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Technical Paper

Turning characteristics of two-axle, four-wheel vehicle running on sandy soft terrain

2000-06-12
2000-05-0395
The objective of the research is to investigate the turning characteristics of a two-axle, four-wheel vehicle at steady-state circular turning on sandy soft terrain. The axle load, lateral force, thrust and effective tractive effort acting on the wheeled vehicle turning on soft and hard terrain were compared. It was observed that the directions of lateral force acting to the front wheel of vehicle running on soft and hard terrain are opposite. Moreover, the lateral force acting to front wheel of the case of vehicle running on soft terrain is larger than that for the case of hard terrain. However, it is found that there is only a little difference between lateral forces acting to rear wheel of vehicle running on soft and hard terrain. It was observed that the axle load of rear wheel was larger than that of front wheel running on soft terrain and the axial force-steering angle relationships of the soft and hard terrain were almost similar.
Technical Paper

Vertical vehicle dynamics on soft ground~Investigations with FEM

2000-06-12
2000-05-0393
The Finite Element Method (FEM) has proved to be a suitable tool for the investigation of wheel-soil interaction. Compared to analytical models, the FEM presents numerous advantages. The sinkage and the deflection of the wheel, the pressure distribution in ground, the motion of the soil and especially the contact shape between the elastic wheel and the deformed soil are gained as simulation results. Moreover, the soil compaction in the depth can be visualized. Using the FEM, effects have been investigated so far with the interaction between a single wheel and soft soil. Because of the change of the ground contour due to the dynamical wheel-loads, depending on the vehicle oscillation, the influence from the pitching and vertical oscillating vehicle has to be considered. Therefore the well-known FEM-based simulation concept VENUS is extended to VENUS-DYN (DYNamic VEhicle NatUre Simulation), that includes a two-dimensional model of a complete vehicle interacting with soft ground.
Technical Paper

Mobility and fuel economy of hybrid-driven vehicles in terrain~Results from computer simulation

2000-06-12
2000-05-0394
An important requirement for the application of hybrid drives in future terrain vehicles is their competitiveness with regard to the driving properties and the fuel economy. Therefore, a two-axle, all-wheel-driven military transport vehicle equipped with a serial hybrid propulsion system has been regarded and examined by computer simulation. The tool, used for this purpose, is the simulation program ORSIS, (Off Road Systems Interactive Simulation), which has been developed at the University of the Federal Armed Forces in Hamburg. By generating a realistic surrounding area with reproducible conditions ORSIS allows an objective comparison of different vehicle types and the investigation of the influence of modified vehicle parameters. The paper presents results from computer simulations which include acceleration and braking procedures, determination of maximum drawbar pull, and the estimation of fuel consumption under realistic conditions by driving on determined routes.
Technical Paper

Speed adaptation system for vehicles using RF communication

2000-06-12
2000-05-0380
This paper introduces a speed adaptation system using roadside-to-vehicle RF communication. The RF transmitter transmits transmitter''s ID, speed limit, message to the drivers. The messages include occurrence of accident, freezing road, existence of gas station, or construction on the road, etc. At present, drivers identify the speed limit from speed sign board. But drivers cannot concentrate his attention continuously on finding speed sign board, so over speed takes place unintentionally. And one of current information medium to the drivers is variable message sign board (VMS) showing the present road status such as severe congestion, occurrence of accident, or heavy rain. But due to high installation cost of VMS, insufficient number of VMS units are installed on the road. So timely notification of traffic accident to the following drivers is impossible now. Our system is low cost to be installed at close intervals on the highway.
Technical Paper

Development of mayday system

2000-06-12
2000-05-0381
In the event of an emergency situation or a roadside trouble, drivers need rapid help. But, in many cases, it takes too much time to get help, and it even results in a more fatal situation. Rapid response to run-off-the-road and other accidents can help reduce the number of resulting deaths. In many countries, mayday service was developed and commercialized to provide a call and dispatching service in an emergency situation. Daewoo Motor is developing a DreamNet™ system which uses technologies for real-time emergency call and dispatching. The DreamNet™ system is composed mainly of in-vehicle unit, communications system and DreamNet™ service center. The system can be operated by user''s request and also be activated by an external event such as accident, emergency and theft of the vehicle. It transmits the location and type of distress information of the vehicle to the DreamNet™ service center.
Technical Paper

A Modeling of the Heart Rate Variability to Estimate Mental Work Load of Driver

2000-06-12
2000-05-0375
When we evaluate the human-machine-environment systems, it is very important to consider not only the performance of the machine system but also the Mental Work Load (MWL) for the operator. Because human being have a high adaptability to their surroundings. Therefore, we constructed the dynamic model of the human-machine-environment system using the Heart Rate Variability.
Technical Paper

