Contactless fan blade bending monitoring method, system and storage medium

Abstract

This invention discloses a non-contact method, system, and storage medium for monitoring the bending of wind turbine blades. The method includes steps such as radar detection using the rotating surface of the wind turbine blade as the detection plane to obtain echo signals, obtaining a three-dimensional point cloud dataset based on the echo signals, determining the blade's axis of symmetry based on the three-dimensional point cloud dataset, obtaining a two-dimensional contour by truncating the three-dimensional point cloud dataset with a plane, determining the blade tip position within the two-dimensional contour, and generating a first alarm message when the distance between the blade tip position and the tower is abnormal. This invention, by performing radar detection on the wind turbine blades and analyzing the echo signals, can obtain data such as the distance between the blade tip position and the tower. The monitoring process requires no contact with the wind turbine blades, does not affect the operation of the blades, and is insensitive to interference factors such as ambient light, environmental vibration, and airflow. The measurement results are relatively accurate, ensuring the safe operation of wind turbine generators. This invention has wide applications in the field of radar technology.

Description

Technical Field

[0001] The present invention relates to the field of radar technology, and in particular to a contactless fan blade bending monitoring method, system and storage medium. Background Art

[0002] Wind turbines, also known as wind turbines, are important new energy equipment. Wind turbine blades are the core components of wind turbines that convert wind energy into electrical energy. The working state of wind turbine blades will affect the performance and benefits of wind turbines. An important evaluation criterion for the working state of wind turbine blades is the bending of wind turbine blades, that is, the deviation of the shape of wind turbine blades from their static state caused by the influence of wind and gravity during operation. Related technologies for monitoring the bending of wind turbine blades include contact resistance strain gauge method, electromagnetic method, fiber-optic blade tip timing method, laser Doppler method, blade tip dynamic pressure diagnosis method, etc. Among these related technologies, the contact resistance strain gauge method and electromagnetic method require additional auxiliary items to be installed on the blades, which will affect the characteristics of the blades to be measured and are not suitable for finished wind turbine blades; the fiber-optic blade tip timing method is easily disturbed by environmental background light; the laser Doppler method is easily disturbed by environmental vibration; and the blade tip dynamic pressure diagnosis method is easily disturbed by airflow. In short, the shortcomings of the related technologies can be summarized as the measurement process will affect the operation of the wind turbine blades, or they are easily disturbed by environmental factors, making it difficult to obtain accurate monitoring results. Summary of the invention

[0003] The object of the present invention is to provide a contactless fan blade bending monitoring method, system and storage medium.

[0004] In one aspect, an embodiment of the present invention includes a contactless method for monitoring the bending of a wind turbine blade, comprising:

[0005] Using the rotating surface of the fan blade as a detection plane, performing radar detection on the detection plane to obtain an echo signal;

[0006] Determine the scattering distribution in space according to the echo signal to obtain a three-dimensional point cloud data set;

[0007] Determine the symmetry axis of the three-dimensional point cloud data set as the symmetry axis of the blade;

[0008] intercepting the three-dimensional point cloud data set with a plane parallel to the blade symmetry axis and perpendicular to the detection plane, aggregating parts of the three-dimensional point cloud data set located on the same section, and obtaining a two-dimensional profile for each section;

[0009] Determine a position in the two-dimensional profile having a maximum support angle variation as a blade tip position;

[0010] Determining the distance between the tip position of the blade and the tower on which the wind turbine blade is mounted;

[0011] When the distance between the tip of the blade and the tower is abnormal, a first alarm message is generated.

[0012] Furthermore, the non-contact wind turbine blade bending monitoring method further includes:

[0013] Obtaining the radar installation height, the height of the center of rotation of the wind turbine blades, and the angle between the blade symmetry axis and the vertical direction;

[0014] Determine the blade length according to the radar installation height, the height of the rotation center of the fan blade, the angle between the blade symmetry axis and the vertical direction, and the blade tip position;

[0015] When the blade length is abnormal, a second alarm message is generated.

