Opportunities on Fuel Economy Utilizing V2V Based Drive Systems 2013-01-0985

It is well known that driver behavior can affect fuel consumption to a large extent hence modifying it can lead to reasonable reduction in the magnitude of 10 to 20%. However, it is also known that effects of training are short lived and therefore many authors and companies suggest the use of monitoring systems, sometimes called eco-driver, which allow recognizing opportunities for reduction.

V2V is an emerging technology which has been widely studied especially for safety applications. In terms of fuel consumption, there has also been a significant effort for methods directed to coordinate the movement of vehicles, especially of trucks, to improve fuel consumption by platooning [1]. In this paper, we look at the issue from the point of view of a single vehicle, in terms of an extension of a standard adaptive cruise control (ACC): is it possible to improve consumption of a vehicle traveling its own way and having to keep safety distance to other vehicles traveling the same route, if information on the driver intentions are transmitted or guessed? To this end we consider the distance between the preceding and the following car as a variable which can be changed freely in a given, velocity dependent range, in order to decrease the level of fuel consumption. The whole issue can be stated as an optimization problem including constraints to account for safety. Introducing a moving horizon solution allows a more realistic view on the possible benefits. For the driver it looks like a standard ACC, albeit with a dynamic change of the distance.

In this paper we show by simulation as well as measurements on the test bench the potential of such a method - which goes about 15% in the case of an FTP-like cycle. Reduction of fuel consumption is studied for a single vehicle and for a line of cars in a heavy, but not congested traffic. The paper shows that in the case of good information on the intended behavior in the next 10 to 15 seconds, a fuel consumption reduction in the range 10 to 20% is achievable.