Research On MAS-Based Method For Urban Rail Transit Train Operation Adjustment

UMT(urban rail transit) has already become the main transportation way on releasing urban traffic pressure for its advantages like high speed, convenience, large-volume and less pollution. Generally, train obey arranged timetable strictly, but, for some random reason, real train running may deflect from timetable. Since UMT has characters including big traffic density and short interval, a train's delay may affect other trains, sometimes, it even affects the whole system; s common work. So research on train adjust methods for Urban Rail Transit is quite important.Train Operation Adjustment has characters like high real time requirement, multi-objective optimization and complex inter-relationship, and it is a multi-input & multi-output system, most parametric variables are nonlinear, time-varying and uncertainty. Therefore, it is hard to make a unified, definitive and formal mathematical model. Aiming at characters above, this paper proposed a MAS-Based Method for Train Operation Adjustment. MAS depends on mutual coordination among Agents in the system, and finally it makes a decision. MAS has features including autonomy, distribution and coordination, also has abilities like self-organization, learning and reasoning. Therefore, it is applicable to apply MAS technology to Train Operation Adjustment.The key work of the paper includes:Put forward that applying the distributed method modeling top-down to the system, design a three-layered system structure, expound the social rules to be obeyed for agents in the structure and the function of agent, still the author construct models for train agent, resource agent and manage agent respectively.(1) Make strategies for local adjustment and global adaptation according to train delay situation, abstracte the process of establishing the train adjust scheme as another process that the train group's reservation and occupancy for shared resources like stations or lines. Put forward a cooperation mode based on reserve-response among agents: train agent applies for resource occupancy to resource agent according to operation state of itself and the planned train graph; resource agent evaluates the application and sends out acceptance or suggestion information. Manage agent presides over management of train and resource all line, also deals with the conflict.(2) Make a formal Description for agent's living Environment by using predicate logic, and knowledge representation for agent. Use message transmit mechanism, combine KQML communication language to realize the communication and cooperation of the system.(3) Simulation Analysis, adjust for different train delay situation, give out adjust result, and analyze for the adjust result.The results show that, MAS-Based Method for Train Operation Adjustment is feasible, and finally it gets a better adjust result.