Browse Topic: Passive restraint systems

Items (1,150)
Find
An Integrated Workflow for Structural Dynamics, Comfort, and Airbag Deployment for Virtual Seat DesignF-0082-2026-03295/5/2026
This paper presents an integrated simulation workflow for aircraft seat development that combines (i) structural dynamics and certification load cases, (ii) occupant comfort and living-space assessment using finite-element digital humans, and (iii) airbag folding, deployment, and calibration using a coupled gas-dynamics solver suited to early-time transients. The workflow is built around a single manufacturing-aware, as-built seat model that is reused across comfort, certification, and restraint-system studies, allowing design iterations to move upstream before design freeze. Each stage is paired with validation or industrial case examples, and the airbag-calibration process is accelerated through reduced-order modeling (ROM) of parameter identification. The result is a practical virtual-seat-development methodology that is sufficiently predictive to de-risk physical testing while remaining fast enough for concept iteration and late-stage compliance support.
Dwarampudi, Ramesh, Vaz, Ignatius
A Study on the Injury Risk of Occupant with Different Head and Neck Rotating Postures under the Frontal Impact Sled Conditions2026-01-05744/7/2026
Drivers obtain road information through head and neck rotation. In order to study the influences of head and neck rotation posture on occupant injury in frontal impact scenario, the THUMS (Total Human Model for Safety) AM50 human body model with five different head and neck rotation postures but without active muscles was adopted to study the biomechanical injury responses of occupant under the frontal impact scenario at 56 km/h in this study. Firstly, the kinematic responses of total body and head acceleration curves at the center of gravity predicted by PMHS (Post Mortem Human Subject) and THUMS AM50 human model under the sled test conditions were compared to verify the simulation model for subsequent study. Then, the THUMS AM50 human model with standard occupant seating posture was adjusted to have five different head and neck rotation postures with 0°, ±20°, and ±40° rotation angle, respectively. Finally, a series of frontal impact sled with or without airbag simulations were conducted for each THUMS AM50 human model with different head and neck rotation postures. The simulation results showed that with the increasing of head and neck rotation angle, the neck injury risk was increased while the thoracic injury risk was decreased. Regardless of whether airbags were present or absent, the model prediction for the standard posture indicated a lower injury risk. And regardless of whether the head and neck posture changed, the airbag always could provide a certain protection in that posture.
Li, Dongqiang, jiang, Yejie, Tan, Chun, Li, Yanyan, Gong, Chuangye, Wu, Hequan, Jiang, Binhui
Numerical Investigation on Thorax Rib Deflections of 50th Male in Vehicle Side Oblique Pole Impact Using Human Body Model2026-01-05664/7/2026
The WorldSID-50M dummy is widely adopted in regulatory and third-party testing programs (e.g., ECE, Euro-NCAP, C-NCAP) owing to its advanced design and superior biofidelity. However, in vehicle side oblique pole crash tests involving shoulder-covered side airbags - an expanded testing modality - excessive deflection of the upper thoracic ribs was observed. Notably, this phenomenon was absent in standard side moving deformable barrier (SMDB) tests. This study pursued two core objectives: (1) to systematically document the excessive upper thoracic rib deflection of the WorldSID-50M dummy in side oblique pole crash tests; and (2) to investigate the influence of arm-thorax interaction on such deflection using a Human Body Model (HBM) representative of a 50th percentile male occupant. Numerical simulation results reveal that while arm-thorax interaction does contribute to rib deflection, its impact on the excessive deflection of the upper thoracic ribs is negligible.
Zhou, DY, Chen, Shaopeng, Yan, Li, Wu, Jing, Liu, Chong, Lv, Xiaojiang, Yang, Heping
Effects of Child Anthropometry, Seatback Angle, Seat Rotation Angle, Seatbelt Force Limiting, and Collision Type on Injury Risk of Child Occupants in Highly Automated Vehicles2026-01-05704/7/2026
This study aimed to evaluate the influence of child anthropometry, seating postures (recline and rotation), seatbelt force limiting, and frontal collision scenarios on the kinematic response and injury risk in highly automated vehicles. The TUST IBMs 6YO-O model was conducted the frontal collisions in sled tests. This simulation matrix includes five percentiles six-year-old occupants (P3, P25, P50, P75, and P97), three seatback angles (20°, 30°, and 45°), four seat rotation angles (0°, 90°, 180°, and 270°), three seatbelt force limiting (2.6 kN, 3.6 kN, and 4.6 kN), and three frontal collision types. Injury risks were assessed including the child occupant's head, neck, chest/abdomen, and lumbar region in each simulation (n=540). The results indicate that the child anthropometry, the seatback angle, and the seat rotation angle have a significant influence on the motion responses. Statistically significant differences between all the groups within each independent variable category were observed based on the analysis of variance. As the child dimension increases, the risk of head injury decreases showing by HIC15, while the risk of neck and lumbar injuries increases. As the seatback angle increases, biomechanical parameters of the head show an increasing trend. The risk of upper neck injury decreases, while the risk of lumbar injury decreases and then increases. As the seat rotation angle increases, the risks of head, neck, and chest injuries initially rise and subsequently decrease, while the risk of lumbar injury demonstrates a downward trend. Seatbelt force limiting exhibited a positive correlation with head, neck, and lumbar injury risks. Consequently, small percentile child experiences higher head loads in smart cockpits, with seatback angle and seat rotation angle being key factors contributing to child injuries. These findings highlight the critical need to address the vulnerability of smaller children in smart cockpits by adapting integrated active and passive safety systems to mitigate their injury risk.
Wang, Yanxin, Zhao, Hongqian, Li, Haiyan, He, Lijuan, Cui, Shihai, Lv, Wenle
Leveraging Machine Learning for Occupant Body Size Estimation via B-Pillar Seatbelt Systems2026-01-05594/7/2026
Occupant body size in vehicles varies significantly, encompassing differences in height, mass, and overall body composition. Adaptive restraint systems, featuring adjustable parameters such as belt load limiters, steering column load limiters and stroke, seat pan stiffness, and airbag pressure, can offer more equitable protection tailored to individual body sizes. In this study, a test rig modeled after the Volvo XC90 (2016) was used to collect data from 46 participants who were dressed in typical summer clothing and seated upright, without slouching or leaning sideways. Stepwise adjustments of the seat pan and seatback were performed. The collected measurements include seat pan movements (front-back and up-down), seatback recline, and key seatbelt-related parameters, such as belt payout length, D-ring angle, lap belt length, and buckle tension. The collected data was then used to train machine learning models to predict individual occupant characteristics: standing height, mass, and seated height. This study shows the challenges and opportunities for occupant body size estimation from seatbelt and seat location inputs. The prediction’s root mean square error across validation dataset was as follows: standing height 8.76cm, mass 11.33kg, and seated height 5.61cm. The prediction of mass fulfilled the defined criterion, while the prediction accuracy for standing height and seated height require further improvement. Our analysis reveals that a key improvement could be achieved by implementing an upgraded lap belt position sensor, given that lap belt length was identified as a dominant feature across models. Furthermore, the analysis suggests that D-ring angle, buckle tension, and seatback recline can be excluded from the input feature set.
Wang, Da, Ahmed, Jawwad, Rowe, Mike, Brase, Dan
Side Crash Pressure Sensor Response Prediction: CPM Approach2026-26-04131/16/2026
Side crashes are generally hazardous because there is no room for large deformation to protect an occupant from the crash forces. A crucial point in side impacts is the rapid intrusion of the side structure into the passenger compartment which need sufficient space between occupants and door trim to enable a proper unfolding of the side airbag. This problem can be alleviated by using the rising air pressure inside the door as an additional input for crash sensing. With improvements in the crash sensor technology, pressure sensors that detect pressure changes in door cavities have been developed recently for vehicle crash safety applications. The crash pulses recorded by the acceleration based crash sensors usually exhibit high frequency and noisy responses. The data obtained from the pressure sensors exhibit lower frequency and less noisy responses. Due to its ability to discriminate crash severities and allow the restraint devices to deploy earlier, the pressure sensor technology has gained its popularity for side crash applications. CAE based calibration approach reduces cost of multiple physical tests required for side airbag algorithm development to deploy the airbags. With a goal to achieve CAE based calibration such that side airbag deployment algorithms can be enhanced with the help of pressure sensors, Corpuscular Particle Method (CPM) was adopted to predict the pressure responses of side crash pressure sensors. The major challenge was to capture the change in pressure accurately in side door cavity during an event of side crashes in digital environment. In addition, the challenge was to develop robust CAE methodology that can predict sensible pressure responses during event of high speed as well as low speed side crashes. This paper describes the innovative CPM airbag based methodology developed to predict the pressure response and its correlation with side impact physical tests.