Structuring Neural Network Driver Model and Analyzing Its Characteristics

2000-06-12
2000-05-0376
Using the results of lane-change tests performed on a driving simulator, driver models were developed by means of a neural-network system. Several kinds of driver visual information were used as input data for structure of the neural network, and the steering angle was employed as learning information. A series of simulations employing the trained neural network was conducted to determine the allowable ranges of initial vehicle position, velocity, stability factor, and other variables for successful lane-change maneuvers and for stable running against side winds.
Technical Paper

Driver → vehicle behavior → intelligent vehicle

2000-06-12
2000-05-0377
In this article, the authors try to get their own contribution for solving any actual problems in vehicle stability and handling framework. It used submodeling techniques for entire dynamic mechanical system. Fuzzy modeling is used for one realistic description of dynamic mechanical system represented by vehicle. It applied one solving algorithm of fuzzy relational equations, having genetics algorithm support technique. Finally, it construct one neural network will be fast learning from relations equations solutions. The online work is required approximate equal with driver behavior.
Technical Paper

Development of a Semi-Active Suspension for a 6×6 Combat Support Vehicle.

2000-06-12
2000-05-0390
In this paper, the development of a full vehicle semi-active suspension controller for a 6×6 CSV (combat support vehicle) is described. The controller uses linear optimal control theory to generate the control gains with the overall aim of reducing ride acceleration and hence maximising cross country speed. A vehicle model is developed to predict ride comfort improvements and, in particular, determine the effect that a roll acceleration weighting factor has on the overall vehicle performance. Subsequently, limited state feedback strategies are evaluated to determine the most effective method of implementation on a real vehicle.
Technical Paper

Expressway speed limits: Germany is right, ECMT is tragically wrong

2000-06-12
2000-05-0362
Three years of research, and two papers, showing a strong correspondence between traffic fatality rates and the business cycle, have proven that, alcohol aside, the fundamental cause of traffic accidents is the mentally distracted driver. This paper is in four parts. A quick review of the discovery/development of the Driver''s Economic Distraction Indicator (DEDI - SAE 970280 on European expressways in the ''70s) and its application to all traffic fatalities in countries around the world (in F98S565). The DEDI is then updated to the ''90s while exploring: a) the use of M2 (as recommended by the American economist, Dr. Milton Friedman) instead of M1; b) OECD''S new Composite Leading Indicators; and c) the use of a locally available leading economic indicator (i.e., new vehicle sales) to give an early warning of a rise in local traffic accidents.
Technical Paper

A forward collision warning an avoidance algorithm

2000-06-12
2000-05-0366
The number of automobiles is rapidly increasing, as are the importance of the car as a way of transportation, and the variety of its uses. In these environments, a safety, one of the primary factors, which must be considered in automotive engineering, demands a system that aids the driver''s perception, in addition to the existing passive method, which relies on just man''s ability. In this point of view, development of the promoted system that complements the passive safety devices is demanded. A system like this should make driving safe and satisfy the need for comfort, while decreasing the driver''s burden and fatigue. The object of this paper is the development of an algorithm that warns the collision ahead and avoids this situation, using some information about the host-car, target-car, surroundings, road conditions, etc. The warning system is developed using a decision algorithm of the degree of safety. To show the validity system based on our safety algorithm.
Technical Paper

The development of in-vehicle unit of advanced vehicle information and communication system

2000-06-12
2000-05-0370
This paper presents an in-vehicle information system, AVICS in development. With AVICS, the driver could get the various information on traffic, news, weather, restaurants, and so on, which the AVICS information center provides via mobile telecommunication network. The driver requests the information to operator in center by voice with hands-free system or by handling the menu offered in the form of web-page. The in-vehicle unit for AVICS is designed to interface with wireless network with a built-in RF MODEM, to control NAVI system, and to display the information on the LCD monitor of AV system. The Internet browser is customized to parse specific HTML tags, application software is realized on 32-bit RISC processor. In this paper, we will overview the concept of AVICS and focus on development of in-vehicle unit of AVICS.
Technical Paper

A throttle/brake control law for vehicle intelligent cruise control

2000-06-12
2000-05-0369
A throttle/brake control law for the intelligent cruise control (ICC) system has been proposed in this paper. The ICC system consists of a vehicle detection sensor, a controller and throttle/brake actuators. For the control of a throttle/brake system, we introduced a solenoid-valve-controlled electronic vacuum booster (EVB) and a step-motor-controlled throttle actuator. Nonlinear computer model for the electronic vacuum booster has been developed and the simulations were performed using a complete nonlinear vehicle model. The proposed control law in this paper consists of an algorithm that generates the desired acceleration/deceleration profile in an ICC situation, a throttle/brake switching logic and a throttle and brake control algorithm based on vehicle dynamics. The control performance has been investigated through computer simulations and experiments.
Technical Paper

