Small-amplitude pitching vibration coupling control system and control method

Abstract

The invention relates to a small-amplitude pitching vibration coupling control system and a control method, and belongs to the pneumatic field, a special control system is designed, the control system comprises a longitudinal excitation device, a transverse excitation device, a motor controller and an upper computer, through coupling control of the longitudinal excitation device and the transverse excitation device, no matter the conditions of a back support, a belly support or a tail support, the motor controller can be controlled to work, and the control system can be controlled. In addition, in the test process, the pitching vibration test of the model can be completed only by sending sinusoidal vibration instructions to the longitudinal motor and the transverse motor through the motor controller, the test process is simple and easy to implement, and the test efficiency is improved. And a large number of tests show that compared with theoretical values, the actual values of the attack angle and the sideslip angle of the model calculated in the coupling excitation mode have very small error data, and enough precision can be obtained.

Description

Technical Field

[0001] The invention relates to a small-amplitude pitch vibration coupling control system and a control method, belonging to the field of pneumatics. Background Art

[0002] Wind tunnel dynamic derivative testing is a primary method for studying the dynamic aerodynamic characteristics of aircraft. Forced vibration derivative tests for aircraft include pitch, roll, yaw, heave, and translation. Pitch and heave vibrations of the model can be induced using a longitudinal excitation device, while roll, yaw, and translation vibrations can be induced using a transverse excitation device. For testing convenience, the transverse and longitudinal excitation devices are typically installed together, using angular coupling to adjust the model's state at different angles of attack and sideslip. Due to the mass of the model's struts, the overall moment of inertia of the mechanism is large during pitch vibration, requiring a high power demand from the longitudinal excitation motor. Consequently, the longitudinal excitation motor is often large and heavy. Typically, the longitudinal motor is fixed to the wind tunnel test section, while the transverse motor is mounted on the longitudinal excitation device. The model is connected to the transverse motor via struts. This connection fixes the longitudinal excitation direction, limiting pitch excitation to zero sideslip.

[0003] Based on this, it is urgent to develop a small-amplitude pitch vibration coupling control system and method to realize the small-amplitude pitch vibration test of the model under arbitrary sideslip angles. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a small-amplitude pitch vibration coupling control system and control method, which realizes a small-amplitude pitch vibration test of a model to be tested under any sideslip angle through coupling control of a longitudinal excitation device and a lateral excitation device.

[0005] The technical solutions of the present invention are as follows:

[0006] A small-amplitude pitch vibration coupling control method, comprising:

[0007] Install a control system, the control system including a longitudinal vibration excitation device, a transverse vibration excitation device, a motor controller and a host computer, wherein the longitudinal vibration excitation device includes a longitudinal motor, a turntable and a longitudinal bracket, and the transverse vibration excitation device includes a transverse motor and a transverse support rod, the longitudinal bracket is connected to the turntable, the longitudinal motor is fixed to the turntable, the transverse support rod is fixed to the transverse motor, the transverse motor is installed on the longitudinal bracket, the model to be tested is fixed to the transverse support rod, the motor controller is connected to the longitudinal motor and the transverse motor, and the host computer is connected to the motor controller;

[0008] Given the angle of attack α and sideslip angle β, the host computer calculates the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation devicem ;

[0009] The host computer is based on the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation device m , calculate the amplitude and phase of the longitudinal excitation device, and the amplitude and phase of the transverse excitation device respectively;

[0010] Given an incoming wind speed, the wind tunnel is started, and the host computer sends control instructions to the motor controller. The control instructions include the calculated amplitude and phase of the longitudinal excitation device and the amplitude and phase, motion form, and motion time of the lateral excitation device. The motor controller controls the operation of the longitudinal motor and the lateral motor according to the control instructions to achieve pitch vibration of the model to be tested at a given angle of attack α and sideslip angle β.

[0011] In the above-mentioned small-amplitude pitch vibration coupling control method, the longitudinal support includes a first support rod and a second support rod, the two ends of the second support rod are respectively connected to two first support rods, the two first support rods are parallel to each other and perpendicular to the second support rods, the second support rod is perpendicular to the turntable, and the transverse motor is installed on the second support rod.

[0012] In the above-mentioned small-amplitude pitch vibration coupling control method, there are three types of connection and support methods between the model to be tested and the transverse support rod. The first is back support, that is, the back of the model to be tested is connected to the transverse support rod, the head of the model to be tested is facing the positive direction of the x-axis, and the back is facing the positive direction of the z-axis; the second is belly support, that is, the belly of the model to be tested is connected to the transverse support rod, the head of the model to be tested is facing the positive direction of the x-axis, and the belly is facing the positive direction of the z-axis; the third is tail support, that is, the tail of the model to be tested is connected to the transverse support rod, the head of the model to be tested is facing the positive direction of the x-axis, and the back is facing the positive direction of the z-axis; wherein the x-axis of the coordinate system oxyz points in the opposite direction of the incoming flow direction, the y-axis is perpendicular to the x-axis and points directly upward, and the z-axis is determined according to the right-hand rule.

