Visual positioning avoidance system of unmanned aerial vehicle and method thereof

Abstract

The application discloses a visual positioning avoidance system and method of a unmanned plane, which comprises an existing unmanned plane, a sensor group and a visual odometer are loaded on the unmanned plane, a rotating unit is installed on the unmanned plane, a binocular camera for collecting flight scene images is installed on the rotating unit, rotation of the rotating unit is synchronous and consistent with a current flight direction of the unmanned plane, a laser scanning ranging unit for measuring the distance of obstacles in the advancing direction is installed on the rotating unit and is consistent with the current flight direction of the unmanned plane, and a miniature processing unit with an image processing module is arranged on the unmanned plane, the binocular camera for collecting flight scene images and the laser scanning ranging unit for measuring the distance of obstacles in the advancing direction are combined, a safe avoidance flight range of the unmanned plane is obtained, and the unmanned plane can automatically avoid obstacles and safely fly.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, specifically to a visual positioning and avoidance system and method for UAVs. Background Technology

[0002] The advancements in microelectronics and sensor technologies in recent years have made fully autonomous unmanned aerial vehicles (UAVs) possible. Currently, the key challenges in autonomous UAV design lie in information acquisition, navigation, and the design of remote control systems. For traditional high-altitude UAVs, a combination of GPS and inertial measurement units (IMUs) can acquire position, attitude, altitude, and heading information for flight control and waypoint navigation. However, for micro-UAVs primarily used in low-altitude, near-ground environments, the flight environment is far more complex. Therefore, the aircraft must not only estimate its own attitude but also perceive its surrounding environment. To achieve autonomous flight of micro-UAVs in low-altitude environments, it is essential to select appropriate sensors to acquire UAV attitude and environmental information; however, existing visual positioning and avoidance systems for UAVs are inadequate for obstacle avoidance in complex flight environments. Therefore, we propose an improved visual positioning and avoidance system for UAVs. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0004] This invention discloses a visual positioning and avoidance system for unmanned aerial vehicles (UAVs), comprising an existing UAV equipped with a sensor array and a visual odometry. The sensor array is used to obtain data such as the UAV's current flight acceleration, angular velocity, pitch angle, roll angle, and yaw angle. The visual odometry obtains the UAV's current visual pose data. Based on the obtained acceleration, angular velocity, pitch angle, roll angle, and yaw angle data, the current flight direction vector of the UAV is obtained. The UAV is equipped with a rotating unit, which is equipped with a binocular camera for acquiring images of the flight scene. The rotation of the rotating unit is synchronized with the UAV's current flight direction. The rotating unit is equipped with a laser scanning ranging unit that is aligned with the UAV's current flight direction and measures the distance to obstacles in the forward direction. The UAV is equipped with a microprocessor unit with an image processing module. The rotating unit, laser scanning ranging unit, visual odometry, and sensor array are all connected to the microprocessor unit. The binocular camera is electrically connected to the image processing module.

[0005] In a preferred embodiment of the present invention, the rotating unit is mounted on a positioning frame at the bottom of the drone. A vertically downward rotating rod is mounted on the positioning frame via bearings. A rotating housing is fixed to the bottom end of the rotating rod. The laser scanning ranging unit and the binocular camera are fixed on the rotating housing. A first drive motor is fixed on the positioning frame to drive the rotating rod to rotate. A first angle sensor is provided on the rotating rod to detect the rotation angle of the rotating rod. Both the first drive motor and the first angle sensor are electrically connected to the microprocessor unit.

[0006] As a preferred embodiment of the present invention, the laser scanning ranging unit includes a positioning seat fixed to a rotating housing, a support plate on the positioning seat, a horizontally arranged rotating shaft on the support plate, a rotating disk at the end of the rotating shaft, a servo motor for driving the rotating shaft to rotate on the positioning seat, a horizontally arranged support plate on the rotating disk, a swing arm for swinging left and right on the support plate, a laser rangefinder installed on the swing arm, and a driving mechanism for driving the swing arm to swing on the rotating disk.

