Patent Grant
11421660
The present application is a national phase of International Application No. PCT/CN2019/092198, filed on Jun. 21, 2019, which claims priority to Chinese Patent Application No. 201811288130.4, filed on Oct. 31, 2018 with the China National Intellectual Property Administration. The entire contents of each of the above-identified applications are incorporated herein by reference.
The following description relates to the field of wind power, more specifically, to a video monitoring method and system for a blade of a wind turbine.
A blade of a wind turbine has an elastomeric structure with a short spanwise direction and a long chordwise direction. As a key component for wind energy absorption, the blade will be prone to vibration and deformation, thereby affecting smooth operation of the wind turbine. Due to complex and changeable operating environments of the wind turbine, a load to which the blade is subjected is large and varies largely in magnitude, during long-term operation, the blade will have different degrees of cracks or deformation, and a failure rate due to blade problems is above 30%. It is therefore important to monitor the blade.
The related art mainly uses a video measurement method to monitor the blade. This video measurement method obtains a displacement and a deformation of each marker point under load by calculating 3D coordinates of marker points of each frame, which has been widely used for non-contact measurement of the blade. However, due to characteristics of high torque and high rotation speed of the blade of wind turbine, image matching directly through marker points is likely to fail to find sub-regions which are similar to each other before and after the deformation, resulting in an unsuccessful matching, thus it is impossible to effectively monitor the blade.
In addition, in the related art, a video camera or a camera used to monitor the blade are usually disposed on the ground or on a side of a nacelle, however, since a diameter of an impeller of a current large megawatt wind turbine is very large (diameters of some impellers are even above 70 meters), and the blade itself has a characteristic of an aerodynamic shape, a relative position between the video camera or the camera and the blade arranged in this way will restrict shooting, result in reduced safety and/or make it impossible to capture an overall image of the blade simply and quickly.
In order to solve at least one of problems described above, the disclosure provides a video monitoring method and system for a blade of a wind turbine.
According to one aspect of the disclosure, a video monitoring method for a blade of a wind turbine is provided. The method includes: calculating a pan value and a tilt value based on each of a plurality of circular arc angles when the blade of the wind turbine is in a stationary state, wherein the plurality of circular arc angles are set based on a circular arc curve on a rotational plane of the blade, which is formed with a first point as a center and a first distance as a radius, wherein the first point is an intersection of a spindle of the wind turbine with the rotational plane of the blade, and the first distance is a distance from the first point to a monitoring part on the blade; and setting the pan value and the tilt value of a video camera to the calculated pan value and tilt value, respectively, to capture the blade.
According to another aspect of the disclosure, a computer-readable storage medium is provided. The computer-readable storage medium may store program instructions that, when executed by a processor, cause the processor to perform the method as described above.
According to another aspect of the disclosure, a computing device is provided. The computing device may include: a processor; and a memory storing program instructions that, when executed by a processor, cause the processor to perform the method as described above.
According to another aspect of the application, a video monitoring system for a blade of a wind turbine is provided. The system includes: a video camera mounted at a top of a nacelle of the wind turbine; and a processor configured to: calculate a pan value and a tilt value based on each of a plurality of circular arc angles when the blade of the wind turbine is in a stationary state, wherein the plurality of circular arc angles are set based on a circular arc curve on a rotational plane of the blade, which is formed with a first point as a center and a first distance as a radius, wherein the first point is an intersection of a spindle of the wind turbine with the rotational plane of the blade, and the first distance is a distance from the first point to a monitoring part on the blade; and wherein the video camera adjusts the pan value and the tilt value to the pan value and the tilt value calculated by the processor, respectively, to capture the blade.
The video monitoring method and system for the blade of the wind turbine according to example embodiments are capable of capturing the blade when the blade is in a stationary state and in a state of motion respectively, performing a fixed-point segmentation shooting when the blade is in the state of motion, and performing the shooting according to a motion trajectory when the blade is in the stationary state; thereby simply and quickly capturing a clear maximum area of the blade or capturing an outer surface of an entire blade body.
Throughout the drawings, the same or similar reference numerals will refer to the same or similar elements. The drawings may not be to scale and, for clarity, illustration and convenience, the relative size, portions and depiction of the elements in the drawings may be exaggerated.