Bhagat, Milind, Narale, Naganath, Mahajan, Ashutosh, Wayal, Virendra, Jadhav, Swapnil
Integrated Evaluation of Pre-Crash Braking and Crash Injury Outcomes Using Human Body Models and ATDs2026-26-00191/16/2026
Traditionally, occupant safety research has centered on passive safety systems such as seatbelts, airbags, and energy-absorbing vehicle structures, all designed under the assumption of a nominal occupant posture at the moment of impact. However, with increasing deployment of active safety technologies such as Forward Collision Warning (FCW) and Autonomous Emergency Braking (AEB), vehicle occupants are exposed to pre-crash decelerations that alter their seated position before the crash. Although AEB mitigates the crash severity, the induced occupant movement leads to out-of-position behavior (OOP), compromising the available survival space phase and effectiveness of passive restraint systems during the crash. Despite these evolving real-world conditions, global regulatory bodies and NCAP programs continue to evaluate pre-crash and crash phases independently, with limited integration. Moreover, traditional Anthropomorphic Test Devices (ATDs) such as Hybrid III dummies, although highly repeatable, lack the bio-fidelity necessary to capture human-like kinematics during pre-crash braking events involving low g. ATDs do not simulate the spinal articulation, posture adjustments and active muscle contraction that occur during emergency maneuvers or pre-crash scenarios. To overcome these limitations, researchers have increasingly turned to Human Body Models (HBMs) such as Total Human Model for Safety (THUMS) and Global Human Body Model Consortium (GHBMC). These models enable high-fidelity finite element (FE) simulations with anatomical realism, allowing for the inclusion of active musculature and posture changes. This study aims to quantify the occupant forward excursion under pre-crash phase (due to AEB) and explore the possibility of an integrated simulation framework that evaluates occupant safety across both pre-crash and crash events. For this, the approach was to carry out full vehicle braking tests (1g braking pulse) with adult male (AM50) volunteers at different speeds to measure forward head excursion during pre-crash. These scenarios were replicated in LS-Dyna using THUMS HBM, showing strong agreement with experimental data. The resulting excursed postures were then used in crash simulations with ATDs to evaluate the effect on injury outcomes. Overall, the findings demonstrate effect of forward excursion on occupant injuries and the effectiveness of HBMs in capturing occupant kinematics, during pre-crash events.
Pendurthi, Chaitanya Sagar, THANIGAIVEL RAJA, T, Kondala, Hareesh, Sudarshan, B.Sudarshan, Nehe, Vaibhav, Rao, Guruprakash
Geometrical Assessment of the Curtain Airbag Coverage in Indian Passenger Vehicles2026-26-00211/16/2026
Curtain airbags are the most effective protective systems to prevent severe/fatal head injuries in side collisions with narrow objects such as poles or trees. One of the important parameters of curtain airbags is the inflated zone i.e. the coverage area of the airbag, which decides the extent of head protection for occupants with different anthropometries in different seating rows. EuroNCAP first introduced the concept of Head Protection Device Assessment (HPDA) in 2015., In addition to the performance requirements in the dynamic test, EuroNCAP started assessing the deployed curtain airbag/s for its area coverage and verification of inflated zones for various anthropometries over occupant rows. In India, there is now a near total adoption of curtain airbags as standard fitment by the OEMs. Further, introduction of Bharat NCAP (BNCAP), a Perpendicular Pole Side Impact test is conducted for assessing the effectiveness of curtain airbags in a dynamic test, but currently, does not perform the HPD assessment. The paper studies the Head Protection Device/Curtain Airbags offered in Passenger Vehicles in India w.r.t. the Head Protection Device Geometric Assessment (HPDA). This assessment analyses the effectiveness of curtain airbags present in Indian passenger vehicles for protection of occupants of different anthropometries. The study is conducted on the vehicles that have been tested at ARAI and are also currently under sale in the Indian market.
Jaju, Divyan, Kulkarni, Dileep, Mahajan, Rahul
Packaging the HPTS Airbag in a Second-Row Seat2026-26-00331/16/2026
Seats of modern cars should necessarily meet the regulatory safety norms along with aesthetics and comfort. In the existing passenger cars prevailing across the Indian subcontinent, the measure of safety has been a challenging one. The stringent regulatory norms thereby make the Airbag very promising. In the Automotive industry, safety features are very important, one of the topmost features which falls in this category is airbags. The driver and passenger safety during high impact collisions and sudden crashes is the key objective of airbag. This safety is provided by the airbag with its automatic deployment. The inflatable airbag is engineering in a way to respond very quickly during a collision and furnish necessary cushioning to decrease the impulse and enhance the safety of the passenger. The technology has been practiced widely upon many vehicles' seats. However, the present work highlights a novel approach of packaging the HPTS air bag in second row seat. This Air bag unit is fitted in the seat back frame at outboard ends of backrest. The modification is done in seat frame, foam, and trim in such a way to Airbags should be deployed in moderate to severe collisions. This study revolves around the integration and modifications in the mandatory HPTS airbag packaging requirements. This study is done to emphasize the engineering and regulatory prerequisites and their respective challenges. This study also touches on the details of mounting schemes and the evaluation of the perceived quality in implementing HPTS airbag feature on the second-row bench seat.
Buradkar, Rajat, Bose, Karthik, Jadhav, Deepika, Balakrishnan, Gangadharan
Safer Trucks for India: Smart Tech Fusion2026-26-00311/16/2026
Commercial vehicle sector (especially trucks) has a major role in economic growth of a nation. With improving infrastructure, increasing number of trucks on roads, accidents are also increasing. As per RASSI (Road Accident Sampling System India) FY2016-23 database, commercial vehicles are involved in 42% of total accidents on Indian roads. Involvement of trucks (N2 & N3) is over 25% of total accidents. Amongst all accident scenarios of N2 &N3, frontal impacts are the most frequent (26%) and causing severe occupant injuries. Today, truck safety development for frontal impact is based on passive safety regulations (viz. front pendulum – AIS029) and basic safety features like seatbelts. In any truck accident, it is challenging rather impossible to manage comprehensive safety only with passive safety systems due to size and weight. Accident prevention becomes imperative in truck safety development due to extremely high energy involved in front impact scenarios. The paper presents a unique safety development approach (for frontal impact safety development for N2 and N3 trucks) which enables smart synthesis of active and passive safety systems to comprehensively address real world safety. Four major areas are identified for truck safety development viz. structural crashworthiness, compatibility, occupant safety and ADAS (Advanced Driver Assistance System). The innovation lies in smart mix of these areas during product safety development. The study presents the safety development of light commercial vehicle (truck) with this approach. Structural crashworthiness & occupant safety are developed with extensive number of CAE simulations. Design is physically validated with frontal impact test. In addition, extensive mileage accumulation is generated across Indian roads to validate ADAS system performance.
Joshi, Kedar Shrikant, Gadekar, Ganesh, Date, Atul, Koralla, Sivaprasad
Achieving Robust Sensing Performance for Six-Airbag Systems: Design Approaches and Validation Techniques for Side Sensing2026-26-00301/16/2026
The proposal of GSR 16(E) in India promotes six airbags in passenger vehicles, aiming to enhance occupant safety. In parallel, the new Bharat New Car Assessment Program (BNCAP) outlines performance protocols that demand robust airbag deployment strategies to achieve a five-star safety rating. One of the critical challenges in meeting both regulatory and consumer safety expectations is the optimal packaging of the airbag Electronic Control Unit (ECU) and its associated impact sensors. These must perform reliably across regulatory tests, BNCAP protocols, and real-world accident scenarios. The location of side acceleration ‘g’ side impact sensors—whether mounted on the side sill, B-pillar, C-pillar, or door structures—is pivotal to achieving consistent and timely side airbag deployment. These sensors must also demonstrate immunity to false triggers or missed events in both static and dynamic misuse and abuse conditions. Ensuring robust sensor performance under these varied conditions is key to the success of the system. This study focuses on evaluating acceleration-based side impact sensors placed at different locations within the vehicle structure, assessing their sensitivity and correlation with airbag deployment performance. Additionally, for compact vehicles where faster deployment of side airbag is essential, the use of pressure-based sensors was investigated. The findings of this study were instrumental in finalizing the optimal packaging strategy for both acceleration and pressure sensors in six-airbag systems.
