CN110291880B

CN110291880B - Multi-arm apple picking robot

Info

Publication number: CN110291880B
Application number: CN201910701295.8A
Authority: CN
Inventors: 疏达; 方晓康; 孙际超; 朱浩杰; 易呈祥; 朱福生; 尚慧茹; 李笑晗; 卢文静; 陈许; 崔祥祥
Original assignee: Anhui Polytechnic University
Current assignee: Anhui Polytechnic University
Priority date: 2019-07-31
Filing date: 2019-07-31
Publication date: 2021-10-22
Anticipated expiration: 2039-07-31
Also published as: CN110291880A

Abstract

The invention discloses a multi-arm apple picking robot which comprises a chassis and a plurality of picking mechanical arms arranged on the chassis, wherein each picking mechanical arm comprises an end effector, an opening and closing control device used for controlling the end effector to be switched between an opening state and a closing state, a first mechanical arm, a second mechanical arm, a first angle adjusting device arranged on the first mechanical arm and used for controlling the opening and closing control device to rotate, a second angle adjusting device arranged on the second mechanical arm and used for controlling the first mechanical arm to rotate, a height adjusting device used for adjusting the height position of the second mechanical arm and a third angle adjusting device connected with the height adjusting device and the second mechanical arm and used for controlling the second mechanical arm to rotate.

Description

Multi-arm apple picking robot

Technical Field

The invention belongs to the technical field of robots, and particularly relates to a multi-arm apple picking robot.

Background

China is a big country for apple production, and apple production has important significance for the development of agricultural economy in China. However, the apple picking in China is basically carried out manually at present, and the picking efficiency is low. In recent years, with the development of agricultural mechanization and automation, research on automatic apple picking robots is receiving more and more attention. However, the existing apple picking robot is mostly a single mechanical arm to work, and though manpower can be replaced for self-picking, the labor force is greatly saved, but the cost is higher, and the picking efficiency still needs to be improved.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a multi-arm apple picking robot, and aims to improve picking efficiency.

In order to achieve the purpose, the invention adopts the technical scheme that: the multi-arm apple picking robot comprises a chassis and a plurality of picking mechanical arms arranged on the chassis, wherein each picking mechanical arm comprises an end effector, an opening and closing control device used for controlling the end effector to be switched between an opening state and a closing state, a first mechanical arm, a second mechanical arm, a first angle adjusting device arranged on the first mechanical arm and used for controlling the opening and closing control device to rotate, a second angle adjusting device arranged on the second mechanical arm and used for controlling the first mechanical arm to rotate, a height adjusting device used for adjusting the height position of the second mechanical arm and a third angle adjusting device connected with the height adjusting device and the second mechanical arm and used for controlling the second mechanical arm to rotate.

The end effector comprises a clamping jaw seat, a main clamping jaw rotatably arranged on the clamping jaw seat, an auxiliary clamping jaw rotatably arranged on the main clamping jaw and an elastic element used for applying elastic acting force for keeping the auxiliary clamping jaw in contact with the apple to the auxiliary clamping jaw, the main clamping jaw is provided with a plurality of main clamping jaws, all the main clamping jaws are circumferentially arranged on the clamping jaw seat, and each main clamping jaw is at least provided with one auxiliary clamping jaw.

The main clamping jaw is provided with a main contact surface used for being in contact with the apple, the auxiliary clamping jaw is provided with an auxiliary contact surface used for being in contact with the apple, the main contact surface and the auxiliary contact surface are both arc surfaces, the axes of the main contact surface and the axis of the auxiliary contact surface are parallel, the auxiliary clamping jaw is located on the inner side of the main clamping jaw, and the elastic element is clamped between the main clamping jaw and the auxiliary clamping jaw.

The opening and closing control device comprises an opening and closing control base, a movable block, a push-pull rod, an opening and closing control motor and a transmission mechanism, wherein the push-pull rod is connected with the movable block and the main clamping jaw in a rotating mode, the opening and closing control motor is arranged on the opening and closing control base, the transmission mechanism is connected with the opening and closing control motor and the movable block and comprises a belt transmission mechanism and a lead screw nut mechanism which are sequentially connected, the opening and closing control base is connected with the first angle adjusting device, and the clamping jaw seat is connected with the opening and closing control base.

The first angle adjusting device comprises a first adjusting seat rotatably connected with the opening and closing control device, a first adjusting motor arranged on the first mechanical arm, a first transmission shaft connected with the first adjusting motor, a shaft sleeve connected with the first adjusting seat and sleeved on the first transmission shaft, and a first transmission mechanism connected with the first transmission shaft and the opening and closing control device.

The first mechanical arm is provided with a first rotation control device used for controlling the first adjusting seat to rotate relative to the first mechanical arm, the first rotation control device comprises a first rotation control motor arranged on the first mechanical arm and a transmission mechanism connected with the first rotation control motor and the shaft sleeve, the shaft sleeve is fixedly connected with the first adjusting seat, and a rotation center line of the first adjusting seat when rotating relative to the first mechanical arm is perpendicular to a rotation center line of the opening and closing control device when rotating relative to the first adjusting seat and perpendicular to a rotation center line of the first mechanical arm when rotating relative to the second mechanical arm.

The second angle adjusting device is arranged on a second adjusting motor on the second mechanical arm and a second transmission mechanism connected with the second adjusting motor and the first mechanical arm.

The third angle adjusting device is arranged on a third adjusting motor on the third mechanical arm and a third transmission mechanism connected with the third adjusting motor and the height adjusting device.

The height adjusting device is connected with the second mechanical arm in a rotating mode, and comprises a sliding seat, a height adjusting base, a height adjusting motor and a height adjusting transmission mechanism, wherein the sliding seat is connected with the second mechanical arm in a rotating mode, the height adjusting motor is arranged on the height adjusting base, the height adjusting transmission mechanism is connected with the height adjusting motor and the sliding seat, and the height adjusting transmission mechanism comprises a gear transmission mechanism and a lead screw nut mechanism which are connected in sequence.

