An accurate positioning device and positioning method for unmanned aerial vehicle

Abstract

The invention relates to the technical field of unmanned aerial vehicles, and discloses an accurate positioning device for unmanned aerial vehicles and a positioning method thereof. The accurate positioning device for unmanned aerial vehicles comprises an unmanned aerial vehicle body, a shell is arranged on the unmanned aerial vehicle body, a positioning mechanism is arranged in the shell, and the positioning mechanism comprises a camera, a lifting component, a rotating component and a deflection component; the camera is arranged in the shell, and the lifting component is used to drive the camera to perform vertical linear motion so as to extend out of the shell for image acquisition; the accurate positioning device for unmanned aerial vehicles and the positioning method thereof drive a plurality of cameras to first descend and extend out of the shell through a driving mechanism, and then automatically complete the deflection of the camera angle during the descent process, and finally the plurality of cameras continue to rotate, so as to expand the angle of image acquisition, collect effective position information of the full range at one time, and perform position calculation, thereby realizing accurate positioning of the unmanned aerial vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and in particular to an accurate positioning device for unmanned aerial vehicles and a positioning method thereof. Background Art

[0002] Unmanned aerial vehicles, or "drones" for short, are unmanned aircraft that are controlled by radio remote control equipment and self-contained program control devices, or are operated completely or intermittently autonomously by on-board computers. Compared with manned aircraft, drones are often more suitable for tasks that are difficult and dangerous. Drones can be divided into military and civilian applications according to their application areas. In the military, drones are divided into reconnaissance aircraft and target aircraft. In the civilian application, drones + industry applications are the real rigid demand for drones. Drones are widely used in aerial photography, agriculture, plant protection, micro selfies, express delivery, disaster relief, wildlife observation, infectious disease monitoring, surveying and mapping, news reporting, power inspections, disaster relief, film and television shooting, creating romance, and other fields.

[0003] The positioning of drones requires the drone's built-in image acquisition device to take pictures of the surrounding environment, so as to calculate the corresponding position for the positioning of the drone. The existing drone positioning device has a small image acquisition viewing angle range and can only collect a small amount of effective position information at one time, which leads to a decrease in the accuracy of drone positioning. At the same time, since the drone is in motion during the shooting process, the time, angle and posture of the image acquisition device will change, resulting in the image acquired by the image acquisition device not matching the expected image, which is not conducive to the subsequent image fusion operation, thus affecting the positioning accuracy.

[0004] In view of this, the present invention proposes an accurate positioning device for a drone and a positioning method thereof to solve the technical problems existing in the prior art. Summary of the invention

[0005] The present invention provides an accurate positioning device for unmanned aerial vehicles and a positioning method thereof, which has the beneficial effect of expanding the viewing angle range of image acquisition by deflecting the shooting angle of a camera and rotating the camera itself 360°, thereby achieving accurate positioning of the unmanned aerial vehicle, and solves the problem of the existing unmanned aerial vehicle positioning device mentioned in the above background technology, that the viewing angle range of image acquisition is small, and the effective position information that can be collected at one time is small, thereby reducing the accuracy of unmanned aerial vehicle positioning.

[0006] The present invention provides the following technical solution: an accurate positioning device for a drone, comprising a drone body, a shell provided on the drone body, a positioning mechanism provided in the shell, the positioning mechanism comprising a camera, a lifting assembly, a rotating assembly and a deflecting assembly;

[0007] The camera is arranged in the housing, the lifting assembly is used to drive the camera to move vertically and linearly to extend out of the housing for image acquisition, the rotating assembly is used to drive the camera to rotate to expand the image acquisition range, and the deflection assembly is used to drive the camera to deflect to further expand the image acquisition range;

[0008] A driving mechanism is also arranged in the shell to drive the positioning mechanism to operate.

[0009] As an optional solution of the accurate positioning device for the drone of the present invention, wherein: the lifting assembly includes a first rotating rod, a lead screw, a nut and a sleeve;

[0010] The first rotating rod is rotatably arranged in the shell, the lead screw is arranged on the first rotating rod, the sleeve is arranged in the shell, and the sleeve is connected to the camera, the nut is arranged on the sleeve, and the nut is threadedly connected to the lead screw.

