Kite type tethered open land grassland inspection robot and inspection method

Abstract

The invention relates to a kite-type tethered open-space grassland inspection robot and an inspection method, and designs kite-type aerial inspection equipment by integrating a steering driving wheel system, a rocker arm system, a suspension system, a frame, a control power supply system, a cooperative mechanical arm system and an inspection kite. A mechanical arm is used for cooperatively releasing and recycling an inspection kite, meanwhile, an anti-winding device for preventing cable winding of a plurality of mooring devices is designed for the first time, and in addition, a set of inspection method for open-ground composite mooring is designed for various systems in the robot. The efficiency and accuracy of grassland inspection under the complex terrain are improved, and important technical support is provided for intelligent management and sustainable development in the agricultural field.

Description

Technical Field

[0001] This project provides a kite-type tethered open-space lawn inspection robot and inspection method. The robot can perform medium- and close-range lawn inspections. This project involves fields such as mechanical manufacturing and communication sensing technology, particularly the acquisition and analysis of image and point cloud data, and the coordinated control of multiple tethered devices. Background Art

[0002] my country is a country rich in grassland resources, with a total grassland area of 265 million hectares. In recent decades, against the backdrop of global climate change and intensified human activities, typical grassland areas have been facing severe challenges such as pasture degradation, desertification, salinization, and soil erosion. Modern technologies are urgently needed to monitor and control grassland resources in a comprehensive, three-dimensional, and multi-layered manner, and to strengthen grassland protection efforts. Therefore, three-dimensional reconstruction of grasslands is extremely important. However, the current grassland inspection field still lacks a mature and effective technical system, especially for three-dimensional grassland reconstruction. Existing outdoor robots are mainly wheeled robots, rail-mounted robots, and tethered drone-guided robots, and their application scenarios are mostly substations, pipelines, and high-voltage lines. There is currently no mature technology for grassland inspection and grassland information extraction, and these robots have certain limitations when applied to grasslands and their model reconstruction tasks.

[0003] Existing grassland robots have poor adaptability in complex terrain, especially on slippery, steep, or obstacle-ridden grasslands. They are prone to stalling or tipping over, limiting the scope and effectiveness of inspections. Furthermore, many inspection drones are susceptible to strong winds during low- and high-altitude inspections, causing them to crash or vibrate violently, rendering them unable to capture usable images. Furthermore, traditional inspection drones rely on very low battery life and require returning to a base station for recharging, significantly reducing data integrity and time alignment during the inspection process. The complexity and diversity of grassland environments require more sophisticated, three-dimensional, and real-time monitoring methods, which traditional single-drone inspections clearly cannot meet. Grassland terrain is complex, encompassing different types of lawns, shrubs, wetlands, and other landforms, and the environment is subject to frequent and unpredictable changes. Therefore, a grassland inspection robot that can adapt to grassland terrain while possessing strong battery life and excellent stability is urgently needed. Summary of the Invention

[0004] To effectively address the challenge of modeling grassland during inspections, we developed a kite-based, tethered open-air grassland inspection robot. This robot combines a specially designed inspection kite, a camera, an IMU module, a GNSS module, an auxiliary manipulator, and an anti-entanglement tethering system. Controlled via ROS2 Humble, it enables detailed inspections at three different altitudes: low altitude, high altitude, and ground level. Specifically, we integrate a drone and a ground inspection vehicle. The drone's high-definition camera collects aerial data, while the ground inspection vehicle uses ground-based LiDAR to further scan the grassland, ensuring comprehensive and accurate data collection. Furthermore, tethering the drone effectively avoids potential energy shortages and signal loss associated with extended flight times, making the inspection process more stable and continuous, enabling continuous data collection and providing long-term, reliable inspection capabilities. This system not only enables efficient grassland inspections and 3D modeling, but also provides accurate basic data for grassland resource management and protection, promoting grassland ecological restoration and sustainable development.

[0005] This invention discloses a kite-type tethered open-air grassland inspection robot and inspection method, aiming to provide a composite robot system capable of efficient inspections in grassland environments. The inspection robot primarily consists of eight systems: a steering drive wheel system, a rocker arm system, a differential suspension system, a vehicle frame, a control and power supply system, a low-altitude inspection kite, a high-altitude inspection kite, and an auxiliary robotic arm. Through the coordinated operation of a ground mobile platform and an aerial kite-type drone, the robot is capable of three-dimensional reconstruction and inspection of grasslands, demonstrating strong off-road capabilities and environmental adaptability.

[0006] The steering drive wheel system is the core component of the robot's ground locomotion. It consists of an off-road tire, wheel hub, in-wheel motor, in-wheel motor bracket, variable-stiffness hydraulic spring, steering bracket, steering bracket flange, flange bearing, and steering wheel box. The steering wheel box includes the steering wheel box body, timing belt pulley bearing, timing belt, small and large timing belt pulleys, steering wheel box cover, and steering motor. The off-road tire is mounted on the wheel hub, which is fixed to the in-wheel motor via a coupling. The in-wheel motor is secured to the in-wheel motor bracket via threaded holes. One end of the variable-stiffness hydraulic spring is bolted to the in-wheel motor bracket via a side hole, and the other end is secured to the steering bracket. The steering bracket flange is secured to the steering bracket via threaded holes. The flange bearing has an interference fit with the steering bracket and a transition fit with the circular hole below the steering wheel box body. The synchronous pulley bearing has a transition fit with the upper circular hole of the steering wheel box body and an interference fit with the large synchronous pulley. The synchronous belt is engaged with the large and small synchronous pulleys. The steering wheel box cover is fixed to the steering wheel box body through the light hole, and the steering motor is connected to the small synchronous pulley through the keyway, thereby achieving precise control of steering.

