Self-adaptive event triggering control method and system of four-rotor aircraft system

Abstract

The invention provides a self-adaptive event triggering control method and system of a four-rotor aircraft system. The method comprises the following steps: establishing a kinetic model of a four-rotor aircraft position subsystem; defining a tracking target position trajectory, constructing a first error model of a position subsystem, and designing a first adaptive controller and a first adaptive law of the position subsystem; constructing a first event trigger control condition of the position subsystem, and designing a Lyapunov function to perform stability verification; establishing a kinetic model of a four-rotor aircraft attitude subsystem; defining a tracking target attitude angle, constructing a second error model of an attitude subsystem, and designing a second adaptive controller and a second adaptive law of the attitude subsystem; and constructing a second event trigger control condition of the attitude subsystem, and designing a Lyapunov function to carry out stability verification.

Description

Technical Field

[0001] The present invention relates to the technical field of quadrotor aircraft, and in particular to an adaptive event triggering control method and system for a quadrotor aircraft system. Background Art

[0002] In recent years, quadrotor aircraft have attracted much attention from researchers due to their outstanding autonomous flight capabilities and high maneuverability. They have been widely used in various application scenarios such as aerial photography, agricultural and forestry plant protection, terrain surveying, and power inspection. Among these many application fields, the position and attitude trajectory tracking control of quadrotor aircraft systems has become the main control target of most motion control systems.

[0003] For the quadcopter system in practical application scenarios, it is susceptible to disturbances caused by model uncertainty, nonlinear dynamics, and a large number of external disturbances in the real flight environment, so higher requirements are placed on the stability and robustness of the control system. However, some current aircraft control schemes impose stricter assumptions on external disturbances, such as being restricted by continuity conditions or constant boundaries. It should be pointed out that state-related and partially norm-bounded disturbances are more common in practical applications, such as internal factors such as inaccurate modeling and disturbances in system structure, as well as external factors such as wind. Therefore, it is necessary to solve the trajectory tracking problem of the quadcopter system under the influence of general internal and external disturbances.

[0004] The trajectory tracking control of the quadrotor system is completed by the controller updating the control signal through the communication network. However, in actual application scenarios, continuous communication consumes a lot of communication resources and increases the communication load of the control system. Therefore, the event-triggered control strategy with the economic advantage of system operation is introduced into the design of the aircraft controller. It has been proved that by triggering the update of the control signal under certain conditions, it can reduce the communication bandwidth requirements and reduce the driving frequency, thereby providing protection for the actuator. At the same time, the design of the event trigger condition should be relatively simple and reliable, because the event trigger condition with many trigger parameters may not be easy to implement in practice. Designing a simple and applicable event trigger mechanism and clarifying the meaning of the trigger parameters can further optimize the aircraft control scheme. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes an adaptive event-triggered control method and system for a quadrotor aircraft system. The method adopts an adaptive compensation control strategy to establish event triggering conditions to save communication resources and reduce actuator drive. Based on adaptive estimation and event triggering conditions, a robust adaptive position and attitude tracking controller is designed to reduce the impact of disturbances and save communication and drive resources, thereby solving the problems of disturbance suppression and resource limitation.

[0006] Some embodiments of the present invention provide an adaptive event-triggered control method for a quadrotor system, comprising the following steps:

[0007] S10: Establish the dynamic model of the quadrotor position subsystem;

[0008] S20: defining a tracking target position trajectory, constructing a first error model of the position subsystem, and designing a first adaptive controller and a first adaptive law of the position subsystem based on the first error model;

[0009] S30: constructing a first event triggering control condition for the position subsystem, and designing a Lyapunov function based on the first error model, the first adaptive controller, and the first adaptive law to perform stability verification;

[0010] S40: Establish the dynamic model of the attitude subsystem of the quadrotor aircraft;

[0011] S50: defining a target attitude angle, constructing a second error model of the attitude subsystem, and designing a second adaptive controller and a second adaptive law of the attitude subsystem based on the second error model;

[0012] S60: Constructing a second event triggering control condition for the attitude subsystem, and designing a Lyapunov function based on the second error model, the second adaptive controller and the second adaptive law to verify stability.

[0013] Some embodiments of the present invention provide an adaptive event-triggered control system for a quadrotor aircraft system, wherein the adaptive event-triggered control method for the quadrotor aircraft system comprises:

[0014] Position subsystem model building module: used to build the dynamic model of the position subsystem of the quadrotor aircraft;

[0015] A first adaptive module: used for defining the tracking target position trajectory, constructing a first error model of the position subsystem, and designing a first adaptive controller and a first adaptive law of the position subsystem based on the first error model;

[0016] A first verification module: used for constructing a first event triggering control condition of the position subsystem, and designing a Lyapunov function based on the first error model, the first adaptive controller and the first adaptive law to perform stability verification;

[0017] Attitude subsystem model building module: used to establish the dynamic model of the attitude subsystem of the quadrotor;

[0018] A second adaptive module: used for defining a target attitude angle, constructing a second error model of the attitude subsystem, and designing a second adaptive controller and a second adaptive law of the attitude subsystem based on the second error model;

[0019] The second verification module is used to construct the second event trigger control condition of the posture subsystem, and to design a Lyapunov function based on the second error model, the second adaptive controller and the second adaptive law to perform stability verification.

