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The foremost aim of the work presented in this paper is to improve fuel economy and decrease CO2 emissions by reducing the aerodynamic drag of passenger vehicles. In vehicle development, computer aided engineering (CAE) methods have become a development driver tool rather than a design assessment tool. Exploring and developing the capabilities of current CAE tools is therefore of great importance. An efficient method for vehicle shape optimization has been developed using recent years' advancements in neural networks and evolutionary optimization. The proposed method requires the definition of design variables as the only manual work. The optimization is performed on a solver approximation instead of the real solver, which considerably reduces computation time. A database is generated from simulations of sampled configurations within the pre-defined design space. The database is used to train an artificial neural network which acts as an approximation to the simulations.

This paper presents measurements on Vehicle to Vehicle (V2V) communication between participants in a platooning application. Platooning, according to the SARTRE concept, implies several vehicles travelling together in tight formation, with a manually driven heavy lead vehicle. The platoon being studied consists of five vehicles; two trucks in the lead and three passenger cars. The V2V-communication node in each vehicle contains an 802.11p radio at 5,9 GHz. It is used to send messages between vehicles to coordinate movements and maintain safety in the platoon. Another cooperative application that relies on V2V-communication is multiple UAVs flying in formation; as investigated in KARYON. This project also investigates cooperative autonomous vehicles. In both applications, V2V-communication is an enabling technology. Two metrics are studied to quantify the V2V-communication quality: system packet error rate and consecutive packet loss.

A primary goal within the industry is to shorten the lead time to get shorter time to market and lower cost. System verification can set the limits for how short the lead time can be. Traditionally verification of automotive communication systems like Remote Keyless Entry, RKE, is performed in a complete vehicle late in the product development process. To fulfill the quality demands during the shorter project time Volvo Cars, VCC, has experienced that it is necessary to develop new requirements and verification methods. Six Sigma contains a complete toolbox to do this in a structured and time efficient way. VCC has together with other Ford Motor Company, FMC, brands and the supplier Continental developed methods and requirements so that the RKE system can be verified before vehicles are built. Only a last validation has to be performed in a complete vehicle.

The Inflatable Curtain (IC) has shown great potential to reduce head injuries in side impacts. This study explores and presents enhanced performance in two steps of improved activation algorithms. Crash data analysis, 21 full scale crash tests and component tests in a custom built drop tower rig have been performed. The IC performance in wider crash scenarios, including side impacts outside the occupant compartment (L-type impacts), was evaluated. Both statistical crash data and in-depth studies were used. It was found in the analysis of real life crashes that moderate to fatal head injuries can occur without intrusion in the occupant compartment. In L-type side impacts, the motion of the occupant relative to the vehicle interior may cause a head impact of sufficiently high severity to cause moderate to severe head injuries. A combined analysis of real world crash data and crash test results indicates that a substantial reduction in moderate to fatal head injuries can be achieved.

A structured, semi-automatic method for reducing a high-fidelity engine model to a fast running one has been developed. The principle of this method rests on the fact that, under certain assumptions, the computationally expensive components of the simulation can be substituted with simpler ones. Thus, the computation speed increases substantially while the physical representation of the engine is retained to a large extent. The resulting model is not only suitable for fast running simulations, but also usable and updatable in later stages of the development process. The thrust of the method is that the calibration of the fast running components is achieved by use of automatically selected neural networks. Two illustrative examples demonstrate the methodology. The results show that the methodology achieves substantial increase in computation speed and satisfactory accuracy.

In order to achieve ultra low emission levels with three-way catalysts, an early accurate air/fuel ratio control is essential. Positioning the oxygen sensor in the first part of the substrate helps to protect the oxygen sensor from being splashed by water during cold start, so that early heating and activation becomes a less limiting factor. For emission control purpose, a position of a rear sensor in the warm part of the catalyst gives improved possibilities for oxygen buffer control during catalyst warming up conditions. This enhances balancing HC and NOx in an early phase. In addition, for OBD reasons it is possible to locate the sensor in any axial position in the catalyst, which improves design possibilities for cold start detection, even for single brick catalyst systems. The paper describes the construction of the catalyst with an integrated oxygen sensor.

