Wind tunnel magnetic suspension balance control system and control method

Abstract

The invention discloses a wind tunnel magnetic suspension balance control system and control method. The system comprises a multi-axis synchronous controller, an eddy current displacement sensor array, a power amplifier and an electromagnetic actuator array. The eddy current displacement sensor array is used for acquiring each degree-of-freedom position of the model; the electromagnetic actuator array and the power amplifier are used for generating electromagnetic force so as to control model displacement; the eddy current sensors and the electromagnetic actuators are arranged in an independent differential mode, electromagnetic force and displacement coupling between components can be reduced, linear control is improved, and therefore the aerodynamic force measurement precision is improved; the multi-axis synchronous controller takes the control target of maintaining the model at the absolute geometric center of each electromagnet group, adopts a composite decoupling control strategy, solves aerodynamic force by monitoring the current variation of a power amplifier, supports online reconfiguration of control parameters, and realizes wide-range and high-precision measurement. According to the invention, low-coupling and high-precision control of the balance system in the wind tunnel based on differential active magnetic suspension is realized.

Description

Technical Field

[0001] This invention relates to the field of wind tunnel testing and measurement technology, and in particular to a wind tunnel magnetic levitation balance control system and control method. Background Technology

[0002] The wind tunnel balance is a core device used in wind tunnel experiments to accurately measure the aerodynamic loads of aircraft models. Currently, the most widely used wind tunnel balances are strain gauge balances. Strain gauge balances indirectly calculate aerodynamic forces by measuring the strain of elastic elements. Although the technology is mature, it has the following inherent defects: (1) there is a coupling effect between the various measurement components, which requires complex decoupling calculations; (2) the range is fixed, which cannot adapt to the load measurement needs of different magnitudes, and the measurement range is limited.

[0003] Electromagnetic suspension balances utilize magnetic levitation technology to achieve contactless support, thus mitigating the interference problem of the support structure to some extent. However, most existing electromagnetic suspension balance technologies are based on the principle of magnetic bearings, which are primarily used for supporting rotating machinery. These bearings typically control only five degrees of freedom, often neglecting to control the roll degree of freedom or only providing passive damping. This design philosophy prevents existing electromagnetic suspension balances from accurately measuring the important aerodynamic component of roll torque.

[0004] In addition, existing electromagnetic suspension balances have the following technical limitations: (1) There is a contradiction between system stiffness and measurement sensitivity, making it difficult to balance dynamic performance and measurement accuracy; (2) The electromagnetic coupling effect between the degrees of freedom affects the measurement accuracy; (3) The range adjustment is difficult and cannot be flexibly adapted to different test conditions.

[0005] Therefore, there is an urgent need in this field for a new type of wind tunnel balance control system that can achieve accurate measurement of all six components and has a wide range adaptability. Summary of the Invention

[0006] The purpose of this invention is to provide a wind tunnel magnetic levitation balance control system and control method. This control system can realize the accurate measurement of six aerodynamic components, including rolling torque, by a wind tunnel magnetic levitation six-component balance, and has the characteristics of wide range and low coupling.

[0007] This invention provides a wind tunnel magnetic levitation balance control system, comprising: A multi-axis synchronous controller is used to execute a six-degree-of-freedom composite decoupling control algorithm; An eddy current displacement sensor array, comprising multiple eddy current sensors, is used to monitor the displacement of the model's connecting axis in six degrees of freedom in real time; the six degrees of freedom include three translational degrees of freedom (X, Y, Z) and three rotational degrees of freedom (roll, pitch, yaw). A power amplifier is used to generate excitation current to drive an electromagnet to produce electromagnetic force. An electromagnetic actuator array, comprising multiple sets of electromagnets, is used to generate electromagnetic force to control the displacement of the model's connecting shafts; The model connection axis is used to suspend the system and connect to the test model.