[0020] Some embodiments of the present invention provide a storage medium for storing a computer program of the adaptive event-triggered control method of the quadrotor aircraft system.

[0021] The beneficial results obtained by the present invention using the above technical solution are:

[0022] (1) The adaptive event-triggered control scheme of the present invention shows stronger ability in handling partially norm-bounded and state-dependent disturbances;

[0023] (2) The event trigger mechanism designed by the present invention based on the adaptive compensation control strategy has higher practicality and feasibility;

[0024] (3) The adaptive event-triggered control scheme proposed in the present invention takes into account the trade-off between steady-state tracking performance and communication resource conservation. By appropriately adjusting key control parameters, a balance can be achieved between control input and resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A flowchart of an adaptive event-triggered control method for a quadrotor system provided by an embodiment of the present invention;

[0026] Figure 2 , Figures 4 to 8 for Figure 1 Flowchart of some steps in the figure;

[0027] Figure 3 It is a schematic diagram of the structure of the position subsystem and attitude subsystem of a quadrotor aircraft in the prior art;

[0028] Fig. 9 It is a schematic diagram of the position trajectory tracking of the quadrotor position subsystem in 3D space;

[0029] Fig.10 It is the position trajectory tracking diagram of the quadrotor position subsystem;

[0030] Fig.11 This is the control input diagram for the quadrotor position subsystem;

[0031] Fig.12 , Fig.13 are the adaptive control parameters k in the position subsystem respectively. 1h ,k 2h , the estimated value of {h=x,y,z};

[0032] Fig.14 The interval time for event triggering in the location subsystem;

[0033] Fig.15 This is the trajectory tracking diagram of the attitude subsystem of the quadrotor aircraft;

[0034] Fig.16 This is the control input diagram for the attitude subsystem of the quadrotor aircraft;

[0035] Fig.17 is the adaptive control parameter d in the attitude subsystem φ ,d θ ,d ψ An estimated value of

[0036] Fig.18 It is the interval time of event triggering in the attitude subsystem;

[0037] Fig.19 and Fig. 20 A schematic diagram of the structure of an adaptive event-triggered control system for a quadrotor aircraft system provided by an embodiment of the present invention;

[0038] Wherein, the reference numerals are:

[0039] 1- Adaptive event-triggered control method for quadrotor aircraft system;

[0040] 2-Adaptive event-triggered control system for quadrotor aircraft system;

[0041] 20-position subsystem model building module;

[0042] 21- first adaptive module;

[0043] 210-a first error model building unit;

[0044] 211-a first adaptive controller design unit;

[0045] 212-First adaptive law design unit;

[0046] 22-first verification module;

[0047] 220-first event trigger condition construction unit;

[0048] 221-First Lyapunov function verification unit;

[0049] 23- Posture subsystem model building module;

[0050] 24- second adaptive module;

[0051] 240-second error model building unit;

[0052] 241-second adaptive controller design unit;

[0053] 242- Second adaptive law design unit;

[0054] 25- second verification module;

[0055] 250-second event trigger condition construction unit;

[0056] 251-Second Lyapunov function verification unit;

[0057] S10~S60, S100~S101, S200~S202, S300~S302, S400~S401, S500~S503, S600~S602-steps. DETAILED DESCRIPTION

[0058] In the prior art, a quadrotor aircraft is usually divided into two parts: a position subsystem and a posture subsystem. Figure 3 As shown, precise control of the aircraft can be achieved. In the prior art, the control of quadrotor aircraft is easily affected by internal and external disturbances and has position and attitude trajectory tracking problems. Therefore, the present invention proposes an adaptive event-triggered control method for a disturbed quadrotor aircraft system, focusing on the event-based position and attitude trajectory tracking control problem of a quadrotor aircraft system with generalized partial norm bounded and state-related disturbances. In order to solve the drawbacks of the prior art solutions, the present invention adopts an adaptive compensation control strategy to establish event triggering conditions to save communication sources and reduce actuator drive; based on adaptive estimation and event triggering conditions, a robust adaptive position and attitude tracking controller is designed to reduce the impact of disturbances and save communication and drive resources, solving the problems of disturbance suppression and resource limitation.

[0059] The technical solution of the present invention is to solve the above problems, and the overall idea is as follows:

[0060] Step 1: Establish the quadrotor position and attitude system model: By considering the quadrotor weight, moment of inertia, flight drag coefficient, distance between the motor shaft and the center of the aircraft and other flight parameters, and considering the internal and external disturbances during the flight, the second-order dynamic model of the aircraft position subsystem is expressed by the dynamic equation;

[0061] Step 2: Set the reference signal to guide the operation of the quadrotor position subsystem, build the aircraft position error model, and design the adaptive aircraft position subsystem controller based on the Lyapunov stability principle and adaptive technology;

[0062] Step 3: Based on the position subsystem error model and adaptive parameters, design the event trigger conditions associated with it, and use Lyapunov's second method to construct the Lyapunov function in combination with adaptive parameters, and verify the stability of the control method according to the Lyapunov stability principle.

