阅读说明：本技术 一种清选风机出风口风向检测装置及方法 (Cleaning fan air outlet wind direction detection device and method ) 是由 马征 马克超 李耀明 王新忠 韩敏 于 2019-08-23 设计创作，主要内容包括：本发明提供一种清选风机出风口风向检测装置及方法,包括风向示踪装置、图像采集装置和控制器；风向示踪装置安装在出风口外,且风向示踪装置可沿风机轴向移动；风向示踪装置包括能够旋转的示踪条；图像采集装置用于采集出风口示踪条的图像,并传递到控制器；控制器与图像采集装置连接,控制器根据图像处理分析示踪条与水平线的夹角,得到风向角度值,为检测风向提供了一种新的检测手段。本发明提供的检测方法自动化程度高,通过检测方法进行图像采集和处理得到相应的角度值,误差小,处理速度快,方法简单,精度高。(The invention provides a cleaning fan air outlet wind direction detection device and a method, comprising a wind direction tracer, an image acquisition device and a controller; the wind direction tracer device is arranged outside the air outlet and can move along the axial direction of the fan; the wind direction tracing device comprises a rotatable tracing bar; the image acquisition device is used for acquiring images of the air outlet tracing strips and transmitting the images to the controller; the controller is connected with the image acquisition device, and the controller obtains a wind direction angle value according to the included angle between the image processing analysis tracer strip and the horizontal line, and provides a new detection means for detecting the wind direction. The detection method provided by the invention has the advantages of high degree of automation, small error, high processing speed, simple method and high precision, and the corresponding angle value is obtained by acquiring and processing the image through the detection method.)

1. A cleaning fan air outlet wind direction detection device is characterized by comprising a tracer bar (4), an image acquisition device and a controller (11);

the tracing strip (4) can be rotatably arranged outside the air outlet (2);

the image acquisition device is used for acquiring images of the tracing strips (4) at the air outlet (2) and transmitting the images to the controller (11);

the controller (11) is connected with the image acquisition device, and the controller (11) analyzes the included angle between the tracing strip (4) and the horizontal line according to image processing to obtain a wind direction angle value.

2. A cleaning fan air outlet wind direction detection device according to claim 1, characterized by further comprising a background plate (3); the tracing strip (4) is rotatably arranged on the background plate (3);

the image acquisition device is used for acquiring images of the tracer strips (4) on the background plate (3).

3. A cleaning fan air outlet wind direction detection device as claimed in claim 2, characterized in that the background plate (3) is provided with a tracer bar support rod (302), and one end of the tracer bar (4) can rotate around the tracer bar support rod (302).

4. A cleaning fan air outlet wind direction detecting device according to claim 2, characterized in that the background plate (3) can move axially along the fan (1);

the background plate (3) is arranged on the fixing rod (5);

the bottom of dead lever (5) is equipped with slider (8), slider (8) are installed on spout (9).

5. A cleaning fan air outlet wind direction detecting device according to claim 1, characterized in that the background plate (3) is further provided with a horizontal reference line (303);

one end of the tracing strip (4) is intersected with one end of the horizontal reference line (303); the background plate (3) is also provided with a cross mark (301).

6. A cleaning fan air outlet wind direction detecting device according to claim 1, characterized in that the image collecting device comprises a camera, a zoom lens (701) and an annular light source (6);

the lens of the camera is a zoom lens (701); the annular light source (6) is mounted on the camera.

7. A cleaning fan air outlet wind direction detecting device according to claim 1, characterized in that the tracer strips (4) include an upper layer of cloth strips (403) and a lower layer of cloth strips (404); the upper layer cloth strip (403) is bonded with the lower layer cloth strip (404);

a plurality of quality sheets (402) are arranged between the upper layer cloth strip (403) and the lower layer cloth strip (404), and gaps exist between the quality sheets (402);

the tracing strips (4) are streamline.

8. A cleaning fan air outlet wind direction detection device according to claim 1, characterized in that the air outlet (2) of the fan (1) is marked with a plurality of point locations along the axial direction, and the image acquisition device acquires position images of the tracer strips (4) at the same height of each point location;

the air outlet (2) of the fan (1) is symmetrically distributed along a plurality of points marked axially by the radial central line of the air outlet (2).