[0008] Furthermore, the eddy currents located in the sensor array include: Two sets of differentially arranged Y-axis eddy current sensors are used to measure the displacement of the normal Y1 axis and Y2 axis, respectively. They are arranged at both ends of the connecting axis of the model and located in the normal mirror symmetry plane. Two sets of differentially arranged Z-axis eddy current sensors are used to measure the lateral displacement of the Z1 and Z2 axes, respectively, and are arranged at the front and rear ends of the model connecting axis and located in the upper and lower symmetry planes. Four sets of differentially arranged X-direction eddy current sensors are used to measure axial X displacement. The four sets of X-direction eddy current sensors are arranged in a cross shape. A set of differentially arranged rotating eddy current sensors is used to measure the rotation angle J; Among them, the lateral Z1 axis and the normal Y1 axis are in the same plane and are orthogonal to each other, and the lateral Z2 axis and the normal Y2 axis are in the same plane and are orthogonal to each other.

[0009] Furthermore, the electromagnetic actuator array includes: Two sets of differentially arranged normal electromagnets are used to measure the normal force Y and pitching moment MZ. They are arranged at both ends of the model connecting axis and located within the normal mirror symmetry plane. Two sets of differentially arranged lateral electromagnets are used to measure the lateral force Z and yaw moment MY. They are arranged at both ends of the model connecting shaft and located within the upper and lower symmetry planes. A set of differentially arranged axial electromagnets is used to measure axial resistance Q; A set of differentially arranged rotating electromagnets is used to measure the rolling torque MX; The normal electromagnet and the lateral electromagnet located at the same end of the connecting axis of the model are orthogonal.

[0010] Furthermore, the multi-axis synchronous controller aims to maintain the model connecting axis at the absolute geometric center position of each electromagnet group in the electromagnetic actuator array, and maintains the constant pose of the model connecting axis by adjusting the electromagnet current.

[0011] Furthermore, the multi-axis synchronous controller is equipped with a control parameter reconfiguration module for adjusting control parameters online or offline, enabling the system to perform wide-range measurements of different loads.

[0012] Furthermore, it also includes a filtering device, which is disposed in the input and output paths of the multi-axis synchronous controller and the power amplifier, for suppressing noise and optimizing system bandwidth and signal-to-noise ratio.

[0013] Furthermore, the multi-axis synchronous controller adopts the NI CompactRIO hardware platform based on FPGA to detect the displacement signal of the eddy current displacement sensor array and simultaneously control the current of each electromagnet to achieve composite decoupled control of six-degree-of-freedom displacement.

[0014] Furthermore, the power amplifier is a linear amplifier with an output current ripple coefficient of less than 1‰.

[0015] Furthermore, the multi-axis synchronous controller is also equipped with a six-component static and dynamic calibration module, which is used to establish the mapping relationship between the current change and the six-component aerodynamic force and torque. The six-component aerodynamic force and torque are obtained by measuring the current change of the power amplifier.

[0016] This invention provides a control method for a wind tunnel magnetic levitation balance, based on the control system, comprising the following steps: S1. The initial control parameters are preset by the multi-axis synchronous controller, and the power amplifier outputs the initial excitation current to drive the electromagnetic actuator array to generate the initial electromagnetic force, so that the model connecting shaft drives the test model to be stably suspended at the absolute geometric center of each group of electromagnets. S2. During the wind tunnel test, the eddy current displacement sensor array collects the six-degree-of-freedom displacement signals of the model's connecting shaft in real time and transmits them to the multi-axis synchronous controller; S3. When the wind tunnel generates airflow that causes the test model to be subjected to aerodynamic forces, the multi-axis synchronous controller adjusts the electromagnet current in real time to make the electromagnetic actuator array generate corresponding restoring forces to maintain the stability of the model's connecting axis. At this time, by measuring the change in current of the power amplifier and combining it with the pre-calibrated current-force relationship matrix, the six aerodynamic components of normal force, pitching moment, lateral force, yaw moment, rolling moment and axial drag can be calculated synchronously. S4. If the load changes, the control parameter reconfiguration module of the multi-axis synchronous controller dynamically adjusts the control parameters to ensure the stability and measurement accuracy of the system under different load conditions, and finally outputs six-component aerodynamic measurement data.