[0063] Step 4: Similar to steps 1 and 2, the attitude subsystem of the quadrotor is represented by the dynamic equation, the reference signal guiding the operation of the attitude subsystem of the quadrotor is set, the attitude error model of the aircraft is constructed, and the adaptive aircraft attitude subsystem controller is designed by combining the adaptive technology;

[0064] Step 5: Similar to step 3, the event triggering conditions are designed by combining the attitude subsystem error model and adaptive parameters. According to the Lyapunov stability principle, the Lyapunov function is constructed to verify the stability of the control method.

[0065] Step 6: Design various flight and adaptive parameters for simulation, and run the simulation through a computer.

[0066] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments to further understand the purpose, solution and effect of the present invention, but it is not intended to limit the scope of protection of the claims attached to the present invention.

[0067] References in the specification to "an embodiment", "another embodiment", "this embodiment", etc., mean that the embodiment being described may include specific features, structures or characteristics, but not every embodiment must include these specific features, structures or characteristics. In addition, such statements do not refer to the same embodiment. Further, when describing specific features, structures or characteristics in conjunction with an embodiment, whether or not there is an explicit description, it is indicated that incorporating such features, structures or characteristics into other embodiments is within the knowledge of those skilled in the art. "Including" and "comprising" mentioned throughout the specification and claims are open-ended terms and should be interpreted as "including but not limited to".

[0068] Figure 1 As shown, it is a flow chart of an adaptive event-triggered control method 1 (hereinafter referred to as method 1) of a quadrotor system provided by an embodiment of the present invention. The method 1 comprises the following steps:

[0069] S10: Establish the dynamic model of the quadrotor position subsystem;

[0070] S20: defining a tracking target position trajectory, constructing a first error model of the position subsystem, and designing a first adaptive controller and a first adaptive law of the position subsystem based on the first error model;

[0071] S30: constructing a first event triggering control condition of the position subsystem, and designing a Lyapunov function based on the first error model, the first adaptive controller and the first adaptive law to verify stability;

[0072] S40: Establish the dynamic model of the attitude subsystem of the quadrotor aircraft;

[0073] S50: defining a target attitude angle, constructing a second error model of the attitude subsystem, and designing a second adaptive controller and a second adaptive law of the attitude subsystem based on the second error model;

[0074] S60: Construct the second event trigger control condition of the attitude subsystem, and design the Lyapunov function based on the second error model, the second adaptive controller and the second adaptive law to verify the stability.

[0075] Specifically: The position and attitude subsystem of the quadrotor aircraft establishes an error model, combines adaptive technology with event triggering mechanism, and designs an adaptive event triggering controller, so that the aircraft system can track the preset position and attitude target trajectory under the influence of general disturbances.

[0076] like Figure 2 As shown, step S10 also includes:

[0077] S100: By considering the weight of the quadrotor, the flight drag coefficient and other flight parameters as well as the influence of the partially norm bounded and state-related disturbances, a dynamic model of the quadrotor position subsystem is established, which is the following formula (1):

[0078]

[0079] Among them, x q ,y q 、z q , x v ,y v 、z v They are the position and velocity states of the quadrotor system in the x, y, and z axes in the ground coordinate system; u x 、u y 、u z They are the control input signals in the x, y, and z axis directions respectively. x , k y , k zand m refer to the air resistance coefficient and mass of the aircraft system in the x, y, and z axes respectively. The positions of the quadcopter in the x, y, and z axes are shown in the figure below. Figure 3 In the prior art ground coordinate system shown, Figure 3 The roll attitude angle, pitch attitude angle and yaw attitude angle in the attitude subsystem are also shown. Figure 3 It is only used to illustrate the position and posture of the quadcopter and is not intended to limit the scope of application of the present invention.

[0080] d x ,d y ,d z They represent the state-dependent and partially norm-bounded disturbances of the aircraft in the x, y, and z axis directions in the ground coordinate system:

[0081] ||d x ||≤δ 1x ||v x ||+δ 2x ,

[0082] ||d y ||≤δ 1y ||v y ||+δ 2y ,

[0083] ||d z ||≤δ 1z ||v z ||+δ 2z .

[0084] where δ 1x ,δ 2x , δ 1y ,δ 2y , δ 3x ,δ 3y are all unknown positive constants.

[0085] S101: Reduce the second-order dynamic equation (1) to the following equation (2):

[0086]

[0087] where x = [x q ;x v ],y=[y q ;y v ],z=[z q ;z v ], j={x,y,z}.

[0088] like Figure 4As shown, in step S20, a predetermined desired trajectory of the position subsystem of the quadrotor aircraft is defined, an error model is established, and then the position subsystem controller is designed in combination with the adaptive technology, which also includes:

[0089] S200: Define x 0q ,y 0q 、z 0q is the reference trajectory of the quadrotor position subsystem, and the error model of the position subsystem (i.e., the first error model) is defined as formula (3):

[0090]

[0091] S201: Based on the first error model, the quadrotor position subsystem adaptive controller (i.e., the first adaptive controller) is designed as formula (4), and the negative impact of general disturbances is eliminated by dynamically adjusting the core parameters of the controller:

[0092] u x (t) = K 1x (t)+K 2x e x (t),

[0093] u y (t) = K 1y (t)+K 2y e y (t),

[0094] u z (t) = K 1z (t)+K 2z e z (t). (4)

[0095] in, K 2x ,K 2y ,K 2z is the system gain matrix and satisfies the following inequality:

[0096] (A x +BK 2x ) T P x +P x (A x +BK 2x ) T <0,

[0097] (A y +BK 2y ) T P y +P y (A y +BK 2y )T <0,

[0098] (A z +BK 2z ) T P z +P z (A z +BK 2z ) T <0.