9. A detection method for a cleaning fan air outlet wind direction detection device according to claims 1-8, characterized by comprising the following steps:

image acquisition and wind direction calculation: the image acquisition device acquires images of the air outlet (2) and the tracing strips (4) and transmits the images to the controller (11); and the controller (11) analyzes the included angle between the tracing strip (4) and the horizontal line according to image processing to obtain a wind direction angle value.

10. A detection method for a cleaning fan air outlet wind direction detection device according to claim 9, characterized in that the image acquisition and wind direction calculation process specifically comprises:

moving the tracer strip (4) to a first point position, and acquiring an image of the tracer strip (4) at the first point position by the image acquisition device and transmitting the image to the controller (11); moving the tracing strip (4) to the next point position at the same height, and acquiring the image of the tracing strip (4) at the point by the image acquisition device and transmitting the image to the controller (11); until the images of the tracing strips (4) at all the point positions are completely collected;

and the controller 11 calculates the included angle between each point position tracing strip (4) and the horizontal reference line (303), and averages the included angles to obtain the detection of the wind direction angle value of the fan air outlet (2) at the same axial height position.

Technical Field

The invention belongs to the field of agricultural machinery, and particularly relates to a cleaning fan air outlet wind direction detection device and method.

Background

Wind direction detection is an important aspect of fan airflow dynamic parameter monitoring. In the field of fluid machinery using air as a medium, the existing wind direction detection technology is mainly used in ventilation pipelines and other scenes, and the wind direction detection technology for the air outlet of a fan is rarely reported.

When the combine harvester harvests in the field, the cleaning device cleans the mixed materials on the sieve surface through the cooperation of the fan and the vibrating screen, removes impurities and obtains clean grains. The wind direction of the air outlet of the fan of the combine harvester has important influence on an airflow field inside the cleaning chamber, errors generated in the manufacturing and assembling processes of the fan can possibly have adverse influence on the wind direction of the air outlet of the fan, the manufacturing and assembling quality of the cleaning fan can be reflected to a certain degree through the wind direction detection of the air outlet of the fan, and at present, no technology for the wind direction of the air outlet of the fan of the combine harvester exists.

The utility model with the patent number of CN208254397U discloses a hand-held anemoscope based on a Hall angle sensor, which comprises a wind direction sensor, a hand-held rod, a signal processing device and a display screen; the wind direction sensor comprises a wind vane and a Hall angle sensor; the patent calculates the wind direction through the corresponding relation between the wind vane rotation angle and the output electric signal. However, the degree of automation of the patent is not high, a manual handheld detection instrument is needed, the influence of a detection environment is easily caused, the detection error is large, and the detection device is not suitable for wind direction detection of a fan air outlet.

The invention patent with the patent number of CN104535790B discloses a wind speed and direction detection device based on a piezoelectric effect, which comprises an induction system and a measurement system, wherein the induction system comprises a vertical rod made of rubber materials, a piezoelectric ceramic piece, a rotating device and a wind receiving device. The wind receiving device is arranged at the top of a building, the wind receiving device swings with wind to drive the piezoelectric ceramic piece on the vertical rod to deform, the generated electric charge outputs voltage through the measuring circuit, the voltage is compared with the collected voltage, the maximum positive voltage and the maximum negative voltage are generated, the wind direction is determined according to the positive voltage and the negative voltage, and then the wind direction is displayed on the display screen. The patent provides a wind direction detection method, but the wind direction measured by the patent can only be judged through the positive and negative of voltage, the result cannot be directly obtained for the angle of the wind direction, and the method is mainly used for detecting the extensive wind direction in the open space at the top of a building and is not suitable for detecting the wind direction of an air outlet of a fan.

