aligned, and the striking vehicle impacted the stationary target vehicle at closing speeds of 4.6, 7.9, 13.5, and 20.9 mph (7.4, 12.7, 21.7, and 33.6 kph). The front and rear bumper covers were removed to allow the response of the bumper systems to be observed during the impact. Vehicle and ATD data were recorded using on-board data acquisition while on- and off-board real-time and high-speed video cameras captured each test from varying perspectives. In addition, post-impact deformation was quantified from three-dimensional scan data and photographs. Data evaluated included vehicle accelerations, change in velocity (Delta-V), restitution, and energy dissipation. Force-displacement curves were developed and compared, and progression of vehicle damage was discussed. Finally, the accuracy of frontal stiffness characteristics derived from barrier testing for predicting energy dissipation in low- to moderate-speed collisions was assessed.
Crosby, CharlesSkiera, JasonBare, CleveComo, StevenMcDowell, Eric
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, DavidParenteau, 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
Evaluation of Harness Tightening Procedures for Child Restraint System (CRS) Sled Testing2019-01-06174/2/2019
Sled testing procedures should reflect a rigorous level of repeatability across trials and reproducibility across testing facilities. Currently, different testing facilities use various methods to set the harness tension for child restraint system (CRS) sled tests. The objective of this study is to identify which harness tightening procedure(s) produce tensions within a reasonable target range while showing adequate reproducibility, repeatability, and ease-of-use. Five harness tightening procedures were selected: A) FMVSS 213 procedure, B) a 3-prong tension gauge, C) ECE R44/R129 procedure, D) two finger method, and E) pinch test. Two CRS models were instrumented with a tension load cell in the harness system. Seven sled room operators were recruited to perform each of the five harness tightening procedures for ten repetitions apiece on both instrumented CRS using a Hybrid III 3-year-old. The static harness tension measured by the load cell was recorded after each procedure was completed. Data were analyzed for mean, variance, reproducibility, and repeatability. Operator feedback surveys were used to quantify ease-of-use. The ECE R44/R129 procedure produced harness tensions which were quite low. The two finger procedure produced the highest tensions while the 3-prong tension gauge, pinch test, and FMVSS 213 procedures produced mid-level tensions. Poor repeatability was apparent for all five harness tightening procedures. The FMVSS 213 method ranked lowest for ease-of-use. Operators preferred using the 3-prong gauge, two finger method, and pinch test. The load cell readings were sensitive to the order and direction in which the operators adjusted the harness components. High amounts of friction within the harness might prevent it from acting as a homogeneous, continuous system. Sequential tightening of the various sections of harness and/or monitoring the tension at multiple locations might be valuable.
Mansfield, JulieBaker, GretchenBolte, John
Innovative Knee Airbag (KAB) Concept for Small Overlap and Oblique Frontal Impacts2019-01-06214/2/2019
Considerable research has been conducted in terms of attempting to reduce lower leg injury risk in full frontal impacts, in some cases by the use of a knee airbag (KAB). However, there has been limited research into the performance of KAB systems during a crash test with increased oblique loading, such as the IIHS small overlap frontal test, an oblique moving deformable barrier test (OI) being researched by NHTSA, and a mobile progressive deformable barrier test (MPDB) that is expected to be implemented by Euro NCAP in the next few years. The objective of the current numerical study was concentrated on the evaluation of an innovative KAB concept design intended to reduce ATD right inboard lower leg/foot responses under small overlap and oblique loading conditions. A novel appendage KAB concept design was developed with the help of morphing and computational studies which were performed with different ATD sizes. In the study, one of the lower leg/foot responses was monitored and compared over a conventional KAB design. Cases investigated in the study showed that the novel appendage KAB concept design acts as a conventional KAB in full frontal impact modes (similar right inboard femur responses) and has the potential to reduce right inboard lower leg/foot responses by an average 16% (small overlap impact mode) and 20% (oblique impact mode) over the conventional KAB design. Furthermore, it was noted that the novel design could potentially be adapted to achieve targeted right inboard lower leg responses in full, offset and oblique frontal crash tests with minimal impact on the left outboard responses.
