Rotorcraft control method and system based on sliding mode active disturbance rejection and improved PD

Abstract

The application discloses a kind of based on sliding mode self-disturbance rejection and improved PD's arm rotorcraft control method and system, wherein the method includes: respectively constructing the dynamics model of rotorcraft and mechanical arm;Improved PD controller is constructed according to the dynamics model of mechanical arm;Estimate the total disturbance estimation value of rotorcraft platform when mechanical arm acts;According to the dynamics model of rotorcraft, sliding mode self-disturbance rejection controller of position loop and attitude loop is constructed;According to total disturbance estimation value, input the sliding mode self-disturbance rejection controller for compensation, obtain output system control quantity, and it is converted into the speed control quantity of four rotors.The method uses extended state observer to observe the mechanical arm disturbance that rotorcraft platform is subjected to, and combines nonlinear sliding mode variable structure control real-time compensation disturbance generated by mechanical arm operation, while based on the improved PD controller of dynamics model design mechanical arm, improve the operation accuracy and stability of arm rotorcraft.

Description

Technical Field

[0001] This invention relates to the field of aircraft technology, and in particular to a control method and system for a rotorcraft with boom based on sliding mode active disturbance rejection and improved PD. Background Technology

[0002] Rotorcraft are small, unmanned aircraft powered by their onboard rotors. Multi-rotor drones, with their hovering, vertical takeoff and landing, and agile movement, can adapt to a wider range of operational environments. However, current drone applications are mainly focused on non-contact tasks such as environmental modeling, agricultural and forestry protection, aerial photography, and power line inspection, lacking effective interaction with the external environment, which significantly limits their practical application. Rotorcraft with arms offer greater spatial accessibility and maneuverability compared to traditional ground-based robots, while also possessing the operational capabilities of a robotic arm. They can reach disaster sites more quickly to deploy equipment and can also rapidly grasp objects in mid-air. This will greatly expand the application areas of drones, shifting them from traditional non-contact operations to proactive contact operations.

[0003] Quadrotors control their attitude and position by adjusting the rotor speed of four motors to change lift. This power generation mechanism results in highly coupled, nonlinear, and underactuated characteristics, making the quadcopter highly sensitive to external disturbances. The movement of the robotic arm causes changes in the center of gravity and moment of inertia, while simultaneously exerting a reaction torque on the fuselage. Tracking a target requires simultaneous position and velocity control of both the fuselage and the robotic arm. Therefore, a controller needs to be designed to analyze the system of quadcopters with robotic arms, eliminate disturbances to the quadcopter during robotic arm operations, improve the control accuracy of the robotic arm, and ensure efficient collaborative operation of quadcopters with robotic arms, showing broad application prospects.

[0004] Traditional PID controllers are error-based linear control methods widely used in rotorcraft control. However, they have poor anti-interference capabilities and struggle to guarantee robustness in the complex nonlinearities and coupling relationships of rotorcraft control with booms. Sliding mode control is a widely used nonlinear variable structure control method that alters the dynamic characteristics of a nonlinear system by applying a high-frequency switching control signal. The system trajectory will reach and remain near the sliding surface within a finite time. It exhibits strong robustness for systems with large uncertainties, time-varying characteristics, and nonlinearity. However, sliding mode controller outputs often contain high-frequency noise, which can easily induce motor chattering when applied to physical systems. Furthermore, it cannot quickly converge to large time-varying disturbances generated during robotic arm movements.

[0005] Precise control of robotic arm motion is a crucial aspect of the accurate operation of rotorcraft with arms. Most existing airborne robotic arm controls are based solely on the kinematic model of the robotic arm, considering only the angle tracking errors of each joint and employing simple feedback control. While this approach is computationally simple and reliable, it fails to account for the dynamic structural changes caused by variations in robotic arm movement and load, and it also neglects the interference of nonlinear terms in the robotic arm's dynamic model, making it difficult to achieve high-speed and precise trajectory tracking. Summary of the Invention

[0006] This invention provides a control method and system for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD, in order to solve the technical problems of high coupling, nonlinearity, underactuation and susceptibility to disturbances caused by robotic arm operation in existing rotorcraft with arms.

