A fully automatic landing longitudinal control method and device with enhanced L1 adaptation

Abstract

The present application belongs to the field of flight control, and particularly relates to a method and apparatus for fully automatic landing longitudinal control with enhanced L1 adaptation. The method comprises: step S1, obtaining the desired altitude of an aircraft at the next moment; step S2, calculating the desired climb angle; step S3, calculating the control law for the desired pitch rate; step S4, performing PD control on the control law for the desired pitch rate to obtain a first control parameter, and performing enhanced L1 adaptive control on the control law for the desired pitch rate to obtain a second control parameter; step S5, calculating an elevator deflection angle command based on the first and second control parameters using a dynamic inverse control law; and step S6, performing longitudinal control of the aircraft based on the elevator deflection angle command. The present application can effectively suppress strong airflow interference at the landing point, thereby improving the robustness of aircraft landing control.

Description

Technical Field

[0001] The present application relates 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 automated landing (FLAT) allows an aircraft to land automatically without pilot intervention, reducing the pilot's workload and increasing landing success rates. Research on FLAT technology is of significant practical significance. Compared to land-based aircraft landings, landing on mobile platforms presents challenges such as short control time, high interference, and high precision requirements. In particular, during actual landing missions, aircraft are subject to strong air currents near the landing point, necessitating enhanced robustness of FLAT control methods. Summary of the Invention

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

[0004] The first aspect of the present application provides a fully automatic landing longitudinal control method with enhanced L1 adaptation, mainly comprising:

[0005] Step S1: Obtain the expected altitude of the aircraft at the next moment;

[0006] Step S2, calculating the expected climb angle;

[0007] Step S3, calculating the control law of the desired pitch angular rate;

[0008] 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;

[0009] Step S5: Calculating an elevator deflection angle command based on the first control parameter and the second control parameter using a dynamic inverse control law;

[0010] Step S6: performing longitudinal control on the aircraft based on the elevator deflection angle instruction.

[0011] Preferably, step S2 further comprises:

[0012] Step S21, determining a longitudinal height change rate instruction according to the desired height and the current height;

[0013] Step S22: adding a height change rate compensation value caused by the change in airflow at the landing point to the longitudinal height change rate instruction to generate a desired longitudinal height change rate instruction;

[0014] Step S23: Calculate the expected climb angle according to the expected longitudinal height change rate instruction.

[0015] Preferably, step S4 further comprises:

[0016] Step S41: inputting 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;

[0017] Step S42: Input the desired pitch rate, the desired pitch rate change rate, and the aircraft pitch rate into a PD controller to obtain a first control parameter.

[0018] Preferably, step S4 further comprises:

[0019] Step S43: Calculate the L1 adaptive law output parameters according to the prediction error of the aircraft pitch rate;

[0020] Step S44: Calculate the second control parameter according to the L1 adaptive law output parameter.

[0021] The second aspect of the present application provides a fully automatic landing longitudinal control device with enhanced L1 self-adaptation, mainly comprising:

[0022] The expected altitude acquisition module is used to obtain the expected altitude of the aircraft at the next moment;

[0023] An expected climb angle calculation module is used to calculate the expected climb angle;

[0024] A desired pitch angle rate control law calculation module is used to calculate the control law of the desired pitch angle rate;

[0025] 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;

[0026] an elevator deflection angle command calculation module, configured to calculate the elevator deflection angle command based on the first control parameter and the second control parameter using a dynamic inverse control law;

[0027] The longitudinal control module is used to perform longitudinal control on the aircraft based on the elevator deflection angle instruction.

[0028] Preferably, the expected climb angle calculation module includes:

[0029] a longitudinal height change rate instruction calculation unit, configured to determine a longitudinal height change rate instruction based on a desired height and a current height;

[0030] a desired longitudinal altitude change rate instruction calculation unit, configured to generate a desired longitudinal altitude change rate instruction by superimposing an altitude change rate compensation value caused by changes in airflow at a landing point on the longitudinal altitude change rate instruction;

[0031] The expected climb angle calculation unit is used to calculate the expected climb angle according to the expected longitudinal height change rate instruction.

[0032] Preferably, the control parameter output module includes:

[0033] 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;

[0034] 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 rate into the PD controller to obtain the first control parameter.

[0035] Preferably, the control parameter output module includes:

[0036] An adaptive law output parameter calculation unit, configured to calculate an L1 adaptive law output parameter based on a prediction error of the aircraft pitch rate;

[0037] The second control parameter acquisition unit is configured to calculate the second control parameter according to the L1 adaptive law output parameter.

