Search Results (8)

Seatbelts are critical components of vehicle safety, continuously evolving through technological advancements and regulatory updates. Traditionally designed to secure occupants during collisions, seatbelt innovations, such as retractors, pretensioners, and load limiters, have significantly enhanced comfort and effectiveness. With the advent of autonomous vehicles, seatbelt systems must adapt to new safety challenges, including real-time tension adjustment through active seatbelt systems. These systems, integrated with active safety technologies like automatic emergency braking, offer a more comprehensive safety solution. Furthermore, seatbelt technology must address the diverse needs of different passenger categories. Quantitative data highlight the role of seatbelts for various passenger categories. Children are 55% more likely to be injured by rear structure intrusion and 27% more likely to suffer from compression into the front seat during rear impacts. Pregnant women generally experience milder injuries but are more prone to abdominal injuries. Older adults, who account for 17% of crash fatalities, are more likely to suffer thoracic injuries and fractures due to increased bone fragility. This review explores the integration of traditional and modern seatbelt systems, focusing on passenger-specific adaptations and the future role of seatbelts in autonomous vehicles. This study is based on a thorough literature review, analyzing data from the Web of Science, Scopus, and SAE databases, where available, to assess the contributions and impact of these innovations. Full article

To validate active human body models for investigating occupant safety in autonomous cars, it is crucial to comprehend the responses of vehicle occupants during evasive maneuvers. This study sought to quantify the behavior of midsize male and small female passenger seat occupants in both upright and reclined postures during three types of vehicle maneuvers. Volunteer tests were conducted using a minivan, where vehicle kinematics were measured with a DGPS sensor and occupant kinematics were captured with a stereo-vision motion capture system. Seatbelt loads, belt pull-out, and footrest reaction forces were also documented. The interior of the vehicle was 3D-scanned for modeling purposes. Results indicated that seatback angles significantly affected occupant kinematics, with small female volunteers displaying reduced head and torso movements, except during emergency braking with a upright posture seatback. Lane-change maneuvers revealed that maximum lateral head excursions varied depending on the maneuver’s direction. The study concluded that seatback angles were crucial in determining the extent of occupant movement, with notable variations in head and torso excursions observed. The collected data assist in understanding occupant behavior during evasive maneuvers and contribute to the validation of human body models, offering essential insights for enhancing safety systems in autonomous vehicles. Full article

Precise and rapid detection of seatbelts is an essential research field for intelligent traffic management. In order to improve the detection precision of seatbelts and speed up algorithm inference velocity, a lightweight seatbelt detection algorithm is proposed. Firstly, by adding the G-ELAN module designed in this paper to the YOLOv7-tiny network, the optimization of construction and reduction of parameters are accomplished, and the ResNet is compressed with the channel pruning approach to decrease computational overheads. Then, the Mish activation function is utilized to replace the Leaky Relu in the neck to enhance the non-linear competence of the network. Finally, the triplet attention module is integrated into the model after pruning to make up for the underlying performance reduction caused by the previous stage and upgrade overall detection precision. The experimental results based on the self-built seatbelt dataset showed that, compared to the initial network, the Mean Average Precision (mAP) achieved by the proposed GM-YOLOv7 was improved by 3.8%, while the volume and the computation amount were lowered by 20% and 24.6%, respectively. Compared with YOLOv3, YOLOX, and YOLOv5, the mAP of GM-YOLOv7 increased by 22.4%, 4.6%, and 4.2%, respectively, and the number of computational operations decreased by 25%, 63%, and 38%, respectively. In addition, the accuracy of the improved RST-Net increased to 98.25%, while the parameter value was reduced by 48% compared to the basic model, effectively improving the detection performance and realizing a lightweight structure. Full article

The reconstruction of traffic accidents has grown as an interdisciplinary field, encompassing bodies of research from automotive engineering, traffic and transport engineering, biomechanics, and forensic sciences. In this work, a method is proposed by which the value of the force in the safety belt buckle can be determined provided the belt buckle is equipped with a pretensioning system with a pyrotechnic trigger in the pretensioner tube, PBP—Pyrotechnical Buckle Pretensioner, or PLP—Pyrotechnical Lap Pretensioner type. The anti-return system of the pretensioner mechanism, which prevents the passenger’s body from moving forward, contains a set of balls that block the movement of the piston in the pretensioner tube after its activation. When limiting the movement, the force the human body exerts on the safety belt webbing is transformed into the deformation of the pretensioner tube by the balls of the anti-return system. Depending on the magnitude of the force, the marks left by the balls differ. This is an alternative method for determining the force that occurs in a seatbelt and causes injury to the occupants of a vehicle. The advantage of this method is that the force in the seatbelt buckle cable can be determined relatively quickly and accurately by analyzing the deformations in the pretensioner tube, without a need for expensive laboratory equipment. The limitation of the model resides in the consideration of a static system with rigid bodies. The correlation between the normal force causing the deformation of the tube and the force in the belt buckle cable is obtained by means of a mechanical model that explains the operation of the anti-return system. By comparing the values of the normal force given by the proposed model and the elastoplastic model, a good correlation is found. Finally, a regression curve is determined to help the expert in approximating the force in the buckle cable depending on the deformation size in the pretensioner tube. The value of this force also enables biomechanical or medical specialists to correlate the degree of injury to occupants of a vehicle depending on the force in the seatbelt. Full article

