| 1. |
- Boström, Ola, 1963, et al.
(författare)
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Comparison of car seats in low speed rear-end impacts using the BioRID dummy and the new neck injury criterion (NIC).
- 2000
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Ingår i: Accident Analysis and Prevention. ; 32:2, s. 321-328
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Tidskriftsartikel (refereegranskat)abstract
- Long-term whiplash associated disorders (WAD) 1-3 sustained in low velocity rear-end impacts is the most common disability injury in Sweden. Therefore, to determine neck injury mechanisms and develop methods to measure neck-injury related parameters are of importance for current crash-safety research. A new neck injury criterion (NIC) has previously been proposed and evaluated by means of dummy, human and mathematical rear-impact simulations. So far, the criterion appears to be sensitive to the major car and collision related risk factors for injuries with long-term consequences. To further evaluate the applicability of NIC, four seats were tested according to a recently proposed sled-test procedure. 'Good' as well as 'bad' seats were chosen on the basis of a recently presented disability risk ranking list. The dummy used in the current tests was the Biofidelic Rear Impact Dummy (BioRID). The results of this study showed that NICmax values were generally related to the real-world risk of long-term WAD 1-3. Furthermore, these results suggested that NICmax calculated from sled tests using the BioRID dummy can be used for evaluating the neck injury risk of different car seats.
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| 2. |
- Boström, Ola, 1963, et al.
(författare)
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Prediction of neck injuries in rear impacts based on accident data and simulations
- 1997
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Ingår i: PROCEEDINGS OF THE 1997 INTERNATIONAL IRCOBI CONFERENCE ON THE BIOMECHANICS OF IMPACT. ; , s. 251-264
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Konferensbidrag (refereegranskat)abstract
- Whiplash associated disorders, occurring in car accidents, are an increasing problem worldwide. According to real-life data from police records, the struck car's velocity change (delta V) and occupant gender are two of the most important factors related to Abbreviated Injury Scale (AIS) 1 neck injuries. In this study, a new rear-impact ranking of cars based on 4432 police reported accidents is presented. The ranking concerns the relative neck injury risk and compensates for the influences of car weight and gender. Moreover, some important factors influencing the risk of AIS 1 neck injury are proposed. These include: the stiffness, damping and yielding characteristics of the seat back, the muscle response of the occupant, and the delta V of the struck car and acceleration pulse. Using a mathematical model it is shown that the influence from these factors can be explained by a recently proposed neck injury criterion (NIC). This criterion is based on the neck motion at the passage of full neck retraction. The NIC, based on a number of volunteer tests, is analysed and validated. The consequence of injury outcome of an observed overall seat back stiffening is also discussed. In conclusion, for delta V below 20 km/h, real-life data show that the geometry of the head restraint is of minor importance. A seat back with low yielding limit or soft performance may be preferable. Moreover, the new NIC seems to be a good predictor of real-life neck injuries.
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| 3. |
- Dean, Morgan E., et al.
(författare)
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Assessing the applicability of impact speed injury risk curves based on US data to defining safe speeds in the US and Sweden
- 2023
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Ingår i: Accident Analysis and Prevention. - 0001-4575. ; 190
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Tidskriftsartikel (refereegranskat)abstract
- Vision Zero is an approach to road safety that aims to eliminate all traffic-induced fatalities and lifelong injuries. To reach this goal, a multi-faceted safe system approach must be implemented to anticipate and minimize the risk associated with human mistakes. One aspect of a safe system is choosing speed limits that keep occupants within human biomechanical limits in a crash scenario. The objective of this study was to relate impact speed and maximum delta-v to risk of passenger vehicle (passenger cars and light trucks and vans) occupants sustaining a moderate to fatal injury (MAIS2+F) in three crash modes: head-on vehicle-vehicle, frontal vehicle–barrier, and front-to-side vehicle-vehicle crashes. Data was extracted from the Crash Investigation Sampling System, and logistic regression was used to construct the injury prediction models. Impact speed was a statistically significant predictor in head-on crashes, but was not a statistically significant predictor in vehicle-barrier or front–to–side crashes. Maximum delta-v was a statistically significant predictor in all three crash modes. A head-on impact speed of 62 km/h yielded 50% (±27%) risk of moderate to fatal injury for occupants at least 65 years old. A head-on impact speed of 82 km/h yielded 50% (±31%) risk of moderate to fatal injury for occupants younger than 65 years. Compared to the impact speeds, the maximum delta-v values yielding the same level of risk were lower within the head-on crash population. A head-on delta-v of 40 km/h yielded 50% (±21%) risk of moderate to fatal injury for occupants at least 65 years old. A head-on delta-v of 65 km/h yielded 50% (±33%) risk of moderate to fatal injury for occupants younger than 65 years. A maximum delta–v value of approximately 30 km/h yielded 50% (±42%) risk of MAIS2+F injury for passenger car occupants in vehicle-vehicle front-to-side crashes. A maximum delta–v value of approximately 44 km/h yielded 50% (±24%) risk of MAIS2+F injury for light truck and van occupants, respectively, in vehicle-vehicle front-to-side crashes.
