| 1. |
- Blissing, Björn, 1978-, et al.
(författare)
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Exploring the suitability of virtual reality for driving simulation
- 2018
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Ingår i: Proceedings of the Driving Simulation Conference 2018. - Antibes, France. - 9782857827344 ; , s. 163-166, s. 163-166
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Konferensbidrag (refereegranskat)abstract
- Head mounted displays (HMDs) is an emerging technology and the availability of affordable systems is growing fast. Replacing projector and large screen solutions with head mounted displays may appear as an appealing solution. However, inherent properties and technical limitations of these systems need to be understood and considered before making the leap to virtual reality.This paper outlines some of the most fundamental limitations of head mounted displays relevant to this context, both from a technical and human factors perspective. Desirable properties of scenarios and types of studies are deduced, based on these limitations. Finally, a meta analysis is performed on the feasibility of transferring simulator studies found in the literature to platforms with head mounted displays. The results suggest that a noticeable amount (40%) of the investigated simulator studies could likely have been performed with head mounted displays. This number could be increased further with technical advances in display resolution, display technology, reduction in latency, etc.
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| 2. |
- Bhatti, Harrison John, 1979-, et al.
(författare)
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A Multidimensional Readiness Index for the Electrification of the Transportation System in China, Norway, and Sweden
- 2023
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Ingår i: Future Transportation. - Basel : MDPI. - 2673-7590. ; 3:4, s. 1360-1384
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Tidskriftsartikel (refereegranskat)abstract
- The main objective of this paper is to develop a readiness index model that can serve as an analytical tool for exploring the achievements of the electrification of transportation systems. We have applied this readiness index model to evaluate the readiness positioning of China, Norway, and Sweden towards transportation electrification. We have chosen these three countries as they represent diversity among countries adopting electric transportation system solutions. Our developed readiness index model has four key dimensions: technological readiness, political readiness, societal readiness, and economic readiness. The embeddedness of all four dimensions in one model provides a multi-perspective way of analyzing and evaluating the readiness levels of countries moving towards transforming their transportation system. Therefore, we named the model a “multidimensional readiness index”. Our main conclusions are that political processes and decisiveness are the most important factors, followed by societal needs and economic ability, with the current technology as the fourth. Without the participation of dedicated and determined political decision makers, the other three factors are challenging to obtain. Political decision makers need to facilitate economic means to support the transformation in society and affected industries to balance the economic disadvantages of the electrically powered vehicle systems until they pass the cost disadvantage turning point. The development of relevant technology is no longer the significant barrier it was at the beginning of this transformation about 20 years ago. The technology for electrically powered transportation systems and devices is widely available now, although it is continuously evolving and being improved. Associated industries cannot be expected to initiate, finance, take risks, and take the lead in this global societal transformation without clear and strong political support.
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| 3. |
- Bianchi Piccinini, Giulio, 1982, et al.
(författare)
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How Do Drivers Respond to Silent Automation Failures? Driving Simulator Study and Comparison of Computational Driver Braking Models
- 2020
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 62:7, s. 1212-1229
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This paper aims to describe and test novel computational driver models, predicting drivers’ brake reaction times (BRTs) to different levels of lead vehicle braking, during driving with cruise control (CC) and during silent failures of adaptive cruise control (ACC). Background: Validated computational models predicting BRTs to silent failures of automation are lacking but are important for assessing the safety benefits of automated driving. Method: Two alternative models of driver response to silent ACC failures are proposed: a looming prediction model, assuming that drivers embody a generative model of ACC, and a lower gain model, assuming that drivers’ arousal decreases due to monitoring of the automated system. Predictions of BRTs issued by the models were tested using a driving simulator study. Results: The driving simulator study confirmed the predictions of the models: (a) BRTs were significantly shorter with an increase in kinematic criticality, both during driving with CC and during driving with ACC; (b) BRTs were significantly delayed when driving with ACC compared with driving with CC. However, the predicted BRTs were longer than the ones observed, entailing a fitting of the models to the data from the study. Conclusion: Both the looming prediction model and the lower gain model predict well the BRTs for the ACC driving condition. However, the looming prediction model has the advantage of being able to predict average BRTs using the exact same parameters as the model fitted to the CC driving data. Application: Knowledge resulting from this research can be helpful for assessing the safety benefits of automated driving.
