Pitaya picking end effector

Abstract

The pitaya picking end effector comprises a fixed disc, a driving disc, a movable assembly and a clamping piece, the movable assembly comprises a driving arm, a driven arm and a limiting rod, the driving arm and the driven arm are rotationally connected to the limiting rod, and the end, away from the limiting rod, of the driving arm is rotationally connected to the driving disc; the limiting rod is arranged around the driving disc, when the driving disc rotates, the driving arm is driven to rotate, the limiting rod is dragged to be close to the middle shaft of the driving disc, a clamping part arranged on the limiting rod forms a clamping position capable of containing a single pitaya fruit, and the pitaya fruit can be clamped in the clamping position. The pitaya picking device has the advantages that the pitaya picking device can clamp the pitaya in a surrounding mode from multiple angles, damage to the pitaya due to concentrated stress is avoided, the pitaya is gently clamped and picked, and the integrity of the pitaya and the high efficiency of the picking process are guaranteed. By means of the design, the picking efficiency is improved, and the picking quality and yield are improved.

Description

Technical Field

[0001] The invention relates to the technical field of end effectors, and in particular to a pitaya picking end effector. Background Art

[0002] Pitaya is a tropical and subtropical fruit belonging to the genus Triangle in the Cactaceae family. It is sometimes called red dragon fruit, green dragon fruit, auspicious fruit, etc. It gets its name from its unique appearance - the skin is bright red or yellow, and the inner flesh is usually white or red with black seeds. There are many scale-like protrusions on the skin of the pitaya. These protrusions are green or yellow-green and arranged longitudinally along the fruit to form a pattern similar to dragon scales. These protrusions are actually structures formed by the degeneration of the leaves on the fruit, called "fins" or "leaf wings."

[0003] When picking pitaya, a certain amount of leaf flesh needs to be cut off to facilitate the transportation and storage of pitaya. Traditional pitaya picking is done by holding the fruit with one hand and using a knife with the other hand to cut or snip the connection between the fruit and the branch. This picking method is very time-consuming and laborious.

[0004] With the development of intelligent agricultural machinery, robots that can automatically pick fruits have emerged. The above-mentioned picking robots are generally composed of a mobile platform, a robotic arm, an end effector and a machine vision system. The end effector is one of the core parts of the picking robot. It is in direct contact with the fruit and has a significant impact on the quality of the finished fruit. The design and application of the end effector directly affect the efficiency and accuracy of crop processing and the degree of damage to the crop. However, there are still some problems that need to be solved in the prior art. Traditional end effectors mainly use hard clamps, which have poor control over the clamping force, and the clamp has a single force direction, which can easily generate concentrated stress on the crop surface and cause static pressure injuries. Summary of the invention

[0005] Therefore, in order to solve the above problems, the object of the present invention is to provide a pitaya picking end effector, comprising:

[0006] A fixed plate, on which a driving motor is provided;

[0007] A driving disk connected to an output end of the driving motor;

[0008] The movable assembly includes an active arm, a driven arm and a limit rod, the active arm and the driven arm are rotatably connected to the limit rod, one end of the active arm away from the limit rod is rotatably connected to the driving plate, and one end of the driven arm away from the limit rod is rotatably connected to the fixed plate;

[0009] A clamping member connected to the limiting rod;

[0010] A plurality of groups of movable components are arranged along the circumference of the fixed disk, and the clamping member is arranged toward the central axis of the driving disk.

[0011] Preferably, the driving disk is coaxial with the fixed disk, the active arm and the driven arm are bent, and the bending direction of the active arm is opposite to the bending direction of the driven arm.

[0012] Preferably, the active arm includes a first active link, a second active link and a third active link connected in sequence, the first active link and the second active link, and the third active link and the second active link have the same preset angle, the outer side surface of the first active link cooperates with the inner side surface of the second active link, and the outer side surface of the second active link cooperates with the inner side surface of the third active link.

[0013] Preferably, the driven arm comprises a first driven link and a second driven link which are connected in sequence, the first driven link and the second driven link have a preset angle, and the outer side surface of the first driven link matches the inner side surface of the second driven link.

