No abstract

No abstract

No abstract

Fuel-efficient driving is difficult in unknown or complex environments. To aid the driver with this task, we present a novel method of tactical route optimization by calculating a short-term fuel-reduced velocity profile. This profile is based on knowledge of location-dependent velocity profiles that are collected by the vehicles over time and shared with other vehicles.To determine a fuel-efficient velocity profile, we first split the planned route into segments. We cluster the historical velocity profiles within each segment using a Dynamic Time Warping algorithm, obtaining classes of velocity profiles and their probabilities. We construct a transition graph between velocity profile classes from adjacent segments and calculate the most probable path through the next segments ahead. This path represents the most likely future velocity profile under the assumption that the driver behaves like previous drivers on the same segment. Given the constraints defined by this profile, we calculate the fuel-reduced velocity profile with help of a shortestpath algorithm in a vehicle-specific fuel-consumption graph. First results in an urban environment indicate possible fuel savings of about 8.3 % compared to the most probable profile.

Many applications for inter-vehicular communication require a very specific test situation in order to be evaluated during a real world experiment. However, in the currently prevailing free-flow experiments the intended situation for the application may not occur in sufficient frequency to provide statistically significant results. In this paper, we argue that the existing experimental approach should therefore be complemented with coordinated experiments. This allows to specifically create the desired test situation.We present a methodology for such controlled experiments. The key to those experiments is the exact coordination of the participating cars' movements as well as a detailed control over all used softand hardware. To illustrate this methodology, we have performed an experiment with two cars that simultaneously approach an urban intersection and measured the radio transmission ranges with and without a road side unit. The results show that cars equipped with communication technology can inform their drivers about the approaching other cars up to ten seconds before a possible accident at such an intersection.