Design method for longitudinal flight model cluster composite PID robust controller

Abstract

The invention provides a design method for a longitudinal flight model cluster composite PID 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; an open-loop cut-off frequency section is directly determined according to the amplitude-frequency characteristics in a flight envelope; a phase margin section corresponding to the cut-off frequency section is directly determined according to the phase-frequency characteristics in the flight envelope; a multi-stage PID controller is additionally arranged, and therefore the number of stages and parameter values of a multi-stage PID robust controller are determined through a model identification method in a phase margin index and system identification process in the whole envelope of an air vehicle; the effect of the controller is verified with the decibel of a magnitude margin index L* in the whole envelope of the air vehicle given; a low-altitude flight robust controller which is small in overshoot and steady and accords with a whole flight envelope is designed from the conceptions of phase margin and magnitude margin.

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 composite PID robust controller, which belongs to the categories of measurement and control technology, flight mechanics and the like. 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-altitude flight controllers v...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the technical defect that the existing method cannot design a small overshoot and stable low-altitude flight controller that meets the stability margin index in the full flight envelope when the model of the aircraft varies greatly in the full flight envelope, the present invention A method for designing a composite PID robust controller for a longitudinal flight model cluster is provided. This method directly determines the amplitude-frequency and phase-frequency characteristics in the full envelope through frequency-sweeping flight tests under the conditions of different altitudes and Mach numbers. Model cluster; directly determine the open-loop cut-off frequency interval according to the amplitude-frequency characteristics in the flight envelope; directly determine the phase margin interval corresponding to the cut-off frequency interval according to the phase-frequency characteristics in the flight envelope; by adding a multi-level PID controller And the phase margin index in the full envelope of the aircraft and the model identification method in the system identification determine the number of stages and parameter values ​​of the multi-level PID robust controller; the amplitude margin index L in the full flight envelope of the aircraft * Verify the controller effect under the given decibel number; design a low-altitude flight robust controller with small overshoot and stability in line with the full flight envelope from the concept of phase margin and amplitude margin

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