A signal acquisition device applied to a wireless rotating strain balance in a wind tunnel

Abstract

The present invention is a signal acquisition device applied to a wireless rotating strain balance in a wind tunnel. The present invention relates to the technical field of strain balance data acquisition. Aiming at the technical problem that the traditional wind tunnel strain balance measurement scheme based on slip rings cannot implement the test of a rotating propeller, the functional modules are highly integrated. Signal acquisition is realized by using three circuit boards, namely an acquisition board, a main control board, and a power supply and angle measurement board, and the acquired data is sent to a control computer in a wireless manner. At the same time, a structure combining a rotor and a stator is invented. The rotor part is combined with the rotating balance, and the stator part is combined with the fixing device, so as to realize high-precision measurement of the signals of the rotating balance.

Description

Technical Field

[0001] The present invention relates to the technical field of strain balance data acquisition, and is a signal acquisition device applied to a wireless rotating strain balance in a wind tunnel. Background Art

[0002] A wind tunnel test refers to an aerodynamic test method in which an aircraft or other object model is placed in a wind tunnel to study the gas flow and its interaction with the model, so as to understand the aerodynamic characteristics of the actual aircraft or other object.

[0003] The theoretical basis of wind tunnel tests is the principle of kinematic relativity and the principle of flow similarity. According to the principle of relativity, the aerodynamic force acting on an aircraft flying in still air is the same as that when the aircraft is stationary and the air blows in the opposite direction at the same speed. However, the frontal area of an aircraft is relatively large. For example, the wingspan of an aircraft is a few meters or more than ten meters at a small scale, and dozens of meters at a large scale (the wingspan of a Boeing 747 is 60 meters). To make the airflow with such a large frontal area blow at a speed equivalent to the flight speed, the power consumption will be astonishing. According to the similarity principle, the aircraft can be made into a geometrically similar small-scale model. As long as certain similarity parameters are kept consistent, the test airflow speed can also be lower than the flight speed within a certain range, and the aerodynamic force acting on the aircraft during actual flight can be deduced based on the test results.

[0004] The theoretical basis of wind tunnel tests is the principle of flow similarity. Due to limitations in aspects such as the size, structure, material, model, and test gas of the wind tunnel, it is impossible to achieve complete similarity with real conditions in wind tunnel tests. Usually, wind tunnel tests are only a partially similar simulation test. Therefore, before the test, the simulation parameters and test plan should be determined according to the actual content, and a suitable wind tunnel and model should be selected. The design and manufacture of the model are a key point in wind tunnel tests. The model should meet the following requirements: the shape is geometrically similar to the actual object or meets the needs of the problem being studied (such as the simulation of internal flow, etc.); the size can ensure the required airflow conditions around the model; the surface state (such as smoothness or roughness, temperature, artificial boundary layer transition measures, etc.) is suitable for the problem being studied; it has sufficient strength and stiffness, and the way of supporting the model has negligible or correctable influence on the test results, can meet the requirements of using test instruments, and is convenient for assembly and disassembly. In addition, some tests have special requirements for stiffness and mass distribution. The material of the model is generally high-strength wood or reinforced plastic in a low-speed wind tunnel, and commonly used carbon steel, alloy steel, or high-strength aluminum alloy in high-speed and hypersonic wind tunnels. Some tests also use other materials according to needs. Models are usually scaled-down, and there are also full-scale models. Sometimes, they can be locally enlarged according to certain requirements. For geometrically symmetric objects, half of the object can also be made into a model using its symmetry.

[0005] The results of wind tunnel tests usually need to be processed and analyzed. The main contents are: converting the measured values into the required aerodynamic characteristic data; analyzing and synthesizing the possible errors introduced in each test link; making physical and mathematical explanations for the test results; and correcting the test results according to the differences between the model flow and the actual flow. The differences between the model flow and the actual flow mainly include: simulation distortion caused by the wind tunnel and the model, such as the difference in Reynolds number, simulation distortion of intake and jet, etc., followed by the interference effects of the wind tunnel wall and the model support; there are also the non-uniformity, turbulence intensity and noise effects of the wind tunnel flow field. Some of them can be corrected through calculations or tests. More importantly, attention should be paid to accumulating experience in using the results of wind tunnel tests.