[0011] As an optional solution of the accurate positioning device for the drone of the present invention, wherein: the rotating assembly includes a rotating drum and a connecting block;

[0012] The rotating drum is rotatably arranged in the shell, the connecting block is rotatably arranged on the sleeve, and the connecting block is slidably arranged in the rotating drum.

[0013] As an optional solution of the accurate positioning device for the drone of the present invention, wherein: the deflection assembly includes a telescopic rod, a connecting rod, a slide groove and a rotation groove;

[0014] The telescopic rod is arranged in the shell, and the two ends of the telescopic rod are respectively hinged to the camera and the connecting block through a hinge shaft, and the connecting rod is hinged to the camera through a hinge shaft. The slide groove and the rotating groove are both opened in the shell, and the slide groove is connected with the rotating groove, and the connecting rod is slidably arranged in the slide groove.

[0015] As an optional solution of the accurate positioning device for the drone of the present invention, there are a plurality of positioning mechanisms, and the plurality of positioning mechanisms are arranged in a circle based on the midpoint of the shell.

[0016] As an optional solution of the accurate positioning device for the drone of the present invention, wherein: the driving mechanism includes a plurality of second rotating rods, a plurality of paddles, a plurality of first gears and a plurality of second gears;

[0017] A plurality of the second rotating rods are rotatably disposed in the housing, a plurality of the paddles and a plurality of the first gears are respectively disposed on a plurality of the second rotating rods, a plurality of the second gears are respectively disposed on a plurality of the first rotating rods, and a plurality of the second gears are respectively meshed with a plurality of the first gears.

[0018] As an optional solution of the accurate positioning device for the drone of the present invention, wherein: the driving mechanism further includes a rotating block, a third gear and a plurality of fourth gears;

[0019] The rotating block is rotatably arranged in the housing, the third gear is arranged on the rotating block, a plurality of the fourth gears are respectively arranged on a plurality of rotating drums, and the plurality of the fourth gears are all meshed with the third gear.

[0020] As an optional solution of the accurate positioning device for the drone of the present invention, wherein: the driving mechanism further includes a spiral track, a motor, a third rotating rod and a push rod;

[0021] The spiral track and the motor are both arranged in the housing, the third rotating rod is arranged on the motor, and the push rod is slidably arranged on the third rotating rod.

[0022] As an optional solution of the accurate positioning device for the drone of the present invention, wherein: the driving mechanism further includes a movable plate, a fourth rotating rod and a torsion spring;

[0023] The fourth rotating rod is rotatably arranged on the shell, the movable plate is arranged on the fourth rotating rod, the torsion spring is sleeved on the fourth rotating rod, one end of the torsion spring is arranged on the shell, and the other end of the torsion spring is arranged on the fourth rotating rod.

[0024] As an optional solution of the accurate positioning device for the drone of the present invention, the processing of the image captured by the camera specifically includes the following steps:

[0025] Step 1): Convert the original RGB image obtained by the drone camera to grayscale and calculate the grayscale value of a pixel (i, j) as shown below:

[0026] Gray1(i,j)=R(i,j)

[0027] Gray2(i,j)=G(i,j)

[0028] Gray3(i,j)=B(i,j)

[0029] Step 2): Use a filtering algorithm to perform image denoising, that is, arrange the pixels in the neighborhood based on sorting, output the sorted values ​​as pixel values, process the values ​​with large differences in surrounding grayscale values, and change the pixels with very large grayscale differences with other pixels in the spatial range into pixel values ​​similar to those of the surrounding pixels, thereby achieving the effect of eliminating noise interference. The filtering algorithm expression is shown in the following formula:

[0030] p(x,y)=Med{f(x,y)}

[0031] In the formula, f(x, y) is the image before processing, p(x, y) is the image after processing, and Med refers to the filtering method;

[0032] Step 3): Image matching, calculate the transformation relationship between images I1(x, y) and I2(x, y), that is, satisfy the following relationship:

[0033] I2(x,y)=g(I1(f(x,y)))

[0034] Among them, I1(x, y) is the reference image, I2(x, y) is the image to be matched; f represents the spatial transformation relationship of the pixel point (x, y), and g represents the grayscale transformation relationship of the pixel point;

[0035] Step 4): Feature extraction and key point detection and positioning, using SIFT algorithm to extract features from the image and perform preliminary and fine screening;

[0036] Step 5): Image fusion, assuming that the input images are a and b, add the grayscale values ​​of all feature points in the overlapped area, and then calculate the average. The value obtained at this time is the new pixel value. The calculation formula is as follows:

[0037]

[0038] In the formula, I a ,I b are input image a and input image b, and g(x,y) is the result image.

