CN103543743A - Method for preventing control plane integral saturation in aircraft ground servo elasticity test - Google Patents

Abstract

The invention belongs to the field of aircraft strength tests, and relates to the category of aircraft aeroelasticity tests, in particular to a method for preventing control plane integral saturation in an aircraft ground servo elasticity test. A real-time emulation system is connected between a flight control sensor and a flight control computer in series. The real-time emulation system comprises a main control computer and an emulation computer. After parameters of a high-pass filter are set and coded in the main control computer, the coded parameters are transmitted to the emulation computer. The parameters of the high-pass filter are designed with the dynamic characters of the control law within the range of the aircraft elastic vibration frequency as the restraint, the time of control plane integral saturation is prolonged, fast control plane integral saturation is effectively restrained, and meanwhile the effect on the test result is reduced to the maximum extent. The filter is placed in an external emulation machine, hardware and software of an onboard control system do not need to be adjusted, the parameters of the filter can be adjusted according to the actual situation in the test, and the method is high in adaptability and practicability.

Description

The anti-integration saturation process of the servo elasticity test rudder face of a kind of aircraft floor

Technical field

The invention belongs to strength of aircraft test field, relate to aircraft aeroelastic effect test category, relate in particular to the anti-integration saturation process of the servo elasticity test rudder face of a kind of aircraft floor.

Background technology

Modern digital fly-by-wire flight control system mostly has attitude and keeps and automatic trim function, and these realizations of controlling function all will configure integral element conventionally in backfeed loop.Owing to there being integral element in backfeed loop, in ground surface servo elasticity test, as long as there is drift or static difference in feedback signal, As time goes on the inclined to one side instruction of rudder is by saturated, when special integration constant in backfeed loop is larger, rudder face will be saturated fast at short notice, cause test to carry out.

At present, the rudder face integration saturation problem occurring in surface servo elasticity test over the ground, conventionally adopt integration short-circuiting method, directly by the integral element of removing in backfeed loop, obviously this,, by the control law dynamic perfromance in aircraft elastic vibration frequency range is changed, affects the reliability of test findings.

Summary of the invention

The object of the invention is: guaranteeing affects under minimum prerequisite the Flight Control Law dynamic perfromance in aircraft elastic vibration frequency range, solve in the servo elasticity test of aircraft floor, the rudder face quick point that exists integral element to cause due to backfeed loop is saturated, the technical matters that cannot normally test.

Technical scheme of the present invention:

Seal in real-time emulation system flying to control between sensor and flight control computer, real-time emulation system comprises main control computer and simulation computer, transfers to simulation computer after completing the setting of Hi-pass filter parameter and compiling in main control computer; In main control computer, the setting of Hi-pass filter parameter is,

1) structure high pass filter function:

$H_F\left(s\right)=\frac{s^2}{s^2+2\·\mathrm{\ξ}\·{\mathrm{\ω}}_n\·s+{\mathrm{\ω}}_n^2}$

In formula: s is Laplace operator, ω _nfor circular frequency, ξ=0.5～1.0 are damping ratio;

2) given damping ratio ξ, solves following constrained optimization problem and obtains ω _n

Wherein i is imaginary symbols, the maximum amplitude deviation that Δ A allows for test, for the maximum skew that test allows, ω ₁the intrinsic elastic vibration circular frequency of lowest-order for aircraft;

3) by ω _nwith ξ substitution above-mentioned steps 1), obtain Hi-pass filter H _f(s) expression;

4) in main control computer, complete Hi-pass filter H _f(s) compiling, generates executable code and transfers to simulation computer;

5) fly to control the Hi-pass filter H of sensor output signal in simulation computer _f(s) eliminate and to enter flight control computer after drift or static difference and carry out the inclined to one side instruction of rudder and solve.

Advantage and good effect that the present invention has are: in the backfeed loop with integrator, introduce Hi-pass filter, the Flight Control Law dynamic perfromance change amount of take in aircraft elastic vibration frequency range is constraint, carry out filter parameter design, extending rudder face integration saturation time, when effectively containment rudder face quick point is saturated, reduce to greatest extent wave filter and introduce the impact on test findings, with respect to the effective reliability of lifting test result of existing integration short-circuiting method.In addition, because the drift of feedback signal or the elimination of static difference are to realize by being placed in the digital filter of real-time emulation system, therefore without aircraft mounted control system hardware and software is carried out to any change, and in process of the test, can to filter parameter, adjust in real time according to actual conditions strong adaptability.

Accompanying drawing explanation

Fig. 1 is principle of the invention schematic diagram.

Embodiment

With reference to accompanying drawing, describe the present invention in detail.

