バックナンバー
International Journal of ITS Research

Regular Papers

03-01
Fusion of Vision, GPS and 3D Gyro Data in Solving Camera Registration Problem for Direct Visual Navigation
pp. 3-12

Zhencheng Hu
Kumamoto University
Keiichi Uchimura
Kumamoto University

(Received 19 Apr. 2005, in revised forms 23 July 2005, 17 Oct. 2005 and 26 Jan. 2006
accepted 9 Jan. 2006)

This paper presents a precise and robust camera registration solution for the novel vision-based road navigation system - VICNAS, which superimposes virtual 3D navigation indicators and traffic signs upon the real road view in an Augmented Reality (AR) space. Traditional vision based or inertial sensor based solutions of registration problem are mostly designed for well-structured environment, which is however unavailable in a wide-open uncontrolled road environment for navigation purposes. This paper proposed a hybrid system that combines computer vision, GPS and 3D inertial gyroscope technologies to provide precise and robust camera pose estimation. The fusion approach is based on our PMM (parameterized model matching) algorithm, in which the road shape model is derived from the digital map data, and matched with road features extracted from real images. Inertial data estimates the initial possible motion, and also serves as relative tolerance to stable the pose output. The algorithms proposed in this paper are validated with the experimental results of real road tests under different road conditions.

Keywords: Data fusion, camera registration problem, augmented reality, vehicle navigation system

03-13
Quantitative Performance Evaluation of Predictive Collision Warning System based on Inter-Vehicle Communication
pp. 13-20

Yuusuke Takatori
Saitama University
Takaaki Hasegawa
Saitama University

(Received 19 Apr. 2005, in revised forms 25 July 2005, 17 Oct. 2005 and accepted 15 Nov. 2005)

In this paper, the safety performance of a predictive collision warning system based on inter-vehicle communication is evaluated quantitatively by using a microscopic traffic simulator. Vehicles equipped with collision warning systems based on inter-vehicle communication exchange front-seat information with surrounding vehicles, and the systems warn the drivers if they detect any danger of collision. This paper focuses on the predictive collision warning system that can be used on multilane highways. First, the properties of the system prediction time are evaluated. Next, the properties of the diffusion ratio of the system are evaluated from the viewpoints of both the road administrators and drivers. The results show that the safety performance of the system from the viewpoint of the former increases drastically when the diffusion ratio exceeds 60%. In addition, the safety performances of vehicles equipped with the system and unequipped vehicles are evaluated quantitatively by microscopic traffic simulation from the viewpoint of the driver. A mixed scenario of equipped and unequipped vehicles is simulated. The simulation result reveals that in the case of unequipped vehicles, the average traveling distance in which no accident occurs does not depend on the diffusion ratio; in contrast, in the case of equipped vehicles, this distance is approximately 1.5-4.0 times greater.

Keywords: inter-vehicle communication, collision warning, microscopic traffic simulation

04-01
An Analysis of the Cost Efficiency of Probe Vehicle Data at Different Transmission Frequencies
pp. 21-28


Kai Liu
Nagoya University
Toshiyuki Yamamoto
Nagoya University
Takayuki Morikawa
Nagoya University

(Received 13 Dec. 2005, in revised form 15 Mar. 2006 and accepted 19 Apr. 2006)

Probe vehicles are promising tools for collecting travel time data because of their ability to provide large amounts of real-time information. However, there are many obstacles to the practical deployment of probe vehicles, one of which is the enormous expense of data transmission. This study attempts to assess the effects of differing transmission intervals (and therefore costs) on the quality of travel time data collected. Two accuracy/error values are examined: map-matching accuracy and the mean absolute percent error (MAPE) of link travel information. In order to determine the most cost-effective probe transmission frequency, the accuracy elasticity of cost is compared for six different ratios of data transmission charge to total communication cost.