[0039] The present invention also discloses a positioning method of an accurate positioning device for a drone, comprising the following steps:

[0040] S1, the motor is operated to drive the push rod to rotate along the surface of the spiral track, and the plurality of paddles are successively driven to rotate, thereby driving the plurality of first rotating rods to rotate, so that the plurality of cameras are lowered and extended out of the housing;

[0041] S2. In the process of the plurality of cameras extending downward out of the housing, the plurality of connecting rods slide from the plurality of slide slots into the plurality of rotating slots. At this time, the plurality of cameras continue to descend and deflect, and then the plurality of cameras stop descending;

[0042] S3. The push rod then rotates along the spiral track to the rotating block, and continues to rotate to drive the rotating block to rotate, thereby driving several cameras to rotate to collect wide-area images and process them to calculate the corresponding positions for positioning.

[0043] The present invention has the following beneficial effects:

[0044] 1. The accurate positioning device and positioning method for the UAV are driven by a driving mechanism to make several cameras first descend and extend out of the shell, and then automatically complete the deflection of the camera angle during the descent. Finally, several cameras continue to rotate, which can expand the angle of image acquisition, collect the full range of effective position information at one time, and perform position calculation, thereby realizing the accurate positioning of the UAV.

[0045] 2. The accurate positioning device and positioning method for the drone can realize the process of first lowering, then deflecting, and then rotating several cameras only by running the motor. First, the push rod spirally slides downward along the surface of the spiral track. During the sliding process, several paddles and several lead screws are first turned to rotate, so that several cameras are lowered. Then the push rod rotates to the rotating block, rotates along the rotating block to drive the rotating block and the third gear to rotate, and then drives several fourth gears and several cameras to rotate.

[0046] 3. The accurate positioning device and positioning method for the drone, when the push rod rotates along the upper end of the rotating block, will push the movable plate to swing up and down continuously. After the image acquisition is completed, when the push rod is driven to rotate in the opposite direction by the reverse operation of the motor, the push rod will slide upward along the movable plate to the track of the spiral track, and then return to the upper origin, and in the process, several paddles are moved in the opposite direction to retract several cameras into the shell.

[0047] 4. The UAV uses an accurate positioning device and a positioning method thereof, and uses an image processing algorithm to process the images taken by the camera, which can achieve matching and fusion of UAV images, obtain high-definition images with complete contour information, and thus achieve accurate positioning of the UAV. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0049] Figure 2 It is a schematic diagram of the local structure of the present invention.

[0050] Figure 3It is a schematic diagram of the local explosion structure of the present invention.

[0051] Figure 4 It is a schematic diagram of the internal structure of the present invention.

[0052] Figure 5 for Figure 4 A partial enlarged view of point A in the middle.

[0053] In the figure: 1. drone body; 2. shell; 3. positioning mechanism; 4. camera; 5. lifting assembly; 501. first rotating rod; 502. lead screw; 503. nut; 504. sleeve; 6. rotating assembly; 601. rotating drum; 602. connecting block; 7. deflection assembly; 701. telescopic rod; 702. connecting rod; 703. slide groove; 704. rotating groove; 8. driving mechanism; 801. second rotating rod; 802. paddle; 803. first gear; 804. second gear; 805. rotating block; 806. third gear; 807. fourth gear; 808. spiral track; 809. motor; 810. third rotating rod; 811. push rod; 812. movable plate; 813. fourth rotating rod; 814. torsion spring. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Example 1

[0056] In order to expand the image acquisition range of the camera 4 so that the drone body 1 can be accurately positioned, embodiment 1 is proposed;

