Design method for longitudinal flight model cluster flutter-restraining composite root-locus compensation robust controller

Abstract

The invention provides a design method for a longitudinal flight model cluster flutter-restraining composite root-locus compensation robust controller. According to the design method, a model cluster composed of amplitude-frequency characteristics and phase-frequency characteristics in a whole envelope is determined directly through frequency sweep flight tests with different heights and different Mach numbers given; a closed-loop pole distribution limiting index described by a corresponding root locus is given according to military standard requirements for amplitude-frequency margin and phase margin, a multi-stage tandem lag-lead compensating controller is additionally arranged, and therefore the number of stages and parameter values of a multi-stage tandem lag-lead compensation robust controller are determined through a model identification method in a closed-loop pole distribution limiting index and system identification process in the whole envelope of an air vehicle; a low-altitude flight robust controller which is capable of restraining flutter, small in overshoot and steady and accords with a whole flight envelope is designed from the conception of closed-loop pole distribution limiting described by a root locus.

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 composite root locus compensation 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-low...

AI Technical Summary

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 defect, the present invention provides a method for designing a robust controller for longitudinal flight model cluster flutter suppression composite root locus compensation, the method directly determines and obtains the full envelope by sweeping flight tests under the conditions of different altitudes and Mach numbers The model cluster composed of the amplitude-frequency and phase-frequency characteristics in the flight envelope; according to the military standard requirements of the amplitude-frequency margin and phase margin in the flight envelope, the closed-loop pole distribution limit index under the corresponding root locus description is given. By adding multi-level The series lag-lead compensation 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 series and parameter values ​​of the multi-level series lag-lead compensation robust controller; from the root locus Based on the concept of the closed-loop pole distribution limit under the description, a robust controller for low-altitude flight that can suppress chatter, have small overshoot, and be stable in line with the full flight envelope is designed.

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