This article describes an expert system for objective rating of subjective characteristics like driving comfort. The system uses radial basis neural networks that can be trained on any dynamic properties, for example acceleration. Training and retraining can be done in real-time. The system includes a measure of the reliability of automatic judgement, which can be used to signal when new training may be necessary. The article shows in detail how the system has been used to automatically judge gearshift comfort for automatic transmission. Tests indicate that the system's accuracy and consistency are as good as one of Volvo's best experts.

Neck injuries resulting from rear end car impacts have attracted increasing attention in recent years. Although usually not life-threatening these injuries can have long-term consequences. The exact mechanism of injury has not yet been established. Several probable mechanisms occurring at different phases during the crash sequence have been suggested by researchers. The accident experience with existing seat and head restraint designs is summarized. The results show that there are many factors influencing the risk of neck injury. A high and fixed-in-position head restraint, positioned close to the head, is beneficial. Also, Individual factors, such as gender and height, and seating position, are shown to have influence on the injury risk.

A positive trend to more frequent use of child restraint systems (CRS) in Sweden, during the last 20 years, is shown in this report. During the same period, the overall injury risk, for different age groups of child occupants, has decreased substantially. This indicates the high effectiveness of the child restraint systems. Children need car occupant safety systems specially designed for their size. This paper clearly states the need for child safety systems and discusses benefits and drawbacks with regard to different restraints, ages and injuries. The analysis points out, that when a crash occurs, the maximum effect of a child restraint system is not reached, if the child is not using the correct system for their size. There is even a tendency that the injury risk increases when children switch from one restraint system to another, i.e. are at the youngest ages for which the specific restraint is recommended. The background data used, is based on Volvo's traffic accident research.

The performance of three different six-year old dummies, the new Hybrid III six-year-old from First Technology Safety Systems, the Part 572 Subpart I and the TNO P6, was compared in a series of HYGE sled tests. The dummies were tested on aftermarket booster cushions in a Volvo 850 sled buck. Two different sled pulses were used: a Volvo 850 30 mph frontal crash pulse and an ECE R.44 pulse. The behavior of the dummies was compared for these two sled pulses. Motion analysis from high speed film was performed, showing the trajectories of the dummy heads. All dummies were fitted with triaxial accelerometers in the head, chest and pelvis. The Hybrid III was also equipped with a chest deflection transducer and Denton six-channel upper neck and five-channel lumbar spine load cells. The signals from a number of these sensors were compared.

This paper reports an investigation of the association between flame kernel movement and cyclic variability and assesses the relative importance of this phenomenon, with all other parameters that show a cyclic variability held constant. The flame is assumed to be subjected to a “random walk” by the fluctuating velocity component of the flow field as long as it is of the order of or smaller than the integral scale. However, the mean velocity also imposes prefered convection directions on the flame kernel motion. Two-point LDA (Laser Doppler Anemometry) measurements of mean velocity, turbulence intensity and integral length scale are used as input data to the simulations. A quasi-dimensional computer code with a moving flame center position is used to simulate the influence of these two components on the performance of an S I engine with a tumble-based combustion system.

Fuel wetting in the inlet port of a gasoline engine was studied using Laser-Induced Fluorescence (LIF). The measurements were done directly on the metal wall surface. Quantitative results were be obtained using a special calibration procedure. The sensitivity of the technique was found to correspond to a fuel layer thickness in the order of 1 μm, and the accuracy was estimated to be approx. 10 %. The engine was run on iso-octane, and in order to obtain fluorescence a dopant (3-pentanone) was added to the fuel. Laser light with a wave length of 266 nm was generated by frequency doubling the light from a Nd-YAG laser in two steps. A laser sheet was directed into the intake port and the fuel layer on the wall could be studied along a line on the bifurcation wall. The fluorescence light was detected with an intensified diode-array camera. The measurements from the fuel film thickness were compared with measurements of the total fuel film mass using an A/F response method.