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| 4. |
- Bühlmann, Erik, et al.
(författare)
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Speed dependency of temperature effects on road traffic noise
- 2015
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Ingår i: INTER-NOISE 2015 - 44th International Congress and Exposition on Noise Control Engineering.
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Konferensbidrag (refereegranskat)abstract
- Recently, a new literature review on the influence of temperature on tire/road noise became available, based on a compilation of large amounts of data from empirical research. This review showed that the effect of temperature is roughly double of that previously assumed and taken account of in international standards. This makes temperature one of the main sources of error in measurement results. Furthermore, it suggested that an additional refinement of the correction approach may be required to improve the accuracy of measurements. As a first attempt for this refinement, this article focuses on the speed dependency of temperature effects.Some past work has detected an influence of speed on the temperature effect, but did not succeed in quantifying this influence or in describing the exact pattern of speed dependency. This work aims to fill this gap byinvestigating speed dependency of temperature effects on tire/road noiseestimating the temperature influence on noise generation mechanisms together with their change with speed, andevaluating the speed influence on overall road traffic noise by including a propulsion noise component while using a new European traffic noise emission model.The article concludes by proposing a method to deal with speed dependency of temperature effects on both, CPX (or OBSI) and SPB measurements, with the ultimate goal of increasing the accuracy of measurement results.
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| 5. |
- Carlson, Annelie, 1969-, et al.
(författare)
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Utveckling av VTI:s modell för beräkning av trafikarbete på svenska vägar
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Varje år tar VTI fram en trafikbeskrivning som omfattar en historisk del samt en prognosdel över det framtida årliga trafikarbetet. Termen trafikarbete betecknar den totala omfattningen av trafik inom ett visst område och under en viss tid. Baserat på resultatet från VTI:s trafikmodell görs sedan en förenklad beskrivning i emissionsberäkningsverktyget HBEFA. Denna trafikbeskrivning ligger sedan till grund för den årliga beräkningen av trafikens emissioner (utsläpp) som sker på Trafikverkets uppdrag. Syftet med projektet som redovisas i VTI notat 30-2013 har varit att genomföra en allmän metodöversyn av detta arbete. Genomgången visar bland annat att en beräkningsmodell ständigt kan utvecklas och förbättras. Nya data har blivit tillgängliga genom mätaravläsningar för körsträckor och bättre underlag finns nu för att ta hänsyn till att tunga lastbilar i betydande utsträckning används för utlandstransporter. En funktionsanpassning som visar körsträcka som funktion av fordonsålder har tagits fram, vilket visar på en god överensstämmelse med de uppmätta körsträckorna för fordon upp till och med ca 25 till 30 år. En känslighetsanalys av att göra olika antaganden vad gäller körsträcka och åldersfördelning visar effekten på mängd bränsleförbrukning och reglerade emissioner på total nivå för olika fordonskategorier.
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| 6. |
- Carlsson, Anna K, 1966, et al.