[0016] Further, determining the blade length according to the radar installation height, the height of the rotation center of the wind turbine blade, the angle between the blade symmetry axis and the vertical direction, and the blade tip position includes:

[0017] According to the formula

[0018] L=(h2-h1-z tip ) / cosθ

[0019] Calculate; where h1 is the radar installation height, h2 is the height of the fan blade rotation center, z tip is the vertical component of the blade tip position, and θ is the angle between the blade symmetry axis and the vertical direction.

[0020] Furthermore, the non-contact wind turbine blade bending monitoring method further includes:

[0021] Determine a contour line as a reference line from the two-dimensional contour corresponding to the cross section passing through the leeward surface of the wind turbine blade; the support angle change in the reference line is less than a threshold value;

[0022] Determine the vertical distance from each point to the reference line from the two-dimensional profile corresponding to the cross section passing through the windward surface of the fan blade;

[0023] Mapping the vertical distance from each point to the reference line into a blade thickness variation curve;

[0024] When the blade thickness variation curve is abnormal, a third alarm message is generated.

[0025] Furthermore, the non-contact wind turbine blade bending monitoring method further includes:

[0026] Obtaining a pre-bent portion curve of the leeward surface of the fan blade;

[0027] Taking the pre-bent portion curve as a starting point and the connection point between the fan blade and the rotating shaft as an end point, fitting the two-dimensional profile corresponding to the cross section passing through the leeward surface of the fan blade to obtain a fitting curve;

[0028] splicing the pre-bent portion curve with the fitting curve to obtain a blade leeward surface curve;

[0029] When the leeward surface curve of the blade is abnormal, a fourth alarm message is generated.

[0030] Further, determining the scattering distribution in space according to the echo signal to obtain a three-dimensional point cloud data set includes:

[0031] Performing three-dimensional spatial orthogonal decomposition, spatial domain to wave number domain transformation and plane wave expansion on the echo signal to obtain a three-dimensional spatial distribution;

[0032] Setting a detection threshold, and determining scattering points in the three-dimensional spatial distribution according to a magnitude relationship between the scattering coefficient of each point in the three-dimensional spatial distribution and the detection threshold;

[0033] The three-dimensional point cloud data set is composed of the scattered points.

[0034] Further, the determining the symmetry axis of the three-dimensional point cloud data set as the symmetry axis of the blade includes:

[0035] Projecting the three-dimensional point cloud data set onto the detection plane to obtain a projection point set;

[0036] A straight line is selected on the detection plane, and when the moment of inertia of the projection point set relative to the straight line is the smallest, the straight line is used as the symmetry axis of the blade.

[0037] Furthermore, the moment of inertia of the projection point set relative to the straight line is determined by the following steps:

[0038] Obtaining the amplitude of each projection point in the projection point set;

[0039] Get the distance of each projection point relative to the straight line;

[0040] The amplitude of each projection point is set to the mass of the same projection point;

[0041] The moment of inertia of the projection point set relative to the straight line is determined according to the cumulative value of the product of the mass of each projection point and the distance relative to the straight line.

[0042] On the other hand, an embodiment of the present invention further includes a contactless fan blade bending monitoring system, comprising:

[0043] A radar module is used to use the rotating surface of the fan blade as a detection plane, perform radar detection on the detection plane, and obtain an echo signal;

[0044] Processing modules for:

[0045] Determine the scattering distribution in space according to the echo signal to obtain a three-dimensional point cloud data set;

[0046] Determine the symmetry axis of the three-dimensional point cloud data set as the symmetry axis of the blade;

[0047] intercepting the three-dimensional point cloud data set with a plane parallel to the blade symmetry axis and perpendicular to the detection plane, aggregating parts of the three-dimensional point cloud data set located on the same section, and obtaining a two-dimensional profile for each section;

[0048] Determine a position in the two-dimensional profile having a maximum support angle variation as a blade tip position;

[0049] Determining the distance between the tip position of the blade and the tower on which the wind turbine blade is mounted;

[0050] When the distance between the tip of the blade and the tower is abnormal, a first alarm message is generated.

[0051] On the other hand, an embodiment of the present invention further includes a storage medium storing a program executable by a processor, wherein the program executable by the processor is used to execute the contactless wind turbine blade bending monitoring method in the embodiment when executed by the processor.

