An angle of attack sensing system for self-identifying angle of attack angle of attack angle of attack angle of attack angle of attack angle of attack angle of attack angle of attack angle of attack angle of

Abstract

The application relates to an angle of attack sensing system and method for self-identifying angle of attack angle deviation, comprising: an angle of attack sensor, comprising: a vane with a shaft coupling, used for sensing the airflow direction and rotating with a wind vane; first and second resolvers, the rotors of the first and second resolvers are driven to rotate with the shaft of the vane through the meshing of driving and driven gears; a third resolver, the rotor of the third resolver is fastened with the shaft of the vane through the shaft coupling; and a processing control module, configured to identify the angle of attack deviation based on the real angle of attack calculation criterion according to the comparison result between the output angles of the respective resolvers, and calculate the corresponding real angle of attack.

Description

Technical Field

[0001] This application relates to the field of flight control, and in particular to an angle-of-attack sensing system and method for self-identifying angle-of-attack angle deviation. Background Technology

[0002] An angle-of-attack sensor (system) is a key component of an aircraft's air data system and flight control system. The angle-of-attack sensor is a device that measures the angle between the aircraft wing and the oncoming airflow (relative wind), known as the angle of attack, which is one of the key fundamental parameters affecting the aircraft's aerodynamic performance.

[0003] Angle of attack (AOA) sensors are generally classified into two types: mechanical and differential pressure. The former uses a freely rotating vane (similar to a weather vane), which naturally aligns with the direction of the airflow. The angle of attack is obtained by measuring the angle between the vane and the fuselage baseline. The latter has multiple pressure orifices on the sensor probe. Using Bernoulli's principle, the angle of attack (airflow angle) relative to the probe is calculated by measuring the pressure difference between the different orifices. Because mechanical AOA sensors have a relatively simple structure, can directly measure airflow direction, and have high reliability due to the absence of complex electronic components, they are still the most common type used in modern aircraft. This application primarily addresses improvements to mechanical AOA sensors.

[0004] Mechanical angle-of-attack sensors detect airflow direction through blades, which then drive a resolver to rotate via the blade shaft, outputting sine and cosine voltage signals. Specifically, the angle-of-attack sensor is essentially a miniature transformer that rotates with the blades. Its principle is based on electromagnetic induction using its internal resolver (also called a "rotary transformer") to directly convert the mechanical angle of the wind vane's rotation into two analog voltage signals with a 90° phase difference. The entire process can be simplified as: blade rotation angle → rotor coil position change → stator coil magnetic flux change → induced sine / cosine voltage, where: Sinusoidal voltage: Vs = k sin(θ) sin(ωt) Cosine voltage: Vc = k cos(θ) sin(ωt) in: k This is the ratio of the excitation voltage to the coil voltage, also known as the voltage ratio. θ This is the output angle of the angle of attack sensor; ω ω is the angular frequency of the excitation signal from the angle-of-attack sensor.

[0005] The output angle of the angle of attack sensor is calculated using the arctangent of the sine and cosine voltages, i.e. θ=tan -1 (Vs / Vc) .

[0006] To achieve signal redundancy and improve data output reliability, an angle-of-attack sensor typically contains two resolvers for measuring the angle of attack. To ensure consistency between the rotation of the two resolvers and the blade, gears are usually used for transmission between the blade's main shaft and the resolver's main shaft. The installation methods for the shaft and gear vary, such as clearance fit between the shaft and gear, followed by positioning and fixing with set screws; or positioning between the shaft and gear using pins, followed by fixing with set screws, etc.

[0007] Because the angle-of-attack sensor operates in harsh environments such as alternating temperatures, low temperatures, and vibrations for extended periods, issues such as unreliable transmission between the shaft and gears, and gear wear may eventually lead to discrepancies between the blade rotation and the resolver rotation, resulting in a deviation in the output angle.

[0008] Therefore, aircraft typically have two or more angle-of-attack sensors installed to provide angle-of-attack data to the aircraft system. However, if the aircraft only uses the independent angle-of-attack data from each individual angle-of-attack sensor, a deviation in the output angle of a single sensor can lead to a decrease in the performance of the system using that signal or cause malfunctions. On the other hand, if a composite angle of attack, such as a vote angle of attack, is used, it may cause a certain numerical deviation in the composite angle of attack, resulting in a decrease in system performance.

