A strawberry picking end effector that integrates support, shearing, and clamping.

Abstract

This invention relates to agricultural and forestry machinery, specifically an integrated strawberry harvesting end effector that combines support, shearing, and clamping. The aim is to provide an integrated strawberry harvesting end effector that is easy to use, highly efficient, compact in structure, and low in manufacturing cost. The technical solution is an integrated strawberry harvesting end effector that includes a connecting base for connecting to the robotic arm of a strawberry harvesting robot; its key feature is that it further includes a base shell connected to the connecting base, and shearing and clamping mechanisms and a support mechanism correspondingly mounted on the base shell.

Description

Technical Field

[0001] This invention relates to agricultural and forestry machinery, specifically a strawberry picking end effector that integrates support, shearing, and clamping. Background Technology

[0002] Traditional end effectors, when harvesting field-grown strawberries, are prone to collisions with branches, mulch, and surrounding fruit during the gripping action, leading to harvesting failures. Furthermore, the delicate and irregularly shaped skin of strawberries makes it difficult for traditional gripping structures to provide flexible support, causing the fruit to fall or resulting in excessive localized pressure, causing bruising and skin damage. While existing gripping-shearing actuators can cut the fruit stem, the support and shearing are not synchronized, resulting in poor movement stability and an inability to adapt to complex harvesting environments with foliage obstruction. Composite actuators are bulky and slow to respond, making it difficult to simultaneously meet the requirements of damage-free harvesting and efficient operation. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and provide an integrated strawberry picking end effector that supports, cuts, and clamps; this end effector is characterized by its ease of use, high working efficiency, compact structure, and low manufacturing cost.

[0004] The technical solution provided by this invention is: A strawberry picking end effector integrating support, shearing, and clamping includes a connecting base connected to the robotic arm of a strawberry picking robot; characterized in that it further includes a base shell connected to the connecting base and shearing clamping mechanism and support mechanism correspondingly installed on the base shell; The shearing and clamping mechanism includes a shearing servo motor, two shearing fingers driven by the shearing servo motor through a pair of gears and connecting rods, and two blades mounted on the two shearing fingers to cut the strawberry stems. The supporting mechanism includes a supporting servo motor, a transmission gear and a transmission rack driven by the supporting servo motor, and a supporting claw driven by the transmission rack through a supporting connecting rod, so as to realize the gathering and lifting of the fruit to be picked.

[0005] The pair of gear connecting rods are a driving gear connecting rod and a driven gear connecting rod with the same structure and symmetrical arrangement; each gear connecting rod is a gear and connecting rod integrally formed structure, and the end of the gear connecting rod away from the gear is provided with a hinge fork, and a finger-clamping hinge hole is made on the hinge fork, and the gears in the two gear connecting rods mesh with each other.

[0006] One end of each of the two shearing fingers is hinged to the driving gear connecting rod and the driven gear connecting rod, respectively. The other end of each of the two shearing fingers serves as a clamping finger. The two blades face each other and are fixed to the clamping fingers of the two shearing fingers, respectively. One end of each of the two shearing pull rods is hinged to the middle of the shearing fingers, and the other end is hinged to the shearing base.

[0007] The supporting servo motor is fixed on the supporting base and the output shaft is arranged horizontally.

[0008] The transmission rack is horizontally movable and positioned on the support base, and meshes with the transmission gear; the transmission gear is fixed on the output shaft of the supporting servo motor.

[0009] One end of the transmission rack is hinged to one end of each of the two pairs of supporting rods; the other ends of the two pairs of supporting rods are respectively hinged to the middle of the supporting claws; one end of the supporting claw is hinged to the supporting base, and the other end is used to lift the fruit.

[0010] In each pair of supporting links: two supporting links are hinged to one supporting claw, and the hinge axes of the supporting links and supporting claws are parallel to each other and inclined to the horizontal plane; the two pairs of supporting links and the hinged supporting claws are arranged symmetrically so that when they open, they tilt and move downward and backward to both sides, and when they close, they extend forward and upward simultaneously, so as to achieve smooth closing of the fruit from far to near.

[0011] The supporting link, supporting claw, transmission rack, and supporting base form a quadrilateral linkage mechanism.

[0012] The support claw is an arc-shaped sheet structure and is made of thermoplastic polyurethane (TPU).

