Full-automatic landing longitudinal control method and device for enhancing L1 self-adaption

Abstract

The invention belongs to the field of flight control, and particularly relates to a full-automatic landing longitudinal control method and device for enhancing L1 self-adaption, and the method comprises the steps: S1, obtaining the expected height of an aircraft at the next moment; s2, calculating an expected climbing angle; s3, calculating a control law of an expected pitch angle rate; s4, performing PD control on the control law of the expected pitch angle rate to obtain a first control parameter, and performing enhanced L1 adaptive control on the control law of the expected pitch angle rate to obtain a second control parameter; s5, based on the first control parameter and the second control parameter, an elevator deflection angle instruction is calculated through a dynamic inverse control law; and S6, carrying out longitudinal control on the aircraft based on the elevator deflection angle instruction. According to the method, the strong airflow interference of the landing point can be effectively inhibited, and the robustness of aircraft landing control is improved.

Description

Technical Field

[0001] The present application belongs to the field of flight control, and in particular to a method and device for fully automatic landing longitudinal control with enhanced L1 adaptation. Background Art

[0002] Fully automatic landing means that the aircraft can be controlled to land automatically without the need for pilot control, which reduces the pilot's operating burden and improves the landing success rate. Research on fully automatic landing technology has great practical significance. Compared with land-based aircraft landing, landing on a mobile platform faces difficulties such as short control time, large interference, and high precision requirements. Especially in actual landing missions, the aircraft will be disturbed by strong airflow near the landing point, so it is necessary to focus on improving the robustness of the fully automatic landing control method. Summary of the invention

[0003] In order to solve the above problems, the present application provides a method and device for fully automatic landing longitudinal control with enhanced L1 adaptation, so as to achieve precise control of the climb angle attitude of the aircraft.

[0004] The first aspect of the present application provides a fully automatic landing longitudinal control method with enhanced L1 adaptation, mainly comprising: Step S1, obtaining the expected height of the aircraft at the next moment; Step S2, calculating the expected climb angle; Step S3, calculating the control law of the desired pitch angle rate; Step S4, performing PD control on the control law of the desired pitch angular rate to obtain a first control parameter, and performing enhanced L1 adaptive control on the control law of the desired pitch angular rate to obtain a second control parameter; Step S5, calculating the elevator deflection angle instruction by a dynamic inverse control law based on the first control parameter and the second control parameter; Step S6: performing longitudinal control on the aircraft based on the elevator deflection angle instruction.

[0005] Preferably, step S2 further comprises: Step S21, determining a longitudinal height change rate instruction according to the desired height and the current height; Step S22, adding a height change rate compensation value caused by the change of airflow at the landing point to the longitudinal height change rate instruction to generate a desired longitudinal height change rate instruction; Step S23, calculating the expected climb angle according to the expected longitudinal height change rate instruction.

[0006] Preferably, step S4 further comprises: Step S41, inputting the control law of the desired pitch angle rate into the command filter to obtain the desired pitch angle rate and the desired pitch angle rate change rate; Step S42: input the desired pitch rate, the desired pitch rate change rate, and the aircraft pitch velocity into a PD controller to obtain a first control parameter.

[0007] Preferably, step S4 further comprises: Step S43, calculating the L1 adaptive law output parameter according to the prediction error of the aircraft pitch angular velocity; Step S44: Calculate the second control parameter according to the L1 adaptive law output parameter.

[0008] The second aspect of the present application provides a fully automatic landing longitudinal control device with enhanced L1 adaptation, mainly comprising: The expected altitude acquisition module is used to obtain the expected altitude of the aircraft at the next moment; An expected climb angle calculation module is used to calculate the expected climb angle; A desired pitch angle rate control law calculation module is used to calculate the control law of the desired pitch angle rate; a control parameter output module, configured to perform PD control on the control law of the desired pitch angular rate to obtain a first control parameter, and perform enhanced L1 adaptive control on the control law of the desired pitch angular rate to obtain a second control parameter; an elevator deflection angle command calculation module, configured to calculate an elevator deflection angle command by a dynamic inverse control law based on the first control parameter and the second control parameter; The longitudinal control module is used to perform longitudinal control on the aircraft based on the elevator deflection angle instruction.