[0009] Therefore, a solution is needed to provide an angle-of-attack sensing system and method that can automatically identify angle-of-attack angle deviations, thereby improving the measurement accuracy of the angle-of-attack sensor itself. Summary of the Invention

[0010] This application provides an angle-of-attack sensing scheme that can self-identify angle deviation, enabling convenient and reliable identification of whether there is a deviation in the angle-of-attack output of the angle-of-attack sensor at the aircraft end.

[0011] According to a first aspect of this application, an angle-of-attack sensing system for self-identifying angle-of-attack angle deviation is provided, comprising: Angle of attack sensor, including: Blades with couplings are used to sense the direction of airflow and rotate with the wind vane; The first resolver and the second resolver, the rotors of the first resolver and the second resolver are driven by the meshing of the driving gear and the driven gear to rotate in linkage with the shaft of the blade; The third resolver, wherein the rotor of the third resolver is fastened to the shaft of the blade via the coupling; and The processing control module is configured to identify angle-of-attack deviations based on the comparison results between the output angles of each resolver, and to calculate the corresponding true angle of attack.

[0012] According to a second aspect of this application, a method for self-identifying angle of attack deviation based on the angle of attack sensing system described in the first aspect is provided, comprising: For each resolver, the excitation voltage is received and the corresponding analog quantity of sine and cosine voltages is output; The received analog quantities of sine and cosine voltages are measured and calculated to generate the corresponding digital quantities of the rotation angle of the angle of attack sensing system, and then sent to the processing and control module. Based on the comparison results between the output angles of each resolver, the angle of attack deviation is identified according to the true angle of attack calculation criterion, and the corresponding true angle of attack is calculated.

[0013] This overview is provided to introduce, in a simplified form, some of the concepts further described in the detailed description below. This overview is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Attached Figure Description

[0014] To describe how the above and other advantages and features of this application are obtained, a more specific description of the application briefly described above will be presented with reference to specific embodiments of the application shown in the accompanying drawings. It will be understood that these drawings depict only typical embodiments of the application and are therefore not intended to limit its scope. The application will be described and explained using the drawings and with the aid of additional features and details, in which: Figure 1 A schematic structural diagram of the sensing detection section of an angle-of-attack sensing system for self-identifying angle-of-attack angle offset according to an embodiment of this application is shown.

[0015] Figure 2 A schematic structural diagram of the angle of attack measurement section of an angle of attack sensing system for self-identifying angle of attack angle offset according to an embodiment of this application is shown.

[0016] Figure 3 A method for self-identifying angle of attack deviation based on the above-described angle of attack sensing system is shown according to an embodiment of this application. Detailed Implementation

[0017] The purpose of this application is to provide an angle-of-attack sensing system that can self-identify angle deviation, enabling convenient and reliable identification of whether there is a deviation in the angle-of-attack output of the angle-of-attack sensing system at the aircraft end.

[0018] Overall, this application adds a third resolver to the existing two-resolver configuration of traditional angle-of-attack sensors, providing a signal redundancy scheme for a three-resolver configuration of angle-of-attack sensors. Measurement accuracy is further improved through comparison and calculation among the three resolvers, thereby reducing the output angle deviation of the angle-of-attack sensing system.

[0019] According to the scheme of this application, the angle of attack sensing system can be divided into a sensing and detection part (i.e., angle of attack sensor) for collecting measurement data and an angle of attack measurement part for processing and analyzing the collected measurement data.

[0020] First, such as Figure 1 The diagram shows a schematic structural diagram of the sensing and detection part (i.e., angle of attack sensor) of an angle of attack sensing system that self-identifies angle of attack angle deviation according to an embodiment of this application.

[0021] The angle of attack sensor of the angle of attack sensing system mainly includes a blade 110, a driving gear 120, a driven gear 130, a first resolver 140 (1) and a second resolver 140 (2), a coupling 150, a third resolver 160, a frame 170, and other necessary circuits and transmission components (not shown).

[0022] Blade 110 is used to sense the direction of airflow and rotate with the wind vane.

