CN114654490A

CN114654490A - Mechanical hand is picked to forest fruit

Info

Publication number: CN114654490A
Application number: CN202210467245.XA
Authority: CN
Inventors: 孙梦梦; 周宏平; 金寿祥
Original assignee: Nanjing Forestry University
Current assignee: Nanjing Forestry University
Priority date: 2022-04-29
Filing date: 2022-04-29
Publication date: 2022-06-24
Anticipated expiration: 2042-04-29
Also published as: CN114654490B

Abstract

The invention provides a forest fruit picking mechanical arm which is simple in structure and convenient to use and can pick fruits, and nondestructive picking can be realized. The clamping jaw moving system comprises a clamping jaw, a connecting rod, a rack, a worm wheel, a cover plate and a worm; the periphery of the worm is meshed with three worm wheels, each worm wheel is rotatably arranged on a worm wheel shaft, and each worm wheel shaft is arranged on a cover plate; the worm is rotationally arranged at the integral connection part of the three cover plates; each connecting rod is respectively hinged with a near shaft part at the lower end of one clamping jaw, which is close to the worm shaft, and a worm gear shaft; a rack meshed with each worm wheel is arranged on a cover plate in a sliding manner, the clamping jaw is a flexible clamping jaw or a non-flexible clamping jaw, and the upper end of each rack is connected with a far shaft part of the lower end of one clamping jaw, which is far away from the axis of the worm; when the worm rotates, the three worm wheels rotate, and the driving rack moves upwards, the upper parts of the three clamping jaws simultaneously move downwards towards the central line to clamp and pick fruits.

Description

Mechanical hand is picked to forest fruit

Technical Field

The invention relates to a fruit picking device, in particular to a fruit picking mechanical arm.

Background

CN106625745A discloses a multi-jaw manipulator, which includes a housing, a plurality of jaws mounted on the housing, and a reciprocating mechanism, wherein the output end of the reciprocating mechanism is provided with a plurality of driving racks, each jaw is provided with a driven rack, one driving rack corresponds to one driven rack to form a set of rack groups, and the driving rack in each rack group is perpendicular to the driven rack; a driving gear is arranged between the driving rack and the driven rack in each rack group, and the driving gear is respectively meshed with the driving rack and the driven rack; the driving rack and the driving gear are arranged in the shell, a plurality of claws surround into a circle, the claws can be arranged on the shell in a radial sliding mode, and the driving rack drives the driven rack to reciprocate through the driving gear, so that the claws slide to be outwards opened or inwards folded. The paws grip the fruits, but cannot effectively pick the fruits.

CN113858241A discloses a torsion shaft type gripping device, comprising: the top of the base plate is provided with a driving device, and the bottom of the base plate is provided with a guide rod group along the circumferential direction; the torsion shaft mechanism is arranged in the center of the substrate and penetrates through the substrate to be connected with the power output end of the driving device; the center of the guide plate group is movably arranged with the torsion shaft mechanism, and the middle of the guide plate group is provided with a sliding gear which is spirally connected with the torsion shaft mechanism; the guide rod group is connected with the guide plate group in a sliding manner, and a gear assembly meshed with the sliding gear is arranged on the guide rod group; the driving device drives the torsion shaft mechanism to move downwards, so that the sliding gear rotates towards the rotating meshing gear assembly. The central torsion shaft is adopted to axially move, and the sliding gear is pushed to drive a plurality of sets of swing gears and swing claws on the periphery to outwardly expand to grab workpieces, so that the fruit picking device is not suitable for picking fruits.

Disclosure of Invention

The invention aims to provide a fruit picking manipulator which is simple in structure and convenient to use and can pick fruits, the fruit picking manipulator does not damage the fruits basically during picking, and nondestructive picking can be realized.

The invention discloses a fruit picking manipulator, which comprises a clamping jaw movement system, wherein the clamping jaw movement system comprises a clamping jaw, a connecting rod 3, a rack 4, a worm wheel 5, a cover plate 9 and a worm 10; the periphery of the worm 10 is meshed with three worm wheels 5 on the same circumference, each worm wheel 5 is rotatably arranged on a worm wheel shaft 6, and each worm wheel shaft 6 is arranged on a cover plate 9; the three cover plates are connected into a whole at the position close to the periphery of the worm 10, and the worm 10 is rotatably arranged at the connection position of the three cover plates through a bearing; the three clamping jaws are positioned on the periphery with the axis of the worm 10 as the central line, and each connecting rod 3 is respectively hinged with a near shaft part at the lower end of one clamping jaw, which is close to the axis of the worm, and a worm wheel shaft 6; a rack 4 engaged with each worm wheel 5 is slidably provided on a cover plate 9,