Makwana, RahulJindal, Pardeep
Probability of Frontal Airbag Deployment in Bumper-Bumper and Underride Collisions2019-01-06204/2/2019
Airbag deployment thresholds can be a useful metric of collision severity in accident reconstruction applications. The National Automotive Sampling System (NASS) has provided a publicly-available database of real-world motor vehicle collisions, including more than 10,000 event data recorder (EDR) reports retrieved from airbag control modules. These reports typically indicate the airbag deployment status and the corresponding Delta-V of each recorded event. A prior study analyzing crash data in the NASS database demonstrated the airbag deployment threshold varies between vehicle manufacturers and over time. However, the analysis was limited to Ford and GM vehicles due to insufficient data. This paper expands on the prior study of frontal airbag deployment thresholds by analyzing newer years of NASS EDR data (4,000 additional reports). We found that the Delta-V threshold for a 50% probability of deployment event is higher for Toyota than for GM and Ford vehicles. Moreover, SUVs and pickup trucks had higher deployment thresholds than sedans. An increase in Delta-V thresholds was observed for more recent vehicle model years. A higher Delta-V is required for frontal airbag deployment in underride collisions, in which a sedan contacted a vehicle with higher ground clearance (SUV, pickup truck, or van), compared to collisions with direct bumper-bumper engagement. Based on the findings, we developed a logistic regression model that predicts the probability of frontal airbag deployment with a known change in velocity (ΔV = 0 to 45 mph), vehicle manufacturer (GM, Toyota, Ford), vehicle type (sedan, SUV, pickup truck), model year (1994-2001, 2002-2016), and impact configuration (underride, bumper-bumper) with 82% accuracy. This study provides information about airbag deployment behavior beyond what is reported in owner’s manuals and National Highway Traffic Safety Administration (NHTSA) guidelines.
Lee, FelixMcCleery, Caitlin H.Ngo, ChristinaLimousis-Gayda, ManonHashish, Rami
Passenger Vehicle Dynamic Response and Characterization of Side Structure during Low- to Moderate-Speed Side Impacts2019-01-04204/2/2019
A significant portion of real-world passenger vehicle side impacts occur at lower speeds than testing conducted by the National Highway Traffic Safety Administration (NHTSA) or the Insurance Institute for Highway Safety (IIHS). Test data from low- to moderate-speed side impacts involving late-model passenger vehicles is limited, making the evaluation of vehicle impact response, occupant loading, and injury potential challenging. This study provides the results of low- to moderate-speed impact testing involving a late-model mid-size sedan. Two full-scale Non-Deformable Moving Barrier (NDMB) side impact crash tests were conducted at speeds of 6.2 mph (10.0 kph) and 13.4 mph (21.6 kph). Instrumentation on the late-model sedan used for the test series included tri-axis accelerometers and seat belt load cells. In both tests, instrumented Hybrid III 50th percentile-male Anthropomorphic Test Devices (ATDs) were restrained in the driver and passenger seats using the standard three-point seat belts. Response data for the vehicle, barrier, and ATDs was recorded using onboard data acquisition, and on- and off-board real-time and high-speed video cameras. In addition, the deformation to the side of the sedan was quantified from pre- and post-test laser scan data. Results from the test series provided data regarding accelerations, velocity change, and restitution. The damage to the side structure of the vehicle was assessed and conclusions regarding damage initiation and damage progression are discussed. Conservation of Momentum and Conservation of Energy analyses are presented and force-displacement characteristics and energy dissipation were evaluated and compared. Utilizing the data that was developed from the test series, vehicle side stiffness modeling was also conducted.