[0057] See also Figure 1-Figure 5 , this embodiment discloses an accurate positioning device for a drone, including a drone body 1, a shell 2 is provided on the drone body 1, a positioning mechanism 3 is provided in the shell 2, and the positioning mechanism 3 includes a camera 4, a lifting component 5, a rotating component 6 and a deflection component 7;

[0058] The camera 4 is arranged in the housing 2, the lifting assembly 5 is used to drive the camera 4 to make vertical linear motion to extend out of the housing 2 for image acquisition, the rotating assembly 6 is used to drive the camera 4 to rotate to expand the image acquisition range, and the deflection assembly 7 is used to drive the camera 4 to deflect to further expand the image acquisition range;

[0059] A driving mechanism 8 is also provided in the housing 2 for driving the positioning mechanism 3 to operate.

[0060] Among them, the shell 2 is installed at the lower end of the drone body 1, and a positioning mechanism 3 is provided in the shell 2 for positioning. The lifting component 5 can drive the camera 4 to extend along the slot at the lower end of the shell 2 for image acquisition. When stored in the shell 2, it protects the camera 4.

[0061] As the camera 4 extends, the head of the camera 4 is deflected by the deflection component 7, and then the camera 4 is rotated by the rotation component 6, so that wide-area image acquisition can be performed. The camera 4 can be connected to the positioning system in the drone body 1 through signals, so that the position is calculated through the collected images to achieve accurate positioning of the drone.

[0062] Example 2

[0063] In order to drive the camera 4 to move up and down, embodiment 2 is proposed;

[0064] This embodiment is an improvement made on the basis of embodiment 1. For details, please refer to Figure 2-Figure 5 , the lifting assembly 5 includes a first rotating rod 501, a lead screw 502, a nut 503 and a sleeve 504;

[0065] The first rotating rod 501 is rotatably disposed in the housing 2 , the lead screw 502 is disposed on the first rotating rod 501 , the sleeve 504 is disposed in the housing 2 , and the sleeve 504 is connected to the camera 4 , the nut 503 is disposed on the sleeve 504 , and the nut 503 is threadedly connected to the lead screw 502 .

[0066] Among them, the first rotating rod 501 is rotatably installed on the upper inner wall of the shell 2, the screw 502 is fixed at the lower end of the first rotating rod 501, the nut 503 is threadedly connected to the surface of the screw 502, the sleeve 504 is fixed on the surface of the nut 503, and the sleeve 504 is connected to the upper end of the camera 4 through the deflection assembly 7.

[0067] The deflection assembly 7 can exert a limiting effect on the sleeve 504, and then the first rotating rod 501 can be rotated to drive the lead screw 502 to rotate, thereby driving the nut 503, the sleeve 504 and the camera 4 to move up and down.

[0068] The lead screw 502 is a self-locking lead screw, and the nut 503 can only be moved by the lead screw 502, but the lead screw 502 cannot be rotated by the nut 503.

[0069] Example 3

[0070] In order to drive the camera 4 to rotate, embodiment 3 is proposed;

[0071] This embodiment is an improvement made on the basis of embodiment 2. For details, please refer to Figure 2-Figure 5 , the rotating assembly 6 includes a rotating drum 601 and a connecting block 602;

[0072] The rotating drum 601 is rotatably disposed in the housing 2 , the connecting block 602 is rotatably disposed on the sleeve 504 , and the connecting block 602 is slidably disposed in the rotating drum 601 .

[0073] The rotating drum 601 is rotatably mounted on the lower inner wall of the housing 2, the connecting block 602 is rotatably mounted on the lower end of the sleeve 504, and the cross-shaped connecting block 602 also slides up and down along the cross-shaped groove of the rotating drum 601. The rotating drum 601 rotates, which drives the connecting block 602 to rotate, and the connecting block 602 is connected to the camera 4, which in turn drives the camera 4 to rotate.

