A lifting-type tea-picking robot

Abstract

This invention discloses a lifting-type tea-picking robot, relating to the fields of agricultural machinery and robotics. It includes a base on which two sets of robotic arms are mounted. Each robotic arm includes a base joint, shoulder joint, elbow joint, wrist rotation joint, wrist deflection joint, and an end effector. The left arm is responsible for lifting, and its end effector, equipped with a parallel-drive lifting end effector, stabilizes the tea bush and reduces swaying during picking. A sponge is attached to the gripper head to minimize damage to the tea bush during operation. The right arm is responsible for picking, and its end effector, driven by a reciprocating electromagnet, precisely picks tea leaves, thus avoiding damage to the tea bush. This invention employs a dual-arm lifting-picking method, improving picking efficiency while ensuring the integrity of the tender buds and avoiding damage to other tea leaves and the tea bush. The high degree of freedom also enhances the applicability and reliability of the tea-picking robot.

Description

Technical Field

[0001] This invention belongs to the field of agricultural machinery and robotics technology, and relates to a lifting-type tea-picking robot. Background Technology

[0002] Manual tea picking is prone to inconsistencies in tea quality and damage to tea trees due to human factors. To address these challenges, a large number of automated tea-picking devices have emerged on the market. While these devices have improved picking efficiency to some extent, most only have simple picking functions and still lack protective measures for tea trees, easily causing damage to tea tree branches and affecting the long-term health of the tea trees. In addition, these devices have limited resistance to environmental interference and are unable to meet the needs of different tea varieties and complex tea garden environments. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to propose a lifting-type tea-picking robot, which uses one robotic arm to hold tea tree branches while another robotic arm performs precise picking, thereby improving tea-picking efficiency and reducing damage to the tea trees.

[0004] The technical solution of the present invention is as follows: The present invention provides a lifting-type tea-picking robot, which includes a base. Two sets of mechanical arms, left (lifting) and right (picking), are arranged on the top left and right sides of the base. The base joints are connected to the transmission shaft by a key. From top to bottom, there are spring washers, upper angular contact bearings, bushings, gears, and angular contact bearings, etc. The angular contact bearing is limited by the internal structure of the base, spring washers, and bushings. The gears are limited by keys and bushings; a first stepper motor is mounted at the rear of the base, and the first stepper motor and the first gear are directly connected by keyways and screws; the three gears are connected by axes and arranged in parallel to each other to form a parallel connection, which can realize synchronous transmission of the two robotic arms.

[0005] Furthermore, the shoulder joint has open sides, and two stepper motors are installed adjacent to each other using bolts. The stepper motors drive harmonic reducers through synchronous pulleys and synchronous belts, and the stepper motors and synchronous pulleys are directly fastened with screws. The harmonic reducers are connected to the base joint and the elbow joint respectively, enabling the shoulder joint and elbow joint to move up and down. In the lifting tea-picking robot, placing the stepper motors as centrally as possible on the shoulder joint makes the end effector lighter and more flexible, improving picking efficiency and accuracy.

[0006] Furthermore, a rectangular slot is opened above the elbow joint, into which the extended elbow joint end is inserted and fixed with screws. The stepper motor on the extended elbow joint is placed as close to the elbow joint as possible, and a harmonic reducer is driven by a synchronous pulley and synchronous belt. The harmonic reducer is connected to the wrist rotation joint, allowing the wrist rotation joint to move left and right. This further reduces the end effector load and greatly simplifies the structural design.

[0007] Furthermore, the wrist rotation joint uses bolts to fix a stepper motor, which is directly connected to a long U-shaped bracket via a key. A servo disc is bolted to both sides of the long U-shaped bracket, and the servo disc is connected to a servo motor. A short U-shaped bracket is bolted to the other end of the servo motor. This structure forms a wrist deflection joint, enabling rotational and left-right deflection movements of the end effector. The increased degrees of freedom allow for complex operations and movement paths.

[0008] Furthermore, the end effector is divided into a lifting end effector (left robotic arm) and a picking end effector (right robotic arm).

[0009] Furthermore, the lifting end effector includes a lifting end effector frame, with two lifting end effector drive links symmetrically arranged on the upper end of the lifting end effector frame. A servo bracket is mounted on the upper end of the lifting end effector drive link, and the servo is installed in the middle of the servo bracket and drives the lifting end effector drive link using a servo shaft. Lifting end effector driver links are symmetrically hinged to the front end of the lifting end effector frame. Lifting end effector grippers are hinged to the front sections of the lifting end effector drive link and the lifting end effector link. A sponge is adhered to the inner side of the lifting end effector gripper. The lifting end effector can support the tea tree branches to stabilize the tea tree and reduce shaking, while the sponge can prevent damage to the branches.

