Wind driven generator blade deformation monitoring method based on micro inertial device and satellite navigation

Abstract

The invention provides a wind driven generator blade deformation monitoring method based on a micro inertial device and satellite navigation, and the method comprises the steps: firstly, selecting a deformation detection point on each blade of a wind driven generator, and installing a micro inertial measurement unit and a satellite navigation system at each detection point; measuring point satellite position information and attitude information when the blade is static are collected for initial calibration; and then, completing data acquisition of an inertia measurement unit and a satellite navigation system in a real-time measurement stage under a real working condition of the blade, carrying out inertia / satellite integrated navigation calculation, and finally, realizing deformation displacement and deformation angle calculation of the fan blade based on coordinate conversion. An effective scheme is provided for online collection of deformation data of the fan blade and health detection of the fan in a real working scene, and the method has important practical application value.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine blade health monitoring technology, specifically relating to a method for monitoring wind turbine blade deformation based on micro inertial devices and satellite navigation. Background Technology

[0002] Wind turbine blades are key components for receiving wind energy, and their reliability directly affects the safe operation of the turbine. Megawatt-class wind turbine blades have a span exceeding 25 meters, with some reaching 60 meters. During high-speed rotation, the blades bear heavy loads, increasing the probability of breakage and bending. Therefore, health monitoring of blade deformation is crucial for optimizing blade structural design, risk warning, and fault diagnosis. Currently, blade deformation information is mainly obtained through two methods: mechanical modeling and direct measurement. Because the load on blades is complex, including aerodynamic forces, inertial forces, centrifugal forces, and their own weight, and influencing factors encompass wind speed, wind direction, laminar flow distribution, blade icing, and mechanical structure, directly modeling the stress on the wind turbine is difficult and cannot cover all application scenarios. Direct measurement of wind turbine deformation is a more practical and effective approach.

[0003] Wind turbines are installed in harsh environments, and their blades operate under unique conditions with high rotation speeds. Traditional measurement methods are often suitable for static measurements in laboratories or at the factory, and are difficult to apply directly to real-world rotating conditions. Traditional deformation measurement methods mainly include: resistance strain gauge measurement, fiber optic grating deformation measurement, and laser projection. Resistance strain gauges can directly calculate strain data from multiple monitoring points on the blade, thus reconstructing the blade deformation results. However, this method uses wired connections, resulting in a large installation workload for the sensors and their conditioning modules, and complex test wiring, making it only suitable for static detection. While fiber optic grating deformation measurement is lightweight and free from electromagnetic interference, its sensors are based on glass fibers, which are fragile and easily broken, making them unreliable in scenarios with rapidly rotating wind turbine blades. Laser projection can perform non-contact measurements of the blade profile, but this method requires unobstructed views and is currently mainly used for detecting the structural dimensions and deformation of static blades. Furthermore, its accuracy is low, making it difficult to meet the requirements for real-time dynamic deformation monitoring of blades.

[0004] Therefore, it is evident that existing solutions are insufficient for high-speed and accurate deformation measurement of wind turbine blades under operating conditions. Real-time dynamic deformation monitoring of wind turbines has become a major challenge in wind turbine blade design and health maintenance. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0006] To address this, the present invention provides a method for monitoring wind turbine blade deformation based on micro-inertial devices and satellite navigation. The proposed solution, based on position measurement via satellite navigation, simultaneously outputs attitude information through inertial-based integrated navigation, increases the measurement frequency of blade deformation, and achieves high-precision time synchronization of multiple measurement points using the second pulse signal from satellite navigation. This provides an effective solution for online acquisition of wind turbine blade deformation data and wind turbine health monitoring in real-world operating scenarios, and has significant practical application value.

[0007] The technical solution of this invention is as follows: This invention provides a method for monitoring the deformation of wind turbine blades based on micro inertial devices and satellite navigation, the method comprising:

[0008] Step 1: Select deformation detection points on each blade of the wind turbine;

[0009] Step 2: Install a micro inertial measurement unit and a satellite navigation system at the deformation detection point;

[0010] Step 3: Perform pre-calibration of wind turbine blade information. The pre-calibration information includes the blade coordinate system and initial blade shape information.