The utility model with the patent number of CN207881825U discloses an ultrasonic wind direction and wind speed measuring device, which comprises a base, a first sensor mounting plate, a second sensor mounting plate, an ultrasonic sensor, a first ultrasonic reflection plate and a second ultrasonic reflection plate; the second sensor mounting plate is fixed on the base, a second ultrasonic reflection plate is fixed at the upper end of the second sensor mounting plate, and three ultrasonic sensors are arranged on the second ultrasonic reflection plate in a regular triangle; the lower extreme of first sensor mounting panel is fixed with first ultrasonic wave reflecting plate install three ultrasonic sensor with the ultrasonic sensor on the second ultrasonic wave reflecting plate on the first ultrasonic wave reflecting plate position that corresponds. But the device still is bigger than normal, and the installation is loaded down with trivial details, consequently is not applicable to cleaning fan's wind direction and detects.

Disclosure of Invention

Aiming at the technical problems, the invention provides a cleaning fan air outlet wind direction detection device and a cleaning fan air outlet wind direction detection method, which at least solve one of the problems. The invention collects the image of the air outlet tracing strip through the image collecting device and transmits the image to the controller; the controller obtains a wind direction angle value according to the included angle between the image processing analysis tracer bar and the horizontal line, and provides a novel wind direction detection technology of the air outlet of the fan.

The technical scheme adopted by the invention for solving the technical problems is as follows: a cleaning fan air outlet wind direction detection device comprises a tracer strip, an image acquisition device and a controller;

the tracing strip can be rotatably arranged outside the air outlet;

the image acquisition device is used for acquiring images of the air outlet tracing strips and transmitting the images to the controller;

the controller is connected with the image acquisition device, and the controller analyzes the included angle between the tracing strip and the horizontal line according to image processing to obtain a wind direction angle value.

In the scheme, the device further comprises a background plate; the tracing strip can be rotatably arranged on the background plate;

the image acquisition device is used for acquiring the image of the tracer strip on the background plate.

Further, be equipped with spike strip branch on the background board, the one end of spike strip can be rotatory around spike strip branch.

In the above scheme, the background plate can move along the axial direction of the fan;

the background plate is arranged on the fixed rod;

the bottom of dead lever is equipped with the slider, the slider is installed on the spout.

In the above scheme, the background plate is further provided with a horizontal reference line;

one end of the tracing strip is intersected with one end of the horizontal reference line;

the background plate is also provided with a cross mark.

In the above scheme, the image acquisition device comprises a camera, a zoom lens and an annular light source;

the lens of the camera is a zoom lens; the annular light source is mounted on the camera.

In the above scheme, the tracing strips comprise an upper layer cloth strip and a lower layer cloth strip; the upper layer cloth strip is bonded with the lower layer cloth strip;

a plurality of quality pieces are arranged between the upper layer cloth strip and the lower layer cloth strip, and gaps exist among the quality pieces;

the tracer strips are streamline.

In the scheme, the air outlet of the fan is marked with a plurality of point positions along the axial direction, and the image acquisition device acquires position images of the tracing strip at the same height of each point position;

and a plurality of point positions of the air outlet of the fan along the axial mark are symmetrically distributed along the radial central line of the air outlet.

A detection method of the cleaning fan air outlet wind direction detection device comprises the following steps:

image acquisition and wind direction calculation: the image acquisition device acquires an image of the air outlet tracing strip and transmits the image to the controller; and the controller analyzes the included angle between the tracing strip and the horizontal line according to image processing to obtain a wind direction angle value.

In the above scheme, the image acquisition and wind direction calculation process specifically includes:

moving the tracing strip to a first point position, and acquiring an image of the tracing strip by the image acquisition device and transmitting the image to the controller; moving the tracing strip to the next point position at the same height, and acquiring the image of the tracing strip by the image acquisition device and transmitting the image to the controller; until the tracer strip images of all the point positions are completely collected;

and the controller calculates the included angle between each point position tracing strip and the horizontal reference line, and the average value is taken to obtain the detection of the wind direction angle value of the air outlet of the fan at the same axial height position.

