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Wind tunnels provide a convenient, repeatable method of assessing vehicle engine cooling, yet important draw-backs are the lack of a moving ground and rotating wheels, blockage constraints and, in some tunnels, the inability to simulate ambient temperatures. A series of on-road and wind-tunnel experiments has been conducted to validate a process for evaluating vehicle cooling system performance in a high blockage aerodynamic wind tunnel with a fixed ground simulation. Airflow through the vehicle front air intake was measured via a series of pressure taps and the wind-tunnel velocity was adjusted to match the corresponding pressures found during the road tests. In order to cope with the inability to simulate ambient temperatures, the technique of Specific Dissipation (SD) was used (which has previously been shown to overcome this problem).

Window buffeting is a major source of flow induced sound and vibration. This paper will describe window buffeting measurements acquired on a full scale vehicle as well as two different simplified small scale models. The experimental data sets included microphone and phase averaged Particle Image Velocimetry (PIV) measurements both of which show that the flow physics are qualitatively and quantitatively similar in all cases. The implication of this result is that simplified laboratory models of a vehicle are sufficient to study the various aspects of window buffeting in full scale vehicles.

As the amount of embedded software in the vehicle increases dramatically, the software design and development tasks are daunting. Over the past few years, the automotive industry has taken measures to increase software re-use and promote competition among basic software vendors. If AUTOSAR has emerged as the de-facto standard for embedded automotive software development, there are numerous challenges ahead as the standard assumes the availability of both the hardware and the associated abstraction layer among others. This can be problematic for developers. Furthermore, engineers may be interested in performing early what if tests - early functional tests - to ensure that their strategies will not cause problems later in the development process. As always, errors are less costly to fix if they can be caught early. With AUTOSAR several thousand parameters have to be configured in about 60 modules.

Aerodynamics plays a key role in nowadays vehicle development, aiming efficiency on fuel consumption, which leads to a green technology. Several initiatives around the world are regulating emissions and efficiency of vehicles such as EURO for European Marketing and the INOVAR Auto Project to be implemented in Brazil on 2017. In order to meet requirements in terms of performance, especially on aerodynamics, automakers are focusing on aero-efficient exterior designs and also adding deflectors, covers, active spoilers and several other features to meet the drag coefficient. Usually, the aerodynamics properties of a vehicle are measured in both CFD simulations and wind tunnels, which provide controlled conditions for the test that could be easily reproduced. During the real operations conditions, external factors can affect the flow over the vehicle such as cross wind in open highways.

The purpose of this study is to develop and to validate the techniques required to perform computational analysis of windshield defogging problem. A numerical model of a simplified test vehicle configuration has been built, which includes the passenger compartment, the windshield and the film of the condensed vapor layer. A transient analysis is performed for the conditions in which cold room test data is available. The results of numerical simulation show very reasonable agreement with the test data.

The outside visibility through the windshield and ORVM visibility through the side glasses are critical for safe driving. The frost deposition on the Windshield and side glasses in the cold climatic condition impairs the outside and ORVM visibility during driving and hence leads to an unsafe driving condition. In India, the regulation AIS-084 governs the defrosting standard. The defrosting performance evaluation by testing cannot be performed at concept stage when the vehicle prototype is not available. It also increases the cost of vehicle development due to increase in the number of prototype used for testing. This paper explains about the in-house developed CFD methodology to evaluate the windshield defrosting performance of the vehicle in the concept stage when no vehicle proto is available and cost of countermeasure for defrosting performance improvent is very less. This methodology is implemented for some of the existing models.

Frosted windshields are common appearances during the cold season. The defrosting of the car's windshield is carried out by just blowing hot air against the inside of the pane. This yields growing temperatures also on the outside and finally makes the ice melt. What may sound quite trivial from the user's point of view is rather more complex in terms of analysis and design. The physical phenomena involved are fluid flow and heat transfer in the air on both sides of the glass as well as inside (conjugated heat transfer) and the phase change in the solidified water. For designing purposes of course complete CFD simulations and investigations in test rigs will be performed. But these are very time consuming and expensive, especially if parameter variations and optimizations tasks have to be accomplished. In this paper a modeling and simulation approach is presented, which allows a quasi 3D modeling of the defrosting of windshields based on 1D simulation techniques.