Kudale, Shailesh, Rao, Guruprakash, wayal, Virendra, Goswami, Tarun
Vehicle Electrical Architecture: A Review of Wiring Harness Routing Optimization Strategies2025-36-013012/18/2025
The modern vehicle electrical architecture consists, on average, of 30 integrated electronic modules (ABS, infotainment, instrument panel, etc.), also known as Electronic Control Units (ECUs), and approximately 300 peripherals such as sensors (collision, temperature, oxygen, position, pressure, etc.) and actuators (window motor, mirror motor, relays, airbag inflator, windshield wiper, etc.). This increase in component integration imposes significant challenges to system installation and design. The interconnection of multiple devices renders harness design an arduous and time-consuming task, especially when conducted manually, resulting in error-prone and suboptimal outcomes. Such a scenario highlights the pressing need for studies on harness routing optimization in the automotive industry. Historically, wiring harness design practices have transitioned from manual approaches to the adoption of advanced computational tools. This methodological transition encompasses the use of various techniques, such as algorithms, 3D simulation, and machine learning, aiming for effective solutions to this complex challenge. In this context, the present work aims to conduct a literature review on wiring harness routing optimization strategies, with an emphasis on their application in vehicular electrical architecture. The current academic literature indicates that advancements in optimization approaches are crucial, especially through the application of methods such as Genetic Algorithms, Agent-Based Modeling and Simulation, Integer Linear Programming (ILP) and Linear Programming (LP) applied to the Steiner Tree Problem, Simulated Annealing, Ant Colony Systems, Particle Swarm, among others. Such methodologies are fundamental not only for developing lighter and more compact harnesses but also for a more efficient exploration of available physical space, culminating in layout development time optimization.
Ribeiro, Thiago, Reis, Breno, Barreto, Zeus, Galeno, Antônio, Pereira, Marcelo, Ferreira, Fláavio Fabrício V. M.
Study on the Sled Test of Far-Side Test and the Influencing Factors of Dummy Damage2025-99-033112/17/2025
The addition of far-side occupants evaluation conditions in C-NCAP2024 version is an important consideration in the development of passive safety in vehicles. This article conducts analysis and research on key points such as test conditions, test results, and influencing factors. Firstly, introduce the test conditions, methods, and protection evaluation of far-side occupants. Secondly, analyze the distribution of factors such as airbag type, armrest height, test waveform, head offset, and dummy damage in the test data. Finally, analyze the influence of five factors, including airbag type, armrest height, test waveform, test conditions, and belt pre-tightening, on the test results. Analysis has found that the WorldSID 50th dummy’s lower neck MX is prone to exceeding high performance limits, compared to single chamber and double chamber airbags, three chamber airbags provide better protection for far-side occupants; For loading waveforms, the probability of the head being in the orange area is lower when the waveform peak is less than 40g, and the probability of the head falling in the green area is lower when the OLC value is greater than 25g.
He, Yonglong, Gu, Haiming, Guo, Xiaotian, Wang, Jingchen
Research and Analysis on Airbag Dangerous Deployment Evaluation Based on 2024 Version C-NCAP2025-99-007310/17/2025
Research on the subjective items of airbag dangerous deployment in the 2024 version of C-NCAP regulations, which includes two aspects: the action of the airbag sweeping over the face and the speed of airbag deployment. This article starts from other aspects. On the one hand, when examining the action of airbags sweeping over the face, it is necessary to consider the acceleration index. Based on the head injury index of the front dummy in collision in C-NCAP, the injury index of face - sweeping risk is defined; On the other hand, the force level of facial injury should also be examined, and the definition and experimental methods should be discussed based on the force level that the head can withstand. Added airbag deployment hazard assessment for the HIII 5 female dummy.
Tian, Wei, Xue, Kaile, Wang, Qinggui
Nonlinear Finite Element Calculation of Ultimate Breakage Load for Pyro-Inflator Housing2025-01-50456/27/2025
Accurate prediction of the ultimate breakage pressure load for pyro-inflator housing is a critical aspect of inflator development. In this study, the tensile test of a specimen, from its initial shape to fracture, is simulated to verify the material properties of the inflator housing. The numerical results demonstrate high accuracy, with the tensile force–displacement curve, maximum tensile force, necking in the concentrated instability zone, fracture location, and inclined angle all closely matching the experimental data. Following material correlation, the ultimate breakage load of the inflator housing under hydrostatic burst test conditions is calculated using an explicit solver. A stress tensor state analysis method is proposed to define the ultimate load based on the onset of plastic instability in the thickness direction at the top center of the inflator. Compared to experimental results, the accuracy of the ultimate breakage pressure prediction using this method is 99.04%, while the accuracy using the arc-length implicit algorithm is 97.10%. By analyzing the stress and strain changes in key positions during uniaxial tensile and hydrostatic burst biaxial tensile tests, this method provides high precision in forecasting ultimate loads and defining fracture strains. Future work will investigate dynamic loading effects and machine learning–enhanced instability criteria, with particular attention to the influence of manufacturing stamping processes on predictive model accuracy.
Wang, Cheng
The Applications of Acoustic Black Holes to Attenuation of Coach/Bus Frame Structure Vibrations2025-01-00655/5/2025
Basic structures of vehicle frames、aircraft fuselages and ship hulls are made of beams、columns and trusses. If Acoustic Black Holes(ABH) are carefully arranged alongside with the wave propagation paths in those structures, the wave propagation paths could be changed at NVH engineers’ will and the structure vibrations can be reduced. Two kinds of ABHs are used in this paper: one is ABH made of Polyurethane(PU), other one is ABH composed of several steel plate 1D ABH stacked up in parallel. Three structures are used to test the effectiveness of ABHs for vibration reductions: a squared hollow sectional steel commonly used in motorcoach/bus chassis and frame structures, a simple frame for motorcoach airbag suspension and a 12m chassis structure. The attached ABHs show a great vibration attenuation in terms of transfer functions on the basic structure element for a motorcoach. The lateral, vertical and longitudinal transfer functions for steel ABHs were greatly reduced from 13.2~14.7 dB. Then test was extended to a simple frame that is common structure for motorcoach airbag suspension. The results show that ABHs have3.6~6.3 dB vibration attenuations. Based on those tests, the ABHs were also added to a 12-meter motorcoach chassis frame. The ABHs were attached at rear left upper disk for airbag suspension and at the seat fixing bolt area, the transfer function from the airbag suspension upper disk to seat fixing bolt area was reduced about 3dB. These effective vibration reductions show the great capabilities of ABHs to attenuate the structure vibrations for motorcoach and bus and ABHs could play a crucial role in attenuating structural vibration, structural noise radiation and structure-borne noise in motorcoach and bus.
Xu, Chuanyan, Wang, Jianjun, Xing, Qisen, Chen, Hengbin, Huang, Xianli
USCAR FRONTAL AIRBAG PERFORMANCE SPECIFICATIONUSCAR52 (Current)4/9/2025
This specification establishes the DV/PV performance and validation requirements for frontal airbag modules, namely driver, passenger, and knee airbags. In cases where airbag designs fall outside the scope of this standard, the Responsible Vehicle Engineering Organization (RVEO) is the final arbiter of all performance requirements within this specification. Additional system level requirements may be introduced by the RVEO but are outside the scope of this specification.
USCAR
Analysis of the Event Data Recorder Vehicle System Data of a GM Vehicle Intelligence Platform Airbag Control Module (SDM50)2025-01-87144/1/2025
The primary function of an Airbag Control Module (ACM), referred to as the Sensing and Diagnostic Module (SDM) by General Motors (GM), is to detect crashes, discriminate crashes, evaluate crash severities, deploy the appropriate restraints, including airbags and pretensioners, and perform system diagnostics. A secondary function of the SDM is to act as an Event Data Recorder (EDR) which records data during the time periods just prior to (pre-crash) and during a crash event. This data consists of restraint and vehicle system data which is collected, processed, and stored in the EDR. Data stored in the EDR is intended to be retrieved after a crash. This data provides operational information on the vehicle’s occupant protection system and other vehicle systems to assess system performance, aid in crash reconstruction, and support improved vehicle safety. A series of vehicle test maneuvers were conducted while injecting a non-deployment crash pulse directly into the SDM to cause the SDM to record an event with related restraint and vehicle system (pre-crash) data. These tests include a variety of constant speed, acceleration, braking, and steering maneuvers. During these maneuvers, vehicle system data was recorded directly from the serial data bus using a passive monitoring tool, tapped sensors, video cameras, and independent onboard instrumentation and that data was compared with the data recorded within the SDM EDR. This paper addresses the operation and accuracy of the vehicle system data recorded for a crash event by the SDM, specifically the SDM50 and its utilization of the GM Vehicle Intelligence Platform (VIP) vehicle serial communication bus. Evaluation of this data provides an understanding of the accuracy of the vehicle system data recorded for a crash event by the SDM.