And a second rotation control motor for controlling the height adjusting base to rotate relative to the chassis is arranged on the chassis, and the rotation center line of the height adjusting base when rotating relative to the chassis is a vertical line.

The multi-arm apple picking robot adopts a multi-arm picking mode, so that the picking efficiency is greatly improved, and the mechanical arms arranged on two sides can simultaneously pick fruits of single-side fruit trees between two rows without returning; in addition, the six-degree-of-freedom mechanical arm is adopted, so that the flexibility of the mechanical arm is greatly improved, and apples at any position can be picked; the mechanical arm adopts a folding modular design, has a compact structure, reduces the occupied space and is convenient to maintain.

Drawings

The description includes the following figures, the contents shown are respectively:

FIG. 1 is a schematic structural view of a multi-arm apple picking robot of the present invention;

FIG. 2 is a schematic structural view of a picking robot;

FIG. 3 is a schematic structural view of an end effector;

FIG. 4 is a schematic view of the connection between the opening/closing control device and the first robot arm;

FIG. 5 is a schematic view of a second angle adjustment device;

FIG. 6 is a schematic view of the structure of the height adjustment mechanism;

labeled as: 1. a chassis; 2. an end effector; 201. a main jaw; 202. a secondary jaw; 203. an elastic element; 204. a jaw seat; 3. an opening/closing control device; 301. a movable block; 302. a push-pull rod; 303. an on-off control motor; 304. an opening and closing control base; 305. a belt drive mechanism; 306. a feed screw nut mechanism; 4. a first angle adjusting device; 401. a first adjusting seat; 402. a first adjustment motor; 403. a first drive shaft; 404. a shaft sleeve; 405. a first transmission mechanism; 5. a second angle adjusting device; 501. a second adjustment motor; 502. a second transmission mechanism; 6. a height adjustment device; 601. a sliding seat; 602. a height adjustment base; 603. a height adjustment motor; 604. a gear transmission mechanism; 605. a feed screw nut mechanism; 606. a guide post; 607. a fixed seat; 7. a third angle adjusting device; 701. a third adjustment motor; 702. a third transmission mechanism; 8. a first rotation control device; 801. a first rotation control motor; 802. a gear transmission mechanism; 9. a first robot arm; 10. a second mechanical arm; 11. an apple collection basket; 12. the second rotation control motor.

Detailed Description

The following detailed description of the embodiments of the present invention will be given with reference to the accompanying drawings for a purpose of helping those skilled in the art to more fully, accurately and deeply understand the concept and technical solution of the present invention and to facilitate its implementation.

It should be noted that, in the following embodiments, the terms "first", "second" and "third" do not denote absolute differences in structure and/or function, nor do they denote a sequential order of execution, but rather are used for convenience of description.

As shown in fig. 1 to 6, the present invention provides a multi-arm apple picking robot, which includes a chassis 1 and a plurality of picking manipulators arranged on the chassis 1, wherein the picking manipulators include an end effector 2, an open/close control device 3 for controlling the end effector 2 to switch between an open state and a closed state, a first manipulator 9, a second manipulator 10, a first angle adjusting device 4 arranged on the first manipulator 9 and used for controlling the open/close control device 3 to rotate, a second angle adjusting device 5 arranged on the second manipulator 10 and used for controlling the first manipulator 9 to rotate, a height adjusting device 6 used for adjusting the height position of the second manipulator 10, and a third angle adjusting device 7 connected with the height adjusting device 6 and the second manipulator 10 and used for controlling the second manipulator 10 to rotate.

Specifically, as shown in fig. 1, a chassis 1 serves as a base for mounting a picking manipulator and other components, the chassis 1 can carry the picking manipulator to move, the chassis 1 generates a driving force for driving the multi-arm apple picking robot to integrally run, the chassis 1 comprises four crawler traveling wheels, the four crawler traveling wheels are arranged on two opposite sides of the chassis 1, and the chassis 1 is good in adaptability to the terrain. The picking manipulator is used as an actuating mechanism for picking apples on fruit trees. The picking manipulator can be provided with a plurality of picking manipulators, and all the picking manipulators are arranged in two rows on the chassis 1, so that the picking efficiency is greatly improved, the picking manipulators arranged on two sides can simultaneously pick apples on apple trees with the row spacing of 2.5-4 m, and fruits between two rows can be picked simultaneously.

As shown in fig. 1 to 3, the end effector 2 is used for gripping an apple when picking the apple, the end effector 2 includes a jaw seat 204, a main jaw 201 rotatably provided on the jaw seat 204, a sub-jaw 202 rotatably provided on the main jaw 201, and an elastic member 203 for applying an elastic force to the sub-jaw 202 to keep the sub-jaw 202 in contact with the apple, the main jaw 201 is provided in plurality and all the main jaws 201 are arranged circumferentially on the jaw seat 204, and at least one sub-jaw 202 is provided on each main jaw 201. The main clamping jaw 201 is of an arc-shaped structure, a first end of the main clamping jaw 201 is rotatably connected with the clamping jaw seat 204, the main clamping jaw 201 extends out towards the outer side of the clamping jaw seat 204, a second end of the main clamping jaw 201 is far away from the clamping jaw seat 204, and the first end and the second end of the main clamping jaw 201 are two opposite ends of the main clamping jaw 201 in the arc length direction. The opening/closing control device 3 is connected to the main jaw 201, and the opening/closing control device 3 controls the main jaw 201 to rotate relative to the jaw base 204 so as to switch the end effector 2 between the open state and the closed state. The jaw base 204 has a center line which is spatially perpendicular to a rotation center line of the main jaw 201 when rotating with respect to the jaw base 204, and all the main jaws 201 are uniformly distributed on the jaw base 204 in a circumferential direction with the center line of the jaw base 204 as a center line. The vertical distance between the first end of the main jaw 201 and the center line of the jaw holder 204 is fixed, and when the opening/closing control device 3 controls the main jaw 201 to rotate relative to the jaw holder 204, the vertical distance between the second end of the main jaw 201 and the center line of the jaw holder 204 changes. When the end effector 2 is switched from the closed state to the open state, the vertical distance between the second ends of the main jaws 201 and the center line of the jaw base 204 is gradually increased, the distance between the second ends of the main jaws 201 is gradually increased, and the end effector 2 is gradually opened to ensure that apples can be picked up or released; when the end effector 2 is switched from the open state to the closed state, the vertical distance between the second ends of the main jaws 201 and the center line of the jaw base 204 is gradually reduced, the distance between the second ends of the main jaws 201 is gradually reduced, and the end effector 2 is gradually closed, so that the apple can be clamped. When picking apples, the opening and closing control mechanism controls the end effector 2 to be switched to an opening state from a closing state, the main clamping jaws 201 are gradually opened, after the apples enter the space between the main clamping jaws 201, the opening and closing control mechanism controls the end effector 2 to be switched to the closing state from the opening state, the main clamping jaws 201 are gradually closed until the main clamping jaws 201 contact the apples, all the main clamping jaws 201 are matched to clamp the apples, meanwhile, the auxiliary clamping jaws 202 contact the apples, and the auxiliary clamping jaws 202 also apply certain pressure to the apples to finish picking actions of the apples.