[0099] Among them, P x ,P y ,P z System gain matrix designed to satisfy the inequality.

[0100] S202: System's adaptive control equation term K 1x (t),K 1y (t),K 1z (t) and the design of the adaptive law are used to eliminate the negative impact caused by the disturbance.

[0101] In the x-axis direction, the adaptive control equation is specifically:

[0102] K 1x (t) = -α x B T P x e x γ x (t),

[0103]

[0104] Among them, the parameter α x Satisfy the condition 0.5<α x <1, is the unknown parameter k 1x ,k 2x The estimation of , and satisfies the following adaptive law (i.e., the first adaptive law in the x-axis direction), as shown in formula (5):

[0105]

[0106]

[0107] Among them, the parameters Parameter ζ x is defined as:

[0108]

[0109] γ 1x ,γ 2x is an unknown positive constant; And meet is the set parameter; at the same time δ ex will be defined in step S30.

[0110] Similarly, the design forms of the adaptive control equations, adaptive laws and adaptive parameters in the v and z axis directions are the same as those in the x axis direction.

[0111] like Figure 5 As shown, in step S30, based on the adaptive compensation control, the event triggering conditions associated therewith are defined, and the Lyapunov function is designed according to the error system and the second Lyapunov method, and the stability of the control method is verified, which also includes:

[0112] S300: Under the event-triggered control framework, the following error vectors are defined:

[0113]

[0114] Among them, t k It refers to the triggering moment when the event triggering condition is met. Similarly, the error and gain vector representation of the other two axes are similar. The error of the adaptive parameter is defined as:

[0115]

[0116] According to the adaptation law in S203, the error system of the adaptive parameters in the x-axis direction is defined as:

[0117]

[0118] The sampling time of the event trigger is determined by the trigger condition, which is determined by the variable δ ex Adjustment, when the variable exceeds the given threshold, that is, triggering an event, update the system control input. Therefore, the event trigger condition (that is, the first event trigger condition in the x-axis direction) defined by the above error system is formula (6):

[0119]

[0120] S301: constructing the first event triggering condition in the y-axis and z-axis directions in the same manner as constructing the first event triggering condition in the x-axis direction.

[0121] S302: To verify the effectiveness of the controller, taking the position in the x-axis direction as an example, the Lyapunov function is designed as formula (7):

[0122]

[0123] γ 1x ,γ 2xis an unknown positive constant. According to the first error model, the first adaptive law and the adaptive error system of the position subsystem, the derivative of equation (7) is obtained to obtain equation (8):

[0124]

[0125] When(A x +BK 2x ) T P x +P x (A x +BK 2x ) T When the condition <0 is met, there is It also shows that each signal in the position subsystem of the quadrotor is bounded, and the tracking error is transformed into a small area that satisfies:

[0126]

[0127] When(A y +BK 2y ) T P y +P y (A y +BK 2y ) T <0,(A z +BK 2z ) T P z +P z (A z +BK 2z ) T When <0 is satisfied, the errors in the y- and z-axis directions also satisfy the same condition.

[0128] like Figure 6 As shown, in step S40, since the attitude of the quadrotor is affected by the lift generated by the rotor, and the lift is determined by the control signal of the position subsystem, the target attitude trajectory of the quadrotor can be obtained by the virtual control input u x 、u y 、u z To calculate:

[0129]

[0130] F d is the target lift generated by the quadrotor rotor, φ d ,θ d , d are the target angles of roll, pitch and yaw attitude angles, ψ d is set to:d =2+sin(0.5t).

[0131] S400: Taking the pitch angle θ as an example, the attitude control dynamics of the pitch angle θ is expressed using a second-order system dynamics model, as shown in the following equation (9):

[0132]

[0133] Among them, a θ1 ,a θ2 is the system gain and satisfies J y , k θ , l is the setting parameter, d θ It is the disturbance effect on the attitude angle system.

[0134] S401: Constructing dynamic models of the pitch and roll attitude angle φ and the yaw attitude angle ψ respectively in the same manner as constructing the dynamic model of the pitch attitude angle θ.

[0135] like Figure 7 As shown, step S50 includes:

[0136] S500: Define θ d is the target angle of the pitch attitude angle θ, and the second error model of the pitch attitude angle θ is constructed as formula (10):

[0137]

[0138] S501: Define φ d , d are the target angles of the roll attitude angle φ and the yaw attitude angle ψ, respectively. In the same way as the second error model of the pitch attitude angle θ is constructed, the second error models of the roll attitude angle φ and the yaw attitude angle ψ are constructed respectively.