[0013] In the above-mentioned small-amplitude pitch vibration coupling control method, given the angle of attack α and the sideslip angle β, the host computer calculates the static angle value ψ of the longitudinal excitation device in the case of back support or belly support. m The static angle value θ with the lateral excitation device m ,include:

[0014] The following relationship exists between the attack angle α, sideslip angle β, longitudinal excitation device rotation angle Ψ, and lateral excitation device rotation angle θ of the model to be tested:

[0015]

[0016] When the model to be tested is at the angle of attack α m , sideslip angle β m When the aircraft is in pitch vibration, the actual angle of attack and sideslip angle change with time and satisfy the following relationship:

[0017]

[0018] where α f (t) = Asin(2πft), f is the vibration frequency, and t is the time. To realize the vibration form of equation (2), the excitation angle of the longitudinal excitation device and the transverse excitation device changes with time as follows:

[0019]

[0020] Among them, ψ m ,θ m Satisfies the following relationship:

[0021]

[0022] In the above-mentioned small-amplitude pitch vibration coupling control method, the host computer uses the static angle value ψ of the longitudinal excitation device to m The static angle value θ with the lateral excitation device m , calculate the amplitude and phase of the longitudinal excitation device, and the amplitude and phase of the transverse excitation device, including:

[0023] Substituting equation (2) and equation (3) into equation (1) and expanding them, we get:

[0024]

[0025] Since the model undergoes a small pitch vibration, ψ f (t), θ f (t), α f (t) are all small quantities, equation (5) is simplified to:

[0026]

[0027] Combining equation (4), we can get:

[0028]

[0029] The amplitude and phase are obtained from equation (7).

[0030] In the above-mentioned small-amplitude pitch vibration coupling control method, given the angle of attack α and the sideslip angle β, under the tail strut condition, the host computer calculates the static angle value ψ of the longitudinal excitation device respectively m The static angle value θ with the lateral excitation device m ,include:

[0031] The following relationship exists between the attack angle α, sideslip angle β, longitudinal excitation device rotation angle Ψ, and lateral excitation device rotation angle θ of the model to be tested:

[0032]

[0033] When the model to be tested is at the angle of attack α m , sideslip angle β m When the aircraft is in pitch vibration, the actual angle of attack and sideslip angle change with time and satisfy the following relationship:

[0034]

[0035] where α f (t) = Asin(2πft), f is the vibration frequency, and t is the time. To realize the vibration form of equation (2), the excitation angle of the longitudinal excitation device and the transverse excitation device changes with time as follows:

[0036]

[0037] Among them, ψ m ,θ m Satisfies the following relationship:

[0038]

[0039] In the above-mentioned small-amplitude pitch vibration coupling control method, the host computer uses the static angle value ψ of the longitudinal excitation device to m The static angle value θ with the lateral excitation device m , calculate the amplitude and phase of the longitudinal excitation device, and the amplitude and phase of the transverse excitation device, including:

[0040] Substituting equation (2) and equation (3) into equation (8) and expanding them, we get:

[0041]

[0042] When the model to be tested (3) vibrates slightly, ψ f (t), θ f (t), α f (t) are all small quantities, equation (9) is simplified to:

[0043]

[0044] Combining equation (4), we can get:

[0045]

[0046] The amplitude and phase are obtained from equation (10).

[0047] A small-amplitude pitch vibration coupling control system, comprising:

[0048] The longitudinal excitation device is used to excite the model to be tested to vibrate in the longitudinal direction, and includes a longitudinal motor, a turntable, and a longitudinal bracket. One end of the longitudinal bracket is connected to the turntable, and the longitudinal motor is fixed to the turntable to drive the longitudinal bracket and the turntable to rotate.

[0049] The transverse excitation device is used to excite the model to be tested to vibrate in the transverse direction, and includes a transverse motor and a transverse support rod, wherein the model to be tested is fixed on the transverse support rod, the transverse support rod is fixed on the transverse motor, and the transverse motor is installed on the longitudinal bracket, and the transverse motor drives the transverse support rod to rotate around its own axis;

[0050] The motor controller receives control instructions from the host computer and controls the longitudinal motor and the transverse motor to work according to the control instructions.

[0051] The host computer calculates the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation device m , according to the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation device m , respectively calculating the amplitude and phase of the longitudinal excitation device, and the amplitude and phase of the lateral excitation device; sending a control instruction to the motor controller, wherein the control instruction includes the calculated amplitude and phase of the longitudinal excitation device, the amplitude and phase of the lateral excitation device, the motion form and the motion time.

