Integrated control method for multi-body coupling motion of aircraft and components thereof

Abstract

The invention provides an integrated control method for multi-body coupling motion of an aircraft and components thereof, and the method comprises the steps: building a full-state dynamic model of the multi-body coupling motion aircraft, and deducing to obtain a scalar differential equation which can display control input and controlled quantity; the method comprises the following steps: firstly, designing a basic control structure of feedback linearization without considering modeling errors, parameter errors and external disturbance; then designing a control structure considering external disturbance and modeling errors, designing a model compensation expansion state observer, carrying out online estimation on the external disturbance and the modeling errors, then compensating the output of the control structure, ensuring a closed-loop control effect, and finally generating the control structure after the external disturbance and the modeling errors are compensated. The method can solve the problems of difficult control structure design, poor control effect and the like of a multi-body coupling motion aircraft dynamics model, and achieves the purpose of high-precision and strong-robustness integrated control of aircraft parts and attitudes.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft control, and relates to an integrated control method for multi-body coupled motion of an aircraft and its components. Background Art

[0002] With the continuous development of aerospace technology, aircraft need to meet more and more diverse mission requirements. Multi-body coupled motion aircraft can control the status of each component of the body through its own multi-actuator actuation to achieve higher maneuverability and flexibility, adapt to more complex flight environments, and have high potential application value in both military and civilian fields. Different from the traditional six-degree-of-freedom dynamics modeling of aircraft, the dynamics model of multi-body coupled motion aircraft has increased several degrees of freedom due to the presence of movable parts, showing multi-body, multi-degree-of-freedom and strong nonlinear characteristics. The parameters such as aerodynamic force / torque, pressure center, center of mass and moment of inertia of multi-body coupled motion aircraft all change greatly with the change of component state, and the complexity of the dynamic model increases dramatically. The traditional control design methods and theories based on the small disturbance assumption are no longer applicable to it, which brings huge challenges to the design of aircraft components and attitude control laws.

[0003] Although domestic and foreign scholars have conducted some research on the control of multi-body coupled motion aircraft, there are still problems such as poor control effect and complicated control laws that are difficult to apply in engineering. Multi-body coupled motion aircraft is a typical strong nonlinear system. Due to its strong coupling of multiple degrees of freedom and strong time-varying characteristics, the use of traditional error control methods such as PID that do not rely on models has problems such as difficulty in parameter tuning and poor control effect. The industry generally uses nonlinear control methods such as backstepping control and sliding film control that rely on prior model information to achieve better control effects. However, considering the modeling errors and external disturbances of the real system, control methods that rely on model information generally have problems such as weak robustness and difficulty in engineering application.

[0004] If the dynamics model of a multi-body coupled motion aircraft is established in accordance with the traditional flight mechanics description framework, the derivation process and representation will be quite complicated, and it will not be able to accurately describe the coupling effect of component actuation on the aircraft's body attitude. Although the representation of the dynamics equation of a multi-body coupled motion aircraft based on the virtual power principle is simple, it generally presents the form of a multi-degree-of-freedom high-dimensional vector differential equation. The control input and the controlled state quantity are implicit in the high-dimensional matrix. The relationship between the controlled quantities such as the aircraft attitude and component state that need to be paid attention to and the control inputs such as the rudder and actuation mechanism is unclear. At the same time, it does not conform to the usage habits of traditional flight mechanics, and it is difficult for designers to directly complete the control structure design for the controlled quantity.

[0005] Due to the complex coupling effects between the components and the main body of a multi-body coupled motion aircraft, no matter which control method is used to carry out control loop design, there will always be two types of prominent problems: First, even if a scalar dynamic equation containing only the controlled states such as components and attitudes and control inputs such as actuators and rudders is obtained, the coupling effects between component actuation and attitude are still serious, and it is difficult to learn from traditional aircraft design ideas to achieve three-channel decoupling control. The coupling effects must be taken into account as prior information when designing the control structure; second, most nonlinear control methods rely on aircraft prior model information, but aircraft face complex flight environments, and real physical processes are bound to have external disturbances and modeling errors, and the robustness of control methods that rely on models is difficult to guarantee.

