Multi-AUV (Autonomous Underwater Vehicle) cooperative control method capable of meeting specified performance requirements

Abstract

The invention discloses a multi-AUV (Autonomous Underwater Vehicle) cooperative control method meeting specified performance requirements, which comprises the following steps of: firstly, determining a cluster system set, recording the total number of individuals in a cluster system as N, and controlling by using a specified multi-AUV communication topological graph; secondly, deploying a follow-up local coordinate system for each individual, constructing an individual AUV dynamical model, and designing a consistency control protocol which converges under different time performance requirements for environmental disturbance suffered by the multi-AUV system; and finally, the individuals carry out distributed information interaction through a communication topological graph, and meanwhile, a cooperative control protocol drives each AUV to realize consistency control convergence. According to the method, different controllers are allowed to be switched to complete multi-AUV cooperative control with different time performance convergence requirements, the defect that environment disturbance related information needs to be known in advance in AUV anti-interference control is overcome, consistent convergence under various time performance requirements is achieved, and meanwhile fault tolerance and robustness of a multi-AUV system are improved.

Description

Technical Field

[0001] This invention relates to the fields of computer science and control technology, and specifically to a multi-AUV cooperative control method that meets specified performance requirements. Background Technology

[0002] The background technology of multi-AUV (Autonomous Underwater Vehicle) cooperative control methods stems from the maturity of single-AUV technology and its limitations in complex tasks, such as insufficient endurance, limited operating range, and poor fault tolerance. This has prompted researchers to draw on multi-robot cooperative theories, such as swarm intelligence algorithms, consensus protocols, and distributed optimization in land robot formations and UAV swarms, and to combine these with the special characteristics of the underwater environment, such as limited communication, strong nonlinear dynamics, and uncertain disturbances. This has led to the development of communication architectures, cooperative navigation, and task allocation and path planning algorithms adapted to underwater multi-AUV cooperation. At the same time, centralized, distributed, and hybrid cooperative control systems are gradually being formed to improve the task efficiency and environmental adaptability of multi-AUV cooperative work.

[0003] Consistency is crucial in multi-AUV cooperative control. It studies how to achieve consensus among multiple AUVs under conditions of incomplete information, communication delays, node failures, or unreliable communication. Solving this problem directly affects the robustness, reliability, and overall performance of the system, thus becoming one of the core challenges of cooperative control. Similar consistency requirements are also widely found in fields such as multi-robot collaboration, blockchain technology, distributed databases, and autonomous driving. Their core goal is to ensure the coordinated and stable operation of distributed systems in complex environments. Existing technologies have the following shortcomings: (1) In multi-AUV cooperative control, problems such as environmental disturbances or controller failures may occur, leading to deviations in control results. Technologies for solving disturbance problems require prior knowledge of the dynamic model or relevant information (disturbance boundaries), but in reality, this information is often unknown. (2) Current multi-AUV cooperative control technologies based on second-order dynamic models have certain limitations: some studies have not deeply analyzed the convergence performance of the system, while others only design dedicated controllers for specific performance requirements, lacking universality. This situation restricts the application effect of multi-AUV cooperative control methods in real complex environments. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-AUV cooperative control method that meets specified performance requirements, so as to solve the problems mentioned in the background art.

[0005] To address the aforementioned technical problems, this invention provides a multi-AUV system anti-interference consistency convergence under different time performance requirements, including finite time, fixed time, and specified time, when the disturbance boundary is unknown. Specifically, it offers the following technical solution: a multi-AUV cooperative control method that meets specified performance requirements, comprising the following operational steps:

[0006] S1: Determine the set of multiple AUV systems. Let there be N autonomous underwater vehicles in the multiple AUV system. The topology is an undirected connected graph and the corresponding adjacency matrix is ​​A.

[0007] Preferably, A = [a ij ]∈R N×N ,i,j=1,2,...,N, where a ij This represents the connection between the i-th AUV and the j-th AUV. When there is communication between the i-th AUV and the j-th AUV, a ij =1, otherwise a ij =0, R N×N Let N be the notation for an N-dimensional matrix, and define N as follows: i Let N be the neighbor set of the i-th AUV. i ={j|a ij =1,j≠i}, and define L as the Laplace matrix.