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| 4. |
- Develet, Jean-Adrien, et al.
(författare)
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Evaluation of the Biofidelity of the BioRID-II and THOR-NT Anthropomorphic Test Devices under Seatbelt Pre-Pretensioner Loading in Stationary Conditions
- 2013
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Ingår i: 2013 Ohio State University Injury Biomechanics Symposium. ; , s. 1-15
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Pre-pretensioners are active and reversible devices that apply light tension to the seatbelt (less than 300N) which pulls road vehicle occupants rearwards and reduce the backset (head-to-head restraint horizontal distance). This action has been found to have the potential to reduce the number of whiplash injuries in rear impacts. However, pre-pretensioners induced a new load case on current Anthropomorphic Test Devices (ATDs) for which they have not been validated. The purpose of this study was to evaluate the biofidelity of two 50th percentile male ATDs (BioRID-II and THOR-NT), under pre-pretensioner loading in a stationary environment. A literature review resulted in three testing positions that either occur frequently (backset exceeding recommendations) or have high injury potential (leaning far forward at the driver and front passenger seats). Experiments comprised six volunteer subjects, the BioRID-II and the THOR-NT. Corridors for the head-neck complex kinematics, and interaction of the subjects with the seatbelt, were generated based on data from the volunteer tests and ATD responses were compared to the corridors in terms of amplitude, peak occurrence and shape. For slight out-of-position cases (backset ~80mm), the THOR-NT was found to be close to relaxed volunteers and the BioRID-II to tense volunteers; both were suitable for pre-pretensioner testing. Although the BioRID-II results were closer to the corridors than the THOR-NT results in the far forward leaning positions, neither showed sufficiently large rearward motions and head rotations to fit the corridors. Furthermore, head rotations were problematic for both ATDs in the three test positions. Therefore, construction changes to both the pelvis and occipital joints are suggested in order to improve the biofidelity of BioRID-II and THOR-NT in far forward leaning positions.
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| 5. |
- Fredriksson, Rikard, 1967, et al.
(författare)
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European NCAP Program Developments to Address Driver Distraction, Drowsiness and Sudden Sickness
- 2021
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Ingår i: Frontiers in Neuroergonomics. - : Frontiers Media SA. - 2673-6195. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Driver distraction and drowsiness remain significant contributors to death and serious injury on our roads and are long standing issues in road safety strategies around the world. With developments in automotive technology, including driver monitoring, there are now more options available for automotive manufactures to mitigate risks associated with driver state. Such developments in Occupant Status Monitoring (OSM) are being incorporated into the European New Car Assessment Programme (Euro NCAP) Safety Assist protocols. The requirements for OSM technologies are discussed along two dimensions: detection difficulty and behavioral complexity. More capable solutions will be able to provide higher levels of system availability, being the proportion of time a system could provide protection to the driver, and will be able to capture a greater proportion of complex real-word driver behavior. The testing approach could initially propose testing using both a dossier of evidence provided by the Original Equipment Manufacturer (OEM) alongside selected use of track testing. More capable systems will not rely only on warning strategies but will also include intervention strategies when a driver is not attentive. The roadmap for future OSM protocol development could consider a range of known and emerging safety risks including driving while intoxicated by alcohol or drugs, cognitive distraction, and the driver engagement requirements for supervision
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| 6. |
- Fredriksson, Rikard, 1967, et al.