[0074] Example 4

[0075] In order to enable the camera 4 to deflect at an angle during the descent process and to apply a limiting effect to the sleeve 504 through the deflection assembly 7, embodiment 4 is proposed;

[0076] This embodiment is an improvement made on the basis of embodiment 3. For details, please refer to Figure 2-Figure 5 , the deflection assembly 7 includes a telescopic rod 701, a connecting rod 702, a slide groove 703 and a rotating groove 704;

[0077] The telescopic rod 701 is arranged in the shell 2, and the two ends of the telescopic rod 701 are respectively hinged to the camera 4 and the connecting block 602 through a hinge shaft. The connecting rod 702 is hinged to the camera 4 through a hinge shaft. The slide groove 703 and the rotating groove 704 are both opened in the shell 2, and the slide groove 703 is connected with the rotating groove 704, and the connecting rod 702 is slidably arranged in the slide groove 703.

[0078] Among them, the two ends of the telescopic rod 701 are hinged to the lower end of the connecting block 602 and the upper end of the camera 4 through a hinge shaft, and the connecting rod 702 is hinged to the surface of the camera 4 through a hinge shaft. The sliding groove 703 is a vertical groove, and the rotating groove 704 is an annular groove.

[0079] When the camera 4 descends and the connecting rod 702 slides along the slide groove 703 to the rotating groove 704, the connecting rod 702 will be blocked. At this time, the first rotating rod 501 continues to rotate to make the camera 4 continue to descend, thereby making the telescopic rod 701 extend and drive the camera 4 to deflect in the direction of the connecting rod 702.

[0080] Subsequently, when the camera 4 rotates, the connecting rod 702 will rotate along the rotating groove 704. When the camera 4 is stored, the camera 4 rotates one circle back to the time when the connecting rod 702 and the slide groove 703 are in engagement, and the camera 4 rises. At this time, the connecting rod 702 slides upward along the slide groove 703, and the telescopic rod 701 contracts to make the camera 4 return to a vertical placement angle.

[0081] Moreover, the connection rod 702 slides along the slide groove 703 to limit the camera 4, the connection block 602 and the sleeve 504. The sleeve 504 and the nut 503 can only move up and down under the drive of the lead screw 502.

[0082] Example 5

[0083] In order to further expand the scope of image acquisition to improve the accuracy of UAV positioning, embodiment 5 is proposed;

[0084] This embodiment is an improvement made on the basis of embodiment 4. For details, please refer to Figure 1-Figure 5 There are a plurality of positioning mechanisms 3 , and the plurality of positioning mechanisms 3 are arranged in a circle based on the midpoint of the shell 2 .

[0085] There are four groups of positioning mechanisms 3 in total, which are arranged in a circle based on the midpoint of the shell 2 and are evenly distributed, so that image information in a wider range can be collected.

[0086] Example 6

[0087] In order to drive the lifting assembly 5 and the rotating assembly 6 to run successively, embodiment 6 is proposed;

[0088] This embodiment is an improvement made on the basis of embodiment 5. For details, please refer to Figure 2-Figure 5 , the driving mechanism 8 includes a plurality of second rotating rods 801, a plurality of paddles 802, a plurality of first gears 803 and a plurality of second gears 804;

[0089] A plurality of second rotating rods 801 are rotatably disposed in the housing 2, a plurality of paddles 802 and a plurality of first gears 803 are respectively disposed on the plurality of second rotating rods 801, a plurality of second gears 804 are respectively disposed on the plurality of first rotating rods 501, and the plurality of second gears 804 are respectively meshed with the plurality of first gears 803;

[0090] The driving mechanism 8 further includes a rotating block 805, a third gear 806 and a plurality of fourth gears 807;

[0091] The rotating block 805 is rotatably disposed in the housing 2, the third gear 806 is disposed on the rotating block 805, and a plurality of fourth gears 807 are respectively disposed on a plurality of rotating drums 601, and the plurality of fourth gears 807 are all meshed with the third gear 806;

[0092] The driving mechanism 8 further includes a spiral track 808, a motor 809, a third rotating rod 810 and a push rod 811;

[0093] The spiral track 808 and the motor 809 are both disposed in the housing 2, the third rotating rod 810 is disposed on the motor 809, and the push rod 811 is slidably disposed on the third rotating rod 810;

[0094] The driving mechanism 8 further includes a movable plate 812, a fourth rotating rod 813 and a torsion spring 814;

[0095] The fourth rotating rod 813 is rotatably disposed on the housing 2 , the movable plate 812 is disposed on the fourth rotating rod 813 , the torsion spring 814 is sleeved on the fourth rotating rod 813 , one end of the torsion spring 814 is disposed on the housing 2 , and the other end of the torsion spring 814 is disposed on the fourth rotating rod 813 .

