Research On Emergency Rescue Vehicle Routing Optimization Considering Time Urgency

After the occurrence of sudden disasters,how to deliver emergency supplies as soon as possible under the demand time requirement for emergency supplies considering demand time has important theoretical value and practical significance.In the existing research,one category is to consider the demand quantity requirement,and to optimize the routing of emergency rescue vehicles with the goal of minimum out-of-stock quantity,maximum demand satisfaction rate,and minimum unmet demand ratio,without considering the time window requirement;the other category is to consider the time window requirement,and to optimize the routing of emergency rescue vehicles with the goal of minimum total delivery time,minimum latest delivery time,and minimum delay penalty cost,but without considering the situation outside the time window The delivery scenario is not considered.In view of the shortcomings of previous studies,this paper considers the actual delivery of distribution vehicles within and outside the time window,constructs the time urgency,establishes a model with the objective of minimizing the sum of the total cost of all affected points,and makes decisions on the distribution routing of emergency rescue vehicles and the amount of distribution through the affected points.The main work of the paper is as follows.This paper first considers only the time urgency of the emergency rescue vehicle path optimization to study.With the goal of minimizing the sum of total costs(early arrival penalty cost+delay penalty cost-delivery bonus cost within the time window),the emergency rescue vehicle routing optimization model is constructed.For the delivery time requirements of emergency supplies considering demand times,it is divided into three situations:the earliest and latest required delivery times of emergency supplies at all affected points are different,the earliest required delivery time of emergency supplies at some affected points is the same but the latest required delivery time is different,and the latest required delivery time of emergency supplies at some affected points is the same but the earliest required delivery time is different,and algorithm A is designed to solve the problem and prove that the algorithm The time complexity of the algorithm is O(ln ~3),where l and n are the number of delivery vehicles and the number of affected points,respectively.Finally,the validity of the model and algorithm is tested by taking the distribution of emergency supplies in the epidemic prevention and control area of Shanghai Jiading District as an example.Second,this paper considers the time urgency and material shortage of emergency rescue vehicle path optimization for research.With the goal of minimizing the sum of total costs(early arrival penalty cost+delay penalty cost-delivery bonus cost within the time window+out-of-stock penalty cost),the emergency rescue vehicle routing optimization model is constructed.For the two situations of sufficient and insufficient distribution vehicles,the algorithm is designed to solve the problem and decide the distribution routing of emergency rescue vehicles and the distribution volume of the affected points.The algorithm ESA is designed when the distribution vehicles are sufficient,and the time complexity of algorithm ESA is proved to be O(ln ~4).The algorithm EDA is designed when the distribution vehicles are insufficient,and the time complexity of algorithm EDA is proved to be O(ln ~3).Finally,the validity of the model and algorithm is tested by taking the distribution of emergency supplies in the epidemic control area of Jiading,Shanghai as an example.