A method and apparatus for automatically adjusting the phase of a cycloidal pitch control

Abstract

The application provides a cyclic-pitch control phase automatic adjustment method, which comprises the following steps: establishing a servo-rotor control linear model; determining the mode of an aircraft; wherein the mode of different aircrafts corresponds to different cyclic-pitch phase angles; obtaining the servo-rotor control linear model according to the mode of the aircraft; wherein the servo-rotor control linear model comprises a coefficient matrix M i ; the aircraft calls the coefficient matrix M i , changes the control law of a flight control system according to the coefficient matrix M i , and realizes automatic adjustment of the cyclic-pitch control phase; simultaneously, the application also provides a cyclic-pitch control phase automatic adjustment device; the method can effectively reduce the rotor hub and blade load and improve various performance indexes of the aircraft by adjusting the cyclic-pitch control phase of the rotor.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cyclic pitch control phase adjustment, and particularly relates to a cyclic pitch control phase automatic adjustment method and device. BACKGROUND

[0002] The pitching and rolling movements of an aircraft using rotors as control surfaces and lift surfaces are achieved by the tilting movements of rotor discs, and the tilting movements of rotor discs are achieved by the cyclic pitch control of corresponding azimuthal blades. When cyclic pitch control is performed, the maximum value of disc cyclic flapping lags behind the maximum value of cyclic pitch control by a certain angle in phase, or in other words, the excitation force lags behind the control response by a certain angle, which is referred to as a cyclic pitch control phase angle (hereinafter referred to as a phase angle).

[0003] For a traditional hinged rotor, the phase angle can be achieved by mechanical structure design, i.e., rotor structure design and the arrangement of a servo mechanism for controlling the rotor structure, because the flight speed is not high. The phase angle achieved by this method is generally a certain fixed value, and cannot be adjusted during flight.

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

[0005] The purpose of the application is to effectively reduce the hub and blade loads by changing the rotor cyclic pitch control phase, and to improve the speed, weight and other indicators of the aircraft.

[0006] In a first aspect, the application provides a cyclic pitch control phase automatic adjustment method, which comprises the following steps:

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

[0008] determining the mode of the aircraft; wherein the modes of different aircrafts correspond to different cyclic pitch angles;

[0009] obtaining the servo-rotor control linearization model according to the mode of the aircraft; wherein the servo-rotor control linearization model comprises a coefficient matrix M i ;

[0010] the aircraft calls the coefficient matrix M i , and adjusts the cyclic pitch control phase according to the coefficient matrix M iThe control law of the flight control system is changed to realize automatic adjustment of the cyclic phase of the cyclic control.

[0011] Preferably, the determination of the mode of the aircraft includes:

[0012] The real-time airspeed of the aircraft is obtained.

[0013] According to the real-time airspeed of the aircraft, the mode of the aircraft is determined.

[0014] Preferably, the establishment of the servo-rotor control linearization model includes:

[0015] The servo-rotor control motion relationship model is established.

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

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

[0018]

[0019] Preferably, the establishment of the servo-rotor control motion relationship model includes:

[0020] The phase angle is set.

[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 through three-dimensional modeling software.

[0022] The motion simulation module is used to simulate the motion of 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 = f1(α) + f2(φ) + f3(β);

[0025] Y = g1(α) + g2(φ) + g3(β);

[0026] Z = h1(α) + h2(φ) + h3(β);

[0027] Wherein, α is the longitudinal cyclic pitch, φ is the lateral cyclic pitch, β is the collective pitch, X is the output of the first servo actuator, Y is the output of the second servo actuator, and Z is the output of the third servo actuator.

[0028] In a second aspect, the application also provides a cyclic-pitch control phase automatic adjustment device, which comprises:

[0029] a modeling unit for establishing a servo-rotor control linearization model;

[0030] a sensing unit for determining a mode of the aircraft; wherein different modes of different aircrafts correspond to different cyclic-pitch phase angles;

[0031] a mapping unit for obtaining the servo-rotor control linearization model according to the mode of the aircraft; wherein the servo-rotor control linearization model comprises a coefficient matrix M i ;

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

[0033] an adjustment unit for changing a flight control system control law according to the coefficient matrix M i to realize automatic adjustment of the cyclic-pitch control phase.

[0034] Preferably, the sensing unit is also used for obtaining a real-time airspeed of the aircraft;

[0035] the sensing unit is also used for determining the mode of the aircraft according to the real-time airspeed of the aircraft.