when the clamping jaw is a non-flexible clamping jaw, the upper end of each rack 4 is hinged with a far shaft part of the lower end of the clamping jaw, which is far away from the axis of the worm; when the worm 10 rotates, the three worm wheels 5 rotate and the driving rack 4 moves upwards, the upper parts of the three clamping jaws move downwards towards the central line at the same time, so that the fruits are clamped and picked;

when the clamping jaw is a flexible clamping jaw, the upper end of each rack 4 is connected with a far shaft part of the lower end of the clamping jaw, which is far away from the axis of the worm; when the worm 10 rotates, the three worm wheels 5 rotate, and the driving rack 4 moves upwards, the far shaft part of the clamping jaw connected with the rack elastically deforms, and the upper parts of the three clamping jaws simultaneously move downwards towards the central line, so that the fruit is clamped and picked.

The fruit picking manipulator further comprises a first servo motor 14 used for driving the worm 10 to rotate, the first servo motor 14 is arranged on the first shell 11, the first shell 11 is fixedly connected with the cover plate 9, and the lower end of the worm 10 is connected with the upper end of an output shaft of the first servo motor 14.

The fruit twisting mechanism comprises a second shell 20, the first shell 11 is rotatably arranged on the second shell 20 by taking the axis of the worm 10 as the axis, and a twisting driving device for driving the first shell 11 to rotate relative to the second shell 20 is arranged on the second shell 20.

The torsional driving device of the fruit picking manipulator comprises a turntable bearing 17, an internal gear meshing 18, an external gear meshing 19 and a second servo motor 21; the second servo motor 21 is fixed on the second shell 20, an internal meshing internal gear 18 meshed with the internal meshing external gear 19 is fixed on an output shaft of the second servo motor 21, the internal meshing external gear 19 is fixed on an inner ring of a turntable bearing 17, the outer ring of the turntable bearing 17 is fixed inside the second shell 20, and the first shell 11 is fixed on the inner ring of the turntable bearing 17.

The fruit picking manipulator further comprises a data acquisition system 300, wherein the data acquisition system 300 comprises a camera 15 arranged on the second shell 20 and an analysis processor used for analyzing and processing images shot by the camera 15 and controlling the first servo motor and the second servo motor to act.

The three worm gears 5, the three racks 4 and the three clamping jaws are respectively and uniformly distributed on the periphery which takes the axis of the worm 10 as the central line.

The invention has the beneficial effects that: the invention adopts a worm to drive three worm wheels simultaneously, and then drives the rack, the clamping jaws and the like to move through the worm wheels, thereby ensuring the synchronous movement of the three clamping jaws. Meanwhile, the clamping jaw movement system can enable the three clamping jaws to move towards the central line to clamp fruits and enable the upper portions of the clamping jaws to move downwards, so that the fruits can be picked off, and the clamping and picking functions can be achieved while the clamping jaw movement system is simple in structure.

If adopt flexible clamping jaw, the distal shaft portion that relies on clamping jaw and rack to be connected takes place elastic deformation for clamping jaw and rack can relative movement, have further simplified the structure, and flexible clamping jaw has avoided causing the external damage to the fruit moreover.

In particular use, the worm may be connected to a variety of worm power devices for driving the worm to rotate, for example, when the worm power device adopts the first servomotor 14, the transmission mechanism is simplified, and the weight is lighter.

The fruit twisting mechanism is adopted to drive the first shell and the clamping jaw movement system to rotate, and the fruit clamped by the clamping jaws can rotate around the central line, so that the fruit can fall off from the fruit tree quickly and effectively.

The fruit twisting mechanism adopts a turntable bearing 17, an internal gear meshing 18, an external gear meshing 19, a servo motor II 21 and the like, the structure is simpler, the internal gear meshing 18 rotates flexibly, the resistance is small, and meanwhile, the fixing of the shell II is facilitated.

By adopting the data acquisition system 300 and the like, the fruits can be identified in real time through the camera, the number, the positions, the sizes and the like of the fruits can be judged, the actions of a clamping jaw motion system, a fruit twisting mechanism and the like are controlled, the fruits are picked, and the automation level and the reliability are improved.

