Hydrofoil ship longitudinal motion attitude control method, system, equipment and medium

Abstract

The invention provides a hydrofoil ship longitudinal motion attitude control method, system and device and a storage medium, and belongs to the field of ship control strategies, and the method comprises the following steps: designing an improved fractional order fast terminal sliding mode controller according to a fractional order theory and a sliding mode control theory; designing a fractional-order nonlinear interference observer by considering external sea wave interference; a nonlinear saturation compensator is designed by considering the saturation condition of an actuating mechanism of the hydrofoil ship; estimating external interference factors and uncertainty factors by using a fractional-order nonlinear interference observer, inputting estimated values of the external interference factors and the uncertainty factors into the controller, designing a sliding mode surface with interference estimation, and compensating saturation of an execution mechanism by using a nonlinear saturation compensator to obtain an optimized fractional-order fast terminal sliding mode controller; according to the method, the optimized fractional order fast terminal sliding mode controller is used for controlling the longitudinal motion attitude of the hydrofoil ship with interference and saturation of the executing mechanism, and the control precision can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of ship control strategies, and in particular relates to a method, system, device and storage medium for controlling the longitudinal motion posture of a hydrofoil vessel. Background Art

[0002] As a fast and high-performance ship, the hydrofoil ship has the characteristics of speed, low resistance, and seaworthiness. Since the hull of the hydrofoil ship is dragged out of the water, only the hydrofoil is below the water surface, which greatly reduces the friction resistance and wave resistance of navigation, and solves the problem of large resistance and limited navigation speed of general displacement ships. However, since the hull is located above the water surface, it is affected by waves, sea breeze, etc. during navigation, and the hull cannot generate restoring force and restoring torque, which greatly reduces navigation stability and safety. Therefore, it is of great significance to design a control strategy to ensure the stability and comfort of hydrofoil ships under external environmental interference.

[0003] The longitudinal motion of a hydrofoil includes pitch and heave, which play an important role in the safety of the hydrofoil. If the longitudinal motion is too large, it is easy to capsize. Therefore, it is particularly important to accurately control the longitudinal motion parameters of the hydrofoil. However, when the hydrofoil is sailing under high waves, the flap actuator is prone to saturation, which makes the designed controller highly conservative, thereby reducing the control performance of the controller and affecting the control accuracy of the longitudinal motion parameters. Summary of the invention

[0004] In order to overcome the problem of low control accuracy of the longitudinal motion posture of a hydrofoil craft in the above-mentioned prior art, the present invention provides a method for controlling the longitudinal motion posture of a hydrofoil craft, comprising the following steps:

[0005] Acquiring motion parameters of the hydrofoil vessel, and constructing a nonlinear dynamic model of the hydrofoil vessel according to the motion parameters;

[0006] Based on the nonlinear dynamic model of the hydrofoil ship, a nonlinear fractional-order sliding surface with disturbance estimation is designed to obtain a fractional-order fast terminal sliding mode controller; the control error of the nonlinear dynamic model control system is obtained, and a fractional-order nonlinear disturbance observer based on the nonlinear dynamic model of the hydrofoil ship is designed according to the control error; the actual output deviation of the fractional-order fast terminal sliding mode controller under saturation limit is obtained, and a nonlinear saturation compensator of the actuator based on the nonlinear dynamic model of the hydrofoil ship is designed;

[0007] A fractional-order nonlinear disturbance observer is used to estimate external disturbance factors and uncertainty factors of a nonlinear dynamic model control system of a hydrofoil vessel, and the estimated values ​​of the external disturbance factors and uncertainty factors are input into a fractional-order fast terminal sliding mode controller, and the parameters of the fractional-order fast terminal sliding mode controller are adjusted. At the same time, the nonlinear saturation compensator is used to compensate for the influence of actuator saturation on the fractional-order fast terminal sliding mode controller, so as to obtain an optimized fractional-order fast terminal sliding mode controller;

[0008] The longitudinal motion posture of the hydrofoil craft is controlled using the optimized fractional-order fast terminal sliding mode controller.

[0009] Preferably, the motion parameters include the hydrofoil vessel's sailing speed, the hydrofoil vessel's vertical displacement, the hydrofoil vessel's vertical motion speed, the hydrofoil vessel's pitch angle and the hydrofoil vessel's pitch angular velocity.

