Transport networks are operated under a pre-designed plan to carry out the trans- portation tasks. Perturbations can inevitably arise exogenously or endogenously, and cause disturbances to the transit of passengers or the delivery of freights. A transitional plan is needed to deal with the perturbations and accomplish the trans- port tasks. The transitional plan is referred to as perturbations management in this study. The first contribution of this work is that we construct the re-planning models for multi-class networks. The perturbation management for the single-class transport network, for instance, a passenger railway network is well studied, however, it is still missing for multi-class transport networks. In real applications, passenger flows and freight flow sometimes co-exist in one system. The volume of freight transport keeps increasing. On the other hand, there are usually multi-mode services associated to finish the transit of one object. The current research is centred around this point. We study perturbation management for multi-class networks, which involve the mixed passenger and freight railway networks and deploy various modes of service vehicles. There are several important research questions regarding the management of heterogeneous traffic flows in case of delays. The first challenge is to get an overview of the focus of the existing literature in rail bound networks and find out what are the promising directions for further research. Second, concerning the modeling part, the challenge is to come up with a replanning strategy and determine the control objective. Another task is to find out how to manage the different flows involved, either for the served clients or for the serving vehicles. Last concern is to explore how to achieve flexibility for the integrated network. The second contribution of this work is that the replanning models arrange the heterogeneous traffic according to their characteristics. When delays occur to a mixed passenger and freight railway network, the replanning gives more flexibility to the freight trains. The underlying reason is that the freight clients, i.e., the shippers care mainly about the finally delivery time instead of the taken route or the waiting time at the intermediate stations. While in the synchromodality replanning, the three modes of service are scheduled according to their applied sub-networks. In the multimodal transport network, the large capacity vehicles are aligned with the freight flows. Another contribution of this thesis is that the models achieve the synchronization of the involved flows. This is vital to perturbation management, even if the applied networks are different. We pursue the synchronization of flows from both time and space dimensions. We adjust the scheduling of the metro vehicles in agreement with the massive passenger flows (Chapter 3). We align the scheduling of three modes of service vehicles according to the delayed preceding vehicles or shipment release (Chapter 5). Meanwhile, the passenger transfer management (Chapter 3 and Chapter 4) and the freight flows re-assignment (Chapter 4 and Chapter 5) is integrated with the re-scheduling. The synergy of the rescheduling and re-assignment can optimally deploy the affected capacity to accomplish the transport tasks and minimize the operation costs.
|Doctor of Philosophy
|7 Jul 2021
|Published - 2021
Bibliographical noteTRAIL Thesis Series no. T2021/23
- perturbation management
- mixed passenger and freight flows