Airfoil gust mitigation feedforward control method based on circular rector control technology

Abstract

The invention relates to the technical field of aircraft control, in particular to an airfoil gust retarding feedforward control method based on a circular rector control technology, which comprises the following steps: modifying the shape of the rear edge of an NACA0012 airfoil, and arranging jet holes in the rear edge to form a circular rector control airfoil; performing a fluid simulation experiment on the circular rector control airfoil based on the gust speed, and constructing a model of the airfoil lift coefficient disturbed by the gust speed; performing a fluid simulation experiment on the circular rector control airfoil based on the jet flow momentum coefficient, and constructing a model of which the airfoil lift coefficient is controlled by the jet flow momentum coefficient; based on the model, obtaining a gust slowing-down feedforward control model of which the input quantity is the vertical gust speed and the output quantity is the jet flow momentum coefficient; controlling jet flow of a trailing edge by adopting the gust slowing-down feedforward control model to complete gust slowing-down control of the circular rector control airfoil; the method can improve the ability of the aircraft to resist the gust disturbance environment.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft control, and in particular to an airfoil gust mitigation feedforward control method based on circulation control technology. Background Art

[0002] Jet control technology is a technology that changes the flow characteristics through the jet holes arranged on the wing, thereby achieving control of the flow including delaying / accelerating transition, suppressing / strengthening turbulence, preventing / promoting separation, and so on, thereby achieving the effect of actively regulating the lift and drag of the aircraft. Circulation control technology is one of the control methods of jet control technology. It is to blow the jet tangentially onto the deflected flap or the curved surface of the object, guide the airflow through a large deflection angle to maintain the attached flow by the balance of centripetal force and pressure difference, and produce the wall effect, thereby regulating the circulation of the wing and changing the lift.

[0003] Gusts are a typical atmospheric disturbance phenomenon, manifested as winds with drastic changes in wind speed in a short period of time. Gusts will generate additional unstable aerodynamic forces and torques, affecting the handling quality, and adversely affecting the comfort and safety of the aircraft. Under the action of sudden vertical gusts, the aircraft will produce instantaneous large accelerations, affecting the handling quality and causing the common "bumping" phenomenon during flight. For passengers on civil aircraft, vertical gusts of medium intensity or above exceeding 6m / s will significantly affect the riding experience, and gusts of more than 15m / s will even cause damage to the aircraft structure and endanger flight safety. In addition, gusts will cause additional aerodynamic loads on the wings, which will have a significant impact on the increase in the weight of the aircraft structure, and the gust loads will also accelerate the fatigue of the wing structure. Therefore, in recent years, the technology for mitigating gust loads has become a focus of research at home and abroad. Summary of the invention

[0004] In view of the above problems, the present invention provides an airfoil gust mitigation feedforward control method based on circulation control technology, which solves the technical problem in the prior art that the aircraft has poor resistance to gust disturbances.

[0005] The present invention provides an airfoil gust mitigation feedforward control method based on circulation control technology, comprising the following steps:

[0006] Step S1, modifying the trailing edge shape of the NACA0012 airfoil, and arranging jet holes at the trailing edge to form a circulation control airfoil;

[0007] Step S2, determining a gust speed parameter of a circulation-controlled airfoil under gust disturbance, performing a fluid simulation experiment on the circulation-controlled airfoil based on the gust speed, and obtaining a first experimental value of the gust speed parameter and the wing lift coefficient; and constructing a model of the airfoil lift coefficient under gust speed disturbance based on the first experimental value;

[0008] Step S3, determining the jet momentum coefficient of the circulation control airfoil during flight, performing a fluid simulation experiment on the circulation control airfoil based on the jet momentum coefficient, and obtaining second experimental values ​​of the jet momentum coefficient and the wing lift coefficient; based on the second experimental values, constructing a model in which the airfoil lift coefficient is controlled by the jet momentum coefficient;

[0009] Step S4, based on the model in which the lift coefficient of the airfoil is disturbed by the vertical gust velocity and the model in which the lift coefficient of the airfoil is controlled by the jet momentum coefficient, a gust mitigation feedforward control model is obtained, the input of which is the vertical gust velocity and the output of which is the jet momentum coefficient;

[0010] Step S5: using the gust mitigation feedforward control model to control the jet at the trailing edge, thereby completing the gust mitigation control of the circulation controlled airfoil.