[0011] Step 4: Real-time acquisition of micro-inertial measurement unit and satellite navigation information at each detection point on the blade;

[0012] Step 5: Based on the measurement data from the micro inertial device and the satellite navigation data, calculate the inertial / satellite integrated navigation results for each measurement point;

[0013] Step 6: Calculate the deformation displacement and deformation angle of the measuring point based on the results of Steps 3 and 5.

[0014] Furthermore, the method for selecting deformation detection points for wind turbine blades is as follows:

[0015] Draw a straight line from the base of the leaf to the tip of the leaf. Select five detection points on the line: the base of the leaf, the midpoint of the line, the tip of the leaf, the midpoint of the line connecting the base of the leaf and the midpoint of the line, and the midpoint of the line connecting the tip of the leaf and the midpoint of the line.

[0016] Furthermore, step two specifically includes:

[0017] A micro inertial measurement unit is installed at the deformation detection point;

[0018] The satellite navigation system uses a satellite navigation system with RTK functionality, and its specific component composition and installation method are as follows:

[0019] A satellite navigation reference station and an RTK transmitter are installed within a predetermined distance on the ground. The antennas of the satellite navigation reference station and the RTK transmitter must be fixed and installed in an area without signal obstruction. A satellite navigation system with RTK functionality is installed at each deformation detection point. This system consists of four parts: a chip-level rover navigation calculation circuit, a chip-level RTK receiver, a miniature rover receiver antenna, and a miniature RTK receiver antenna. The rover navigation calculation circuit and the satellite navigation reference station are configured with a matching communication protocol. A dual-antenna satellite navigation positioning and orientation system is installed at the central shaft of the wind turbine, with two antennas installed along the straight line of the shaft.

[0020] Furthermore, satellite navigation reference stations and RTK transmitters are installed within a 100-meter radius on the ground.

[0021] Furthermore, step three specifically includes:

[0022] 1) Calibration data acquisition:

[0023] Select a windless day, activate the ground reference station and satellite navigation systems at each measuring point, set the blades to stand still for a set time, and collect the rotational data of the wind turbine's central shaft within that time period. Record this data as follows: Counterclockwise is positive, horizontal is zero;

[0024] The position information of the dual-antenna satellite navigation system at the center shaft of the wind turbine is collected within a set static time period, and the average value is calculated and denoted as .

[0025] The heading angle information of the dual-antenna satellite navigation system at the center shaft of the wind turbine is collected within a set stationary time period, and the average value is calculated and denoted as . Counterclockwise is positive, north is zero;

[0026] The position information transmitted by the RTK satellite navigation chip at each wind turbine blade measuring point within a set static time period is collected and the average value is calculated. The position information of the j-th measuring point on the i-th blade is denoted as... Among them, the measuring point j at the root of the leaf is 1, and the measuring point j from the root of the leaf to the top of the leaf is incremented by one in sequence;

[0027] When stationary, the micro-inertial measurement units at each measuring point perform initial alignment, and the roll angle results obtained from the initial alignment are recorded. Record the pitch angle results obtained from the initial alignment as follows Where i and j represent the i-th leaf and the j-th measuring point. The measuring point j at the root of the leaf is 1, and the measuring point j is incremented by one from the root of the leaf to the top of the leaf.

[0028] 2) Establishment of the blade coordinate system:

[0029] For each blade, a blade coordinate system is established. The blade coordinate system for the i-th blade is defined as follows: the origin is set to... The X-axis is defined by the direction from back to front of the two satellite antennas at the central shaft of the wind turbine, and the Y-axis is defined by the direction from the root of the wind turbine blade to the tip of the blade. The Z-axis is designed according to the right-hand rule with respect to the X-axis and Y-axis.

[0030] 3) Calculation of initial blade shape information:

[0031] Initial shape information of a blade refers to the relative position of each measuring point on the blade with respect to the blade root when the blade is undeformed. The calculation steps are as follows:

[0032]

[0033] in, The coordinate transformation matrix is ​​calculated using the following formula:

[0034]

[0035] Furthermore, the time limit is set to ten minutes.