[0006] Therefore, it is urgent to study the control design method of multi-body coupled motion aircraft, design nonlinear control structure based on the refined dynamic model, and further introduce observers to compensate for external disturbances and modeling errors, so as to provide a new technical approach to solve the control problems of multi-body coupled motion aircraft and improve the robustness of closed-loop control systems. Summary of the invention

[0007] The present invention aims to solve at least one of the problems existing in the prior art.

[0008] To this end, the present invention provides an integrated control method for the multi-body coupled motion of an aircraft and its components. The method is closely based on engineering practice and can solve the problems of difficult control structure design and poor control effect caused by the overly complex dynamic model of the multi-body coupled motion aircraft, thereby achieving the purpose of high-precision and robust integrated control of aircraft components and attitudes.

[0009] The technical solution of the present invention is:

[0010] An integrated control method for multi-body coupled motion of an aircraft and its components, the steps of the method are as follows:

[0011] Step 1: According to the real physical characteristics of the actuating parts and actuators of the aircraft and their geometric positional relationship relative to the aircraft body, a full-state dynamic model of the multi-body coupled motion aircraft is established based on the virtual power principle;

[0012] Step 2: extract the descriptive variables related to the component movement and posture change in the full-state dynamics model as the controlled quantity according to the control requirements, and derive the scalar differential equation that can explicitly contain the control input and the controlled quantity;

[0013] Step 3: Based on the scalar differential equation containing the control input and the controlled quantity, without considering the modeling error, parameter error and external disturbance, the basic control structure of feedback linearization is designed to realize the decoupled control of the controlled quantity;

[0014] Step four, based on the basic control structure of step three, design a control structure that takes external disturbances and modeling errors into consideration, and design a model-compensated extended state observer to estimate the external disturbances and modeling errors online, and then compensate for the output of the control structure of this step, so as to restore the real system of the aircraft to the nominal system of the aircraft established based on the prior model information of the aircraft, thereby ensuring the closed-loop control effect, and finally generating a control structure that compensates for the external disturbances and modeling errors.

[0015] Furthermore, the aircraft has two actuators: one is a sliding actuator, which controls the actuating component A to move linearly along the axial direction with a displacement s; the other is two rotation actuators, which respectively control the actuating component B1 and the actuating component B2 to rotate around their respective rudder axes;

[0016] The multi-body coupled motion is the coupling of the motion of the aircraft, the linear motion of the actuating component A, and the rotational motion of the actuating components B1 and B2.

[0017] Furthermore, in step 1, the full-state dynamic model of the multi-body coupled motion aircraft is established based on the virtual power principle: the sum of the virtual power of the translational inertial force and the virtual power of the rotational inertial force is equal to the virtual power of the external force. The specific expression is shown in formula (1):

[0018]

[0019] In the formula, r c,i ,ω i F is the radius vector and angular velocity vector of the rigid body’s center of mass; a,i ,M a,i is the external force and torque on the rigid body; m i is the rigid body mass; J i is the moment of inertia; g is the gravitational acceleration vector; is the measured value of the rigid body angular velocity vector.

[0020] Furthermore, in step 2, the derived scalar differential equation that can explicitly contain the control input and the controlled quantity is:

[0021] Select the fuselage as the main rigid body and the actuator component as the slave rigid body, select the description variable q as the controlled variable, the description variable q includes: the fuselage center of mass coordinates x, coordinates y, the fuselage pitch angle θ, component A displacement s, component B1 rotation angle χ; select the control input according to the description variable q, the control input includes: the fuselage axial control force Δf x , body normal control force Δf y 、Elevator deflection δ z 、Component A control force F s 、Component B1 control torque M w ;

[0022] According to the controlled variable and the control input, the control input is explicitly included in the scalar differential equation by decomposing the aerodynamic force and aerodynamic torque, and the scalar differential equation for control loop design is obtained as shown in formula (2):

[0023]

[0024] In the formula, is the derivative of the pitching moment with respect to the rudder deflection, which is a known quantity,

[0025] is the mass matrix coefficient, is the force matrix coefficient.