[0010] Preferably, the design of a fractional-order fast terminal sliding mode controller for a nonlinear dynamic model control system of a hydrofoil vessel comprises the following steps:

[0011] Design of nonlinear fractional sliding surfaces with disturbance estimation;

[0012] Obtaining an adaptive time-varying parameter of a nonlinear fractional-order sliding surface, and designing an adaptive arrival rate of the nonlinear fractional-order sliding surface according to the adaptive time-varying parameter;

[0013] A fractional-order fast terminal sliding mode controller is designed according to the nonlinear fractional-order sliding mode surface and the adaptive arrival rate.

[0014] Preferably, the fractional-order fast terminal sliding mode controller is as follows:

[0015]

[0016] Among them, D 1-α It is a 1-α order fractional operation, α is the fractional order, 0<α<1, S + is the generalized inverse, is the adaptive time-varying parameter, k3 is a constant parameter, ε is an arbitrary parameter, S is the sliding surface, W is the upper bound of the lumped disturbance, P is a constant matrix, μ=0.2785, λ、β>0 are all constant parameters, g is the design parameter of the disturbance observer, B is the control matrix, f(x1,x2) is the nonlinear term of the system, x1=[z,θ] T is the actual value of the system state, z represents the longitudinal displacement of the hydrofoil ship, θ represents the pitch angle of the hydrofoil ship, and x d is the expected value of the system state, is the second-order derivative of the expected value of the system state, is the aggregate interference estimate, χ∈R 2×2 is the constant matrix to be selected, e1=x1-x dis the system control error, is the derivative of the system control error, p and q are odd numbers and satisfy 0<p<q<2p, p=3, q=5 is the parameter of the saturation compensation system, K1=diag(k a1 ,k b1 ),K2=diag(k a2 ,k b2 ) are all positive definite matrices, k a1 ,k a2 ,k b1 ,k b2 They are all constant parameters, 0<m<1, n>1 are positive constants.

[0017] Preferably, the fractional-order nonlinear disturbance observer is as follows:

[0018]

[0019] Where, e1 = x1-x d is the system control error, x d is the expected value of the system state, x1=[z,θ] T is the actual value of the system state, z represents the longitudinal displacement of the hydrofoil ship, θ represents the pitch angle of the hydrofoil ship, represents the total interference estimate of the system, 0<α<1 is the fractional order, g is the design parameter of the interference observer, g=diag(g1,g2), g1, g2, λ1, λ2 are all constant parameters, L is the observer variable, D α is a fractional order operation, 0<α<1 is a fractional order, sign(·) is the sign function, f(x1,x2) is the nonlinear term of the system, B is the control matrix, and u is the system control input.

[0020] Preferably, the nonlinear saturation compensator is as follows:

[0021]

[0022] Among them, u i is the output of the controller, δ is the actual output of the control under saturation limit, Δu=δ-u is the deviation between the designed controller and the actual output of the controller, Indicates the state of the compensation system, k3>1, ρ>0 are constant parameters, D α-1 (BΔu) is the fractional order of BΔu, δ imax is the maximum output value, δ imin is the minimum output value, sat(u i ) is the saturation limit function of the controller output, and τ is a defined constant.

[0023] The present invention also provides a hydrofoil vessel longitudinal motion attitude control system, comprising:

[0024] A hydrofoil ship model building module is used to obtain motion parameters of the hydrofoil ship and build a nonlinear dynamic model of the hydrofoil ship according to the motion parameters;

[0025] The controller building module is used to design a nonlinear fractional-order sliding surface with disturbance estimation based on the nonlinear dynamic model of the hydrofoil ship, and obtain a fractional-order fast terminal sliding mode controller; obtain the control error of the nonlinear dynamic model control system, and design a fractional-order nonlinear disturbance observer based on the nonlinear dynamic model of the hydrofoil ship according to the control error; obtain the actual output deviation of the fractional-order fast terminal sliding mode controller under saturation limit, and design a nonlinear saturation compensator for the actuator based on the nonlinear dynamic model of the hydrofoil ship;

