Stratosphere airship increment backstepping control method based on time delay estimation

Abstract

The application discloses a stratosphere airship incremental backstepping control method based on time delay estimation and belongs to the technical field of automatic control, and comprises the following steps: step one, establishing a stratosphere airship attitude control model; step two, calculating an expected angular velocity inner loop control quantity, preliminarily calculating an attitude inner loop control expected value according to a sensor value by means of an incremental backstepping method; step three, estimating an angular acceleration value according to an adaptive operator method; and step four, calculating an expected angular velocity channel control quantity and calculating an actual control quantity of a control channel according to a designed control law. The application provides the stratosphere airship incremental backstepping control method based on time delay estimation, combines time delay estimation and incremental backstepping control, enhances robustness under model uncertainty, has a lower requirement for modeling accuracy, has higher robustness and has better control precision.

Description

Technical Field

[0001] This invention belongs to the field of automatic control technology, and in particular relates to an incremental backstepping control method for stratospheric airships based on time delay estimation. Background Technology

[0002] The stratosphere, as an airspace with untapped potential, has attracted significant research interest. Stratospheric airships, which utilize the stable atmospheric conditions of the stratosphere, have also experienced rapid development at this juncture. These airships are capable of performing various missions, including formation flying and space relay. The dynamic characteristics of these airships are highly unique, exhibiting significant nonlinearity, strong coupling effects, and characteristics that are difficult to model accurately. Simultaneously, the stratospheric environment also contains many unpredictable disturbances. These factors make the complex control systems of these airships extremely challenging.

[0003] Stratospheric airships commonly employ model-based control techniques. Over-reliance on precise system models can reduce the recoverability and robustness of airship navigation solutions in control system design. More adaptive and fault-tolerant control methods may be better suited to improving the reliability of airship guidance systems under various operating environments. During day and night cycles, airships need to adjust ballast and jettison loads to maintain a stable attitude, leading to changes in the center of gravity. This implies that existing model-based control methods have certain limitations in airship control systems. Summary of the Invention

[0004] The purpose of this invention is to provide an incremental backstepping control method for stratospheric airships based on time delay estimation, which solves the problems of existing technologies that generally use model-based control techniques for stratospheric airships, which rely excessively on accurate system models and have limitations.

[0005] To achieve the above objectives, this invention provides an incremental backstepping control method for stratospheric airships based on time delay estimation, comprising the following steps:

[0006] Step 1: Establish a stratospheric airship attitude control model;

[0007] Step 2: Calculate the desired angular velocity inner loop control quantity. Based on the sensor values, perform an incremental backstepping method for preliminary calculation to obtain the desired attitude inner loop control value.

[0008] Step 3: Estimate the angular acceleration value using the adaptive operator method;

[0009] Step 4: Calculate the desired angular velocity channel control quantity, and calculate the actual control quantity of the control channel based on the designed control law.

[0010] Preferably, the specific process of establishing the stratospheric airship attitude control model in step one is as follows:

[0011] S11. Obtain the angular velocity control equations of the stratospheric airship through the kinematic and dynamic equations of the airship.

[0012]

[0013]

[0014] Where, the angular velocity vector Ω = [p, q, r] T Let p represent the component of the airship's angular velocity in the machine system, q represent the airship's roll angular velocity, r represent the airship's pitch angular velocity, and B represent the airship's yaw angular velocity. 22 This represents the attitude control matrix, where Euler angles Θ = [θ, ψ, φ]. T θ represents the pitch angle of the airship within the airship system; ψ represents the yaw angle of the airship within the airship system; φ represents the roll angle of the airship within the airship system; F ω τ represents the torque vector that controls the angular velocity of the airship. ω This represents the input control quantity used to control the angular velocity of the airship. δ represents the vector derivative of the airship's attitude angle. ω τ represents the interference caused by channel coupling. υ This represents the input control quantity for controlling the speed of the airship, and K represents the rotation matrix;

[0015] S12. Considering the dynamic model under the movement of the center of gravity, the control matrix is ​​modeled as follows:

[0016]

[0017] in and The control matrices ΔF represent the actual force and actual torque, respectively. w and ΔB 22 The control matrix represents the change in the center of gravity due to disturbances or operational effects.

[0018] Preferably, the specific expression for calculating the inner loop control quantity of the desired angular velocity in step two is as follows:

[0019]

[0020] Where e θ =Θ-Θ d For attitude angle error, Θ d K1 is the input desired angle, and K2 is the input control matrix. Let be the derivative of the desired attitude angle.

[0021] Preferably, the specific calculation method for estimating the angular acceleration value in step three using the adaptive operator method is as follows:

[0022]

[0023]

[0024] Where e Ω =Ω-Ω d For attitude angular velocity error, Ω d The desired angular velocity value calculated in step two. This is the estimated value of interference within the system. The derivative of the estimated disturbance value within the system. This is the estimated value of the system control matrix disturbance. τ is the derivative of the disturbance estimate of the system control matrix. w0 Let represent the input value at the current time, eye(3) represent a 3x3 diagonal matrix, Γ1 represent the disturbance estimation parameters, and Γ2 represent the control matrix estimation parameters. The adaptive projection operator Proj(α,β) is defined as follows:

[0025]

[0026] Where α and β represent the input values, and Let α and β represent the maximum and minimum values, respectively. i This represents the components of the input value, where ε is a given threshold.