[0008] S2: Deploy a local coordinate system for each individual AUV.

[0009] Preferably, the dynamic model of an individual AUV is as follows:

[0010]

[0011] in, For P i The derivative with respect to time, P i P represents the position of the i-th AUV in the global coordinate system. i =[x i ,y i ,z i ]^T∈R 3 x i ,y i ,z i R represents the coordinates of the i-th AUV on the x-axis (left-right), y-axis (front-back), and z-axis (up-down), respectively. 3 It is a three-dimensional column vector symbol. For V i The derivative with respect to time, V i V represents the linear velocity of the i-th AUV. i =[u i ,v i ,w i]^T∈R 3 u i ,v i ,w i J represents the velocity components of the i-th AUV along the x-axis, y-axis, and z-axis, respectively. i J represents the global and local coordinate system transformation matrix for the i-th AUV. i ∈R 3×3 R 3×3 This is a three-dimensional matrix notation. M represents the inertia matrix, M = diag{m1, m2, m3} ∈ R. 3×3 m1, m2, and m3 represent the moments of inertia about the x-axis, y-axis, and z-axis, respectively, and D i Represents the damping matrix, D i ∈R 3 ×3 , τ i τ ωi τ represents the system input and environmental disturbance of the i-th AUV, respectively. i ∈R 3 , τ ωi ∈R 3 .

[0012] S3: To address environmental disturbances experienced by multi-AUV systems, a consensus control protocol is designed that converges under different time performance requirements, driving the multi-AUV system to achieve cooperative control.

[0013] Preferably, the controller is designed as follows:

[0014]

[0015] Among them, V i (t) represents the linear velocity of the i-th AUV at time t, Z 1i (t) represents the position consistency error of the i-th AUV at time t. P i (t), P j (t) represents the positions of the i-th and j-th AUVs at time t, respectively, Z 2ti (t) represents the velocity consistency error of the i-th AUV at time t. V i (t), V j (t) represents the linear velocities of the i-th and j-th AUVs at time t, respectively, and k i (t) is a parameter designed based on different time performance, k i (t)≥1, g(·) represents the direction function, f(·) represents the attribute function, and Θ(·) represents the nonlinear function, which is used to realize the coordinated control of multiple time performances of a multi-AUV system.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The second-order system controller designed in the present invention adopts an adaptive method, which makes up for the deficiency of the existing second-order system anti-disturbance consistency control in which disturbance-related information needs to be obtained in advance. Furthermore, it extends the consistency controller performance for second-order systems, which can meet three different time performance requirements, improves the flexibility and practicality of the controller, and ultimately achieves stable multi-AUV cooperative control under unknown environmental disturbance conditions. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0018] In the attached diagram:

[0019] Figure 1 A flowchart of a multi-AUV cooperative control method that meets specified performance requirements provided in an embodiment of the present invention;

[0020] Figure 2 This is a multi-AUV communication topology diagram provided in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of positional consistency convergence provided in an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram illustrating the speed consistency convergence provided in an embodiment of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Combination Figures 1-4 The present invention provides the following technical solution: a multi-AUV cooperative control method that meets specified performance requirements, comprising the following operational steps:

[0025] S1: Determine a set of multiple AUV systems. Let N be the number of autonomous underwater vehicles (AUVs) in the system, and let A be the adjacency matrix of an undirected connected graph. A = [a ij ]∈R N×N ,i,j=1,2,...,N, where a ij This represents the connection between the i-th AUV and the j-th AUV. When there is communication between the i-th AUV and the j-th AUV, aij =1, otherwise a ij =0, R N ×N Let N be the symbol for an N-dimensional matrix. Define N... i Let N be the neighbor set of the i-th AUV. i ={j|a ij =1,j≠i}, and define L as the Laplace matrix.

[0026] S2: Deploy a local coordinate system for each individual AUV.

