Search Results

The thermal comfort of passengers within a vehicle is often the main objective for the climate control engineer; however, the need to maintain adequate visibility through the front and side windows of a vehicle is a critical aspect of safe driving. This paper compares the performance of the side window defrosting and demisting mechanism of several current model vehicles. The study highlights the drawbacks of current designs and points the way to improved passive defrosting mechanisms. The investigation is experimental and computational. The experiments are carried out using full-scale current vehicle models. The computational study, which is validated by the experiments, is used to perform parametric investigation into the side window defrosters performance. The results show that the current designs of the side-defroster nozzles give maximum airflow rates in the vicinity of the lower part of the window, which yields unsatisfactory visibility.

Experimental and numerical approaches were adopted to understand flow behavior and performance of centrifugal fans in an automotive HVAC blower system. This work is directed at improving the performance of a conventional forward-curved centrifugal fan for a given small scroll casing. Recent requirements in the design of the multiblade centrifugal fan being used in automotive HVAC blowers are not only higher pressure rise and lower noise, but also better packaging in the automobile cabin. In order to meet these requirements, among various well-known design factors affecting the fan performance, principal parameters related to the rotor shape were modified and detailed flow analysis was carried out. Measurements have been made by means of a miniature five-hole probe and a pressure scanning system connected to an online data acquisition system.

An innovative seat back design for fold down split-rear seat backs has been developed for application in SUV’s, MPV’s and hatchbacks. The all-thermoplastic seat back design meets US and European government regulations such as, the FMVSS 210, 207 in the US, and ECE 17 (luggage retention) in Europe. It is also expected to meet the newly introduced FMVSS 225 (child seat belt tether load) requirement. Currently application of the blow molded seat back is limited to sedans where the seat belt anchor loads are transmitted to a steel package shelf. For applications where the seat-belt anchor loads are transmitted to the seat back, hefty steel frame and reinforcements are required which add weight and cost to the seat back. The same is true for seats that need to comply with the European luggage retention requirement.

Historically, polyurethane foam has been classified and determined by IFD (Indentation Force Deflection) and density. The IFD test measures the load bearing property of the foam at a given deflection. However, the expectation of the automotive specifications is that these properties will also define durability and comfort of the foam when used in complete seat applications. Today’s automotive customers are asking for vehicles that last longer, with higher expectations in comfort, appearance, and durability performance. New targets are vehicles that will have satisfactory performance for 150,000 to 200,000 miles. We at Johnson Controls believe that to achieve these types of customer performance standards, new definitions of the molded foams are required. This paper will explain how a new test measurement, called hysteresis loss, is required to meet these new customer requirements.

New developments in the use of two-dimensional displays to supplement driver vision have made it more important to understand the roles that various distance cues play in driver perception of distance in more conventional ways of viewing the road, including direct vision and viewing through rearview mirrors. The current study was designed to investigate the role of binocular distance cues for perception of distance in rearview mirrors. In a field experiment, we obtained data to estimate the importance of binocular cues for distance judgments under conditions representative of real-world traffic. The results indicate that, although binocular cues are potentially available to drivers, these cues probably play little or no role in distance judgments in rearview mirrors in normal driving situations.

Comfort performance has developed into a central theme of vehicle seating design due to the role of the seat as the interface between the vehicle and the human. These comfort performance requirements exercise considerable influence over the specifications of the polyurethane foam that serves as a primary load-bearing material in the seat assembly. Various test protocols have been established to measure and predict comfort performance for polyurethane foam. One of the most important test methods is the vibration transmissivity test, used to characterize the response of a material to vibration of varying frequency and energy. This test methodology measures the performance of polyurethane foam alone to the performance of a fully assembled seat in a vehicle driven on a road surface. As such, there are a variety of test conditions employed to characterize transmissivity performance.

