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Estimation and prediction of residual life and reliability are serious concerns in life cycle management for aging structures. Laboratory testing replicating fatigue loading for a typical military aircraft wing skin was undertaken. Specimens were tested until their fatigue life expended reached 100% of the component fatigue life. Then, scanning electron microscopy was used to quantify the size and location of fatigue cracks within the high stress regions of simulated fastener holes. Distributions for crack size, nearest neighbor distances, and spatial location were characterized statistically in order to estimate residual life and to provide input for life cycle management. Insights into crack initiation and growth are also provided.

In an effort to understand steering systems performance and properties at the microscopic level, we developed Multibody simulations that include multiple three-dimensional gear surfaces that are in a dynamic state of contact and separation. These validated simulations capture the dynamics of high-speed impact of gears traveling small distances of 50 microns in less than 10 milliseconds. We exploited newly developed analytic, numeric, and computer tools to gain insight into steering gear forces, specifically, the mechanism behind the inception of mechanical knock in steering gear. The results provided a three dimensional geometric view of the sequence of events, in terms of gear surfaces in motion, their sudden contact, and subsequent force generation that lead to steering gear mechanical knock. First we briefly present results that show the sequence of events that lead to knock.

Steer-by-wire systems (SBW) offer the potential to enhance steering functionality by enabling features such as automatic lane keeping, park assist, variable steer ratio, and advanced vehicle dynamics control. The lack of a steering intermediate shaft significantly enhances vehicle architectural flexibility. These potential benefits led GM to include steer-by-wire technology in its next generation fuel cell demonstration vehicle, called “Sequel.” The Sequel's steer-by-wire system consists of front and rear electromechanical actuators, a torque feedback emulator for the steering wheel, and a distributed electronic control system. Redundancy of sensors, actuators, controllers, and power allows the system to be fault-tolerant. Control is provided by multiple ECU's that are linked by a fault-tolerant communication system called FlexRay. In this paper, we describe the objectives for fault tolerance and performance that were established for the Sequel.

An algorithm, which determines the range of a preceding vehicle by a single image, had been proposed. It uses a “Range-Window Algorithm”. Here in order to realize higher robustness and stability, the pattern matching is incorporated into the algorithm. A single camera system using this algorithm has an advantage over the high cost of stereo cameras, millimeter wave radar and non-robust mechanical scanning in some laser radars. And it also provides lateral position of the vehicle. The algorithm uses several portions of a captured image, namely windows. Each window is corresponding to a predetermined range and has the fixed physical width and height. In each window, the size and position of objects in the image are estimated through the ratio between the widths of the objects and the window, and a score is given to each object. The object having the highest score is determined as the best object. The range of the window corresponding to the best object becomes an estimated range.

Three dimensional acoustic entertainment enables the listener to experience sounds emanating from all around them, rather than being limited to the space between a pair of stereo speakers. It provides the artist with an enhanced sonic pallet to place sound sources in three dimensional space, as well as potential for a more realistic music reproduction experience. With the popularity of the Digital Versatile Disc (DVD), the technology successfully migrated from the movie theater into the “home theater”. The multichannel replacements for the audio CD (DVD-Audio and Super Audio CD) are enhancing the advancement into the automotive space. Automotive interiors are readymade for multichannel reproduction, but the automotive environment offers some challenges as well. This paper will discuss the market and technical potential for automotive applications of three dimensional sound, matters to take into account, media choices, distribution considerations and a look toward the future.

Electronics components are estimated to be between 9 to 15 % of a total vehicle cost, and this trend will remain strong for the next years. The amount of electronics content in a vehicle has grown steadily since 1970's, and as a result, development challenges such as testing and validation are a key aspect of its overall development costs. Testing costs can amount easily to US$ 500 k in medium complex automotive parts of a vehicle (e.g. instrument cluster) depending on a specific OEM customer demand, and this on top of limited regional laboratory capacity can also lead to increased testing time. The goal of this paper is to outline key aspects of electronics in vehicle components testing, including overall costs and timing, and propose a lean approach to optimize such costs & timing. The key aspects of such optimization include not only resources, but also laboratories and upfront OEM customer planning.