Smyth, Brian, Crosby, Charles L, Bickhaus, Ryan, Smith, James, Edmunds, Dustin, Floyd, Donald, Modi, Vipul, Outlaw, RaShawndra D., Wright, Jeff
Headliner Design Considerations to Meet Safety and Regulations2025-01-82454/1/2025
Headliners are one of the largest components inside an automobile, stretching from the front windshield to the rear windshield. Besides its aesthetic purpose, it contributes to multiple other purposes like housing different components, helps in NVH, defines the interior roominess, and plays a crucial role in defining the deployment of curtain airbag. The headliner also plays a role in meeting regulatory requirements like upward visibility and headroom requirements of the occupants. During the deployment of curtain airbag, it is important that the headliner-pillar interface aids in the easy opening of airbag, with the least hindrance. This is defined by multiple factors like the location of headliner-pillar interface, its distance from the airbag ramp bracket, the position of the inflator, the mountings of the headliner and pillar trims, to name a few. Also, during the deployment of the airbag, it is important that parts such as grabhandle, speaker grilles, etc which are fitted on the headliner does not get detached or break off, which in turn can be dangerous to the occupants. The design of pillar trims and the ramp bracket also plays a critical role in ensuring that the pillar trim edges are secure during the airbag deployment, and aid in the easy release of airbag into the cabin. Incorrect design of headliner or pillar trim, can result in different problems such as improper airbag deployment, airbag getting struck between pillar trim to body, fly-off of headliner child parts, etc. This would also result in several iterations of design which is a waste of time and resources. In this paper, we cover various design aspects of headliner assembly to meet the safety and regulations and have an improved deployment of curtain airbag. By considering the design aspects upfront, we were able to save at least two iterations of air bag deployment and quicken the development time by four months.
Sabesan, Arvind Kochi, D., Anantha, Kakani, Phani Kumar
Effects of Aging on PVC-Based Instrument Panel Skin for Passenger Airbag Deployment Analysis2025-01-83214/1/2025
Plasticized polyvinyl chloride (PVC) has many applications in automotive industry including electrical harnesses, door handles, seat and head rest covers, and instrument panel (IP) and other interior trim. In IP applications, the PVC skin plays a critical role in passenger airbag deployment (PAB) by tearing along the scored edge of the PAB door and allowing the door to open and the airbag to inflate to protect the occupant. As part of the IP, the PVC skin may be exposed to elevated temperatures and ultraviolet (UV) radiation during the years of the vehicle life cycle which can affect the PVC material properties over time and potentially influence the kinematics of the airbag deployment. Chemical and thermal aging of plasticized PVC materials have been studied in the past, yet no information is found on how the aging affects mechanical properties at high rates of loading typical for airbag deployment events. This paper compares mechanical properties of the virgin PVC-based IP skin material with the same material after it has been exposed to 110°C for 400h. Both, virgin and aged materials, were tested at three temperatures, viz. -30°C, 23°C and 85°C and at four strain rates ranging from 0.01/s to 100/s. Finally, effects of the aged material on the PAB deployment simulation are discussed.
G, Karthigan, Savic, Vesna, Ravichandran, Gowrishankar
Deployment of Electrically Activated Automotive Airbags for Automobile ReclamationJ1855_202412 (Current)12/10/2024
This SAE Recommended Practice describes the method for safe deployment of airbag modules in vehicles equipped with electrically actuated airbag systems for the purpose of disposal. It is intended to provide a procedure that does not require significant technical expertise, is easy to operate, and is readily available to be used by automobile dismantlers or vehicle shredders to deploy airbag modules prior to automobile reclamation.
Inflatable Restraints Committee
An Intelligent Estimation of Dynamic Vehicle Mass for Electric Vehicle2024-28-022912/5/2024
Dynamic Vehicle mass is one of the most critical parameters in automotive controls such as battery management, transmission shift scheduling, distance-to-empty predictions and most importantly, various active and passive safety systems. This work aims to find out dynamic Vehicle mass for Electric Vehicles in real time transient driving conditions. The work proposes a real-time approach in finding Dynamic vehicle mass where accumulated Energy based vehicle performance, an improvement to the vehicle dynamics equation, has been employed for consistent and accurate results. Factors affecting vehicle mass such as road grade, dynamic friction coefficient, driving pattern, wheel slip etc. have been considered for model optimization. Here recursive Bayesian state estimator has been used for finding vehicle mass as a constant state variable while time varying forgetting factors are used to nullify the impact of major losses. Algorithm is auto tuned using Machine Learning techniques to first find out stable driving conditions and subsequently go for model application to converge towards the end results. The performance of the proposed vehicle mass estimator is validated against several groups of payload in varying surrounding conditions. The results demonstrate that the output of the model is well within 10% to 15% error in all such cases and consistent results are obtained for more than 90% of the test scenarios.
Pandey, Suchit, Sarkar, Prasanta, Sawhney, Chandan, Kondhare, Manish, Joshi, Pawan, CH, Sri Ram
ZF's latest safety advances open up, tighten up and DOUBLE DOWN24AUTP08_028/1/2024
ZF rethinks safety with new airbags, belt tensioner. ZF knows that the steering wheel remains one of the most relevant components in an automotive interior, because this is where drivers have direct contact to the vehicle. As steering wheels become adorned with more functions than some drivers know what to do with, ZF put Marc Schledorn in charge of the teams rethinking how the driver airbag could operate in a world with ever-busier steering wheels. The solution is a new type of steering wheel airbag that ZF Lifetec (ZF's renamed Passive Safety Systems division) announced in June. Instead of moving through a thermoplastic airbag cover mechanically fixed in the center of the wheel, Schledorn told SAE Media, the new design positions the airbag on the top side of the steering wheel and then expands through the upper rim of the wheel when needed.
Blanco, Sebastian
Study of Crew Seat Impact Attenuation System for Indian Manned Space Mission2024-26-04696/1/2024
The descent phase of Indian Manned Space Mission culminates with a crew module impacting at a predetermined site in Indian waters. During water impact, huge loads are experienced by astronauts. This demands an impact attenuation system which can attenuate the impact loads and reduce the acceleration experienced by astronauts to safe levels. Current state of the art impact attenuation systems uses honeycomb core, which is passive and can only be used once (at touchdown impact) during the entire mission. Active and reusable attenuation systems for crew modules are still an unexplored territory. Three configurations of impact attenuators are selected for this study for the crew module configuration, namely, hydraulic damper, hydro-pneumatic damper and airbag systems. All the subsystems are mathematically modelled, and initial sizes are estimated using Genetic Algorithm and SQP optimization techniques. Semi-active control for Hydraulic and Hydro-Pneumatic dampers are implemented and evaluated against its passive counterpart. An airbag impact attenuation system is studied and its performance in two configurations, stuck and unstuck are evaluated. Venting will not cease for the former configuration, whereas it is pressure controlled for the latter. For zero-degree impact load case, Brinkley DRI (Direct Response Index), a NASA HSIR index on the risk of likelihood of spinal damage, is reduced by 36% for hydraulic damper and 22% for Hydro-Pneumatic damper using semi-active control and 15% for Airbag system. Hydraulic dampers were proven to be superior to Airbag and Hydro-Pneumatic systems within the spatial constraints imposed by the present crew module configuration.
Avirah, Nohin K, Lakshman, Dasu Deva Karthik, Potnuru, Sai Santhosh, Pramod, Athul P, Kurian, Sabin
Analysis of the Event Data Recorder (EDR) Function of a GM Active Safety Control Module (EOCM3 LC)2024-01-28884/9/2024
The Advanced Driver Assistance System (ADAS) is a comprehensive feature set designed to aid a driver in avoiding or reducing the severity of collisions while operating the vehicle within specified conditions. In General Motors (GM) vehicles, the primary controller for the ADAS is the Active Safety Control Module (ASCM). In the 2013 model year, GM introduced an ASCM utilizing the GM internal nomenclature of External Object Calculation Module (EOCM) in some of their vehicles produced for the North American market. Similar to the Sensing and Diagnostic Module (SDM) utilized in the restraints system, the EOCM3 LC contains an Event Data Recorder (EDR) function to capture and record information surrounding certain ADAS or Supplemental Inflatable Restraint (SIR) events. The ASCM EDR contains information from external object sensors, various chassis and powertrain control modules, and internally calculated data. This event data includes date and time, GPS location, driver inputs and vehicle responses, and information regarding ADAS objects of interest. This paper addresses the operation and accuracy of the EDR data recorded by an ASCM, specifically the GM EOCM3 LC, and its utilization of the GM Vehicle Intelligence Platform (VIP) inter-module serial communication bus. A series of vehicle Automatic Emergency Braking (AEB) test maneuvers were conducted, triggering the ASCM EDR function. The vehicle dynamic state was independently monitored and recorded by onboard instrumentation and compared to the ASCM recorded data. Evaluation of these data provides a better understanding of the accuracy and timing of this event data recorded by the General Motors' ASCM.