[0011] Preferably, the step S1 specifically comprises: for the NACA0012 airfoil, removing the original pointed trailing edge and replacing it with a semicircular trailing edge, and respectively arranging jet grooves at the upper and lower positions of the semicircular trailing edge.

[0012] Preferably, the step S2 specifically includes:

[0013] Step S2-1, taking the vertical gust speed that satisfies the 3211 multi-step excitation signal as the gust speed parameter, performing a simulation experiment by a computational fluid dynamics numerical calculation method, and obtaining data on the vertical gust speed and lift coefficient changing with time;

[0014] Step S2-2: Based on the data of vertical gust velocity and lift coefficient changing with time, a model of the lift coefficient of the circulation controlled airfoil being disturbed by vertical gust velocity is established by least square method and ARMA model identification method.

[0015] Preferably, in step S2-1, the 3211 multi-step excitation signal includes four signal segments arranged in chronological order with a duration length ratio of 3:2:1:1, and the speed amplitude ratio of each signal segment is 1:-1:1:-1.

[0016] Preferably, the step S2-2 specifically includes:

[0017] The vertical gust speed u obtained g and the corresponding lift coefficient C of the circulation-controlled airfoil l As external variables and system variables respectively, the weight coefficient of the ARMA model of lift coefficient affected by gust disturbance is solved by the least square method;

[0018] The ARMA model expression of the airfoil lift coefficient subject to vertical gust velocity disturbance is:

[0019]

[0020] Among them C l (k) represents the lift coefficient C l The value at time k, i, j are weight coefficient indexes, is the weight coefficient of the gust disturbance ARMA model determined by the least squares method, u g (kj) represents the value of vertical gust speed at time kj, and are the orders of the lift coefficient term and the vertical gust velocity term in the gust disturbance ARMA model, respectively, and can be determined by obtaining the minimum root mean square error between the lift coefficient predicted by the model and the lift coefficient obtained by simulation.

[0021] Preferably, the step S3 specifically includes:

[0022] Step S3-1, introducing a jet whose characteristics of the blowing momentum coefficient changing with time satisfying the random white noise at the jet hole, performing a simulation experiment by using a computational fluid dynamics numerical calculation method, and obtaining data on the changes of the lift coefficient and the jet momentum coefficient of the circulation-controlled airfoil with time;

[0023] Step S3-2, based on the data of the lift coefficient and the jet momentum coefficient of the circulation-controlled airfoil changing with time, a model of the influence of the lift coefficient of the circulation-controlled airfoil on the jet momentum coefficient is established by using the least square method and the ARMA model identification method;

[0024] Step S3-3, based on the model in which the lift coefficient of the circulation-controlled airfoil is controlled by the jet momentum coefficient, solving the feedback controller parameters to obtain the optimal feedback-controlled jet momentum coefficient of the lift coefficient of the circulation-controlled airfoil.

[0025] Preferably, the step S3-2 specifically includes:

[0026] The jet momentum coefficient C μ and the corresponding lift coefficient C of the circulation-controlled airfoil l As external variables and system variables, the ARMA model of lift coefficient affected by jet momentum coefficient is solved by least square method;

[0027] The ARMA model expression of lift coefficient affected by jet momentum coefficient is:

[0028]

[0029] Among them, C μ (kj) represents the value of the jet momentum coefficient at time kj, A i , B j The ARMA model weight coefficient of the jet momentum coefficient determined by the least squares method.a With n b are the orders of the lift coefficient term and the jet momentum coefficient term in the jet control ARMA model, respectively, and can be determined by obtaining the minimum root mean square error between the lift coefficient predicted by the model and the lift coefficient obtained by simulation.

