The following hypothesis is tested by the research: A single crash test contains information that can be used to predict vehicle response accounting for different crash conditions such as vehicle mass and initial velocity and thus can be used to predict the effect on occupant injury risk for varying occupant positions within a vehicle It is established that the response of the crumple zone is influential in the level of injury risk. The metric for such response in common use is the NHTSA linear stiffness parameter. This parameter is used to show that stiffness increases with vehicle mass in a demographic setting. However, by comparing vehicle mass trends over 28 years of crash testing with similar trends in stiffness, a mass influence in the stiffness increase is implicated. This influence is supported by the introduction of a mass-independent stiffness metric, called reluctance, which shows a lesser increase in mass-independent stiffness over the 28 years. The idea that stiffness should increase with vehicle mass runs counter to intuition and is tested by comparing two identical vehicles in crash tests where one of the vehicles carries an extra 555kg. The idea is further tested by simulation using a multiple mass-spring model on vehicles, varying mass and impact velocity. Using the reluctance stiffness metric it was concluded that increased vehicle mass decreases stiffness, confirming intuition. Using the injury risk metric of contact velocity differential between occupant and interior of the vehicle it is shown that increased vehicle mass reduces injury. This has important implications for the industry where a marginal performer in a compliance crash test needs only to increase production vehicle mass to reduce injury levels to the statutory injury reference values. A fleet study presents evidence of increasing average vehicle mass. The study observes that blunt injury generally commences prior to vehicle rebound and continues well into rebound. Recognizing vehicle rebound to be influential in almost all blunt injury led to analysis of the fleet for improvement to this injury parameter. Using specific energy absorption as criterion, 18 modern cars were compared with 19 cars 15-17 years older at compliance test velocities. No improvement was discerned. Similarly, two baskets of cars (n=41 modern & n=32 older) tested at NCAP speeds separated by nominally 20 years failed to show improvement in rebound velocity. The implications for this study of the rebound findings was to ensure that the model presented was capable of representing injury into the rebound phase of the crash. To assist in this, a rebound formulation to reflect varying initial velocity was determined to be a linear function, studying 7 models of vehicles involved in 20 crashes at nominally 40, 48 & 56 km/h crash speeds. Occupant position within a vehicle is identified as an important variable in injury determination. Vehicle crash tests require seating positions to be set to mid-track adjustment. This discriminates against vehicles having more "legroom" while appearing to be fair, using seating adjustment as the determinant. An empirical mathematical model is proposed permitting crash test results to be extended to investigate the effects of varying occupant positions thus eliminating the legroom anomaly. In addition to the varying occupant position facility, the mathematical model can easily accommodate changes in vehicle mass and varying impact velocity showing fidelity with test data. The model is used to show that injury risk in the National Fleet has not improved over an 18-year period of crash testing.

Teknikutvecklingen inom bilbranschen ökar i takt med konsumenters krav på multifunktionella system. Mobiltelefoner är ett vanligt inslag i konsumenternas vardag och används dessvärre även under bilkörning. Det finns ett tydligt samband mellan mobilanvändning bakom ratten och antalet trafikolyckor. Detta antal skulle kunna minska om infotainmentsystem kan erbjuda samma funktionalitet fast på ett mer trafiksäkert sätt. Det finns idag riktlinjer gällande användarupplevelse och trafiksäkerhet från Android och NHTSA. Denna uppsats syftar till att undersöka hur väl dessa befintliga riktlinjer går att kombinera samt att ta fram nya riktlinjer för hur utvecklare kan förhålla sig till köpfunktionalitet i en infotainmentapplikation. För att uppnå detta har en prototyp av en infotainmentapplikation med sådan funktionalitet utvecklats och utvärderats med hjälp av observationer. Den insamlade data från utvecklingsprocessen har sedan analyserats och sammanställts. Resultatet presenterats slutligen i form av framtagna riktlinjer som fungerar likt en rekommendation för utvecklare i framtiden.

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The 85th percentile off-road glances while performing three tasks on an in-vehicle system while driving in a simulator was investigated. The tasks were a radio task, a telephone task and a sound settings task which were performed at three occasions each. The distribution of 85th percentile off-road glance durations for each subject and task showed that durations differed between individuals rather than between tasks. It also turned out that durations longer than 2.00 seconds were not rare and 2 of 16 subjects had durations longer than 2.00 seconds in the radio task. Even though the distribution showed small differences between tasks on an individual level, differences on a group level were found between the tasks. A tendency of a learning effect was found, which implied a decrease in 85th percentile off-road glance durations as the tasks were performed at several occasions. A tendency of a floor effect in 85th percentile off-road glance durations, when the subjects are familiarized with tasks, was also found. Performance on a computerized trail-making test, measuring ability of visual search, motor speed and mental flexibility, was found not to be related with 85th percentile off-road glance durations.

"Mammalian skeletal muscle is a very complicated biological structure to model due to its non-homogeneous and non-linear material properties as well as its complex geometry. Finite element discrete one-dimensional Hill-based elements are largely used to simulate muscles in both passive and active states. There are, however, several shortfalls to utilizing one-dimensional elements, such as the impossibility to represent muscle physical mass and complex lines of action. Additionally, the use of one-dimensional elements restricts muscle insertion sites to a limited number of nodes causing unrealistic loading distributions in the bones. The behavior of various finite element muscle models was investigated and compared to manually calculated muscle behavior. An improved finite element muscle model consisting of shell elements and Hill-based contractile truss elements in series and parallel was ultimately developed. The muscles of the thigh were then modeled and integrated into an existing 50th percentile musculo-skeletal model of the knee-thigh-hip complex. Impact simulations representing full frontal car crashes were then conducted on the model and the pre-loading effects from active thigh muscles on the femur were investigated and compared to cadaver sled test data. It was found that the active muscles produced a pre-load femoral axial force that acted to slightly stabilize the rate of stress intensification on critical stress areas on the femur. Additionally, the active muscles served to direct the distribution of stress to more concentrated areas on the femoral neck. Furthermore, the pre-load femoral axial force suggests that a higher percentage of injuries to the knee-thigh-hip complex may be due to the effects of active muscles on the femur. "