[0010] Furthermore, the harvesting end effector includes a collection box, on which a reciprocating electromagnet is fixed by bolts at the upper end. The output end of the reciprocating electromagnet push rod is hinged to a harvesting end effector connecting rod. The other end of the end effector connecting rod is hinged to the top of the moving blade. Moving blade-reset spring connectors are hinged at both ends of the moving blade. Electromagnet-reset spring connectors are fixed to both sides of the reciprocating electromagnet by screws. The moving blade-reset spring connectors are connected to the corresponding electromagnet-reset spring connectors through reset springs.

[0011] Furthermore, the visual camera is bolted to a long U-shaped bracket.

[0012] Furthermore, bolt holes are provided around the base to facilitate transplantation to other equipment, and testing tools and equipment can be installed.

[0013] The beneficial effects of this invention are: 1. The lifting tea-picking robot is equipped with two sets of robotic arms, left and right. The left robotic arm is responsible for lifting tea tree branches, while the right robotic arm is responsible for precise picking. This makes the picking process more efficient, reduces the waiting and switching time when operating a single robotic arm, and significantly improves the overall tea-picking efficiency. (Improved tea-picking efficiency); 2. The sponge adhering to the inner side of the end effector gripper further reduces damage to the tea tree and ensures the long-term health of the tea tree. (Reduces tea tree damage); 3. The wrist deflection joint design increases the degree of freedom of the end effector, enabling complex operations and movement paths. This allows the robot to maintain stable operation even when facing various environmental disturbances, improving adaptability and reliability. (Enhanced applicability). Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a front view of the bottom transmission mechanism in this invention; Figure 3 yes Figure 2 Top view; Figure 4 This is an exploded view of the robotic arm structure in this invention; Figure 5 This is a schematic diagram of the lifting mechanism in this invention; Figure 6 This is a schematic diagram of the harvesting mechanism in this invention; In the diagram: 1 is the base; 2a is the first stepper motor, 2b is the second stepper motor, 2c is the third stepper motor, 3a is the first gear, 3b is the second gear, 4 is the drive shaft, 5 is the bushing, 6 is the angular contact bearing, 7 is the spring washer, 8 is the base joint, 9 is the shoulder joint, 10 is the synchronous pulley, 11 is the synchronous belt, 12 is the harmonic reducer, 13 is the elbow joint, 14 is the extended elbow joint, 15 is the wrist rotation joint, 16a is the long U-shaped bracket, 16b is the short U-shaped bracket, and 16c is the servo motor. 16d is the servo disc, 16e is the servo motor bracket, 17 is the vision camera, 18 is the lifting end effector frame, 19 is the lifting end effector drive linkage, 20 is the lifting end effector gripper head, 21 is the sponge body, 22 is the lifting end effector linkage, 23 is the reciprocating electromagnet, 24 is the electromagnet-return spring connector, 25 is the return spring; 26 is the moving blade-return spring connector, 27 is the picking end effector linkage; 28 is the moving blade, 29 is the stationary blade, and 30 is the data acquisition box. Detailed Implementation

[0015] The specific technical solution of the present invention will be further described in detail below with reference to specific examples.

[0016] As shown in the figure, the lifting tea-picking robot of the present invention includes a base 1. Two sets of mechanical arms, left (lifting) and right (picking), are arranged on the top left and right sides of the base 1. The base joint 8 is connected to the transmission shaft 4 by a key. A spring washer 7 is arranged on the transmission shaft 4 and below the base joint 8. An angular contact bearing 6 is arranged at the lower end of the spring washer 7. The upper end of the angular contact bearing 6 is limited by the spring washer 7, and the lower end is limited by the bushing 5 and the internal structure of the base 1. A bushing 5 is connected to the lower end of each of the angular contact bearings 6. A second gear 3b is provided at the lower end of each of the two bushings 5. The second gear 3b is connected to the transmission shaft 4 by a key. Its upper end is limited by the bushing 5 and its lower end is limited by the shaft shoulder. The lower end of the gear 3b is the angular contact bearing 6. Here, the upper end of the angular contact bearing 6 is limited by the shaft shoulder and the lower end is limited by the internal structure of the base 1.

[0017] A first stepper motor 2a is fixed to the rear end of the base 1 by screws. The first stepper motor 2a is a closed-loop stepper motor of model 86BYG250B, and the corresponding driver model is DM860H. The first stepper motor 2a is directly connected to the first gear 3a through a keyway and screws. The three gears (two second gears 3b and one first gear 3a) are connected by an axis and arranged in parallel to each other to form a parallel connection, which can realize the synchronous transmission of the two robotic arms and more realistically simulate human behavior.