(författare)
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European NCAP Program Developments to Address Driver Distraction, Drowsiness and Sudden Sickness
- 2021
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Ingår i: Frontiers in Neuroergonomics. - : Frontiers Media SA. - 2673-6195. ; 2
-
Tidskriftsartikel (refereegranskat)abstract
- Driver distraction and drowsiness remain significant contributors to death and serious injury on our roads and are long standing issues in road safety strategies around the world. With developments in automotive technology, including driver monitoring, there are now more options available for automotive manufactures to mitigate risks associated with driver state. Such developments in Occupant Status Monitoring (OSM) are being incorporated into the European New Car Assessment Programme (Euro NCAP) Safety Assist protocols. The requirements for OSM technologies are discussed along two dimensions: detection difficulty and behavioral complexity. More capable solutions will be able to provide higher levels of system availability, being the proportion of time a system could provide protection to the driver, and will be able to capture a greater proportion of complex real-word driver behavior. The testing approach could initially propose testing using both a dossier of evidence provided by the Original Equipment Manufacturer (OEM) alongside selected use of track testing. More capable systems will not rely only on warning strategies but will also include intervention strategies when a driver is not attentive. The roadmap for future OSM protocol development could consider a range of known and emerging safety risks including driving while intoxicated by alcohol or drugs, cognitive distraction, and the driver engagement requirements for supervision and take-over performance with assisted and automated driving features.
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| 7. |
- Fredriksson, Rikard, 1967, et al.
(författare)
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Integrated bicyclist protection systems - potential of head injury reduction combining passive and active protection systems
- 2015
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Ingår i: 24th International Technical Conference on the Enhanced Safety of Vehicles.
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Konferensbidrag (refereegranskat)abstract
- In recent years both pedestrian passive and active safety systems, such as pedestrian bonnets/airbags and autonomous braking, have emerged on the market and are estimated to be effective to reduce injury of vulnerable road users in car crashes. A natural next step is to develop similar protection systems for bicyclists. The aim of this study was to investigate the potential bicyclist head injury reduction from passive and active protection systems compared to an integrated system. The German In-Depth Accident Study (GIDAS) database was queried from 1999 to 2014 for severely (AIS3+) head injured bicyclists when struck by passenger car fronts. This resulted in 34 cases where information was sufficient for both the pre-crash and the in-crash part of the event. The default passive protection system was designed to mitigate head injuries caused by the bonnet area, A-pillars, and the lower windscreen (instrument panel) area (deployable hood and windshield airbag). To estimate the hood and airbag performance risk reduction functions were used based on experimental tests with and without the systems. The active protection system was an autonomous braking system, which was activated one second prior to impact if the bicyclist was visible to a forward-looking sensor. Maximum speed reduction was estimated using road condition information in each case. The integrated system was a direct combination of the passive and active protection systems. Case by case the effect from each of the active, passive and integrated systems was estimated. For the integrated system, the influence of the active system on the passive system performance was explicitly modelled in each case. A sensitivity analysis was performed varying the coverage area of the passive protection system and the activation criteria of the active system. The integrated system resulted in 29%-62% higher effectiveness than the best single system of active respectively passive protection system in reducing the number of bicyclists sustaining severe (AIS3+) head injuries. These values were statistically tested and found to be significant. The study is based on representative data from Germany, but may not be representative to countries with a different car fleet or infrastructure. This study indicates that integrated systems of passive and active vulnerable road user countermeasures offer a significantly increased potential for head injury reduction compared to either of the two systems alone.
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| 8. |
- Huang, Sunan, 1979, et al.