[0139] S502: For the pitch attitude angle θ, in order to obtain an asymptotically stable attitude angle error that gradually converges to 0, the virtual signal is designed to be:

[0140]

[0141] Among them, k θ1 is the designed experimental constant; an error system about the virtual signal is defined as:

[0142]

[0143]

[0144] According to the virtual signal and the error system of the virtual signal, the adaptive controller (second adaptive controller) of the pitch attitude angle θ is designed as formula (11):

[0145]

[0146] in,

[0147] is the design parameter, is a constant boundary The estimate of is updated under the control of the following adaptive law (i.e., the second adaptive law), as shown in formula (12):

[0148]

[0149] where λ θ is a designed positive constant; definition Define the error system with the following adaptive parameters:

[0150]

[0151] S503: For the roll attitude angle φ and the yaw attitude angle ψ, the second adaptive controller and the second adaptive law for the roll attitude angle φ and the yaw attitude angle ψ are designed in the same way as the second adaptive controller and the second adaptive law for the pitch attitude angle θ (refer to formulas (11) and (12)).

[0152] like Figure 8 As shown, in step S60, it further includes:

[0153] S600: Through the error system of adaptive parameters and attitude angle control input, the attitude event trigger condition (i.e., the second event trigger condition of the pitch attitude angle θ) is designed as formula (13):

[0154]

[0155] S601: Construct the second event trigger conditions for the roll attitude angle φ and the yaw attitude angle ψ respectively in the same manner as the second event trigger condition for the pitch attitude angle θ (i.e., refer to formula (13)).

[0156] S602: Lyapunov verification of the stability of the attitude subsystem controller, defining the Lyapunov function as equation (14):

[0157]

[0158] According to the second adaptive controller and the second adaptive law, the error system of the adaptive parameters, etc., the Lyapunov function is derived as formula (15):

[0159]

[0160] in,

[0161] Therefore, when When Also available:

[0162]

[0163] It can be seen that the formula is bounded, and e θ , is a continuous signal, and by Barbalat's lemma we know

[0164] Similarly, the controller stability verification of the φ and ψ attitude angles is similar.

[0165] Finally, the position and attitude subsystem of the quadrotor aircraft is simulated by computer. This example uses computer software MATLAB to verify method 1.

[0166] For the simulation of the position subsystem, the flight parameters are selected as follows:

[0167] The quadrotor system control parameters in step S10 are selected as follows:

[0168] k x =k y =0.01Ns / m,k z =0.012Ns / m, m=0.468kg;

[0169] The general perturbation to the position subsystem is:

[0170] [d x (t);d y (t);d z (t)] T =[0.1×sin(0.1t),0.05×v x (t),0.1+0.05×v z (t)] T

[0171] In step S20, the desired trajectory of the position subsystem is selected as:

[0172] [x 0 (t);y 0 (t); z 0 (t)] T =[sin(0.5t); cos(0.5t); 2+0.5sin(0.5t)] T m;

[0173] The initial value of the aircraft position subsystem is selected as:

[0174] [x(t 0 );y(t 0 ); z(t 0 )] T =[-1,-1,2] T m;

[0175] The initial value of the adaptive law is chosen as:

[0176]

[0177] The parameters in the adaptive controller and the adaptive law are selected as:

[0178] α x =0.7,β x =0.995,ò x =10 -5 ,{γ 1x ,γ 2x}=50;

[0179] The parameters in the y and z axis directions are the same; the system gain matrix that meets the following conditions is designed as follows: (A x +BK 2x ) T P x +P x (A x +BK 2x ) T <0,

[0180] (A y +BK 2y ) T P y +P y (A y +BK 2y ) T <0,

[0181] (A z +BK 2z ) T P z +P z (A z +BK 2z ) T <0.

[0182] {K 2x ,K 2y ,K 2z}=[-1.3125,-0.9161],

[0183]

[0184] Parameter selection of attitude subsystem:

[0185] In step S40, the flight parameters of the aircraft attitude subsystem are selected as:

[0186] {J x ,J y ,J z}=0.0023N·m,{k φ ,k θ ,k ψ}=0.012N·s / rad, l=0.3m,

[0187] The general disturbance to the attitude subsystem is:

[0188] [w φ (t),w θ (t),w ψ (t)] T =[0.1×sin(t),0.1×cos(t),0.2-0.1×sin(0.1t)] T

[0189] The initial value of the aircraft attitude subsystem is selected as:

[0190] [θ(t 0 ),φ(t 0 ),ψ(t 0 )] T =[0,0,0] T

[0191] In step S50, the initial value of the adaptive law is selected as:

[0192]

[0193] The parameters in the adaptive controller and the adaptive law are selected as:

[0194] α θ =1.2,β θ =0.95,ò x =10 -5 ,λ θ =0.5,k θ1 =5,

[0195] The parameters of the other two attitude angles are the same.

[0196] Result description:

[0197] like Fig. 9 , Fig.10As shown, the position subsystem of the quadrotor aircraft can operate stably in a flight environment with general disturbances and stably track the given trajectory.

[0198] like Fig.11 , Fig.12 , Fig.13 As shown, the control input and adaptive estimation of the quadrotor position subsystem enhance the robustness and stability of the system and eliminate the negative effects of external disturbances.

[0199] like Fig.14 As shown, the event triggering interval of the quadrotor position subsystem can ensure that the control input is updated after the set conditions are met, reducing the waste of communication resources and lowering the drive frequency.

[0200] like Fig.15 As shown, the attitude subsystem of the quadrotor aircraft can track the target with a given attitude angle under disturbance interference.

[0201] like Fig.16 , Fig.17 As shown, the adaptive controller and adaptive law of the attitude subsystem of the quadrotor aircraft can mitigate the negative impact of disturbances.

