Camera gimbal based on multi-rotor drone

Abstract

This invention discloses a camera gimbal based on a multi-rotor drone, belonging to the field of drone technology. The drone part includes a center plate main body, a center plate upper plate mounted on top of the center plate main body, landing gear mounted below the center plate main body, and an onboard computer and camera mounted on the center plate upper plate. Sensors are mounted between the center plate main body and the center plate upper plate, and an optical flow meter is mounted below the center plate main body. A 4000mAh 4S large battery is mounted between the landing gear and the center plate main body. The camera of the drone is fixed by a dedicated camera gimbal. A pressure sensor is placed in the center of the camera gimbal's groove. For most monocular and binocular camera models on the market, when placed on the gimbal, the pressure sensor senses the weight and controls the fixing clamps on both sides of the gimbal to automatically clamp the camera. The fixing clamps have a certain angle of change in all directions, allowing the camera to adjust the field of view in all directions (up, down, left, and right).

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) technology, specifically relating to a camera gimbal based on a multi-rotor UAV. Background Technology

[0002] Multirotor drones are a type of rotary-wing drone, characterized by their high flexibility, stability, and vertical takeoff and landing capabilities, making them more maneuverable than fixed-wing drones. Therefore, multirotor drones have a wider range of applications. With the development of multirotor drone technology in recent years, they have found widespread use in both civilian and military fields. In civilian applications, they can be used for aerial photography, power line inspection, and logistics; in military applications, they can be used for military reconnaissance and target engagement. Multirotor drones can achieve autonomous control and remote command without a pilot.

[0003] For indoor positioning and navigation technology of multi-rotor UAVs, traditional UAVs typically use a combination of inertial navigation systems (INS) and global positioning systems (GPS) to achieve positioning and navigation. However, in some environments, due to factors such as building obstruction or radio interference, GPS signals are weak and sometimes completely unusable. Therefore, researching a navigation method in GPS-free environments has become a technical challenge that needs to be overcome in current research.

[0004] Because the inertial navigation systems of indoor multi-rotor drones suffer from severe zero drift, they achieve high positioning accuracy for short periods. However, over time, error accumulation leads to a continuous decrease in measurement accuracy, making them unsuitable for standalone use and requiring integration with other sensors. In recent years, an increasing number of researchers have incorporated laser rangefinders and visual sensors into drone positioning and navigation. Visual devices include airborne and external vision systems, with external vision primarily consisting of optical motion capture systems. Other technologies such as Bluetooth positioning, Ultra-Wideband (UWB) positioning, WiFi positioning, ultrasonic positioning, and positioning using lighting equipment are also being applied to indoor positioning and navigation.

[0005] For airborne visual sensor positioning, the main methods include monocular vision, which relies primarily on cameras for calibration. Target distance information is calculated through the correspondence between target features and images. Specifically, a color-coded reference line is laid on the measured ground, and the position information of the reference features is compared with the image information acquired by the airborne visual sensor. Binocular vision, also known as stereo vision, uses two cameras to obtain the phase difference between images from the left and right cameras, and combines this with a spatial projection relationship established by a camera model to obtain position information. Therefore, monocular or binocular cameras are crucial for aircraft positioning and navigation; most multi-rotor UAVs require monocular or multi-view cameras for positioning, navigation, and data acquisition. Summary of the Invention

[0006] Based on the aforementioned requirements for multi-rotor drone applications, this invention proposes a camera gimbal for multi-rotor drones. By installing a specially designed camera gimbal on the drone, it can autonomously clamp and fix cameras of any size to most monocular and binocular cameras on the market, thereby meeting different flight and shooting needs. Furthermore, the various devices on the drone are rationally arranged, resulting in a compact and flexible overall size with long battery life.

[0007] This invention relates to a camera gimbal for a multi-rotor drone. The multi-rotor drone includes a center plate, a center plate body, an onboard computer, a battery, a tripod, a camera gimbal, a camera, sensors, an optical flow meter, a fan, a Wi-Fi antenna, a GPS, and an image transmission module.