[0006] In wind tunnel tests, the strain balance is an important method commonly used to obtain the aerodynamic characteristics of the test product. Most of the existing balance signal data acquisitions are composed of separate instruments, which are large in size, unable to integrate the data acquisition system into the wind tunnel balance, and even more unable to be applied to the contra-rotating propeller test. In view of this, the present invention highly integrates functional modules and transmits the acquired data to the control computer in a wireless form, realizing the miniaturization, wireless power supply and wireless data transmission of the balance signal data acquisition system, and applying it to other wind tunnel tests such as the contra-rotating propeller test. Therefore, the present invention has very important research significance, remarkable social benefits and broad application prospects.

[0007] The contra-rotating propeller test equipment is mainly used for the wind tunnel test of an open rotor engine. The front and rear two-stage propellers can be adjusted separately in terms of rotational speed and blade angle. In the contra-rotating propeller wind tunnel test, due to space limitations and high rotational speed requirements for the drive of the propeller, two turbine air motors with relatively high power density are usually used for driving, with a rotational speed of up to 10,000 revolutions per minute. The drive shafts of the two sets of propellers transmit force in the form of an outer shaft and an inner shaft. Among them, the balance signal of the rotating shaft of the propeller driven by the outer shaft cannot be transmitted outward through wires and slip rings. This complex structural form requires that the balance signal of the wind tunnel balance be transmitted in a wireless form under high rotational speed and limited space conditions. Summary of the Invention

[0008] Aiming at the deficiencies of the existing technology and to solve the above problems, the present invention proposes a signal acquisition device applied to a wireless rotating strain balance in a wind tunnel.

[0009] The present invention provides the following technical solutions:

[0010] A signal acquisition device applied to a wireless rotating strain balance in a wind tunnel, the device includes: an acquisition board, a main control board, a power supply and angle detection board, a non-rotating fixing device, a bearing, an inner support of the rotating device, a signal connector, a board-to-board connector, a power receiving coil, a power supply coil, a phase detection sensor, a radially magnetized permanent magnet, a wireless power supply board, fastening screws, an outer support of the rotating device and a power supply connector;

[0011] The rotor part includes: an inner support of the slewing device, an outer support of the slewing, a collection board, a main control board, and a power supply and angle detection board;

[0012] The stator part includes: a non-rotating fixing device, a wireless power supply board, and a radially magnetized permanent magnet;

[0013] The collection board, the main control board, and the power supply and angle detection board are assembled together with the inner support of the slewing device by fastening screws. The electrical signal connection between the collection board, the main control board, and the power supply and angle detection board is realized by an inter-board signal connector to transmit electrical signals;

[0014] The power supply connector mounts the wireless power supply board on the non-rotating fixing device, and the radially magnetized permanent magnet and the bearing are installed through grooves;

[0015] The rotor part and the stator part are connected by a bearing and an outer support of the slewing device;

[0016] The power supply coil is mounted on the wireless power supply board, the power receiving coil is mounted on the power supply and angle detection board, and the power supply coil wirelessly powers the power receiving coil; the phase detection sensor is mounted on the power supply and angle detection board for phase detection; the signal connector connects the collection board and the balance for signal acquisition.

[0017] Preferably, the collection board includes three parts: bridge power supply, signal conditioning, and analog-to-digital conversion. The bridge power supply provides a high-precision constant voltage source for the strain sensor, which is realized by a chip ADR3650 with high stability, high precision, and low temperature drift;

[0018] The signal conditioning circuit amplifies and filters the tiny signal output by the strain sensor with high precision to meet the full-scale input requirements of the analog-to-digital conversion circuit, which is realized by INA133, ADA4522-2, and resistive-capacitive elements;

[0019] The analog-to-digital conversion unit converts the analog signal output by the strain sensor into a digital signal for subsequent processing. This unit is realized by an ADS8598S chip with a resolution of 18 bits.

[0020] Preferably, the main control board includes three parts: a main controller, sampling control, and wireless communication; the main controller realizes the setting of analog-to-digital conversion, data processing, and sending the data to the control computer through a wireless module, which is realized by an ARM chip.

