Method for determining equivalent aeroservoelasticity (ASE) robust stability of statically unstable aircraft through flight test

Abstract

The invention discloses a method for determining the equivalent aeroservoelasticity (ASE) robust stability of a statically unstable aircraft through a flight test, which is used for solving the technical problem of large modeling errors of the conventional flight test determination method. The technical scheme is that: a closed loop transfer function frequency characteristic matrix of a multi-loop system of the statically unstable aircraft can be obtained through a sweep frequency flight test; a relational expression between a closed loop transfer function and ASE stability is established according to a corresponding relation between the closed loop transfer function and an open loop transfer function; and the closed loop transfer function frequency characteristic matrix of the system is subjected to characteristic decomposition, and a multi-loop stability margin analysis scalar equation is obtained according to the critical stability condition of the system, so that the ASE stability of the whole loop is calculated, and problem difficulty is greatly simplified.

Description

technical field [0001] The invention relates to a flight test determination method, in particular to a flight test determination method for equivalent aeroservoelasticity (ASE) robust stability of a statically unstable aircraft. Background technique [0002] The research purpose of the aeroservoelastic stability analysis is to rely on the aeroservoelastic model and combine the flight test data to analyze and predict the stability of the aeroservoelastic system, and finally determine the flight envelope of the stable flight of the aircraft. The traditional stability analysis method is to analyze each loop of the system one by one with the help of flight test, and use the classic Bode diagram or Nyquist diagram to obtain the amplitude margin and phase angle margin of the system. However, for modern aircraft, due to the use of a multi-loop fly-by-wire control system, the aeroservoelastic system also has a relatively complex coupling relationship. The above-mentioned SISO system...

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Problems solved by technology

[0004] In order to overcome the shortcomings of the existing flight test determination methods with large modeling errors, the present invention provides a flight test determination method for the equivalent aeroservoelastic robust stability of statically unstable aircraft. The method can obtain static The closed-loop transfer function frequency characteristic matrix of the unstable aircraft multi-loop system, according to the corresponding relationship between the closed-loop transfer function and the open-loop transfer function, establishes the relationship between the closed-loop transfer function and the ASE stability, and the frequency of the system closed-loop transfer function The characteristic matrix is ​​subjected to eigendecomposition, and the multi-loop stability margin analysis scalar equation is obtained according to the critical stability conditions of the system, so as to calculate the ASE stability of the overall loop

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