Flap rudder servo system and control method for hypersonic wind tunnel dynamic test model

Abstract

The present invention belongs to the technical field of hypersonic wind tunnel test, and discloses a hypersonic wind tunnel dynamic test model Flap rudder surface servo system and a control method thereof. A step servo motor and a transmission module are fixed on the frame of the servo system, and a rudder deflection angle detection module is fixed on the rudder surface; the servo system drives the rudder surface to deflect through the transmission module and adjusts the rudder surface deflection angle; at the same time, the rudder surface deflection angle is measured through the rudder deflection angle detection module. The control method includes determining the control target of the servo system; establishing a mathematical model of a step servo motor servo controller; establishing a mathematical model of a step servo motor transmission structure; establishing a mathematical model of a rudder deflection angle detection module; establishing a servo control model; and performing rudder surface control. The servo system and its control method can be applied to dynamic wind tunnel tests of hypersonic aircraft, and have engineering practical value.

Description

Technical Field

[0001] The present invention belongs to the technical field of hypersonic wind tunnel tests, and in particular relates to a hypersonic wind tunnel dynamic test model Flap control surface servo system and a control method thereof. Background Art

[0002] As the military capabilities of various countries continue to improve, hypersonic aircraft have become a key part of national defense. In the field of offense and defense, the performance of hypersonic aircraft directly determines the probability of penetration and hit of hypersonic aircraft. As the core component of hypersonic aircraft, the shape and performance of the servo system greatly affect the attitude control and performance of hypersonic aircraft in the service environment.

[0003] The wind tunnel test model servo system is used in the dynamic test model variable rudder deflection wind tunnel test to simulate various motion states of hypersonic aircraft. The wind tunnel test model servo system is placed inside the test model and reliably connected to the control rudder blade. It automatically moves according to the specified deflection angle to achieve automatic change of the dynamic test model rudder deflection angle. It can accurately control and measure the model rudder surface attitude in real time, and improve the accuracy and efficiency of the model aerodynamic measurement.

[0004] At present, wind tunnel test model servo systems are mainly used in low-speed and subsonic wind tunnels. Generally, small-load servo systems for model aircraft or real servo systems used in aircraft are selected. Special servo systems are also designed for some special simulation needs.

[0005] In 2012, Wang Hui et al. [Development of Wind Tunnel Test Model Servo System, Experimental Fluid Mechanics, 2012, 03[J].] designed a servo consisting of a displacement sensor, a controller, a connecting rod and a double hinge mechanism. The servo has a small size, light weight, good load characteristics, and is ideal in temperature stability and shock load stability. The servo has high control accuracy, high servo test accuracy, and reliable operation in a low-speed wind tunnel. The use of this servo has increased the efficiency of a certain aircraft's full rudder efficiency test by 3 times, and reduced the wind tunnel operation time by 36.5%.

[0006] In 2014, the China Patent Literature Database published an invention by Che Binghui's team titled "A Low-speed Wind Tunnel Force Measurement Test Model Automatic Servo" (ZL201420386906.7). This patent designs a test model servo for a low-speed wind tunnel that integrates an elevator, a rudder and a control system. The computer controls the test model to automatically adjust the rudder angle in the wind tunnel, which is 40% more efficient than manually adjusting the rudder angle.

[0007] In 2016, Liang Jianliang et al. [Optimization Design and Development of Small Electric Servo Transmission Mechanism, Mechanical Research and Application, 2016, 04 [J].] designed a small electric servo transmission mechanism consisting of a screw nut pair and a connecting rod mechanism. The small electric servo transmission mechanism improves the efficiency and accuracy of wind tunnel tests, increases the deflection angle of the servo, increases the deflection angle adjustment range, and achieves a smooth change in the servo rotation speed; the maximum rudder angle given reaches 69.89°, the average angular velocity is 2.331° / s, and the standard deviation of angular velocity fluctuation is 0.0813.

[0008] In 2021, Zhang Haihang's team from Harbin Institute of Technology [Research on Electric Variable Control Surface System in Wind Tunnel Test, Zhang Haihang, Harbin Institute of Technology, 2021, [D].] designed a servo with a ball screw and six-link structure, and studied the electric variable control surface system installed inside the aircraft scale model in the wind tunnel test, mainly from the aspects of structural optimization design, nonlinear interference factor analysis and control method. The servo can withstand a certain aerodynamic load, has locking and remote control capabilities, high measurement accuracy, improved transmission efficiency, and has the advantages of small size and weight, fewer structural parts, low complexity and high reliability.

[0009] In 2022, the China Patent Literature Library disclosed the invention of Li Guangliang's team, entitled A servo model for a wind tunnel test model (ZL202223219584.0). This patent designed a wind tunnel test model servo with a rotating shaft pin method. Through gears, drive shafts, forks and encoders, the end feedback of the rudder angle and the closed-loop control of the servo are realized. The rudder angle accuracy of the servo unit in the wind tunnel test is within 0.05°, and it has the advantages of small size and high precision.

[0010] In summary, due to the low wind speed and small simulated load in low-speed and sub-transsonic wind tunnel flow fields, the load on the servo is not high; the low-speed and sub-transsonic wind tunnels have large calibers, large test model sizes, large allowable space for the servo system, and large servo volume; currently, the servo system of wind tunnel test models is mainly used in low-speed and sub-transsonic wind tunnels. Relatively speaking, the hypersonic wind tunnel has a small caliber, small test model size, and smaller allowable space for the servo system of the wind tunnel test model. The simulated dynamic pressure of the hypersonic wind tunnel flow field is high, and the load on the servo system is large. At the same time, the dynamic test of the hypersonic wind tunnel has high requirements for the control accuracy of the rudder deflection. The existing wind tunnel test model servo system cannot be used in a hypersonic wind tunnel.