[0027] In this embodiment, the individual AUV dynamics model is as follows:

[0028]

[0029] in, For P i The derivative with respect to time, P i P represents the position of the i-th AUV in the global coordinate system. i =[x i ,y i ,z i ]^T∈R 3 x i ,y i ,z i R represents the coordinates of the i-th AUV on the x-axis (left-right), y-axis (front-back), and z-axis (up-down), respectively. 3 It is a three-dimensional column vector symbol. For V i The derivative with respect to time, V i V represents the linear velocity of the i-th AUV. i =[u i ,v i ,w i ]^T∈R 3 u i ,v i ,w i J represents the velocity components of the i-th AUV along the x-axis, y-axis, and z-axis, respectively. i J represents the global and local coordinate system transformation matrix for the i-th AUV. i ∈R 3×3 R 3×3 This is a three-dimensional matrix notation. M represents the inertia matrix, M = diag{m1, m2, m3} ∈ R. 3×3 m1, m2, and m3 represent the moments of inertia about the x-axis, y-axis, and z-axis, respectively, and D i Represents the damping matrix, D i ∈R 3 ×3 , τi τ ωi τ represents the system input and environmental disturbance of the i-th AUV, respectively. i ∈R 3 , τ ωi ∈R 3 .

[0030] S3: Based on S2, a consensus control protocol is designed to converge under different time performance requirements to address environmental disturbances experienced by multi-AUV systems, thereby driving the multi-AUV system to achieve cooperative control.

[0031] In this embodiment, to achieve consistent control convergence under different time performance requirements when subjected to an unknown upper bound disturbance, the following controller is designed:

[0032]

[0033] Among them, V i (t) represents the linear velocity of the i-th AUV at time t, Z 1i (t) represents the position consistency error of the i-th AUV at time t. P i (t), P j (t) represents the positions of the i-th and j-th AUVs at time t, respectively, Z 2i (t) represents the velocity consistency error of the i-th AUV at time t. V i (t), V j (t) represents the linear velocities of the i-th and j-th AUVs at time t, respectively, and k i (t) is a parameter designed based on different time performance, k i (t)≥1, g(·) represents the direction function, f(·) represents the attribute function, and Θ(·) represents the nonlinear function, which is used to realize the coordinated control of multiple time performances of a multi-AUV system.

[0034] For example, the choice of the direction function g(·) satisfies the following conditions:

[0035]

[0036] That is, xg(x) = |x|g(|x|), where x represents the independent variable, and there are three possible choices for its selection:

[0037] (1) Sign function:

[0038] (2) Boundary layer function: Parameters representing the adjustment of boundary layer thickness;

[0039] (3) Linear saturation function: This parameter represents the parameter used to adjust the threshold of the linear interval.

[0040] For example, the selection of the attribute function f(·) satisfies the following conditions:

[0041] (1) f(x) ≥ 0;

[0042] (2) F(|x|)=|x|g(|x|)f(|x|) is a monotonically increasing concave function;

[0043] The attribute functions will be designed based on different time performance requirements:

[0044] (1) Finite-time convergence:

[0045]

[0046] Where δ represents the finite-time convergence coefficient, δ>0, and ε represents the finite-time convergence exponent. Under the regulation of this property function, the states of each AUV in a multi-AUV system can achieve coordination within a finite time.

[0047] (2) Fixed-time convergence:

[0048]

[0049] Where δ1 and δ2 represent the convergence coefficients at a fixed time, δ1>0 and δ2>0 respectively, and p and q represent the convergence exponents at a fixed time respectively. Under the regulation of this attribute function, the states of each AUV in the multi-AUV system can achieve coordination within a fixed time.

[0050] (3) Convergence within a specified time:

[0051] f(|x|)=|x|,

[0052]

[0053] Where σ represents the convergence coefficient at a specified time, ζ represents the convergence boundary parameter at a specified time, σ≥1, ζ>0. Let H(t) be the derivative of H(t) with respect to time. H(t) represents the convergence adjustment function at a specified time, T represents a pre-set specified time point, and t represents the current time. Under the regulation of this property function, the states of each AUV in a multi-AUV system can achieve coordination within a specified time.