[0017] In summary, compared with the prior art, the present invention has the following advantages: The technical solution provided by this invention obtains the precise position of each degree of freedom of the test model by setting up an eddy current displacement sensor array, and generates electromagnetic force by setting up an electromagnetic actuator array and a power amplifier to control the displacement of the test model. The eddy current displacement sensor array and the electromagnetic actuator array are arranged independently and differentially, which helps to reduce the coupling between electromagnetic force and displacement components, improve linear control, and thus improve the accuracy of aerodynamic force measurement. The multi-axis synchronous controller aims to maintain the test model at the absolute geometric center of each group of electromagnets, and adopts a composite decoupling control strategy. It calculates aerodynamic force by monitoring the current change of the power amplifier and supports online reconfiguration of control parameters to achieve wide-range, high-precision measurement. This invention realizes low-coupling, high-precision control of a wind tunnel balance system based on differential active magnetic levitation. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a structural block diagram of the control system in an embodiment of the present invention; Figure 2 This is a schematic diagram showing the layout of the eddy current displacement sensor array in an embodiment of the present invention; Figure 3 This is a schematic diagram showing the layout of the electromagnetic actuator array in an embodiment of the present invention; Figure 4 This is a block diagram of the aerodynamic measuring device of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1-Multi-axis synchronous controller; 2-Eddy current displacement sensor array; 201-First Y-axis eddy current sensor; 202-First Z-axis eddy current sensor; 203-Second Y-axis eddy current sensor; 204-Second Z-axis eddy current sensor; 205-Third Y-axis eddy current sensor; 206-Third Z-axis eddy current sensor; 207-Fourth Y-axis eddy current sensor; 208-Fourth Z-axis eddy current sensor; 209-First X-axis eddy current sensor; 210-Second X-axis eddy current sensor; 211-Third X-axis eddy current sensor; 212-Fourth X-axis eddy current sensor; 213-Fifth X-axis eddy current sensor; 214-Sixth X-axis eddy current sensor; 215-Seventh X-axis eddy current sensor; 216-Eighth X-direction eddy current sensor; 217-First rotating eddy current sensor; 218-Second rotating eddy current sensor; 219-Thrust disk; 3-Power amplifier; 4-Electromagnetic actuator array; 401-First normal electromagnet; 402-Second normal electromagnet; 403-First lateral electromagnet; 404-Second lateral electromagnet; 405-Third normal electromagnet; 406-Fourth normal electromagnet; 407-Third lateral electromagnet; 408-Fourth lateral electromagnet; 409-First axial electromagnet; 410-Second axial electromagnet; 411-First rotating electromagnet; 412-Second rotating electromagnet; 5-Model connecting shaft; 6-Filtering device; 7-Experimental model; 8-Wind tunnel support; 9-Mechanical backup protection device. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Example A wind tunnel magnetic levitation balance control system is disclosed. The wind tunnel application scenario of this invention is mainly high-precision aerodynamic testing of aircraft models.

[0025] like Figure 1 As shown, it includes a multi-axis synchronous controller 1, an eddy current displacement sensor array 2, a power amplifier 3, an electromagnetic actuator array 4, and a model connection axis 5. The specific contents are as follows: The displacement of the model connecting shaft 5, which is fixedly connected to the test model, in six degrees of freedom is monitored in real time by the eddy current displacement sensor array 2. The multi-axis synchronous controller 1 aims to maintain the model connecting shaft 5 at the absolute geometric center of each differentially arranged set of electromagnets. When the wind tunnel generates airflow and the model connecting shaft 5 is subjected to aerodynamic forces, the multi-axis synchronous controller 1 adjusts the electromagnet current in real time to make the electromagnetic actuator array 4 generate a corresponding restoring force to maintain the stability of the model connecting shaft 5. At this time, by measuring the change in current of the power amplifier 3 and combining it with the pre-calibrated current-force relationship matrix, the six aerodynamic components of normal force, pitching moment, lateral force, yaw moment, rolling moment and axial drag can be calculated synchronously. The control parameter reconfiguration module enables the system to have a wide range measurement capability from the smallest to the largest load, and finally realizes high-precision aerodynamic measurement under non-contact support.

