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Technical Paper

Electrochromic Glazings for Use in Automobiles

1996-04-01
91A110
In the present paper we will outline the principles, designs, problems and benefits of electrochromic coatings and present our own laboratory results. The effect of electrochromic coatings on the thermal comfort of a parked vehicle is theoretically calculated and the results confronted with the performances of selective coatings.
Technical Paper

Multifunctional Glasses for Automotive

1996-04-01
91A109
The windows of a vehicle have to satisfy the following driver and passenger needs concerning visibility and climate perception both related to active safety: transparency, reluctance, dazzling, glare and diffused light (scattering). All functions are related to visibility and so to the optics of glazing, solar control, deicing, defogging, demisting. The task of material science is to find the multifunctional glasses solving simultaneously problems of visibility, safety and comfort. Particular kind of glasses, colored, wired, coated, electrochromic, liquid crystal, photochromic can be already considered solutions which can operate passively or actively. The example of passive solar control and active heatable coated glasses is shown as a possible practical multifunctional glass very soon.
Technical Paper

Trends and Forecasts for Turbocharging

1988-03-01
871147
Predictable and unpredictable forces will change the direction of the charge-air systems industry. The driver of diesel engine development will be the stringent emissions regulations of the 1990s. The drivers in the gasoline engine market will be improved fuel economy, performance, durability and emissions. Forces will also influence the charge-air marketplace, including changes in emission standards, national fiscal policies, political issues, fuel prices, alternate fuels and consumer tastes. The world community mandate for engines that are clean, quiet, durable and fuel efficient will be satisfied, increasingly, by first-tier component suppliers developing integrated systems solutions.
Technical Paper

Modeling and Measurement of Occupied Car Seats

1999-05-17
1999-01-1690
An overview of model development for seated occupants is presented. Two approaches have been investigated for modeling the vertical response of a seated dummy: finite element and simplified mass-spring-damper methods. The construction and implementation of these models are described, and the various successes and drawbacks of each modeling approach are discussed. To evaluate the performance of the models, emphasis was also placed on producing accurate, repeatable measurements of the static and dynamic characteristics of a seated dummy.
Technical Paper

Bosch ESP Systems: 5 Years of Experience

2000-05-15
2000-01-1633
Although the total number of car occupants involved in accidents in Germany has not significantly reduced during the past 10 years, the number of fatalities has steadily decreased. Most of the severe accidents result from a loss of control of the car. The problem of the driver losing control of his car will be explained. This problem is then used to formulate the goal for the vehicle dynamics control system ESP (Electronic Stability Program, also known as VDC). The approach chosen to reach this goal will then be shown. It will be shown that the vehicle slip angle is a crucial indicator for the maneuverability of the automobile. Since the complete vehicle state is not readily available, estimation algorithms are used to supply the control algorithms with sufficient information. With the automatic control of the slip angle the required yaw moment can be generated by individual wheel slip control.
Technical Paper

Using μ Feedforward for Vehicle Stability Enhancement

2000-05-01
2000-01-1634
Vehicle stability augmentation has been refined over many years, and currently there are commercial systems that control right/left braking and throttle to create vehicles that remain controlled when road conditions are very poor. These systems typically use yaw rate and lateral acceleration in their control philosophy. The tire/road friction coefficient, μ, has a significant role in vehicle longitudinal and lateral control, and there has been associated efforts to measure or estimate the road surface condition to provide additional information for the stability augmentation system. In this paper, a differential braking control strategy using yaw rate feedback, coupled with μ feedforward is introduced for a vehicle cornering on different μ roads. A nonlinear 4-wheel car model is developed. A desired yaw rate is calculated from the reference model based on the driver steering input.
Technical Paper

Dynamic Analysis of Crew Seats and Cockpit Interiors

2000-05-09
2000-01-1674
Improved safety standards are becoming a focus of the aerospace industry. In particular, standards for occupant protection have been changed to include dynamic seat testing and occupant injury assessment. Methods to model these situations are evolving. A method of modeling an occupant on a crew seat during a sled test is presented. This method combines a rigid body occupant model with a finite element model of the crew seat structure. Validation to sled test results obtained with the model is also presented. Modeling dynamic events with MADYMO software has been proven to be efficient and accurate in many aerospace and automotive applications. Using this tool, a model was developed to investigate how modeling can be used efficiently to provide guidance in crashworthy design. Both finite element methods (FEM) and multibody techniques were used to create a detailed model of a typical aircraft crew seat.
Technical Paper