As shown in fig. 1 to 3, the main jaw 201 has a main contact surface for contacting with an apple, the sub-jaw 202 has a sub-contact surface for contacting with an apple, the main contact surface and the sub-contact surface are both arc surfaces and the axes of the main contact surface and the sub-contact surface are parallel, the sub-jaw 202 is located at the inner side of the main jaw 201 and the elastic element 203 is clamped between the main jaw 201 and the sub-jaw 202. The main contact surface is the surface facing the apple on the main clamping jaw 201, the auxiliary contact surface is the surface facing the apple on the auxiliary clamping jaw 202, the axis of the main contact surface is parallel to the rotation center line of the main clamping jaw 201, the axis of the auxiliary contact surface is parallel to the rotation center line of the auxiliary clamping jaw 202, and the rotation center line of the auxiliary clamping jaw 202 is parallel to the rotation center line of the main clamping jaw 201. The auxiliary clamping jaw 202 is of an arc-shaped structure, the length of the auxiliary clamping jaw 202 is smaller than that of the main clamping jaw 201, the first end of the auxiliary clamping jaw 202 is rotatably connected with the main clamping jaw 201, the second end of the auxiliary clamping jaw 202 is far away from the main support, the first end and the second end of the auxiliary clamping jaw 202 are opposite ends of the auxiliary clamping jaw 202 in the arc length direction, the distance between the first end of the auxiliary clamping jaw 202 and the clamping jaw seat 204 is larger than that between the second end of the auxiliary clamping jaw 202 and the clamping jaw seat 204, the distance between the first end of the auxiliary clamping jaw 202 and the second end of the main clamping jaw 201 is smaller than that between the second end of the auxiliary clamping jaw 202 and the second end of the main clamping jaw 201, the main contact surface extends from the second end of the main clamping jaw 201 to the first end of the main auxiliary clamping jaw 202, and the auxiliary contact surface extends from the first end of the auxiliary clamping jaw 202 to the second end of the auxiliary clamping jaw 202. The elastic element 203 is clamped between the main clamping jaw 201 and the second end of the auxiliary clamping jaw 202, the elastic element 203 is preferably a cylindrical helical spring and is a compression spring, and when an apple is not picked up, the elastic acting force exerted by the elastic element 203 on the auxiliary clamping jaw 202 causes the second end of the auxiliary clamping jaw 202 to move away from the main clamping jaw 201, so that the second end of the auxiliary clamping jaw 202 gradually approaches to the center line of the clamping jaw seat 204. In the apple picking process, the end effector 2 is switched to the open state, after an apple enters between the main clamping jaws 201, the auxiliary clamping jaws 202 are in contact with the surface of the apple, in the process that the end effector 2 is switched from the open state to the closed state, under the action of the elastic element 203, certain pressure is applied to the apple by the auxiliary clamping jaws 202, the apple is pushed to move towards the direction far away from the clamping jaw seat 204 by the pressure applied to the apple by the auxiliary clamping jaws 202 until the surface of the apple is in contact with the main contact surface of the main clamping jaws 201, then the apple is clamped by all the main clamping jaws 201 in a matching mode, and the end effector 2 is switched to the closed state to complete the picking action of the apple. Due to the arrangement of the auxiliary clamping jaw 202, in the process that the end effector 2 picks up the apples and transfers the apples to the apple collecting basket on the chassis for collection, the auxiliary clamping jaw 202 can enable the apples to be kept in a contact state with the main clamping jaw 201, so that the apples can be more firmly grabbed, the apples are not easy to slide and fall off, and the reliability is high.

The end effector of the structure adopts the three main clamping jaws, is uniformly distributed on the circumference, has a self-centering structure on one hand, does not need to be accurately aligned with the center of an apple during picking, can be kept at the central position even if the apple deviates a little distance, can reduce the picking precision requirement, and is favorable for controlling the clamping force on the other hand. In addition, the structure of formula of enveloping is adopted, not only makes the apple be difficult for dropping, snatchs firmly, in addition because the area of contact of main clamping jaw and vice clamping jaw arcwall face is big for under the condition of not damaging the apple, increase clamping-force.

