Pitaya picking end effector
By designing a wraparound clamping end effector for dragon fruit harvesting, the problems of poor clamping force control and concentrated stress were solved, achieving efficient and low-damage harvesting results.
Patent Information
- Application Number
- CN202422842961.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2034-11-20
AI Technical Summary
The existing dragon fruit harvesting end effector has poor clamping force control and the clamping claw applies force in a single direction, which easily generates concentrated stress on the fruit surface, leading to static pressure injury.
Design an end effector comprising a fixed disk, a drive disk, a movable component, and a clamping element. The movable component consists of an active arm, a driven arm, and a limiting rod. The clamping element is made of flexible material and surrounds the fruit. The drive disk rotates to move the limiting rod and the clamping element closer to the fruit, evenly distributing the clamping force and avoiding stress concentration.
It achieves gentle clamping of dragon fruit, reduces physical damage, improves harvesting efficiency and fruit integrity, and enhances harvesting quality and yield.
Smart Images
Figure CN223584791U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of end effector, in particular to a kind of pitaya picking end effector. BACKGROUND
[0002] Pitaya is a kind of tropical and subtropical fruit, belongs to cactus family triangular column genus, sometimes also be called red dragon fruit, green dragon fruit, auspicious fruit etc..It is named for its unique appearance-the outer skin presents bright red or yellow, internal pulp is usually white or red, with black seeds.Pitaya has many scales-like protrusions on the outer skin, these protrusions are green or yellow-green, along the longitudinal direction of fruit, form the pattern similar to dragon scale.These protrusions are actually the structure of leaf degeneration on fruit, called "wing" or "leaf wing".
[0003] Pitaya needs to cut a certain amount of leaf meat when picking fruit, to facilitate the transportation and storage of pitaya.The traditional pitaya picking, all by artificial one hand holds fruit, uses knife with the other hand to cut or cut the position of fruit and branch connection, such picking mode, very time-consuming and laborious.
[0004] With the development of intelligent agricultural machinery, there appears a robot capable of automatically picking fruit.The above picking robot is generally composed of a mobile platform, a mechanical arm, an end effector and a machine vision system, etc.The end effector is one of the core parts of the picking robot, directly contacts with the fruit, and has a great influence on the finished product quality of the fruit, and the design and application of the end effector directly affect the efficiency, precision and damage degree of crop processing.However, there are still some problems to be solved in the prior art.The traditional end effector mainly uses hard gripper, and the gripping force control is poor, and the force direction of the gripper is single, which is easy to produce concentrated stress on the surface of the crop and static pressure injury. SUMMARY
[0005] Therefore, in order to solve the above problems, the purpose of the present application is to provide a kind of pitaya picking end effector, comprising:
[0006] Fixed disc, the fixed disc is equipped with driving motor;
[0007] Driving disc, the driving disc is connected on the output end of driving motor;
[0008] Movable assembly, the movable assembly includes driving arm, driven arm and limit rod, the driving arm and the driven arm are rotatably connected to the limit rod, one end of the driving arm away from the limit rod is rotatably connected to the driving disc, one end of the driven arm away from the limit rod is rotatably connected to the fixed disc;
[0009] Clamping piece, the clamping piece is connected to the limit rod;
[0010] A plurality of activity assemblies are arranged along the circumference of the fixed disc, and the clamping pieces are arranged towards the central axis of the driving disc.
[0011] Preferably, the driving disc is coaxial with the fixed disc, the driving arm and the driven arm are in a bent shape, and the bending direction of the driving arm is opposite to that of the driven arm.
[0012] Preferably, the driving arm comprises a first driving link, a second driving link and a third driving link connected in sequence, the first driving link and the second driving link, and the third driving link and the second driving link have the same preset included angle, the outer side surface of the first driving link is matched with the inner side surface of the second driving link, and the outer side surface of the second driving link is matched with the inner side surface of the third driving link.
[0013] Preferably, the driven arm comprises a first driven link and a second driven link connected in sequence, the first driven link and the second driven link have a preset included angle, and the outer side surface of the first driven link is matched with the inner side surface of the second driven link.
[0014] Preferably, the fixed disc is provided with an arc-shaped groove, one side of the driving disc towards the fixed disc is connected with a limiting sheet, and the limiting sheet extends into the arc-shaped groove.
[0015] Preferably, the clamping piece is made of flexible material, comprises two connecting ends connected to adjacent two limiting rods respectively, and comprises a clamping surface facing the central axis of the driving disc.
[0016] Preferably, the clamping surface is provided with an arch-shaped body.
[0017] Preferably, a plurality of clamping pieces are arranged equidistantly along the axial direction of the limiting rod.