[0023] The drive gear 120 is coaxially fixedly connected to the blade 110 and rotates synchronously with the blade 110.

[0024] Driven gear 130 meshes with driving gear 120 and is used to change the direction of the rotation axis to facilitate the coaxial arrangement of subsequent multi-path resolvers.

[0025] The third resolver 160 includes a rotor 161 and a stator 162. The rotor 161 is securely and reliably connected to the shaft of the blade 110 via a coupling 150. This connection includes, but is not limited to, keyed connections, pin connections, and interference fits.

[0026] The system includes a first resolver 140(1) comprising a rotor 141(1) and a stator 142(1) and a second resolver 140(2) comprising a rotor 141(2) and a stator 142(2). Both resolvers are arranged along parallel axes and are coaxially connected to the driven gear 130. That is, the rotors of the first resolver 140(1) and the second resolver 140(2) are driven to rotate in linkage with the shaft of the blades via the meshing of the driving gear 120 and the driven gear 130, respectively.

[0027] The coupling 150 is connected at one end to the shaft of the blade 110, and at the other end to the rotor 161 of the third resolver 160, so that the rotor 161 and the blade 110 rotate synchronously.

[0028] The frame 170 serves both as the mounting support base for the entire angle-of-attack sensing system and as an external interface for mounting onto the aircraft. The drive gear 120, driven gear 130, first resolver 140(1), second resolver 140(2), coupling 150, and third resolver 160 are all mounted within the frame 170 via bearings or supports to maintain their relative positions.

[0029] It should be noted that the first parser 140 (1), the second parser 140 (2), and the third parser 160 may be the same or different depending on the actual situation.

[0030] Based on the schematic structure of the angle-of-attack sensor described above in the angle-of-attack sensing system, the specific schematic working process of the angle-of-attack sensor is described below.

[0031] In actual operation, the angle of attack sensing system is installed in the correct position on the aircraft via frame 170. During flight, blade 110 rotates with the relative motion between the aircraft and the air. On one hand, this rotation drives the drive gear 120 to rotate via the shaft on blade 110, and the drive gear 120 then drives the driven gear 130 to rotate via gear meshing. Then, the driven gear 130 drives the rotors of the first resolver 140 (1) and the second resolver 140 (2) to rotate, thereby causing the first resolver 140 (1) and the second resolver 140 (2) to output sine and cosine voltages respectively. On the other hand, blade 110 drives the rotor 161 of the third resolver 160 to rotate synchronously via coupling 150, thereby causing the third resolver 160 to also output sine and cosine voltages.

[0032] Since the blade 110 and the rotor 161 are directly and reliably connected by a coupling, and the two are always synchronized, the angle of the third resolver 160 can be used as a reference.

[0033] The rotor 141(1) of the first resolver 140(1) and the rotor 141(2) of the second resolver 140(2) are indirectly connected to the shaft of the blade 110 by the meshing of the driving gear 120 and the driven gear 130, respectively. Therefore, their angles may be affected by factors such as unreliable transmission between the shaft and the gear, between the gears, and gear wear, resulting in deviations. Therefore, their angles are used as auxiliary references.

[0034] By measuring the sine and cosine voltages output by the first resolver 140 (1), the second resolver 140 (2), and the third resolver 160 respectively, the signals can be compared to determine whether there is an angular offset in the outputs of the first resolver 140 (1), the second resolver 140 (2), and / or the third resolver 160.

[0035] Specifically, in Figure 2 The diagram shows a schematic structural diagram of the angle of attack measurement section of an angle of attack sensing system according to an embodiment of this application.

[0036] As shown in the figure, the angle of attack measurement section of the angle of attack sensing system 201 includes three excitation and measurement devices corresponding to three resolvers, respectively. The first resolver (equivalent to...) Figure 1 One end (rotor) of the first resolver 140 (1) is indirectly connected to the shaft of the blade 110 by the meshing of the driving gear and the driven gear, and the other end (output) is connected to the first excitation and measuring device 202; the second resolver (equivalent to Figure 1 The second resolver 140 (2) is connected to the shaft of the blade 110 via the meshing of the driving gear and the driven gear at one end (rotor), and the other end (output) is connected to the second excitation and measuring device 203; while the third resolver (equivalent to Figure 1 One end (rotor) of the third resolver 160 is directly connected to the blade, while the other end (output) is connected to the third excitation and measurement device 204.