Bare, Cleve, Skiera, Jason, Smyth, Brian, Beetham, Tommy, Floyd, Donald, Koo, Winston, Newell, Devin
Art Meets Automotive: Design of a Curve-Adaptive Origami Gripper for Handling Textiles on Non-Planar Mold Surfaces2024-01-25754/9/2024
The handling of flexible components creates a unique problem set for pick and place automation within automotive production processes. Fabrics and woven textiles are examples of flexible components used in car interiors, for air bags, as liners and in carbon-fiber layups. These textiles differ greatly in geometry, featuring complex shapes and internal slits with varying material properties such as drape characteristics, crimp resistance, friction, and fiber weave. Being inherently flexible and deformable makes these materials difficult to handle with traditional rigid grippers. Current solutions employ adhesive, needle-based, and suction strategies, yet these systems prove a higher risk of leaving residue on the material, damaging the weave, or requiring complex assemblies. Pincer-style grippers are suitable for rigid components and offer strong gripping forces, yet inadvertently may damage the fabric, and introduce wrinkles / folded-over edges during the release process. Non-planar surfaces such as the curvature of a mold, introduce additional placement challenges. Thus, a contour-adapting end-effector able to manipulate textiles without damage is desired. This research explores the feasibility of a Miura-Origami fold for material handling. The geometric tessellation is to create a curve-fitting, self-collapsing gripper. Living hinge elements are integrated to achieve controlled compliance. Variants are built using a material extrusion additive manufacturing process. The design parameters are outlined, and a set of origami grippers are built for experimental testing. The compression forces and deflection are measured. These grippers are spring-like but exhibit some unique characteristics. More research needs to be performed to understand the merits and limitations of this gripper strategy.
Strelkova, Dora, Urbanic, Ruth Jill
Analysis of Fluid Evidence on Various Vehicle Components2024-01-24674/9/2024
Determining occupant kinematics in a vehicle crash is essential when understanding injury mechanisms and assessing restraint performance. Identifying contact marks is key to the process. This study was conducted to assess the ability to photodocument the various fluids on different vehicle interior component types and colors with and without the use of ultraviolet (UV) lights. Biological (blood, saliva, sweat and skin), consumable and chemical fluids were applied to vehicle interior components, such as seatbelt webbing, seat and airbag fabrics, roof liner and leather steering wheel. The samples were photodocumented with natural light and UV light (365 nm) exposure immediately after surface application and again 14 days later. The review of the photos indicated that fabric type and color were important factors. The fluids deposits were better visualized on non-porous than porous materials. For example, blood was better documented on curtain airbags than side or driver airbags. Blood and chemical fluids were more difficult to document on black than beige seatbelt webbing, while skin showed better on black webbing. Biological fluids were better detected with UV light. The visual presentation did not change substantially between initial and follow-up documentation with and without UV light. Fluids and components with luminescent properties were also factors. This study provides a photodocumentation summary of biological and other fluids on vehicle interior components. In conclusion, UV light exposure was helpful in highlighting some fluid deposits during crash investigation. While UV illumination provided additional insight, further investigation is necessary to discriminate and differentiate fluids present.
Boysen, Kevin, Parenteau, Chantal, Toomey, Daniel, Gregg, Richard H.
Side Impact Characteristics in Modern Light Vehicles2024-01-26464/9/2024
Occupant protection in side impacts, in particular for near-side occupants, is a challenge due to the occupant’s close proximity to the impact. Near-side occupants have limited space to ride down the impact. Curtain and side airbags fill the gap between occupant and the side interior. This analysis was conducted to provide insight on the characteristics of side impacts and the relevancy of currently regulated test configurations. For this purpose, 2007-2015 NASS-CDS and 2017-2021 CISS side crash data were analyzed for towed light vehicles. 2008 and newer model year vehicle data was selected to ensure that most vehicles were equipped with side/curtain airbags. The results showed that side impacts accounted for approximately 26.7% of the vehicles involved and 18.9% of the vehicles with at least one seriously injured occupant. Most side impacts involved damage to the front and front-to-center of the vehicle. For seriously injured (MAIS 3+F) occupants, impacts to the occupant compartment accounted for more than 83% when near-sided and 86% when far-sided. Most serious-to-fatally injured near- and far-side occupants were involved in pure lateral (3 o’clock, 9 o’clock) and slightly oblique (2 o’clock, 10 o’clock) impacts. The overall risk of serious injury was highest in distributed and front-to-center impacts. The occupant injury risk was more than 2 times higher when near-sided than far-sided, highlighting the need to test at this location. The median delta-V associated with serious injury to far-side occupants was 6.0 km/h higher than for near-side occupants, at 31.3 km/h and 25.4 km/h, respectively. Understanding crash characteristics provides insight into field relevancy of crash scenarios used to evaluate occupant responses. The results from this study suggest that current side impact standards are representative of a serious real world side impact.
Parenteau, Chantal, Ault, B. Nicholas, Toomey, Daniel, Krishnaswami, Ram, Burnett, Roger
Effects of Anthropometry and Passive Restraint Deployment Timing on Occupant Metrics in Moderate-Severity Offset Frontal Collisions2024-01-27494/9/2024
There are established federal requirements and industry standards for frontal crash testing of motor vehicles. Consistently applied methods support reliability, repeatability, and comparability of performance metrics between tests and platforms. However, real world collisions are rarely identical to standard test protocols. This study examined the effects of occupant anthropometry and passive restraint deployment timing on occupant kinematics and biomechanical loading in a moderate-severity (approximately 30 kph delta-V) offset frontal crash scenario. An offset, front-to-rear vehicle-to-vehicle crash test was performed, and the dynamics of the vehicle experiencing the frontal collision were replicated in a series of three sled tests. Crash test and sled test vehicle kinematics were comparable. A standard or reduced-weight 50th percentile male Hybrid III ATD (H3-50M) or a standard 5th percentile female Hybrid III ATD (H3-5F) was belted in the driver’s seating position. In the crash test, the frontal airbag and lap and shoulder belt pretensioners deployed on commands from the vehicle’s airbag control module (ACM). In the sled tests, deployments were commanded with either similar timing or 12 milliseconds earlier. Small, measurable differences in occupant kinematics and biomechanical loading were observed. All biomechanical metrics were low compared to injury assessment reference values (IARVs), consistent with the moderate severity of the tests. The variations in parameters in these tests did not result in suboptimal interactions with restraints, such as submarining, belt webbing migration, or bottoming-out of the airbag resulting in direct occupant loading to the steering wheel. These results indicate that the variations in occupant anthropometry and restraint deployment times investigated did not substantially alter the low risk of serious injuries.
Courtney, Amy, Crosby, Charles, Miller, Bruce, Osterhout, Aaron, Walker, James, Gondek, Jonathon
Research on Occupant Injury Prediction Method of Vehicle Emergency Call System Based on Machine Learning2024-01-20104/9/2024
The on-board emergency call system with accurate occupant injury prediction can help rescuers deliver more targeted traffic accident rescue and save more lives. We use machine learning methods to establish, train, and validate a number of classification models that can predict occupant injuries (by determining whether the MAIS (Maximum Abbreviated Injury Scale) level is greater than 2) based on crash data, and ranked the correlation of some factors affecting vehicle occupant injury levels in accidents. The optimal model was selected by the model prediction accuracy, and the Grid Search method was used to optimize the hyper-parameters for the model. The model is based on 2799 two-vehicle collision accident data from NHTSA CISS (The Crash Investigation Sampling System of NHTSA) traffic accident database.The results show that the model achieves high-precision prediction of occupant injury MAIS level (recall rate 0.8718, AUC(Area under Curve) 0.8579) without excluding vehicle model, and the top 8 relevant features given by the model are: lateral speed change, occupant age, longitudinal speed change, seat belt usage, occupant gender, lateral speed change direction, airbag trigger, and longitudinal speed change direction. We believe that this method can be used to complete organ-level post-crash injury prediction after adding more features, which has great potential to improve the efficiency of traffic accident rescue and reduce the casualty rate.
Huida, Zhang, Liu, Yu, Rui, Yang, Wu, Xiaofan, Fan, Tiqiang, Wan, Xinming
A Study on Optimizing Headlining Open-Structure for Face-to-Face Roof-Airbag Deployment2024-01-23944/9/2024
In this study, an optimized structure for opening the headlining considering the deployment of the face-to-face roof airbag was studied. It was confirmed that the deployment performance differs depending on the skin of the headlining, and a standardized structure with mass production was proposed. Non-woven fabric and Tricot skin, which are economical and high-end specifications, satisfy the performance of PVC fusion application specifications after cutting 80% of the skin. The structure that satisfies the entire body including the knit specifications is a type that separates the roof airbag area piece, the corresponding soft piece is separated, and the deployment performance is satisfied with safety. Therefore, the structure is proposed as a standardized structure. This structure is expected to be applicable to roof DAB (Driver Airbag), PAB (Passenger Airbag), and Sunroof Airbag, which will be necessary technologies to secure indoor space. Regardless of which area the airbag will be applied to, and which area the headlining skin specifications will be selected by the customer, it can be applied only if the mounting bracket conditions are satisfied. A patent will be applied for the structure to secure intellectual property rights.