[0052] The beneficial effects of the present invention are as follows: by performing radar detection on wind turbine blades and analyzing the echo signals, data such as the distance between the tip position of the blade and the tower can be obtained, and a first alarm message can be generated based on the abnormality of the data. Since data such as the distance between the tip position of the blade and the tower can reflect the normal degree of bending of the wind turbine blades, if the distance between the tip position of the blade and the tower is abnormal, it indicates that the bending of the wind turbine blades exceeds the normal range, thereby generating an alarm message, which can remind maintenance personnel to perform maintenance operations to ensure the safe operation of the wind turbine generator. During the monitoring process, the radar module does not need to contact the wind turbine blades, will not affect the operation of the wind turbine blades, and is insensitive to interference factors such as ambient background light, ambient vibration and airflow, and the measurement results are more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A schematic diagram of the installation position of the radar module in the embodiment;

[0054] Figure 2 A schematic diagram of a spatial rectangular coordinate system in an embodiment;

[0055] Figure 3 is a flow chart of a method for monitoring fan blade bending in an embodiment;

[0056] Figure 4 A schematic diagram of plane interception of three-dimensional point cloud data in an embodiment;

[0057] Figure 5 is a schematic diagram of a two-dimensional profile on a cross section in an embodiment;

[0058] Figure 6 is a schematic diagram of a support angle in an embodiment;

[0059] Figure 7 is a schematic diagram of a pre-bent portion of a fan blade in an embodiment;

[0060] Figure 8 It is a schematic diagram of the blade leeward surface curve obtained by fitting in the embodiment. DETAILED DESCRIPTION

[0061] In this embodiment, a fan blade bending monitoring system can be used to execute a fan blade bending monitoring method, wherein the fan blade bending monitoring system includes a radar module and a processing module, the radar module refers to a functional unit that can emit a beam and detect an echo, and the processing module refers to a functional unit that can control the operation of the radar module and analyze and process the echo. The radar module and the processing module can be integrated into a whole product or can be separately set. For example, the radar module is separately packaged into a whole, and a server set in the cloud is used as a processing module. The radar module and the processing module are connected through a communication network.

[0062] In this embodiment, refer to Figure 1 , a radar module can be installed on the tower of a wind turbine that is in normal operation or in research and testing. The wind turbine is located at the position shown in ① on the tower, and the radar module can be installed at the position shown in ② or ③ on the windward side of the tower, and the antenna surface of the radar module can face the direction of the wind turbine blades. If the wind direction of the wind turbine installation site changes frequently, a variable direction mechanism can be used to install the radar module on the tower so that the radar module can rotate around the tower so that the radar module antenna surface remains facing the direction of the wind turbine blades.

[0063] In this embodiment, refer to Figure 1 , the installation position of the radar module can vary at various heights between positions. The algorithm process of this embodiment is described by taking the radar module installed at position as an example, and the height of the position from the ground is slightly higher than the height of the blade tip from the ground. For the convenience of description, a coordinate system can be established first. Figure 2, establish a spatial rectangular coordinate system O-xyz, in which the rotating surface of the fan blade can be used as the detection plane, specifically a rotating surface of the hub part of the fan blade is used as the radar detection plane, the intersection of the beam emitted by the radar module and the radar detection plane is used as the origin O, the vertical upward direction is used as the positive direction of the z-axis, and the direction from the radar detection plane to the radar antenna aperture is used as the positive direction of the x-axis. The distance between the detection plane and the antenna aperture is d, and the specific value of d can be set by adjusting the position of the radar module and setting the working parameters of the radar module when installing the radar module.

[0064] In this embodiment, refer to Figure 3 The fan blade bending monitoring method performed by the fan blade bending monitoring system comprises the following steps:

[0065] S1. Using the rotating surface of the fan blade as the detection plane, radar detection is performed on the detection plane to obtain an echo signal;

[0066] S2. Determine the scattering distribution in space according to the echo signal to obtain a three-dimensional point cloud data set;

[0067] S3. Determine the symmetry axis of the three-dimensional point cloud data set as the symmetry axis of the blade;

[0068] S4. intercepting the three-dimensional point cloud data set with a plane parallel to the blade symmetry axis and perpendicular to the detection plane, aggregating the parts of the three-dimensional point cloud data set located on the same section, and obtaining a two-dimensional profile for each section;

[0069] S5. determining the position with the maximum change of the support angle in the two-dimensional profile as the blade tip position;

[0070] S6. Determine the distance between the blade tip position and the tower on which the wind turbine blade is mounted;

[0071] S7. When the distance between the tip of the blade and the tower is abnormal, a first alarm message is generated.

