CN111580552A

CN111580552A - Automatic flight control method for circular flight path of airplane

Info

Publication number: CN111580552A
Application number: CN202010386373.2A
Authority: CN
Inventors: 周中盼; 贾自立; 冯书君; 宁亚锋; 徐坚; 何巧云; 王卫东; 谷计划; 回小晶; 陈海龙
Original assignee: AVIC Shaanxi Aircraft Industry Group Corp Ltd
Current assignee: Shaanxi Aircraft Industry Co Ltd
Priority date: 2020-05-09
Filing date: 2020-05-09
Publication date: 2020-08-25
Anticipated expiration: 2040-05-09
Also published as: CN111580552B

Abstract

The invention belongs to the technical field of aviation, and provides a control method for accurately controlling a horizontal flight path of an airplane and enabling the airplane to automatically fly according to a preset circular flight path. In particular to an automatic flight control method for a circular flight path of an airplane. The method is based on the existing method, overcomes the problem that the existing control method is influenced by the control precision, wind, sideslip and the like of the system, and leads the airplane to generate stable flight path deviation, provides a control method for accurately controlling the horizontal flight path of the airplane and leading the airplane to automatically fly according to the preset circular flight path, and has the advantages of simplicity, reliability, small change and convenient operation.

Description

Automatic flight control method for circular flight path of airplane

Technical Field

The invention belongs to the technical field of aviation, and particularly relates to an automatic flight control method for a circular flight path of an airplane.

Background

In the flying process, according to the use requirement, sometimes the airplane needs to be controlled to automatically fly according to the horizontal track of the standard circle (hereinafter, the airplane is referred to as the circle track automatic flight) by taking a certain fixed geographical position as the center of the circle for a long time, namely the airplane needs to be controlled to enable the horizontal track to be the standard circle. The common horizontal flight path automatic control method of the airplane is that according to information such as real-time position coordinates of the airplane, real-time speed vectors of the airplane and the like provided by an airplane navigation system, a preset horizontal flight path coordinate analytic equation is combined to calculate flight path deviation and flight path deviation rate, then the turning degree-gradient size required by the airplane is calculated, and the automatic flight control system is used as an executing mechanism to control the airplane to turn according to the calculated gradient, so that the airplane automatically follows the preset horizontal flight path. In the circular track automatic flight, the airplane needs to always turn at a certain slope, meanwhile, due to the influence of the control precision, wind, sideslip and the like of the system, the common control method is easy to enable the airplane to generate stable track deviation, the true horizontal track of the airplane is a concentric circle at the inner side (or the outer side) of the preset circular track, and the airplane cannot be accurately controlled to automatically fly according to the preset circular track.

According to the automatic control theory, in order to eliminate the steady-state error of the system, an integral link can be introduced into the system, however, in the process that the airplane keeps the circular track and automatically flies, the airplane is always in a turning maneuver state, the automatic flight control system is required to quickly follow the control command, and the horizontal track of the airplane can be kept in an error loop which takes the preset circular track as a central line and the control precision as the width. The introduction of the integral loop reduces the following response speed of the automatic flight control system to the control command, so that a method of directly integrating the flight path deviation cannot be adopted to eliminate the stable flight path deviation generated by the airplane.

Disclosure of Invention

The invention overcomes the defects of the prior common control method, eliminates the stable flight path deviation generated by the prior control method, and provides a control method for accurately controlling the horizontal flight path of the airplane and enabling the airplane to automatically fly according to the preset circular flight path.

Technical scheme

In order to solve the technical problems, the invention is realized by the following technical scheme:

automatic flight control method for circular flight path of airplane

1. And according to the expected circular track radius, calculating a theoretical turning slope required by the airplane by using the airplane turning simplified dynamic analysis model, and taking the theoretical turning slope as a reference slope for controlling the turning of the airplane by using the automatic flight control system.

2. And revising the reference gradient by combining the aerodynamic characteristic analysis of the airplane and engineering experience according to the preset use environment of the airplane so as to reduce the influence of wind on a control result.

3. And a fixed angle is superposed on the reference gradient to eliminate the influence of the control precision of the system.

4. According to a common airplane horizontal track automatic control method, an airplane horizontal motion response mathematical simplified model with an automatic flight control system is established, a corrected gradient calculation relation based on the common airplane horizontal track automatic control method is designed, and an airplane horizontal track corrected gradient is calculated by utilizing track deviation and track deviation rate.

And finally, adding the reference gradient, the superposed fixed angles and the corrected gradient calculated according to the steps to be used as a target gradient of the automatic flight control system, and controlling the airplane to automatically fly along the target gradient to realize the automatic control of the horizontal track of the airplane to be a standard circular track.

When the horizontal track correction gradient of the airplane is calculated in step 4, the whole circular track flying process of the airplane is divided into a plurality of stages,

different correction gradient calculation methods are designed at different stages.

At the initial stage of the circular flight path flight process, the stages are divided by the flight path deviation of the airplane, when the flight path deviation is more than a set fixed value, the corrected gradient is calculated according to the common automatic control method of the horizontal flight path of the airplane,

when the flight path deviation is not larger than the set fixed value, after the theoretical correction gradient is calculated according to a common airplane horizontal flight path automatic control method, the theoretical correction gradient is artificially amplified according to a designed functional relation to be used as an actual correction gradient;

after the circular track flying process enters the error ring zone, the included angle (track deflection angle) between the horizontal speed direction of the airplane and the tangential direction of the real-time position of the airplane at the radial projection point of the circular track is taken as the judgment basis,

when the flight path deflection angle is smaller than a preset fixed value, integrating the horizontal flight path deviation of the airplane, calculating the obtained integral value according to a designed functional relation, and superposing the integral value on the theoretical correction gradient calculated according to a common airplane horizontal flight path automatic control method.