Park, Jiseob
Machine-Learning-Accelerated Simulations for the Design of Airbag Constrained by Obstacles at Rest2023-22-00013/4/2024
Predicting airbag deployment geometries is an important task for airbag and vehicle designers to meet safety standards based on biomechanical injury risk functions. This prediction is also an extraordinarily complex problem given the number of disciplines and their interactions. State-of-the-art airbag deployment geometry simulations (including time history) entail large, computationally expensive numerical methods such as finite element analysis (FEA) and computational fluid dynamics (CFD), among others. This complexity results in exceptionally large simulation times, making thorough exploration of the design space prohibitive. This paper proposes new parametric simulation models which drastically accelerate airbag deployment geometry predictions while maintaining the accuracy of the airbag deployment geometry at reasonable levels; these models, called herein machine learning (ML)-accelerated models, blend physical system modes with data-driven techniques to accomplish fast predictions within a design space defined by airbag and impactor parameters. These ML-accelerated models are evaluated with virtual test cases of increasing complexity: from airbag deployments against a locked deformable obstacle to airbag deployments against free rigid obstacles; the dimension of the tested design spaces is up to six variables. ML training times are documented for completeness; thus, airbag design explorers or optimization engineers can assess the full budget for ML-accelerated approaches including training. In these test cases, the ML-accelerated simulation models run three orders of magnitude faster than the high-fidelity multi-physics methods, while accuracies are kept within reasonable levels within the design space.
Valenzuela del Rio, Jose E., Lancashire, Richard, Chatrath, Karan, Ritmeijer, Peter, Arvanitis, Elena, Mirabella, Lucia
Performance of Five-Point Seat Belt on Occupant Safety in Vehicle on Frontal Crash Test2023-01-51692/23/2024
In day-to-day life, accidents do occur frequently all around the globe. It is difficult to prevent these accidents as they occur due to different reasons, which cannot be easily controlled. However, the fatal injuries occurring to passengers can be reduced by installing efficient safety systems in vehicles, which will help in saving the lives of mankind. Many safety systems are being installed in vehicles such as seat belt restraints, airbags, etc. Generally, three-point seat belts are installed in passenger vehicles for safety purposes. This type of seat belt doesn't arrest the entire motion of the occupant's body during vehicle crashes, which can lead to fatal injuries and sometimes even death during vehicle crashes. To buckle passengers with seats, we can use five-point seat belts which will help in mitigating the injuries as compared to three-point seat belts. In this paper, we evaluate the performance of five-point seat belts on occupant safety during vehicle crashes on flat rigid barriers using LS-DYNA.
Vinodh, T., Dineshkumar, C., Jeyakumar, P.D., Muthiya, Solomon Jenoris, Vinayagam, Nadana Kumar, Christu Paul, R., Dhanraj, Joshuva Arockia
Event Data Recorder Trigger Probability in the Crash Investigation Sampling System Database2024-01-50272/23/2024
The objective of this study was to quantify the field performance of passenger vehicle event data recorders (EDRs) in recording data into non-volatile memory at the 8 km/h delta-v (Δv) trigger threshold specified by Title 49, Part 563 of the Code of Federal Regulations (Part 563). Part 563 applies to passenger vehicles manufactured on or after September 1, 2012. The trigger threshold is distinct from the threshold required to deploy an airbag. Events meeting the trigger threshold will cause data to be preserved on the EDR even if airbags are not deployed. This is the first study to quantify EDR trigger threshold performance. This data is valuable in the evaluation of sub-airbag deployment crashes. The study was accomplished via analysis of EDR and reconstructed Δv data from 3,960 cases in the Crash Investigation Sampling System (CISS) database maintained by the National Highway Traffic Safety Administration (NHTSA). The binary presence or non-presence of an event on the EDRs of vehicles exposed to a collision was compared to the CISS reconstructed Δv for each vehicle. Logistic regression models were developed to predict the probability of an event present on the EDR at the trigger threshold. We found that vehicles manufactured by Toyota had lower Δv thresholds compared to other manufacturers. For Toyota manufactured vehicles, the probability of an EDR event at 8 km/h ranged from 87% to 99%. EDR event probabilities for non-Toyota vehicles in vehicle-to-vehicle collisions ranged from 58% to 93% for Part 563 compliant vehicles and 33% to 83% for pre-Part 563 vehicles. The persistence of EDR events in memory was analyzed using the number of ignition cycles present between events and imaging of the EDR, finding average duration of 3,595 ignition cycles for pre-existing EDR events unrelated to the CISS case.
Watson, Richard A., Bonugli, Enrique, Greenston, Mathew, Santos, Erick, Martinez, Jonathan
Safer Buses for Passengers and Pedestrians: Crashes and Injury Analyses from Indian and German In-Depth Data2024-26-00041/16/2024
Bus transport is an important element in a sustainable transport strategy. The objective of this study is to understand crashes and injuries involving buses, suggest potential passive-safety interventions, estimate their effectiveness, and compare their effectiveness between Germany and India. Descriptive analysis of crash data from the German In-depth Accident Study (GIDAS) and the Road Accident Sampling System India (RASSI) database was performed in two parts: First, bus passengers and their injuries were analyzed and second, pedestrian injuries in bus-to-pedestrian crashes were analyzed. Lastly, interventions were suggested, and their effectiveness was estimated. Analysis of bus passengers showed that most moderate-to-critical injuries in the GIDAS data were to the head caused by interior bus components. In the RASSI data, head injuries were also frequent, often due to bus interior contact, but also due to ejection and impact to the ground or bus exterior. As many as 31% of all moderate-to-critical injuries in RASSI occurred due to ejection, none in the GIDAS data. Negligible seatbelt usage in the GIDAS data and non-existent use in RASSI demands some explanation. In bus-to-pedestrian crashes, impacts to the front of the bus were the most frequent scenario in both countries. Head injuries were frequent in both GIDAS and RASSI, predominantly due to an impact with the bus front or the ground. To mitigate these injuries, the suggested interventions are seatbelts, pedestrian airbags, and pedestrian underrun protection. These interventions were estimated to annually save up to 180 injured pedestrians and 469 injured bus occupants in Germany, and 5,613 injured pedestrians and 36,271 injured bus occupants in India. To conclude, while the need for better data and more rigorous intervention analysis in future work are discussed, the highlighted safety issues and potential interventions can guide discussion and action plans for safer buses.
Ranmal, Aarti, Jeppsson, Hanna, Strandroth, Johan, Lubbe, Nils
Headliner Composition Optimization without Compromising the Safety and Performance2024-26-01901/16/2024
Reducing material wherever there is a possibility in automobile industry is inevitable for weight and cost saving. This paper explains about the possibilities of optimizing the material composition of automotive Headliners (also called as Roof liners) without affecting the performance and safety criteria. In this paper, we are targeting at optimizing the individual constituents of a composite Headliner. A conventional Headliner comprises of many sandwich layers of which PU foam shares the major percentage of the composition contributing to 80% of the Headliner thickness. In this paper, we are discussing about the optimization done in Headliner sandwich constituents without affecting the core performance parameters of headliner such as curtain airbag deployment, ergonomic regulations, drop test etc. By incorporating this change, without significant changes in other layers, overall weight reduction of ~24% and overall cost reduction of ~24% is achieved.
D, Gowtham, Vadla, Vilas, Bhaskararao, Pathivada, Sai, Konduru, Bornare, Harshad, Ritesh, Kakade, Deoli, Manish, Kakani, Phani Kumar
Importance of Pole Side Impact Test for Assessment of Curtain Airbags2024-26-00191/16/2024
Government of India, in 2017, mandated a Side Impact Test (AIS 099 technically aligned to UN ECE Regulation No. 95.03 series of amendments) on M1 category Passenger Vehicles to ensure protection of occupants in lateral impact accident scenarios. Later, in 2022, a draft notification has been issued by the Government mandating installation of 6 airbags (2 Nos of thorax side airbags, 2 Nos of head protection or curtain airbags in addition to already mandated installation of Driver and Passenger Airbags) in all such passenger vehicles. However, the vehicles fitted with side thorax airbag and curtain airbags are proposed to be assessed as per AIS099 test only. Curtain Airbags are typically installed to protect occupant’s head from severe injuries in narrow object impacts simulated in Pole Side Impact Test Configurations. However, at present, India has not notified an equivalent standard to UN R135 demanding performance of the vehicle in pole side impact scenarios. Typically, OEMs may need to perform a series of Side MDB and Pole Side Impact Tests in order to integrate the thorax and side curtain airbags in the vehicle structure and to optimize their performance. However, non-existence of a mandatory standard for Pole Side Impact scenario creates a gap in the regulatory requirements and may lead to situations wherein such airbags are not validated to the minimum performance requirements. This paper compares the structural performance and occupant protection performance of the vehicles that are equipped with side thorax airbag and side curtain airbag in an AIS099 and UN R135 test scenario. The paper attempts to highlight the importance of conducting a Side Pole test in addition to the Side Impact test on a vehicle to better judge the performance of a thorax side and curtain airbag.
