Helicopter vibration control method, device and storage medium based on mechanical impedance

Abstract

The present invention provides a helicopter vibration control method, device and storage medium based on mechanical impedance. The method of the present invention utilizes parallel adaptive feedforward control and feedback control based on mechanical impedance design, which can effectively avoid the difficulty of complex structure dynamic modeling, improve the reliability and control performance of control system modeling, and realize steady-state, transient and broadband vibration suppression. The feedback control based on mechanical impedance design effectively improves the system dynamic characteristics while accelerating the convergence performance of adaptive feedforward control, which can effectively improve the vibration suppression performance and convergence speed of the helicopter vibration active control system.

Description

Technical Field

[0001] The invention belongs to the field of active helicopter vibration control, and in particular relates to a helicopter vibration control method, device and storage medium based on mechanical impedance. Background Art

[0002] Helicopters are always in a complex aerodynamic environment during flight. Rotating parts such as rotors and engines will generate alternating loads, causing the helicopter to be in a severe vibration state. High vibration levels seriously affect the work efficiency of pilots, the reliability of onboard equipment, and the comfort of crew members. Effectively controlling the vibration level of helicopters has become an inevitable requirement. Active control of helicopter structural response with strong adaptability, good control effect, and small additional mass has become an important development direction in the field of helicopter vibration control.

[0003] Practical and efficient adaptive algorithms are a key link in the active control of helicopter structural response, affecting control performance and engineering application value. Adaptive feedforward control can effectively reduce the steady-state response of the system, but it is difficult to improve the dynamic characteristics of the system to achieve transient and broadband vibration suppression. Feedback control can effectively improve the dynamic characteristics of the system to achieve transient and broadband vibration suppression, thereby improving the convergence performance of adaptive feedforward control. A reliable and accurate system model is the basis of control system design. For complex helicopter body structures, it is difficult to effectively model them through finite element, structural analysis and other technologies. Experimental testing technology based on mechanical impedance has become an effective technical means for complex structural dynamics modeling. Summary of the invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a helicopter vibration control method, device and storage medium based on mechanical impedance in view of the shortcomings of the prior art, so as to achieve the improvement of system dynamic characteristics and steady-state response control, and effectively improve the vibration suppression performance and convergence speed of the helicopter vibration active control system.

[0005] The method includes adaptive feedforward control and output feedback control;

[0006] The adaptive feedforward control is implemented by reference signal synthesis, feedforward controller and adaptive control method;

[0007] The output feedback control is implemented by displacement and velocity feedback, and the output feedback controller parameters are calculated using the mechanical impedance of the controlled system.

[0008] The reference signal is integrated according to the characteristics of the helicopter rotor, and the rotor speed signal Ω is obtained by the rotor speed sensor to obtain the control frequency kNΩ, where N is the number of rotor blades and k is the control frequency order;

[0009] The reference signal is integrated, and the reference signal of the kth channel is x k(n) = [cos(kNΩn) sin(kNΩn)] T , where n is a discrete time variable and T represents the matrix transpose;

[0010] The feedforward controller is implemented in a parallel structure in an adaptive notch according to the control frequency. The adaptive notch controller for the control frequency kNΩ includes two control weight coefficients w kc (n) and w ks (n), that is, W k (n)=[w kc (n) w ks (n)] T , W k (n) is the notch filter weight coefficient vector of the kth harmonic frequency, k = 1, ..., N k

[0011] Optionally, the adaptive control method adopts a filtered x-LMS algorithm, and the formula is:

[0012] Where e(n) is the displacement control error response of the control system, μ k To correct the step size, The reference signal is filtered by the control channel, and the optional W k (0) = 0;

[0013] The output feedback control includes a feedback controller and feedback controller gain parameter setting;

[0014] The feedback controller is e(n), are the displacement and speed control error responses of the control system, G and F are the gain parameters of the feedback controller, I is the unit matrix, and det represents the determinant.

[0015] The feedback controller gain parameter is set by the closed-loop characteristic equation of the control system based on the mechanical impedance Z(s) of the controlled structure: f(G, F, s) = det(I + Z(s) -1 B2(G+sF)D0) and the expected extreme point of the closed-loop system are determined, s is the Lagrangian operator, B2 is the control input position parameter, D0 is the sensor position parameter, I is the unit matrix, det means to obtain the determinant; f is the definition name of the function on the right, that is, the part on the right side of the equal sign.

