Research On The Path Optimization Problems For Two-way Logistics In Logistics Distribution System

The ultimate goal of logistics is to satisfy the needs of users. The logistics distribution is a key section in logistics activities, and it is the end link of the logistics activities. Since the distribution costs takes a high percentage in the whole cost of logistics activities, that will directly influence the economic benefit of enterprise, a proper arrangement of logistics solutions and reduction of logistics costs is very important for related logistics enterprises. This thesis mainly focuses on the routing optimization for the bidirectional logistics routing problems.The present situation of existing logistics routing optimization methods in relevant research area is briefly described, and then relevant logistics knowledge is introduced. On this basis, the necessity of research on bidirectional logistics routing optimization is analyzed and the characteristics and principles of the bidirectional logistics routing are explained further.According to the characteristics of bidirectional logistics, the research effort in the thesis has focuses on seeking the affects of delivery quantity and pick up quantity on routing selection. Considered the transport costs is mainly determined by the total length of the truck path, a mathematical model of vehicle routing optimization is proposed. The proposed model, taking comprehensive factors and actual situation into account when choosing routes between nodes, could coordinate the relationship of volume and transportation costs effectively.To solve the proposed routing optimization model, an ant colony algorithm is offered. The algorithm is tested by data from a standard library Solomon and the results showed that the ant colony algorithm is verified to solve the vehicle routing optimization under bidirectional logistics environment with simultaneous delivery and pickup. A comparison with other related approach in the literature is carried out, and it was found that the proposed model for vehicle routing problem, which take into account the influences of the amount of goods when delivering or picking up, showed greater performance.Finally, some parameters of the ant colony algorithm were analyzed by studying the specific impact of their size on the algorithm performance value. The results proved that the selected parameter in our algorithm is available.