A high-quality tea picking device based on a rope-driven soft manipulator

Abstract

The present invention relates to agricultural machinery, with the purpose of providing a high-quality tea picking device based on a rope-driven soft manipulator. The device can achieve rapid and precise picking of high-quality tea by mimicking manual picking methods, thereby improving the quality of mechanized picking of high-quality tea and reducing the impact on tea tree growth. The technical solution is: a high-quality tea picking device based on a rope-driven soft manipulator, characterized by comprising: a connecting frame connected to the picking device's mechanical arm and equipped with a mounting plate, a drive motor fixed to the mounting plate and having a driving gear mounted on the motor shaft, a driven gear positioned on the mounting plate and meshing with the driving gear, two soft manipulator fingers fixed to the driven gear, a rope fixing member fixed to the motor shaft and driving the soft manipulator via a rope, a fan negative pressure device fixed to the mounting plate for collecting tea leaves, and a release structure provided at the air intake of the fan negative pressure device.

Description

Technical Field

[0001] The invention relates to agricultural machinery, in particular to a high-quality tea picking device based on a rope-driven soft manipulator. Background Art

[0002] At present, the picking of bulk tea has been basically mechanized, while the picking of high-quality tea still relies mainly on manual picking due to the stringent picking requirements; due to the rising labor costs, the production cost of high-quality tea continues to rise. The current high-quality tea picking robot adopts a blade shearing picking method, such as the tea picking robot described in CN202011023271.0, which includes a mobile system, a suction system, and a pruning system, wherein the pruning system is a base and also an installation platform for the mobile system and the suction system. The front end of the pruning system is provided with multiple scissor-like saw cuts, which can be used to prune and pick tea leaves. When picking high-quality tea in this way, the blade will squeeze the tea stems to form an elliptical incision. The incision is uneven and has a large number of burrs. The tea stem tissue is torn at the breaking point, and the inside of the broken part is also damaged by the squeezing effect, thereby producing excessive tissue fluid. After picking, the tea stem incision is exposed to the air, and the broken part and the internal damaged tissue are widely oxidized. In contrast, manual picking involves squeezing the tea stems with fingers, leaving the broken sections flat and burr-free. After the same oxidation time, the oxidized area of ​​the fracture produced by manual picking is significantly smaller than that of the shear-type picking cut, significantly reducing the impact on the tea plant. Furthermore, the shear-type high-quality tea picking robot has a large blade at the end, making it easy to shear old leaves or tea stems near the target buds when picking high-quality tea, affecting the subsequent processing of the buds. Therefore, designing a high-quality tea picking device based on a soft robot arm to quickly pick high-quality tea is of great significance. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide a high-quality tea picking device based on a rope-driven soft manipulator. The device can achieve fast and accurate picking of high-quality tea by imitating manual picking methods, thereby improving the quality of mechanized picking of high-quality tea and reducing the impact on the growth of tea trees.

[0004] The technical solution provided by the present invention is:

[0005] A high-quality tea picking device based on a rope-driven soft manipulator is characterized in that: the device includes a connecting frame connected to the picking device mechanical arm and equipped with a mounting plate, a driving motor fixed to the mounting plate and equipped with a driving gear on the motor shaft, a driven gear positioned on the mounting plate and meshing with the driving gear, two soft manipulator fingers fixed to the driven gear, a rope fixing part fixed to the motor shaft and driving the soft manipulator through a rope, a fan negative pressure device fixed to the mounting plate for collecting tea leaves, and a release structure arranged at the air suction port of the fan negative pressure device.

[0006] The driving gear is an incomplete gear; the driven gear is rotatably positioned on the mounting plate through a mounting shaft.

[0007] The two soft robotic fingers have the same structure. Each soft robotic finger includes a finger mounting block, a proximal knuckle, a middle knuckle, and a distal knuckle, which are connected in sequence through a sheet-like flexible part and have two rope holes respectively. One end of the two ropes is fixed to the distal knuckle, and the other ends pass through the middle knuckle, proximal knuckle and the rope holes on the finger mounting block in parallel and then extend to the rope fixing part on the motor shaft for fixation, so as to realize the opposite movement of the two soft robotic fingers during operation.

[0008] The soft mechanical fingers are fixed on the driven gear facing each other through the finger mounting block; the proximal knuckle and the middle knuckle, and the middle knuckle and the distal knuckle are connected by flexible parts, and the end of the proximal knuckle facing away from the middle knuckle is fixed on the finger mounting block.

[0009] In the proximal phalanx, middle phalanx and distal phalanx, the end surfaces facing each other between the two components are made into inclined surfaces to form a stepped space with a larger top and a smaller bottom, and the space between the two components decreases successively to achieve orderly bending of different phalanxes during work.

