CN-120295356-B - Spacecraft attitude control method based on event triggering

CN120295356BCN 120295356 BCN120295356 BCN 120295356BCN-120295356-B

Abstract

The invention discloses a spacecraft finite time sliding mode attitude control method based on dynamic threshold triggering, which comprises the following steps of firstly, and establishing an attitude tracking error model of the spacecraft through a kinematic and dynamic model based on quaternion. Then, a finite-time nonsingular sliding mode surface is designed, and a fuzzy logic system is combined to perform approximate processing on concentrated disturbance in the system, so that the anti-interference capability and control precision of the system are improved. Finally, a limited time gesture tracking controller is designed through a dynamic threshold triggering mechanism, and control updating is triggered only when the system state change reaches a preset threshold, so that communication and calculation burden is obviously reduced, and the system is ensured to be converged and kept stable in a limited time. According to the invention, by introducing a dynamic threshold trigger mechanism and a limited time sliding mode control technology, the control update frequency is simplified, and the precise processing of concentrated disturbance is realized by combining a fuzzy logic system, so that the control precision and stability of the system are improved, and a solid technical support is provided for spacecraft attitude control.

Inventors

ZHANG YING
LI XINUO
WU AIGUO
LI ZHI
HUANG QIN

Assignees

哈尔滨工业大学(深圳)(哈尔滨工业大学深圳科技创新研究院)

Dates

Publication Date: 20260512
Application Date: 20250324

Claims (7)

1. The spacecraft attitude control method based on event triggering is characterized by comprising the following steps of: Firstly, establishing a spacecraft model based on quaternions, defining an attitude tracking error and an angular velocity tracking error, and converting the spacecraft model into a tracking error model; step two, designing a sliding mode surface S, and ensuring that the attitude tracking error q ev can be converged to an original point in a limited time when the sliding mode surface S=0; Step three, aiming at concentrated disturbance in the model, approximating the concentrated disturbance by using a fuzzy logic system, wherein the specific steps are as follows: Step three, deriving the sliding die surface S in the step two to obtain a concentrated disturbance y in the system: Wherein, the Γ=diag(Γ 1 ,Γ 2 ,Γ 3 ), i=1,2,3, As the centralized disturbance of the system, psi is an auxiliary variable; step three, aiming at the concentrated disturbance gamma obtained in the step three, approximating the concentrated disturbance gamma by using a fuzzy logic system: Υ(S)=θ(S) T Φ(S) Wherein S is an input vector, phi (S) is a fuzzy basis function, and theta (S) is a corresponding coordinate of gamma (S) under phi (S); Step four, designing a dynamic event trigger mechanism, and designing a spacecraft limited time attitude tracking controller on the basis of the dynamic event trigger mechanism to ensure that the system can converge in limited time, wherein the method comprises the following specific steps of: Step four, assuming that the kth sampling point of the spacecraft state is t k , then the kth+1th sampling point is t k+1 , a measurement error e S ＝S(t)-S(t k ),e F ＝F(t)-F(t k is defined, S (t) and S (t k ) respectively represent values of S at times t and t k , and F (t) and F (t k ) respectively represent values of F at times t and t k , where the triggering condition of the dynamic threshold trigger is as follows: t k+1 ＝inf{t>t k |||e S || 2 ≥α 1 ||S|| 2 +γ 1 +h 1 (t) Or e F || 2 ≥α 2 ||S｜| 2 +γ 2 +h 2 (t) } Wherein α 1 ,α 2 ∈(0,1),γ 1 ,γ 2 ≥0,H 1 (·),H 2 (·) is the local lipshitz continuous k ∞ function; step four, designing a finite time controller tau on the basis of the step four: Wherein, the Respectively, the estimated values of S, theta and F, wherein theta (t k ) represents the value of theta at the time of t k , and k is more than 0; step four, defining a Lyapunov function v=v 1 +V 2 : Wherein, the For fuzzy weights Is used for the error of (a), The update law of (2) is: Wherein the method comprises the steps of β>0; And fifthly, combining an event triggering mechanism with a limited time controller to form a closed-loop control structure of the system, wherein the limited time controller ensures that the spacecraft tracks the target gesture in the closed-loop system, and the event triggering mechanism obtains the actual control moment of the spacecraft to realize stable control of the spacecraft gesture.
2. The spacecraft attitude control method based on event triggering according to claim 1, wherein the specific steps of the step one are as follows: Step one, a rigid spacecraft with external interference is considered, and a spacecraft kinematics and dynamics model based on quaternion is established: Wherein ω represents an angular velocity, Representing quaternion, q 0 is a scalar part, q v is a vector part, J is rotational inertia of the spacecraft, τ represents control moment, d represents external disturbance, I 3 represents a3×3 identity matrix, and [ omega × ] represents a cross operator; step one, defining a system gesture and an expected gesture Attitude tracking error between Q d0 ,q dv is a scalar portion and a vector portion of q d , q e0 ,q ev is a scalar portion and a vector portion of q e , respectively, and an angular velocity tracking error ω e ＝ω-Cω d ,ω d is defined as a desired angular velocity, to obtain a tracking error model: wherein c represents the rotation matrix.
3. The method for controlling the attitude of the spacecraft based on the event triggering according to claim 2, wherein in the step one, a cross operator Is defined as: Wherein ω i is the angular velocity component in three directions, i=1, 2,3, respectively.
4. The spacecraft attitude control method based on event triggering according to claim 2, wherein in the step one,
5. The spacecraft attitude control method based on event triggering according to claim 2, wherein the specific steps of the second step are as follows: step two, defining a sliding die surface s as follows: Wherein q evi is the component of each direction of q ev , lambda 1 >0,λ 2 >0, a >1; Step two, defining Lyapunov function And derives it: it is guaranteed that it can converge to the origin in a limited time when s=0.
6. The method according to claim 5, wherein in the first step, the function sig (·) is defined as sig a (x)＝[|x 1 | a ·sgn(x 1 ),…,|x n | a ·sgn(x n )] T ,x＝[x 1 ,x 2 ,…,x n ] T being an n-dimensional vector, and x n being an nth component of x.
7. The method for controlling the attitude of a spacecraft based on event triggering according to claim 1, wherein in the third step, the auxiliary variable ψ is defined as:

