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Model-Based Design with production code generation has been extensively utilized throughout the automotive software engineering community because of its ability to address complexity, productivity, and quality challenges. With new applications such as lane departure warning or electromechanical steering, engineers have begun to consider Model-Based Design to develop embedded software for applications that need to comply with safety standards such as IEC 61508. For in-vehicle applications, IEC 61508 is often considered state-of-the-art or generally accepted rules of technology (GART) for development of high-integrity software [6, 11]. In order to demonstrate standards compliance, the objectives and recommendations outlined in IEC 61508-3 [8] must be mapped onto processes and tools for Model-Based Design. This paper discusses a verification and validation workflow for developing in-vehicle software components which need to comply with IEC 61508-3 using Model-Based Design.

Virtual simulation of passenger compartment climatic conditions is becoming increasingly important as a complement to the wind tunnel and field testing to achieve improved thermal comfort while reducing the vehicle development time and cost. The vehicle cabin is subjected to various thermal environments. At the same time many of the design parameters are dependent on each other and the relationship among them is quite complex. Therefore, an experimental parametric study is very time consuming. The present 3-D RadTherm analysis coupled with the 3-D CFD flow field analysis takes into account the geometrical configuration of the passenger compartment which includes glazing surfaces and pertinent physical and thermal properties of the enclosure with particular emphasis on the glass properties. Virtual Thermal Comfort Engineering (VTCE) is a process that takes into account the cabin thermal environment coupled with a human physiology model.

Many approaches have been taken to determine the burning velocity in internal combustion engines. Experimentally, the burning velocity has been determined in optically accessible gasoline engines by tracking the propagation of the flame front from the spark plug to the end of the combustion chamber. These experiments are costly as they require special imaging techniques and major modifications in the engine structure. Another approach to determine the burning velocity is from 3D CFD simulation models. These models require basic information about the mechanisms of combustion which are not available for distillate fuels in addition to many assumptions that have to be made to determine the burning velocity. Such models take long periods of computational time for execution and have to be calibrated and validated through experimentation.

An experimental study was conducted to evaluate the effect of water absorption on tensile and fatigue behaviors of an impact-modified short glass fiber polyamide-6 and a short glass fiber polybutylene terephthalate. Specimens were prepared in the longitudinal and transverse directions with respect to the injection mold flow direction and immersed in water. Kinetics of water absorption was studied and found to follow the Fick's law. Tensile tests were performed at room temperature with specimens in the longitudinal and transverse directions and with various degrees of water absorption. Mathematical relations were developed to represent tensile properties as a function of water content. Load-controlled tension-tension fatigue tests were conducted in both longitudinal and transverse directions and correlations between tensile and fatigue strengths were obtained. Specimen fracture surfaces were also microscopically studied and mechanisms of tensile and fatigue failures were identified.

Due to magnesium alloy's poor weldability, other joining techniques such as laser assisted self-piercing rivet (LSPR) are used for joining magnesium alloys. This research investigates the fatigue performance of LSPR for magnesium alloys including AZ31 and AM60. Tensile-shear and coach peel specimens for AZ31 and AM60 were fabricated and tested for understanding joint fatigue performance. A structural stress - life (S-N) method was used to develop the fatigue parameters from load-life test results. In order to validate this approach, test results from multijoint specimens were compared with the predicted fatigue results of these specimens using the structural stress method. The fatigue results predicted using the structural stress method correlate well with the test results.

Gas Metal Arc Welding (GMAW) is widely employed for joining relatively thick sheet steels in automotive body-in-white structures and frames. The GMAW process is very flexible for various joint geometries and has relatively high welding speed. However, fatigue failures can occur at welded joints subjected to various types of loads. Thus, vehicle design engineers need to understand the fatigue characteristics of welded joints produced by GMAW. Currently, automotive structures employ various advanced high strength steels (AHSS) such as dual-phase (DP) and transformation-induced plasticity (TRIP) steels to produce lighter vehicle structures with improved safety performance and fuel economy, and reduced harmful emissions. Relatively thick gages of AHSS are commonly joined to conventional high strength steels and/or mild steels using GMAW in current body-in-white structures and frames.