Design and Test of an Improved Crashworthiness Small Composite Airframe

2000-05-09
2000-01-1673
The goals of this NASA Phase II SBIR program were to develop design methodology to improve occupant survivability in small composite airplanes. Current technology small airplanes absorb crash energy primarily in the cabin structure. The current study tried to increase strength of the occupant compartment and design energy absorbing structure outside the passenger compartment. Dynamics of the crash event were analyzed using a PC version of DYNA3D. Four full scale tests in two crash scenarios were conducted at the NASA Impact Dynamics Test Facility with test parameters set to allow direct comparison with prior NASA/FAA tests. Results indicate that occupant survivability can be improved with moderate weight penalty.
Technical Paper

A Stochastic Approach for Occupant Crash Simulation

2000-04-02
2000-01-1597
Stochastic simulation is used to account for the uncertainties inherent to the system and enables the study of crash phenomenon. For analytical purposes, random variables such as material crash properties, angle of impact, human response and the like can be characterized using statistical models. The methodology outlined in this approach is based on using the information about the probability of random variables along with structural behavior in order to quantify the scatter in the structural response. Thus the analysis gives a more complete picture of the actual simulation. Practical examples for the use of this technique are demonstrated and an overview of this approach is presented.
Technical Paper

Improving the Ride & Handling Qualities of a Passenger Car via Modification of its Rear Suspension Mechanism

2000-05-01
2000-01-1630
This paper presents the results of a recent project of IKCo’s research center to modify the Paykan 1600’s rear suspension mechanism with the purpose of improving the car’s comfort, stability and handling qualities. The car was originally equipped with a solid rear axle with leaf springs. By replacing the original mechanism with a three-link mechanism with panhard bar and coil springs, the ride comfort and handling characteristics of the car were noticeably improved.3-D, nonlinear ride and handling models were developed and analyzed to determine the important kinematics and dynamic effects of the new mechanism on vehicle responses. To verify the analytical results, subjective tests were carried out on the vehicle. The results of these tests demonstrated remarkable improvement of the dynamics behavior of the car.
Technical Paper

A Simple and Efficient Description of Car Body Movements for Use in Virtual Prototyping and Ride Comfort Evaluation

2000-05-01
2000-01-1629
Ideally, ride comfort evaluation, or any field evaluating human perception of motion, would be greatly simplified if such evaluation could be made based upon a single number or a simple curve that correlates with the perception of motion. The paper describes a ride comfort descriptor of pitch movements that is simple to use in virtual prototyping and ride comfort evaluations. This descriptor, i.e. Pitch Indicator, is validated in a calculation model, ride comfort measurements and subjective evaluations.
Technical Paper

Utilizing a Genetic Algorithm to Optimize Vehicle Simulation Trajectories: Determining Initial Velocity of a Vehicle in Yaw

2000-05-01
2000-01-1616
A method was developed for determining the unknown initial velocity of vehicles in yaw based upon evidence of the vehicle’s trajectory. The problem is formulated as an optimization problem by minimizing the error between a simulation trajectory and the known vehicle trajectory as per tire marks. A search simulation is coded in Matlab. An objective function is formulated based upon the error between the search simulation’ trajectories and the trajectory prescribed by the tire mark evidence. Initial conditions and step driver inputs are the design variables. A genetic algorithm routine coded in Matlab, GAOT (Genetic Algorithm Optimization Toolbox), is implemented to determine the solution vector that results in a simulation trajectory that minimizes the objective function. Target simulations are created using EDVSM (Engineering Dynamics Vehicle Simulation Model). The optimization algorithm is implemented and errors in the resultant velocities are reported.
Technical Paper

Motorcycle Suspension Development Using Ride Comfort Analysis with a Laboratory Test System

1999-09-28
1999-01-3276
An analytical approach to developing motorcycle suspensions is presented. Typical uncontrolled and subjective evaluations that place limits on suspension development are curtailed through the use of a laboratory-based road simulation technique, which evaluates vehicle ride quality. Ride comfort is calculated using a specifically tailored NASA model after primary and secondary frequency regimes have been established for this type of motorcycle. Correlation between road and laboratory simulation is measured and compared to the road data variance. A designed experiment evaluates changes in ride quality as a function of suspension and tire pressure adjustments. Various suspension settings are repeated on the simulator and corresponding ride numbers are calculated for both environments. An analysis is performed to correlate ride quality improvements on the simulator with ride quality improvements in the field.
Technical Paper