[0202] like Fig.18 As shown, the event triggering mechanism of the attitude subsystem of the quadrotor aircraft can reduce the communication frequency and save communication resources.

[0203] The following is a system embodiment corresponding to the above method embodiment. This embodiment can be implemented in conjunction with the above embodiment. The relevant technical details mentioned in the above embodiment are still valid in this embodiment. In order to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied in the above embodiment.

[0204] like Fig.19 and Fig. 20 As shown, the present invention provides a schematic diagram of the structure of an adaptive event-triggered control system 2 (hereinafter referred to as system 2) for a quadrotor aircraft system, using Figure 1 or Figure 2 The method 1 comprises:

[0205] Position subsystem model building module 20: used to establish a dynamic model of the position subsystem of the quadrotor aircraft;

[0206] The first adaptive module 21 is used to define the tracking target position trajectory, construct a first error model of the position subsystem, and design a first adaptive controller and a first adaptive law of the position subsystem based on the first error model;

[0207] The first verification module 22 is used to construct the first event trigger control condition of the position subsystem, and to design the Lyapunov function based on the first error model, the first adaptive controller and the first adaptive law to perform stability verification;

[0208] Attitude subsystem model building module 23: used to establish the dynamics model of the attitude subsystem of the quadrotor aircraft;

[0209] The second adaptive module 24 is used to define the target attitude angle, construct a second error model of the attitude subsystem, and design a second adaptive controller and a second adaptive law of the attitude subsystem based on the second error model;

[0210] The second verification module 25 is used to construct the second event trigger control condition of the attitude subsystem, and to design the Lyapunov function based on the second error model, the second adaptive controller and the second adaptive law to perform stability verification.

[0211] Specifically, the position subsystem model building module 20 is used to establish the dynamic model of the position subsystem of the quadrotor aircraft by considering the flight parameters such as the weight of the quadrotor aircraft, the flight drag coefficient, and the influence of partial norm bounded and state-related disturbances, which is formula (1), and reduce the second-order dynamic equation (1) to transform it into formula (2).

[0212] The first adaptive module 21 is used to define a predetermined desired trajectory of the quadrotor position subsystem, establish an error model, and then design a position subsystem controller in combination with adaptive technology, including:

[0213] The first error model building unit 210 is used to define x 0q ,y 0q 、z 0q is the reference trajectory of the quadrotor position subsystem, and the error model of the position subsystem (i.e., the first error model) is defined as formula (3);

[0214] The first adaptive controller design unit 211 is used to design the adaptive controller of the quadrotor position subsystem (i.e., the first adaptive controller) as formula (4) based on the first error model, and eliminate the negative impact of general disturbances by dynamically adjusting the core parameters of the controller;

[0215] The first adaptive law design unit 212: adaptive control equation term K for the position subsystem in the x, y, and z axis directions 1x (t),K 1y (t),K 1z (t) and the design of adaptive laws to eliminate the negative impact of disturbances.

[0216] The first verification module 22 is used to define the event triggering conditions associated with the adaptive compensation control, and to design the Lyapunov function according to the error system and the Lyapunov second method, and to verify the stability of the control method, including:

[0217] The first event trigger condition construction unit 220 is used to define the error vector, the error of the adaptive parameter, and the first event trigger condition in the x, y, and z axis directions under the event trigger control framework.

[0218] The first Lyapunov function verification unit 221 is used to verify the effectiveness of the controller. Taking the position in the x-axis direction as an example, the Lyapunov function is defined as formula (7). According to the first error model, the first adaptive law and the adaptive error system of the position subsystem, formula (7) is derived to obtain formula (8). Formula (8) shows that each signal in the position subsystem of the quadrotor aircraft is bounded. When (A y +BK 2y ) T P y +P y (A y +BK 2y ) T <0,(A z +BK 2z ) T P z +P z (A z +BK 2z ) T <0, the errors in the y- and z-axis directions also meet the same conditions.

[0219] In the attitude subsystem model building module 23, since the attitude of the quadrotor is affected by the lift generated by the rotor, and the lift is determined by the control signal of the position subsystem, the target attitude trajectory of the quadrotor can be obtained by the virtual control input u x 、u y 、u z To calculate:

[0220]

[0221] F d is the target lift generated by the quadrotor rotor, φ d ,θ d , d are the target angles of roll, pitch and yaw attitude angles, ψ d is set to: d =2+sin(0.5t).

[0222] Taking the pitch angle θ as an example, the attitude control dynamics of the pitch angle θ is expressed using the second-order system dynamics model, as shown in Equation (9).

[0223] The dynamic models of the pitch and roll attitude angle φ and the yaw attitude angle ψ are constructed in the same manner as the dynamic model of the pitch attitude angle θ.

