Study On Airport Gate Assignment Problem Based-on Operational Safety

Gates are important facilities and key resources in civil airport. Selecting and assigning available gate for each arriving and departing flight is a key activity in airport operations. The existing researches on gate assignment problem are mainly based on operational efficiency, while aircraft safety about the gate assignments almost could not be considered in details. Based on conceptual innovation and existing researches on efficiency, this paper will study the airport gate assignment problem (AGAP) which considering both operational safety and efficiency by using the philosophy of"nip in the bud"in safety management.This thesis discusses AGAP in detail and points out deficiencies of existing researches. New idea of this paper for studying AGAP is achieving the win-win situation of operational safety and efficiency. Airport gates and flights are described. And then constraints and existing main optimal objectives are formulated, and factors affecting problem solving and approaches are discussed. Based on the analysis of the operational process of aircrafts on the apron, gate assignment problem considering operational safety is studied when gates are adequate at first. The proactive approach of"avoid conflict in advance"is adopted by regarding restricted conditions of potential power-in vs. push-out conflict as safety constraints, and then the model with conflict-avoidance is proposed. A mathematical programming technique is used to achieve optimal resolution when the problem scale is small. While the scale is much larger, coarse-grain parallel genetic algorithms(CPGA) is designed to get satisfactory solutions by taking into account the rapid growth of the number of variables and constraints which contribute to combinatorial explosion. The ultimate purpose is enhancing the operational efficiency with avoiding conflict.Given to the heavy traffic of airports, temporary gate shortages are common phenomenon. Considering the algorithmic unsolvability for gate shortages and strict constraints, minimizing waiting time of passengers to relieve conflicts is proposed as optimization objective, and new model based on operational safety of gate assignment problem is presented. CPGA is adopted to solve the model. The optimization of the model can get the safest assignment while reducing unsafe factors such as conflicts of power-in/push-out, taxiing conflicts in apron, and utilizing conflicts for temporary gate shortages.Multi-objective optimization model with conflict-avoidance is studied while gates are adequate. The fuzzy membership grades of gate idle periods are used to describe the matching degree of flight-to-gate instead of the determinate 0-1 relationship. Adjustment function on membership degree is introduced to transfer two objectives into one. CPGA is adopted to get a reasonable trade-off between these two conflict objectives based on avoiding conflict.Over-constrained multi-objective model which considering both operational safety and efficiency is studied. The objevctives inculde minimizing the waiting time of relative passengers based on safety, the fuzzy walking distance of total passengers and the fuzzy baggage transport distance. Multi-objective coarse-grain parallel genetic algorithm is designed to solve the problem. The optimization result can get a set of Pareto solutions which evenly distributed in the Pareto front for airport managers'choice.In addition, some main objectives of existing gate assignment problem are analyzed and discussed. The algorithm for optimizing the robustness of gate assignment is presented. The optimization characteristic of minimizing the total passengers walking distance is analyzed. The algorithm for maximizing the rate of flight-to-bridge while gates are heterogeneous is developed. The gate reassignment problem is analyzed and modeled while flight schedule are changed, and heuristic algorithm and tabu search algorithm is adopted to optimize the model.