A wheeled-legged grassland soil collection robot and its usage method

Abstract

This invention relates to a wheeled-legged grassland soil sampling robot and its usage method, comprising a walking mechanism, a soil sampling mechanism, a sensing mechanism, a steering mechanism, a control system, a storage mechanism, and a chassis. The walking mechanism adopts a wheel-leg hybrid layout, adaptable to the uneven environment of grasslands, and can flexibly switch between wheeled and legged walking modes, possessing excellent obstacle-crossing ability. The soil sampling mechanism and storage mechanism together constitute an integrated "drilling + sampling + pushing + collecting" operation. By pre-loosening the soil with multiple drill bits, the soil penetration resistance is significantly reduced. Combined with an automatic soil pushing and circulating soil storage structure, the automation level and operational efficiency of soil sampling are significantly improved. This invention provides strong technical support for producers to obtain grassland soil physicochemical analysis data, deduce the spatial distribution of grassland soil resources, predict pasture growth status, and scientifically plan pasture grazing behavior, and has good practicality and application value.

Description

Technical Field

[0001] This invention relates to the fields of robot chassis navigation and steering, undisturbed soil collection, and multi-degree-of-freedom robotic arm operation technology, and particularly to a wheeled-legged grassland soil collection robot and its usage method. Background Technology

[0002] With the intensification of climate change and improper human production activities in recent years, grassland vegetation has been damaged, grasslands have degraded, forage yields have decreased, soil structure has been destroyed, and soil erosion has occurred. Grassland ecosystems are facing an increasingly serious trend of degradation, with declining productivity and ecological functions, posing a huge threat to grassland ecosystems, animal husbandry, and human health, creating a vicious cycle. Therefore, efficient and rapid collection of grassland soil data to provide support for soil physicochemical analysis, obtain spatial distribution of grassland soil resources, predict grassland forage growth, and scientifically plan grassland grazing behavior can effectively solve the problem of overgrazing and thus effectively alleviate the current state of grassland degradation.

[0003] Traditional manual sampling methods suffer from problems such as complex operation, low accuracy, data lag, and lack of information management, making it difficult to meet the needs of modern grassland management. Existing machine sampling equipment also has limitations: mechanical operation can easily damage the original soil structure and layers, resulting in samples that cannot truly reflect the natural state of the soil; a single operation cannot perform multiple samplings, making it difficult to meet the needs of multi-group comparative analysis; and the equipment has limited functions and low intelligence, making it difficult to adapt to the complex terrain and diverse sampling scenarios of grasslands.

[0004] Therefore, in the face of complex grassland environments, how to take into account the passability of grassland terrain and design an automatic grassland soil collection device to realize the automatic collection and collection of grassland soil samples, and improve the automation and intelligence level of grassland soil sampling, remains an urgent problem to be solved in current grassland soil collection work. Summary of the Invention

[0005] The purpose of this invention is to provide a wheeled-legged grassland soil collection robot and its usage method to solve various problems encountered in the above-mentioned work scenarios.

[0006] To achieve the above objectives, this application provides the following technical solution: A wheeled-legged grassland soil collection robot includes: The robot consists of seven parts: a walking mechanism, a soil sampling mechanism, a sensing mechanism, a steering mechanism, a control system, a storage mechanism, and a chassis. The walking mechanisms are deployed at the front left, rear left, front right, and rear right of the chassis, collectively responsible for the robot's movement. The soil sampling mechanism is located in the central area of ​​the chassis and is responsible for collecting grassland soil. The sensing mechanism is deployed at the front of the chassis and is responsible for sensing the terrain. The steering mechanism is installed in the front-middle part of the chassis and is responsible for controlling the steering of the two walking mechanisms at the front left and front right. The control system is installed at the top of the chassis and provides decision-making support for the robot. The storage mechanism is arranged around the soil sampling mechanism and is responsible for storing the collected soil samples.

[0007] The walking mechanism is equipped with anti-skid tires for grassland operation, providing strong traction. The tires are powered by a stepper motor mounted on the inner side of the lower leg's inner plate, connected to a small synchronous pulley at its end. Power is transmitted via a conveyor belt to a large synchronous pulley, and then through the tire's main shaft to the tire. Wheel axle washers are mounted on the lower outer sides of both the inner and outer plates of the lower leg, with end cap bearings on both sides providing support and a center of rotation for the tire's main shaft. The tires feature a front fork design to mitigate wheel tilting caused by unilateral mounting. The upper inner and outer plates of the upper lower leg are connected to a dual-axis servo motor via an active servo and a driven servo, respectively. This dual-axis servo motor serves as... The knee joint power source drives the lower leg to swing and connects to the thigh. The inner side of the upper end of the thigh is connected to another dual-axis servo motor, which serves as the power source for the hip joint, through an active servo and a driven servo in the same way. This dual-axis servo motor drives the entire walking mechanism to rotate. The dual-axis servos at the corresponding positions of the left rear and right rear walking mechanisms are fixed to the chassis servo mounting plates. The dual-axis servos at the corresponding positions of the left front and right front walking mechanisms are connected to the lower end of the turntable bearing. The walking mechanism can switch modes according to the working environment. On rugged sections, it can switch from wheeled to footed mode. At this time, the stepper motor is locked, and the tires, as the end of the wheel legs, move in a walk gait, which has a strong obstacle crossing ability.