[0036] Furthermore, step four specifically includes:

[0037] 1) Satellite navigation data acquisition:

[0038] Activate the ground reference station and satellite navigation systems at each measuring point to collect the rotation data of the wind turbine's central shaft, denoted as γ. cente Counterclockwise is positive, horizontal is zero. The position information of the dual-antenna satellite navigation system at the center shaft of the wind turbine is collected and denoted as P. center (x center ,y center ,z center ); Collect the heading angle information of the dual-antenna satellite navigation system at the center shaft of the wind turbine, denoted as ψ. center Counterclockwise is positive, and north is zero; the position information sent by the RTK satellite navigation chip at each wind turbine blade measuring point is collected, and the position information of the j-th measuring point on the i-th blade is denoted as P. i,j (x i,j ,y i,j ,z i,j ), where the measuring point j at the root of the leaf is 1, and the measuring point j from the root of the leaf to the top of the leaf is incremented by one in sequence;

[0039] 2) Inertial Measurement Unit Data Acquisition:

[0040] The micro-inertial measurement unit outputs gyroscope and accelerometer data from each wind turbine blade measuring point. The gyroscope data from the j-th measuring point on the i-th blade is denoted as... In this system, the measuring point j at the blade root is set to 1, and the measuring points j from the blade root to the blade tip are incremented by one sequentially. The accelerometer data at the j-th measuring point of the i-th blade is denoted as... Among them, the measuring point j at the root of the leaf is 1, and the measuring point j from the root of the leaf to the top of the leaf is incremented by one.

[0041] Furthermore, step five specifically includes:

[0042] 1) Establish the state equations and measurement equations of the integrated navigation system:

[0043] The state equation is X k =Φ k,k-1 X k-1 +w k-1 , where Φ k,k-1 For t k Time to t k-1 The one-step transition matrix at time t; w k-1 For the system excitation noise sequence at t k-1 The value at time, X k For state variables at t k The value at time, X k-1 For state variables at t k-1 The value at time, X k Including the north-to-east misalignment angle North-East Velocity Error δv n =[δV n δV u δV e ] T Latitude error Altitude error δh, longitude error δλ, and gyroscope drift ε of the carrier system b =[ε x ε y ε z ] T Zero bias of the accelerometer in the load system Load system arm error L out Time delay T d ;

[0044] The measurement equation is Z k =H k X k +V k Among them, Z k For measurement at t k The value at time t, that is, the difference between the position and velocity information output by satellite navigation and the position and velocity information calculated by inertial navigation. k The value at time; H k For the measurement matrix at t k The value at time; V kTo measure the noise sequence at t k The numerical value at any given time;

[0045] 2) Based on the state equation and measurement equation, the inertial navigation error X is calculated using the Kalman filter algorithm. k ;

[0046] 3) Based on the inertial navigation error estimation result X k Correcting inertial navigation:

[0047] Based on the inertial navigation error estimation result X k The inertial navigation system is calibrated to obtain precise position and attitude information for each measuring point. The position information of the j-th measuring point on the i-th blade is denoted as P. i,j (x i,j ,y i,j ,z ij The measurement point j at the leaf root is marked as 1, and the measurement points j from the leaf root to the leaf tip are incremented by one sequentially; the roll angle result of the j-th measurement point of the i-th leaf is γ. i,j The pitch angle of the i-th blade at the j-th measuring point is θ. i,j , where i and j represent the i-th leaf and the j-th measuring point. The measuring point j at the leaf root is 1, and the measuring point j is incremented by one from the leaf root to the leaf tip.

[0048] Furthermore, in step six, the deformation displacement of the measuring point is obtained in the following manner:

[0049] Calculate the projection of the relative position of the blade measuring point with respect to the center of the rotation axis in the blade coordinate system. The calculation formula is as follows:

[0050]

[0051] in, The coordinate transformation matrix is ​​calculated using the following formula:

[0052]

[0053] Projection of the relative position of the blade measuring point with respect to the center of the rotation shaft in the blade coordinate system Subtracting the initial shape information of the blade yields the blade deformation displacement information ΔP. i,j (x i,j ,y i,j ,z i,j The calculation formula is:

[0054]

[0055] Furthermore, in step six, the deformation angle of the measuring point is obtained in the following way:

[0056] The deformation angle of the measuring point includes the roll angle of the blade. and bending angle The formulas for calculating the changes in pitch and roll angles, corresponding to the inertial / satellite integrated navigation systems, are as follows:

[0057]

[0058] Where i and j represent the j-th measurement point of the i-th leaf, the measurement point j at the root of the leaf is 1, and the measurement point j from the root of the leaf to the top of the leaf is incremented by one.

