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Zhou W.,National Institute of Design | Cheng X.,Indian Ministry of Railways | Cheng X.,C3 Group | Zhao H.,National Institute of Design | Wang S.,Tsinghua National Laboratory for Information Sciences and Technology
Zhongguo Tiedao Kexue/China Railway Science | Year: 2010

In order to solve the problem of the static test methods which execute test according to the fixed test sequence set, this paper proposes a dynamic test method for the testing of train control system. This method uses the test results obtained from the last test sequence execution as the feedback for the next test sequence selection to set up a testing close loop. If there was no fault detected after executing one test sequence, the test actuator executes the following test sequence. If faults were detected, the test actuator updates the test model of the system under test and generates new test sequence set according to new test model and test aim with the least cost, and then executes test according to new test sequence set. The simulation results show that the effective test efficiency and test coverage rate have been evidently increased by the dynamic test method, and no fake test results were given during the testing.


Xu N.,China Academy of Railway Sciences | Zhang J.,Indian Ministry of Railways | Zhang J.,C3 Group | Wang C.,China Academy of Railway Sciences | And 3 more authors.
Zhongguo Tiedao Kexue/China Railway Science | Year: 2010

For the online test of the balises which are widely used in China high speed railway, several crucial techniques of the balise onboard test equipment are researched by using RF theory, digital signal processing, spectrum analysis and virtual instruments theory etc. Balise onboard test equipment adopts efficient power amplification circuit and low-noise amplifier (LNA). The design of filter for receiving and transmitting signals is optimized to guarantee the high fidelity and high reliability of the analog signals that enter the analog-to-digital converter. The 5 MHz analog-to-digital converter with high degree of accuracy and digital lowpass filter are used to eliminate the undesired signal to the A1 interface. The high speed DDR2 chip is used to construct FIFO memory management module to implement the cache of post-filter signals. The sample signal is transmitted to the industrial computer by the high-speed optical fiber and Ethernet. The virtual oscillograph, frequency spectrograph, field intensity indicator and error rate tester are developed on the industrial computer. The balise onboard test equipment has been dynamically tested, which provides important technical support for correct online test and synthetical judgement of balise performance qualitatively and quantificationally.


Who: The Smart Mobility Showcase will feature insight from mayors and thought leaders from across the U.S. who will share real-world insight into how smart mobility is reshaping cities. What: The C3 Group returns to Austin for its fourth-annual Smart Mobility Showcase to explore ways technology is transforming transportation. When: Saturday, March 11, 2017, 1:30 - 6 p.m. CST. VIP Preview from 12:30 to 1:30 p.m. CST. Registration: Registration is free at: https://www.eventbrite.com/e/c3-smart-mobility-showcase-tickets-27472523056. Members of the media should contact Stephannie Depa at (415) 358-2485, sdepa@breakawaycom.com for access to the VIP luncheon and to schedule individual interviews and demos. Participating companies will include Ford, Hyundai, Nissan, Bosch, HERE, INRIX, Kelly Blue Book, Pioneer and Samsung, among others. Thought leaders from automotive, technology, policy and research will discuss a variety of topics in interactive panel sessions. The Smart Mobility Showcase will close with a reception featuring the music of Austin recording artist Brittany Shane and food from the world-famous Stubb's BBQ. For more information on the C3 Group please visit www.cthreegroup.com. SPECIAL NOTE TO MEDIA: Members of the press are invited to attend a luncheon and preview of event highlights and demos from 12:30 - 1:30 p.m., including interviews with Doug Newcomb and sponsor companies. Members of the press can register for free. Contact sdepa@breakawaycom.com for registration code and to schedule meetings during the preview.


