Cooperative control of high-speed trains for headway regulation: A self-triggered model predictive control based approach

The advanced train-to-train and train-to-ground communication technologies equipped in high-speed railways have the potential to allow trains to follow each with a steady headway and improve the safety and performance of the railway systems. A key enabler is a train control system that is able to respond to unforeseen disturbances in the system (e.g., incidents, train delays), and to adjust and coordinate the train headways and speeds. This paper proposes a multi-train cooperative control model based on the dynamic features during train longitude movement to adjust train following headway. In particular, our model simultaneously considers several practical constraints, e.g., train controller output constraints, safe train following distance, as well as communication delays and resources. Then, this control problem is solved through a rolling horizon approach by calculating the Riccati equation with Lagrangian multipliers. Due to the practical communication resource constraints and riding comfort requirement, we also improved the rolling horizon approach into a novel self-triggered model predictive control scheme to overcome these issues. Finally, two case studies are given through simulation experiments. The simulation results are analyzed which demonstrate the effectiveness of the proposed approach

Train Timetabling Optimisation Model Considering Headway Coordination between Mainline and Depot

This paper proposes an optimisation model for an urban rail transit line timetable considering headway coordination between the mainline and the depot during the transition period. The model accounts for the tracking operation scenario of trains inserted from the depot onto the mainline and related train operation constraints. The optimisation objectives are the number of trains inserted, maximum train capacity rate and average headway deviation. Second-generation non-dominated sorting genetic algorithm is designed to solve the model. A case study shows that optimisation achieves a total of 25 trains inserted, a maximum train capacity rate of 0.975 and an average headway deviation of 9.5 s, resulting in significant improvements in train operations and passenger satisfaction. Compared with the current train timetable before optimisation, the average dwell time and the maximum train capacity rate at various stations have been reduced after optimisation. The proposed model and approach can be used for train timetabling optimisation and managing the operations of urban rail transit lines

Closer running - railway capacity analysis and timetable improvement

Sufficient railway capacity can deliver enhanced reliability, customer experience and better revenue outcomes. Through qualitative and quantitative analysis, the result shows that it is not appropriate to try to improve capacity by changing train speed and braking rate as they are both limited by physics. Also, train length has a minor negative impact on the line capacity, even though passenger capacity can be increased significantly by coupling more carriages. So, optimising operational strategy is the reasonable and achievable approach to capacity improvement. While running at different speeds is an organisational problem without any upside, the research on an effective stopping pattern strategy is underdeveloped with potential benefits. Therefore, a stopping pattern algorithm and a novel timetabling method are proposed in this thesis. These tools provide an approach to timetable improvement and future dynamic (re-)scheduling to handle unexpected delays and failures rapidly in a heavily trafficked area. Meanwhile, combining relative braking distance approach and moving block system, an advanced signalling system concept is introduced, namely, the Optimised Headway Distance Moving Block. The simulation shows that reducing the technical headway in line with the principles of it could increase capacity by nearly 60% compared to the traditional moving block system