[0007] One embodiment of the present invention provides a control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD, comprising:

[0008] Step S1: Construct the dynamic model of the rotorcraft and the dynamic model of the robotic arm;

[0009] Step S2: Construct an improved PD controller based on the dynamic model of the robotic arm;

[0010] Step S3: Estimate the total disturbance to the rotorcraft platform when the robotic arm moves based on the extended state observer;

[0011] Step S4: Construct sliding mode active disturbance rejection controllers for position loop and attitude loop based on the dynamic model of the rotorcraft;

[0012] Step S5: The total disturbance estimate is input into the sliding mode active disturbance rejection controller of the position loop and attitude loop for compensation, and the output system control quantity is obtained. The system control quantity is then converted into the speed control quantity of the four rotors.

[0013] Another embodiment of the present invention provides a control system for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD, comprising:

[0014] The first building module is used to build the dynamic model of the rotorcraft and the dynamic model of the robotic arm;

[0015] The design module is used to build an improved PD controller based on the dynamic model of the robotic arm;

[0016] The estimation module is used to estimate the total disturbance to the rotorcraft platform during the manipulator's movements based on the extended state observer;

[0017] The second construction module is used to design and construct a sliding mode active disturbance rejection controller for the position loop and attitude loop based on the dynamic model of the rotorcraft.

[0018] The compensation and conversion module is used to compensate the sliding mode active disturbance rejection controller of the position loop and attitude loop according to the total disturbance estimate, obtain the output system control quantity, and convert the system control quantity into the speed control quantity of the four rotors.

[0019] Another embodiment of the present invention provides a control device for a rotorcraft with an arm, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD as described in the above embodiment.

[0020] In another aspect, the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the control method for a rotorcraft with arm based on sliding mode active disturbance rejection and improved PD as described in the above embodiments.

[0021] The technical solution of the present invention achieves at least the following beneficial technical effects:

[0022] (1) Compared with traditional linear controllers, this invention utilizes sliding mode variable structure control to address the nonlinearity and coupling problems of the system model. It designs a dual-loop controller to solve the high-precision tracking problem when the aircraft attitude changes significantly. This can effectively achieve precise control of the robotic arm and observation and suppression of robotic arm disturbances, ensuring stable control of the aircraft.

[0023] (2) A saturation function is designed to replace the sign function to eliminate the output jitter of the traditional sliding mode controller. At the same time, an extended state observer is used to observe the disturbance of the robotic arm and bring the disturbance observation value into the controller, which effectively eliminates the influence of the robotic arm's movement.

[0024] (3) Compared with a single kinematics-based robotic arm controller, the present invention proposes an improved PD controller based on the robotic arm dynamics model, which takes into account the changes in dynamic structure and the interference of nonlinear terms in the dynamics model caused by the movement and load of the robotic arm, thereby improving the accuracy and speed of robotic arm control.

[0025] (4) This invention combines the advantages of sliding mode controller, extended state observer and improved PD controller, and improves the anti-interference ability and control accuracy of the aircraft in the stable operation of the rotorcraft with arm, and has high engineering application value.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0028] Figure 1 This is a flowchart of a control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD according to an embodiment of the present invention;

[0029] Figure 2 This is a coordinate system definition diagram of a rotorcraft with arms according to an embodiment of the present invention;

[0030] Figure 3 This is a simplified PD-controlled robotic arm response diagram according to an embodiment of the present invention;

[0031] Figure 4 This is a response diagram of an improved PD-controlled robotic arm according to an embodiment of the present invention;

[0032] Figure 5 This is a pitch observation effect diagram of a rotorcraft with an arm according to an embodiment of the present invention;

[0033] Figure 6 This is a structural diagram of a control system for a rotorcraft with an arm, according to an embodiment of the present invention.