[0014] Preferably, an arc-shaped groove is provided on the fixed disk, and a limiting plate is connected to a side of the active disk facing the fixed disk, and the limiting plate extends into the arc-shaped groove.

[0015] Preferably, the clamping member is made of a flexible material, and comprises two connecting ends respectively connected to two adjacent limiting rods, and the clamping member comprises a clamping surface, and the clamping surface faces the central axis of the driving disk.

[0016] Preferably, an arched body is provided on the clamping surface.

[0017] Preferably, a plurality of clamping members are equidistantly arranged along the axial direction of the limiting rod.

[0018] Preferably, the clamping members on adjacent limiting rods are staggered, and a staggered gap is formed between two adjacent clamping members on the limiting rod, and the staggered gap is greater than the width of the clamping member.

[0019] Preferably, a strain gauge is provided on the arch body for detecting the deformation amount of the clamping member.

[0020] The beneficial effects of the present invention are:

[0021] The limit rod in the present invention is arranged around the driving disk. When the driving disk rotates, it drives the main arm to rotate, and involves the limit rod to make it close to the central axis of the driving disk. The clamping piece arranged on the limit rod forms a clamping position that can accommodate a single pitaya fruit, and gradually shrinks as the driving disk rotates. Finally, the fruit can be clamped in a surrounding manner from multiple angles to avoid concentrated stress damage to the fruit, thereby achieving gentle clamping and picking of the pitaya, ensuring the integrity of the fruit and the efficiency of the picking process. This design not only improves the picking efficiency, but also greatly reduces the physical damage to the fruit, and improves the picking quality and yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a structural schematic diagram of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of the drive disk;

[0025] Figure 3 It is a structural schematic diagram of a fixed disk;

[0026] Figure 4 It is a cross-sectional structural schematic diagram of the present invention;

[0027] Figure 5 It is a schematic diagram of the structure of the limit rod and the clamping member;

[0028] Figure 6 It is a schematic diagram of the structure when the clamping member is folded;

[0029] Figure 7 It is a schematic diagram of the structure when the active arm and the driven arm are folded;

[0030] Figure 8 is a schematic diagram of the structure of the clamping member;

[0031] Explanation of the accompanying drawings: 1. fixed plate; 11. driven arm; 111. first driven link; 112. second driven link; 12. second rotating end; 13. arc groove; 2. driving motor; 3. driving plate; 31. active arm; 311. first active link; 312. second active link; 313. third active link; 32. first rotating end; 33. limit plate; 4. limit rod; 5. clamping member; 51. clamping surface; 52. arch body; 6. strain gauge.

[0032] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0034] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] Embodiment 1:

[0037] Figure 1-Figure 7 A pitaya picking end effector provided by the present invention is shown, comprising a fixed disk 1, a driving motor 2 is fixed on the fixed disk 1, an output end of the driving motor 2 is rotatably connected to a driving disk 3, the driving disk 3 is coaxial with the fixed disk 1, and a movable component is arranged on the outer side of the driving disk 3 and the fixed disk 1, and the movable component is arranged in a circular array with the central axis of the driving disk 3 as the center, and the movable component comprises a limit rod 4, an active arm 31, and a driven arm 11, wherein the limit rod 4 is arranged on the outer side of the driving disk 3 and the active disk, two ends of the active arm 31 are respectively rotatably connected to the limit rod 4 and the driving disk 3, and two ends of the driven arm 11 are respectively rotatably connected to the limit rod 4 and the fixed disk 1, and a clamping member 5 is provided on the side of the limit rod 4 facing the central axis of the driving disk 3.

[0038] A plurality of surrounding clamping members 5 are arranged toward the central axis of the driving disk 3 to form a clamping position. When the driving motor 2 controls the driving disk 3 to rotate, the connection end of the active arm 31 and the driving plate, and the connection end of the driven arm 11 and the fixed disk 1 move away from each other, and pull the limiting rod 4 toward the central axis of the driving disk 3. The clamping members 5 connected to the limiting rod 4 move accordingly, and the clamping position gradually shrinks until the clamping members 5 abut against the outer skin of the fruit and exert a suitable clamping force. Since the clamping members 5 are distributed around the periphery of the fruit, the clamping force they exert is evenly distributed on the outer skin of the fruit, and it is difficult to generate concentrated stress, thereby avoiding compression damage to the fruit.