[0052] In the above-mentioned small-amplitude pitch vibration coupling control system, the longitudinal support includes a first support rod and a second support rod, the two ends of the second support rod are respectively connected to the two first support rods, the two first support rods are parallel to each other and perpendicular to the second support rods, the second support rod is perpendicular to the turntable, and the transverse motor is installed on the second support rod.

[0053] In the above-mentioned small-amplitude pitch vibration coupling control system, there are three types of connection and support methods between the model to be tested and the transverse support rod. The first is back support, that is, the back of the model to be tested is connected to the transverse support rod, the head of the model to be tested is facing the positive direction of the x-axis, and the back is facing the positive direction of the z-axis; the second is belly support, that is, the belly of the model to be tested is connected to the transverse support rod, the head of the model to be tested is facing the positive direction of the x-axis, and the belly is facing the positive direction of the z-axis; the third is tail support, that is, the tail of the model to be tested is connected to the transverse support rod, the head of the model to be tested is facing the positive direction of the x-axis, and the back is facing the positive direction of the z-axis; wherein the x-axis of the coordinate system oxyz points in the opposite direction of the incoming flow direction, the y-axis is perpendicular to the x-axis and points directly upward, and the z-axis is determined according to the right-hand rule.

[0054] In the above-mentioned small-amplitude pitch vibration coupling control system, in the case of back support or belly support, the host computer (5) calculates the static angle value ψ of the longitudinal excitation device respectively m The static angle value θ with the lateral excitation device m , according to ψm and θ m Calculate the amplitude and phase of the longitudinal excitation device and the amplitude and phase of the transverse excitation device separately, including:

[0055] The following relationship exists between the attack angle α, sideslip angle β, longitudinal excitation device rotation angle Ψ, and lateral excitation device rotation angle θ of the model to be tested:

[0056]

[0057] When the model to be tested is at the angle of attack α m , sideslip angle β m When the aircraft is in pitch vibration, the actual angle of attack and sideslip angle change with time and satisfy the following relationship:

[0058]

[0059] where α f (t) = Asin(2πft), f is the vibration frequency, and t is the time. To realize the vibration form of equation (2), the excitation angle of the longitudinal excitation device and the transverse excitation device changes with time as follows:

[0060]

[0061] Among them, ψ m ,θ m Satisfies the following relationship:

[0062]

[0063] Substituting equation (2) and equation (3) into equation (1) and expanding them, we get:

[0064]

[0065] Since the model undergoes a small pitch vibration, ψ f (t), θ f (t), α f (t) are all small quantities, equation (5) is simplified

[0066] becomes:

[0067]

[0068] Combining equation (4), we can get:

[0069]

[0070] The amplitude and phase are obtained from equation (7).

[0071] In the above-mentioned small-amplitude pitch vibration coupling control system, under the tail strut condition, the host computer calculates the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation device m , according to ψ m and θ m Calculate the amplitude and phase of the longitudinal excitation device and the amplitude and phase of the transverse excitation device separately, including:

[0072] The following relationship exists between the attack angle α, sideslip angle β, longitudinal excitation device rotation angle Ψ, and lateral excitation device rotation angle θ of the model to be tested:

[0073]

[0074] When the model to be tested (3) is at the angle of attack α m , sideslip angle β m When the aircraft is in pitch vibration, the actual angle of attack and sideslip angle change with time and satisfy the following relationship:

[0075]

[0076] where α f (t) = Asin(2πft), f is the vibration frequency, and t is the time. To realize the vibration form of equation (2), the excitation angle of the longitudinal excitation device and the transverse excitation device changes with time as follows:

[0077]

[0078] Among them, ψ m ,θ m Satisfies the following relationship:

[0079]

[0080] Substituting equation (2) and equation (3) into equation (8) and expanding them, we get:

[0081]

[0082] When the model to be tested vibrates slightly, ψ f (t), θ f (t), α f (t) are all small quantities, equation (9) is simplified to:

[0083]

[0084] Combining equation (4), we can get:

[0085]

[0086] The amplitude and phase are obtained from equation (10).

[0087] Compared with the prior art, the present invention has at least the following beneficial effects:

[0088] (1) The embodiment of the present invention provides a small-amplitude pitch vibration coupling control system and control method. A dedicated control system is designed. Through the coupling control of the longitudinal excitation device and the lateral excitation device, a small-amplitude pitch vibration test of the model to be tested under any sideslip angle can be achieved regardless of the back support, belly support or tail support.