[0018] like Figure 4 As shown, a shoulder joint 9 is connected to the upper end of the base joint 8. The shoulder joint 9 has open sides, and a first stepper motor 2a and a second stepper motor 2b are mounted on its back side via bolts. The shaft ends of the first stepper motor 2a and the second stepper motor 2b are directly fastened to the synchronous pulleys 10 with screws. The second stepper motor 2b is a model HSTM57 stepper motor, and the synchronous pulley 10 is a model 2GTS8M synchronous pulley. The synchronous pulleys 10 are mounted on the upper and lower ends of the synchronous belt 11, which is a model 2GTAT5 belt. The first stepper motor 2a and the second stepper motor 2b are connected to the synchronous belt 11 via the synchronous pulleys 10. The harmonic reducer 12 is a model GSF-05-XX-1U, which is ultra-small in size and has an ultra-long lifespan. The harmonic reducer 12 driven by the first stepper motor 2a is connected to the base joint 8 by screws, which can realize the up and down movement of the shoulder joint 9. The harmonic reducer 12 driven by the second stepper motor 2b is connected to the elbow joint 13 by screws, which can realize the up and down movement of the elbow joint 13. By arranging the first stepper motor 2a and the second stepper motor 2b as close as possible to the shoulder joint 9, the working pressure on the elbow joint 13 can be reduced, making the end more lightweight and flexible, and improving harvesting efficiency and accuracy.

[0019] An extended elbow joint 14 is fixed to the upper end of the elbow joint 13 by a pre-set groove and screws. A third stepper motor 2c is bolted to the inner side of the extended elbow joint 14. The third stepper motor 2c is a stepper motor of model HSTM42. The wrist rotation joint 15 is controlled by the third stepper motor 2c driving the harmonic reducer through the synchronous pulley 10 and the synchronous belt 11. This allows the wrist rotation joint 15 to move left and right. Both robotic arms rotate inward to better simulate manual tea picking. At the same time, the design of the stepper motor structure further reduces the end load and improves picking efficiency and accuracy.

[0020] A third stepper motor 2c is bolted to the inner side of the bottom end of the wrist rotation joint 15. The third stepper motor 2c is directly connected to the long U-bracket 16b via a key. A servo disk 16d is symmetrically installed inside the long U-bracket 16b and is connected internally via the shaft of a servo motor 16c. The servo motor 16c is a dual-axis servo motor of model RDS3115-30kg, which has a large torque and is highly responsive. The other side of the servo motor 16c is connected to the short U-bracket 16b via screws. These devices form a wrist deflection joint, which can realize the left and right deflection movement of the end effector, thereby giving the end effector more degrees of freedom, enabling more complex operations, and better path planning.

[0021] Two sets of robotic arms are symmetrically distributed at the top of the base 1. The left robotic arm has a picking end effector at its end, and the right robotic arm has a lifting end effector at its end.

[0022] like Figure 5 As shown, the short U-shaped bracket 16b at the end of the wrist rotation joint 15 is connected to the servo bracket 16e by bolts. A servo motor 16c is installed inside the servo bracket 16e. The bottom of the servo motor 16c is symmetrically connected to the lifting end effector drive linkage 19 through the servo motor axis. The two lifting end effector drive linkages 19 move by transmitting torque through gears. A lifting end effector frame 18 is installed at its bottom end. Four lifting end effector linkages 22 are symmetrically hinged to the front end of the lifting end effector frame 18. The lifting end effector linkages 22 clamp and hinge the lifting end effector gripper head 20. A sponge 21 is adhered inside the lifting end effector gripper head 20. The sponge 21 can effectively protect the tea tree branches and avoid damage to the tea tree caused by excessive bearing force. The lifting end effector can assist the tea tree branches to stabilize the tea tree and reduce shaking, and minimize external interference to the harvesting end effector.