[0037] These three resolvers are connected to three excitation and measurement devices 202, 203, and 204, respectively, receiving the excitation voltage provided by them and outputting corresponding analog sine and cosine voltages. The analog quantities are measured and calculated in each excitation and measurement device to obtain the digital quantity of the corresponding rotation angle of the angle of attack sensing system; then, the data is uniformly sent to the processing and control module 205 for data processing. The processing and control module 205 is configured to identify the angle of attack deviation based on the comparison results between the output angles of each resolver and the true angle of attack calculation criteria, and calculate the corresponding true angle of attack for use by the user system.

[0038] Specifically, the data processing mainly includes, but is not limited to: 1) Monitoring 1: Calculate whether the difference between the output angles of the first resolver and the second resolver exceeds the threshold X. If it exceeds the threshold, report "Resolver1 and Resolver2 Miscompare". The threshold X represents the allowable range of error between the first resolver and the second resolver due to different connection methods, resolver types and other factors. 2) Monitoring 2: Calculate whether the difference between the output angles of the first and third resolvers exceeds the threshold Y. If it exceeds the threshold, report "Resolver1 and Resolver3 Miscompare". The threshold Y represents the allowable error range between the first or second resolver and the third resolver due to factors such as connection method, resolver type and other factors. 3) Monitoring 3: Calculate whether the difference between the output angles of the second and third resolvers exceeds the threshold Y. If it exceeds the threshold, report "Resolver2 and Resolver3 Miscompare".

[0039] 4) Based on the above monitoring and comparison results, follow the basic rules below to identify the angle of attack deviation and calculate the true angle of attack: a) If the accuracy of the third parser is lower than that of the first parser and / or the second parser, it can only be used as a benchmark for comparison or as a backup angle after degradation; if the accuracy of the third parser also meets the requirements for normal use, the angle of the third parser can be used first; in the event of failure of the third parser, the data of the first parser and / or the third and second parsers are used as backups (see Table 1 below). b) Using the angle of the third parser 160 as a reference, a specified threshold can be set to monitor whether the angles of the first parser 140 (1) and / or the second parser 140 (2) have shifted.

[0040] As mentioned above, the third resolver 160 is directly connected to the blade, and the first resolver 140 (1) and the second resolver 140 (2) are linked with the blade through gears. The first resolver 140 (1) and the second resolver 140 (2) adopt the same resolver configuration and can be interchanged with each other, while the third resolver 160 can be different from or the same as the first resolver 140 (1) and the second resolver 140 (2).

[0041] Based on this, the comparison between the third resolver 160 and the first resolver 140 (1) and the second resolver 140 (2) requires setting thresholds X and Y to account for the effects caused by different connection methods, resolver types, etc. Specifically, the thresholds X and Y can be set based on factors such as gear transmission errors, component installation accuracy, resolver accuracy requirements, and safety and airworthiness requirements in aircraft integration. At the same time, a certain time window should be designed when judging the thresholds X and Y to avoid instantaneous false alarms.

[0042] The following example illustrates the calculation logic of the monitoring thresholds X and Y.

[0043] Assume the transmission gear parameters of the above angle of attack sensor are: module m=0.3, number of teeth z=90, gear accuracy grade 6. The center distance error of gear installation is 0.02mm, the parallelism error is 0.01mm, the radial runout error after gear installation is 0.005mm, the accuracy of the third resolver 160 directly connected to the blade through the coupling is ±0.1 degrees, the accuracy of the first resolver 140(1) and the second resolver 140(2) connected to the blade through gear transmission is ±0.15 degrees, and the coupling transmission accuracy is 0.05 degrees. Therefore, the following calculations can be performed: 1) Gear transmission accuracy: Based on empirical formulas, the cumulative total error of the gear pitch is calculated to be 10.734 micrometers, resulting in a maximum angular error of 0.0455 degrees for a single gear. The radial runout error results in an error of 0.0212 degrees, and the parallelism error causes an error of 0.0340 degrees. Therefore, the total transmission error of the two gears is calculated to be 0.0758 degrees. 2) Since the first resolver 140 (1) and the second resolver 140 (2) are driven by gears and blades, their output accuracy is the result of the combined effect of the transmission gear accuracy, the transmission gear installation accuracy, and the resolver accuracy. Therefore, based on the above errors, the output accuracy of the first resolver 140 (1) and the second resolver 140 (2) is calculated to be approximately 0.1681 degrees. 3) The third resolver 160 is directly connected to the blade through a coupling to achieve transmission. Its output accuracy is the result of the combined effect of the coupling transmission accuracy and the resolver accuracy. Therefore, the output accuracy of the third resolver 160 is calculated to be approximately 0.1118 degrees. 4) Combining the output accuracy of the above single parser, the relative accuracy of the output of the first parser 140 (1) and the second parser 140 (2) can be calculated to be approximately 0.2377 degrees; the relative accuracy of the output of the first parser 140 (1) and the second parser 140 (2) with the third parser 160 is 0.2018 degrees.