[0089] (2) The small-amplitude pitch vibration coupling control system and control method provided by the embodiment of the present invention only need to send sinusoidal vibration instructions to the longitudinal and lateral motors through the motor controller during the test to complete the pitch vibration test of the model. The test process is simple and easy to implement. In addition, a large number of tests have shown that the actual values ​​of the model angle of attack and sideslip angle calculated by the coupling excitation method of the present invention are very small when compared with the theoretical values. The coupling excitation method provided by the present invention can obtain sufficient accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 Schematic diagram of the pitch vibration coupling control system (back support / abdominal support) in an embodiment of the present invention;

[0091] Figure 2 Schematic diagram of the pitch vibration coupling control system (tail strut) in an embodiment of the present invention;

[0092] Longitudinal vibration device (longitudinal motor 1-1, turntable 1-2, longitudinal support 1-3), transverse vibration device (transverse motor 2-1, transverse support rod 2-2), model to be tested 3, motor controller 4, host computer 5;

[0093] Figure 3 : This is the error diagram between the actual angle of attack amplitude and the theoretical amplitude of the model to be tested in the embodiment of the present invention (under back support conditions);

[0094] Figure 4 : This is the error diagram between the actual sideslip angle and the theoretical sideslip angle of the model to be tested in the embodiment of the present invention (under back support conditions);

[0095] Figure 5 : This is a diagram showing the error between the actual angle of attack amplitude and the theoretical amplitude of the model to be tested in an embodiment of the present invention (under the tail strut condition);

[0096] Figure 6 This is an error diagram between the actual sideslip angle and the theoretical sideslip angle of the model to be tested in an embodiment of the present invention (under tail strut conditions). DETAILED DESCRIPTION

[0097] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments:

[0098] like Figure 1 、 2 As shown, the small-amplitude pitch vibration coupling control system of the present invention includes a longitudinal excitation device, a lateral excitation device, a model to be tested 3, a motor controller 4 and a host computer 5, wherein:

[0099] The longitudinal excitation device is used to excite the model to perform periodic forced vibration in the longitudinal direction. The longitudinal excitation device includes a longitudinal motor 1-1, a turntable 1-2, and a longitudinal bracket 1-3. The longitudinal bracket 1-3 is connected to the turntable 1-2. In the embodiment of the present invention, one end of the longitudinal bracket 1-3 is connected to the center position of the upper surface of the turntable 1-2, and the longitudinal motor 1-1 is fixed to the lower surface of the turntable 1-2, driving the longitudinal bracket 1-3 and the turntable 1-2 to rotate around the y direction. The x-axis of the oxyz coordinate system is in the opposite direction of the incoming flow direction, the y-axis is perpendicular to the x-axis and points directly upward, and the z-axis is perpendicular to the x-axis and the y-axis according to the right-hand rule and points to the right, such as Figure 1 、 2 shown.

[0100] The longitudinal support 1-3 includes a first support rod and a second support rod. The two ends of the second support rod are respectively connected to the two first support rods. The two first support rods are parallel to each other and perpendicular to the second support rod. The second support rod is perpendicular to the turntable 1-2. The horizontal motor 2-1 is installed on the second support rod.

[0101] The transverse excitation device is used to excite the model to perform periodic forced vibration in the transverse direction. The transverse excitation device includes a transverse motor 2-1 and a transverse support rod 2-2. The transverse support rod 2-2 is fixed to the transverse motor 2-1, which is mounted on the longitudinal support 1-3. Driven by the transverse motor 2-1, the transverse support rod 2-2 rotates around its own axis. The model 3 to be tested is fixed to the transverse support rod 2-2.

[0102] The model 3 to be tested is fixed on the transverse support rod 2-2 and is forced to vibrate under the excitation of the longitudinal excitation device and the transverse excitation device. There are three support methods: back support, the back of the model 3 is connected to the transverse support rod 2-2, the head of the model 3 faces the positive direction of the x-axis, and the back faces the positive direction of the z-axis (such as Figure 1 As shown); abdominal support, similar to the back support, the abdomen of the model is connected to the transverse support rod 2-2, the head of the model 3 faces the positive direction of the x-axis, and the abdomen faces the positive direction of the z-axis; tail support, the tail of the model is connected to the transverse support rod 2-2, the head of the model 3 faces the positive direction of the x-axis, and the back faces the positive direction of the z-axis (as shown Figure 2 shown).

[0103] The motor controller 4 receives the control instruction sent by the host computer 5, sends a sinusoidal vibration instruction to the longitudinal motor 1-1 and the transverse motor 2-1, and controls the longitudinal motor 1-1 and the transverse motor 2-1 to work according to the control instruction.

[0104] Host computer 5, calculates the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation device m , according to the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation device m , respectively calculate the amplitude and phase of the longitudinal excitation device, as well as the amplitude and phase of the lateral excitation device; send a control instruction to the motor controller 4, which includes the calculated amplitude and phase of the longitudinal excitation device, as well as the amplitude and phase of the lateral excitation device, the motion form and the motion time.

