Research On Optimization Of Scheduling For Towing Tractors Based On Airport Collaborative Decision Making

In recent years,the scale of airports in our country is expanding day by day and the number of flights is increasing every day.The ground service of aircraft is facing huge pressure.The method of dispatching vehicles by human will be difficult to adapt the rapid development of airports.Attracting a large number of scholars to carry out the optimization of scheduling for service vehicles.However,these research work is not detailed enough,which is hard to apply in the actual support operation.The research direction of this paper is a scheduling optimization of towing tractors.Combining with the update frequency of the airport-collaborative decision making system to obtain the target off-block time within the target period and considering the uncertain time of push back and tractors’ travelling as well as the cumulative effect of tractors’ tasks.The scheduling optimization model of tractors under centralized strategy was established,including minimization of the mismatches between tractors and aircraft and the delay time of push back.Due to the disadvantages of the centralized dispatching strategy,to be exact,the tractors operating areas were not fixed,leading to the remote dispatching sometimes.As a result,the applicability of this method was limited in the application of multiple service areas in large airports.On this basis,we established the dispatching optimization model of tractors under distributed strategy by setting the attribute of tractors’ service area and increasing the optimization goal of minimizing the number of cross-regional scheduling of tractors.The scheduling algorithms for tractors under centralized and distributed strategies were developed based on improved NSGA-Ⅱ.The traditional NSGA-Ⅱ algorithm was improved by setting preference for evolution and designing crossover and mutation operator.And the preference was reducing the number of mismatches between vehicles and aircraft as well as delay time of operation.Based on the actual operation data of a large airport in southwest China,the above algorithms were used to formulate tractors scheduling schemes.Compared with schemes developed by manual scheduling methods,the time-consuming of scheduling schemes,the average travel time of tractors and the variance of the number of flights served are reduced by up to 72.82%,52.96% and 55.36% respectively.Compared with the traditional NSGA-Ⅱalgorithm,the pareto solutions are more fully evolved and the minimum number of tractors and the minimum average driving time are reduced by 11.11% and 50.06% respectively.In addition,compared with the centralized scheduling scheme,the operation area of the distributed scheduling scheme is more fixed,and the minimum average driving time is reduced by 48.50%.However,the centralized scheduling scheme is better in time-consuming.On this basis,the applicability of the two methods is summarized.Finally,in order to guide the actual operation,the scheduling software under different methods is developed based on MATLAB-GUI platform.