[0030] Preferably, the step S3-3 specifically includes:

[0031] The lift coefficient circulation control model is rewritten into the form of discrete state space:

[0032]

[0033] in:

[0034]

[0035] B=[B0 0 0 … 0 1 0 0 … 0] T

[0036]

[0037] D=B0

[0038] The optimal control index function is defined as:

[0039]

[0040] Among them, J is the optimal control index, x is the state vector, Q is the semi-positive definite weighting matrix, R is the weighting coefficient, R>0, and t is the time;

[0041] The Riccati algebraic equation satisfied by the optimal state feedback gain is:

[0042] PA+A T P-PBR -1 B T P+Q=0

[0043] Among them, P is an auxiliary constant matrix to be solved, A T , B T are the transpose of A and B, R -1 is the reciprocal of R;

[0044] After solving P, the optimal feedback matrix K is obtained as:

[0045] K=R -1 B T P

[0046] Finally, the optimal feedback control jet momentum coefficient C is obtained μ for:

[0047] C μ=-Kx.

[0048] Preferably, the step S4 specifically includes:

[0049] Using the model of lift coefficient disturbed by vertical gust velocity, the vertical gust velocity u of the incoming flow is input g , and the lift coefficient C caused by gusts is obtained l ;

[0050] C l As the lift coefficient C at time k-1 l (k-1) Substitute the state vector x(k) into the optimal control matrix K to obtain the jet momentum coefficient of the optimal feedback control when the input is the vertical gust speed;

[0051] The final input is the vertical gust speed u g , the output is the jet momentum coefficient C μ , the controlled quantity is the lift coefficient C l Feedforward control model for gust mitigation of circulation controlled airfoil.

[0052] Compared with the prior art, the present invention has at least the following beneficial effects:

[0053] (1) The present invention establishes a model of the lift coefficient of the circulation-controlled airfoil subject to vertical gust velocity disturbance by using computational fluid dynamics numerical calculation methods and ARMA model identification methods. This enables the system to accurately predict the lift changes caused by gusts.

[0054] (2) By introducing the jet momentum coefficient and establishing a model of its influence on the lift coefficient, the system can effectively regulate the jet momentum to cope with the influence of vertical gusts.

[0055] (3) The present invention generates aerodynamic forces of equal magnitude and opposite direction through circulation control technology, thereby reducing the wing gust load, improving the flight performance of the aircraft in a gust disturbance environment, and effectively mitigating the impact of gusts. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The drawings are only for the purpose of illustrating particular embodiments and are not to be construed as limiting the invention.

[0057] Figure 1 A flow chart of the airfoil gust mitigation feedforward control method based on circulation control technology provided by the present invention.

[0058] Figure 2 Schematic diagram of the circulation controlled airfoil provided by the present invention.

[0059] Figure 3 A schematic diagram of the vertical gust velocity variation over time of the 3211 multi-step excitation gusts used for identification provided by the present invention.

[0060] Figure 4 A schematic diagram of the prediction effect of the identified airfoil lift coefficient gust disturbance model provided by the present invention on the lift coefficient change caused by "1-cos" type gusts.

[0061] Figure 5 A schematic diagram of the gust mitigation control effect provided by the present invention. DETAILED DESCRIPTION

[0062] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. In addition, the present invention can also be implemented in other ways different from those described herein, and therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0063] In order to illustrate the effectiveness of the method proposed by the present invention, the above technical solution of the present invention is described in detail below through a specific embodiment. Figure 1 As shown, a feedforward control method for airfoil gust mitigation based on circulation control technology is disclosed. The specific implementation steps are as follows:

[0064] Step S1, modifying the trailing edge shape of the NACA0012 airfoil, and arranging jet holes at the trailing edge to form a circulation control airfoil;

[0065] In this step, the trailing edge shape of the NACA0012 airfoil is modified. The specific modification method is: remove the original sharp trailing edge at 94.3% of the original airfoil chord length and replace it with a semicircular trailing edge with a radius r of 0.714% times the chord length, so as to construct the Coanda trailing edge commonly used in jet airfoils. At the same time, jet grooves are set in the upper and lower parts of the trailing edge respectively, and the ratio of the height of the jet groove to the radius of the semicircular trailing edge is 1:20. The modified circulation control airfoil is shown in the figure below. Figure 2 shown.

[0066] Step S2, determining the gust speed parameters of the circulation controlled airfoil under gust disturbance, performing a fluid simulation experiment on the circulation controlled airfoil based on the gust speed, and obtaining first experimental values ​​of the gust speed parameters and the wing lift coefficient; based on the first experimental values, constructing a model of the airfoil lift coefficient being disturbed by the vertical gust speed.