Description

Spacecraft attitude control method based on event triggering Technical Field The invention belongs to the field of spacecraft attitude control, relates to a spacecraft attitude control method, and in particular relates to a spacecraft finite time sliding mode attitude control method based on dynamic threshold triggering. Background With the rapid development of the aerospace technology, the modern spacecraft has increasingly complex functions, and higher requirements are put on a gesture control system of the modern spacecraft. The traditional attitude control method mostly adopts a periodic or continuous control strategy, and has the problems of high communication frequency, high energy consumption, low resource utilization rate and the like although the basic requirements can be met. The event triggering control is used as an emerging control strategy, and can trigger control actions according to system state changes, so that unnecessary operations are reduced, the communication and calculation burden of a system is effectively reduced, and the resource utilization efficiency is improved. Although event-triggered control has shown significant advantages in the fields of robots, network control systems and the like, the application in spacecraft attitude control is still in a preliminary research stage, and is mainly focused on theoretical discussion and simulation verification. Therefore, the application of the event triggering control to spacecraft attitude tracking control has important research value, not only can enrich the existing control theory, but also can promote the development and application of spacecraft control technology. Disclosure of Invention In order to overcome the limitations of the traditional method and improve the resource utilization efficiency and control precision, reliable support is provided for spacecraft attitude control and scientific technology propulsion, and the invention provides a spacecraft attitude control method based on event triggering. According to the method, a dynamic threshold trigger mechanism is designed, and a limited time controller is combined, so that the communication efficiency is improved, the tracking effect and stability of the system are guaranteed, and solid technical support is provided for nonlinear system control. The invention aims at realizing the following technical scheme: a spacecraft attitude control method based on event triggering comprises the following steps: Firstly, building a spacecraft model based on quaternion, defining an attitude tracking error and an angular velocity tracking error, and converting the spacecraft model into a tracking error model, wherein the method comprises the following specific steps of: Step one, a rigid spacecraft with external interference is considered, and a spacecraft kinematics and dynamics model based on quaternion is established: Wherein ω represents an angular velocity, Represents a quaternion, q 0 is a scalar portion, q v is a vector portion, and satisfiesJ is the rotational inertia of the spacecraft, τ represents the control moment, d represents the external disturbance, I 3 represents a 3×3 identity matrix, [ omega × ] represents a cross operator; step one, defining a system gesture and an expected gesture Attitude tracking error betweenQ d0,qdv is a scalar portion and a vector portion of q d, q e0,qev is a scalar portion and a vector portion of q e, respectively, and an angular velocity tracking error ω e＝ω-Cωd,ωd is defined as a desired angular velocity, to obtain a tracking error model: wherein C represents a rotation matrix; Step two, designing a sliding mode surface S, and ensuring that the attitude tracking error q ev can be converged to an original point in a limited time when the sliding mode surface S=0, wherein the specific steps are as follows: step two, defining a sliding die surface S as follows: Wherein q evi is the directional component of q ev, λ 1>0,λ2 >0, a >1, function sig (·) is defined as siga(x)＝[|x1|a·sgn(x1),…,|xn|a·sgn(xn)]T,x＝[x1,x2,…,xn]T being an n-dimensional vector, x i (i=1, 2,., n) being the i-th component of x; Step two, defining Lyapunov function And derives it: Ensuring that it can converge to the origin in a limited time when s=0; Step three, aiming at concentrated disturbance in the model, approximating the concentrated disturbance by using a fuzzy logic system, wherein the specific steps are as follows: Step three, deriving the sliding die surface S in the step two to obtain a concentrated disturbance y in the system: Wherein, the Γ=diag(Γ1,Γ2,Γ3),i=1,2,3,As the centralized disturbance of the system, psi is an auxiliary variable; step three, aiming at the concentrated disturbance gamma obtained in the step three, approximating the concentrated disturbance gamma by using a fuzzy logic system: Υ(S)=θ(S)TΦ(S) Wherein S is an input vector, phi (S) is a fuzzy basis function, and theta (S) is a corresponding coordinate of gamma (S) under phi (S); Step four, des