[0021] Preferably, the sampling control part: generates a sampling control signal based on the angle signal to achieve complete synchronous acquisition of the angle and the measured signal;

[0022] Receives the digital signal after analog-to-digital conversion is completed and sends it to the main controller;

[0023] Wireless communication completes TCP / IP communication based on WIFI, transmits the sampled data to the control computer, and receives control instructions from the control computer.

[0024] Preferably, the power supply and angle detection board includes three parts: angle detection, power receiving coil, and power supply conditioning; the angle detection is realized by the off-axis absolute value angle decoding chip MT6709 and four Hall sensors MT9101. During rotation, the angle measurement is achieved by sensing the magnetic field intensity of the permanent magnet.

[0025] Preferably, the power receiving coil and the power supply conditioning part realize wireless power supply. The power receiving coil senses the change of the alternating magnetic field of the power supply coil, and its output is supplied to the power supply conditioning circuit, and various voltages required by the subsequent circuits are output to realize wireless power supply.

[0026] Preferably, the angle detection consists of four linear Hall elements and one decoding chip. The four Hall elements respectively output differential sine and cosine signals SIN_P, SIN_N, COS_P, and COS_N. The decoding chip outputs A, B, and Z signals according to the four signals, and divides 0° to 360° into 1024 steps.

[0027] Preferably, to obtain the sampling signal AD_CONV, perform an exclusive NOR operation on A and B and then add it to Z, that is Obtain AD_CONV, control the analog-to-digital conversion by AD_CONV, complete signal acquisition, and achieve complete synchronization of the angle and the measured signal.

[0028] Preferably, in order to obtain the angle value, it is necessary to count according to Z and AD_CONV to obtain the angle count value ANGLE, and add it to the high 10 bits of the measurement data and transmit it to the main control computer together.

[0029] Preferably, in the STAT1 state, when Z = 1, the angle count ANGLE = 0, and enter the STAT2 state. In this state, when AD_CONV = 1, ANGLE is incremented by 1, and at the same time, the signal Z is detected. When Z = 1, enter the STAT1 state, and so on, to realize that the angle count value ANGLE is in the range of 0 to 511, and the absolute angle

[0030] The present invention has the following beneficial effects:

[0031] Compared with the prior art, the present invention:

[0032] The present invention solves the technical problem that the traditional measurement scheme of a wind tunnel strain balance based on a slip ring cannot be applied to the contra-rotating propeller test. The contra-rotating propeller test equipment is mainly used for the wind tunnel test of an open rotor engine. The front and rear two-stage propellers can be adjusted separately in terms of rotational speed and blade angle. In the contra-rotating propeller wind tunnel test, due to space limitations and high rotational speed requirements for the drive of the propellers, two turbine air motors with relatively high power density are usually used for driving, with a rotational speed up to 10,000 revolutions per minute. The transmission shafts of the two sets of propellers transmit force in the form of an outer shaft and an inner shaft. Among them, the balance signal of the rotating shaft of the propeller driven by the outer shaft cannot be transmitted outward through wires and slip rings. This complex structural form requires that the balance signal of the wind tunnel must be transmitted wirelessly under the conditions of high rotational speed and limited space. Therefore, the development of the wireless transmission technology for the rotating shaft balance signal lays a good foundation for the subsequent open rotor wind tunnel test.

[0033] The present invention realizes the completely synchronous acquisition of the angle and measurement data based on a magnetic induction sensor.

[0034] The present invention provides a structural design of a signal acquisition device for a wind tunnel rotating strain balance.

[0035] By combining a rotor and a stator, the present invention realizes the miniaturization and integrated design of the collector, and perfectly solves the problems that the traditional acquisition equipment of the rotating balance is large in volume and the data acquisition system cannot be integrated into the wind tunnel balance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 It is a schematic block diagram of the signal acquisition device of the present invention;

[0038] Figure 2 It is a schematic diagram of the angle detection principle of the present invention;

[0039] Figure 3 They are the A, B, and Z signals output by the decoding chip of the present invention;

[0040] Figure 4 It is a schematic diagram of the generation principle of the conversion signal of the present invention;

[0041] Figure 5 It is a schematic diagram of the angle counting principle of the present invention;

[0042] Figure 6 It is a schematic structural diagram of the signal acquisition device of the present invention. Detailed implementation manners

[0043] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0045] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0046] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0047] The present invention is described in detail below in conjunction with specific embodiments. Specific Embodiment 1:

[0049] According to Figures 1 to 6 As shown, the specific optimized technical solution adopted by the present invention to solve the above technical problems is: The present invention relates to a signal acquisition device applied to a wireless rotating strain balance in a wind tunnel.