[0007] The rocker arm system, a crucial structure connecting the drive wheels to the vehicle frame, consists of a rocker arm flange, a connecting sleeve, front and rear wheel connectors, and a rocker arm bracket. The rocker arm flange is parallel to the horizontal plane and bolted to the upper cover of the steering wheel housing. The connecting sleeve connects the rocker arm flange to the front and rear wheel connectors through holes. The rear wheel connector is connected to the front end of the rocker arm bracket via a bearing. The rocker arm bracket is an extended linear structure, with a circular connecting hole for mounting the front swivel bearing and its bracket. A pair of reinforced support arms are designed in the center, with a through-hole at the top for mounting the rear swivel bearing and its bracket. The front wheel connector is bolted to the rocker arm bracket. The front end of the front swivel bearing is connected to the through-hole above the front wheel connector via a bearing, while the rear end of the rear swivel bearing is connected to the through-hole above the centerline of the rocker arm bracket via a bearing. The front and rear ends of the limit damping spring are bolted to the rear end of the front swivel bearing and the front end of the rear swivel bearing, respectively, to ensure system stability during motion.

[0008] The differential suspension system improves the robot's adaptability to complex terrain. It consists of a rocker arm connector, a suspension hinge rod, a damping assembly, a ball hinge, a center suspension side bracket, and a center suspension. The rocker arm connector is mated to the vehicle frame via a screw bearing, and its front flange is bolted to four threaded holes symmetrically located on the lower center of the rocker arm bracket. The suspension hinge rod is bolted to the rocker arm connector, with the damping spring bolted to its end. The damping assembly is connected to the ball hinge at the other end. The ball hinge is bolted to the center suspension side bracket, which is bolted to the center suspension bracket. An anti-over-rotation torsion spring is fixed to the center suspension bracket at one end and to the vehicle frame at the other end to prevent excessive rotation of the suspension system.

[0009] The frame system is the supporting structure of the entire robot, consisting of the frame, slots for low-altitude kites, slots for high-altitude kites, a cable hole, and a battery slot. A bearing is fitted into a hole in the rear side of the frame, with the central rod of the center suspension having an interference fit. A stud passes through the bearing hole and connects to the center suspension, which is then bolted to the rear plane of the frame. A bearing is also fitted into a hole in the side of the frame, with an interference fit in the rocker arm connector. A stud passes through the bearing hole and connects to the central hole of the rocker arm connector, which is then bolted to the side plane of the frame. Facing the rear of the frame, the left front portion features an integrated robotic arm connection platform with six centrally symmetrical threaded holes. The right side of the frame features slots for low-altitude kites and high-altitude kites, with a cable hole drilled in the center of the rear. To the right of the motor hole is a slot for the servo, which is embedded in the frame. A battery slot is located in the lower center of the rear, with the central hole connecting to the cable hole.

[0010] The control and power supply system provides power and control for the robot. It consists of a battery, cable winch, winch motor, winch motor bracket, anti-entanglement disk, timing belt system, and cables. The battery is secured in the battery compartment of the frame, while the winch motor and its bracket are fixed to the anti-entanglement disk. The timing belt system includes a large and small timing pulley, a timing belt, and a timing belt servo. The large timing pulley is secured to the robot via a keyway on its upper side through a shaft that passes through the anti-entanglement disk. The hollow shaft on its lower side is inserted into the cable hole. The small timing pulley mates with the output end of the timing belt servo through toothed holes. The timing belt servo is secured to the frame with bolts, ensuring orderly cable retraction and deployment.

[0011] The low-altitude inspection kite is a kite-like drone consisting of a low-altitude kite-like fuselage, a high-resolution RGB camera, a micro electric actuator, a control rod, a rotor and its sleeve, a rotor bracket, a flight control module, and a tethering cable connector. The low-altitude kite-like fuselage is triangular in shape, with the April Tag identification code printed on the rear. Inside, a slot is provided for mounting the high-resolution RGB camera. One end of the electronic actuator secures to the through-holes on the left and right sides of the fuselage with an interference fit, while the outer end extends into the sleeve hole at the end of the control rod with a clearance fit. The other end of the control rod connects to the sleeve below the rotor with a latch, and the rotor bracket is secured to the rotor sleeve with four centrally symmetrical screws and threaded holes. The fuselage is surface-etched with circuitry, and the flight control module is mounted on the rear side of the fuselage. The tethering cable connector is glued to the tail of the drone with strong glue and connects to the cable. It also connects to the high-resolution RGB camera and flight control module via circuitry.

[0012] The high-altitude inspection kite has a similar structure to the low-altitude kite, consisting of a high-altitude kite-style fuselage, a high-resolution multispectral camera, a miniature electric actuator, a steering rod, a rotor and its sleeve, a rotor bracket, a flight control module, and a tether cable connector. The high-altitude kite fuselage is triangular in shape, also bearing the April Tag identification code on the rear. Inside, a slot is provided for mounting the high-resolution multispectral camera. One end of the electronic actuator secures to the through-holes on the left and right sides of the fuselage with a slight interference fit, while the outer end extends into the sleeve hole at the end of the steering rod with a clearance fit. The other end of the steering rod connects to the sleeve below the rotor with a latch, and the rotor bracket is secured to the rotor sleeve with four centrally symmetrical screws and threaded holes. The fuselage is surface-etched with circuitry. The flight control module is mounted on the rear side of the fuselage. The tether cable connector is glued to the tail of the drone with strong glue and connects to the cable. It also connects to the high-resolution multispectral camera and flight control module via the etched circuitry.