Zhao H.,Beijing Jiaotong University | Tang K.,Indian Ministry of Railways | Tang K.,C3 Group | Li W.,Beijing Jiaoda Signal Technology Ltd Company | And 4 more authors.
Zhongguo Tiedao Kexue/China Railway Science | Year: 2010

The dynamic characteristics of the Balise Transmission Module (BTM) were analyzed. The basic concepts with relation to the dynamic characteristics of BTM were differentiated and analyzed, such as the static action range, dynamic action range, the minimum permitted action range and the receiving capability of BTM, etc. Mathematical formulas were built so as to illustrate these concepts explicitly. The calculation algorithms for the key parameters of BTM dynamic characteristics as well as the test methodology for the dynamic characteristics of BTM equipment were presented. A speed adaptability assessment process for BTM under high speed condition was thus proposed as follows. Firstly, the external constraints were determined, including railway line environment, locomotive environment and equipment installation. Secondly, the availability requirement for BTM was confirmed. Thirdly, the indexes for the minimum permitted action distance, the minimum permitted action time, the dynamic receiving capability and dynamic processing capability of BTM were calculated. Finally, the speed adaptability of the proposed BTM equipment was evaluated through comparing the actual parameters acquired by testing and the required specification determined by the above steps. Therefore, the quantitative assessment for BTM dynamic characteristics and high-speed adaptability were realized.


Zhang Y.,National Institute of Design | Liu C.,Indian Ministry of Railways | Liu C.,C3 Group | Li Q.,National Institute of Design | And 4 more authors.
Zhongguo Tiedao Kexue/China Railway Science | Year: 2010

The safety related risks of radio block center (RBC) were recognized from the points of view of RBC by the analysis of the structure and function of RBC system. Two categories of safety risks called train over-speeding and train trip were concluded. The fault tree analysis (FTA) method was used to analyze the reason of the two categories of safety risks. Firstly, fault trees of them were constructed respectively. Then the least cut sets of the trees were solved, and all the reasons which could result in the two categories of safety risks were recognized. According to the result of analysis, the first direct reason of train over-speeding is the sending of the wrong movement authority (MA) or any other message in relation to the speed from RBC to automatic train protection system (ATP), and the second direct reason is not sending the MA or any other message in relation to the speed which should be sent to ATP. The first direct reason of train trip is the sending of wrong MA or conditional emergency stop message (CEM) to ATP, and the second direct reason is not sending the shortened MA or CEM or unconditional emergency stop message in time. After the analysis and summary, 11 reasons are concluded and divided into 5 categories, and then countermeasures are proposed for each of them. The application on the pilot line of Wuhan-Guangzhou high-speed railway demonstrates the effectiveness and practicability of the countermeasures.


Huang W.,National Institute of Design | Huang W.,C3 Group | Ji X.,Indian Ministry of Railways | Ji X.,C3 Group | And 4 more authors.
Zhongguo Tiedao Kexue/China Railway Science | Year: 2010

From the aspect of the engineering construction for CTCS-3 train control system, several crucial techniques for the high speed adaptability of CTCS-3 train control onboard equipment were researched, which included the speed/distance measurement strategy based on the data fusion of the multi-channel speed sensors, train brake model and CTCS-3/CTCS-2 dynamic transition mechanism, etc.. According to the characteristics of various speed sensors, wheel speed sensors combined with Doppler radars were used to achieve the safety of train speed measurement. The federated Kalman filter was adopted to propose the speed/distance measurement algorithm policy based on multi-sensor data fusion. Considering the control characteristics of the train moving object, and on the basis of UIC 544-1 standard, an improved segment deceleration calculation based braking model was then presented to balance the train operation safety and efficiency. For the compatibility and reliability of the train operation modes, a CTCS-2/CTCS-3 compatible dual redundant design was applied in CTCS-3 train control onboard equipment, which made it possess CTCS-3 and CTCS-2 control train functions at the same time. By sharing the input information and exchanging the information during level transition, the CTCS-2/CTCS-3 dynamic conversion mechanism was realized to obtain the smooth dynamic switchover. The implementation in Wuhan-Guangzhou high speed railway has proved that the research findings can meet the safety requirement for high speed train operation, and improve the train operation efficiency as well as the ride comfort during level transition.