[0027] The adaptive estimation of angular acceleration is designed as follows:

[0028]

[0029] In the formula, Indicates the level of control at the current moment. This represents the estimated value of the control matrix. This represents the current estimated disturbance value.

[0030] Preferably, the specific calculation method for the desired angular velocity channel control quantity in step four is as follows:

[0031] S41. Correct the control matrix:

[0032]

[0033] in, For the corrected control matrix, The design matrix is ​​used to estimate the corrected control matrix;

[0034] S42. Design of the angular velocity channel control update law:

[0035]

[0036] Where K2 is the control parameter input vector;

[0037] S43. The actual allocated control quantity is:

[0038]

[0039] in, This indicates the current control input value.

[0040] Therefore, the present invention employs the above-mentioned incremental backstepping control method for stratospheric airships based on time delay estimation, which has the following beneficial effects:

[0041] (1) This method can mitigate the performance degradation caused by sensor delay, telemetry noise, and model parameter uncertainty. This is achieved by online estimation and compensation of coupling error dynamics in an incremental nonlinear control architecture;

[0042] (2) In the presence of input lag and output signal distortion, the developed angular velocity controller successfully achieves rapid setpoint tracking without continuous oscillation.

[0043] (3) The inherent adaptive estimation characteristics of this method reduce the dependence on high-fidelity analysis models, simplify the update law of the compensator, and enhance the ability to resist the uncertainty of the unmodeled part.

[0044] (4) The method has a simple overall structure and is easy to implement in engineering. Control engineers can freely set the desired position or desired attitude angle of the airship according to the actual situation. This method will calculate the corresponding control quantity and transmit it directly to the actuator to achieve control of the position or attitude of the stratospheric airship.

[0045] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0046] Figure 1 This is an overall flowchart of an incremental backstepping control method for stratospheric airships based on time delay estimation, according to the present invention.

[0047] Figure 2 This is a schematic diagram of the stratospheric airship used in this invention. Detailed Implementation

[0048] The following detailed description of embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0049] Please see Figure 1-2 An incremental backstepping control method for stratospheric airships based on time delay estimation includes the following steps:

[0050] Step 1: Establish a stratospheric airship attitude control model; the specific process is as follows:

[0051] S11. Obtain the angular velocity control equations of the stratospheric airship through the kinematic and dynamic equations of the airship.

[0052]

[0053]

[0054] Where, the angular velocity vector Ω = [p, q, r] T Let p represent the component of the airship's angular velocity in the machine system, q represent the airship's roll angular velocity, r represent the airship's pitch angular velocity, and B represent the airship's yaw angular velocity. 22 This represents the attitude control matrix, where Euler angles Θ = [θ, ψ, φ]. T θ represents the pitch angle of the airship within the airship system; ψ represents the yaw angle of the airship within the airship system; φ represents the roll angle of the airship within the airship system; F ω τ represents the torque vector that controls the angular velocity of the airship. ω This represents the input control quantity used to control the angular velocity of the airship. δ represents the vector derivative of the airship's attitude angle. ω τ represents the interference caused by channel coupling. υ This represents the input control quantity for controlling the speed of the airship, and K represents the rotation matrix;

[0055] S12. Considering the dynamic model under the movement of the center of gravity, the control matrix is ​​modeled as follows:

[0056]

[0057] in and The control matrices ΔF represent the actual force and actual torque, respectively. w and ΔB 22 The control matrix represents the change in the center of gravity due to disturbances or operational effects.

[0058] Step 2: Calculate the desired angular velocity inner loop control quantity. Based on the sensor values, perform an incremental backstepping method for preliminary calculation to obtain the desired attitude inner loop control value. The specific expression for calculating the desired angular velocity inner loop control quantity is as follows:

[0059]

[0060] Where e θ =Θ-Θ dFor attitude angle error, Θ d K1 is the input desired angle, and K2 is the input control matrix. Let be the derivative of the desired attitude angle.

[0061] Step 3: Estimate the angular acceleration value using the adaptive operator method; the specific calculation method is as follows:

[0062]

[0063]

[0064] Where e Ω =Ω-Ω d For attitude angular velocity error, Ω d The desired angular velocity value calculated in step two. This is the estimated value of interference within the system. The derivative of the estimated disturbance value within the system. This is the estimated value of the system control matrix disturbance. The derivative of the disturbance estimate of the system control matrix. Let represent the input value at the current time, eye(3) represent a 3x3 diagonal matrix, Γ1 represent the disturbance estimation parameters, and Γ2 represent the control matrix estimation parameters. The adaptive projection operator Proj(α,β) is defined as follows:

[0065]

[0066] Where α and β represent the input values, and Let α and β represent the maximum and minimum values, respectively. i This represents the components of the input value, where ε is a given threshold.

