In order to train and test the functionality of the CBTC signal system, this paper designs simulation platform’s architecture and function module based on the CBTC principle firstly. Then, it detailedly discusses the main content and key algorithms about train module and trackside module. Finally, it builds CBTC simulation test platform, used for training of rail transit signal related specialized student and detecting the main function of actual CBTC system based on Shanghai Metro Line 9.
With the development of computer technology and communication technology, communication-based train control system (CBTC) has become the mainstream train control technology in the field of domestic and international rail transportation industry [
According to the IEEE 1474.1, CBTC is continuous train automatic control system [
CBTC system is mainly composed of the following subsystems: ATS subsystem, including ATS server and multiple ATS station; trackside subsystem, including zone controller subsystem and interlocking subsystem; vehicle subsystem and the communication between each subsystems [
According to the principle of CBTC, the simulation platform is divided into the following modules: trackside module, train module and ATS module, as shown in
Trackside module simulates the functions of zone controller and interlock, mainly including the route processing and authorization calculation [
Authorized processing model of state machine, as shown in
CBTC has higher train positioning accuracy. Therefore, train module mainly simulates the train movement process, including the accurate position of the train, speed calculation. In calculating the train speed and position, this module adopts following model, considering the influence of grade to the train acceleration.
At the same time, in order to update the train front and rear position, this train module uses the following algorithm. As shown in
Step 1: Train moves forward/backward on the track, and update strain front and rear position respectively. It calculates the train front position, going to Step 2, the rear position, going to Step 3.
Step 2: If the train front position crossed the track boundary, going to Step 4; otherwise, update train front position, going to Step 3.
Step 3: If the train rear position crossed the track boundary, going to Step 5; otherwise, update the train rear position, going to Step 5.
Step 4: Update the train front edge information and the train front offset at edge.
Step 5: Update the train rear edge information and the train rear offset at edge.
Step 6: Train location update success, the end.
It uses tools of QT and C++ to develop a simulation platform based on CBTC as, CBTC system’s ATS client interface as Shanghai Metro Line 9 as example, shown in
This platform includes the following experiments, shown in
Training programs | Properties (verification/synthesis/design/innovation) | Hours |
---|---|---|
Route control experiment | Synthesis | 8 |
Train control experiment | Synthesis | 8 |
Switch control experiment | Synthesis | 8 |
Schedule function test experiment | Synthesis | 8 |
Platform control experiment | Synthesis | 8 |
LMA experiment | Synthesis | 8 |
Fault simulation experiment | Synthesis | 12 |
These experiments are not only suitable for students of rail transit control major, but also suitable for students of rail transit operation and management.
The test platform uses common interface, and it can test the actual signal system’s subsystem function, including the vehicle subsystem and trackside subsystem test, as follows:
1) Detection external signal function from vehicle controller
It simulates the electrical interface between vehicle controller unit and vehicle system, and the external interface of the vehicle controller. The reliability, integrity, and security about signal input and output of the vehicle controller can be detected through this function.
2) Safety function detection of vehicle controller unit
Safety function detection of vehicle controller mainly include: the safety train speed and safety position; the train over speed protection function; the safety interval function of the train; the train slide down protection function etc.
3) Automatic driving function detection
Detection the reliability about automatic train operation. For example, the precision and accuracy of alignment the station alignment while the train operation under various conditions.
The CBTC platform can not only simulate the main functions of CBTC system under normal circumstances, but also simulate emergency process functions. Through the construction of the platform and the related experimental training, it helps students learn the architecture and function of CBTC system and improve the teaching effect. At the same time, with the development of the platform, it also can be applied in the safety assessment and detection of metro signal system.
The authors gratefully acknowledge the support of the following projects:
1) The Training Project of Youth College Teachers of Shanghai Municipal Education Commission (ZZGJD13042).
2) The research of general technology about interface between vehicle and ATC signal (JS-BZ13R006).
JikangXu,LijunChen,WeiminGao,MinjieZhao, (2015) CBTC Simulation Platform Design and Study. Journal of Computer and Communications,03,61-67. doi: 10.4236/jcc.2015.39007