A portable unmanned aerial vehicle ground height calibration device

Abstract

The utility model belongs to unmanned plane ground calibration technical field discloses a kind of portable unmanned plane ground height calibration device, including calibration cloth and the support of being arranged in the lower end of calibration cloth, the support is detachably connected with calibration cloth by connecting piece, grid pattern is provided on the calibration cloth for camera calibration, calibration cloth and support are fixedly installed on ground during unmanned plane operation, folding installation is in suitcase during non-operation, calibration cloth adopts map folding structure, cloth surface preset horizontal and vertical crease, can be quickly folded and be convenient for storage and carry. The upper end of calibration cloth fixed installation is thus away from ground, avoid sundry interference, effectively improve the flatness of mark cloth surface and the accuracy of image shooting, hanging ring and ground nail hole are provided on calibration cloth, cloth surface can be fixed according to actual topographic condition Selection ground nail, hanging rope, significantly enhanced wind resistance and anti-interference ability, ensure reliable use under different topography and weather conditions.

Description

Technical Field

[0001] This utility model belongs to the field of UAV ground calibration technology, and relates to a portable UAV ground altitude calibration device. Background Technology

[0002] In recent years, drones have been widely used in various fields such as geographic surveying, environmental monitoring, agricultural remote sensing, and emergency disaster relief. The image data they acquire is characterized by high precision and high consistency, which is a key foundation for achieving reliable spatial measurement. To achieve geometric correction, scale transformation, and 3D reconstruction of aerial imagery, ground calibration is widely used as a key auxiliary measurement tool, providing spatial references and dimensional standards to support the accuracy requirements of drone aerial photography operations.

[0003] Ground calibration typically employs rigid calibration plate structures, generally with metal or plastic frames as the main body. While these structures offer high stability, they are heavy, bulky, and difficult to transport. They are also challenging to deploy and relocate quickly in complex field terrain, severely limiting their application in surveying tasks requiring high mobility. Furthermore, they primarily provide a two-dimensional scale reference and lack the ability to calibrate common optical distortions in image systems. For example, inherent radial and tangential distortions of camera lenses, as well as perspective distortions caused by shooting angles, cannot be effectively corrected using such calibration plates, thus hindering the realization of high-precision photogrammetry and 3D reconstruction. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a portable ground altitude calibration device for unmanned aerial vehicles.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This utility model provides a portable drone ground altitude calibration device, including a calibration cloth and a bracket disposed at the lower end of the calibration cloth. The bracket is detachably connected to the calibration cloth via a connector. The calibration cloth is provided with a grid pattern for camera calibration. The calibration cloth and the bracket are fixedly installed on the ground during drone operation and folded and installed in a carrying bag during non-operation periods.

[0006] Furthermore, the calibration cloth is provided with hanging loops for fixed connection with sandbags.

[0007] Furthermore, the lower end of the bracket is provided with a support leg, which is detachably connected to the bracket.

[0008] Furthermore, the bracket includes several transverse and longitudinal support rods, with two adjacent transverse support rods and two adjacent longitudinal support rods fixedly connected by a first joint, and two adjacent transverse support rods and two adjacent longitudinal support rods fixedly connected by a second joint.

[0009] Furthermore, the calibration cloth is provided with a black and white checkerboard pattern for drone viewpoint recognition.

[0010] Furthermore, the calibration fabric is a polyester coated fabric or an Oxford cloth.

[0011] Furthermore, a base is provided at the lower end of the support leg, and the base is fixedly connected to the support leg.

[0012] Furthermore, the calibration cloth has ground nail holes at its four corners, which are fixedly connected to the ground by fasteners.

[0013] Furthermore, the first connector is a two-way connector, and the second connector is a three-way connector.

[0014] Furthermore, the transverse and longitudinal struts are made of aluminum alloy.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: This utility model discloses a portable ground altitude calibration device for drones. The calibration cloth adopts a map-style folding structure with pre-set horizontal and vertical creases on the cloth surface, allowing for quick folding for easy storage and carrying. The calibration cloth is fixedly installed at the upper end, thus keeping it away from the ground and avoiding interference from debris, effectively improving the flatness of the calibration cloth surface and the accuracy of image capture.

[0016] This utility model discloses a portable UAV ground altitude calibration device. The calibration cloth and bracket are fixedly installed on the ground during UAV operation and folded and installed in a carrying bag when not in operation, reducing component loss and extending service life. The entire set of equipment can be easily transported to any field or on-site operation location, ensuring that the calibration cloth remains stable during UAV operation, providing a basis for accurate camera calibration and angle recognition, and effectively eliminating measurement errors caused by calibration plate shaking.

[0017] This utility model discloses a portable UAV ground altitude calibration device. The calibration cloth is equipped with hanging rings and ground stake holes. Ground stakes and hanging ropes can be selected to fix the cloth surface according to the actual terrain conditions, which significantly enhances the wind resistance and anti-interference ability and ensures reliable use under different terrain and climate conditions.

