"The system is switched, and the trains are ready. Start the test now!"

"Trains of Line 4 have run through Baoshan Road Station."

"Trains of Line 3 have been diverted to the common section."

"Trains of Line 3 are heading for the parking line of Shanghai Railway Station."

"Trains of Line 3 and 4 have completed a quick return."

……

In the late night of June 28 at Shanghai Metro Baoshan Road Station, CASCO's train autonomous circumambulate system (TACS) based on train-to-train communication successfully passed the driverless tests on Shanghai Metro Lines 3 and 4, and was  unanimously praised by the review experts with all the verification indicators meeting the expectations.

Expert review meeting at Baoshan Road Station verification project

Organized by the Technology Center of Shanghai Shentong Metro Group, experts from Shanghai Transportation Trade Association, various metro companies and the Design Institute participated in the expert review meeting of this verification project. In the late night of June 28, the experts measured several key functions and performance indicators of TACS system based on train-to-train communication in UTO mode, including turnout performance, convergence performance, return interval, shuttling at any station and returning at any point, etc.

CASCO's Technical Director Wang Xiaoyong is performing on-site demonstration on the testing train

In the afternoon of June 29, by comparing the measured data with the simulation results of the existing system and the TACS system based on train-to-train communication, the experts at the meeting reviewed the site verification results of the CASCO's TACS system, and all confirmed that all the on-site verification indicators met the expectations. It is especially worth mentioning that all trains in this test adopted the UTO mode for the whole process, setting a national precedent.

Expert review meeting of the verification project

As a prominent representative of highly efficient train control systems of urban rail transit, the TACS system based on train-to-train communication is safe, efficient, flexible, economic and easy to deploy. Compared with the traditional CBTC system, the TACS system based on train-to-train communication has more compact equipment and more flat architecture. The systems are highly integrated, and trains interact with each other directly, which can greatly improve the system performance and transportation capability, and provide flexible and diversified driving organization modes to help deal with various faults and emergencies. In addition, the TACS system based on train-to-train communication can also provide a new option for the extension and expansion of existing lines in the application, which can further reduce the operation and maintenance costs. In 2019, research on this technology was included in the encouraged list in the Catalog for Industry Restructuring by the National Development and Reform Commission.

As early as 2010, CASCO and Shanghai Shentong Metro Group carried out the preparatory research of the TACS system based on train-to-train communication, i.e. "Research on the Improvement of Shanghai Metro CBTC System". The research was completed in June 2015 and was identified by the Shanghai Municipal Science and Technology Commission as an achievement of science and technology. On the basis of this research achievement, CASCO further completed the independent research and development of the TACS system based on train-to-train communication, and the verification of the laboratory level function and performance, and obtained several core invention patents.

In early 2019, in order to further verify the performance of the TACS system based on train-to-train communication on actual lines, especially the actual performance indicators with multiple trains in UTO mode, the "Shanghai Lines 3 and 4 Verification Project" was launched with the strong support of Shanghai Shentong Metro Group. In order to ensure the safety of Lines 3 and 4, CASCO carried out strict project safety management and safety certification besides the safety certification of TACS system based on train-to-train communication, and designed a switchover system with SIL4safety level. Until the successful completion of this on-site test, all the predetermined scenes and related functions and performances of CASCO's TACS system based on train-to-train communication verification project were realized, and no potential safety risks were found during the whole project. All the verification indicators have met the expectations. The system became the first TACS system based on train-to-train communication in China to complete the train test on operation lines, and also took the lead to implement the test with multiple trains in UTO mode, again reflecting the innovation ability and practitioner spirit of Shanghai Shentong Metro Group and CASCO.

The successful completion of all on-site train testing of CASCO's TACS system based on train-to-train communication indicates that the system is ready for commercial use and will provide new options for new urban rail transit projects and the upgrade and transformation of existing lines. At present, China is vigorously promoting the construction of new infrastructure. The successful development and application of TACS system based on train-to-train communication will further promote the informatization, intelligentization and intellectualization of China's urban rail industry, and help to build safer, more convenient, more efficient, greener and more economic intelligent urban rail transit, thus contributing to the construction of a powerful transportation country and the improvement of the layout of new infrastructure.