A Dynamic Pushback Control Model for Departure Flights Considering Reapplication Intervals

Long taxiway queues during the departure process of flights at large hub airports will cause large fuel consumption and exhaust emissions. Aiming to tackle this problem, an improved N-control linear policy (NCLP) with multiple application intervals is proposed based on the traditional N-Control strategy. The model can gradually reduce the flight exit permission rate when the real-time queue length exceeds the set/predefined/configured optimal taxiway queue length threshold, achieving more flexible dynamic departure control. The taxiway queuing system and boarding gate virtual queuing system are built by setting the intervals for flight resubmission equal to the runway service time. A comprehensive cost objective function for taxiway fuel consumption and boarding gate occupancy penalty is constructed. A continuous time Markov chain based optimization algorithm is proposed to achieve a dual loop between taxiway capacity and dynamic pushback control strategy, thus determining the optimal taxiway queue threshold between fuel consumption and gate penalty cost. A simulation experiment is conducted on the actual operating data of Beijing Capital International Airport. The results show that when the length of the taxiway queue reaches the optimal threshold, the NCLP control strategy has significant advantages over the uncontrolled situation and the traditional N-Control strategy. This model can reduce the average taxi waiting time from 9.51 min to 6.94 min throughout the day, and reduce fuel consumption and total operating costs by 27.07% and 23.91% respectively compared with the N-Control strategy, which verifies the effectiveness of the proposed model in reducing airport taxi fuel consumption.