CN114654490B

CN114654490B - Forest fruit picking manipulator

Info

Publication number: CN114654490B
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: 2023-09-29
Anticipated expiration: 2042-04-29
Also published as: CN114654490A

Abstract

The invention provides a forest fruit picking manipulator which is simple in structure, convenient to use and capable of picking fruits off, and can realize nondestructive picking. The clamping jaw moving system comprises clamping jaws, a connecting rod, a rack, a worm wheel, a cover plate and a worm; the periphery of the worm is meshed with three worm gears, each worm gear is rotatably arranged on one worm gear shaft, and each worm gear shaft is arranged on one cover plate; the worm is rotatably arranged at the integral joint of the three cover plates; each connecting rod is hinged with a near shaft part, close to the axis of the worm, of the lower end of one clamping jaw and one worm wheel shaft respectively; 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 an inflexible 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 and the three worm wheels rotate to drive the racks to move upwards, the upper parts of the three clamping jaws simultaneously approach the center line and simultaneously move downwards, so that fruits are clamped and picked.

Description

Forest fruit picking manipulator

Technical Field

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

Background

CN106625745a discloses a multi-claw mechanical arm, which comprises a shell, a plurality of claws arranged on the shell, and a reciprocating mechanism, wherein the output end of the reciprocating mechanism is provided with a plurality of driving racks, each claw is provided with a driven rack, one driving rack corresponds to one driven rack to form a group of racks, and the driving racks in each rack group are vertical to the driven racks; 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, the plurality of claws are enclosed into a circle, the claws can be radially and slidably arranged on the shell, and the driving rack drives the driven rack to reciprocate through the driving gear, so that the claws slide outwards or inwards to retract. The claws can grasp fruits, but cannot pick the fruits effectively.

CN113858241a discloses a torsion shaft gripping device, comprising: the base plate, the said top has driving devices, the bottom has guide bar groups along the circumference; the torsion shaft mechanism is arranged at the center of the base plate and penetrates through the base plate 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 a sliding gear in spiral connection with the torsion shaft mechanism is arranged in the middle of the guide plate group; the guide rod group is in sliding connection with the guide plate group, 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 axially rotates to engage with the gear assembly for rotation. The device adopts a central torsion shaft to axially move so as to push the sliding gear to drive a plurality of sets of swing gears and swing claws on the periphery to outwardly expand and grasp a workpiece, so that the device is not suitable for picking fruits.

Disclosure of Invention

The invention aims to provide the forest fruit picking manipulator which has a simple structure, is convenient to use, can pick fruits off, can not damage the fruits basically during picking, and can realize nondestructive picking.

The invention discloses a fruit picking manipulator which comprises a clamping jaw moving system, wherein the clamping jaw moving 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 gears 5 positioned on the same circumference, each worm gear 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 joint of the three cover plates through a bearing; the three clamping jaws are positioned on the periphery taking the axis of the worm 10 as a central line, and each connecting rod 3 is hinged with a near shaft part of 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 one clamping jaw, which is far away from the axis of the worm; when the worm 10 rotates and the three worm gears 5 rotate to drive the rack 4 to move upwards, the upper parts of the three clamping jaws move downwards towards the central line at the same time, so that fruits are clamped and picked up;

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 one clamping jaw, which is far away from the axis of the worm; when the worm 10 rotates and the three worm gears 5 rotate to drive the rack 4 to move upwards, the far shaft part connected with the rack by the clamping jaws elastically deforms, and the upper parts of the three clamping jaws simultaneously approach the center line and simultaneously move downwards, so that fruits are clamped and picked up.

The forest fruit picking manipulator further comprises a first servo motor 14 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 picking manipulator further comprises a fruit torsion mechanism, wherein the fruit torsion 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 torsion driving device for driving the first shell 11 to rotate relative to the second shell 20 is arranged on the second shell 20.