[0050] The device provided by the present invention includes: a collection board 1, a main control board 2, a power supply and angle detection board 3, a non-rotating fixing device 4, a bearing 5, an inner support 6 of the rotating device, a signal connector 7, a board-to-board connector 8, a power receiving coil 9, a power supply coil 10, a phase detection sensor 11, a radially magnetized permanent magnet 12, a wireless power supply board 13, fastening screws 14, an outer support 15 of the rotating device, and a power supply connector 16;

[0051] The rotor part includes: the inner support 6 of the slewing device, the outer support 15 of the slewing device, the acquisition board 1, the main control board 2, and the power supply and angle detection board 3;

[0052] The stator part includes: the non-rotating fixing device 4, the wireless power supply board 13, and the radially magnetized permanent magnet 12;

[0053] The acquisition board 1, the main control board 2, and the power supply and angle detection board 3 are assembled together with the inner support 6 of the slewing device by fastening screws 14. The electrical signal connection between the acquisition board 1, the main control board 2, and the power supply and angle detection board 3 is realized by the board-to-board connector 8 to transmit electrical signals;

[0054] The power supply connector 16 mounts the wireless power supply board 13 on the non-rotating fixing device 4, and the radially magnetized permanent magnet 12 and the bearing 5 are installed through grooves;

[0055] The rotor part and the stator part are connected by the bearing 5 and the outer support 15 of the slewing device;

[0056] The power supply coil 10 is installed on the wireless power supply board 13, the power receiving coil 9 is installed on the power supply and angle detection board 3, and the power supply coil 10 wirelessly powers the power receiving coil 9; the phase detection sensor 11 is installed on the power supply and angle detection board 3 for phase detection; the signal connector 7 connects the acquisition board 1 and the balance for signal acquisition.

[0057] The acquisition board 1 includes three parts: bridge power supply, signal conditioning, and analog-to-digital conversion. The bridge power supply provides a high-precision constant voltage source for the strain sensor, which is realized by the high-stability, high-precision, and low-temperature-drift chip ADR3650;

[0058] The signal conditioning circuit amplifies and filters the tiny signal output by the strain sensor with high precision to meet the full-scale input requirements of the analog-to-digital conversion circuit, which is realized by INA133, ADA4522-2, and resistive-capacitive elements;

[0059] The analog-to-digital conversion unit converts the analog signal output by the strain sensor into a digital signal for subsequent processing. This unit is realized by the ADS8598S chip with a resolution of 18 bits.

[0060] The main control board 2 includes three parts: the main controller, sampling control, and wireless communication; the main controller realizes the setting of analog-to-digital conversion, data processing, and sending the data to the control computer through the wireless module, which is realized by the ARM chip.

[0061] The sampling control part: generates a sampling control signal based on the angle signal to achieve fully synchronous acquisition of the angle and the measured signal;

[0062] Receives the digital signal after analog-to-digital conversion and sends it to the main controller;

[0063] Wireless communication completes TCP / IP communication based on WIFI, transmits the sampled data to the control computer, and receives control instructions from the control computer.

[0064] The power supply and angle detection board 3 includes three parts: angle detection, power receiving coil, and power supply conditioning; the angle detection is realized by the off-axis absolute value angle decoding chip MT6709 and four Hall sensors MT9101. During the rotation process, the angle measurement is realized by sensing the magnetic field strength of the permanent magnet.

[0065] The power receiving coil and the power supply coil parts realize wireless power supply. The power receiving coil senses the change of the alternating magnetic field of the power supply coil, and its output is supplied to the power supply conditioning circuit, and the output satisfies various voltages required by the subsequent circuits to realize wireless power supply.

