Pressure adaptive flexible grasping robotic arm for desert tree planting

Abstract

The application is suitable for the field of automation equipment, and provides a pressure self-adaptive flexible gripping mechanical arm for desert tree planting, which is a three-section column modular structure, is composed of a light-weight protective guide rail, a multi-degree-of-freedom modular mechanical arm and a pressure self-adaptive flexible mechanical claw connected coaxially in sequence, and each unit is detachably connected through quick-change pin shafts.The light-weight protective guide rail realizes dust prevention by using built-in slide rails and upper cleaning micro-holes; the multi-degree-of-freedom modular mechanical arm realizes light weight and high rigidity by using hollow transmission rods and triangular reinforcing rib supports; the pressure self-adaptive flexible mechanical claw realizes lossless and stable gripping of irregular sand willow seedlings by using an asymmetric arc envelope structure matched with a thin film type force sensor closed loop control; and a posture compensation mechanism is further arranged to ensure that the seedlings are vertically planted into the soil.The application solves the problems of easy jamming of the kinematic pair in the desert windy and sandy environment, difficulty in field maintenance, damage and tilting planting of the seedlings, and improves the operation reliability and the survival rate of the seedlings.

Description

Technical Field

[0001] This invention belongs to the field of automated equipment, and in particular relates to a pressure-adaptive flexible gripping robotic arm for desert tree planting. Background Technology

[0002] With the acceleration of global desertification control, the use of automated robots to replace manual labor in afforestation in extreme desert environments has become an industry trend. Sand willow, as an excellent windbreak and sand-fixing shrub, is widely used in the control of desertification in Northwest my country. Traditional mechanized tree planting equipment is mostly designed for regular terrain and standardized seedlings. However, in actual desert operations, the environment is extremely harsh (high temperature, strong winds and sandstorms), and the terrain is highly undulating, placing extremely high demands on the mechanical reliability, mobility, and ease of maintenance of automated equipment.

[0003] The existing equipment has the following technical problems in actual desert operations:

[0004] The guide rail has an open structure and lacks specific protective measures against the extremely fine sand and dust of the desert. Sand particles can easily penetrate the moving parts, causing a surge in frictional resistance, motor overload, guide rail jamming, and component wear. The robotic arm has a complex and redundant structure, excessive weight, and high end-effector inertia, resulting in severe vibrations during high-speed starts and stops and during desert bumps, reducing the positioning accuracy of gripping and deployment while increasing drive energy consumption. The guide rail, robotic arm, and gripper are rigidly coupled or integrally welded structures without modular quick-change design. Damaged core components require complete disassembly and repair, which is problematic in the desert. Rapid on-site repairs are not possible in the hinterland, resulting in excessively long average repair times and poor operational continuity. The rigid flat gripper is a point-contact clamping structure without an adaptive envelope design, making it extremely unsuitable for irregular sand willow seedlings with varying diameters and branches. Furthermore, the lack of clamping force detection and closed-loop control devices means the clamping force remains constant and cannot be adjusted, leading to high rates of seedling drop and bark damage. The gripper's posture changes synchronously with the robot's body, and it cannot automatically correct itself on slopes and uneven terrain, causing the sand willow seedlings to tilt into the soil, violating the requirement for vertical rooting and significantly reducing the seedling survival rate. Summary of the Invention

[0005] The purpose of this invention is to provide a pressure-adaptive flexible gripping robotic arm for desert tree planting, aiming to solve the problems existing in the background art.

[0006] This invention is implemented as follows: a pressure-adaptive flexible gripping robotic arm for desert afforestation, comprising:

[0007] The lightweight protective guide rail is bolted to the robot frame. The lightweight protective guide rail includes a bottom rotating disk and a built-in dustproof guide rail. The bottom rotating disk is connected to the robot body and driven by a rotating gear, providing rotational support; the built-in dustproof guide rail is supported by a cylindrical support that limits rotation and is driven by the bottom gear.