[0009] Preferably, the expected climb angle calculation module includes: A longitudinal height change rate instruction calculation unit, used to determine a longitudinal height change rate instruction according to a desired height and a current height; A desired longitudinal height change rate instruction calculation unit, used for superimposing a height change rate compensation value caused by the change of airflow at the landing point on the basis of the longitudinal height change rate instruction to generate a desired longitudinal height change rate instruction; The expected climb angle calculation unit is used to calculate the expected climb angle according to the expected longitudinal height change rate instruction.

[0010] Preferably, the control parameter output module includes: A filtering unit, configured to input the control law of the desired pitch angle rate into a command filter to obtain the desired pitch angle rate and the desired pitch angle rate change rate; The first control parameter acquisition unit is used to input the desired pitch angle rate, the desired pitch angle rate change rate, and the aircraft pitch angle velocity into the PD controller to obtain the first control parameter.

[0011] Preferably, the control parameter output module includes: An adaptive law output parameter calculation unit, used for calculating the L1 adaptive law output parameter according to the prediction error of the aircraft pitch angular velocity; The second control parameter acquisition unit is used to calculate the second control parameter according to the L1 adaptive law output parameter.

[0012] The present application can effectively suppress strong airflow interference at the landing point and improve the robustness of the aircraft landing control. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a flow chart of a preferred embodiment of the fully automatic landing longitudinal control method with enhanced L1 adaptation of the present application. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0015] The first aspect of the present application provides a fully automatic landing longitudinal control method with enhanced L1 adaptation, such as Figure 1 As shown, it mainly includes: Step S1, obtaining the expected height of the aircraft at the next moment; Step S2, calculating the expected climb angle; Step S3, calculating the control law of the desired pitch angle rate; Step S4, performing PD control on the control law of the desired pitch angular rate to obtain a first control parameter, and performing enhanced L1 adaptive control on the control law of the desired pitch angular rate to obtain a second control parameter; Step S5, calculating the elevator deflection angle instruction by a dynamic inverse control law based on the first control parameter and the second control parameter; Step S6: performing longitudinal control on the aircraft based on the elevator deflection angle instruction.

[0016] In step S1, the expected height of the aircraft at the next moment is usually given by the expected path generation algorithm of the aircraft. Given the current position coordinates and motion information of the aircraft, the current position, speed, angular velocity and other information of the mobile platform where the aircraft lands, and the expected path parameters, the expected height value of the aircraft at the next step can be calculated. .

[0017] With the expected altitude, the expected climb angle can be calculated in step S2. In some optional embodiments, step S2 further includes: Step S21, determining a longitudinal height change rate instruction according to the desired height and the current height; Step S22, adding a height change rate compensation value caused by the change of airflow at the landing point to the longitudinal height change rate instruction to generate a desired longitudinal height change rate instruction; Step S23, calculating the expected climb angle according to the expected longitudinal height change rate instruction.

[0018] In this embodiment, the desired height is first calculated The difference from the current height H : . Then the longitudinal altitude change rate command is generated through the longitudinal guidance law : .in is the current airspeed of the aircraft, is the current climb angle of the aircraft, To control the parameters, Is the difference The first derivative of Is the difference Then in step S22, considering the effect of the wake caused by the movement of the mobile platform on the landing point of the aircraft, the height change rate compensation value is increased , generate the desired longitudinal height change rate command : Finally, in step S23, the expected climb angle is calculated according to the expected longitudinal height change rate instruction. : .

[0019] With the expected climb angle ,refer to Figure 1 , in step S3, the control law of the desired pitch angle rate can be calculated: , is the proportional controller parameter, is the expected climb angle With the current climb angle The difference.

[0020] In step S4, the control law for the desired pitch rate is , two controllers are used to control the pitch angle rate, one is the PD controller and the other is the enhanced L1 adaptive controller.

[0021] In some optional implementations, step S4 further includes: Step S41, inputting the control law of the desired pitch angle rate into the command filter to obtain the desired pitch angle rate and the desired pitch angle rate change rate; Step S42: input the desired pitch rate, the desired pitch rate change rate, and the aircraft pitch velocity into a PD controller to obtain a first control parameter.

[0022] refer to Figure 1 In the PD controller, the control rate of the desired pitch angle rate is first Input into the command filter to obtain the desired pitch angle rate and the desired pitch angle rate change rate. The command filter complex frequency domain expression is: ; Expected pitch rate and the expected pitch rate change rate The expression is: ,in, Expected pitch rate The second-order derivative of are the instruction filter parameters.