The transition to Model-Based Design must be managed carefully, both to demonstrate short-term benefits and to establish a culture that enables the full realization of the theoretical benefits of this approach. In this paper we introduce the concepts of Model-Based Design, highlight some of its benefits, and then discuss in detail the 10 best practices for adopting a Model-Based Design culture across an organization. These best practices have been gleaned from successful and not-so-successful transformations to Model-Based Design at companies from a variety of different industries.

Many of the multimedia and convenience features in today's passenger vehicles involve Human Machine Interfaces (HMIs), such as the radio face plate or the remote key fob. The functional requirements for these systems are often written in terms of the customer interaction with the interface device. In the past, design engineers would not begin to test requirements for these systems until prototype hardware was available. However, many product development organizations are shifting from this hardware-based traditional development cycle, which relies on designing via a prototype and test iteration, to Model-Based Design. Unfortunately, testing systems with complex human machine interface requirements becomes less intuitive when the prototypes are removed from the design process, because the test cases must be scripted into the modeling environment instead of being applied directly to a prototype of the interface device.

Current trends in the automotive, aerospace and other industries are resulting in the development of exceptionally large system-level models of control law or physical system behaviors. This is especially true in the propulsion systems algorithm and software development areas. The MathWorks has been actively engaged with a number of engineering groups faced with industry demands of increased software feature content with higher complexity and a shorter turn-around time. This paper discusses a roadblock encountered on a typical propulsion system software simulation due to its sheer size. It also discusses challenges, results, and lessons learned in solving the above problem from both a tool technology and engineering perspective.

Today, many leading automotive OEMs and Suppliers are adopting Model-Based Design for the development of embedded systems applications. In this paper, the authors review the challenges of performing configuration management that is adequate for use in a production environment of the models and associated files central to Model-Based Design.

The steady growth in the number of electronic control units on the average vehicle and the complexity of the algorithms that reside on these controllers has resulted in one of the most significant initiatives in the automotive industry in years. AUTOSAR - the Automotive Open System Architecture - has united more than 100 companies, automobile manufacturers, suppliers and tool vendors to develop a standard architecture for electronic control units. By the end of 2006 Version 2.1 was released, and now OEMs as well as suppliers have started to develop and integrate AUTOSAR-compliant functionality and components into vehicles. This paper will focus on the approach and challenges faced by engineers developing AUTOSAR-compliant production code using Model-Based Design.

The successful deployment of modeling packages across large organizations depends on the adoption of a uniform set of modeling standards within the organization. Further, the automation of modeling standards enforcement greatly facilitates their adoption. This paper examines several case studies of large-scale deployment of Model-Based Design and the areas where standards enforcement automation was employed. The paper further examines several areas where automation could be employed to improve the deployment process.

Hardware-in-the-loop (HIL) testing has become an essential verification step in the development of vehicle electronics and software systems. New system concepts continue to drive the requirements for HIL systems. The use of an open architecture for HIL testing provides many benefits to meet these requirements quickly and cost effectively. In this paper we will discuss the development of an open architecture HIL system for a J1939 bandwidth study. We will show how this HIL system was used to test and validate that a heavily loaded networks can operate without compromising the performance of safety critical systems

Aerodynamic forces are the result of various complex viscous flow phenomena such as three-dimensional turbulent boundary layer on the body surfaces, longitudinal vortices induced by three-dimensional boundary layer separation, and high turbulence caused by flow separations. Understanding the flow characteristics and, especially, how the aerodynamic forces are influenced by the changes in the vehicle body shape, are very important in order to improve vehicle aerodynamics (particularly for low drag shapes). The present study was an attempt to provide insights for better understanding of the complex three-dimensional flow field around a vehicle by observing the limiting surface streamlines and the surface pressure gradients in the stream-wise and the transverse directions. The main objective of this work is to provide a comprehensive diagnostic analysis of the basic flow features in order to learn more about the flow separations in three-dimensions.