[0008] A multi-degree-of-freedom modular robotic arm, with one end mounted on a lightweight protective guide rail via a slider, provides the robotic gripper with multi-degree-of-freedom attitude adjustment and precise position movement. The multi-degree-of-freedom modular robotic arm includes a support rod, a triangular rib support, a first support robotic arm, and a second support robotic arm. The lower end of the support rod is hinged to a limiting rotating cylindrical support, allowing it to pitch and swing within a preset limit angle around the hinge point. The triangular rib support is fixedly connected between the support rod and the first support robotic arm. The end of the first support robotic arm is hinged to the second support robotic arm, and both are driven by matching servo motors.

[0009] A pressure-adaptive flexible mechanical gripper is mounted at one end of the multi-degree-of-freedom modular robotic arm and connected to the second supporting robotic arm via a quick-change pin, serving as the actuating end for grasping seedlings. The pressure-adaptive flexible mechanical gripper includes a gripper mounting base, which is fixedly connected to the end of the second supporting robotic arm. This gripper serves as a swing joint at the end of the robotic arm, driving the entire gripping mechanism to pitch and swing. Simultaneously, it acts as the mounting base for the gripping mechanism, transmitting power and motion to the end effector.

[0010] Furthermore, the lightweight protective guide rail also includes: a dustproof end cap for protecting the limiting device and the hollow part; two small end openings for removing sand and adding guide rail lubricating oil after disassembly; and a hollow transmission rod, which is a thin-walled hollow metal tube structure with a tube wall thickness of 3-5mm, for rotating at a constant speed under the action of the drive motor, driving the slider to move linearly along the built-in slide rail.

[0011] Furthermore, in the multi-degree-of-freedom modular robotic arm, both the first supporting robotic arm and the second supporting robotic arm adopt a hollow and lightweight design; at the connecting base of the first supporting robotic arm and the second supporting robotic arm, as well as at the junction of the robotic arm and the guide rail slider, triangular reinforcing rib brackets are connected, and the support bushing of each rotary joint and the main arm are connected by two reinforcing ribs to form a stable triangular force-bearing truss.

[0012] Furthermore, the pressure-adaptive flexible mechanical gripper also includes: a synchronous clamping gear pair, consisting of a pair of meshing cylindrical gears, mounted on the gripper mounting base; a gripper drive linkage connecting the synchronous clamping gear pair and the gripper finger body; the gripper finger body, which clamps and releases the seedling through opening and closing actions; first, second, and third cylindrical guide protrusions, respectively arranged inside the gripper finger body and slidingly engaged with it; first, second, and third elastic elements, respectively fitted onto the tails of the three cylindrical guide protrusions; and a thin-film force sensor, fixedly embedded inside the gripper finger body.

[0013] Furthermore, the signal from the thin-film force sensor is connected to the main control unit, which presets a safety clamping force threshold and forms a closed-loop control with the drive mechanism; when the clamping force reaches the preset threshold, the main control unit immediately cuts off the power to the drive mechanism.

[0014] Furthermore, the robotic arm also includes an attitude compensation mechanism, which has a tilt sensor to collect the tilt state data of the robot body in real time and transmit it to the main control unit. The main control unit calculates the compensation angle based on the data and drives three mutually perpendicular rotary joints to move synchronously to adjust the spatial attitude of the robotic gripper.

[0015] Furthermore, the lightweight protective guide rail also has upper cleaning micro-holes, which are evenly opened at the top of the guide rail column along the axial direction. The cleaning micro-holes are 1-2mm in diameter and are connected to the slide rail cavity inside the housing. A dust filter is installed at the cleaning micro-hole.

[0016] The present invention provides a pressure-adaptive flexible gripping robotic arm for desert tree planting, which has the following beneficial effects:

[0017] The pressure-adaptive flexible gripping robotic arm for desert tree planting provided by this invention physically blocks sand and dust intrusion through a hidden structure with built-in slide rails. Combined with the upper cleaning micro-holes, it automatically discharges intruding sand and dust using the air pressure difference generated by the movement of the slider. This constructs a dust prevention and removal system that combines active protection and passive cleaning, greatly improving the working life and stability in extreme wind and sand environments.

