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Accurate evaluation of vehicles' transient total power requirement helps achieving further improvements in vehicle fuel efficiency. When operated, the air-conditioning (A/C) system is the largest auxiliary load on a vehicle, therefore accurate evaluation of the load it places on the vehicle's engine and/or energy storage system is especially important. Vehicle simulation models, such as "Autonomie," have been used by OEMs to evaluate vehicles' energy performance. However, the load from the A/C system on the engine or on the energy storage system has not always been modeled in sufficient detail. A transient A/C simulation tool incorporated into vehicle simulation models would also provide a tool for developing more efficient A/C systems through a thorough consideration of the transient A/C system performance. The dynamic system simulation software MATLAB/Simulink® is frequently used by vehicle controls engineers to develop new and more efficient vehicle energy system controls.

Not all software tools are created equal and not all software tools are created to perform the same tasks. Therefore, different software tools are used to perform different tasks. However, being able to share the information between the different software tools, without having to manually re-enter (duplicate) any of the information, can save a lot of time and improve the quality of the product. The control software interface presented in this paper, allows system engineers to exchange data between software tools in an efficient manner which maximizes each tools capabilities and ultimately reduces development time and improves the quality of the product.

The work presented here outlines the development of a robust CAO tool for optimal design of electromagnetic retarder machines. The developed EM-CAO tool is then used to perform a wide variety of CAE/CAO tasks, from automatically computing the torque versus rpm performance curves of the EM retarder to performing optimization. Two specific examples of optimal design of the EM retarder are reported. Through the use of a task manager/optimizer repetitive jobs are fully automated thereby making the analysis and optimization of electromagnetic retarders faster and user-friendlier.

A twenty-five kilowatt (peak power for one minute), permanent magnet electric machine for a hybrid electric vehicle application was designed and tested. The electric machine is located in the clutch housing of an automatically shifted manual transmission and is subjected to 120 °C continuous ambient temperatures. The package constraints and duty cycle requirements resulted in an extremely challenging thermal design for an electric machine. The losses in the machine were predicted using models based on first principles and the heat transfer in the machine was modeled using computational fluid dynamics. The simulations were compared to test results over a variety of operating conditions and the results were used to validate the models. Parametric studies were conducted to evaluate the performance of potting materials and cooling topologies.

Same of the more enticing and productive opportunities to a useful work in product assurance are those of influencing the design of a product. The primary concern of design assurance is preventing or correcting those design errors that lead to poor product integrity. One of the tools used by the development teams in many organizations is the Design Review. The impact in cost and quality is directly affected by the correct utilization of the tool.

This paper discusses our experiences on the implementation and benefits of using the Hardware-In-the-Loop (HIL) systems for Powertrain control system software verification and validation. The Visteon HIL system integrated with several off-the-shelf diagnostics and calibration tools is briefly explained. Further, discussions on test automation sequence control and failure insertion are outlined The capabilities and advantages of using HIL for unit level software testing, open loop and closed-loop system testing, fault insertion and test automation are described. HIL also facilitates Software and Hardware Interface validation testing with low-level driver and platform software. This paper attempts to show the experiences with and capabilities of these HIL systems.

There are many opportunities in a current automotive HVAC case for improved performance, and cost savings. Based on these opportunities, a new HVAC case design has been developed. This new design is smaller and lighter than current cases while meeting many of the performance requirements. The case also features a unique plenum design for air distribution to the three modes, panel, floor, and defrost. The results of simulation and laboratory testing confirmed the concept of the new HVAC design.

As powertrains continue to get more efficient, less waste heat is available for warming the passenger compartment. Although several supplemental heating devices are currently on the market, including electric heaters, viscous heaters, and fuel operated heaters, they each have shortcomings related to cost, capacity, efficiency, and/or environmental concerns[1]. In an attempt to provide superior time-to-comfort in a cost, weight, package efficient, and environmentally friendly manner, an R134a heat pump (HP) system was developed. Several technical issues were overcome while developing this system. Production vehicles have been retrofitted to incorporate the R134a heat pump system and tested in a climatic wind tunnel. Test results for a -18°C warm-up test were compared to baseline data, showing significant improvements in average discharge air and breath level temperatures.

Water condensate retained inside an automotive evaporator has remained as one of the primary sources of unpleasant “odors”, which in turn can drive up the warranty cost for automotive manufacturers. The “wet” evaporator fin can also underperform due to the presence of condensate blocking the air passage. Moreover, condensate retention can be a potential factor of freezing up evaporators. Thus, an evaporator fin must be designed such that it can shed and drain water condensate as well as provide an excellent heat transfer capability. While the importance of water retention is well known, there seems lacking of a comprehensive way to evaluate the water retention characteristics of a particular product. In this work, attempts were made to answer four questions: (1) What is the mechanism that controls water condensate retention characteristics in an automotive evaporator? (2) Can different water retention evaluation methods reveal the same characteristics?

This paper presents an unambiguous and intuitive method for identification of steering column resonant (SCR) mode of vibration. One simple but overlooked technique to determine the SCR mode in-vehicle is to provide local stiffnesses of the body locations where the Instrument Panel (IP) attaches, to the IP suppliers to be used in their design and development. This paper describes how this technique is useful in predicting the first few important in-vehicle steering column modes for different classes of vehicles, with examples presented in each class. The results obtained from such analyses are compared against those from direct in-buck simulations. This technique is not limited to its application in developing IP systems, but can easily be extended to include other systems such as seats, fuel tanks, etc. Also it is shown that a design optimization analysis may be performed using these attachment stiffnesses as design variables resulting in a system level solution.

