Evaluating Communications and Idm in a Context of a Cca Application for Vanets

Adaptive Cruise Control Systems (ACC) are becoming essential in developing advanced vehicular applications/services which help to reduce the risk of accidents and offer better conditions for comfort in the driving experience, Hartenstein and Leberteaux (2008). The IDM (Intelligent Driver Model) is a realistic car-following model whose main feature is the use of physical-oriented parameters to explain the different aspects related to mobility of vehicles. It has been evaluated as an ACC car-following scheme for future automatic car-driving, Kesting and Treiber (2010). However, IDM has been at first conceived to operate under general carfollowing conditions, Treiber (2000), where, for certain values of the model parameters, car traffic can be realistically recreated. Nevertheless, extreme but relevant situations, such as emergency braking, are not considered in detail. As we will show, the model parameters are not properly tuned to operate under these particular circumstances, mainly because related driving comfort (driving aggressiveness) is not actually taken into account. Therefore, in this paper we propose to benefit from the vehicle-to-vehicle communications (V2V) paradigm to enhance the functionality of ACC systems by performing a dynamic real-time tuning scheme of such model parameters. The application under test is a Cooperative Chain Collision Avoidance (CCA) application (Tomas-Gabarron, 2010) in which, in addition to achieve a significant lower number of vehicle accidents, the resulting deceleration policy provides a scheme that smoothens deceleration changes to further increase comfort even in these critical conditions.