[0023] like Figure 6As shown, the short U-shaped bracket 16b at the end of the wrist rotation joint 15 is connected to the short U-shaped bracket 16b of the harvesting end effector by a cross bolt. A collection box 30 is bolted to the inner side of the short U-shaped bracket 16b. A reciprocating electromagnet 23, model LSD-1564B, is fixed to the top of the collection box 30 by screws. Compared to pneumatic or hydraulic actuators, it has stronger programmability and can output more accurate harvesting force. A harvesting end effector connecting rod 27 is hinged to the push rod output end of the reciprocating electromagnet 23. The other end of the harvesting end effector connecting rod 27 is hinged to the top of the moving blade 28. On both sides of the top of the moving blade 28... A movable blade-reset spring connector 26 is hinged to the reciprocating electromagnet 23, and electromagnet-reset spring connectors 24 are fixed to both sides of the electromagnet 23 by screws. The movable blade-reset spring connector 26 and the corresponding electromagnet-reset spring connector 24 are connected by a reset spring 25. A stationary blade 29 is hinged to the bottom front side of the collection box 30. The rear end of the collection box 30 is connected to the air tube to transport the collected tea leaves. The collection box 30 is made of transparent PC material, which has the characteristics of heat resistance and impact resistance. At the same time, the transparent material can minimize interference with the image captured by the vision camera 17. This demonstrates that the picking device has the advantages of high efficiency, high precision, and reduced damage to tea trees.

[0024] A vision camera 17 is bolted to the upper end of the long U-shaped bracket 16b at the end of the wrist rotation joint 15. The vision camera 17 is an Astra Pro Plus depth camera, which provides depth ranging detection and can be used for accurate attitude estimation, virtual reality, 3D reconstruction and other tasks. It has high precision and significant advantages in complex environments.

[0025] In addition, threaded holes are pre-set around the base 1 to facilitate transplantation to other equipment for installing tool storage boxes, etc., which facilitates daily inspection and maintenance of the robot.

[0026] The CPU22 was selected as the control hardware system, and the EM223 was selected as the I / O expansion module. Siemens' built-in programming software can be used to design the overall control system of the tea-picking robot. The control program in this design is divided into four main parts: the main program, the reset program, the automatic loop program, and the protection program. The reset program activates just before the tea-picking robot begins work, restoring the left and right robotic arms, the lifting end effector, and the picking end effector to their default positions. Once all components of the tea-picking robot have reset to their default positions, the main program starts running, and the tea-picking robot begins its cyclical picking operation. The protection program is used to prevent damage to the tea-picking robot in case of a malfunction in the control system, allowing all parts of the machine to return to their preset normal operating state.

[0027] The working principle of this invention is as follows: A lifting-type tea-picking robot is placed at the front end of a tea tree. A vision camera 17 on the upper end of the long U-shaped support 16b captures images of the tea tree and its surrounding environment. Based on image processing algorithms, the image data is analyzed to identify the position and maturity of the tea leaves. This invention is mainly for picking premium teas, so shape recognition is chosen here. Based on the image processing results, the system calculates the three-dimensional coordinates of the tea leaves and sequentially marks the three-dimensional coordinates of the upper branches of the tea leaves, ultimately generating a picking path. Three stepper motors and the servo motors 16c at the end of the wrist flip joint 15 are driven simultaneously to adjust the position of the left and right robotic arms. Then, the vision cameras 17 on the left and right robotic arms continuously identify tea tree-related information. The left robotic arm moves to the designated coordinates according to the three-dimensional coordinates of the branches, and the servo motor 16c of the lifting end effector works, driving the lifting end effector linkage. Drive 19, causing the lifting end effector gripper 20 to move, ultimately clamping the tea tree branch and ensuring its stability. Simultaneously, based on the information of the tea tree branch on the left arm, the three-dimensional coordinates of the tea leaves on the corresponding branch are selected, allowing the buds to enter the opening of the collection box 30. After visual imaging and recognition confirms the accuracy, the reciprocating electromagnet 23 on the collection box 30 is energized. The push rod of the reciprocating electromagnet 23 pushes the moving blade 28 to close, which, together with the stationary blade 29, cuts off the bud and lifts it into the collection box 30. Immediately afterwards, the reciprocating electromagnet 23 is de-energized, and under the action of the return spring 25, the moving blade 28 quickly returns to its original position and opens. To reduce the impact of contact between tea leaves or external factors such as wind during the picking process, the visual camera 17 needs to continuously identify and update, thus repeating the process to pick the next bud.

[0028] This lifting-type tea-picking robot uses the left hand to lift the tea tree and the right hand to pick the tea leaves. Through a vision detection system, advanced robotic arm design, and efficient control system, it can achieve efficient, precise, and low-damage picking of tea leaves, while minimizing the impact of external factors on the tea leaves.