[0010] In the non-working state, the plane formed by the center lines of the two rope holes in the finger mounting block, the proximal knuckle, the middle knuckle and the distal knuckle is spaced apart from the plane of the flexible member to serve as a force arm for bending the knuckle when the rope is pulled.

[0011] The material of the soft mechanical finger is rubber, and a rubber cover similar to skin is bonded to the surface.

[0012] The fan negative pressure device includes a fan and a fan connecting plate, and the fan is a high-power fan driven by a brushless motor; the release structure includes an arc-shaped protrusion located at the edge of the fan air inlet, and the arc-shaped protrusion is located on the rotation trajectory of the soft mechanical finger so that the movement of the soft mechanical finger is obstructed and deformed to reduce the clamping force on the tea buds.

[0013] The rope is a slightly elastic rope.

[0014] The motor is a servo motor, a stepper motor or a steering gear.

[0015] The beneficial effects of the present invention are:

[0016] The soft robotic arm employed in the device provided by the present invention mimics the plucking method of human hands, minimizing damage to individual tea buds and the impact on tea plant growth. It also utilizes only a single motor and a single blower to pluck and collect individual tea buds, reducing the weight of the tea plucking device. The soft robotic arm is rope-driven, enabling passive stiffness changes and increasing load capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the main structure of an embodiment of the present invention.

[0018] Figure 2 It is a schematic diagram of the three-dimensional structure of an embodiment of the present invention.

[0019] Figure 3 2 is a schematic diagram of the main structure of the soft robotic finger in an embodiment of the present invention.

[0020] Figure 4 Schematic diagram of the three-dimensional structure of the soft robotic finger in an embodiment of the present invention.

[0021] Figure 5 2 is a schematic diagram of the three-dimensional structure of a rope fixing member in an embodiment of the present invention.

[0022] Figure 6 It is an enlarged structural schematic diagram of the air inlet portion of the fan in an embodiment of the present invention.

[0023] Figure 7 Schematic diagram of the working state of the soft mechanical finger clamping a single tea bud in an embodiment of the present invention.

[0024] Figure 8 This is a schematic diagram of the main structure of the soft mechanical fingers and the clamped single tea bud moving to the air inlet of the fan in an embodiment of the present invention.

[0025] Figure 9 yes Figure 8 Schematic diagram of the left viewing direction.

[0026] Figure 10 It is a schematic diagram of the three-dimensional structure of the soft mechanical finger and the clamped single tea bud when moving to the air inlet of the fan in an embodiment of the present invention.

[0027] Numbers in the figure: connecting frame 1, mounting plate 2, driven gear 3, driving gear 4, soft mechanical finger 5, proximal knuckle 5-1, middle knuckle 5-2, distal knuckle 5-3, finger mounting block 5-6, first flexible member 5-4, second flexible member 5-5, rope 6, fan connecting plate 7, fan negative pressure device 8, drive motor 9, rope fixing member 10, mounting shaft 11, arc-shaped protrusion 12, single tea bud 13. DETAILED DESCRIPTION

[0028] The following is further described with reference to the embodiments shown in the accompanying drawings.

[0029] like Figure 1 and Figure 2 The high-quality tea picking device based on a rope-driven soft manipulator shown in the figure includes a connecting frame 1 connected to the picking device robotic arm and equipped with a mounting plate, a driving motor 9 fixed on the mounting plate 2 and equipped with a driving gear 4 on the motor shaft, a driven gear 3 positioned on the mounting plate and meshing with the driving gear, two soft manipulator fingers 5 fixed on the driven gear, a rope fixing part 10 fixed on the motor shaft and driving the soft manipulator through a rope 6, a fan negative pressure device 8 fixed on the mounting plate for collecting tea leaves, and a release structure arranged at the air suction port of the fan negative pressure device for releasing the picked tea buds.

[0030] The connecting frame 1 is connected to the mounting plate 2 via a T-shaped slider nut; the soft manipulator 5 is connected to the driven gear 3 via bolts; the fan connecting plate 7 and the drive motor 9 are both connected to the mounting plate 2 via corresponding bolts; the driving gear 4 is an incomplete boss spur gear, fixed to the motor shaft of the drive motor 9 via a tightening screw; the driven gear 3 (an internal gear, as shown in the figure) is connected to the mounting shaft 11 via a matching bearing and meshes with the driving gear. The mounting shaft is fixed to the mounting plate and arranged perpendicular to the mounting plate. When the driving gear and the driven gear are not meshed, the driven gear does not rotate with the driving gear; when the driving gear and the driven gear are meshed, the driven gear rotates clockwise with the driving gear.

