Optimization for vehicle scheduling in iron and steel works based on semi-trailer swap transport

In order to solve internal logistics problems of iron and steel works, such as low transportation efficiency of vehicles and high transportation cost, the production process and traditional transportation style of iron and steel works were introduced. The internal transport tasks of iron and steel works were grouped based on cluster analysis according to demand time of the transportation. An improved vehicle scheduling model of semi-trailer swap transport among loading nodes and unloading nodes in one task group was set up. The algorithm was designed to solve the vehicle routing problem with simultaneous pick-up and delivery (VRPSPD) problem based on semi-trailer swap transport. A solving program was written by MATLAB software and the method to figure out the optimal path of each grouping was obtained. The dropping and pulling transportation plan of the tractor was designed. And an example of semi-trailer swap transport in iron and steel works was given. The results indicate that semi-trailer swap transport can decrease the numbers of vehicles and drivers by 54.5% and 88.6% respectively compared with decentralized scheduling in iron and steel works, and the total distance traveled reduces by 43.5%. The semi-trailer swap transport can help the iron and steel works develop the production in intension.