Armed Vehicle Routing Problems Study Based On Multi Emergencies

In reality,the operation of a vehicle will always be affected by numerous uncertain factors,e.g.traffic congestion and road closure because of necessary maintenance.As to armed police which deals with unexpected incidents,it needs to re-plan the routine and re-deploy vehicles due to the impact of multi-point emergencies.Since it is often hard to acquire the requirements of vehicles in advance during the process of handling emergencies,police officers tend to estimate the requirements empirically based on probability theory.Meanwhile,because it is impossible to predict the occurring time of multi-point emergencies,the vehicle scheduling and routine planning which based on deterministic theory could do nothing to solve the problems.Based on the facts discussed above,it is urgent to carry out the method of vehicle routine planning under uncertain conditions.After a comprehensive study of the conventional Vehicle Routing Problem(VRP),we found that the theory and methods of single demand point VRP can be applied to multiple demand points VRP.This paper focus on the vehicle scheduling scheme under emergency situations,which includes:(1)summarizing the elementary knowledge of VRP,analyzing the concepts and categories of vehicle scheduling as well as the features of VRP methods,studying the impact of emergences on VRP and the requirement features of multi-point emergencies,investigating the features and patterns as well as processes of VRP under emergency conditions;(2)establishing and solving the VRP model of initial scheduling and subsequent scheduling respectively,put forward the patterns of multi-point emergencies scheduling;(3)proposing the VRP model within the minimum time which takes account of road capacity,traffic congestion,uncertain arrival time and other uncertainties;(4)establishing VRP model on the basis of ant colony algorithms,solving the model using Matlab language,validating the effectiveness and feasibility of the method;(5)introducing the features and analytical procedures of heuristic algorithms,analyzing the VRP under uncertain conditions,establishing the corresponding mathematical model and solving it with heuristic algorithm,validating the proposed method by an actual case.