Skiera, JasonCrosby, CharlesBare, CleveParadiso, MarcCampbell, Gregory
A Resonant Capacitive Coupling WPT-Based Method to Power and Monitor Seat Belt Buckle Switch Status in Removable and Interchangeable Seats2019-01-04654/2/2019
In this study, we present an intelligent and wireless subsystem for powering and communicating with three sets of seat belt buckle sensors that are each installed on removable and interchangeable automobile seating. As automobile intelligence systems advance, a logical step is for the driver’s dashboard to display seat belt buckle indicators for rear seating in addition to the front seating. The problem encountered is that removable and interchangeable automobile seating outfitted with wired power and data links are inherently less reliable than rigidly fixed seating, as there is a risk of damage to the detachable power and data connectors throughout end-user seating removal/re-installation cycles. The present study tackles this issue through outfitting three removable and interchangeable rear seat assemblies with resonant capacitive coupling wireless power transfer as to power each rear seat across a variable gap between the interior paneling and that side of the seat closest to the interior paneling. A fundamental design challenge this system presented was the need to develop a rugged method to account for different sizes of seating, and hence to accommodate variable wireless power gaps. This issue was addressed via use of impedance matching technology to present a nearly constant load impedance to the dc-to-radiofrequency power inverter. The wirelessly received power enabled additional electronics added to the rear seat assemblies to wirelessly communicate the seat belt buckle states to a central hub where it was displayed via a custom graphical interface. Our approach involved the visibly imperceptible integration of resonant capacitively-coupled transmitting and receiving antennae behind the interior paneling for the transmitter and underneath the outer fabric of the rear seating. The resulting subsystem demonstrated the ability to power both the seat belt buckle switches and wireless communication over a range of wireless power gaps.
Cuddihy, MarkPottle, Brian
Evaluation of Occupant Kinematics in Low- to Moderate-Speed Frontal and Rear-End Motor Vehicle Collisions2019-01-12264/2/2019
Low- to moderate-speed motor vehicle collisions are a common crash type and are sometimes associated with injury complaints. Understanding occupant motion (kinematics) in response to low- and moderate-speed motor vehicle collisions is important for evaluating occupant interactions with interior vehicle structures, including the restraint systems, with the ultimate goal of assessing injury potential. Furthermore, quantitative occupant kinematic data from full-scale crash testing of late-model passenger vehicles is limited for collisions at low- to moderate-speeds. The current study reports kinematic data from full-scale frontal and rear-end crash tests of late-model, mid-size sedans with delta-Vs ranging from 6.0 to 19.0 kph (3.7 to 11.8 mph) and 5.6 to 19.5 kph (3.5 to 12.1 mph), respectively. For each test vehicle, the motion of a Hybrid III 50th-percentile male anthropomorphic test device (ATD) restrained in the driver seat was recorded using high-speed onboard video. Motion tracking of the video was used to evaluate the excursion and velocity of each ATD’s head, shoulder, elbow, and knee with respect to the vehicle interior. Restraint loads were recorded via load cells placed on the driver’s torso and lap belts. For both the frontal and rear-end collisions, the maximum excursion and velocity of the ATD with respect to the occupant compartment generally increased with increasing delta-V. During the occupant rebound phase of the rear-end collisions, the maximum excursion and velocity of the ATD also generally increased with increasing delta-V and was generally less than its initial rearward excursion and velocity.