[0018] This invention relates to a portable drone ground altitude calibration device. The calibration cloth features a black and white checkerboard pattern, ensuring high saliency of the calibration pattern even against complex backgrounds. This effectively reduces the impact of environmental background, color variations, and texture interference on the recognition process. It enables the drone to clearly capture and lock onto the calibration cloth in various lighting conditions, both indoors and outdoors, guaranteeing a high success rate for calibration and recognition tasks. Attached Figure Description

[0019] Figure 1This is a schematic diagram of the unfolded calibration cloth in an embodiment of this utility model; Figure 2 This is a schematic diagram of the structure of the bracket and legs in the embodiment of this utility model.

[0020] Figure label: 1-Calibration cloth; 2-Bracket; 3-Connector; 4-Feet; 5-Base support. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0022] Example 1 This utility model discloses a portable drone ground altitude calibration device, comprising a calibration cloth 1 and a bracket 2 disposed at the lower end of the calibration cloth 1. The bracket 2 is detachably connected to the calibration cloth 1 via a connector 3. The calibration cloth 1 has a grid pattern for camera calibration. During drone operation, the calibration cloth 1 and the bracket 2 are fixedly installed on the ground; when not in operation, they are folded and stored inside a carrying bag. The carrying bag has an EVA foam lining and a waterproof Oxford cloth outer shell, with internal sorting mesh pockets and securing straps for easy component sorting. The carrying bag also features a thickened handle and shoulder strap for easy single-person carrying and transportation.

[0023] In this embodiment, the calibration cloth 1 is 2.5 meters × 2.5 meters in size. The surface of the calibration cloth 1 is printed with a black and white checkerboard pattern, which is divided into 25 square grids in 5 rows × 5 columns. Each grid has a side length of 50 centimeters. Figure 1 As shown. The checkerboard pattern has significant image recognition capabilities and can be effectively used for geometric calibration, automatic corner extraction, and image scaling of UAV aerial images. Furthermore, the checkerboard pattern has high contrast and clear boundaries, making it suitable for computer vision systems to identify intersections, facilitating the extraction of influence scale, geometric correction, and area calculation. Calibration cloth 1 is made of polyester coated fabric or Oxford cloth, which is waterproof, sunproof, abrasion-resistant, and slip-resistant, suitable for outdoor use.

[0024] By using the checkerboard pattern on calibration cloth 1, camera distortion caused by aerial photography can be effectively analyzed, including nonlinear imaging errors such as radial distortion, tangential distortion, and perspective distortion. This allows for precise camera calibration and parameter correction, effectively improving image measurement accuracy and consistency, and meeting the technical requirements of high-precision aerial photography measurement.

[0025] Furthermore, the calibration cloth 1 adopts a map-style folding structure design, meaning that horizontal and vertical creases are pre-set on the calibration cloth 1, allowing it to be folded into a neat rectangle along the predetermined creases. The overall thickness after folding is small, making it easy to store and carry. In summary, it not only allows for quick unfolding and folding but also ensures good flatness after unfolding.

[0026] To improve stability in the field, the calibration fabric 1 is equipped with hanging loops and ground stake holes along its edges. The hanging loops connect to sandbags to enhance wind resistance and fixation. The ground stake holes allow for flexible selection of ground stakes and ropes based on actual terrain conditions, ensuring reliable use under various terrain and climate conditions. The ground stake holes are fitted with ground stakes and fixed in soft soil to secure the calibration fabric 1.

[0027] A support 2 is provided at the lower end of the calibration cloth 1, which is detachably connected to the calibration cloth 1 via a connector 3. The support 2 consists of several transverse and longitudinal support rods. Adjacent transverse support rods and two longitudinal support rods are fixedly connected via a first joint, and adjacent transverse support rods and longitudinal support rods are fixedly connected via a second joint. Figure 2 As shown, the horizontal and vertical supports are interconnected to form a rectangle. To improve the stability of the support 2, horizontal and vertical supports can be added within the rectangle to form a cross, star, or grid pattern to enhance the structural stability of the support 2. The horizontal and vertical supports are made of aluminum alloy.

[0028] The lower end of the bracket 2 is provided with a support leg 4 and a base 5. In this embodiment, the support leg 4 is 10cm high. In addition, the support leg 4 can also be configured as a telescopic structure. The base 5 is a rubber base, which is used for anti-slip and adapts to different ground undulations.

[0029] All parts are folded and stored inside the bag when not in use. The bag features an EVA foam lining and a thickened waterproof Oxford cloth outer layer, providing excellent pressure resistance and abrasion resistance. The bag has multi-functional compartments and Velcro straps for organizing and storing accessories such as calibration fabric, supports, feet, ground stakes, and sandbags. The bag's dimensions are 50cm × 40cm × 15cm, adjustable to suit different needs. It includes thickened handles and shoulder straps, allowing for one-handed carrying or double-shoulder carrying, facilitating transportation and deployment by a single person.