Compared with the prior art, the invention has the beneficial effects that: the invention collects the image of the air outlet tracing strip through the image collecting device and transmits the image to the controller; the controller analyzes the included angle between the tracer strip and the horizontal line according to image processing to obtain the wind direction angle value, and a new detection means is provided for detecting the wind direction. The detection method provided by the invention has the advantages of high degree of automation, small error, high processing speed, simple method and high precision, and the corresponding angle value is obtained by acquiring and processing the image through the detection method.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is an axial view of a cleaning fan outlet wind direction detecting device according to an embodiment of the present invention;

FIG. 2 is a side view of a tracer according to an embodiment of the invention;

FIG. 3 is a front view of a tracer according to an embodiment of the invention;

FIG. 4 is an enlarged view at FIG. 3I;

FIG. 5 is a front view of a detection device according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a tracer bar configuration according to an embodiment of the invention;

FIG. 7 is a block diagram of a detection device in accordance with an embodiment of the present invention;

FIG. 8 is a flow chart of angle measurement according to an embodiment of the present invention.

In the figure: 1-a fan, 2-an air outlet, 3-a background plate, 4-a tracing strip, 5-a fixed rod, 6-a ring light source, 7-an industrial CCD, 8-a slide block, 9-a slide groove, 10-a tripod, 11-a controller, 301-a cross mark, 302-a tracing strip support rod, 303-a horizontal reference line, 304-a step groove, 401-a buckle, 402-a metal sheet, 403-an upper layer of cloth strip, 404-a lower layer of cloth strip and 701-a zoom lens.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present invention and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

As shown in fig. 1, which is a preferred embodiment of the cleaning fan air outlet wind direction detection device of the present invention, the cleaning fan air outlet wind direction detection device includes a wind direction tracer, an image acquisition device and a controller 11; the wind direction tracing device is arranged outside the air outlet 2 and can move along the axial direction of the fan 1; the wind direction tracer comprises a rotatable tracer bar 4; the image acquisition device is used for acquiring images of the tracing strips 4 at the air outlet 2 and transmitting the images to the controller 11; the controller 11 is connected with the image acquisition device, and the controller 11 analyzes the included angle between the tracer strip 4 and the horizontal line according to image processing to obtain a wind direction angle value. The wind direction angle of the air outlet of the fan is detected based on an image processing method, the wind direction is reflected by detecting the included angle between the tracer bar and the horizontal reference line, and a new detection means is provided for detecting the wind direction.

According to this embodiment, the controller may be a computer.

According to the present embodiment, it is preferable that the wind direction tracing device further includes a background plate 3, as shown in fig. 2, the tracing bar 4 is rotatably mounted on the background plate 3; the image acquisition device is used for acquiring the image of the tracer strip 4 on the background plate 3. As shown in fig. 2, the dotted line part represents the position of the tracer bar 4 in the initial state, i.e. when the fan is not started; the solid line part shows the position of the tracer strip 4 when the fan is running, i.e. when the fan is operating steadily.

According to the present embodiment, preferably, a horizontal reference line 303 is further provided on the background plate 3; one end of the tracer strip 4 intersects one end of a horizontal reference line 303. According to the present embodiment, it is preferable that the background plate 3 is further provided with a cross mark 301. Specifically, three cross marks 301 are shown, and are respectively located at the upper left corner, the upper right corner and the lower right corner of the background plate 3; a horizontal reference line 303 is positioned at the lower side of the background plate 3, and the horizontal reference line 303 is collinear with a horizontal line formed by connecting the center of the tracer bar support rod 302 and the cross mark 301 at the lower right corner and is used as a reference datum for the rotation of the tracer bar 4;

according to this embodiment, it is preferred, background board 3 lower left corner is equipped with tracer strip branch 302, as shown in fig. 3 and 4, be equipped with the ladder groove 304 on the tracer strip branch 302, the one end of tracer strip 4 is passed through buckle 401 and is installed in ladder groove 304, and the one end of tracer strip 4 can be rotatory around tracer strip branch 302. Tracer 4 has certain distance, about 8mm in 1 axial direction of fan and background board 3, and tracer 4 can rotate around tracer branch 302 under the effect of 2 air currents in air outlet.

According to the present embodiment, it is preferable that the background plate 3 is mounted on a fixing rod 5; the base of the fixed rod 5 is fixed on a sliding block 8 through a bolt, the sliding block 8 is installed on a sliding groove 9, and the sliding block 8 can move in the sliding groove 9 along the axial direction of the fan 1.