[0034] Figure 7 This is a structural diagram of a sliding mode adaptive controller according to an embodiment of the present invention;

[0035] Figure 8 This is a comparison diagram of the operation control effect of a rotorcraft with an arm according to an embodiment of the present invention;

[0036] Figure 9 This is a schematic diagram of the control system of a rotorcraft with arm based on sliding mode active disturbance rejection and improved PD according to an embodiment of the present invention. Detailed Implementation

[0037] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0038] The control method and system for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD according to embodiments of the present invention will be described below with reference to the accompanying drawings. First, the control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD according to embodiments of the present invention will be described with reference to the accompanying drawings.

[0039] Figure 1 This is a flowchart of a control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD according to an embodiment of the present invention.

[0040] like Figure 1 As shown, the control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD includes the following steps:

[0041] In step S1, the dynamic model of the rotorcraft and the dynamic model of the robotic arm are constructed.

[0042] Furthermore, in one embodiment of the present invention, step S1 specifically includes:

[0043] Step S101: Define the coordinate systems of the preset rotorcraft with arms to determine the transformation relationship between each coordinate system;

[0044] Step S102: Describe the kinematic model of the arm-type rotorcraft according to each coordinate system;

[0045] Step S103: Based on the kinematic model of the rotorcraft with arm, establish the dynamic model of the rotorcraft using the Newton-Euler method, and establish the dynamic model of the robotic arm using the Lagrange method.

[0046] Specifically, to construct a motion model of a rotorcraft with arms, it is necessary to first define a unified coordinate system, and then describe the motion relationships of the various parts, such as... Figure 2 Define the inertial coordinate system S n (o n ,x n ,y n ,z n ), Body coordinate system S b (o b ,x b ,y b ,z b ) and the robot arm joint coordinate system ∑ i (o i ,x i ,y i ,z i (i = 0, 1, 2). The rotation matrix from the self-frame to the inertial frame obtained by rotating in the ZYX order is expressed as:

[0047]

[0048] In formula (1), φ is the roll angle along the x-axis, θ is the pitch angle along the y-axis, and ψ is the yaw angle along the z-axis. Therefore, the angular velocity transformation relationship of the aircraft is:

[0049]

[0050] The aircraft in inertial frame S n The translational velocity can be expressed as:

[0051]

[0052] When the change in the aircraft's attitude angle is small, we have: sinφ≈sinθ≈sinψ≈0, cosφ≈cosθ≈cosψ≈1. We can introduce the assumption of small angles to simplify the derivation of the formulas. At this time, equations (2) and (3) can be rewritten as follows:

[0053]

[0054]

[0055] according to Figure 2 The coordinate system constructed in the table is used to derive the forward and inverse kinematics of the robotic arm through geometric analysis. For ease of description, the meanings of the symbols are defined as shown in Table 1.

[0056] Table 1. Meaning of Symbols

[0057]

[0058] Based on the joint angle, the position coordinates of the end effector can be obtained as follows:

[0059]

[0060] Differentiating the position, we can obtain the end effector velocity as follows:

[0061]

[0062] Forward kinematics calculations help to understand the working behavior of the robotic arm in the joint space, but inverse kinematics solutions are also needed in the workspace to drive the end effector. When performing inverse kinematics solutions, attention must be paid to solvability and multiple solutions. The rotation angles of link 2 and link 1 are obtained as follows:

[0063] θ2=arctan2(sin(θ2),cos(θ2)) (8)

[0064] θ1=arctan2(x3,z3)-arctan2(L2sin(θ2),L1+L2cos(θ2)) (9)

[0065] Next, we use the Newton-Euler method to establish a dynamic model of the rotorcraft. First, we consider the translational motion. According to Newton's equations, we have:

[0066]

[0067] The rotation matrix can be used to determine the position of the body in the inertial coordinate system S. n The total lift force experienced by the lower body is:

[0068]

[0069] In formulas (10) and (11), F g Let F be the projection of gravity in the inertial frame of reference, and f be the translational perturbation force. b For the aircraft in the body coordinate system S b Given the total lift force acting on the aircraft, the dynamic equation for the translational motion of the quadrotor is:

[0070]

[0071] According to Euler's equations:

[0072]

[0073] In formula (13), M is the control torque, ω is the angular velocity of the quadrotor body, J is the rotational inertia matrix of the quadrotor platform, and τ is the disturbance torque.