[0016] According to the closed-loop characteristic equation of the control system, the objective function is constructed Where λ is the expected pole value of the closed-loop system;

[0017] Minimize the objective function Controller gain parameters G, F;

[0018] Optionally, the objective function is iteratively minimized using the Gauss-Newton method To adjust the feedback controller parameter Φ = [GF] T , specifically including the following steps:

[0019] Step a1, arbitrarily set the initial value of the feedback controller parameter Φ0 = [G0 F0] T and threshold ε, which is used to control the minimization of the objective function Iteration process, optional, Φ0 = [0 0] T , the threshold value ε is ε=10 -3 ;

[0020] Step a2, calculating the Jacobian matrix of the closed-loop characteristic equation f(G, F) of the control system

[0021] Step a3, substitute the current parameter value Φ i =[G i F i ] T , we get f(G i ,F i ), J(G i ,F i ), where G i 、F i is the current controller gain parameter;

[0022] Step a4, calculate the Hessian matrix H(G i ,F i )=J(G i ,F i ) T J(G i ,F i );

[0023] Step a5: Update the controller parameter value Φ based on the results of steps a3 and a4 i+1 =Φ i -H(G i ,F i ) -1 J(G i ,F) T f(G i ,F);

[0024] Step a6, substitute Φ i+1 =[G i+1 F i+1 ] T Calculate the objective function value Compare With the size of the threshold ε, if Return to step a2, if Get the feedback controller parameter Φ=Φ i+1 .

[0025] The control input u(n) of the method of the present invention is u ff (n)+u fb (n), where u ff (n) is the adaptive feedforward control input, u fb (n) is the impedance-based feedback control input; the formula is as follows:

[0026]

[0027]

[0028] Where N k The maximum frequency order of control.

[0029] On the other hand, the present invention also provides a helicopter vibration control device based on mechanical impedance, comprising:

[0030] An adaptive feedforward control module, used for adaptive feedforward control;

[0031] An output feedback control module, used for output feedback control;

[0032] The adaptive feedforward control is implemented by reference signal synthesis, feedforward controller and adaptive control method;

[0033] The output feedback control is implemented by displacement and velocity feedback, and the output feedback controller parameters are calculated using the mechanical impedance of the controlled system.

[0034] On the other hand, the present invention further provides a storage medium storing a computer program or instruction, which implements the helicopter vibration control method based on mechanical impedance when the computer program or instruction is executed.

[0035] The present invention has the following beneficial effects:

[0036] (1) The design of mechanical impedance feedback controller based on experimental testing can effectively avoid the difficulties in complex structural dynamics modeling and improve the reliability and control performance of control system modeling;

[0037] (2) Adaptive feedforward control - Output feedback composite control based on mechanical impedance can effectively achieve steady-state, transient and broadband vibration suppression. Feedback control effectively improves the system dynamics while accelerating the convergence performance of adaptive feedforward control. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0039] Figure 1 The schematic diagram of the method of the present invention.

[0040] Figure 2 This is a flow chart of the adaptive feedforward control provided by the present invention.

[0041] Figure 3 The feedback control flow chart provided by the present invention.

[0042] Figure 4 The present invention provides a control effect diagram of the technical solution under steady-state harmonic excitation.

[0043] Figure 5 The invention provides a control effect diagram of the technical solution under time-varying excitation conditions. DETAILED DESCRIPTION

[0044] like Figure 1 As shown, the present invention provides a helicopter vibration control method based on mechanical impedance, including adaptive feedforward control and output feedback control, wherein P(z) is the main channel mechanical impedance, Z(s) is the control channel mechanical impedance, d(n) is the uncontrolled response, y(n) is the control channel response, e(n) is the displacement control error response, u ff (n) is the feedforward control input, u fb (n) is the feedback control input, u(n) is the compound control input;

[0045] The adaptive feedforward control is realized by adaptive notching in parallel, such as Figure 2 As shown, x k (n) = [cos(kNΩn) sin(kNΩn)] T is the feedforward control reference signal of the kth harmonic frequency, W k (n) is the notch filter weight coefficient vector of the kth harmonic frequency, k = 1, ..., N k ,u k (n)(k=1,…,N k ) is the feedforward control input of the kth harmonic frequency, is the estimated value of the mechanical impedance of the control channel, is the reference signal of the kth harmonic frequency filtered by the control channel, u ff (n) is the feedforward control input;

[0046] The output feedback control is realized by displacement and velocity feedback, such as Figure 3 As shown, the output feedback controller parameters are calculated using the impedance of the controlled system. G and F are the gain parameters of the feedback controller, and u fb (n) is the feedback control input, e(n), They are the displacement and speed control error responses of the control system, respectively, and d / dt represents the derivative;

[0047] Step 1, the adaptive feedforward control is implemented by reference signal synthesis, feedforward controller and adaptive control method;

[0048] Step 101, determining the number N of rotor blades according to the helicopter rotor characteristics;

