A high-order differential-based unmanned aerial vehicle attitude stabilization method

Abstract

The application provides a UAV attitude stabilizing method based on high-order differentiation, which first installs a gyroscope to measure a UAV pitch angle and a rate signal, then solves a pitch angle error and an integral signal; then estimates an attack angle based on force and torque balance according to a nominal value of aerodynamic parameters; then designs a second-order differential inertial combined filter to obtain a filtered differential signal of the pitch angle rate and the pitch angle error; then designs an adaptive compensation total signal related to the error, the angle of attack and the error differential through error adaptive compensation, so as to solve the error problem of the nominal value of the aerodynamic parameters; then solves a high-order differential signal of the pitch angle rate through discrete differentiation and acceleration full integral, and finally realizes strong stabilizing and high-performance flight of the UAV through equivalent control, error proportional integral control, adaptive control and high-order differential combined control.

Description

Technical Field

[0001] This invention relates to the field of aircraft attitude control, and more specifically, to a method for stabilizing the attitude of a UAV based on higher-order differentials. Background Technology

[0002] With the development of science and technology, UAV attitude stabilization and tracking control technology plays an important role in both military and civilian fields. To improve the stability and reliability of UAV flight, introducing sufficient damping into the control is the preferred method. Differentiation is the best way to increase system damping and enhance system stability. Currently, the traditional method is to measure the pitch rate signal, i.e., the pitch angle differential signal, using a gyroscope. While pitch acceleration signals are measured and used in some large manned aircraft, their measurement accuracy is limited, and the measuring instruments are expensive. Therefore, pitch acceleration is rarely introduced into the control of UAVs to improve system stability. Based on the above background reasons, this invention provides a method that uses a second-order differential inertial combined filter, discrete differentiation, and acceleration full integration to solve the high-order differential signal of the pitch rate and introduce it into pitch attitude control, thereby increasing the stability margin of attitude angle tracking control. At the same time, adaptive and equivalent control methods are used to improve the dynamic performance of attitude control, and traditional error proportional-integral control is used to improve control accuracy, while error feedback is used to improve anti-interference capability. This makes the whole method have high theoretical and engineering application value.

[0003] It should be noted that the information in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a method for attitude stabilization of unmanned aerial vehicles based on high-order differentials, thereby overcoming the problems of low stability margin and dynamic performance of aircraft attitude control caused by defects in related technologies.

[0005] According to one aspect of the present invention, a method for stabilizing the attitude of a UAV based on high-order differentials is provided, comprising the following five steps:

[0006] Step S10: Install a gyroscope on the UAV to measure the pitch angle signal of the UAV, and set the pitch angle command signal according to the UAV flight mission. Then compare the pitch angle error signal to obtain the pitch angle error integral signal. Install a rate gyroscope on the UAV to measure the pitch rate signal of the UAV. Then, based on the nominal value of the UAV aerodynamic coefficient and the pitch deflection signal, solve the UAV angle of attack force balance estimation signal and the UAV angle of attack moment balance estimation signal. Then calculate the average value to obtain the UAV angle of attack rate estimation signal.

[0007] Step S20: Based on the pitch rate signal of the UAV, design a second-order differential inertial combined filter to obtain the pitch rate filtered differential signal; based on the pitch error signal, design a second-order differential inertial combined filter to obtain the pitch error filtered differential signal; then, based on the pitch error filtered differential signal, pass it through the second-order differential inertial combined filter to obtain the pitch error secondary filtered differential signal.

[0008] Step S30: Based on the pitch angle error signal, pitch angle error filtered differential signal, pitch angle error second-order filtered differential signal, and angle of attack rate estimation signal, design the angular error adaptive compensation coefficient growth rate signal, angular error differential adaptive compensation coefficient growth rate signal, angular error second-order filtered differential adaptive compensation coefficient growth rate signal, and angle of attack adaptive compensation coefficient growth rate signal, respectively; then integrate them to obtain the angular error adaptive compensation coefficient signal, angular error differential adaptive compensation coefficient signal, angular error second-order filtered differential adaptive compensation coefficient signal, and angle of attack adaptive compensation coefficient signal.

