Research On Dynamic Vehicle Scheduling Strategies And Methods

Public transport system is an important part of urban infrastructure. The efficiency and safety of a public transport system is not only need advanced hardware equipment and technology, but also need more advanced management and scheduling system, which is the command centre of the daily operation. An advanced scheduling system is not only the basic guarantee for the normal operation of public transport; bus also the guarantee for improving the usage of vehicle and production efficiency of staff.Vehicle scheduling plays a crucial role in public transport. An efficient schedule can help bus companies reduce operating costs while being an essential guide to daily operations. Currently, almost all the vehicle scheduling methods in our country are static, which result in low flexibility and capacity in response to abnormal. So the precompiled schedule is usually hard to be adhered to in practice due to the diversity of traffic and driving conditions. Therefore, dynamic vehicle scheduling becomes an important supplement to the daily operations. Because of the complexity and diversity of dynamic scheduling problem, the mathematical model of optimization is very difficult, so in this paper, a Hierarchical Task Network(HTN) based dynamic vehicle scheduling approach is proposed. In the approach, two strategies are devised according to the practical scheduling philosophy. The first is to reschedule for individual vehicle independently(RIVI), the objective is to maximize the execution of the precompiled schedule. The second is to reschedule for multiple vehicles simultaneously(RMVS), which aims to maintain the planed headways. The approach is implemented based on the Simple Hierarchical Ordered Planner 2(SHOP2), experimental results show that the approach has good adaptability to different initial vehicle states and considerable efficiency for solving the vehicle scheduling problem dynamically.