M. Rapone

Experimental Evaluation of Fuel Consumption and Emissions in Congested Urban Traffic

In this paper, first results regarding measurements of fuel consumption and emissions, relative to different traffic conditions and a specific urban area, are presented. The experimental approach used for the evaluation of emissions consists in: (a) recording on-road car and engine operating conditions during designed trips performed in the center of Naples (Italy) by an instrumented car, (b) determining by multivariate statistical analysis driving cycles characterizing typical traffic conditions, (c) measuring emissions and fuel consumption in laboratory using defined driving cycles. Fuel flow rate measurements are performed at each second, while emissions are detected along a cycle and an average value per kilometer is obtained. Operating conditions of engine during laboratory testing are related to on-road operating conditions by comparing fuel consumption and exhaust gases temperatures measurements performed on-road and in laboratory by the same device.

An integrated knowledge base for modelling and predicting vehicle real-world emissions as a function of driving behaviour kinematics

A multivariate modelling approach was developed by Istituto Motori to model and predict vehicle real-world emissions. Complex driving kinematics is represented by two blocks of variables, which require the development of a hierarchical multiblock emission model, where the two blocks of variables represent overall and instantaneous features of each driving cycle associated to a trip. The multiblock model was applied to analyze and model emissions of the large database built in the ARTEMIS project. In this database we collected emission measurements performed in European laboratories relative to real driving cycles which are statistically representative of many European traffic/road conditions from congested to rush-hour traffic in urban, rural and highway roads. Data concern a varied fleet of vehicles differing in technology and class. To develop a tool useful for mobility analysts for traffic environmental impact assessment, a knowledge base was envisaged to integrate the data warehouse and the model base to build a user interface for driving cycle kinematics and emission analysis. In this paper the modelling approach is presented together with overall emission and driving kinematics characterization based on experimental results, as well as functional analysis of the knowledge base structure and the information tool.

Preliminary results on emissions and driving behavior of ATENA fleet test project in Naples

One of the objectives of the Atena project [1] was the definition of a methodology for the predictive evaluation of the environmental impact of different types of vehicles used in an urban scenario. The target is to obtain a methodology that allow the decision maker to verify in simulation the effects of possible measures like low enforcement to the access restrictions or vehicle fleet composition. The main obstacle is the realisation and the managing of real driving cycles in order to that overtake the limits derived from the utilisation of typical cycles (i.e. ECE o NEDC) or the simple consideration of average speed. The starting point is a digital representation of the urban network where all the roads are represented with one or more arcs and for all this arcs is available an estimation of the traffic variables like the vehicle flow [vehicles per hour] or the average speed [kph]. Every arc is described in terms of traffic parameters like the type of road (i.e. highway, district road). The results presented in this work will be the starting point for the definition of one methodology to describe the emissions of vehicles fleets in terms of traffic parameters.