[0059] The above technical solution addresses the challenge of real-time measurement of wind turbine blade deformation. First, deformation detection points are selected on each wind turbine blade, and a micro inertial measurement unit (IMU) and satellite navigation system are installed at each point. Satellite position and attitude information of the measurement points when the blade is stationary is collected for initial calibration. Then, during the real-time measurement phase under actual blade operating conditions, data acquisition by the IMU and satellite navigation system is completed, and inertial / satellite combined navigation calculations are performed. Finally, based on coordinate transformation, the deformation displacement and deformation angle of the wind turbine blade are calculated. This ultimately forms an online monitoring method for wind turbine blade deformation based on micro inertial devices and satellite navigation.

[0060] The proposed solution, based on satellite navigation for position measurement, simultaneously outputs attitude information through inertial-based integrated navigation, increases the measurement frequency of blade deformation, and achieves high-precision time synchronization of multiple measurement points using the second pulse signal from satellite navigation. This provides an effective solution for online acquisition of wind turbine blade deformation data and wind turbine health monitoring in real-world operating scenarios, and has significant practical application value. Attached Figure Description

[0061] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0062] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0063] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0064] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0065] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0066] refer to Figure 1 In one embodiment of the present invention, a method for detecting wind turbine blade deformation based on micro inertial devices and satellite navigation is provided, comprising the following steps:

[0067] Step 1: Select deformation detection points on each blade of the wind turbine.

[0068] The method for selecting deformation detection points for wind turbine blades is as follows:

[0069] Draw a straight line from the base of the leaf to the tip of the leaf. Select five detection points on the line: the base of the leaf, the midpoint of the line, the tip of the leaf, the midpoint of the line connecting the base of the leaf and the midpoint of the line, and the midpoint of the line connecting the tip of the leaf and the midpoint of the line.

[0070] Step 2: Install a micro inertial measurement unit and a satellite navigation system at the deformation detection point.

[0071] The satellite navigation system must be equipped with RTK functionality. The specific components and installation methods are as follows:

[0072] A satellite navigation reference station and an RTK transmitter are installed within a 100-meter radius on the ground. The antennas for both the satellite navigation reference station and the RTK transmitter must be mounted on tripods in an area free from signal obstruction. An RTK-enabled satellite navigation system is installed at each deformation detection point. This system comprises four parts: a chip-level rover navigation calculation circuit, a chip-level RTK receiver, a miniature rover receiver antenna, and a miniature RTK receiver antenna. The rover navigation calculation circuit and the satellite navigation reference station are configured with a matching communication protocol. A dual-antenna satellite navigation positioning and orientation system is installed at the central shaft of the wind turbine, with two antennas installed along the straight line of the shaft.

[0073] Step 3: Pre-calibration of wind turbine blade information

[0074] The blade pre-calibration information includes the blade coordinate system and initial blade shape information. The specific calibration method is as follows:

[0075] 1) Calibration data acquisition:

[0076] Select a windless day, activate the ground reference station and satellite navigation systems at each measuring point, and allow the blades to remain stationary for ten minutes. Collect the rotational position data of the wind turbine's central shaft during these ten minutes of stationary operation, and record it as follows. Counterclockwise is positive, unit is rad, horizontal is zero. The position information of the dual-antenna satellite navigation system at the center shaft of the wind turbine is collected over a ten-minute stationary period, and the average value is calculated and denoted as . The heading angle information of the dual-antenna satellite navigation system at the center shaft of the wind turbine was collected over a static ten-minute period, and the average value was calculated and denoted as . Counterclockwise is positive, unit is rad, north is zero. The position information transmitted by the RTK satellite navigation chip from each wind turbine blade measuring point within a 10-minute stationary period is collected and the average value is calculated. The position information of the j-th measuring point on the i-th blade is denoted as... In this system, the measuring point j at the blade root is set to 1, and the measuring points j from the blade root to the blade tip are incremented by one sequentially. When stationary, the micro-inertial measurement units at each measuring point perform initial alignment, and the roll angle result obtained from the initial alignment is recorded. Record the pitch angle results obtained from the initial alignment as follows Where i and j represent the i-th leaf and the j-th measuring point. The measuring point j at the root of the leaf is 1, and the measuring point j is incremented by one from the root of the leaf to the top of the leaf.