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

[0037] the modeling unit is also used for linearization fitting of the servo-rotor control motion relationship model to establish the servo-rotor control linearization model taking rotor cyclic-pitch control as motion input (α, φ, β) and taking output displacement (X, Y, Z) of three servo actuators as output; wherein the servo-rotor control linearization model is:

[0038]

[0039] Preferably, the modeling unit is also used for setting a phase angle;

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

[0041] the modeling unit is also used for motion simulation of the model of spatial position relationship of the servo-rotor control mechanism through a motion simulation module to obtain the servo-rotor control motion relationship model;

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

[0043] X = f1 (a) + f2 (φ) + f3 (β) ;

[0044] Y = g1 (a) + g2 (φ) + g3 (β) ;

[0045] Z = h1 (a) + h2 (φ) + h3 (β) ;

[0046] Wherein, a is the longitudinal pitch, φ is the lateral pitch, β is the collective pitch, X is the first servo actuator output, Y is the second servo actuator output, and Z is the third servo actuator output.

[0047] The beneficial technical effects of the present application are:

[0048] The method adjusts the periodic pitch phase according to the periodic pitch phase adjustment requirement of the aircraft, analyzes the motion law between the rotor control mechanism and the servo mechanism, designs the servo-rotor control mathematical relationship function corresponding to different flight modes, and realizes the automatic adjustment of the periodic control phase with different modes of the aircraft. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 is a periodic pitch control phase angle diagram provided by the embodiment of the present application;

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

[0051] Figure 3 is a flowchart of a periodic pitch control phase automatic adjustment method provided by the embodiment of the present application;

[0052] Wherein: 1 is a main shaft, 2 is a servo mechanism, 3 is an automatic inclinator, 4 is a pitch control rod, and 5 is a rotor blade. DETAILED DESCRIPTION

[0053] The present application provides an aircraft periodic pitch control phase automatic adjustment method and device. The method adjusts the periodic pitch phase according to the periodic pitch phase adjustment requirement of the aircraft, analyzes the motion law between the rotor control mechanism and the servo mechanism, designs the servo-rotor control mathematical relationship function corresponding to different flight modes, and realizes the automatic adjustment of the periodic control phase with different modes of the aircraft.

[0054] The method adjusts the periodic pitch control phase of the rotor, which can effectively reduce the rotor hub and blade load and improve the performance indicators of the aircraft.

[0055] Please refer to Figures 1-3In the embodiments of the present application, the present application provides a periodic pitch control phase adjustment method, comprising:

[0056] 1. Establishing a servo-rotor control mathematical model

[0057] Step 1) As shown in the following formula (1), under the condition of phase angle Δψ, a servo-rotor control motion relationship model is established by modeling through a three-dimensional modeling software and motion simulation by using a motion simulation module according to the arrangement of a servo mechanism and a rotor control mechanism. Figure 2

[0058] X = f1 (a) + f2 (φ) + f3 (β) ;

[0059] Y = g1 (a) + g2 (φ) + g3 (β) ;

[0060] Z = h1 (a) + h2 (φ) + h3 (β) ;

[0061] Wherein, a is a longitudinal pitch, φ is a lateral pitch, β is a total pitch, X is a first servo actuator output, Y is a second servo actuator output, Z is a third servo actuator output, f1, f2, f3, g1, g2, g3, h1, h2, h3 are mathematical function expressions.

[0062] Step 2) Linear fitting is performed on the servo-rotor control motion relationship model to establish a servo-rotor control linear model with rotor pitch control as motion input (a, φ, β) and output displacement (X, Y, Z) of three servo actuators as output, as shown in the following formula (2), wherein M is a coefficient matrix.

[0063]

[0064] Step 3) Steps 1) and 2) are repeated under different phase angles Δψ to obtain the coefficient matrix M under different phase angles. i

[0065]

[0066] 2. According to the real-time airspeed of the aircraft, different aircraft modes (m i ) are divided, different periodic pitch phase angles corresponding to different aircraft modes are obtained according to known aerodynamic principles, and the aircraft mode m i -coefficient matrix M i relationship table is obtained, as shown in the following table 1. Table 1 is the aircraft mode m i -coefficient matrix M i relationship table.

[0067] Wherein, according to the difference of different aircrafts, the aircraft mode m i ​​The determined conditions 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 m1 [a > v1 < b] M1 2 m2 [b ≥ v2 < c] [M2] 3 m3 [c > v3 < f] [M3] … … … …

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

[0071] 4 The aircraft changes the control law of the flight control system by calling different coefficient matrices, and realizes the automatic adjustment function of the cyclic-pitch control phase.

[0072] 5 When the aircraft is converted in different modes, the flight control system needs to set a smooth adjustment mechanism for the phase angle, which can ensure the coordination of the cyclic-pitch control movement and prevent the instantaneous drastic changes of the aircraft attitude and state in the transition process. Possible smooth adjustment mechanisms include that the aircraft cannot adjust across modes (i.e., cannot be adjusted from mode m1 to m3 directly); the smooth adjustment mechanism also includes smoothing the instructions when switching modes, which can adopt methods such as moving average filtering, weighted moving average, exponential smoothing, etc.