[0066] The angle detection consists of four linear Hall elements and one decoding chip. The four Hall elements respectively output differential positive and cosine signals SIN_P, SIN_N, COS_P, and COS_N. The decoding chip outputs A, B, and Z signals according to the four signals, and divides 0° to 360° into 1024 steps.

[0067] Obtain the sampling signal AD_CONV, perform an exclusive NOR operation on A and B and then add Z, that is Get AD_CONV, control the analog-to-digital conversion by AD_CONV, complete the signal acquisition, and realize the complete synchronization of the angle and the measured signal.

[0068] In order to obtain the angle value, it is necessary to count according to Z and AD_CONV to obtain the angle count value ANGLE, add it to the high 10 bits of the measurement data, and transmit it to the main control computer together.

[0069] In the STAT1 state, when Z = 1, the angle count ANGLE = 0, and it enters the STAT2 state. In this state, when AD_CONV = 1, ANGLE is incremented by 1, and at the same time, the signal Z is detected. When Z = 1, it enters the STAT1 state, and so on, to realize that the angle count value ANGLE is within the range of 0 to 511, and the absolute angle

[0070] The present invention solves the technical problem that the traditional wind tunnel strain balance measurement scheme based on slip rings cannot realize the test of rotating propellers.

[0071] The present invention solves the technical problem that the traditional wind tunnel strain balance measurement scheme based on slip rings cannot be applied to the contra-rotating propeller test. The contra-rotating propeller test equipment is mainly used for the open rotor engine wind tunnel test. The front and rear two-stage propellers can be adjusted separately in terms of rotational speed and blade angle. In the contra-rotating propeller wind tunnel test, due to space limitations and high rotational speed requirements for the drive of the propellers, two turbine air motors with relatively high power density are usually used for driving, with a rotational speed of up to 10,000 revolutions per minute. The transmission shafts of the two sets of propellers transmit force in the form of an outer shaft and an inner shaft. Among them, the balance signal of the rotating shaft of the propeller driven by the outer shaft cannot be transmitted outward through wires and slip rings. This complex structural form requires that the balance signal of the wind tunnel must be transmitted wirelessly under the conditions of high rotational speed and limited space. Therefore, the development of the wireless transmission technology for the rotating shaft balance signal lays a good foundation for the subsequent open rotor wind tunnel test.

[0072] The present invention realizes the completely synchronous acquisition of the angle and measurement data based on magnetic induction sensors.

[0073] The present invention provides a structural design of a signal acquisition device for a wind tunnel rotating strain balance.

[0074] By combining the rotor and the stator, the present invention realizes the miniaturization and integrated design of the collector, perfectly solving the problems that the traditional acquisition equipment of the rotating balance is large in volume and the data acquisition system cannot be integrated into the wind tunnel balance. Specific Embodiment Two:

[0076] The difference between the second embodiment and the first embodiment of the present invention lies only in:

[0077] Principle description;

[0078] Principle of the signal acquisition device

[0079] The sampling device is divided into, in principle: a collection board, a control board, a power supply and angle detection board installed in the rotor part, and a permanent magnet and a wireless power supply board installed in the stator part. As Figure 1 shown, it realizes the completely synchronous acquisition of the angle and the measured strain.

[0080] (1) Collection board

[0081] The collection board is composed of three parts: bridge power supply, signal conditioning and analog-to-digital conversion. The bridge power supply provides a high-precision constant voltage source for the strain sensor, which is realized by the chip ADR3650 with high stability, high precision and low temperature drift.

[0082] The signal conditioning circuit amplifies and filters the tiny signal output by the strain sensor with high precision to meet the full-scale input requirements of the analog-to-digital conversion circuit, which is realized by INA133, ADA4522-2 and resistive-capacitive elements.

[0083] The analog-to-digital conversion unit converts the analog signal output by the strain sensor into a digital signal for subsequent processing, and this unit is implemented by the ADS8598S chip with a resolution of 18 bits.

[0084] (2) Main control board

[0085] The main control board consists of three parts: a main controller, sampling control, and wireless communication. The main controller realizes the setting of analog-to-digital conversion, data processing, and sends the data to the control computer through the wireless module, which is implemented by an ARM chip.