[0049] Step 102, obtain a rotor speed signal Ω from a rotor speed sensor, and obtain a control frequency kNΩ, where k = 1, 2, ..., N k To control the frequency order, N k The harmonic order to be controlled is determined by the controller design requirements, and the optional N k =3;

[0050] Step 103, using the rotor speed and the number of blades to obtain the reference signal x of the kth channel for adaptive feedforward control k (n) = [cos(kNΩn) sin(kNΩn)] T , where n is a discrete time variable;

[0051] Step 104: adaptive feedforward control of the control structure W of the kth channel k (n) contains two control parameters, namely W k (n)=[w kc (n) w ks (n)] T , assign the initial value W k (0) = [0 0] T ;

[0052] Step 105, the adaptive feedforward controller parameter correction in step 104 is implemented by using the filtered x-LMS algorithm, and where μ k To correct the step size, The reference signal is filtered through the control channel;

[0053] Step 106: adaptive feedforward control u of the kth channel k (n) = W k (n) T ·x k (n);

[0054] Step 107: Adaptive feedforward control

[0055] Step 2, the output feedback control based on mechanical impedance includes feedback controller and feedback controller gain parameter setting;

[0056] Step 201, the feedback controller structure is e(n), are the control system displacement and speed control error responses, respectively, G and F are controller gain parameters;

[0057] Step 202: The feedback controller parameters G and F are controller gain parameters obtained by the closed-loop characteristic equation of the control system based on the mechanical impedance Z(s) of the controlled structure: f(G, F, s) = det(I + Z(s) -1 B2(G+sF)D0) and the expected extreme point of the closed-loop system are determined, s is the Lagrangian operator, B2 is the control input position parameter, D0 is the sensor position parameter, I is the unit matrix, and det means to obtain the determinant;

[0058] Step 203: construct an objective function based on the closed-loop characteristic equation of the control system described in step 202. Where, f(G, F) = det(I + Z(λ) -1 B2(G+λF)D0), λ is the expected pole value of the closed-loop system;

[0059] Step 204, using the Gauss-Newton method to iteratively minimize the objective function To adjust the feedback controller parameter Φ = [GF] T ;

[0060] Step 20401, arbitrarily give the initial value of the feedback controller parameter Φ0 = [G0 F0] T and threshold ε, which is used to control the minimization of the objective function Iteration process, optional, Φ0 = [0 0] T , the threshold value ε is ε=10 -3 ;

[0061] Step 20402, calculate the Jacobian matrix of the closed-loop characteristic equation f(G, F) of the control system

[0062] Step 20403, substitute the current parameter value Φ i =[G i F i ] T , we get f(G i ,F i ), J(G i ,F i );

[0063] Step 20404, calculate the Hessian matrix H(G i ,F i )=J(G i ,F i ) T J(G i,F i );

[0064] Step 20405, update the controller parameter value Φ based on the results of steps 20403 and 20404 i+1 =Φ i -H(G i ,F i ) - 1 J(G i ,F) T f(G i ,F);

[0065] Step 20406, substitute Φ i+1 =[G i+1 F i+1 ] T Calculate the objective function value Compare With the size of the threshold ε, if Return to step 20402, if Get the feedback controller parameter Φ=Φ i+1 ;

[0066] Step 205, calculating the feedback control input

[0067] Step 3, calculate the control input u(n)=u ff (n)+u fb (n),u ff (n) is the adaptive feedforward control input obtained in step 107, u fb (n) is the feedback control input obtained in step 205;

[0068] Figure 4 Control effect diagram of the composite control method under steady-state harmonic excitation, Figure 5 The control effect diagram of the composite control method under the condition of time-varying excitation due to the change of flight state of the simulated helicopter is given, which shows that the composite control method has the steady-state harmonic control capability characterized by helicopter vibration suppression, adaptive tracking control capability and excellent convergence performance.

[0069] This embodiment also provides a helicopter vibration control device based on mechanical impedance, including:

[0070] An adaptive feedforward control module, used for adaptive feedforward control;

[0071] An output feedback control module, used for output feedback control;

[0072] The adaptive feedforward control is implemented by reference signal synthesis, feedforward controller and adaptive control method;

[0073] The output feedback control is implemented by displacement and velocity feedback, and the output feedback controller parameters are calculated using the mechanical impedance of the controlled system.

[0074] The apparatus according to the embodiment of the present application can be implemented in various terminal devices, such as a server of a distributed computing system. In one example, the apparatus according to the embodiment of the present application can be integrated into the terminal device as a software module and / or a hardware module. For example, the apparatus can be a software module in the operating system of the terminal device, or can be an application developed for the terminal device; of course, the apparatus can also be one of the many hardware modules of the terminal device.