[0008] The main body of the soil-boring mechanism is connected to the chassis via four hydraulic cylinders. The hydraulic cylinders are connected to flanges on the outer casing via piston rods, and their telescopic movement provides lifting power for the main body of the soil-boring mechanism. The operating power of the soil-boring mechanism is provided by a 57 stepper motor mounted on the outer casing. Its power output shaft is connected to a small bevel gear via a key pin one. The small bevel gear meshes with a large bevel gear. The large bevel gear is connected to the upper end of the hollow shaft of the main shaft module via a key pin two. The keyway at the lower end of the hollow shaft is connected to the central gear via a key pin three. End cap bearings are installed on the upper surface of the outer casing and the center of the base plate to provide a rotation center for the hollow shaft, and a fixing ring one is installed at the upper end of the hollow shaft for limiting movement. The central gear is supported by a sleeve between it and the base plate. A soil-boring pipe is installed at the lower end of the base plate for soil-boring operations. (The components are: fixing ring one, end cap bearing two, central gear, sleeve one, soil-boring pipe, and key pin three.) Hollow shafts together form the main shaft module. Five secondary shaft modules with similar structures to the main shaft module are evenly arranged around the main shaft module. The edge gears of the secondary shaft modules mesh with the central gear, and their centers are connected to the soil sampling shaft via a key pin. End cap bearings are installed on the upper surface of the outer shell and around the base plate to provide the rotation center of the soil sampling shaft. The upper end of the soil sampling shaft is equipped with a fixing ring for limiting. The edge gears are supported by a sleeve between them and the base plate. The lower end of the soil sampling shaft is connected to the auger drill bit via a coupling. A 57 stepper motor transmits power to the hollow shaft through a bevel gear combination. The hollow shaft then drives the auger drill bit to rotate through the gear combination to loosen the soil around the soil sampling pipe and reduce the penetration resistance. A bulldozer rod is installed inside the soil sampling pipe. The bulldozer rod passes through the hollow shaft and its end is always inside the soil sampling pipe. Its upper end is connected to a horizontal bearing on the chassis. The upper and lower sides of the horizontal bearing are limited by three pairs of fixing rings for limiting the bulldozer rod. When the soil sampling mechanism rises with the retraction of the hydraulic cylinder, the bulldozer rod pushes the soil out of the soil sampling pipe through relative motion.

[0009] The sensing mechanism is installed at the front of the robot. Its core component is the Yushu 4D L1 LiDAR, which can rotate 360 ​​degrees autonomously. The LiDAR is mounted on a radar bracket. The sensing mechanism can drive the LiDAR to swing synchronously in the pitch direction. The pitch motion is powered by a 42-stepper motor fixed to the chassis via a motor bracket. The stepper motor transmits power to a stepped shaft via a coupling. The stepped shaft is supported by vertical bearings, and a small gear is installed at the other end. The small gear is limited on both sides by retaining rings and meshes with a large gear. The large gear is mounted on the radar rotation shaft via retaining rings. The threaded hole on its outer surface is fixed to the inner surface of the right side of the radar bracket. Power is transmitted to the radar bracket through gear meshing, causing it to rotate around the radar rotation shaft. The radar rotation shaft is supported by two vertical bearings. By using the pitch motion of the radar bracket and the rotation of the LiDAR itself, the sensing mechanism can obtain more comprehensive terrain information in front of the robot.

[0010] The steering mechanism is essentially an Ackermann trapezoidal structure. Power is provided by a single-axis servo motor fixed to the upper surface of the chassis via a servo motor mounting bracket. The servo motor output shaft is connected to a pinion gear three via a metal servo disc. The pinion gear three meshes with the rack, converting the servo motor's rotational motion into the rack's left and right translational motion. L-shaped connectors are connected to both sides of the rack, and the L-shaped connectors are connected to the rocker arms. The other end of the rocker arm is connected to the upper surface of the inner ring of the turntable bearing. The turntable bearing is divided into inner and outer parts. The outer ring is fixed to the chassis via a threaded hole, and the inner ring can rotate under the drive of the rocker arm. The lower surface of the inner ring is connected to the dual-axis servo motor of the walking mechanism. The rack translates left and right under the drive of the pinion gear, and through the L-shaped connector, it drives the left and right rocker arms to rotate at different angles along the center of the turntable bearing, thereby driving the left front and right front walking mechanisms to turn. This ensures that the inner wheel rotates at a greater angle than the outer wheel when turning, reducing tire slippage during robot turning.

[0011] The control system consists of a GNSS positioning sensor, an STM32F407IGH6 microcontroller control board, an onboard industrial computer, and a battery. The entire system is mounted on the chassis, and the battery powers all the robot's components. The onboard industrial computer is responsible for overall task planning and decision-making, while the microcontroller control board receives commands from the industrial computer and controls the various actuators. The GNSS positioning sensor acquires the robot's real-time position information, guiding it to the designated work point and facilitating its return journey.

[0012] The storage mechanism mainly consists of a storage unit and an execution unit. The main body of the storage unit is a ring-shaped support installed under the chassis, surrounding the soil extraction mechanism. This support has an inner and outer two-layer structure, forming a ring-shaped guide rail that can hold the soil storage pipe. Spring valves are installed on both its left and right openings. Each spring valve consists of a mounting plate, a pin, a torsion spring, and a movable plate. The mounting plate is fixed at the opening, and the torsion spring causes the movable plate to generate an inward pushing force to prevent the soil storage pipe from falling off during operation. During operation, the soil storage pipe is taken out from the left side of the storage unit and inserted from the right side; the left side is always empty. The ring design of the unit enables efficient recycling of storage space; the main body of the execution unit is a robotic arm, with each joint powered by a single-axis servo motor. The uppermost servo motor is fixed on the chassis and connected to the upper arm connector via a circular servo disk. The lower end of the upper arm connector is connected to the upper arm and has a servo motor at the same position. The upper end of the forearm is connected to the upper arm and is equipped with a servo motor. The two servo motors serve as the power source for the corresponding joints. The robotic arm installed at the end of the forearm is equipped with two servo motors, which control its opening, closing and rotation respectively. This multi-degree-of-freedom execution unit can flexibly complete the actions of taking out and putting back the soil storage tube.