[0086] The functions of the sampling control part are as follows: (a) Generate a sampling control signal based on the angle signal to achieve complete synchronous acquisition of the angle and the measured signal; (b) Receive the digital signal after analog-to-digital conversion and send it to the main controller.

[0087] Wireless communication completes TCP / IP communication based on WIFI, transmits the sampling data to the control computer, and receives control instructions from the control computer.

[0088] (3) Power supply and angle detection board

[0089] This part consists of three parts: angle detection, power receiving coil, and power supply conditioning. The angle detection principle is realized by the off-axis absolute value angle decoding chip MT6709 and four Hall sensors MT9101. During the rotation process, the angle measurement is realized by sensing the magnetic field strength of the permanent magnet.

[0090] The power receiving coil and power supply conditioning part realize wireless power supply. The power receiving coil senses the change of the alternating magnetic field of the power supply coil, and its output is supplied to the power supply conditioning circuit, and the output satisfies various voltages required by the subsequent circuits to realize wireless power supply.

[0091] (4) Realization of angle detection and synchronous sampling

[0092] The angle detection principle is as Figure 2 shown, which consists of four linear Hall elements and one decoding chip. The four Hall elements respectively output differential positive and cosine signals SIN_P, SIN_N, COS_P, and COS_N. The decoding chip outputs A, B, and Z signals according to the four signals. As Figure 3 shown, 0° to 360° is divided into 1024 steps.

[0093] In order to obtain the sampling signal AD_CONV, perform an exclusive NOR operation on A and B and then add it to Z, that is to get AD_CONV, as Figure 4 shown. The analog-to-digital conversion is controlled by AD_CONV to complete signal acquisition, realizing complete synchronization of the angle and the measured signal.

[0094] To obtain the angle value, it is necessary to count according to Z and AD_CONV to obtain the angle count value ANGLE, add it to the upper 10 bits of the measurement data, and transmit it to the main control computer together. Its working principle is as Figure 5 shown. In the STAT1 state, when Z = 1, the angle count ANGLE = 0, and then it enters the STAT2 state. In this state, when AD_CONV = 1, ANGLE is incremented by 1, and at the same time, the signal Z is detected. When Z = 1, it enters the STAT1 state, and so on, to achieve the angle count value ANGLE within the range of 0 to 511, and the absolute angle

[0095] The present invention aims at the technical problem that the traditional wind tunnel strain balance measurement scheme based on slip rings cannot achieve the test of the rotating propeller. It highly integrates the functional modules, uses three circuit boards such as an acquisition board, a main control board, and a power supply and angle measurement board to realize signal acquisition, and sends the acquired data to the control computer in a wireless form. At the same time, a structure based on the combination of a rotor and a stator is invented. The rotor part is combined with the rotating balance, and the stator part is combined with the fixing device, so as to realize the high-precision measurement of the rotating balance signal.

[0096] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "N" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. Any process or method description shown in the flowchart or described in other ways herein can be understood as representing a module, segment, or part of code including one or more executable instructions for implementing a customized logic function or process. The scope of the preferred embodiments of the present invention includes additional implementations, where the functions can be executed in a manner that is not shown or discussed, including in a substantially simultaneous manner or in a reverse order according to the involved functions, which should be understood by those skilled in the art of the embodiments of the present invention.

