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Delphi's Zero Resistance Technology (ZRT) is a revolutionary new product/process that enables the reduction of mass and volume from a traditional wiring assembly. ZRT is defined as a minimal (zero) resistance change over time. The ZRT product is an electrical/electronic connection system which provides a viable solution for high density and limited space wiring applications. The ZRT process is a semi-automated wiring harness manufacturing system with flexibility to produce harnesses to the customer demand.

The initial presence and dynamic formation of internal voids in human body models have been subjects of discussion within the human body modeling community. The relevant physics of the human body are described and the importance of capturing this physics for modeling of internal organ interactions is demonstrated. Basic modeling concepts are discussed along with a proposal of simulation setups designed to verify model behavior in terms of volume and pressure between internal organs.

Measured vehicle loads have traditionally been used as the basis for development of component, subsystem and vehicle level durability tests. The use of measured loads posed challenges due to the availability of representative hardware, scheduling, and other factors. In addition, stress was placed on existing procedures and methods by aggressive product development timing, variety in tuning and equipment packages, and higher levels of design optimization. To meet these challenges, General Motors developed new processes and technical competencies which enabled the direct substitution of analytically synthesized loads for measured data. This process of Virtual Road Load Data Acquisition (vRLDA) enabled (a) conformance to shortened product development cycles, (b) greater consistency between design targets and validation requirements, and (c) more comprehensive data.

There is an increasing demand in automated manufacturability analysis of metal castings at the initial stages of their design. This paper presents a system developed for virtual manufacturability analysis of casting components. The system can be used by a casting designer to evaluate manufacturability of a part designed for various manufacture processes including casting, heat treatment, and machining. The system uses computational geometrics and geometric reasoning to extract manufacturing features and geometry characteristics from a part CAD model. It uses an expert system and a design database consisting of metal casting, heat treatment and machining process knowledge and rules to present manufacturability analysis results and advice to the designer. Application of the system is demonstrated for the manufacturability assessment of automotive cast aluminum components.

Recent changes to the U.S. CAFÉ (Corporate Average Fuel Economy) requirements have caused increased focus on alternative vehicle component designs that offer mass savings while maintaining overall vehicle design and performance targets. The instrument panel components comprise approximately 6% of the total vehicle interior mass and are thus a key component of interest in mass optimization efforts. Typically, instrument panel structures are constructed of low carbon tubular steel cross car members with welded stamped steel component brackets. In some cases, instrument panel structures have incorporated high strength low alloy (HSLA) steels to reduce mass by reducing gage. In this study, aluminum low mass instrument panel structure concept designs are developed. This paper illustrates the differences between a HSLA steel solution and four different aluminum instrument panel structure designs.

This paper describes rationale for determining the apportionment of variable or ‘shuttered’ airflow and non-variable or static airflow through openings in the front of a vehicle as needed for vehicle cooling. Variable airflow can be achieved by means of a shutter system, which throttles airflow through the front end and into the Condenser, Radiator, and Fan Module, (CRFM). Shutters originated early in the history of the auto industry and acted as a thermostat [1]. They controlled airflow as opposed to coolant flow through the radiator. Two benefits that are realized today are aerodynamic and thermal gains, achieved by restricting unneeded cooling airflow. Other benefits exist and justify the use of shutters; however, there are also difficulties in both execution and practical use. This paper will focus on optimizing system performance and execution in terms of the two benefits of reduced aerodynamic drag and reduced mechanical drag through thermal control.

The comfort assessment of seats in the automotive industry has historically been accomplished by subjective ratings. This approach is expensive and time consuming since it involves multiple prototype seats and numerous people in supporting processes. In order to create a more efficient and robust method, objective metrics must be developed and utilized to establish measurable boundaries for seat performance. Objective measurements already widely accepted, such as IFD (Indentation Force Deflection) or CFD (Compression Force Deflection) [1], have significant shortcomings in defining seat comfort. The most obvious deficiency of these component level tests is that they only deal with a seats' foam rather than the system response. Consequently, these tests fail to take into account significant factors that affect seat comfort such as trim, suspension, attachments and other components.