[0031] like Figure 3 and Figure 4The two soft robotic fingers 5 shown have the same structure, both including a proximal phalanx 5-1, a middle phalanx 5-2, a distal phalanx 5-3, a finger mounting block 5-6, flexible members 5-4 and 5-5, and a drive rope 6, and are fixed to the driven gear oppositely through the finger mounting block. The proximal phalanx 5-1 and the middle phalanx 5-2 are connected by a first sheet-like flexible member (such as a spring steel sheet), and the middle phalanx 5-2 and the distal phalanx 5-3 are connected by a second sheet-like flexible member (such as a spring steel sheet); the first flexible member 5-4 is shorter and the second flexible member 5-5 is longer. Each phalanx is appropriately chamfered and rounded, and its size and shape are similar to those of a human hand; and each phalanx is provided with two rope holes so that the rope 6 (preferably a micro-elastic rope) can pass through for driving. Two ropes are arranged parallel to each other, with one end fixed to the distal phalanx. The other end passes through the rope holes in the middle and proximal phalanxes, as well as the finger mounting blocks 5-6, before being extended to the rope fixing member 10 on the motor shaft for fixation. (The rope fixing member has corresponding through-holes through which the ropes pass and are then secured with a tightening screw.) This enables the two soft robotic fingers to move toward each other during operation. The end of the proximal phalanx facing away from the middle phalanx is fixed to the finger mounting block, which also has bolt holes for bolting to the driven gear.

[0032] Depend on Figure 3 It can be seen that in the proximal phalanx 5-1, middle phalanx 5-2, and distal phalanx 5-3, the end surfaces facing each other are made into inclined surfaces to form a stepped space with a larger top and a smaller bottom, and the space between the two parts decreases successively to achieve orderly bending of different phalanges during work.

[0033] In the non-operating state, the plane formed by the centerlines of the two rope holes in the finger mounting block 5-6, the proximal phalanx 5-1, the middle phalanx 5-2, and the distal phalanx 5-3 is spaced apart from the plane of the flexible member. This spacing is the moment arm that causes the phalanxes to bend when the rope is pulled. The first flexible member 5-4 and the second flexible member 5-5 are flexible and can bend, thereby driving the corresponding phalanxes to move. Because the first flexible member is relatively short, when the rope 6 is pulled, the proximal phalanx 5-1 and the middle phalanx 5-2 come into contact first, shortening the effective bending length of the soft finger and increasing its bending stiffness. Continued rope pulling causes the middle phalanx and the distal phalanx 5-3 to come into contact, completing the soft finger's actuation and enabling it to clamp a single tea bud. During the bending process, the proximal phalanx and the middle phalanx come into contact first, followed by the middle phalanx and the distal phalanx, gradually increasing stiffness. This allows the soft finger to withstand large loads, meeting the kinematic and mechanical requirements of tea picking.

[0034] Depend on Figure 6It can be seen that: the fan negative pressure device includes a fan connecting plate 7 and a fan fixed to the mounting plate through the fan connecting plate, and the fan is a high-power fan driven by a brushless motor (a fan for use with a powerful vacuum motor cleaner); the release structure includes an arc-shaped protrusion 12 located at the edge of the fan air inlet, the left side of the arc-shaped protrusion is perpendicular to the axis, and the right side is a bevel, which is arranged on the rotation trajectory of the soft mechanical finger (preferably, the axis of the fan air inlet is perpendicular to the rotation trajectory); when the driven gear rotates clockwise, it drives the two soft mechanical fingers to swing clockwise; the soft mechanical finger on the left is blocked by the bevel of the arc-shaped protrusion and forced to deform (deformed in the axial direction of the fan air inlet), so that the clamping parts of the two soft mechanical fingers are staggered by a certain distance in the axial direction of the fan air inlet, thereby reducing the clamping force on the carried tea buds, and the tea buds are separated from the soft mechanical fingers and sucked into the air inlet under the action of negative pressure.

[0035] The working principle of the present invention is:

[0036] (1) Figure 1 As shown, the soft robotic finger is in the open state;

[0037] (2) The entire tea picking device is positioned above the tea bud 13 to be picked by the robotic arm, and then the driving motor 9 starts working, driving the rope 6 to rotate clockwise, thereby driving the two soft robotic fingers 5 to bend towards each other and clamp the tea bud, so as to imitate the human hand squeezing the tea stem. Figure 6 As shown in FIG. 4 , the driving gear 4 is an incomplete gear, so the driving gear 4 is not meshed with the driven gear 3 during this process.

[0038] (3) After the soft mechanical fingers clamp the tea bud, the driving gear starts to mesh with the driven gear, thereby driving the two soft mechanical fingers to rotate rapidly clockwise. The tea bud will be broken due to the continuous force, and the soft mechanical fingers continue to rotate with the tea bud and move quickly to the air inlet of the fan installation device 8. The soft mechanical finger on the left is pressed by the arc protrusion 12 and deforms in the axial direction of the air inlet, as shown in FIG. Figure 8 and Figure 9 shown.