[0023] Then, in step S42, the first control parameter is calculated by the following PD controller formula: : ; in, is the actual value of the aircraft's current pitch rate, refer to Figure 1 , obtained by the aircraft longitudinal dynamics actuator after executing the input elevator deflection angle command, is the proportional control parameter.

[0024] In some optional implementations, step S4 further includes: Step S43, calculating the L1 adaptive law output parameter according to the prediction error of the aircraft pitch angular velocity; Step S44: Calculate the second control parameter according to the L1 adaptive law output parameter.

[0025] This embodiment provides the control process of the second controller, namely the L1 adaptive controller, referring to Figure 1 The L1 adaptive controller of the present application is an enhanced controller, including a control law module, an adaptive law module and a state predictor. In the control law module, the second control parameter is calculated using the following formula: : ; in, is a first-order low-pass filter, is the filter parameter, s is the Laplace operator; is the output of the adaptive law module. In the adaptive law module, ;in, , , , , , , is the sampling time, is the control parameter, is the prediction error of the aircraft pitch velocity, the observed value given by the state predictor The actual value of the current pitch rate of the aircraft given by the aircraft longitudinal dynamics actuator Calculate and obtain, that is In the state observer, the first-order derivative of the observed value ,in, , are the parameters of the reference model, , , , , , All are intermediate variables.

[0026] Then, in step S5, the two control parameters are combined to calculate the elevator deflection angle instruction by the dynamic inverse control law. : .

[0027] Among them, the function The expression is ,function The expression is ; , , is the moment of inertia of the aircraft on each axis, for Axis and The moment of inertia of the axis, , , are the roll, pitch, and yaw angular velocities of the aircraft, is the dynamic pressure, is the wing area, is the average aerodynamic chord length, , , is the pitching moment parameter.

[0028] Finally, in step S6, according to the elevator deflection angle instruction To control the aircraft longitudinally, Figure 1 The input is then sent to the aircraft longitudinal dynamics actuator to calculate the control quantity of the motion force and displacement of each actuator unit.

[0029] Compared with the prior art, this application can effectively suppress airflow interference and comprehensively utilize L1 adaptive control theory to improve the robustness of the control method. In the process of applying this application, the control engineer converts the calculated control quantity into an inner loop command to control the aircraft according to the actual given expected path to complete the longitudinal motion control task of the aircraft's fully automatic landing.

[0030] The second aspect of the present application provides an enhanced L1 adaptive fully automatic landing longitudinal control device corresponding to the above method, mainly comprising: The expected altitude acquisition module is used to obtain the expected altitude of the aircraft at the next moment; An expected climb angle calculation module is used to calculate the expected climb angle; A desired pitch angle rate control law calculation module is used to calculate the control law of the desired pitch angle rate; a control parameter output module, configured to perform PD control on the control law of the desired pitch angular rate to obtain a first control parameter, and perform enhanced L1 adaptive control on the control law of the desired pitch angular rate to obtain a second control parameter; an elevator deflection angle command calculation module, configured to calculate an elevator deflection angle command by a dynamic inverse control law based on the first control parameter and the second control parameter; The longitudinal control module is used to perform longitudinal control on the aircraft based on the elevator deflection angle instruction.

[0031] In some optional implementations, the expected climb angle calculation module includes: A longitudinal height change rate instruction calculation unit, used to determine a longitudinal height change rate instruction according to a desired height and a current height; A desired longitudinal height change rate instruction calculation unit, used for superimposing a height change rate compensation value caused by the change of airflow at the landing point on the basis of the longitudinal height change rate instruction to generate a desired longitudinal height change rate instruction; The expected climb angle calculation unit is used to calculate the expected climb angle according to the expected longitudinal height change rate instruction.

[0032] In some optional implementations, the control parameter output module includes: A filtering unit, configured to input the control law of the desired pitch angle rate into a command filter to obtain the desired pitch angle rate and the desired pitch angle rate change rate; The first control parameter acquisition unit is used to input the desired pitch angle rate, the desired pitch angle rate change rate, and the aircraft pitch angle velocity into the PD controller to obtain the first control parameter.