[0105] The small-amplitude pitch vibration coupling control method provided by the present invention is implemented using the above-mentioned control system, and the specific method includes the following steps:

[0106] 1. Install the control system. Connect the longitudinal bracket 1-3 to the turntable 1-2, fix the longitudinal motor 1-1 to the turntable 1-2, fix the transverse support rod 2-2 to the transverse motor 2-1, install the transverse motor 2-1 on the longitudinal bracket 1-3, fix the model to be tested 3 on the transverse support rod 2-2, connect the motor controller 4 to the longitudinal motor 1-1 and the transverse motor 2-1, and connect the host computer 5 to the motor controller 4.

[0107] 2. Given the angle of attack α and the sideslip angle β, the host computer 5 calculates the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation device m ; According to the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation device m , calculate the amplitude and phase of the longitudinal excitation device, and the amplitude and phase of the transverse excitation device respectively;

[0108] 2.1 Back support / abdominal support conditions

[0109] In the case of back support / abdominal support, the model's angle of attack α, sideslip angle β, longitudinal excitation device rotation angle Ψ, and lateral excitation device rotation angle θ have the following relationship:

[0110]

[0111] When the model is at an angle of attack α m , sideslip angle β m When the aircraft is in pitch vibration, the actual angle of attack and sideslip angle change with time and satisfy the following relationship:

[0112]

[0113] where α f(t) = Asin(2πft), where f is the vibration frequency and t is the time. To achieve the vibration form of equation (2), let the excitation angle of the longitudinal and transverse excitation devices change with time as follows:

[0114]

[0115] Among them, ψ m ,θ m Satisfies the following relationship:

[0116]

[0117] Substituting equation (2) and equation (3) into equation (1) and expanding them, we get:

[0118]

[0119] Since the model undergoes a small pitch vibration, ψ f (t), θ f (t), α f (t) are all small quantities, equation (5) can be simplified to

[0120]

[0121] Combining equation (4), we can get:

[0122]

[0123] It can be seen from equation (7) that under the back support or belly support conditions, when the model undergoes a small pitch vibration, the excitation vibrations of the longitudinal and lateral excitation devices can be approximated as sinusoidal vibrations, and the amplitude and phase can be obtained respectively from equation (7).

[0124] 2.2. Tail support conditions

[0125] Similarly, in the case of the tail strut, the following relationship exists between the angle of attack α, sideslip angle β, longitudinal excitation device rotation angle Ψ, and lateral excitation device rotation angle θ of the model 3 to be tested:

[0126]

[0127] When the model to be tested (3) is at the angle of attack α m , sideslip angle β m When the aircraft is in pitch vibration, the actual angle of attack and sideslip angle change with time and satisfy the following relationship:

[0128]

[0129] where α f(t) = Asin(2πft), f is the vibration frequency, and t is the time. To realize the vibration form of equation (2), the excitation angle of the longitudinal excitation device and the transverse excitation device changes with time as follows:

[0130]

[0131] Among them, ψ m ,θ m Satisfies the following relationship:

[0132]

[0133] Substituting equation (2) and equation (3) into equation (8) and expanding them, we get:

[0134]

[0135] When the model vibrates slightly, ψ f (t), θ f (t), α f (t) are all small quantities, equation (9) can be simplified to

[0136]

[0137] Combining equation (4), we can get:

[0138]

[0139] Equation (10) is the angular excitation value that the excitation device needs to provide when the model undergoes a small pitch vibration under the tail strut condition. It is also a sinusoidal vibration. The amplitude and phase of the two mechanisms can be obtained respectively from Equation (10).

[0140] 3. Given the incoming wind speed, start the wind tunnel, and the host computer 5 sends a control instruction to the motor controller 4. The control instruction includes the calculated amplitude and phase of the longitudinal excitation device and the amplitude and phase, motion form, and motion time of the lateral excitation device. The motor controller 4 controls the longitudinal motor 1-1 and the lateral motor 2-1 according to the control instruction to achieve the pitch vibration of the model 3 to be tested at the given angle of attack α and sideslip angle β.

[0141] The small-amplitude pitch vibration coupling control method provided by the present invention realizes the small-amplitude pitch vibration of the model under given attack angle and sideslip angle conditions through coupling control of a longitudinal excitation device and a lateral excitation device.

[0142] Example 1

[0143] The following is the model back support state (such as Figure 1 ) to conduct theoretical deduction.

[0144] When the model 3 to be tested is subjected to pitching vibration with an amplitude of A = 5° and a frequency of f = 2 Hz at a back support angle of α = 50° and a sideslip angle of β = 40°, the static angle values ​​ψ of the longitudinal and lateral excitation devices are calculated according to equation (4): m =35.93°,θ m =52.55°. According to equation (7), the amplitude and phase of the longitudinal and transverse excitation devices are calculated respectively. The amplitude of the longitudinal excitation device is 3.04° and the phase is 0; the amplitude of the transverse excitation device is 2.88° and the phase is 0.