[0039] The active arm 31, the driven arm 11 and the limit rod 4 should form a stable and reliable mechanical linkage structure to ensure that the drive disk 3 can drive the limit rod 4 to move closer to / away from the center of the drive disk 3 when it rotates. When viewed from the horizontal plane, the connection end between the active arm 31 and the drive disk 3 is set as the first rotation end 32, and the connection end between the driven arm 11 and the fixed disk 1 is set as the second rotation end 12. The radial direction of the drive disk 3 - the line connecting the limit rod 4 and the center point of the drive disk 3 is taken as the reference line. When the first rotation end 32 and the second rotation end 12 are arranged on the same side of the reference line, due to the mechanical interference between the fixed disk 1 and the driven arm 11, the drive disk 3 will be unable to drive the active arm 31 and the limit rod 4 to rotate.

[0040] Therefore, the positions of the first rotating end 32 and the second rotating end 12 are allocated in a targeted manner. Specifically, the first rotating end 32 and the second rotating end 12 are respectively arranged on both sides of the baseline. When the first rotating end 32 and the second rotating end 12 are respectively arranged on both sides of the baseline, the line connecting the first rotating end 32 and the limiting rod 4 and the line connecting the second rotating end 12 and the limiting rod 4 have a preset angle relative to the baseline, and the two angles are in opposite directions. When the driving disk 3 rotates, it will drive the active arm 31 and the driven arm 11 to rotate, the first rotating end 32 and the second rotating end 12 are relatively close to / away from each other, and the limiting rod 4 is close to / away from the center of the driving disk 3. The movable assembly composed of the active arm 31, the driven arm 11 and the limiting rod 4 can move normally, thereby achieving the purpose of the limiting rod 4 being controlled by the rotation of the driving disk 3 to move closer to / away from the center of the driving disk 3.

[0041] In this embodiment, when the driving disk 3 is set to rotate clockwise, the limit rod 4 is close to the center of the driving disk 3, and when it rotates counterclockwise, the limit rod 4 is away from the center of the driving disk 3. If the rotation angle of the driving disk 3 is not restricted, the movable component may fail. Specifically, when the driving disk 3 rotates to control the limit rod 4 to be away from the driving disk 3, the first rotating end 32 and the second rotating end 12 will coincide with the reference line after approaching each other. At this time, the movement directions of the active arm 31 and the driven arm 11 are uncontrollable. It is possible that both of them deviate to one side of the reference line at the same time, and mechanical interference occurs, causing the movable component to get stuck. It is also possible that the active arm 31 and the driven arm 11 alternate positions, and the driving disk 3 rotates counterclockwise, which causes the limit rod 4 to approach the center of the driving disk 3. Therefore, the rotation angle of the driving disk 3 is limited by the mechanical structure. Specifically, the fixed disk 1 is provided with an arc groove 13, and the active disk is connected to a limiting plate 33 on one side facing the fixed disk 1. The limiting plate 33 extends into the arc groove 13. The arc groove 13 limits the limiting plate 33, so that the driving disk 3 and the limiting plate 33 rotate within a preset angle range. In this embodiment, the angle range is specifically set to 90°.

[0042] In the present embodiment, there are a total of eight groups of movable components, which may cause mechanical interference between adjacent active arms 31 and passive arms 11, limiting their own rotation angles. Therefore, the active arm 31 and the passive arm 11 are designed to be bent, and the bending direction of the active arm 31 is opposite to the bending direction of the passive arm 11. The bent active arm 31 and the passive arm 11 can be folded to form a spiral structure.

[0043] The active arm 31 and the driven arm 11 of the bent design can also mechanically interfere with the driving disk 3 or the active disk through their own structure to prevent the driving disk 3 from over-rotating, thereby controlling the rotation angle range of the driving disk 3 in disguised form.