[0013] The auxiliary manipulator arm is used for kite deployment and folding, as well as for auxiliary operations. It consists of a manipulator base, joint motor, motor frame, motor frame connector, manipulator upper arm, manipulator forearm, and a gripping mechanism. The manipulator base is bolted to the manipulator connection platform on the vehicle frame. The joint motor is secured to the motor frame cavity through threaded holes in the outer ring. The raised portion of the motor frame fits into the recessed hole on the underside of the motor frame connector and is secured with side bolts. The protruding portion of the motor frame connector is bolted to the threaded hole in the inner ring of the joint motor. The manipulator upper arm is bolted to the raised portions of the second and third motor frames from the bottom up, and the manipulator forearm is bolted to the raised portions of the third and fourth motor frames. The gripping mechanism is mounted on the sixth motor frame connector and consists of a servo housing, a gripper servo, a gripper mounting plate, a main gripper arm, a secondary gripper arm, and the gripper. The servo housing is bolted to the recessed bottom portion of the motor frame connector. The gripper servo is bolted to the threaded holes in the servo housing, and the gripper mounting plate is bolted to four threaded holes in the servo housing. The main gripper arm seamlessly mates with the servo head via toothed slots. The auxiliary gripper arm is inserted into the through-holes on both sides of the gripper mounting plate via latches. The main and auxiliary gripper arms are bolted to threaded holes on the side of the gripper. The gripper's contact surface is covered with a convex-concave rubber material to enhance gripping stability.

[0014] The working process of the present invention relates to a kite-type tethered open space grassland inspection method. Before the start of the mission, it is necessary to check the inspection vehicle's battery, robotic arm, kite storage bin and RTK system, select a suitable low-altitude or high-altitude kite, and calibrate the robotic arm. At startup, the robotic arm removes the kite from the storage bin and adjusts it to a horizontal posture. The inspection vehicle accelerates to provide initial power, and the kite's rotors start to maintain lift and posture. Low-altitude kites rely on rotors for power, while high-altitude kites mainly rely on wind power to rise and adjust their posture through rotors. During the inspection process, the RTK system obtains the kite's position in real time, and the anti-entanglement disk dynamically adjusts its direction based on the data to ensure that the cable is not entangled. After the mission is completed, the kite lands in the recovery area, and the robotic arm uses the camera to identify the image code to accurately grab the kite, retract it, and store it in the bin. The system stores the inspection data, checks the equipment status, and resets it, putting the robot into standby mode.

[0015] The inspection method of this inspection robot includes the following steps: First, before the mission begins, the inspection vehicle completes a self-check to ensure sufficient battery power and that components such as the robotic arm, kite storage compartment, RTK system, and anti-entanglement disk are functioning properly. The operator selects a low-altitude or high-altitude kite based on the mission requirements and checks its storage status. The robotic arm then performs a self-check and calibration to ensure accurate grasping and adjusts to its initial position. Next, after the inspection vehicle is activated, the robotic arm grabs the target kite from the storage compartment, adjusts its angle to maintain a horizontal position, accelerates to provide initial thrust, and activates the kite's rotors to provide lift and attitude control. Once the kite reaches an appropriate altitude, the robotic arm releases the target kite. Low-altitude kites rely on their rotors for continuous propulsion, while high-altitude kites use wind power to rise and adjust their attitude. Once the kites are airborne, the low-altitude kite relies on its rotors for propulsion and attitude control, while the high-altitude kite glides with the wind and maintains stability through its rotors. The RTK system obtains real-time positioning information, and the anti-entanglement disk dynamically adjusts its direction to prevent cable entanglement. The kite is equipped with RGB and multispectral cameras to capture images. The data is transmitted in real time to the inspection vehicle and uploaded to the ground station. Once the inspection is complete, the kite lowers its altitude and approaches the recovery area. The robotic arm uses the camera to identify the image code, accurately grasps the kite, stably grips it, and slowly retracts it to its storage location. Finally, after the kite is recovered, the inspection data is stored in the ground station. The inspection vehicle checks the equipment status and resets the system, returning to standby mode.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The inspection kite structure in the tethered kite inspection system proposed in this invention significantly improves grassland inspection coverage and data collection efficiency, freeing it from the spatial limitations of traditional inspection methods and making the inspection process more efficient and precise. This invention integrates advanced tethered drone systems with ground-based robotics technology. The inspection kite adopts a kite-like design, enabling flexible operation at low and high altitudes, covering large grassland areas. The tethered drone, with its high-resolution RGB camera and precise multispectral sensor, captures high-quality grassland images and data, providing comprehensive support for grassland resource monitoring. The tethered design ensures a stable connection with the ground robot, avoiding the susceptibility of traditional drones to wind, and enhancing the reliability and safety of inspections.

[0017] 2. This invention proposes a tethered kite system with dual tethered kites and their anti-winding device, which can significantly improve the continuity and stability of grassland inspections. This eliminates the power and control limitations of traditional drone inspections, making the inspection process more efficient and accurate. This dual tethered kite system enables simultaneous low- and high-altitude inspections, providing multi-level data collection and comprehensive coverage of grassland environments. The anti-winding device effectively prevents cable entanglement, ensuring the continuity and safety of equipment operation during inspections. The tethered design incorporates ground robotics technology to provide continuous power support and extend inspection time. The RTK system simultaneously locates the kite's position in real time, ensuring high-precision data collection and meeting the requirements of intelligent grassland inspections.

