Design method of compound root locus multilevel pid robust controller for cluster flutter suppression of longitudinal flight model

Abstract

The invention provides a design method of a longitudinal flight model cluster flutter-suppression composite root-locus multi-level PID (proportion integration differentiation) robust controller. The design method includes: directly determining and acquiring a model cluster which is constituted according to amplitude-frequency and phase-frequency characteristics within the full envelop through sweep flight tests on set conditions of different heights and different Mach numbers; according to military standard requirements on amplitude-frequency margin and phase margin, providing the closed-loop pole distribution limit index corresponding to root-locus description, determining number of levels and parameter values of the multi-level PID robust controller by a model identification method applied to system identification according to requirements of the closed-loop pole distribution limit index within the full envelope of an aircraft after adding the multi-level PID controller; designing the small-overshoot stable low-altitude flight controller capable of suppressing flutter and meeting requirement of the flight full envelop from the concept of root-locus description based closed-loop pole distribution limit.

Description

technical field [0001] The invention relates to a design method of an aircraft controller, in particular to a design method of a longitudinal flight model cluster flutter suppression compound root locus multi-stage PID robust controller, which belongs to the categories of measurement and control technology and flight mechanics. Background technique [0002] The control of the take-off and landing process of the aircraft plays an important role in flight safety; due to the large change in flight speed during the take-off and landing process of the aircraft, even according to the longitudinal model, it will face strong nonlinear problems; on the other hand, the control rudder of the aircraft has saturation, dead zones, etc. Phenomenon; From the perspective of flight safety, when flying at ultra-low altitudes (such as aircraft takeoff / landing), the controller must ensure that the system has a certain stability margin, no overshoot and stability, which makes the design of ultra-l...

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Problems solved by technology

[0006] In order to overcome the fact that the existing method cannot design a stable low-altitude flight controller that meets the stability margin index in the full flight envelope and can suppress flutter when the model of the aircraft changes greatly in the full flight envelope Technical defects, the present invention provides a method for designing a longitudinal flight model cluster flutter suppression compound root locus multi-stage PID robust controller, which is directly determined by sweeping flight tests at different altitudes and Mach numbers to obtain full A model cluster composed of amplitude-frequency and phase-frequency characteristics within the envelope; according to the military standard requirements for amplitude-frequency margin and phase margin within the flight envelope, the closed-loop pole distribution limit index under the description of the corresponding root locus is given. By adding The multi-level PID controller and the closed-loop pole distribution limit index in the full envelope of the aircraft and the model identification method in system identification determine the number of stages and parameter values ​​​​of the multi-level PID robust controller; the closed-loop pole distribution limit under the description of the root locus Design a low-altitude flight controller that can suppress flutter, have small overshoot, and be stable in line with the full flight envelope

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