As shown in fig. 1 to 3, the opening/closing control device 3 includes an opening/closing control base 304, a movable block 301, a push-pull rod 302 rotatably connected to the movable block 301 and the main jaw 201, an opening/closing control motor 303 disposed on the opening/closing control base 304, and a transmission mechanism connected to the opening/closing control motor 303 and the movable block 301, the transmission mechanism includes a belt transmission mechanism 305 and a lead screw nut mechanism 306 connected in sequence, the opening/closing control base 304 is connected to the first angle adjusting device 4, and the jaw base 204 is connected to the opening/closing control base 304. The opening and closing control motor 303 is a motor for providing a rotating force, the opening and closing control motor 303 is fixedly arranged on the opening and closing control base 304, the opening and closing control base 304 is fixedly connected with the clamping jaw seat 204, the belt transmission mechanism 305 is used for transmitting the rotating force generated by the opening and closing control motor 303 to the screw rod nut mechanism 306, a driving belt wheel of the belt transmission mechanism 305 is connected with a motor shaft of the opening and closing control motor 303, a driven belt wheel of the belt transmission mechanism 305 is connected with one end of a screw rod of the screw rod nut mechanism 306, the movable block 301 is fixedly connected with a nut of the screw rod nut mechanism 306, a shaft hole for inserting the other end of the screw rod nut mechanism 306 is arranged in the center of the clamping jaw seat 204, the center line of the clamping jaw seat 204 is also the axis line of the screw rod nut mechanism 306, and the opening and closing control base 304 and the clamping jaw seat 204 provide a supporting effect for the screw rod of the screw rod nut mechanism 306. The movable block 301 is located between the jaw seat 204 and the opening and closing control base 304, the push-pull rod 302 is located on the outer side of the jaw seat 204, one end of the push-pull rod 302 is rotatably connected with the movable block 301, the other end of the push-pull rod 302 is rotatably connected with the main jaw 201, a connection point of the push-pull rod 302 and the main jaw 201 is located between the first end and the second end of the main jaw 201, a distance between the connection point of the push-pull rod 302 and the main jaw 201 and the first end of the main jaw 201 is smaller than a distance between the connection point of the push-pull rod 302 and the main jaw 201 and the second end of the main jaw 201, the number of the push-pull rods 302 is the same as that of the main jaws 201, and each push-pull rod 302 is rotatably connected with one main jaw 201. When the opening and closing control motor 303 operates, the generated power is transmitted to the lead screw and nut mechanism 306 through the belt transmission mechanism 305, the lead screw and nut mechanism 306 drives the movable block 301 to move along the axial direction, the movable block 301 drives the main clamping jaw 201 to rotate through the push-pull rod 302, and the switching of the end effector 2 between the opening state and the closing state is realized.

The opening and closing control device 3 having the above structure is actually a slider-rocker mechanism, and can convert the linear motion of the movable block 301 into the rotary motion of the clamping jaw and provide a certain clamping force. The mechanism has simple and compact structure, good forward and backward running characteristics and easy design and manufacture. The movable block 301 is driven by the ball screw mechanism 306, so that on one hand, accurate opening and closing control can be realized, for apples of different sizes, the opening angle of the clamping jaw can be adjusted, and the picking efficiency is improved to a certain extent; on the other hand, the screw transmission pair can provide a large axial force, the main clamping jaw 201 is provided with a force sensor, and the clamping force can be timely adjusted according to a feedback signal of the force sensor on the main clamping jaw 201.

As shown in fig. 1 to 4, the first angle adjusting device 4 includes a first adjusting base 401 rotatably connected to the open/close control device 3, a first adjusting motor 402 disposed on the first robot arm 9, a first transmission shaft 403 connected to the first adjusting motor 402, a sleeve 404 connected to the first adjusting base 401 and sleeved on the first transmission shaft 403, and a first transmission mechanism 405 connected to the first transmission shaft 403 and the open/close control device 3. The first adjusting base 401 is rotatably connected to the opening/closing control base 304, the first angle adjusting device 4 is used for controlling the opening/closing control base 304 to rotate relative to the first adjusting base 401, and a rotation center line of the opening/closing control base 304 when rotating relative to the first adjusting base 401 is perpendicular to a center line of the jaw base 204 and intersects with the center line. The first adjustment motor 402 is fixedly provided on the first robot arm 9, and the first adjustment motor 402 is a motor that provides a rotational force. The first transmission mechanism 405 is preferably a bevel gear mechanism, one end of the first transmission shaft 403 is connected to a motor shaft of the first adjustment motor 402, one end of the first transmission shaft 403 is fixedly connected to a drive bevel gear of the first transmission mechanism 405, and a driven bevel gear of the first transmission mechanism 405 is fixedly connected to the opening/closing control base 304. The shaft sleeve 404 is a hollow cylinder with two open ends, one end of the shaft sleeve 404 is fixedly connected with the first adjusting seat 401, the other end of the shaft sleeve 404 is located inside the first mechanical arm 9, the first mechanical arm 9 provides a supporting effect for the shaft sleeve 404, the first adjusting seat 401 is located outside the first mechanical arm 9, the shaft sleeve 404 provides a supporting effect for the first transmission shaft 403, and the first transmission shaft 403 penetrates through the shaft sleeve 404. When the first adjustment motor 402 operates, the rotational force generated by the first adjustment motor 402 is transmitted to the open/close control base 304 through the first transmission shaft 403 and the first transmission mechanism 405, the open/close control base 304 is driven to rotate relative to the first adjustment seat 401, and the open/close control base 304 drives the end effector 2 to synchronously rotate, thereby realizing the adjustment of the posture of the end effector 2.