[0018] 3. The rocker arm and suspension systems of the ground robot in this invention significantly enhance the stability and safety of the robot's inspections, freeing it from the environmental constraints of traditional ground robots and making the inspection process more efficient and precise. The rocker arm system's flexible rotational design enhances the robot's adaptability in complex grassland terrain, while the suspension system utilizes variable-stiffness hydraulic springs and differential suspension to absorb bumps and maintain smooth operation. The ground robot penetrates complex areas, utilizing diverse sensors to acquire microscopic grassland data and forming an air-ground collaborative system with a tethered drone. These designs ensure efficient operation of the robot on uneven grasslands, improving inspection coverage and data quality.

[0019] 4. The robotic arm in this invention coordinates the release and retrieval of drones, significantly improving the operational stability and safety of inspection kites in the frequently bumpy environment of grasslands. This eliminates the environmental limitations of traditional manual operations and makes the inspection process more efficient and accurate. The robotic arm precisely grasps and releases the inspection kite, and combined with the April Tag recognition code, achieves accurate positioning, ensuring operational accuracy in bumpy terrain. Furthermore, this invention collects vibration displacement frequencies, inputs them into the GRC-NN model to calculate weights, and then inputs them into the POS for optimization. Finally, the resulting values are input into the fuzzy PID control to control the various joints of the robotic arm to compensate for position deviations caused by the vehicle's bumpy displacement during grassland operation. The ground robot, through the robotic arm, collaborates with the tethered drone, reducing the need for manual intervention and acquiring large-scale grassland images and microscopic data. The stable design of the gripping mechanism ensures the safe retrieval of the kite in complex environments, enhancing the autonomy and reliability of the air-ground collaborative system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] Figure 1This is a schematic diagram of the overall structure of the inspection robot in one embodiment of the present invention; Figure 2 A top view of an inspection robot according to an embodiment of the present invention; Figure 3 A schematic structural diagram of a steering drive system according to an embodiment of the present invention; Figure 4 A supplementary schematic diagram of the structure of a steering drive system in one embodiment of the present invention; Figure 5 This is a schematic structural diagram of a rocker arm system in one embodiment of the present invention; Figure 6 A schematic structural diagram of a differential suspension system according to an embodiment of the present invention; Figure 7 A schematic structural diagram of a vehicle frame according to an embodiment of the present invention; Figure 8 Schematic diagram of the wire hole in the frame according to one embodiment of the present invention; Figure 9 A schematic diagram of the structure of a control power supply system in one embodiment of the present invention; Figure 10 A schematic structural diagram of an anti-entanglement disk and a control power supply system according to an embodiment of the present invention; Figure 11 A schematic structural diagram of the upper side of a low-altitude inspection kite in one embodiment of the invention; Figure 12 A schematic structural diagram of the lower side of a low-altitude inspection kite in one embodiment of the invention; Figure 13 A schematic diagram of the structure of a high-altitude inspection kite in one embodiment of the invention; Figure 14 A schematic diagram of the structure below the high-altitude inspection kite in one embodiment of the invention; Figure 15 A schematic structural diagram of an auxiliary robotic arm in one embodiment of the invention; Figure 16 A schematic structural diagram of the auxiliary robotic arm gripping mechanism in one embodiment of the invention; The meaning of each reference numeral in the accompanying drawings: 1- Steering drive wheel system, 2- Rocker arm system, 3- Differential suspension system, 4- Frame, 5- Control and power supply system, 6- Low-altitude inspection kite, 7- High-altitude inspection kite, 8- Auxiliary robotic arm; 11-off-road tire, 12-wheel hub, 13-hub motor, 14-hub motor bracket, 15-variable stiffness hydraulic spring, 16-steering bracket, 17-steering bracket flange, 18-flange bearing, 19-steering wheel box, 191-steering wheel box body, 192-synchronous pulley bearing, 193-synchronous belt (1), 194-small synchronous pulley (1), 195-large synchronous pulley (1), 196-steering wheel box cover, 197-steering motor; 21- rocker arm end flange, 22- connecting sleeve, 23- front wheel connector, 24- rear wheel connector, 25- rocker arm bracket, 26- front swivel bearing, 27- rear swivel bearing, 28- limit damping spring; 31-rocker arm connector, 32-suspension hinge rod, 33-damping spring, 34-ball hinge, 35-center suspension side bracket, 36-center suspension, 37-anti-over-rotation torsion spring; 41-frame, 42-low-altitude kite slot, 43-high-altitude kite slot, 44-wire hole, 45-battery slot, 46-servo slot, 47-robotic arm base; 51-battery, 52-cable winch, 53-winch motor, 54-winch motor bracket, 55-anti-entanglement disk, 56-synchronous belt system, 561-large synchronous pulley 2, 562-small synchronous pulley 2, 563-synchronous belt 2, 564-synchronous belt servo, 57-cable; 61- low-altitude kite-style fuselage, 62- RGB high-resolution camera, 63- micro electric push rod, 64- steering connecting rod, 65- rotor and its sleeve, 66- rotor bracket, 67- flight control module, 68- tethering line interface; 71- high-altitude kite-type fuselage, 72- high-resolution multispectral camera, 63- micro electric push rod, 64- control connecting rod, 65- rotor and its sleeve, 66- rotor bracket, 67- flight control module, 68- tethering line interface; 81- Robotic arm base, 82- Joint motor, 83- Motor frame, 84- Motor frame connector, 85- Robotic arm upper arm, 86- Robotic arm forearm, 87- Gripping mechanism, 871- Servo housing, 872- Gripper servo, 873- Gripper fixing plate, 874- Gripper main rudder arm, 875- Gripper auxiliary rudder arm, 876- Gripper. Example

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0024] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0025] In the absence of conflicts, the embodiments and features of the embodiments of the present invention may be combined with each other. The technical solutions of the embodiments of the present invention will be described below in conjunction with the accompanying drawings of the embodiments of the present invention.