[0075] Alternatively, in another example, the apparatus and the terminal device may also be separate terminal devices, and the apparatus may be connected to the terminal device via a wired and / or wireless network, and transmit the interactive information in accordance with an agreed data format.

[0076] This embodiment further provides a storage medium storing a computer program or instruction. When the computer program or instruction is executed, the helicopter vibration control method based on mechanical impedance is implemented.

[0077] The present invention provides a helicopter vibration control method, device and storage medium based on mechanical impedance. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be considered as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A helicopter vibration control method based on mechanical impedance, characterized in that: Includes adaptive feedforward control and output feedback control; The adaptive feedforward control is implemented by reference signal synthesis, feedforward controller and adaptive control method; The output feedback control is realized by displacement and velocity feedback, and the output feedback controller parameters are calculated using the mechanical impedance of the controlled system; The output feedback control includes a feedback controller and feedback controller gain parameter setting; The feedback controller is e(n), are the control system displacement and speed control error responses, respectively, G and F are controller gain parameters; The feedback controller gain parameter is set by the closed-loop characteristic equation of the control system based on the mechanical impedance Z(s) of the controlled structure: f(G, F, s) = det(I + Z(s) -1 B2(G+sF)D0) and the expected extreme point of the closed-loop system are determined, s is the Lagrangian operator, B2 is the control input position parameter, D0 is the sensor position parameter, I is the unit matrix, and det means to obtain the determinant; According to the closed-loop characteristic equation of the control system, the objective function is constructed Where λ is the expected pole value of the closed-loop system; Minimize the objective function Controller gain parameters G, F.

2. The method according to claim 1, characterized in that The reference signal is integrated according to the characteristics of the helicopter rotor, and the rotor speed signal Ω is obtained by the rotor speed sensor to obtain the control frequency kNΩ, where N is the number of rotor blades and k is the control frequency order; The reference signal of the kth channel is x k (n) = [cos(kNΩn)sin(kNΩn)] T , where n is the discrete time variable and T represents the matrix transpose.

3. The method according to claim 2, characterized in that The feedforward controller is implemented in a parallel structure in an adaptive notch according to the control frequency. The adaptive notch controller for the control frequency kNΩ includes two control weight coefficients w kc (n) and w ks (n), that is, W k (n)=[w kc (n)w ks (n)] T , W k (n) is the notch filter weight coefficient vector for the kth harmonic frequency.

4. The method according to claim 3, characterized in that The adaptive control method adopts the filtered x-LMS algorithm, and the formula is: Where e(n) is the displacement control error response of the control system, μ k To correct the step size, The reference signal is filtered through the control channel.

5. The method according to claim 4, characterized in that The objective function is iteratively minimized using the Gauss-Newton method To adjust the feedback controller parameter Φ = [GF] T , specifically including the following steps: Step a1, arbitrarily set the initial value of the feedback controller parameter Φ0 = [G0 F0] T and threshold ε, which is used to control the minimization of the objective function Iterative process; Step a2, calculating the Jacobian matrix of the closed-loop characteristic equation f(G, F) of the control system Step a3, substitute the current parameter value Φ i =[G i F i ] T , we get f(G i ,F i ), J(G i ,F i ), where G i 、F i is the current controller gain parameter; Step a4, calculate the Hessian matrix H(G i ,F i )=J(G i ,F i ) T J(G i ,F i ); Step a5: Update the controller parameter value Φ based on the results of steps a3 and a4 i+1 =Φ i -H(G i ,F i ) -1 J(G i ,F) T f(G i ,F); Step a6, substitute Φ i+1 =[G i+1 F i+1 ] T Calculate the objective function value Compare With the size of the threshold ε, if Return to step a2, if Get the feedback controller parameter Φ=Φ i+1 .

6. The method according to claim 5, characterized in that The control input of the method is u(n)=u ff (n)+u fb (n), where u ff (n) is the adaptive feedforward control input, u fb (n) is the impedance-based feedback control input, and the formula is as follows: Where N k The maximum frequency order of control.

7. A helicopter vibration control device based on mechanical impedance implemented by the method according to any one of claims 1 to 6, characterized in that: include: An adaptive feedforward control module, used for adaptive feedforward control; An output feedback control module, used for output feedback control; The adaptive feedforward control is implemented by reference signal synthesis, feedforward controller and adaptive control method; The output feedback control is implemented by displacement and velocity feedback, and the output feedback controller parameters are calculated using the mechanical impedance of the controlled system.

8. A storage medium, characterized in that: A computer program or instruction is stored, and when the computer program or instruction is executed, the method according to any one of claims 1 to 6 is implemented.

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