«fiOki 
5B-3-1 
Mobile Mapping Technologies for Safety Driving Assistance in ITS 
Yutaka Shimogaki, Tooru Kitagawa, Yoshiki Yamano, Katunori Takahashi 
AAS Research Institute, Asia Air Survey Co., Ltd. 
8-10, Tamura-cho, Atsugi-shi, Kanagawa-ken, 243-0016, JAPAN 
E-mail: ys.shimogaki@ari.ajiko.co.jp 
KEYWORDS: Mobile Mapping System, INS/DGPS integration, ITS, Safety Driving Assistance 
ABSTRACT 
This paper presents mobile mapping technologies to support effectively Safety Driving Assistance in 
the Intelligent Transport Systems (ITS), that acquires the road-related spatial data in advance and 
combines them with the equipment mounted on the car while running. The mobile mapping system 
(MMS) developed by Asia Air Survey co., ltd. consists of a measurement vehicle and a data processing 
unit. The measurement vehicle equipped with.a strapdown Inertial Navigation System (INS), a 
differential GPS receiver, an odometer (wheel sensor), two pairs of cameras and an industrial PC 
collects position, attitude data and a sequence of terrestrial digital images while driving at regular 
speeds. The data processing unit extracts the road infrastructure data from the collected data 
through image processing and close-range photogrammetry. A series of field tests have been 
conducted to verify the feasibility of the MMS under different conditions. The accuracy of the 
Hybrid Inertial Surveying System (HISS) which is the core unit of the measurement vehicle was less 
than several meters in 3D position and less than 0.02 degrees in 3D attitude in urban areas where 
GPS signals are blocked by tall buildings intermittently. It was verified that the system could 
measure road alignment information such as the gradient and the radius of curvature even in the 
tunnel because the INS is tightly integrated with the GPS or the odometer. In this paper, after 
introducing briefly the trend on ITS in Japan, an overview of the MMS and the Kalman filter model 
in the HISS is described. Field tests and the results are also discussed. Finally, the role of MMS in 
ITS is emphasized. 
1. INTRODUCTION 
In the coming new generation, the Japanese 
government issued the Comprehensive Plan for 
the Promotion of Intelligent Transport System 
(ITS) aimed at solving safety, efficiency, and 
comfort in connection with road transportation 
by using advanced information technology. 
Among ITS projects, AHS (Automated Highway 
System) is technically the most difficult 
program. This project is supported by the 
communications between the road and the 
vehicle. Namely by providing road-related 
information from the road infrastructure to the 
telecommunication equipment mounted on the 
car, it gives a warning of danger to a driver and 
performs automated driving finally. One of 
them is the road alignment information. 
The road alignment information is available 
from the design plan at that time if the road 
has not been improved. As a practical matter, 
the condition of road changes by the repeated 
maintenance work. Accordingly, to get the 
information from the map is required. But, in 
case of a topographical map with a scale of 
1:25000, which is renewed most frequently, the 
period to change is 5 years in urban area. 
Therefore on the newly constructed or 
improved road, it is impossible to get up-to-date 
information from the map. 
In order to solve this problem, we present the 
mobile mapping system (MMS) to acquire the 
road alignment information efficiently by 
traveling the vehicle with the various sensors. 
The Inertial Navigation System (INS), which is 
usually used in the aerospace industry, outputs 
3D attitudes of the body with respect to local 
level coordinate system. When it is equipped 
with the land vehicle, it provides the road 
gradient from roll angle, the radius of 
curvature from heading angle. And also, on 
account of high rate, the continuous road 
profile can be acquired at intervals of several 
ten centimeters. Nevertheless, the INS has the