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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

A Model-Based Failsafe System for the Continental TEVES Electronic-Stability-Program (ESP)

2000-05-15
2000-01-1635
The Electronic Stability Program (ESP) is a vehicle dynamics control system that supports the driver in critical driving situations. A basic component integrated in the ESP-system is an on-line sensor monitoring system which is mainly used for detecting faults in sensors as early as possible so that an erroneous control or system malfunction can be prevented. Aim of this contribution is to present a model based sensor monitoring system for ESP that was developed, implemented, and is produced in large volumes by Continental Teves.
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

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

A Triaxial Accelerometer Small Enough to Fit in Your Ear

2000-03-06
2000-01-1379
Crash testing injury calculations have historically been based on measurements of forces and accelerations on cadavers subjected to crashes. For example, the Head Injury Criteria (HIC) was developed by bolting accelerometers to the skulls of cadavers and comparing the actual damage to the head and brain to the measured acceleration. These calculations are currently being improved by evaluating the injuries sustained by race car drivers involved in crashes during races. Biomechanics researchers have installed accelerometers to measure the race car accelerations during a crash. To further improve the injury assessment capabilities, the researchers would like to measure the actual acceleration of the driver’s head. Unfortunately race drivers, unlike cadavers, object to having accelerometers bolted to their skulls. Mounting accelerometers on the racing helmets gives some data, but the drivers head can move within the helmet during a crash.
Technical Paper

Customer Fuel Consumption – The Vehicle Data Bus as Real–World Information Source

2000-03-06
2000-01-1337
Road to rig problems exist as long as vehicles are being tested. Many approaches and methods exist to produce test cycles for rigs or test tracks, in order to produce viable results for the generation of statements concerning such crucial aspects as durability and fuel consumption. Modern model strategies again demand shorter–than–ever development periods, whilst meeting better–than–ever the needs and demands of special target groups. Therefore, the testing methods must also be refined, in order to gain a closer correlation to the customer's vehicle deployment. The approach introduced here makes use of real–world customer data for obtaining a closer look at how the vehicle is used by different customer groups, in different countries. The data is collected by small and unobtrusive dataloggers installed in customer vehicles. As these customers are using their own vehicles in everyday life, being unaware of the acquisition process, a database of real customer usage is generated.
Technical Paper

Audio–Only Access to Internet Information in a Car

2000-03-06
2000-01-0816
This paper describes work undertaken at Siemens Corporate Research to design an unobtrusive, non–visual browser for electronic mail and the World Wide Web (WWW) suitable for car drivers. This voice–driven, interactive audio–only browser is able to describe the document structure and speak the document content.
Technical Paper

A New EPS Control Strategy to Improve Steering Wheel Returnability

2000-03-06
2000-01-0815
This paper proposes a new Electric Power Steering (EPS) control strategy that enables improvement to steering-wheel returnability. Using a conventional EPS controller, frictional loss torque in the steering mechanism reduces steering-wheel returnability, which drivers occasionally perceive as unpleasant. This phenomena occurs in any EPS system regardless of motor type or mounting location. To improve steering-wheel returnability for EPS-equipped vehicles, we developed a new control strategy based on estimation of alignment torque generated by tires and road surfaces. This proposed control strategy requires no supplemental sensors like steering-wheel angle or motor-angle sensors. We experimented with this proposed control algorithm using a test vehicle and confirmed that it enables improved steering wheel returnability and also better on-center feeling.
Technical Paper

Development of Sleeper Cabin Cold Storage Type Cooling System

2000-03-06
2000-01-1271
When truck drivers rest in the truck sleeper cabin in the summer, air conditioning for the sleeper is highly desirable. Current practice is to run the engine for air conditioning, however, this practice wastes fuel and is environmentally unsound. This “Cold storage type cooling system” can cool the truck sleeper cabin without running the engine when the truck is parked and thus would be preferable from the view-point of fuel savings and environmental protection. The system we developed can be added to existing air conditioning systems and essentially consists of “cold storage cells” containing water as the cold storage material. The cold storage cells are fitted between evaporator tubes. By making the refrigerant alternately flow between the main evaporator and cold storage evaporator, the cold storage cells are charged while the truck is driving. When the truck is stopped, the sleeper cabin can be cooled by allowing the “cold storage cells” to discharge.
Technical Paper

Improving Vehicle Windshield Defrosting and Demisting

2000-03-06
2000-01-1278
This paper examines the prevailing fluid flow and heat transfer on the windshield of a full–scale vehicle and examines ways of promoting efficient de–icing and demisting. It establishes that present methods of defrosting and demisting windshields are inefficient; since the first area cleared is below the driver's eye level and even this result only occurs some considerable time after the blower has been switched on. The complexity of the windshield topography and the defroster nozzle geometry yield inadequate flow mixing, poor momentum interchange and consequently dead flow zones in critical visibility areas. This study explores ways of improving the defrosting and demisting process through passive means and using the existing air handling system of the vehicle. The results presented are from numerical simulations validated by experiment.
Technical Paper

Driver Fatalities in Frontal Crashes of Airbag-Equipped Vehicles: A Review of 1989-96 NASS Cases