[0096] The push rod 811 slides up and down in the vertical slide groove on the surface of the third rotating rod 810. The operation of the motor 809 drives the third rotating rod 810 to rotate, and then the push rod 811 spirally slides downward along the surface of the spiral track 808, and successively shifts the four shifting pieces 802, so that the four second rotating rods 801 rotate, and then the four first gears 803, the four second gears 804 and the four first rotating rods 501 rotate.

[0097] Then, after the push rod 811 continues to slide downward over the movable plate 812, it will slide along the upper end of the rotating block 805, and push the protrusion at the upper end of the rotating block 805 to drive the rotating block 805 and the third gear 806 to rotate, thereby driving the four fourth gears 807 and the four cameras 4 to rotate.

[0098] When the push rod 811 rotates along the upper end of the rotating block 805 , it passes through the movable plate 812 and pushes the movable plate 812 to swing back and forth with the fourth rotating rod 813 as the axis under the elastic force of the torsion spring 814 .

[0099] When recovering, the motor 809 rotates in the reverse direction, driving the push rod 811 to rotate in the reverse direction, which will drive the push rod 811 to slide upward along the surface of the movable plate 812 and the spiral track 808 to return to the origin. At the same time, the four paddles 802 are reversely moved to make the four cameras 4 rise and be retracted into the housing 2.

[0100] Example 7

[0101] This embodiment discloses a positioning method for an accurate positioning device for a drone. For details, please refer to Figure 1-Figure 5 , including the following steps:

[0102] S1, the motor 809 is operated to drive the push rod 811 to rotate along the surface of the spiral track 808, and the plurality of paddles 802 are successively driven to rotate, thereby driving the plurality of first rotating rods 501 to rotate, so that the plurality of cameras 4 are lowered and extended out of the housing 2;

[0103] S2, when the plurality of cameras 4 extend downward out of the housing 2, the plurality of connecting rods 702 slide from the plurality of slide slots 703 into the plurality of rotation slots 704, at which time the plurality of cameras 4 continue to descend and deflect, and then the plurality of cameras 4 stop descending;

[0104] S3. Then the push rod 811 rotates along the spiral track 808 to the rotating block 805, and continues to rotate to drive the rotating block 805 to rotate, thereby driving several cameras 4 to rotate to collect wide-area images to calculate the corresponding positions for positioning.

[0105] By running the motor 809, the four cameras 4 can be successively lowered, deflected and rotated to collect images, process them and position them.

[0106] Embodiment 8:

[0107] Since the drone is in motion during the shooting process, the time, angle and posture of the camera shooting will change, resulting in that the image obtained by the camera is inconsistent with the expected image, which is not conducive to the subsequent image fusion operation, thereby affecting the positioning accuracy. Therefore, in order to further improve the positioning accuracy, it is necessary to process the image taken by the camera, and thus embodiment 8 is proposed. Specifically,

[0108] The processing of the image captured by the camera specifically includes the following steps:

[0109] Step 1): Convert the original RGB image obtained by the drone camera to grayscale and calculate the grayscale value of a pixel (i, j) as shown below:

[0110] Gray1(i,j)=R(i,j)

[0111] Gray2(i,j)=G(i,j)

[0112] Gray3(i,j)=B(i,j)

[0113] Step 2): Use a filtering algorithm to perform image denoising, that is, arrange the pixels in the neighborhood based on sorting, output the sorted values ​​as pixel values, process the values ​​with large differences in surrounding grayscale values, and change the pixels with very large grayscale differences with other pixels in the spatial range into pixel values ​​similar to those of the surrounding pixels, thereby achieving the effect of eliminating noise interference. The filtering algorithm expression is shown in the following formula:

