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The long time needed for the application and the money involved are some of the main obstacles preventing the CNG vehicles market penetration, costs are always too high and application time always too long compared with the relatively small volumes. Besides the activities to be carried out on the original engine control system to integrate the gas system are unwelcome by the OEM as they require a re-validation of already validated components/systems. This issue became more critical since the EOBD system has been installed into the vehicles as the extremely heavy validation activity are jeopardized by the gas system and the major part of the calibration/validation work shall be repeated. A new gas control system has been developed with the aims to achieve the best performances in terms of power, driveability, emissions, without any modifications on the OEM system, very short application time and costs.

The Finite Element Analysis (FEA) is widely used in automotive industry for many applications, such as structural analysis, computational fluid dynamics (CFD), vibration behavior and acoustic properties, crashworthiness and, more recently, manufacturing process simulation. For all these FEA applications, accuracy is always a key issue. The analysis accuracy depends mainly on two factors: on one hand the FEA codes and on the other hand the definition of boundary conditions and material properties. Over the years, most FEA codes are well tested for accuracy through numerous benchmarks: therefore breakthroughs in further accuracy improvement from the aspect of FEA codes are difficult to achieve. On the other aspect, there is some room for FEA improvement by means of more accurate definition of material properties. In this paper, a new methodology for improving analysis accuracy by considering thickness variations of the component is proposed and validated using a structural body part.

The attention to the perceived quality, e.g. the quality as it is evaluated by the final customer, is becoming more and more important for the car makers. The paper describes how such aspects of braking system feel quality, joined with brake thermal constraints and interactions with other vehicle subsystems, such as suspensions, tyres and rims, can become manageable by an engineering process. In order to do that experienced designers define: longitudinal brake performance, stability limits in braking in a turn by comparison with referenced cars; brake thermal constraints; brake system constraints due to interactions with other vehicle subsystems. For perceived quality, on the other hand, it's necessary to take a different kind of approach in order to define targets.

Autonomous Driving is one of the main subjects of academic research and one important trend in the automotive industry. With the advent of self-driving vehicles, the interest around trajectory planning raises, in particular when a customer-oriented analysis is performed, since more and more the carmakers will have to pay attention to the handling comfort. With that in mind, an experimental approach is proposed to assess the main characteristics of human driving and gain knowledge to enhance quality of autonomous vehicles. Focusing on overtaking maneuvers in a highway environment, four comfort indicators are proposed aiming to capture the key aspects of the chosen paths of a heterogeneous cohort. The analysis of the distribution of these indicators (peak to peak lateral acceleration, RMS lateral acceleration, Smoothness and Jerk) allowed the definition of a human drive profile.

Natural gas is a promising alternative fuel for internal combustion engine application due to its low carbon content and high knock resistance. Performance of natural gas engines is further improved if direct injection, high turbocharger boost level, and variable valve actuation (VVA) are adopted. Also, relevant efficiency benefits can be obtained through downsizing. However, mixture quality resulting from direct gas injection has proven to be problematic. This work aims at developing a mono-fuel small-displacement turbocharged compressed natural gas engine with side-mounted direct injector and advanced VVA system. An injector configuration was designed in order to enhance the overall engine tumble and thus overcome low penetration.

The complexity of environmental problem is characterised by the typical difficulty to find an unique quantitative measure for “being green”. Environmental damage cannot easily be compared with parameters such as cost or time that are “hard” metrics. However, techniques like Life Cycle Assessment should make it possible comparing products based on the basis of their environmental profile. In this study a modelled approach that allows to integrate Life Cycle Assessment considerations within multi-criteria analysis methodology is described: this integration is clearly exemplified by a simple software tool called ECOCOST. ECOCOST represents an effort to join different field of evaluation, other than environmental, to the Life Cycle Assessment: then environmental results emerged from LCA can be matched with other kind of evaluation, economical and technical in particular.