Jaju, Divyan, Kulkarni, Dileep, Mahindrakar, Rahul, Mahajan, Rahul
RAMP Bracket Angle Optimization Coupled with Improved Head Room2024-26-00161/16/2024
Restraint systems in automotives are inevitable for the safety of passengers. Curtain airbag is one such restraint system in automotives that reduces the risk of injury to passengers during crash, without which head injury is inevitable during side crash of a vehicle. So successful deployment of curtain airbag (henceforth called as CAB) is very important in automotive safety during crash. This paper dwells about the optimization done in ramp bracket angle with successful deployment of curtain airbag. This optimization has paved the way for increasing the head-roominess by ~15% and to respect the safety and styling intent in the vehicle successfully. Providing a ramp bracket at the lower bottom side of CAB guides the airbag successfully during deployment. Ramp bracket angle plays a vital role in guiding the airbag inside the passenger’s cabin without any obstruction. This paper challenges the conventional ramp bracket angle followed for CAB deployment with an alternate angle and has successfully validated the same. This paper also throws light upon the flushness criteria to be followed between ramp bracket and environment parts.
D, Gowtham, L, Dharshan, Bornare, Harshad, Ritesh, Kakade, Deoli, Manish, Bhaskararao, Pathivada, Gangapuram, Suresh, Kakani, Phani Kumar
Novel Method for Vehicle Pulse Prediction2024-26-00021/16/2024
Airbags are crucial elements of passive safety in vehicles that help minimizing occupant injuries during various crash scenarios such as frontal, side, and oblique impacts. Airbags in cars are now mandatory in many countries, and their performance depends on how well the system is designed. A well-tuned airbag deployment algorithm is necessary to score superior NCAP safety ratings. Tuning of airbag deployment algorithms requires several data points which are obtained through actual crash testing. This is a cumbersome and expensive process as it involves crash tests for each scenario (e.g., full front barrier, offset deformable barrier, angled impact, etc.) at multiple test speeds. These tests are destructive and render the vehicles only worthy of scrap. The data gathered from various sensors (acceleration, pressure, etc.) is used to develop robust vehicle model specific algorithms that must correctly identify the crash scenario and send airbag firing signal at the optimal pre-decided time. The question is, can we reduce the number of crash tests and still develop an equally robust airbag deployment system? In this work, we discuss a novel method of crash pulse sensing. It is a semi-empirical model that uses both physics-based and data-based approach. Our proposed model uses logged crash data for certain speeds and generates crash pulse for the remaining required speeds - thus reducing the number of required actual tests. Model is validated for different crash scenarios. We estimate that this model could potentially reduce a significant cost and development time.
Kumar, Ayush
Foam and FRP Sheets Packaging for Headliner Stiffness at Curtain Airbag Area2024-26-00081/16/2024
As we all know, automotive headliners are an essential component of any car’s interior as they cover all the internal components and provide a clean and finished look. Headliners not only increase the aesthetic appeal of a car’s interior, but also acts as an insulation and sound absorption source. As per the latest Government norms, Curtain Airbag (henceforth called as CAB) has been made mandatory and this change calls for the corresponding changes in the Headliner packaging of all passenger vehicles. In general, curtain air-bag deployment calls for a twist open of Headliner at lateral sides (a portion below Hinge-line) during the deployment. This enables the inflated airbag to flow inside the passenger cabin to protect the passenger from any injury. Conventionally no components are packaged below the hinge-line area of headliner to avoid obstruction for CAB deployment and any part fly-off concerns. For this reason, no foams/components are kept below the hinge-line region of the headliner. In this paper we are discussing the pros of introducing the Polyurethane (henceforth called as PU) foams below the hinge-line without hampering the CAB deployment criteria. This paper also dwells upon the characteristic and type of the foams that need to be used to serve the purpose. These foams have been specifically designed to increase the stiffness and solidity of Headliner at all joinery/interface areas without any compromise on the CAB deployment requirements mandated by ARAI*. Height and the width of the foams are optimized to act as a guide for deployment rather than obstructing it.
D, Gowtham, L, Dharshan, Bornare, Harshad, Ritesh, Kakade, Deoli, Manish, Vadla, Vilas, Kakani, Phani Kumar
USCAR INFLATOR TECHNICAL REQUIREMENTS AND VALIDATIONUSCAR24-3 (Current)12/12/2023
This specification establishes the performance and validation requirements for the inflator assembly used in airbag modules.
USCAR
Influence of Pre-Crash Vehicle Maneuvers on Front Passenger Safety Performance Response09-11-02-00219/20/2023
Pre-crash vehicle maneuvers are known to affect occupant posture and kinematics, which consequently may influence injury risks during a collision. In this study, the influence of pre-crash vehicle maneuvers on the injury risks of front-seated occupants during a frontal crash was numerically evaluated. A generic buck vehicle model was developed based on a publicly available FE model, which included the vehicle interior and the front passenger airbag (PAB). The pre-crash phase was simulated using specific rigid-body human models with active joints (GHBMCsi-pre models) developed based on exterior shapes of the simplified deformable human model (GHBMCsi) representing a 50th male subject. Two pre-crash maneuvers representing (1) a generic 1g braking and (2) turning-and-braking scenarios were simulated. Then, the kinematics data of belted GHBMCsi-pre models were transferred using a developed switch algorithm to the corresponding GHBMCsi models, which can predict occupant injury risks. Finally, an FMVSS 208 pulse (NCAP pulse with delta V of 56 km/h) was applied to simulate the in-crash phase. Injury metrics were recorded for the belted GHBMCsi model to evaluate the passenger injury risks. Overall, it was concluded that pre-crash braking decreased the severity of injury sustained by the passenger. The success of the methodology used in this study, to simulate reasonable and computationally efficient pre-crash and in-crash phases, suggests using it for more advanced studies where additional parameters (e.g., BMI, age, etc.) could also be taken into consideration.
Dahiya, Akshay, Untaroiu, Costin
Experimental Assessment of Human and Crash Dummy Skin to Vehicle Air Bag Fabric Coefficients of Friction09-11-03-00149/18/2023
Oblique motor vehicle crashes can cause serious head or brain injuries due to contact with interior vehicle structures even with the deployment of air bags, as they are not yet completely successful in preventing traumatic brain injury. Rotational head velocity is strongly correlated to the risk of brain injury, and this head motion is potentially related to the tangential friction force developed during contact between the head and air bags. Although crash test dummy head skins are designed with appropriate mass properties and anthropometry to simulate the normal direction impact response of the human head, it is not known whether they accurately represent the frictional properties of human skin during air bag interaction. This study experimentally characterized the dynamic friction coefficient between human/dummy skins and air bag fabrics using a pin-on-disc tribometer. Human skin samples were harvested from five locations (left and right forehead, left and right cheek, and chin) from male and female postmortem human subjects (PMHSs); some samples had previously been frozen and some were fresh. Crash dummy head skin samples were obtained from Hybrid III, ES-2re, and THOR-50M 50th-percentile male anthropomorphic test devices (ATDs) and were characterized in both chalked and unchalked conditions. Fabric samples were obtained from five different air bags spanning various vehicle manufacturers and interior mounting locations. Neither sex, linear speed, nor the harvested skin location on the head played a significant role on the dynamic friction between PMHS skin samples and air bag fabrics, while PMHS skin samples that had not been previously frozen had a higher coefficient of friction than those that had. Further, increasing normal load reduced the dynamic friction coefficient between PMHS skin samples and air bag fabrics. Unchalked ATD head skins exhibited significantly higher dynamic friction coefficients than PMHS skins for the air bag fabrics tested. The presence of a thin chalk layer on ATD skins reduced friction and produced dynamic friction coefficients with air bag fabrics that were not significantly different from those of PMHS skins; however, neither unchalked nor chalked ATD head skins differentiated the air bag fabric dynamic friction coefficients in the same pattern as the PMHS skin samples.