[0114] p(x,y)=Med{f(x,y)}

[0115] In the formula, f(x, y) is the image before processing, p(x, y) is the image after processing, and Med refers to the filtering method;

[0116] Step 3): Image matching, calculate the transformation relationship between images I1(x, y) and I2(x, y), that is, satisfy the following relationship:

[0117] I2(x,y)=g(I1(f(x,y)))

[0118] Among them, I1(x, y) is the reference image, I2(x, y) is the image to be matched; f represents the spatial transformation relationship of the pixel point (x, y), and g represents the grayscale transformation relationship of the pixel point;

[0119] Step 4): Feature extraction and key point detection and positioning, using SIFT algorithm to extract features from the image and perform preliminary and fine screening;

[0120] Step 5): Image fusion, assuming that the input images are a and b, add the grayscale values ​​of all feature points in the overlapped area, and then calculate the average. The value obtained at this time is the new pixel value. The calculation formula is as follows:

[0121]

[0122] In the formula, I a ,I b are input image a and input image b, and g(x,y) is the result image.

[0123] By using the above-mentioned image processing algorithm to process the images taken by the camera, it is possible to achieve matching and fusion of UAV images, obtain high-definition images with complete contour information, and thus realize accurate positioning of the UAV.

[0124] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0125] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An accurate positioning device for an unmanned aerial vehicle, characterized in that: The invention comprises an unmanned aerial vehicle body (1), wherein a shell (2) is arranged on the unmanned aerial vehicle body (1), a positioning mechanism (3) is arranged inside the shell (2), and the positioning mechanism (3) comprises a camera (4), a lifting component (5), a rotating component (6) and a deflecting component (7); The camera (4) is arranged in the housing (2); the lifting assembly (5) is used to drive the camera (4) to perform vertical linear motion so as to extend out of the housing (2) to perform image acquisition; the rotating assembly (6) is used to drive the camera (4) to rotate so as to expand the image acquisition range; and the deflection assembly (7) is used to drive the camera (4) to deflect so as to further expand the image acquisition range; A driving mechanism (8) is also provided in the housing (2) for driving the positioning mechanism (3) to operate; The lifting assembly (5) comprises a first rotating rod (501), a lead screw (502), a nut (503) and a sleeve (504); the first rotating rod (501) is rotatably arranged in the housing (2), the lead screw (502) is arranged on the first rotating rod (501), the sleeve (504) is arranged in the housing (2), and the sleeve (504) is connected to the camera (4), the nut (503) is arranged on the sleeve (504), and the nut (503) is threadedly connected to the lead screw (502); The rotating assembly (6) comprises a rotating drum (601) and a connecting block (602); the rotating drum (601) is rotatably disposed in the housing (2), the connecting block (602) is rotatably disposed on the sleeve (504), and the connecting block (602) is slidably disposed in the rotating drum (601); The deflection assembly (7) comprises a telescopic rod (701), a connecting rod (702), a slide groove (703) and a rotating groove (704); the telescopic rod (701) is arranged in the shell (2), the two ends of the telescopic rod (701) are respectively hinged to the camera (4) and the connecting block (602) through a hinge shaft, the connecting rod (702) is hinged to the camera (4) through a hinge shaft, the slide groove (703) and the rotating groove (704) are both opened in the shell (2), and the slide groove (703) is connected to the rotating groove (704), and the connecting rod (702) is slidably arranged in the slide groove (703).

2. The accurate positioning device for a drone according to claim 1, characterized in that: A plurality of the positioning mechanisms (3) are provided, and the plurality of the positioning mechanisms (3) are arranged in a circle based on the midpoint of the shell (2).

3. The accurate positioning device for a drone according to claim 1 or 2, characterized in that: The driving mechanism (8) comprises a plurality of second rotating rods (801), a plurality of paddles (802), a plurality of first gears (803) and a plurality of second gears (804); A plurality of the second rotating rods (801) are rotatably arranged in the housing (2), a plurality of the paddles (802) and a plurality of the first gears (803) are respectively arranged on a plurality of the second rotating rods (801), a plurality of the second gears (804) are respectively arranged on a plurality of the first rotating rods (501), and a plurality of the second gears (804) are respectively meshed with a plurality of the first gears (803).

