A method for adjusting a control surface allocation scheme for dynamically adjusting aircraft handling performance

Abstract

The application provides a method for adjusting a rudder surface distribution scheme for dynamically adjusting aircraft control performance, obtaining a first rudder surface distribution scheme with high control performance under an X-shaped rudder blade layout; obtaining a second rudder surface distribution scheme with low control performance under the X-shaped rudder blade layout; designing a transition algorithm when the rudder surface distribution scheme is dynamically switched; and based on the transition algorithm, using the change of dynamic pressure to dynamically switch the first rudder surface distribution scheme and the second rudder surface distribution scheme. The application ensures moderate rudder surface control performance in the flight process by adjusting the rudder surface distribution scheme online.

Description

Technical Field

[0001] The present invention belongs to the field of aerospace technology, and in particular relates to a control surface distribution scheme adjustment method for dynamically adjusting the control performance of an aircraft. Background Art

[0002] Aircraft generally have four control surfaces, arranged in a cross or X-shape. A reasonable control surface distribution scheme needs to be designed to ensure that the aircraft has appropriate maneuverability. The aerodynamic forces and aerodynamic torques generated during flight are distributed to the three channels of pitch, yaw, and roll to ensure the accuracy of the aircraft's flight trajectory and attitude control. When the flight pressure is too high, the control ability of the control surfaces will become too strong. Due to the existence of the servo dead zone, the attitude cannot be accurately controlled, causing the aircraft to oscillate back and forth near the attitude index. When the flight pressure is too low, the control ability of the control surfaces will become too small, resulting in the aircraft being unable to correct trajectory or attitude deviations in a timely manner, resulting in technical indicators not being met. Ensuring the accuracy of the aircraft's trajectory and attitude control during flight is a top priority of the flight mission. How to dynamically adjust the aircraft's maneuverability during flight is a key technology in aircraft development. Summary of the Invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides a control surface allocation scheme adjustment method for dynamically adjusting the aircraft's maneuverability, which solves the above-mentioned problems.

[0004] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0005] This solution provides a method for adjusting the control surface allocation scheme for dynamically adjusting the aircraft's maneuverability, including:

[0006] S1. Obtaining a first rudder surface allocation scheme with high maneuverability under an X-shaped rudder blade layout;

[0007] S2. Obtaining a second rudder surface allocation scheme with low maneuverability under an X-shaped rudder blade layout;

[0008] S3. Based on the transition algorithm when the rudder surface allocation scheme is dynamically switched, the first rudder surface allocation scheme and the second rudder surface allocation scheme are dynamically switched by utilizing the change in dynamic pressure to complete the adjustment of the rudder surface allocation scheme.

[0009] Beneficial effects of the present invention:

[0010] The application provides a rudder surface distribution scheme adjustment method for dynamically adjusting aircraft control performance, and comprises the following contents: obtaining a first rudder surface distribution scheme with high control performance under an X-shaped rudder piece layout; obtaining a second rudder surface distribution scheme with low control performance under the X-shaped rudder piece layout; designing a transition algorithm during dynamic switching of the rudder surface distribution scheme; and based on the transition algorithm, dynamically switching the first rudder surface distribution scheme and the second rudder surface distribution scheme by using the change of dynamic pressure. In the case that flight dynamic pressure affects the control performance of the aircraft rudder surface, and further affects the control effect of the aircraft control system, in order to dynamically adjust the control performance of the aircraft during flight, the online adjustment of the rudder surface distribution scheme algorithm is used to switch the rudder surface distribution scheme of the aircraft according to the current flight dynamic pressure, the control instructions of each rudder piece of the aircraft are generated in real time, and the single rudder control instructions in the switching process are smoothed and transitioned, so as to ensure the attitude control accuracy of the aircraft in the large dynamic pressure. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 The method flowchart of the application. DETAILED DESCRIPTION

[0012] The specific embodiments of the application are described below to facilitate the understanding of the application by those skilled in the art, but it should be clear that the application is not limited to the scope of the specific embodiments, and for those skilled in the art, it is obvious that various changes are within the spirit and scope of the application defined and determined by the appended claims, and all the application and creation using the concept of the application are within the scope of protection.