[0067] A fluid simulation experiment is carried out on the circulation controlled airfoil by using a computational fluid dynamics numerical calculation method. A gust disturbance is introduced using the moving boundary method. The vertical gust velocity is used as the gust velocity parameter. The data of the lift coefficient of the circulation controlled airfoil changing with time under the gust disturbance whose time-varying characteristics of the vertical gust velocity meet the 3211 multi-step excitation signal are calculated.

[0068] The schematic diagram of the vertical gust velocity disturbance signal is as follows: Figure 3 As shown, the 3211 multi-step excitation signal includes four signal segments arranged in time sequence with a duration length ratio of 3:2:1:1, and the speed amplitude ratio of each signal segment is 1:-1:1:-1.

[0069] The vertical gust speed u obtained g and the corresponding circulation-controlled airfoil lift coefficient C l As external variables and system variables, the weighted coefficients of the time series variables are solved by the least squares method, and the ARMA model identification method is used to establish the model of the lift coefficient of the circulation-controlled airfoil subject to vertical gust velocity disturbance. The ARMA model expression of the airfoil lift coefficient subject to gust disturbance is:

[0070]

[0071] Among them C l (k) represents the lift coefficient C l The value at time k, i, j are weight coefficient indexes, is the weight coefficient of the gust disturbance ARMA model determined by the least squares method, u g (kj) represents the value of vertical gust speed at time kj, and are the orders of the lift coefficient term and the vertical gust velocity term in the gust disturbance ARMA model, respectively, and can be determined by obtaining the minimum root mean square error between the lift coefficient predicted by the model and the lift coefficient obtained by simulation.

[0072] In order to verify the accuracy of the identified gust disturbance model in predicting the gust response of the airfoil, a "1-cos" gust load was applied to the airfoil, and the CFD simulation results were compared with the model prediction results, such as Figure 4 As shown in Figure 2, it can be seen that the model obtained by ARMA model identification can accurately predict the change of lift coefficient caused by gust disturbance.

[0073] Step S3, determining the jet momentum coefficient of the circulation controlled airfoil during flight, performing a fluid simulation experiment on the circulation controlled airfoil based on the jet momentum coefficient, and obtaining second experimental values ​​of the jet momentum coefficient and the wing lift coefficient; based on the second experimental values, constructing a model in which the airfoil lift coefficient is controlled by the jet momentum coefficient.

[0074] In this step, a fluid simulation experiment is conducted on the circulation control airfoil by using a computational fluid dynamics numerical calculation method. Using the velocity inlet boundary condition, a jet with a blowing momentum coefficient that changes with time and satisfies the random white noise is introduced at the jet hole to calculate the data of the lift coefficient and jet momentum coefficient of the circulation control airfoil that change with time. Among them, the momentum coefficient expression of the jet is:

[0075]

[0076] in, is the mass flow rate at the jet outlet; V jet is the jet velocity; ρ ∞ is the far-field current density; V ∞ is the far-field incoming flow velocity; S represents the reference area. For a two-dimensional airfoil, it is the chord length c of the airfoil.

[0077] The jet momentum coefficient C μ and the corresponding circulation-controlled airfoil lift coefficient C l The weighted coefficients of the time series variables are solved by the least square method as external variables and system variables respectively, and the ARMA model identification method is used to establish a model in which the lift coefficient of the circulation controlled airfoil is controlled by the jet momentum coefficient.

[0078] The ARMA model expression of the airfoil lift coefficient affected by the jet momentum coefficient is:

[0079]

[0080] Among them, C μ (kj) represents the value of the jet momentum coefficient at time kj, A i , B j The ARMA model weight coefficient of the jet momentum coefficient determined by the least squares method. a With n b are the orders of the lift coefficient term and the jet momentum coefficient term in the jet control ARMA model, respectively, and can be determined by obtaining the minimum root mean square error between the lift coefficient predicted by the model and the lift coefficient obtained by simulation.