Drawings

FIG. 1 is a schematic perspective view of a forest fruit picking flexible manipulator;

FIG. 2 is a perspective view of the jaw movement system;

FIG. 3 is a perspective view of the jaw movement system (with the cover plate removed);

FIG. 4 is a perspective view of the fruit twisting mechanism, data acquisition system;

FIG. 5 is a partial cross-sectional view of the fruit twisting mechanism

FIG. 6 is a cross-sectional view A-A of FIG. 4;

FIG. 7 is a cross-sectional view B-B of FIG. 4;

FIG. 8 is a schematic view of a forest fruit picking flexible robot;

FIG. 9 is another schematic view of a forest fruit picking flexible robot;

FIG. 10 is a schematic view of a forest fruit picking flexible manipulator in fruit clamping;

fig. 11 is a robot work flow diagram.

In the figure, 100-clamping jaw movement system, 200-fruit twisting mechanism, 300-data acquisition system,

the device comprises a flexible clamping jaw 1, a pin shaft 2, a connecting rod 3, a rack 4, a worm wheel 5, a worm wheel shaft 6, a fixing piece 7, an angular contact ball bearing 8, a cover plate 9, a worm 10, a shell I11, a connecting sleeve 12, a flat key 13, a servo motor I14, a camera 15, a fastener 16, a turntable bearing 17, an internal gear 18, an external gear 19, a shell II 20, a servo motor II 21 and a base 22.

Detailed Description

Referring to fig. 1 and 2, the mechanical arm for picking forest fruits mainly comprises a clamping jaw movement system 100, a fruit twisting mechanism 200 and a data acquisition system 300.

Jaw movement system 100:

referring to fig. 2 and 3, the jaw moving system 100 is mainly composed of a flexible jaw 1, a pin shaft 2, a connecting rod 3, a rack 4, a worm wheel 5, a worm wheel shaft 6, an angular contact ball bearing 8, a cover plate 9 and a worm 10. One end of the worm 10 is in interference fit with the angular contact ball bearing 8, and the angular contact ball bearing 8 is fixed by a reserved cylindrical space formed by combining the three cover plates 9. The worm 10 is meshed with the worm wheel 5 to transmit power, and the worm wheel 5 is meshed with the rack 4. A bottom plate is reserved at the bottom of the cover plate 9 to prevent the rack 4 from being separated, and the side, without the tooth shape, of the rack 4 is designed to be in a protruding shape and matched with the concave shape at one side of the cover plate 9 to form a moving pair. The bottom of the flexible clamping jaw 1 is provided with two assembly points, one of the assembly points (a far shaft part far away from the worm axis) is connected with one end of the rack 4 to form interference fit, and the other assembly point (a near shaft part near the worm axis) is coaxially matched with a small end surface hole of the connecting rod 3 and is connected by a pin shaft 2. Then the cover plate 9, the worm wheel 5 and the hole of the connecting rod 3 are coaxially matched and fixed by a worm wheel shaft 6. The spiral line of the worm 10 is designed to be right-handed, when the first servo motor 14 outputs torque, the worm 10 is driven to rotate clockwise (the top of the manipulator is in a top view direction), the worm wheel 5 rotates clockwise (the top of the manipulator is in a top view direction), and the rack 4 meshed with the worm wheel 5 moves upwards, so that the upper portion of the flexible clamping jaw 1 is bent inwards to be grabbed, and the upper portion of the flexible clamping jaw 1 is slightly moved downwards. Conversely, the output torque of the servo motor I14 drives the worm 10 to rotate anticlockwise, so that the flexible clamping jaw 1 is opened outwards.

Fruit twisting mechanism 200:

referring to fig. 4-7, the fruit twisting mechanism 200 mainly comprises a stator 7, an angular contact ball bearing 8, a first housing 11, a connecting sleeve 12, a flat key 13, a first servo motor 14, a turntable bearing 17, an internal meshing gear 18, an internal meshing external gear 19, a second housing 20 and a second servo motor 21. Three fixing sheets 7 are welded to the top of the first shell 11, and the three fixing sheets 7 can play a role in fixing and clamping the cover plate 9 to prevent the clamping jaw movement system 100 from rotating. The top of the first shell 11 is provided with an angular contact ball bearing 8 (in interference fit). The first servo motor 14 is connected with the shell 11 through a screw, an output shaft of the first servo motor 14 is connected with one end of the connecting sleeve 12 through a flat key 13, and the other end of the connecting sleeve 12 is fixedly connected with the worm 10. The bottom of the first housing 11 is bolted to the inner ring of the slewing bearing 17, and the internal external gear 19 is also bolted to the inner ring of the slewing bearing 17 (the two can be considered as a whole). A square sheet is designed inside a second shell 20 fixed on the outer ring of the turntable bearing 17, and a second servo motor 21 is assembled on the square sheet (the second servo motor 21 is equivalently fixed on the second shell 20) and connected with the square sheet through screws. An output shaft of the second servo motor 21 is connected with the internal gear ring 18, and the internal gear ring 18 and the external gear ring 19 are assembled to form meshing transmission. The second servo motor 21 outputs torque to the internal gear ring 18, so that the internal gear ring 19 and the inner ring of the turntable bearing 17 rotate, the first shell 11 fixed on the inner ring of the turntable bearing 17 rotates together, and the rotation of the manipulator is realized. When picking, the manipulator rotates to twist off the connection part of the fruit and the branch. Three worm wheels 5, three racks 4 and three flexible clamping jaws are respectively and uniformly distributed on the periphery which takes the axis of the worm 10 as the central line.