[0026] The present invention uses a kite-type tethered open-air grassland inspection robot to conduct large-scale grassland inspections. The project's goal is to monitor grassland growth, pest and disease conditions, and the distribution of water and nutrients. Traditional drones, due to battery life limitations, are often limited to short-term flights and require frequent landings for battery replacement, impacting inspection efficiency and continuity. Furthermore, grassland inspections often encounter strong winds, making them unsuitable for low- and high-altitude inspections by drones. To overcome this problem, the present invention employs a tethered kite-type open-air grassland inspection model. The tethered kite-type open-air grassland 3D reconstruction inspection robot includes six major systems: a steering drive wheel system 1, a rocker arm system 2, a differential suspension system 3, a vehicle frame 4, a control and power supply system 5, and a tethered drone 6.

[0027] For the movement of the inspection robot chassis, the steering drive wheel system 1, the rocker arm system 2, and the differential suspension system 3 are involved. The structures involved are: the steering drive wheel system 1 is composed of an off-road tire 11, a wheel hub 12, a hub motor 13, a hub motor bracket 14, a variable stiffness hydraulic spring 15, a steering bracket 16, a steering bracket flange 17, a flange bearing 18, a steering wheel box 19, and a steering motor 197. The steering wheel box 19 includes a steering wheel box body 191, a synchronous pulley bearing 192, a synchronous belt 193, a small synchronous pulley 194, a large synchronous pulley 195, and a steering wheel box cover 196. The off-road tire 11 is mounted on the wheel hub 12, and the wheel hub is fixed to the hub motor 13 through a coupling. The hub motor 13 It is fixed to the hub motor bracket 14 through a threaded hole, the hydraulic spring 15 is fixed to the hub motor bracket 14 through a side light hole by bolts, and the other end is fixed to the steering bracket 16 by bolts. The steering bracket flange 17 is fixed to the steering bracket 16 through a threaded hole, the flange bearing 18 is interference fit with the steering bracket 16, and transition fit with the lower circular hole of the steering box body 191, the synchronous pulley bearing 192 is transition fit with the upper circular hole of the steering box body 191, and interference fit with the large synchronous pulley 195, the synchronous belt 193 is meshed with the large and small synchronous pulleys, the steering wheel box upper cover 196 is fixed to the threaded hole of the steering box body 191 through the light hole, and the steering motor 197 is connected and fixed to the small synchronous pulley 194 through a keyway.

[0028] For the robot's obstacle crossing function, the rocker arm system 2 involved is composed of a rocker arm end flange 21, a connecting sleeve 22, a front wheel connector 23, a rear wheel connector 24, and a rocker arm bracket 25. The rocker arm end flange is connected to the steering wheel box cover parallel to the horizontal plane by bolts, and the connecting sleeve connects the rocker arm end flange to the front wheel connector and the rear wheel connector through a hole. The rear wheel connector is connected to the front end of the rocker arm bracket through a bearing. The rocker arm bracket presents an extended straight line structure, and its circular connecting hole is installed with the front rotary bearing and its bracket. The central part structure includes a pair of support arms with a reinforced design. There is a through hole at the upper end of the central part for installing the rear rotary bearing and its bracket, the front wheel connector is connected to the rocker bracket by bolts, the front end of the front rotary bearing is connected to the through hole above the front wheel connector through a bearing, and the rear end of the rear rotary bearing is connected to the through hole above the center line of the rocker bracket through a bearing. The front and rear ends of the limit damping spring are respectively fixed to the rear end of the front rotary bearing and the front end of the rear rotary bearing by bolts. When the robot travels on low-elevation terrain, the variable stiffness hydraulic spring 15 can absorb the vibration of smaller undulations, avoiding damage to the equipment caused by small and frequent bumps during the robot inspection process. When overcoming obstacles, the front movable end frame rotates, compressing the limit damping spring 28 to enhance the robot's grip and obstacle-crossing performance; when the robot travels on terrain with large lateral undulations, such as pits and small slopes, the differential suspension system starts to work. The differential suspension system consists of a rocker arm connector 31, a suspension hinge rod 32, a damping spring 33, a ball hinge 34, a central suspension side bracket 35, and a central suspension 36. The rocker arm connector 31 is matched with the frame 4 through a screw bearing, and the front flange of the rocker arm connector 31 is bolted to the four symmetrical threaded holes at the bottom of the rocker arm bracket 25. The suspension hinge rod 32 is connected to the rocker arm bracket 25 through a screw bearing. The bolt cooperates with the rocker arm connector 31, and the end of the suspension hinge rod 32 is connected to the damping spring 33 by a bolt. The other end of the damping spring is connected to the ball hinge, and the ball hinge is fixed to the center suspension side bracket 35 by bolts. The center suspension side bracket 35 cooperates with the center suspension 36 by bolts. The wheels and the front end of the rocker arm located above the low terrain will move downward, and the rocker arm will rotate so that the rear end of the rocker arm is raised relative to the frame. Correspondingly, the rear end wheel located above the high terrain will be supported by the opposite direction of the ground, so that the grip of the inspection robot is greatly improved in this case, thereby improving a more considerable contouring effect. The above obstacle crossing function systems are all integrated on the frame 4. A bearing is transitionally fitted in the rear side hole of the frame 4. The central rod of the center suspension 36 is interference fit with the bearing. A stud passes through the bearing hole and the center suspension 36 and fixes the center suspension to the rear plane of the frame through bolts. A bearing is transitionally fitted in the side hole of the frame and is interference fit with the rocker arm connector 31. A stud passes through the bearing hole and the central hole of the rocker arm connector and fixes the rocker arm connector to the side plane of the frame through bolts.