According to the present embodiment, preferably, the image capturing device includes a camera, a zoom lens 701, a ring light source 6 and a tripod 10, as shown in fig. 5, the camera may be an industrial CCD7, the zoom lens 701 is mounted on an industrial CCD7, and the industrial CCD7 and the ring light source 6 are fixed on the tripod 10 and connected to the controller 11 through data lines. The lens of the industrial CCD7 is required to be distortion-free, and is a zoom lens 701, so that the adjustment of the focal length within a certain range is realized, and the composition is convenient; the resolution of the industrial CCD7 meets the requirement of 200-400 ten thousand pixels, and the frame rate is 30 frames/second; when taking a photo, 15-20 photos are required to be taken every second. The axis of the annular light source 6 is coincident with the axis of a zoom lens 701 of the industrial CCD7, and the color temperature of the annular light source 6 is adjustable.

According to this embodiment, the tracer strip 4 preferably includes an upper layer cloth strip 403 and a lower layer cloth strip 404, as shown in fig. 6; the upper cloth strip 403 is adhered to the lower cloth strip 404, a plurality of quality sheets 402 are arranged between the upper cloth strip 403 and the lower cloth strip 404, and gaps exist between the quality sheets 402. The length-width ratio of the tracer strips 4 is 8:1, and the length of the tracer strips is 80 mm.

According to this embodiment, it is preferred that tracer 4 is streamlined, and the air current of being convenient for passes through, suppresses the violent undulant of tracer 4, guarantees that tracer 4 is undulant smoothly outside air outlet 2.

According to the present embodiment, the background plate 3 and the trace strip 4 are preferably formed with a color contrast, such as a black-and-white color contrast, for image processing. The mass pieces 402 are iron pieces, each piece having a mass of 50g, and the iron pieces and the number thereof can be arranged according to fig. 6.

According to this embodiment, preferably, the air outlet 2 of the fan 1 marks a plurality of point locations along the axial direction, and the image acquisition device acquires position images of the tracer strips 4 of the wind direction tracer at the same height at each point location.

According to this embodiment, preferably, the plurality of point locations of the air outlet 2 of the fan 1 marked along the axial direction are symmetrically distributed along the radial center line of the air outlet 2, and if the measured wind direction angles of the two point locations at the symmetrical positions do not form a mirror surface, the problem of the manufacturing and assembling quality of the fan is reflected to a certain extent. The sliding block 8 stops at each point, and the industrial CCD7 takes pictures for storage; the positions of the industrial CCD7 and the annular light source 6 are always unchanged, when the background plate 3 and the tracing strip 4 move to the next point position along with the slide block 8, the focal length of the zoom lens 701 always ensures that the sizes of the tracing strips 4 in the shot image are consistent according to the distance between the lens and the tracing strip 4 and the cross mark 301 on the background plate 3, and the image processing is facilitated. The lens axis of the industrial CCD7 is perpendicular to the background plate 3, and the shooting visual angle covers the tracer 4, and is used for shooting the image formed by the tracer 4 and the horizontal reference line 303 under the action of the air flow at the air outlet 2 of the fan.

Based on the hardware and software, the angle of the tracer strip 4 relative to the horizontal reference line 303 at different positions is continuously collected, processed and analyzed, and the measured angle at each position is counted to obtain the wind direction angle at the position.

As shown in fig. 7, the controller 11 includes an image receiving module, an image processing module, and a result display module.

The image receiving module is responsible for collecting the images of the air outlet tracing strips 4 and transmitting the images to the image processing module; the image processing module is responsible for processing and analyzing the image and calculating an included angle between the tracing strip 4 and the horizontal reference line 303; and the result display module is responsible for displaying and storing the processing result. The image receiving module, the processing module and the display module are composed of programs written by MATLAB language. The image receiving module controls the industrial CCD7 to photograph the tracing strip 4 on the front side of the air outlet 2, the photographed image is input to the controller 11 to be subjected to image processing, and an included angle between the tracing strip 4 and the horizontal reference line 303 is obtained through processing. The image processing module performs gray processing on the acquired image of the tracer 4, then performs binarization processing, then performs edge extraction by using a Canny function in MATLAB language, takes the pixel point of the image as a two-dimensional array, determines a straight line by using two points, calculates the slope of the straight line, and then converts the straight line into an angle in a visual absolute coordinate system to serve as the wind direction angle reflected by the tracer 4. The invention utilizes MATLAB language to carry out image processing, curve fitting and other methods for quantification on the image, the provided detection method has high automation degree, the corresponding angle value is obtained by carrying out image acquisition and processing through the detection method, the error is small, the processing speed is high, the method is simple, and the precision is high.

