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Squeak and rattle (S&R) are nonstationary annoying and unwanted noises in the car cabin that result in considerable warranty costs for car manufacturers. Introduction of cars with remarkably lower background noises and the recent emphasis on electrification and autonomous driving further stress the need for producing squeak- and rattle-free cars. Automotive manufacturers use several road disturbances for physical evaluation and verification of S&R. The excitation signals collected from these road profiles are also employed in subsystem shaker rigs and virtual simulations that are gradually replacing physical complete vehicle test and verification. Considering the need for a shorter lead time and the introduction of optimisation loops, it is necessary to have efficient and inclusive excitation load cases for robust S&R evaluation.

To improve fuel efficiency and facilitate handling of the vehicle in a dense city environment, it should be as small as possible given its intended application. This downsizing trend impacts the size of the engine bay, where the air filter box has to be packed in a reduced space, still without increased pressure drop, reduced load capacity nor lower filtering efficiency. Due to its flexibility and reduced cost, CFD simulations play an important role in the optimization process of the filter design. Even though the air-flow through the filter box changes as the dust load increases, the current modeling framework seldom account for such time dependence. Volvo Car Corporation presents an industrial affordable model to solve the time-dependent dust load on filter elements and calculate the corresponding flow behavior over the life time of the air filter box.

The aim of the presented research is to propose and benchmark two brake models, namely the novel dynamic ILVO (Ilmenau-Volvo) model and a neural-network based regression. These can estimate the evolution of the brake friction between pad and disc under different load conditions, which are typically experienced in vehicle applications. The research also aims improving the knowledge of the underlying mechanism related to the evolution of the BLFC (boundary layer friction coefficient), the reliability of virtual environment simulations to speed up the product development time and reducing the amount of vehicle test in later phases and finally improving brake control functions. With the support of extensive brake dynamometer testing, the proposed models are benchmarked against State-of-the-Art. Both approaches are parametrized to render the friction coefficient dynamics with respect to the same input parameters.

Today automotive system suppliers develop more-or-less independent systems, such as brake, power steering and suspension systems. In the future, car manufacturers like Volvo will build up vehicle control systems combining their own algorithms with algorithms provided by automotive system suppliers. Standardization of interfaces to actuators, sensors and functions is an important enabler for this vision and will have major consequences for functionality, prices and lead times, and thus affects both vehicle manufacturers and automotive suppliers. The investigation of the level of appropriate interfaces, as part of the European BRAKE project, is described here. Potential problems and consequences are discussed from both a technical and a business perspective. This paper provides a background on BRAKE and on the functional decomposition upon which the interface definitions are based. Finally, the interface definitions for brake system functionality are given.

A two-state forward dynamic programming algorithm is evaluated in a series hybrid drive-train application with the objective to minimize fuel consumption when look-ahead information is available. The states in the new method are battery state-of-charge and engine speed. The new method is compared to one-state dynamic programming optimization methods where the requested generator power is found such that the fuel consumption is minimized and engine speed is given by the optimum power-speed efficiency line. The other method compared is to run the engine at a given operating point where the system efficiency is highest, finding the combination of engine run requests over the drive-cycle that minimizes the fuel consumption. The work has included the engine torque and generator power as control signals and is evaluated in a full vehicle-simulation model based on the Volvo Car Corporation VSIM tool.

Flow visualization techniques are widely used in aerodynamics to investigate the surface trace pattern. In this experimental investigation, the surface flow pattern over the rear end of a full-scale passenger car is studied using tufts. The movement of the tufts is recorded with a DSLR still camera, which continuously takes pictures. A novel and efficient tuft image processing algorithm has been developed to extract the tuft orientations in each image. This allows the extraction of the mean tuft angle and other such statistics. From the extracted tuft angles, streamline plots are created to identify points of interest, such as saddle points as well as separation and reattachment lines. Furthermore, the information about the tuft orientation in each time step allows studying steady and unsteady flow phenomena. Hence, the tuft image processing algorithm provides more detailed information about the surface flow than the traditional tuft method.

Passenger cars equipped with diesel engines will meet challenging emission legislation for the coming decade, with introduction of Euro6 and Euro7, which comprises reduced NOX emissions and possibly new driving cycles including off-cycle limits. The technology measures to meet these legislative limits comprise a broad spectrum of engine and aftertreatment, i.e., engine measures such as improved fuel injection with respect to mass and timing, improved exhaust gas recirculation, improved warm-up and reduced friction, as well as aftertreatment measures such as selective catalytic reduction and lean NOX trap in combination with diesel particulate filter, and the thereby associated engine control. The resulting technology matrix is therefore large, and calls for a multidisciplinary simulation approach for appropriate selection and optimization of technology and control with the objectives and constraints of emissions, fuel consumption, performance and cost.

