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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

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

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.
Technical Paper

Optimal Suspension Damping for Improved Driver- and Road- Friendliness of Urban Buses

1999-11-15
1999-01-3728
Dynamic interactions of urban buses with urban roads are investigated in view of the vibration environment for the driver and dynamic tire forces transmitted to the roads. The static and dynamic properties of suspension component and tires are characterized in the laboratory over a wide range of operating conditions. The measured data is used to derive nonlinear models of the suspension component, and a tire model as a function of the normal load and inflation pressure. The component models are integrated to study the vertical and roll dynamics of front and rear axles of the conventional and modern low floor designs of urban buses. The resulting nonlinear vehicle models are thoroughly validated using the fieldmeasured data on the ride vibration and tire force response of the buses.
Technical Paper

Investigation of Wheeled Tractors Ride Comfort Using Hydraulic Semi-Active Suspension System

1999-11-15
1999-01-3727
In this paper, an electronically controlled hydraulic semiactive system for the seat suspension of wheeled tractors is theoretically designed to improve the driver ride comfort. Using a three degrees of freedom mathematical model, the damping force controller is designed based on optimal control theory and Nelder / Mead Simplex minimization method to perform a limited state feedback information. The controller considers the damping constraint which adapts the actual damping between the prescribed limits. The model results are generated when excited by a statistically random road profile. The results are presented in time and frequency domains. The driver vertical acceleration for semi-active and conventional passive systems are compared at similar root mean square (r.m.s) value of suspension working space. The semiactive system achieved a significant improvement, 18 percent, over the passive system with no power requirement from the tractor engine.
Technical Paper

Life Cycle Considerations as a Foundation for Improved Cost Assessments

2000-04-26
2000-01-1481
Key drivers in our global economy are mainly cost. The growing importance of environmental themes does not change this view. Today very often economic performance and environmental friendliness are considered to be non-compatible. The reasoning for this is mainly, that environmental protection is seen defensive and end-of-pipe oriented. If an organizations emphasis is only legal compliance, such arguments are especially true. Here filters, sewage plants and waste management are real cost drivers. In order to overcome this non-beneficial situation, new approaches are inevitable. Offensive approaches are required to meet both, economic and environmental targets. LCA has in the past only been used to assess a systems environmental performance. Therefore many data were collected and assessed, but only from an environmental standpoint. However, this time and cost intensive data collection has also significantly contributed to arguments against the use of LCA.
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.
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