The present R&D work has been carried out as an industrial- academic-governmental joint project headed by Dr. Sadayuki Tsugawa, a professor of Meijo University, and Leader of ITS Research Group, Intelligent Systems Research Institute (ISI), National Institute of Industrial Science and Technology (AIST), an independent administrative institution, under METI Program “Regional Renaissance Consortium” in collaboration with the Chubu Science and Technology Center (CSTC) and the Consortium “Human Centered ITS View Aid System”. Member organizations of the Consortium are listed below. The human-centered ITS view system described here is the result of three-year R&D efforts from FY2001.
The project aims at the development of a driver assistance system, kind enough but not annoying, and at the same time, really helpful to aged drivers, ensuring improved acceptance by drivers. The system consists of three subsystems for sensing, inter-vehicle communications and information display, and requires none of special infrastructures installed on the road. The sensing and display systems are mounted on a vehicle, and the system function is augmented by the inter-vehicle communications.
Member organizations of the consortium: Aisin AW Co., Ltd.; Koito Mfg. Co.,Ltd.; Kojima Press Co., Ltd.; Tokai Rika Co., Ltd.; TrafficSim Co., Ltd.; Nagoya Electric Works Co., Ltd.; Wako Giken Co., Ltd.; Meijo University; Aichi Industrial Technology Institute; and ISI-AIST.
It is one of important objectives of the Intelligent Transport System (ITS) to provide safer, more efficient and more reliable means of transportation to anybody at any time. It is necessary, therefore, to design the system so as to be adaptable to any type of drivers to improve the driver acceptance, just like other ITS-related systems.
The driver assistance must be in a moderate mode when a driver is alert and in a high conscious level, but must be in a alarming mode when a driver is drowsy and in a low conscious level.
The driver adaptive assistance system is important in an aged society. Driver’s capabilities of sensing, decision making and operation are widely variable depending upon personal characters. Generally speaking, an elderly driver’s performance for sensing, decision making and operation tends to have longer delay and poorer accuracy in comparison to that of younger person.
The tendency must be reflected in the design of a driver assistance system, particularly in Japan where the proportion of aged population is growing rapidly. The ratio of people 65 years old and over in the total population was 14.5% in 1995, and is expected to be 25.2% in 2015. The number of aged drivers will rise quickly in the near future, doubling the present value to about 14 millions in 2010.
The percentage of aged drivers (65 years or older) in licensed drivers is 9.29%, that in fatal and heavy injury cases of primary responsibility is over 10% and that in dead cases is 15.5%. The data suggest, the importance and necessity of a driver assistance system adapted to any category of drivers’ age group. The human-centered ITS view aid system reported here is focusing on such a system.
System Overview
The “Human-Centered ITS View Aid System’ is a three-year project (FY2001 to 2003) entrusted to the “Regional Renaissance Consortium” under the auspices of the Ministry of Economy, Trade and Industry (METI). The Consortium is composed of automotive parts makers, a university, a public research institute and AIST. Its designation, “Human- Centered” is derived from the driver-adaptive nature of assistance, and “View Aid” from the expanded horizon of sensing functions through inter-vehicle communications.
The Human-Centered ITS View Aid System is based on concepts of usability and universal design, claiming that the assistance should cover any category of drivers’ characters: level of consciousness, alertness, skill, age and so on.
The Human-Centered ITS View Aid System consists of three subsystems: sensing, inter-vehicle communications and information display. The system is characterized by a stand-alone operation without infrastructure intelligence. It works with vehicle-mounted sensing and display systems, being augmented by inter-vehicle communications.
1. Sensing System
Sensing of the Human-Centered ITS View Aid System includes road surface monitoring, inter-vehicle distance measurement and driver monitoring. The driver monitoring involves two functions of drowsiness monitoring and pulsation monitoring.
1.1 Road Surface Monitoring
The polarized reflected light provides information whether the road is wet or not. Light reflected from the road surface is divided into vertical and horizontal components with a polarizing filter, and the wetness is recognized on the basis of intensity ratio of the two components. When the road surface is wet, the horizontal component of polarized light is minimized to zero for the incident angle equal to 53.1° (Brewster’s angle), while the vertical component increases with the incident angle. The wet condition of road surface including snow and ice coverings is detected with the energy intensity ratio between vertical and horizontal components. This sensing system involves a difficulty: the incident angle for a CCD camera mounted on the inside of windshield is close to 90°, where the energy intensity of vertical component is nearly equal to that of horizontal one, making it extremely difficult to detect the wetness.
1.2 Driver Monitoring
The driver monitoring consists of blink detection with a vision system, and pulsation detection with a micro-displacement monitoring based on magnetic sensor.
(1) Blink Detection
Out of driver’s face, imaged by a CCD camera, an area around the eye is extracted through the image processing. In order to ensure robust detection, the driver’s face is illuminated intermittently with an infrared LED in synchronization with the CCD camera. The camera is mounted behind a rearview mirror, which reflects visible light but is transparent for infrared light. This arrangement makes it possible that the driver is not aware of being monitored.
(2) Pulsation Detection
A magnetic sensor is used for detecting pulsation, to recognize micro-displacement of an iron piece caused by the pulse-beat.
2. Inter-vehicle Communication System
The inter-vehicle communication system in the Human-Centered ITS View Aid System is based on the 5.8GHz DSRC which was used in the cooperative driving in Demo2000. The communications are used not for vehicle control but for transmission of incident info and road surface data from the preceding car to the following one. While a 30cm high antenna was used in the Demo2000 cooperative driving held in 2000, a smaller antenna has been newly developed for the inter-vehicle communications in the present trial.
3. Display System
The Human-Centered ITS View Aid System is characterized by the adaptive control of display and alert timing depending upon the traffic scene in front of the vehicle and the driver’s conditions. When the driver is alerted enough, and the traffic status is less urgent, the level of interference is moderated. On the other hand, when the driver is drowsy or in case of pressing urgency in traffic, alarm is given more quickly and intensively using both visual and auditory means.