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Technical Paper

Production Solutions for Utilization of Both R1234yf and R134a in a Single Global Platform

2009-04-20
2009-01-0172
As global automobile manufacturers prepare for the phase-out of R134a in Europe, they must address the issue of using the new refrigerant for European sales only or launching the product worldwide. Several factors play into this decision, including cost, service, risk, customer satisfaction, capacity, efficiency, etc. This research effort addresses the minimal vehicle-level hardware differences necessary to provide a European solution of R1234yf while continuing to install R134a into vehicles for the rest of the world. It is anticipated that the same compressor, lubricant and condenser; most fluid transport lines; and in most cases the evaporator can be common between the two systems.
Technical Paper

Humidity Effects on a Carbon Hydrocarbon Adsorber

2009-04-20
2009-01-0873
Because combustion engine equipped vehicles must conform to stringent hydrocarbon (HC) emission requirements, many of them on the road today are equipped with an engine air intake system that utilizes a hydrocarbon adsorber. Also known as HC traps, these devices capture environmentally dangerous gasoline vapors before they can enter the atmosphere. A majority of these adsorbers use activated carbon as it is cost effective and has excellent adsorption characteristics. Many of the procedures for evaluating the adsorbtive performance of these emissions devices use mass gain as the measurand. It is well known that activated carbon also has an affinity for water vapor; therefore it is useful to understand how well humidity must be controlled in a laboratory environment. This paper outlines investigations that were conducted to study how relative humidity levels affect an activated carbon hydrocarbon adsorber.
Technical Paper

International Product User Research: Concurrent Studies Comparing Touch Screen Feedback in Europe and North America

2009-04-20
2009-01-0779
This paper describes two studies; each conducted concurrently in North America and Europe to assess subjective impressions and simulated driving task performance using a touch screen interface with different types of auditory and haptic feedback. The first study investigated subjective impressions of four types of touch screen feedback in a static laboratory setting. The second study investigated the influence of the same four touch screen feedback types on simulated driving task performance using the lane change test (LCT). Results of the first study revealed significant similarities and differences in subjective impressions between respondents in each of the two regions studied. Results of the second study revealed differences in task performance that suggest distinct participant strategies in each of the two regions studied.
Technical Paper

Statistical Identification and Analysis of Vehicle Noise Transfer Paths

2005-05-16
2005-01-2511
Identification of vibration transfer paths is critical to proper isolation of vibration excitations from becoming objectionable noise in a vehicle. Traditional transfer path methods involve comparing vibration inputs to the outputs of each joint. This method can be time consuming and inefficient due to a complexity of paths. A new statistical method was developed to improve the efficiency of testing. This method requires the measurement of the excitation vibration input at each joint of the source component and response sound measurements in the vehicle. Identification of transfer paths using regression analysis will determine the trouble paths to scrutinize.
Technical Paper

Designing a Tuned Torsional Damper for Automotive Applications Using FEA and Optimization

2005-05-16
2005-01-2293
Tuned mass dampers are frequently used in vehicles to resolve vibration issues arising from problematic torsional modes. The design of a tuned damper is straightforward, but evaluating its effect on other system modes is time consuming. An upfront design tool will accelerate the process of designing and evaluating the damper's affect on system level dynamic characteristics. Computer aided engineering tools have been developed to design a tuned torsional damper using two different approaches. In the first approach, a two-degree of freedom torsional system model is utilized. In the second approach, a detailed finite element model of a driveline system is considered. In the second approach, the effect of the damper to the vehicle driveline system response at the hypoid pinion nose and other desired locations is studied to assess the effectiveness of the damper design. In both approaches, the damper rotational inertia is considered as a design variable.
Technical Paper

