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This paper provides an overview of the new MISRA publication, Guidelines for Safety Analysis of Vehicle-Based Programmable Systems. It describes a process which needs to be incorporated into a company's or organization's management structure so they can manage safety effectively. The MISRA Safety Process comprises two principal phases: Preliminary Safety Analysis and Detailed Safety Analysis. The former identifies what needs to be done; the latter demonstrates that it has been done correctly.

With the increasing dependence on advanced electronic systems to control the functionality of road vehicles, the consideration of functional system safety as part of the design and implementation process for these systems is growing in importance. An important part of such a process is to undertake a hazard analysis. Emerging standards and guidelines, such as ISO 26262 and MISRA Safety Analysis, contain a requirement to perform preliminary hazard analysis in order to identify unwanted events (typically at the vehicle level) that can result from technological causes, and to set safety requirements for the system under development to mitigate the risk associated with those events. In this paper, a generic approach to automotive hazard analysis is described. The method is based upon a generalized model of the causal chain that leads from a low-level fault in an electronic system through to the potential for an unwanted event at the vehicle level.

There are many aspects of the unsteady flow around fastback passenger cars that remain to be understood. These include the source and nature of unsteady flow structures, the relevant time-scales, the effect of geometric parameters and the impact of the unsteadiness in terms of steady and unsteady forces on the vehicle. This paper investigates large scale unsteady structures in the wake of the Ahmed form and of a scale model of a real car shape using two wind tunnels and model scales between 12.5% and 40%. The unsteadiness demonstrated only low coherence and weak periodicity and the Strouhal number of a given structure varied from tunnel to tunnel indicating a high sensitivity to external influences. Nevertheless, a novel visualization technique, used to display the results of time-accurate pressure probe measurements, was able to reveal structures involving both symmetric and anti-symmetric oscillations in the strength of the rear-pillar vortices.

A driver model has been created in order to aid the development of new technologies that have the potential to enhance vehicle handling. This paper describes an investigation into the representation of different steering styles for human performance modeling. Different steering styles result in individual drivers using different steering inputs when negotiating an identical manoeuvre. The work is motivated by the effect of different steering styles on drivers' assessments of vehicles and the consequent possibility of engineering future vehicles to optimise the driver/vehicle combination. To achieve this optimisation, a driver model that is able to digitally represent different steering styles is required. Optimal control theory is used to formulate such a driver model; a cost functional represents the driver's motivation.

State of the art demonstrates that weight of vehicle increases with length of car body. Integration of powertrain in mid rear underfloor location enables to shorten car body by more than 0,5m and to save partially heavy longitudinal members. Underfloor integration of power train induces higher stance floor for more conviviality of passengers visibility. Safety factors are improved by lowering gravity centre, better repartition of front / rear masses during braking, easier management of crash by straighter and higher front longitudinal members and free front space. Space frame architecture simplifies light weight technologies application by using 2D bended aluminum profiles. Low investment is ensured by minimising castings application to suspension attachments and interlinking upperbody to underbody. Floor and external panels are designed for aluminum sheet stampings.

Growing concerns about the environmental impact of road vehicles will lead to a reduction in the aerodynamic drag for all passenger cars. This includes Sport Utility Vehicles (SUVs) and light trucks which have relatively high drag coefficients and large frontal area. The wind tunnel remains the tool of choice for the vehicle aerodynamicist, but it is important that the benefits obtained in the wind tunnel reflect improvements to the vehicle on the road. Coastdown measurements obtained using a Land Rover Freelander, in various configurations, have been made to determine aerodynamic drag and these have been compared with wind tunnel data for the same vehicle. Repeatability of the coastdown data, the effects of drag variation near to zero yaw and asymmetry in the drag-yaw data on the results from coastdown testing are assessed. Alternative blockage corrections for the wind tunnel measurements are examined.

Wind tunnel tests have been conducted on a simple bluff body model, representing a car like shape, to investigate drag reduction opportunities from injecting low velocity air into the base region. This flow is known as base bleed. Most tests have been carried out using a square back shape. The effects of flow rate, porosity and porosity distribution over the base area have been investigated. In all cases drag is reduced with increasing bleed rate, but the optimum porosity is a function of bleed rate. A significant part of the drag reduction occurs without the bleed flow and arises from the presence of a cavity in the model. The effects of cavity size are examined for different base configurations. Some factors affecting implementation are considered.

Active suspension components have an effect on fatigue life of attached parts. This effect can be both positive or negative for the complete suspension system. Traditionally fatigue analyses at chassis were carried out on component level. Measured wheel force transducer loads from the test track were broken down to component section loads using an MBS software. In a second step these loads were used to drive a linear static fatigue analysis to determine the durability of different suspension parts. This article shows a new method for dynamic durability analysis on system or even vehicle level. How to take into account active suspension components by means of cosimulation between the MBS and controller software is demonstrated for two examples, an Active Roll-Control system (ARC) and by actively influencing the vertical loadpath in a rear suspension.

This paper addresses the question of how to apply the Safety Integrity Level (SIL) requirements of the generic industrial functional safety standard IEC61508 to software developed using a control-model with target source code automatically generated from the model itself. This standard is being widely adopted in Europe, but betrays its age as the established techniques it references do not explicitly include model based software development now becoming standard in the automotive industry. It has also been criticised for being very prescriptive. The approach taken here is to determine the goals required by the standard and then recommend techniques to achieve these for each of the control-model based software development lifecycle phases. This study considers SIL 1, 2 and 3 requirements.

As the discipline of Functional Safety spreads from its traditional industries such as process and aviation to the automotive sector, this paper - based on the MISRA Safety Analysis Guidelines - describes how a functional safety lifecycle can be applied in a way which is both appropriate for automotive systems and aligned with international standards such as IEC 61508.