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

A servo-elasticity, flight test technology, applied in the field of price determination, can solve problems such as complex calculation, and achieve the effect of reducing conservatism

CN102081349AInactive Publication Date: 2011-06-01NORTHWESTERN POLYTECHNICAL UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2011-06-01
Estimated Expiration
Not applicable · inactive patent

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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.
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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...

Examples

Embodiment Construction

[0024] Refer to attached picture. (a) Phantom breaks the loop, when one input is given to the signal, the other input is zero, using a linear sweep signal (f 0 is the starting frequency, f 1 is the cut-off frequency, r=(f 1 -f 0 ) / T, T is sweep time) or logarithmic sweep signal

[0025] f(t)=A(t)sin{2πf 0 / r·[exp(rt)-1]}(f 0 is the starting frequency, f 1 is the cut-off frequency, r=ln(f 1 / f 0 ) / T, T is the frequency sweep time) to excite the aircraft, the frequency characteristics of the aircraft longitudinal dual-input-dual-output aircraft can be obtained

[0026] G ( jω ) = 2 ( jω + 1 ) ( 0.2 ...