Emulating the Behavior of Truck Drivers in the Longitudinal Control of Headway

1999-11-15
1999-01-3706
This paper describes control system and psychological concepts enabling the development of a simulation model suitable for use in emulating driver performance in situations involving the longitudinal control of the distance and headway-time to a preceding vehicle. The developed model has mathematical expressions and relationships pertaining to the driver's skill in operating the brake and accelerator (“inverse dynamics”) and the driver's perceptual and decision-making capabilities (“desired dynamics”). Simulation results for driving situations involving braking and accelerating are presented to aid in understanding the research work.
Technical Paper

Steering Performance Evaluation - Heavy-Duty Highway Tractor Wander Test

1999-11-15
1999-01-3764
Heavy-duty highway tractors are the topic of various studies and tests to understand vehicle wander as a contributing factor to driver fatigue. Subtle variations in steering system characteristics can create measurable differences in performance, and operators may have different subjective opinions of the same system. This paper's purpose is to examine wander test setup and data analysis for tests conducted on an International® Model 9200 tractor-trailer at the Navistar Technology and Engineering Center in Fort Wayne, Indiana. Instrumented data and subjective ratings were collected using five power steering gears, evaluated by six drivers, operating over a specific test route.
Technical Paper

How Diagnostics Contribute to Vehicle Productivity and Driver Retention

1999-11-15
1999-01-3751
This paper begins with an outline of the cost structure of operating a commercial vehicle. The focus is on maintenance costs and how diagnostics and prognostics can lower costs. The paper then describes a link between vehicle productivity, driver productivity and driver satisfaction. Examples of onboard and offboard diagnostic systems will be used to illustrate how users create a vehicle that is “the best place to work” for drivers.
Technical Paper

INNOVATIVE ELECTRONICS A Key to Safety, Driver Retention, and Customer Service

1999-11-15
1999-01-3750
The following information is intended to provide a front line perspective of what benefits have been realized in safety, driver acceptance, and customer service, given the level of technology available to the medium and heavy duty truck and bus industry today. It does not specifically address the manner or method of technology utilized for such achievement, moreover it addresses the enhancements that specific components have made possible. Personal experiences are presented to support the benefits and a wish list of the latest technology available concludes this presentation.
Technical Paper

High-Level In-Vehicle Decision Support

1999-11-15
1999-01-3752
This paper documents the current realities of in-vehicle navigation systems in terms of their functionality, scope and responsiveness. It discusses the evolution of these systems with the advent of wireless communications. Addressed are the issues associated with delivery and utilization of real-time traffic, incident, and weather information to and by in-vehicle navigation systems. Also discussed are other High-level in-vehicle decisions that can be supported by the marriage of wireless communications with in-vehicle navigation. Applications considered range from the choosing of alternate waypoints and destinations (where to get gas, where to park), to the host of nRouteCommerce transactions that can be more efficiently achieved with the support of in-vehicle navigation (reserving a parking space, resetting household thermostats as you approach home). Implications on driver workload, in-vehicle processing, wireless bandwidth and Internet traffic are discussed.
Technical Paper

Ergonomic Designs of Mercedes-Benz Trucks at DaimlerChrysler

1999-11-15
1999-01-3736
This paper describes the procedure used to ensure that new trucks of the brand Mercedes-Benz meet the ergonomic requirements of all drivers, using the example of the semitrailer. Mercedes-Benz trucks are sold in different countries. Because of this, varying legal requirements, different sizes of drivers and different lifestyles and habits have to be considered. To solve this problem perfectly, new methods and tools have been acquired, resulting in increasing optimization of the process of truck development.
Technical Paper

Using Modern Technology to Improve Truck Seating

1999-11-15
1999-01-3735
Many advancements have been made through the use of technology that give seat manufacturers the capability to provide greatly improved truck seats. Until recently the design and development of new seating was accomplished primarily through static surveys. Modern technologies available today will reduce cost, development time, and the overall effort associated with utilizing real people to develop a seating project. In many instances when these seats were placed into vehicles with actual truck drivers riding in them for many hours a day, the drivers inputs resulted in multiple revisions to the original seat to satisfy their comfort issues. With modern technologies such as computer generated seat modeling, pressure mapping, and our state of the art test equipment such as a six–axis ride simulator, it has become part of any new seat development program to acquire field ride data in specific trucks and duplicate these inputs in the test laboratory.
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