[0018] Preferably, the clamping pieces on adjacent limiting rods are arranged in a staggered manner, a staggered gap is formed between the adjacent two clamping pieces on the limiting rod, and the staggered gap is larger than the width of the clamping piece.
[0019] Preferably, the arch-shaped body is provided with a strain gauge for detecting the deformation amount of the clamping piece.
[0020] The present application has the following advantages:
[0021] In the present application, the limiting rods are arranged around the driving disc, when the driving disc rotates, the driving arm is driven to rotate, and the limiting rods are pulled to move closer to the central axis of the driving disc, the clamping pieces arranged on the limiting rods form a clamping position capable of accommodating a single pitaya fruit, and gradually shrink with the rotation of the driving disc, finally can clamping the fruit from multiple angles in a surrounding manner, avoiding concentrated stress damage to the fruit, realizing the soft clamping and picking of 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, improves the picking quality and yield. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 This is a schematic diagram of the structure of the present invention;
[0024] Figure 2 This is a schematic diagram of the drive disk structure;
[0025] Figure 3 This is a schematic diagram of the fixed disk structure;
[0026] Figure 4 This is a cross-sectional structural diagram of the present invention;
[0027] Figure 5 A schematic diagram of the limiting rod and clamping components;
[0028] Figure 6 This is a schematic diagram of the structure when the clamping components are retracted;
[0029] Figure 7 This is a schematic diagram of the structure when the driving arm and driven arm are retracted.
[0030] Figure 8 This is a schematic diagram of the clamping component.
[0031] Explanation of reference numerals in the attached figures: 1. Fixed plate; 11. Driven arm; 111. First driven link; 112. Second driven link; 12. Second rotating end; 13. Arc groove; 2. Drive motor; 3. Drive plate; 31. Active arm; 311. First active link; 312. Second active link; 313. Third active link; 32. First rotating end; 33. Limiting plate; 4. Limiting rod; 5. Clamping component; 51. Clamping surface; 52. Arched body; 6. Strain gauge.
[0032] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0033] The technical solutions of the present invention will be clearly and completely described below with reference to 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" and the like indicate the orientation or positional relationship 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, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.
[0035] Unless otherwise expressly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0036] Embodiment 1:
[0037] Figures 1-7 A fire dragon fruit picking end effector provided by the present application is shown, which comprises a fixed disc 1, a driving motor 2 is fixed on the fixed disc 1, the output end of the driving motor 2 is rotationally connected with a driving disc 3, the driving disc 3 is coaxial with the fixed disc 1, a movable assembly is arranged outside the driving disc 3 and the fixed disc 1, the movable assembly is arranged in a circumferential array around the central axis of the driving disc 3, the movable assembly comprises a limiting rod 4, a driving arm 31 and a driven arm 11, wherein the limiting rod 4 is arranged outside the driving disc 3 and the fixed disc 1, the two ends of the driving arm 31 are rotationally connected with the limiting rod 4 and the driving disc 3 respectively, the two ends of the driven arm 11 are rotationally connected with the limiting rod 4 and the fixed disc 1 respectively, and a clamping piece 5 is arranged on the side of the limiting rod 4 facing the central axis of the driving disc 3.
[0038] The plurality of circumferentially arranged clamping pieces 5 face the central axis of the driving disc 3 and form a clamping position, when the driving motor 2 controls the rotation of the driving disc 3, the connection end of the driving arm 31 and the connection end of the driven arm 11 are away from each other, and pull and drag the limiting rod 4 to move towards the central axis of the driving disc 3, the clamping piece 5 connected with the limiting rod 4 moves accordingly, the clamping position gradually shrinks, until the clamping piece 5 abuts against the fruit skin and applies a suitable clamping force, since the clamping pieces 5 are circumferentially distributed around the fruit, the clamping force applied by the clamping pieces 5 is uniformly distributed on the fruit skin, and it is difficult to produce concentrated stress, thereby avoiding damage to the fruit under pressure.
[0039] The driving arm 31, the driven arm 11 and the limiting rod 4 form a stable and reliable mechanical linkage structure, which ensures that the limiting rod 4 can be driven to move towards or away from the center of the driving disc 3 when the driving disc 3 rotates. When viewed from the horizontal direction, the connecting end of the driving arm 31 and the driving disc 3 is defined as the first rotating end 32, and the connecting end of the driven arm 11 and the fixed disc 1 is defined as the second rotating end 12. With the driving disc 3 as the reference line, when the first rotating end 32 and the second rotating end 12 are arranged on the same side of the reference line, the fixed disc 1 and the driven arm 11 will interfere with each other, which will cause the driving disc 3 to be unable to drive the driving arm 31 and the limiting rod 4 to rotate.