[0013] A method for using a wheeled-legged grassland soil collection robot includes: The operator manually inputs the latitude and longitude coordinates of the sampling points into the vehicle-mounted industrial control computer. Based on its own position and the coordinates of each sampling point, the vehicle-mounted industrial control computer uses an improved greedy algorithm to generate a set of operation instructions for the global sampling sequence and global path, which is stored in its own cache and awaits to be sent to the microcontroller segment by segment. The robot proceeds to the sampling point according to the path planned by the on-board industrial control computer. At the same time, it activates the sensing mechanism, uses LiDAR to continuously collect surrounding 3D point cloud data, and transmits the data to the on-board industrial control computer in real time via Ethernet. The vehicle-mounted industrial control computer uses statistical filtering for noise reduction, RANSAC ground segmentation, Euclidean clustering and other methods to process and acquire point cloud data. It extracts potholes, bumps and vegetation obstacles around the travel path, generates a local optimal obstacle avoidance trajectory through dynamic window method, sends real-time driving instructions to the microcontroller frame by frame and adjusts the travel speed according to the terrain undulation. The high-precision GNSS positioning sensor outputs the robot's real-time latitude and longitude to the vehicle-mounted industrial control computer, which converts it into planar coordinates to calibrate the robot's current position in real time. After the robot arrives at the sampling site, the walking mechanism switches to the support operation state. The hydraulic cylinder drives the soil sampling mechanism to move downward through the piston rod. The 57 stepper motor drives the main shaft module to rotate stably through the bevel gear set. The central gear of the main shaft module meshes precisely with the edge gears of the five secondary shaft modules, driving the five spiral drill bits to rotate synchronously and uniformly around the soil sampling tube. During the descent of the soil sampling tube, the surrounding grassland soil is continuously pre-loosened. Then the soil sampling tube is completely inserted into the soil to complete the soil sampling. After the operation is completed, the hydraulic cylinder drives the soil sampling mechanism to move upward through the piston rod. At this time, the robotic arm of the execution unit clamps an empty soil storage tube from the left side of the storage unit and places it below the soil sampling tube. The push rod remains in the same position. During the upward movement of the soil sampling mechanism, the collected soil is pushed out and falls into the soil storage tube below through relative motion. Then the robotic arm puts the soil storage tube containing the soil sample into the storage unit from the right side. The soil sampling mechanism rises to its original position, the walking mechanism switches back to walking mode, and the robot goes to the next sampling point until all operations are completed and returns.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. The switchable dual-mode wheel-leg composite structure design adopts a hip + knee joint dual servo drive structure, combined with a grass anti-slip tire front fork mounting method and a synchronous belt pulley power transmission mechanism, forming an integrated wheel-leg walking mechanism that can adapt to different grassland terrains and freely switch between legged and wheeled walking modes. On flat roads, it uses wheeled high-speed travel, while on rugged roads, it switches to legged walk gait to complete obstacle crossing operations, solving the problems of poor adaptability and easy slippage of traditional robots on grassland terrain.

[0015] 2. The integrated soil sampling structure design of "drilling + sampling + pushing" features five spiral drill bits evenly distributed around the circumference of the sampling tube to loosen the soil. A 57-stepper motor serves as the power source, driving the main shaft module to rotate via a bevel gear set. The central gear of the main shaft module meshes with the edge gears of the five secondary shaft modules, causing the five spiral drill bits to rotate synchronously around the sampling tube. When the sampling tube is pressed down to penetrate the soil for sampling, the spiral drill bits pre-loosen the surrounding grassland soil, significantly reducing the resistance when the sampling tube penetrates the soil. The hydraulic cylinder provides lifting power to the soil sampling mechanism through the extension and retraction of the piston rod. The pusher rod passes through the hollow shaft of the main shaft module and is fixed to the chassis at its upper end. After soil sampling is completed, as the soil sampling mechanism rises with the hydraulic cylinder, the pusher rod automatically pushes out the soil collected in the sampling tube through relative motion. No additional pusher drive components are needed, achieving a powerless linkage of "penetration sampling - automatic pushering," effectively solving the technical problems of grassland soil compaction and the difficulty of soil penetration.

[0016] 3. The circular circulation soil sample storage structure design employs an inner and outer two-layer circular support to form a circular guide rail. Multiple soil storage tubes can be mounted on the guide rail, achieving efficient recycling of space. Spring valves are installed on the left and right openings of the circular guide rail. Through the torsion spring, the movable plate provides a continuous inward clamping force, which can effectively limit the soil storage tubes and ensure that the soil storage tubes will not detach from the guide rail or fall off during the robot's movement and operation in the grassland. During operation, the cyclic logic of "taking an empty tube on the left and filling a tube on the right" is strictly followed, which greatly improves the soil sample storage capacity and operational continuity, and further enhances the efficiency of the robot's batch sampling in the field.

[0017] 4. Based on the Ackermann rack and pinion steering structure design, a single-axis servo motor is used as the steering power source. The rotational motion of the gear is converted into the left and right translation of the rack. Both ends of the rack are connected to L-shaped connectors, which in turn drive the rocker arm to swing. The other end of the rocker arm is fixed to the inner ring of the turntable bearing, thereby driving the left and right front walking mechanisms to turn synchronously. This structure strictly follows the Ackermann steering principle, ensuring that the rotation angle of the inner walking mechanism is greater than that of the outer one when turning. From a structural perspective, this effectively reduces the slippage of the tires on the grassland surface, improves steering accuracy and ground adaptability, and significantly simplifies the control logic and reduces control complexity compared to traditional multi-degree-of-freedom steering structures.

[0018] 5. An automated operation method combining global planning and local obstacle avoidance: This method employs a path planning approach that combines "improved greedy algorithm for global planning with dynamic window method for local obstacle avoidance." The onboard industrial control computer generates a global sampling sequence and path instruction set based on the input latitude and longitude coordinates of the sampling points using an improved greedy algorithm. The omnidirectional LiDAR of the sensing mechanism collects surrounding 3D point cloud data in real time and transmits it to the industrial control computer. After processing the point cloud data through denoising, segmentation, and clustering, the industrial control computer generates a locally optimal obstacle avoidance trajectory using the dynamic window method. Simultaneously, it uses the robot's position information output in real time from the GNSS positioning sensor to dynamically calibrate the trajectory, achieving accurate path planning and efficient obstacle avoidance in complex grassland terrain. This completely solves the technical pain points of traditional pure latitude and longitude planning, which is prone to collisions, and pure local perception planning, which is prone to global disorientation, ensuring the safety and continuity of robot operations.