[0026] like Figure 1 , Figure 2 and Figure 3As shown, the eddy current displacement sensor array 2 is used to monitor the displacement of the model connecting shaft 5 in six degrees of freedom in real time. The elements are arranged differentially, and each component is arranged independently, which improves the displacement measurement accuracy and is used for decoupling control, thus improving the model's position control accuracy and consequently, the aerodynamic measurement accuracy. The specific layout is as follows: Two sets of mutually orthogonal eddy current sensors are arranged at the Y1-O-Z1 plane of the model connecting shaft 5. The first set is located along the Y1 axis: including a first Y-axis eddy current sensor 201 and a second Y-axis eddy current sensor 203, used to detect the normal displacement of the model connecting shaft 5 in the Y1-O-Z1 plane; the second set is located along the Z1 axis: including a first Z-axis eddy current sensor 202 and a second Z-axis eddy current sensor 204, used to detect the lateral displacement of the model connecting shaft 5 in the Y1-O-Z1 plane. After the multi-axis synchronous controller 1 detects the first set of eddy current displacement signals in the Y1 axis, it changes the current of the first normal electromagnet 401 and the second normal electromagnet 402 to control the displacement of the model connecting shaft 5 to stabilize in the middle position; after the multi-axis synchronous controller 1 detects the second set of eddy current displacement signals in the Z1 axis, it changes the current of the first lateral electromagnet 403 and the second lateral electromagnet 404 to control the displacement of the model connecting shaft 5 to stabilize in the middle position.

[0027] The eddy current displacement sensor array 2 is further arranged as follows: two sets of mutually orthogonal eddy current sensors are arranged at the Y2-O'-Z2 plane of the model connecting axis 5. The first set is located along the Y2 axis and includes a third Y-axis eddy current sensor 205 and a fourth Y-axis eddy current sensor 207, used to detect the normal displacement of the model connecting axis 5 at the Y2-O'-Z2 plane; the second set is located along the Z2 axis and includes a third Z-axis eddy current sensor 206 and a fourth Z-axis eddy current sensor 208, used to detect the lateral displacement of the model connecting axis 5 at the Y2-O'-Z2 plane. After detecting the first set of eddy current displacement signals along the Y2 axis, the multi-axis synchronous controller 1 changes the currents of the third normal electromagnet 405 and the fourth normal electromagnet 406 to control the displacement of the model connecting axis 5 to stabilize at the intermediate position; after detecting the second set of eddy current displacement signals along the Z2 axis, the multi-axis synchronous controller 1 changes the currents of the third lateral electromagnet 407 and the fourth lateral electromagnet 408 to control the displacement of the model connecting axis 5 to stabilize at the intermediate position.

[0028] The eddy current displacement sensor array 2 is further arranged in the following specific layout: four sets of X-axis eddy current sensors are symmetrically arranged on both sides of the model thrust disk 219 of the model connecting shaft 5. The four sets of X-axis eddy current sensors are evenly distributed and are used to accurately measure the displacement of the model connecting shaft 5 in the X-axis direction. The first set includes the first X-axis eddy current sensor 209 and the second X-axis eddy current sensor 210. The second set includes the third X-axis eddy current sensor 211 and the fourth X-axis eddy current sensor 212. The third set includes the fifth X-axis eddy current sensor 213 and the sixth X-axis eddy current sensor 214. The fourth set includes the seventh X-axis eddy current sensor 215 and the eighth X-axis eddy current sensor 216. The system can accurately detect the coupling interference of the model connecting shaft 5 on the axial displacement when it moves around the axis in the normal and lateral directions. After detecting the displacement signal, the multi-axis synchronous controller 1 controls the current of the first axial electromagnet 409, the second axial electromagnet 410, the first normal electromagnet 401, the second normal electromagnet 402, the third normal electromagnet 405, the fourth normal electromagnet 406, the first lateral electromagnet 403, the second lateral electromagnet 404, the third lateral electromagnet 407, and the fourth lateral electromagnet 408 through a composite decoupling control strategy, thereby controlling the displacement of the model connecting shaft 5 to be stable in the middle position.