As shown in fig. 1 to fig. 3, a first rotation control device 8 for controlling the first adjusting base 401 to rotate relative to the first robot arm 9 is disposed on the first robot arm 9, and the first rotation control device 8 includes a first rotation control motor 801 disposed on the first robot arm 9 and a transmission mechanism connected to the first rotation control motor 801 and the shaft sleeve 404, and the transmission mechanism is a gear transmission mechanism 802. The boss 404 is fixedly connected to the first adjustment base 401, and a rotation center line of the first adjustment base 401 when rotating with respect to the first robot arm 9 is perpendicular to a rotation center line of the opening/closing control device 3 when rotating with respect to the first adjustment base 401 and to a rotation center line of the first robot arm 9 when rotating with respect to the second robot arm 10. The first rotation control motor 801 is fixedly provided on the first robot arm 9, and the first rotation control motor 801 is a motor that provides a rotational force. The gear transmission mechanism 802 includes a driving gear and a driven gear which are engaged with each other, the driving gear of the gear transmission mechanism 802 is coaxially and fixedly connected with a motor shaft of the first rotation control motor 801, the driven gear of the gear transmission mechanism 802 is coaxially and fixedly connected with the shaft sleeve 404, and the driving gear and the driven gear of the gear transmission mechanism 802 are cylindrical gears. When the first rotation control motor 801 operates, the rotation force of the first rotation control motor 801 is transmitted to the shaft sleeve 404 through the gear transmission mechanism 802, the shaft sleeve 404 is driven to rotate relative to the first mechanical arm 9, the shaft sleeve 404 drives the opening and closing control device 3 and the end effector 2 to synchronously rotate through the first adjusting seat 401, and then the adjustment of the angle and the posture of the end effector 2 is realized.

In the first rotation control device 8 with the above structure, the first rotation control motor 801 is disposed outside, and the open gear transmission is adopted, so as to control the length of the first robot arm 9, and the structure is compact. The first adjustment motor 402 and the first rotation control motor 801 are almost side by side, and are different in that one is located inside the first robot arm 9 and the other is located outside, and the first adjustment motor 402 and the first rotation control motor 801 are designed in an overlapped manner, so that the length and the weight distribution of the first robot arm 9 are controlled, and on one hand, excessive deflection caused by excessive length and weight outward movement is avoided, and on the other hand, the angular momentum generated when the base rotates is reduced, and the load borne by the base is reduced. The first rotation control means 8 functions to the end effector 2 in that it can change the axis of the bevel gear in the first angle adjusting means 4 by rotating the shaft housing 404, thereby allowing the end effector 2 to pick up in a spherical work space.

As shown in fig. 1 to 4, the second angle adjusting device 5 is disposed on a second adjusting motor 501 of the second robot arm 10, and a second transmission mechanism 502 connected to the second adjusting motor 501 and the first robot arm 9, the second angle adjusting device 5 is configured to control the first robot arm 9 to rotate relative to the second robot arm 10, a rotation center line of the first robot arm 9 when rotating relative to the second robot arm 10 is spatially perpendicular to a center line of the gripper base 204, and a rotation center line of the first robot arm 9 when rotating relative to the second robot arm 10 is also spatially perpendicular to an axis of the shaft sleeve 404. The second adjusting motor 501 is fixedly arranged on the second mechanical arm 10, the second adjusting motor 501 is a motor for providing a rotating force, the first mechanical arm 9 has a certain length, one end of the first mechanical arm 9 in the length direction is rotatably connected with one end of the second mechanical arm 10, and the shaft sleeve 404 extends out from the other end of the first mechanical arm 9 in the length direction. The second transmission mechanism 502 is preferably a bevel gear mechanism, a driving bevel gear of the second transmission mechanism 502 is coaxially and fixedly connected with a motor shaft of the second adjusting motor 501, and a driven bevel gear of the second transmission mechanism 502 is coaxially and fixedly connected with the first mechanical arm 9. When the second adjusting motor 501 operates, the rotating force generated by the second adjusting motor 501 is transmitted to the first mechanical arm 9 through the second transmission mechanism 502, the first mechanical arm 9 is driven to rotate relative to the second mechanical arm 10, the first mechanical arm 9 drives the end effector 2 to synchronously rotate through the first angle adjusting device 4 and the opening and closing control device 3, and then the angle and the posture of the end effector 2 are adjusted.

As shown in fig. 1 to 5, the third angle adjusting device 7 is disposed on a third adjusting motor 701 of the third robot arm, and a third transmission mechanism 702 connected to the third adjusting motor 701 and the height adjusting device 6, the third angle adjusting device 7 is configured to control the second robot arm 10 to rotate relative to the height adjusting device 6, a rotation center line of the second robot arm 10 when rotating relative to the height adjusting device 6 is spatially perpendicular to a center line of the gripper base 204, and a rotation center line of the second robot arm 10 when rotating relative to the height adjusting device 6 is parallel to a rotation center line of the first robot arm 9 when rotating relative to the second robot arm 10. The third adjusting motor 701 is fixedly arranged on the second mechanical arm 10, the third adjusting motor 701 is a motor for providing a rotating force, the second mechanical arm 10 has a certain length, one end of the second mechanical arm 10 in the length direction is rotatably connected with the first mechanical arm 9, and the other end of the second mechanical arm 10 in the length direction is rotatably connected with the height adjusting device 6. The third transmission mechanism 702 is preferably a bevel gear mechanism, a driving bevel gear of the third transmission mechanism 702 is coaxially and fixedly connected with a motor shaft of the third adjusting motor 701, and a driven bevel gear of the third transmission mechanism 702 is fixedly connected with the height adjusting device 6. When the third adjusting motor 701 operates, the driving bevel gear is driven to rotate, the driven bevel gear is kept still, the driving bevel gear rolls along the driven bevel gear, the second mechanical arm 10 is driven to rotate relative to the height adjusting device 6, adjustment of the size of an included angle between the length direction of the second mechanical arm 10 and a vertical surface is achieved, the second mechanical arm 10 drives the end effector 2 to synchronously rotate through the first mechanical arm 9, the first angle adjusting device 4 and the opening and closing control device 3, and then adjustment of the angle and the posture of the end effector 2 is achieved.