[0011] At present, in the field of hypersonic wind tunnel dynamic tests, there is an urgent need to develop a corresponding wind tunnel test model servo system, and there is an urgent need to develop a hypersonic wind tunnel dynamic test model Flap rudder surface servo system and a control method thereof. Summary of the invention

[0012] One technical problem to be solved by the present invention is to provide a Flap rudder surface and servo system for a hypersonic wind tunnel dynamic test model. Another technical problem to be solved by the present invention is to provide a control method for a Flap rudder surface and servo system for a hypersonic wind tunnel dynamic test model, so as to carry out dynamic test research on aircraft in a hypersonic wind tunnel.

[0013] The hypersonic wind tunnel dynamic test model Flap rudder surface servo system of the present invention comprises a frame, a step servo motor, a transmission module, a rudder deflection angle detection module and a rudder surface; the step servo motor and the transmission module are fixed on the frame, and the rudder deflection angle detection module is fixed on the rudder surface;

[0014] The steering gear system drives the rudder surface to deflect and adjust the rudder surface angle through the transmission module; at the same time, the rudder surface angle is measured through the rudder angle detection module.

[0015] Furthermore, the frame includes a frame body, a motor mounting seat, a lower cover plate, an upper cover plate and positioning pins;

[0016] The frame body is a bilaterally symmetrical frame structure; the central cavity I of the frame body is used to fix and install the screw nut assembly of the transmission module; the front end surface of the frame body is fixed with a motor mounting seat by screws, and the step servo motor is fixedly installed on the motor mounting seat by screws; the rear end of the frame body extends out a bilaterally symmetrical semicircular protrusion I, and the two semicircular protrusions I are provided with left and right through steering gear connecting shaft mounting holes (35); the lower cover plate and the upper cover plate are respectively fixed to the upper surface and the lower surface of the frame body by screws, and are used to close the central cavity I of the frame body; the positioning pin is inserted into the outer frame of the frame body from top to bottom, and is used to locate the installation position of the steering gear system on the dynamic test model;

[0017] The frame body, motor mounting base, lower cover and upper cover are all made of 30CrMnSiA material, which meets the strength requirements, stiffness requirements and overall weight reduction requirements of the steering gear system.

[0018] Further, the coupling comprises an intermediate disk arranged on the motor shaft of the step servo motor and two grooves arranged on the lead screw of the lead screw nut assembly, the intermediate disk matches with the grooves to lock the motor shaft and the lead screw;

[0019] The coupling compensates for the relative displacement between the motor shaft and the screw during installation and operation. The relative displacement includes axial displacement, radial displacement and angular displacement.

[0020] Furthermore, the screw nut assembly includes a slider, a nut, a screw, a guide rail, two thrust bearings, a screw front end bearing, a screw nut gland, a rear retaining ring, a screw rear end bearing and a bearing cover plate; the screw nut assembly decelerates the rotational force output by the step servo motor and transmits it to the connecting rod assembly;

[0021] There are two guide rails, which are fixed symmetrically in the central cavity I of the frame body;

[0022] The slider is a left-right symmetrical structure; the central cavity II of the slider matches the nut, and the bayonet on the left and right sides are respectively mounted on the guide rails on the left and right sides; the left and right sides of the slider extend forward with symmetrical semicircular protrusions II, and the two semicircular protrusions II are provided with connecting rod shaft mounting holes that penetrate left and right;

[0023] The front part of the lead screw is equipped with a nut, and the lead screw passes through the central cavity II of the slider from back to front until the nut is placed in the central cavity II of the slider; the stepping servo motor drives the lead screw to rotate through the coupling, driving the nut to drive the slider to move forward and backward along the guide rail;

[0024] The front end of the screw is equipped with the first thrust bearing, the front end bearing of the screw, the second thrust bearing and the screw nut gland in sequence from front to back. The nut and the slider are fixedly connected by screws distributed along the circumference of the screw nut gland. The front end bearing of the screw is located between the two thrust bearings, bearing axial and radial loads, used to support and transmit axial force and reduce friction. The screw nut gland provides stable support for the screw to prevent deformation.

[0025] The rear end of the screw is sequentially equipped with a rear retaining ring, a rear end bearing of the screw and a bearing cover plate from front to back; the rear end bearing of the screw is used to transmit axial force and reduce friction; the rear retaining ring and the bearing cover plate are used to close the rear end face of the screw and protect various bearings in the screw nut assembly.

[0026] Furthermore, the rudder surface includes a rudder surface body, a rudder connecting shaft, a rudder connecting shaft baffle and a rudder surface side cover plate;

[0027] The front end of the rudder surface body is a connecting column, on which a first group of holes I and a second group of holes II are arranged, the central axes of the two groups of holes are parallel to each other, the first group of holes I includes two holes I located on the inner side and symmetrically, and the second group of holes II includes two holes II located on the outer side and symmetrically; the steering gear connecting shaft is inserted into the two holes I of the first group of holes I and the two steering gear connecting shaft mounting holes (35) on the frame body; one end face of the steering gear connecting shaft is fixed with a rudder angle detection module baffle, and the other end face is fixed with a rudder angle detection module baffle, and the rudder angle detection module baffle and the steering gear connecting shaft baffle protect the steering gear connecting shaft from being hit and damaged by external objects;

[0028] The rear end of the rudder surface body is the rudder surface wing, and the rudder surface side cover plate is fixed on the rudder surface wing, and the rudder surface side cover plate is used to close the windward side of the rudder surface wing.