The forest fruit picking manipulator comprises a rotary table bearing 17, an inner meshing internal gear 18, an inner meshing external gear 19 and a second servo motor 21; the second servo motor 21 is fixed on the second shell 20, an internally-meshed internal gear 18 meshed with an internally-meshed external gear 19 is fixed on an output shaft of the second servo motor 21, the internally-meshed external gear 19 is fixed on an inner ring of the turntable bearing 17, an 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 for analyzing and processing images shot by the camera 15 and controlling the first servo motor and the second servo motor to act.

According to the forest fruit picking manipulator, the three worm gears 5, the three racks 4 and the three clamping jaws are respectively and uniformly distributed on the periphery taking the axis of the worm 10 as the center line.

The invention has the beneficial effects that: according to the invention, one worm is adopted to drive three worm gears simultaneously, and then the worm gears drive racks, clamping jaws and the like to move, so that the synchronous movement of the three clamping jaws is ensured. Simultaneously, the clamping jaw motion system not only can make three clamping jaws to the central line remove and press from both sides tight fruit, also makes clamping jaw upper portion down to can take off the fruit, though simple structure, can realize pressing from both sides tight and picking function simultaneously.

If the flexible clamping jaw is adopted, the far shaft part connected with the rack by virtue of the clamping jaw is elastically deformed, so that the clamping jaw and the rack can relatively move, the structure is further simplified, and the flexible clamping jaw is prevented from damaging the outside of fruits.

In particular use, the worm may be coupled to a variety of worm power means for driving the worm in rotation, for example, of course, the worm power means may be a servo motor 14 which simplifies the transmission and may be of lower weight.

The fruit torsion mechanism is adopted to drive the shell I, the clamping jaw moving system and the like to rotate, and the fruit clamped by the clamping jaws can rotate around the central line, so that the fruit can be quickly and effectively dropped off from the fruit tree.

The fruit torsion mechanism adopts a turntable bearing 17, an inner meshing internal gear 18, an inner meshing external gear 19, a second servo motor 21 and the like, is simpler in structure, flexible in rotation of the inner meshing internal gear 18 and small in resistance, and is convenient for fixing the second shell.

The data acquisition system 300 and the like are adopted, fruits can be identified in real time through a camera, the number, the position, the size and the like of the fruits are judged, the movements of the clamping jaw moving system, the fruit torsion 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 flexible robotic arm for picking fruit trees;

FIG. 2 is a perspective view of a 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 flexible robotic arm for picking fruit trees;

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

FIG. 10 is a schematic view of a flexible robotic arm for picking fruit in real time while gripping the fruit;

fig. 11 is a schematic diagram of a robot work flow.

In the figure, a clamping jaw movement system, a fruit torsion mechanism, a data acquisition system and a data acquisition system are respectively arranged at the bottom of the drawing,

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, a picking manipulator for fruit trees mainly comprises a clamping jaw moving system 100, a fruit torsion mechanism 200 and a data acquisition system 300.

Jaw motion system 100:

referring to fig. 2 and 3, the jaw moving system 100 mainly comprises a flexible jaw 1, a pin 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 cylinder space reserved by combining the three cover plates 9 together. The worm 10 is meshed with the worm wheel 5 to transmit power, and the worm wheel 5 is meshed with the rack 4. The bottom plate is reserved at the bottom of the cover plate 9 to prevent the rack 4 from being separated, and one side of the rack 4 without tooth shape is designed to be a protruding shape which is 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 assembly point (a far shaft part far away from the axis of the worm) is connected with one end of the rack 4 to form interference fit, and the other assembly point (a near shaft part close to the axis of the worm) is coaxially matched with a small end face hole of the connecting rod 3 and is connected by the pin shaft 2. And then the cover plate 9, the worm wheel 5 and the holes of the connecting rod 3 are coaxially matched, and the worm wheel shaft 6 is used for fixing. 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 the overlooking direction), the worm wheel 5 rotates clockwise (the manipulator is in the righting direction), the rack 4 meshed with the worm wheel 5 moves upwards, so that the upper part of the flexible clamping jaw 1 bends inwards to be grabbed, and the upper part of the flexible clamping jaw 1 moves downwards slightly. Conversely, the first servo motor 14 outputs torque to drive the worm 10 to rotate anticlockwise, so that the flexible clamping jaw 1 is outwards opened.