[0019] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 This is a schematic diagram of the overall structure of a wheeled-legged grassland soil collection robot according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the walking mechanism structure in one embodiment of the present invention; Figure 3 This is a schematic diagram of the soil sampling mechanism in one embodiment of the present invention; Figure 4 This is a schematic diagram of the sub-shaft module structure in one embodiment of the present invention; Figure 5 This is a schematic diagram of the spindle module structure in one embodiment of the present invention; Figure 6 This is a schematic diagram of the sensing structure in one embodiment of the present invention; Figure 7 This is a schematic diagram of the steering structure in one embodiment of the present invention; Figure 8 This is a schematic diagram of the control module structure in one embodiment of the present invention; Figure 9 This is a schematic diagram of the storage structure in one embodiment of the present invention; Figure 10 This is a schematic diagram of a storage unit structure in one embodiment of the present invention; Figure 11 This is a schematic diagram of the execution unit structure in one embodiment of the present invention; Figure 12 This is a schematic diagram of soil extraction and support operations in one embodiment of the present invention; The meanings of the labels in the attached diagram are as follows: 1-Walking mechanism, 2-Soil-collecting mechanism, 3-Sensing mechanism, 4-Steering mechanism, 5-Control system, 6-Storage mechanism, 7-Chassis; 1-1 Servo mounting plate, 1-2 Dual-axis servo, 1-3 Driven servo disc, 1-4 Thigh, 1-5 Lower leg outer side plate, 1-6 42 Stepper motor, 1-7 Tire spindle, 1-8 Axle washer, 1-9 End cap bearing 1, 1-10 Grass anti-skid tire, 1-11 Large synchronous belt pulley, 1-12 Conveyor belt, 1-13 Small synchronous belt pulley, 1-14 Lower leg inner side plate, 1-15 Driven servo disc; 2-1 Fixed ring three, 2-2 Horizontal bearing, 2-3 Bulldozer rod, 2-4 Motor base, 2-5 57 Stepper motor, 2-6 Housing, 2-7 Base plate, 2-8 Sub-shaft module, 2-9 Main shaft module, 2-10 Large bevel gear, 2-11 Key pin two, 2-12 Small bevel gear, 2-13 Key pin one, 2-14 Flange, 2-15 Piston rod, 2-16 Hydraulic cylinder; 2-8-1 Fixed ring II, 2-8-2 End cover bearing III, 2-8-3 Edge gear, 2-8-4 Sleeve II, 2-8-6 Coupling, 2-8-7 Spiral drill bit, 2-8-8 Soil sampling shaft, 2-8-9 Flat key pin IV; 2-9-1 Fixing ring one, 2-9-2 End cover bearing two, 2-9-3 Center gear, 2-9-4 Sleeve one, 2-9-5 Soil sampling pipe, 2-9-6 Flat key pin three, 2-9-7 Hollow shaft; 3-1 Vertical bearing, 3-2 Stepped shaft, 3-3 Pinion II, 3-4 Retaining ring, 3-5 Large gear II, 3-6 Radar rotating shaft, 3-7 Yushu 4D L1 lidar, 3-8 Radar bracket, 3-9 42 stepper motor, 3-10 Coupling, 3-11 Motor bracket; 4-1 Single-axis servo motor, 4-2 Metal servo disc, 4-3 Pinion 3, 4-4 L-type connector, 4-5 Rocker arm, 4-6 Turntable bearing, 4-7 Rack, 4-8 Servo motor mounting bracket; 5-1 Battery, 5-2 Vehicle-mounted industrial control computer, 5-3 STM32F407IGH6 microcontroller control board, 5-4 GNSS positioning sensor; 6-1 Storage unit, 6-2 Execution unit; 6-1-1 Ring bracket, 6-1-2 Soil storage pipe, 6-1-3 Pin, 6-1-4 Movable plate, 6-1-5 Torsion spring, 6-1-6 Mounting plate; 6-2-1 Single-axis servo motor, 6-2-2 Circular servo disc, 6-2-3 Arm connector, 6-2-4 Arm, 6-2-5 Forearm, 6-2-6 Robotic arm; The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0025] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings.

[0026] A wheeled-legged grassland soil collection robot includes: The robot consists of seven parts: a walking mechanism 1, a soil sampling mechanism 2, a sensing mechanism 3, a steering mechanism 4, a control system 5, a storage mechanism 6, and a chassis 7. The walking mechanism 1 is deployed at the front left, rear left, front right, and rear right of the chassis 7, collectively responsible for the movement of the chassis 7. The soil sampling mechanism 2 is located in the central area of ​​the chassis 7 and is responsible for collecting grassland soil. The sensing mechanism 3 is deployed at the front of the chassis 7 and is responsible for sensing the terrain. The steering mechanism 4 is installed in the front-middle part of the chassis 7 and is responsible for controlling the steering of the two walking mechanisms 1 at the front left and front right. The control system 5 is installed at the top of the chassis 7 and provides decision-making support for the robot. The storage mechanism 6 is arranged around the soil sampling mechanism 2 and is responsible for storing the collected soil samples.