(författare)
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Performance Analysis of a Bumper-Pedestrian Contact Sensor System by Using FE Models
- 2008
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Ingår i: International Journal of Crashworthiness. - : Informa UK Limited. - 1358-8265 .- 1754-2111. ; 13:2, s. 149-157
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Tidskriftsartikel (refereegranskat)abstract
- A pedestrian contact sensor in the car bumper is a potential solution to trigger an active hood system. Because of the high level of temperature dependency for the bumper foam stiffness, the sensor output can be unstable at varying temperatures. A new contact sensor was therefore developed to provide a temperature-independent measurement for pedestrian impacts.This study analyzed the performance of the bumper-pedestrian contact sensor system. First, a baseline Finite Element (FE) bumper model of a production car was developed and validated. Based on the baseline model, an improved bumper model was subsequently developed to meet the requirements of the lower legform impact tests proposed by Working Group 17 of the European Enhanced Vehicle-safety Committee (EEVC WG17). Second, a FE human lower extremity model was developed. Using this model, the baseline and improved bumper models were further evaluated in terms of the predicted knee ligament raptures and long bone fractures. Finally, the new contact sensor was built into the improved bumper model. A performance study was then conducted to evaluate the sensor effectiveness. Consequently, a better diameter for the sensor tube was identified in terms of the temperature stability and mass sensitivity of the sensor output.
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| 9. |
- Håland, Yngve, 1945, et al.
(författare)
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THE EFFECT OF CAR SEATS ON NECK INJURIES IN LOW-SPEED REAR IMPACTS
- 1997
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Ingår i: ISATA MAGAZINE.
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Konferensbidrag (refereegranskat)abstract
- Neck injuries often occur at low impact velocities, typically less than 20kph. Such accidents usually result in minor 'whiplash' injuries, but about 10% of them lead to permanent disability with degree of disability over 10%. Factors that could influence the risk of sustaining neck injuries in rear impacts include: (1) the distance between the head and the head restraint; (2) the seat's stiffness structure; and (3) the car's rear structure. This article outlines some tests to show whether the seats or the structure affect neck injuries more. Two cars, with empty weights 705kg and 725kg, were impacted from the rear at 20kph by a mobile barrier in two full-scale rear-impact tests. The drivers' seats were retained, but the front passenger seats and their attachments were swapped over. Various motion sensors and high-speed cameras recorded the motions of the dummies in the passenger seats. The motion of dummies in mini-sled rear-impact tests was also recorded. It was found that seat design, not car structure, was the reason for differential dummy loading. Dummy acceleration does not really start until car acceleration has almost finished. The article finally evaluates some new principles for designing a car seat, which aim to minimise the motion between the lower and upper ends of the cervical spine in a rear collision.
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| 10. |
- Palao, Adriano, et al.
(författare)
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EURO NCAP’S CURRENT AND FUTURE IN-CABIN MONITORING SYSTEMS ASSESSMENT
- 2023
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Ingår i: 27th ESV Conference Proceedings.
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Konferensbidrag (refereegranskat)abstract
- Informed by international research and crash data, Euro NCAP has developed a Test and Assessment protocol to measure the performance of direct Driver State Monitoring (DSM) systems, which is implemented from January 2023 as part of the Safety Assist – Safe Driving protocol of the star rating. This protocol was developed in collaboration with experts from several OEMs and Tier 1 and 2 suppliers, and it is aimed at promoting standard fitment of driver monitoring systems that effectively detect impaired and distracted driving, eventually triggering the appropriate vehicle response strategies to warn driver and/or mitigate risks. Getting the full score in the Occupant State Monitoring (OSM) area will only be possible with direct monitoring systems. The protocol describes the DSM system requirements across three areas: Sensing (system performance degradation in the presence of several noise variables such as stature, light, facial features); Driver State (system capability to effectively deem the driver as distracted, fatigued or unresponsive); and Vehicle Response (vehicle deploying timely and appropriate response strategies, eventually avoiding the accident or mitigating its severity). This paper discusses the rationale behind the assessment methodology and the resulting protocol, and how Euro NCAP envisions DSM as an effective tool to reducing/mitigating a wide variety of traffic accidents. Over the course of 2023 test campaign, Euro NCAP will collect extensive insights from both a practical implementation and technology capability perspective, opening the door for on-going improvements and further requirements. In the coming decade, Euro NCAP expects Driver (or Occupant) State Monitoring systems to tackle areas such as driver engagement, intoxication, optimized passive restraints, child presence detection, optimized passive safety, as well as enhancing the performance and intuitiveness of other ADAS by making them work in synchrony with the driver behavior – eventually increasing driver acceptance [1]. Lastly, the 2023 requirements for direct DSM are based on parameters related to eye gaze and head posture – these are subject to be expanded, allowing for new methods and systems to be used in future.
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