Method and device for automatically adjusting periodic variable pitch control phase

Abstract

The invention provides a periodic variable pitch control phase automatic adjustment method. The method comprises the following steps: establishing a servo-rotor control linearization model; determining the mode of the aircraft; wherein the modals of different aircrafts need to correspond to different periodic variable pitch phase angles; according to the mode of the aircraft, the servo-rotor control linearization model is obtained; wherein the servo-rotor control linearization model comprises a coefficient matrix Mi; the aircraft calls the coefficient matrix Mi, the control law of a flight control system is changed according to the coefficient matrix Mi, and automatic adjustment of the periodic variable pitch control phase is achieved; meanwhile, the invention further provides a device for automatically adjusting the periodic variable pitch control phase. According to the method, by adjusting the control phase of the periodic variable pitch of the rotor, the rotor hub and blade loads can be effectively reduced, and various performance indexes of an aircraft are improved.

Description

Technical Field

[0001] The present application belongs to the technical field of periodic pitch control phase adjustment, and in particular, relates to a periodic pitch control phase automatic adjustment method and device. Background Art

[0002] The pitch and roll motions of an aircraft using a rotor as a control surface and a lift surface are achieved through the tilting motion of the rotor blades, and the tilting motion of the rotor blades is achieved through the cyclic pitch control of the corresponding azimuth blades. When performing cyclic pitch control, the maximum value of the cyclic flapping of the blades lags behind the maximum value of the cyclic pitch control by a certain angle in phase, or the exciting force lags behind the control response by a certain angle, which is called the cyclic pitch control phase angle (hereinafter referred to as the phase angle).

[0003] For traditional articulated rotors, due to the low flight speed, the phase angle is generally achieved through mechanical structure design, that is, the rotor structure design and the arrangement of the servo mechanism that controls the rotor structure. The phase angle achieved in this way is generally a fixed value and cannot be adjusted during flight.

[0004] For some aircraft with special rotors or special configurations, the phase angle needs to be adjusted. For example, for aircraft using a rigid rotor system, as the forward flight speed increases, the lift is increasingly concentrated on the forward blade, which also causes the stress on the hub and blade root to increase. In particular, when the speed exceeds a certain value, the load will increase sharply. This phenomenon limits the speed of the aircraft, increases the weight of the aircraft, and also affects the various performance indicators of the aircraft. Summary of the invention

[0005] Purpose of the invention: By changing the phase of the rotor cyclic pitch control, the hub and blade loads can be effectively reduced, and the aircraft speed, weight and other indicators can be improved.

[0006] In a first aspect, the present application provides a method for automatically adjusting the phase of a periodic variable pitch maneuver, the method comprising the following steps:

[0007] Establish a servo-rotor control linearization model;

[0008] Determine the mode of the aircraft; different modes of different aircraft need to correspond to different periodic variable pitch phase angles;

[0009] According to the mode of the aircraft, the servo-rotor control linearization model is obtained; wherein the servo-rotor control linearization model includes a coefficient matrix M i ;

[0010] The aircraft calls the coefficient matrix M i , according to the coefficient matrix M iChange the control law of the flight control system to achieve automatic adjustment of the cyclic pitch control phase.

[0011] Preferably, the determining the mode of the aircraft comprises:

[0012] Get the real-time airspeed of the aircraft;

[0013] The mode of the aircraft is determined according to the real-time airspeed of the aircraft.

[0014] Preferably, the establishing of the servo-rotor control linearization model comprises:

[0015] Establish a servo-rotor control motion relationship model;

[0016] The servo-rotor control motion relationship model is linearly fitted to establish the servo-rotor control linearization model with rotor pitch control as motion input (α, φ, β) and the output displacement (X, Y, Z) of three servo actuators as output.

[0017] Preferably, the servo-rotor control linearization model is:

[0018]

[0019] Preferably, the establishing of the servo-rotor control motion relationship model comprises:

[0020] Set the phase angle;

[0021] According to the phase angle and the arrangement of the servo-rotor control mechanism, a model of the spatial position relationship of the servo-rotor control mechanism is obtained by using a three-dimensional modeling software;

[0022] The motion simulation module is used to perform motion simulation on the model of the spatial position relationship of the servo-rotor control mechanism to obtain the servo-rotor control motion relationship model.

[0023] Preferably, the servo-rotor control motion relationship model is:

[0024] X=f 1 (α)+f 2 (φ)+f 3 (β);

[0025] Y=g 1 (α)+g 2 (φ)+g 3 (β);

[0026] Z=h 1 (α)+h 2 (φ)+h 3 (β);

[0027] Among them, α-longitudinal pitch change, φ-lateral pitch change, β-total pitch change, X-first servo actuator output, Y-second servo actuator output, Z-third servo actuator output.