[0074] Further, by combining the small-angle assumption of attitude angles, the dynamic equation of the rotational motion of the UAV platform (i.e., the attitude dynamic model of the rotorcraft) is derived as follows:

[0075]

[0076] Finally, this invention uses the following Euler-Lagrange equations to construct the dynamic model of the robotic arm:

[0077]

[0078] In formula (15), L = E k -E p For Lagrange operators, E k and E p These represent the total kinetic energy and total potential energy of the system, respectively, with generalized coordinates θ. i τ is the rotation angle of the i-th joint of the robotic arm. i It is related to the generalized coordinate θ i The relevant generalized force, i.e. the driving torque of the i-th joint, is derived to have the Lagrangian function as follows:

[0079]

[0080] Substituting into equation (15), we can obtain the dynamic model of the robotic arm as follows:

[0081]

[0082] In step S2, an improved PD controller is constructed based on the dynamic model of the robotic arm.

[0083] Furthermore, in one embodiment of the present invention, step S2 specifically includes:

[0084] Step S201: Define the mass matrix, nonlinear terms related to angular velocity, and gravity compensation based on the dynamic model of the robotic arm;

[0085] Step S202: Improve the PD controller by adding a mass matrix, nonlinear terms, and gravity compensation to obtain an improved PD controller.

[0086] Specifically, the mass matrix H is first defined based on the dynamic model of the robotic arm. m The nonlinear term C related to angular velocity m Gravity compensation G m as follows:

[0087]

[0088]

[0089]

[0090] The improved PD controller is designed as follows:

[0091]

[0092] In formula (21), K p K is the gain coefficient. d θ is the differential coefficient. d For the expected joint angle, Let θ be the expected joint angular velocity and θ be the joint angle feedback. This is for joint angular velocity feedback.

[0093] With the rotor platform fixed, the effectiveness of the improved PD controller proposed in this invention was tested, and the mass feedforward matrix H was verified. m With nonlinear term C m Regarding the impact on control performance, with the same controller parameters, the initial state of the robotic arm is set to θ1=θ2=0, and the desired state is θ1=θ2=pi / 2. Compare... Figure 3 and Figure 4It can be observed that considering the mass matrix feedforward and nonlinear terms results in better control performance, faster stabilization, and smaller overshoot. However, without considering the nonlinear terms and mass matrix feedforward, the control parameters cannot be adaptively calculated based on the system configuration, leading to disturbances during startup, slower stabilization with multiple oscillations before stabilization, and larger overshoot. This verifies the advantages of the improved PD controller in controlling airborne robotic arms.

[0094] In step S3, the total disturbance to the rotorcraft platform during the robotic arm's movement is estimated based on the extended state observer.

[0095] Furthermore, in one embodiment of the present invention, step S3 specifically includes:

[0096] Step S301: Analyze the system state variables of the preset rotorcraft with arms, and expand the system state variables;

[0097] Step S302: Introduce a nonlinear function to construct an observer for the expanded system state variables;

[0098] Step S303: Tune the observer parameters to obtain the total disturbance estimate.

[0099] Specifically, an extended state observer is used to examine the perturbation torque of the robotic arm's motion with respect to the pitch direction of the quadcopter. First, for a general second-order system:

[0100]

[0101] In formula (22), f(x1,x2,t) is the total disturbance, b is the gain coefficient, and u is the system control quantity. Here, f(x1,x2,t) is considered a state of the system, and x3 = f(x1,x2,t) is used to expand the state quantity. Since it is also an unknown quantity, then:

[0102]

[0103] Let e ​​= z1 - x1, and introduce a nonlinear function fal(e,a,δ) to construct an observer for the extended system to solve for the total disturbance estimate z3, as follows:

[0104]

[0105]

[0106] In formulas (24) and (25), z1, z2, and z3 are the observed values ​​of system states x1, x2, and x3, respectively; a1, a2, and a3 are the powers of the fal function; β1, β2, and β3 are the observer gain coefficients; and δ is the filter factor of the fal function.

