CN110663358A

CN110663358A - Mechanical arm for adjusting inclination angle based on line driving and fruit picking device

Info

Publication number: CN110663358A
Application number: CN201910934968.4A
Authority: CN
Inventors: 李安海; 葛德俊; 张承前
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2020-01-10

Abstract

The invention discloses a mechanical arm for adjusting an inclination angle based on line driving and a fruit picking device, which comprise a first arm, a second arm and a connecting plate, wherein one end of the connecting plate is hinged with the first arm through a first pin shaft, the other end of the connecting plate is hinged with the second arm through a second pin shaft, one end of the first arm close to the connecting plate is provided with a first arc surface, one end of the second arm close to the connecting plate is provided with a second arc surface tangent to the first arc surface, the second arc surface rolls along the first arc surface in the circumferential direction under the constraint of the connecting plate and does not slide relatively, an included angle formed by the axes of the first arm and the second arm is changed, the arc contact surface between the mechanical arms is matched with a pulley block for driving, and the fixed pulley-movable pulley winding mode of a steel cable is matched to realize the tension amplification effect, so that the driving moment of a motor is reduced, and the rotational inertia of the tail end of the mechanical, the effects of more accurate position adjustment and quick response are achieved.

Description

Mechanical arm for adjusting inclination angle based on line driving and fruit picking device

Technical Field

The application relates to the field of agricultural equipment, in particular to a mechanical arm and a fruit picking device based on a line drive adjusting inclination angle.

Background

Along with the rapid development of the orchard industry, the machine for picking fruits is gradually popularized, wherein the fruit picking robot becomes important labor force for replacing manpower, the labor intensity of workers can be reduced, the product quality can be better controlled, and the fruits can be harvested in time.

The inventor finds that the currently used fruit picking robot has various types, for a robot with a joint type mechanical arm as a main operation element, because a motor, a reducer and the like are concentrated at the joint tail end of the mechanical arm, the moment of inertia of the tail end of the mechanical arm is increased due to the heavy element, but the fruit on a fruit tree is densely distributed, and the execution tail end needs to be frequently adjusted in a small range.

Disclosure of Invention

The purpose of this application is to the defect that prior art exists, provides a arm and fruit picking device based on line drive adjusts inclination, and circular arc contact surface cooperation assembly pulley drive through between the arm has realized the effect that tension enlargies in the fixed pulley-movable pulley wire winding mode of cooperation steel cable to reduce the drive moment of motor, reduced the terminal inertia of arm, reached the effect of more accurate position adjustment and quick response.

The first purpose of this application is to provide a mechanical arm based on line drive adjusts inclination, adopts following technical scheme:

including first arm, second arm and connecting plate, the one end of connecting plate is articulated through first round pin axle with first arm, and the other end is articulated through second round pin axle with the second arm, the one end that first arm is close to the connecting plate is equipped with first arc surface, and the one end that the second arm is close to the connecting plate is equipped with the second arc surface tangent with first arc surface, the second arc surface rolls and does not take place relative slip along first arc surface circumference under the restraint of connecting plate, changes the contained angle that first arm and second arm axis formed.

Furthermore, the two sides of the first arm are respectively provided with a first pulley block and a second pulley block, the two sides of the second arm are respectively provided with a third pulley block and a fourth pulley block, the first arm is further provided with a driving wheel, the driving wheel is matched with a transmission rope, one end of the transmission rope is fixed on the first pulley block, the other end of the transmission rope sequentially bypasses the third pulley block, the driving wheel and the fourth pulley block and then is fixed on the second pulley block, and the driving wheel changes the axial distance between the first pulley block and the third pulley block and the axial distance between the second pulley block and the fourth pulley block through driving the transmission rope and is used for driving the second arm to rotate around the axis of the first arc surface.

Furthermore, the axes of the first arc surface, the first pulley block and the second pulley block are coplanar; and the axes of the second arc surface, the third pulley block and the fourth pulley block are coplanar.

Furthermore, a tensioning wheel is arranged on the first arm and/or the second arm, and the tensioning wheel is used for being matched with the transmission rope to tension.

The second purpose of this application is to provide a fruit picking device, adopts following technical scheme:

the mechanical arm with the inclination angle adjusted based on the linear driving is characterized by comprising a base and the mechanical arm with the inclination angle adjusted based on the linear driving, wherein a driving arm is installed on the base, the tail end of the driving arm is hinged to a first arm of the mechanical arm with the inclination angle adjusted based on the linear driving, and the driving arm can rotate around the axis of the driving arm and can change the included angle between the tail end of the driving arm and the first arm.