This paper describes a new 4.5-Liter V8 engine, VK45DE, which was developed for the use in the Infiniti Q45 sporty luxury sedan. The VK45DE engine, the replacement of the VH41DE for the Infiniti Q45 2000 model, is a new generation V8 engine that produces high output power at top-end speed and also generates ample torque at low and middle engine speed. Furthermore, this engine achieved best in class quietness that is pleasing the customer throughout the range of loads and speeds. Development efforts were focused on how to highly balance the need for performance with the need for quietness and smoothness. This paper provides details of this VK45DE engine as well as highlights of individual technologies that support highly balanced performance of this engine.

This paper describes the new inline 4-cylinder QR engine series that is available in 2.0-liter and 2.5-liter versions. The next-generation QR engine series incorporates new and improved technologies to provide an optimum balance of power, quietness and fuel economy. Its quiet operation results from the adoption of a compact balancer system and the reduced weight of major moving parts. Power and fuel economy have been enhanced by a two-stage cooling system, a continuous variable valve timing control system, a dual close coupled catalyst system, electronic throttle control and an improved direct-injection system. The latter includes an improved combustion chamber concept and improved fuel spray characteristics achieved by driving the injector by battery voltage. A lightweight and compact engine design has been achieved by adopting a high-pressure die cast aluminum cylinder block, resin intake manifold and rocker cover and a serpentine belt drive.

Due to environmental and legislative concerns, less polluting and more efficient vehicle powertrain systems must be developed. A first step is a simple, low cost system such as the presented Engine Stop-Start (ESS) system. A 1.9 liter four-cylinder spark-ignition engine with a four-speed automatic transmission was modified to enable fuel off-on transitions during decelerations and stops. Additional hardware includes a 7 kW electric motor-generator, a power electronics module with an inverter and a DCDC converter, a 36 Volt nominal battery system, and minor modifications to the transmission. A control scheme was developed which takes advantage of the system's fuel saving potential while minimally affecting driveability. Tests have shown EPA City fuel economy gains of approximately 12-14 percent while maintaining the same emissions classification. The EPA Highway fuel economy was increased by approximately 1 percent.

Automotive interiors are undergoing rapid transformation with the introduction of invisible PSIR integral systems. This styling trend requires continuous class A surface for the Instrument Panel (IP) and introduces complexities in the design and analysis of PSIR integral systems. The most important criterion for airbag doors is that it must open as intended, at the tearseam, within the deployment temperature range and without fragmentation. Consequently it is imperative that in analytical simulations, the finite element model of the tearseam is accurate. The accuracy of the model is governed by (a) optimal level of refinement, (b) surface geometry representation and (c) material model. This paper discusses modeling methodology for tearseams with respect to mesh refinement and the effect of geometry.

The design of the newly developed Toyota AZ series 4 cylinder engine has been optimized through both simulations and experiments to improve heat transfer, cooling water flow, vibration noise and other characteristics. The AZ engine was developed to achieve good power performance and significantly reduced vibration noise. The new engine meets the LEV regulations due to the improved combustion and optimized exhaust gas flow. A major reduction in friction has resulted in a significant improvement in fuel economy compared with conventional models. It also pioneered a newly developed resin gear drive balance shaft.

A technique to strengthen body frame with a polymeric structural foam has been developed with benefits of reducing vehicle weight and improving drivability and fuel economy. The idea of this new technology was evolved from the concept that body frame strength will increase drastically if the body frames are prevented from folding on collision. The energy of a collision impact would be effectively absorbed if weak portions of body frames are reinforced by a high strength structural foam. The new technology composed of the high strength structural foam and a light-weight frame structure with partial foam filling is reported here.

Contemporary interior designs make increasing use of soft feel and color harmony to provide a more luxurious and attractive environment for the driver and passengers. At the same time, progress in part manufacturing methods has increased the need for materials designed to work well in a variety of processes, such as injection molding, extrusion, blow molding, rotational molding and others. The focus of this paper will be on materials which are pre-colored to match OEM standards and are therefore capable of producing “ready-to-install” components without expensive post-operations like painting. The materials discussed will be in the 55–90 Shore A hardness range typically preferred by designers today, thereby avoiding the undesirable hard, “plastic” impression some other materials require as a trade-off. Plasticized PVC is often used in these applications for its good balance of performance and cost.

