Ichiro Kageyama

ON A NEW DRIVER MODEL WITH FUZZY CONTROL

SUMMARY This paper constitutes the first step in developing a new driver model. This model includes mental influence as a risk from the environment which a driver uses to decide his course and also to decide the inputs to the vehicle, not only steering but also fore and aft force. A fuzzy control method is used to decide the risk level, and to control the vehicle as an expert system. The calculation results show that this driver model is able to control a mathematical vehicle model such as an ordinary driver-vehicle system, and is useful for the investigation of vehicle handling and stability.

Study on a road surface sensing system for snow and ice road

This paper deals with the fundamental research related to a new sensing system for road surface as the first step to construct an identification tool for the friction coefficient of the road ahead. In this paper, the albedo value is used for the measurement. Because the previous albedo meter measured the road surface by using sunlight, it was not used at night. Therefore, we propose a vehicle-mounted road surface sensing system by using a pair of solar cells with an additional light. From the experimental results, it is shown that the sensing system can measure the difference of road conditions, not only during daytime but also at night. For high reliability of detection, an image processing system of the road surface is proposed. It is shown that the sensor fusion can recognize the difference of the road surface.

STABILIZATION OF PASSENGER CAR-CARAVAN COMBINATION USING FOUR WHEEL STEERING CONTROL

SUMMARY This study aims to stabilize the trailer at high speed. The behavior of passenger cars with four wheel steering system, vehicles with rear wheel steering and of trailer and passenger car are similar. This is regarded as an optimal regulator problem with linear equation of motion, and a state variables feedback control system is adopted. The problem of stability at high speed on a straight course can be solved. Therefore, the passenger car-trailer system can be stabilized. Furthermore, this study indicates the way forward to stabilize a passenger car-trailer system.

A study on the braking stability of articulated heavy vehicles

Abstract This paper describes the stability of a tractor–semitrailer combination while braking. We first constructed nonlinear equations of motion for articulated vehicles with 8 degrees of freedom. Secondly, a simulation study was carried out to model vehicle performance in realistic situations. Jackknifing was recreated by simulation under conditions of traveling down a longitudinal road gradient. A study of the load rate of each tire showed that our model accurately describes the mechanism of jackknifing as well as the motion of limit performance conditions. Finally, the relationship between articulated vehicle, road gradient and limit performance is shown.

STUDY ON CONSTRUCTION OF A RIDER ROBOT FOR TWO-WHEELED VEHICLE

Abstract In this study, we constructed a fully autonomous two-wheeled vehicle (the Rider Robot) which was used for evaluation of dynamics. As the first step of the study, we constructed the control algorithms and the control system. The control algorithms consist of the standing stability control which keeps the perpendicular motion, and the directional control which follows the target course. These algorithms were determined based on human riders behavior. The system was constructed using some actuators and sensors. The results show that Rider Robot could follow the target course while keeping the standing stability. Consequently, there is considerable validly in these constructed algorithms and the system.

A RESEARCH ON ANALYTICAL METHOD OF DRIVER-VEHICLE-ENVIRONMENT SYSTEM FOR CONSTRUCTION OF INTELLIGENT DRIVER SUPPORT SYSTEM

In this study, a driver model with the multiple regression and the neural network is constructed to analyze the relationship between the drivers control action and the information that includes data of vehicle behavior and environment. Using these models, effectiveness of the information to control the action of a driver is examined. To evaluate the intelligent driver support systems, Mental Work Load (MWL) model is constructed with the multiple regression and the neural network. MWL is expressed as Heart Rate Variability (HRV). Measured HRV data and calculated HRV data with MWL model show good agreement. Effectiveness of information is examined using the MWL model. From these results, it is shown that the analytical method with the drivers MWL can be used to assess and improve the intelligent driver support systems as the next stage of this research.

Steering control for advanced guideway bus system with all-wheel steering system

This article proposes a steering control strategy for articulated buses equipped with an all-wheel steering system to eliminate off-tracking. In this system, the center of each axle passes through the same locus, which is similar to the operation of trains. This control system was validated by means of a numerical simulation, using a vehicle dynamics model and some experiments with a scaled vehicle model. The proposed control system was confirmed to be effective in eliminating off-tracking for articulated buses.

A study on tire modeling for camber thrust and camber torque

Abstract This study deals with a tire model for camber thrust and camber torque on an irregular road surface such as road with ruts. At first, tire characteristics with camber angle are measured, for example dimensions of contact area, width, radius of tire and so on. In this research, it is shown to be necessary to those for tire model. The design parameters of brush model are decided. In this tire model, it is considered that the dimensions of contact area is related to the tire camber angle and load, and also the contact pressure is changed according to the contact length, and also the rigidity is changed according to the contact pressure. Finally, it is shown that the calculation result of the tire model has a good expression for the characteristics of camber thrust and camber torque.

A modeling of heart rate variability to estimate mental work load

Recently, many kinds of machines have been introduced in various fields in our society. We are touching machine systems everyday at various times. Therefore, we need to establish a method of evaluation of comfortable and safe operating conditions in human-machine systems. The authors consider the modeling of heart rate variability to estimate mental work load during driving.

Effects of multiple axles on the lateral dynamics of multi-articulated vehicles

This paper describes an analytical study of the lateral dynamics of multi-articulated vehicles with multiple axles. A linear planar model of vehicle dynamics is adopted for multiple-axle vehicle combinations with an optional number of trailers. Two tractor and double-trailer combinations are examined for their directional stability and response. Non-oscillatory stability and steering sensitivity in steady-state turning and lane changing are analysed using a stability factor of multiple-axle vehicle combinations. Off-tracking in the steady-state turning of multiple-axle vehicle combinations is also analysed. Numerical calculations for oscillatory stability, steering sensitivity, and off-tracking are presented for multiple-axle vehicle combinations.