[0097] The above is only a preferred embodiment of a signal acquisition device applied to a wind tunnel wireless rotating strain balance. The protection scope of a signal acquisition device applied to a wind tunnel wireless rotating strain balance is not limited to the above embodiments. All technical solutions falling within this concept belong to the protection scope of the present invention. It should be noted that for those skilled in the art, several improvements and changes made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A signal acquisition device for a wireless rotating strain balance in a wind tunnel, characterized by: The device comprises: an acquisition board, a main control board, a power supply and angle detection board, a non-rotating fixing device, a bearing, an inner support of a rotary device, a signal connector, an inter-board connector, a power receiving coil, a power supply coil, a phase detection sensor, a radially magnetized permanent magnet, a wireless power supply board, a fastening screw, an outer support of a rotary device and a power supply connector; The rotor part includes: internal support of the rotary device, external support of the rotary device, acquisition board, main control board and power supply and angle detection board; The stator part includes: a non-rotating fixing device, a wireless power supply board and a radially magnetized permanent magnet; The acquisition board, main control board and power supply and angle detection board are connected to the inner support of the rotary device by fastening screws, and the connection of electrical signals between the acquisition board, main control board and power supply and angle detection board adopts inter-board connectors to realize the transmission of electrical signals; The power supply connector mounts the wireless power supply board on a non-rotating fixture, and the radially magnetized permanent magnet and the bearing are mounted through grooves; The rotor part and the stator part are connected by bearings and external supports of the slewing device; The power supply coil is installed on the wireless power supply board, and the power receiving coil is installed on the power supply and angle detection board. The power supply coil provides wireless power to the power receiving coil; the phase detection sensor is installed on the power supply and angle detection board for phase detection; the signal connector connects the acquisition board and the balance for signal acquisition; The main control board includes three parts: main controller, sampling control and wireless communication; the main controller realizes the setting of digital-to-analog conversion, data processing and sending data to the control computer through the wireless module, which is realized by the ARM chip.

2. The device according to claim 1, characterized in that: The acquisition board includes three parts: bridge power supply, signal conditioning and analog-to-digital conversion. The bridge power supply provides a high-precision constant voltage source to the strain sensor, which is realized by the high-stability, high-precision, low-temperature drift chip ADR3650. The signal conditioning circuit amplifies and filters the tiny signal output by the strain sensor with high precision to meet the full-scale input requirements of the analog-to-digital conversion circuit. This is achieved by INA133, ADA4522-2, and resistor-capacitor components. The analog-to-digital conversion unit converts the analog signal output by the strain sensor into a digital signal for subsequent processing. The unit is implemented by the ADS8598S chip with a resolution of 18 bits.

3. The device according to claim 1, characterized in that: Sampling control part: generates sampling control signal based on angle signal to realize complete synchronous acquisition of angle and measured signal; Receive the digital signal after analog-to-digital conversion and send it to the main controller; Wireless communication completes WIFI-based TCP / IP communication, transmits sampled data to the control computer, and receives control instructions from the control computer.

4. The device according to claim 3, characterized in that: The power supply and angle detection board consists of three parts: angle detection, power receiving coil and power supply conditioning. Angle detection is achieved by the off-axis absolute angle decoding chip MT6709 and four Hall sensors MT9101. During the rotation process, angle measurement is achieved by sensing the magnetic field strength of the permanent magnet.

5. The device according to claim 4, characterized in that: The receiving coil and the power supply coil realize wireless power supply. The receiving coil senses the changes in the alternating magnetic field of the power supply coil, and its output is supplied to the power supply conditioning circuit, which outputs various voltages required by the subsequent circuits to realize wireless power supply.

6. The device according to claim 5, characterized in that: Angle detection consists of 4 linear Hall elements and 1 decoding chip. The 4 Hall elements output differential sine and cosine signals SIN_P, SIN_N, COS_P and COS_N respectively. The decoding chip outputs A, B, and Z signals based on the 4 signals, dividing 0° to 360° into 1024 steps.

7. The device according to claim 6, characterized in that: Get the sampling signal AD_CONV, perform XOR operation on A and B and then add them to Z, that is, AD_CONV is obtained, and the analog-to-digital conversion is controlled by AD_CONV to complete signal acquisition, thereby achieving complete synchronization between the angle and the measured signal.

8. The device according to claim 7, characterized in that: In order to obtain the angle value, it is necessary to count according to Z and AD_CONV, obtain the angle count value ANGLE, add it to the upper 10 bits of the measurement data, and transmit it to the host computer.

9. The device according to claim 8, characterized in that: In the STAT1 state, when Z=1, the angle count ANGLE=0, and enter the STAT2 state. In this state, when AD_CONV=1, ANGLE is increased by 1, and the signal Z is detected at the same time. When Z=1, it enters the STAT1 state, and so on, to achieve the angle count value ANGLE in the range of 0 to 511, and the absolute angle

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