[0072] Step S1 may be performed by a radar module in the fan blade bending monitoring system. Other steps except step S1 may be performed by a processing module in the fan blade bending monitoring system.

[0073] In step S1, the radar module moves along the O-yz plane using a phased array beam, where the wave number of the phased array beam is k, and the components of k in the three orthogonal directions of x, y and z are k x , k y , k z ,satisfy The echo signal obtained by the radar module is represented as E(y,z,k).

[0074] In step S2, according to the formula E(x,y,k)=∫∫∫σ(x,y,z)·exp[-j(k x x+k y y+k z z)]dxdydz performs three-dimensional orthogonal decomposition of the echo signal E(y,z,k), according to the formula σ(x,y,z)=IFT 3D {FT 2D {E(x,y,k)}} transforms the echo signal E(y,z,k) from the spatial domain to the wavenumber domain and performs a plane wave expansion to obtain the three-dimensional spatial distribution σ(x,y,z).

[0075] The three-dimensional spatial distribution σ(x, y, z) is obtained by calculation, that is, the scattering coefficient of each point in the three-dimensional imaging area is obtained, and the three-dimensional imaging result is obtained.

[0076] Next, the detection threshold is set, and the scattering points in the three-dimensional spatial distribution are determined according to the size relationship between the scattering coefficient of each point in the three-dimensional spatial distribution and the detection threshold. Specifically, the points in the three-dimensional spatial distribution with a scattering coefficient greater than the detection threshold can be determined as scattering points. All scattering points constitute the three-dimensional point cloud data set C 3d .

[0077] In step S3, the three-dimensional point cloud dataset C is determined 3d Specifically, the minimum inertia method is used to determine the 3D point cloud dataset C 3d In this embodiment, refer to Figure 2 , the radar antenna aperture is parallel to the radar detection plane, and the three-dimensional point cloud dataset C 3d Project it onto the detection plane, that is, the O-yz plane, and obtain the projection point set. Detect the symmetry axis of the projection point set on the detection plane. First, take a straight line f(z)=ky+b on the O-yz plane, and regard each point in the projection point set as a mass point. The mass of a point is numerically the same as the amplitude of the point. For example, for N points in the projection point set, each point can be represented by the coordinates (y i ,z i ) indicates that the amplitude of each point is μ, then the moment of inertia of the projected point set relative to the straight line f(z)=ky+b is in Its meaning is that the point (y i ,z i ) and the straight line f(z) = ky + b, that is, the moment of inertia of the projection point set relative to the straight line is the cumulative value of the product of the mass of each projection point and the distance relative to the straight line. Find the corresponding parameters k and b when I takes the minimum value, and the straight line f(z) = ky + b determined by the parameters k and b is the 3D point cloud data set C3d The symmetry axis of the blade.

[0078] In step S4, refer to Figure 4 , the 3D point cloud dataset is intercepted by a plane parallel to the blade symmetry axis and perpendicular to the detection plane. Each plane generates a cross section after intercepting the 3D point cloud dataset. The parts of the 3D point cloud dataset located on the same cross section are aggregated. Each cross section has a 2D contour formed by intercepting the 3D point cloud dataset. Each 2D contour can be generally expressed as Γ 2d .

[0079] The two-dimensional profile on one of the cross sections is as follows Figure 5 As shown, Figure 5 The plane is one of the cross sections, each triangle represents a point on the cross section in the three-dimensional point cloud dataset, and the dotted line on the edge represents a two-dimensional contour on the cross section, which can be specifically represented as a curve Γ(y,z).