[0044] The bending shapes of the active arm 31 and the driven arm 11 are specifically designed. Specifically, the active arm 31 includes a first active link 311, a second active link 312 and a third active link 313 connected in sequence. The first active link 311 and the second active link 312, as well as the third active link 313 and the second active link 312 have the same preset angle. When the active arm 31 is folded, the outer side surface of the first active link 311 cooperates with the inner side surface of the second active link 312, and the outer side surface of the second active link 312 cooperates with the inner side surface of the third active link 313; the driven arm 11 includes a first driven link 111 and a second driven link 112 connected in sequence. The first driven link 111 and the second driven link 112 have a preset angle. When the driven arm 11 is folded, the outer side surface of the first driven link 111 cooperates with the inner side surface of the second driven link 112.

[0045] More bends in the active arm 31 can increase the gripping stroke. If the active arm and the driven arm 11 have the same number of bends, the minimum contraction inner diameter of the end effector will be too large, which may result in the inability to establish the clamping force and wrapping force for the pitaya.

[0046] The clamping member 5 is made of a flexible material, specifically TPU (thermoplastic polyurethane elastomer rubber), which can undergo a certain degree of elastic deformation. Figure 8 In other drawings of the specification, the clamping member 5 has a rotating shaft in the middle. This design is for the convenience of motion simulation by 3D drawing software and is not an actual structure. The clamping member 5 has two connecting ends respectively connected to two adjacent limit rods 4. The clamping member 5 includes a clamping surface 51, which faces the central axis of the driving disk 3. The clamping surface 51 is provided with an arch 52, which can directly contact the fruit skin to apply a clamping force.

[0047] In order to avoid stress concentration, multiple clamping members 5 are arranged along the axial direction of the limiting rod 4, and the clamping members 5 on adjacent limiting rods 4 are staggered, and a staggered gap is formed between two adjacent clamping members 5 on the limiting rod 4. The staggered gap is larger than the width of the clamping member 5, and can allow adjacent clamping members 5 to pass through. Figure 5, the eight limiting rods 4 are set in sequence as rod a, rod b, rod c, rod d, rod e, rod f, rod g, and rod h, and the clamping parts 5 are divided into seven layers from top to bottom along the axial direction of the limiting rods 4, and four clamping parts 5 are set in each layer. The clamping parts 5 of the first layer are set as parts 1, parts 2, parts 3, and parts 4. The two ends of part 1 are respectively connected to rod a and rod b, the two ends of part 2 are respectively connected to rod c and rod d, the two ends of part 3 are respectively connected to rod e and rod f, and the two ends of part 4 are respectively connected to rod g and rod h; the clamping parts 5 of the second layer are set as parts 5, parts 6, parts 7, and parts 8, and the two ends of part 5 are respectively Connect rod b and rod c, the two ends of component 6 are respectively connected to rod d and rod e, the two ends of component 7 are respectively connected to rod f and rod g, and the two ends of component 8 are respectively connected to rod h and rod a; the third layer of clamping components 5 are set to components 9, 10, 11, and 12, the two ends of component 9 are respectively connected to rod a and rod b, the two ends of component 10 are respectively connected to rod c and rod d, the two ends of component 11 are respectively connected to rod e and rod f, and the two ends of component 12 are respectively connected to rod g and rod h; and so on, seven layers of clamping components 5 are staggered to greatly reduce the stress concentration on the fruit skin and avoid fruit damage.

[0048] Working principle:

[0049] In the initial state of the end effector, the drive motor 2 is not started, the drive disc 3 is in a stationary state, and the clamping member 5 is opened due to the long distance between the limit rods 4, forming a larger clamping position, and the dragon fruit can enter smoothly. The staff manually or through mechanical equipment puts the end effector on the outside of the dragon fruit, and then starts the drive motor 2 and outputs a rotational torque to the drive disc 3, so that the drive disc 3 rotates clockwise. As the drive disc 3 rotates, the active arm 31 and the driven arm 11 start to move due to the rotational connection relationship with the limit rod 4. The limit rod 4 brings the clamping member 5 closer to the dragon fruit, and the clamping position is gradually reduced until the clamping member 5 abuts against the surface of the dragon fruit and applies an appropriate clamping force. Since the clamping member 5 is arranged in a ring, the clamping force can be evenly distributed to prevent excessive local stress from causing damage to the fruit.

