Im) 
  
  
Z 
670.112 
632.276 
670.499 
642.721 
675.543 
374.536 
635.654 
  
Collinearity 
Solution 
-905.689| 
-43.345 
2050.393 
6.76591 
-48.082952 
7.037074 
Collinearity 
Solution 
508.68 
-27.811 
2518.132 
5.927163 
-3.342869 
-3.09521 
  
  
Collinearity | 
Solution 
1852.0851 
-33.8971 
2238.2361 
8.161595 
34. 
-0.912 
  
  
MEASUREMENT OF RAILWAY SURFACE FLAWS WITH THE CCD LINE SENSOR CAMERA SYSTEM 
Yoshitaka Matsumoto, Osamu Murakami 
CORE Corp. 
3-4-15-903 Mita, Minato-ku, Tokyo, 108, Japan 
TEL: +81-3-3456-1911 FAX: +81-3-3453-4167 
Masaya Nakagawa 
Technical Center, East Japan Railway Company 
2-1-19 Hiro-machi, Shinagawa-ku, Tokyo, 104, Japan 
TEL: +81-3-5709-3665 
FAX: +81-3-5709-3666 
Commission V, IWG V/III 
KEY WORDS: Measurement, CCD, Digital, Recording, Line Camera, Railway 
ABSTRACT 
For railway companies, the maintenance of railway tracks is one of the most important subjects to keep the safe transportation. 
Especially, the railway tracks of the Shinkansen ( the high speed railway system of Japan ) requires to pay much more attentions to 
the maintenance for it's high speed traffics. — The rail surface's flaws, which are caused by wheels of the train when it runs at high 
speed, make noises to the surroundings and also make unpleasant vibrations to the passengers. Recently, the progresses of the 
technology based on the image sensing and measuring are very successful. 
This paper reports an application for railway 
maintenance by the image measuring technology with the image of the CCD Line Sensor Camera . 
Main contents of this paper are, 
(1) The introduction of the system's architecture 
The measuring system is consisted on a CCD Line Sensor Camera, a high speed digital data recorder, and an UNIX work 
station (SUN : SS-2). The Camera and the Data recorder takes the image data which resolution is 0.5 millimeters per line 
at the speed of twenty kilometers per hour. 
data is recorded successively on the digital data tape. 
(2) The way to measure the rail surface's flaw 
And, the recorder takes the Image data of four cameras at same time. All 
Almost part of the rail surface is polished to flat by the wheels of train like as a mirror. When contriving to illuminate 
the rail surface, it is possible to get image the flaw part as very different image from the flat part, and possible to classify the 
condition of the rail surface from the numerical number which is processed by the UNIX work station. 
BACK GROUND 
At present, most of maintenance for railway tracks are done by 
human's patrolling on foot, and it's difficult to detect wrong 
parts immediately. — As the total length of the railway is too 
long, for example, the total length of TOHOKU Shinkansen 
railway (East Japan Railway Company) is approximately one 
thousand kilometers, depending on the human patrolling to 
check the condition of railways consumes too much time and 
human powers. And , it's necessary to keep many patrol 
men who should have special knowledge for the railway 
maintenances. 
On the other hand, for the reason of the Shinkansen trains’ 
speeds are very high ( more than two hundred kilometers per 
hour ), it is impossible to maintain the railway in the daytime. 
And it becomes hard work to maintain them should be done 
only at midnight. Under this circumstance, it is required to 
research the detection method of the roughness and flaws on 
railway surface from photos or motion images. 
SYSTEM OUTLINE 
The inspecting system, now under developing, is consisted on a 
CCD Line Sensor Camera (Line Camera) for capturing the 
successive images, a Digital Data Recorder (DDR) that can 
record a large image data, and an engineering work station 
(EWS) which is processing that image data. (Figure 1. ) 
  
FIELD EQUIPMENTS Motor Car 
Digital Data Recorder 
   
  
      
Camera and Light Frame 
fi A 
  
  
  
Railway 
Light Line 
Sensor Line Camera Driver AC Power Supply 
Camera 
LABORATORY 
Digital Data Recorder 
Wrok Station 
  
  
   
INTERFACE 
t—— A SZ 
  
  
  
  
  
  
  
Data Tape 
(Recorded in the field) 
(SUN Sparc2) 
Data is transfered from DDR to Workstation 
in 8 Bit parallel with custom interface . 
  
  
  
Figure 1. The Line Camera System Constitution 
At the filed, these units ( the Line Camera and the Digital Data 
Recorder ) are loaded on the trolley and pulled by the engine 
which is called the Motor Car, and the image data is recorded 
in real time to the data tape in DDR ( Digital Data Recorder ). 
Those data are sent to the engineering work station ( SUN : 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996