This paper is an extension to the work presented in part I [1]. The control objective is still the same - use a logic based control design technique to assign a wheel slip, λ, to each corner of a vehicle, to track overall desired vehicle dynamics. As in part I, a fuzzy logic based controller is the primary control, with additional logic to select the inside/outside classifiers for the wheels. In part I, only the reduction of yaw rate error, e, was considered. It was shown that, although the overall system had satisfactory performance, there was slight deteriorization in the tracking performance when trying to compensate through a significant vehicle sideslip angle, β. In this paper, additional logic is introduced into the control to limit the vehicle sideslip angle, β; thus, allowing for a more robust desired yaw rate, Ωd, tracking control performance. The emergency lane change maneuver is simulated to show the effectiveness of the redesigned control.

For A/C and cooling systems development is usual send vehicles to US or Europe for wind tunnel tests, witch is expensive and has a long lead-time. Here in Brazil Delphi has at the Piracicaba Technical Center a chamber equipped with temperature control and chassis dynamometer. There is a up-grade project for it that consist in add ducts with fans inside the chamber that will get air from the chamber, already in the right temperature, accelerate and homogenate the air flow and blow it out direct to the front end of the vehicle. For development purposes may be possible eliminate totally the necessity of sending vehicle abroad. It was then decided to use CFD simulation to predict firstly the required fan power necessary to supply winds until 120 km/h at the front end of the vehicle and secondly predict the airflow pattern inside the chamber, considering chamber inlet air, chamber outlet air, exhaust outlet, duct outlet and flow pattern around the vehicle.

Digital human models (DHM) are now widely used to assess worker tasks as part of manufacturing simulation. With current DHM software, the simulation engineer or ergonomist usually makes a manual estimate of the likely worker standing location with respect to the work task. In a small number of cases, the worker standing location is determined through physical testing with one or a few workers. Motion capture technology is sometimes used to aid in quantitative analysis of the resulting posture. Previous research has demonstrated the sensitivity of work task assessment using DHM to the accuracy of the posture prediction. This paper expands on that work by demonstrating the need for a method and model to accurately predict worker standing location. The effect of standing location on work task posture and the resulting assessment is documented through three case studies using the Siemens Jack DHM software.

Delivering the appropriate material data for CAE analysis of plastic components is not as straight forward as it would seem to be. While a few of the properties typically used by resin manufacturers and material engineers to describe a plastic are useful to the analysis community (density, CLTE), most are not (flexural modulus, notched izod). In addition some properties such as yield stress are defined differently by the analysis community than by the materials community. Lastly, secondary operations such as painting or chrome plating significantly change the behavior of components with plastic substrates. The materials engineering community and the CAE analysis community must work together closely to develop the material data necessary to increase the capability of the analysis. This paper will examine case studies where these issues have required modifications to the material property data to increase the fidelity of the CAE analysis.

In this paper, a low-cost means to improve fuel economy in conventional vehicles by employing ultracapacitor based Active Energy Recovery Buffer (AERB) scheme will be presented. The kinetic energy of the vehicle during the coast down events is utilized to charge the ultracapacitor either directly or through a dc-dc converter, allowing the voltage to increase up to the maximum permissible level. When the vehicle starts after a Stop event, the energy stored in the capacitor is discharged to power the accessory loads until the capacitor voltage falls below a minimum threshold. The use of stored capacitor energy to power the accessory loads relieves the generator torque load on the engine resulting in reduced fuel consumption. Two different topologies are considered for implementing the AERB system. The first topology, which is a simple add-on to the conventional vehicle electrical system, comprises of the ultracapacitor bank and the dc-dc converter connected across the dc bus.

Spot welds have two separation modes: interfacial and button pullout. Most of existing publications [8,9,10,11,12] focused on button pullout. This is because for the same sheet metal and gage combination, button pullout leads to higher separation load than interfacial separation. With the push for lighter vehicles, high strength and ultra high strength steels are used. To further reduce mass, welding flanges are getting narrower. The welding tips are getting smaller. The weld nugget diameters are smaller as a result. The separation mode for certain load cases is no longer nugget pullout, but interfacial instead. This lowers the weld's maximum load capacity. In order for CAE simulated prediction to correlate to physical behaviors of vehicle structures, it is important to define and reconfirm separation criteria. New tests and analyses are necessary.