[0030] In summary, this utility model discloses a portable UAV ground altitude calibration device, comprising a calibration cloth 1 with a black and white checkerboard pattern, a support 2, legs 4, a base 5, and a carrying bag. The calibration cloth 1 adopts a map-style folding design for easy and quick unfolding and storage. The support 2 and legs 4 ensure that the calibration cloth 1 is flat and at a certain height from the ground during deployment, avoiding ground interference. The calibration cloth 1 has hanging rings and ground stake holes on its edges to ensure stability in complex field environments. It can achieve accurate area calculation of aerial photography impact and camera distortion analysis, significantly improving the accuracy and efficiency of UAV aerial surveying and mapping, and is suitable for frequent relocation operations in complex field terrain conditions.

[0031] How to use a portable UAV ground altitude calibration device: First, open the bag and take out each component. Unfold the calibration cloth 1 along the preset folds and lay it in the designated area. Then, insert the bracket 2 and the support legs 4 to lift the calibration cloth 1. Finally, secure the edges with ground pegs or hanging ropes. After aerial photography is completed, the user can disassemble, fold, and pack each component in reverse order to quickly complete the recovery and relocation operations.

[0032] Specifically: Select a flat area without bumps or standing water, lay the calibration cloth 1 flat on the ground, then assemble the bracket 2 and legs 4. Adjust the height of the legs 4 according to the flatness of the ground and the needs of aerial photography to ensure that the height of the four bracket sets 2 is consistent. Then, fix the four bracket sets to the bracket 2 with connectors.

[0033] For soft ground such as soil or grass, remove the ground stake, pinch the top ring of the stake with your thumb and forefinger, tilt the stake at a 45° angle, align it with the calibration cloth 1 and the adjacent support 2, and gently insert it into the ground. The insertion depth should be such that the ring is close to the ground, ensuring that the calibration cloth 1 is flat and wrinkle-free. For hard ground such as cement or asphalt, remove the hanging rope, hook one end of the rope onto the hook on the calibration cloth 1, and hook the other end onto a fixed object such as a tree trunk or tripod. Pull the hanging rope with both hands to adjust the length until the cloth is taut. Finally, gently press the cloth surface to check for levelness. Once confirmed, the drone can be started for calibration.

[0034] After the aerial photography is completed, retrieve the equipment in reverse order: first, unhook the hooks and remove the ground stakes or ropes; clean the ground stakes of dirt and put them back in the bag; fold the ropes neatly and store them; then, hold the connection between the bracket 2 and the leg 4 and rotate counterclockwise to remove the leg 4; next, fold the four corners of the calibration cloth towards the center, gradually gather it along the original creases, and gently smooth out the wrinkles during the folding process; finally, put all the parts into the bag in order and zip it up to complete the retrieval.

[0035] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

Claims

1. A portable UAV ground altitude calibration device, characterized in that: It includes a calibration cloth (1) and a bracket (2) set at the lower end of the calibration cloth (1). The bracket (2) is detachably connected to the calibration cloth (1) via a connector (3). The calibration cloth (1) is provided with a grid pattern for camera calibration. The calibration cloth (1) and the bracket (2) are fixedly installed on the ground during the operation of the drone and folded and installed in a bag during non-operation periods.

2. The portable UAV ground altitude calibration device according to claim 1, characterized in that: The calibration cloth (1) is provided with a hanging ring for fixed connection with the sandbag.

3. The portable UAV ground altitude calibration device according to claim 2, characterized in that: The lower end of the bracket (2) is provided with a support leg (4), and the support leg (4) is detachably connected to the bracket (2).

4. The portable UAV ground altitude calibration device according to claim 1, characterized in that: The bracket (2) includes several horizontal and vertical supports. Two adjacent horizontal supports and two adjacent vertical supports are fixedly connected by a first joint, and two adjacent horizontal supports and two adjacent vertical supports are fixedly connected by a second joint.

5. The portable UAV ground altitude calibration device according to claim 1, characterized in that: The calibration cloth (1) is provided with a black and white checkerboard pattern for UAV viewpoint recognition.

6. The portable UAV ground altitude calibration device according to claim 5, characterized in that: The calibration fabric (1) is a polyester coated fabric or an Oxford cloth.

7. The portable UAV ground altitude calibration device according to claim 3, characterized in that: The lower end of the support leg (4) is provided with a base (5), and the base (5) is fixedly connected to the support leg (4).

8. The portable UAV ground altitude calibration device according to claim 7, characterized in that: The calibration cloth (1) has ground nail holes at its four corners, which are fixedly connected to the ground by fasteners.

9. The portable UAV ground altitude calibration device according to claim 4, characterized in that: The first connector is a two-way connector, and the second connector is a three-way connector.

10. The portable UAV ground altitude calibration device according to claim 4, characterized in that: The transverse and longitudinal support rods are made of aluminum alloy.

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