Design Evaluations On IRS Axle System NVH Through Analytical Studies

2005-05-16
2005-01-2289
Axle whine is an important driveline NVH issue that originates in the hypoid gear sets due to transmitted error excitations. Improving gear quality to reduce the transmitted error has a cost penalty, as well as practical manufacturing limitations. On the other hand, axle system dynamics play a significant role in the system response to gear excitations and in transmissibility from gears to the structure. Analytical tools can be used to tune axle system dynamics in order to alleviate noise and vibration issues. Analytical results can be utilized to evaluate design alternatives, reduce the number of prototypes, thus to reduce product development time. However, analytical results need to be verified and correlated with test results. In this paper, dynamic behavior of a driveline system is investigated. The finite element model is validated at both component and system levels using frequency response functions and mode shapes.
Technical Paper

Analytical Calculation of the Critical Speed of a Driveshaft

2005-05-16
2005-01-2310
Determination of the critical speed of a driveshaft is critical for development and validation of its design for use in a vehicle because of its destructive effects. Typical calculations to determine critical speed are either over simplistic and not very accurate or very complicated requiring CAE software and capabilities. An analytical five-section non-prismatic beam model was developed to fill in this gap. The model was developed to compute the critical speed in a worksheet and proven to be as or more accurate as utilizing FEA methods. The model worksheet calculates the critical speed for one-piece conventional driveshafts and adapted for Visteon's Slip-In-Tube (SIT) driveshafts.
Technical Paper

On the Use of BEA with Engine Simulation as an Input to Predict Air Induction Inlet Noise

2005-05-16
2005-01-2350
Engine air induction noise can play a significant role in the reduction of vehicle interior noise levels and tuning interior sound quality. Given the need to reduce prototyping and testing costs, it is important to gain an understanding of the level and frequency structure of the noise radiating from the open inlet of the air induction system. Engine simulation used independently can predict inlet noise; however, its utility is limited to systems that are largely one-dimensional. Systems that exhibit a three-dimensional nature, such as the wave dynamics in an engine air cleaner, require a more intensive approach. Boundary Element Analysis (BEA) has been demonstrated to be a tool that can be used to predict the frequency response of ducted systems and is particularly useful in highly three-dimensional systems.
Technical Paper

Software Validation a Vital Activity for a Mature Product Development Organization

2005-11-22
2005-01-4168
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.
Technical Paper

Closed Loop Maximum Dilution Limit Control using In-Cylinder Ionization Signal

2005-10-24
2005-01-3751
This paper presents a combustion stability index derived from an in-cylinder ionization signal to control the engine maximum EGR limit. Different from the existing approaches that use the ionization signal values to gauge how much EGR was added during the combustion, the proposed method concentrates on using the ionization signal duration and its stochastic properties to evaluate the end result of EGR on combustion stability. When the duration index or indexes are higher than pre-determined values, the EGR limit is set. The dynamometer engine test results have shown promise for closed loop EGR control of spark ignition engines.
Technical Paper

Improved Hydraulic Power Steering Pump Design Using Computer Tools

2005-04-11
2005-01-1269
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.
Technical Paper

Automating Instrument Panel Head Impact Simulation

2005-04-11
2005-01-1221
Occupant head impact simulations on automotive instrument panels (IP) are routinely performed as part of an integrated design process during the course of IP development. Based on the requirements (F/CMVSS, ECE), head impact zones on the IP are first established, which are then used to determine the various “hit” locations to be tested/analyzed. Once critical impact locations are identified, CAE simulations performed which is a repetitive process that involves computing impact angles, positioning the rigid head form with an assigned initial velocity and defining suitable contacts within the finite element model. A commercially available CAE process automation tool was used to automate these steps and generate a head impact simulation model. Once the input model is checked for errors by the automated process, it can be submitted to a solver without any user intervention for analysis and report generation.
Technical Paper

Simple Application of DOE Methods to Reduce Whistle Noise in a HPAS Pump Relief Valve