[0026] Furthermore, in step 3, without considering modeling error, parameter error and external disturbance, the designed feedback linearization basic control structure is:

[0027] The scalar differential equation of formula (2) can be further rewritten as shown in formula (15):

[0028]

[0029] Where:

[0030]

[0031] After that, nonlinear compensation is introduced based on the idea of ​​feedback linearization to transform the complex control of the multi-body coupled motion aircraft into a simple linear control, thus realizing the decoupling control of each controlled variable. After the control variable u is introduced, the dynamic system of the multi-body coupled motion aircraft is expressed in the form shown in equation (18):

[0032] Mu+F=T F τ (6)

[0033] Combining equations (15) and (18), since M is a symmetric positive definite matrix and is invertible, the nonlinear term is eliminated, and the decoupled linear time-invariant system is obtained:

[0034]

[0035] Based on this, PD control, which is convenient for engineering application, is introduced to construct an ideal closed-loop control system:

[0036]

[0037] In the formula and e=(qq d ) is the state quantity differential and state quantity error, q d , is the state quantity, state quantity differential, state quantity second-order differential instruction, k dis the differential gain matrix, k p is the proportional gain matrix, and the model control algorithm based on feedback linearization is:

[0038]

[0039] Therefore, equation (21) is the basic control structure of feedback linearization without considering external disturbances and modeling errors.

[0040] Furthermore, by substituting equation (21) into equation (18), the error equation of the closed-loop control system is obtained as follows:

[0041]

[0042] By changing k d , k p The poles corresponding to any controlled quantity are configured to the specified position to obtain the desired dynamic characteristics and ensure that the tracking error of the closed-loop control system to the command converges asymptotically to 0.

[0043] Furthermore, in step 4, the control structure considering external disturbance and modeling error is designed as follows:

[0044] Considering external disturbances and modeling errors, the longitudinal channel dynamics equation of a multi-body coupled motion vehicle is:

[0045]

[0046] Where M0 and F0 represent the model prior information for multi-body coupled motion vehicle dynamics modeling, ΔM and ΔF represent the modeling error, and τ d represents external disturbance;

[0047] At this time, the model control algorithm based on the feedback linearization idea is:

[0048]

[0049] Therefore, formula (24) is the control structure of feedback linearization considering external disturbances and modeling errors;

[0050] Substituting equation (24) into equation (18), the error equation of the closed-loop control system is obtained as follows:

[0051]

[0052] make d is the total disturbance including modeling error and external disturbance;

[0053] Therefore, the longitudinal channel dynamics equation of the multi-body coupled motion aircraft described by equation (23) can be further written as follows under the condition of considering the total disturbance:

[0054]

[0055] Furthermore, in the fourth step, the model compensation extended state observer is designed as:

[0056] make Assuming that d is continuously differentiable, x2 can be used as a new expanded state, and the multi-body coupled motion aircraft dynamics system can be expanded into the following state space form:

[0057]

[0058] Therefore, the extended state observer for model compensation can be written as follows:

[0059]

[0060] In the formula, z1 is the estimated value of the descriptive variable q, z2 is the estimated value of the total disturbance d of the model, and λ i >0 indicates the basic frequency point when the i-th state is subjected to disturbance observation; ξ i >0 indicates the frequency conversion factor when the i-th state is disturbed and observed; μ i >0 indicates the error switching factor when the i-th state is disturbed and observed.

[0061] Furthermore, in the fourth step, the control structure after compensating for the external disturbance and modeling error is:

[0062]

[0063] Therefore, formula (29) is a control structure that takes into account external disturbances and modeling errors and compensates for them.