[0040] Therefore, the positions of the first rotating end 32 and the second rotating end 12 are specifically allocated, and the first rotating end 32 and the second rotating end 12 are arranged on opposite sides of the reference line. When the first rotating end 32 and the second rotating end 12 are arranged on opposite sides of the reference line, 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 included angle with the reference line, and the directions of the two included angles are opposite. When the driving disc 3 rotates, the driving arm 31 and the driven arm 11 will rotate, the first rotating end 32 and the second rotating end 12 will move towards or away from each other, the limiting rod 4 will move towards or away from the center of the driving disc 3, and the movable assembly formed by the driving arm 31, the driven arm 11 and the limiting rod 4 can normally move, thereby achieving the purpose of controlling the limiting rod 4 to move towards or away from the center of the driving disc 3 by the rotation of the driving disc 3.
[0041] In the embodiment, when the driving disc 3 rotates clockwise, the limiting rod 4 moves towards the center of the driving disc 3, and when the driving disc 3 rotates counterclockwise, the limiting rod 4 moves away from the center of the driving disc 3. If the rotation angle of the driving disc 3 is not limited, the movable assembly may fail. Specifically, when the driving disc 3 controls the limiting rod 4 to move away from the center of the driving disc 3, the first rotating end 32 and the second rotating end 12 will move towards each other and then coincide with the reference line. At this time, the movement direction of the driving arm 31 and the driven arm 11 is uncontrollable, and it is possible that the two arms will simultaneously deviate to one side of the reference line, causing mechanical interference and resulting in the movable assembly being stuck. Alternatively, the driving arm 31 and the driven arm 11 may alternately move, and the counterclockwise rotation of the driving disc 3 may cause the limiting rod 4 to move towards the center of the driving disc 3. Therefore, the rotation angle of the driving disc 3 is limited by a mechanical structure. Specifically, the fixed disc 1 is provided with an arc-shaped groove 13, and the driving disc 3 is connected with a limiting piece 33 on the side facing the fixed disc 1. The limiting piece 33 extends into the arc-shaped groove 13, and the arc-shaped groove 13 limits the limiting piece 33, so that the driving disc 3 and the limiting piece 33 rotate within a preset angle range. In the embodiment, the angle range is specifically set to 90°
[0042] There are eight groups of active components in this embodiment, which can easily cause mechanical interference between adjacent active arms 31 and driven arms 11, thereby limiting the rotation angle of the active arms 31 and the driven arms 11. Therefore, the active arms 31 and the driven arms 11 are designed to be bent, and the bending direction of the active arms 31 is opposite to that of the driven arms 11. The bent active arms 31 and the driven arms 11 can be folded to form a spiral structure.
[0043] The bent active arms 31 and the driven arms 11 can also interfere with the driving disc 3 through their own structure, thereby avoiding excessive rotation of the driving disc 3 and indirectly controlling the rotation angle range of the driving disc 3.
[0044] The bent shape of the active arms 31 and the driven arms 11 is 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, and 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 included 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, and the first driven link 111 and the second driven link 112 have a preset included 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] The bending of the active arms 31 can increase the gripping stroke. If the number of bending of the active arms and the driven arms 11 is consistent, the minimum inner diameter of the end effector will be larger, which may cause the establishment of the clamping force and the wrapping force of the dragon fruit to be impossible.
[0046] The clamping piece 5 is made of flexible material, specifically tpu (thermoplastic polyurethane elastomer rubber), which can deform elastically to a certain extent. Details are shown in Figure 8 The clamping piece 5 has a rotating shaft in the middle in other drawings of the specification, which is designed to facilitate motion simulation by three-dimensional drawing software, and is not the actual structure. The clamping piece 5 has two connecting ends connected to two adjacent limiting rods 4, and includes a clamping surface 51 facing the central axis of the driving disc 3. An arcuate body 52 is arranged on the clamping surface 51, which can directly contact the fruit skin and apply clamping force.