[0007] As a preferred embodiment of the present invention, the driving mechanism includes a semi-circular rotating wheel located at the tail end of the swing arm, an external gear ring arranged along the circumference of the rotating wheel, a positioning block mounted on the support plate, a limiting groove on the positioning block, a sliding block inserted in the limiting groove and sliding along the limiting groove, a spur rack fixed on the outer side of the sliding block and meshing with the external gear ring, and a reciprocating mechanism for driving the spur rack to reciprocate.

[0008] As a preferred embodiment of the present invention, the reciprocating mechanism includes a turntable mounted on a support plate, an eccentrically connected rod hinged to the turntable, the outer end of the eccentrically connected rod being hinged to the end of a straight rack, a base frame on the turntable, and a second drive motor for driving the turntable to rotate fixed on the base frame.

[0009] As a preferred embodiment of the present invention, a second angle sensor is provided on the rotating shaft.

[0010] A method for a visual positioning and avoidance system for unmanned aerial vehicles (UAVs) includes the following steps:

[0011] Step 1: First, obtain data such as the drone's current flight acceleration, angular velocity, pitch angle, roll angle, and yaw angle through the sensor array; then, obtain the drone's current visual pose data through the visual odometry.

[0012] Step 2: Obtain the current flight direction vector of the UAV based on the obtained data such as acceleration, angular velocity, pitch angle, roll angle, and yaw angle;

[0013] Step 3: Based on the obtained current flight direction vector of the drone, control the rotating unit to rotate synchronously, so that the rotation of the rotating unit is synchronized with the current flight direction of the drone; then use the binocular camera to record the scene in front of the drone's current flight direction to obtain background model data, and at the same time use the laser scanning ranging unit to measure the distance of obstacles in the forward direction to obtain background distance data; integrate the background model data and background distance data to obtain the obstacle avoidance model.

[0014] Step 4: Based on the obstacle avoidance model, the drone's current flight direction vector, and the drone's current visual pose data, determine the safe flight range for drone flight.

[0015] As a preferred technical solution of the present invention, the method of using a laser scanning ranging unit to measure the distance of obstacles in the direction of the drone's movement is as follows: the second drive motor drives the rotating disk to rotate, which in turn drives the laser rangefinder to rotate up and down. At the same time, the drive mechanism drives the swing arm to swing back and forth. The combination of the two allows the laser rangefinder to perform a three-dimensional spatial scan of the obstacles in front of the drone, and then obtain a three-dimensional background distance data.

[0016] As a preferred technical solution of the present invention, the method of controlling the rotating unit to rotate synchronously so that the rotation of the rotating unit is synchronized with the current flight direction of the UAV is to determine the rotation angle of the rotating rod according to the current flight direction vector of the UAV and the current visual pose data of the UAV, and then drive the rotating rod to rotate to the determined rotation angle under the driving action of the first drive motor, so that the rotation of the rotating unit is synchronized with the current flight direction of the UAV.

[0017] The beneficial effects of this invention are:

[0018] The visual positioning and avoidance system of this type of UAV uses a rotating unit that is synchronized with the UAV's current flight direction. This rotating unit is equipped with a binocular camera to capture images of the flight scene, and a laser scanning ranging unit that measures the distance to obstacles in the direction of flight, also synchronized with the UAV's current flight direction. During flight, the system first obtains data such as the UAV's current acceleration, angular velocity, pitch angle, roll angle, and yaw angle through a sensor array; a visual odometry obtains the UAV's current visual pose data; based on the obtained acceleration, angular velocity, pitch angle, roll angle, and yaw angle data, the UAV's current flight direction vector is calculated. This calculated flight direction vector is then used to control the rotating unit to rotate synchronously, ensuring that the rotation of the rotating unit is synchronized with the flight direction. The drone maintains a synchronized flight direction. Then, a binocular camera captures the scene ahead of the drone's current flight path, obtaining background model data. Simultaneously, a laser scanning ranging unit measures the distance to obstacles in the forward direction, obtaining background distance data. The background model data and background distance data are integrated to obtain an obstacle avoidance model. Based on the obstacle avoidance model, the drone's current flight direction vector, and the drone's current visual pose data, the safe obstacle avoidance range for the drone is determined. This invention combines a binocular camera that captures flight scene images with distance measurement of obstacles in the forward direction to obtain the safe obstacle avoidance range for the drone, thus achieving automatic obstacle avoidance and ensuring safe flight. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the structure of a visual positioning and avoidance system for an unmanned aerial vehicle (UAV) according to the present invention.

