A gust mitigation control system and method for multi-control-face aircraft

Abstract

This invention discloses a gust mitigation control system and method applicable to multi-control-surface aircraft, belonging to the field of multi-control-surface aircraft control. The method of this invention includes a gust mitigation control law, gust mitigation control law activation and deactivation logic, and mitigation control surface (spoiler, flap) allocation logic. This method is superimposed on the original control system of the aircraft as a top-level structure. By adopting a direct lift control method, it can greatly reduce the overload of gusts on the aircraft without changing the pitch attitude of the aircraft, and can quickly counteract the effects of gusts. The system of this invention has the advantages of minimal change in aircraft attitude when activated and no impact on normal flight when deactivated. At the same time, the direct lift control method can reduce the additional torque generated by control surface deflection, thus stabilizing the flight trajectory.

Description

Technical Field

[0001] This invention belongs to the field of multi-control surface aircraft control, specifically relating to a gust mitigation control system and method that can be used for multi-control surface aircraft. Background Technology

[0002] To achieve higher economic efficiency and lower fuel consumption, modern aircraft often employ aerodynamic designs with high aspect ratios to obtain a higher lift-to-drag ratio. However, the strength issues arising from high aspect ratios must also be considered. During flight, aircraft inevitably encounter gusts of varying severity, which have a significant impact, especially on high aspect ratio aircraft. Gusts exacerbate changes in wing root loading, causing pitch oscillations and reducing ride quality. Even short-duration gusts can cause fatigue damage to key load-bearing components, shortening the aircraft's service life. Therefore, it is necessary to study how to reduce the impact of gusts during flight. Summary of the Invention

[0003] This invention provides a gust mitigation control system and method for multi-control-face aircraft, which solves the problem of increased overload in aircraft under gust conditions in the prior art, and provides a control surface allocation method to improve the stability and control performance of multi-control-face aircraft.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A gust mitigation control system for multi-control-surface aircraft includes: control surfaces, sensors, a gust mitigation controller, a distributor, and an active disturbance rejection controller.

[0006] The control surfaces are used to control the aircraft's attitude. The control surfaces include ailerons, elevators, rudders, spoilers, and flaps, wherein the spoilers and flaps are direct lift control surfaces. The sensors are used to detect the aircraft's attitude and transmit the detected aircraft attitude signals to the active disturbance rejection controller (ADRC). The ADRC calculates control commands for the control surfaces. The distributor distributes the calculated control commands to the control surfaces. The gust mitigation controller responds to the direct lift control surface commands. The direct lift control surfaces reduce the pitch moment caused by control surface deflection, and the ADRC implements active disturbance rejection control.

[0007] The position and size of the direct lift control surface can be adjusted according to the aircraft's design parameters and actual operating conditions. It can be a leading edge flap, a trailing edge flap, or a combination of multiple control surfaces, or any other control surface that can generate lift, so as to respond quickly and reduce pitching moment.

[0008] The active disturbance rejection controller can calculate control surface commands based on real-time measurements of aircraft overload and target overload, thereby achieving precise control of aircraft overload while counteracting overload changes caused by gusts.

[0009] A gust mitigation control method applicable to multi-control-face aircraft includes the following steps:

[0010] S1. A closed-loop gust mitigation control scheme is adopted, and a direct lift gust mitigation control system is designed. Flaps and spoilers are used as two direct force control surfaces for the aircraft's gust mitigation. A direct lift gust mitigation control law is designed based on the active disturbance rejection control method.

[0011] S2. A control distribution method for gust mitigation control was designed for overdrive systems with multiple control surfaces. The flaps and spoilers are used as direct lift control surfaces. The distributor distributes the commands output by the controller to the control surfaces to improve the deflection efficiency of the control surfaces.

[0012] Beneficial Effects: This invention provides a gust mitigation control system and method for multi-control-surface aircraft. The method includes a gust mitigation control law, gust mitigation control law activation / deactivation logic, and mitigation control surface (spoiler, flap) allocation logic. Control surface commands for multiple control surfaces are given and allocated by an active disturbance rejection controller, achieving optimal control surface performance. This invention uses direct lift control surfaces and active disturbance rejection control. The direct lift control method can significantly reduce the overload of gusts on the aircraft without changing the aircraft's pitch attitude, quickly offsetting the effects of gusts and improving the aircraft's control efficiency and stability. The system's advantages include rapid tracking of overloads and reduction of pitch torque caused by control surface deflection, effectively solving the problem of sudden changes in state variables such as overload and angular velocity when large aspect ratio aircraft are disturbed in gusts, thus improving the aircraft's safety and stability in gusts. Moreover, the system has the advantages of minimal change in aircraft attitude when activated and no impact on normal flight when deactivated. Simultaneously, the direct lift control method can reduce the additional torque generated by control surface deflection, stabilizing the flight trajectory. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a gust reduction control method in an embodiment of the present invention;

[0014] Figure 2 This is a schematic diagram of the aircraft control surfaces in an embodiment of the present invention;

[0015] Figure 3 This is a schematic diagram of the layout of the gust mitigation control system in an embodiment of the present invention;

[0016] Figure 4 This is an example of an aircraft overload response diagram in an embodiment of the present invention;

[0017] Figure 5 This is an example of an aircraft altitude response diagram in an embodiment of the present invention. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments:

[0019] like Figure 1 As shown, a gust mitigation control method applicable to multi-control-face aircraft includes the following steps:

[0020] S1. A closed-loop gust mitigation control scheme is adopted, and a direct lift gust mitigation control system is designed. Flaps and spoilers are used as two direct force control surfaces for the aircraft's gust mitigation. The direct lift gust mitigation control law is designed based on the active disturbance rejection control method.

