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Technical Paper

Performance Analysis of Data-Driven Plant Models on Embedded Systems

2016-11-08
2016-32-0089
Data-driven plant models are well established in engine base calibration to cope with the ever increasing complexity of today’s electronic control units (ECUs). The engine, drive train, or entire vehicle is replaced with a behavioral model learned from a provided training data set. The model is used for offline simulations and virtual calibration of ECU control parameters, but its application is often limited beyond these use cases. Depending on the underlying regression algorithm, limiting factors include computationally expensive calculations and a high memory demand. However, development and testing of new control strategies would benefit from the ability to execute such high fidelity plant models directly in real-time environments. For instance, map-based ECU functions could be replaced or enhanced by more accurate behavioral models, with the implementation of virtual sensors or online monitoring functions.
Technical Paper

Improving Fuel Economy of Thermostatic Control for a Series Plugin-Hybrid Electric Vehicle Using Driver Prediction

2016-04-05
2016-01-1248
This study investigates using driver prediction to anticipate energy usage over a 160-meter look-ahead distance for a series, plug-in, hybrid-electric vehicle to improve conventional thermostatic powertrain control. Driver prediction algorithms utilize a hidden Markov model to predict route and a regression tree to predict speed over the route. Anticipated energy consumption is calculated by integrating force vectors over the look-ahead distance using the predicted incline slope and vehicle speed. Thermostatic powertrain control is improved by supplementing energy produced by the series generator with regenerative braking during events where anticipated energy consumption is negative, typically associated with declines or decelerations.
Technical Paper

Development of the T-74 (PT6) Turboprop/Turboshaft Engine

1963-01-01
470029
The PT6 turboprop/turboshaft engine is described and the development history of the engine is outlined. The areas covered include performance growth from initial to production ratings, durability development, systems development, and flight testing. The current firm applications and the further growth of the engine are described.
Technical Paper

Reliability Estimation and Failure Prediction of Highway Tractor Components

1982-02-01
820979
A method of predicting highway truck/tractor component lives based on warranty data is provided. This method incorporates computer modeling techniques into standard reliability analysis procedures to facilitate Reliability Estimation and Failure Prediction. Specifically, published truck/tractor usage data provided the basis for the computer modeling, and Weibull Distribution Analysis methods were utilized for Reliability Estimation. General considerations in the development of the computer model, and specific suggestions for the application of the method to vehicle applications other than highway truck/tractors are provided.
Technical Paper

Tool Support for Analyzing and Optimization Methods in Early Brake System Sizing Phases

2000-03-06
2000-01-0442
The manufacturers of passenger cars increasingly assign development and production of complete subsystems to the supplying industry. A brake system supplier has to give predictions about system quality and performance long time before the first prototypical system is built or even before the supplier gets the order for system development. Nowadays, the usage of computer-aided system design and simulation is essential for that task. This article presents a tool designed to support the development process. A special focus will be on how to define quality. A formal definition of quality is provided, illustrated and motivated by two examples.
Technical Paper

The Transient Temperature Distribution in a Heavy Duty Brake System During Fatigue Crack Testing

2000-03-06
2000-01-0441
A transient numerical heat transfer model has been developed for the purpose of estimating the time-dependent temperature distribution in a heavy duty drum brake system. The model is based on a forward-difference explicit finite difference solution of the heat equation, in combination with a non-uniform pressure distribution for energy input, based on observed brake lining wear. Temperatures predicted by the model were compared to experimental dynamometer drum temperature measurements. The model was utilized to simulate a common industrial test for evaluation of brake drum resistance to thermo-mechanical fatigue cracking. Thermo-physical property variation and drum wall thickness were shown to exert a strong influence on the predicted temperature gradients and fatigue cracking susceptibility.
Technical Paper

Brake System with Double Link-Type Variable Ratio Brake Pedal

2000-03-06
2000-01-0438
In the past, in order to have good brake effectiveness, it was necessary to adopt high coefficient friction materials for pads or linings, or enlarged brake effective radii. But high coefficient material can create problems such as noise or vibration. And increasing effective radii is limited by the wheel package. A high pedal ratio can provide good effectiveness, but also leads to long pedal travel and poor brake feel. Specifically for trucks and SUV's with large GVW's, it can be difficult to achieve both good brake effectiveness and good pedal feel. In response to this difficult design challenge, a double link-type variable ratio pedal was developed for a production application.
Technical Paper