[0038] This application can effectively suppress strong airflow interference at the landing point and improve the robustness of aircraft landing control. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This 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

[0040] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the implementation of this application will be described in more detail below in conjunction with the drawings in the implementation of this application. In the drawings, the same or similar numbers 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 should not 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 conjunction with the drawings.

[0041] 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:

[0042] Step S1: Obtain the expected altitude of the aircraft at the next moment;

[0043] Step S2, calculating the expected climb angle;

[0044] Step S3, calculating the control law of the desired pitch angular rate;

[0045] 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;

[0046] Step S5: Calculating an elevator deflection angle command based on the first control parameter and the second control parameter using a dynamic inverse control law;

[0047] Step S6: performing longitudinal control on the aircraft based on the elevator deflection angle instruction.

[0048] 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 rate and other information of the mobile platform where the aircraft lands, and the expected path parameters, the expected height value H of the aircraft at the next step can be calculated. des .

[0049] With the expected altitude, the expected climb angle can be calculated in step S2. In some optional embodiments, step S2 further includes:

[0050] Step S21, determining a longitudinal height change rate instruction according to the desired height and the current height;

[0051] Step S22: adding a height change rate compensation value caused by the change in airflow at the landing point to the longitudinal height change rate instruction to generate a desired longitudinal height change rate instruction;

[0052] Step S23: Calculate the expected climb angle according to the expected longitudinal height change rate instruction.

[0053] In this embodiment, the desired height H is first calculated. des The difference H from the current height H e :H e =H des -H. The longitudinal guidance law is then used to generate the longitudinal altitude rate of change command. Where V kis the current airspeed of the aircraft, γ is the current climb angle of the aircraft, k hp ,k hi ,k hd is the control parameter, is the difference H e The first derivative of is the difference H e Then in step S22, considering the influence of the wake caused by the movement of the mobile platform on the landing of the aircraft, the altitude change rate compensation value is increased. Generates desired longitudinal altitude rate command Finally, in step S23, the desired climb angle γ is calculated according to the desired longitudinal height change rate instruction. des :

[0054] With the expected climb angle γ des ,refer to Figure 1 In step S3, the control law of the desired pitch angle rate can be calculated: com =K γp γ e , K γp is the proportional controller parameter, γ e is the expected climb angle γ des The difference from the current climb angle γ.

[0055] In step S4, the control law q for the desired pitch rate is com , two controllers are used to control the pitch angle rate, one is the PD controller and the other is the enhanced L1 adaptive controller.

[0056] In some optional embodiments, step S4 further includes:

[0057] Step S41: inputting 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;

[0058] Step S42: Input the desired pitch rate, the desired pitch rate change rate, and the aircraft pitch rate into a PD controller to obtain a first control parameter.

[0059] refer to Figure 1 In the PD controller, first the desired pitch angle rate q is set to com Input into the command filter to obtain the desired pitch rate and the desired pitch rate change rate. The command filter complex frequency domain expression is:

[0060]

[0061] Expected pitch rate qref and the expected pitch angle rate of change The expression is:

[0062] in, Expected pitch rate q ref The second derivative of ξ nq ,w nq are the instruction filter parameters.

[0063] Then, in step S42, the first control parameter is calculated by the following PD controller formula:

[0064] Among them, q is the actual value of the aircraft's current pitch angle rate, refer to Figure 1 , obtained by the aircraft longitudinal dynamics actuator after executing the input elevator deflection angle instruction, k q is the proportional control parameter.

[0065] In some optional embodiments, step S4 further includes:

[0066] Step S43: Calculate the L1 adaptive law output parameters according to the prediction error of the aircraft pitch rate;

[0067] Step S44: Calculate the second control parameter according to the L1 adaptive law output parameter.

[0068] This embodiment provides the control process of the second controller, namely the L1 adaptive controller, referring to Figure 1 The L1 adaptive controller of this 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:

[0069]

[0070] in, is a first-order low-pass filter, w cq is the filter parameter, s is the Laplace operator; is the output of the adaptive law module. In the adaptive law module, in, A sq =A mq +k sq , A mq =[-w q ], B mq =[1], T s is the sampling time, k sq is the control parameter, is the prediction error of the aircraft pitch rate, the observation value given by the state predictor It is calculated with the actual value q of the aircraft's current pitch rate given by the aircraft's longitudinal dynamics actuator, that is, In the state observer, the first derivative of the observation Where r = w q q com , w q are the parameters of the reference model, B dq 、A dq , Φ q 、A sq 、A mq 、B mq All are intermediate variables.

[0071] Then, in step S5, the two control parameters are combined to calculate the elevator deflection angle instruction δ by the dynamic inverse control law. ec :

[0072]

[0073] Among them, the expression of function f1 is The expression of function g1 is I x , I y , I z is the moment of inertia of the aircraft on each axis, I zx is the product of inertia between the x-axis and the z-axis, p, q, and r are the roll, pitch, and yaw angular rates of the aircraft, Q is the dynamic pressure, S is the wing area, and c is the average aerodynamic chord length. is the pitching moment parameter.