[0073] In other embodiments of the present application, the present application also provides a cyclic-pitch control phase automatic adjustment device, comprising:

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

[0075] A sensing unit for obtaining information such as real-time airspeed of the aircraft, which can determine the current mode of the aircraft;

[0076] A mapping unit for calling the corresponding coefficient matrix M i according to the real-time airspeed through table lookup;

[0077] A computing unit for adjusting the control law parameters of the flight control system according to different coefficient matrices, and also for smoothing the output instructions when the aircraft is converted in different modes;

[0078] An adjustment unit for outputting the changed flight control system control law to adjust the cyclic-pitch control phase.

[0079] In summary, the present application provides an aircraft cyclic pitch control phase automatic adjustment method and device. The method adjusts the cyclic pitch control phase of the aircraft according to the requirements of the aircraft, 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 the automatic adjustment of the cyclic control phase with different modes of the aircraft. By adjusting the cyclic pitch control phase of the rotor, the load of the rotor hub and the blade can be effectively reduced, and the performance indicators of the aircraft can be improved.

[0080] It should be noted that the method can balance the rotor load and the performance of the aircraft by adjusting the cyclic pitch control phase of the rotor, and improve the performance indicators of the aircraft. Through theoretical analysis, simulation, test and other means, the adjustment requirements of the cyclic pitch control phase under different flight states and control modes are determined. The motion law between the rotor control mechanism and the servo mechanism is analyzed through the modeling of the motion mechanism. The servo mechanism-rotor control mechanism mathematical relationship is linearized, which is convenient for the flight control system to call the related function. The adjustment smoothing mechanism of the cyclic pitch control phase needs to be set when the flight state and the control mode are converted.

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

Claims

1. A method for automatic phase adjustment of periodic pitch control, characterized in that, The method comprises the following steps: establishing a servo-rotor control linearization model, comprising: establishing a servo-rotor control motion relationship model; performing linearization fitting on the servo-rotor control motion relationship model to establish the servo-rotor control linearization model taking rotor pitch control as motion input (α, φ, β) and output displacement (X, Y, Z) of three servo actuators as output; wherein α is longitudinal pitch, φ is lateral pitch, β is total pitch, X is first servo actuator output, Y is second servo actuator output, and Z is third servo actuator output; acquiring real-time airspeed of the aircraft; determining a mode of the aircraft according to the real-time airspeed of the aircraft; wherein different modes of different aircrafts correspond to different cyclic pitch phase angles; acquiring the servo-rotor control linearization model according to the mode of the aircraft; wherein the servo-rotor control linearization model comprises a coefficient matrix M; the aircraft calling the coefficient matrix M to change a flight control system control law according to the coefficient matrix M, so as to realize automatic adjustment of a cyclic pitch control phase.

2. The method of claim 1, wherein, the servo-rotor control linearization model is:

3. The method of claim 2, wherein, the servo-rotor control motion relationship model is established by: setting a phase angle; modeling by a three-dimensional modeling software according to the phase angle and arrangement of a servo-rotor control mechanism to obtain a model of spatial position relationship of the servo-rotor control mechanism; performing motion simulation on the model of spatial position relationship of the servo-rotor control mechanism by a motion simulation module to obtain the servo-rotor control motion relationship model.

4. The method of claim 3, 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).

5. A cyclic pitch control phase automatic adjustment device, characterized by, the device comprises: a modeling unit for establishing a servo-rotor control linearization model; comprising: establishing a servo-rotor control motion relationship model; performing linearization fitting on the servo-rotor control motion relationship model to establish the servo-rotor control linearization model taking rotor pitch control as motion input (α, φ, β) and output displacement (X, Y, Z) of three servo actuators as output; wherein α is longitudinal pitch, φ is lateral pitch, β is total pitch, X is first servo actuator output, Y is second servo actuator output, and Z is third servo actuator output; a sensing unit for acquiring real-time airspeed of the aircraft; determining a mode of the aircraft according to the real-time airspeed of the aircraft; wherein different modes of different aircrafts correspond to different cyclic pitch phase angles; a mapping unit for acquiring the servo-rotor control linearization model according to the mode of the aircraft; wherein the servo-rotor control linearization model comprises a coefficient matrix M; the mapping unit is also used for the aircraft to call the coefficient matrix M; an adjusting unit for changing a flight control system control law according to the coefficient matrix M, so as to realize automatic adjustment of a cyclic pitch control phase.

6. The apparatus of claim 5, wherein, the servo-rotor control linearization model is:

7. The apparatus of claim 6, wherein, the modeling unit is further configured to set a phase angle; the modeling unit is further configured to model, according to the phase angle and an arrangement of the servo-rotor control mechanism, a spatial position relationship of the servo-rotor control mechanism by using a three-dimensional modeling software to obtain a model of the spatial position relationship of the servo-rotor control mechanism; the modeling unit is further configured to simulate motion of the model of the spatial position relationship of the servo-rotor control mechanism by using a motion simulation module to obtain a servo-rotor control motion relationship model; wherein the servo-rotor control motion relationship model is: X = f1(a) + f2(p) + f3(b); Y = g1(a) + g2(p) + g3(b); Z = h1(a) + h2(p) + h3(b).

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