[0029] For long inspection tasks, the robot is continuously powered by the onboard cable system to avoid the problem of limited battery life of traditional batteries. The control power supply system 5 consists of a battery 51, a cable winch 52, a winch motor 53, a winch motor bracket 54, a cable 55, and an IMU module 56. The battery 51 is fixed in the slot of the frame 4, the frame winch motor 53 and its bracket 54 are fixed to the frame, and the cable 55 is wound in the groove of the winch 52 according to its length. The IMU module 56 connecting the tethered drone and the inspection vehicle is fixed to the tethered drone (6) in flight. The tethered drone used for inspection tasks consists of a landing gear 61, a side beam 62 and its bracket, a camera module 63 and its bracket, a DC power supply connector 64, a lower splint 65, an upper splint 66, an arm 67, a rotor 68 and its motor, and a flight control module 69. The landing gear is fixed to the connecting frame below the lower splint by bolts, the side beam and its bracket are fixed to the threaded holes on the front and rear sides of the lower splint by bolts, the camera module and its bracket are coaxially matched with the side rod through the hole above the bracket, the upper splint, the end of the arm, and the lower splint are clamped and fixed by bolts, the rotor and its motor are fixed to the other end of the arm by bolts, the flight control module is fixed to the lower splint by bolts and the DC power supply connector is glued with glue, and the DC connector is connected to the end port of the cable led out from the frame. To ensure the tethered drone maintains stable flight and avoid cable tension or loosening during inspection missions, this system uses an IMU module to monitor the tethered drone's posture in real time to reduce errors caused by changes in the posture of the aerial tethered device, ensure the stability and continuity of the grassland image data, and enable the generated image point cloud data to be directly mapped to the real geographic coordinate system, thereby enhancing the geographic information validity of the point cloud data.

[0030] During flight, tethered equipment usually needs to perform observation operations at different altitudes due to different inspection purposes. Therefore, the present invention designs a dual-tethered inspection equipment, namely a 6-low-altitude inspection kite and a 7-high-altitude inspection kite. Each inspection kite is designed to be streamlined and has a mechanism that can adjust the direction of the 65-rotor and its sleeve forward and backward: the 6-low-altitude inspection kite is mainly driven by the 65-rotor and its sleeve, supplemented by the gliding of the streamlined shell. The 65-rotor and its sleeve mainly serve as a power source and are mainly used for near-ground fine inspections in grassland inspections, such as grassland three-dimensional reconstruction, specific monitoring of pests and diseases, and plant growth monitoring. The 7-high-altitude inspection kite mainly uses the streamlined shell to glide at high altitude, and the 65-rotor and its sleeve mainly play the role of stabilizing the device posture. It is mainly used for large-scale data inspections at medium and high altitudes in grassland inspections, such as biomass monitoring, vegetation coverage and green normalization index based on hyperspectral analysis, etc.

[0031] The power requirements of the present invention are also encompassed. During operation, the flight control module 67 receives commands from the inspection robot or the control room to adjust its altitude. The flight control module 67 converts the required power into a signal and feeds it back to the DC-DC converter via PWM. This distributes the voltage of the inspection robot's onboard power supply, thereby dynamically adjusting the voltage required for the tethered drone to make dynamic adjustments in real time. In this embodiment, the tethered drone is connected to the ground inspection vehicle via a 57-cable. The 57-cable provides continuous power support, enabling the tethered drone to conduct long, efficient inspections above the grass without interrupting its mission to replace the battery.

[0032] This system enables continuous inspections on grasslands, covering a wider area. Furthermore, the 57-meter cable prevents tethered drones from losing control or crashing due to power failure. The combination of inspection vehicles and tethered drones effectively enhances the project's automation level, reduces manual intervention, and improves work efficiency. Furthermore, the 57-meter cable connection ensures stable data transmission, enabling real-time feedback and analysis of monitoring data, enhancing inspection accuracy.

[0033] During travel, the robot control system can adjust the retraction and extension of the cable 57 in real time based on sampling requirements via the winch motor 53, preventing the cable 57 from being too long or too short, thereby ensuring stable power transmission and preventing tangling or excessive stretching of the cable 57. Furthermore, to prevent entanglement of the cables 57 during aerial inspections by multiple inspection kites in the present invention, the present invention proposes a special 55-anti-entanglement disk structure and method for preventing entanglement of the cables 57. This structure operates by acquiring the relative position and angle between the inspection kite and the inspection vehicle chassis via RTK-GNSS. The line connecting the two points of the inspection kite is obtained from this original relative position. The 56-synchronous belt system controls the rotation of the anti-entanglement disk 55, ensuring that the axis line of the winch motor 53, fixed to the anti-entanglement disk 55, is always aligned with the projection line of the inspection kite on the ground. Combined with the aforementioned method for real-time retraction and extension of the tethered cable 57 via the winch motor 53, this prevents tethered equipment from becoming tangled during inspections.