[0008] The center plate is fixed to the center plate body at its four corners via aluminum pillars. Propellers are also installed at the four corners of the center plate body's bottom surface. The onboard computer is fixedly mounted to the center of the top surface of the center plate via aluminum pillars. A 4000mAh 4S battery is used, mounted in the center of the bottom surface of the center plate body via a battery holder. A tripod is mounted at the bottom of the battery holder. An optical flow meter is fixedly mounted at the center of the bottom of the center plate body. Wi-Fi antennas are located on the left and right sides of the onboard computer, penetrating the perforated sections of the center plate and the center plate body, and are longitudinally positioned within sleeves designed on the center plate. A GPS device is mounted on the top surface of the center plate, located behind the onboard computer. Sensors are positioned between the center plate body and the center plate, fixed to a mounting plate on the upper surface of the center plate body. The image transmission module is installed on the top surface of the center plate, located to the left or right of the airborne computer; the image transmission module is connected to the antenna connectors at the top of the two wifi antennas by an antenna connector; the fan is installed above the image transmission module; the camera is installed on a camera pan-tilt unit, which is installed on a pitch adjustment platform installed in front of the airborne computer.

[0009] The aforementioned camera pan-tilt unit is a rectangular box structure with a base, left and right side walls, and a rear side wall, which is fixed to the center plate via shock-absorbing ball joints. A pressure sensor is installed at the center of the top surface of the camera pan-tilt unit base; plate-shaped fixing clamps are mounted on the left and right sides of the camera pan-tilt unit, and the left and right movement of the fixing clamps is driven by a drive motor; at the same time, the fixing clamps also have a rotating pair that rotates around its own axis.

[0010] When the camera is placed on the camera pan-tilt head, the pressure sensor mounted on the camera pan-tilt head senses the pressure. The pressure is converted into an electrical signal that is positively correlated with the external force and output to the onboard computer. The onboard computer then drives the drive motor to work, which in turn drives the two fixed clamps on both sides to move relative to each other and clamp the camera.

[0011] The advantages of this invention are:

[0012] 1. The multi-rotor drone in this invention has a propeller wheelbase of only 200mm and is equipped with a 4000mAh 4s large battery. The multi-rotor drone is small and flexible in size and has a long battery life, enabling it to complete high-intensity continuous work.

[0013] 2. The camera pan-tilt unit in this invention has a certain degree of versatility. It can be placed in most models of monocular and binocular cameras. When the camera is placed in the camera pan-tilt unit of this invention, the pressure sensor at the center of the camera pan-tilt unit groove will sense a certain pressure, and the fixing clip will automatically clamp the camera and firmly fix it in the camera pan-tilt unit.

[0014] 3. In this invention, the camera pan-tilt unit has a certain adjustable angle in all directions. Therefore, the camera fixed on the camera pan-tilt unit can adjust the camera's field of view in all directions (up, down, left, and right) to adapt to different shooting needs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the multi-rotor UAV in this invention;

[0016] Figure 2 This is a schematic diagram of the bottom structure of the multi-rotor UAV in this invention;

[0017] Figure 3 This is a schematic diagram of the battery structure of the multi-rotor UAV in this invention;

[0018] Figure 4 This is a schematic diagram of the camera pan-tilt structure in this invention;

[0019] Figure 5 This is a schematic diagram of the internal drive mechanism of the camera pan-tilt unit in this invention.