[0067] The adaptive estimation of angular acceleration is designed as follows:

[0068]

[0069] In the formula, Indicates the level of control at the current moment. This represents the estimated value of the control matrix. This represents the current estimated disturbance value.

[0070] Step 4: Calculate the desired angular velocity channel control quantity. Based on the designed control law, calculate the actual control quantity of the control channel. The specific calculation method for the desired angular velocity channel control quantity is as follows:

[0071] S41. Correct the control matrix:

[0072]

[0073] in, For the corrected control matrix, The design matrix is ​​used to estimate the corrected control matrix;

[0074] S42. Design of the angular velocity channel control update law:

[0075]

[0076] Where K2 is the control parameter input vector;

[0077] S43. The actual allocated control quantity is:

[0078]

[0079] in, This indicates the current control input value.

[0080] Therefore, this invention employs the aforementioned incremental backstepping control method for stratospheric airships based on time delay estimation. By integrating incremental control and time delay estimation, a linear time-invariant system related to attitude angle tracking error is obtained, where the time delay estimation error is considered a disturbance of the system. Simultaneously, adaptive techniques are used to reduce the impact of noise and center of gravity changes on the system's robustness.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for incremental backstepping control of a stratospheric airship based on time delay estimation, characterized in that, Includes the following steps: Step 1: Establish a stratospheric airship attitude control model; Step 2: Calculate the desired angular velocity inner loop control quantity. Based on the sensor values, perform an incremental backstepping method for preliminary calculation to obtain the desired attitude inner loop control value. Step 3: Estimate the angular acceleration value using the adaptive operator method; Step 4: Calculate the desired angular velocity channel control quantity, and calculate the actual control quantity of the control channel based on the designed control law; The specific calculation method for estimating the angular acceleration value using the adaptive operator method in step three is as follows: in For attitude angular velocity error, The desired angular velocity value and angular velocity vector are calculated in step two. The component of the airship's angular velocity in the machine system, This is the estimated value of interference within the system. The derivative of the estimated disturbance value within the system. This is the estimated value of the system control matrix disturbance. The derivative of the disturbance estimate of the system control matrix. This represents the input value at the current moment. Represents a 3x3 diagonal matrix. Indicates the disturbance estimation parameters. Denotes the parameters estimated from the control matrix, where the adaptive projection operator... The definition is as follows: in, and These represent the input values, and They represent Maximum and minimum values, Represents the components of the input value. Given a threshold; The adaptive estimation of angular acceleration is designed as follows: In the formula, Indicates the level of control at the current moment. This represents the estimated value of the control matrix. This represents the current estimated disturbance value; The specific calculation method for the desired angular velocity channel control quantity in step four is as follows: S41. Correct the control matrix: in, For the corrected control matrix, To design the matrix, which is used to estimate the corrected control matrix. This represents the derivative of the airship's attitude angle vector. Represents Euler angles. This represents the torque vector that controls the angular velocity of the airship. Represents the attitude control matrix. The torque vector representing the force controlling the angular velocity of the airship; S42. Design of the angular velocity channel control update law: in, For the control parameter input vector, Represents the rotation matrix. This refers to the attitude angle error; S43. The actual allocated control quantity is: in, This indicates the current control input value.

2. The incremental backstepping control method for stratospheric airships based on time delay estimation according to claim 1, characterized in that, The specific process of establishing the stratospheric airship attitude control model in step one is as follows: S11. Obtain the angular velocity control equations of the stratospheric airship through the kinematic and dynamic equations of the airship. Wherein, angular velocity vector The component of the airship's angular velocity in the machine system, This represents the airship's roll angular velocity. This indicates the pitch rate of the airship. This indicates the yaw rate of the airship; Represents the attitude control matrix, Euler angles , Represents the pitch angle of the airship within the airship system; This represents the yaw angle of the airship within the airship system; Represents the roll angle of the airship within the airship system; This represents the torque vector that controls the angular velocity of the airship. This represents the input control quantity used to control the angular velocity of the airship. This represents the derivative of the airship's attitude angle vector. This indicates interference caused by channel coupling. This represents the input control quantity used to control the speed of the airship. Represents the rotation matrix; S12. Considering the dynamic model under the movement of the center of gravity, the control matrix is ​​modeled as follows: in and The control matrices represent the actual force and the actual torque, respectively. and The control matrix represents the change in the center of gravity due to disturbances or operational effects.

3. The incremental backstepping control method for stratospheric airships based on time delay estimation according to claim 1, characterized in that, The specific expression for calculating the inner loop control quantity of the desired angular velocity in step two is as follows: in For attitude angle error, The input is the desired angle. For the input control matrix, The derivative of the desired attitude angle, Represents the rotation matrix. Represents Euler angles.

Images