[0029] Furthermore, the connecting rod assembly includes a crank connecting rod and two connecting rod shafts, and the two connecting rod shafts are respectively located at the front and rear ends of the crank connecting rod;

[0030] The connecting rod shaft at the front end of the crank connecting rod is inserted into the connecting rod shaft mounting hole of the slider of the screw nut assembly, and the connecting rod shaft at the rear end of the crank connecting rod is inserted into the second group of holes II of the rudder surface body of the rudder surface; the connecting rod shaft at the front end of the crank connecting rod is higher than the connecting rod shaft at the rear end of the crank connecting rod; when the slider moves forward, the crank connecting rod drives the rudder surface to rotate upward, and when the slider moves backward, the crank connecting rod drives the rudder surface to rotate downward.

[0031] Further, the rudder angle detection module includes a magnetic turntable, a magnetoresistive effect sensor and a rudder angle detection module baffle;

[0032] A magnetic turntable is fixed on the inner side of the baffle of the rudder angle detection module, and a semi-enclosed manner is adopted to protect the magnetic turntable; a magnetoresistive effect sensor is fixedly installed on the rear end surface of the frame body of the frame by screws, opposite to the magnetic turntable;

[0033] When the crank-connecting rod drives the rudder surface to rotate, the magnetic turntable rotates synchronously with the rudder surface, causing the magnetic field strength inside the magnetic turntable to change and generating a magnetic field strength change signal. The magnetoresistive effect sensor detects the magnetic field strength change signal and transmits the magnetic field strength change signal to the computer. The computer collects and decodes the signal to obtain the rudder surface rotation angle.

[0034] The control method of the hypersonic wind tunnel dynamic test model Flap control surface servo system of the present invention comprises the following steps:

[0035] S10. Determine the control target of the steering gear system;

[0036] The Flap rudder servo system of the hypersonic wind tunnel dynamic test model works in constant force mode, and the working states include one or a combination of two or more of co-pushing, co-pulling, braking, and push-pull interlocking. It is necessary to design a servo controller dedicated to the stepper servo motor. The servo controller uses FPGA for core development, and it is also necessary to design a dedicated electrical control program to control the deflection angle of the driving rudder surface accurately.

[0037] S20. Establishing a mathematical model of a stepping servo motor servo controller;

[0038] Torque , the mathematical model of the stepper servo motor servo controller is simplified to:

[0039] ;

[0040] ;

[0041] ;

[0042] in, is the rotation angle of the motor shaft relative to the initial position; is the DC bus voltage of the motor; is the electromagnetic time constant; is the motor time constant, ; is the inductor, is the resistance, is the load torque, is the electromotive force constant, is the torque coefficient; is the complex frequency variable in Laplace transform;

[0043] Transfer function of the motor :

[0044] ;

[0045] in, It is the electromotive force transmission system. is the electromagnetic torque; is the input voltage;

[0046] The driver amplifies the control signal output by the servo controller and drives the stepper servo motor (2). After mathematical modeling, a proportional link is formed in the system. ;

[0047] S30. Establishing a mathematical model of the stepping servo motor transmission structure;

[0048] The screw nut assembly decelerates the rotational force output by the stepper servo motor and transmits it to the connecting rod assembly, which drives the rudder surface to deflect to form a proportional link. ;make ;

[0049] S40. Establishing a mathematical model of the rudder angle detection module;

[0050] The rudder angle detection module converts the rudder surface deflection position feedback signal into an electrical signal and transmits it to the stepper servo motor servo controller, forming a proportional link in the system, recorded as ;

[0051] S50. Establish a steering gear control model;

[0052] The simplified electric servo transfer function is written in the form of a differential equation:

[0053] ;

[0054] in, is the DC bus voltage of the motor, is the rudder surface deflection angle, is the input voltage, is the output voltage; according to the selected step servo motor performance parameters and rudder angle design index requirements, the theoretical parameters of the servo model are obtained as follows:

[0055] ;

[0056] The differential equation of the input and output of the servo system is as follows:

[0057] ;

[0058] S60. Perform rudder control;

[0059] The servo controller sends a control signal to the electrical control program to drive the stepper servo motor to rotate, and transmits power to the rudder surface through the transmission module to drive the rudder surface to rotate. At the same time, the rudder angle detection module feeds back the rudder angle measurement signal in real time to determine whether the rudder surface has reached the specified position.

[0060] The stepper servo motor used in the Flap rudder servo system of the hypersonic wind tunnel dynamic test model of the present invention is a new type of servo motor that integrates servo control technology into the stepper motor. It has precise position and speed control performance, that is, it has the advantages of both the stepper motor and the servo motor, and can provide power and braking for the servo system.