[0021] Figure 2 This is a schematic diagram of the installation of the rotating unit of a visual positioning and avoidance system for a drone according to the present invention.

[0022] Figure 3 This is a schematic diagram of the structure of the laser scanning ranging unit of a visual positioning and avoidance system for a drone according to the present invention;

[0023] Figure 4 This is a schematic diagram of the drive mechanism of a visual positioning and avoidance system for a drone according to the present invention.

[0024] Figure 5 This is a schematic diagram of the limiting groove structure of a visual positioning and avoidance system for a drone according to the present invention;

[0025] Figure 6 This is a system block diagram of a visual positioning and avoidance system for an unmanned aerial vehicle (UAV) according to the present invention.

[0026] Figure 7 This is a flowchart of a method for a visual positioning and avoidance system for unmanned aerial vehicles (UAVs) according to the present invention.

[0027] In the diagram: 1. UAV; 2. Sensor group; 3. Visual odometer; 4. Rotating unit; 5. Binocular camera; 6. Laser scanning ranging unit; 7. Image processing module; 8. Microprocessor unit; 9. Positioning frame; 10. Positioning seat; 11. Support plate; 12. Rotating shaft; 13. Rotary disk; 14. Servo motor; 15. Support plate; 16. Swing arm; 17. Laser rangefinder; 18. Drive mechanism; 19. Rotary wheel; 20. External gear ring; 21. Positioning block; 22. Limiting groove; 23. Sliding block; 24. Spur rack; 25. Reciprocating mechanism; 26. Turntable; 27. Eccentric connecting rod; 28. Base frame; 29. ​​Second drive motor; 30. Second angle sensor; 31. Rotating rod; 32. Rotating housing; 33. First drive motor; 34. First angle sensor. Detailed Implementation

[0028] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0029] Example: Figure 1-7 As shown, the present invention discloses a visual positioning and avoidance system for a drone, comprising an existing drone 1, wherein the drone 1 is equipped with a sensor group 2 and a visual odometry 3. The sensor group 2 is used to obtain data such as acceleration, angular velocity, pitch angle, roll angle, and yaw angle of the drone 1 during current flight; the visual odometry 3 obtains the current visual pose data of the drone; and the current flight direction vector of the drone 1 is obtained based on the obtained data such as acceleration, angular velocity, pitch angle, roll angle, and yaw angle; a rotation unit 4 is installed on the drone 1, the rotation unit 4... Unit 4 is equipped with a binocular camera 5 for acquiring images of the flight scene. The rotation of the rotating unit 4 is synchronized with the current flight direction of the UAV 1. The rotating unit 4 is equipped with a laser scanning ranging unit 6 that is aligned with the current flight direction of the UAV 1 and measures the distance to obstacles in the forward direction. The UAV 1 is equipped with a microprocessor unit 8 with an image processing module 7. The rotating unit 4, the laser scanning ranging unit 6, the visual odometer 3, and the sensor group 2 are all connected to the microprocessor unit 8. The binocular camera 5 is electrically connected to the image processing module 7.