[0077] 2) Establishment of the blade coordinate system:

[0078] For each blade, a blade coordinate system is established. The blade coordinate system for the i-th blade is defined as follows: the origin is set to... The X-axis is defined by the direction from back to front of the two satellite antennas at the central shaft of the wind turbine, and the Y-axis is defined by the direction from the root of the wind turbine blade to the tip of the blade. The Z-axis is designed according to the right-hand rule with respect to the X-axis and Y-axis.

[0079] 3) Calculation of initial blade shape information:

[0080] Initial shape information of a blade refers to the relative position of each measuring point on the blade with respect to the blade root when the blade is undeformed. The calculation steps are as follows:

[0081]

[0082] in, The coordinate transformation matrix is ​​calculated using the following formula:

[0083]

[0084] Step 4: Real-time acquisition of micro-inertial measurement unit and satellite navigation information at each detection point on the blade.

[0085] 1) Satellite navigation data acquisition:

[0086] Activate the ground reference station and satellite navigation systems at each measuring point to collect the rotation data of the wind turbine's central shaft, denoted as γ. cente Counterclockwise is positive, unit is rad, horizontal is zero. The position information of the dual-antenna satellite navigation system at the center shaft of the wind turbine is collected and denoted as P. center (x center ,y center ,z center The heading angle information of the dual-antenna satellite navigation system at the central shaft of the wind turbine is collected and denoted as ψ. center Counterclockwise is positive, unit is rad, north is zero. The position information transmitted by the RTK satellite navigation chip at each wind turbine blade measuring point is collected. The position information of the j-th measuring point on the i-th blade is denoted as P. i,j (x i,j ,y i,j ,z i,j ), where the measuring point j at the root of the leaf is 1, and the measuring point j from the root of the leaf to the top of the leaf is incremented by one in sequence;

[0087] 2) Inertial Measurement Unit Data Acquisition:

[0088] The micro-inertial measurement unit outputs gyroscope and accelerometer data from each wind turbine blade measuring point. The gyroscope data at the j-th measuring point on the i-th blade is denoted as... In this system, the measuring point j at the blade root is set to 1, and the measuring points j from the blade root to the blade tip are incremented by one sequentially. The accelerometer data at the j-th measuring point of the i-th blade is denoted as... Among them, the measuring point j at the root of the leaf is 1, and the measuring point j from the root of the leaf to the top of the leaf is incremented by one in sequence;

[0089] Step 5: Calculate the inertial / satellite integrated navigation results for each measuring point.

[0090] Based on measurement data from micro-inertial devices and satellite navigation data, the inertial / satellite integrated navigation results for each measurement point are calculated. Specific steps include:

[0091] 1) Establish the state equations and measurement equations of the integrated navigation system:

[0092] The state equation is X k =Φ k,k-1 X k-1 +w k-1 , where Φ k,k-1 For t k Time to t k-1 The one-step transition matrix at time t; w k-1 For the system excitation noise sequence at t k-1 The value at time, X k For state variables at t k The value at time, X k-1 For state variables at t k-1 The value at time, X k Including the north-to-east misalignment angle North-East Velocity Error δv n =[δV n δV u δV e ] T Latitude error Altitude error δh, longitude error δλ, and gyroscope drift ε of the carrier system b =[ε x ε y ε z ] T Zero bias of the accelerometer in the load system Load system arm error L out Time delay T d ;

[0093] The measurement equation is Z k =H k X k +V k Among them, Z k For measurement at t k The value at time t, that is, the difference between the position and velocity information output by satellite navigation and the position and velocity information calculated by inertial navigation.k The value at time; H k For the measurement matrix at t k The value at time; V k To measure the noise sequence at t k The numerical value at any given time;

[0094] 2) Based on the state equation and measurement equation, the inertial navigation error X is calculated using the Kalman filter algorithm. k ;

[0095] 3) Based on the inertial navigation error estimation result X k Correcting inertial navigation:

[0096] Based on the inertial navigation error estimation result X k The inertial navigation system is calibrated to obtain precise position and attitude information for each measuring point. The position information of the j-th measuring point on the i-th blade is denoted as P. i,j (x i,j ,y i,j ,z ij The measurement point j at the leaf root is marked as 1, and the measurement points j from the leaf root to the leaf tip are incremented by one. The roll angle result of the j-th measurement point of the i-th leaf is γ. i,j The pitch angle of the i-th blade at the j-th measuring point is θ. i,j , where i and j represent the i-th leaf and the j-th measuring point. The measuring point j at the root of the leaf is 1, and the measuring point j is incremented by one from the root of the leaf to the top of the leaf.

[0097] Step Six: Calculation of Deformation Displacement and Deformation Angle at Measuring Points

[0098] 1) Calculation of deformation displacement at measuring points:

[0099] First, calculate the projection of the relative position of the blade measuring point with respect to the center of the rotation shaft in the blade coordinate system. The calculation formula is as follows:

[0100]

[0101] in, The coordinate transformation matrix is ​​calculated using the following formula:

[0102]

[0103] Then, the projection of the relative position of the blade measuring point with respect to the center of the rotation axis in the blade coordinate system is used. Subtracting the initial shape information of the blade yields the blade deformation displacement information ΔP. i,j (x i,j ,y i,j ,z i,j The calculation formula is:

[0104]

[0105] 2) Calculation of the deformation angle at the measuring point:

[0106] The deformation angle of the measuring point includes the roll angle of the blade. and bending angle These correspond to the changes in pitch and roll angles in inertial / satellite integrated navigation, respectively. The calculation formulas are as follows:

[0107]

[0108] Where i and j represent the j-th measurement point of the i-th leaf, the measurement point j at the root of the leaf is 1, and the measurement point j from the root of the leaf to the top of the leaf is incremented by one.

[0109] In other words, this embodiment of the invention first selects deformation detection points on each blade of the wind turbine and installs a micro inertial measurement unit and a satellite navigation system at each detection point to collect the satellite position and attitude information of the measurement points when the blade is stationary for initial calibration. Then, during the real-time measurement phase under actual blade operating conditions, data acquisition by the inertial measurement unit and the satellite navigation system is completed, inertial / satellite combined navigation calculations are performed, and finally, the deformation displacement and deformation angle of the wind turbine blade are calculated based on coordinate transformation.

[0110] Therefore, this invention addresses the challenge of real-time measurement of wind turbine blade deformation. First, deformation detection points are selected on each wind turbine blade, and a micro inertial measurement unit (IMU) and satellite navigation system are installed at each point. Satellite position and attitude information of the measurement points when the blade is stationary is collected for initial calibration. Then, during real-time measurement under actual blade operating conditions, data acquisition by the IMU and satellite navigation system is completed, and inertial / satellite combined navigation calculations are performed. Finally, based on coordinate transformation, the deformation displacement and deformation angle of the wind turbine blade are calculated. This ultimately forms an online monitoring method for wind turbine blade deformation based on micro inertial devices and satellite navigation.

[0111] The solution proposed in this invention can simultaneously output attitude information through inertial-based integrated navigation, based on satellite navigation for position measurement, and improve the measurement frequency of blade deformation. Furthermore, it achieves high-precision time synchronization of multiple measurement points using the second pulse signal from satellite navigation. This provides an effective solution for online acquisition of wind turbine blade deformation data and wind turbine health monitoring in real-world operating scenarios, and has significant practical application value.

[0112] The features described and / or illustrated above with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, and / or in combination with or in lieu of features in other embodiments.

[0113] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, components, or combinations thereof.

[0114] The methods described above in this invention can be implemented in hardware or in combination with software. This invention relates to computer-readable programs that, when executed by a logic component, enable the logic component to implement the aforementioned apparatus or constituent parts, or to implement the various methods or steps described above. This invention also relates to storage media for storing the above programs, such as hard disks, magnetic disks, optical disks, DVDs, flash memory, etc.

[0115] Many features and advantages of these embodiments are apparent from this detailed description, and therefore the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since many modifications and alterations will readily occur to those skilled in the art, the embodiments of the invention are not intended to be limited to the precise structures and operations illustrated and described, but rather to encompass all suitable modifications and equivalents falling within their scope.