Stop and go cruise control

2000-06-12
2000-05-0368
This paper will address the basic requirements for realizing a stop and go cruise control system. Issues discussed comprise: functional, sensor and basic HMI requirements, primary characterization of naturalistic stop and go driving, and the basic approach of the transformation of situational knowledge in an elementary controller.
Technical Paper

Map database for ITS and driver assistance

2000-06-12
2000-05-0371
Today''s maturing navigable map database serves as one of the cornerstones needed for the development and growing commercial success of ITS applications worldwide. Beyond convenience and commercial success, tomorrow''s map database will help make the automotive environment progressively safer and more secure.
Technical Paper

Total networked truck driver information and multiplexing vehicle area networks

2000-06-12
2000-05-0372
The truck market is more and more demand driven and complexity has grown substantially. Especially in combination with sophisticated bodies and trailers flexible electronic solutions are required to cope with this complexity. A new approach to meet these demands is to use standardized PLC functionality for vehicle multiplexing and visualization electronics. The VDO KIBES Mk II system is such a solution especially designed for the commercial vehicle market. With software-controlled modules replacing hardwired control centers the vehicles can be easily differentiated at the latest possible time. For the traffic information terminals the first devices are modern radios. Besides classical traffic news the RDS/TMC system delivers continuous digital information for the chosen area. Alternatively telematic service providers can transmit trip-individual traffic and weather information, e.g., through GSM mobile phones.
Technical Paper

Development of cabin air filter with aldehyde capture function

2000-06-12
2000-05-0343
Aldehydes are the cause of sick house syndrome or chemical sensitivity and have harmful influences for human beings. In the cabin of vehicle, aldehydes which are included in the volatilization gas from the interior materials, DE emission gas in intake air, cigarette smoke and so on spoil the comfortableness. Active carbon, which has been used as an adsorbent, shows an excellent removal efficiency for most of the gas components by physical adsorption. But for aldehydes, it has difficulty because aldehydes are hard to be adsorbed physically. We have developed new aldehydes adsorbent undergoing addition reaction with gaseous aldehydes on its surface. Aldehydes capture material (ACM) make use of the chemical reaction using a resorcin as a reagent and an H-type zeolite as a water-containing support, and active hydrogen is used as a catalyst to promote the reaction. In addition, we have applied ACM to cabin air filter (CAF) of vehicle.
Technical Paper

The development of vibration transmissivity calculation of full-foam seat cushions

2000-06-12
2000-05-0351
Full-foam-type seat cushion for vehicle is made of such elements as panel, foam pad, and surface seat and each element individually effects on dynamic vibration comfort performance during riding. The most important requirement is to reduce resonance magnification of seat close to 6 Hz, which is the natural frequency of the human body''s internal organs. Conventionally, the prediction of the resonance frequency characteristics of the seat cushion is seldom done by calculation at design stage before evaluation of prototype test. This paper reports that it becomes possible to predict vibration property of seat cushion at design stage by solving vibration equation, which is obtained by replacing seat cushion structure with vibration system model having spring element and damping element equivalent to designed seat cushion and by making graph of resonance frequency characteristics using calculation program provided in this paper.
Technical Paper

Application of feedforward controller on a four-wheel-steering car: The concept

2000-06-12
2000-05-0352
In this paper will be presented an alternative of feedforward controller (FFC) system to overcome four-wheel-steering weaknesses. The system estimates vehicle output parameters that consists of lateral acceleration (v), roll rate (ϑ) and yaw rate (φ) as well as the correct input parameters of vehicle that consists of longitudinal sped (Uo) and steering wheel (δsw). To estimate vehicle output parameters used will be full car mathematical model. The estimated vehicle output parameters together with given vehicle input parameters are used to estimate understeer coefficient (Ku). Finally, it will be used to compute the correct vehicle input parameters required by the 4WS system.
Technical Paper

The Clonk Phenomenon - a Load Change Reaction to be Balanced in Terms of Comfort and Engine Response

2000-06-12
2000-05-0327
The customers demand of a good vehicle agility consists of a quick reaction of the vehicle with the actuation of the throttle pedal on one hand and a high comfort level of vibration and noise within the vehicle on the other hand, which means the reduction of disturbing side effects. In order to achieve a satisfactory compromise it is necessary to gain a deeper understanding of the complex, high dynamic vibrations system “vehicle / drive train”. For several years the ika has been carrying out such detailed vehicle investigations and test bench measurements in addition to comprehensive CAE analysis for various research projects in partnership with different vehicle manufacturers.
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