[0081] In the above formula, C l (k) and C μ (k) is rewritten as a state vector:

[0082] x(k)=[C l (k-1)…C l (kn a )C μ (k-1)…C μ (kn b +1)]

[0083] Then, based on the model that the lift coefficient of the circulation controlled airfoil is controlled by the jet momentum coefficient, the feedback controller parameters are solved to obtain the optimal feedback controlled jet momentum coefficient of the lift coefficient of the circulation controlled airfoil.

[0084] The airfoil lift coefficient circulation control model obtained by step S3 can be rewritten into the form of discrete state space:

[0085]

[0086] in:

[0087]

[0088] B=[B0 0 0 … 0 1 0 0 … 0] T

[0089]

[0090] D=B0

[0091] The optimal control index function is defined as:

[0092]

[0093] Among them, J is the optimal control index, x is the state vector, Q is the semi-positive definite weight matrix, R is the weight coefficient, R>0, and t is the time.

[0094] The Riccati algebraic equation satisfied by the optimal state feedback gain is:

[0095] PA+A T P-PBR -1 B T P+Q=0

[0096] Among them, P is an auxiliary constant matrix to be solved, A T , B T are the transpose of A and B, R -1 It is the reciprocal of R.

[0097] After solving P, the optimal feedback matrix K is obtained as:

[0098] K=R -1 B T P

[0099] Finally, the optimal feedback control jet momentum coefficient is obtained as:

[0100] C μ =-Kx

[0101] Step S4, based on the model in which the lift coefficient of the airfoil is disturbed by the vertical gust velocity and the model in which the lift coefficient of the airfoil is controlled by the jet momentum coefficient, a gust mitigation feedforward control model is obtained, the input of which is the vertical gust velocity and the output of which is the jet momentum coefficient;

[0102] In this step, the present invention uses the model of the circulation control airfoil lift coefficient being disturbed by the vertical gust velocity, by inputting the vertical gust velocity u of the incoming flow g , we can get the lift coefficient change C caused by gusts l . l As the lift coefficient C at time l-1 l (l-1) Substitute the state vector x(k) into the optimal control matrix K, and the optimal feedback control jet momentum coefficient when the input is the vertical gust speed can be derived, thereby achieving the vertical gust speed u g , the output is the jet momentum coefficient C μ , the controlled quantity is the airfoil lift coefficient C l Circulation Control Airfoil Gust Mitigation Feedforward Control.

[0103] Step S5: using the gust mitigation feedforward control model to control the jet at the trailing edge, thereby completing the gust mitigation control of the circulation controlled airfoil.

[0104] This method is used to implement load mitigation in MATLAB simulation software for gust disturbances with vertical wind speeds that vary randomly over time. The effect is as follows: Figure 5 As shown in the figure, it can be seen that after the control is applied, the amplitude of the lift coefficient change caused by the gusts is significantly reduced, which greatly improves the safety of the aircraft flying in a gust disturbance environment.

[0105] Although the specific embodiments of the present invention depict various actions or steps in a specific order, this should be understood as requiring such actions or steps to be performed in the specific order shown or in a sequential order, or requiring all illustrated actions or steps to be performed to obtain the desired results. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure. Certain features described in the context of a separate embodiment can also be implemented in a single implementation in combination. On the contrary, the various features described in the context of a single implementation can also be implemented in multiple implementations individually or in any suitable sub-combination. The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

[0106] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A feedforward control method for mitigating airfoil gusts based on circulation control technology, characterized in that: The following steps are involved: Step S1, modifying the trailing edge shape of the NACA0012 airfoil, and arranging jet holes at the trailing edge to form a circulation control airfoil; Step S2, determining a gust speed parameter of a circulation-controlled airfoil under gust disturbance, performing a fluid simulation experiment on the circulation-controlled airfoil based on the gust speed, and obtaining a first experimental value of the gust speed parameter and the wing lift coefficient; and constructing a model of the airfoil lift coefficient under gust speed disturbance based on the first experimental value; Step S3, determining the jet momentum coefficient of the circulation control airfoil during flight, and performing a fluid simulation experiment on the circulation control airfoil based on the jet momentum coefficient to obtain second experimental values ​​of the jet momentum coefficient and the wing lift coefficient; Based on the second experimental value, a model is constructed in which the lift coefficient of the airfoil is controlled by the jet momentum coefficient; Step S4, based on the model in which the lift coefficient of the airfoil is disturbed by the vertical gust velocity and the model in which the lift coefficient of the airfoil is controlled by the jet momentum coefficient, a gust mitigation feedforward control model is obtained, the input of which is the vertical gust velocity and the output of which is the jet momentum coefficient; Step S5: using the gust mitigation feedforward control model to control the jet at the trailing edge, thereby completing the gust mitigation control of the circulation controlled airfoil.