The disclosure may have various variations and various embodiments, and it should be understood that the disclosure is not limited to these embodiments, but includes all variations, equivalents, and alternatives within the spirit and scope of the disclosure. For example, the sequences of operations described herein are merely examples, and are not limited to those set forth herein, hut may be changed as will be apparent after an understanding of the disclosure of this application, with the exception of operations necessarily occurring in a certain order. In addition, descriptions of features that are known in the art may be omitted for increased clarity and conciseness. The terminology used in example embodiments of the disclosure is only used to describe specific embodiments, but is not intended to limit the example embodiments. The singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It will be understood that, although the terms “first”, “second”, “third”, etc. may be used in the specification to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element may also be referred to as a second element, and similarly, a second element may also be referred to as a first element, without departing from the spirit and scope of the disclosure.
Referring to
Referring to
According to an example embodiment of the disclosure, the video camera for capturing blades is mounted at a top of the nacelle of the wind turbine. As a preferred embodiment, the video camera is mounted on a wind measurement bracket at the top of the nacelle of the wind turbine.
Referring to
As described above, a relative position of the video camera and the blade will limit shooting, so a video monitoring method and a system for a blade of a wind turbine according to an example embodiment are intended to adjust a shooting angle and a camera magnification factor of the video camera, so as to control the video camera (e.g., a camera, or preferably a PTZ (Pan-Tilt-Zoom) camera rotating by 360 degrees) to easily and quickly capture a clear maximum area of the blade (e.g., an outer surface of the entire blade as shown in
Referring to
As described above, the video camera 101 may be a camera, preferably a PTZ camera rotating by 360 degrees. According to the example embodiment, as shown in
In one example embodiment, when blades of the wind turbine are in a stationary state, the processor 103 may calculate a shooting angle of the video camera, i.e., a pan (P, Pan) value and a tilt (T, Tilt) value of a video shooting angle, where the pan value P indicates a left and right control angle of the video camera and the tilt value T indicates a vertical control angle of the video camera.
Specifically, the processor 103 may be configured to calculate the pan value and the tilt value based on each of a plurality of circular arc angles, when the blades of the wind turbine are in a stationary state. According to the example embodiment, the plurality of circular arc angles are set based on a circular curve on a rotational plane of the blades, which is formed with a first point as a center and a first distance as a radius, where the first point is an intersection of a spindle of the wind turbine with the rotational plane of the blades, and the first distance is a distance from the first point to a monitoring part on the blades. An operation that the processor 103 calculates the pan value and the tilt value will be described in detail later with reference to
In this case, the video recorder 101 adjusts the pan value and the tilt value to the pan value and the tilt value calculated by the processor 103, respectively, to capture the blades. According to the example embodiment, the processor 103 may also set a zoom factor of the video camera 101 to a Zooming value (Z, Zoom) preset for the monitoring part. The setting of the Zooming value Z will be described in detail later.
In one example embodiment, when the blades are in a state of motion, the processor 103 may, based on a position of the monitoring part in the blades, set the pan value and the tilt value of the video camera to a particular pan value and tilt value. According to the example embodiment, the monitoring part may include one or more of the following parts: a blade root, an upper housing of a blade wing, a lower housing of the blade wing, and blade tips of the upper and lower housings. Usually, in order to monitor the overall status of the blades, it is necessary to capture all of the aforementioned parts.
In this case, the video camera 101 adjusts the pan value and the tilt value to the particular pan value and tilt value set by the processor 103 to capture the blades. For example, the particular pan value and tilt value can be set for different monitoring parts depending on the model of the wind turbine and the sizes of the blades. In other words, according to the example embodiment of the disclosure, the video camera captures the blade in segments for each monitoring part.
Table 1 below lists the particular pan value, tilt value and zooming value set for different monitoring parts.
In Table 1, the zooming value Z set for the monitoring part can also be applied to the zoom factor of the video camera when the blade is in the stationary state. The values shown in Table 1 are only embodiments listed for specific PTZ values set for a wind turbine of a specific model, and the disclosure is not limited thereto.
According to the example embodiment of the disclosure, when the blades are in the stationary state or in the state of motion, the video camera adjusts the zoom factor adaptively for the different monitoring parts, enlarges and clearly capture the blade tips which are difficult to monitor, and may normally capture the blade wings. Specifically, if the monitoring part is the tip of the blade, the zooming value is a value greater than 1 (e.g., 7 or 10 in Table 1), so as to enlarge and capture the blade tip; if the monitoring part is the blade wing, the zooming value is 1, so as to normally capture the blade wing. However, this is only exemplary, and the zoom factor of the video camera 101 may achieve automatic zooming to automatically obtain a clear image of the monitoring part.
When the blades are stationary (i.e., a wind turbine shutdowns), the blades may not captured at a specified position, and in this case it is necessary to control the video camera to search and capture the blades along a fixed circular arc curve, i.e., a cruise along a circular arc curve. For example, a small circular arc curve is required if the blade root is captured, and a large circular arc curve is required if the blade tip is captured.