[0061] The hypersonic wind tunnel dynamic test model Flap control surface steering gear system and control method thereof of the present invention have the following characteristics:

[0062] a. The steering gear drive, transmission and rudder angle measurement unit are compact and small in size, and can be directly installed inside the test model, with a total weight of 4.83kg;

[0063] b. The servo has high repeatability and a wide range of motion. The servo motion speed is >30° / s, the motion range is greater than -30°~+5°, the servo motion positioning accuracy is <0.1°, and the repeatability is better than 0.1°. It can accurately adjust the angle of the rudder blade in the hypersonic wind tunnel test;

[0064] c. High rudder angle measurement accuracy and fast response. The rudder angle measurement accuracy is better than 0.02°, the real-time performance is better than 1ms, the delay error is ≤5ms, and the rudder overshoot is ≤10%. It can quickly adjust the angle of the rudder blade in the hypersonic wind tunnel test;

[0065] d. The servo can realize automatic adjustment of the rudder angle. The displacement and control process of automatic adjustment can be set and automatically executed as required before the system is operated, and the input position command can also be executed in real time;

[0066] e. The steering gear uses a crank connecting rod for transmission, which has high transmission efficiency.

[0067] The hypersonic wind tunnel dynamic test model Flap rudder surface servo system and the control method thereof of the present invention are based on mechanical transmission and control science, and adopt a screw nut-connecting rod structure, which has a simple and compact structure, a small volume, a large change angle, and can be built inside the rudder blade; the servo motion positioning accuracy and repeatability are high, the rudder deflection angle measurement accuracy is high, and the delay is small, thereby improving the measurement sensitivity and accuracy of the servo; miniaturization, high load, and high precision are achieved, and the servo can be applied to the dynamic wind tunnel test of hypersonic aircraft, and has engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a transmission principle diagram of the Flap rudder servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0069] Figure 2 It is a schematic diagram of the overall structure of the Flap control surface servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0070] Figure 3 It is a schematic diagram of the frame structure in the Flap rudder servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0071] Figure 4 It is a schematic diagram of the structure of a stepping servo motor in the Flap rudder servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0072] Figure 5 It is a cross-sectional view of the connection between the stepping servo motor and the screw shaft in the Flap rudder servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0073] Figure 6 It is a schematic diagram of a transmission module in the Flap rudder servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0074] Figure 7 It is a schematic diagram of the screw nut assembly of the transmission module in the Flap rudder servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0075] Figure 8 It is a schematic diagram of a connecting rod assembly of a transmission module in a Flap rudder servo system of a hypersonic wind tunnel dynamic test model of the present invention;

[0076] Fig. 9 It is a structural schematic diagram of a rudder angle detection module in a Flap rudder surface servo system of a hypersonic wind tunnel dynamic test model of the present invention;

[0077] Fig.10 It is a schematic diagram of the control surface structure in the Flap control surface servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0078] Fig.11 It is a schematic diagram of the rudder surface structure of the Flap rudder surface servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0079] Fig.12 It is an overall explosion diagram of the Flap control surface servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0080] Fig.13 It is a stepping servo motor control model in the control method of the Flap control surface servo system of the hypersonic wind tunnel dynamic test model of the present invention;

[0081] Fig.14 It is a Flap rudder surface servo control model in the control method of the Flap rudder surface servo system of the hypersonic wind tunnel dynamic test model of the present invention.

[0082] In the figure, 1. frame; 2. step servo motor; 3. transmission module; 4. rudder angle detection module; 5. rudder surface; 6. frame body; 7. motor mounting seat; 8. lower cover plate; 9. upper cover plate; 10. positioning pin; 11. lead screw nut assembly; 12. connecting rod assembly; 13. slider; 14. nut; 15. lead screw; 16. guide rail; 17. thrust bearing; 18. lead screw front end bearing; 19. lead screw nut gland; 20. rear retaining ring; 21. lead screw rear end bearing; 22. bearing cover plate; 23. crank connecting rod; 24. connecting rod shaft; 25. magnetic turntable; 26. magnetoresistance effect sensor; 27. rudder angle detection module baffle plate; 28. rudder surface body; 29. ​​servo connecting shaft; 30. servo connecting shaft baffle plate; 31. rudder surface side cover plate; 32. servo connecting shaft mounting hole; 33. hole I; 34. hole II. DETAILED DESCRIPTION

[0083] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0084] like Figure 1 to Figure 12 As shown, the hypersonic wind tunnel dynamic test model Flap rudder surface servo system of the present invention comprises a frame 1, a step servo motor 2, a transmission module 3, a rudder deflection angle detection module 4 and a rudder surface 5; the step servo motor 2 and the transmission module 3 are fixed on the frame 1, and the rudder deflection angle detection module 4 is fixed on the rudder surface 5;

[0085] The steering gear system drives the rudder surface 5 to deflect through the transmission module 3 to adjust the rudder surface deflection angle; at the same time, the rudder surface deflection angle is measured through the rudder deflection angle detection module 4.

[0086] Furthermore, the frame 1 includes a frame body 6, a motor mounting seat 7, a lower cover plate 8, an upper cover plate 9 and a positioning pin 10;

[0087] The frame body 6 is a bilaterally symmetrical frame structure; the central cavity I of the frame body 6 is used to fix the screw nut assembly 11 of the transmission module 3; the front end surface of the frame body 6 is fixed to the motor mounting seat 7 by screws, and the step servo motor 2 is fixedly mounted on the motor mounting seat 7 by screws; the rear end of the frame body 6 extends out a bilaterally symmetrical semicircular protrusion I, and the two semicircular protrusions I are provided with a steering gear connecting shaft mounting hole 32 that penetrates the left and right sides; the lower cover plate 8 and the upper cover plate 9 are respectively fixed to the upper surface and the lower surface of the frame body 6 by screws, and are used to close the central cavity I of the frame body 6; the positioning pin 10 is inserted into the outer frame of the frame body 6 from top to bottom, and is used to locate the installation position of the steering gear system on the dynamic test model;

[0088] The frame body 6, the motor mounting base 7, the lower cover plate 8 and the upper cover plate 9 are all made of 30CrMnSiA material, which meets the strength requirements, rigidity requirements and the overall weight reduction requirements of the steering gear system.