[0224] The second adaptive module 24 comprises:

[0225] The second error model building unit 240 is used to define θ d is the target angle of the pitch attitude angle θ, and the second error model of the pitch attitude angle θ is constructed as formula (10); and is used to define ψ d , d are target angles of the roll attitude angle φ and the yaw attitude angle ψ, respectively. In the same manner as the second error model of the pitch attitude angle θ is constructed, the second error models of the roll attitude angle φ and the yaw attitude angle ψ are respectively constructed;

[0226] The second adaptive controller design unit 241 is used to design the adaptive controller (second adaptive controller) of the pitch attitude angle θ as equation (11), and is used to design the second adaptive controller of the roll attitude angle φ and the yaw attitude angle ψ in the same way as the second adaptive controller of the pitch attitude angle θ;

[0227] The second adaptive law design unit 242 is used to design the second adaptive law for the pitch attitude angle θ as shown in equation (12), and is used to design the second adaptive law for the roll attitude angle φ and the yaw attitude angle ψ in the same manner as the second adaptive law for the pitch attitude angle θ.

[0228] The second verification module 25 further comprises:

[0229] The second event trigger condition construction unit 250 is used to design the attitude event trigger condition (i.e., the second event trigger condition of the pitch attitude angle θ) as formula (13) through the error system of adaptive parameters and the attitude angle control input, and to construct the second event trigger conditions of the roll attitude angle φ and the yaw attitude angle ψ in the same way as the second event trigger condition of the pitch attitude angle θ (i.e., refer to formula (13)).

[0230] The second Lyapunov function verification unit 251 is used to verify the temperature property of the second adaptive controller of the attitude subsystem, specifically: define the Lyapunov function formula (14), and according to the second adaptive controller and the second adaptive law, the error system of the adaptive parameters, etc., the Lyapunov function formula (14) is derived as formula (15). Therefore, when When Also available: It can be seen that the formula is bounded, and eθ , is a continuous signal, and by Barbalat's lemma we know

[0231] Similarly, the controller stability verification of the φ and ψ attitude angles is similar.

[0232] Another embodiment of the present invention further provides a storage medium for storing execution Figure 1 The computer program of the adaptive event-triggered control method 1 of the quadrotor system shown. For example, computer program instructions, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. The program instructions for calling the method of the present invention may be stored in a fixed or removable storage medium, and / or transmitted through a data stream in a broadcast or other signal-bearing medium and / or stored in a storage medium that runs according to the program instructions.

[0233] In summary, the present invention uses an adaptive event-triggered control strategy to enable the position and attitude subsystems of the quadcopter to have better stability and robustness. Adaptive compensation control is adopted. Under the disturbance conditions with bounded partial norms and state correlation, the position and attitude subsystems can track the given target and operate stably. At the same time, the controller parameters are dynamically adjusted according to external changes under the control of the adaptive law to eliminate the negative impact of the disturbance. The event trigger mechanism can reduce the frequency of updating and communication of the control signal, save communication resources, and protect the actuator. At the same time, the event trigger condition is related to the adaptive parameter, which has higher practicality and ease of implementation, and can obtain a more acceptable balance between control input and resource utilization.

[0234] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which belong to the protection scope of the present invention.

Claims

1. An adaptive event-triggered control method for a quadrotor system, characterized in that: include: S10: Establish the dynamic model of the quadrotor position subsystem; S20: defining a tracking target position trajectory, constructing a first error model of the position subsystem, and designing a first adaptive controller and a first adaptive law of the position subsystem based on the first error model; S30: constructing a first event triggering control condition for the position subsystem, and designing a Lyapunov function based on the first error model, the first adaptive controller, and the first adaptive law to perform stability verification; S40: Establish the dynamic model of the attitude subsystem of the quadrotor aircraft; S50: defining a target attitude angle, constructing a second error model of the attitude subsystem, and designing a second adaptive controller and a second adaptive law of the attitude subsystem based on the second error model; S60: Constructing a second event triggering control condition for the attitude subsystem, and designing a Lyapunov function based on the second error model, the second adaptive controller and the second adaptive law to verify stability.

2. The method according to claim 1, characterized in that The step S10 further comprises: S100: Based on the flight parameters of the quadrotor and the influence of the partially norm-bounded and state-related disturbances, a dynamic model of the quadrotor position subsystem is established as follows: Among them, x q ,y q 、z q , x v ,y b 、z v are the position and speed of the quadrotor in the x, y, and z axes in the ground coordinate system; u x 、u y 、u z are the control input signals in the x, y, and z axis directions respectively, k x , k y , k z and m refer to the air resistance coefficient of the quadrotor system in the x, y, and z axes and the mass of the quadrotor, respectively; d x ,d y ,d z They represent the state-dependent and partially norm-bounded disturbances of the quadrotor in the x, y, and z axis directions in the ground coordinate system, respectively, and satisfy the following conditions: ||d x ||≤δ 1x ||v x ||+δ 2x , ||d y ||≤δ 1y ||v y ||+δ 2y , ||d z ||≤δ 1z ||v z ||+δ 2z , where δ 1x ,δ 2x , δ 1y ,δ 2y , δ 3x ,δ 3y are all unknown normal constants; S101: Reduce the order of equation (1) to equation (2): where x = [x q ; x v , y = [y q ; y v , z = [z q ; z v , B = [0; 1], j = {x, y, z}.