Claims

1. A lifting-type tea-picking robot, comprising a base (1), characterized in that, A left robotic arm and a right robotic arm are respectively installed on the left and right sides of the top of the base (1). A base joint (8) is installed on the lower side of both the left and right robotic arms. A drive shaft (4) is installed on the lower side of both base joints (8). Both base joints (8) and drive shafts (4) are connected by keys. The base joint (8) of the left robotic arm and the connected drive shaft (4) are connected from top to bottom to a spring washer (7), an upper angular contact bearing, a second gear (3b) and an angular contact bearing (6). The base joint (8) of the right robotic arm and the connected drive shaft (4) are connected from top to bottom to a spring washer (7), an upper angular contact bearing, a second gear (3b) and an angular contact bearing (6). A first stepper motor (2a) is installed at the rear of the top of the base (1) and on the side near the right robotic arm. A first gear (3a) is installed at the lower end of the first stepper motor (2a). The first stepper motor (2a) and the first gear (3a) are connected by a keyway and screws. A bushing (5) is installed on the lower side of each of the angular contact bearings (6); The second gear (3b) on the left and right robotic arms is limited by a key and a bushing (5) to the connected transmission shaft (4); The three gears, namely the second gear (3b) at the left robotic arm, the first gear (3a) and the second gear (3b) at the right robotic arm, are connected by an axis and arranged in parallel to each other to form a parallel connection. The drive shaft (4), spring washer (7), first gear (3a), second gears (3b) on both sides, and angular contact bearings (6) on both sides are limited and placed inside the base (1) by the connected bushings (5); Both sides of the base joint (8) are connected to the hollow shoulder joint (9) and elbow joint (13). The second stepper motor (2b) is fixed to the shoulder joint (9) with bolts. The second stepper motor (2b) drives the harmonic reducer (12) connected by a synchronous pulley (10) and a synchronous belt (11). The second stepper motor (2b) and the synchronous pulley (10) are directly fastened with screws. The harmonic reducer (12) is connected to the base joint (8) and the elbow joint (13) respectively. A rectangular slot is provided above the elbow joint (13), and an extended elbow joint (14) is placed in the rectangular slot. The end of the extended elbow joint (14) is inserted into the rectangular slot and fixed with screws. A third stepper motor (2c) is placed on the extended elbow joint (14) near the elbow joint (13). The third stepper motor (2c) is also driven by a harmonic reducer (12) connected by a separately placed synchronous pulley (10) and synchronous belt (11). The harmonic reducer (12) is connected to a wrist rotation joint (15). A stepper motor is installed at the wrist rotation joint (15). The stepper motor is fixed to the wrist rotation joint (15) with bolts. The stepper motor is connected to a long U-shaped bracket (16a) via a key. A servo disk (16d) is fixed to both sides of the inside of the long U-shaped bracket (16a) with bolts. A servo motor (16c) is connected to the servo disk (16d). A short U-shaped bracket (16b) is fixed to the other end of the servo motor (16c) with bolts. A vision camera (17) is also mounted on the long U-shaped bracket (16a) by bolts. An end effector is installed at the lower end of each of the long U-shaped supports (16a). The end effector installed on the right robotic arm is a picking end effector, and the end effector installed on the left robotic arm is a lifting end effector. The lifting end effector includes a lifting end effector frame (18), two lifting end effector drive links (19) are symmetrically arranged at the upper end of the lifting end effector frame (18), a servo bracket (16e) is arranged at the upper end of the lifting end effector drive links (19), a servo (16c) is arranged at the middle position of the servo bracket (16e), and the lifting end effector drive links (19) are driven by the servo shaft of the servo (16c). Two lifting end effector links (22) are symmetrically hinged at the front end of the lifting end effector frame (18), and lifting end effector grippers (20) are hinged at the front end of the lifting end effector drive links (19) and the lifting end effector links (22). A sponge (21) is adhered to the inner side of the lifting end effector grippers (20). The harvesting end effector includes a collection box (30), and a reciprocating electromagnet (23) is fixed to the upper end of the collection box (30) by bolts. The reciprocating electromagnet (23) is hinged to the output end of the reciprocating electromagnet push rod and a harvesting end effector connecting rod (27). A moving blade (28) is hinged to the other end of the harvesting end effector connecting rod (27) and is connected to the top of the moving blade (28). The moving blade (28) is hinged to both ends with a moving blade-reset spring connector (26). Electromagnet-reset spring connectors (24) are fixedly mounted on both sides of the reciprocating electromagnet (23) by screws. The moving blade-reset spring connector (26) and the corresponding electromagnet-reset spring connector (24) are connected by a reset spring (25); A stationary blade (29) is placed on the side of the collection box (30) near the moving blade (28); The side wall of the acquisition box (30) is connected to the corresponding short U-shaped bracket (16b); Bolt holes are provided around the base (1).

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