1, the flying to control between sensor and flight control computer and seal in real-time emulation system of aircraft, real-time emulation system comprises main control computer and simulation computer;

2, in main control computer, complete the setting of Hi-pass filter parameter, specific as follows:

1), according to the width phase frequency characteristic of typical second-order system in control theory, structure high pass filter functional form is as follows:

$H_F\left(s\right)=\frac{s^2}{s^2+2\·\mathrm{\ξ}\·{\mathrm{\ω}}_n\·s+{\mathrm{\ω}}_n^2}$

In formula: s is Laplace operator, ω _nfor circular frequency, ξ=0.5～1.0 are damping ratio;

2) selected damping ratio ξ (value of ξ and aircraft lowest-order elastic vibration model frequency exist proportional relation), with Hi-pass filter H _f(s) in the amplitude minimum at 0.01 times of aircraft lowest-order Elastic mode frequency place as objective function, construct following constrained optimization problem

Wherein i is imaginary symbols, the maximum amplitude deviation that Δ A allows for test,

for the maximum skew that test allows, ω ₁the intrinsic elastic vibration circular frequency of lowest-order for aircraft.

3) solve above-mentioned steps 2) the constrained optimization problem of constructing, obtain ω _n

4) by ω _nwith ξ substitution above-mentioned steps 1), obtain Hi-pass filter H _f(s) expression;

3, in main control computer to Hi-pass filter H _f(s) compile, generate executable code and transfer to simulation computer;

4, fly to control the Hi-pass filter H of sensor output signal in simulation computer _f(s) eliminate and to enter flight control computer after drift and static difference and carry out the inclined to one side instruction of rudder and solve, thereby avoid rudder face quick point saturated.

Embodiment

1, seal in real-time emulation system flying to control between sensor and flight control computer, real-time emulation system comprises main control computer and simulation computer

2, in main control computer, complete the setting of Hi-pass filter parameter, specific as follows

1) structure high pass filter functional form is as follows:

$H_F\left(s\right)=\frac{s^2}{s^2+2\mathrm{\ξ}{\mathrm{\ω}}_n\·s+{\mathrm{\ω}}_n^2}$

2) choose ξ=0.707 and solve following constrained optimization problem

Δ A=0.18dB wherein,

ω ₁=11.6rad/s

Obtain ω _n=0.4293, Hi-pass filter H _f(s) expression:

$H_F\left(s\right)=\frac{s^2}{s^2+0.6066\·s+0.184}$

3, the Hi-pass filter H setting up in main control computer _f(s) model, compiles and is downloaded to simulation computer;

4, pitch angle feedback signal is first carried out high-pass filtering by replicating machine, after send into again flight control computer and carry out control law and resolve output rudder inclined to one side instruction;

5,, during autopilot engagement, there is integral element in pitch angle backfeed loop

there is the static difference of 2.3 degree in surface servo elasticity test medium dip angle, ground, if pitch angle signal is not carried out to high-pass filtering, rudder face will reach full drift angle 20 degree after control system is connected 14 seconds, but pitch angle signal is after above-mentioned high-pass filtering is processed, after system is connected 30m minute, rudder face still remains on neutral position.

Claims (1)

1. the anti-integration saturation process of the servo elasticity test rudder face of aircraft floor, it is characterized in that, seal in real-time emulation system flying to control between sensor and flight control computer, real-time emulation system comprises main control computer and simulation computer, after completing the setting of Hi-pass filter parameter and compiling, transfers to simulation computer in main control computer; In main control computer, the setting of Hi-pass filter parameter is,

1) structure high pass filter function:

$H_F\left(s\right)=\frac{s^2}{s^2+2\·\mathrm{\ξ}\·{\mathrm{\ω}}_n\·s+{\mathrm{\ω}}_n^2}$

In formula: s is Laplace operator, ω _nfor circular frequency, ξ=0.5～1.0 are damping ratio;

2) given damping ratio ξ, solves following constrained optimization problem and obtains ω _n

Wherein i is imaginary symbols, the maximum amplitude deviation that Δ A allows for test,

for the maximum skew that test allows, ω ₁the intrinsic elastic vibration circular frequency of lowest-order for aircraft;

3) by ω _nwith ξ substitution above-mentioned steps 1), obtain Hi-pass filter H _f(s) expression;

4) in main control computer, complete Hi-pass filter H _f(s) compiling, generates executable code and transfers to simulation computer;

5) fly to control the Hi-pass filter H of sensor output signal in simulation computer _f(s) eliminate and to enter flight control computer after drift or static difference and carry out the inclined to one side instruction of rudder and solve.

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