[0018] The hollow transmission rod combined with the triangular stability link design reduces the overall weight and rotational inertia of the machine, while using the geometric stability of the triangle to suppress the chatter during high-speed start-up and shutdown of the robotic arm, achieving a balance between high rigidity and lightweight, and improving operating accuracy. The entire system adopts a three-section modular design, transforming the guide rail, robotic arm and robotic gripper into independently replaceable standard units, connected by quick-change pins, which greatly shortens the average maintenance time and reduces the difficulty and cost of field maintenance.

[0019] By using an asymmetric arc-shaped envelope structure and a flexible buffer layer, multi-point gripping of irregular sand willow seedlings is achieved. Combined with closed-loop pressure control of a thin-film force sensor, the technical contradiction between stable gripping and non-destructive protection is resolved, effectively protecting the seedling epidermis and improving the planting survival rate.

[0020] The multi-degree-of-freedom posture compensation mechanism ensures that the seedlings are always planted in a posture perpendicular to the horizontal plane on slopes and uneven terrain, thus guaranteeing the consistency of planting posture. Attached Figure Description

[0021] Figure 1 This invention provides a schematic diagram of the overall structure of a pressure-adaptive flexible gripping robotic arm for desert tree planting;

[0022] Figure 2 The structural diagram of the gripper for a pressure-adaptive flexible gripping robotic arm for desert afforestation provided by the present invention;

[0023] Figure 3 This is a partial structural diagram of the gripper of a pressure-adaptive flexible gripping robotic arm for desert afforestation provided by the present invention.

[0024] In the attached diagram: 1. Bottom rotating wheel; 2. Built-in dustproof guide rail; 3. Dustproof end cap; 4. Support rod; 5. End opening; 6. Triangular rib support; 7. First support robotic arm; 8. Second support robotic arm; 9. Gripper mounting base; 10. Synchronous gripping gear pair; 11. Gripper drive linkage; 12. Gripper finger; 13. First cylindrical guide protrusion; 14. Second cylindrical guide protrusion; 15. Third cylindrical guide protrusion; 16. First elastic element; 17. Second elastic element; 18. Thin-film force sensor; 19. Third elastic element. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0027] like Figures 1 to 3 As shown, the pressure-adaptive flexible gripping robotic arm for desert tree planting in this embodiment has a three-section cylindrical modular structure. It consists of three core functional units: a lightweight protective guide rail, a multi-degree-of-freedom modular robotic arm, and a pressure-adaptive flexible robotic claw, which are coaxially connected in sequence. Each unit is detachable and quick-change connected through quick-change pins.

[0028] (a) Lightweight protective guide rail

[0029] The lightweight protective guide rail is bolted to the robot frame, serving as the moving base and power transmission foundation for the entire robotic arm. Specifically, it includes:

[0030] Bottom rotating wheel 1: Connected to the vehicle body, driven by the vehicle body rotating gear, it can rotate around the vertical axis, synchronously driving the built-in dustproof guide rail 2 and the limit rotating cylindrical support 3 fixedly connected to it to rotate as a whole, playing a role in rotational support.

[0031] Built-in dustproof guide rail 2: Supported by a cylindrical base for limiting rotation, it is driven by a bottom gear. The sliding track of this guide rail is completely embedded inside the cylindrical housing, which features a fully enclosed design. Only the necessary gap for connection with the multi-degree-of-freedom modular robotic arm is reserved at the slider position, and the gap is sealed with a flexible gasket. This "hidden" layout physically prevents sand and dust from directly contacting the slide rail surface.

[0032] Dustproof end cover 3: Installed at the end of the guide rail, it is used to protect the internal limiting device and hollow part, and also facilitates maintenance.

[0033] Support rod 4: Its lower end is hinged to the limiting rotating cylinder support, and it can pitch and swing around the hinge point within a preset limit angle, synchronously transmitting the rotational motion and pitch swing to the upper robotic arm body. The rotation range of the support rod is the limit angle.

