Computer Aided Dispatch For City Pickup And Delivery Under Fuzzy Conditions

In current research, costs of pickup and delivery are described not very accurately, uncertain information is assumed not very reasonably, efficiency of dynamic pickup and delivery dispatch method is not high. Therefore, cost function to evaluate dispatch solution is establlished, membership function of fuzzy information is simulated and efficient algorithms such as Random Reasonable Tabu Algorithm and Synchronized Optimization Algorithm are designed. These are all basis to design efficient and practical computer aided dispatch system for city pickup and delivery.In this thesis, mathematic system of pickup and delivery problem is set up and shortest routes set under complex road network model are fast solved by Sector Dijkstra Algorithm. Carriage arranging cost is calculated through fuzzy judgment method. Fuel cost, depreciation cost, driver cost and common load/unload cost are all taken into consideration. Therefore, cost function of pickup and delivery is established to evaluate dispatch solution. Membership function of fuzzy velocity and fuzzy pickup volume is simulated based on traffic data on typical roads and operation data in real logistics enterprise. Subjective evaluation index from dispatcher is brought in to describe multiple fuzzy restrictions in pickup and delivery problem.Second, pickup and delivery problem under fuzzy velocity and fuzzy pickup volume is described. Random Reasonable Tabu Algorithm is put forwards. Analyzing the routes feasibility, Random reasonable dynamic derivative method is designed. Dual-aspiration criterion based on equilibrium theory and minimum cost theory as well as self-adaptive Tabu length selection strategy is applied. Method that can fast create initial feasible solution is given.Third, when new pickup client comes into pickup and delivery execution process, start time of dynamic dispatch is determined. Concept of"virtual client"is assumed to turn the dynamic problem into static. Based on this, solving strategy is designed, which combines the Synchronized Optimization Algorithm and by-way insertion algorithm tightly, then selects the solution by fuzzy judgement method. Vehicle location change, which comes from uncertainty of execution time, may influence the optimization result. In order to eliminate this influence, subsection fuzzy evolutive method is designed to estimate vehicle location.The situation is analyzed, when planned solution of pickup and delivery can not be operated because tasks change.Two-phase emergency dispatch algorithm is set up, which separates changed clients and changed routes.At last, computer aided dispatch system for pickup and delivery is explained in detail. Pickup and delivery cost function, static dispatch algorithm and dynamic dispatch algorithm are validated in practice. Half a year operation of this system shows that computer aided dispatch system for pickup and delivery meets the designed requirements in stability, safety and real-time performance.