As shown in fig. 1 to 6, the height adjustment device 6 is configured to control the second mechanical arm 10 to move along a vertical direction, the second mechanical arm 10 drives the end effector 2 to rotate synchronously through the first mechanical arm 9, the first angle adjustment device 4, and the opening/closing control device 3, so as to adjust the height position of the end effector 2, the height adjustment device 6 includes a sliding seat 601, a fixed seat 607, a height adjustment base 602, a height adjustment motor 603 disposed on the height adjustment base 602, and a height adjustment transmission mechanism connected to the height adjustment motor 603 and the sliding seat 601, which are connected in sequence, and the height adjustment transmission mechanism includes a gear transmission mechanism 604 and a nut screw mechanism 605. The height adjusting motor 603 is a motor for providing a rotating force, the height adjusting motor 603 is fixedly arranged on the height adjusting base 602, the gear transmission mechanism 604 is used for transmitting the rotating force generated by the height adjusting motor 603 to the feed screw nut mechanism 605, a driving gear and a driven gear of the gear transmission mechanism 604 are both cylindrical gears, the driving gear of the gear transmission mechanism 604 is connected with a motor shaft of the height adjusting motor 603, the driven gear of the gear transmission mechanism 604 is connected with one end of a feed screw of the feed screw nut mechanism 605, the sliding seat 601 is fixedly connected with a nut of the feed screw nut mechanism 605, a shaft hole for inserting the other end of the feed screw nut mechanism 605 is arranged in the center of the fixed seat 607, the feed screw of the feed screw nut mechanism 605 is vertically arranged, and the height adjusting base 602 and the fixed seat 607 provide a supporting function for the feed screw of the feed screw nut mechanism 605. The sliding seat 601 is located between the fixed seat 607 and the height adjusting base 602, the height adjusting base 602 is located below the sliding seat 601, the fixed seat 607 is located above the sliding seat 601, the sliding seat 601 is rotatably connected with the upper end of the second mechanical arm 10, and the driven bevel gear of the third transmission mechanism 702 is fixedly connected with the sliding seat 601. The height adjusting base 602 is provided with guide posts 606 for guiding the sliding seat 601, the guide posts 606 are vertically arranged, the axes of the guide posts 606 are parallel to the axis of the lead screw nut mechanism 605, the guide posts 606 are provided with a plurality of guide posts 606, all the guide posts 606 are uniformly distributed along the circumferential direction by taking the axis of the lead screw nut mechanism 605 as the central line, and the sliding seat 601 is provided with guide holes for the guide posts 606 to pass through. When the height adjusting motor 603 operates, the generated power is transmitted to the lead screw and nut mechanism 605 through the gear transmission mechanism 604, the lead screw and nut mechanism 605 drives the sliding seat 601 to move along the vertical direction, and the sliding seat 601 drives the second mechanical arm 10 to move synchronously, so that the height position of the end effector 2 is adjusted.

As shown in fig. 1 and 6, in the present embodiment, three guide posts 606 are provided in total.

The height adjusting device 6 of the above structure is actually a screw elevator. The mechanical arm has the advantages of stable lifting process, small reversing impact, capability of realizing accurate control in the height direction, and capability of stabilizing the mechanical arm by means of a brake in an alternating current servo motor although self-locking cannot be formed. The three guide posts 606 are uniformly distributed in the circumferential direction, so that on one hand, the sliding direction of the sliding seat 601 is controlled, the degree of freedom is limited, and the end face of the sliding seat is kept horizontal to the base; on the other hand, the overturning moment generated by the cantilever on one side is borne, and the linear bearing is arranged between the guide hole and the guide column 606, so that the friction, the control precision and the bearing moment can be reduced.

As shown in fig. 1 to 6, a second rotation control motor 12 for controlling the rotation of the height adjusting base 602 relative to the chassis 1 is provided on the chassis 1, and the rotation center line of the height adjusting base 602 when rotating relative to the chassis 1 is a vertical line. The height adjusting base 602 is rotatably disposed on the chassis 1, the second rotation control motor 12 is a motor for providing a rotation force, the second rotation control motor 12 is fixedly disposed on the chassis 1, and a motor shaft of the second rotation control motor 12 is fixedly connected to the height adjusting base 602 at a center of the height adjusting base 602. After the second rotation control motor 12 operates, the second rotation control motor 12 can drive the height adjustment base 602 to rotate around the axis thereof, the height adjustment base 602 drives the second mechanical arm 10 to rotate synchronously through the sliding seat 601, and the second mechanical arm 10 drives the end effector 2 to rotate synchronously through the first mechanical arm 9, the first angle adjustment device 4 and the opening and closing control device 3, so as to adjust the posture of the end effector 2.

The picking manipulator of the structure is a six-degree-of-freedom mechanical arm, has extremely high flexibility, and can pick apples at any positions. The six degrees of freedom include a movement degree of freedom, namely a screw nut lifting mechanism, so that the working range of the mechanical arm can cover apples at higher positions, and the three degrees of freedom of rotation of the first mechanical arm 9, the second mechanical arm 10 and the wrist (corresponding to the joint of the first adjusting seat 401 and the opening and closing control base 304) can execute more complicated fruit stem separation actions.

The invention is described above with reference to the accompanying drawings. It is to be understood that the specific implementations of the invention are not limited in this respect. Various insubstantial improvements are made by adopting the method conception and the technical scheme of the invention; the present invention is not limited to the above embodiments, and can be modified in various ways.

Claims

1. Robot is picked to multi-arm apple, its characterized in that: the picking manipulator comprises an end effector, an opening and closing control device for controlling the end effector to be switched between an opening state and a closing state, a first mechanical arm, a second mechanical arm, a first angle adjusting device arranged on the first mechanical arm and used for controlling the opening and closing control device to rotate, a second angle adjusting device arranged on the second mechanical arm and used for controlling the first mechanical arm to rotate, a height adjusting device used for adjusting the height position of the second mechanical arm and a third angle adjusting device connected with the height adjusting device and the second mechanical arm and used for controlling the second mechanical arm to rotate;