[0089] Further, the coupling comprises an intermediate disk provided on the motor shaft of the step servo motor 2 and two grooves provided on the lead screw 15 of the lead screw nut assembly 11, the intermediate disk matches with the grooves to lock the motor shaft and the lead screw 15;

[0090] The coupling compensates for the relative displacement between the motor shaft and the lead screw 15 during installation and operation, and the relative displacement includes axial displacement, radial displacement and angular displacement.

[0091] Furthermore, the screw nut assembly 11 includes a slider 13, a nut 14, a screw 15, a guide rail 16, two thrust bearings 17, a screw front end bearing 18, a screw nut gland 19, a rear retaining ring 20, a screw rear end bearing 21 and a bearing cover plate 22; the screw nut assembly 11 decelerates the rotational force output by the step servo motor 2 and transmits it to the connecting rod assembly 12;

[0092] There are two guide rails 16, which are fixed symmetrically in the central cavity I of the frame body 6;

[0093] The slider 13 is a bilaterally symmetrical structure; the central cavity II of the slider 13 matches the nut 14, and the bayonet holes on the left and right sides are respectively mounted on the guide rails 16 on the left and right sides; the left and right sides of the slider 13 extend forward with symmetrical semicircular protrusions II, and the two semicircular protrusions II are provided with connecting rod shaft 24 mounting holes that penetrate left and right;

[0094] The front section of the lead screw 15 is fitted with a nut 14, and the lead screw 15 passes through the central cavity II of the slider 13 from the back to the front until the nut 14 is placed in the central cavity II of the slider 13; the stepping servo motor 2 drives the lead screw 15 to rotate through the coupling, driving the nut 14 to drive the slider 13 to move forward and backward along the guide rail 16;

[0095] The front end of the screw 15 is provided with the first thrust bearing 17, the front end bearing 18 of the screw, the second thrust bearing 17 and the screw nut gland 19 in sequence from front to back. The nut 14 and the slider 13 are fixedly connected by screws distributed along the circumference of the screw nut gland 19. The front end bearing 18 of the screw is located between the two thrust bearings 17, bearing axial and radial loads, and used to support and transmit axial force and reduce friction. The screw nut gland 19 provides stable support for the screw 15 to prevent deformation.

[0096] The rear end of the screw 15 is sequentially mounted with a rear retaining ring 20, a screw rear end bearing 21 and a bearing cover plate 22 from front to back; the screw rear end bearing 21 is used to transmit axial force and reduce friction; the rear retaining ring 20 and the bearing cover plate 22 are used to close the rear end surface of the screw 15 and protect various bearings in the screw nut assembly 11.

[0097] Furthermore, the rudder surface 5 includes a rudder surface body 28, a rudder connecting shaft 29, a rudder connecting shaft baffle 30 and a rudder surface side cover 31;

[0098] The front end of the rudder surface body 28 is a connecting column, on which a first group of holes I and a second group of holes II are arranged, the central axes of the two groups of holes are parallel to each other, the first group of holes I includes two holes I33 located on the inner side and symmetrically, and the second group of holes II includes two holes II34 located on the outer side and symmetrically; the steering gear connecting shaft 29 is inserted into the two holes I33 of the first group of holes I and the two steering gear connecting shaft mounting holes 32 on the frame body 6; one end face of the steering gear connecting shaft 29 is fixed with a rudder angle detection module baffle 27, and the other end face is fixed with a rudder angle detection module baffle 30, the rudder angle detection module baffle 27 and the steering gear connecting shaft baffle 30 protect the steering gear connecting shaft 29 from being hit and damaged by external objects;

[0099] The rear end of the rudder surface body 28 is the rudder surface wing surface, and the rudder surface side cover plate 31 is fixed on the rudder surface wing surface. The rudder surface side cover plate 31 is used to close the windward side of the rudder surface wing surface.

[0100] Furthermore, the connecting rod assembly 12 includes a crank connecting rod 23 and two connecting rod shafts 24, and the two connecting rod shafts 24 are respectively located at the front and rear ends of the crank connecting rod 23;

[0101] The connecting rod shaft 24 at the front end of the crank connecting rod 23 is inserted into the connecting rod shaft 24 mounting hole of the slider 13 of the screw nut assembly 11, and the connecting rod shaft 24 at the rear end of the crank connecting rod 23 is inserted into the second group of holes II of the rudder surface body 28 of the rudder surface 5; the connecting rod shaft 24 at the front end of the crank connecting rod 23 is higher than the connecting rod shaft 24 at the rear end of the crank connecting rod 23; when the slider 13 moves forward, the crank connecting rod 23 drives the rudder surface 5 to rotate upward, and when the slider 13 moves backward, the crank connecting rod 23 drives the rudder surface 5 to rotate downward.

