1、附 录 附录 A 外 文 Technology Features Reasearch of Japanese Railway Signal System This paper begins with the developing history and technical classification of railway transportation, introduces the railway control system used in Japan, analyzes its technology features respectively from the aspects of el
2、ectronic, computer and communication technology, and at last proposes the technical developing direction of future train control system. 1、 Introduction In the early days of railways, there was no signaling system. A station attendant showed the signal of go or stop by gestures. But people would mak
3、e some mistakes which caused accidents. Signaling system prevents the accidents efficiently. Early signal system in Japan was Automatic Traffic Stop (ATS) devices. This device could automatically stop the train when it received the stop signal. Even if the driver ignored the alarm of the train-borne
4、 stop device, the device on the track could stop the train automatically. ATS-P (Automatic Train Stop Protection) was developed to raise efficiency. Using the responder to send a receive data signal, ATS-P system transmits information of the distance about the next stop to the train via the track, a
5、nd then the system generates a train speed-checking pattern with these information. ATC (Automatic Train Control) system is developed to resolve problems of ATS-P. In ATC system, safety operation procedure will be activated to guarantee the safe performance of the train when the train operator made
6、mistakes. To meet the needs of the modern massive high-efficient transportation, new traffic control systems are emerging such as ATACS (Advanced Train Administration Communication System), CBTC (Communication Based Train Control), etc. With the integration of railway signal and communication techno
7、logy, track structure of new pattern and additional train-borne functions. This paper proposes the features of the current railway control system in Japan with the development history of the railway signal system as background, and then shows its key technology and developments in future. 2、 Railway
8、 Signal Systems The first railway transportation system began to operate in 1830 between Liverpool and Manchester. Signal system was introduced to improve safety and to cope with the increase of traffic volume. In 1841, the signal technology was used at the two ends of the North Midland tunnel at th
9、e first time. The track circuit for the train detecting was invented in 1872. The following will analyze typical railway signal system developed by Japan National Railways (JNR) and East Japan Railway. For these systems, the level is determined by fixed block or moving block system. Train position l
10、ocating is taken by the track circuit or onboard train locating device. The information is transmitted through the track circuit or radio. (ATS-S)system (Kera, 2000 is automatic train stop device which was introduced into JNR to prevent train collision. In a block section where a train is present, a
11、 track circuit detects the train position information, and the control device turns the signal for the section to Red. This status indicates that no other train can go into this block section. All of the other trains must stop before the section. Signals of other sections, into which a train can go,
12、 are Green or Yellow. Permitted speed is determined according to the distance to the section with the red signal. There is important relationship between the signal status of a section and the train position. The block system used in ATS which is consisted of the track circuit and signal device is b
13、ased on the fixed block section. ATS-P improved to correct a weakness of ATS-S. By using digital information from a transponder, ATS-P transmits information about signal aspects and the distance to the next stop signal from the trackside to the train and uses this information to generate the train s
14、peed checking pattern. Then the computer compares the actual speed and this pattern. If the actual speed exceeds the pattern speed, the braking system will start. Different from ATS-S, ATS-P won t require the driver verify. When the train speed approaches the danger pattern, it will alarm the driver
15、. The system engages the service brake at maximum power automatically when the speed pattern approaches the danger pattern. D (Decentralized)-ATC is an intelligent on-board system. Every train calculates its appropriate permitted speed according to the stop position information from the ATC central
16、logic system. In high traffic density braking on time can be realized by pattern control. The cost of ground devices is reduced by using general information equipment and a decentralized system. The system contains the flexibility of be able to shorten the train headway without changing ground equip
17、ment when rolling stock performance is improved. Operability is improved by indicating the train usage on routes to drivers. Along with information technology develops so rapidly, a new railway traffic control system appears. The system can make trains know its own position information and the dista
18、nce with others. The developing system is called ATACS (advanced train administer and communication system).ATACS is a new rail control system based on information technology and ADS technology. 3、 Technology Features of Japanese Railway Signal System Decentralized Technology Feature At first ATC wa
19、s used for supporting the safety supers-peed system of the Japanese Shinkansen, and then was introduced to traditional rail system to shorten the distance between trains. But it cant work effectively because of the ATC technology limit. In this background D-ATC (data decentralized ATC) based on ADS
20、(autonomous and decentralized system) developed as the level 2 system. In D-ATC system every train is allowed to calculate its own speed. JR East developed a kind of Shinkansen D-ATC, in which data communication was used. The D-ATC is officially called DS-ATC. The system is used on Keihin-Tohoku lin
21、e called D-ATC, while in Shinkansen called DS-ATC. In the ATC system the speed signal is in the drivers cab, which received permitted speed information from the ground equipment continuously. ATC s central logic system transmits ATC signals to track circuit. ATC signals are about speed information,
22、while they are used as train detection signals. The logic device can determine the section on which a train is present by monitoring the level of received ATC signal power because the wheels of the train short the track circuits. To set the rack circuit boundary and speed pattern is to sustain train
23、 s headway, which is necessary for train traffic control. In the ATC system the central logic system undertakes the most train interval control. The on-board system controls the braking system according to the instructions from the central logic system. Distance between trains is an important concept in railway transportation control. In this control method the system recognizes the distance between two consecutive trains firstly. Then the system controls their speed to insure a safe distance. In order to realize this distance control, various new functions are required,
