The Bi-objective Emergency Supplies Delivery Problrm Based On Synchronized Truck-drone Delivery

In recent years,the frequent occurrence of natural disasters has brought tremendous damage to many parts of the world.In response to mitigating the serious consequences of disasters,people are paying increasing attention to such events.How to effectively warn,handle and recover from sudden natural disasters has become a major challenge for all countries across the globe.Therefore,it is urgent for scholars in the field of emergency management to study efficient and effective delivery methods for emergency supplies.The main purpose of emergency logistics is to provide disaster victims with the necessary goods for survival and to minimize their perceived suffering.In this thesis,the synchronized truck-drone delivery approach which combines the strength of large capacity and long distance of trucks as well as the speed and flexibility of drones is applied to the post-disaster emergency supplies delivery.It is expected that this approach is able to quickly provide victims with urgent supplies after a disaster.In addition,in order to measure the perceived suffering of the victims due to the lack of supplies or services,a deprivation cost function is proposed in this study.Considering factors such as the maximum flight time and weight of the drone,the disaster-stricken sites are divided into the following two categories: sites that can only be served by trucks,and those can be served by both trucks and drones.Based on this,the synchronized truck-drone delivery routing model is constructed with the goal of minimizing the total logistics cost and the deprivation cost suffered by the disaster victims.To avoid dealing with the two objectives of logistics cost and deprivation cost through subjective weight factors,this study uses an improved elitist nondominated sorting genetic algorithm(INSGAⅡ)to solve the model.Meanwhile,the decoding part of the INSGA-Ⅱ algorithm is redesigned according to the characteristics of the objective function.In the numerical experiment section,multiobjective algorithm evaluation metrics,Hypervolume metric and coverage rate C,are introduced to adjust the parameters of the improved algorithm,and compare the non-dominated solution sets of the synchronized truck-drone delivery mode with the truck-only delivery mode,respectively.The comparisons of the non-dominated solution sets of instances with different sizes in the two modes reveal that the non-dominated solution sets of the synchronized truck-drone delivery mode can completely cover the non-dominated solution sets of the truck-only delivery.Moreover,sensitivity analysis on the drone-to-truck speed ratio and the maximum duration of drone flight time shows that enhancing the speed and maximum duration of drone flight is a critical factor in improving rescue efficiency and reducing the suffering of victims.Our model and algorithm are also examined in the real case of Houston flood in 2017 and effective route solutions for emergency supplies delivery are generated.