[0028] In a second aspect, the present application further provides a periodic variable pitch control phase automatic adjustment device, the device comprising:

[0029] A modeling unit, used to establish a servo-rotor control linearization model;

[0030] Sensitive unit, used to determine the mode of the aircraft; different modes of different aircraft need to correspond to different periodic variable distance phase angles;

[0031] A mapping unit is used to obtain the servo-rotor control linearization model according to the mode of the aircraft; wherein the servo-rotor control linearization model includes a coefficient matrix M i ;

[0032] The mapping unit is also used for the aircraft to call the coefficient matrix M i ;

[0033] Adjust the unit according to the coefficient matrix M i Change the control law of the flight control system to achieve automatic adjustment of the cyclic pitch control phase.

[0034] Preferably, the sensitive unit is also used to obtain the real-time airspeed of the aircraft;

[0035] The sensitive unit is also used to determine the mode of the aircraft according to the real-time airspeed of the aircraft.

[0036] Preferably, the modeling unit is also used to establish a servo-rotor control motion relationship model;

[0037] The modeling unit is further used to perform linear fitting on the servo-rotor control motion relationship model, and establish the servo-rotor control linearization model with rotor pitch control as motion input (α, φ, β) and output displacements (X, Y, Z) of three servo actuators as output; wherein the servo-rotor control linearization model is:

[0038]

[0039] Preferably, the modeling unit is further used to set the phase angle;

[0040] The modeling unit is further used to perform modeling through three-dimensional modeling software according to the phase angle and the arrangement of the servo-rotor control mechanism to obtain a model of the spatial position relationship of the servo-rotor control mechanism;

[0041] The modeling unit is further used to use a motion simulation module to perform motion simulation on the model of the spatial position relationship of the servo-rotor control mechanism to obtain the servo-rotor control motion relationship model;

[0042] Wherein, the servo-rotor control motion relationship model is:

[0043] X=f 1 (α)+f 2 (φ)+f 3 (β);

[0044] Y=g 1 (α)+g 2 (φ)+g 3 (β);

[0045] Z=h 1 (α)+h 2 (φ)+h 3 (β);

[0046] Among them, α-longitudinal pitch change, φ-lateral pitch change, β-total pitch change, X-first servo actuator output, Y-second servo actuator output, Z-third servo actuator output.

[0047] Beneficial technical effects of this application:

[0048] According to the periodic pitch phase adjustment requirements of the aircraft, this method designs the servo-rotor control mathematical relationship function corresponding to different flight modes by analyzing the motion law between the rotor control mechanism and the servo mechanism, and realizes the automatic adjustment of the periodic control phase with different aircraft modes. By adjusting the periodic pitch control phase of the rotor, this method can effectively reduce the rotor hub and blade loads and improve various performance indicators of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the phase angle of periodic variable pitch control provided in an embodiment of the present application;

[0050] Figure 2 is a schematic diagram of a servo-rotor control mechanism provided in an embodiment of the present application;

[0051] Figure 3 It is a flow chart of a method for automatic adjustment of phase of periodic variable pitch control provided in an embodiment of the present application;

[0052] Among them: 1-main shaft, 2-servo mechanism, 3-automatic inclinator, 4-pitch rod, 5-propeller blade. DETAILED DESCRIPTION

[0053] The present invention provides a method and device for automatically adjusting the phase of cyclic pitch control of an aircraft. According to the cyclic pitch phase adjustment requirements of the aircraft, the method analyzes the motion law between the rotor control mechanism and the servo mechanism, designs a servo-rotor control mathematical relationship function corresponding to different flight modes, and realizes automatic adjustment of the cyclic control phase with different modes of the aircraft.

[0054] This method can effectively reduce the rotor hub and blade loads and improve various performance indicators of the aircraft by adjusting the control phase of the rotor's cyclic pitch change.

[0055] See also Figure 1-Figure 3 In an embodiment of the present application, the present application provides a method for adjusting a phase of a periodic variable pitch control, comprising:

[0056] 1 Establishing the mathematical model of servo-rotor control

[0057] Step 1) Figure 2 As shown, the phase angle is Δψ. According to the arrangement of the servo mechanism and the rotor control mechanism, the model is built by three-dimensional modeling software, and the motion simulation module is used to perform motion simulation to establish the servo-rotor control motion relationship model.