Simulation of Complex Illumination Systems in the Field of Automotive Lighting

2000-03-06
2000-01-0431
For the automotive industry the styling of headlamps become more and more important. Clear lens design with facetted freeform reflector represent the status quo of modern headlamps. Additionally the available construction volume decreases and at the same time the requirements to the light distribution increases. For that reason precise simulation of light distribution in an early stage of the development is absolutely necessary. It will be shown exemplary how these methods work and why their use is strongly recommended. The results can be compared with measurements conducted on existing headlamps and demonstrate the benefit of these methods. Due to more powerful computational models and increased computer capability these simulation tools will be improved even more in the near future.
Technical Paper

Front Fog Lamp Performance

2000-03-06
2000-01-0433
This paper presents a review of the effects of fog on visibility during nighttime driving conditions and the factors influencing the performance of a front fog lamp. The effects on visibility due to beam pattern characteristics, mounting height, and lamp aim are studied using current mathematical models for fog veiling luminance, target luminance, and target contrast. A comparison is made of two different fog lamp photometry standards to show how each performs in terms of fog veiling luminance, target contrast, and glare for the opposing driver. The effects of varying the vertical aim of each fog lamp standard are studied in order to make conclusions about the correct lamp aim and tolerances required for fog lamp aiming. The effects of fog lamp mounting height and driver position are studied. Conclusions are made concerning optimum mounting height, aim, and beam pattern for fog lamps for vehicles with different driver positions.
Technical Paper

Innovative High Efficient Headlamp System Using Concave or Convex Lenses

2000-03-06
2000-01-0427
This paper describes a new headlamp design evaluation and simulation program that provides greater freedom and improved efficiency in light distribution design, using either concave or convex lens and a reflector with a NURBS (Non-Uniform Rational B-Spline Surface), for one of its free surfaces. It also offers simulation results of light distribution designs using this program in order to produce various headlamps, including high-efficiency and flat headlamps, each with a concave lens, and a thin headlamp with a convex lens.
Technical Paper

Stress Analysis and Strength Evaluation of Bonded Shrink Fitted Joints Subjected to Torsional Loads

2000-03-06
2000-01-0426
This paper deals with stress analysis and strength evaluation of bonded shrink fitted joints subjected to torsion. The stress distributions in the adhesive layer of bonded shrink fitted joints are analyzed by using the axisymmetric theory of elasticity when an external torsion is applied to the upper end of shaft. The effect of the outer diameter and the stiffness of rings on the interface stress distributions are clarified by the numerical calculations. Using the interface stress distributions, joint strength is predicted. In addition, joint strength was measured experimentally. It is seen that a rupture of adhesive layer is initiated from the upper edge of the interfaces when a torsion is applied to the upper end of shaft. The numerical result are in fairly good agreement with the experimental results. It is found that the joint strength of bonded shrink fitted joints is greater than that of shrink fitted joints.
Technical Paper

Use of Waterborne, “Bakeable” Technology for Sealing Interior Seams in the Paint Shop-A Halogen Free Approach

2000-03-06
2000-01-0425
The use of products containing polyvinyl chloride resin (PVC), in Paint Shop sealing applications, is a well-established practice at today's automobile manufactures. PVC technology has dominated this part of the manufacturing process due to the performance and cost effectiveness of the finished products. This paper will describe the use of a halogen free, waterborne technology, which compares favorably with both the performance and financial attributes of PVC products.
Technical Paper

Requirements for Improved Performance of Specialty Sealing and Bonding Materials for Automotive Applications

2000-03-06
2000-01-0423
Driven by global pressures of weight reduction and cost savings, suppliers of specialty sealing and bonding products to the automotive industry have responded by expanding the focus of their product development activities. OEM engineering practices have brought about significant changes within the specialty sealing and bonding supply base. The successful suppliers in this market have responded to these pressures and initiated changes in the processes through which their materials are developed and released into production. In an industry historically populated by chemists and manufacturing process engineers, new requirements have led to an increase in application engineers and technical specialists, providing the necessary vehicle development expertise to the sealant industry. To support these expanded roles, new research and development facilities and associated advanced technologies have become a critical requirement.
Technical Paper

Engineering Development and Performance of an Integrated Structural Instrument Panel Assembly and Heater-Ventilation-Air-Conditioning Assembly

2000-03-06
2000-01-0416
Textron Automotive Trim, Valeo Climate Control, and Torrington Research Company, with assistance from GE Plastics, have developed an integrated instrument panel system to meet ever-increasing industry targets for: Investment and piece-cost reduction; Mass/weight savings; Quality and performance improvements; Packaging and space availability; Government regulation levels; and Innovative technology. This system, developed through feedback with the DaimlerChrysler Corporation, combines the distinctive requirements of the instrument panel (IP) with the heater-ventilation-air-conditioning (HVAC) assembly. Implementing development disciplines such as benchmarking, brainstorming, and force ranking, a number of concepts were generated and evaluated. Using a current-production, small, multi-purpose vehicle environment, a mainstream concept was designed and engineered.
Technical Paper