Furthermore, a manipulator is installed at one end, far away from the first arm, of the second arm, the manipulator is installed at the tail end of the second arm through a revolute pair and used for changing a horizontal included angle between the manipulator and the second arm, and the manipulator is used for grabbing and picking fruits.

Furthermore, a conveying pipe is arranged below the manipulator, one end of the conveying pipe is communicated with the collecting box, and the other end of the conveying pipe faces the manipulator and is used for bearing fruits picked by the manipulator and conveying the fruits into the collecting box through the conveying pipe.

Furthermore, the conveying pipe is a hose, one end close to the manipulator can change along with the position of the manipulator, and the conveying pipe is positioned below the manipulator and is kept facing the manipulator.

Furthermore, the manipulator comprises a grabbing part and a cutter, the cutter is fixed, and the grabbing part is used for driving the fruit, enabling the handle part of the fruit to contact with the cutter and cutting off the handle part.

Compared with the prior art, the application has the advantages and positive effects that:

(1) the arc surfaces of the contact parts of the first arm and the second arm are arranged, the two arc surfaces are in tangential contact, and are matched with the pulley block drive of the upper side and the lower side, so that the steel cables of the upper side and the lower side can be ensured to do symmetrical antagonistic linear motion to sequentially prevent the contact parts of the arc surfaces of the first arm and the second arm from sliding, thereby ensuring that pure rolling is realized, achieving the effect of accurately adjusting the included angle of the first arm and the second arm, adopting pure rolling transmission, avoiding response delay caused by sliding, and ensuring quick response in the mechanical arm adjusting process;

(2) the transmission rope is wound on the labor-saving pulley block formed by the fixed pulley and the movable pulley, so that the tension is amplified, the required driving torque is reduced, and compared with the existing joint manipulator, the size of a driving element can be reduced, so that the rotational inertia of the mechanical arm is reduced, the rigidity of the mechanical arm is increased, and the mechanical arm is suitable for small-amplitude high-frequency angle adjustment;

(3) the rotary mechanism at the bottom is matched with the rotary mechanism of the end effector, and only the rotary mechanism at the tail end is adjusted when the rotary mechanism acts in a small range, so that the driving frequency of the rotary mechanism at the bottom is reduced, and the effects of quickness, response and more flexible small-range action are achieved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.

Fig. 1 is a schematic view of the overall structure of a robot arm and a base according to embodiment 1 of the present application;

fig. 2 is a schematic structural view of an end effector in embodiment 1 of the present application;

fig. 3 is a schematic winding view of the steel cable according to embodiment 1 of the present invention.

Wherein: 1, a base; 2, a slewing mechanism; 3 driving the arm; 4 a first motor; 5 a first arm; 6 a second motor; 7, a transmission rope; 8 a first tensioning wheel base; 9 a first tensioning wheel; 10 a first sheave base; 11 a first pulley block; 12 connecting plates; 13 a third pulley block; 14 a third sheave base; 15 a second arm; 16 rotating cylinder connecting plates; 17 rotating the cylinder; 18 telescopic cylinder connecting plates; 19 telescopic cylinders; 20, a knife handle; 21, a blade; 22 an opening and closing cylinder; 23 a first grasping finger; 24 opening and closing cylinder connecting plates; 25 conveying pipes; 26 a collection box; 27 a second tensioning wheel mount; 28 a second tensioning wheel; 29 a second sheave mount; 30 a second pulley block; 31 a fourth pulley block; 32 a fourth sheave base; 33 second gripper finger.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an", and/or "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof;

for convenience of description, the words "up", "down", "left" and "right" in this application, if any, merely indicate correspondence with the directions of up, down, left and right of the drawings themselves, and do not limit the structure, but merely facilitate the description of the invention and simplify the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

The terms "mounted", "connected", "fixed", and the like in the present application should be understood broadly, and for example, the terms "mounted", "connected", and "fixed" may be fixedly connected, detachably connected, or integrated; the two components can be connected mechanically or electrically, directly or indirectly through an intermediate medium, or connected internally or in an interaction relationship, and the terms used in the present invention should be understood as having specific meanings to those skilled in the art.