Bruno, AlexanderToney-Bolger, MeganGeorge, JuffKoller, JeffreyFilatov, AntonOlberding, Joseph
Quantification of Sternum Morphomics and Injury Data2019-01-12174/2/2019
Crash safety researchers have an increased concern regarding the decreased thoracic deflection and the contributing injury causation factors among the elderly population. Sternum fractures are categorized as moderate severity injuries, but can have long term effects depending on the fragility and frailty of the occupant. Current research has provided detail on rib morphology, but very little information on sternum morphology, sternum fracture locations, and mechanisms of injury. The objective of this study is two-fold (1) quantify sternum morphology and (2) document sternum fracture locations using computed tomography (CT) scans and crash data. Thoracic CT scans from the University of Michigan Hospital database were used to measure thoracic depth, manubriosternal joint, sternum thickness and bone density. The sternum fracture locations and descriptions were extracted from 63 International Center for Automotive Medicine (ICAM) crash cases, of which 22 cases had corresponding CT scans. The University of Michigan Internal Review Board (HUM00043599 and HUM00041441) approved the use of crash cases and CT scan data. The sternum morphomics data showed the thoracic depth increased, except for the 60-74-year-old age group. The average sternum thickness was greater in the older age groups. The sternum bone density decreased from youngest to oldest age groups. The angle between the manubrium and the sternum body decreased by 5.6° between the youngest and oldest age groups. The frequency of sternum fractures increased after age 45. Fractures were most frequent in the sternum body. The seat belt webbing was coded as the source of 54% of the sternum fractures.
Bunn, BarbaraJohannson, SuzanneKohoyda-Inglis, CarlaWang, StewartParenteau, ChantalHolcombe, Sven
Challenges in the Regulatory Framework of Automated Driving2019-26-00971/9/2019
Automated Driving (AD) is foreseen to be one of the major social and technological challenges in the coming years. Many manufacturers are developing new models with cutting-edge functionalities, which are not included in the scope of the current regulatory framework. Apart from demonstrating their know-how and expertise about AD, their willingness to sell their AD models in the European market is accelerating the rule-making system. However, which is the roadmap for the European regulatory framework? Policy makers and regulatory bodies are pushing their boundaries at all levels (national and international) in order to introduce modifications in existing regulations. These regulations will enable the introduction of these new functionalities into the market. Without decreasing the standards of safety and security, the implementation of a clear and harmonized regulatory framework and approval process is extremely needed. The last amendments of the UN Regulation n°79 related to steering equipment or the creation of new standards such as the ISO 21448 regarding Safety and Intended Functionality (SOTIF) are examples of recent efforts from the regulatory bodies to achieve this goal. The aim of this paper is to show the regulatory framework state of the art regarding automated driving. In order to provide a thorough understanding of the forthcoming amendments and new standards, the different challenges that the European Commission (EC) / United Nations Economic Commission for Europe (UNECE) are facing will be analysed, as well as the different approaches to be considered by the international regulatory bodies. Finally, as a result of this research, the conclusions will be exposed as considerations and proposals for all players involved in this change of paradigm: users, manufacturers, authorities of approval and technical services.
Lafuente, IgnacioTobar, MartaLuján, CarlesMartínez Rami, Estrella
LEAN Techniques for Effective, Efficient and Secure Information Processing in Automotive Homologation2019-26-03351/9/2019
It is an established fact that virtual knowledge based engineering has revolutionized R & D activities by streamlining processes, ensuring productivity and accuracy. This has resulted in freeing up time for quality interpretational work and decision making for engineering the best of products. Subsequently, homologation is a mandatory requisite activity for product signoff. It certifies the quality of the product and is an important factor in giving the product an authenticity for sale in the market. Homologation entails compliance to regulations existing in form of well-established standards which elaborate systematic and detailed guidelines on conducting physical testing for automotive systems, sub-systems or components for specific vehicle types. The contemporary homologation scenario encompasses heavy usage of virtual platform tasks like data acquisition, application of heuristics from the standards, post processing, classification, test output report and type approval certificate generation. It is highly desirable that the homologation procedure needs to be streamlined and of high fidelity through seamless integration of all steps involved in the information processing as well as effective capture of homologation knowledge in a virtual form. This can be achieved by LEAN knowledge based techniques. The author hereby elucidates such a LEAN knowledge based framework that captures the heuristics outlined in the homologation standards in a form comprising of a structured taxonomy to address each of the compliance requirements, and seamlessly integrates them with all the upstream and downstream information processing tasks involved in the certification. Two sample tools are showcased for expounding the efficacy of this framework. These tools are integrated into the daily test procedures followed by the testing personnel, ensuring phenomenal productivity and accuracy. In addition, these tools leverage frugal automation platforms available right on the desktop, rendering them highly cost effective. Thus both tacit and explicit regulatory and process knowledge is captured and secured effectively which also conforms to requirements of system standards such as IS0 9001 and IS0 27001.