[0026] A controller optimization module is used to estimate external disturbance factors and uncertainty factors of the hydrofoil vessel nonlinear dynamic model control system using a fractional-order nonlinear disturbance observer, and input the estimated values ​​of the external disturbance factors and uncertainty factors into the fractional-order fast terminal sliding mode controller, adjust the parameters of the fractional-order fast terminal sliding mode controller, and use the nonlinear saturation compensator to compensate for the influence of actuator saturation on the fractional-order fast terminal sliding mode controller, so as to obtain an optimized fractional-order fast terminal sliding mode controller;

[0027] The attitude control module is used to control the longitudinal motion attitude of the hydrofoil craft using an optimized fractional-order fast terminal sliding mode controller.

[0028] The present invention also provides a computer device, comprising a memory and a processor; the memory stores a computer program, and the processor is used to run the computer program in the memory to execute the hydrofoil craft longitudinal motion posture control method.

[0029] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program is suitable for being loaded by a processor to execute the method for controlling the longitudinal motion posture of a hydrofoil craft.

[0030] The method, system, device and storage medium for controlling the longitudinal motion posture of a hydrofoil vessel provided by the present invention have the following beneficial effects:

[0031] During the navigation of hydrofoil vessels, it is inevitable that they will be affected by the interference of sea waves, resulting in unstable navigation. The present invention reduces the conservatism of the design by designing a fractional-order nonlinear interference observer, and can estimate the interference of external interference factors and uncertain factors, thereby compensating for interference in the design process of the controller and improving control performance and accuracy; the present invention can consider the estimated compensation of lumped interference by designing a fractional-order fast terminal sliding mode controller and a sliding mode surface with interference estimation, further weaken the influence of interference, have lower conservatism, and improve the control accuracy of longitudinal motion attitude; the present invention compensates for the saturation of the actuator by designing a nonlinear saturation compensator, realizes anti-saturation control, reduces the influence of the actuator saturation on the control performance, improves the control accuracy of the longitudinal motion attitude, and realizes stable and safe navigation of the hydrofoil vessel. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiment of the present invention and its design scheme, the following briefly introduces the drawings required for this embodiment. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 It is a flow chart of a method for controlling the longitudinal motion posture of a hydrofoil vessel according to an embodiment of the present invention;

[0034] Figure 2 This is a heave displacement effect diagram of the hydrofoil vessel of the present invention;

[0035] Figure 3 This is a rendering of the pitch angle of the hydrofoil vessel of the present invention. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention and implement it, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the scope of protection of the present invention.

[0037] Example

[0038] The present invention provides a method for controlling the longitudinal motion posture of a hydrofoil vessel, specifically: Figure 1 As shown, the following steps are included:

[0039] Step 1: Obtain the motion parameters of the hydrofoil craft and build a nonlinear dynamic model of the hydrofoil craft based on the motion parameters.

[0040] Considering random wave interference, a nonlinear dynamic model of hydrofoil boat dynamics is established according to the kinematic and dynamic characteristics of hydrofoil boat navigation:

[0041]

[0042] Where m is the mass of the hydrofoil, U e is the navigation speed of the hydrofoil, z is the vertical displacement of the hydrofoil, w is the vertical motion speed of the hydrofoil, θ is the pitch angle of the hydrofoil, q is the pitch angular velocity of the hydrofoil, represents the derivative of the hydrodynamic force in the z-axis with respect to the vertical displacement velocity derivative, represents the inertia force parameter of the hydrofoil ship, Z w It represents the derivative of the hydrodynamic force along the z-axis with respect to the vertical displacement velocity, i.e., Z w =dZ / dw,Z z represents the derivative of the hydrodynamic force about the vertical displacement in the z-axis, The derivative of the hydrodynamic force about the pitch angular velocity in the z-axis, Z q represents the derivative of the hydrodynamic force about the pitch angular velocity in the z-axis, Z θ represents the derivative of the hydrodynamic force about the pitch angle, Z δe is the inner flap control force parameter, δ e and δ f are the control angles of the front and rear hydrofoil flaps, Z δf is the rear flap control force parameter, Z S 、M S are the disturbance force and disturbance moment generated by random waves on the fully immersed hydrofoil craft, represents the derivative of the hydrodynamic moment on the y-axis with respect to the vertical displacement velocity derivative, M w It represents the derivative of the hydrodynamic moment on the y-axis with respect to the vertical displacement velocity, that is, M w =dM / dw,M z represents the derivative of the hydrodynamic moment about the y-axis with respect to the vertical displacement, represents the derivative of the hydrodynamic moment about the y-axis with respect to the derivative of the pitch angular velocity, The moment of inertia parameter about the y-axis, M q represents the derivative of the hydrodynamic moment about the y-axis with respect to the pitch angular velocity, M θ represents the derivative of the hydrodynamic moment about the y-axis with respect to the pitch angle, M δe is the inner flap control torque parameter, M δf Outer flap control torque parameters.