[0116] The parts of this invention not described in detail are techniques known to those skilled in the art.

Claims

1. A method for monitoring wind turbine blade deformation based on micro-inertial devices and satellite navigation, characterized in that, The method includes: Step 1: Select deformation detection points on each blade of the wind turbine; Step 2: Install a micro inertial measurement unit and a satellite navigation system at the deformation detection point; Step 3: Perform pre-calibration of wind turbine blade information. The pre-calibration information includes the blade coordinate system and initial blade shape information. Step 4: Real-time acquisition of micro-inertial measurement unit and satellite navigation information at each detection point on the blade; Step 5: Based on the measurement data from the micro inertial device and the satellite navigation data, calculate the inertial / satellite integrated navigation results for each measurement point; Step 6: Calculate the deformation displacement and deformation angle of the measuring point based on the results of Steps 3 and 5.

2. The method according to claim 1, characterized in that, The method for selecting deformation detection points for wind turbine blades is as follows: Draw a straight line from the base of the leaf to the tip of the leaf. Select five detection points on the line: the base of the leaf, the midpoint of the line, the tip of the leaf, the midpoint of the line connecting the base of the leaf and the midpoint of the line, and the midpoint of the line connecting the tip of the leaf and the midpoint of the line.

3. The method according to claim 1, characterized in that, Step two specifically includes: A micro inertial measurement unit is installed at the deformation detection point; The satellite navigation system uses a satellite navigation system with RTK functionality, and its specific component composition and installation method are as follows: A satellite navigation reference station and an RTK transmitter are installed within a predetermined distance on the ground. The antennas of the satellite navigation reference station and the RTK transmitter must be fixed and installed in an area without signal obstruction. A satellite navigation system with RTK functionality is installed at each deformation detection point. This system consists of four parts: a chip-level rover navigation calculation circuit, a chip-level RTK receiver, a miniature rover receiver antenna, and a miniature RTK receiver antenna. The rover navigation calculation circuit and the satellite navigation reference station are configured with a matching communication protocol. A dual-antenna satellite navigation positioning and orientation system is installed at the central shaft of the wind turbine, with two antennas installed along the straight line of the shaft.

4. The method according to claim 1, characterized in that, Install satellite navigation reference stations and RTK transmitters within a 100-meter radius of the ground.

5. The method according to claim 1, characterized in that, Step three specifically includes: 1) Calibration data acquisition: Select a windless day, activate the ground reference station and satellite navigation systems at each measuring point, set the blades to stand still for a set time, and collect the rotational data of the wind turbine's central shaft within that time period. Record this data as follows: Counterclockwise is positive, and horizontal is zero; The position information of the dual-antenna satellite navigation system at the center shaft of the wind turbine is collected within a set static time period, and the average value is calculated and denoted as . ; The heading angle information of the dual-antenna satellite navigation system at the center shaft of the wind turbine is collected within a set static time period, and the average value is calculated and denoted as . Counterclockwise is positive, and north is zero; The position information transmitted by the RTK satellite navigation chip at each wind turbine blade measuring point within a set static time period is collected and the average value is calculated. The position information of the j-th measuring point on the i-th blade is denoted as... Among them, the measuring point j at the root of the leaf is 1, and the measuring point j from the root of the leaf to the top of the leaf is incremented by one in sequence; When stationary, the micro-inertial measurement units at each measuring point perform initial alignment, and the roll angle results obtained from the initial alignment are recorded. Record the pitch angle result obtained from the initial alignment as follows: , where i and j represent the i-th leaf and the j-th measuring point. The measuring point j at the root of the leaf is 1, and the measuring point j is incremented by one from the root of the leaf to the top of the leaf. 2) Establishment of the blade coordinate system: For each blade, a blade coordinate system is established. The blade coordinate system for the i-th blade is defined as follows: the origin is set to... The X-axis is defined by the direction from back to front of the two satellite antennas at the central shaft of the wind turbine, and the Y-axis is defined by the direction from the root of the wind turbine blade to the tip of the blade. The Z-axis is designed according to the right-hand rule with respect to the X-axis and Y-axis. 3) Calculation of initial blade shape information: Initial shape information of a blade refers to the relative position of each measuring point on the blade with respect to the blade root when the blade is undeformed. The calculation steps are as follows: ， in, The coordinate transformation matrix is ​​calculated using the following formula: 。 6. The method according to claim 1, characterized in that, Set the time to ten minutes.