2005-05-16
2005-01-2468
The present work demonstrates the application of Design of Experiments (DOE) statistical methods to the design and the improvement of a hydraulic steering pump noise, vibration, and harshness (NVH) performance in relief. DOE methods were applied to subjective ratings to examine the effect of several different factors, as well as the interactions between these factors on pump relief NVH. Specifically, the DOE was applied to the geometry of the cross ports on a hydraulic relief valve to improve “whistle” noise in the pump. Statistical methods were applied to determine which factors and interactions had a significant effect on pump whistle. These factors were used to produce a more robust cross port configuration reducing whistle noise. Lastly, the final configuration was experimentally verified on the test apparatus and subjectively confirmed in vehicle-level testing.
Technical Paper

Multivariate Statistical Methods for the Analysis of NVH Data

2005-05-16
2005-01-2518
The present work discusses the application of multivariate statistical methods for the analysis of NVH data. Unlike conventional statistical methods which generally consider single-value, or univariate data, multivariate methods enable the user to examine multiple response variables and their interactions simultaneously. This characteristic is particularly useful in the examination of NVH data, where multiple measurements are typically used to assess NVH performance. In this work, Principal Components Analysis (PCA) was used to examine the NVH data from a benchmarking study of hydraulic steering pumps. A total of twelve NVH measurements for each of 99 pump samples were taken. These measurements included steering pump orders and overall levels for vibration and sound pressure level at two microphone locations. Application of the PCA method made it possible to examine the entire set of data at once.
Technical Paper

Localized Nonlinear Model of Plastic Air Induction Systems for Virtual Design Validation Tests

2005-04-11
2005-01-1516
Plastic air induction system (AIS) has been widely used in vehicle powertrain applications for reduced weight, cost, and improved engine performance. Physical design validation (DV) tests of an AIS, as to meet durability and reliability requirements, are usually conducted by employing the frequency domain vibration tests, either sine sweep or random vibration excitations, with a temperature cycling range typically from -40°C to 120°C. It is well known that under high vibration loading and large temperature range, the plastic components of the AIS demonstrate much higher nonlinear response behaviors as compared with metal products. In order to implement a virtual test for plastic AIS products, a practical procedure to model a nonlinear system and to simulate the frequency response of the system, is crucial. The challenge is to model the plastic AIS assembly as a function of loads and temperatures, and to evaluate the dynamic response and fatigue life in frequency domain as well.
Technical Paper

Radar-based Target Tracking Method: Application to Real Road

2005-04-11
2005-01-1478
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.
Technical Paper

Combustion Characteristics Detection for Low Pressure Direct Injection Engines Using Ionization Signal

2006-10-16
2006-01-3317
It is well-known that in-cylinder ionization signals can be used for detecting combustion characteristics of IC (Internal Combustion) engines. For example, engine misfire, incomplete combustion (or partial-burn), knock, MBT (Minimum spark advance for Best Torque) timing and combustion stability can be detected using in-cylinder ionization signals. In addition, closed loop combustion spark timing control strategies have been developed to control engine MBT timing and to manage spark timing advance (knock) and retard (incomplete combustion) limits. In-cylinder ionization signals can also be used for closed loop control of maximum equivalence ratio (lean limit) at a desired combustion stability level. Up to now, most of the ionization applications have been for PFI (Port Fuel Injection) engines. This paper presents ionization detection for gasoline Direct Injection (DI) engines.
Technical Paper

New Designs and Concepts for Vehicle Entertainment Systems

2006-11-21
2006-01-2828
The need for entertainment is a constant desire since human beans started to use vehicles for short and long distance travel. The radio, a home entertainment revolution, was the first one to be incorporated. The information and entertainment that initially brought the radio to the vehicles also started a major change on the interior and electrical systems. This revolution will require changes in vehicle design to accommodate the new concepts and features.
Technical Paper

An Efficient Alternative for Computing Algorithm Detection Thresholds

2006-04-03
2006-01-0009
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.
Technical Paper

Target Tracking by a Single Camera Based on Range-Window Algorithm and Pattern Matching

2006-04-03
2006-01-0140
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.
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