[0043] After sorting:

[0044]

[0045] x1=[z,θ] T is the system status, d wis the system lumped disturbance, f(x1,x2) is the system nonlinear term, u is the system control input, and B is the control matrix.

[0046] Step 2: According to the fractional order theory and sliding mode control theory, a fractional order fast terminal sliding mode controller based on the nonlinear dynamic model of the hydrofoil vessel is designed. The specific process is as follows:

[0047] First, the nonlinear fractional-order sliding surface with disturbance estimation is designed as:

[0048]

[0049] Among them, S is the sliding surface, χ∈R 2×2 is the constant matrix to be selected, λ, β>0 are constant parameters, D α-1 Indicates fractional order, 0<α<1, p, q are both odd parameters, and satisfy 0<p<q<2p. Considering the characteristics of the hydrofoil system model, to ensure rapid convergence, p=3, q=5, x d is the expected value of the system state, x1=[z,θ] T is the actual value of the system state, z represents the longitudinal displacement of the hydrofoil ship, θ represents the pitch angle of the hydrofoil ship, e1=x1-x d is the system control error.

[0050] In order to ensure the rapid convergence of the sliding surface and high-precision control accuracy, the adaptive arrival rate with inverse tangent function is designed as:

[0051]

[0052] Where K1 = diag(k a1 ,k b1 ), K2=diag(k a2 ,k b2 ) are all positive definite matrices, is an adaptive time-varying parameter, 0<m<1, n>1 are all positive constants, ε is a constant parameter, W is the upper bound of the lumped interference, μ=0.2785, P is a constant matrix, λ is a constant parameter, g is the design parameter of the interference observer, S T Indicates the transpose of the matrix, k a1 ,k a2 ,k b1 ,k b2 All are constant parameters.

[0053] The fractional-order fast terminal sliding mode controller is as follows:

[0054]

[0055] Among them, D 1-αIt is a 1-α order fractional operation, α is the fractional order, 0<α<1, S + is the generalized inverse, is the adaptive time-varying parameter, k3 is a constant parameter, ε is an arbitrary parameter, S is the sliding surface, W is the upper bound of the lumped disturbance, P is a constant matrix, μ=0.2785, λ、β>0 are all constant parameters, g is the design parameter of the disturbance observer, B is the control matrix, f(x1,x2) is the nonlinear term of the system, x1=[z,θ] T is the actual value of the system state, z represents the longitudinal displacement of the hydrofoil ship, θ represents the pitch angle of the hydrofoil ship, and x d is the expected value of the system state, is the second-order derivative of the expected value of the system state, is the aggregate interference estimate, χ∈R 2×2 is the constant matrix to be selected, e1=x1-x d is the system control error, is the derivative of the system control error, p and q are odd numbers and satisfy 0<p<q<2p, p=3, q=5 is the parameter of the saturation compensation system, K1=diag(k a1 ,k b1 ), K2=diag(k a2 ,k b2 ) are all positive definite matrices, k a1 ,k a2 ,k b1 ,k b2 They are all constant parameters, 0<m<1, n>1 are positive constants.

[0056] In summary, the fractional-order fast terminal sliding mode controller is designed based on the fractional-order theory, and a nonlinear fractional-order sliding mode surface with disturbance estimation is designed to further weaken the influence of disturbances and reduce the conservatism of the fractional-order fast terminal sliding mode controller.