Keywords: Cost efficiency, Probe vehicle data, Transmission frequencies

04-04
Analysis on Effects of Social Experiment of Smart IC at Kamigo Service Area
pp. 29-38

Motohiro Fujita
Nagoya Institute of Technology
Koji Suzuki
Nagoya Institute of Technology
Makoto Hasegawa
Nagoya Institute of Technology
Takaya Ichikawa
Pacific Consultants Co., LTD
Yohei Kawamura
Nagoya Institute of Technology

(Received 22 May. 2006, in revised form 8 Sept. 2006 and accepted 27 Oct. 2006)

In Japan, the social experiment of Smart IC has been introduced in order to utilize existing expressway effectively, to ease traffic congestion around urban area and to activate local community since 2004. In this paper, we focus on the social experiment of Smart IC at Kamigo service area and analyze the factors affecting choice behavior of Smart IC, inhabitants’ consciousness for the continued operation of Smart IC and users’ satisfaction for the Smart IC by a questionnaire survey. As a result, both serviceability and issues by introducing Smart IC were clearly shown from the viewpoint of users and residents.

Keywords: Smart IC, social experiment, Kamigo Service Area

04-08
Analysis of Road Potential and Bottlenecks Based on Operating Speed
pp. 39-46

Hiroshi Warita
The University of Tokyo
Hiroaki Okamura
Sai Traffic Planning Co., Ltd.
Hirohisa Morita
Nihon University
Masao Kuwahara
The University of Tokyo
Edward Chung
The University of Tokyo

(Received 9 June 2006, in revised forms 13 Sept. 2006, 23 Oct. 2006 and accepted 27 Oct. 2006)

Vehicle detectors have been installed at approximately every 300 meters on each lane on Tokyo metropolitan expressway. Various traffic data such as traffic volume, average speed and time occupancy are collected by vehicle detectors. We can understand traffic characteristics of every point by comparing traffic data collected at consecutive points. In this study, we focused on average speed, analyzed road potential by operating speed during free-flow conditions, and identified latent bottlenecks. Furthermore, we analyzed effects for road potential by the rainfall level and day of the week. It’s expected that this method of analysis will be utilized for installation of ITS such as drive assist, estimation of parameters for traffic simulation and feedback to road design as congestion measures.

Keywords: Road potential, Operating speed, Percentile speed, Latent bottleneck

04-12
Study on Improving Angular Acceleration Feel of the Driving Simulator and its Effects on Drivers’ Behaviors
pp. 47-52

Masaaki Onuki
The University of Tokyo
Yoshihiro Suda
The University of Tokyo
Yoshiyuki Takahashi
Toyo University
Hisanao Komine
The University of Tokyo
Kosuke Matsushita
The University of Tokyo

(Received 26 June 2006, in revised form 25 Sept. 2006 and accepted 25 Oct. 2006)

In recent years, studies on the motion and human interface of the vehicle have been performed. Due to the rapid advancement of computer technologies, it becomes possible in driving simulators to display detailed scenes and provide realistic motion feels of the vehicle driving. Driving simulators are widely utilized in the research and development of vehicles that account for the driver behavior in a virtual traffic environment. However, some drivers feel sick during and after the driving. It could be caused by deep immersion of visual and motion feels. The driver feels the difference between the real driving and the virtual one. This paper presents about the development of the turning table in the driving simulator. It can provide yawing motion which is approximately same as actual one. It is shown in this paper that the use of the turning table leads to more realistic drivers’ feel for the steering actions. Furthermore, the effect of the angular accelerations on the drivers’ behaviors is demonstrated using the turning table installed in the driving simulator.

Keywords: Driving Simulator, Turning Table, Simulator Sickness, Driver Behavior

Technical Note

04-07
Development and Evaluation of In-vehicle Signing System Utilizing RFID tags as Digital Traffic Signs
pp. 53-58

Yoshimichi Sato
Tome Public Works and Construction Office, Miyagi Prefectural Government
Koji Makanae
Dept. of Spatial Design and Information Systems, Miyagi University


(Received 29 May 2006, in revised form 9 Nov. 2006 and accepted 10 Nov. 2006)

Vehicle drivers are requested to collect dynamic visual information on such matters as other vehicles and traffic signals, and static visual information including traffic signs, and to maneuver the vehicle accordingly. However, traffic signs and other static visual information are more likely to be overlooked than dynamic visual information during maneuver. In this study, an in-vehicle signing system was built and assessed that uses general-purpose RFID tags as digital traffic signs, and a field test was conducted using tags installed on a road to verify whether the system worked effectively or not. A laboratory test was also carried out using a video of vehicle travel to have subjects experience maneuver. Then, it was found that providing visual an vocal information in the vehicle was effective.

Keywords: in-vehicle signing system, RFID, traffic Sign