[0021] S2. A control distribution method for gust mitigation control is designed for overdrive systems with multiple control surfaces. The flaps and spoilers are used as direct lift control surfaces. The distributor distributes the commands output by the controller to the control surfaces to improve the deflection efficiency of the control surfaces.

[0022] Considering the matrix form of small longitudinal perturbations, we can obtain short-period approximate equations, and gusts are more severe in short-period modes. The short-period state equations are simplified as follows:

[0023]

[0024] Where A z For normal acceleration, Z δ =[Z e Z flap Z sp ] is the manipulator derivative, δ = [δ e ,δ flap ,δ sp ] T The deflection angle of the control surface. V represents the uncertainty estimate of the overload caused by the gust, and V is the vacuum velocity.

[0025] Differentiating the expression, we get:

[0026]

[0027] In the formula Substituting into the formula, we can obtain

[0028]

[0029] The aerodynamic parameters of an aircraft change drastically in gusts of wind, especially the Z-axis, which includes the angle of attack term. α Therefore, it is treated as a disturbance term, and the total disturbance of the aircraft is assumed to be:

[0030]

[0031] Direct lift control does not manipulate the elevator to prevent conflict with the stability augmentation system, and instead directs the elevator deflection. The influence is also treated as a disturbance term, and the expression can then be rewritten as follows:

[0032]

[0033] The gust reduction control law can be obtained as follows:

[0034]

[0035] Where Z2 is the estimate of the disturbance value;

[0036] This yields the gust reduction control quantity, and a pseudo-inverse method is used to design a distributor to allocate the control quantity to the flaps and spoilers:

[0037] U = W u -1 (B u W u -1 ) + v

[0038] Among them B u W is a 1×m vector. u =diag[W1 W2 … W m ] is a weighted matrix, obtained based on the control effectiveness and deflection rate of the direct lift control surfaces, where m is the number of aircraft control surfaces.

[0039] from Figure 4 and Figure 5 It can be seen that the above method can fully allocate the output of the gust mitigation control system to the mitigation control surfaces and can effectively reduce the overload of the aircraft in gusts, which has certain feasibility and advantages.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gust mitigation control method applicable to multi-control-face aircraft, characterized in that, Includes the following steps: S1. A closed-loop gust mitigation control scheme is adopted, and a direct lift gust mitigation control system is designed. Flaps and spoilers are used as two direct force control surfaces for the aircraft's gust mitigation. A direct lift gust mitigation control law is designed based on the active disturbance rejection control method. The active disturbance rejection control method includes treating the impact of elevator deflection on the aircraft overload as a disturbance term to prevent conflict with the aircraft stability augmentation system. S2. A control allocation method for gust mitigation control is designed for overdrive systems with multiple control surfaces. Flaps and spoilers are used as direct lift control surfaces. The distributor allocates the controller's output commands to the control surfaces, improving their deflection efficiency. Considering the matrix form of small longitudinal disturbances, a short-period approximate equation is obtained. The short-period state equation is as follows: ， in Normal acceleration, To manipulate the derivative, The deflection angle of the control surface. For the uncertainty estimate of gust overload, It is the vacuum velocity; Differentiating the above equation, we get: ， In the formula Substituting into the formula, we can obtain ； The gust reduction control law is: ， in For the estimation of the disturbance value, Differentiate for normal acceleration; This yields the gust reduction control quantity, and a pseudo-inverse method is used to design a distributor to allocate the control quantity to the flaps and spoilers: ， in It is The vector, This is a weighted matrix; it is obtained based on the control effectiveness and deflection rate of the direct lift control surfaces. The number of aircraft controls.

2. The gust mitigation control method for multi-control-face aircraft according to claim 1, characterized in that, Assume the total disturbance of the aircraft is: ， Includes angle of attack term and elevator deflection The effect of is taken as a disturbance term, then: 。 3. The gust mitigation control method for multi-control-face aircraft according to claim 1, characterized in that, The gust mitigation control system includes: control surfaces, sensors, a gust mitigation controller, a distributor, and an active disturbance rejection controller; the control surfaces include flaps and spoilers, which are used as direct lift control surfaces; the sensors are used to detect the aircraft attitude; the active disturbance rejection controller is used to calculate the control commands for the direct lift control surfaces, wherein the active disturbance rejection controller also treats the impact of elevator deflection on aircraft overload as a disturbance term to prevent conflict with the aircraft stability augmentation system; the distributor is used to distribute the calculated control commands to the flaps and spoilers; and the gust mitigation controller is used to respond to the control commands.

4. The gust mitigation control method for multi-control-face aircraft according to claim 3, characterized in that, The control surfaces include ailerons, elevators, and rudders.

5. The gust mitigation control method for multi-control-face aircraft according to claim 3 or 4, characterized in that, The position and size of the direct lift control surfaces are adjusted according to the aircraft's design parameters and actual operating conditions.

6. The gust mitigation control method for multi-control-face aircraft according to claim 3, characterized in that, The active disturbance rejection controller calculates control surface commands based on real-time measured aircraft overload and target overload, achieving precise control of aircraft overload while counteracting overload changes caused by gusts.

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