A fixed-base driving simulator with a 14-degree of freedom vehicle dynamics model was used to compare the lane tracking performance of test subjects using a joystick steering controller to that using a conventional steering wheel. Three driving situations were studied: a) straight-line highway driving, b) winding road driving (country road), and c) evasive maneuvering - a double lane change event. In addition, three different joystick force-feedback settings were evaluated: i) linear force feedback, ii) non-linear, speed sensitive force feedback and iii) no force feedback. A conventional steering wheel with typical passenger car force feedback tuning was used for all of the driving events for comparison.

Rising costs continue to be a problem within the automotive industry. One way to address these rising costs is through modularity. Modular systems provide the ability to achieve product variety through the combination and standardization of components. Modular design approaches used in development of vehicle electrical, electronic, and software (EES) systems allow sharing of architectures/modules between different product lines (vehicles). This modular design approach may provide economies of scale, reduced development time, reduced order lead-time, easier product diagnostics, maintenance and repair. Other benefits of this design approach include development of a variety of EES systems through component swapping and component sharing. In this paper, new optimization algorithms and software tools are presented that allow vehicle EES system design engineers to develop modular architectures/modules that can be shared across vehicle platforms (for OEMs) and across OEMs (for suppliers).

This work demonstrates a practical method for predicting vehicle-level automotive steering system NVH performance from component-level NVH measurements of hydraulic steering pumps. For this method, in-vehicle measurements were completed to quantify vehicle noise path characteristics, including steering system structure borne, fluid borne and airborne paths. At the component level, measurements of steering pump reaction forces, sound power and dynamic hydraulic pressure were also completed. The vehicle-level measurement data was used to construct NVH transfer functions for the vehicle. These transfer functions were in turn combined with the pump component data measured on a test stand to create a prediction for steering pump order vehicle interior noise. The accuracy of these predicted values was assessed through comparison with actual vehicle interior noise measurements.

Although not completely understood, rotor distortion due to bolt-up is an issue commonly found in conventional brake rotor design. In this paper, bolt-up is addressed by utilizing optimization and contact analysis methods. These methods give greater insight to the contributing factors that influence bolt-up distortion. In particular, the optimization method defines the approximate geometric shape required for a brake rotor based on optimizing one or more variables. By utilizing the non-linear contact analysis method, the results from the optimization analysis are validated. In general, the results show that bolt-up distortion is not significantly affected by changing design features, variables or combinations of design features and variables. However, significant improvement in bolt-up distortion is noticed when changes are made to the brake rotor and the wheel bearing hub.

A hydraulic steering pump system will be considered in this report. The objective is to improve the design of a specific power steering pump using computational fluid dynamics (CFD) tools. The first part of this report deals with a pump oil seal leak. The thermal and fluid environments have been simulated. A variable fluid viscosity is used, showing a 15-20% increase in peak temperature. Potential improvements in product design have been suggested. The second part deals with using computer tools to reduce redundant testing. This includes use of parametric approach towards optimization. A rotating grid approach (basic moving mesh technique) is used.

Principle of the target tracking method for the Adaptive Cruise Control (ACC) system, which is applicable to non-uniform or transient condition, had been proposed by one of the authors. This method does not need any other information rather than that from the radar and host vehicle. Here the method is modified to meet more complex traffic scenarios and then applied to data measured on real highway. The modified method is based on the phase chart between the lateral component of the relative velocity and azimuth of a preceding vehicle. From the trace on the chart, the behavior of a preceding vehicle is judged and the discrimination between the lane change and curve-entry/exit can be made. The method can deal with the lane-change of a preceding vehicle on the curve as well as on the straight lane. And it is applied to more than 20 data including several road/vehicle conditions: road is straight, or turns right or left; vehicles are motorbikes, sedans and trucks.