[0009] Step S40: Based on the pitch rate signal of the UAV, design a first-order inertial filter to obtain the first-order inertial differential signal of the pitch rate; then use the time constant of the second-order differential inertial combined filter to solve the second-order discrete differential signal of the pitch rate; then obtain the first-order discrete differential signal of the pitch rate through Euler integration; and finally obtain the discrete differential signal of the pitch rate through full integration of velocity and acceleration.

[0010] Step S50: Construct an equivalent control signal for the UAV pitch moment based on the estimated angle-of-attack rate signal, the UAV pitch rate signal, and the nominal value of the UAV aerodynamic coefficients; then multiply the pitch error signal, the pitch error filtered differential signal, the pitch error second-order filtered differential signal, the estimated angle-of-attack rate signal, the angle error adaptive compensation coefficient signal, the angle error differential adaptive compensation coefficient signal, the angle error second-order filtered differential adaptive compensation coefficient signal, and the angle of attack adaptive compensation coefficient signal accordingly to obtain the total UAV pitch uncertainty compensation signal; then, based on the... The pitch angle error signal and the pitch angle error integral signal described above are used to construct the UAV proportional-integral control signal. Then, based on the UAV's pitch rate signal, pitch rate filtered differential signal, pitch rate first-order discrete differential signal, and pitch velocity discrete differential signal, the UAV's higher-order differential damping comprehensive signal is calculated. Finally, the UAV pitch torque equivalent control signal, the UAV pitch uncertainty compensation total signal, and the UAV proportional-integral control signal are superimposed to obtain the final pitch rudder deflection signal, which is sent to the UAV pitch rudder system to realize the UAV pitch channel's tracking of the desired pitch angle and stable flight.

[0011] In one exemplary embodiment of the present invention, a gyroscope is installed on the UAV to measure the UAV's pitch angle signal, and a pitch angle command signal is set according to the UAV's flight mission. The pitch angle error signal is then obtained by comparison, and integrated to obtain the pitch angle error integral signal. A rate gyroscope is installed on the UAV to measure the UAV's pitch rate signal. Then, based on the nominal values ​​of the UAV's aerodynamic coefficients and the pitch deflection signal, the UAV's angle-of-attack force balance estimation signal and angle-of-attack moment balance estimation signal are inversely solved. The average value is then calculated to obtain the UAV's angle-of-attack rate estimation signal, including:

[0012] ;

[0013]

[0014] ;

[0015] ;

[0016] ;

[0017] in This is the pitch angle signal for the drone. This is the pitch angle command signal. To obtain the pitch angle error signal, This is the integral signal of the pitch angle error; The pitch rate signal of the UAV. , , , , This refers to the nominal value of the aerodynamic coefficients of the UAV, which are constant parameters; For pitch deflection signal, For the estimation signal of the angle-of-attack force balance of the UAV, For the estimation signal of the angle-of-attack moment balance of the UAV, The signal is used to estimate the angle of attack rate of the UAV.

[0018] In one exemplary embodiment of the present invention, a second-order differential inertial combined filter is designed based on the pitch rate signal of the UAV to obtain a pitch rate filtered differential signal; a second-order differential inertial combined filter is designed based on the pitch error signal to obtain a pitch error filtered differential signal; and then, based on the pitch error filtered differential signal, a second-order differential inertial combined filter is used to obtain a pitch error secondary filtered differential signal, including:

[0019] ;

[0020] ;

[0021] ;

[0022] in , , , , These are the constant filtering parameters for the second-order differential inertial combined filter; The differential operator for the transfer function of a second-order differential inertial combined filter; The pitch rate is filtered differential signal; This is the differential signal filtered for pitch angle error; This is the differential signal after secondary filtering of the pitch angle error.

