Dynamic Event-Triggering Control for Virtual Coupling of Virtual Track Trains Considering Communication Delay

Virtual coupling technology, achieved through inter-train cooperative control in wireless communication networks, can effectively manage both periodic and random passenger flow. Hence, it has gradually become a research hotspot in the field of train operation control. However, communication delays inherent in wireless networks can lead to delays in information interactions between trains, undermining the stability of virtual coupling and potentially causing train collisions, thereby posing a threat to operational safety. To enhance the engineering application of virtual coupling technology in virtual track trains operating in complex traffic environments, this paper proposes a dynamic event-triggering controller for virtual coupling that takes into account communication delays commonly encountered in wireless communication, from the perspective of optimizing communication transmission mechanism. Firstly, a dynamics model with heterogeneous nodes for train groups and a time-varying delay model for communication networks were constructed, establishing control targets based on the cruising characteristics of train groups and the communication mechanism of the controller. Then, a consensus control protocol was developed, along with an improved dynamic event-triggering mechanism to establish a trigger threshold that is dynamically adjusted based on the actual communication delays. Finally, in the virtual coupling application scenarios of group establishment and stable cruising, the existing event-triggering mechanism with fixed parameters was compared to the proposed dynamic event-triggering mechanism through simulations. Simulation results show the effectiveness of the proposed dynamic event-triggering controller in adjusting state feedback and controlling update frequency based on the actual communication delays. Compared to the existing event-triggering mechanism, the proposed approach not only improved stability under high dynamic links, but also reduced the frequency of communication and control updates. Specifically, the communication frequency decreased by about 50% and the global communication occupancy rate is reduced by 5 to 12 percentage points, indicating enhanced energy savings for trains.