Modeling For Loading Planning Problem In Container Terminal

Quay crane is the main handling equipment between container ships and terminal, which working performance would directly affect the operation efficiency of the whole port. At the same time, with the rising of container throughput and the scale of container vessels becoming larger, container loading sequence problem becomes significant. It becomes an important scheduling optimization problem for all container terminals in the world that how to improve the efficiency of loading and unloading operation and reduce service time of the container ships.In this paper, we study the practical optimization problems of quay cranes scheduling and loading-sequence plan at container terminals, and focus on the defects of delaying of vessels and quay cranes of a poor efficiency loading process plan and handling operation in reality. We formulate the corresponding mathematical models for the problems, and propose the improved strategies, then design the heuristic approach for the medium and large-scale problem. At the same time, we develop the container terminal optimization systems. This work can be divided into the following three aspects:1) Study the crane scheduling problem with the constraints of no-crossing and safety distance between quay cranes. The problem can be formulated as a mixed-integer linear programming (MILP) model. Owing to the complexity of the problem, the general optimization software is difficult to obtain the optimal solution for large-scale problems directly. Therefore, the heuristic algorithms based on equal allocation of quay crane are developed. Computational experiments show that the model and the approach proposed in this study are effective.2) Study the loading-sequence problem in port container terminals. The target is to ensure the loading rate and quality, and meanwhile consider the stability of vessels in loading process. The problem also can be formulated as a mixed-integer linear programming (MILP) model. In this paper, we develop the heuristics base on stability of vessels considering for the model of medium-scale and large-scale problem. Numerical experiments were performed to verify the model and the algorithm. 3) Develop the load plan module of the container terminal optimization systems. This part of the work is composed of the sub-module of Quay crane and sub-module of loading-sequence plan. Aiming to the dynamic factors in the real logistics at the container terminal, we make system functions and optimization algorithms adaptive design and improvement, in order to improve the adaptability of the systems.Through the study of the above model and algorithm, we can get more reasonable, fast, safe operation scheduling solution. It’s useful to improve the efficiency of the port operation, reduce logistics cost and increase the profit at the container terminal.