2000-03-06
2000-01-1003
Using data from the National Automotive Sampling System/Crashworthiness Data System (NASS/CDS) for1995-96, this study updates previous analyses of driver fatalities in airbag-equipped vehicles in the NASS/CDS database for 1989-93 and 1989-94. A total of 59 cases of frontal crashes of airbag-equipped vehicles with driver fatalities were identified in these 8 years of NASS/CDS data, but in 9 cases the fatalities were not related to the impacts (e.g., fire, medical condition). Vehicle intrusion was the cause of the fatal injuries in 27 cases, and 7drivers died from injuries sustained when they were either partially or totally ejected from their vehicles. There was one case in which the airbag did not deploy, although the crash conditions indicated it should have. One driver died from contact with a nonintruding vehicle surface, and the causes of the fatal injuries in 5 cases were unknown.
Technical Paper

Air Diffusion Concept for Climate Comfort Improvement

2000-03-06
2000-01-0979
Current systems of air diffusion inside the car cabin are leading in some conditions to passenger discomfort. To solve this problem our company has developed a new concept of air diffusion. It consists in an air distribution system composed of a wide central air diffusion area on the top of the instrument panel and two lateral outlets. To evaluate the comfort performances of the concept a methodology based on experiments, simulation and subjective evaluation has been defined and used. The comparison between the current air diffusion and the new one shows a significant impact on the driver's and passenger's comfort. The purpose of this paper is to describe the methodology developed to analyze the air diffusion impact on the comfort and the improvements obtained by the new concept.
Technical Paper

Vehicle Defroster System Evaluation

2000-03-06
2000-01-0984
Vehicle defrost systems are required to defrost the windshield and side windows in a short period. This portion of the HVAC system is not only required to work without interfering with operator comfort relating to high temperatures being felt by the drivers face, but also relating to noise. Add to these restrictions the requirement that the defrost outlets used must be esthetically pleasing, and one can see how much development time is required to design an effective defrost system. Once a design is established, it must be tested. The methods currently used to test defrost performance leaves much to be desired, due to the time required to transpose actual test results into usable data. This transposition includes removing marked tracing from the windows in a cold chamber to trace paper, and then the trace paper needs to be reduced into manageable sizes of paper.
Technical Paper

Design and Analysis of CAN Networks for Vehicles

2000-09-11
2000-01-2585
CAN based protocols for on- and off-highway applications are very popular. Designers of these systems need to know prior to implementation if the communications design will meet all the timing requirements, especially when critical machine control is involved. An analysis of the system that is accurate and easy to understand is needed. Further, tools are needed to allow “what if” analysis of varying messaging and priority schemes. The methods described in this paper are useful for standard protocols like SAE J1939 and ISO 11783 as well as for proprietary protocols. A communication modeling method using Rate Monotonic Analysis is possible. The theory and analysis method developed by others is applied to the J1939 situation. Some equations are modified to make it more realistic such as the calculation of stuff bits. The model is easily implemented with a spreadsheet.
Technical Paper

Application of the 3-D CAD Manikin RAMSIS to Heavy Duty Truck Design at Freightliner Corporation

2000-06-06
2000-01-2165
This paper describes application examples of RAMSIS, a 3-D CAD human model for ergonomic truck evaluations, to truck design. RAMSIS realistically simulates truck driver postures and locations, an important prerequisite to having confidence in subsequent ergonomic analyses. We show examples of how visibility evaluations compare to traditional SAE methods, arm reach and force evaluation; and an example for entry/exit evaluations.
Technical Paper

Anthropometric and Postural Variability: Limitations of the Boundary Manikin Approach

2000-06-06
2000-01-2172
Human figure models are commonly used to facilitate ergonomic assessments of vehicle driver stations and other workplaces. One routine method of workstation assessment is to conduct a suite of ergonomic analyses using a family of boundary manikins, chosen to represent a range of anthropometric extremes on several dimensions. The suitability of the resulting analysis depends both on the methods by which the boundary manikins are selected and on the methods used to posture the manikins. The automobile driver station design problem is used to examine the relative importance of anthropometric and postural variability in ergonomic assessments. Postural variability is demonstrated to be nearly as important as anthropometric variability when the operator is allowed a substantial range of component adjustment. The consequences for boundary manikin procedures are discussed, as well as methods for conducting accurate and complete assessments using the available tools.
Technical Paper

Influence of Forces on Comfort Feeling in Vehicles

2000-06-06
2000-01-2171
When investigating the posture comfort in vehicles two important influencing factors can be distinguished: In order to evaluate these influences a combined laboratory-field-experiment was carried out. A real car was equipped with cameras to record the body posture and the joint angles. The static forces exerted by the driver on his contact points were recorded in a corresponding mock-up. The forces to maintain the body posture were calculated. The following results were found:
Technical Paper

Comparison of Methods for Predicting Automobile Driver Posture

2000-06-06
2000-01-2180
Recent research in the ASPECT (Automotive Seat and Package Evaluation and Comparison Tools) program has led to the development of a new method for automobile driver posture prediction, known as the Cascade Model. The Cascade Model uses a sequential series of regression functions and inverse kinematics to predict automobile occupant posture. This paper presents an alternative method for driver posture prediction using data-guided kinematic optimization. The within-subject conditional distributions of joint angles are used to infer the internal cost functions that guide tradeoffs between joints in adapting to different vehicle configurations. The predictions from the two models are compared to in-vehicle driving postures.
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