[0074] Finally, in step S6, the elevator deflection angle command δ ec To control the aircraft longitudinally, Figure 1 The input is sent to the aircraft longitudinal dynamics actuator to calculate the control quantity of the motion force and displacement of each actuator unit.

[0075] Compared to existing technologies, this application effectively suppresses airflow disturbances and comprehensively utilizes L1 adaptive control theory to improve the robustness of the control method. When applying this application, control engineers convert the calculated control variables into inner-loop commands based on the actual desired path to control the aircraft, thereby completing the longitudinal motion control task of the aircraft for fully automatic landing.

[0076] A second aspect of the present application provides a fully automatic landing longitudinal control device with enhanced L1 adaptation corresponding to the above method, mainly comprising:

[0077] The expected altitude acquisition module is used to obtain the expected altitude of the aircraft at the next moment;

[0078] An expected climb angle calculation module is used to calculate the expected climb angle;

[0079] A desired pitch angle rate control law calculation module is used to calculate the control law of the desired pitch angle rate;

[0080] 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;

[0081] an elevator deflection angle command calculation module, configured to calculate the elevator deflection angle command based on the first control parameter and the second control parameter using a dynamic inverse control law;

[0082] The longitudinal control module is used to perform longitudinal control on the aircraft based on the elevator deflection angle instruction.

[0083] In some optional implementations, the expected climb angle calculation module includes:

[0084] a longitudinal height change rate instruction calculation unit, configured to determine a longitudinal height change rate instruction based on a desired height and a current height;

[0085] a desired longitudinal altitude change rate instruction calculation unit, configured to generate a desired longitudinal altitude change rate instruction by superimposing an altitude change rate compensation value caused by changes in airflow at a landing point on the longitudinal altitude change rate instruction;

[0086] The expected climb angle calculation unit is used to calculate the expected climb angle according to the expected longitudinal height change rate instruction.

[0087] In some optional implementations, the control parameter output module includes:

[0088] 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;

[0089] 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 rate into the PD controller to obtain the first control parameter.

[0090] In some optional implementations, the control parameter output module includes:

[0091] An adaptive law output parameter calculation unit, configured to calculate an L1 adaptive law output parameter based on a prediction error of the aircraft pitch rate;

[0092] The second control parameter acquisition unit is configured to calculate the second control parameter according to the L1 adaptive law output parameter.

[0093] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A fully automatic landing longitudinal control method with enhanced L1 adaptation, characterized in that: include: Step S1: Obtain the expected altitude of the aircraft at the next moment; Step S2, calculating the expected climb angle; Step S3, calculating the control law of the desired pitch angular 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 an elevator deflection angle command based on the first control parameter and the second control parameter using a dynamic inverse control law; Step S6: performing longitudinal control on the aircraft based on the elevator deflection angle instruction.

2. The method for fully automatic landing longitudinal control with enhanced L1 adaptation according to 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 in airflow at the landing point to the longitudinal height change rate instruction to generate a desired longitudinal height change rate instruction; Step S23: Calculate 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 according to claim 1, characterized in that: Step S4 further comprises: Step S41: inputting 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; Step S42: Input the desired pitch rate, the desired pitch rate change rate, and the aircraft pitch rate into a PD controller to obtain a first control parameter.

4. The method for fully automatic landing longitudinal control with enhanced L1 adaptation according to claim 3, characterized in that: Step S4 further comprises: Step S43: Calculate the L1 adaptive law output parameters according to the prediction error of the aircraft pitch rate; 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 the elevator deflection angle command based on the first control parameter and the second control parameter using a dynamic inverse control law; 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 according to claim 5, characterized in that: The expected climb angle calculation module includes: a longitudinal height change rate instruction calculation unit, configured to determine a longitudinal height change rate instruction based on a desired height and a current height; a desired longitudinal altitude change rate instruction calculation unit, configured to generate a desired longitudinal altitude change rate instruction by superimposing an altitude change rate compensation value caused by changes in airflow at a landing point on the longitudinal altitude 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 according to claim 5, characterized in that: 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 rate into the PD controller to obtain the first control parameter.

8. The fully automatic landing longitudinal control device with enhanced L1 adaptation according to claim 7, characterized in that: The control parameter output module includes: An adaptive law output parameter calculation unit, configured to calculate an L1 adaptive law output parameter based on a prediction error of the aircraft pitch rate; The second control parameter acquisition unit is configured to calculate the second control parameter according to the L1 adaptive law output parameter.

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