[0107] The observer parameters were retuned as follows: a1 = 1, a2 = 0.5, a3 = 0.25; β1 = 30, β2 = 300, β3 = 1000, δ = 0.006, b = 1. For example... Figure 5 As shown, by using the observer to estimate the various state variables in the pitch direction of the rotorcraft with arms, it can be demonstrated that the designed extended state observer meets the mission requirements.

[0108] In step S4, a sliding mode active disturbance rejection controller for the position loop and attitude loop is constructed based on the dynamic model of the rotorcraft.

[0109] Furthermore, in one embodiment of the present invention, step S4 specifically includes:

[0110] Step S401: Preset the traditional sliding mode controller for constructing the position ring of the sliding surface;

[0111] Step S402: Construct an exponential reaching rate to make the conventional sliding mode controller converge to the sliding surface, and calculate the position loop control quantity according to the exponential reaching rate to construct a position loop sliding mode controller;

[0112] Step S403: Calculate and output the desired attitude value and lift control value based on the position loop control value;

[0113] Step S404: Construct a traditional sliding mode controller with an attitude loop based on the desired attitude value, calculate and output the three-axis torque control quantity;

[0114] Step S405: Based on the three-axis torque control quantity and combined with the total disturbance estimate, construct an attitude slip mode controller with self-disturbance rejection capability.

[0115] Step S406: Construct Lyapunov functions to prove the stability of the sliding mode active disturbance rejection controller for the position loop and attitude loop.

[0116] It should be noted that before step S402, the sign function in the traditional sliding mode active disturbance rejection controller needs to be replaced with a saturation function.

[0117] Specifically, such as Figure 5 As shown, we first consider the position controller, taking the x-direction as an example, and define the error function:

[0118] e x =xx d (26)

[0119] Define the sliding surface as:

[0120]

[0121] Differentiating both sides of equation (27) and combining them with the translational motion dynamics model (i.e., the dynamics model of the translational motion of a quadcopter), we can obtain:

[0122]

[0123] To eliminate output jitter in traditional sliding mode controllers, a saturation function is designed to replace the sign function, and an exponential reaching rate is constructed as follows:

[0124]

[0125]

[0126] Combining equations (28) and (29), the x-direction control quantity can be obtained as follows:

[0127]

[0128] To demonstrate the stability of the system, this embodiment of the invention employs Lyapunov's second method to prove the stability of the control system for nonlinear systems, defining the Lyapunov function as:

[0129]

[0130] Differentiating both sides of equation (32) and combining them with equation (29), we get:

[0131]

[0132] And there is V x A value >0 indicates that the system will definitely converge to the designed sliding surface. Similarly, the control outputs in the y and z directions of the position loop can be obtained, and can be summarized as follows:

[0133]

[0134] Given the expected yaw angle ψ d In the case of [U] obtained above x U y U z ] T Substituting into the dynamic model, we can obtain:

[0135]

[0136] Further calculate the expected roll angle φ d And the expected pitch angle θ d for:

[0137]

[0138]

[0139] Then obtain the [φ] from the position ring d ,θ d ,ψ d ]T Substituting into the attitude loop, taking pitch angle as an example, we define the error function:

[0140] e θ =θ-θ d (38)

[0141] Define the sliding surface as:

[0142]

[0143] Differentiating both sides of equation (39) and combining them with equation (14), we get:

[0144]

[0145] The exponential convergence rate is:

[0146]

[0147] By combining equations (40) and (41), the pitch direction control value can be obtained as follows:

[0148]

[0149] Similarly, Lyapunov's second method is used to prove the system's stability, and the Lyapunov function is defined as follows:

[0150]

[0151] Differentiating both sides of equation (43) and combining them with equation (41), we get:

[0152]

[0153] And there is V θ A value greater than 0 indicates that the system will converge to the designed sliding surface. Similarly, controllers for roll and yaw directions can be designed, and the control variables are summarized as follows:

[0154]

[0155] In step S5, the sliding mode active disturbance rejection controllers of the position loop and attitude loop are compensated according to the total disturbance estimate to obtain the output system control quantity, and the system control quantity is converted into the speed control quantity of the four rotors, so that the rotorcraft with arms can achieve stable attitude control according to the output of the controller.