Thipse, Yogesh
Assessment of Thoracic Response and Injury Risk Using the Hybrid III, THOR-M, and Post-Mortem Human Surrogates under Various Restraint Conditions in Full-Scale Frontal Sled Tests2018-22-000111/12/2018
A total of 20 full-scale frontal sled tests were conducted using the Hybrid III (HIII), THOR-M and post-mortem human surrogates (PMHSs) to evaluate the thoracic biofidelity of the HIII and THOR-M under various belted restraint conditions. Each surrogate was tested under three belted restraint conditions: knee bolster, knee bolster and steering wheel airbag, and knee bolster airbag and steering wheel airbag. In order to assess the relative biofidelity of each ATD, external thoracic deflections were quantitatively compared between the ATDs and PMHSs using an objective rating metric. The HIII had slightly higher biofidelity than the THOR-M for the external thoracic deflections. Specifically, the THOR-M lower chest was more compliant compared to the other surrogates. However, the THOR-M exhibited expansion of the lower chest opposite belt loading, which was also observed to some degree in the PMHSs. The efficacy of the current injury risk prediction instrumentation and criteria were also evaluated for each surrogate. The THOR-M and its proposed injury risk criteria predicted the injuries observed in the PMHS tests better than the HIII. The PMHS injury criteria over-predicted the amount of chest deflection necessary to produce a severe injury and, consequently, under-predicted injury risk. The results of this study indicate that further testing should be performed to evaluate the biofidelity of the THOR-M thorax under more conditions. Furthermore, current thoracic injury risk criteria, which were developed using censored data, may not be effective at predicting injuries for all restraints and experimental conditions.
Albert, Devon LBeeman, Stephanie MKemper, Andrew R
The Effects of Inboard Shoulder Belt and Lap Belt Loadings on Chest Deflection2018-22-000211/12/2018
Chest injuries occur frequently in frontal collisions. During impact, tension in the lap belt is transferred to the inboard shoulder belt, which compresses the lower ribs of the occupant. In this research, inboard shoulder belt and lap belt geometries and forces were investigated to reduce chest deflection. First, the inboard shoulder belt geometry was changed by the lap/shoulder belt (L/S) junction for the rear seat occupant in sled tests using Hybrid III finite element simulation, sled tests and THOR simulation. As the L/S junction was closer to the ASIS (anterior superior iliac spine), chest deflection of the Hybrid III was smaller. The L/S junction around the ilium has the potential to reduce chest deflection without significant increase of head excursion. For THOR, although the chest deflection reduction effect due to closer L/S junction to the ASIS was observed, chest deflection was still substantially large since the lap belt overrode the ASIS. Second, measures to hook the ASIS of the THOR by the lap belt were examined. Sled tests at 30 and 50 km/h were conducted with THOR in the rear seat, and it was demonstrated that the outboard lap belt and buckle pretensioners improved the lap belt and ASIS interaction, and were also useful in reducing the deflection at the inboard-side of the lower chest. Finally, the lap belt overlap with the ASIS was compared among 10 volunteers, Hybrid III, and THOR. Some volunteers had the ASIS located at the torso-thigh junction, and the lap belt did not overlap the ASIS sufficiently. However, although the ASIS location of THOR is also at the torso-thigh junction, the lap belt overlapped the ASIS because of the abdomen’s and femur’s shape. In the future, it will be necessary to consider that the outboard lap belt and buckle pretensioners are also effective for the ASIS restraint of all human car occupants.
Mizuno, KojiYoshida, RyoichiNakajima, YutakaTanaka, YoshihikoIshigaki, RyotaHosokawa, NaruyukiHitosugi, Masahito
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