[0030] The rotating unit 4 is mounted on the positioning frame 9 at the bottom of the UAV 1. A vertically downward rotating rod 31 is mounted on the positioning frame 9 via bearings. A rotating housing 32 is fixed to the bottom end of the rotating rod 31. The laser scanning ranging unit 6 and the binocular camera 5 are fixed on the rotating housing 32. A first drive motor 33 is fixed on the positioning frame 9 to drive the rotating rod 31 to rotate. A first angle sensor 34 is provided on the rotating rod 31 to detect the rotation angle of the rotating rod 31. The first drive motor 33 and the first angle sensor 34 are both electrically connected to the microprocessor unit 8.

[0031] The laser scanning ranging unit 6 includes a positioning seat 10 fixed to the rotating housing 11. The positioning seat 10 is provided with a support plate 11. The support plate 11 is provided with a horizontally arranged rotating shaft 12. The end of the rotating shaft 12 is provided with a rotating disk 13. The positioning seat 10 is equipped with a servo motor 14 that drives the rotating shaft 12 to rotate. The rotating disk 13 is provided with a horizontally arranged support plate 15. The support plate 15 is provided with a swing arm 16 that swings left and right. The swinging part of the swing arm 16 is equipped with a laser rangefinder 17. The rotating disk 13 is provided with a drive mechanism 18 that drives the swing arm 16 to swing.

[0032] The drive mechanism 18 includes a semi-circular rotating wheel 19 located at the tail end of the rocker arm 16. The rotating wheel 19 is provided with an external gear ring 20 arranged circumferentially along the rotating wheel 19. A positioning block 21 is installed on the support plate 15. The positioning block 21 is provided with a limiting groove 22. A sliding block 23 is inserted in the limiting groove 22 and slides along the limiting groove 22. A spur rack 24 that meshes with the external gear ring 20 is fixed on the outside of the sliding block 23. A reciprocating mechanism 25 that drives the spur rack 24 to reciprocate is provided on the support plate 15.

[0033] The reciprocating mechanism 25 includes a turntable 26 mounted on a support plate 15. An eccentric connecting rod 27 is hinged to the turntable 26. The outer end of the eccentric connecting rod 27 is hinged to the end of a rack 24. A base frame 28 is mounted on the rotating disk 13. A second drive motor 29 for driving the turntable 26 to rotate is fixed on the base frame 28.

[0034] A second angle sensor is provided on the rotating shaft.

[0035] A method for a visual positioning and avoidance system for unmanned aerial vehicles (UAVs) includes the following steps:

[0036] Step 1: First, obtain data such as the drone's current flight acceleration, angular velocity, pitch angle, roll angle, and yaw angle through the sensor array; then, obtain the drone's current visual pose data through the visual odometry.

[0037] Step 2: Obtain the current flight direction vector of the UAV based on the obtained data such as acceleration, angular velocity, pitch angle, roll angle, and yaw angle;

[0038] Step 3: Based on the obtained current flight direction vector of the drone, control the rotating unit to rotate synchronously, so that the rotation of the rotating unit is synchronized with the current flight direction of the drone; then use the binocular camera to record the scene in front of the drone's current flight direction to obtain background model data, and at the same time use the laser scanning ranging unit to measure the distance of obstacles in the forward direction to obtain background distance data; integrate the background model data and background distance data to obtain the obstacle avoidance model.

[0039] Step 4: Based on the obstacle avoidance model, the drone's current flight direction vector, and the drone's current visual pose data, determine the safe flight range for drone flight.

[0040] The method of using a laser scanning ranging unit to measure the distance of obstacles in the direction of the drone's movement is as follows: the second drive motor drives the rotating disk to rotate, which in turn drives the laser rangefinder to rotate up and down. At the same time, the drive mechanism drives the swing arm to swing back and forth. The combination of the two allows the laser rangefinder to perform a three-dimensional spatial scan of the obstacles in front of the drone, and then obtain a three-dimensional background distance data.