[0145] Given the incoming wind speed, start the wind tunnel. When the incoming flow stabilizes, the host computer sends a motion command to the motor controller, specifying the motor motion form as sinusoidal motion, inputting the amplitude, phase, and motion time, and controlling the longitudinal and lateral excitation devices to perform sinusoidal vibrations to achieve the pitch vibration of the model at an angle of attack α = 50° and a sideslip angle β = 40°.

[0146] The actual values ​​of the model angle of attack and sideslip angle calculated by the coupled excitation method of equation (7) are compared with the theoretical values, as shown in Figure 3 、 4 As shown in Figure 3, the maximum error between the actual angle of attack amplitude of the model under test and the theoretical amplitude is 1.0%, and the maximum error between the actual sideslip angle of the model and the theoretical sideslip angle is 0.5%, indicating that the coupled excitation method of equation (7) can achieve sufficient accuracy.

[0147] Example 2

[0148] The following tail support state (such as Figure 2 ) to conduct theoretical deduction.

[0149] When the model is subjected to pitch vibration with amplitude A = 5° and frequency f = 2 Hz at the tail boom attack angle α = 50° and sideslip angle β = 40°, the actual values ​​of the model attack angle and sideslip angle calculated by the coupled excitation method of equation (10) are compared with the theoretical values, as shown in the following example: Figure 5 、 6 As shown in Figure 1, the maximum error between the actual angle of attack amplitude of the model and the theoretical amplitude is 0.6%, and the maximum error between the actual sideslip angle of the model and the theoretical sideslip angle is 0.4%, indicating that the coupled excitation method of equation (10) can achieve sufficient accuracy.

[0150] These results demonstrate that, regardless of the dorsal, ventral, or tail support configuration, the model can achieve small pitch vibrations through sinusoidal excitation coupling control of the lateral and longitudinal excitation devices. During the test, the model's pitch vibration test was completed simply by sending sinusoidal vibration commands to the longitudinal and lateral motors through the motor controller.

[0151] The above description is only the best specific implementation method of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

[0152] The contents not described in detail in the specification of the present invention belong to the common knowledge of professionals in this field.

Claims

1. A small-amplitude pitch vibration coupling control method, characterized in that: include: Installing a control system, the control system comprising a longitudinal excitation device, a transverse excitation device, a motor controller (4) and a host computer (5), wherein the longitudinal excitation device comprises a longitudinal motor (1-1), a turntable (1-2) and a longitudinal bracket (1-3), the transverse excitation device comprises a transverse motor (2-1) and a transverse support rod (2-2), the longitudinal bracket (1-3) is connected to the turntable (1-2), the longitudinal motor (1-1) is fixed to the turntable (1-2), the transverse support rod (2-2) is fixed to the transverse motor (2-1), the transverse motor (2-1) is installed on the longitudinal bracket (1-3), the model to be tested (3) is fixed to the transverse support rod (2-2), the motor controller (4) is connected to the longitudinal motor (1-1) and the transverse motor (2-1), and the host computer (5) is connected to the motor controller (4); Given the angle of attack α and the sideslip angle β, the host computer (5) calculates the static angle value ψ of the longitudinal excitation device respectively m The static angle value θ with the lateral excitation device m ; The host computer (5) is configured to generate a static angle value ψ of the longitudinal excitation device according to the static angle value ψ of the longitudinal excitation device. m The static angle value θ with the lateral excitation device m , calculate the amplitude and phase of the longitudinal excitation device, and the amplitude and phase of the transverse excitation device respectively; Given an incoming wind speed, the wind tunnel is started, and a host computer (5) sends a control instruction to a motor controller (4). The control instruction includes the amplitude and phase of the longitudinal excitation device and the amplitude and phase, motion form and motion time of the lateral excitation device obtained by calculation. The motor controller (4) controls the longitudinal motor (1-1) and the lateral motor (2-1) to operate according to the control instruction, thereby achieving pitch vibration of a model to be tested (3) under a given angle of attack α and sideslip angle β.

2. The small-amplitude pitch vibration coupling control method according to claim 1, characterized in that: The longitudinal support (1-3) comprises a first support rod and a second support rod, the two ends of the second support rod are respectively connected to the two first support rods, the two first support rods are parallel to each other and perpendicular to the second support rod, the second support rod is perpendicular to the turntable (1-2), and the transverse motor (2-1) is installed on the second support rod.