[0034] The inspection robot has a built-in implementation method that begins with a self-check to ensure the 51-cell battery is fully charged, the 8-cell auxiliary manipulator is functioning properly, and the kite storage compartment and RTK system are operating stably. The operator selects either the 6-cell low-altitude inspection kite or the 7-cell high-altitude inspection kite based on the inspection mission, checks its storage status, and calibrates the 8-cell auxiliary manipulator through the system to ensure precise grasping and release. After activation, the 8-cell auxiliary manipulator retrieves the target kite from the storage compartment and adjusts its angle to maintain a horizontal position to prevent tilt from affecting flight. The inspection vehicle accelerates to provide initial thrust to the kite, and the 65-cell rotor and its sleeve activate to provide lift and attitude control. Once the kite reaches the appropriate altitude, the 8-cell auxiliary manipulator gradually releases, completing the release. The 6-cell low-altitude inspection kite relies on the 65-cell rotor and its sleeve for continuous power, while the 7-cell high-altitude inspection kite primarily uses wind power for lift, maintaining stable direction and speed through the 65-cell rotor and its sleeve.

[0035] During the inspection, the 6-kite low-altitude inspection kite uses a 62-pixel RGB high-resolution camera to collect detailed close-up grassland data, while the 7-kite high-altitude inspection kite uses a 72-pixel high-resolution multispectral camera to capture wide-area grassland information. The RTK system obtains precise positioning data in real time and transmits it to the inspection vehicle and ground control. The 55-pixel anti-entanglement reel at the rear of the inspection vehicle dynamically adjusts its direction based on the kite's position, ensuring that the payout axis is parallel to the kite's connecting line and preventing entanglement or kinking in the 57-pixel cable. Upon completion of the mission, the kite lowers its altitude and gradually approaches the recovery area. The camera at the end of the 8-pixel auxiliary robotic arm recognizes the April Tag code beneath the kite, accurately grasps it, and adjusts its angle based on the kite's posture. Once the kite descends to a certain height, the 8-pixel auxiliary robotic arm securely grips it and slowly retracts it to its storage location, completing the inspection and recovery. Data is synchronously stored to the ground station for subsequent analysis. The inspection vehicle then checks the equipment status, resets itself, and enters standby mode.

Claims

1. A kite-type tethered open space grass inspection robot, characterized in that : It includes eight systems, namely a steering drive wheel system (1), a rocker system (2), a differential suspension system (3), a frame system (4), a control power supply system (5), a low-altitude inspection kite (6), a high-altitude inspection kite (7) and an auxiliary mechanical arm (8). In the rocker system (2), the rocker end flange (21) is connected to the steering wheel box cover (196) by bolts in parallel with the horizontal plane. The connecting sleeve (22) connects the rocker end flange (21) to the front wheel connector (23) and the rear wheel connector (24) through a hole. The rear wheel connector is connected to the front end of the rocker bracket (25) through a bearing. The rocker bracket (25) is extended. The linear structure has a circular connecting hole installed with the front rotary bearing (26) and its bracket. The central part structure includes a pair of support arms with a reinforced design. The through hole at the upper end of the central part is used to install the rear rotary bearing (27) and the bracket. The front wheel connector (23) is connected to the rocker bracket (25) by bolts. The front end of the front rotary bearing (26) is connected to the through hole above the front wheel connector (23) by a bearing. The rear end of the rear rotary bearing (27) is connected to the through hole above the center line of the rocker bracket (25) by a bearing. The front end and rear end of the limit damping spring (28) are respectively fixed to the rear end of the front rotary bearing (26) and the front end of the rear rotary bearing (27) by bolts.

2. The inspection robot according to claim 1, characterized in that: The rocker arm connector (31) in the differential suspension system (3) is matched with the frame system (4) through a screw bearing, the front flange of the rocker arm connector (31) is connected to the lower part of the rocker arm bracket (25), the suspension hinge rod (32) is matched with the rocker arm connector (31) through a bolt, the end of the suspension hinge rod (32) is connected to the damping spring (33) through a bolt, the other end of the damping assembly is connected to the ball hinge, the ball hinge is fixed to the center suspension side bracket (35) through a bolt, the center suspension side bracket (35) is matched with the center suspension (36) through a bolt, and one end of the anti-over-rotation torsion spring (37) is fixed to the center suspension bracket, and the other end is fixed to the frame system.

3. The inspection robot according to claim 1, characterized in that: In the steering drive wheel system (1), an off-road tire (11) is mounted on a wheel hub (12), the wheel hub is fixed to a wheel hub motor (13) via a coupling, the wheel hub motor (13) is fixed to a wheel hub motor bracket (14) via a threaded hole, one end of a variable stiffness hydraulic spring (15) is fixed to the wheel hub motor bracket (14) via a side light hole, and the other end is fixed to a steering bracket (16), a steering bracket flange (17) is fixed to the steering bracket (16) via a threaded hole, and a flange bearing (18) is fixed to the steering bracket (16). The steering bracket (16) is interference-fitted and transition-fitted with the circular hole below the steering wheel housing (191). The synchronous pulley bearing (192) is transition-fitted with the circular hole above the steering wheel housing (191) and interference-fitted with the large synchronous pulley (195). The synchronous belt (193) is meshed with the large and small synchronous pulleys. The steering wheel housing upper cover (196) is fixed to the steering wheel housing (191) through the light hole. The steering motor (197) is connected and fixed to the small synchronous pulley (194) through the keyway.