[0013] EMBODIMENT

[0014] As Figure 1 shown, the application provides a rudder surface distribution scheme adjustment method for dynamically adjusting aircraft control performance, comprising the following steps:

[0015] S1, obtaining a first rudder surface distribution scheme with high control performance under an X-shaped rudder piece layout, specifically:

[0016] designing a first rudder surface distribution scheme P1 with high control performance under the X-shaped rudder piece layout, defining that when looking from the tail of the aircraft to the head, the full-moving tail rudder is rotated to a positive deflection angle in the clockwise direction from the initial installation position, and the deflection angles of the four full-moving tail rudders are respectively defined as , , , , the equivalent roll rudder deflection angle , the equivalent yaw rudder deflection angle , and the equivalent pitch rudder deflection angle Under this scheme, four single-plate rudders are each assigned aerodynamic force and aerodynamic moment by three control channels, and the rudder synthesis formula is as follows:

[0017] (1)

[0018] The rudder assignment formula is as follows:

[0019] (2)

[0020] Wherein, formula (1) and formula (2) are denoted as a first rudder surface assignment scheme P1.

[0021] S2, obtaining a second rudder surface assignment scheme with low maneuverability under the X-shaped rudder layout, which is specifically:

[0022] Designing a second rudder surface assignment scheme P2 with low maneuverability under the X-shaped rudder layout, defining that when looking from the tail of the aircraft to the head, the full-moving tail rudder is rotated in the clockwise direction from the initial installation position to the positive deflection angle, and the deflection angles of the four full-moving tail rudders are respectively denoted as , , , , defining the equivalent roll rudder deflection angle , the equivalent yaw rudder deflection angle , and the equivalent pitch rudder deflection angle , under this scheme, each control channel is only provided with aerodynamic force and aerodynamic moment by two single-plate rudders, and the rudder synthesis formula is as follows:

[0023] (3)

[0024] The rudder assignment formula is as follows:

[0025] (4)

[0026] Wherein, formula (3) and formula (4) are denoted as a second rudder surface assignment scheme P2.

[0027] S3, based on the transition algorithm of the rudder surface assignment scheme, the first rudder surface assignment scheme and the second rudder surface assignment scheme are dynamically switched by using the change of dynamic pressure, and the adjustment of the rudder surface assignment scheme is completed, which is specifically:

[0028] A linear algorithm is adopted to linearly transition the rudder command of a single-plate rudder, so as to ensure the smoothness of the controller command in the switching process of the rudder assignment scheme. Defining the single-plate rudder command under the rudder assignment scheme applied before switching as , the single-plate rudder command under the rudder assignment scheme applied after switching as , the output single-plate rudder command at the time of switching as , and the expression of the output single-plate rudder command at the time of switching as:

[0029] (5)

[0030] wherein K is a transition coefficient, and the value thereof is determined as follows:

[0031] ;

[0032] wherein, is the time of switching of the rudder allocation scheme, is the flight time, is the transition time, which can be 0.4s.

[0033] The rudder allocation scheme is dynamically switched according to the change in dynamic pressure. When the dynamic pressure gradually increases, the rudder allocation scheme is switched from P1 to P2 when , the control ability of the aircraft is reduced, so that a small control deviation can calculate a large rudder deflection angle, to ensure the control accuracy; after the dynamic pressure gradually decreases, the rudder allocation scheme is switched from P2 to P1 when , the output single rudder control command; wherein, is the critical dynamic pressure value when the rudder allocation scheme is switched, The value of can be 30000Pa.

[0034] In this embodiment, the flight dynamic pressure during flight can be calculated as wherein, is the atmospheric density, is the flight speed, and the values of the atmospheric density and the flight speed can be obtained by the aerodynamic sensors of the aircraft.

[0035] In this way, the control ability of the aircraft can be improved, so that a larger control deviation can calculate a smaller rudder deflection angle, thereby ensuring the control ability and avoiding the saturation of the rudder surface.