[0044] In addition, considering that aircraft manufacturers also conduct system integration architecture and safety analysis when developing aircraft, they may impose accuracy requirements on angle of attack signals. For example, if it is confirmed that the output error of the angle of attack sensor on a certain type of aircraft should not be greater than 0.3 degrees, then it can be confirmed that the monitoring threshold X of the first resolver 140 (1) and the second resolver 140 (2) can be selected between 0.24 degrees and 0.3 degrees, and the monitoring threshold Y between the first resolver 140 (1) or the second resolver 140 (2) and the third resolver 160 can be selected between 0.21 degrees and 0.3 degrees.

[0045] Based on the above basic rules, the following explains how to identify the angle of attack offset and calculate the true angle of attack by comparing the sine and cosine voltages output by the three resolvers.

[0046] exist Figure 3 The present invention illustrates a method for self-identifying angle of attack deviation based on the above-described angle of attack sensing system according to an embodiment of the present application.

[0047] First, in step 302, for each resolver, the excitation voltage is received and the corresponding analog quantity of sine and cosine voltages is output; That is, the three resolvers in the angle of attack sensing system receive excitation voltage from the excitation and measurement devices connected to them, and output the analog quantities of the generated sine and cosine voltages to the corresponding excitation and measurement devices.

[0048] Subsequently, in step 304, the excitation and measurement device measures and calculates the received analog quantities of sine and cosine voltages to generate the corresponding digital quantities of the rotation angle of the angle of attack sensing system, and sends them to the processing and control module.

[0049] Next, in step 306, the processing control module identifies the angle of attack deviation based on the comparison results between the output angles of each resolver and the true angle of attack calculation criterion, and calculates the corresponding true angle of attack, wherein the following data processing is performed: 1) Monitoring 1: Calculate whether the difference between the output angles of the first resolver and the second resolver exceeds the threshold X. If it exceeds the threshold, report "Resolver1 and Resolver2 Miscompare". 2) Monitoring 2: Calculate whether the difference between the output angles of the first resolver and the third resolver exceeds the threshold Y. If it exceeds the threshold, report "Resolver1 and Resolver3 Miscompare". 3) Monitoring 3: Calculate whether the difference between the output angles of the second and third resolvers exceeds the threshold Y. If it exceeds the threshold, report "Resolver2 and Resolver3 Miscompare".

[0050] Subsequently, in step 308, based on the results of the above monitoring and processing, the corresponding true angle of attack is calculated according to the true angle of attack calculation criteria for use by the user system.

[0051] Examples of the true angle of attack calculation criteria are shown in Table 1 below:

[0052] Table 1: Criteria for Calculating the Actual Angle of Attack in Examples

[0053] As can be seen from Table 1, the monitoring process results fall into the following eight categories: Scenario 1: The difference between the output angles of the first and second resolvers does not exceed the threshold X, the difference between the output angles of the first and third resolvers does not exceed the threshold Y, and the difference between the output angles of the second and third resolvers does not exceed the threshold Y. In this case, it indicates that the angle outputs of each resolver are not abnormal, and therefore, all can be used. Therefore, the average of the output angles of the three resolvers is used as the true angle of attack to improve accuracy.

