Research On Post-earthquake Rescue Vehicle Routing Optimization Model Based On Time-space Network

China is a country with a very large land area,and many natural disasters occur every year.The occurrence of a strong earthquake will cause a large number of casualties and economic losses,hindering the development of the country.And studying the path planning of post-earthquake rescue vehicles can effectively reduce the loss of life and property caused by the earthquake,which is of great significance to the government and people in responding to sudden earthquake disasters.The research in this thesis is mainly based on the optimization of conventional vehicle path planning models,considering the characteristics of earthquake disasters,taking these specific factors into the model,and making the post-earthquake rescue vehicle path planning model more optimized.Firstly,this thesis introduces some features of the time-space network model on the conventional vehicle rescue path planning model.The post-earthquake rescue mainly considers the urgency of time.The rescue vehicle must deliver the allocated materials to the demand point in the shortest time.The change of the state of the vehicle during the distribution process over time plays an important role in the overall coordination of the headquarters.Therefore,in this thesis,by introducing the characteristics of time-space travel arcs in the time-space network model with both time-space information,the process of starting a vehicle from the path planning model to the affected point and returning to the starting point is regarded as a period of time travel arc.At the same time,the amount of material carried can be regarded as the flow on the arc,so that the real-time status of the vehicle on the predetermined line can be accurately grasped,which is more conducive to the overall scheduling of the material by the superior.This thesis also considers the impact of road information changes on vehicle routing during vehicle distribution.The road may be interrupted due to aftershocks,landslides,mudslides,etc.The previously interrupted roads may also become accessible due to emergency repairs,so the driving routes formulated at the beginning are no longer optimal.At this time,the vehicle routes must be re-planned.Vehicles will perform tasks along the newly planned route after reaching the next disaster site.Finally,this article also considers the impact of dynamically changing material demand information on vehicle path planning when the supply of materials is in short supply during the initial period after the earthquake.In the case of insufficient supplies after the earthquake,only by achieving the fairest possible distribution of supplies can the psychological sentiments of the affected people be better stabilized.If the demand for materials is fixed at each demand point,it only needs to be evenly distributed at the beginning.However,the actual situation after the earthquake is that the demand at each demand point will gradually increase with the progress of the rescue process and the improvement of data statistics.Therefore,the method adopted in this article is to distribute according to the initial allocation plan before obtaining changes in demand information.After the change in demand information is obtained,the remaining materials are distributed fairly according to the demand of the remaining service points,so as to ensure the rationality of the material distribution.This thesis optimizes the path planning model of rescue vehicles by considering the above factors,selects the genetic algorithm to solve the model,and finally verifies the feasibility and effectiveness of the model through actual case analysis.