[0057] Step 3: Obtain the control error of the nonlinear dynamic model control system, and design a fractional-order nonlinear disturbance observer based on the nonlinear dynamic model of the hydrofoil vessel according to the control error, as follows:

[0058]

[0059] Where, e1 = x1-x d is the system control error, x d is the expected value of the system state, x1=[z,θ] T is the actual value of the system state, z represents the longitudinal displacement of the hydrofoil ship, θ represents the pitch angle of the hydrofoil ship, represents the total interference estimate of the system, 0<α<1 is the fractional order, g is the design parameter of the interference observer, g=diag(g1,g2), g1, g2, λ1, λ2 are all constant parameters, L is the observer variable, D α is a fractional order operation, sign(·) is the sign function, u is the system control input, B is the control matrix, and f(x1,x2) is the system nonlinear term.

[0060] The designed disturbance observer is based on the nonlinear dynamic model of the hydrofoil ship and the fractional-order theory. Compared with the previous observers, it has lower conservatism, improved estimation accuracy and better applicability. By designing a fractional-order nonlinear disturbance observer, the influence of external disturbances and system uncertainty can be taken into account, the estimation of lumped disturbances can be realized, and disturbance compensation can be realized in the design process of the fractional-order fast terminal sliding mode controller.

[0061] Step 4: Obtain the actual output deviation of the fractional-order fast terminal sliding mode controller under saturation limit, and design a nonlinear saturation compensator for the actuator based on the nonlinear dynamic model of the hydrofoil vessel, as follows:

[0062]

[0063] Among them, u i is the output of the controller, δ is the actual output of the control under saturation limit, Δu=δ-u is the deviation between the designed controller and the actual output of the controller, Indicates the state of the compensation system, k3>1, ρ>0 are constant parameters, D α-1 (BΔu) is the fractional order of BΔu, δ imax is the maximum output value, δ imin is the minimum output value, sat(u i ) is the saturation limit function of the controller output, and τ is a defined constant.

[0064] The designed nonlinear saturation compensator has fractional-order operation. The nonlinear saturation compensator can further consider the saturation of the flap actuator, ensure the performance of the fractional-order fast terminal sliding mode controller of the actuator under saturation and the stability of navigation, and improve the compensation effect.

[0065] Step 5: Use a fractional-order nonlinear disturbance observer to estimate the external disturbance factors and uncertainty factors of the hydrofoil vessel nonlinear dynamic model control system, and input the estimated values ​​of the external disturbance factors and uncertainty factors into the fractional-order fast terminal sliding mode controller, adjust the parameters of the fractional-order fast terminal sliding mode controller, and use the nonlinear saturation compensator to compensate for the influence of actuator saturation on the fractional-order fast terminal sliding mode controller, so as to obtain an optimized fractional-order fast terminal sliding mode controller.

[0066] Step 6: Use the optimized fractional-order fast terminal sliding mode controller to control the longitudinal motion posture of the hydrofoil craft.

[0067] In order to verify the effectiveness of the designed fractional-order fast terminal sliding mode controller, the present invention conducts simulation experiments on the designed fractional-order fast terminal sliding mode controller in Matlab. Figure 2 and Figure 3 The heave displacement and pitch angle results of the hydrofoil vessel are obtained by using the fractional-order fast terminal sliding mode controller of the present invention. It can be seen from the figure that the fractional-order fast terminal sliding mode controller improves the control accuracy, and the pitch and heave motions both vary within a smaller range, which proves the effectiveness of the design of the fractional-order fast terminal sliding mode controller.

[0068] The present invention also provides a hydrofoil vessel longitudinal motion attitude control system, which comprises a hydrofoil vessel model building module, a controller building module, a controller optimization module and an attitude control module. The hydrofoil model construction module is used to obtain the motion parameters of the hydrofoil and construct the nonlinear dynamic model of the hydrofoil according to the motion parameters; the controller construction module is used to design a nonlinear fractional-order sliding surface with interference estimation based on the nonlinear dynamic model of the hydrofoil to obtain a fractional-order fast terminal sliding controller; the control error of the nonlinear dynamic model control system is obtained, and a fractional-order nonlinear interference observer based on the nonlinear dynamic model of the hydrofoil is designed according to the control error; the actual output deviation of the fractional-order fast terminal sliding controller under saturation limit is obtained, and a nonlinear saturation compensator of the actuator based on the nonlinear dynamic model of the hydrofoil is designed; the controller optimization module is used to estimate the external interference factors and uncertainty factors of the nonlinear dynamic model control system of the hydrofoil using the fractional-order nonlinear interference observer, and input the estimated values ​​of the external interference factors and uncertainty factors into the fractional-order fast terminal sliding controller, adjust the parameters of the fractional-order fast terminal sliding controller, and use the nonlinear saturation compensator to compensate for the influence of the actuator saturation on the fractional-order fast terminal sliding controller to obtain an optimized fractional-order fast terminal sliding controller; the attitude control module is used to control the longitudinal motion attitude of the hydrofoil using the optimized fractional-order fast terminal sliding controller.