[0023] In one exemplary embodiment of the present invention, based on the pitch angle error signal, the pitch angle error filtered differential signal, the pitch angle error second-order filtered differential signal, and the angle of attack rate estimation signal, respectively, an adaptive compensation coefficient growth rate signal for angle error, an adaptive compensation coefficient growth rate signal for angle error differential, an adaptive compensation coefficient growth rate signal for angle error second-order filtered differential, and an adaptive compensation coefficient growth rate signal for angle of attack are designed; then, after integration, the adaptive compensation coefficient signals for angle error, angle error differential, angle error second-order filtered differential, and angle of attack are obtained, including:

[0024] ;

[0025] ;

[0026] ;

[0027] ;

[0028] ;

[0029] ;

[0030] ;

[0031]

[0032] in For constant time parameters, , This is a constant parameter used to adjust the rate at which the adaptive compensation coefficient increases. The signal representing the growth rate of the adaptive compensation coefficient for angular error; The signal represents the growth rate of the adaptive compensation coefficient for the differential angle error. The signal is the growth rate signal of the adaptive compensation coefficient for the second-order filtering of angular error; This is the signal indicating the growth rate of the angle-of-attack adaptive compensation coefficient. This is the adaptive compensation coefficient signal for angular error; The adaptive compensation coefficient signal for the differential of the angle error; The adaptive compensation coefficient signal for the second-order filtering differential of the angular error; This is the angle-of-attack adaptive compensation coefficient signal.

[0033] In one exemplary embodiment of the present invention, based on the pitch rate signal of the UAV, a first-order inertial filter is designed to obtain the first-order inertial differential signal of the pitch rate; then, using the time constant of the second-order differential inertial combined filter, the second-order discrete differential signal of the pitch rate is solved; then, the first-order discrete differential signal of the pitch rate is obtained through Euler integration; and finally, the discrete differential signal of the pitch rate is obtained through full integration of velocity and acceleration, including:

[0034] ;

[0035] ;

[0036] ;

[0037] ;

[0038] in This is a constant time parameter; The pitch angular rate is the first-order inertial differential signal; It is the second-order discrete differential signal of the pitch angular rate; These are constant integration parameters; It is the first-order discrete differential signal of the pitch angular rate; It is the discrete differential signal of pitch angular velocity.

[0039] In one exemplary embodiment of the present invention, an equivalent control signal for the UAV pitch moment is constructed based on the estimated angle-of-attack rate signal, the UAV pitch rate signal, and the nominal value of the UAV aerodynamic coefficients. Then, the UAV pitch uncertainty compensation signal is obtained by multiplying the pitch error signal, the pitch error filtered differential signal, the pitch error second-order filtered differential signal, the estimated angle-of-attack rate signal, the angle error adaptive compensation coefficient signal, the angle error differential adaptive compensation coefficient signal, the angle error second-order filtered differential adaptive compensation coefficient signal, and the angle of attack adaptive compensation coefficient signal. Next, a proportional-integral control signal for the UAV is constructed based on the pitch error signal and the pitch error integral signal. Then, a higher-order differential damping comprehensive signal for the UAV pitch is calculated based on the UAV pitch rate signal, the pitch rate filtered differential signal, the first-order discrete differential signal of the pitch rate, and the discrete differential signal of the pitch velocity. Finally, the equivalent control signal for the UAV pitch moment, the total UAV pitch uncertainty compensation signal, and the UAV proportional-integral control signal are superimposed to obtain the final pitch deflection signal, including:

[0040] ;

[0041] ;

[0042] ;

[0043] ;

[0044] ;

[0045] in This is the equivalent control signal for the pitch torque of the UAV. To compensate for the pitch uncertainty of the UAV; To construct the proportional-integral control signal for the UAV; For the high-order differential damping synthesis signal of UAV pitch; For pitch deflection signal, , , , , , These are constant control parameters.

[0046] Beneficial effects

[0047] This invention provides a high-order differential-based attitude stabilization method for unmanned aerial vehicles (UAVs). Its main innovations are as follows: First, by installing gyroscopes to measure the UAV's pitch angle and velocity signals, and based on the concept of force and torque balance, the angle of attack is estimated using aerodynamic coefficients, solving the problem of difficulty in angle of attack measurement while requiring angle of attack information in the construction of equivalent control. Second, the equivalent control method is introduced through nominal aerodynamic coefficients, improving the dynamic performance and stability of the system response. Third, an adaptive automatic compensation total control quantity for system uncertainties is designed using an error adaptive method, solving the uncertainty problem caused by aerodynamic coefficient errors in the construction of equivalent control and angle of attack estimation. Fourth, through the design of a second-order differential inertial combined filter and the solution method of discrete differential and acceleration full integral, a high-order differential combined control term for the pitch channel is obtained, improving the stability margin of the pitch channel, increasing the damping of the pitch channel, and also improving the dynamic performance of the entire control system.