Federal legislation for head impact protection in upper automotive interiors (FMVSS 201U) has presented a unique energy management problem for the automotive industry. Due to extremely tight packaging conditions, energy absorbers are required to have efficiencies which exceed those of traditional foam materials, and force the development of new methods of energy absorption. The push toward shortened design cycle times has required the use of predictive engineering tools such as finite element analysis. Predictive tools which can accurately drive design direction reduce design cycle times, costs associated with multiple prototype part builds, and costs associated with physical testing. Over the last few years, the inclusion of FMVSS 201U energy absorbing countermeasures in the upper interior trim has been largely experimental in nature, yielding solutions which are costly in both time and money.

Non-planar driver's side rear-view mirrors provide a wider field-of-view than planar mirrors, but produce a minified image. A field experiment was conducted to measure the performance of drivers when making lane change decisions based on mirror information. Four mirror types were included: a planar mirror, a spherical convex mirror and two aspherical mirrors (radius of curvature 1400 and 2000 mm, respectively). Non-planar mirrors improved drivers' detection of adjacent vehicles due to wider fields of view. Drivers' experience with non-planar mirrors did not generally compensate for the negative effect of accepting smaller gaps, with the exception of drivers who were accustomed to spherical convex mirrors. No increase in the visual workload was required to process information in non-planar mirrors. The conclusion was that the relative benefits of non-planar mirrors should be greater than the negative effects.

Headlight glare is a continuing problem that has resisted efforts to solve it until now. A novel approach is provided in this paper by doping the glass with Neodymium Oxide, a rare earth compound, to filter out the excess yellow light. Neodymium Oxide doped lighting improves black and white contrast, so one can see road markings easier. The primary colors red, green and blue are enhanced with increased saturation, making them easier to see at low levels of illumination. Preliminary results indicate that “spots in your eyes” are reduced in intensity and in duration in the visual field. Apparent glare is reduced by a factor of 6 to 7 compared with standard lamps.

Multiple automotive systems are now being developed which require an imager or vision chip to provide information regarding vehicle surroundings, vehicle performance, and vehicle passenger compartment status. Applications include lane departure, lane tracking, collision avoidance, as well as occupant position, impaired driver, and occupant identification. These applications share many requirements, including robust design, tolerance for the automotive environment, built in self-test, wide dynamic range, and low cost. In addition, each application has unique requirements for resolution, sensitivity, imager aspect ratio, and output format. In many cases, output will go directly to vehicle systems for processing, without ever being displayed to the driver. Commercial imager chips do not address this wide spectrum of requirements. A CMOS imager chip has been designed to address these unique automotive requirements.

Automating the task of high beam switching will significantly improve nighttime driving safety, especially for pedestrians, by providing the maximum amount of illumination possible for a given driving condition while not exposing an oncoming or preceding driver to an uncomfortable level of glare. While there have been many prior attempts to perform this task, these systems have been plagued by their inability to detect distant taillamps and by their tendency to switch to low beams for reasons other than the presence of other vehicles. This paper will describe a new device which overcomes these limitations through the use of an image processing system which detects other traffic and switches the high beams accordingly.

European car manufacturers, setmakers and research institutes have been working for the last decade on Adaptive Frontlighting Systems (AFS). Due to the fact, that an AFS is no longer a single part of the car, it will have to be regarded in systems context with sensor and control devices resulting in a rising complexity. In order to help the engineer in developing an AFS, the software-tool AFSim has been programmed providing functions to swivel and to dim the light-distribution of a headlight on a freely programmable road with curves. The software package AFSim has been recently expanded with further functions facing the range of a headlight.

High intensity discharge lights (HID) are the innovation step that is now beginning to penetrate in all car classes. Investigating drivers, all results show that the benefits are visible to them and positively accepted. The quantification of the improvements has yet been insufficiently examined. In this article some of the aspects will be highlighted.