[0034] End opening 5: Two small openings are provided on the guide rail column to drain internal sand or add guide rail lubricating oil during disassembly.

[0035] Hollow transmission rod: Utilizing a thin-walled hollow metal tube structure with a wall thickness of 3-5mm. Through mechanical simulation analysis and torsional strength physical testing, this structure reduces weight by 40%-50% compared to traditional solid transmission rods while ensuring power transmission stability and torsional strength. Under the action of the drive motor, the hollow transmission rod rotates at a uniform speed, driving the slider to move smoothly in a straight line along the built-in slide rail.

[0036] In addition, a series of tiny cleaning micro-holes with a diameter of 1-2 mm are evenly distributed along the axial direction at the top of the guide rail column. These micro-holes are connected to the slide rail cavity inside the housing, and dust filters are installed at the micro-holes. When the slider reciprocates within the built-in slide rail, it changes the air pressure inside the slide rail cavity, creating a pressure difference between the inside and outside. This pressure difference allows even a very small amount of sand or dust that may accidentally enter the housing to be automatically discharged through the cleaning micro-holes. Simultaneously, the cleaning micro-holes can be connected to an external air-blowing device for active air-blowing maintenance during equipment downtime.

[0037] (II) Multi-degree-of-freedom modular robotic arm

[0038] The multi-degree-of-freedom modular robotic arm has one end slidably mounted on a built-in slide rail of a lightweight protective guide rail via a slider, and the other end connected to a pressure-adaptive flexible robotic gripper via a quick-change pin. Specifically, it includes:

[0039] Triangular rib support 6: It is fixedly connected between the support rod 4 and the first support robotic arm 7, and has no relative movement; it only serves to strengthen the structure.

[0040] First support robotic arm 7: Its end is hinged to the second support robotic arm 8. The first support robotic arm is driven by a matching servo motor and can perform pitching motion.

[0041] The second support robotic arm 8 is hinged to the first support robotic arm and driven by a matching servo motor. Through the coordinated pitch and swing of the two joints, it enables a wide range of precise adjustments to the spatial position of the end effector.

[0042] The clamp mounting base 9 is fixedly connected to the end of the second support robotic arm 8. As the swing joint at the end of the robotic arm, it can drive the entire clamping mechanism to swing in pitch and sway, which is used to adjust the soil entry angle and placement posture of the sand willow seedlings. At the same time, it serves as the mounting base of the clamping mechanism, transmitting power and movement to the end.

[0043] Both the first supporting robotic arm 7 and the second supporting robotic arm 8 adopt a hollow and lightweight design. Specifically, finite element analysis and topology optimization are performed on the forearm of the robotic arm (the end closest to the robotic claw). Based on the actual force distribution law of the arm, redundant mass areas with no or low force are removed, and regular hole-cutting is performed (the hole is reinforced with chamfers to prevent stress concentration).

[0044] At the connecting bases of each segment of the robotic arm (i.e., the joint turning points) and at the junctions between the robotic arm and the guide rail slider, triangular reinforcing rib supports are integrally cast or welded. Between the support bushing of each rotary joint and the main arm, two reinforcing ribs form a stable triangular load-bearing truss. Based on the principle of triangular geometric stability, this design transforms the single-point shear force on the joint bearings into the overall tensile and compressive stress of the support, effectively counteracting end-effector sway and structural elastic deformation caused by inertia.

[0045] (III) Pressure-adaptive flexible mechanical gripper

[0046] A pressure-adaptive flexible robotic gripper is mounted at the end of a multi-degree-of-freedom modular robotic arm, serving as the actuating end for grasping seedlings. Specifically, it includes:

[0047] Synchronous clamping gear pair 10: Composed of a pair of meshing cylindrical gears, mounted on the clamping device mounting base 9. Driven by the drive unit, it rotates and outputs synchronous and opposite rotational motion through gear meshing, ensuring that the left and right gripper fingers move synchronously in opposite directions, thus achieving centering of the clamping action.