[0013] The beneficial effects of this invention are: (1) The shearing clamping mechanism and the supporting mechanism in this invention are arranged in layers. The supporting claw first forms a flexible support for the strawberry, which completely solves the problem of fruit falling during the picking process. At the same time, it avoids the collision and interference between the end effector and branches, leaves and mulch. It is particularly suitable for picking operations in complex environments of ground-planted strawberries.

[0014] (2) The active gear connecting rod and the driven gear connecting rod in the shearing and clamping mechanism are both integrally formed gear connecting rod structures. Combined with the quadrilateral connecting rod mechanism, it ensures that the opening and closing posture of the shearing clamp finger is stable, and the blade completes the cutting and clamping of the fruit stem simultaneously. The supporting claw is an arc-shaped structure that fits the shape of the strawberry fruit, avoiding excessive local pressure that could damage the fruit skin and achieving non-destructive harvesting.

[0015] (3) The support mechanism adopts a flexible support design and achieves compound motion through quadrilateral linkage transmission. The support claws extend forward simultaneously while closing, which can smoothly gather the fruit from far to near into the support claws, greatly improving the support fit and fruit grasping stability, and further reducing the harvesting damage rate.

[0016] (4) The present invention adopts dual servo motors for independent drive. The shearing mechanism is driven by gear meshing and the supporting mechanism is driven by gear rack. The power transmission is smooth. The whole is equipped with only two power sources, which makes the control simple. The overall structure is compact, with few parts and low manufacturing cost, and is suitable for automated strawberry picking operations.

[0017] (5) The base shell of the present invention is provided with three main connecting holes and one auxiliary fixing hole. The connecting base can be assembled and fixed by one of the main connecting holes and reinforced with the auxiliary fixing hole. The picking angle and posture of the end effector can be flexibly adjusted to meet the picking needs of strawberries with different growth postures. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present invention.

[0019] Figure 2 This is an isometric schematic diagram of an embodiment of the present invention (the connecting base is hidden).

[0020] Figure 3 for Figure 1 A three-dimensional structural diagram of the shearing and clamping mechanism.

[0021] Figure 4 for Figure 1 A schematic diagram illustrating the connection relationship between the gear connecting rod, the shearing rod, and the shearing clamp finger in the embodiment.

[0022] Figure 5 for Figure 4 The diagram shows the connection relationship between the components, the shear base, and the shear servo motor.

[0023] Figure 6 for Figure 1 A schematic diagram of the main structure of the support mechanism in the embodiment.

[0024] Figure 7 for Figure 6 A top-down structural diagram (rotated 90 degrees counterclockwise).

[0025] Figure 8 for Figure 7 A schematic diagram of the structure viewed from below.

[0026] Figure 9 for Figure 8 A partial sectional view.

[0027] Figure 10 This is one of the working state diagrams of an embodiment of the present invention (the supporting mechanism is in front of the fruit).

[0028] Figure 11 This is the second working state diagram of an embodiment of the present invention (the supporting mechanism supports the fruit, and the shearing clamping mechanism shears the fruit stem).

[0029] Figure label: 1. Base housing; 11. Main connecting hole; 12. Auxiliary fixing hole; 2. Shearing clamping mechanism; 21. Shearing servo; 22. Shearing base; 222. Base connecting hole; 223. Rear pull rod hinge hole; 23. Drive gear connecting rod; 231. Finger hinge hole; 24. Driven gear connecting rod; 25. Shearing pull rod; 251. Front pull rod hinge hole; 26. Shearing finger; 27. Blade; 3. Support mechanism; 31. Supporting servo; 32. Supporting base; 321. Fixed mounting hole; 322. Middle hinge hole; 33. Transmission gear; 34. Transmission rack; 341. Rack hinge hole; 35. Supporting connecting rod; 351. Claw hinge hole; 36. Supporting claw; 4. Connecting base. Detailed Implementation

[0030] by Figure 1 To accurately determine orientation: the positive and negative directions of the x-axis are right; the positive and negative directions of the y-axis are front and back; and the positive and negative directions of the z-axis are up and down.

[0031] The following description, in conjunction with the embodiments shown in the accompanying drawings, provides further details.

[0032] Figure 1 , Figure 2 The end effector shown includes a base shell 1, a shearing and clamping mechanism 2 and a supporting mechanism 3 arranged on the upper and lower layers of the base shell, and a connecting base 4 connecting the base shell to the strawberry picking robot arm. The base shell 1 has three main connecting holes 11 and one auxiliary fixing hole 12 on its left and right sides, respectively. Connecting rods fixed to both sides of the connecting base 4 are fixed to the base shell 1 via bolts through one of the main connecting holes 11. The auxiliary fixing hole 12 is used to assist in fixing the base shell to the connecting base 4 via bolts. The shearing base 22 of the shearing and clamping mechanism 2 and the supporting base 32 of the supporting mechanism 3 are respectively fixed to the upper and lower layers inside the base shell 1 via bolts. The two sets of mechanisms are installed independently and do not interfere with each other.