[0156] Specifically, the total disturbance estimate z3 obtained in step S3 is added to the system's control output to achieve compensation:

[0157]

[0158] like Figure 7As shown, the sliding mode adaptive controller structure that finally introduces the extended state observer is presented.

[0159] The lift provided by the rotor is related to its rotational speed. The magnitude of the lift experienced by a quadcopter is:

[0160]

[0161] In equation (47) ω i (i = 1, 2, 3, 4) represents the motor speed; C T is the lift coefficient of the rotor.

[0162] Considering the rotational motion of the drone, and neglecting the gyroscopic torque, the roll, pitch, and yaw moments generated along the three axes for the "×" configuration drone are as follows:

[0163]

[0164] In formula (48), C M Let d be the distance from the center of each rotor to the center of mass of the UAV, where d is the anti-torque coefficient.

[0165] Ultimately, the desired rotational speed of each rotor can be obtained, and the actuator outputs this speed to control the aircraft to execute commands. Finally, the control effects of the PID controller and the sliding mode adaptive controller in the x-direction and pitch direction are compared during the movement of the robotic arm. Figure 8 As shown, it is clear that during the 8-12s movement of the robotic arm, the controller successfully compensated for the interference of the robotic arm, and no serious following error occurred. The overshoot of the attitude loop and position loop was reduced, ensuring the accuracy of platform position tracking during operation.

[0166] In summary, this invention proposes a control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and an improved PD controller. By utilizing sliding mode variable structure control to address the nonlinearity and coupling issues of the system model, a dual-loop controller is designed to solve the high-precision tracking problem during large attitude changes in the aircraft. This effectively achieves precise control of the robotic arm and the observation and suppression of robotic arm disturbances, ensuring stable control of the aircraft. A saturated function is designed to replace the sign function, eliminating the output jitter of the traditional sliding mode controller. Simultaneously, an extended state observer is used to observe robotic arm disturbances and incorporate the observed values ​​into the controller, effectively eliminating the influence of robotic arm movements. An improved PD controller based on the robotic arm dynamics model considers the changes in dynamic structure and the interference of nonlinear terms in the dynamics model caused by robotic arm movement and load variations, improving the accuracy and speed of robotic arm control. By combining the advantages of sliding mode controllers, extended state observers, and improved PD controllers, this method improves the anti-interference capability and control accuracy of rotorcraft with arms in stable operation tasks, demonstrating high engineering application value.

[0167] Next, with reference to the accompanying drawings, a control system for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD proposed according to an embodiment of the present invention is described.

[0168] Figure 9 This is a schematic diagram of the control system of a rotorcraft with arm based on sliding mode active disturbance rejection and improved PD according to an embodiment of the present invention.

[0169] like Figure 9 As shown, the system 10 includes: a first construction module 100, a design module 200, an estimation module 300, a second construction module 400, and a compensation and transformation module 500.

[0170] The first building module 100 is used to build the dynamic model of the rotorcraft and the dynamic model of the robotic arm.

[0171] In one embodiment of the present invention, the first construction module 100 is specifically used for: defining various coordinate systems of a preset rotorcraft with an arm to determine the transformation relationship between each coordinate system; describing the kinematic model of the rotorcraft with an arm according to each coordinate system; and establishing a dynamic model of the rotorcraft with the arm based on the kinematic model of the rotorcraft with the arm using the Newton-Euler method, and establishing a dynamic model of the robotic arm using the Lagrange method.

[0172] Design module 200 is used to build an improved PD controller based on the dynamics model of the robotic arm.