[0033] In some optional implementations, the control parameter output module includes: An adaptive law output parameter calculation unit, used for calculating the L1 adaptive law output parameter according to the prediction error of the aircraft pitch angular velocity; The second control parameter acquisition unit is used to calculate the second control parameter according to the L1 adaptive law output parameter.

[0034] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A fully automatic landing longitudinal control method with enhanced L1 adaptation, characterized in that: include: Step S1, obtaining the expected height of the aircraft at the next moment; Step S2, calculating the expected climb angle; Step S3, calculating the control law of the desired pitch angle rate; Step S4, performing PD control on the control law of the desired pitch angular rate to obtain a first control parameter, and performing enhanced L1 adaptive control on the control law of the desired pitch angular rate to obtain a second control parameter; Step S5, calculating the elevator deflection angle instruction by a dynamic inverse control law based on the first control parameter and the second control parameter; Step S6: performing longitudinal control on the aircraft based on the elevator deflection angle instruction.

2. The fully automatic landing longitudinal control method with enhanced L1 adaptation as claimed in claim 1, characterized in that: Step S2 further comprises: Step S21, determining a longitudinal height change rate instruction according to the desired height and the current height; Step S22, adding a height change rate compensation value caused by the change of airflow at the landing point to the longitudinal height change rate instruction to generate a desired longitudinal height change rate instruction; Step S23, calculating the expected climb angle according to the expected longitudinal height change rate instruction.

3. The fully automatic landing longitudinal control method with enhanced L1 adaptation as claimed in claim 1, characterized in that: Step S4 further comprises: Step S41, inputting the control law of the desired pitch angle rate into the command filter to obtain the desired pitch angle rate and the desired pitch angle rate change rate; Step S42: input the desired pitch rate, the desired pitch rate change rate, and the aircraft pitch velocity into a PD controller to obtain a first control parameter.

4. The fully automatic landing longitudinal control method with enhanced L1 adaptation as claimed in claim 3, characterized in that: Step S4 further comprises: Step S43, calculating the L1 adaptive law output parameter according to the prediction error of the aircraft pitch angular velocity; Step S44: Calculate the second control parameter according to the L1 adaptive law output parameter.

5. A fully automatic landing longitudinal control device with enhanced L1 adaptation, characterized in that: include: The expected altitude acquisition module is used to obtain the expected altitude of the aircraft at the next moment; An expected climb angle calculation module is used to calculate the expected climb angle; A desired pitch angle rate control law calculation module is used to calculate the control law of the desired pitch angle rate; a control parameter output module, configured to perform PD control on the control law of the desired pitch angular rate to obtain a first control parameter, and perform enhanced L1 adaptive control on the control law of the desired pitch angular rate to obtain a second control parameter; an elevator deflection angle command calculation module, configured to calculate an elevator deflection angle command by a dynamic inverse control law based on the first control parameter and the second control parameter; The longitudinal control module is used to perform longitudinal control on the aircraft based on the elevator deflection angle instruction.

6. The fully automatic landing longitudinal control device with enhanced L1 adaptation as claimed in claim 5, characterized in that: The expected climb angle calculation module includes: A longitudinal height change rate instruction calculation unit, used to determine a longitudinal height change rate instruction according to a desired height and a current height; A desired longitudinal height change rate instruction calculation unit, used for superimposing a height change rate compensation value caused by the change of airflow at the landing point on the basis of the longitudinal height change rate instruction to generate a desired longitudinal height change rate instruction; The expected climb angle calculation unit is used to calculate the expected climb angle according to the expected longitudinal height change rate instruction.

7. The fully automatic landing longitudinal control device with enhanced L1 adaptation as claimed in claim 5, characterized in that: The control parameter output module comprises: A filtering unit, configured to input the control law of the desired pitch angle rate into a command filter to obtain the desired pitch angle rate and the desired pitch angle rate change rate; The first control parameter acquisition unit is used to input the desired pitch angle rate, the desired pitch angle rate change rate, and the aircraft pitch angle velocity into the PD controller to obtain the first control parameter.

8. The fully automatic landing longitudinal control device with enhanced L1 adaptation as claimed in claim 7, characterized in that: The control parameter output module comprises: An adaptive law output parameter calculation unit, used for calculating the L1 adaptive law output parameter according to the prediction error of the aircraft pitch angular velocity; The second control parameter acquisition unit is used to calculate the second control parameter according to the L1 adaptive law output parameter.

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