In the North American automotive industry, various advanced high strength steels (AHSS) are used to lighten vehicle structures, improve safety performance and fuel economy, and reduce harmful emissions. Relatively thick gages of AHSS are commonly joined to conventional high strength steels and/or mild steels using Gas Metal Arc Welding (GMAW) in the current generation body-in-white structures. Additionally, fatigue failures are most likely to occur at joints subjected to a variety of different loadings. It is therefore critical that automotive engineers need to understand the fatigue characteristics of welded joints. The Sheet Steel Fatigue Committee of the Auto/Steel Partnership (A/S-P) completed a comprehensive fatigue study on GMAW joints of both AHSS and conventional sheet steels including: DP590 GA, SAE 1008, HSLA HR 420, DP 600 HR, Boron, DQSK, TRIP 780 GI, and DP780 GI steels.

Weld Joints are widely used in automotive and aerospace industry. The main issue in the weld joints is the quality inspection to detect the disconnection in the welded area. In this paper, Shearographic technique with dynamic excitation is introduced to test the weld joints. In the experiments, the coupons are of 4 very thin layers of metal sheets welded together. The goal is to find out if there are any disconnections between the layers. They are clamped and then excited by a PZT actuator from behind. A real time digital Shearographic system with a self-refreshed reference image technology has been developed to display the measuring result, i.e. shearogram. A big range of driving frequencies is scanned to find the proper frequency and amplitude that can help to identify the disconnections. The results show that when the driving frequency reaches the resonance frequency, there will be big amplitude and thus a fringe pattern becomes visible on the coupon surface.

A critical market driver for rear axle lubricants continues to be the improved fuel efficiency, which is related to improvements in power transfer efficiency. Power transfer efficiency improvements are achieved with a reduction in the kinematic viscosity (KV) of rear axle lubricants. General Motors (GM) recently reduced the recommended viscosity grade for their rear axle lubricants from the Society of Automotive Engineers standard (SAE) 75W-90 to SAE 75W-85. This reduction in viscosity continues to require the optimization of rear axle lubricants to ensure durability. Lubricants that form thick elastohydrodynamic (EHD) films and are shear stable even when lower kinematic viscosities are required. This work depicts how a rear axle lubricant was developed and improved with the proper selection of base oil and polymer. This newly developed SAE 75W-85 rear axle fluid was incorporated as factory fill in 2019 in T1 LDPU-GMC Sierra and Chevrolet Silverado 1500 series pickup trucks.

To provide customers with the latest features, new passenger cars can have more than 50 microprocessors. With this increasing electronic complexity, the process by which the requirements are captured, a design evolves and is verified, becomes increasing critical to the overall success of the design. In this paper, the authors demonstrate how using Model-Based Design with a Systems Engineering approach can address some common failure modes that arise during the traditional automotive design process.

General Motors (GM), the Department of Energy (DOE), and other U.S. government and industry leaders have joined together to challenge students from 17 North American universities to apply advanced technologies toward the energy and environmental issues facing the automotive industry through the “Challenge X: Crossover to Sustainable Mobility” competition. This competition departs from previous ones by requiring students to use the same product development process that is used by the industry, which emphasizes the use of models. Through the words of students and mentors, this paper reports on some key lessons the students learned in the first year of the competition and the extraordinary insights mentors and university teams gained in the process.

Methods for controlling execution order in traditional text-based languages such as C and Fortran are well established. The transition to graphical programs has revealed some of the hidden issues inherent in any scheduling routine, specifically data dependency and data protection (in multirate systems). Graphical programming languages provided built-in diagnostics that allow users to analyze the data dependencies to develop optimal schedules from a data propagation perspective. This paper examines one heuristic that can be used to develop an optimal schedule for an arbitrary model.