[0048] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0049] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0050] Figure 1 This invention provides a flowchart of a UAV attitude stabilization method based on high-order differentials.

[0051] Figure 2 This is the pitch angle signal curve (unit: degrees) of the UAV using the method provided in the embodiments of the present invention.

[0052] Figure 3 This is the pitch angle error signal curve (unit: degrees) of the method provided in the embodiments of the present invention.

[0053] Figure 4 This is the pitch angle error integral signal curve (unitless) of the method provided in the embodiments of the present invention.

[0054] Figure 5 This is the estimated angle-of-attack rate (AOA) signal (unit: degrees) of the UAV provided by the method in the embodiments of the present invention.

[0055] Figure 6 This is the pitch angle error second-filter differential signal curve (unitless) of the method provided in the embodiments of the present invention.

[0056] Figure 7 This is the discrete differential signal curve of pitch angular velocity (unitless) provided by the method in the embodiments of the present invention.

[0057] Figure 8 This is the pitch deflection angle signal curve (unit: degrees) of the method provided in the embodiments of the present invention. Detailed Implementation

[0058] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of the invention. However, those skilled in the art will recognize that the technical solutions of the invention may be practiced with one or more of these specific details omitted, or other methods, components, apparatus, steps, etc., may be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of the invention.

[0059] This invention provides a method for attitude stabilization of unmanned aerial vehicles (UAVs) based on high-order differential equations. First, a gyroscope is installed to measure the pitch angle and rate signals of the UAV. Then, the pitch angle error and integral signal are calculated. Next, the angle of attack is estimated based on force and torque balance according to the nominal values ​​of aerodynamic parameters. Then, a second-order differential inertial combination filter is designed to obtain the filtered differential signals of pitch rate and pitch angle error. Then, an adaptive compensation total signal related to error design error, angle of attack, and error differential is used to solve the error problem of the nominal values ​​of aerodynamic parameters. Finally, the high-order differential signal of the pitch rate is calculated by discrete differential and full acceleration integration. Finally, through equivalent control, error proportional-integral control, adaptive control, and high-order differential combination control, the UAV achieves strong stability and high-performance flight.

[0060] Below, we will combine the appendix Figure 1 The present invention provides a further explanation and description of a UAV attitude stabilization method based on higher-order differentials. (Reference) Figure 1 As shown, this method for stabilizing the attitude of a UAV based on higher-order differentials includes the following steps:

[0061] Step S10 can be broken down into the following four sub-steps. First, install a gyroscope on the drone, measure the drone's pitch angle signal, and set the pitch angle command signal according to the drone's flight mission. Then, compare the results to obtain the pitch angle error signal as follows:

[0062] ;

[0063] in This is the pitch angle signal for the drone. The pitch angle command signal is selected in this case. Spend, To obtain the pitch angle error signal, its variation curve is as follows: Figure 3 As shown in the figure. The pitch angle signal of the UAV in this case exhibits the following variation curve: Figure 2 As shown.

[0064] The second step is to integrate the pitch angle error signal to obtain the integrated pitch angle error signal as follows:

[0065]

[0066] in The integral signal of pitch angle error is shown in the curve below. Figure 4 As shown.

[0067] The third step involves installing a rate gyroscope on the drone to measure its pitch rate signal. Then, based on the nominal values ​​of the drone's aerodynamic coefficients and the pitch deflection signal, the estimated angle-of-attack force balance signal and the estimated angle-of-attack moment balance signal are derived as follows:

[0068] ;

[0069] ;

[0070] in The pitch rate signal of the UAV. , , , , Here is the nominal value of the aerodynamic coefficient of the drone, which is a constant parameter. In this case, it is selected as [value missing]. , , , , ; For pitch deflection signal, For the estimation signal of the angle-of-attack force balance of the UAV, This is a signal used to estimate the angle-of-attack torque balance of the UAV.