Just as introduced in the background art, in the prior art, because motors, speed reducers and the like are all concentrated on the tail ends of all joints of a mechanical arm, the moment of inertia of the tail ends of the mechanical arm can be increased due to heavy elements, but the distribution of fruits on fruit trees is dense, frequent small-range adjustment needs to be carried out on the execution tail ends, and when the low load and the application needing quick response are carried out, the mechanical arm is difficult to achieve quick response and accurate adjustment, so that the tail end parts of the mechanical arm are difficult to accurately reach the designated position, the picking efficiency of the fruits is lowered, and aiming at the technical problems, the mechanical arm and the fruit picking device with the inclination angle adjusted based on line driving are provided.

Example 1

In a typical embodiment of the present application, as shown in fig. 1-3, a fruit picking apparatus is provided with a robot arm that adjusts an inclination angle based on a line drive.

As shown in fig. 1, the device comprises a base 1, wherein a driving arm 3 and a collecting box are arranged at the upper part of the base, the driving arm is mounted on the base through a swing mechanism 2, and the swing mechanism can drive the driving arm to perform a swing motion in a horizontal plane, so that the orientation of the driving arm is adjusted to adjust the operation range; the rotary mechanism can select a revolute pair, and is driven by matching a motor with a gear to drive the rotary mechanism to rotate.

The mechanical arm is arranged at one end, far away from the base, of the driving arm and used for adjusting the inclination angle based on line driving, the mechanical arm is arranged at one end, far away from the driving arm, of the mechanical arm and used for picking fruits based on the line driving and the inclination angle adjusting, and the mechanical arm is arranged at one end, far away from the driving arm, of the mechanical.

The mechanical arm for adjusting the inclination angle based on the line driving comprises a first arm 5, a second arm 15 and a connecting plate, wherein one end of the connecting plate is hinged with the first arm through a first pin shaft, the other end of the connecting plate is hinged with the second arm through a second pin shaft, a first arc surface is arranged at one end, close to the connecting plate, of the first arm, a second arc surface tangent to the first arc surface is arranged at one end, close to the connecting plate, of the second arm, the second arc surface rolls along the circumferential direction of the first arc surface under the constraint of the connecting plate and does not slide relatively, and the included angle formed by the axes of the first arm and the second arm is changed; a first arm of the mechanical arm for adjusting the inclination angle based on linear driving is hinged to the driving arm, and a first motor 4 is matched at the hinged point and used for driving the first arm to rotate around the hinged point to change the included angle between the driving arm and the first arm.

Specifically, the first motor drives the first arm through the speed reducer, so that on one hand, the force of the first motor on the first arm can be improved, on the other hand, the position of the first motor is convenient to adjust, and the rotational inertia of the tail end of the first motor is improved; the first arc surface and the second arc surface are both arc surfaces with the same radius, and the two arc surfaces are kept in close contact; in order to improve the connection stability between first arm and the second arm, the connecting plate have two, correspond respectively and install the both ends at the round pin axle, can both form stable restraint to the both ends of two round pin axles.

Furthermore, for the driving part, two sides of the first arm are respectively provided with a first pulley block and a second pulley block, two sides of the second arm are respectively provided with a third pulley block and a fourth pulley block, the first arm is also provided with a driving wheel, the driving wheel is matched with a transmission rope 7, one end of the transmission rope is fixed on the first pulley block, the other end of the transmission rope sequentially rounds the third pulley block, the driving wheel and the fourth pulley block and then is fixed on the second pulley block, and the driving wheel changes the axial distance between the first pulley block and the third pulley block and the axial distance between the second pulley block and the fourth pulley block by driving the transmission rope and is used for driving the second arm to rotate around the axis of the first arc surface; the driving wheel is matched with a second motor 6, in the embodiment, the second motor is arranged at the middle section of the first arm, and an output shaft is matched with the driving wheel through a speed reducer; the transmission rope is a steel cable;

the axes of the first arc surface, the first pulley block and the second pulley block are coplanar; the axes of the second arc surface, the third pulley block and the fourth pulley block are coplanar; and a tensioning wheel is arranged on the first arm and/or the second arm and is used for being tensioned by matching with a transmission rope.