[0080] In step S5, a corner point detection method based on sharpness is used to obtain a two-dimensional contour Γ 2d The position where the support angle changes the most is the position of the blade tip. Figure 6 As shown, for one of the two-dimensional contours Γ 2d , take the two-dimensional profile Γ 2d Any point P i , take this point as the center and take the two-dimensional contour Γ 2d The fragment that supports the point is the two points P at a distance k from the point. i-k and P i+k Define the line segment P i P i-1 and P i P i+1 The angle α between the two is the support angle of the point. The smaller the support angle, the sharper the point is. Find Γ 2d The point with the largest change in upper support angle, and all two-dimensional contours Γ 2d The point with the largest change in support angle is compared to determine the point with the largest change in support angle as the blade tip position P tip .

[0081] After executing steps S1 to S5, data such as the blade symmetry axis, the two-dimensional profile, and the blade tip position can be obtained.

[0082] Reference Figure 3, on the basis of executing steps S1-S4, S5-S7 can be executed. Specifically, in step S6, in the O-xyz coordinate system, the position of the radar module is (-d, 0, 0). Since the blades rotate and remain on the same plane, the difference between the x-coordinate of each point and the x-coordinate (-d) of the radar module can be used as the distance between the blade and the vertical plane where the radar is located when the blade is in a vertical position. Then, combined with the installation method of the radar module and the shape of the wind turbine tower, the distance between the tip of the blade and the tower is calculated. Specifically, according to the two-dimensional profile Γ corresponding to the section passing through the leeward side of the wind turbine blade 2d For each point on the O-xyz coordinate system, obtain the distribution range of its z coordinate in the O-xyz coordinate system [z1,2]. Since the wind turbine tower is rotationally symmetrical, according to the tower design data and the radar installation height, calculate the radius r(z) of the wind turbine tower within the height range of [h1+z1,h1+z2] above the ground on the wind turbine tower. The vertical distance from the radar module installation position to the wind turbine tower rotation center is d r Indicates that the distance between each point on the leeward contour and the z-axis in [z1,z2] is d t Then, the distance between the blade and the radar plane and the distance between the tower and the radar plane are added to obtain the distance L(z) between the leeward side of the wind turbine blade and the windward side of the tower, that is, L(z) = d t (z)+[d r -r(z)]. The minimum value of L(z) is taken as the distance between the wind turbine tower and the tip of the wind turbine blade and output.

[0083] In step S7, the distance between the blade tip position and the wind turbine tower is compared with a normal range, where the normal range can be determined through testing or the manufacturer's instructions. If the distance between the blade tip position and the wind turbine tower is not within the normal range, then it is determined that the distance between the blade tip position and the wind turbine tower is abnormal, and a first alarm message is generated.

[0084] Reference Figure 3 , based on the execution of steps S1-S5, S8-S10 can be executed. Specifically, in step S8, by consulting the construction records when installing the wind turbine, the radar installation height h1, the wind turbine blade rotation center height h2, and the angle θ between the blade symmetry axis and the vertical direction can be determined. Then, the blade tip position P tip The coordinates in the corresponding section are converted to the O-xyz coordinate system to determine the blade tip position P tip The coordinates in the spatial coordinate system O-xyz are (x tip ,y tip ,z tip ). In step S9, according to the vertical height component z of the blade tip position tip, radar installation height h1, fan blade rotation center height h2, and the angle θ between the blade symmetry axis and the vertical direction, the blade length L can be calculated. The specific calculation formula is:

[0085] L=(h2-h1-z tip ) / cosθ.

[0086] In step S10, the blade length L is compared with a normal range, wherein the normal range can be determined by testing or manufacturer's instructions. If the blade length L is not within the normal range, the blade length L is judged to be abnormal, and a second alarm message is generated.

[0087] Reference Figure 3 , based on the execution of steps S1-S4, S11-S14 can be executed. Specifically, in step S11, a contour line is determined as a reference line from the two-dimensional contour corresponding to the cross section passing through the leeward side of the fan blade. The contour line used as the reference line should meet the following conditions: Figure 6 The support angle changes of each part calculated by the method shown are all less than a set threshold value, that is, the sudden change of the contour line used as the reference line is small. In step S12, the above points P are determined from the two-dimensional contour corresponding to the cross section passing through the windward surface of the fan blade. i The vertical distance to the reference line r i In step S13, each point P i The vertical distance to the reference line r i Mapping into a blade thickness variation curve, for example, establishing a plane rectangular coordinate system and plotting points, the horizontal coordinates of the plotted points are based on the point P i The coordinates or numbers of the points are the same or have a linear function relationship. The vertical coordinate of the point drawn is the point P corresponding to the horizontal coordinate. i The corresponding vertical distance r i The plotted points directly form or are fitted to obtain the blade thickness variation curve.