Li K.,Beijing Jiaotong University | Li K.,C3 Group | Xu T.,Beijing Jiaotong University | Tang T.,Beijing Jiaotong University
Zhongguo Tiedao Kexue/China Railway Science | Year: 2010

The coordination between the on-board equipment of Chinese Train Control System Level 3 (CTCS-3) and the Radio Block Center (RBC) is realized by the collision avoidance protocol (CAP). According to the safety requirement for train collision avoidance, the model of CAP is represented by safety use case diagram and safety class diagram in the safety UML to implement the following safety functions: the train speed can never exceed the desired speed in any interval and the train position is never beyond the end of Movement Authority(MA). The safety function of CAP is implemented by the formal refinement of the continuous and discrete collision avoidance strategies. The former gives the static structure, the dynamic interaction and the continuous control strategy of CAP in the case that the speed and the position of the train are continuous variables. Otherwise, the latter has achieved the discretization for the continuous collision avoidance strategy by discrete logic. The CAP real-time program code is generated through the further refinement of the discrete collision avoidance strategy. The correctness and the safety of the refinement for the continuous and discrete collision avoidance strategies as well as the final code generation have been guaranteed by the rigorous reasoning based on the formal logic-Weakly monotonic time extension of iterative Duration Calculus (WDC*).


Wu D.,Beijing Jiaotong University | Xiong J.,Indian Ministry of Railways | Xiong J.,C3 Group | Zhu G.,Beijing Jiaotong University | Zhong Z.,Beijing Jiaotong University
Zhongguo Tiedao Kexue/China Railway Science | Year: 2010

According to the theory of John Berry, the moment method was adopted to compute the site attenuation (SA) through establishing a simulation model of a test site based on the equivalent circuit of the specific balun. The differences (ΔSA) between the simulated SA of an actual site and the SA of the ideal site was used as the correction values for correcting the measured SA on the actual site. The influences (ΔSA) of the site size, the controlling room and the lightening rods on SA were computed respectively. The integrated influence of all factors was computed too. The simulated SA of the actual site was compared with the measured SA. Results show that these three factors all have effect on SA. The maximum difference (ΔSA) is up to 0.74 dB. The computed ΔSA can be considered as the correction of the measured SA on an actual test site. The computed SA basically agrees with the measured SA of the actual site, which demonstrates the effectiveness of the proposed method.


Xiong L.,Beijing Jiaotong University | Lu X.,Indian Ministry of Railways | Lu X.,C3 Group | Zhong Z.,Beijing Jiaotong University | And 2 more authors.
Zhongguo Tiedao Kexue/China Railway Science | Year: 2010

According to the characteristics of the wireless channel and the scenarios of high-speed railway, this paper introduces the methods of small-scale fading modeling with various scenarios for the wireless channel of high-speed railway GSM-R system. With the methods for modeling, the parameters of high-speed railway small-scale fading channels in time domain and frequency domain, such as the delay spread, the coherence bandwidth, the level crossing rate and the coherence time, are quantitatively discussed with simulation and computing. The Hard-In-the-Loop (HIL) simulation test bench for high-speed railway GSM-R communications system is built, and the performance of high-speed GSM-R system is evaluated. The simulation and experimental results show that the communication quality will decline at different degrees with the increase of the running speed. The communication quality in the downlink at the train speed of 350 km · h-1 is worse than that at 80 km · h-1 to a certain extent. Whereas, it still can meet the requirement of GSM-R system, which indicates that the communication quality of high-speed railway is guaranteed. However, the communication quality will deteriorate seriously at 500 km · h-1. To improve the design of the receiver is the key to solving the problem of communication quality deterioration.


Cai B.,Beijing Jiaotong University | Liu D.,Indian Ministry of Railways | Liu D.,C3 Group | Shangguan W.,Beijing Jiaotong University | And 3 more authors.
Zhongguo Tiedao Kexue/China Railway Science | Year: 2010

Based on multi-resolution modeling and High Level Architecture (HLA), CTCS-3 train control system simulation was studied. According to the structure of CTCS-3, four key modules including Radio Block Center (RBC), train control center (TCC), the balise information transmission module and the on-board vital computer were chosen to constitute the train control model. Based on the difference of the information transmission level, using multi-resolution modeling method, the different modules of train control model were divided into high, middle and low resolution module. The HLA simulation technology was used to construct the property publication and the ordering relationship of train control model federation object module and federation member, and the train control simulation process was realized with RTI software. The simulation realized the following simulation scenes, which included the connection and disconnection of the train control model and RTI software, the movement authorization generation realized by RBC and TCC in different resolution, the on-board vital computer computed object distance curve and train running view display, etc. The simulation results have validated the feasibility of the multi-resolution modeling method in CTCS-3 simulation.

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