Flow noise from automotive HVAC (Heating, Ventilating and Air Conditioning) systems is one of the major considerations of occupant comfort. The noise generated at high blower speed is a major contributor to the vehicle interior noise. This paper reviews automotive HVAC air rush noise prediction models for estimating register, buck (air handling subsystem) and vehicle noise levels. The vehicle noise prediction method correlates well with measured noise levels at driver right ear location: with a standard deviation of 1.31 dB where standard deviation is the difference between measured and predicted noise levels for a sample size of 10 vehicles.

Stabilizer bars in a suspension system are supported with bushings by a frame structure. To prevent the axial movement of the stabilizer bar within the bushing, several new stabilizer bar-bushing systems have been developed. The new systems introduce permanent compressive force between the bar and the bushing thereby preventing the relative movement of the bar within the bushing. This mechanical bond between the bar and the bushing can eliminate features such as grippy flats, collars etc. In addition, by controlling the compression parameters, the properties of the bushing such as bushing rates can be tuned and hence can be used to improve the ride and handling performance of the vehicle. In this paper, nonlinear CAE tools are used to evaluate one such compressively loaded bushing system. Computational difficulties associated with modeling such a system are discussed.

Customer clinics and surveys have revealed the increased importance to the customer of good defrost and demist performance in their vehicle. Achieving this level of performance, within the time and cost constraints of a modern vehicle development program, places increased reliance on computational (CAE) techniques. However, this paper describes how the optimum development process should be to combine this reliance upon CAE methods with a newly developed experimental technique. This new laser Doppler velocimetry (LDV) based methodology is employed at all stages of the development process and complements the CAE techniques perfectly. The end result is optimized airflow management within the vehicle cabin – essential if good defrost and demist performance is to be achieved in a vehicle.

Visteon has developed a CAE procedure to qualify instrument panel (IP) products under the vehicle key life test environments, by employing a set of CAE simulation and durability techniques. The virtual key life test method simulates the same structural configuration and the proving ground road loads as in the physical test. A representative dynamic road load profile model is constructed based on the vehicle proving ground field data. The dynamic stress simulation is realized by employing the finite element transient analysis. The durability evaluation is based on the dynamic stress results and the material fatigue properties of each component. The procedure has helped the IP engineering team to identify and correct potential durability problems at earlier design stage without a prototype. It has shown that the CAE virtual key life test procedure provides a way to speed up IP product development, to minimize prototypes and costs.

Realizing the value of knowledge, corporations are turning to Knowledge Based Engineering (KBE) as a design process. A fuel rail KBE tool was created at Visteon with the purpose of increasing knowledge retention and delivering knowledge based designs to the customer much quicker than with conventional methods. Currently, both engineers and CAD designers are using the Fuel Rail KBE Modeler at Visteon. It has been used on many vehicle programs and has saved the company countless person-hours of development time. The Fuel Rail KBE Modeler is a powerful tool that saves resources through automation of both the design and analysis processes. This paper documents the incorporation of automated FEA capability into the KBE environment.

GENPAD® is a knowledge-based, three-dimensional modeling computer tool developed by Visteon to create occupant-friendly interiors. GENPAD quickly and easily produces zones to evaluate ergonomic aspects of vehicle interiors such as reach, clearance, vision, and reflection. These zones are produced from automated design studies based on experience and engineering standards accepted by the automotive industry. Without GENPAD, a single study requires an experienced engineer 4-6 hours to complete. Multiple studies require several engineers weeks to perform. The methods used are also error-prone due to complex instructions. To overcome these challenges, GENPAD provides over 50 ergonomic packaging studies that produce accurate results in minutes, not weeks, every time.

Traditionally, the passenger airbag door for an instrument panel (I/P) is a separate component assembled to the substrate, where the panel has an opening for the airbag module. The airbag door (usually made of TPE material) arrives to the assembly line from the airbag module supplier to be installed to the I/P. The grain and gloss between the door cover and the I/P class “A” surface must match closely. This paper describes the implementation of the passenger airbag door as an integral part of the instrument panel. This approach provides superior craftsmanship to the vehicle interior system. The I/P area that contains the seamless passenger airbag is weakened from the B-surface.

Recycled resins can meet performance requirements on products which were initially designed for virgin materials. Olefinic instrument panel (I/P) scrap is being recycled from the Mazda Tribute and the Ford Escape into glove box bins. As a result, a quality part is being supplied to the customer and Visteon's Saline Plant has realized both increased plant operating efficiencies and landfill cost avoidance. The development process is described including: plant regrind sources, part molding and testing.

This paper introduces the Driver Stability System (DSS) at Visteon. DSS is a new active comfort / safety system for automobiles which controls the seat bolsters independently in real time to enhance the lateral support of the occupants. Under turning maneuvers, DSS reacts to the vehicle dynamics to provide an increased contact area between the occupants and their seats, allowing optimal occupant location with respect to such variables as steering wheel angle, lateral acceleration, yaw rate, and vehicle velocity. The lateral force compensation is directly coupled to the dynamic movement of vehicle chassis and the change of road profile. The system consists of the seat bolster assembly including DC motors, wheel speed sensors, steering wheel sensor, lateral accelerometer, yaw rate sensor, and electronic control unit (ECU). This paper also discusses the control concept of DSS and its realistic controller structure.

Occupant knee impact simulations are performed in the automotive industry as an integrated design process during the course of instrument panel (IP) development. All major automakers have different categories of dynamic testing methods as part of their design process in validating their designs against the FMVSS 208 requirement. This has given rise to a corresponding number of knee impact simulations performed at various stages of product development. This paper investigates the advantages and disadvantages of various types of these knee impact simulations. Only the knee load requirement portion of the FMVSS208 is considered in this paper.