[0054] (4) The nonlinear function Θ(·) is designed as follows:

[0055]

[0056] Where ∈ represents a positive constant, used to switch between modes for eliminating unknown disturbances. This is the adaptive gain, used to estimate the underwater environmental disturbances experienced by the i-th AUV, with its initial value... The design is as follows:

[0057]

[0058] Where ρ represents the disturbance estimation exponent, ρ∈[1,3], μ is a positive constant, and m represents the disturbance estimation coefficient. max The value of m represents the maximum value of the moment of inertia. min Represents the minimum value of the moment of inertia, m max =max(m1,m2,m3),m min =min(m1,m2,m3), used to estimate disturbances.

[0059] In this embodiment, the stability of the multi-AUV system is proven using Lyapunov stability theory. For simplicity, subsequent formulas are omitted (t). The constructed Lyapunov function is as follows:

[0060]

[0061] Where P and V represent the position and velocity of the multi-AUV system, respectively. This represents the difference between the estimated disturbance and the actual disturbance. r * Assuming an upper bound for actual underwater environmental disturbances, its derivative can be derived to satisfy the following equation:

[0062]

[0063] Where, k i k represents different time performance parameters. min k represents the minimum value among different time performance parameters. min =min(k1,k2...k N N represents the number of AUVs in the multi-AUV system, F represents a monotonically increasing concave function composed of a direction function and a property function, Γ represents the minimum value of parameters λ2 and μ, Γ = min(λ2, μ), λ2 is the second minimum eigenvalue of the Laplacian matrix of the system connectivity graph, and n1 is a positive integer less than n. ι, These are configurable parameters used to achieve stability of the Lyapunov function.

[0064] In this embodiment, the uniform convergence time of the system under the three time performance requirements is as follows:

[0065] (1) Finite-time: The direction function is set as g(|x|)=sign(x), and the attribute function is set as f(|x|=δ|x|. ε The Lyapunov function in finite time with respect to the initial state V(0) Converging inward to the boundary ψ, where The finite time T1 is used to adjust the system to achieve coordinated control.

[0066] (2) Fixed time: The direction function is set as g(|x|)=sign(x), and the attribute function is set as f(|x|=δ1|x|. p +δ2|x| q The Lyapunov function will occur in a fixed time. Converging inward to the boundary ψ, where

[0067]

[0068]

[0069] parameter Consistent with ψ and the finite-time design, a fixed time T2 is used to adjust the system to achieve coordinated control.

[0070] (3) Specifying the time: Let T3 be the specified time point for system convergence, the direction function be g(|x|)=sign(x), the attribute function be f(|x|=|x|), and the gain function be... in If σ≥1 and ζ>0, then the multi-AUV system can achieve consistency within a specified time T3.

[0071] For example, taking a fixed-time convergence requirement as an example, Figure 3 The final position and velocity consistency convergence results for the i-th AUV are presented. This invention allows switching between different controllers to complete multi-AUV cooperative control with different time performance convergence requirements, and requires almost no information related to environmental disturbances. The results show that the consistency under controller-driven control is stably converged. In summary, this invention effectively solves the multi-AUV cooperative control problem under environmental disturbances, and after the system converges, tasks such as data collection and environmental monitoring can be carried out.

[0072] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0073] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-AUV cooperative control method that meets specified performance requirements, characterized in that: Includes the following steps: S1: Determine the set of multiple AUV systems, and let N be the number of autonomous underwater robots in the multiple AUV system; S2: Deploy a local coordinate system for each individual AUV to construct an individual AUV dynamic model; S3: Based on S2, a consensus control protocol that converges under different time performance requirements is designed to address environmental disturbances experienced by multi-AUV systems, thereby driving the multi-AUV system to achieve cooperative control. The different time performance characteristics include: finite-time convergence, fixed-time convergence, and specified-time convergence.

2. The multi-AUV cooperative control method according to claim 1, characterized in that: S1 also includes: the topological structure and the corresponding adjacency matrix; The topology is an undirected connected graph; The corresponding adjacency matrix is: A = [a ij ]∈R N×N i,j = 1,2,...,N; Among them, a ij This represents the connection between the i-th AUV and the j-th AUV. When there is communication between the i-th AUV and the j-th AUV, a ij =1, otherwise a ij =0, R N×N Symbols for N-dimensional matrices; Synchronization definition N i Let N be the neighbor set of the i-th AUV. i ={j|a ij =1,j≠i}, and define L as the Laplace matrix.