[0027] The walking mechanism of the wheeled-legged grassland soil collection robot also includes the following details: The walking mechanism 1 is equipped with grass-resistant anti-skid tires 1-10, providing strong grip during grassland operation. The tires 1-10 are powered by a stepper motor 1-6 mounted inside the inner side plate 1-14 of the lower leg, with its end connected to a small synchronous pulley 1-13. Power is transmitted via a conveyor belt 1-12 to a large synchronous pulley 1-11, and then through the tire spindle 1-7 to the tires 1-10. Wheel axle washers 1-8 are mounted on the lower outer sides of the inner and outer side plates 1-14 and 1-5 of the lower leg. End cap bearings 1-9 are mounted on both sides of the washers to provide support and a rotation center for the tire spindle 1-7. The tires 1-10 employ a front fork design to mitigate wheel tilting caused by unilateral installation. The upper ends of the inner and outer side plates 1-14 and 1-5 of the lower leg are connected to a dual-axis servo motor 1-2 via an active servo disc 1-15 and a driven servo disc 1-3, respectively. The lower leg is driven to swing as the power source of the knee joint and connected to the thigh 1-4. The inner side of the upper end of the thigh 1-4 is connected to another dual-axis servo motor 1-2, which serves as the power source of the hip joint, through the active servo disk 1-15 and the driven servo disk 1-3 in the same way. The dual-axis servo motor 1-2 drives the entire walking mechanism 1 to rotate. The dual-axis servo motors 1-2 at the corresponding positions of the left rear and right rear walking mechanisms 1 are fixed to the chassis servo motor mounting plate 1-1. The dual-axis servo motors 1-2 at the corresponding positions of the left front and right front walking mechanisms 1 are connected to the lower end of the turntable bearing 4-6. The walking mechanism 1 can switch modes according to the working environment. On rugged sections, it can switch from wheeled to footed mode. At this time, the stepper motor 1-6 is locked, and the tire 1-10, as the end of the wheel leg, moves in a walk gait, which has a strong obstacle crossing ability.

[0028] The soil-collecting mechanism of the wheeled-legged grassland soil-collecting robot also includes the following details: The main body of the soil-collecting mechanism 2 is connected to the chassis 7 via four hydraulic cylinders 2-16. The hydraulic cylinders 2-16 are connected to the flanges 2-14 on the outer shell 2-6 via piston rods 2-15. Their telescopic movement provides lifting power for the main body of the soil-collecting mechanism 2. The operating power of the soil-collecting mechanism 2 is provided by a 57 stepper motor 2-5 mounted on the outer shell 2-6. Its power output shaft is connected to a small bevel gear 2-12 via a key pin 2-13. The small bevel gear 2-12 meshes with a large bevel gear 2-10. The large bevel gear 2-10 is connected to the upper end of the hollow shaft 2-9-7 of the main shaft module 2-9 via a key pin 2-11. The keyway at the lower end of the hollow shaft 2-9-7 is connected to the central gear 2-9-3 via a key pin 3-9-6. End cap bearings 2-9-2 are installed on the upper surface of the outer shell 2-6 and the center of the base plate 2-7. The hollow shaft 2-9-7 provides a center of rotation, and a retaining ring 2-9-1 is installed at the upper end of the hollow shaft 2-9-7 for limiting. The central gear 2-9-3 is supported by a sleeve 2-9-4 between it and the base plate 2-7. A soil sampling pipe 2-9-5 is installed at the lower end of the base plate 2-7 for soil sampling operations. The retaining ring 2-9-1, the end cap bearing 2-9-2, the central gear 2-9-3, the sleeve 2-9-4, the soil sampling pipe 2-9-5, the key pin 2-9-6, and the hollow shaft 2-9-7 together form the main shaft module 2-9. Five secondary shaft modules 2-8, which have a similar structure to the main shaft module 2-9, are evenly arranged around the main shaft module 2-9. The edge gear 2-8-3 of the secondary shaft module 2-8 meshes with the central gear 2-9-3, and its center is connected to the soil sampling shaft 2-8-8 via the key pin 2-8-9. The connection is as follows: The upper surface of the outer shell 2-6 and the four sides of the base plate 2-7 are equipped with end cap bearings 2-8-2, providing a rotation center for the soil sampling shaft 2-8-8. A retaining ring 2-8-1 is installed at the upper end of the soil sampling shaft 2-8-8 for limiting its position. The edge gear 2-8-3 is supported by a sleeve 2-8-4 between it and the base plate 2-7. The lower end of the soil sampling shaft 2-8-8 is connected to the auger drill bit 2-8-7 via a coupling 2-8-6. A stepper motor 2-5 transmits power to the hollow shaft 2-9-7 through a bevel gear assembly. The hollow shaft 2-9-7 then drives the auger drill bit 2-8-7 to rotate, loosening the soil around the soil sampling tube 2-9-5 and reducing penetration resistance. A bulldozer rod 2-3 is installed inside the soil sampling tube 2-9-5, passing through the hollow shaft 2-9-7 and with its end always located within the soil sampling tube 2-9-5. Inside, its upper end is connected to the horizontal bearing 2-2 on the chassis 7. The upper and lower sides of the horizontal bearing 2-2 are limited by the fixing rings 2-1 to limit the bulldozer rod 2-3. When the soil-taking mechanism 2 rises and contracts with the hydraulic cylinder 2-16,The bulldozer rod 2-3 uses relative motion to push soil out of the soil extraction pipe 2-9-5.

[0029] The sensory mechanism of the wheeled-legged grassland soil collection robot also includes the following details: The sensing mechanism 3 is installed at the front of the robot. Its core component is the Yushu 4DL1 LiDAR 3-7, capable of 360-degree autonomous rotation. This LiDAR is mounted on a radar bracket 3-8. The sensing mechanism 3 drives the LiDAR 3-7 to synchronously oscillate in the pitch direction. The pitch motion is powered by a 42-stepper motor 3-9 fixed to the chassis 7 via a motor bracket 3-11. This stepper motor transmits power to a stepped shaft 3-2 via a coupling 3-10. The stepped shaft 3-2 is supported by a vertical bearing 3-1, and a pinion 3-3 is mounted on the other end. The pinion 3-3 is limited on both sides by retaining rings 3-4 and meshes with a large gear 3-5. The large gear 3-5 is mounted on the radar rotation shaft 3-6 via retaining rings 3-4. Its outer surface threaded hole is fixed to the inner right surface of the radar bracket 3-8. Power is transmitted to the radar bracket 3-8 through gear meshing, causing it to rotate around the radar rotation shaft 3-6. Supported by two vertical bearings 3-1, the sensing mechanism 3 can acquire more comprehensive terrain information in front of the robot through the pitching motion of the radar bracket 3-8 and the rotation of the lidar 3-7 itself.