Fruit twist mechanism 200:

referring to fig. 4 to 7, the fruit twisting mechanism 200 mainly comprises a fixing piece 7, an angular contact ball bearing 8, a first shell 11, a connecting sleeve 12, a flat key 13, a first servo motor 14, a turntable bearing 17, an internal gear 18, an external gear 19, a second shell 20 and a second servo motor 21. Three fixing sheets 7 are welded on 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 moving system 100 from autorotation. The top of the first shell 11 is provided with an angular contact ball bearing 8 (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 race of the turret bearing 17, and the internally meshed external gear 19 is also bolted to the inner race of the turret bearing 17 (both can be considered as a unit). The second housing 20 fixed to the outer ring of the turntable bearing 17 is internally provided with a square plate, and the second servo motor 21 is assembled on the square plate (the second servo motor 21 is fixed to the second housing 20 in an equivalent manner) and is connected by screws. An output shaft of the second servo motor 21 is connected with the internal gear 18, and the internal gear 18 and the external gear 19 are assembled to form meshing transmission. The second servo motor 21 outputs a torque to the internally toothed gear 18, so that the internally toothed external gear 19 and the inner ring of the turntable bearing 17 rotate, and the first housing 11 fixed on the inner ring of the turntable bearing 17 rotates together, thereby realizing the rotation of the manipulator. The mechanical arm rotates to cut off the connection part of the fruit and the branch when picking. The three worm gears 5, the three racks 4 and the three flexible clamping jaws are respectively and uniformly distributed on the periphery taking the axis of the worm 10 as the center line.

Data acquisition system 300:

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

Claims

1. Forest fruit picking manipulator, 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 gears (5) positioned on the same circumference, each worm gear (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 joint of the three cover plates through a bearing; the three clamping jaws are positioned on the periphery taking the axis of the worm (10) as a central line, and each connecting rod (3) is hinged with a near shaft part, close to the axis of the worm, of the lower end of one clamping jaw and one worm wheel shaft (6) respectively; 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 and the three worm wheels (5) rotate to drive the rack (4) to move upwards, the upper parts of the three clamping jaws simultaneously approach to the central line, so that fruits are 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 one clamping jaw, which is far away from the axis of the worm; when the worm (10) rotates and the three worm wheels (5) rotate to drive the rack (4) to move upwards, the clamping jaw and the far shaft part connected with the rack elastically deform, and the upper parts of the three clamping jaws simultaneously approach to the central line, so that fruits are clamped;

the fruit twisting device also comprises a fruit twisting mechanism and a first servo motor (14) for driving the worm (10) to rotate, wherein 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 torsion mechanism comprises a second shell (20), wherein 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 torsion driving device for driving the first shell (11) to rotate relative to the second shell (20) is arranged on the second shell (20).

2. The fruit picking manipulator of claim 1, wherein: the torsion driving device comprises a turntable bearing (17), an inner meshing internal gear (18), an inner meshing external gear (19) and a second servo motor (21); the second servo motor (21) is fixed on the second shell (20), an inner meshing inner gear (18) meshed with the inner meshing outer gear (19) is fixed on an output shaft of the second servo motor (21), the inner meshing outer gear (19) is fixed on an inner ring of the turntable bearing (17), an outer ring of the turntable bearing (17) is fixed in the second shell (20), and the first shell (11) is fixed on an inner ring of the turntable bearing (17).

3. The fruit picking manipulator of claim 2, wherein: the device also 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 for analyzing and processing images shot by the camera (15) and controlling the first servo motor and the second servo motor to act.

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