Environmental evaluation of Intelligent Cruise Control (ICC) vehicles

Abstract

During the last decade considerable research and development efforts have been devoted to automating vehicles in an effort to improve safety and efficiency of vehicle following. Several designs for automatic vehicle following controllers exist that satisfy stability criteria and ensure tight vehicle following. However, it is not known how these controllers will affect fuel consumption and air pollution in the presence/absence of traffic disturbances. The purpose of this paper is environmentally evaluate such a control system design, namely the Intelligent Cruise Control (ICC) system. This is done using a Comprehensive Modal Emissions Model (CMEM) that calculates vehicle emissions depending on its mode of operation, i.e. steady state cruise, acceleration/deceleration, among others. The ICC is designed to guarantee accurate speed and position tracking during `smooth' acceleration maneuvers. As a consequence, fuel consumption and air pollution is reduced by 8.5% and 8.1%-18.4% respectively due to the presence of 10% ICC vehicles during smooth acceleration maneuvers. Furthermore, human factor considerations dictate that the response of an ICC vehicle should be smooth. As a result, improvements of the order of 28.5% and 1.5%-60.6% can be observed during rapid acceleration transients in fuel consumption and air pollution levels, respectively, due to the presence of 10% semi-automated vehicles. Due to the randomness and uncertainties in human driving, the numbers obtained are qualitatively valid and demonstrate the beneficial effect of ICC vehicles on air quality and fuel consumption.