[0064] By applying the above technical solution, the present invention has the following beneficial effects:

[0065] (1) The present invention proposes an integrated control method for the multi-body coupled motion of an aircraft and its components, and specifically relates to a multi-body coupled motion aircraft dynamics model established based on the principle of virtual power, and a control law design method for realizing integrated strong robust control of aircraft components and attitude; the present invention implements decoupling control of the controlled state through feedback linearization for the scalar differential equation of the controlled state of the multi-body coupled motion aircraft established based on the principle of virtual power, and can better cope with the adverse effects on the attitude of the aircraft caused by the multi-body nonlinear coupled motion of the aircraft and its components, achieve integrated control of the aircraft and its components, and can be used to guide the design of integrated control of components and attitude of multi-body coupled motion aircraft.

[0066] (2) Based on the basic design idea of ​​frequency adaptive switching extended state observer, the present invention proposes a frequency adaptive model compensation extended state observer. The state equation of the observer is established on the basis of prior model information, which can estimate the modeling error and external disturbance other than the prior model information of the multi-body coupled motion aircraft online. After compensation, the real system of the aircraft can always be consistent with the nominal system of the aircraft used to design the feedback linearization control law. The introduction of prior model information reduces the difficulty of the observer to estimate the disturbance, and improves the robustness of the closed-loop control system while ensuring the tracking accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0068] Figure 1 A schematic diagram of a multi-body coupled motion aircraft is given;

[0069] Figure 2 The integrated control structure diagram for the multi-body coupled motion of the aircraft and its components is given;

[0070] Figure 3 The pitch angle control response diagram for the integrated control of the multi-body coupled motion of the aircraft and its components is given;

[0071] Figure 4 The control response diagram of the integrated control component A for the multi-body coupled motion of the aircraft and its components is given;

[0072] Figure 5 The control response diagram of the integrated control component B1 for the multi-body coupled motion of the aircraft and its components is given;

[0073] Figure 6 The observation diagram of pitch velocity disturbance for integrated control of multi-body coupled motion of aircraft and its components is given. DETAILED DESCRIPTION

[0074] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0075] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0076] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0077] Embodiment 1:

[0078] This embodiment provides an integrated control method for multi-body coupled motion of an aircraft and its components, and the steps of the method are as follows:

[0079] Step 1: According to the real physical characteristics of the actuating parts and actuators of the aircraft and their geometric positional relationship relative to the aircraft body, a full-state dynamic model of the multi-body coupled motion aircraft is established based on the virtual power principle;

[0080] Step 2: According to the control requirements, the state quantities (i.e., descriptive variables) related to the component actuation and posture change in the full-state dynamics model are extracted as the controlled quantities, and the scalar differential equations that can explicitly contain the control input and the controlled quantities are derived to facilitate the design of the basic control structure.

[0081] Step 3: Based on the scalar differential equations that explicitly contain the control input and the controlled quantity, without considering the modeling error and external uncertainty, the basic control structure of feedback linearization is designed to achieve decoupled control of the controlled quantity, ensuring that the controlled quantity can quickly and accurately track the command under ideal conditions without external disturbance;

[0082] Step four, based on the basic control structure of step three, design a control structure that takes external disturbances and modeling errors into consideration, and design a model-compensated extended state observer to estimate the external disturbances and modeling errors online, and then compensate for the output of the control structure of this step, so as to restore the real system of the aircraft to the nominal system of the aircraft established based on the prior model information of the aircraft, thereby ensuring the closed-loop control effect, and finally generating a control structure that compensates for the external disturbances and modeling errors.

[0083] Embodiment 2:

[0084] Based on Example 1, this embodiment provides a specific example of an integrated control method for multi-body coupled motion of an aircraft and its components:

[0085] See attached Figure 1 The aircraft mainly has two types of actuators: one is a sliding actuator, which controls the actuating component A to move linearly along the axial direction with a displacement s; the other is two rotating actuators, which respectively control the actuating components B1 and B2 to rotate around their respective rudder axes along the fuselage;

[0086] The multi-body coupled motion is the coupling of the motion of the aircraft, the linear motion of the actuating component A, and the rotational motion of the actuating components B1 and B2;

[0087] Step 1: Establish the full-state dynamics model of the multi-body coupled motion aircraft based on the principle of virtual power:

