CN-122018534-A - Nonsingular predetermined time aircraft increment attitude control method

CN122018534ACN 122018534 ACN122018534 ACN 122018534ACN-122018534-A

Abstract

The invention discloses a non-singular predetermined time aircraft incremental attitude control method which comprises the steps of establishing an attitude dynamics model, converting the attitude dynamics model into an angular rate equation in a strictly feedback nonlinear form, performing first-order Taylor expansion on the angular rate equation to obtain an incremental dynamics equation in the nonlinear form, designing a predetermined time attitude angle controller and an attitude angle virtual controller of an aircraft, designing the predetermined time incremental angular rate controller of the aircraft and an angular rate virtual controller in a non-singular predefined time convergence form, and modifying the controller by utilizing the output of a filter to obtain the non-singular predetermined time incremental angular rate controller and the angular rate virtual controller. The controller is designed to be nonsingular, so that the stability of a closed-loop control system is ensured, the robustness and the anti-interference capability of the system can be effectively improved by the incremental controller, the convergence time of the attitude angle controller can be custom designed by a user, and the convergence time is not influenced by the initial state of the system.

Inventors

SHI JINGPING
HUANG SHAN
QU XIAOLEI
Jiao Daixin
LV YONGXI
DU ZHIHUI

Assignees

西北工业大学

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (8)

1. A non-singular predetermined time aircraft delta attitude control method, comprising: S1, establishing an attitude dynamics model of an aircraft according to aerodynamic data, and converting the attitude dynamics model into an angular rate equation of the aircraft, wherein the angular rate equation of the aircraft is in a strict feedback nonlinear form facing control; s2, performing first-order Taylor expansion on an angular rate equation of the aircraft to obtain a nonlinear incremental kinetic equation; s3, designing a preset time attitude angle controller of the aircraft according to the attitude angle information and the attitude angle instruction, and designing a non-singular pre-defined time convergence type attitude angle virtual controller; S4, designing a preset time increment type angular rate controller of the aircraft according to the angular acceleration information, the angular velocity information, the attitude angle controller and the attitude angle virtual controller, and designing an angular rate virtual controller in a nonsingular predefined time convergence form; S5, designing a non-singular preset time filter, and utilizing the differential of an angular rate instruction output by the filter and the differential of the angular rate instruction of the angular rate controller and the angular rate virtual controller to respectively replace the angular rate instruction and the angular rate instruction of the understudy speed controller and the angular rate virtual controller to obtain the preset time increment type angular rate controller without singular points and the preset time increment type angular rate virtual controller without singular points.
2. The nonsingular predetermined time aircraft incremental attitude control method according to claim 1, wherein in S1, the attitude dynamics model of the aircraft is as follows: Wherein, the Is an attitude angle vector of the aircraft, Is that Is used for the differentiation of the (c) and (d), 、、 Respectively representing pitch angle, roll angle and yaw angle of the aircraft, A transition matrix representing attitude angle differentiation and angular rate, As a vector of the angular rate, Is that Is used for the differentiation of the (c) and (d), In order for the angular acceleration to be the same, 、、 The roll angle rate, pitch angle rate and yaw angle rate are expressed respectively, In order to have a matrix of moment of inertia, Is a matrix of aerodynamic moments.
3. The nonsingular predetermined time aircraft delta attitude control method according to claim 2, wherein in S1, the aircraft angular rate equation is as follows: Wherein, the As a non-linear term of the term, In order to control the performance matrix, For the control performance matrix generated by the control surface, In order to control the amount of input, 、、、、、 Respectively a left inner aileron, a left outer aileron, a right inner aileron, a right outer aileron, a duck wing and a rudder, wherein Q is dynamic pressure, For the area of the wing of the aircraft, For a diagonal matrix with respect to the spanwise and average aerodynamic chord length of the wing, And Respectively representing the spanwise and average aerodynamic chord lengths of the wing, A diagonal matrix is represented and, , , Respectively a rolling moment coefficient, a pitching moment coefficient and a yawing moment coefficient which are generated by an airplane body, For the roll damping derivative, For the roll-yaw coupling derivative, For the pitch damping derivative, For the yaw-roll coupling derivative, For the course damping derivative, , , Is the airspeed.
4. A non-singular predetermined time aircraft delta attitude control method according to claim 3, wherein in S2, the delta kinetic equation in nonlinear form is as follows: Wherein, the For the angular acceleration at the moment of sampling, For the control performance matrix at the sampling instant, , Is a control surface deflection command, and is used for controlling the steering surface to deflect, For the control surface deflection command at the sampling instant, As a residual term, For the angular acceleration vs. angular rate bias at the sampling instant, , For the angular rate at the moment of sampling, As the small items of the higher order, Gradually decreasing as the sampling frequency increases, Is satisfied by the mould of (2) , Is a bounded positive constant.
5. The nonsingular predetermined time aircraft incremental attitude control method according to claim 4, wherein in S3, the predetermined time attitude angle controller is as follows: Wherein, the In the event of an angular rate command, In order to be an instruction of the attitude angle, Is the derivative of the attitude angle command, Is a virtual controller of attitude angle.
6. The nonsingular predetermined time aircraft delta attitude control method of claim 5, wherein the attitude angle virtual controller is as follows: Wherein, the Is a virtual controller for the attitude angle, For the tracking error of the attitude angle, , , As a function of the sign of the symbol, , , , , 、、 And The control parameters are to be designed.
7. The nonsingular predetermined time aircraft delta attitude control method according to claim 6, wherein in S4, the predetermined time delta angular rate controller is as follows: Wherein, the As a virtual controller of the angular rate, The following is shown: Wherein, the Indicating the angular rate tracking error, , , , , 、 And Is a positive parameter to be designed.
8. The non-singular predetermined time aircraft delta attitude control method of claim 7, wherein the predetermined time delta angular rate controller without singularities in S5 is as follows: Predetermined time increment type angular rate virtual controller without singular point The following are provided: Wherein, the An angular rate command for the filter output.