(författare)
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Anthropometric Specifications, Development, and Evaluation of EvaRID : A 50th Percentile Female Rear Impact Finite Element Dummy Model
- 2014
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Ingår i: Traffic Injury Prevention. - : Taylor & Francis. - 1538-9588 .- 1538-957X. ; 15:8, s. 855-865
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Whiplash-associated disorders (WADs), or whiplash injuries, due to low-severity vehicle crashes are of great concern in motorized countries and it is well established that the risk of such injuries is higher for females than for males, even in similar crash conditions. Recent protective systems have been shown to be more beneficial for males than for females. Hence, there is a need for improved tools to address female WAD prevention when developing and evaluating the performance of whiplash protection systems. The objective of this study is to develop and evaluate a finite element model of a 50th percentile female rear impact crash test dummy.Methods: The anthropometry of the 50th percentile female was specified based on literature data. The model, called EvaRID (female rear impact dummy), was based on the same design concept as the existing 50th percentile male rear impact dummy, the BioRID II. A scaling approach was developed and the first version, EvaRID V1.0, was implemented. Its dynamic response was compared to female volunteer data from rear impact sled tests.Results: The EvaRID V1.0 model and the volunteer tests compared well until ~250 ms of the head and T1 forward accelerations and rearward linear displacements and of the head rearward angular displacement. Markedly less T1 rearward angular displacement was found for the EvaRID model compared to the female volunteers. Similar results were received for the BioRID II model when comparing simulated responses with experimental data under volunteer loading conditions. The results indicate that the biofidelity of the EvaRID V1.0 and BioRID II FE models have limitations, predominantly in the T1 rearward angular displacement, at low velocity changes (7 km/h). The BioRID II model was validated against dummy test results in a loading range close to consumer test conditions (EuroNCAP) and lower severity levels of volunteer testing were not considered.The EvaRID dummy model demonstrated the potential of becoming a valuable tool when evaluating and developing seats and whiplash protection systems. However, updates of the joint stiffness will be required to provide better correlation at lower load levels. Moreover, the seated posture, curvature of the spine, and head position of 50th percentile female occupants needs to be established and implemented in future models.
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| 7. |
- Carlsson, Anna K, 1966, et al.
(författare)
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Dynamic kinematic responses of female volunteers in rear impacts and comparison to previous male volunteer tests
- 2011
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-9588 .- 1538-957X. ; 12:4, s. 347-357
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The objective was to quantify dynamic responses of 50th percentile females in rear impacts and compare to those from similar tests with males. The results will serve as a basis for future work with models, criteria, and safety systems.Methods: A rear impact sled test series with 8 female volunteers was performed at velocity changes of 5 and 7 km/h. The following dynamic response corridors were generated for the head, T1 (first thoracic vertebra) and head relative to T1: (1) accelerations in posterior-anterior direction, (2) horizontal and vertical displacements, (3) angular displacements for 6 females close to the 50th percentile in size. Additionally, the head-to-head restraint distance and contact time and neck injury criterion (NIC) were extracted from the data set. These data were compared to results from previously performed male volunteer tests, representing the 50th percentile male, in equivalent test conditions. T-tests were performed with the statistical significance level of.05 to quantify the significance of the parameter value differences for the males and females.Results: At 7 km/h, the females showed 29 percent earlier head-to-head restraint contact time (p =.0072); 27 percent shorter horizontal rearward head displacement (p =.0017); 36 percent narrower head extension angle (p =.0281); and 52 percent lower NIC value (p =.0239) than the males in previous tests. This was mainly due to 35 percent shorter initial head-to-head restraint distance for the females (p =.0125). The peak head acceleration in the posterior-anterior direction was higher and occurred earlier for the females.Conclusions: The overall result indicated differences in the dynamic response for the female and male volunteers. The results could be used in developing and evaluating a mechanical and/or mathematical average-sized female dummy model for rear impact safety assessment. These models can be used as a tool in the design of protective systems and for further development and evaluation of injury criteria. © 2011 Taylor & Francis Group, LLC.
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| 8. |
- Carlsson, Anna K, 1966, et al.
(författare)
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Female volunteer motion in rear impact sled tests in comparison to results from earlier male volunteer tests
- 2008
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Ingår i: 2008 INTERNATIONAL IRCOBI CONFERENCEONTHE BIOMECHANICS OF INJURY17. – 19. September 2008– BERN (Switzerland)PROCEEDINGS. ; , s. 461-464, s. 461-464
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Konferensbidrag (refereegranskat)abstract
- Vehicle related crashes causing neck injuries (whiplash) are costly and common, and injury statistic data shows a larger risk of neck injuries for females than for males. This study aims at investigating differences between female and male dynamic response in rear impacts. Rear impact sled tests with female volunteers were carried out and the results were compared with previously performed tests with males in matching test conditions. The volunteer tests were performed at a change of velocity of 7 km/h. The comparison of the average response of the males and the females and their response corridors showed several differences. The horizontal head acceleration peak value was on average 40% higher and occurred on average 18% earlier for the female volunteers compared to the male volunteers. The NIC value was 45% lower and 30% earlier for the females, probably due to a 27% smaller initial head-to-head restraint distance and thereby a 24% earlier head restraint contact. The results provide characteristic differences between dynamic responses of females and males in low speed rear impacts. These results contribute to the understanding of human dynamic response in rear impacts. In addition, they can be used in the process of future development if numerical and/or mechanical human models for crash testing.