[0030] The steering mechanism of the wheeled-legged grassland soil collection robot also includes the following details: Steering mechanism 4 is essentially an Ackermann trapezoidal structure. Power is provided by a single-axis servo motor 4-1, fixed to the upper surface of chassis 7 via servo motor mounting bracket 4-8. The servo motor output shaft connects to pinion gear 4-3 via metal servo disc 4-2. Pinion gear 4-3 meshes with rack 4-7, converting the servo motor's rotational motion into the rack 4-7's left-right translation. L-shaped connectors 4-4 are connected to both sides of rack 4-7, and these connectors are connected to rocker arms 4-5. The other end of rocker arm 4-5 connects to the upper surface of the inner ring of turntable bearing 4-6. Turntable bearing 4-6 consists of inner and outer parts. The outer ring is fixed to chassis 7 via threaded holes, while the inner ring can rotate under the influence of rocker arm 4-5. The lower surface of the inner ring is connected to the dual-axis servo motor 1-2 of the travel mechanism 1. Rack 4-7 translates left and right under the influence of pinion gear 4-3, via L-shaped connectors 4-4... The conversion drives the left and right rocker arms 4-5 to rotate at different angles along the center of the turntable bearing 4-6, thereby driving the left front and right front walking mechanisms 1 to turn, and ensuring that the inner wheel rotates at a greater angle than the outer wheel when turning, reducing the slippage of the tires 1-10 during the robot's turning process.

[0031] The control system of the wheeled-legged grassland soil collection robot also includes the following details: The control system 5 consists of a GNSS positioning sensor 5-4, an STM32F407IGH6 microcontroller control board 5-3, an onboard industrial control computer 5-2, and a battery 5-1. The entire system is mounted on the chassis 7, and the battery 5-1 is responsible for powering all robot components. The onboard industrial control computer 5-2 is responsible for overall task planning and decision-making, the microcontroller control board 5-3 is responsible for receiving instructions from the industrial control computer and controlling each actuator, and the GNSS positioning sensor 5-4 guides the robot to the predetermined work point and completes the return trip by acquiring the robot's real-time position information.

[0032] The storage mechanism of the wheeled-legged grassland soil collection robot also includes the following details: The storage mechanism 6 mainly includes a storage unit 6-1 and an execution unit 6-2. The main body of the storage unit 6-1 is a ring-shaped bracket 6-1-1 installed on the lower part of the chassis 7 and surrounding the soil-collecting mechanism 2. This bracket has an inner and outer two-layer structure and forms a ring-shaped guide rail that can carry the soil-collecting tube 6-1-2. Spring valves are installed on both its left and right openings. The spring valves consist of a mounting plate 6-1-6, a pin 6-1-3, a torsion spring 6-1-5, and a movable plate 6-1-4. The mounting plate 6-1-6 is fixed at the opening, and the torsion spring 6-1-5 causes the movable plate 6-1-4 to generate an inward pushing force to prevent the soil-collecting tube 6-1-2 from falling off during movement. During operation, the soil-collecting tube 6-1-2 is taken out from the left side of the storage unit 6-1 and put in from the right side, with the left side always empty. The ring-shaped design of the storage unit 6-1 achieves efficient recycling of the storage space. The main body of the execution unit 6-2 is a robotic arm, with each joint controlled by a single-axis servo motor 6-2-1. As the power source, the uppermost servo motor is fixed on the chassis 7 and connected to the upper arm connector 6-2-3 via a circular servo disk 6-2-2. The lower end of the upper arm connector 6-2-3 is connected to the upper arm 6-2-4 and a servo motor is located at the same position. The upper end of the forearm 6-2-5 is connected to the upper arm 6-2-4 and is equipped with a servo motor. The two servo motors serve as the power source for the corresponding joints. The robotic arm 6-2-6 installed at the end of the forearm 6-2-5 is equipped with two servo motors, which control its opening, closing and rotation respectively. This multi-degree-of-freedom execution unit 6-2 can flexibly complete the actions of taking out and putting back the soil storage tube 6-1-2.

[0033] A method for using a wheeled-legged grassland soil collection robot includes: The operator manually inputs the latitude and longitude coordinates of the sampling points into the vehicle-mounted industrial control computer 5-2. Based on its own position and the coordinates of each sampling point, the vehicle-mounted industrial control computer 5-2 uses an improved greedy algorithm to generate a set of operation instructions for the global sampling sequence and global path, which is stored in its own cache and awaits to be sent to the microcontroller 5-3 segment by segment. The robot proceeds to the sampling point according to the path planned by the vehicle-mounted industrial control computer 5-2. At the same time, it activates the sensing mechanism 3, uses the lidar 3-7 to continuously collect the surrounding three-dimensional point cloud data, and transmits the data to the vehicle-mounted industrial control computer 5-2 in real time via Ethernet. The vehicle-mounted industrial control computer 5-2 uses statistical filtering for noise reduction, RANSAC ground segmentation, Euclidean clustering and other methods to process and acquire point cloud data. It extracts potholes, bumps and vegetation obstacles around the travel path, generates a local optimal obstacle avoidance trajectory through dynamic windowing, and sends real-time driving commands frame by frame to the microcontroller 5-3 and adjusts the travel speed according to the terrain undulations. The high-precision GNSS positioning sensor 5-4 outputs the robot's real-time latitude and longitude to the vehicle-mounted industrial control computer 5-2, which converts it into planar coordinates to calibrate the robot's current position in real time. After the robot arrives at the sampling site, the walking mechanism 1 switches to the support operation state. The hydraulic cylinder 2-16 drives the soil sampling mechanism 2 to move downward through the piston rod 2-15. The stepper motor 2-5 drives the main shaft module 2-9 to rotate stably through the bevel gear set. The center gear 2-9-3 of the main shaft module 2-9 precisely meshes with the edge gears 2-8-3 of the five secondary shaft modules 2-8, driving the five spiral drill bits 2-8-7 to rotate synchronously and uniformly around the soil sampling tube 2-9-5. During the descent of the soil sampling tube 2-9-5, the surrounding grassland soil is continuously pre-loosened. Then, the soil sampling tube 2-9-5 is completely inserted into the soil, completing the soil sampling. After the operation is completed, the hydraulic cylinder 2-16 drives the soil sampling mechanism 2 to move upward through the piston rod 2-15. At this time, the robotic arm of the execution unit 6-2 clamps an empty soil storage tube 6-1-2 from the left side of the storage unit 6-1 and places it below the soil sampling tube 2-9-5. The push rod 2-3 remains in the same position. During the upward movement of the soil sampling mechanism 2, the collected soil is pushed out and falls into the lower soil storage tube 6-1-2 through relative movement. Then, the robotic arm puts the soil storage tube 6-1-2 containing the soil sample into the storage unit 6-1 from the right side. The soil sampling mechanism 2 rises to its original position, the walking mechanism 1 switches back to walking mode, and the robot moves to the next sampling point until all operations are completed and returns.