Modern automobiles utilize stabilizer bars to increase vehicle roll stiffness. Stabilizer bars are laterally mounted torsional springs which resist vertical displacement of the wheels relative to one another. A stabilizer bar is constructed in such a way that it will meet package constraints and fatigue requirements. In order to design a robust stabilizer bar, Taguchi's “Design of Experiment method” is used. The objective of this paper is to develop a robust stabilizer bar design that will maximize the fatigue life and the roll stiffness while minimizing weight. This study is based on results obtained by CAE analysis.

A dynamic computer model of automotive air conditioning systems was developed. The model uses simulation software for the coding of 1-D heat transfer, thermodynamics, fluid flow, and control valves. The same software is used to model 3-D solid dynamics associated with mechanical mechanisms of the compressor. The dynamics of the entire AC system is thus simulated within the same software environment. The results will show the models potential applications in component and system design, calibration and control.

Maximum Brake Torque (MBT) timing for an internal combustion engine is the minimum advance of spark timing for best torque. Traditionally, MBT timing is an open loop feedforward control whose values are experimentally determined by conducting spark sweeps at different speed, load points and at different environmental operating conditions. Almost every calibration point needs a spark sweep to see if the engine can be operated at the MBT timing condition. If not, a certain degree of safety margin is needed to avoid pre-ignition or knock during engine operation. Open-loop spark mapping usually requires a tremendous amount of effort and time to achieve a satisfactory calibration. This paper shows that MBT timing can be achieved by regulating a composite feedback measure derived from the in-cylinder ionization signal referenced to a top dead center crank angle position. A PI (proportional and integral) controller is used to illustrate closed-loop control of MBT timing.

Nowadays, ever market vehicle change affects body, suspension & steering gear systems. The purpose of this report is to quantify the methodology for evaluating and improving rattle mechanical noises in power rack & pinion steering systems. It is very important the correct process be used to adjust and approve the power steering gears in order to prevent the knock noise issue on services (warranty). This report describes how Visteon's Engineering makes efforts to achieve a reduction in warranty issues due to mechanical noise in the power steering gear, which affects its performance. We refer to this mechanical noise as “Knocking Noise” which derives from the gearing (meshing) adjustment loss. This experiment, supported by the Six Sigma methodology, led to new knowledge on how to improve the method of meshing adjust and test approval in process through of Design of Experiments (DOE).

The era of the vehicle as a standalone non-connected entity is rapidly drawing to a close. The “Box” on four wheels is being opened to multiple communication channels based on consumer demand and expectations of the latest features, functions and content. Concurrently, automotive planners, marketers, engineers, and system architects are subject to increased complexity as a result of the rapidly evolving consumer electronics industry. This paper will discuss many of the limitations of existing automotive business models in attempting to successfully implement and meet consumer expectations. It will also propose a structural framework for automotive planners, marketers, engineers, and system architects to be able to better understand and predict consumer acceptance of electronics, multimedia features, and in-vehicle content access.

Data design is a very critical step in the model-based software development process. This paper discusses the importance of a data dictionary in modeling, automatic code generation and in creating model dependency graphs.

Software is today one of the most important components of electronic products. The capture and validation of the requirements makes a difference if the product will fulfill the customer's expectations or generate enormous frustration. The correct implementation of software validation makes the Product Development Organization more mature and reliable. Software validation is an opportunity for the product development team to identify if the requirements and customer expectations were achieved. It is also used to identify the risks and possible improvements to the product. Software testing is one element of a brooder topic that is often referred to as verification and validation (V&V). Verification refers to the set of activities that ensure that software correctly implements a specific function. Validation refers to a different set of activities that ensure that the software that has been built is traceable to customer requirements.

Commonly, a significant event is detected when a normally stable engine parameter (ex. sensor voltage, sensor current, air flow, pedal position, fuel level, tire pressure, engine acceleration, etc.) transiently exceeds a calibrated detection threshold. Many implementations of detection thresholds rely on multi-input lookup tables or functions and are complex and difficult to calibrate. An approach is presented to minimize threshold calibration effort and complexity, while improving detection performance, by dynamically computing thresholds on-line based on current real-time data. Determining engine synchronization without a camshaft position sensor is presented as an illustrative application.