[0029] The eddy current displacement sensor array 2 is further arranged as follows: a first rotating eddy current sensor 217 and a second rotating eddy current sensor 218 are arranged to detect the displacement on the rotational degree of freedom J of the model connecting shaft 5. The first rotating eddy current sensor 217 and the second rotating eddy current sensor 218 are arranged at corresponding circumferential positions on the model connecting shaft 5 and are located within the rotational symmetry plane. After detecting the displacement signal, the multi-axis synchronous controller 1 controls the current of the first rotating electromagnet 411 and the second rotating electromagnet 412 to control the model connecting shaft 5 to stabilize at the intermediate angle on the rotational degree of freedom J.

[0030] Combination Figure 1 and Figure 3The electromagnetic actuator array 4 comprises multiple differential electromagnet groups specifically configured for measuring six components of force and torque. The specific layout includes: two sets of mutually orthogonal electromagnets arranged at the Y1-O-Z1 plane of the model connecting axis 5, namely the first set and the second set. The first set includes a first normal electromagnet 401 and a second normal electromagnet 402, and the second set includes a first lateral electromagnet 403 and a second lateral electromagnet 404. Two sets of mutually orthogonal electromagnet groups are arranged at the Y2-O'-Z2 plane of the model connecting axis 5, namely the third set and the fourth set. The third set includes a third normal electromagnet 405 and a fourth normal electromagnet 406, and the fourth set includes a third lateral electromagnet 407 and a fourth lateral electromagnet 408. The first and third sets of electromagnets jointly suspend the model's connecting shaft 5 in the normal direction, simultaneously measuring the normal force Y and pitching moment MZ; the second and fourth sets of electromagnets jointly suspend the model's connecting shaft 5 in the lateral direction, simultaneously measuring the lateral force Z and yaw moment MY.

[0031] Combination Figure 1 and Figure 3 The electromagnetic actuator array 4 layout further includes: a fifth set of electromagnets arranged at the axial midpoint of the supporting model connecting shaft 5, the fifth set of electromagnets including a first axial electromagnet 409 and a second axial electromagnet 410, the first axial electromagnet 409 and the second axial electromagnet 410 being located on both sides of the thrust disk 219, used for levitation control of X-axis displacement and measurement of axial resistance Q. A sixth set of electromagnets is arranged on the rotational degree of freedom J of the model connecting shaft 5, the sixth set of electromagnets including a first rotary electromagnet 411 and a second rotary electromagnet 412, used for levitation control of the model connecting shaft 5 to stabilize at the midpoint angle on the rotational degree of freedom J and measurement of rolling torque MX.

[0032] like Figure 4 As shown, the device for aerodynamic measurement using the control system provided by this invention mainly includes a model connecting shaft 5 (equivalent to a magnetic balance float), a test model 7, and a wind tunnel support 8. One end of the model connecting shaft 5 is connected to the wind tunnel support 8, and the other end is fixedly connected to the test model 7. It also includes a mechanical backup protection device 9, used to support and protect the test model in the event of a power outage or system failure. The mechanical backup protection device 9 can be a conventional device in the art.

[0033] In this embodiment, the power amplifier 3 is a current-type analog linear amplifier, and its output current ripple coefficient needs to be less than 1‰ to ensure the accuracy of aerodynamic measurement.

[0034] The multi-axis synchronous controller 1 aims to maintain the float at the absolute geometric center of each group of electromagnets. It maintains a constant pose of the model's connecting axis 5 by adjusting the current of each electromagnet. The multi-axis synchronous controller 1 utilizes an FPGA-based NI CompactRIO hardware platform to precisely detect the displacement signal of the eddy current displacement sensor array 2 at high frequency, while simultaneously controlling the current of each electromagnet in the electromagnetic actuator array 4, achieving composite decoupled control of the displacement of the model's connecting axis 5. The multi-axis synchronous controller 1 includes a control parameter reconfiguration module for online or offline adjustment of control parameters, enabling accurate measurement of a wide range of loads from minimal to maximum. The multi-axis synchronous controller 1 also includes a six-component static and dynamic calibration module to establish the mapping relationship between current changes and six-component aerodynamic forces and torques. These six-component aerodynamic forces and torques are obtained by measuring the current changes of the power amplifier.