Automotive turbo compressors generate high frequency noise in the air intake system. This sound generation is of importance for the perceived sound quality of luxury cars and may need to be controlled by the use of silencers. The silencers usually contain resonators with slits, perforates and cavities. The purpose of the present work is to develop acoustic models for these resonators where relevant effects such as the effect of a realistic mean flow on losses and 3D effects are considered. An experimental campaign has been performed where the two-port matrices and transmission loss of sample resonators have been measured without flow and for two different mean flow speeds. Models for two resonators have been developed using 1D linear acoustic theory and a FEM code (COMSOL Multi-physics). For some resonators a separate linear 1D Matlab code has also been developed.

A broad measurement campaign was run at Volvo aiming at the evaluation of dispersion in test-based NVH characteristics of a car body and at the derivation of reference data for judging the accuracy of CAE predictions. Within this work 6, nominally identical, vehicles were tested. Tests included operational noise on Complete Vehicle (CV) level (road noise, engine noise and idling noise), NTF, VTF & Acoustic FRF measurements in CV, Trimmed Body (TB) & TB-Stripped (TBS) configurations. Additionally, modal analysis and NTF, VTF, AFRF tests were carried out on 4 BIPs of the same vehicle type. Further, limited tests were carried out on 28 vehicles of the same type. The aim of the work was to study the development of dispersion with increasing complexity of the test object, from the BIP to TB and CV.

Maintaining the current ratio between certified and the customer-observed fuel consumption even with future required levels poses a considerable challenge. Increasing the efficiency of the driveline enables certified fuel consumption down to a feasible level in the order of 80 g CO₂/km using fossil fuels. Mainly affecting off-cycle fuel consumption, energy amounts used to create good interior climate as well as energy-consuming options and features threaten to further increase. Progressing urbanization will lead to decreasing average vehicle speeds and driving distances. Highly efficient powertrains come with decreased amounts of waste energy traditionally used for interior climate conditioning, thus making necessary a change of auxiliary systems.

This paper describes results from fault injection experiments using heavy ions in the time-triggered communication protocol for safety critical distributed systems (TTP/C, C1 implementation). The observed results show that arbitrary faults in one erroneous node could cause inconsistencies in the cluster and thus jeopardize correctly working nodes and the whole communication system. The described inconsistencies resulted from either asymmetric value faults or slightly out of specification timing faults. This system behavior can be partly explained by too strict constraints on the fault handling algorithms using the membership agreement protocol.

In areas such as Active Safety, new technologies, designs (e.g. AUTOSAR) and methods are introduced at a rapid pace. To address the new demands, and also requirements on Functional Safety imposed by ISO 26262, the support for engineering methods, including tools and data management, needs to evolve as well. Generic and file-based data management tools, like spreadsheet tools, are popular in the industry due to their flexibility and legacy in the industry but provide poor control and traceability, while rigid and special-purpose tools provide structure and control of data but with limited evolvability. As organizations become agile, the need for flexible data management increases. Since products become more complex and developed in larger and distributed teams, the need for more unified, controlled, and consistent data increases.

Volvo Car Corporation has developed a Reference Architecture for PAG1 Infotainment Systems. A Reference Architecture is an architecture scoping over more than a single system, i.e. an architecture aimed for a family of systems. The Infotainment Reference Architecture has since 2001 been successfully applied for the PAG family which so far covers the infotainment systems of Volvo XC90, Volvo S40/V50, Jaguar XK, Aston Martin DB9 and the brand new Volvo S80. In 1999, the system design departments started up with the clear objective to develop a system solution aiming for the PAG infotainment system family. The work was carried out according to the established development process at Volvo Cars. A year later a discouraging design review was performed. The number of involved functions, the level of function interaction and the distribution of functionalities between ECUs resulted in a non-manageable system solution.

We describe experiments and numerical modeling of snow surface contamination on two simplified automotive bluff bodies: The Ahmed body and a wedge. The purpose was twofold: 1) To obtain well defined experimental results of snow contamination on simple geometries; 2) To propose a numerical modeling approach for snow contamination. The experiments were performed in a climatic wind tunnel using a snow cannon at −15 °C and the results show that the snow accumulation depends on the aerodynamics of the studied bluff bodies. Snow accumulates on surfaces in proximity to the aerodynamic wakes of the bodies and characteristic snow patterns are obtained on side surfaces. The numerical modeling approach consisted of an aerodynamic setup coupled with Lagrangian particle tracking. Particles were determined to adhere or rebound depending on an adhesion model combined with a resuspension criterion.

Most OEMs are shifting their strategy and way of thinking regarding ECUs. This, in combination with the electrification of vehicles and the shift towards software-based companies (car as a device), implies one of the biggest paradigm changes in automotive history. On the other hand, despite the current struggles, remarkable advances have been made in electronic technology during the past few years. These developments have opened a door to very promising enabling technology, with exterior lighting as a main target market. These circumstances seem to have created a perfect storm leading to new strategies for electronic control and driving for (front and rear) exterior lighting. We, at our company, have investigated the enabling technology, challenges, and benefits of this emerging exterior lighting approach, that we call ‘ECU-Less’.