Wipe quality of wiper systems is influenced not only by the definition of the wiper system, but also by the shape of the glass. In order to optimize the overall performance of the system, Valeo Wiper Systems has developed an optimization algorithm, which is based on geometrical criteria. The multi-criteria objective not only considers wipe quality but also constraints by glass feasibility and respect of optical standards. As the direct derivation of the objective functions is not available, a neural network approximation is used at the place of the real function. A neural network with several outputs enables the engineer to include his knowledge in the optimization loop by changing disciplinary weights.

In this paper we investigate the influence of the aerodynamics of the vehicle on the performance of the washer fluid spray. A planar windshield block model with various windshield angles, as well as a “generic” passenger car shape with a fixed windshield angle, is used for the present studies. CFD simulations of the flow field and the spray trajectories are undertaken in this study. The effect of windshield angles, nozzle location and crosswind on the spray performance is presented in this paper. For very large windshield angles of around 60° (measured from the vertical plane), there is no flow separation in the hood-windshield intersection region and the spray trajectory is significantly affected by the airstream for all nozzle locations.

A resonance measurement methodology has been developed by Valeo Wiper Systems in order to determine the best frame tube configuration of a new project. The wiper system mechanism is operated by a motor that propagate noise and vibration to the system. It is known that the frequencies that causes bad sensation to the human hearing are the low frequencies, and it is necessary to determine a frame tube that decreases the vibration and do not pass these vibrations to the vehicle body. There are two ways to reduce the vibration propagated by the motor to the vehicle: broke the resonance in the frame tube with different designs or use grommets in the contact surface between the vehicle body and the wiper mechanism. The resonance analysis has been performed by using an impact hammer and accelerometers that measure the vibration propagated.

Optimizing the wiper system performance motivates the design engineer to create a product as robust as possible against the occurrence of wipe defects related to vibratory phenomena between the rubber blade and the windshield. In some configurations, these vibrations generate visual or audible annoyance for the driver. These instabilities phenomena only appear under specific operating and environmental conditions characterized by windshield moisture and cleanness, contact pressure of the rubber blade on the glass, attack angle of the wiper blade on the windshield, component stiffness, windshield curvature etc. In the process of eliminating all potential instabilities, modeling the wiper system structures can contribute to understand its working dynamics. Therefore, a new computation tool is developed and validated by experimentation on a specific test bench.

An increasingly important, yet often underestimated task of modern vehicle design is the system interconnect, commonly known as the wire harness. The continual increase in on–board vehicle electronics is causing an exponential expansion in wire harness complexity. To meet these challenges, software tools have been developed to assist the harness designer in the various tasks from system partitioning to signal integrity analysis. This paper will discuss the key problem areas of the wire harness design, along with the design and analysis capabilities of the SaberHarness™ tool suite.

Due to increasing amount of modules and customized options in commercial vehicles, it becomes more and more difficult to verify the circuit design. In this paper, a wire segment error locating algorithm is proposed to automate the exact wire segment error locating process. When a wrong connection is found by existing tool, guided by the exact description of wire segment error, this algorithm can locate exact wire segment error in the connection by searching for the one that has at least one neighboring segment from a correct connection.

Due to the rapid development in the technological aspect of the autonomous vehicle (AV), there is a compelling need for research in the field vehicle efficiency and emission reduction without affecting the performance, safety and reliability of the vehicle. Electric vehicle (EV) with rechargeable battery has been proved to be a practical solution for the above problem. In order to utilize the maximum capacity of the battery, a proper power management and control mechanism need to be developed such that it does not affect the performance, reliability and safety of vehicle. Different optimization techniques along with deterministic dynamic programming (DDP) approach are used for the power distribution and management control. The battery-operated electric vehicle can be recharged either by plug-in a wired connection or by the inductive mean (i.e. wirelessly) with the help of the electromagnetic field energy.