[0069] The present invention also provides a computer device, including a memory and a processor; the memory stores a computer program, and the processor is used to run the computer program in the memory to execute the hydrofoil vessel longitudinal motion posture control method.

[0070] The present invention also provides a computer-readable storage medium, which stores a computer program. The computer program is suitable for loading into a processor to execute the method for controlling the longitudinal motion posture of a hydrofoil craft.

[0071] The embodiments described above are only preferred specific implementation modes of the present invention, and the protection scope of the present invention is not limited thereto. Any simple changes or equivalent replacements of the technical solutions that can be obviously obtained by any technician familiar with the field within the technical scope disclosed in the present invention belong to the protection scope of the present invention.

Claims

1. A method for controlling the longitudinal motion posture of a hydrofoil vessel, characterized in that: The steps include: Acquiring motion parameters of the hydrofoil vessel, and constructing a nonlinear dynamic model of the hydrofoil vessel according to the motion parameters; Based on the nonlinear dynamic model of hydrofoil craft, a nonlinear fractional-order sliding surface with disturbance estimation is designed, and a fractional-order fast terminal sliding mode controller is obtained. Obtain the control error of the nonlinear dynamic model control system, and design a fractional-order nonlinear disturbance observer based on the nonlinear dynamic model of the hydrofoil vessel according to the control error; obtain the actual output deviation of the fractional-order fast terminal sliding mode controller under saturation limit, and design a nonlinear saturation compensator for the actuator based on the nonlinear dynamic model of the hydrofoil vessel; A fractional-order nonlinear disturbance observer is used to estimate external disturbance factors and uncertainty factors of a nonlinear dynamic model control system of a hydrofoil vessel, and the estimated values ​​of the external disturbance factors and uncertainty factors are input into a fractional-order fast terminal sliding mode controller, and the parameters of the fractional-order fast terminal sliding mode controller are adjusted. At the same time, the nonlinear saturation compensator is used to compensate for the influence of actuator saturation on the fractional-order fast terminal sliding mode controller, so as to obtain an optimized fractional-order fast terminal sliding mode controller; The longitudinal motion posture of the hydrofoil craft is controlled using the optimized fractional-order fast terminal sliding mode controller.

2. The method for controlling the longitudinal motion posture of a hydrofoil vessel according to claim 1, characterized in that: The motion parameters include the hydrofoil ship's sailing speed, the hydrofoil ship's vertical displacement, the hydrofoil ship's vertical motion speed, the hydrofoil ship's pitch angle and the hydrofoil ship's pitch angular velocity.

3. The method for controlling the longitudinal motion posture of a hydrofoil vessel according to claim 1, characterized in that: The method for designing a fractional-order fast terminal sliding mode controller for a nonlinear dynamic model control system of a hydrofoil vessel comprises the following steps: Design of nonlinear fractional sliding surfaces with disturbance estimation; Obtaining an adaptive time-varying parameter of a nonlinear fractional-order sliding surface, and designing an adaptive arrival rate of the nonlinear fractional-order sliding surface according to the adaptive time-varying parameter; A fractional-order fast terminal sliding mode controller is designed according to the nonlinear fractional-order sliding mode surface and the adaptive arrival rate.

