Flight test determination method of multi-input and multi-output equivalent pneumatic servo elastic robust stability

Abstract

The invention discloses a flight test determination method of the multi-input and multi-output equivalent pneumatic servo elastic robust stability, used for solving the technical problems of the conservation and complex calculation of the traditional robust analysis method. Based on the technical scheme, the flight test determination method comprises the following steps of obtaining an open-loop transfer function frequency characteristic matrix of a multi-input and multi-output system through a frequency sweeping flight test and the like; lagging a phase angle through serial gaining at each loop; obtaining a scalar judgment formula of phase and amplitude margin between two adjacent flutter frequency regions according to direct equivalence of the closed-loop frequency characteristics by carrying out characteristic decomposition on the system open-loop transfer function frequency characteristic matrix; and calculating the phase margin and the ASE stability at the flutter frequency in a mode similar to a single-input and single-output system. The invention simplifies the problems through characteristic linear conversion, obtains the scalar judgment formula, gives a calculation method of the flutter boundary stability, the margin and the safety during elastic flight of a canard wing aircraft and reduces the conservation of the traditional method.

Description

technical field [0001] The invention relates to a direct equivalent determination method of flight test for aerodynamic servo elastic stability, in particular to a flight test determination method of multi-input-multi-output equivalent aerodynamic servo elastic robust stability. Background technique [0002] The research purpose of the stability analysis of aeroservoelasticity (ASE) is to analyze and predict the stability of the aeroservoelastic system based on the aeroservoelastic model and combined with the flight test data, 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 relati...

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Problems solved by technology

[0004] In order to overcome the disadvantages of conservatism and complex calculation of the existing robust analysis methods, the present invention provides a multi-input-multi-output equivalent aerodynamic servoelastic robust stability flight test determination method, the method through the frequency sweep flight test and other methods to obtain the open-loop transfer function frequency characteristic matrix of the multi-input-multi-output system. The series gain of each loop can lag the phase angle. By performing eigendecomposition on the system open-loop frequency characteristic matrix, the closed-loop The direct equivalence of the frequency characteristics obtains the scalar judgment formula of the phase and amplitude margins, and the phase margin and ASE stability can be calculated in a manner similar to the single-input-single-output system at the flutter frequency

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