Description

Nonsingular predetermined time aircraft increment attitude control method Technical Field The invention relates to the technical field of attitude control, in particular to a nonsingular predetermined time aircraft increment attitude control method. Background The fixed wing aircraft has excellent stability and practicality, and plays an irreplaceable role in a plurality of key fields such as logistics transportation, scouting, searching and rescuing and the like. Attitude control of fixed wing aircraft has long presented significant challenges, mainly due to inherent nonlinear dynamics of the aircraft system itself, strong coupling between multiple channels, and complex control surface distribution issues, while also coping with persistent external airflow disturbances and model uncertainties. Particularly in certain special task scenarios, to meet high mobility requirements, higher standards are put forward on the dynamic performance and robustness of the flight control system. In view of the above problems, various control strategies have been proposed in the related art, such as conventional back-step control, L1 adaptive control, and incremental dynamic back-control. However, most of these methods only ensure the asymptotic convergence of the closed-loop system, and there is still room for improvement in terms of convergence speed and immunity. For this reason, a limited time control method is introduced to enhance the robustness of the system and to accelerate the convergence process. However, the upper limit of the convergence time of the method is severely dependent on the initial state of the system, and when the initial value is large, the finite time convergence is difficult to realize. To further overcome the above limitations, fixed time control strategies have been developed whose upper convergence time bound is independent of the system initial value. However, the upper bound is still affected by system parameters, and when model parameters are complex or uncertain, it is difficult to accurately estimate convergence time, which limits the practical application of the model in a flight control system to a certain extent. The predetermined time control method shows unique advantages in this context. The method can ensure that the tracking error converges to a desired neighborhood within a time preset by a user, and the time upper bound can be explicitly adjusted independently of the initial conditions of the system. More importantly, the decoupling between the convergence time and the controller parameters is realized by the control of the preset time, and the stability time of the decoupling depends on only one directly adjustable design parameter, so that the engineering practicability is greatly improved. However, the existing predetermined time control method may have a singular value problem in the virtual control amount derivation process, resulting in unstable system. To avoid singular points, current research is mostly handled by constructing piecewise continuous functions or quadratic fractional functions, but this often results in complexity of stability demonstration and increases on-line computational burden. Accordingly, there is a need to improve one or more problems in the related art as described above. It is noted that this section is intended to provide a background or context for the technical solutions of the present disclosure as set forth in the claims. The description herein is not admitted to be prior art by inclusion in this section. Disclosure of Invention The present invention is directed to a non-singular predetermined-time aircraft delta attitude control method that, at least in part, overcomes one or more of the problems due to the limitations and disadvantages of the related art. The invention provides a nonsingular predetermined time aircraft increment attitude control method, which comprises the following steps: S1, establishing an attitude dynamics model of an aircraft according to aerodynamic data, and converting the attitude dynamics model into an angular rate equation of the aircraft, wherein the angular rate equation of the aircraft is in a strict feedback nonlinear form facing control; s2, performing first-order Taylor expansion on an angular rate equation of the aircraft to obtain a nonlinear incremental kinetic equation; s3, designing a preset time attitude angle controller of the aircraft according to the attitude angle information and the attitude angle instruction, and designing a non-singular pre-defined time convergence type attitude angle virtual controller; S4, designing a preset time increment type angular rate controller of the aircraft according to the angular acceleration information, the angular velocity information, the attitude angle controller and the attitude angle virtual controller, and designing an angular rate virtual controller in a nonsingular predefined time convergence form; S5, designing a non-singular preset time filter, and uti