the end effector is used for clamping apples when picking apples, and comprises a jaw seat, three main jaws rotatably arranged on the jaw seat, auxiliary jaws rotatably arranged on the main jaws and elastic elements for applying elastic acting force to the auxiliary jaws to enable the auxiliary jaws to be in contact with the apples, all the main jaws are circumferentially arranged on the jaw seat, and each main jaw is provided with at least one auxiliary jaw; the main clamping jaw is of an arc-shaped structure, the first end of the main clamping jaw is rotatably connected with the clamping jaw seat, the main clamping jaw extends out towards the outer side of the clamping jaw seat, the second end of the main clamping jaw is far away from the clamping jaw seat, and the first end and the second end of the main clamping jaw are two opposite ends of the main clamping jaw in the arc length direction;

the opening and closing control device is connected with the main clamping jaw and used for controlling the main clamping jaw to rotate relative to the clamping jaw seat so as to realize the switching of the end effector between an opening state and a closing state; the clamping jaw seat is provided with a central line which is vertical to a rotating central line of the main clamping jaw when rotating relative to the clamping jaw seat in space, and all the main clamping jaws are uniformly distributed on the clamping jaw seat along the circumferential direction by taking the central line of the clamping jaw seat as the central line; the vertical distance between the first end of the main clamping jaw and the central line of the clamping jaw seat is fixed, and when the opening and closing control device controls the main clamping jaw to rotate relative to the clamping jaw seat, the vertical distance between the second end of the main clamping jaw and the central line of the clamping jaw seat changes; when the end effector is switched from a closed state to an open state, the vertical distance between the second ends of the main clamping jaws and the central line of the clamping jaw seat is gradually increased, the distance between the second ends of the main clamping jaws is gradually increased, and the end effector is gradually opened to ensure that apples can be picked up or released; when the end effector is switched from the open state to the closed state, the vertical distance between the second ends of the main clamping jaws and the central line of the clamping jaw seat is gradually reduced, the distance between the second ends of the main clamping jaws is gradually reduced, and the end effector is gradually closed to ensure that the apple can be clamped; when apples are picked, the opening and closing control mechanism controls the end effector to be switched from a closed state to an open state, the main clamping jaws are gradually opened, after the apples enter the space between the main clamping jaws, the opening and closing control mechanism controls the end effector to be switched from the open state to the closed state, the main clamping jaws are gradually closed until the main clamping jaws contact the apples, all the main clamping jaws are matched to clamp the apples, meanwhile, the auxiliary clamping jaws contact the apples, and certain pressure is applied to the apples by the auxiliary clamping jaws to finish picking actions of the apples;

the main clamping jaw is provided with a main contact surface for contacting with the apple, the auxiliary clamping jaw is provided with an auxiliary contact surface for contacting with the apple, the main contact surface and the auxiliary contact surface are both arc surfaces, the axes of the main contact surface and the auxiliary contact surface are parallel, the auxiliary clamping jaw is positioned on the inner side of the main clamping jaw, and the elastic element is clamped between the main clamping jaw and the auxiliary clamping jaw; the main contact surface is the apple-facing surface on the main clamping jaw, the auxiliary contact surface is the apple-facing surface on the auxiliary clamping jaw, the axis of the main contact surface is parallel to the rotation central line of the main clamping jaw, the axis of the auxiliary contact surface is parallel to the rotation central line of the auxiliary clamping jaw, and the rotation central line of the auxiliary clamping jaw is parallel to the rotation central line of the main clamping jaw; the auxiliary clamping jaw is of an arc-shaped structure, the length of the auxiliary clamping jaw is smaller than that of the main clamping jaw, the first end of the auxiliary clamping jaw is rotatably connected with the main clamping jaw, the second end of the auxiliary clamping jaw is far away from the main support, the first end and the second end of the auxiliary clamping jaw are opposite ends in the arc length direction of the auxiliary clamping jaw, the distance between the first end of the auxiliary clamping jaw and the clamping jaw seat is larger than the distance between the second end of the auxiliary clamping jaw and the clamping jaw seat, the distance between the first end of the auxiliary clamping jaw and the second end of the main clamping jaw is smaller than the distance between the second end of the auxiliary clamping jaw and the second end of the main clamping jaw, the distance between the second end of the auxiliary clamping jaw and the first end of the main clamping jaw is smaller than the distance between the first end of the auxiliary clamping jaw and the first end of the main clamping jaw, the main contact surface extends from the second end of the main clamping jaw to the first end of the auxiliary clamping jaw, and the auxiliary contact surface extends from the first end of the auxiliary clamping jaw to the second end of the auxiliary clamping jaw; the elastic element is clamped between the main clamping jaw and the second end of the auxiliary clamping jaw, the elastic element is a cylindrical spiral spring and a compression spring, and when the apple is not picked up, the second end of the auxiliary clamping jaw moves towards the direction far away from the main clamping jaw under the elastic acting force applied by the elastic element to the auxiliary clamping jaw, so that the second end of the auxiliary clamping jaw is gradually close to the central line of the clamping jaw seat; in the apple picking process, the end effector is switched to an open state, the auxiliary clamping jaws are in contact with the surface of an apple after the apple enters the space between the main clamping jaws, in the process that the end effector is switched from the open state to a closed state, certain pressure is applied to the apple by the auxiliary clamping jaws under the action of the elastic element, the pressure applied to the apple by the auxiliary clamping jaws pushes the apple to move towards the direction away from the clamping jaw seat until the surface of the apple is in contact with the main contact surface of the main clamping jaws, then the apple is clamped by all the main clamping jaws in a matched mode, and the end effector is switched to the closed state to complete the picking action of the apple;