[0035] like Figure 1 As shown, it also includes a filter device 6, which is set in the input and output paths of the multi-axis synchronous controller 1 and the power amplifier 3, to suppress noise and optimize system bandwidth and signal-to-noise ratio.

[0036] It should be noted that: in this embodiment, each group of eddy current sensors in the eddy current displacement sensor array 2 is arranged differentially; and each group of electromagnets in the electromagnetic actuator array 4 is arranged differentially.

[0037] The method for controlling a wind tunnel magnetic levitation balance using the above-mentioned control system includes the following steps: S1. By presetting the initial control parameters through the multi-axis synchronous controller 1, the power amplifier 3 outputs the initial excitation current to drive the electromagnetic actuator array 4 to generate the initial electromagnetic force, so that the model connecting shaft 5 drives the test model to be stably suspended at the absolute geometric center of each group of magnets. S2. During the wind tunnel test, the eddy current displacement sensor array 2 collects the six-degree-of-freedom displacement signals of the model connecting axis 5 in real time and transmits them to the multi-axis synchronous controller 1. S3. When the wind tunnel generates airflow that causes the test model to be subjected to aerodynamic forces, the multi-axis synchronous controller 1 adjusts the electromagnet current in real time to make the electromagnetic actuator array 4 generate a corresponding restoring force to keep the model connection axis 5 stable. At this time, by measuring the change in current of the power amplifier 3 and combining it with the pre-calibrated current-force relationship matrix, the six aerodynamic components of normal force, pitching moment, lateral force, yaw moment, rolling moment and axial drag can be calculated synchronously. S4. If the load changes, such as the change in current exceeding the preset threshold, the control parameter reconfiguration module dynamically adjusts the control parameters to ensure the stability and measurement accuracy of the system under different load conditions, and finally outputs six-component aerodynamic measurement data.

[0038] Compared with the prior art, the present invention has the following advantages: I. The wind tunnel magnetic levitation balance control system proposed in this invention adopts a high-precision eddy current displacement sensor array and sets up differential arrangement of each unit and independent layout between each component, which improves the measurement accuracy of displacement, reduces the displacement coupling effect between degrees of freedom, and thus improves the accuracy of aerodynamic measurement.

[0039] Second, the invention sets up an orthogonal layout for the longitudinal and lateral electromagnetic actuator array, which reduces the electromagnetic force coupling between components; the electromagnets and eddy current sensors are arranged on the same plane, which is beneficial for high-precision displacement control.

[0040] Third, the multi-axis synchronous controller in this invention uses a composite decoupling control strategy to position the model at the absolute geometric center of each differential electromagnet group, reducing the coupling interference between each measurement component. It only needs to establish an accurate mapping relationship between the current change and the aerodynamic force and torque, which reduces the difficulty of electromagnetic force calibration.

[0041] Fourth, the multi-axis synchronous controller in this invention is equipped with a control parameter reconfiguration module, which adopts online parameter configuration and realizes a wide range measurement of a single balance from the smallest to the largest load.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wind tunnel magnetic levitation balance control system, characterized in that, include: A multi-axis synchronous controller is used to execute a six-degree-of-freedom composite decoupling control algorithm; An eddy current displacement sensor array, comprising multiple eddy current sensors, is used to monitor the displacement of the model's connecting axis in six degrees of freedom in real time; the six degrees of freedom include three translational degrees of freedom (X, Y, Z) and three rotational degrees of freedom (roll, pitch, yaw). A power amplifier is used to generate excitation current to drive an electromagnet to produce electromagnetic force. An electromagnetic actuator array, comprising multiple sets of electromagnets, is used to generate electromagnetic force to control the displacement of the model's connecting shafts; The model connection axis is used to suspend the system and connect to the test model.