[0071] The fourth step is to average the estimated angle-of-attack force balance signal and the estimated angle-of-attack moment balance signal of the UAV to obtain the estimated angle-of-attack angular rate signal of the UAV as follows:

[0072] ;

[0073] in The angle-of-attack rate of the UAV is estimated by the following curve. Figure 5 As shown.

[0074] Step S20 can be broken down into the following three sub-steps. First, based on the pitch rate signal of the UAV, design a second-order differential inertial combined filter to obtain the pitch rate filtered differential signal as follows:

[0075] ;

[0076] in , , , , The constant filtering parameters for the second-order differential inertial combined filter are selected as follows in this case: , , , , ; The differential operator for the transfer function of a second-order differential inertial combined filter; This is the differential signal filtered for pitch angular rate.

[0077] The second step involves designing a second-order differential inertial combination filter based on the pitch angle error signal, resulting in the following pitch angle error filtered differential signal:

[0078] ;

[0079] in This is the differential signal filtered for pitch angle error.

[0080] The third step involves using the pitch angle error filtered differential signal as described above, and then passing it through a second-order differential inertial combination filter to obtain the pitch angle error second-order filtered differential signal as follows:

[0081] ;

[0082] in The pitch angle error is a second-order filtered differential signal, and its variation curve is as follows: Figure 6 As shown.

[0083] Step S30 can be broken down into the following two sub-steps. First, based on the pitch angle error signal, the pitch angle error filtered differential signal, the pitch angle error second-order filtered differential signal, and the angle of attack rate estimation signal, design the following adaptive compensation coefficient growth rate signals for angle error, differential angle error, second-order filtered differential angle error, and angle of attack:

[0084] ;

[0085] ;

[0086] ;

[0087] ;

[0088] in For constant time parameters, , , , This is a constant parameter used to adjust the growth rate of the adaptive compensation coefficient; in this case, it is selected as [value missing]. , , , ; The signal representing the growth rate of the adaptive compensation coefficient for angular error; The signal represents the growth rate of the adaptive compensation coefficient for the differential angle error. The signal is the growth rate signal of the adaptive compensation coefficient for the second-order filtering of angular error; This is the signal for the growth rate of the angle-of-attack adaptive compensation coefficient.

[0089] The second step involves integrating the signals to obtain the adaptive compensation coefficients for angular error, the derivative adaptive compensation coefficients for angular error, the second-order filtered derivative adaptive compensation coefficients for angular error, and the adaptive compensation coefficients for angle of attack, as shown below:

[0090] ;

[0091] ;

[0092] ;

[0093]

[0094] in This is the adaptive compensation coefficient signal for angular error; The adaptive compensation coefficient signal for the differential of the angle error; The adaptive compensation coefficient signal for the second-order filtering differential of the angular error; This is the angle-of-attack adaptive compensation coefficient signal.

[0095] Step S40 can be broken down into the following four sub-steps. First, based on the pitch rate signal of the UAV, design a first-order inertial filter to obtain the first-order inertial differential signal of the pitch rate as follows:

[0096] ;

[0097] in For constant time parameters; in this case, we select [value]. , It is the first-order inertial differential signal of the pitch angular rate.

[0098] The second step involves using the time constant of a second-order differential inertial combined filter to solve for the second-order discrete differential signal of the pitch rate, as follows:

[0099] ;

[0100] in It is the second-order discrete differential signal of the pitch angular rate; For constant integration parameters, we choose in this case. .

[0101] The third step is to obtain the first-order discrete differential signal of the pitch rate through Euler integration, as follows:

[0102] ;

[0103] in It is the first-order discrete differential signal of the pitch angular rate.

[0104] The fourth step is to obtain the discrete differential signal of the pitch angular velocity by fully integrating the velocity and acceleration, as follows:

[0105] ;

[0106] in The pitch angular velocity discrete differential signal has the following variation curve: Figure 7 As shown.

[0107] Step S50 can be broken down into the following five sub-steps. The first step is to construct the equivalent control signal for the UAV's pitch moment based on the estimated angle-of-attack rate signal, the UAV's pitch rate signal, and the nominal values ​​of the UAV's aerodynamic coefficients, as follows:

[0108] ;

[0109] in This is the equivalent control signal for the pitch torque of the UAV.