7. The method according to claim 1, characterized in that, Step four specifically includes: 1) Satellite navigation data acquisition: Activate the ground reference station and satellite navigation systems at each measuring point to collect the rotation data of the wind turbine's central shaft, and record it as follows: Counterclockwise is positive, horizontal is zero. The position information of the dual-antenna satellite navigation system at the center shaft of the wind turbine is collected and denoted as... Collect the heading angle information of the dual-antenna satellite navigation system at the center shaft of the wind turbine, and record it as... Counterclockwise is positive, and north is zero; the position information sent by the RTK satellite navigation chip at each wind turbine blade measuring point is collected, and the position information of the j-th measuring point on the i-th blade is denoted as... Among them, the measuring point j at the root of the leaf is 1, and the measuring point j from the root of the leaf to the top of the leaf is incremented by one in sequence; 2) Inertial Measurement Unit Data Acquisition: The micro-inertial measurement unit outputs gyroscope and accelerometer data from each wind turbine blade measuring point. The gyroscope data from the j-th measuring point on the i-th blade is denoted as... In this system, the measuring point j at the blade root is marked as 1, and the measuring points j from the blade root to the blade tip are incremented by one sequentially. The accelerometer data of the j-th measuring point on the i-th blade is denoted as... Among them, the measuring point j at the root of the leaf is 1, and the measuring point j from the root of the leaf to the top of the leaf is incremented by one.

8. The method according to claim 1, characterized in that, Step five specifically includes: 1) Establish the state equations and measurement equations of the integrated navigation system: The state equation is ,in, for Time to The one-step transition matrix at time step; For the system excitation noise sequence in The value of the moment. For state variables in The value of the moment. For state variables in The value of the moment. Including the north-to-east misalignment angle North-East Speed ​​Error Latitude error Height error Longitude error gyroscope drift in the carrier system Zero bias of the accelerometer in the load system , load system arm error Time delay ; The measurement equation is ,in, For measurement The numerical value at a given moment, that is, the difference between the position and velocity information output by satellite navigation and the position and velocity information calculated by inertial navigation. The numerical value at any given time; For the measurement matrix in The numerical value at any given time; To measure the noise sequence in The numerical value at any given time; 2) Based on the state equation and measurement equation, the Kalman filter algorithm is used to calculate the inertial navigation error. ; 3) Based on inertial navigation error estimation results Correcting inertial navigation: Based on inertial navigation error estimation results The inertial navigation system is calibrated to obtain precise position and attitude information for each measuring point. The position information of the j-th measuring point on the i-th blade is denoted as... The measurement point j at the blade root is marked as 1, and the measurement point j from the blade root to the blade tip is incremented by one sequentially; the roll angle result of the j-th measurement point of the i-th blade is... The pitch angle result of the i-th blade at the j-th measuring point is: , where i and j represent the i-th leaf and the j-th measuring point. The measuring point j at the leaf root is 1, and the measuring point j is incremented by one from the leaf root to the leaf tip.

9. The method according to claim 1, characterized in that, In step six, the deformation displacement of the measuring point is obtained in the following way: Calculate the projection of the relative position of the blade measuring point with respect to the center of the rotation shaft in the blade coordinate system. The calculation formula is as follows: ,in, The coordinate transformation matrix is ​​calculated using the following formula: ， Projection of the relative position of the blade measuring point with respect to the center of the rotation shaft in the blade coordinate system Subtracting the initial shape information of the blade yields the blade deformation and displacement information. The calculation formula is: 。 10. The method according to claim 1, characterized in that, In step six, the deformation angle of the measuring point is obtained in the following way: The deformation angle of the measuring point includes the roll angle of the blade. and bending angle These correspond to the changes in pitch and roll angles in inertial / satellite integrated navigation, respectively, and are calculated using the following formulas: ， , where i and j represent the j-th measurement point of the i-th leaf, the measurement point j at the root of the leaf is 1, and the measurement point j from the root of the leaf to the top of the leaf is incremented by one.

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