4. The method for controlling the longitudinal motion posture of a hydrofoil vessel according to claim 1, characterized in that: The fractional-order fast terminal sliding mode controller is as follows: Among them, D 1-α It is a 1-α order fractional operation, α is the fractional order, 0<α<1, S + is the generalized inverse, is the adaptive time-varying parameter, k3 is a constant parameter, ε is an arbitrary parameter, S is the sliding surface, W is the upper bound of the lumped disturbance, P is a constant matrix, μ=0.2785, λ、β>0 are all constant parameters, g is the design parameter of the disturbance observer, B is the control matrix, f(x1,x2) is the nonlinear term of the system, , x1=[z,θ] T is the actual value of the system state, z represents the longitudinal displacement of the hydrofoil ship, θ represents the pitch angle of the hydrofoil ship, and x d is the expected value of the system state, is the second-order derivative of the expected value of the system state, is the aggregate interference estimate, χ∈R 2×2 is the constant matrix to be selected, e1=x1-x d is the system control error, is the derivative of the system control error, p and q are odd numbers and satisfy 0<p<q<2p, p=3, q=5, is the parameter of the saturation compensation system, K1=diag(k a1 ,k b1 ),K2=diag(k a2 ,k b2 ) are all positive definite matrices, k a1 ,k a2 ,k b1 ,k b2 They are all constant parameters, 0<m<1, n>1 are positive constants.

5. The method for controlling the longitudinal motion posture of a hydrofoil vessel according to claim 1, characterized in that: The fractional-order nonlinear disturbance observer is as follows: Where, e1 = x1-x d is the system control error, x d is the expected value of the system state, x1=[z,θ] T is the actual value of the system state, z represents the longitudinal displacement of the hydrofoil ship, θ represents the pitch angle of the hydrofoil ship, represents the total interference estimate of the system, g is the design parameter of the interference observer, g = diag (g1, g2), g1, g2, λ1, λ2 are all constant parameters, L is the observer variable, D α is a fractional order operation, 0<α<1 is a fractional order, sign(·) is the sign function, f(x1,x2) is the system nonlinear term, u is the system control input, and B is the control matrix.

6. The method for controlling the longitudinal motion posture of a hydrofoil vessel according to claim 1, characterized in that: The nonlinear saturation compensator is as follows: Among them, u i is the output of the controller, δ is the actual output of the control under saturation limit, Δu=δ-u is the deviation between the designed controller and the actual output of the controller, Indicates the state of the compensation system, k3>1, ρ>0 are constant parameters, D α-1 (BΔu) is the fractional order of BΔu, δ imax is the maximum output value, δ imin is the minimum output value, sat(u i ) is the saturation limit function of the controller output, and τ is a defined constant.

7. A hydrofoil longitudinal motion attitude control system, characterized in that: include: A hydrofoil ship model building module is used to obtain motion parameters of the hydrofoil ship and build a nonlinear dynamic model of the hydrofoil ship according to the motion parameters; The controller building module is used to design a nonlinear fractional-order sliding surface with disturbance estimation based on the nonlinear dynamic model of the hydrofoil vessel, and obtain a fractional-order fast terminal sliding mode controller; Obtain the control error of the nonlinear dynamic model control system, and design a fractional-order nonlinear disturbance observer based on the nonlinear dynamic model of the hydrofoil vessel according to the control error; obtain the actual output deviation of the fractional-order fast terminal sliding mode controller under saturation limit, and design a nonlinear saturation compensator for the actuator based on the nonlinear dynamic model of the hydrofoil vessel; A controller optimization module is used to estimate external disturbance factors and uncertainty factors of the hydrofoil vessel nonlinear dynamic model control system using a fractional-order nonlinear disturbance observer, and input the estimated values ​​of the external disturbance factors and uncertainty factors into the fractional-order fast terminal sliding mode controller, adjust the parameters of the fractional-order fast terminal sliding mode controller, and use the nonlinear saturation compensator to compensate for the influence of actuator saturation on the fractional-order fast terminal sliding mode controller, so as to obtain an optimized fractional-order fast terminal sliding mode controller; The attitude control module is used to control the longitudinal motion attitude of the hydrofoil craft using an optimized fractional-order fast terminal sliding mode controller.

8. A computer device, characterized in that: It comprises a memory and a processor; the memory stores a computer program, and the processor is used to run the computer program in the memory to execute the method for controlling the longitudinal motion posture of a hydrofoil craft according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is suitable for being loaded by a processor to execute the method for controlling the longitudinal motion posture of a hydrofoil craft according to any one of claims 1 to 6.

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