2. The airfoil gust mitigation feedforward control method based on circulation control technology according to claim 1 is characterized in that: The step S1 specifically includes: For the NACA0012 airfoil, the original pointed trailing edge is removed and replaced with a semicircular trailing edge, and jet grooves are respectively arranged at the upper and lower positions of the semicircular trailing edge.

3. The airfoil gust mitigation feedforward control method based on circulation control technology according to claim 2 is characterized in that: The step S2 specifically includes: Step S2-1, taking the vertical gust speed that satisfies the 3211 multi-step excitation signal as the gust speed parameter, performing a simulation experiment by a computational fluid dynamics numerical calculation method, and obtaining data on the vertical gust speed and lift coefficient changing with time; Step S2-2: Based on the data of vertical gust velocity and lift coefficient changing with time, a model of the lift coefficient of the circulation controlled airfoil being disturbed by vertical gust velocity is established by least square method and ARMA model identification method.

4. The airfoil gust mitigation feedforward control method based on circulation control technology according to claim 3 is characterized in that: In step S2-1, the 3211 multi-step excitation signal includes four signal segments arranged in time sequence with a duration length ratio of 3:2:1:1, and the speed amplitude ratio of each signal segment is 1:-1:1:-1.

5. The airfoil gust mitigation feedforward control method based on circulation control technology according to claim 4 is characterized in that: The step S2-2 specifically includes: The vertical gust speed u obtained g and the corresponding lift coefficient C of the circulation-controlled airfoil l They are used as external variables and system variables respectively, and the weight coefficient of the ARMA model of lift coefficient affected by gust disturbance is solved by the least squares method.

6. The airfoil gust mitigation feedforward control method based on circulation control technology according to claim 5 is characterized in that: The step S3 specifically includes: Step S3-1, introducing a jet whose characteristics of the blowing momentum coefficient changing with time satisfying the random white noise at the jet hole, performing a simulation experiment by using a computational fluid dynamics numerical calculation method, and obtaining data on the changes of the lift coefficient and the jet momentum coefficient of the circulation-controlled airfoil with time; Step S3-2, based on the data of the lift coefficient and the jet momentum coefficient of the circulation-controlled airfoil changing with time, a model of the influence of the lift coefficient of the circulation-controlled airfoil on the jet momentum coefficient is established by using the least square method and the ARMA model identification method; Step S3-3, based on the model in which the lift coefficient of the circulation-controlled airfoil is controlled by the jet momentum coefficient, solving the feedback controller parameters to obtain the optimal feedback-controlled jet momentum coefficient of the lift coefficient of the circulation-controlled airfoil.

7. The airfoil gust mitigation feedforward control method based on circulation control technology according to claim 6 is characterized in that: The step S3-2 specifically includes: The jet momentum coefficient C μ and the corresponding lift coefficient C of the circulation-controlled airfoil l The ARMA model in which the lift coefficient is affected by the jet momentum coefficient is solved by the least squares method, taking them as external variables and system variables respectively.

8. The airfoil gust mitigation feedforward control method based on circulation control technology according to claim 7 is characterized in that: The step S4 specifically includes: Using the model of lift coefficient disturbed by vertical gust velocity, the vertical gust velocity u of the incoming flow is input g , and the lift coefficient C caused by gusts is obtained l ; C l As the lift coefficient C at time k-1 l (k-1) Substitute the state vector x(k) into the optimal control matrix K to obtain the jet momentum coefficient of the optimal feedback control when the input is the vertical gust speed; The final input is the vertical gust speed u g , the output is the jet momentum coefficient C μ , the controlled quantity is the lift coefficient C l Feedforward control model for gust mitigation of circulation controlled airfoil.

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