[0054] Case 2: The difference between the output angles of the first and second resolvers exceeds the threshold X, while the difference between the output angles of the first and third resolvers does not exceed the threshold Y, and the difference between the output angles of the second and third resolvers does not exceed the threshold Y. This indicates that one or both of the first and second resolvers are abnormal. Therefore, the output angle of the third resolver is directly used as the true angle of attack.

[0055] Case 3: The difference between the output angles of the first and second resolvers does not exceed the threshold X, the difference between the output angles of the first and third resolvers exceeds the threshold Y, and the difference between the output angles of the second and third resolvers does not exceed the threshold Y. In this case, it indicates that the first resolver may be malfunctioning. Therefore, the average of the output angles of the second and third resolvers is used as the true angle of attack.

[0056] Case 4: The difference between the output angles of the first and second resolvers does not exceed the threshold X, the difference between the output angles of the first and third resolvers does not exceed the threshold Y, and the difference between the output angles of the second and third resolvers exceeds the threshold Y. In this case, it indicates that the second resolver may be malfunctioning. Therefore, the average of the output angles of the first and third resolvers is used as the true angle of attack.

[0057] Case 5: The difference between the output angles of the first and second resolvers exceeds the threshold X, the difference between the output angles of the first and third resolvers exceeds the threshold Y, and the difference between the output angles of the second and third resolvers does not exceed the threshold Y. In this case, it indicates that the first resolver is abnormal. Therefore, the average of the output angles of the second and third resolvers is used as the true angle of attack.

[0058] Case 6: The difference between the output angles of the first and second resolvers exceeds the threshold X, the difference between the output angles of the first and third resolvers does not exceed the threshold Y, and the difference between the output angles of the second and third resolvers exceeds the threshold Y. This indicates that the second resolver is malfunctioning. Therefore, the average of the output angles of the first and third resolvers is used as the true angle of attack.

[0059] Case 7: The difference between the output angles of the first and second resolvers does not exceed the threshold X, the difference between the output angles of the first and third resolvers exceeds the threshold Y, and the difference between the output angles of the second and third resolvers also exceeds the threshold Y. This indicates that the third resolver is malfunctioning. Therefore, the average of the output angles of the first and second resolvers is used as the true angle of attack.

[0060] Case 8: The difference between the output angles of the first and second resolvers exceeds the threshold X, the difference between the output angles of the first and third resolvers exceeds the threshold Y, and the difference between the output angles of the second and third resolvers also exceeds the threshold Y. This indicates that the first, second, and third resolvers may all be malfunctioning. In this case, the output angle of the third resolver is directly used as the true angle of attack.

[0061] Finally, in step 310, based on the changes in the output angle-of-attack deviation of each resolver, the trend of output error change of the angle-of-attack sensing system is determined, and the performance degradation of the angle-of-attack sensing system is identified. This step can be optional. By monitoring and recording the changes in the output angle-of-attack deviation of each resolver of the angle-of-attack sensing system, combined with historical experience, the trend of output error change of the angle-of-attack sensing system can be predicted, thereby further predicting the performance degradation of the angle-of-attack sensing system. This helps ground personnel replace the angle-of-attack sensing system before a real failure occurs, improving aircraft flight safety.

[0062] It should be understood that although in some of the above cases the individual resolvers are directly averaged, in a preferred embodiment, different weights can be assigned to the first, second, and third resolvers based on factors such as their different types and installation locations. This allows the calculation of the true angle of attack to be based on these weights, rather than a simple average. For example, if the third resolver uses a more reliable angle of attack sensor type, it can be given a higher weight when calculated together with the other resolvers. Depending on the specific application scenario, technicians can flexibly set these weights to make the angle of attack calculation more accurate.

[0063] advantage: As described above, because the angle-of-attack sensing system in this application uses three resolvers to output angle measurements separately and compare them with each other, the testability and data reliability of the angle-of-attack sensing system are improved. Therefore, a more flexible design can be adopted at the aircraft end. Furthermore, by designing a specified threshold, the angle deviation output by the angle-of-attack sensing system and the calculation of the true angle of attack can be accurately detected, thereby realizing comprehensive monitoring of the angle-of-attack sensor performance and improving the safety level of the angle-of-attack system.