[0058] X=f 1 (α)+f 2 (φ)+f 3 (β);

[0059] Y=g 1 (α)+g 2 (φ)+g 3 (β);

[0060] Z=h 1 (α)+h 2 (φ)+h 3 (β);

[0061] Among them, α-longitudinal pitch change, φ-lateral pitch change, β-total pitch change, X-first servo actuator output, Y-second servo actuator output, Z-third servo actuator output, f 1 、f 2 、f 3 , g 1 , g 2 , g 3 、h 1 、h 2 、h 3 ——Mathematical function expression.

[0062] Step 2) Linearize the servo-rotor control motion relationship model and establish a servo-rotor control linearization model with rotor pitch control as motion input (α, φ, β) and the output displacement (X, Y, Z) of the three servo actuators as output, as shown in Formula 1, where M is the coefficient matrix;

[0063]

[0064] Step 3) Repeat steps 1) and 2) at different phase angles Δψ to obtain the coefficient M at different phase angles. i matrix;

[0065]

[0066] 2 According to the real-time airspeed of the aircraft, different aircraft modes (m i ), according to the known aerodynamic principles, different aircraft modes correspond to different periodic variable pitch phase angles, and the aircraft mode m is obtained i — Coefficient matrix M i The relationship table is shown in Table 1 below. Table 1 shows the aircraft mode m i — Coefficient matrix M i Relationship table.

[0067] Among them, according to the differences between different aircraft, the aircraft mode m i The conditions to be determined are not limited to real-time airspeed, but also include pilot instructions, aircraft attitude, overload, etc.

[0068] Table 1

[0069] Serial number Aircraft Mode Real-time airspeed Coefficient Matrix 1 <![CDATA[m 1 ]]> <![CDATA[a≥v 1 <b]]> <![CDATA[M 1 ]]> 2 <![CDATA[m 2 ]]> <![CDATA[b≥v 2 <c]]> <![CDATA[M 2 ]]> 3 <![CDATA[m 3 ]]> <![CDATA[c≥v 3 <f]]> <![CDATA[M 3 ]]> … … … …

[0070] 3 The flight control computer obtains the real-time airspeed of the aircraft through the sensor, determines the mode of the aircraft through the real-time airspeed, and obtains the corresponding coefficient matrix M by looking up Table 1 i .

[0071] 4 The aircraft changes the control law of the flight control system by calling different coefficient matrices to realize the automatic adjustment function of the cyclic variable pitch control phase.

[0072] 5 When the aircraft switches between different modes, the flight control system needs to set up a smooth adjustment mechanism for the phase angle, which can ensure the coordination of the cyclic pitch control movement and prevent the aircraft attitude and state from changing dramatically in the transition process. Possible smooth adjustment mechanisms include that the aircraft cannot cross the mode adjustment rules (that is, it cannot be adjusted directly from mode m1 to m3); the smooth adjustment mechanism also includes smoothing the instructions when switching modes, which can adopt moving average filtering, weighted moving average, exponential smoothing and other methods.

[0073] In other embodiments of the present application, the present application further provides a periodic variable pitch control phase automatic adjustment device, comprising:

[0074] Storage unit for storing aircraft mode m i ——Real-time airspeed v——Coefficient matrix M i Mapping relationship;

[0075] Sensitive unit, used to obtain information such as the real-time airspeed of the aircraft, which can determine the current mode of the aircraft;

[0076] The mapping unit is used to call the corresponding coefficient matrix M by looking up the table according to the real-time airspeed i ;

[0077] The calculation unit adjusts the control law parameters of the flight control system according to different coefficient matrices, and is also used to smoothly calculate the output instructions when the aircraft switches between different modes;

[0078] The adjustment unit is used to output the changed flight control system control law and adjust the cyclic pitch control phase.

[0079] In summary, the present invention provides a method and device for automatically adjusting the phase of cyclic pitch control of an aircraft. According to the cyclic pitch phase adjustment requirements of the aircraft, the method analyzes the motion law between the rotor control mechanism and the servo mechanism, designs a servo-rotor control mathematical relationship function corresponding to different flight modes, and realizes automatic adjustment of the cyclic control phase with different modes of the aircraft. By adjusting the control phase of the cyclic pitch of the rotor, the method can effectively reduce the rotor hub and blade loads and improve various performance indicators of the aircraft.

[0080] It should be noted that this method can achieve a certain balance between the rotor load and the aircraft performance by adjusting the control phase of the cyclic pitch change of the rotor, and improve the performance indicators of the aircraft; through theoretical analysis, simulation, experiments and other means, the adjustment requirements of the cyclic pitch change control phase under different flight states and control modes are determined. Through the modeling of the motion mechanism, the motion law between the rotor control mechanism and the servo mechanism is analyzed; by linearizing the mathematical relationship between the servo mechanism and the rotor control mechanism, it is convenient for the flight control system to call related functions; when switching between different flight states and different control modes, a smooth adjustment mechanism for the cyclic pitch change control phase needs to be set.