[0088] In step S14, the root mean square error between the blade thickness change curve and the normal curve is calculated, and a threshold for judging whether the root mean square error is too large is determined through testing or the manufacturer's instructions. If the root mean square error between the blade thickness change curve and the normal curve is too large compared with the threshold, it is judged that the blade thickness change curve deviates from the normal curve, and a third alarm information is generated.

[0089] Reference Figure 3 , based on the execution of steps S1-S4, S15-S18 can be executed. Specifically, in step S15, the pre-bent portion curve of the leeward surface of the wind turbine blade is obtained, referring to Figure 7If there is a pre-bent part on the fan blade, the pre-bent part curve can be obtained from the fan blade design data. Figure 8 As shown in the B1B2 section of the reference Figure 8 Taking the upper end point B2 of the pre-bent portion curve B1B2 as the starting point and the connection point B3 between the fan blade and the shaft as the end point, a quadratic interpolation fitting is performed on the two-dimensional profile corresponding to the cross section passing through the leeward side of the fan blade to obtain a fitting curve. Figure 8 The portion indicated by B2B3 is a fitting curve. In step S17, the pre-bent portion curve B1B2 is spliced ​​with the fitting curve B2B3 to obtain the blade leeward surface curve B1B3.

[0090] In step S18, the root mean square error between the blade leeward surface curve and the normal curve is calculated, and a threshold for judging whether the root mean square error is too large is determined through testing or the manufacturer's instructions. If the root mean square error between the blade leeward surface curve and the normal curve is too large compared with the threshold, it is judged that the blade leeward surface curve deviates from the normal curve, and a fourth alarm information is generated.

[0091] In this embodiment, the non-contact wind turbine blade bending monitoring system can obtain data such as the distance between the blade tip position and the tower, the blade length, the blade thickness change curve, and the blade leeward surface curve by performing radar detection on the wind turbine blade and analyzing the echo signal, and generate the first alarm information, the second alarm information, the third alarm information, and the fourth alarm information according to the abnormality of these data. Since the data such as the distance between the blade tip position and the tower, the blade length, the blade thickness change curve, and the blade leeward surface curve can reflect the normal degree of the bending of the wind turbine blade, as long as one of the data such as the distance between the blade tip position and the tower, the blade length, the blade thickness change curve, and the blade leeward surface curve is abnormal, it indicates that the bending of the wind turbine blade exceeds the normal range, thereby generating an alarm information, which can remind the maintenance personnel to perform maintenance operations, etc., to ensure the safe operation of the wind turbine generator. During the monitoring process, the radar module does not need to contact the wind turbine blade, will not affect the operation of the wind turbine blade, and is insensitive to interference factors such as ambient background light, ambient vibration, and airflow, and the measurement result is more accurate.

[0092] A computer program for executing the contactless fan blade bending monitoring method in this embodiment can be written and written into a computer device or storage medium. When the computer program is read out and run, the contactless fan blade bending monitoring method in this embodiment is executed, thereby achieving the same technical effect as the contactless fan blade bending monitoring method in the embodiment.

[0093] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it may be directly fixed or connected to another feature, or it may be indirectly fixed or connected to another feature. In addition, the descriptions of up, down, left, right, etc. used in this disclosure are only relative to the relative positional relationship of the components of the present disclosure in the accompanying drawings. The singular forms of "a", "said" and "the" used in this disclosure are also intended to include the plural forms, unless the context clearly indicates other meanings. In addition, unless otherwise defined, all technical and scientific terms used in this embodiment have the same meaning as those generally understood by technicians in this technical field. The terms used in the specification of this embodiment are only for describing specific embodiments, not for limiting the present invention. The term "and / or" used in this embodiment includes any combination of one or more related listed items.