2. The control system according to claim 1, characterized in that, The eddy current displacement sensor array includes: Two sets of differentially arranged Y-axis eddy current sensors are used to measure the displacement of the normal Y1 axis and Y2 axis, respectively. They are arranged at both ends of the connecting axis of the model and located in the normal mirror symmetry plane. Two sets of differentially arranged Z-axis eddy current sensors are used to measure the displacement of the normal Z1 axis and Z2 axis, respectively; they are arranged at both ends of the model connecting axis and located within the upper and lower symmetry planes; Four sets of differentially arranged X-direction eddy current sensors are used to measure axial X displacement. The four sets of X-direction eddy current sensors are arranged in a cross shape. A set of differentially arranged rotating eddy current sensors is used to measure the rotation angle J; Among them, the lateral Z1 axis and the normal Y1 axis are in the same plane and are orthogonal to each other, and the lateral Z2 axis and the normal Y2 axis are in the same plane and are orthogonal to each other.

3. The control system according to claim 2, characterized in that, The electromagnetic actuator array includes: Two sets of differentially arranged normal electromagnets are used to measure the normal force Y and pitching moment MZ. They are arranged at both ends of the model connecting axis and located within the normal mirror symmetry plane. Two sets of differentially arranged lateral electromagnets are used to measure the lateral force Z and yaw moment MY. They are positioned at both ends of the model's connecting axis and within the upper and lower symmetry planes; A set of differentially arranged axial electromagnets is used to measure axial resistance Q; A set of differentially arranged rotating electromagnets is used to measure the rolling torque MX; The normal electromagnet and the lateral electromagnet located at the same end of the connecting axis of the model are orthogonal.

4. The control system according to claim 3, characterized in that, The multi-axis synchronous controller aims to maintain the model connection axis at the absolute geometric center of each group of electromagnets in the electromagnetic actuator array, and maintains the model connection axis pose constant by adjusting the electromagnet current.

5. The control system according to claim 1, characterized in that, The multi-axis synchronous controller is equipped with a control parameter reconfiguration module, which is used to adjust the control parameters online or offline, so as to realize the system's wide range measurement of different loads.

6. The control system according to claim 1, characterized in that, It also includes a filtering device, which is installed in the input and output paths of the multi-axis synchronous controller and the power amplifier, to suppress noise and optimize system bandwidth and signal-to-noise ratio.

7. The control system according to claim 1, characterized in that, The multi-axis synchronous controller uses the NI CompactRIO hardware platform based on FPGA to detect the displacement signal of the eddy current displacement sensor array and control the current of each electromagnet at the same time, so as to realize the composite decoupled control of six-degree-of-freedom displacement.

8. The control system according to claim 1, characterized in that, The power amplifier is a linear amplifier with an output current ripple coefficient of less than 1‰.

9. The control system according to claim 1, characterized in that, The multi-axis synchronous controller is also equipped with a six-component static and dynamic calibration module, which is used to establish the mapping relationship between the current change and the six-component aerodynamic force and torque. The six-component aerodynamic force and torque are obtained by measuring the current change of the power amplifier.

10. A control method for a wind tunnel magnetic levitation balance, characterized in that, The control system based on any one of claims 1-9 includes the following steps: S1. The initial control parameters are preset by the multi-axis synchronous controller, and the power amplifier outputs the initial excitation current to drive the electromagnetic actuator array to generate the initial electromagnetic force, so that the model connecting shaft drives the test model to be stably suspended at the absolute geometric center of each group of electromagnets. S2. During the wind tunnel test, the eddy current displacement sensor array collects the six-degree-of-freedom displacement signals of the model's connecting shaft in real time and transmits them to the multi-axis synchronous controller; S3. When the wind tunnel generates airflow that causes the test model to be subjected to aerodynamic forces, the multi-axis synchronous controller adjusts the electromagnet current in real time to make the electromagnetic actuator array generate corresponding restoring forces to maintain the stability of the model's connecting axis. At this time, by measuring the change in current of the power amplifier and combining it with the pre-calibrated current-force relationship matrix, the six aerodynamic components of normal force, pitching moment, lateral force, yaw moment, rolling moment and axial drag can be calculated synchronously. S4. If the load changes, the control parameter reconfiguration module of the multi-axis synchronous controller dynamically adjusts the control parameters to ensure the stability and measurement accuracy of the system under different load conditions, and finally outputs six-component aerodynamic measurement data.

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