[0064] Although the techniques have been described using language specific to structural features and / or methodological actions, it should be understood that the appended claims are not necessarily limited to the described features or actions. Rather, these features and actions are described as exemplary forms of implementing these techniques.

[0065] The operations of the example processes are shown in separate boxes and are summarized with reference to these boxes. These processes are shown as a flow of logical boxes, each of which may represent one or more operations that can be implemented using hardware, software, or a combination thereof. In the context of software, these operations represent computer-executable instructions stored on one or more computer-readable media that, when executed by one or more processors, cause one or more processors to perform a given operation. Generally, computer-executable instructions include routines, programs, objects, modules, components, data structures, etc., that perform a particular function or implement a particular abstract data type. The order in which the operations are described is not intended to be construed as limiting, and any number of the operations may be executed in any order, combined in any order, subdivided into multiple sub-operations, and / or executed in parallel to implement the described process. The described process may be executed by resources associated with one or more computing devices, such as one or more internal or external CPUs or GPUs, and / or one or more pieces of hardware logic, such as FPGAs, DSPs, or other types of accelerators.

[0066] All of the methods and processes described above can be embodied in software code modules executed by one or more general-purpose computers or processors, and can be fully automated via these software code modules. These code modules can be stored on any type of computer-executable storage medium or other computer storage device. This code can also be packaged into corresponding computer program products. Some or all of these methods can alternatively be embodied in dedicated computer hardware.

[0067] Any routine description, element, or box in the flowcharts described herein and / or in the accompanying drawings should be understood as potentially representing a module, segment, or portion of code comprising one or more executable instructions for implementing a specific logical function or element in that routine. Alternative implementations are included within the scope of the examples described herein, wherein elements or functions may be removed or performed inconsistently with the order shown or discussed, including substantially synchronous or reverse order execution, depending on the functionality involved, as will be understood by those skilled in the art.

[0068] While different embodiments have been described above, it should be understood that they are merely examples and not limitations. Those skilled in the art will appreciate that various modifications in form and detail may be made without departing from the spirit and scope of this application as defined in the appended claims. Therefore, the breadth and scope of this application disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely by the appended claims and their equivalents.

Claims

1. An angle-of-attack sensing system for self-identifying angle-of-attack deviation, comprising: Angle of attack sensor, including: Blades with couplings are used to sense the direction of airflow and rotate with the wind vane; The first resolver and the second resolver, the rotors of the first resolver and the second resolver are driven by the meshing of the driving gear and the driven gear to rotate in linkage with the shaft of the blade; The third resolver, wherein the rotor of the third resolver is fastened to the shaft of the blade via the coupling; and The processing control module is configured to identify angle-of-attack deviations based on the comparison results between the output angles of each resolver, and to calculate the corresponding true angle of attack.

2. The angle of attack sensing system as described in claim 1, characterized in that, It also includes excitation and measurement devices connected to each of the resolvers, for providing excitation voltage to the connected resolvers and receiving analog quantities of the sine and cosine voltages output by them; measuring and calculating the received analog quantities of each sine and cosine voltage to obtain the digital quantity of the corresponding rotation angle of the angle of attack sensing system and sending it uniformly to the processing and control module.

3. The angle of attack sensing system as described in claim 1, characterized in that, The processing control module performs the following data processing: 1) Monitoring 1: Calculate whether the difference between the output angles of the first resolver and the second resolver exceeds the threshold X. If it exceeds the threshold X, report "Resolver1 and Resolver2 Miscompare". 2) Monitoring 2: Calculate whether the difference between the output angles of the first resolver and the third resolver exceeds the threshold Y. If it exceeds the threshold Y, report "Resolver1 and Resolver3 Miscompare". 3) Monitoring 3: Calculate whether the difference between the output angles of the second resolver and the third resolver exceeds the threshold Y. If it exceeds the threshold Y, report "Resolver2 and Resolver3 Miscompare".

4. The angle of attack sensing system as described in claim 3, characterized in that, The threshold X represents the allowable error range between the first parser and the second parser due to different connection methods, parser types, and other factors; the threshold Y represents the allowable error range between the first parser or the second parser and the third parser due to connection methods, parser types, and other factors.