4. The accurate positioning device for a drone according to claim 3, characterized in that: The driving mechanism (8) further comprises a rotating block (805), a third gear (806) and a plurality of fourth gears (807); The rotating block (805) is rotatably disposed in the housing (2), the third gear (806) is disposed on the rotating block (805), a plurality of fourth gears (807) are respectively disposed on a plurality of rotating drums (601), and the plurality of fourth gears (807) are all meshed with the third gear (806).

5. The accurate positioning device for a drone according to claim 4, characterized in that: The driving mechanism (8) further comprises a spiral track (808), a motor (809), a third rotating rod (810) and a push rod (811); The spiral track (808) and the motor (809) are both arranged in the housing (2), the third rotating rod (810) is arranged on the motor (809), and the push rod (811) is slidably arranged on the third rotating rod (810).

6. The accurate positioning device for a drone according to claim 5, characterized in that: The driving mechanism (8) further comprises a movable plate (812), a fourth rotating rod (813) and a torsion spring (814); The fourth rotating rod (813) is rotatably arranged on the shell (2), the movable plate (812) is arranged on the fourth rotating rod (813), the torsion spring (814) is sleeved on the fourth rotating rod (813), one end of the torsion spring (814) is arranged on the shell (2), and the other end of the torsion spring (814) is arranged on the fourth rotating rod (813).

7. The accurate positioning device for a drone according to claim 6, characterized in that: The process also includes processing the image captured by the camera, which specifically includes the following steps: Step 1): Convert the original RGB image obtained by the drone camera to grayscale and calculate the grayscale value of a pixel (i, j) as shown below: Gray1(i,j)=R(i,j) Gray2(i,j)=G(i,j) Gray3(i,j)=B(i,j) Step 2): Use a filtering algorithm to perform image denoising, that is, arrange the pixels in the neighborhood based on sorting, output the sorted values ​​as pixel values, process the values ​​with large differences in surrounding grayscale values, and change the pixels with very large grayscale differences with other pixels in the spatial range into pixel values ​​similar to those of the surrounding pixels, thereby achieving the effect of eliminating noise interference. The filtering algorithm expression is shown in the following formula: p(x,y)=Med{f(x,y)} In the formula, f(x, y) is the image before processing, p(x, y) is the image after processing, and Med refers to the filtering method; Step 3): Image matching, calculate the transformation relationship between images I1(x, y) and I2(x, y), that is, satisfy the following relationship: I2(x,y)=g(I1(f(x,y))) Among them, I1(x, y) is the reference image, I2(x, y) is the image to be matched; f represents the spatial transformation relationship of the pixel point (x, y), and g represents the grayscale transformation relationship of the pixel point; Step 4): Feature extraction and key point detection and positioning, using SIFT algorithm to extract features from the image and perform preliminary and fine screening; Step 5): Image fusion, assuming that the input images are a and b, add the grayscale values ​​of all feature points in the overlapped area, and then calculate the average. The value obtained at this time is the new pixel value. The calculation formula is as follows: In the formula, I a ,I b are input image a and input image b, and g(x,y) is the result image.

8. The positioning method of the accurate positioning device for unmanned aerial vehicle according to claim 7, characterized in that: The steps include: S1, the motor (809) is operated to drive the push rod (811) to rotate along the surface of the spiral track (808), and the plurality of paddles (802) are successively driven to rotate, thereby driving the plurality of first rotating rods (501) to rotate, so that the plurality of cameras (4) are lowered and extended out of the housing (2); S2, when the plurality of cameras (4) extend downwardly out of the housing (2), the plurality of connecting rods (702) slide from the plurality of sliding grooves (703) into the plurality of rotating grooves (704), at which time the plurality of cameras (4) continue to descend and deflect, and then the plurality of cameras (4) stop descending; S3, the push rod (811) then rotates along the spiral track (808) to the rotating block (805), and continues to rotate to drive the rotating block (805) to rotate, thereby driving a plurality of cameras (4) to rotate to collect wide-area images and process them to calculate the corresponding positions for positioning.

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