[0094] It should be understood that, although the term first, second, third etc. may be adopted to describe various elements in the present disclosure, these elements should not be limited to these terms. These terms are only used to distinguish the same type of elements from each other. For example, without departing from the scope of the present disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element. The use of any and all examples or exemplary language ("for example", "such as" etc.) provided by the present embodiment is only intended to better illustrate embodiments of the present invention, and unless otherwise required, the scope of the present invention will not be limited.

[0095] It should be appreciated that embodiments of the present invention may be implemented or enforced by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable memory. The method may be implemented in a computer program using standard programming techniques - including a non-transitory computer-readable storage medium configured with a computer program, wherein the storage medium so configured causes the computer to operate in a specific and predefined manner - according to the methods and drawings described in the specific embodiments. Each program may be implemented in a high-level procedural or object-oriented programming language to communicate with a computer system. However, if desired, the program may be implemented in an assembly or machine language. In any case, the language may be a compiled or interpreted language. In addition, the program may be run on a programmed ASIC for this purpose.

[0096] In addition, the operations of the process described in this embodiment may be performed in any suitable order, unless otherwise indicated in this embodiment or otherwise clearly contradicted by the context. The process described in this embodiment (or variations and / or combinations thereof) may be performed under the control of one or more computer systems configured with executable instructions, and may be implemented as a code (e.g., executable instructions, one or more computer programs, or one or more applications) executed jointly on one or more processors, by hardware or a combination thereof. The computer program includes a plurality of instructions that may be executed by one or more processors.

[0097] Further, the method can be implemented in any type of computing platform that is operably connected to a suitable computer, including but not limited to a personal computer, a minicomputer, a mainframe, a workstation, a network or distributed computing environment, a separate or integrated computer platform, or in communication with a charged particle tool or other imaging device, etc. Various aspects of the present invention can be implemented in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, an optical read and / or write storage medium, a RAM, a ROM, etc., so that it can be read by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the process described herein. In addition, the machine-readable code, or a portion thereof, can be transmitted via a wired or wireless network. When such media includes instructions or programs that implement the steps described above in conjunction with a microprocessor or other data processor, the invention described in this embodiment includes these and other different types of non-transitory computer-readable storage media. When programmed according to the methods and techniques of the present invention, the present invention also includes the computer itself.

[0098] The computer program can be applied to input data to perform the functions described in the present embodiment, thereby converting the input data to generate output data stored in a non-volatile memory. The output information can also be applied to one or more output devices such as a display. In a preferred embodiment of the present invention, the converted data represents a physical and tangible object, including a specific visual depiction of the physical and tangible object produced on the display.

[0099] The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of protection of the present invention. Within the scope of protection of the present invention, its technical scheme and / or implementation method may have various modifications and changes.

Claims

1. A non-contact fan blade bending monitoring method, characterized in that: include: Using the rotating surface of the fan blade as a detection plane, performing radar detection on the detection plane to obtain an echo signal; Determine the scattering distribution in space according to the echo signal to obtain a three-dimensional point cloud data set; Determine the symmetry axis of the three-dimensional point cloud data set as the symmetry axis of the blade; intercepting the three-dimensional point cloud data set with a plane parallel to the blade symmetry axis and perpendicular to the detection plane, aggregating parts of the three-dimensional point cloud data set located on the same section, and obtaining a two-dimensional profile for each section; Determine a position in the two-dimensional profile having a maximum support angle variation as a blade tip position; The support angle is a line segment and Angle ,in , and For the two-dimensional profile The point in Determining the distance between the tip position of the blade and the tower on which the wind turbine blade is mounted; When the distance between the tip of the blade and the tower is abnormal, a first alarm message is generated.

2. The non-contact wind turbine blade bending monitoring method according to claim 1, characterized in that: Also includes: Obtaining the radar installation height, the height of the center of rotation of the wind turbine blades, and the angle between the blade symmetry axis and the vertical direction; Determine the blade length according to the radar installation height, the height of the rotation center of the fan blade, the angle between the blade symmetry axis and the vertical direction, and the blade tip position; When the blade length is abnormal, a second alarm message is generated.