Fig. 8 shows a detection method of the cleaning fan air outlet wind direction detection device, which comprises the following steps:

a preparation stage: arranging an image acquisition device and a wind direction tracing device;

a starting stage: starting the industrial CCD7 and the controller 11 in the image acquisition device;

image acquisition and wind direction calculation: the image acquisition device gathers the image of 2 spike strips 4 of air outlet to transmit controller 11, controller 11 obtains wind direction angle value according to the contained angle of image processing analysis spike strip 4 and water flat line.

According to this embodiment, preferably, the image acquisition and wind direction calculation process specifically includes:

moving the tracing strip 4 to a first point position, and adjusting the focal length of a zoom lens 701 to enable the cross mark 301 on the background plate 3 to be in the shot image; the image acquisition device acquires the image of the tracer strip 4 and transmits the image to an image receiving module of the controller 11; the image receiving module transmits the image to the image processing module, the image processing module processes the image of the tracer strip 4 to further obtain an included angle between the tracer strip 4 and a horizontal line, and the image processing module inputs the angle value to the result display module;

moving the tracing strip 4 to the next point position at the same height through the sliding block 8, adjusting the focal length of the zoom lens 701, and always ensuring that the tracing strip 4 in the shot image is consistent with the tracing strip 4 in the shot image of the first point position according to the distance between the lens 701 and the tracing strip 4 and the cross mark 301 on the background plate 3; the image acquisition device acquires the image of the tracer strip 4 and transmits the image to the image receiving module of the controller 11; the image receiving module transmits the image to the image processing module, the image processing module processes the image of the tracer strip 4 to further obtain an included angle between the tracer strip 4 and a horizontal line, and the image processing module inputs the angle value to the result display module; until the images of the tracing strips 4 at all the point positions are completely collected;

and an image processing module of the controller 11 calculates an included angle between each point position tracing strip 4 and the horizontal reference line 303, and averages the included angles to obtain the detection of the wind direction angle value of the fan air outlet 2 at the same axial height position.

According to this embodiment, preferably, the calculation of the included angle between each point location tracer 4 and the horizontal reference line 303 is specifically performed by the following steps:

the controller 11 reads the image of the tracing strip 4 of the image acquisition device, and performs gray processing and edge extraction on the image; the method uses the edge extraction method in the image processing, and has the advantages of low misjudgment rate, less misjudgment of edge points as non-edge points and high positioning precision, namely, the edge points are accurately positioned on the pixels with the maximum gray level change.

Determining a two-dimensional array of pixel points in the image, establishing a coordinate system, taking rows Y1 and Y2, and defining initial variables X1 and X2;

in order to prevent noise interference, range limitation is carried out on pixel points i which are measured and calculated, points are circularly acquired, and all pixel points of a given row are traversed within a certain range;

determining a straight line by two points, calculating the slope k of the straight line, converting the slope k into an angle in a visual absolute coordinate system, circularly acquiring and processing images within time t, and obtaining an angle average value to obtain a wind direction angle value.

The wind direction angle of the position with the same height is obtained by continuously collecting, processing and analyzing the angles of the tracer strips 4 relative to the horizontal reference line 303 at different positions with the same height, counting the angles measured at each position and averaging.

It should be understood that although the present description has been described in terms of various embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and those skilled in the art will recognize that the embodiments described herein may be combined as suitable to form other embodiments, as will be appreciated by those skilled in the art.

The above-listed detailed description is only a specific description of a possible embodiment of the present invention, and they are not intended to limit the scope of the present invention, and equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the scope of the present invention.