[0088] The virtual power principle is the physical basis for establishing the dynamic model of a multi-body coupled motion aircraft. For any multi-body coupled motion aircraft dynamic system, the virtual power principle can be expressed as follows: the sum of the virtual power of the translational inertial force and the virtual power of the rotational inertial force is equal to the virtual power of the external force. The specific expression is shown in formula (1):

[0089]

[0090] In the formula, r c,i ,ω iF is the radius vector and angular velocity vector of the rigid body’s center of mass; a,i ,M a,i is the external force and torque on the rigid body; m i is the rigid body mass; J i is the moment of inertia; g is the gravitational acceleration vector; is the measured value of the rigid body angular velocity vector;

[0091] The formula (1) is the full-state dynamics model of the multi-body coupled motion aircraft.

[0092] Step 2: Extract the state quantity (i.e., description variable) related to the component movement and posture change in the full-state dynamics model as the controlled quantity, and derive the scalar differential equation that can explicitly contain the control input and the controlled quantity:

[0093] According to the relative motion form between the fuselage and the actuator and between the actuator components of the multi-body coupled motion aircraft, the fuselage is selected as the main rigid body and the actuator components are selected as the slave rigid body, and then the description variable q is selected as the controlled variable, and the description variable q includes: the coordinates x and y of the center of mass of the fuselage, the pitch angle θ of the fuselage, the displacement s of component A, and the rotation angle χ of component B1; the control input is selected according to the description variable q, and the control input includes: the axial control force Δf of the fuselage x , body normal control force Δf y 、Elevator deflection δ z 、Component A control force F s 、Component B1 control torque M w ;

[0094] According to the controlled variable and the control input, the control input is explicitly included in the scalar differential equation by decomposing the aerodynamic force and aerodynamic torque, and the scalar differential equation for control loop design is designed as shown in formula (2):

[0095]

[0096] In the formula, is the derivative of the pitching moment with respect to the rudder deflection, which is a known quantity,

[0097] is the mass matrix coefficient, specifically:

[0098]

[0099] M 13 =M 31 =-n1 cosθ-n2sinθ, M 14 =M 41 =-m2cosθ, M 15 =M 51 =2m1(x w sinχ+zw cosχ)cosθ(21) M 23 =M 32 =-n1 sinθ+n2cosθ,M 24 =M 42 =-m2sinθ,M 25 =M 52 =2m1(x w sinχ+z w cosχ)sinθ(22)

[0102] M 34 =M 43 =m2y s , M 35 =M 53 =2m1(y w -y b )(z w cosχ+x w sinχ) (23)

[0103] n1=m2y s +2m1(y b -y w ), n2=2m1(x b -x w cosχ+z w sinχ)+m2(x s -s) (24)

[0104]

[0105] is the force matrix coefficient, specifically:

[0106]

[0107]

[0108] Where P is the thrust of the aircraft. In equations (3) to (14), the parameters appearing are defined as shown in Table 1, where the direction of the fuselage system is consistent with the direction of the basis vector of the aircraft system:

[0109] Table 1 Definition of parameters of multi-body coupled motion aircraft dynamics model

[0110]

[0111]

[0112] It can be seen from the above equations (2)-(14) that the mass matrix coefficients and force matrix coefficients of the multi-body coupled motion aircraft are no longer constant matrices, but functions of state variables, which change with time. There are also many descriptive variables in the force matrix, which can fully consider the strong nonlinear and multi-degree-of-freedom coupling unsteady effects between the aircraft attitude and the motion of the actuator.