As an advanced driver assistance system, automatic emergency braking (AEB) can effectively reduce accidents by using high-precision and high-coverage sensors. In particular, it has a significant advantage in reducing front-end collisions and rear-end accidents. Unfortunately, avoiding side collisions is a challenging problem for AEB. To tackle these challenges, we propose active seat belt pretensioning on driver injury in vehicles equipped with AEB in unavoidable side crashes. Firstly, records of impact cases from China’s National Automobile Accident In-Depth Investigation System were used to investigate a scenario in which a vehicle is impacted by an oncoming car after the vehicle’s AEB system is triggered. The scenario was created using PreScan software. Then, the simulated vehicles in the side impact were devised using a finite element model of the Toyota Yaris and a moving barrier. These were constructed in HyperMesh software along with models of the driver’s side seatbelt, side airbag, and side curtain airbag. Moreover, the models were verified, and driver out-of-position instances and injuries were evaluated in simulations with different AEB intensities up to 0.7 g for three typical side impact angles. Last but not least, the optimal combination of seatbelt pretensioning and the timing thereof for minimizing driver injury at each side impact angle was identified using orthogonal tests; immediate (at 0 ms) pretensioning at 80 N was applied. Our experiments show that our active seatbelt with the above parameters reduced the weighted injury criterion by 5.94%, 22.05%, and 20.37% at impact angles of 90°, 105°, and 120°, respectively, compared to that of a conventional seatbelt. The results of the experiment can be used as a reference to appropriately set the collision parameters of active seat belts for vehicles with AEB. Full article

The COVID-19 travel restriction orders have significantly reduced travel and generally lowered the risk of road traffic collisions, but many accounts suggest an increase in risky driving behaviors and consequent fatal crashes during the shelter-in-place period. Risky driving behaviors including failure to wear a seatbelt, speeding, and drunk driving were observed to be the leading contributing factors of the fatalities. Whereas the fatal crashes that characterized the shelter-in-place period has become a topical issue, the high number of crashes that occurred as a result of the panic shopping and increased travel activities in the weeks before the shelter-in-place order have not received much attention. In this study, we investigated the differences and similarities in the effects of the factors that were associated with crash injury severity before, during, and after the shelter-in-place order. The study used crash data from the state of Alabama for the 2020 calendar year. Preliminary data analysis revealed interesting variations in crash trends across the three periods. It was found that the highest weekly crash frequency occurred in the immediate week before the shelter-in-place order, and a higher proportion of crashes that occurred between 6 p.m. and 6 a.m. and those that occurred in residential areas happened during the shelter-in-place period while shopping area crashes, manufacturing/industrial area crashes, rear-end collisions, and crashes involving female drivers occurred mostly before the shelter-in-place period. Three injury severity models were developed using random parameters logit with heterogeneity in means and variances approach. The results showed that major injury crashes occurred mainly in rural areas and occurred due to speeding, fatigue driving, and failure to use a seatbelt. The effects of these factors on crash outcome did not vary across the year, indicating that the shelter-in-place order did not impact the driving behaviors of the driver population that got into major injury crashes. The results further revealed that the effects of some crash factors, such as road type and manner of collision, varied across the periods. The findings of the study provide a deeper, data-driven understanding of how driving behaviors and associated crash outcomes may be affected by extreme events such as the COVID-19 shelter-in-place. Full article

We compared the independent predictive factors for moderate and severe injuries, along with characteristics and outcomes of motor vehicle collisions, between pregnant and non-pregnant women. Using 2001–2015 records from the National Automotive Sampling System/Crashworthiness Data System, we selected 736 pregnant women and 21,874 non-pregnant women having any anatomical injuries. Pregnant women showed less severe collisions, fewer fatalities, and less severe injuries in most body regions than non-pregnant women. In pregnant women, the rate of sustaining abbreviated injury scale (AIS) scores 2+ injuries was higher for the abdomen only. For non-pregnant women, rear seat position, airbag deployment, multiple collisions, rollover, force from the left, and higher collision velocity had a positive influence on the likelihood of AIS 2+ injuries, and seatbelt use and force from the rear had a negative influence. There is a need for further development of passive safety technologies for restraint and active safety features to slow down vehicles and mitigate collisions. The influencing factors identified may be improved by safety education. Therefore, simple and effective interventions by health professionals are required that are tailored to pregnant women. Full article

One way to avoid detection of law enforcement officials if you are engaging in illegal activities is to wear a seatbelt. Therefore, an unintended consequence of laws allowing people to possess marijuana for medical purposes is that seatbelt use may decline among groups whose possession of marijuana is now legal. We find a decrease in seatbelt use among middle-aged males, providing evidence that drivers use seatbelts as a means to avoid police interaction. We find no such reduction in seatbelt use among those less likely to possess medical marijuana cards. Our evidence supports the contention that drivers use seatbelts more if they fear interaction with law enforcement officials, which is consistent with evidence of heightened seatbelt use among drunk drivers. These findings are important in understanding how to best design traffic safety laws and enforce them. Full article