Claims

1. A wheeled-legged grassland soil collection robot, characterized in that, include: The system comprises a walking mechanism (1), a soil sampling mechanism (2), a sensing mechanism (3), a steering mechanism (4), a control system (5), a storage mechanism (6), and a chassis (7). The walking mechanism (1) is deployed sequentially at the front left, rear left, front right, and rear right of the chassis (7) in the direction of travel. The soil sampling mechanism (2) is deployed in the middle of the chassis (7) for collecting grassland soil. The sensing mechanism (3) is deployed in front of the chassis (7) for sensing the terrain. The steering mechanism (4) is deployed in the front middle part of the chassis (7). The control system (5) is installed on the upper end of the chassis (7). The storage mechanism (6) is set up around the soil sampling mechanism (2) for storing the collected soil samples. The storage mechanism (6) mainly includes a storage unit (6-1) and an execution unit (6-2). The main structure of the storage unit (6-1) is a ring bracket (6-1-1). The ring bracket (6-1-1) is installed on the lower part of the chassis (7) and surrounds the soil extraction mechanism (2). The ring bracket (6-1-1) has inner and outer layers, and the ring guide rail formed can carry the soil storage pipe (6-1-2). Spring valves are installed on the openings on both the left and right sides. The spring valves are composed of an mounting plate (6-1-6), a pin (6-1-3), a torsion spring (6-1-5), and a movable plate (6-1-4). The mounting plate (6-1-6) is installed at the opening of the ring bracket (6-1-1). The torsion spring (6-1-5) causes the movable plate (6-1-4) to generate an inward thrust, ensuring that the soil storage pipe (6-1-2) will not fall off during the movement. During operation, it is taken out from the left side and put in from the right side.

2. The data collection robot according to claim 1, characterized in that, The walking mechanism (1) uses grass anti-skid tires (1-10). The tires (1-10) are powered by a 42-stepper motor (1-6). The 42-stepper motor (1-6) is installed on the inner side of the lower leg inner plate (1-14), and its end is connected to a small synchronous pulley (1-13). The small synchronous pulley (1-13) transmits power to the large synchronous pulley (1-11) through a conveyor belt (1-12). The large synchronous pulley (1-11) is connected to the tire spindle (1-7), which in turn transmits power to the tires (1-10). The front fork design reduces wheel tilting caused by single-sided installation. The upper ends of the inner lower leg plate (1-14) and the outer lower leg plate (1-5) are connected to the dual-axis servo motor (1-2) through the active servo disc (1-15) and the driven servo disc (1-3) respectively. The other end of the dual-axis servo motor (1-2) is connected to the thigh (1-4). Depending on the working environment, the walking mechanism (1) can switch from wheel mode to foot mode. The 42 stepper motor (1-6) is locked, and the tire (1-10) serves as the end of the wheel leg, moving forward in a walk gait to improve obstacle crossing ability.

3. The data collection robot according to claim 1, characterized in that, The main structure of the soil-collecting mechanism (2) is connected to the chassis (7) through four hydraulic cylinders (2-16). The retraction movement of the hydraulic cylinders provides lifting power for the main structure of the soil-collecting mechanism (2). The working part of the soil-collecting mechanism (2) is powered by a 57 stepper motor (2-5), which is mounted on the outer shell (2-6) through a motor mount (2-4). The power output shaft is connected to the small bevel gear (2-12) through a flat key pin one (2-13). The small bevel gear (2-12) meshes with the large bevel gear (2-10). The upper end of the main shaft module (2-9) is a hollow shaft (2-9-7). The keyway at the upper end of the hollow shaft (2-9-7) is connected to the large bevel gear (2-10) through a flat key pin two (2-11). The keyway at the lower end is connected to the center gear (2-9-3) through a flat key pin three (2-9-6). The central gear (2-9-3) is supported by sleeve one (2-9-4) between it and the base plate (2-7). A soil sampling pipe (2-9-5) is installed at the lower end of the base plate (2-7) to supply soil sampling operations. The edge gear (2-8-3) meshes with the central gear (2-9-3). The center is connected to the middle keyway of the soil sampling shaft (2-8-8) through the flat key pin four (2-8-9). The lower end of the soil sampling shaft (2-8-8) is connected to the auger drill bit (2-8-7) through the coupling (2-8-6). Five secondary shaft modules (2-8) are evenly installed around the main shaft module (2-9). The 57 stepper motor (2-5) transmits power to the hollow shaft (2-9-7) through a bevel gear combination. The hollow shaft (2-9-7) finally transmits power to the auger drill bit (2-8-7) through a gear combination for its rotation.