[0102] Furthermore, the rudder angle detection module 4 includes a magnetic turntable 25, a magnetoresistive effect sensor 26 and a rudder angle detection module baffle 27;

[0103] The magnetic turntable 25 is fixed inside the baffle 27 of the rudder angle detection module, and the magnetic turntable 25 is protected in a semi-enclosed manner; the magnetoresistive effect sensor 26 is fixedly installed on the rear end surface of the frame body 6 of the frame 1 by screws, opposite to the magnetic turntable 25;

[0104] When the crank connecting rod 23 drives the control surface 5 to rotate, the magnetic turntable 25 rotates synchronously with the control surface 5, causing the magnetic field strength inside the magnetic turntable 25 to change, generating a magnetic field strength change signal, and the magnetoresistive effect sensor 26 detects the magnetic field strength change signal and transmits the magnetic field strength change signal to the computer. The computer collects and decodes the signal to obtain the rotation angle of the control surface 5.

[0105] The control method of the hypersonic wind tunnel dynamic test model Flap control surface servo system of the present invention comprises the following steps:

[0106] S10. Determine the control target of the steering gear system;

[0107] The Flap rudder servo system of the hypersonic wind tunnel dynamic test model works in constant force mode, and the working states include one or a combination of two or more of co-pushing, co-pulling, braking, and push-pull interlocking; it is necessary to design a servo controller dedicated to the stepper servo motor 2, and the servo controller adopts FPGA for core development. It is also necessary to design a dedicated electrical control program to control the rudder deflection angle of the driving rudder surface 5 accurately;

[0108] S20. Establishing a mathematical model of the servo controller of the stepping servo motor 2;

[0109] By Laplace transform, we can establish Fig.13 The mathematical model of the servo controller of the step servo motor 2 shown;

[0110] Torque , the mathematical model of the stepper servo motor 2 servo controller is simplified to:

[0111] ;

[0112] in ;

[0113] ;

[0114] in, is the rotation angle of the motor shaft relative to the initial position; is the DC bus voltage of the motor; is the electromagnetic time constant; is the motor time constant, ; is the inductor, is the resistance, is the load torque, is the electromotive force constant, is the torque coefficient; is the complex frequency variable in Laplace transform; then the transfer function of the motor is :

[0115] ;

[0116] in, It is the electromotive force transmission system. , is the electromotive force coefficient; is the torque transfer system, ; , , ; is the electromagnetic time coefficient, is the torque coefficient, is the back EMF value, is the magnetic field strength of the motor, is the diameter of the motor, is the current; is the input voltage;

[0117] Substituting the parameters, we get the transfer function of the motor :

[0118] ;

[0119] in, is the electromagnetic torque;

[0120] The driver amplifies the control signal output by the servo controller and drives the stepper servo motor 2. After mathematical modeling, a proportional link is formed in the system. ;

[0121] S30. Establishing a mathematical model of the transmission structure of the stepping servo motor 2;

[0122] The screw nut assembly 11 decelerates the rotational force output by the step servo motor 2 and transmits it to the connecting rod assembly 12. The connecting rod assembly 12 drives the control surface 5 to deflect to form a proportional link. ;make ;

[0123] S40. Establishing a mathematical model of the rudder angle detection module 4;

[0124] The rudder angle detection module 4 converts the deflection position feedback signal of the rudder surface 5 into an electrical signal and transmits it to the servo controller of the stepping servo motor 2, forming a proportional link in the system, which is recorded as ;

[0125] S50. Establish a steering gear control model;

[0126] The steering gear control model is shown in Fig.14 ;

[0127] The simplified electric servo transfer function is written in the form of a differential equation:

[0128] ;

[0129] in, is the DC bus voltage of the motor, is the deflection angle of rudder surface 5, is the input voltage, is the output voltage; according to the performance parameters of the selected step servo motor 2 and the rudder angle design index requirements, the theoretical parameters of the servo model are obtained as follows:

[0130] ;

[0131] The differential equation of the input and output of the servo system is as follows:

[0132] ;

[0133] S60. Control the rudder 5;

[0134] The servo controller sends a control signal to the electrical control program to drive the step servo motor 2 to rotate, and transmits power to the rudder surface 5 through the transmission module 3 to drive the rudder surface 5 to rotate. At the same time, the rudder angle detection module 4 feeds back the rudder angle measurement signal in real time to determine whether the rudder surface 5 has reached the specified position.

[0135] Embodiment: The servo system and control method of the Flap rudder surface of the hypersonic wind tunnel dynamic test model of this embodiment meet the following relevant technical indicators and requirements:

[0136] 1. Automatic locking and unlocking can be achieved, and the rudder torque is ≥60Nm;

[0137] 2. Load index: rated output torque of a single servo ≥ 50 Nm; maximum load torque ≥ 100 Nm; servo mass ≤ 5 kg;

[0138] 3. Movement indicators: movement range ≥ ± 30°, movement positioning accuracy 0.1°, repeatability accuracy 0.1°, servo movement speed ≥ 50° / s;

[0139] 4. Technical indicators of servo measurement and control: rudder angle measurement accuracy is better than 0.02°, rudder angle measurement real-time is better than 1ms, rudder surface 5 deflection delay error ≤5ms, servo overshoot ≤10%, servo system bandwidth (dynamic response) ≥5Hz.