[0113] Step 3: Based on the scalar differential equations that explicitly contain the control input and the controlled quantity, the basic control structure of feedback linearization is designed without considering modeling errors, parameter errors and external disturbances:

[0114] Without considering modeling errors, parameter errors and external disturbances, the scalar differential equation of equation (2) can be further rewritten as shown in equation (15):

[0115]

[0116] Where:

[0117]

[0118] After that, nonlinear compensation is introduced based on the idea of ​​feedback linearization to transform the complex control of the multi-body coupled motion aircraft into a relatively simple linear control, thus realizing the decoupling control of each controlled variable. After the control variable u is introduced, the dynamic system of the multi-body coupled motion aircraft can be expressed as shown in equation (18):

[0119] Mu+F=T F τ (35)

[0120] Combining equations (15) and (18), and because M is a symmetric positive definite matrix and is invertible, if the nonlinear terms are eliminated, the decoupled linear time-invariant system can be obtained:

[0121]

[0122] Based on this, PD control, which is convenient for engineering application, is introduced to construct an ideal closed-loop control system:

[0123]

[0124] In the formula and e=(qq d ) is the state quantity differential and state quantity error, q d , is the state quantity, state quantity differential, state quantity second-order differential instruction, k d is the differential gain matrix, k p is the proportional gain matrix, and the model control algorithm based on feedback linearization is:

[0125]

[0126] Therefore, equation (21) is the basic control structure of feedback linearization without considering external disturbances and modeling errors;

[0127] Then, by substituting equation (21) into equation (18), the error equation of the closed-loop control system can be obtained as:

[0128]

[0129] In an ideal situation, by changing k d , k p The pole corresponding to any controlled quantity (i.e., the characteristic root of the state quantity error e obtained by formula (22)) is configured to the specified position to obtain the desired dynamic characteristics and ensure that the tracking error of the closed-loop control system for the command converges asymptotically to 0, ensuring that the controlled quantity can quickly and accurately track the command under ideal conditions without external disturbance.

[0130] Step 4: Design a model-compensated extended state observer to improve the robustness of the closed-loop control system:

[0131] In reality, there must be external disturbances and modeling errors in the aircraft. The longitudinal channel dynamics equation of a multi-body coupled motion aircraft can be written in the following general form:

[0132]

[0133] Where M0 and F0 represent the model prior information used for dynamic modeling of multi-body coupled motion aircraft, ΔM and ΔF represent the two error terms in the modeling error, and τ d represents external disturbance;

[0134] At this time, the model control algorithm based on the feedback linearization idea is:

[0135]

[0136] Therefore, formula (24) is the feedback linearization control structure considering external disturbances and modeling errors;

[0137] Then, substituting equation (24) into equation (18), the error equation of the closed-loop control system can be obtained as follows:

[0138]

[0139] make d is the total disturbance including external disturbance and modeling error. It is known that the basic control loop based on feedback linearization using equation (24) only compensates for the known nonlinear part. External disturbance and modeling error will inevitably lead to the degradation of closed-loop control system tracking performance, and in severe cases, the control will become unstable.

[0140] Therefore, the longitudinal channel dynamics equation of the multi-body coupled motion aircraft described by equation (23) can be further written as follows under the condition of considering external disturbances and modeling errors:

[0141]

[0142] In order to improve the robustness of the closed-loop control system, compensation for external disturbances and modeling errors is considered, so that the inner loop based on the feedback linearization control algorithm remains consistent with the prior model and the closed-loop tracking performance is guaranteed. In order to achieve the purpose of model compensation, the disturbance observer design idea commonly used in engineering is selected to observe and compensate the total disturbance d in real time.

[0143] Considering that the differential term of the state quantity can be measured by the sensor in practical applications, let Assuming that d is continuously differentiable, x2 can be used as a new expanded state, and the multi-body coupled motion aircraft dynamics system can be expanded into the following state space form:

[0144]

[0145] According to equation (27), the frequency adaptive switching extended state observer shown in equation (28) is designed to estimate the total disturbance d online, and the real system of the aircraft is restored to the nominal system of the aircraft based on the prior model information through compensation to ensure the effect of the basic control loop. The extended state observer used for model compensation can be written as follows:

[0146]

[0147] In the formula, z1 is the estimated value of the descriptive variable q, z2 is the estimated value of the total disturbance d, and λ i >0 indicates the basic frequency point when the i-th state is subjected to disturbance observation; ξ i >0 indicates the frequency conversion factor when the i-th state is disturbed and observed; μ i >0 indicates the error switching factor when the i-th state is disturbed and observed.

