Study On The Cruise Trajectory Optimization Method Of Large Civil Aircraft In RTA

The flight performance management is the important of the flight management system(FMS),the flight trajectory optimization is a key technology of the flight performance management,this paper to meet the required time of arrival(RTA)cruise trajectory optimization method and simulation experiment research.Research in this paper to the independent research and development in our country FMS has theoretical guidance,and has great significance to the development of our country civilian aircraft and operation.The main work of this paper is as follows:(1)Aiming at acquiring the incomplete aerodynamic parameters of A320 from JSBSim,completed the fitting of aerodynamic parameters,and established the A320 6-Dof aircraft model.Based on Simulink,built a flight simulation platform consisting of flight path loading module,guidance module and flight control module,which provides a simulation verification platform for the research of the algorithm in this paper.(2)Aiming at the difficulty in acquiring the modeling parameters of civil aircraft engine,put forward that the automatic thrust calculation method.In this method,the continuous thrust value of two gears is obtained by using the two-dimensional linear interpolation method in the engine gear only with the Idlethrust and the Milthrust.In this paper,the equivalent throttle degree between two gears is obtained by the method of trim linearization,and the automatic thrust calculation is realized.Based on the combined control system was designed and realized the speed control of four basic modes and special speed control modes in flight simulation,and the speed control error is less than 0.5m/s.(3)Aiming at modal directly the height of the switching control method for dynamic performance is bad,with exponential function as the prototype function,the given altitude,the relationship between the current altitude and vertical speed is deduced,put forward an altitude-hold/vertical speed integrated control method that can satisfy the altitude-hold,also can realize the altitude change.Simulation analysis on the flight simulation platform of the A320 show that this method can achieve altitude non-oscillatory control,and the steady-state error is well suppressed.(4)Aiming at trajectory prediction method based on coordinate transformation is easy to cause error,using the theory of map projection transform latitude into isometric latitude,directly according to the route of latitude and longitude information level flight trajectory prediction.According to the civil aviation administration of China issued 2014 route map,the initial flight plan of Beijing and xi ’an was obtained,and the prediction of the flight trajectory of Beijing and xi ’an was completed.The prediction error of the turning center to the starting point and the end point indicates that the flight path prediction algorithm of this paper is accurate.(5)Consider air-traffic controllers or weather form air zone,given the constraints of the Dijkstra multi-trajectory optimization algorithm,according to the civil aviation administration of China issued 2014 route map,select eight routes of Beijing-xian,under the condition of with and without constraints using the Dijkstra algorithm for trajectory optimization,more effective shortest paths are obtained.(6)In this paper,proposed a flight path optimization method based on automatic thrust calculation,which by using(2)lack of engine thrust gear automatically under the force calculation method to calculate the instantaneous thrust is proposed,completed the fuel consumption calculation,and implements the single trajectory optimization algorithm of direct operating cost(DOC)and the RTA performance index calculation.Under the DOC performance constraint,the single trajectory optimization completed different flight conditions,the A320 flight simulation have been carried out to verify the simulation platform,the simulation results show that: in view of the DOC performance optimization is effective.The optimal flight speed and the minimum fuel consumption of different RTA performance indexes are optimized.The adjustable time interval of Beijing-xi ’an cruise section is calculated,which can optimizes the same bending radius of track prediction speed and roll Angle,and can not trigger trajectory reprediction when RTA changes.