3. The small-amplitude pitch vibration coupling control method according to claim 1, characterized in that: The connection support modes of the model to be tested (3) and the transverse support rod (2-2) include three types. The first type is back support, that is, the back of the model to be tested (3) is connected to the transverse support rod (2-2), the head of the model to be tested (3) faces the positive direction of the x-axis, and the back faces the positive direction of the z-axis; the second type is belly support, that is, the belly of the model to be tested (3) is connected to the transverse support rod (2-2), the head of the model to be tested (3) faces the positive direction of the x-axis, and the belly faces the positive direction of the z-axis; the third type is tail support, that is, the tail of the model to be tested (3) is connected to the transverse support rod (2-2), the head of the model to be tested (3) faces the positive direction of the x-axis, and the back faces the positive direction of the z-axis; wherein the x-axis of the coordinate system oxyz points to the opposite direction of the incoming flow direction, the y-axis is perpendicular to the x-axis and points directly upward, and the z-axis is determined according to the right-hand rule.

4. The small-amplitude pitch vibration coupling control method according to claim 3, characterized in that: Given the angle of attack α and the sideslip angle β, in the case of back support or belly support, the host computer (5) calculates the static angle value ψ of the longitudinal excitation device respectively m The static angle value θ with the lateral excitation device m ,include: The following relationship exists between the attack angle α, sideslip angle β, longitudinal excitation device rotation angle Ψ, and lateral excitation device rotation angle θ of the model to be tested (3): When the model to be tested (3) is at the angle of attack α m , sideslip angle β m When the aircraft is in pitch vibration, the actual angle of attack and sideslip angle change with time and satisfy the following relationship: where α f (t) = Asin(2πft), f is the vibration frequency, and t is the time. To realize the vibration form of equation (2), the excitation angle of the longitudinal excitation device and the transverse excitation device changes with time as follows: Among them, ψ m ,θ m Satisfies the following relationship:

5. The small-amplitude pitch vibration coupling control method according to claim 4, characterized in that: The host computer (5) is configured to generate a static angle value ψ of the longitudinal excitation device according to the static angle value ψ of the longitudinal excitation device. m The static angle value θ with the lateral excitation device m , calculate the amplitude and phase of the longitudinal excitation device, and the amplitude and phase of the transverse excitation device, including: Substituting equation (2) and equation (3) into equation (1) and expanding them, we get: Since the model undergoes a small pitch vibration, ψ f (t), θ f (t), α f (t) are all small quantities, equation (5) is simplified to: Combining equation (4), we can get: The amplitude and phase are obtained from equation (7).

6. The small-amplitude pitch vibration coupling control method according to claim 3, characterized in that: Given the angle of attack α and the sideslip angle β, in the case of the tail strut, the host computer (5) calculates the static angle value ψ of the longitudinal excitation device respectively m The static angle value θ with the lateral excitation device m ,include: The following relationship exists between the attack angle α, sideslip angle β, longitudinal excitation device rotation angle Ψ, and lateral excitation device rotation angle θ of the model to be tested (3): When the model to be tested (3) is at the angle of attack α m , sideslip angle β m When the aircraft is in pitch vibration, the actual angle of attack and sideslip angle change with time and satisfy the following relationship: where α f (t) = Asin(2πft), f is the vibration frequency, and t is the time. To realize the vibration form of equation (2), the excitation angle of the longitudinal excitation device and the transverse excitation device changes with time as follows: Among them, ψ m ,θ m Satisfies the following relationship:

7. The small-amplitude pitch vibration coupling control method according to claim 6, characterized in that: The host computer (5) is configured to generate a static angle value ψ of the longitudinal excitation device according to the static angle value ψ of the longitudinal excitation device. m The static angle value θ with the lateral excitation device m , calculate the amplitude and phase of the longitudinal excitation device, and the amplitude and phase of the transverse excitation device, including: Substituting equation (2) and equation (3) into equation (8) and expanding them, we get: When the model to be tested (3) vibrates slightly, ψ f (t), θ f (t), α f (t) are all small quantities, equation (9) is simplified to: Combining equation (4), we can get: The amplitude and phase are obtained from equation (10).