[0020] In the picture:

[0021] 1-Center plate upper plate 2-Center plate main body 3-Airborne computer

[0022] 4-Battery 5-Tripod 6-Camera Pan / Tilt Head

[0023] 7-Camera 8-Sensor 9-Optical Flow Meter

[0024] 10-Fan 11-Wi-Fi 12-GPS

[0025] 13-Image transmission module 14-Lampshade 15-Base

[0026] 16-Propeller 4a-Front Upper Plate 4b-Rear Upper Plate

[0027] 4c - Bottom plate; 4d - Long aluminum column; 4e - Short aluminum column

[0028] 4f - Lower aluminum post socket; 4g - Upper aluminum post socket; 5a - Front stand

[0029] 5b - Rear leg; 5c - Leg crossbar; 6a - Pressure sensor

[0030] 6b-Fixing clamp; 6c-Lead screw; 6d-Nut

[0031] 6e - Transmission gear; 6f - Drive motor Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings.

[0033] This invention discloses a multi-rotor unmanned aerial vehicle (UAV), comprising a center plate 1, a center plate body 2, an onboard computer 3, a battery 4, a tripod 5, a camera gimbal 6, a camera 7, a sensor 8, an optical flow meter 9, a fan 10, a Wi-Fi antenna 11, a GPS 12, and an image transmission module 13. Figure 1 , Figure 2 As shown.

[0034] The center plate 1 and the center plate body 2 are square plates of equal size, with rounded corners at all four circumferential directions. The center plate 1 and the center plate body 2 are parallel and symmetrically arranged vertically. An aluminum column perpendicular to the center plate body 2 is set between the four corners. Two aluminum columns are set along the arc at each corner position. The two ends of each aluminum column are connected and fixed to the center plate 1 and the center plate body 2 respectively, so as to fix the relative position of the center plate 1 and the center plate body 2.

[0035] At the four corners between the center plate 1 and the center plate body 2, lampshades 14 are installed. These lampshades are arc-shaped and located outside the two aluminum pillars at the four corners, with their outer walls flush with the arc edges of the center plate 1 and the center plate body 2. Lights are installed inside the lampshades 14 to provide nighttime illumination for the drone. At the four corners of the bottom surface of the center plate body 2, bases 15 are also installed, on which rotors equipped with propellers 16 are mounted. The propellers 16 have a wheelbase of 200mm and blade size of 5 inches.

[0036] The aforementioned center plate 1 and center plate body 2 have multiple cutouts of different shapes to reduce weight, depending on the installation position of the mounted equipment. The uncut parts are used to fix and connect the equipment, including the airborne computer 3, battery 4, camera pan-tilt head 6, sensor 8 and optical flow meter 9.

[0037] The airborne computer 3 is a rectangular PCB board integrating various functional modules; each corner of the PCB board is fixedly mounted to the center of the top surface of the central plate 1 via aluminum pillars. One short side of the PCB board is parallel to one side of the central plate 1, positioning that side at the front of the entire UAV.

[0038] Battery 4 uses a 4000mAh 4S battery, which makes the drone's structure compact yet provides long-lasting operation. Battery 4 is mounted on the center of the bottom surface of the main body 2 via a battery bracket. Figure 3 As shown, the battery rack includes a front upper plate 4a, a rear upper plate 4b, and a lower plate 4c. The battery is disposed between the front upper plate 4a, the rear upper plate 4b, and the lower plate 4c. The front upper plate 4a is fixed to the lower plate 4c on both sides by a set of two aluminum pillars, and its front end is fixed to the lower plate 4c by a single aluminum pillar. Similarly, the rear upper plate 4b is fixed to the lower plate 4c on both sides by a set of two aluminum pillars, and its rear end is fixed to the lower plate 4c by a single aluminum pillar.

[0039] Each group of aluminum columns consists of one long aluminum column 4d and one short aluminum column 4e. The installation method for each group of aluminum columns is the same. The installation method for one group of aluminum columns on the front upper plate side is explained below:

[0040] In this group of aluminum columns, the bottom end of the long aluminum column 4d is inserted and fixed into the opening A on the lower aluminum column socket 4f mounted on the base plate, and the other end passes through the opening A of the upper aluminum column socket 4g mounted on the bottom surface of the front upper plate 14a, and protrudes from the top surface of the front upper plate 4a, making this end the protruding end. The bottom end of the short aluminum column 4e is inserted and fixed into the opening B on the lower aluminum column socket 4f, and the other end is inserted and fixed into the opening B of the upper aluminum column socket 4g. The installation method for the aluminum columns at the front end of the front upper plate 4a and the rear end of the rear upper plate 4b is the same as the installation method for the short aluminum column 4e.