Injuries in side impact collisions constitute one fourth of the serious or fatal injuries sustained by occupants in ordinary passenger cars. The Volvo Side Impact Protection System (SIPS) provides a substantially enhanced protection for car occupants in side collisions. The protection level of the SIPS system has been further increased by the addition of the Sipsbag, a quick-deploying side impact airbag system integrated in the seat backrest. The design of the non-electrical Sipsbag system is explained, as well as the advantages with a completely seat-integrated system. The process to industrialise the side airbag concept is summarised. Laboratory test results are discussed. Using methodology to correlate laboratory test data with accident data, an estimate of the injury-reducing effectiveness of the SIPS and Sipsbag system is made.

In air bag tests without a restraining seat belt (FMVSS208) several users of the Hybrid III dummy have reported a pelvic interference problem during the tests. An insufficient range of motion and a hard metal to metal contact between the pelvis and femur has lead to unexpected chest acceleration waveforms. The paper gives a mechanical analysis of this phenomenon, explaining how the forces acting on the dummy lead to a rotation of the pelvis and femur and how forces arise between the pelvis and the chest. Finally two sample tests where the pelvic interference problem has occurred are presented.

OBD II established a new level for automotive on board diagnostics. This concept, state of the art, is already introduced on the market, MY-94, ( reference 1). We will now go one step further by introducing the Diagnose 2 Concept. With D2 we connect almost all ECU's in a vehicle to the same diagnostic communication bus, connected to the same pin, (pin 7 in the J1962 connector). It will now be possible to hook up to all ECU's with one connector, the OBD II connector inside the passenger compartment, (this will not be any problem for a properly programmed OBD II Scan Tool, as it only will look for the emission related ECU's).

Frontal collisions account for the majority of car accidents. Regulations have been in effect since the late sixties, aiming at assuring a basic safety performance for cars in this type of crash. From a legislative point of view tests as e.g. FMVSS 208 are about to be complemented by other frontal impact configurations. Two of the reasons behind this is to allow assessment also of asymmetric loads to the vehicle front and the level of passenger compartment intrusion. This paper offers a comparison of different frontal crash tests, including Volvo's Severe Partial Overlap Collision (SPOC) and offset tests against a deformable barrier. The methods are evaluated with respect to their results, both from a dummy performance point of view and based on car deformation characteristics. Also, the practicability and possible effect on vehicle designs are discussed.

Even though child restraint systems (CRS) are very effective there are still serious problems because of non-use or misuse. This is often due to the fact that the installation of the CRS in the cars is difficult, complicated and unstable. A standardised interface between the CRS and the car seat would solve these problems. Within the IS0 Committee ISO/TC22/SC12NVGl this item has been raised and several proposals for an “ISOFIX have been discussed. Apart from the installation aspects, other features e.g. disconnection of passenger airbags can be included in the system. Several concepts called ISOFlX type 1 to 7 with different working names e.g. DELTAFIX, EASY-FIX, MONOFIX and UNlFlX have been evaluated. The handling performance of some of the prototypes have been tested by customer evaluation with very positive results. Crash performance has also been investigated. The paper will give an update on the latest progress of this development, including a preliminary specification.

Electrochemical Impedance Spectroscopy (EIS) and Thermal Wave Imaging (TWI) are complementary techniques which can be used to detect and estimate Impact Induced Corrosion (IIC) at the metal-polymer interface. This paper describes the use of the above techniques to detect Impact Induced Corrosion in a variety of pre-coated and painted sheet steels. It has been possible to show, that IIC is a threshold phenomenon and depends on the type of galvanized coating. Evaluation of IIC, using a high performance indoor accelerated test and preliminary data from the proving grounds are presented in this paper.

This paper describes the OBD II System in the Volvo 850 Turbo. This car is equipped with a new engine, a 5-cylinder, in-line, 2.3 liter design, mounted transversely in the car. The system uses the new Bosch Motronic M4.3 Powertrain Control Module, The realization of the new diagnostic regulation is described with examples. The development of new, specialized diagnostic equipment is also described.

Research on frontal collisions has been the theme of numerous papers and publications over the years. The relevance of the subject is clearly demonstrated by different accident studies. The analysis shows that apart from the traditional high speed full frontal barrier impact, it is also necessary to simulate tests at lower speeds and partial overlap collisions at high speeds. This paper describes one of the frontal impact situations, the Severe Partial Overlap Collision (SPOC); accident analyses leading to a test method and its application by description of a new car design concept.