Specifically, in this embodiment, referring to fig. 1, a first pulley base 10 is fixed above the first arm 5 near the hinge of the connecting plate 12, and a first pulley block 11 is installed on the upper portion of the first pulley base 10; a second pulley base 29 is fixed below the first arm 5 close to the hinged part of the connecting plate 12, a second pulley block 30 is installed at the lower part of the second pulley base 29, the distance between the circle center of the first pulley block 11 and the circle center of the second pulley block 30 is equal to that of the first arc surface of the first arm 5, and three points are collinear. A first tensioning wheel base 8 is fixed at the position, far away from the hinge joint of the connecting plate 12, of the outer side of the first arm 5, and a first tensioning wheel 9 is installed at the upper part of the first tensioning wheel base 8; a second tensioning wheel base 27 is fixed at the hinged position of the inner side of the first arm 5 far away from the connecting plate 12, and a second tensioning wheel 28 is installed at the lower part of the second tensioning wheel base 27. A third pulley base 14 is fixed on the outer side of the second arm 15, and a third pulley block 13 is installed on the upper part of the third pulley base 14; a fourth pulley base 32 is fixed on the inner side of the second arm 15, a fourth pulley block 31 is installed on the upper portion of the fourth pulley base 32, the distance between the circle center of the third pulley block 13 and the circle center of the fourth pulley block 31 is equal to the distance between the circle center of the second arc surface of the second arm 15, the three points are collinear, the distance between the circle center of the third pulley block 13 and the circle center of the second arc surface of the second arm 15 is equal to the distance between the circle center of the first pulley block 11 and the circle center of the first arc surface of the first arm 5, and therefore it can be guaranteed that the steel cable does antagonistic linear motion and the two arc surfaces of the first arm 5 and the second arm 15 do rolling contact motion all the time.

The wire winding mode of the steel cable is as shown in fig. 3, the first pulley block, the second pulley block, the third pulley block and the fourth pulley block respectively comprise two pulleys coaxially arranged, one end of the steel cable is fixed on one pulley of the first pulley block, and then is fixed on the other pulley of the second pulley block after sequentially passing around one pulley of the third pulley block, the other pulley of the first pulley block, the other pulley of the third pulley block, the first tensioning wheel, the driving wheel, the second tensioning wheel, one pulley of the fourth pulley block, one pulley of the second pulley block and the other pulley of the fourth pulley block, so as to complete the closed-loop transmission of the whole pulley mechanism; the wire winding mode of the steel cable can realize the effect of amplifying tension, thereby reducing the driving torque of the motor, saving energy and simultaneously increasing the rigidity of the mechanical arm.

Furthermore, a manipulator is mounted at one end, far away from the first arm, of the second arm, the manipulator is mounted at the tail end of the second arm through a revolute pair and used for changing a horizontal included angle between the manipulator and the second arm, and the manipulator is used for grabbing and picking fruits; the manipulator comprises a grabbing part and a cutter, the cutter is fixed, and the grabbing part is used for driving the fruit, enabling the handle part of the fruit to contact the cutter and cutting off the handle part;

preferably, in order to receive picked fruits, a conveying pipe is arranged below the manipulator, one end of the conveying pipe is communicated with the collecting box, and the other end of the conveying pipe faces the manipulator and is used for receiving the fruits picked by the manipulator and conveying the fruits into the collecting box through the conveying pipe.

Specifically, in this embodiment, a rotating cylinder connecting plate 16 is fixed at the end of the first arm 15, the rotating cylinder 17 is installed at the lower part of the rotating cylinder connecting plate 16, the cylindrical part of the telescopic cylinder connecting plate 18 is fixed at the rotating part of the rotating cylinder 17, a telescopic cylinder 19 is installed at the end of the telescopic cylinder connecting plate 18, one side of an opening and closing cylinder connecting plate 24 is fixed at the telescopic part of the telescopic cylinder 19, an opening and closing cylinder 22 is installed at the other side of the opening and closing cylinder connecting plate 24, a first clamping finger 23 and a second clamping finger 33 for clamping an apple are respectively fixed at two symmetrical opening and closing parts of the opening and closing cylinder 22, and rubber layers are attached to the inner sides of the first clamping finger 23 and the second clamping finger 33 to prevent the clamping force from damaging the. The upper part of the telescopic cylinder connecting plate 18 is also fixed with a knife handle 20, and the tail end of the knife handle 20 is provided with a blade 21 for cutting off fruit stalks. A delivery pipe 25 is also mounted on the inside of the first arm 15, the end of the delivery pipe 25 leading into a collection tank 26.

In addition, the conveying pipe is a hose, one end close to the manipulator can change along with the position of the manipulator, and the conveying pipe is positioned below the manipulator and keeps facing the manipulator; in the process that the manipulator changes the relative position with the collecting box, the upper end of the hose can be kept below the manipulator and is communicated with the collecting box; the inside of the collecting box is pasted with a plastic foam plate to prevent the fruits from being damaged after entering the collecting box from the conveying pipe.