[0041] The method for controlling the rotating unit to rotate synchronously so that the rotation of the rotating unit is synchronized with the current flight direction of the UAV is to determine the rotation angle of the rotating rod based on the current flight direction vector and the current visual pose data of the UAV, and then drive the rotating rod to rotate to the determined rotation angle under the drive of the first drive motor, so that the rotation of the rotating unit is synchronized with the current flight direction of the UAV.

[0042] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A visual positioning and avoidance system for unmanned aerial vehicles (UAVs), characterized in that: The system includes an existing unmanned aerial vehicle (UAV) (1), which is equipped with a sensor group (2) and a visual odometry (3). The sensor group (2) is used to obtain the acceleration, angular velocity, pitch angle, roll angle and yaw angle information data of the UAV (1) during its current flight. The visual odometry (3) obtains the current visual pose data of the UAV. The current flight direction vector of the UAV (1) is obtained based on the obtained acceleration, angular velocity, pitch angle, roll angle and yaw angle information data. The UAV (1) is equipped with a rotation unit (4), which is equipped with a device for capturing images of the flight scene. The device has a binocular camera (5), and the rotation of the rotating unit (4) is synchronized with the current flight direction of the UAV (1). The rotating unit (4) has a laser scanning ranging unit (6) that is consistent with the current flight direction of the UAV (1) and measures the distance to obstacles in the forward direction. The UAV (1) is equipped with a micro-processing unit (8) with an image processing module (7). The rotating unit (4), the laser scanning ranging unit (6), the visual odometer (3), and the sensor group (2) are all connected to the micro-processing unit (8). The binocular camera (5) is electrically connected to the image processing module (7). The rotating unit (4) is set on the positioning frame (9) at the bottom of the UAV (1). A vertically downward rotating rod (31) is mounted on the positioning frame (9) via a bearing. A rotating housing (32) is fixed at the bottom end of the rotating rod (31). The laser scanning ranging unit (6) and the binocular camera (5) are fixed on the rotating housing (32). A first drive motor (33) is fixed on the positioning frame (9) to drive the rotating rod (31) to rotate. A first angle sensor (34) is provided on the rotating rod (31) to detect the rotation angle of the rotating rod (31). The first drive motor (33) and the first angle sensor (34) are both electrically connected to the microprocessor unit (8). The laser scanning ranging unit (6) includes a positioning seat (10) fixed to the rotating housing (32), a support plate (11) on the positioning seat (10), a horizontally arranged rotating shaft (12) on the support plate (11), a rotating disk (13) at the end of the rotating shaft (12), a servo motor (14) for driving the rotating shaft (12) to rotate on the positioning seat (10), a horizontally arranged support plate (15) on the rotating disk (13), a swing arm (16) for swinging left and right on the support plate (15), a laser rangefinder (17) on the swing arm (16), and a driving mechanism (18) for driving the swing arm (16) to swing on the rotating disk (13). The drive mechanism (18) includes a semi-circular rotating wheel (19) located at the tail end of the swing arm (16). The rotating wheel (19) is provided with an external gear ring (20) arranged circumferentially around the rotating wheel (19). A positioning block (21) is installed on the support plate (15). A limiting groove (22) is provided on the positioning block (21). A sliding block (23) that slides along the limiting groove (22) is inserted in the limiting groove (22). A straight rack (24) that meshes with the external gear ring (20) is fixed on the outside of the sliding block (23). A reciprocating mechanism (25) that drives the straight rack (24) to reciprocate is provided on the support plate (15). The reciprocating mechanism (25) includes a turntable (26) mounted on a support plate (15), an eccentric connecting rod (27) hinged to the turntable (26), the outer end of the eccentric connecting rod (27) being hinged to the end of a rack (24), a base frame (28) mounted on the rotating disk (13), a second drive motor (29) for driving the turntable (26) to rotate fixed on the base frame (28), and a second angle sensor (30) mounted on the rotating shaft (12).

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