[0033] like Figure 3 , Figure 4 , Figure 5As shown: In the shearing clamping mechanism 2, the shearing servo motor 21 is fixed to the shearing base 22 by bolts, and the output shaft of the shearing servo motor 21 is fixed to the drive gear connecting rod 23 by a round flange; the drive gear connecting rod 23 is a gear and connecting rod integrally formed structure, and the end of the gear connecting rod away from the gear is provided with a hinge fork, and the hinge fork is provided with a finger-clamping hinge hole 231; the driven gear connecting rod 24 is also of the same structure: the gear and connecting rod are integrally formed structure, and the end of the gear connecting rod away from the gear is provided with a hinge fork, and the hinge fork is provided with a finger-clamping hinge hole 231; the drive gear and the driven gear mesh with each other, and the driven gear connecting rod 24 is hinged to the driven gear hinge hole 224 of the shearing base 22 by a pin. One end of each of the two shearing fingers 26 is hinged to the finger hinge hole 231 of the driving gear connecting rod 23 and the finger hinge hole 231 of the driven gear connecting rod 24, respectively, via pins. One end of each of the two shearing pull rods 25 is hinged to the middle of the shearing fingers 26 via the front pull rod junction hole 251, and the other end is hinged to the shearing base 22 via the rear pull rod hinge hole 223. The other end of each of the two shearing fingers serves as a clamping finger, and the two blades 27 face each other and are fixed to the top of the clamping fingers of the two shearing fingers 26 with countersunk bolts. When the shearing servo is started, the two shearing fingers can be driven to open or close via the two gear connecting rods, and the two blades remain parallel to each other during the opening and closing of the two shearing fingers.

[0034] like Figures 6 to 9 As shown: In the support mechanism 3, the support servo motor 31 is fixed to the support base 32 by bolts passing through the servo motor mounting hole 324 of the support base 32, and the output shaft is arranged horizontally (the output shaft axis is parallel to the x-axis); the transmission gear 33 is fixedly connected to the output shaft of the support servo motor 31 by bolts; the support base 32 is also horizontally provided with a mounting slot hole 323, and the transmission rack 34 is horizontally movable (the moving axis is parallel to the y-axis) and installed in the mounting slot hole 323; the transmission gear 33 and the transmission rack 34 mesh with each other; the hinge hole 341 at one end of the transmission rack 34 is respectively hinged to one end of two pairs of support connecting rods 35 by pins, and the other end of the two pairs of support connecting rods 35 is respectively hinged to the claw hinge hole 351 in the middle of the two support claws 36 by pins; one end of the two support claws 36 is respectively hinged to the middle hinge hole 322 in the support base 32 by pins, and the other end of the two support claws 36 is used to support the fruit. In each pair of supporting links: two supporting links are hinged to the corresponding two sides of a supporting claw, and the hinge axes of the supporting links and the supporting claw are parallel to each other and inclined to the horizontal plane (the plane passing through the x and y axes); (from Figure 6 , Figure 7It can be seen that the two pairs of supporting links and the hinged supporting claws are symmetrically arranged. The supporting links, supporting claws, transmission racks, and supporting base form a quadrilateral linkage mechanism. The supporting mechanism uses a quadrilateral linkage mechanism to achieve flexible supporting composite motion. When the supporting links 35 open, the two symmetrical supporting claws 36 tilt and move downward and backward to both sides respectively, and when they close, they extend forward and upward simultaneously, smoothly gathering the fruit from far to near into the supporting claws. The supporting claws 36 are arc-shaped sheet structures made of thermoplastic polyurethane (TPU) to protect the harvested fruit and prevent damage.