[0041] After installing each aluminum column in the above manner, the battery 4 can be clamped and fixed between the front upper plate 4a, the rear upper plate 4b and the bottom plate 4c to form an overall battery assembly; and in the battery assembly, the long aluminum column 4d of the two sets of aluminum columns on the same side of the battery 4 is arranged opposite to each other, and the top protruding end passes through the through hole opened on the bottom surface of the central plate body 2 and is fixedly connected to the upper plate 1 of the central plate, so that the battery 4 is hoisted to the middle position below the central plate body 2.

[0042] The tripod 5 includes a front tripod 5a, a rear tripod 5b, and a tripod crossbar 5c. The front tripod 5a and the rear tripod 5b are trapezoidal structures with a top frame and side frames, and are respectively fixedly installed at the front and rear positions of the bottom of the aforementioned battery rack lower plate 4c via the top frame.

[0043] The optical flow meter 9 is fixedly installed at the center of the lower part of the central plate body 2.

[0044] The Wi-Fi antenna 11 is located on the left and right sides of the onboard computer 3, passes through the hollowed-out part of the surface of the central plate 1 and the central plate body 2, and is inserted into the sleeve designed on the central plate 1 for longitudinal positioning.

[0045] The GPS12 is mounted on the top surface of the center plate 1, located behind the airborne computer 3.

[0046] The sensor is disposed between the central plate body 2 and the central plate upper plate 1, and is fixed on the mounting plate on the upper surface of the central plate body 2.

[0047] The image transmission module 13 is mounted on the top surface of the center plate 1, located to the left or right of the onboard computer 3. The image transmission module is connected to the antenna connectors at the top of the two Wi-Fi antennas 5 via the antenna connector 12. The fan 4 is mounted above the image transmission module.

[0048] like Figure 4 As shown, the camera pan-tilt head 5 is a rectangular box structure with a base, left and right side walls, and a rear side wall. A rectangular groove is formed in the center of the bottom surface of the base, and cylindrical grooves are formed at the four corners of the rectangular groove. The camera pan-tilt head 5 is mounted on a pitch adjustment platform mounted on the upper surface of the center plate 1.

[0049] Four shock-absorbing balls are installed at the four corners of the top surface of the pitch adjustment platform. The four shock-absorbing balls are respectively embedded and fixed in the four grooves on the bottom surface to complete the installation of the camera pan-tilt unit 6.

[0050] A pressure sensor 6a is installed at the center of the top surface of the camera pan-tilt head 6 base. The rear side wall serves as a pan-tilt head baffle to stabilize the camera 7 and prevent it from falling off due to inertia.

[0051] The camera pan-tilt head 9 has adjustable angle fixing clamps 6b mounted on the inner walls of both sides. The fixing clamps 6b are plate-shaped structures, and both fixing clamps 6b are mounted on the inner walls of the camera pan-tilt head 9 through a transmission mechanism, which enables the relative horizontal movement of the two fixing clamps 6b.

[0052] like Figure 5As shown, the transmission mechanism includes a lead screw 6c, a nut 6d, a transmission gear 6e, and a drive motor 6f. The lead screw 6c is hollow and threaded into a horizontally threaded hole on the side wall of the camera pan-tilt unit 9. A nut 6d is threaded onto the lead screw 6c, located inside the side wall of the camera pan-tilt unit, limiting its axial position relative to the wall surface. The nut 6d also has teeth on its circumference, meshing with the transmission gear 6e. The transmission gear 6e is coaxially fixedly mounted on the output shaft of the drive motor 6f; the drive motor 6f is fixedly mounted on the bottom surface inside the camera pan-tilt unit 6 via a motor bracket. Through the two transmission mechanisms, the drive motor 6f drives the transmission gear 6e to rotate, which in turn drives the nut 6d to rotate, achieving linear axial movement of the lead screw 6c. This allows the distance between the two fixing clamps 6b to be adjustable, accommodating the clamping and fixing of cameras 7 of different sizes.