Referring to
The circular arc angle a is a circular arc angle set based on the circular arc curve. According to the example embodiment of the disclosure, one circular arc angle a corresponds to one shooting angle of the video camera (i.e., a pan value and a tilt value). Thus, setting a plurality of circular arc angles based on the circular arc curve corresponds to continually adjusting the video camera with a plurality of shooting angles to capture the blades, i.e., controlling the video camera to search and capture the blades along a fixed circular arc curve.
Referring to
According to the example embodiment of the disclosure, the processor 103 may calculate the pan value and the tilt value corresponding to each of the plurality of circular arc angles, based on a geometric relationship among the first distance r, a second distance d from the video camera A to the first point O and a third distance R from the video camera A to the second point C, a relationship among the pan value P, the tilt value T, the first distance r and the third distance R, as well as a relationship among each of the plurality of circular arc angles and the pan value and the tilt value of the video camera.
Specifically, the processor 103 may calculate the pan value P and the tilt value T corresponding to each circular arc angle a according to the following expressions (1) through (3).
d2+r2R2 (1)
(sin(P)×R)2+(sin(T)×R)2=r2 (2)
sin(P)/sin(T)=tan(a) (3)
The expression (1) denotes the geometric relationship among the first distance r, the second distance d from the video camera A to the first point O and the third distance R from the video camera A to the second point C, the expression (2) denotes the relationship among the pan value P, the tilt value T, the first distance r and the third distance R, and the expression (3) denotes the relationship among the circular arc angles and the pan value and the tilt value of the video camera. The expressions (1) through (3) are only optimal examples of the disclosure, however, the disclosure is not limited thereto.
In one example embodiment, the circular arc angle a of 0 degree indicates a vertical downward direction (i.e., a direction of a tower). In this case, due to a position limitation of the video camera, the circular arc angle a is set within a range of −45 degree to 225 degree based on engineering practice experience, such that it can ensure that the video camera can scan (i.e., capture) at least two blades.
According to the expressions (1) through (3), the pan value P and the tilt value T corresponding to any angle a can be calculated. In one example embodiment, at the circular arc angle a=−45 degree at which the video camera begins shooting, it can be calculated that sin(p)=−r/2R, sin(T)=−sin(P)=r/2R; at the circular arc angle a=225 degree at which the video camera ends shooting, it can be calculated that sin(p)=r/2R, sin(T)=−sin(P)=r/2R. In one embodiment, in tan(a), the value of a is taken with a cycle of 180 (i.e., −90 to 90) degree, P or T in sin(P) or sin(T) is taken with a cycle of 360 degree, e.g., tan(a) equals to −1 for both a=−45 degree and a=135 degree, and in this case there are two cases for sin(P)/sin(T)=tan(a)=−1: case 1 in which sin(P) is a positive value and sin(T) is a negative value; case 2 in which sin(P) is a negative value and sin(T) is a positive value. At this time, it can be determined whether sin(P) and sin(T) apply to case 1 or case 2 based on whether a is −45 degree or 135 degree.
As an example, and in conjunction with Table 1,
The video camera may be mounted at the top of the nacelle of the wind turbine as shown in
Referring to
In step 603, when the blade is in a state of motion, the pan value and the tilt value of the video camera are set to a specific pan value and tilt value according to a position of the monitoring part in the blade, to capture the blade.
The operation of the processor 103 for calculating the pan value and the tilt value and the setting of the zoom factor of the video camera described above with reference to
The video monitoring method and system for the blade of the wind turbine according to the example embodiment are capable of capturing the blade when the blade is in a stationary state and in a state of motion respectively, performing the fixed-point segmentation shooting when the blade is in the state of motion, and performing the shooting according to a motion trajectory when the blade is in the stationary state; thereby simply and quickly capturing a clear maximum area of the blade or capturing an outer surface of an entire blade body.