Several heater cores failed due to erosion by cavitation. After analysis, most of failures were explained by the presence of impurities in the heater core. It was then decided with the customer to use CFD simulation in order to prove that the cavitation was not caused by design concept of the tank. In this paper, we present the results of heater core simulations done in 2D and in 3D with Fluent. The objective is to simulate the pressure and velocity distribution within the heater core and to verify if the zones of low pressure are below the saturation vapour pressure of the fluid causing cavitation. In these areas, the deterioration of the tubes might occur due to erosion by cavitation.

Trivial Principal Component method (TPC) was developed recently to model a system based on measured data. It is a statistical method that utilizes Eigen-pairs of covariance matrix obtained from the measured data. It determines linear coefficients of a model by using the trivial eigenvector corresponding to the least eigenvalue. In general, linear modeling accuracy depends on the strength of nonlinearity and interaction terms as well as measurement error. In this paper, the TPC method is extended to analyze residual (error) vector to identify significant higher order and interaction terms that contribute to the modeling error. Subsequently, these additional terms are included for constructing a robust system model. Also, an iterative TPC analysis is proposed for the first time to correct the model gradually till the least eigenvalue becomes minimum.

Automobile drivers/passengers perceive automatic transmission (AT) shift quality through the torque transferred by the transmission. Clearly, torque regulation is important for transmission control. Unfortunately, a physical torque sensor has been too costly for production applications. With no torque measurement for feedback, controls in AT is mainly implemented in an open-loop fashion. Therefore, complicated adaptation algorithms are necessary while undesired shifts may still occur. To further simplify the controls and enhance its consistency and robustness, a direct torque feedback has long been desired in transmission control synthesis and development. A “virtual” torque sensor (VTS) algorithm has recently been developed to show a good potential in estimating relative torque along transmission output shaft using transmission output speed sensor and wheel speed sensors.

Due to the multitude of external design constraints, such as increasing fuel economy standards, and the increasing number of global vehicle programs, developers of automotive transmission controls have had to cope with increasing levels of system complexity while at the same time being forced by the marketplace to improve system quality, reduce development costs, and improve time to market. General Motors Powertrain (GMPT) chose to meet these challenges through General Motors Company's Road-to-Lab-to-Math (RLM) strategy, particularly the Math-based method of a virtual vehicle simulation environment called System Simulation. The use of System Simulation to develop transmission control algorithms has enabled GMPT to improve product quality and reduce development times and costs associated with the dependence on physical prototypes. Additionally, System Simulation has facilitated the reuse of GMPT controls development assets, improving overall controls development efficiency.

Utilization of direct injection systems is one of the most promising technologies for fuel economy improvement for SI engine powered passenger cars. Engine performance is essentially influenced by the characteristics of the injection equipment. This paper will present CFD analyses of a swirl type GDI injector carried out with the Multiphase Module of AVL's FIRE/SWIFT CFD code. The simulations considered three phases (liquid fuel, fuel vapor, air) and mesh movement. Thus the transient behavior of the injector can be observed. The flow phenomena known from measurement and shown by previous simulation work [2, 7, 10, 11] were reproduced. In particular the simulations shown in this paper could explain the cause for the outstanding atomization characteristics of the swirl type injector, which are caused by cavitation in the nozzle hole.

The torque converter and torque converter clutch are critical devices governing overall power transfer efficiency in automatic transmission powertrains. With calibrations becoming more aggressive to meet increasing fuel economy standards, the torque converter clutch is being applied over a wider range of driving conditions. At low engine speed and high engine torque, noise and vibration concerns originating from the driveline, powertrain or vehicle structure can supersede aggressive torque converter clutch scheduling. Understanding the torsional characteristics of the torque converter clutch and its interaction with the drivetrain can lead to a more robust design, operation in regions otherwise restricted by noise and vibration, and potential fuel economy improvement.

Lean-burn SIDI engine technology offers improved fuel economy; however, the reduction of NOx during lean-operation continues to be a major technical hurdle in the implementation of energy efficient technology. There are several aftertreatment technologies, including the lean NOx trap and active urea SCR, which have been widely considered, but they all suffer from high material cost and require customer intervention to fill the urea solution. Recently reported passive NH₃-SCR system - a simple, low-cost, and urea-free system - has the potential to enable the implementation of lean-burn gasoline engines. Key components in the passive NH₃-SCR aftertreatment system include a close-coupled TWC and underfloor SCR technology. NH₃ is formed on the TWC with short pulses of rich engine operation and the NH₃ is then stored on the underfloor SCR catalysts.