Multi-input-multi-output aircraft equivalent stability margin robustness determining method

Abstract

The invention discloses a multi-input-multi-output aircraft equivalent stability margin robustness determining method for solving the technical problem that the existing aircraft stability margin determining method is complicated in determining a noise-containing multi-input-multi-output system. The technical scheme adopted by the invention is as follows: determining an open loop transfer function matrix of an uncertain multi-loop system; serially connecting a phase angle with gain and lag to the open loop transfer function matrix of the system; carrying out eigen decomposition on the frequency characteristic matrix of the open loop transfer function of the system; and obtaining a multi-loop stability margin analysis scalar equation by adopting matrix equivalence transformation. Therefore, the phase margin and amplitude margin of the whole loop can be analyzed conveniently.

Description

technical field [0001] The invention relates to a flight test determination method for the stability quality of an aircraft, in particular to a robust determination method for equivalent stability margins of a multi-input-multi-output aircraft. Background technique [0002] Stability margin is an important performance index to evaluate a flight control system, indicating the reliability of system stability. The stability margin of the system includes two aspects: gain stability margin and phase stability margin. The research on the stability margin of SISO system is relatively mature, and it is easy to obtain from the classic Bode or Nyquist diagram. For the stability margin of the aircraft, a series of sweep flight tests are required, and then it is determined whether the stability margin index is satisfied or not. Nowadays, many aircraft have canards, and the longitudinal and lateral headings can be expressed as two-input-two-output systems. The stability margin cannot b...

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Problems solved by technology

[0007] In order to overcome the shortcomings of the existing methods for determining aircraft stability margins that are complex when determining noise-containing multiple-input-multiple-output systems, the present invention provides a method for robustly determining equivalent stability margins of multiple-input-multiple-output aircraft. The method establishes the open-loop transfer function matrix of the uncertain multi-loop system, connects the system open-loop transfer function matrix with a gain and lag phase angle, and performs eigendecomposition on the frequency characteristic matrix of the system open-loop transfer function, and adopts matrix equivalent transformation Obtain the multi-loop stability margin analysis scalar equation; thus calculate the phase margin and amplitude margin of the overall loop

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