It has been proved from many studies and applications that, to improve fuel economy, is necessary to operate near lean limit without exceeding it, to avoid unstable engine running and resulting car surging. On this purpose, besides a precise and flexible control system, an engine stability sensor, to adopt closed loop control strategies, is needed. A research has been carried out on different measurement methodologies with the aim of developing a reliable and low cost stability sensor to be used on production cars. For this reason sensors yet applied in automotive field, like accelerometer and pick-up or oriented to this application, like ring pressure sensors, have been used. As basis of comparison the cyclic dispersion,measured with a pressure sensor inside the combustion chamber, has been considered.

The AICC is an assisting system for controlling relative speed and distance between two vehicles in the same lane. The AICC system may be considered as an extension of a traditional cruise control, not only keeping a fixed speed of the vehicle, but correcting it also to that of a slower one ahead. The main objective of this paper is to illustrate the design of the intelligent cruise control system involving the automatic control of throttle position and braking systems. There is much evidence nowadays that fuzzy approaches to real problems, where the linear control theory fails or can't provide an available and robust design solution, are often the best alternative to more familiar schemes.

One of the way for improving environmental performances of car propulsion system is the adoption of hybrid systems where the internal combustion engine (ICE) is coupled or temporary overtaken by an electric motor. The reference prototype of this article is the FIAT Multipla Hybrid where are possible three functional modes: Pure Electric mode, Serial Hybrid and Parallel Hybrid. Particularly it was approached the torque splitting algorithm applied to the parallel hybrid one; the work was first tested in simulation, after implemented in the electronic control units and finally tested on the field using the test bench of the 10 hybrid vehicles that belongs to the Atena Project [1].

The behavior of an automotive dashboard has been evaluated using mathematical FEM models in combination with explicit structural codes in accordance with EEC homologation test 78/632. The test simulates the impact of the human head against the dashboard which can occur during a front crash. The simulation of the impact phenomenon in the basic dashboard configuration was examined as related to a series of design variants elaborated to eliminate critical areas. Variations in the stresses were determined in the component in reference to the basic model. An indispensable premise to achieving these results was the execution of FEM process simulations aimed at obtaining the actual distribution of the mechanical strength properties, which were weighted according to the localized influence of different temperatures and flow stresses during injection.

Methodologies of a vehicle assessment through computer simulation comes to enable every day to preview difficulties in developing models, which also contributes to reducing the time to develop a new model. For initial assessment of the vibroacoustic behavior of a vehicle, in the early months of development, the frequency response functions, known as inertance (a/F), are analyzed, at the points of attachment of the engine and suspension to the body still in the Body-in-White configuration. Usually the finite element simulations are performed up to the limit of 300Hz. In the aim at increasing the range of inertance analysis, enabling a more comprehensive analysis in NVH, the results by elements finites simulation were compared, in this work, with the results obtained in experimental measurements focused on the validation of this simulation methodology until the limit of 800Hz.

A new category of hypereutectic aluminum liners, made by PM route is now available on the market (SILITEC) and it is successfully applied to high-pressure die casting process to produce open deck cylinder blocks. The claimed achievable engine performances over cast-iron liners (weight saving, reduction of oil consumption, optimal heat transfer, wear and friction losses reduction) justify the interest of automotive industry in developing such a technology. The paper will present the experience and the achieved results in permanent mold gravity casting with Silitec liners, where metal flow definition and temperature distribution control make the casting technique more challenging for the manufacturing of closed deck cylinder blocks.

One of the objectives of the Atena project was the definition of methods 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 allows the decision maker to verify in simulation the effects of possible measures like the law enforcement to the access restrictions or vehicle fleet composition. The main obstacle is the realization and managing of real driving cycles in order to overtake the limits derived from the utilization of typical cycles (i.e., ECE + EUDC) 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 these arcs are 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 cabin comfort is one of the most competitive issues in the automotive area of business. The thermal comfort and the environmental well-being are fundamental performances that contribute to generate the more general idea of perceived quality. The CRF developed in the past the concept so-called “healthy bubble” that was implemented in the Lancia Dialogos concept car. The passengers are surrounded by an air bubble, created by generating low velocity air flows, that are diffused through the interior panels and components (e.g. dashboard, roof, back of the seats, etc.), and by surfaces temperature control (e.g. carpet, seats, etc.). At present the original idea has generally been accepted, and different solutions to diffuse air and to control surface temperature of vehicle interiors have been proposed by some automotive supplier.