the opening and closing control device comprises an opening and closing control base, a movable block, a push-pull rod, an opening and closing control motor and a transmission mechanism, wherein the push-pull rod is rotatably connected with the movable block and the main clamping jaw; the opening and closing control motor is a motor for providing a rotating force, the opening and closing control motor is fixedly arranged on the opening and closing control base, the opening and closing control base is fixedly connected with the clamping jaw seat, the belt transmission mechanism is used for transmitting the rotating force generated by the opening and closing control motor to the screw rod nut mechanism, a driving belt wheel of the belt transmission mechanism is connected with a motor shaft of the opening and closing control motor, a driven belt wheel of the belt transmission mechanism is connected with one end of a screw rod of the screw rod nut mechanism, a movable block is fixedly connected with a nut of the screw rod nut mechanism, a shaft hole for inserting the other end of the screw rod nut mechanism is formed in the center of the clamping jaw seat, the central line of the clamping jaw seat is also the axis of the screw rod nut mechanism, and the opening and closing control base and the clamping jaw seat provide a supporting effect for the screw rod of the screw rod nut mechanism; the movable block is positioned between the jaw clamping seat and the opening and closing control base, the push-pull rod is positioned on the outer side of the jaw clamping seat, one end of the push-pull rod is rotatably connected with the movable block, the other end of the push-pull rod is rotatably connected with the main jaw, the connection point of the push-pull rod and the main jaw is positioned between the first end and the second end of the main jaw, the distance between the connection point of the push-pull rod and the main jaw and the first end of the main jaw is smaller than the distance between the connection point of the push-pull rod and the main jaw and the second end of the main jaw, the number of the push-pull rods is the same as that of the main jaws, and each push-pull rod is rotatably connected with one main jaw; when the opening and closing control motor operates, the generated power is transmitted to the screw rod nut mechanism through the belt transmission mechanism, the screw rod nut mechanism drives the movable block to move along the axial direction, the movable block drives the main clamping jaw to rotate through the push-pull rod, and the switching of the end effector between an opening state and a closing state is realized;

the first angle adjusting device comprises a first adjusting seat rotationally connected with the opening and closing control device, a first adjusting motor arranged on the first mechanical arm, a first transmission shaft connected with the first adjusting motor, a shaft sleeve connected with the first adjusting seat and sleeved on the first transmission shaft, and a first transmission mechanism connected with the first transmission shaft and the opening and closing control device; the first angle adjusting device is used for controlling the opening and closing control base to rotate relative to the first adjusting base, and a rotating center line of the opening and closing control base when rotating relative to the first adjusting base is perpendicular to a center line of the clamping jaw seat and intersected with the center line; the first adjusting motor is fixedly arranged on the first mechanical arm and is a motor for providing rotating force; the first transmission mechanism is a bevel gear mechanism, one end of a first transmission shaft is connected with a motor shaft of the first adjusting motor, one end of the first transmission shaft is fixedly connected with a driving bevel gear of the first transmission mechanism, and a driven bevel gear of the first transmission mechanism is fixedly connected with the opening-closing control base; the shaft sleeve is a cylinder with two open ends and a hollow interior, one end of the shaft sleeve is fixedly connected with the first adjusting seat, the other end of the shaft sleeve is positioned in the first mechanical arm, the first mechanical arm provides a supporting effect for the shaft sleeve, the first adjusting seat is positioned outside the first mechanical arm, the shaft sleeve provides a supporting effect for the first transmission shaft, and the first transmission shaft penetrates through the shaft sleeve; when the first adjusting motor operates, the rotating force generated by the first adjusting motor is transmitted to the opening and closing control base through the first transmission shaft and the first transmission mechanism, the opening and closing control base is driven to rotate relative to the first adjusting base, and the opening and closing control base drives the end effector to synchronously rotate so as to adjust the posture of the end effector;

the first mechanical arm is provided with a first rotation control device for controlling the first adjusting seat to rotate relative to the first mechanical arm, the first rotation control device comprises a first rotation control motor arranged on the first mechanical arm and a transmission mechanism connected with the first rotation control motor and a shaft sleeve, and the transmission mechanism is a gear transmission mechanism; the shaft sleeve is fixedly connected with the first adjusting seat, and a rotating center line of the first adjusting seat when rotating relative to the first mechanical arm is vertical to a rotating center line of the opening and closing control device when rotating relative to the first adjusting seat and vertical to a rotating center line of the first mechanical arm when rotating relative to the second mechanical arm; the first rotation control motor is fixedly arranged on the first mechanical arm and is a motor for providing a rotating force; the gear transmission mechanism comprises a driving gear and a driven gear which are meshed with each other, the driving gear of the gear transmission mechanism is coaxially and fixedly connected with a motor shaft of the first rotation control motor, the driven gear of the gear transmission mechanism is coaxially and fixedly connected with the shaft sleeve, and the driving gear and the driven gear of the gear transmission mechanism are cylindrical gears; when the first rotary control motor operates, the rotating force of the first rotary control motor is transmitted to the shaft sleeve through the gear transmission mechanism, the driving shaft sleeve rotates relative to the first mechanical arm, the shaft sleeve drives the opening and closing control device and the end effector to synchronously rotate through the first adjusting seat, and then the angle and the posture of the end effector are adjusted.

2. The multi-arm apple picking robot of claim 1, wherein: the second angle adjusting device is arranged on a second adjusting motor on the second mechanical arm and a second transmission mechanism connected with the second adjusting motor and the first mechanical arm.

3. The multi-arm apple picking robot of claim 1, wherein: the third angle adjusting device is arranged on a third adjusting motor on the second mechanical arm and a third transmission mechanism connected with the third adjusting motor and the height adjusting device.

4. The multi-arm apple picking robot of claim 1, wherein: the height adjusting device is connected with the second mechanical arm in a rotating mode, and comprises a sliding seat, a height adjusting base, a height adjusting motor and a height adjusting transmission mechanism, wherein the sliding seat is connected with the second mechanical arm in a rotating mode, the height adjusting motor is arranged on the height adjusting base, the height adjusting transmission mechanism is connected with the height adjusting motor and the sliding seat, and the height adjusting transmission mechanism comprises a gear transmission mechanism and a lead screw nut mechanism which are connected in sequence.

5. The multi-arm apple picking robot of claim 4, wherein: and a second rotation control motor for controlling the height adjusting base to rotate relative to the chassis is arranged on the chassis, and the rotation center line of the height adjusting base when rotating relative to the chassis is a vertical line.