An Experimental and Modeling Study of Cordierite Traps - Pressure Drop and Permeability of Clean and Particulate Loaded Traps

2000-03-06
2000-01-0476
A model for calculating the trap pressure drop, particulate mass inside the trap and various particulate and trap properties was developed using the steady-state data and the theory developed by Konstandopoulos & Johnson, 1989. Changes were made with respect to the calculation of clean pressure drop, particulate layer porosity and the particulate layer permeability. This model was validated with the data obtained from the steady-state data run with different traps supplied by Corning Inc. The data were collected using the 1988 Cummins L-10 heavy-duty diesel engine using No.2 low sulfur diesel fuel. The three different traps were EX 80 (100 cell density), EX 80 (200 cell density) and EX 66 (100 cell density) all with a 229 mm diameter and 305 mm length. These traps were subjected to different particulate matter loadings at different speeds. The traps were not catalyzed.
Technical Paper

Validation of the Coupled PC-CRASH - MADYMO Occupant Simulation Model

2000-03-06
2000-01-0471
During recent years the accident simulation program PCCRASH was developed, which allows to simulate the vehicles movement before, during and after the impact. As shown in several publications, the software allows to calculate the 3D movement of all involved vehicles. Within SAE 1999-01-0444 a new coupling interface of PC-CRASH and the software MADYMO, developed by TNO in the Netherlands was published. During last year's publication only few validation cases, mainly related to rear end impacts could be demonstrated. In the mean while several well documented tests have been performed to validate the performance of this model also in frontal and lateral collisions as well as rollovers. A special series of sled tests has been performed to study the movement of the passenger during and after the collision for various impact angles. These tests were performed on an active sled at various test speeds.
Technical Paper

Offtracking: History, Analysis, and Simulation

2000-03-06
2000-01-0465
Offtracking is the term used to describe the difference in path radii between the leading and trailing axle of a vehicle as it maneuvers around a turn. This phenomenon probably has been observed from the time multi-axle vehicles first were constructed. As vehicles, particularly articulated trucks, have become larger and longer, and the urban environment has become more compact and crowded, practical safety concerns relating to offtracking have increased. The geometric design of streets and highways, and of parking lots and trucking yards, will be affected by the maximum offtracking of vehicles using those facilities. In some accident investigations, offtracking is a primary consideration. Much of present offtracking analysis is based upon a “zero-speed” assumption. In other words, the magnitude of offtracking is computed simply as a kinematic problem, with no dynamic effects considered.
Technical Paper

HVE EDSMAC4 Trailer Model Simulation Comparison with Crash Test Data

2000-03-06
2000-01-0467
Engineering Dynamics Corporation (EDC) recently updated the Human, Vehicle, Environment (HVE) software program to enable modeling of passenger cars and light trucks towing trailers. This paper reports on a comparison between the HVE EDSMAC4 collision module of the 3-dimensional computer simulation program and instrumented crash tests, in which one vehicle in each test was a pickup truck pulling a trailer. Use of the EDSMAC4 trailer model was found to provide better correlation between the simulation and test damage profiles, rest positions, vehicle trajectories, velocities, and Delta-V. It was also determined that the NHTSA-derived stiffness coefficients are sensitive to the impact configuration and depending on the impact configuration, it may be necessary to refine the coefficients according to the configuration.
Technical Paper

Heavy Truck Rollover Crashworthiness: Testing Methods and Development of Recommended Practices

2000-03-06
2000-01-0470
Testing methods and SAE Recommended Practices were developed for evaluating both the ability of a truck cab to resist roof loading in a rollover environment and the occupant kinematics and injury potential for occupants in a 90-degree heavy truck rollover. In evaluating a heavy truck roof for its ability to resist rollover loads, real-world accident data was analyzed and full-scale tests were performed to define the rollover environment. It was found that testing methods currently in place for passenger cars were not sufficient to represent the loading mechanisms that typically occur in a heavy truck rollover. An SAE Recommended Practice (RP) for both dynamic and quasi-static roof load testing was developed, and tests were conducted to evaluate their use. To evaluate heavy truck occupant safety in a 90-degree rollover, independent of roof intrusion, a rollover simulator was developed. The simulator allows occupant restraints, seats, and interiors to be evaluated for injury mechanisms.
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