3. The non-contact wind turbine blade bending monitoring method according to claim 2, characterized in that: The determining of the blade length according to the radar installation height, the height of the rotation center of the fan blade, the angle between the blade symmetry axis and the vertical direction, and the blade tip position includes: According to the formula Calculate; where is the radar installation height, is the rotation center height of the fan blade, is the vertical component of the blade tip position, is the angle between the blade symmetry axis and the vertical direction.

4. The non-contact wind turbine blade bending monitoring method according to claim 1, characterized in that: Also includes: Determine a contour line as a reference line from the two-dimensional contour corresponding to the cross section passing through the leeward surface of the fan blade; The support angle change in the reference line is less than a threshold value; Determine the vertical distance from each point to the reference line from the two-dimensional profile corresponding to the cross section passing through the windward surface of the fan blade; Mapping the vertical distance from each point to the reference line into a blade thickness variation curve; When the blade thickness variation curve is abnormal, a third alarm message is generated.

5. The non-contact wind turbine blade bending monitoring method according to claim 1, characterized in that: Also includes: Obtaining a pre-bent portion curve of the leeward surface of the fan blade; Taking the pre-bent portion curve as a starting point and the connection point between the fan blade and the rotating shaft as an end point, fitting the two-dimensional profile corresponding to the cross section passing through the leeward surface of the fan blade to obtain a fitting curve; splicing the pre-bent portion curve with the fitting curve to obtain a blade leeward surface curve; When the leeward surface curve of the blade is abnormal, a fourth alarm message is generated.

6. The non-contact wind turbine blade bending monitoring method according to any one of claims 1 to 5, characterized in that: Determining the scattering distribution in space according to the echo signal to obtain a three-dimensional point cloud data set includes: Performing three-dimensional spatial orthogonal decomposition, spatial domain to wave number domain transformation and plane wave expansion on the echo signal to obtain a three-dimensional spatial distribution; Setting a detection threshold, and determining scattering points in the three-dimensional spatial distribution according to a magnitude relationship between the scattering coefficient of each point in the three-dimensional spatial distribution and the detection threshold; The three-dimensional point cloud data set is composed of the scattered points.

7. The non-contact wind turbine blade bending monitoring method according to any one of claims 1 to 5, characterized in that: The step of determining the symmetry axis of the three-dimensional point cloud data set as the symmetry axis of the blade includes: Projecting the three-dimensional point cloud data set onto the detection plane to obtain a projection point set; A straight line is selected on the detection plane, and when the moment of inertia of the projection point set relative to the straight line is the smallest, the straight line is used as the symmetry axis of the blade.

8. The non-contact wind turbine blade bending monitoring method according to claim 7, characterized in that: The moment of inertia of the projection point set relative to the straight line is determined by the following steps: Obtaining the amplitude of each projection point in the projection point set; Get the distance of each projection point relative to the straight line; The amplitude of each projection point is set to the mass of the same projection point; The moment of inertia of the projection point set relative to the straight line is determined according to the cumulative value of the product of the mass of each projection point and the distance relative to the straight line.

9. A non-contact fan blade bending monitoring system, characterized in that: include: A radar module is used to use the rotating surface of the fan blade as a detection plane, perform radar detection on the detection plane, and obtain an echo signal; Processing modules for: Determine the scattering distribution in space according to the echo signal to obtain a three-dimensional point cloud data set; Determine the symmetry axis of the three-dimensional point cloud data set as the symmetry axis of the blade; intercepting the three-dimensional point cloud data set with a plane parallel to the blade symmetry axis and perpendicular to the detection plane, aggregating parts of the three-dimensional point cloud data set located on the same section, and obtaining a two-dimensional profile for each section; Determine a position in the two-dimensional profile having a maximum support angle variation as a blade tip position; The support angle is a line segment and Angle ,in , and For the two-dimensional profile The point in Determining the distance between the tip position of the blade and the tower on which the wind turbine blade is mounted; When the distance between the tip of the blade and the tower is abnormal, a first alarm message is generated.

10. A storage medium storing a program executable by a processor, characterized in that: The processor-executable program is used to execute the contactless wind turbine blade bending monitoring method as described in any one of claims 1-8 when executed by the processor.

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