[0140] The main components of the rudder system of the hypersonic wind tunnel dynamic test model Flap rudder surface of this embodiment are selected as follows:

[0141] The stepper servo motor 2 of this embodiment selects the Japanese MOONS' AM17R series stepper servo motor, which has a built-in high-resolution encoder with 20,000 pulses / turn, can provide precise positioning accuracy, and the positioning error is only ±1 pulse (0.018°). The maximum speed of the stepper servo motor 2 is 3000rpm and the maximum torque is 0.87Nm, which meets the use requirements of deflection angle and torque.

[0142] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and implementation modes. For those familiar with the art, all features disclosed in the present invention, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way without departing from the principles of the present invention. The present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. Hypersonic wind tunnel dynamic test model Flap control surface servo system, characterized by: The steering gear system comprises a frame (1), a stepping servo motor (2), a transmission module (3), a rudder angle detection module (4) and a rudder surface (5); the stepping servo motor (2) and the transmission module (3) are fixed on the frame (1), and the rudder angle detection module (4) is fixed on the rudder surface (5); The steering gear system drives the rudder surface (5) to deflect through the transmission module (3) to adjust the rudder surface deflection angle; at the same time, the rudder surface deflection angle is measured through the rudder deflection angle detection module (4); The frame (1) comprises a frame body (6), and the frame body (6) is a bilaterally symmetrical frame structure; a central cavity I of the frame body (6) is used for fixing and installing a lead screw nut assembly (11) of a transmission module (3); The lead screw nut assembly (11) decelerates the rotational force output by the step servo motor (2) and transmits it to the connecting rod assembly (12); There are two guide rails (16), which are symmetrically fixed in the central cavity I of the frame body (6); The slider (13) is of a bilaterally symmetrical structure; the central cavity II of the slider (13) matches the nut (14), and the bayonet holes on the left and right sides are respectively mounted on the guide rails (16) on the left and right sides; the left and right sides of the slider (13) extend forward symmetrically with semicircular protrusions II, and the two semicircular protrusions II are provided with connecting rod shaft (24) mounting holes that penetrate left and right; The front section of the lead screw (15) is fitted with a nut (14), and the lead screw (15) passes through the central cavity II of the slider (13) from the back to the front until the nut (14) is placed in the central cavity II of the slider (13); the stepping servo motor (2) drives the lead screw (15) to rotate through the coupling, driving the nut (14) to drive the slider (13) to move forward and backward along the guide rail (16); The front end of the lead screw (15) is provided with a first thrust bearing (17), a lead screw front end bearing (18), a second thrust bearing (17) and a lead screw nut gland (19) in sequence from front to back, and the nut (14) and the slider (13) are fixedly connected by screws distributed along the circumference of the lead screw nut gland (19); the lead screw front end bearing (18) is located between the two thrust bearings (17), bears axial and radial loads, is used to support and transmit axial force, and reduces friction; the lead screw nut gland (19) provides stable support for the lead screw (15) to prevent deformation; The rear end of the lead screw (15) is provided with a rear retaining ring (20), a lead screw rear end bearing (21) and a bearing cover plate (22) in sequence from front to rear; the lead screw rear end bearing (21) is used to transmit axial force and reduce friction; the rear retaining ring (20) and the bearing cover plate (22) are used to seal the rear end surface of the lead screw (15) and protect various bearings in the lead screw nut assembly (11).

2. The hypersonic wind tunnel dynamic test model Flap control surface servo system according to claim 1, characterized in that: The frame (1) further comprises a motor mounting seat (7), a lower cover plate (8), an upper cover plate (9) and a positioning pin (10); The front end surface of the frame body (6) is fixed with a motor mounting seat (7) by screws, and the step servo motor (2) is fixedly mounted on the motor mounting seat (7) by screws; a left-right symmetrical semicircular protrusion I is extended from the rear end of the frame body (6), and the two semicircular protrusions I are provided with left-right penetrating steering gear connecting shaft mounting holes (32); the lower cover plate (8) and the upper cover plate (9) are respectively fixed to the upper surface and the lower surface of the frame body (6) by screws, and are used to close the central cavity I of the frame body (6); the positioning pin (10) is inserted into the outer frame of the frame body (6) from top to bottom, and is used to locate the installation position of the steering gear system on the dynamic test model; The frame body (6), the motor mounting seat (7), the lower cover plate (8) and the upper cover plate (9) are all made of 30CrMnSiA material, meeting the strength requirements, rigidity requirements and overall weight reduction requirements of the steering gear system.

3. The hypersonic wind tunnel dynamic test model Flap control surface servo system according to claim 2, characterized in that: The coupling comprises an intermediate disk arranged on the motor shaft of the step servo motor (2) and two grooves arranged on the lead screw (15) of the lead screw nut assembly (11), the intermediate disk matching the grooves to lock the motor shaft and the lead screw (15); The coupling compensates for the relative displacement between the motor shaft and the lead screw (15) during installation and operation, and the relative displacement includes axial displacement, radial displacement and angular displacement.