[0148] The multi-body coupled motion aircraft components and attitude control algorithm after the extended state observer is introduced for model compensation is shown in equation (29), and the closed-loop control loop structure is as follows: Figure 2 As shown:

[0149]

[0150] Therefore, formula (29) is a control structure that takes external disturbances and modeling errors into consideration and compensates for them.

[0151] After completing the closed-loop control structure design according to the above steps, the effectiveness simulation analysis of the control method is carried out under ideal conditions and under conditions with various uncertainties and disturbances. The results are as follows: Figure 3-Figure 6 The simulation results show that the integrated control method for the multi-body coupled motion of the aircraft / components proposed in this embodiment overcomes the strong nonlinear and complex influence of the component actuation on the aircraft attitude, and can achieve accurate and fast tracking of the attitude angle command and the component actuation command. Under ideal conditions, the command tracking adjustment time is fast and there is basically no steady-state error. Under various uncertain conditions, it can still ensure good control effects and has strong robustness, which verifies the effectiveness of the proposed control method.

[0152] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0153] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0154] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An integrated control method for multi-body coupled motion of an aircraft and its components, characterized in that: The steps of this method are as follows: Step 1: According to the real physical characteristics of the actuating parts and actuators of the aircraft and their geometric positional relationship relative to the aircraft body, a full-state dynamic model of the multi-body coupled motion aircraft is established based on the virtual power principle; Step 2: extract the descriptive variables related to the component movement and posture change in the full-state dynamics model as the controlled quantity according to the control requirements, and derive the scalar differential equation that can explicitly contain the control input and the controlled quantity; Step 3: Based on the scalar differential equation containing the control input and the controlled quantity, without considering the modeling error, parameter error and external disturbance, the basic control structure of feedback linearization is designed to realize the decoupled control of the controlled quantity; Step four, based on the basic control structure of step three, design a control structure that takes external disturbances and modeling errors into consideration, and design a model-compensated extended state observer to estimate the external disturbances and modeling errors online, and then compensate for the output of the control structure of this step, so as to restore the real system of the aircraft to the nominal system of the aircraft established based on the prior model information of the aircraft, thereby ensuring the closed-loop control effect, and finally generating a control structure that compensates for the external disturbances and modeling errors.

2. The integrated control method for multi-body coupled motion of an aircraft and its components as claimed in claim 1, characterized in that: The aircraft has two actuators: one is a sliding actuator, which controls the actuating component A to move linearly along the axial direction with a displacement s; the other is two rotation actuators, which respectively control the actuating component B1 and the actuating component B2 to rotate around their respective rudder axes; The multi-body coupled motion is the coupling of the motion of the aircraft, the linear motion of the actuating component A, and the rotational motion of the actuating components B1 and B2.

3. The integrated control method for multi-body coupled motion of an aircraft and its components as claimed in claim 2, characterized in that: In step 1, the full-state dynamic model of the multi-body coupled motion aircraft is established based on the virtual power principle: the sum of the virtual power of the translational inertial force and the virtual power of the rotational inertial force is equal to the virtual power of the external force. The specific expression is shown in formula (1): In the formula, r c,i ,ω i F is the radius vector and angular velocity vector of the rigid body’s center of mass; a,i ,M a,i is the external force and torque on the rigid body; m i is the rigid body mass; J i is the moment of inertia; g is the gravitational acceleration vector; is the measured value of the rigid body angular velocity vector.

4. The integrated control method for multi-body coupled motion of an aircraft and its components as claimed in claim 3, characterized in that: In step 2, the derived scalar differential equation that can explicitly contain the control input and the controlled quantity is: Select the fuselage as the main rigid body and the actuator component as the slave rigid body, select the description variable q as the controlled variable, the description variable q includes: the fuselage center of mass coordinates x, coordinates y, the fuselage pitch angle θ, component A displacement s, component B1 rotation angle χ; select the control input according to the description variable q, the control input includes: the fuselage axial control force Δf x , body normal control force Δf y 、Elevator deflection δ z 、Component A control force F s 、Component B1 control torque M w ; According to the controlled variable and the control input, the control input is explicitly included in the scalar differential equation by decomposing the aerodynamic force and aerodynamic torque, and the scalar differential equation for control loop design is obtained as shown in formula (2): In the formula, is the derivative of the pitching moment with respect to the rudder deflection, which is a known quantity, is the mass matrix coefficient, is the force matrix coefficient.