[0081] The method for automatic adjustment of the phase of aircraft cyclic pitch control proposed in the present invention can be well applied to the overall design of aircraft and the control law design of fly-by-wire flight control system. This method is accurate and efficient and can solve the contradiction between the load and performance of the aircraft's rigid rotor during high-speed flight, thereby improving the performance of the aircraft.

Claims

1. A method for automatically adjusting the phase of a periodic variable pitch maneuver, characterized in that: The method comprises the following steps: Establish a servo-rotor control linearization model; Determine the mode of the aircraft; different modes of different aircraft need to correspond to different periodic variable pitch phase angles; According to the mode of the aircraft, the servo-rotor control linearization model is obtained; wherein the servo-rotor control linearization model includes a coefficient matrix M i ; The aircraft calls the coefficient matrix M i , according to the coefficient matrix M i Change the control law of the flight control system to achieve automatic adjustment of the cyclic pitch control phase.

2. The method according to claim 1, characterized in that The determining the mode of the aircraft includes: Get the real-time airspeed of the aircraft; The mode of the aircraft is determined according to the real-time airspeed of the aircraft.

3. The method according to claim 1, characterized in that The step of establishing a servo-rotor control linearization model comprises: Establish a servo-rotor control motion relationship model; The servo-rotor control motion relationship model is linearly fitted to establish the servo-rotor control linearization model with rotor pitch control as motion input (α, φ, β) and the output displacement (X, Y, Z) of three servo actuators as output.

4. The method according to claim 3, characterized in that The servo-rotor control linearization model is:

5. The method according to claim 4, characterized in that The establishing of the servo-rotor control motion relationship model comprises: Set the phase angle; According to the phase angle and the arrangement of the servo-rotor control mechanism, a model of the spatial position relationship of the servo-rotor control mechanism is obtained by using a three-dimensional modeling software; The motion simulation module is used to perform motion simulation on the model of the spatial position relationship of the servo-rotor control mechanism to obtain the servo-rotor control motion relationship model.

6. The method according to claim 5, characterized in that The servo-rotor control motion relationship model is: X = f1(α)+f2(φ)+f3(β); Y = g1(α)+g2(φ)+g3(β); Z = h1(α)+h2(φ)+h3(β); Among them, α-longitudinal pitch change, φ-lateral pitch change, β-total pitch change, X-first servo actuator output, Y-second servo actuator output, Z-third servo actuator output.

7. A periodic variable pitch control phase automatic adjustment device, characterized in that: The device comprises: A modeling unit, used to establish a servo-rotor control linearization model; Sensitive unit, used to determine the mode of the aircraft; different modes of different aircraft need to correspond to different periodic variable distance phase angles; A mapping unit is used to obtain the servo-rotor control linearization model according to the mode of the aircraft; wherein the servo-rotor control linearization model includes a coefficient matrix M i ; The mapping unit is also used for the aircraft to call the coefficient matrix M i ; Adjust the unit according to the coefficient matrix M i Change the control law of the flight control system to achieve automatic adjustment of the cyclic pitch control phase.

8. The device according to claim 7, characterized in that The sensitive unit is also used to obtain the real-time airspeed of the aircraft; The sensitive unit is also used to determine the mode of the aircraft according to the real-time airspeed of the aircraft.

9. The device according to claim 8, characterized in that The modeling unit is also used to establish a servo-rotor control motion relationship model; The modeling unit is further used to perform linear fitting on the servo-rotor control motion relationship model, and establish the servo-rotor control linearization model with rotor pitch control as motion input (α, φ, β) and output displacements (X, Y, Z) of three servo actuators as output; wherein the servo-rotor control linearization model is:

10. The device according to claim 9, characterized in that The modeling unit is further used to set the phase angle; The modeling unit is further used to perform modeling through three-dimensional modeling software according to the phase angle and the arrangement of the servo-rotor control mechanism to obtain a model of the spatial position relationship of the servo-rotor control mechanism; The modeling unit is further used to use a motion simulation module to perform motion simulation on the model of the spatial position relationship of the servo-rotor control mechanism to obtain the servo-rotor control motion relationship model; Wherein, the servo-rotor control motion relationship model is: X = f1(α)+f2(φ)+f3(β); Y = g1(α)+g2(φ)+g3(β); Z = h1(α)+h2(φ)+h3(β); Among them, α-longitudinal pitch change, φ-lateral pitch change, β-total pitch change, X-first servo actuator output, Y-second servo actuator output, Z-third servo actuator output.

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