[0048] Gripper drive linkage 11: connects the synchronous clamping gear pair 10 and the gripper finger body 12, converting the rotational motion of the gear into the opening and closing swing of the gripper finger body, and amplifying the clamping force through the crank-connecting rod mechanism principle.

[0049] Gripper finger 12: Two symmetrical gripping arms on the left and right sides, which clamp and release the seedlings through opening and closing actions.

[0050] The first cylindrical guide protrusion 13, the second cylindrical guide protrusion 14, and the third cylindrical guide protrusion 15 are respectively arranged on the inner side of the gripper fingers 12, slidingly engaging with the gripper fingers and adaptively extending and retracting radially. The surfaces of these protrusions are entirely covered with low-friction, high-wear-resistant, and flexible materials such as polytetrafluoroethylene (or nylon) to form a flexible buffer layer. When the gripper is closed, the protrusions form multi-point contact support with the seedling's bark, creating a ring-shaped clamping structure.

[0051] The first elastic element 16, the second elastic element 17, and the third elastic element 19 are respectively fitted onto the tail of the three cylindrical guide protrusions. They compress and rebound synchronously with the extension and retraction of the protrusions, ensuring that the guide protrusions can return to their original positions after the work is completed.

[0052] Thin-film force sensor 18: Fixedly embedded inside the gripper finger body 12, it opens and closes synchronously with the gripper finger body. When the gripper closes, the force sensor detects the clamping force in real time and sends the signal to the main control unit.

[0053] The front claw assembly is made of high-strength, lightweight alloy material. Its inner wall curve adopts an asymmetrical arc profile, which is formed by two arc surfaces with different curvatures smoothly spliced ​​together to form a self-centering central envelope area. This envelope area has been verified through extensive testing to adaptively match irregular cross-sections of willow seedlings within a diameter range of 10-40mm.

[0054] II. Control System and Working Logic

[0055] The main control unit presets a safety clamping force threshold (e.g., adjustable from 5-15N) and forms a closed-loop control with the drive mechanism. When the mechanical gripper closes, the thin-film force sensor 18 detects the clamping force in real time; when the clamping force reaches the preset threshold, the main control unit immediately cuts off the power to the drive mechanism, forcibly stopping the gripper closing action. If the clamping force does not reach the threshold but the gripper travel has reached its maximum position, it is determined as a clamping failure and an alarm is triggered.

[0056] The attitude compensation mechanism is equipped with a tilt sensor that collects real-time tilt data of the robot body (including pitch angle, roll angle, etc.) and transmits the data to the main control unit in real time. The main control unit automatically calculates the compensation angle based on the data and drives the three mutually perpendicular rotary joints to move synchronously, precisely adjusting the spatial attitude of the robotic claw to ensure that the sand willow seedlings always maintain a planting posture perpendicular to the horizontal plane, with a compensation response time ≤0.5s.

[0057] III. Action Flow

[0058] The overall motion logic of the robotic arm in this invention follows a fixed sequence of "guide rail positioning—robotic arm extension—robotic gripper envelopment—attitude compensation—transfer and placement—circular dust removal," and is controlled uniformly by the robot's main control system throughout the entire process. The specific execution process is as follows:

[0059] Guide rail positioning: The hollow transmission rod inside the lightweight protective guide rail rotates at a constant speed under the action of the drive motor, driving the slider to make a smooth linear motion along the built-in slide rail, thereby moving the multi-degree-of-freedom modular robotic arm precisely to the position where the sand willow seedlings are to be clamped in the seedling storage box. During this process, the hidden structure of the built-in slide rail and the flexible sealing gasket ensure that the robotic arm operates with low friction and without jamming in a high dust environment.

[0060] Robotic arm extension: The multi-degree-of-freedom modular robotic arm extends synchronously and smoothly through its multi-degree-of-freedom joints, driving the pressure-adaptive flexible robotic claw at the end to slowly approach the willow seedling to be clamped until the claw reaches the preset clamping position. Due to the effect of the triangular stability link structure, the robotic arm can quickly stop vibrating at the moment of positioning, ensuring clamping and positioning accuracy (positioning error ≤1mm).