5. The integrated control method for multi-body coupled motion of an aircraft and its components as claimed in claim 4, characterized in that: In step 3, without considering modeling errors, parameter errors and external disturbances, the designed feedback linearization basic control structure is: The scalar differential equation of formula (2) can be further rewritten as shown in formula (15): Where: After that, nonlinear compensation is introduced based on the idea of ​​feedback linearization to transform the complex control of the multi-body coupled motion aircraft into a simple linear control, thus realizing the decoupling control of each controlled variable. After the control variable u is introduced, the dynamic system of the multi-body coupled motion aircraft is expressed in the form shown in equation (18): Mu+F=T F τ (6) Combining equations (15) and (18), since M is a symmetric positive definite matrix and is invertible, the nonlinear term is eliminated, and the decoupled linear time-invariant system is obtained: Based on this, PD control, which is convenient for engineering application, is introduced to construct an ideal closed-loop control system: In the formula and e=(qq d ) is the state quantity differential and state quantity error, q d , is the state quantity, state quantity differential, state quantity second-order differential instruction, k d is the differential gain matrix, k p is the proportional gain matrix, and the model control algorithm based on feedback linearization is: Therefore, equation (21) is the basic control structure of feedback linearization without considering external disturbances and modeling errors.

6. The integrated control method for multi-body coupled motion of an aircraft and its components as claimed in claim 5, characterized in that: Substituting equation (21) into equation (18), the error equation of the closed-loop control system is obtained as follows: By changing k d , k p The poles corresponding to any controlled quantity are configured to the specified position to obtain the desired dynamic characteristics and ensure that the tracking error of the closed-loop control system to the command converges asymptotically to 0.

7. The integrated control method for multi-body coupled motion of an aircraft and its components as claimed in claim 5, characterized in that: In step 4, the control structure considering external disturbances and modeling errors is designed as: Considering external disturbances and modeling errors, the longitudinal channel dynamics equation of a multi-body coupled motion vehicle is: Where M0 and F0 represent the model prior information used for dynamic modeling of multi-body coupled motion aircraft, ΔM and ΔF represent the two error terms in the modeling error, and τ d represents external disturbance; At this time, the model control algorithm based on the feedback linearization idea is: Therefore, formula (24) is the control structure of feedback linearization considering external disturbances and modeling errors; Substituting equation (24) into equation (18), the error equation of the closed-loop control system is obtained as follows: make d is the total disturbance including modeling error and external disturbance; Therefore, the longitudinal channel dynamics equation of the multi-body coupled motion aircraft described by equation (23) can be further written as follows under the condition of considering the total disturbance:

8. The integrated control method for multi-body coupled motion of an aircraft and its components as claimed in claim 7, characterized in that: In the fourth step, the model-compensated extended state observer is designed as: make Assuming that d is continuously differentiable, x2 can be used as a new expanded state, and the multi-body coupled motion aircraft dynamics system can be expanded into the following state space form: Therefore, the extended state observer for model compensation can be written as follows: In the formula, z1 is the estimated value of the descriptive variable q, z2 is the estimated value of the total disturbance d of the model, and λ i >0 indicates the basic frequency point when the i-th state is subjected to disturbance observation; ξ i >0 indicates the frequency conversion factor when the i-th state is disturbed and observed; μ i >0 indicates the error switching factor when the i-th state is disturbed and observed.

9. The integrated control method for multi-body coupled motion of an aircraft and its components as claimed in claim 8, characterized in that: In the fourth step, the control structure after compensating for external disturbances and modeling errors is: Therefore, formula (29) is a control structure that takes into account external disturbances and modeling errors and compensates for them.

Images