Technical effects

The method is simple and reliable, has small change and convenient operation, designs and corrects the gradient in stages, has strong universality by introducing the characteristic of an integral link in due time, and can be widely applied to automatic flight control of other horizontal flight paths.

Drawings

FIG. 1 is a flow chart of the implementation of the method

FIG. 2 is a simplified dynamics analysis of aircraft turning

FIG. 3 is a schematic diagram of a conventional method for automatically controlling a horizontal flight path of an aircraft

Detailed Description

The invention relates to an automatic flight control method for a circular flight path of an airplane, which is explained in detail by combining the accompanying drawings:

1. by using the simplified dynamics analysis model for airplane turning shown in fig. 1, the theoretical turning gradient required by the airplane can be calculated and used as the reference gradient for controlling the airplane turning by the automatic flight control system. Wherein V is the ground speed of the aircraft, g is the gravitational acceleration, and R is the planned circular trajectory radius.

2. And according to the preset use environment of the airplane, assuming that the maximum wind speed which can be met by the airplane is Vw, correcting the reference gradient to be Vw.

3. According to the measurement and control precision of each relevant system of the airplane and by combining engineering experience, a fixed angle value is determined comprehensively and specifically and is superposed on a reference gradient for eliminating the influence caused by the control precision of the system, and after the step, the target gradient of the automatic flight control system is obtained.

4. According to a common automatic control method of the horizontal flight path of the airplane, the flight path deviation D and the flight path deviation rate are utilized to calculate the horizontal flight path corrected gradient of the airplane. After this step, the target grade of the automatic flight control system.

5. And (4) judging the current track deviation D, if the D is larger than a preset value D0, amplifying the target gradient calculated in the step (4) by k times to be used as the current final target gradient, and after the step, obtaining the target gradient of the automatic flight control system.

6. And if D is not greater than a preset value D0, judging a track deflection angle phi, and if phi is greater than a preset value phi 0, finally obtaining the target gradient.

7. If phi is not larger than the preset value phi 0, integrating the flight path deviation D and calculating the correction gradient. After this step, the target grade of the automatic flight control system.

8. The target gradient calculated by the steps is used as a control target of the automatic flight control system, namely, the horizontal flight path of the airplane is accurately controlled, so that the airplane automatically flies according to the preset circular flight path.

Claims

1. An automatic flight control method for a circular flight path of an airplane is characterized by comprising the following steps:

1) according to the expected circular track radius, calculating a theoretical turning slope required by the airplane by using an airplane turning simplified dynamic analysis model, and using the theoretical turning slope as a reference slope for controlling the turning of the airplane by an automatic flight control system;

2) revising the reference gradient by combining the aerodynamic characteristic analysis of the airplane and engineering experience according to the preset use environment of the airplane to reduce the influence of wind on a control result;

3) superposing a fixed angle on the reference gradient to eliminate the influence of the control precision of the system;

4) according to a common airplane horizontal track automatic control method, an airplane horizontal motion response mathematical simplified model with an automatic flight control system is established, a corrected gradient calculation relation based on the common airplane horizontal track automatic control method is designed, and an airplane horizontal track corrected gradient is calculated by utilizing track deviation and track deviation rate.

2. The method as claimed in claim 1, wherein the reference gradient, the fixed angle of each stack, and the correction gradient calculated in the above steps are added to be used as a target gradient of the automatic flight control system, and the airplane is controlled to automatically follow the target gradient, so as to realize automatic control of the horizontal trajectory of the airplane to be a standard circular trajectory.

3. The method for controlling the automatic circular flight path of the airplane as claimed in claim 1, wherein the whole circular flight path flight process of the airplane is divided into a plurality of stages when the horizontal flight path corrected gradient of the airplane is calculated in 4).

4. The method as claimed in claim 3, wherein different corrective gradient calculation methods are designed at different stages.

5. The method as claimed in claim 4, wherein the phase is divided by the flight path deviation in the initial stage of the circular flight, and when the flight path deviation is greater than a predetermined fixed value, the corrected gradient is calculated according to the conventional horizontal flight path automatic control method.

6. The method as claimed in claim 4, wherein when the deviation of the flight path is not greater than the predetermined fixed value, the theoretical correction gradient is calculated according to a conventional horizontal flight path automatic control method of the aircraft, and then the theoretical correction gradient is artificially amplified according to a designed functional relationship to be used as the actual correction gradient.

7. The method as claimed in claim 3, wherein after the circular flight path enters the error loop, the angle between the horizontal speed of the aircraft and the tangential direction of the real-time position of the aircraft at the radial projection point of the circular flight path is used as the basis for determining.

8. The method as claimed in claim 3, wherein when the track deviation angle is less than a predetermined fixed value, the integration of the horizontal track deviation of the aircraft is started, and the obtained integrated value is calculated according to the designed functional relationship and is superimposed on the theoretical correction gradient calculated according to the conventional horizontal track automatic control method of the aircraft.