[0173] In one embodiment of the present invention, the design module 200 is specifically used to: define a mass matrix, nonlinear terms related to angular velocity, and gravity compensation based on the dynamic model of the robotic arm; and improve the PD controller by using the mass matrix, nonlinear terms, and gravity compensation to obtain an improved PD controller.

[0174] The estimation module 300 is used to estimate the total disturbance to the rotorcraft platform when the robotic arm moves, based on the extended state observer.

[0175] In one embodiment of the present invention, the estimation module 300 is specifically used to: analyze the system state variables of a preset rotorcraft with arms, and expand the system state variables; introduce a nonlinear function to construct an observer for the expanded system state variables; and tune the parameters of the observer to obtain the total disturbance estimate.

[0176] The second building module 400 is used to design and build a sliding mode active disturbance rejection controller for the position loop and attitude loop based on the dynamic model of the rotorcraft.

[0177] In one embodiment of the present invention, the second construction module 400 is specifically used for: constructing a conventional sliding mode controller with a position loop based on a preset sliding surface; constructing an exponential reaching rate to converge the conventional sliding mode controller to the sliding surface, and calculating the position loop control quantity based on the exponential reaching rate to construct a sliding mode controller with a position loop; calculating and outputting the attitude expectation value and lift control quantity based on the position loop control quantity; constructing a conventional sliding mode controller with an attitude loop based on the attitude expectation value, and calculating and outputting the three-axis torque control quantity; constructing an attitude loop sliding mode controller with self-disturbance rejection capability based on the three-axis torque control quantity and combined with the total disturbance estimate; and constructing a Lyapunov function to prove the stability of the sliding mode self-disturbance rejection controllers of the position loop and attitude loop.

[0178] The compensation and conversion module 500 is used to compensate the sliding mode active disturbance rejection controllers of the position loop and attitude loop based on the total disturbance estimate, obtain the output system control quantity, and convert the system control quantity into the speed control quantity of the four rotors.

[0179] It should be noted that the foregoing explanation of the control method embodiment for a rotorcraft with arm based on sliding mode active disturbance rejection and improved PD also applies to the control coefficients of the rotorcraft with arm based on sliding mode active disturbance rejection and improved PD in this embodiment, and will not be repeated here.

[0180] The control system for a rotorcraft with an arm, proposed according to embodiments of the present invention, is based on sliding mode active disturbance rejection and an improved PD controller. It utilizes sliding mode variable structure control to address the nonlinearity and coupling issues of the system model, and designs a dual-loop controller to solve the high-precision tracking problem when the aircraft's attitude changes significantly. This effectively achieves precise control of the robotic arm and the observation and suppression of robotic arm disturbances, ensuring stable control of the aircraft. A saturated function is designed to replace the sign function, eliminating the output jitter of the traditional sliding mode controller. Simultaneously, an extended state observer is used to observe robotic arm disturbances and input the observed disturbance values ​​into the controller, effectively eliminating the influence of robotic arm movements. An improved PD controller, based on the robotic arm dynamics model, considers the changes in dynamic structure and the interference of nonlinear terms in the dynamics model caused by robotic arm movement and load variations, improving the accuracy and speed of robotic arm control. By combining the advantages of sliding mode controllers, extended state observers, and improved PD controllers, this system enhances the anti-interference capability and control accuracy of rotorcraft with arms in stable operation tasks, demonstrating high engineering application value.

[0181] To achieve the above embodiments, the present invention also proposes a control device for a rotorcraft with an arm, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD as described in the foregoing embodiments.

[0182] To implement the above embodiments, the present invention also proposes a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the control method for a rotorcraft with arm based on sliding mode active disturbance rejection and improved PD as described in the foregoing embodiments.

[0183] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0184] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0185] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of the invention pertain.

[0186] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0187] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0188] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it includes one or a combination of the steps of the method embodiments.