[0050] The end effector is connected to the external rotating mechanical arm. After the end effector has clamped the dragon fruit, the rotating mechanical arm drives the end effector to rotate forward and reverse to fatigue and break the root, thereby cutting off the connection between the dragon fruit and the fruit tree. The rotating mechanical arm is a conventional technology in this field and will not be described in detail here.

[0051] Embodiment 2:

[0052] Figure 1-Figure 7A pitaya picking end effector provided by the present invention is shown. The difference between this embodiment and embodiment 1 is that a strain gauge 6 is mounted on the arch 52 for detecting the deformation of the clamping member 5. The strain gauge 6 is electrically connected to the detection device. This embodiment is applied to the laboratory. In the laboratory, the rotation amount of the driving disk 3 is determined after comprehensive analysis based on the feedback data of the strain gauge 6 and the damage degree of the clamped fruit, so as to ensure the integrity of the fruit picked when the end effector is actually used.

[0053] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A pitaya picking end effector, characterized in that: include: A fixed disk (1), wherein a driving motor (2) is provided on the fixed disk (1); A driving disk (3), the driving disk (3) is connected to the output end of the driving motor (2); A movable assembly, the movable assembly comprising an active arm (31), a driven arm (11) and a limiting rod (4), the active arm (31) and the driven arm (11) being rotatably connected to the limiting rod (4), one end of the active arm (31) away from the limiting rod (4) being rotatably connected to the driving disk (3), and one end of the driven arm (11) away from the limiting rod (4) being rotatably connected to the fixed disk (1); A clamping member (5), the clamping member (5) is connected to the limiting rod (4); A plurality of groups of movable components are arranged along the circumference of the fixed disk (1), and the clamping member (5) is arranged toward the central axis of the driving disk (3).

2. The pitaya picking end effector according to claim 1, characterized in that: The driving disk (3) is coaxial with the fixed disk (1); the active arm (31) and the driven arm (11) are bent; and the bending direction of the active arm (31) is opposite to the bending direction of the driven arm (11).

3. The pitaya picking end effector according to claim 2, characterized in that: The active arm (31) comprises a first active link (311), a second active link (312) and a third active link (313) which are connected in sequence; the first active link (311) and the second active link (312), and the third active link (313) and the second active link (312) have the same preset angle; the outer side surface of the first active link (311) cooperates with the inner side surface of the second active link (312), and the outer side surface of the second active link (312) cooperates with the inner side surface of the third active link (313).

4. The pitaya picking end effector according to claim 2, characterized in that: The driven arm (11) comprises a first driven link (111) and a second driven link (112) which are connected in sequence, the first driven link (111) and the second driven link (112) have a preset angle, and the outer side surface of the first driven link (111) matches the inner side surface of the second driven link (112).

5. The pitaya picking end effector according to claim 2, characterized in that: The fixed disk (1) is provided with an arc-shaped groove (13), and a side of the active disk facing the fixed disk (1) is connected to a limiting plate (33), and the limiting plate (33) extends into the arc-shaped groove (13).

6. The pitaya picking end effector according to claim 1, characterized in that: The clamping member (5) is made of a flexible material. The clamping member (5) comprises two connection ends respectively connected to two adjacent limit rods (4). The clamping member (5) comprises a clamping surface (51), and the clamping surface (51) faces the central axis of the driving disk (3).

7. The pitaya picking end effector according to claim 6, characterized in that: An arched body (52) is provided on the clamping surface (51).

8. The pitaya picking end effector according to claim 6, characterized in that: A plurality of clamping members (5) are equidistantly arranged along the axial direction of the limiting rod (4).

9. The pitaya picking end effector according to claim 8, characterized in that: The clamping members (5) on adjacent limiting rods (4) are arranged in a staggered manner, and a staggered gap is formed between two adjacent clamping members (5) on the limiting rod (4), and the staggered gap is greater than the width of the clamping member (5).

10. The pitaya picking end effector according to claim 7, characterized in that: The arched body (52) is provided with a strain gauge (6) for detecting the deformation amount of the clamping member (5).

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