[0061] Mechanical claw envelopment: The gripping arms of the pressure-adaptive flexible mechanical claw slowly open to their maximum opening under the action of the drive mechanism, smoothly enveloping the willow seedling to be gripped. Subsequently, the drive mechanism drives the gripping arms to slowly and uniformly close, and the asymmetrical arc-shaped inner wall of the front claw assembly guides the willow seedling into the self-centering central envelope area, with the guide protrusions forming multi-point contact support with the seedling's surface. A thin-film force sensor 18 accurately detects the gripping force in real time. When the gripping force reaches the preset safety threshold, the main control unit immediately cuts off the power of the drive mechanism, and the gripping arms stop closing, completing the non-destructive and stable envelopment gripping of the willow seedling.

[0062] Attitude Compensation: The tilt sensor of the attitude compensation mechanism collects the tilt status data of the robot body in real time and transmits it to the main control unit. The main control unit automatically and quickly calculates the compensation angle based on the data, drives the three mutually perpendicular rotary joints to move synchronously, and precisely adjusts the spatial attitude of the mechanical claw to ensure that the sand willow seedlings always maintain a planting posture perpendicular to the horizontal plane.

[0063] Transplanting and Placement: The lightweight protective guide rail and the multi-degree-of-freedom modular robotic arm work together smoothly to drive the robotic gripper to precisely transport the sand willow seedlings held in the gripper to the top of the pre-drilled hole in the desert. After reaching the placement position, the main control unit issues a command, and the drive mechanism drives the gripping arm to slowly and smoothly open, releasing the sand willow seedlings so that they fall vertically and steadily into the drilled hole.

[0064] Circular dust removal: After the delivery action is completed, the multi-degree-of-freedom modular robotic arm drives the slider to reset at a constant speed along the built-in slide rail of the lightweight protective guide rail. During the reset process, the slider reciprocates, changing the air pressure in the slide rail cavity. The air pressure difference is used to automatically discharge any small amount of sand or dust that may accidentally enter the cavity through the upper cleaning micro-holes, completing one automatic dust removal cycle and preparing for the next operation.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pressure-adaptive flexible gripping robotic arm for desert afforestation, characterized in that, The pressure-adaptive flexible gripping robotic arm for desert afforestation includes: The lightweight protective guide rail is fixed to the robot frame by bolts. The lightweight protective guide rail includes a bottom rotating wheel (1) and a built-in dustproof guide rail (2). The bottom rotating wheel (1) is connected to the vehicle body and is driven by the rotating gear of the vehicle body, which plays a role in rotational support. The built-in dustproof guide rail (2) is supported by a cylindrical support that limits rotation and is driven by the rotation of the bottom gear. A multi-degree-of-freedom modular robotic arm, with one end mounted on the lightweight protective guide rail via a slider, is used to provide the robotic claw with multi-degree-of-freedom attitude adjustment and precise position movement; the multi-degree-of-freedom modular robotic arm includes a support rod (4), a triangular rib support (6), a first support robotic arm (7) and a second support robotic arm (8). The lower end of the support rod (4) is hinged to a limiting rotating cylindrical support, and can swing in pitch within a preset limit angle around the hinge point. The triangular rib support (6) is fixedly connected between the support rod (4) and the first support robotic arm (7). The end of the first support robotic arm (7) is hinged to the second support robotic arm (8), and both are driven by matching servo motors. The pressure-adaptive flexible mechanical claw is installed at one end of the multi-degree-of-freedom modular robotic arm and connected to the second support robotic arm (8) via a quick-change pin. It serves as the execution end for grasping seedlings. The pressure-adaptive flexible mechanical claw includes a gripper mounting base (9), which is fixedly connected to the end of the second support robotic arm (8). It acts as a swing joint at the end of the robotic arm, driving the entire gripping mechanism to swing in pitch. At the same time, it serves as the mounting base of the gripping mechanism, transmitting power and motion to the end.