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| 9. |
- Carlsson, Anna K, 1966, et al.
(författare)
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Motion of the Head and Neck of Female and Male Volunteers in Rear Impact Car-to-Car Impacts
- 2012
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-9588 .- 1538-957X. ; 13:4, s. 378-387
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The objectives of this study were to quantify and compare dynamic motion responses between 50th percentile female and male volunteers in rear impact tests. These data are fundamental for developing future occupant models for crash safety development and assessment.Methods: High-speed video data from a rear impact test series with 21 male and 21 female volunteers at 4 and 8 km/h, originally presented in Siegmund et al. (1997), were used for further analysis. Data from a subset of female volunteers, 12 at 4 km/h and 9 at 8 km/h, were extracted from the original data set to represent the 50th percentile female. Their average height was 163 cm and their average weight was 62 kg. Among the male volunteers, 11 were selected, with an average height of 175 cm and an average weight of 73 kg, to represent the 50th percentile male. Response corridors were generated for the horizontal and angular displacements of the head, T1 (first thoracic vertebra), and the head relative to T1. T-tests were performed with the statistical significance level of.05 to quantify the significance of the differences in parameter values for the males and females.Results: Several differences were found in the average motion response of the male and female volunteers at 4 and 8 km/h. Generally, females had smaller rearward horizontal and angular motions of the head and T1 compared to the males. This was mainly due to shorter initial head-to-head restraint distance and earlier head-to-head restraint contact for the females. At 8 km/h, the female volunteers showed 12 percent lower horizontal peak rearward head displacement (P =.018); 22 percent lower horizontal peak rearward head relative to T1 displacement (P =.018); and 30 percent lower peak head extension angle (P =.001). The females also had more pronounced rebound motion.Conclusions: This study indicates that there may be characteristic differences in the head-neck motion response between 50th percentile males and females in rear impacts. The exclusive use of 50th percentile male rear impact dummies may thus limit the assessment and development of whiplash prevention systems that adequately protect both male and female occupants. The results of this study could be used in the development and evaluation of a mechanical and/or computational average-sized female dummy model for rear impact safety assessment. These models are used in the development and evaluation of protective systems. It would be of interest to make further studies into seat configurations featuring a greater head-to-head restraint distance. © 2012 Copyright Taylor and Francis Group, LLC.
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| 10. |
- Chai, Hua
(författare)
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Comparison of Field Speed Data Collection Methods
- 2013
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Ingår i: Proceedings of the 16th International Conference Road Safety on Four Continents. - Linköping : Statens väg- och transportforskningsinstitut.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this report, the characteristics of the applied on-site measurement methods were explored based on theoretical study. According to the comparison of the five methods, it is indicated that the radar and GPS are easier to measure the speed; however, compared with the radio and mirror measurements, the external environmental factors could be hard to be avoided so that the unexpected speeds exist in the data processing. Moreover, the attributes and distributions of each measurement have been achieved applying statistics cooperated with relevant software. Comparing the results of histograms and goodness-of-fit tests of the methods, it could be concluded that the speed data of ATC are more representative of the traffic condition due to the better normalcy. In the conclusion, several suggestions are presented: (1) the unexpected speeds were observed because of manual or mechanical problems, therefore the operations could be strictly in accord with the requirements of each measurement; (2) during the data processing, the statistics should be applied properly, especially the determination of sample size should be taken more consideration, and the coefficients should be selected in terms of different requirements of the analysis
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