[0110] The second step involves multiplying the pitch angle error signal, the pitch angle error filtered differential signal, the pitch angle error second-order filtered differential signal, the angle of attack rate estimation signal, the angle error adaptive compensation coefficient signal, the angle error differential adaptive compensation coefficient signal, the angle error second-order filtered differential adaptive compensation coefficient signal, and the angle of attack adaptive compensation coefficient signal accordingly to obtain the total UAV pitch uncertainty compensation signal as follows:

[0111] ;

[0112] in The total signal is used to compensate for pitch uncertainty of the UAV.

[0113] The third step involves constructing the UAV proportional-integral control signal based on the pitch angle error signal and the pitch angle error integral signal, as follows:

[0114] ;

[0115] in To construct the proportional-integral control signal for the UAV, , For constant control parameters, in this case, we select... , .

[0116] The fourth step involves calculating the UAV's higher-order differential damping composite pitch signal based on the UAV's pitch rate signal, pitch rate filtered differential signal, first-order discrete differential signal of pitch rate, and discrete differential signal of pitch velocity, as follows:

[0117] ;

[0118] in For the high-order differential damping synthesis signal of UAV pitch; This is the pitch deflection signal. , , , For constant control parameters, we select [value] in this case. , , , .

[0119] The fifth step involves superimposing the equivalent control signal of the UAV's pitch moment, the total signal for compensating for the UAV's pitch uncertainty, and the UAV's proportional-integral control signal to obtain the final pitch deflection signal. This signal is then sent to the UAV's pitch control system to achieve the UAV's pitch channel tracking of the desired pitch angle and stable flight, as follows:

[0120] ;

[0121] in The pitch deflection signal is shown in the curve below. Figure 8 As shown.

[0122] Finally, the pitch deflection signal is transmitted to the aircraft's pitch channel rudder system to enable the aircraft's pitch angle to track the desired pitch angle command.

[0123] Depend on Figure 2 It can be seen that the final aircraft overload can stably track the desired pitch angle command of 6 degrees in about 3 seconds, indicating that the method provided by this invention has good speed and stability. Figure 3 It can be seen that the attitude angle error can quickly converge to 0. Due to the introduction of integral control of the total signal for UAV pitch uncertainty compensation, there is no steady-state error. It is evident that the method provided by this invention has excellent accuracy. Figure 4 This is the integral curve of the pitch angle error. Figure 5 For estimating the angle of attack rate of the UAV, Figure 8 The final pitch deflection curve shows a smooth change, approaching 0 in steady state. Therefore, this case demonstrates that the method provided by this invention has significant engineering practical value, and also possesses considerable theoretical and engineering value.