[0039] (4) As the soft mechanical finger 5 on the left is squeezed and deformed, the clamping force on the tea bud becomes smaller. At this time, the fan of the fan negative pressure device 8 is started, causing the air inlet to be in a negative pressure state. The tea bud 13 is absorbed by the negative pressure and enters the air inlet, completing the plucking of the tea bud. Then, the driving motor is reversed, and the driving gear also drives the driven gear to rotate in the opposite direction, so that the driven gear is separated from the arc protrusion and returns to the initial state. A tea bud plucking action is completed. Repeat the above plucking action, and the tea bud plucking is carried out continuously.

[0040] In summary, the advantages of the present invention are:

[0041] (1) The structure is simple, and only one motor and one fan are needed to achieve accurate and non-destructive picking of single tea buds;

[0042] (2) The soft robotic fingers are made of rubber material, which can fit well with the target tea buds, achieving the greatest possible damage-free picking;

[0043] (3) The soft robotic finger can passively change its stiffness during the driving process, which improves its load capacity and meets the load requirements for picking tea leaves.

[0044] Finally, it should be noted that the above examples are merely specific embodiments of the present invention. The present invention is not limited to the above embodiments and is subject to numerous variations. All variations that can be directly derived or conceived by a person of ordinary skill in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A high-quality tea picking device based on a rope-driven soft manipulator, characterized by: The device comprises a connecting frame (1) connected to a mechanical arm of a picking device and equipped with a mounting plate (2), a driving motor (9) fixed on the mounting plate and equipped with a driving gear (4) on the motor shaft, a driven gear (3) positioned on the mounting plate and meshing with the driving gear, two soft mechanical fingers (5) fixed on the driven gear, a rope fixing member fixed on the motor shaft and driving the soft mechanical fingers through a rope (6), a fan negative pressure device (8) fixed on the mounting plate for collecting tea leaves, and a release structure provided at the air suction port of the fan negative pressure device; The two soft robotic fingers have the same structure. Each soft robotic finger comprises a proximal finger joint (5-1), a middle finger joint (5-2), and a distal finger joint (5-3) which are sequentially connected by a sheet-like flexible member and each of which has two rope holes. One end of each of the two ropes is fixed to the distal finger joint, and the other ends of the two ropes pass through the rope holes on the middle finger joint, the proximal finger joint, and the finger mounting block (5-6) in parallel and then extend to the rope fixing member (10) on the motor shaft for fixing, so as to realize the two soft robotic fingers moving toward each other during operation. The fan negative pressure device includes a fan and a fan connecting plate (7), and the fan is a high-power fan driven by a brushless motor; the release structure includes an arc-shaped protrusion (12) located at the edge of the fan air inlet, and the arc-shaped protrusion is located on the rotation trajectory of the soft mechanical finger so that the soft mechanical finger is hindered in movement and deformed to reduce the clamping force on the tea buds.

2. The high-quality tea picking device based on a rope-driven soft manipulator according to claim 1 is characterized in that: The driving gear is an incomplete gear; the driven gear is rotatably positioned on the mounting plate via a mounting shaft (11).

3. The high-quality tea picking device based on a rope-driven soft manipulator according to claim 2 is characterized in that: The soft mechanical fingers are fixed on the driven gear facing each other through the finger mounting block; the proximal knuckle and the middle knuckle, and the middle knuckle and the distal knuckle are connected by flexible parts, and the end of the proximal knuckle facing away from the middle knuckle is fixed on the finger mounting block.

4. The high-quality tea picking device based on a rope-driven soft manipulator according to claim 3 is characterized in that: In the proximal phalanx, middle phalanx and distal phalanx, the end surfaces facing each other between the two components are made into inclined surfaces to form a stepped space with a larger top and a smaller bottom, and the space between the two components decreases successively to achieve orderly bending of different phalanxes during work.

5. The high-quality tea picking device based on a rope-driven soft manipulator according to claim 4 is characterized in that: In the non-working state, the plane formed by the center lines of the two rope holes in the finger mounting block, the proximal knuckle, the middle knuckle and the distal knuckle is spaced apart from the plane of the flexible member to serve as a force arm for bending the knuckle when the rope is pulled.

6. The high-quality tea picking device based on a rope-driven soft manipulator according to claim 5, characterized in that: The material of the soft manipulator is rubber, and a rubber cover similar to skin is bonded to the surface.

7. The high-quality tea picking device based on a rope-driven soft manipulator according to claim 6, characterized in that: The driving motor is a servo motor, a stepping motor or a steering gear.

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