4. The inspection robot according to claim 2, characterized in that: In the frame system (4), a bearing is transitionally fitted in the rear hole of the frame (41), the central rod of the central suspension (36) is interference-fitted with the bearing, the side hole of the frame is transitionally fitted with a bearing and interference-fitted with the rocker arm connector (31), and the rocker arm connector (31) is fixed to the side plane of the frame (41); the left front part of the frame is a mechanical arm base (47) integrated with the frame, the mechanical arm base (47) is provided with six centrally symmetrical threaded holes, the right side of the frame (41) is provided with a low-altitude kite slot (42) and a high-altitude kite slot (43), a wire hole (44) is drilled in the center of the rear side of the frame, a battery slot (45) is provided in the center of the lower rear side of the frame to embed the battery (51), and a through hole is provided in the center of the battery slot (45) to communicate with the wire hole (44).

5. The inspection robot according to claim 1, characterized in that: The frame winch motor (53) and its bracket (54) in the control power supply system (5) are fixed on the anti-winding disk (55), and the synchronous belt system (56) is composed of a large synchronous pulley (561), a small synchronous pulley (562), a synchronous belt (563) and a synchronous belt servo (564). The upper side of the large synchronous pulley (561) has a shaft passing through the anti-winding disk (55) and fixed to it by a keyway. The lower side of the large synchronous pulley has a hollow shaft inserted into the wire hole (44). The small synchronous pulley (562) and the output end of the synchronous belt servo (564) are matched by embedding the tooth hole. The synchronous belt servo (564) and the frame are matched by bolts on both sides of the servo slot (46).

6. The inspection robot according to claim 2, characterized in that: The low-altitude kite-type fuselage (61) of the low-altitude inspection kite (6) is triangular and has an April Tag identification code printed on the rear side. A slide groove is provided on the inner side of the fuselage for installing an RGB high-resolution camera (62). One end of the electronic push rod (63) is fixed to the inside of the through holes on the left and right sides of the low-altitude kite-type fuselage (61) through interference fit, and the outer end is inserted into the inside of the sleeve hole at one end of the control connecting rod (64) through clearance fit. The other end of the control connecting rod (64) is connected to the rotor and its sleeve (65) through a pin. The flight control module (67) is installed on the rear side of the low-altitude kite-type fuselage (61). The mooring line interface (68) is bonded to the tail of the low-altitude inspection kite (6) and connected to the cable (57).

7. The inspection robot according to claim 1, characterized in that: The clamping mechanism (87) in the auxiliary mechanical arm (8) is installed on the motor frame (83) connector matched with the sixth motor frame (83). The clamping mechanism (87) is composed of a steering gear housing (871), a clamping claw steering gear (872), a clamping claw fixing plate (873), a clamping claw main rudder arm (874), a clamping claw auxiliary rudder arm (875), and a clamping claw (876). The clamping claw steering gear (872) is fixed on a threaded hole in the steering gear housing (871). The clamping claw fixing plate (873) is fixed on the steering gear housing (871), the clamping claw main rudder arm (874) is seamlessly matched with the steering gear housing (871) through the internal toothed slot, the clamping claw auxiliary rudder arm (875) is inserted into the through holes on both sides of the clamping claw fixing plate (873) through the pin, and both ends of the clamping claw main rudder arm (874) and the clamping claw auxiliary rudder arm (875) are fixed on the side of the clamping claw (876), and the contact surface of the clamping claw (876) is affixed with a concave and convex rubber material.

8. A kite-type tethered open space grass inspection method, utilizing the inspection robot according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Before the mission begins, the inspection vehicle must complete an equipment self-check to ensure sufficient battery power and that components such as the robotic arm, kite storage compartment, RTK system, and anti-entanglement disk are functioning properly. The operator selects a low-altitude or high-altitude kite based on the inspection mission requirements and uses the system to check the kite's storage status. The robotic arm performs a self-check and calibration, and is adjusted to the appropriate initial position, ready to execute the mission. S2: After the inspection vehicle starts, the robotic arm grabs the target kite from the storage bin and adjusts its angle to keep the kite level to prevent tilting that affects flight. The inspection vehicle accelerates to provide initial pulling force for the kite, while the kite's rotors begin to operate to provide lift and attitude control. When the kite reaches an appropriate height, the robotic arm gradually releases, completing the release. S3: After the kite is launched, low-altitude kites rely primarily on rotors for power and attitude control. High-altitude kites are launched using wind and rotor power. They glide with the wind while maintaining stability through rotor adjustment. The RTK system obtains precise positioning information in real time and transmits the data to the inspection vehicle and ground control terminal. The anti-entanglement disk on the rear side of the inspection vehicle dynamically adjusts its direction based on the kite's position information, ensuring that the pay-off axis is always parallel to the kite cable, preventing cable entanglement or knotting. The inspection kite is equipped with RGB cameras and high-resolution multispectral cameras to capture ground targets and collect data. During the inspection process, the data is transmitted back to the inspection vehicle in real time and further uploaded to the ground station for storage and analysis. S4: After the inspection is completed, the kite lowers its altitude and gradually approaches the recovery area of the inspection vehicle. The camera at the end of the robotic arm recognizes the code under the kite and accurately performs a collaborative grasping operation. The grasping angle is adjusted according to the kite's posture. When the kite descends to a certain height, the robotic arm stably grips the kite and slowly retracts it. The kite is placed in the corresponding storage location, completing the inspection and recovery. S5: After the kite is recovered, the inspection data is synchronously stored in the ground station for subsequent analysis and recording. The inspection vehicle conducts an equipment inspection to ensure that there are no abnormalities in the robotic arm, storage bin and anti-entanglement disk. At the same time, the system is reset to restore the inspection robot to standby status for the next mission.

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