4. The hypersonic wind tunnel dynamic test model Flap control surface servo system according to claim 3, characterized in that: The rudder surface (5) comprises a rudder surface body (28), a rudder connecting shaft (29), a rudder connecting shaft baffle (30) and a rudder surface side cover plate (31); The front end of the rudder surface body (28) is a connecting column, on which a first group of holes I and a second group of holes II are arranged, the central axes of the two groups of holes are parallel to each other, the first group of holes I includes two holes I (33) located on the inner side and symmetrically, and the second group of holes II includes two holes II (34) located on the outer side and symmetrically. The steering gear connecting shaft (29) is inserted into the two holes I (33) of the first group of holes I and the two steering gear connecting shaft mounting holes (32) on the frame body (6). A rudder angle detection module baffle (27) is fixed on one end face of the steering gear connecting shaft (29), and a rudder angle detection module baffle (30) is fixed on the other end face. The rudder angle detection module baffle (27) and the steering gear connecting shaft baffle (30) protect the steering gear connecting shaft (29) from being hit and damaged by external objects. The rear end of the rudder surface body (28) is a rudder surface wing surface, and a rudder surface side cover plate (31) is fixed on the rudder surface wing surface. The rudder surface side cover plate (31) is used to close the windward surface of the rudder surface wing surface.

5. The hypersonic wind tunnel dynamic test model Flap control surface servo system according to claim 4, characterized in that: The connecting rod assembly (12) comprises a crank connecting rod (23) and two connecting rod shafts (24), wherein the two connecting rod shafts (24) are respectively located at the front and rear ends of the crank connecting rod (23); The connecting rod shaft (24) at the front end of the crank connecting rod (23) is inserted into the connecting rod shaft (24) mounting hole of the slider (13) of the screw nut assembly (11), and the connecting rod shaft (24) at the rear end of the crank connecting rod (23) is inserted into the second group of holes II of the rudder surface body (28) of the rudder surface (5); the connecting rod shaft (24) at the front end of the crank connecting rod (23) is higher than the connecting rod shaft (24) at the rear end of the crank connecting rod (23); when the slider (13) moves forward, the crank connecting rod (23) drives the rudder surface (5) to rotate upward, and when the slider (13) moves backward, the crank connecting rod (23) drives the rudder surface (5) to rotate downward.

6. The hypersonic wind tunnel dynamic test model Flap control surface servo system according to claim 5, characterized in that: The rudder angle detection module (4) comprises a magnetic turntable (25), a magnetoresistive effect sensor (26) and a rudder angle detection module baffle (27); A magnetic turntable (25) is fixed on the inner side of the baffle plate (27) of the rudder angle detection module, and the magnetic turntable (25) is protected in a semi-enclosed manner; a magnetoresistive effect sensor (26) is fixedly mounted on the rear end surface of the frame body (6) of the frame (1) by means of screws, and is opposite to the magnetic turntable (25); When the crank connecting rod (23) drives the control surface (5) to rotate, the magnetic turntable (25) rotates synchronously with the control surface (5), causing the magnetic field intensity inside the magnetic turntable (25) to change, generating a magnetic field intensity change signal, and the magnetic resistance effect sensor (26) detects the magnetic field intensity change signal and transmits the magnetic field intensity change signal to the computer, which collects and decodes the signal to obtain the rotation angle of the control surface (5).

7. A control method for a hypersonic wind tunnel dynamic test model Flap rudder surface servo system, which is used for the hypersonic wind tunnel dynamic test model Flap rudder surface servo system as claimed in any one of claims 1 to 6, characterized in that it comprises the following steps: S10. Determine the control target of the steering gear system; The Flap rudder servo system of the hypersonic wind tunnel dynamic test model works in a constant force mode, and the working state includes one or a combination of two or more of co-pushing, co-pulling, braking, and push-pull interlocking; it is necessary to design a servo controller dedicated to the stepping servo motor (2), and the servo controller adopts FPGA for core development. It is also necessary to design a dedicated electrical control program to control the driving rudder surface (5) to the correct rudder deflection angle; S20. Establish a mathematical model of the servo controller of the stepping servo motor (2); Torque , the mathematical model of the stepper servo motor (2) servo controller is: ； ； ； in, is the rotation angle of the motor shaft relative to the initial position; is the DC bus voltage of the motor; is the electromagnetic time constant; is the motor time constant, ; is the inductor, is the resistance, is the load torque, is the electromotive force constant, is the torque coefficient; is the complex frequency variable in Laplace transform; Transfer function of the motor : ； in, It is the electromotive force transmission system. is the electromagnetic torque; is the input voltage; The driver amplifies the control signal output by the servo controller and drives the stepper servo motor (2). After mathematical modeling, a proportional link is formed in the system. ; S30. Establishing a mathematical model of the transmission structure of the stepping servo motor (2); The connecting rod assembly (12) drives the rudder surface (5) to deflect to form a proportional link ;make ; S40. Establishing a mathematical model of the rudder angle detection module (4); The rudder angle detection module (4) converts the deflection position feedback signal of the rudder surface (5) into an electrical signal and transmits it to the servo controller of the stepping servo motor (2), forming a proportional link in the system, which is recorded as ; S50. Establish a steering gear control model; The simplified electric servo transfer function is written in the form of a differential equation: ； in, is the DC bus voltage of the motor, is the deflection angle of the rudder surface (5), is the input voltage, is the output voltage; according to the performance parameters of the selected step servo motor (2) and the rudder angle design index requirements, the theoretical parameters of the servo model are obtained as follows: ； The differential equation of the input and output of the servo system is as follows: ； S60. Control the rudder (5); The servo controller sends a control signal to the electrical control program to drive the step servo motor (2) to rotate, and transmits power to the rudder surface (5) through the transmission module (3), driving the rudder surface (5) to rotate. At the same time, the rudder angle detection module (4) feeds back the rudder angle measurement signal in real time to determine whether the rudder surface (5) has reached the specified position.

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