5. The angle of attack sensing system as described in claim 3, characterized in that, The true angle of attack calculation criteria include the following eight cases: Case 1: The difference between the output angles of the first resolver and the second resolver does not exceed the threshold X, the difference between the output angles of the first resolver and the third resolver does not exceed the threshold Y, and the difference between the output angles of the second resolver and the third resolver does not exceed the threshold Y. In this case, it indicates that there is no abnormality in the angle output of each resolver, and the average value of the output angles of the three resolvers is used as the true angle of attack. Case 2: The difference between the output angles of the first resolver and the second resolver exceeds the threshold X, the difference between the output angles of the first resolver and the third resolver does not exceed the threshold Y, and the difference between the output angles of the second resolver and the third resolver does not exceed the threshold Y. In this case, it indicates that one or both of the first resolver and the second resolver are abnormal, and the output angle of the third resolver is directly used as the true angle of attack. Case 3: The difference between the output angles of the first resolver and the second resolver does not exceed the threshold X, the difference between the output angles of the first resolver and the third resolver exceeds the threshold Y, and the difference between the output angles of the second resolver and the third resolver does not exceed the threshold Y. In this case, it indicates that the first resolver may be malfunctioning, and the average value of the output angles of the second resolver and the third resolver is used as the true angle of attack. Case 4: The difference between the output angles of the first resolver and the second resolver does not exceed the threshold X, the difference between the output angles of the first resolver and the third resolver does not exceed the threshold Y, and the difference between the output angles of the second resolver and the third resolver exceeds the threshold Y. In this case, it indicates that the second resolver may be malfunctioning, and the average value of the output angles of the first resolver and the third resolver is used as the true angle of attack. Case 5: The difference between the output angles of the first resolver and the second resolver exceeds the threshold X, the difference between the output angles of the first resolver and the third resolver exceeds the threshold Y, and the difference between the output angles of the second resolver and the third resolver does not exceed the threshold Y. In this case, it indicates that the first resolver is abnormal, and the average value of the output angles of the second resolver and the third resolver is used as the true angle of attack. Case 6: The difference between the output angles of the first resolver and the second resolver exceeds the threshold X, the difference between the output angles of the first resolver and the third resolver does not exceed the threshold Y, and the difference between the output angles of the second resolver and the third resolver exceeds the threshold Y. In this case, it indicates that the second resolver is abnormal, and the average value of the output angles of the first resolver and the third resolver is used as the true angle of attack. Case 7: The difference between the output angles of the first resolver and the second resolver does not exceed the threshold X, the difference between the output angles of the first resolver and the third resolver exceeds the threshold Y, and the difference between the output angles of the second resolver and the third resolver also exceeds the threshold Y. In this case, it indicates that the third resolver is abnormal, and the average value of the output angles of the first resolver and the second resolver is used as the true angle of attack. Case 8: The difference between the output angles of the first resolver and the second resolver exceeds the threshold X, the difference between the output angles of the first resolver and the third resolver exceeds the threshold Y, and the difference between the output angles of the second resolver and the third resolver also exceeds the threshold Y. In this case, it indicates that the first resolver, the second resolver, and the third resolver may all be malfunctioning. The output angle of the third resolver is directly used as the true angle of attack.

6. The angle of attack sensing system as described in claim 5, characterized in that, In addition to averaging the output angles of each resolver, different weights can be set for the first resolver, the second resolver, and the third resolver, so that the true angle of attack can be calculated according to the weights.

7. The angle of attack sensing system as described in claim 1, characterized in that, The parsers may be the same or different.

8. A method for self-identifying angle of attack deviation based on an angle of attack sensing system as described in any one of claims 1-7, comprising: For each resolver, the excitation voltage is received and the corresponding analog quantity of sine and cosine voltages is output; The received analog quantities of sine and cosine voltages are measured and calculated to generate the corresponding digital quantities of the rotation angle of the angle of attack sensing system, and then sent to the processing and control module. Based on the comparison results between the output angles of each resolver, the angle of attack deviation is identified according to the true angle of attack calculation criterion, and the corresponding true angle of attack is calculated. Based on the changes in the output angle of attack deviation of each resolver, the trend of output error change of the angle of attack sensing system is determined, and the performance degradation of the angle of attack sensing system is identified.

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