2. The pressure-adaptive flexible gripping robotic arm for desert afforestation according to claim 1, characterized in that, The lightweight protective rail also includes: Dustproof end cap (3) is used to protect the limiting device and the hollow part; The end opening (5) consists of two small openings for removing the rear sand discharge and adding guide rail lubricant; The hollow transmission rod is a thin-walled hollow metal tube structure with a wall thickness of 3-5mm. It is used to rotate at a constant speed under the action of the drive motor, driving the slider to move linearly along the built-in slide rail.

3. The pressure-adaptive flexible gripping robotic arm for desert afforestation according to claim 1, characterized in that, The multi-degree-of-freedom modular robotic arm also includes: The gripper mounting base (9) is fixedly connected to the end of the second support robotic arm (8); Both the first supporting robotic arm (7) and the second supporting robotic arm (8) adopt a hollow lightweight design, and their structures conform to the stress analysis in finite element simulation. At the connection base of the first supporting robotic arm (7) and the second supporting robotic arm (8), as well as at the junction of the robotic arm and the guide rail slider, there are triangular reinforcing rib brackets. Between the support bushing of each rotating joint and the main arm, two reinforcing ribs form a stable triangular force-bearing truss.

4. The pressure-adaptive flexible gripping robotic arm for desert afforestation according to claim 3, characterized in that, The pressure-adaptive flexible mechanical gripper also includes: The synchronous clamping gear pair (10) consists of a pair of meshing cylindrical gears, which are driven to rotate by the drive unit. The gear meshing outputs synchronous and opposite rotational motion, which is used to provide synchronous transmission for the opening and closing of the gripper; the synchronous clamping gear pair (10) is mounted on the gripper mounting base (9); The gripper drive linkage (11) connects the synchronous gripping gear pair (10) and the gripper finger body (12) to convert the rotational motion of the gear into the opening and closing swing of the gripper finger body (12); The gripper fingers (12) clamp and release the seedlings through opening and closing movements; The first cylindrical guide protrusion (13), the second cylindrical guide protrusion (14), and the third cylindrical guide protrusion (15) are respectively arranged on the inner side of the gripper finger body (12) and slide in cooperation with the gripper finger body (12); The first elastic element (16), the second elastic element (17), and the third elastic element (19) are respectively fitted onto the tail of the first cylindrical guide protrusion (13), the second cylindrical guide protrusion (14), and the third cylindrical guide protrusion (15), and the compression and rebound actions are completed synchronously with the extension and retraction of the protrusion. A thin-film force sensor (18) is fixedly embedded inside the gripper finger body (12) and moves synchronously with the gripper finger body (12) to detect the gripping force in real time and feed it back to the main control unit.

5. The pressure-adaptive flexible gripping robotic arm for desert afforestation according to claim 4, characterized in that, The signal from the thin-film force sensor (18) is input to the main control unit, which presets a safety clamping force threshold and forms a closed-loop control with the drive mechanism. When the mechanical gripper closes, the thin-film force sensor (18) detects the clamping force in real time. When the clamping force reaches the preset threshold, the main control unit immediately cuts off the power of the drive mechanism and forcibly stops the gripper closing action.

6. The pressure-adaptive flexible gripping robotic arm for desert afforestation according to claim 1, characterized in that, It also includes an attitude compensation mechanism, which has a tilt sensor to collect the tilt state data of the robot body in real time and transmit the data to the main control unit in real time. The main control unit automatically calculates the compensation angle based on the data and drives three mutually perpendicular rotary joints to move synchronously, so as to accurately adjust the spatial attitude of the mechanical claw and ensure that the sand willow seedling always maintains a planting posture perpendicular to the horizontal plane.

7. The pressure-adaptive flexible gripping robotic arm for desert afforestation according to claim 2, characterized in that, The lightweight protective guide rail also has upper cleaning micro-holes, which are evenly opened at the top of the guide rail column along the axial direction. The cleaning micro-holes are 1-2mm in diameter and are connected to the slide rail cavity inside the housing. A dust filter is installed at the cleaning micro-hole.

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