Noll, Scott, Dong, Sheng, Kang, Yun-Seok, Bolte, John, Stammen, Jason, Moorhouse, Kevin
Recommended Corrosion Test Methods for Commercial Vehicle ComponentsJ2721_202305 (Current)5/31/2023
This document establishes recommended practices to validate acceptable corrosion performance of metallic components and assemblies used in medium truck, heavy truck, and bus and trailer applications. The focus of the document is methods of accelerated testing and evaluation of results. A variety of test procedures are provided that are appropriate for testing components at various locations on the vehicle. The procedures incorporate cyclic conditions including corrosive chemicals, drying, humidity, and abrasive exposure. These procedures are intended to be effective in evaluating a variety of corrosion mechanisms as listed in Table 1. Test duration may be adjusted to achieve any desired level of exposure. Aggravating conditions such as joint rotation, mechanical stress, and temperature extremes are also considered. This document does not address the chemistry of corrosion or methods of corrosion prevention. For information in these areas, refer to SAE J447 or similar standard.
Truck and Bus Total Vehicle Steering Committee
Modeling of Gas Charging and Discharging for Airbag Suspension System and Control of Height Adjustment2023-01-06604/11/2023
Taking a closed airbag suspension system as studying objects, the nonlinear dynamic model of the reservoir, compressor, solenoid valve, pipeline and air spring is established. The compressor exhaust volume, solenoid valve flow rate and air spring charging and discharging rate are calculated and compared with experiment to validate the model. Taking pressure difference and height adjustment rate under different working conditions of an airbag suspension as control measures, a control strategy is developed based on the established nonlinear dynamic model. The result indicates that when the vehicle is in curb weight, design weight and GVW (gross vehicle weight), the working time of the compressor can be reduced by 13.6%, 15.1% and 46.5%, respectively, compared with the conventional mode, during a height adjustment cycle. Then a state observer is proposed to estimate the steady-height for reducing the disturbance of measured height from road excitation. According to the required height error and pipeline pressure, a method for adjusting compressor speed to reduce the influence of pipeline pressure on height adjustment accuracy is proposed.
Deng, Lin, Lv, Hui, Shangguan, Wenbin
Characterization and Modeling of Instrument Panel Textile Trim Materials for Passenger Airbag Deployment Analysis2023-01-09304/11/2023
Premium instrument panels (IPs) contain passenger airbag (PAB) systems that are typically comprised of a stiff plastic substrate and a soft ‘skin’ material which are adhesively bonded. During airbag deployment, the skin tears along the scored edges of the door holding the PAB system, the door opens, and the airbag inflates to protect the occupant. To accurately simulate the PAB deployment dynamics during a crash event all components of the instrument panel and the PAB system, including the skin, must be included in the model. It has been recognized that the material characterization and modeling of the skin tearing behavior are critical for predicting the timing and inflation kinematics of the airbag. Even so, limited data exists in the literature for skin material properties at hot and cold temperatures and at the strain rates created during the airbag deployment. This paper presents tensile test results of one typical skin material conducted at four different strain rates of 0.01/s, 1/s, 10/s, and 100/s. Challenges in testing are discussed. A material modeling methodology is proposed that accounts for anisotropy, loading rate sensitivity and failure, and is verified by comparison of results from simulation and physical tests. Finally, recommendations for setting proper contact parameters between different parts in the model and for proper representation of the adhesive between the instrument panel substrate and skin are presented.
G, Karthigan, Savic, Vesna, Hu, Sibo, Ravichandran, Gowrishankar, Tripathy, Biswajit
ES2re, WS50M, and Human Body Models in Far-Side Pole Impacts2023-01-05584/11/2023
Driver oblique far-side sled impacts were simulated with three surrogates. The EuroSID side impact dummy with rib extension (ES2re), the WorldSID side impact 50th percentile male dummy (WS50M), and the Global Human Body Modeling Consortium’s 50th percentile male human body (GHBM) models. The versions of the surrogates’ models were 7.0, 7.5.1, and 5.0, respectively. Surrogates were seated in the front left driver seat in a virtual generic crossover sled environment. The Finite Element (FE) based environment consisted of a driver seat, a center console, and a passenger seat. Two restraint systems were considered for each surrogate: belt only (BO) and belt plus a generic seat-mounted far-side impact airbag (BB). Surrogates were restrained using a 3-point belt that has a digressive shoulder force load limiter, and retractor, and anchor pretensioners. The far-side airbag used was a 37-liter in volume and has two chambers. Surrogate head excursions and injury indices for each surrogate were compared. The WS50M kinematics were closer to the GHBM than those of the ES2re. The WS50M predicted 4.7 and 0.5% probability of AIS3+ neck injuries in the BO and BB, respectively. ES2re predicted 48 and 30% probability of AIS3+ thoracic injuries, respectively. Whereas the WS50M predicted 0.5 and 0.0%, respectively. The GHBM had 12 fractures in 8 ribs and no fracture, respectively.
El-Jawahri, Raed E.
Evaluation of Occupant Kinematics and Kinetics during Moderate Severity Simulated Frontal Impacts with and without Frontal Airbag Deployment2023-01-05594/11/2023
Airbag and seat belt pretensioner deployment characteristics depend on multiple factors, such as the magnitude, direction, and rate of vehicle deceleration as detected by vehicle crash sensors and evaluated by vehicle-specific algorithms. Frontal airbag and pretensioner deployments are likely to be commanded during frontal crash events with high initial vehicle deceleration typically associated with high vehicle change in velocity (delta-V). However, within a range of moderate changes in vehicle speeds, referred to as the “gray zone,” a vehicle-specific algorithm may or may not command deployment depending on crash pulse parameters and occupant sensing, among other items. Publicly available testing in the moderate-speed range is lacking and would be useful to evaluate the effects of airbag and pretensioner deployment on occupant kinematics and loading. In this study, sled tests were performed using a standard passenger vehicle buck simulating frontal deceleration impact events in a “gray-zone” severity of 19 kph (12 mph) delta-V and in a typical deployment severity of 32 kph (20 mph) delta-V. Matched sled tests were performed with and without airbag deployment with instrumented Hybrid III 50th percentile anthropomorphic test devices (ATDs) properly belted in the driver and front passenger seats. Additionally, one paired test was conducted at 19 kph with and without pretensioner deployment in the presence of airbag deployment. Airbag deployment for the 19 kph delta-V tests did not significantly affect occupant kinematics or loading compared to the non-deployment tests, while some differences were apparent for the 32 kph delta-V tests. In all tests, injury metrics were well below applicable injury assessment reference values (IARVs).
Sharpe, Sarah S., Grijalva, Sandra, Allin, Leigh, Courtney, Amy, Toney-Bolger, Megan, Pokutta-Paskaleva, Anastassia, Crosby, Charles L., Carhart, Michael
A Study on Estimation Tool of Occupant Injury Risk for Deriving Integrated Safety Scenarios2023-01-06524/11/2023
‘Active safety systems’ are actively being developed to prevent collisions. The integration of ‘active safety systems’ and traditional ‘passive safety systems’ such as seatbelt and airbags is an important issue. The ‘Integrated safety’ performance is that comprehensively controls the performance of ‘active’ and ‘passive’ safety systems to reduce occupant injuries. To develop ‘integrated safety’ performance, it is important to develop crash scenarios for autonomous vehicles. This study is about the development of ‘Estimation Tool of Occupant Injury Risk’ for deriving risk integrated safety scenarios focused on occupant injury. The results of random traffic simulation using ‘Virtual Prototype’ were used to select parameters, and ‘MADYMO Equivalent Simplified Vehicle Crash Analysis Model’ was used to derive F-D characteristics for each vehicle collision condition. The ‘Estimation Tool of Occupant Injury Risk’ was developed through the analysis of occupant injuries using the Hyundai Active Human Model for Safety (HAHMS).
Han, Kwang Cheol, Seo, Bo Pil, Unger, Michiel
Event Data RecorderJ1698_202303 (Current)3/1/2023
This SAE Recommended Practice describes common definitions and operational elements of Event Data Recorders. The SAE J1698 series of documents consists of the following: SAE J1698-1 - Event Data Recorder - Output Data Definition: Provides common data output formats and definitions for a variety of data elements that may be useful for analyzing vehicle crash and crash-like events that meet specified trigger criteria. SAE J1698-2 - Event Data Recorder - Retrieval Tool Protocol: Utilizes existing industry standards to identify a common physical interface and define the protocols necessary to retrieve records stored by light duty vehicle Event Data Recorders (EDRs). SAE J1698-3 - Event Data Recorder - Compliance Assessment: Defines procedures that may be used to validate that relevant EDR output records conform with the reporting requirements specified in Part 563, Table 1 during the course of FMVSS-208, FMVSS-214, and other applicable vehicle level crash testing.
Event Data Recorder Committee
Items per page:
1 – 50 of 1150