[0053] The hollow lead screw 6c has an internal thread structure. A rotating shaft is designed at the center of the back side of the fixing clamp 5. This shaft is coaxially placed inside the hollow lead screw 6c and connected via a thread, thus connecting the fixing clamp 6b to the transmission mechanism. It can rotate around the threaded shaft. The fixing clamp 6b can be selected with different curved surfaces to connect to the lead screw 6b, depending on the surface curves of the mounting positions on the left and right sides of the camera.

[0054] Therefore, when installing the camera 7, a matching fixing clamp 6b is selected according to the surface curve of the clamping position on the left and right sides of the camera 7. According to the camera's pitch angle, the angle of the fixing clamp 6b is adjusted by rotating the fixing clamp 6b so that the clamping surface of the fixing clamp 6b fits against the outer wall of the camera 7 during clamping, thus fixing the camera 7 more securely and avoiding damage to the camera 7's outer shell.

[0055] When the camera 7 is placed on the camera pan-tilt head 6, the pressure sensor 6a mounted on the camera pan-tilt head 6 will sense a certain pressure. This pressure is converted into an electrical signal that is positively correlated with the external force and output to the onboard computer 3. The onboard computer 3 drives the motor 6c to work, and the motor 6c drives the fixing clamp 6b to clamp the camera 7.

[0056] Once camera 7 is clamped, its left and right directions can be adjusted by controlling the two motors 6c to move in opposite directions. Simultaneously, the pitch angle can be adjusted after the camera is clamped via a pitch adjustment platform, enabling the multi-rotor aircraft to more easily complete various shooting tasks.

Claims

1. A multi-copter drone based camera gimbal, characterized by: The camera gimbal is a rectangular box structure with a base, left and right side walls, and a rear side wall. A rectangular groove is opened in the center of the bottom surface of the camera gimbal, and cylindrical grooves are opened at the four corners of the rectangular groove. The four shock-absorbing balls installed on the top of the drone are respectively embedded and fixed in the four grooves on the bottom surface to complete the installation of the camera gimbal. A pressure sensor is installed at the center of the top surface of the camera gimbal base. Plate-shaped fixing clamps are installed on the left and right sides inside the camera gimbal, and the fixing clamps have a left and right movement range, which is driven by a drive motor. At the same time, the fixing clamps also have a rotating joint that rotates around its own axis. When the camera is placed on the camera gimbal, the pressure sensor installed on the camera gimbal senses the pressure. The pressure is converted into an electrical signal positively correlated with the external force and output to the onboard computer. The computer drives the drive motor to work, and the drive motor drives the fixing clamps on both sides to move relative to each other and clamp the camera. The aforementioned fixing fixtures are mounted on the inner wall of the camera pan-tilt unit via a transmission mechanism. The transmission mechanism includes a lead screw, a nut, a transmission gear, and a drive motor. The lead screw is a hollow lead screw that engages with a threaded hole horizontally opened on the side wall of the camera pan-tilt unit. A nut is threaded onto the lead screw and is located inside the side wall of the camera pan-tilt unit, limiting the axial position of the nut relative to the wall surface. The nut also has teeth on its circumference that mesh with the transmission gear. The transmission gear is coaxially fixedly mounted on the output shaft of the drive motor. The drive motor is fixedly mounted on the bottom surface inside the camera pan-tilt unit via a motor bracket. The drive motor in the two transmission mechanisms drives the transmission gear to rotate, which in turn drives the nut to rotate, achieving linear motion of the lead screw along the axial direction and allowing the distance between the two fixing fixtures to be adjusted.

