Multi-loop aircraft model cluster flutter restraining composite root locus multistage PID (Proportion Integration Differentiation) robust controller design method

Abstract

The invention provides a multi-loop aircraft model cluster flutter restraining composite root locus multistage PID (Proportion Integration Differentiation) robust controller design method. The method comprises the following steps: directly determining to obtain a model cluster constructed by amplitude frequency and phase frequency features in a full envelope by means of frequency sweeping flight test under the condition that different heights and Mach numbers are given; giving a closed loop pole distribution limitation index under corresponding root locus description through multi-loop model equivalence according to an amplitude frequency margin in the flight envelope and a phase margin military standard requirement, determining the stage number and parameter value of a multistage PID robust controller by adding the multistage PID robust controller, the closed-loop pole distribution limitation index in the full envelope of an air craft and a model identification method in system identification; designing a low-altitude flight aircraft which is accordant with the full envelope, can be used for restraining flutter, has low overshot and is stable on the basis of the concept of closed-loop pole distribution limitation under root locus description.

Description

technical field [0001] The invention relates to a design method of an aircraft controller, in particular to a design method of a multi-loop aircraft 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 inability of existing methods to design a stable low-altitude flight controller that meets the stability margin index in the full flight envelope and can suppress flutter under the condition that the aircraft model changes greatly in the full flight envelope Technical defect, the present invention provides a multi-circuit aircraft model cluster flutter suppression compound root locus multi-stage PID robust controller design method, the method is directly determined by sweeping flight tests under the given different altitudes and Mach numbers A model cluster composed of amplitude-frequency and phase-frequency characteristics in the full envelope; according to the military standard requirements of amplitude-frequency margin and phase margin in the flight envelope, through multi-loop model equivalence, the corresponding root locus description is given The limit index of closed-loop pole distribution is determined by adding the multi-stage PID controller and the closed-loop pole distribution limit index within the full envelope of the aircraft and the model identification method in system identification to determine the number of stages and parameter values ​​of the multi-stage PID robust controller; from the root Based on the concept of closed-loop pole distribution limitation under trajectory description, a low-altitude flight controller that can suppress flutter, have small overshoot, and be stable in line with the full flight envelope is designed

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