The data acquisition system 300:

referring to fig. 4 and 8, the data acquisition system 300 is mainly composed of a camera 15, a fastener 16 and a base 22, wherein a cylinder with a spiral line is arranged below the camera 15 and fixedly connected with the fastener 16, the fastener 16 is fixed on the base 22, and the base 22 is connected on the second casing 20. The camera 15 collects the image and transmits the image to the computer for processing and analysis, and the specific flow is shown in fig. 11.

Claims

1. Mechanical hand is picked to forest fruit, including clamping jaw motion system, characterized by: the clamping jaw movement system comprises clamping jaws, a connecting rod (3), a rack (4), a worm wheel (5), a cover plate (9) and a worm (10); the periphery of the worm (10) is meshed with three worm wheels (5) positioned on the same circumference, each worm wheel (5) is rotatably arranged on one worm wheel shaft (6), and each worm wheel shaft (6) is arranged on one cover plate (9); the three cover plates are connected into a whole at the position close to the periphery of the worm (10), and the worm (10) is rotatably arranged at the connection position of the three cover plates through a bearing; the three clamping jaws are positioned on the periphery with the axis of the worm (10) as the central line, and each connecting rod (3) is respectively hinged with a near shaft part at the lower end of one clamping jaw, which is close to the axis of the worm, and a worm wheel shaft (6); a rack (4) meshed with each worm wheel (5) is arranged on a cover plate (9) in a sliding way,

when the clamping jaw is a non-flexible clamping jaw, the upper end of each rack (4) is hinged with a far shaft part of the lower end of one clamping jaw, which is far away from the axis of the worm; when the worm (10) rotates, the three worm wheels (5) rotate, and the driving rack (4) moves upwards, the upper parts of the three clamping jaws simultaneously approach to the central line, so that the fruit is clamped;

when the clamping jaw is a flexible clamping jaw, the upper end of each rack (4) is connected with a far shaft part of the lower end of the clamping jaw, which is far away from the axis of the worm; when the worm (10) rotates, the three worm wheels (5) rotate, and the driving rack (4) moves upwards, the far shaft parts of the clamping jaws connected with the rack are elastically deformed, and the upper parts of the three clamping jaws simultaneously approach to the central line, so that the fruit is clamped.

2. The fruit picking manipulator as claimed in claim 1, wherein: the worm gear mechanism further comprises a first servo motor (14) used for driving the worm (10) to rotate, the first servo motor (14) is arranged on the first shell (11), the first shell (11) is fixedly connected with the cover plate (9), and the lower end of the worm (10) is connected with the upper end of an output shaft of the first servo motor (14).

3. The fruit picking manipulator as claimed in claim 2, wherein: the fruit twisting mechanism comprises a second shell (20), the first shell (11) is rotatably arranged on the second shell (20) by taking the axis of the worm (10) as the axis, and a twisting driving device for driving the first shell (11) to rotate relative to the second shell (20) is arranged on the second shell (20).

4. The fruit picking manipulator as claimed in claim 3, wherein: the torsion driving device comprises a turntable bearing (17), an internal gear (18), an external gear (19) and a servo motor II (21); a second servo motor (21) is fixed on a second shell (20), an internal meshing internal gear (18) meshed with an internal meshing external gear (19) is fixed on an output shaft of the second servo motor (21), the internal meshing external gear (19) is fixed on an inner ring of a turntable bearing (17), an outer ring of the turntable bearing (17) is fixed inside the second shell (20), and a first shell (11) is fixed on the inner ring of the turntable bearing (17).

5. The fruit picking manipulator as claimed in claim 4, wherein: the intelligent control system further comprises a data acquisition system (300), wherein the data acquisition system (300) comprises a camera (15) arranged on the second shell (20) and an analysis processor which is used for analyzing and processing images shot by the camera (15) and controlling the first servo motor and the second servo motor to act.

6. The fruit picking manipulator as claimed in claim 1, wherein: three worm wheels (5), three racks (4) and three clamping jaws are respectively and uniformly distributed on the periphery which takes the axis of the worm (10) as the central line.