Claims

1. A method for stabilizing the attitude of a UAV based on higher-order differentials, characterized in that, Includes the following steps: Step S10: Install a gyroscope on the UAV, measure the pitch angle signal of the UAV, set the pitch angle command signal according to the UAV flight mission, then compare to obtain the pitch angle error signal, and then integrate to obtain the pitch angle error integral signal. A rate gyroscope is installed on the UAV to measure the pitch rate signal. Then, based on the nominal values ​​of the UAV's aerodynamic coefficients and the pitch deflection signal, the estimated angle-of-attack force balance signal and the estimated angle-of-attack moment balance signal are obtained by inverse solving. The average value is then calculated to obtain the estimated angle-of-attack rate signal of the UAV as follows: ； ； ； ； in This is the pitch angle signal for the drone. This is the pitch angle command signal. To obtain the pitch angle error signal, This is the integral signal of the pitch angle error; The pitch rate signal of the UAV. , , , , This refers to the nominal value of the aerodynamic coefficients of the UAV, which are constant parameters; For pitch deflection signal, For the estimation signal of the angle-of-attack force balance of the UAV, For the estimation signal of the angle-of-attack moment balance of the UAV, Estimating the angle of attack rate of the UAV; Step S20: Based on the pitch rate signal of the UAV, design a second-order differential inertial combined filter to obtain the pitch rate filtered differential signal; based on the pitch error signal, design a second-order differential inertial combined filter to obtain the pitch error filtered differential signal; then, based on the pitch error filtered differential signal, pass it through the second-order differential inertial combined filter to obtain the pitch error second-order filtered differential signal as follows: ； ； ； in , , , , These are the constant filtering parameters for the second-order differential inertial combined filter; The differential operator for the transfer function of a second-order differential inertial combined filter; The pitch rate is filtered differential signal; This is the differential signal filtered for pitch angle error; This is the differential signal after second-order filtering of the pitch angle error; Step S30: Based on the pitch angle error signal, pitch angle error filtered differential signal, pitch angle error second-order filtered differential signal, and angle of attack rate estimation signal, respectively design the angular error adaptive compensation coefficient growth rate signal, angular error differential adaptive compensation coefficient growth rate signal, angular error second-order filtered differential adaptive compensation coefficient growth rate signal, and angle of attack adaptive compensation coefficient growth rate signal; then integrate them respectively to obtain the angular error adaptive compensation coefficient signal, angular error differential adaptive compensation coefficient signal, angular error second-order filtered differential adaptive compensation coefficient signal, and angle of attack adaptive compensation coefficient signal as follows: ； ； ； ； ； ； ； in For constant time parameters, , , , This is a constant parameter used to adjust the rate at which the adaptive compensation coefficient increases. The signal representing the growth rate of the adaptive compensation coefficient for angular error; The signal represents the growth rate of the adaptive compensation coefficient for the differential angle error. The signal is the growth rate of the differential adaptive compensation coefficient for the second-order filtering of angular error. This is the signal indicating the growth rate of the angle-of-attack adaptive compensation coefficient. This is the adaptive compensation coefficient signal for angular error; The adaptive compensation coefficient signal for the differential angle error; The adaptive compensation coefficient signal for the second-order filtering differential of the angular error; This is the angle-of-attack adaptive compensation coefficient signal; Step S40: Based on the pitch rate signal of the UAV, a first-order inertial filter is designed to obtain the first-order inertial differential signal of the pitch rate; then, using the time constant of the second-order differential inertial combined filter, the second-order discrete differential signal of the pitch rate is solved; then, the first-order discrete differential signal of the pitch rate is obtained through Euler integration; finally, the discrete differential signal of the pitch rate is obtained through full integration of velocity and acceleration as follows: ； ； ； ； in This is a constant time parameter; The pitch angular rate is the first-order inertial differential signal; It is the second-order discrete differential signal of the pitch angular rate; The parameter is a constant integral. It is the first-order discrete differential signal of the pitch angular rate; The pitch angular velocity is a discrete differential signal; Step S50: Construct an equivalent control signal for the UAV pitch moment based on the estimated angle-of-attack rate signal, the UAV pitch rate signal, and the nominal value of the UAV aerodynamic coefficients; then multiply the pitch error signal, the pitch error filtered differential signal, the pitch error second-order filtered differential signal, the estimated angle-of-attack rate signal, the angle error adaptive compensation coefficient signal, the angle error differential adaptive compensation coefficient signal, the angle error second-order filtered differential adaptive compensation coefficient signal, and the angle of attack adaptive compensation coefficient signal accordingly to obtain the total UAV pitch uncertainty compensation signal; then, based on the... The pitch angle error signal and the pitch angle error integral signal are used to construct the UAV proportional-integral control signal. Then, based on the UAV's pitch rate signal, pitch rate filtered differential signal, pitch rate first-order discrete differential signal, and pitch velocity discrete differential signal, the UAV's higher-order differential damping comprehensive signal is calculated. Finally, the UAV pitch torque equivalent control signal, the UAV pitch uncertainty compensation total signal, and the UAV proportional-integral control signal are superimposed to obtain the final pitch rudder deflection signal, which is sent to the UAV pitch rudder system to achieve the UAV pitch channel tracking the desired pitch angle and stable flight as follows: ； ； ； ； ； in This is the equivalent control signal for the pitch torque of the UAV. To compensate for the pitch uncertainty of the UAV; To construct the proportional-integral control signal for the UAV; For the high-order differential damping synthesis signal of UAV pitch; For pitch deflection signal, , , , , , These are constant control parameters.

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