Real-time control of metro train dynamics with minimization of train time-headway variance

Abstract

We present here a real-time control model for the train dynamics in a linear metro line system. The model describes the train dynamics taking into account average passenger arrival rates on platforms, including control laws for train dwell and run times, based on the feedback of the train dynamics. The model extends a recently developed Max-plus linear traffic model with demand-dependent dwell times and a run time control. The extension permits the elimination of eventual irregularities on the train time-headway. The resulting train dynamics are interpreted as a dynamic programming system of a stochastic optimal control problem of a Markov chain. The train dynamics still admit a stable stationary regime with a unique average growth rate interpreted as the asymptotic average train time-headway. Moreover, beyond the transient regime of the train dynamics, our extension guarantees uniformity in time of the train time-headways at every platform.

Deep Reinforcement Q-Learning for Intelligent Traffic Control in Mass Transit

“…Specifically, the train dynamics are represented by a discrete event system that captures various traffic constraints such as dwell and safe-separation time constraints [16][17][18]. Additional research has extended this approach to incorporate passenger demand [19][20][21][22][23][24], model traffic on mass transit lines with junctions [25][26][27], and simulate mass transit lines with skip-stop policies [28,29]. In our work, we extend the existing traffic model by introducing the control of passenger inflows to platforms.…”

Max-plus modeling of traffic on passenger railway lines with a junction: fundamental diagram and dynamic control

“…Finally, an enhanced dynamic control is presented for a linear line, see Schanzenbächer et al [36]. In case of a perturbation on the train time-headway, an temporary additional control on the dwell times is applied which re-harmonizes the train headways on the line while avoiding excessive train dwell times.…”

Comprehensive passenger demand-dependent traffic control on a metro line with a junction and a derivation of the traffic phases

“…We distinguish three parts of the metro line: a central part and two branches crossing at the junction. The metro line is discretized in space into a number of segments as in [7,8,9,10,13,14,15], all following the same discrete event modeling approach. A first model for the train dynamics on a metro line with a junction has been proposed in [13], with train dwell and run times respecting given lower bounds, i.e.…”

“…Finally, [15] propose a new control on the train dwell times, which allows to minimize headway variance. However, this control is not taken into account in the here presented model for a metro line with a junction.…”