[0036] In this embodiment, the transition algorithm is used, the oscillation amplitude of the attack angle is smaller, the oscillation frequency is lower, and the control accuracy is improved. The oscillation amplitude and oscillation frequency of the single rudder rudder command also become smaller, and the rudder command is more stable. As can be seen from the results, this method has obvious effect and high engineering value.

[0037] This embodiment provides a method for adjusting the rudder surface allocation scheme for dynamically adjusting aircraft maneuverability. To dynamically adjust the aircraft's maneuverability during flight, an online rudder surface allocation algorithm is employed to switch the aircraft's rudder surface allocation scheme based on the current flight pressure. Control commands for each rudder element are generated in real time, and the control commands for each rudder element during the switching process are smoothed and transitioned, ensuring the aircraft's attitude control accuracy under high dynamic pressure conditions. The present invention operates in a simple and reliable manner, and the command correction method is easy to operate and effective.

Claims

1. A method for adjusting a control surface allocation scheme for dynamically adjusting an aircraft's maneuverability, characterized in that: The following steps are included: S1. Obtain the first rudder surface allocation scheme with high maneuverability under the X-shaped rudder blade layout; design the first rudder surface allocation scheme P1 with high maneuverability under the X-shaped rudder blade layout, define the positive deflection angle as the clockwise rotation of the end edge of the full-movable tail rudder from the initial installation position when looking from the tail to the head of the aircraft. The four full-movable tail rudder deflection angles are recorded as 、 、 、 , defines the equivalent roll rudder angle , equivalent yaw rudder angle , equivalent pitch rudder angle ; Among them, the four single-piece rudders all distribute aerodynamic force and aerodynamic torque through three control channels. The rudder synthesis formula is as follows: (1) The rudder distribution formula is as follows: (2) Among them, formula (1) and formula (2) are recorded as the first rudder surface allocation scheme P1; S2. Obtain a second rudder surface allocation scheme with low maneuverability under an X-shaped rudder blade layout; design a second rudder surface allocation scheme P2 with low maneuverability under an X-shaped rudder blade layout, defining a positive deflection angle as the clockwise rotation of the end edge of the full-movable tail rudder from the initial installation position when looking from the tail to the head of the aircraft. The four full-movable tail rudder deflection angles are recorded as 、 、 、 , defines the equivalent roll rudder angle , equivalent yaw rudder angle , equivalent pitch rudder angle ; Among them, each control channel is provided with aerodynamic force and aerodynamic torque by only two single-piece rudders, and the rudder synthesis formula is as follows: (3) The rudder distribution formula is as follows: (4) Among them, formula (3) and formula (4) are recorded as the second rudder surface allocation scheme P2; S3, based on the transition algorithm when the rudder surface allocation scheme is dynamically switched, the first rudder surface allocation scheme and the second rudder surface allocation scheme are dynamically switched by utilizing the change of dynamic pressure to complete the adjustment of the rudder surface allocation scheme; a linear algorithm is adopted to perform a linear transition on the rudder command of the single-chip rudder to ensure smooth controller command during the switching of the rudder allocation scheme; the single-chip rudder command under the rudder allocation scheme applied before the switching is defined as , the single-chip rudder command under the rudder allocation scheme applied after switching is , the single-chip rudder command output during switching is , the expression of the single-chip rudder command output during switching is: (5) Where K is the transition coefficient, and the value is obtained as follows: ； in, The moment when the rudder allocation scheme switches, For flight time, is the transition duration, which can be 0.4s; According to the change of dynamic pressure, the rudder distribution scheme is dynamically switched. When the dynamic pressure gradually increases, , the rudder distribution scheme is switched from P1 to P2, which reduces the control ability of the aircraft, so that a small control deviation can calculate a large rudder deflection angle to ensure control accuracy; after the dynamic pressure gradually decreases, when , the rudder allocation scheme is switched from P2 to P1, and a single yaw control command is output; among them, is the critical dynamic pressure value when switching the rudder distribution scheme.

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