2. The multi-copter based camera gimbal of claim 1, wherein: Four shock-absorbing balls are installed on the top surface of the pitch adjustment platform mounted on the top of the drone.

3. The camera gimbal based on a multi-rotor UAV as described in claim 1, characterized in that: The multi-rotor drone includes a center plate, a center plate body, an onboard computer, a battery, a tripod, a camera gimbal, a camera, sensors, an optical flow meter, a fan, a Wi-Fi antenna, and a GPS and image transmission module; The center plate is fixed to the center plate body at its four corners by aluminum columns; propellers are also installed at the four corners of the bottom surface of the center plate body; the airborne computer is fixedly installed on the center of the top surface of the center plate via aluminum columns; the battery is a 4000mAh 4S battery, which is installed in the middle of the bottom surface of the center plate body via a battery rack; the tripod is installed at the bottom of the battery rack; the optical flow meter is fixedly installed at the center of the bottom of the center plate body. The Wi-Fi antennas are located on the left and right sides of the onboard computer, penetrating the hollowed-out portion of the center plate and the main body surface, and are vertically positioned within the sleeves designed on the center plate. The GPS is installed on the top surface of the center plate, located behind the onboard computer. The sensor is located between the main body of the center plate and the center plate, fixed to the mounting plate on the upper surface of the main body of the center plate. The image transmission module is installed on the top surface of the center plate, located on the left or right side of the onboard computer. The image transmission module is connected to the antenna connectors at the top of the two Wi-Fi antennas via an antenna connector. The fan is installed above the image transmission module. The camera is installed on a camera pan-tilt unit, which is installed in front of the recording computer.

4. The multi-copter based camera gimbal of claim 3, wherein: Lampshades are also installed at the four corners between the center plate and the center plate body.

5. The multi-copter based camera gimbal of claim 3, wherein: The center plate and the center plate body have cutouts of different shapes depending on the installation position of the mounted equipment. The uncut parts are used to connect the mounted equipment.

6. The camera gimbal based on a multi-rotor UAV as described in claim 3, characterized in that: One short side of the PCB board is set parallel to one side of the center board, making that side the front of the entire drone.

7. The multi-copter based camera gimbal of claim 3, wherein: The battery rack includes a front upper plate, a rear upper plate, and a lower plate; the battery is disposed between the front upper plate, the rear upper plate, and the lower plate; the front upper plate is fixed to the lower plate by a set of two aluminum pillars on each side, and the front end is fixed to the lower plate by a single aluminum pillar; similarly, the rear upper plate is fixed to the lower plate by a set of two aluminum pillars on each side, and the rear end is fixed to the lower plate by a single aluminum pillar. Each group of the above-mentioned aluminum columns consists of one long aluminum column and one short aluminum column. The installation method for each group of aluminum columns is the same, as follows: In this group of aluminum columns, the bottom end of the long aluminum column is inserted into the opening A on the lower aluminum column socket installed on the base plate, and the other end passes through the positioning opening A on the upper aluminum column socket installed on the bottom surface of the upper plate and protrudes from the top surface of the upper plate, making this end the protruding end; the bottom end of the short aluminum column is inserted into the opening B on the lower aluminum column socket, and the other end is inserted into the opening B on the upper aluminum column socket. After installation in the above manner, the battery is clamped and fixed between the front upper plate, the rear upper plate and the bottom plate to form an integral battery assembly; and in the battery assembly, the long aluminum column of the two sets of aluminum columns on the same side of the battery is arranged opposite to each other, and the top protruding end passes through the through hole opened on the bottom surface of the central plate body and is fixedly connected to the upper plate of the central plate.

8. The multi-copter based camera gimbal of claim 3, wherein: The tripod includes a front tripod, a rear tripod, and a tripod crossbar; the front tripod and the rear tripod are trapezoidal structures with a top frame and two side frames, and the left and right sides of the front and rear tripods are connected and positioned by the tripod crossbar.

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