The working process of the fruit picking device of the application is described with reference to the attached drawings:

wheels are arranged below the base 1 and used for walking in an orchard, the swing mechanism can drive the driving arm 3 to rotate so as to enable the whole picking manipulator to rotate, the first motor 4 can drive the first arm 5 to enable the first arm to do pitching motion at a certain angle, then the second motor 6 does confrontation linear motion with a tension amplification effect by driving a steel cable, the second arc surface of the second arm 15 is driven to do rolling motion around the first arc surface at the tail end of the first arm 5, and therefore the second arm 15 achieves pitching motion at a certain angle. Then the rotary cylinder 17 can stop at three positions of-90 °, 0 ° and 90 ° relative to the original position of fig. 2, so as to increase the degree of freedom of the end effector, then the telescopic cylinder 19 extends forward, the opening and closing cylinder 22 drives the first clamping finger 23 and the second clamping finger 33 to clamp the apple, the telescopic cylinder 19 retracts backward after clamping the apple, the blade 21 can cut off the apple stem during the retracting process, then the rotary cylinder 17 returns to the position of 0 °, and then the opening and closing cylinder 22 drives the first clamping finger 23 and the second clamping finger 33 to open, so that the fruit falls into the collection box 22 along the conveying pipe 25.

The rotary mechanism at the bottom is matched with the rotary mechanism of the end effector, and only the rotary mechanism at the tail end is adjusted when the rotary mechanism acts in a small range, so that the driving frequency of the rotary mechanism at the bottom is reduced, and the effects of quickness, response and more flexible small-range action are achieved.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. The utility model provides an arm based on line drive adjusts inclination, a serial communication port, including first arm, second arm and connecting plate, the one end of connecting plate is articulated through first round pin axle with first arm, and the other end is articulated through second round pin axle with the second arm, the one end that the first arm is close to the connecting plate is equipped with first arc surface, and the one end that the second arm is close to the connecting plate is equipped with the second arc surface tangent with first arc surface, the second arc surface rolls and does not take place relative slip along first arc surface circumference under the restraint of connecting plate, changes the contained angle that first arm and second arm axis formed.

2. The mechanical arm for adjusting the inclination angle based on the line drive as claimed in claim 1, wherein two sides of the first arm are respectively provided with a first pulley block and a second pulley block, two sides of the second arm are respectively provided with a third pulley block and a fourth pulley block, the first arm is further provided with a driving wheel, a driving rope is matched on the driving wheel, one end of the driving rope is fixed on the first pulley block, the other end of the driving rope sequentially bypasses the third pulley block, the driving wheel and the fourth pulley block and then is fixed on the second pulley block, and the driving wheel changes the axial distance between the first pulley block and the third pulley block and the axial distance between the second pulley block and the fourth pulley block by driving the driving rope and is used for driving the second arm to rotate around the first arc surface axis.

3. The mechanical arm for adjusting the inclination angle based on the line drive as claimed in claim 2, wherein the axes of the first arc surface, the first pulley block and the second pulley block are coplanar; and the axes of the second arc surface, the third pulley block and the fourth pulley block are coplanar.

4. The mechanical arm for adjusting the inclination angle based on the wire drive according to claim 3, wherein the first arm and/or the second arm is provided with a tension wheel for tensioning in cooperation with the driving rope.

5. A fruit picking apparatus comprising a mechanical arm for adjusting the tilt angle based on a wire drive as claimed in any one of claims 1 to 4.

6. The fruit picking apparatus of claim 5, further comprising a base on which a driving arm is mounted through a swing mechanism, the driving arm having a distal end hinged to a first arm of a robotic arm that adjusts an inclination angle based on a line drive, the driving arm being capable of changing an angle between the distal end of the driving arm and the first arm.

7. The fruit picking apparatus of claim 6, wherein the end of the second arm remote from the first arm is mounted with a manipulator mounted at the end of the second arm by a revolute pair for varying the horizontal angle of the manipulator to the second arm, the manipulator being for grasping and picking the fruit.

8. The fruit picking apparatus as claimed in claim 7, wherein a duct is provided below the manipulator, one end of the duct is connected to the collection box, and the other end of the duct is open to the manipulator for receiving the fruits picked by the manipulator and transporting the fruits to the collection box through the duct.

9. Fruit picking apparatus as claimed in claim 8, in which the duct is a hose, the end adjacent the robot being capable of following the position of the robot, being located below the robot and remaining facing the robot.

10. The fruit picking apparatus of claim 6, wherein the robot comprises a grasping portion and a knife, the knife is fixed, the grasping portion is used for carrying the fruit and making the stem of the fruit contact the knife and cut off the stem.