[0189] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0190] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD, characterized in that, Includes the following steps: Step S1: Construct the dynamic model of the rotorcraft and the dynamic model of the robotic arm; Step S2: Construct an improved PD controller based on the dynamic model of the robotic arm; Step S3: Estimate the total disturbance to the rotorcraft platform when the robotic arm moves based on the extended state observer; Step S4: Construct sliding mode active disturbance rejection controllers for position loop and attitude loop based on the dynamic model of the rotorcraft; Step S5: The total disturbance estimate is input into the sliding mode active disturbance rejection controller of the position loop and attitude loop for compensation, and the output system control quantity is obtained. The system control quantity is then converted into the speed control quantity of the four rotors. Step S4 specifically includes: Step S401: Preset the traditional sliding mode controller for constructing the position ring of the sliding surface; Step S402: Construct an exponential convergence rate to make the conventional sliding mode controller converge to the sliding surface, and calculate the position loop control quantity according to the exponential convergence rate to construct a position loop sliding mode controller; Step S403: Calculate and output the attitude expectation value and lift control value based on the position loop control value; Step S404: Construct a traditional sliding mode controller with an attitude loop based on the desired attitude value, and calculate and output the three-axis torque control quantity; Step S405: Based on the three-axis torque control quantity and combined with the total disturbance estimate, construct an attitude slip mode controller with self-disturbance rejection capability; Step S406: Construct a Lyapunov function to prove the stability of the sliding mode active disturbance rejection controller for the position loop and attitude loop.

2. The control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD according to claim 1, characterized in that, Step S1 specifically includes: Step S101: Define the coordinate systems of the preset rotorcraft with arms to determine the transformation relationship between each coordinate system; Step S102: Describe the kinematic model of the rotorcraft with arms according to the respective coordinate systems; Step S103: Based on the kinematic model of the rotorcraft with arm, establish the dynamic model of the rotorcraft using the Newton-Euler method, and establish the dynamic model of the robotic arm using the Lagrange method.

3. The control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD according to claim 1, characterized in that, Step S2 specifically includes: Step S201: Define the mass matrix, nonlinear terms related to angular velocity, and gravity compensation according to the dynamic model of the robotic arm; Step S202: Improve the PD controller by using the mass matrix, the nonlinear term, and the gravity compensation to obtain the improved PD controller.

4. The control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD according to claim 3, characterized in that, The improved PD controller is: in, To improve the PD controller, This is the gain coefficient. The differential coefficients are... For the expected joint angle, For the expected joint angular velocity, For joint angle feedback, For joint angular velocity feedback, For the quality matrix, It is a nonlinear term. This is for gravity compensation.

5. The control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD according to claim 1, characterized in that, Step S3 specifically includes: Step S301: Analyze the system state variables of the preset arm-type rotorcraft and expand the system state variables; Step S302: Introduce a nonlinear function to construct an observer for the expanded system state variables; Step S303: Tune the parameters of the observer to obtain the total disturbance estimate.

6. The control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD according to claim 1, characterized in that, Before step S402, the sign function in the traditional sliding mode active disturbance rejection controller needs to be replaced with a saturation function.

7. A control system for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD, characterized in that, The control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD as described in any one of claims 1-6 includes: The first building module is used to build the dynamic model of the rotorcraft and the dynamic model of the robotic arm; The design module is used to build an improved PD controller based on the dynamic model of the robotic arm; The estimation module is used to estimate the total disturbance to the rotorcraft platform during the manipulator's movements based on the extended state observer; The second construction module is used to design and construct a sliding mode active disturbance rejection controller for the position loop and attitude loop based on the dynamic model of the rotorcraft. The compensation and conversion module is used to compensate the sliding mode active disturbance rejection controller of the position loop and attitude loop according to the total disturbance estimate, obtain the output system control quantity, and convert the system control quantity into the speed control quantity of the four rotors.

8. A control device for a rotorcraft with an arm, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the control method for a rotorcraft with an arm based on sliding mode active disturbance rejection and improved PD as described in any one of claims 1-6.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the control method for a rotorcraft with arm based on sliding mode active disturbance rejection and improved PD as described in any one of claims 1-6.

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