Future vehicles will have many features that include, but are not limited to, drive-by-wire, telematics, pre-crash warning, highway guidance and traffic alert systems. From time to time the vehicles will need to have their software modules updated for various reasons, such as to introduce new features in vehicles, the need to change the navigation map, the need to fine tune various features of the vehicles, etc. A remote software update has a number of advantages, such as it does not require consumers to take their vehicles to the dealers, and the dealers do not need to spend time on vehicles on an individual basis. Thus, remote software updates can save consumers' valuable time, as well as cost savings for the vehicle manufacturers. Since wireless links have limited bandwidth, uploading software in thousands of vehicles in a cost-effective and timely manner is a challenge. Another major issue related to the remote software update is the security of the update process.

Modern vehicle design involves configuration of various sensors and actuators spread across the vehicle. These sensors and actuators placed at various locations in the vehicle need to be connected with Electronic Control Units (ECUs). As long as wires are used for these connections, cost and time required for installation and maintenance are major concerns for OEMs. A wireless sensor network (WSN) can reduce length of wiring harness and can save time as well as cost of its installation. It also provides flexibility in deciding location of ECU according to desired shape of the vehicle. This paper presents a way to build a strong, secured wireless network in vehicle. The proposed method of encryption and decryption ensures that, sensor and actuator data is available only to required ECUs and not to any other unintended receiver. A novel method is proposed in order to achieve this. Sensors and actuators in the vehicle are segregated according to their location.

Impacts with trees and wooden utility poles represent a significant subset of vehicular collisions. For example, while fixed object collisions account for less than 8% of all crashes, they represent nearly 30% of all fatal crashes. Also, nearly half (over 43%) of all fixed-object impacts are into a tree, pole, or post. This paper is viewed as a first attempt to understand the energy absorbing processes operating when vehicles strike trees and wooden poles in order to make reasonable estimates of the magnitude of the tree/pole energy dissipated in the crash. This initial study is comprised of a literature review, a series of scale model pole/pendulum impacts, and an analytical study which is comprised of both a static analysis and a dynamic finite element model (FEM) analysis of a vehicle/pole impact. As a result of this work, a methodology has been evolved for making estimates of tree/pole energy.

Externally applied unbalanced forces and their corresponding impulses are generally excluded from consideration in regards to the evaluation of the collision phase events for a system comprised of two motor vehicles undergoing collinear impact. This exclusion is generally warranted secondary to the fact that the collision force and its corresponding impulse are dominant during the collision phase. Conceptually, two exclusions exist to this approach. The first is the situation in which significant physical restraints are present to the displacement of one or both collision partners and are of sufficient magnitude as to require inclusion. Generally, this represents the exceptional case and includes, but is not limited to, situations in which one vehicle is snagged, in a non-eccentric manner, by a rigid narrow-width object such as a pole or other similar restraint, prior to the occurrence of the subsequent vehicle-to-vehicle collision under evaluation.

The current test methods are insufficient to evaluate and ensure the safety and reliability of vehicle system for all possible dynamic situations including the worst cases such as rollover, spin-out and so on. Although the known NHTSA J-turn and Fish-hook steering maneuvers are applied for the vehicle performance assessment, they are not enough to predict other possible worst case scenarios. Therefore, it is crucial to search for the various worst cases including the existing severe steering maneuvers. This paper includes the procedure to search for other useful worst case based upon the existing worst case scenarios in terms of rollover and its application in simulation basis. The human steering angle is selected as a design variable and optimized to maximize the index function to be expressed in terms of vehicle roll angle. The obtained scenarios were enough to generate the worse cases than NHTSA ones.

One of the key premises of the ISO 26262 functional safety standard is the development of an appropriate Technical Safety Concept for the item under development. This is specified in detail in Part 4 of the standard - Product development at the system level. The Technical safety requirements and the technical safety concept form the basis for deriving the hardware and software safety requirements that are then used by engineering teams for developing a safe product. Just like any other form of product development, making multiple revisions of the requirements are highly undesirable. This is primarily due to cost increases, chances of having inconsistencies within work products and its impact on the overall project schedule. Good technical safety requirements are in fact the foundation for an effective functional safety implementation.