4. The data collection robot according to claim 3, characterized in that, The soil sampling tube (2-9-5) has a bulldozer rod (2-3) inside. Its upper end is connected to a horizontal bearing (2-2) installed on the chassis (7). The horizontal bearing (2-2) is limited on both sides by a fixing ring (2-1). The bulldozer rod (2-3) passes through the hollow shaft (2-9-7) and its end is always inside the soil sampling tube (2-9-5). When the soil sampling mechanism (2) rises with the hydraulic cylinder (2-16) as it contracts, the soil inside the soil sampling tube (2-9-5) can be pushed out.

5. The data collection robot according to claim 1, characterized in that, The sensing mechanism (3) is installed at the front of the robot. Its main component is the Yushu 4D L1 laser radar (3-7), which is mounted on the radar bracket (3-8). It can rotate 360 ​​degrees. The sensing mechanism (3) can swing in the pitch direction for the laser radar (3-7). The power source for the pitch action is a 42 stepper motor (3-9), which is fixed by a motor bracket (3-11) mounted on the chassis (7).

6. The data collection robot according to claim 1, characterized in that, The steering mechanism (4) has an Ackermann trapezoidal structure as its core. The power source is a single-axis servo motor (4-1), which is fixed to the upper surface of the chassis (7) by a servo motor mounting bracket (4-8). The servo motor output shaft is connected to the pinion gear 3 (4-3) through a metal servo disc (4-2). The pinion gear 3 (4-3) meshes with the rack (4-7) to convert the rotational motion of the servo motor into the left and right translational motion of the rack (4-7). The rack (4-7) is connected to the L-shaped connector (4-4) on both sides. The L-shaped connector (4-4) is connected to the rocker arm (4-5). The other end of the rocker arm (4-5) is connected to the upper surface of the inner ring of the turntable bearing (4-6). The turntable bearing (4-6) is divided into inner and outer parts. The outer ring is fixed to the chassis (7) through a threaded hole. The inner ring can rotate under the drive of the rocker arm (4-5).

7. The data collection robot according to claim 1, characterized in that, The main body of the execution unit (6-2) is a robotic arm structure. The power source for each joint is a single-axis servo motor (6-2-1). The uppermost single-axis servo motor (6-2-1) is mounted on the chassis (7) and connected to the upper arm connector (6-2-3) via a circular servo disc (6-2-2). The lower end of the upper arm connector (6-2-3) is connected to the upper arm (6-2-4). At the same position, another single-axis servo motor (6-2-1) also serves as a power source. Similarly, the lower arm (6-2... -5) The upper end is connected to the upper arm (6-2-4) and is equipped with a single-axis servo motor (6-2-1). A manipulator (6-2-6) is installed at the end of the forearm (6-2-5) and equipped with two single-axis servo motors (6-2-1). One is responsible for the opening and closing movement of the manipulator (6-2-6), and the other is responsible for the overall rotation of the manipulator (6-2-6). The execution unit (6-2) has multiple degrees of freedom and can flexibly complete the actions of taking out and putting back the soil storage tube (6-1-2).

8. A method of using the wheeled-legged grassland soil collection robot according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Input the latitude and longitude coordinates of the sampling point into the vehicle-mounted industrial control computer (5-2). Based on its own position, the vehicle-mounted industrial control computer (5-2) uses an improved greedy algorithm to generate a global sampling sequence and a global path operation instruction set, which is stored in the industrial control computer cache and waits to be sent to the microcontroller segment by segment. S2, the robot starts to head to the sampling point according to the path planned by the industrial control computer, and opens the sensing mechanism (3) to continuously collect the surrounding three-dimensional point cloud data using the lidar (3-7) and transmit it to the vehicle-mounted industrial control computer (5-2) in real time via Ethernet. S3, the vehicle-mounted industrial control computer (5-2) processes point cloud data through statistical filtering denoising, RANSAC ground segmentation, Euclidean clustering, etc., extracts potholes, bumps, vegetation obstacles around the travel path, and uses the dynamic window method to generate a local optimal obstacle avoidance trajectory. It sends real-time driving instructions to the microcontroller frame by frame and adjusts the travel speed according to the terrain undulation. The high-precision GNSS positioning sensor (5-4) outputs the robot's real-time latitude and longitude to the vehicle-mounted industrial control computer (5-2), which converts it into planar coordinates and calibrates the robot's current position in real time. S4, after the robot arrives at the sampling location, the walking mechanism (1) switches to the support operation state. The hydraulic cylinder (2-16) drives the soil sampling mechanism (2) to move downward through the piston rod (2-15). The 57 stepper motor (2-5) drives the main shaft module (2-9) to rotate stably through the bevel gear set. The center gear (2-9-3) of the main shaft module (2-9) meshes precisely with the edge gears (2-8-3) of the five secondary shaft modules (2-8), driving the five spiral drill bits (2-8-7) to rotate synchronously and uniformly around the soil sampling tube (2-9-5). During the soil sampling process, the surrounding grassland soil is continuously pre-loosened. Then, the soil sampling tube (2-9-5) is completely inserted into the soil for soil sampling. S5. After the operation is completed, the hydraulic cylinder (2-16) drives the soil sampling mechanism (2) to move upward through the piston rod (2-15). At this time, the robotic arm of the execution unit (6-2) clamps a soil storage tube (6-1-2) from the left side of the storage unit (6-1) and places it below the soil sampling tube (2-9-5). The position of the push rod (2-3) remains unchanged. During the upward movement of the soil sampling mechanism (2), the push rod (2-3) pushes out the collected soil through relative movement and falls into the soil storage tube (6-1-2) below. The robotic arm of the execution unit (6-2) puts the soil storage tube (6-1-2) containing the soil sample into the right side of the storage unit (6-1). The soil sampling mechanism (2) rises to its original position, the walking mechanism (1) switches back to the walking state and goes to the next sampling point until the operation is completed and the robot returns.

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