Virtual Coupling Formation Control for Heterogeneous High-Speed-Trains With Uncertain Dynamics, Nonuniform Communication Delays and Switching Topologies

The Virtual Coupling (VC) control problem becomes more challenging when considering High-Speed Trains (HST), where unexpected/unpredictable external factors, nonlinearities effects and unavoidable communication impairments have a stronger impact on trains convoy performance and safety because of the higher velocity operative range. To simultaneously handle all these critical aspects in a unified framework, this paper proposes a novel robust distributed time-delay control strategy which ensures the VC of autonomous connected HST under variable inter-train spacing policy which accounts for the effective convoy conditions. This is also guaranteed in the presence of variations in the active communication links as a result of cooperative manoeuvres. By exploiting matrix theory and the Lyapunov-Krasovskii approach, we derive the control gains tuning procedure and the exponential stability conditions, which are expressed as a set of feasible delay-dependent Linear Matrix Inequalities. These latter allow analytically evaluating the stability margin of the VC convoy with respect to uncertainties, unmodeled dynamics and the maximum allowable delay upper bound, as well as ensuring, based on a desired exponential decay rate, that the closed-loop state trajectories remain bounded within a safe region. Theoretical derivation is confirmed by an extensive simulation campaign, also including different railways cooperative maneuvers, Monte Carlo analysis and comparative evaluation against an alternative strategy.