3. The method according to claim 2, characterized in that The step S20 further comprises: S200: Define x 0q ,y 0q 、z 0q For the tracking target position trajectory, the first error model is constructed as: e qx =x q -x 0q , and qy =and q -and 0q , yes qz =with q -with 0q ; S201: Based on the first error model, the first adaptive controller is designed as follows: u x (t)=K 1x (t)+K 2x e x (t), u y (t)=K 1y (t)+K 2y e y (t), u z (t)=K 1z (t)+K 2z e z (t), in, K 2x ,K 2y ,K 2z is the system gain matrix and satisfies the following inequality: (A x +BK 2x ) T P x +P x (A x +BK 2x ) T <0, (A y +BK 2y ) T P y +P y (A y +BK 2y ) T <0, (A z +BK 2z ) T P z +P z (A z +BK 2z ) T <0, Among them, P x ,P y ,P z The system gain matrix designed to satisfy the inequality; S202: Design of adaptive control equation term K 1x (t),K 1y (t),K 1z (t) and the first adaptive law, comprising: in the x-axis direction, the adaptive control equation is designed as: in, Parameter α x Satisfy the condition 0.5<α x <1, is the unknown parameter k 1x ,k 2x The estimate, In the x-axis direction, the first adaptive law is designed as: parameter Parameter ζ x for: γ 1x ,γ 2x is an unknown positive constant; And meet ∈ x is the set parameter, In the y and z axis directions, the adaptive control equation term K 1y (t),K 1z (t) and the first adaptive law and the adaptive control equation term K in the x-axis direction 1x (t) has the same design form as the first adaptive law.

4. The method according to claim 3, characterized in that The step S30 further comprises: S300: Under the event-triggered control framework, the following error vector is defined in the x-axis direction: Among them, t k It refers to the triggering moment when the event triggering condition is met. The error of the adaptive parameter is defined as: According to the first adaptive law in step S202, the error system of the adaptive parameters in the x-axis direction is defined as: Then in the x-axis direction, the first event triggering condition satisfies the following formula: Among them, δ ex represents the error vector; S301: constructing the first event triggering condition in the y-axis and z-axis directions in the same manner as constructing the first event triggering condition in the x-axis direction.

5. The method according to claim 1, characterized in that: The step S40 further comprises: S400: Construct a dynamic model of the pitch attitude angle θ: Among them, a θ1 ,a θ2 is the system gain and satisfies J y , k θ , l is the setting parameter, d θ is the disturbance effect on the dynamic model of the pitch attitude angle; S401: Constructing the dynamic models of the roll attitude angle φ and the yaw attitude angle ψ respectively in the same manner as constructing the dynamic model of the pitch attitude angle θ.

6. The method according to claim 5, characterized in that The step S50 further comprises: S500: Define θ d is the target angle of the pitch attitude angle θ, and the second error model of the pitch attitude angle θ is constructed as: e θ (t)=θ d -i, S501: Define φ d , d are target angles of the roll attitude angle φ and the yaw attitude angle ψ, respectively. The second error models of the roll attitude angle φ and the yaw attitude angle ψ are respectively constructed in the same manner as the second error model of the pitch attitude angle θ.

7. The method according to claim 6, characterized in that The step S50 further comprises: S502: For the pitch attitude angle θ, the virtual signal is designed to be: Among them, k θ1 is the designed experimental constant, and the error system of the virtual signal is defined as: According to the virtual signal and the error system of the virtual signal, the second adaptive controller of the pitch attitude angle θ is designed as: Among them, α θ ∈(1,2), is the design parameter, is a constant boundary The estimate is updated by the following second adaptive law control where λ θ is a designed positive constant; definition The error system of the adaptive parameters in the second adaptive law for constructing the pitch attitude angle θ is: S504: For the roll attitude angle φ and the yaw attitude angle ψ, design the second adaptive controller and the second adaptive law for the roll attitude angle φ and the yaw attitude angle ψ in the same way as the second adaptive controller and the second adaptive law are designed for the pitch attitude angle θ.

8. The method according to claim 7, characterized in that The step S60 comprises: S600: The second event triggering condition of the pitch attitude angle θ is constructed by using the error system of the adaptive parameters in the second adaptive law of the pitch attitude angle θ: S601: Constructing the second event trigger conditions of the roll attitude angle φ and the yaw attitude angle ψ respectively in the same manner as constructing the second event trigger condition of the pitch attitude angle θ.

9. An adaptive event-triggered control system for a quadrotor aircraft system, characterized in that: The method according to any one of claims 1 to 8, comprising: Position subsystem model building module: used to build the dynamic model of the position subsystem of the quadrotor aircraft; A first adaptive module: used for defining the tracking target position trajectory, constructing a first error model of the position subsystem, and designing a first adaptive controller and a first adaptive law of the position subsystem based on the first error model; A first verification module: used for constructing a first event triggering control condition of the position subsystem, and designing a Lyapunov function based on the first error model, the first adaptive controller and the first adaptive law to perform stability verification; Attitude subsystem model building module: used to establish the dynamic model of the attitude subsystem of the quadrotor; A second adaptive module: used for defining a target attitude angle, constructing a second error model of the attitude subsystem, and designing a second adaptive controller and a second adaptive law of the attitude subsystem based on the second error model; The second verification module is used to construct the second event trigger control condition of the posture subsystem, and to design a Lyapunov function based on the second error model, the second adaptive controller and the second adaptive law to perform stability verification.

10. A storage medium, characterized in that: A computer program for storing a method for executing an adaptive event-triggered control method for a quadrotor aircraft system according to any one of claims 1 to 8.

Images