Various steps of the method described in
The various steps of the method described in
While specific example embodiments of the disclosure have been described referring to
| Number | Date | Country | Kind |
|---|---|---|---|
| 201811288130.4 | Oct 2018 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2019/092198 | 6/21/2019 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2020/087946 | 5/7/2020 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 8041540 | Kerber | Oct 2011 | B2 |
| 10584683 | Lysgaard | Mar 2020 | B2 |
| 10815966 | Burns | Oct 2020 | B1 |
| 20090266160 | Jeffrey | Oct 2009 | A1 |
| 20100084864 | Lucks | Apr 2010 | A1 |
| 20110049886 | Becker | Mar 2011 | A1 |
| 20110103933 | Olesen | May 2011 | A1 |
| 20110205348 | Fritz | Aug 2011 | A1 |
| 20110206511 | Frydendal | Aug 2011 | A1 |
| 20120076345 | Fritz | Mar 2012 | A1 |
| 20130300855 | Fritz | Nov 2013 | A1 |
| 20140184794 | Coombs | Jul 2014 | A1 |
| 20140267693 | Newman | Sep 2014 | A1 |
| 20140356164 | Asheim | Dec 2014 | A1 |
| 20150043769 | Newman | Feb 2015 | A1 |
| 20150116131 | Ikeda | Apr 2015 | A1 |
| 20160017866 | Craft | Jan 2016 | A1 |
| 20160040655 | Kötting | Feb 2016 | A1 |
| 20160055400 | Jorquera | Feb 2016 | A1 |
| 20160063350 | Newman | Mar 2016 | A1 |
| 20170249511 | Newman | Aug 2017 | A1 |
| 20180003161 | Michini | Jan 2018 | A1 |
| 20180273173 | Moura | Sep 2018 | A1 |
| 20190024628 | De Barros | Jan 2019 | A1 |
| 20190072082 | Lysgaard | Mar 2019 | A1 |
| 20190130768 | Clark | May 2019 | A1 |
| 20190226457 | Bertolotti | Jul 2019 | A1 |
| 20190370999 | Liu | Dec 2019 | A1 |
| 20200018291 | Rosen | Jan 2020 | A1 |
| 20200025176 | Georgeson | Jan 2020 | A1 |
| 20200260013 | Kaufmann | Aug 2020 | A1 |
| 20200293045 | Ghiglino Novoa | Sep 2020 | A1 |
| Number | Date | Country |
|---|---|---|
| 2732406 | Aug 2011 | CA |
| 102192717 | Sep 2011 | CN |
| 102539438 | Jul 2012 | CN |
| 102706885 | Oct 2012 | CN |
| 103335604 | Oct 2013 | CN |
| 108152295 | Jun 2018 | CN |
| 108459027 | Aug 2018 | CN |
| 102011016868 | Oct 2011 | DE |
| 102011088447 | Jun 2013 | DE |
| 102012203455 | Sep 2013 | DE |
| 102013110898 | Aug 2014 | DE |
| 102014014386 | Apr 2016 | DE |
| 102016108954 | Nov 2017 | DE |
| 201670147 | Aug 2017 | DK |
| 2357359 | Aug 2011 | EP |
| 2481924 | Aug 2012 | EP |
| 2853729 | Apr 2015 | EP |
| 2887030 | Jun 2015 | EP |
| 3002455 | Apr 2016 | EP |
| 3279470 | Feb 2018 | EP |
| 3343030 | Jul 2018 | EP |
| 3457326 | Sep 2019 | EP |
| 2011127605 | Jun 2011 | JP |
| 2014519024 | Aug 2014 | JP |
| 10-2014-0000612 | Jan 2014 | KR |
| WO-2009129617 | Oct 2009 | WO |
| WO-2011163498 | Dec 2011 | WO |
| WO-2012097475 | Jul 2012 | WO |
| WO-2012152561 | Nov 2012 | WO |
| WO-2014145537 | Sep 2014 | WO |
| WO-2014187463 | Nov 2014 | WO |
| WO-2016033181 | Mar 2016 | WO |
| WO-2016169959 | Oct 2016 | WO |
| Entry |
|---|
| Baqersad, Javad & Poozesh, Peyman & Niezrecki, Christopher & Harvey, Eric & Yarala, Rahul. (2014). Full Field Inspection of a Utility Scale Wind Turbine Blade Using Digital Image Correlation. 10.13140/2.1.2891.2960. (Year: 2014). |
| D. Y. Kim, H.-B. Kim, W. S. Jung, S. Lim, J.-H. Hwang and C.-W. Park, “Visual testing system for the damaged area detection of wind power plant blade,” IEEE ISR 2013, 2013, pp. 1-5, doi: 10.1109/ISR.2013.6695675. (Year: 2013). |
| International Search Report in corresponding International Application No. PCT/CN2019/092198, dated Sep. 19, 2019 (5 pages). |
| First Office Action in corresponding Chinese Application No. 201811288130.4, dated Aug. 20, 2020 (12 pages). |
| First Examination Report in corresponding India Application No. 202117021493, dated Feb. 23, 2022 (6 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20220003212 A1 | Jan 2022 | US |
