MODEL OF FLIGHT TECHNICAL ERROR IN SYMMETRICAL PLANE FOR PERFORMANCE BASED NAVIGATION

In the performance based navigation（PBN）,the flight technical error（FTE）and the navigation system error（NSE）are two main parts of total system error（TSE）.The implementation of PBN requires pre-flight prediction and en-route short-term dynamical prediction of TSE.Once the sum of predicted FTE and NSE is greater than the specified PBN value,PBN cannot operate.Thus,it requires accurate modeling and thorough analysis of the two main contributors.Multiple-input multiple-output（MIMO）longitudinal flight control system of ARIC model is designed using the linear quadratic Gaussian and loop transfer recovery（LQG/LTR）method,and FTE in symmetrical plane of aircraft is analyzed during the turbulence disturbed approach.The error estimation mapping function of FTE in symmetrical plane and its bound estimation model are proposed based on the singular value theory.The model provides an approach based on the forming mechanism of FTE,rather than the costly flight test and the data fitting.Real-data based simulation validates the theoretical analysis of FTE in symmetrical plane.It also shows that FTE is partially caused by the turbulence fluctuation disturbance when the automatic flight control system（AFCS）is engaged and increases with escalating the environmental turbulence intensity.

Lateral Flight Technical Error Estimation Model for Performance Based Navigation

Flight technical error （FTE） combined with navigation system error （NSE） is the main part of total system error （TSE） in performance based navigation （PBN）. The implementation of PBN requires pre-flight prediction and en-route short-term dynamical prediction of the TSE. Once the sum of predicted lateral FTE and NSE is greater than the specified PBN value, the PBN cannot operate. Thus, accurate modeling and thorough analysis of lateral FTE are indispensible. Multiple-input multiple-output （MIMO） lateral track control system of a transport aircraft is designed using linear quadratic Gaussian and loop transfer recovery （LQG/LTR） method, and the lateral FTE of a turbulence disturbed approach operation is analyzed. The error estimation mapping function of latera FTE and its bound estimation algorithm are proposed based on singular value theory. According to the forming mechanism of lateral FTE, the algorithm considers environmental turbulence fluctuation disturbance, aircraft dynamics and con- trol system parameters. Real-data-based Monte-Carlo simulation validates the theoretical analysis of FTE. It also shows that FTE is mainly caused by turbulence fluctuation disturbance when automatic flight control system （AFCS） is engaged and would in- crease with escalating environmental turbulence intensity.

Research on FMC analytic algorithm of PBN track transition coding

Airborne navigation database(NavDB)coding directly affects the result of analysis on the instrument flight procedure by the modern aircraft flight management computer(FMC).A reasonable flight track transition mode can improve the track tracking accuracy and flight quality of the aircraft.According to the path terminator(PT)and track transition characteristics of the performance based navigation(PBN)instrument flight procedure and by use of the world geodetic system(WGS)-84 ellipsoidal coordinate system,the algorithms for“fly by”and“fly over”track transition connections are developed,together with the algorithms for coordinates of fix-to-altitude(FA)altitude termination point and heading-to-an-intercept(VI)track entry point and for track transition display of the navigation display(ND).According to the simulation carried out based on the PBN instrument approach procedure coding of a certain airport and the PBN route data at a high altitude,the algorithm results are consistent with the FMC-calculated results and the actual ND results.