[0035] Before the invention is put into operation, the connecting base 4 is first installed on the robotic arm of the strawberry picking robot. The connecting base 4 can be fixed to the main connecting hole 11 of the base shell 1 according to the strawberry's growth posture. The picking angle of the end effector is adjusted, and the assembly is reinforced through the auxiliary fixing hole 12. Then, the vision system (existing technology) on the strawberry picking robot's robotic arm identifies when the end effector approaches the strawberry (see...). Figure 10 The supporting mechanism 3 and the shearing clamping mechanism 2 are in the open state. During operation, the supporting servo motor 31 drives the transmission gear 33 to rotate, which in turn drives the transmission rack 34 installed in the mounting slot hole 323 to move. The supporting connecting rod 35 drives the supporting claw 36 to perform a flexible supporting movement of closing and extending forward, gathering and flexibly lifting the fruit from far to near. Subsequently, the shearing servo motor 21 drives the driving gear connecting rod 23 to rotate, and the driven gear connecting rod 24 meshes and rotates synchronously. The shearing pull rod 25 constrains the transmission trajectory, the shearing clamping finger 26 closes smoothly, and the blade 27 simultaneously cuts the fruit stem and completes the clamping (see...). Figure 11 After harvesting, the shearing servo motor 21 and the supporting servo motor 31 rotate in opposite directions, the shearing gripper 26 and the supporting claw 36 reset and unfold, and the strawberries fall smoothly, preparing for the next harvest.

Claims

1. A strawberry picking end effector integrating support, shearing, and clamping, comprising a connecting base (4) for connecting to the robotic arm of a strawberry picking robot; characterized in that: It also includes a base shell (1) that connects to the connecting base, and a shearing clamping mechanism (2) and a supporting mechanism (3) that are installed on the base shell respectively. The shearing clamping mechanism (2) includes a support servo motor (21), two shearing fingers (26) driven by the shearing servo motor through a pair of gears and connecting rods, and two blades (27) mounted on the two shearing fingers to cut the strawberry stem; The supporting mechanism (3) includes a supporting servo motor (31), a transmission gear (33) and a transmission rack (34) driven by the supporting servo motor, and a supporting claw (36) driven by the transmission rack through a supporting connecting rod, so as to realize the gathering and lifting of the fruit to be picked.

2. The integrated strawberry picking end effector with support-cutting-clamping as described in claim 1, characterized in that: The pair of gear connecting rods are a driving gear connecting rod (23) and a driven gear connecting rod (24) with the same structure and symmetrical arrangement; each gear connecting rod is a gear and connecting rod integrally formed structure, and the end of the gear connecting rod away from the gear is provided with a hinge fork, and a finger-clamping hinge hole (231) is made on the hinge fork, and the gears in the two gear connecting rods mesh with each other.

3. The integrated strawberry picking end effector with support-cutting-clamping mechanism according to claim 2, characterized in that: One end of each of the two shearing levers (25) is hinged to the middle of the shearing clamp (26), and the other end is hinged to the shearing base (22); the other end of each of the two shearing clamps serves as a clamping finger, and the two blades (27) face each other and are fixed on the clamping fingers of the two shearing clamps (26).

4. The integrated strawberry picking end effector with support-cutting-clamping mechanism according to claim 3, characterized in that: The supporting servo motor (31) is fixed on the supporting base (32) and the output shaft is arranged horizontally.

5. The integrated strawberry picking end effector with support-cutting-clamping mechanism according to claim 4, characterized in that: The transmission rack (34) is horizontally movable and positioned on the support base (32) and meshes with the transmission gear; the transmission gear (33) is fixedly connected to the output shaft of the support servo motor (31).

6. The integrated strawberry picking end effector with support-cutting-clamping mechanism according to claim 5, characterized in that: One end of the transmission rack (34) is hinged to one end of two pairs of supporting rods (35), and the other end of the two supporting rods is hinged to the middle of the supporting claw (36); one end of the supporting claw (36) is hinged to the supporting base (32), and the other end is used to support the fruit.

7. The integrated strawberry picking end effector with support-cutting-clamping mechanism according to claim 6, characterized in that: Each pair of supporting links (35) is hinged to one of the supporting claws (36), and the hinge axes involved are parallel to each other and inclined to the horizontal plane; the two pairs of supporting links and the hinged supporting claws are arranged symmetrically so that when they open, they tilt and move downward and backward to both sides, and when they close, they extend forward and upward simultaneously, thereby realizing the smooth closing of the fruit from far to near.

8. The integrated strawberry picking end effector with support-cutting-clamping mechanism according to claim 7, characterized in that: The supporting link (35), the supporting claw (36), the transmission rack (34), and the supporting base (32) form a quadrilateral linkage mechanism.

9. The integrated strawberry picking end effector with support-cutting-clamping mechanism according to claim 8, characterized in that: The support claw (36) is an arc-shaped sheet structure and is made of thermoplastic polyurethane material.

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