8. A small-amplitude pitch vibration coupling control system, characterized in that: include: A longitudinal excitation device is used to excite the model to be tested (3) to vibrate in the longitudinal direction, comprising a longitudinal motor (1-1), a turntable (1-2) and a longitudinal bracket (1-3), wherein one end of the longitudinal bracket (1-3) is connected to the turntable (1-2), and the longitudinal motor (1-1) is fixed on the turntable (1-2) to drive the longitudinal bracket (1-3) and the turntable (1-2) to rotate; A transverse excitation device is used to excite the model to be tested (3) to vibrate in the transverse direction, comprising a transverse motor (2-1) and a transverse support rod (2-2), wherein the model to be tested (3) is fixed on the transverse support rod (2-2), the transverse support rod (2-2) is fixed on the transverse motor (2-1), the transverse motor (2-1) is mounted on the longitudinal bracket (1-3), and the transverse motor (2-1) drives the transverse support rod (2-2) to rotate around its own axis; The motor controller (4) receives a control instruction sent by a host computer (5), and controls the longitudinal motor (1-1) and the transverse motor (2-1) to operate according to the control instruction. The host computer (5) calculates the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation device m , according to the static angle value ψ of the longitudinal excitation device m The static angle value θ with the lateral excitation device m , respectively calculating the amplitude and phase of the longitudinal excitation device, and the amplitude and phase of the lateral excitation device; sending a control instruction to the motor controller (4), the control instruction including the calculated amplitude and phase of the longitudinal excitation device, the amplitude and phase of the lateral excitation device, the motion form and the motion time.

9. The small-amplitude pitch vibration coupling control system according to claim 8, characterized in that: The longitudinal support (1-3) comprises a first support rod and a second support rod, the two ends of the second support rod are respectively connected to the two first support rods, the two first support rods are parallel to each other and perpendicular to the second support rod, the second support rod is perpendicular to the turntable (1-2), and the transverse motor (2-1) is installed on the second support rod.

10. The small-amplitude pitch vibration coupling control system according to claim 8, characterized in that: The connection support modes of the model to be tested (3) and the transverse support rod (2-2) include three types. The first type is back support, that is, the back of the model to be tested (3) is connected to the transverse support rod (2-2), the head of the model to be tested (3) faces the positive direction of the x-axis, and the back faces the positive direction of the z-axis; the second type is belly support, that is, the belly of the model to be tested (3) is connected to the transverse support rod (2-2), the head of the model to be tested (3) faces the positive direction of the x-axis, and the belly faces the positive direction of the z-axis; the third type is tail support, that is, the tail of the model to be tested (3) is connected to the transverse support rod (2-2), the head of the model to be tested (3) faces the positive direction of the x-axis, and the back faces the positive direction of the z-axis; wherein the x-axis of the coordinate system oxyz points to the opposite direction of the incoming flow direction, the y-axis is perpendicular to the x-axis and points directly upward, and the z-axis is determined according to the right-hand rule.

11. The small-amplitude pitch vibration coupling control system according to claim 10, characterized in that: In the case of back support or abdominal support, the host computer (5) calculates the static angle value ψ of the longitudinal excitation device respectively m The static angle value θ with the lateral excitation device m , according to ψ m and θ m Calculate the amplitude and phase of the longitudinal excitation device and the amplitude and phase of the transverse excitation device separately, including: The following relationship exists between the attack angle α, sideslip angle β, longitudinal excitation device rotation angle Ψ, and lateral excitation device rotation angle θ of the model to be tested (3): When the model to be tested (3) is at the angle of attack α m , sideslip angle β m When the aircraft is in pitch vibration, the actual angle of attack and sideslip angle change with time and satisfy the following relationship: where α f (t) = Asin(2πft), f is the vibration frequency, and t is the time. To realize the vibration form of equation (2), the excitation angle of the longitudinal excitation device and the transverse excitation device changes with time as follows: Among them, ψ m ,θ m Satisfies the following relationship: Substituting equation (2) and equation (3) into equation (1) and expanding them, we get: Since the model undergoes a small pitch vibration, ψ f (t), θ f (t), α f (t) are all small quantities, equation (5) is simplified to: Combining equation (4), we can get: The amplitude and phase are obtained from equation (7).

12. The small-amplitude pitch vibration coupling control system according to claim 10, characterized in that: In the case of the tail support, the host computer (5) calculates the static angle value ψ of the longitudinal excitation device respectively m The static angle value θ with the lateral excitation device m , according to ψ m and θ m Calculate the amplitude and phase of the longitudinal excitation device and the amplitude and phase of the transverse excitation device separately, including: The following relationship exists between the attack angle α, sideslip angle β, longitudinal excitation device rotation angle Ψ, and lateral excitation device rotation angle θ of the model to be tested (3): When the model to be tested (3) is at the angle of attack α m , sideslip angle β m When the aircraft is in pitch vibration, the actual angle of attack and sideslip angle change with time and satisfy the following relationship: where α f (t) = Asin(2πft), f is the vibration frequency, and t is the time. To realize the vibration form of equation (2), the excitation angle of the longitudinal excitation device and the transverse excitation device changes with time as follows: Among them, ψ m ,θ m Satisfies the following relationship: Substituting equation (2) and equation (3) into equation (8) and expanding them, we get: When the model to be tested (3) vibrates slightly, ψ f (t), θ f (t), α f (t) are all small quantities, equation (9) is simplified to: Combining equation (4), we can get: The amplitude and phase are obtained from equation (10).

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