3. The multi-AUV cooperative control method according to claim 2, characterized in that: The individual AUV dynamics model is as follows: in, For P i The derivative with respect to time, P i P represents the position of the i-th AUV in the global coordinate system. i =[x i ,y i ,z i ]^T∈R 3 x i ,y i ,z i R represents the coordinates of the i-th AUV on the x-axis (left-right), y-axis (front-back), and z-axis (up-down), respectively. 3 It is a three-dimensional column vector symbol. For V i The derivative with respect to time, V i V represents the linear velocity of the i-th AUV. i =[u i ,v i ,w i ]^T∈R 3 u i ,v i ,w i J represents the velocity components of the i-th AUV along the x-axis, y-axis, and z-axis, respectively. i J represents the global and local coordinate system transformation matrix for the i-th AUV. i ∈R 3×3 R 3×3 This is a three-dimensional matrix notation, where M represents the inertia matrix, M = diag{m1,m2,m3}∈R. 3×3 m1, m2, and m3 represent the moments of inertia about the x-axis, y-axis, and z-axis, respectively, and D i Represents the damping matrix, D i ∈R 3×3 , τ i τ ωi τ represents the system input and environmental disturbance of the i-th AUV, respectively. i ∈R 3 , τ ωi ∈R 3 .

4. The multi-AUV cooperative control method according to claim 3, characterized in that: S3 includes the following controller: Among them, V i (t) represents the linear velocity of the i-th AUV at time t, Z 1i (t) represents the position consistency error of the i-th AUV at time t. P i (t), P j (t) represents the positions of the i-th and j-th AUVs at time t, respectively, Z 2i (t) represents the velocity consistency error of the i-th AUV at time t. V i (t), V j (t) represents the linear velocities of the i-th and j-th AUVs at time t, respectively, and k i (t) represents the parameters designed based on different time performance, k i (t)≥1, g(·) represents the direction function, f(·) represents the attribute function, and Θ(·) represents the nonlinear function, which is used to realize the coordinated control of multiple time performances of a multi-AUV system.

5. A multi-AUV cooperative control method that meets specified performance requirements according to claim 4, characterized in that: The direction function g(·) satisfies the following condition: Where xg(x) = |x|g(|x|), x represents the independent variable, which can be selected from: sign function, boundary layer function, and linear saturation function.

6. A multi-AUV cooperative control method that meets specified performance requirements according to claim 5, characterized in that: The symbol function is: The boundary layer function is: Parameters representing the adjustment of boundary layer thickness; The linear saturation function is: This represents the parameter used to adjust the threshold of the linear interval.

7. A multi-AUV cooperative control method that meets specified performance requirements according to claim 6, characterized in that: The attribute function f(·) satisfies the following conditions: f(x)≥0; F(|x|)=|x|g(|x|)f(|x|), F(|x|) is a monotonically increasing concave function; the specified time performance requirements include: finite time convergence, fixed time convergence, and specified time convergence.

8. A multi-AUV cooperative control method that meets specified performance requirements according to claim 7, characterized in that: The finite-time convergence refers to the state of each AUV in a multi-AUV system achieving coordination within a finite time; the fixed-time convergence refers to the state of each AUV in a multi-AUV system achieving coordination within a fixed time; and the specified-time convergence refers to the state of each AUV in a multi-AUV system achieving coordination within a specified time.

9. A multi-AUV cooperative control method that meets specified performance requirements according to claim 8, characterized in that: The nonlinear function Θ(·) is designed as follows: Where ∈ represents a positive constant used to switch between modes for eliminating unknown disturbances. This is the adaptive gain, used to estimate the underwater environmental disturbances experienced by the i-th AUV, with its initial value... The design is as follows: Where ρ represents the disturbance estimation exponent, ρ∈[1,3], μ is a positive constant, and m represents the disturbance estimation coefficient. max The value of m represents the maximum value of the moment of inertia. min This represents the minimum value of the moment of inertia, i.e., m. max =max(m1,m2,m3),m min =min(m1,m2,m3), used to estimate disturbances.

10. A multi-AUV cooperative control method that meets specified performance requirements according to claim 9, characterized in that: The S3 also includes proving the stability of the multi-AUV system using Lyapunov stability theory.

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