[0047] To avoid stress concentration, a plurality of clamping pieces 5 are arranged along the axial direction of the limiting rod 4, and the clamping pieces 5 on the adjacent limiting rods 4 are arranged in a staggered manner. A staggered gap is formed between the two adjacent clamping pieces 5 on the limiting rod 4, and the staggered gap is larger than the width of the clamping piece 5, so that the adjacent clamping piece 5 can pass through. Details are shown in Figure 5Eight limit rods 4 are sequentially set as rod a, rod b, rod c, rod d, rod e, rod f, rod g, and rod h, and the clamping pieces 5 are divided into seven layers along the limit rods 4 in the axial direction from top to bottom, four clamping pieces 5 are arranged in each layer, the clamping pieces 5 in the first layer are set as piece 1, piece 2, piece 3, and piece 4, the two ends of the piece 1 are connected with the rod a and the rod b respectively, the two ends of the piece 2 are connected with the rod c and the rod d respectively, the two ends of the piece 3 are connected with the rod e and the rod f respectively, and the two ends of the piece 4 are connected with the rod g and the rod h respectively; the clamping pieces 5 in the second layer are set as piece 5, piece 6, piece 7, and piece 8, the two ends of the piece 5 are connected with the rod b and the rod c respectively, the two ends of the piece 6 are connected with the rod d and the rod e respectively, the two ends of the piece 7 are connected with the rod f and the rod g respectively, and the two ends of the piece 8 are connected with the rod h and the rod a respectively; the clamping pieces 5 in the third layer are set as piece 9, piece 10, piece 11, and piece 12, the two ends of the piece 9 are connected with the rod a and the rod b respectively, the two ends of the piece 10 are connected with the rod c and the rod d respectively, the two ends of the piece 11 are connected with the rod e and the rod f respectively, and the two ends of the piece 12 are connected with the rod g and the rod h respectively; the seven layers of clamping pieces 5 are sequentially and staggeringly arranged, which greatly reduces the stress concentration on the outer skin of the fruit and avoids damage to the fruit.
[0048] Working principle:
[0049] In the initial state of the end effector, the driving motor 2 is not started, the driving disc 3 is in a static state, and the clamping pieces 5 are open due to the far distance between the limit rods 4, forming a larger clamping position, so that the pitaya can smoothly enter. The staff manually or through mechanical equipment puts the end effector on the outside of the pitaya, and then starts the driving motor 2 and outputs the rotary torque to the driving disc 3, so that the driving disc 3 rotates clockwise. With the rotation of the driving disc 3, the driving arm 31 and the driven arm 11 start to act due to the rotational connection relationship with the limit rod 4, the limit rod 4 with the clamping piece 5 approaches the pitaya, and the clamping position is gradually reduced until the clamping piece 5 abuts against the surface of the pitaya and applies appropriate clamping force. Since the clamping pieces 5 are arranged in a ring shape, the clamping force can be uniformly distributed to prevent local stress from being too large and causing damage to the fruit.
[0050] The end effector is connected to the rotating mechanical arm of the external device. When the end effector clamps the pitaya, the end effector is driven by the rotating mechanical arm to rotate forward and backward, so that the root of the pitaya is fatigued and broken, thereby cutting off the connection between the pitaya and the fruit tree. The rotating mechanical arm is a conventional technology in the art, and will not be described here.
[0051] Example 2:
[0052] Figures 1-7The application provides a picking end effector for pitaya, and the difference between the embodiment and the embodiment 1 is that the arch-shaped body 52 is loaded with a strain gauge 6 for detecting the deformation of the clamping piece 5, and the strain gauge 6 is electrically connected to a detection device. The embodiment is applied to a laboratory, and the feedback data of the strain gauge 6 and the damage degree of the clamped fruit are comprehensively judged to determine the rotation amount of the driving disc 3, so that the integrity of the picked fruit in actual use of the end effector is ensured.
[0053] Obviously, the above embodiments of the application are only examples for clearly illustrating the application, and are not intended to limit the implementation modes of the application. Those skilled in the art can make various obvious changes, re-adjustments and replacements without departing from the protection scope of the application. It is unnecessary and impossible to enumerate all the implementation modes. Any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the claims of the application.
Claims
1. A dragon fruit picking end effector, characterized in that, The utility model relates to a kind of rotary clamp, including: Fixed disc (1), fixed disc (1) is equipped with driving motor (2); Driving disc (3), driving disc (3) is connected on the output end of driving motor (2); Movable assembly, movable assembly includes driving arm (31), driven arm (11) and limiting rod (4), driving arm (31) and driven arm (11) are rotatably connected to limiting rod (4), the one end of driving arm (31) away from limiting rod (4) is rotatably connected to driving disc (3), the one end of driven arm (11) away from limiting rod (4) is rotatably connected to fixed disc (1); Clamping piece (5), clamping piece (5) is connected to limiting rod (4); If several groups of movable assemblies are arranged along the circumference of fixed disc (1), clamping piece (5) is arranged towards the central axis of driving disc (3).
2. The dragon fruit picking end effector of claim 1, wherein, Driving disc (3) is coaxial with fixed disc (1), the driving arm (31) and driven arm (11) are bent, and the bending direction of the driving arm (31) is opposite to the bending direction of the driven arm (11).
3. The dragon fruit picking end effector of claim 2, wherein, The driving arm (31) includes sequentially connected first driving link (311), second driving link (312) and third driving link (313), and the first driving link (311) and the second driving link (312) and the third driving link (313) and the second driving link (312) have the same preset included angle, the outer side surface of the first driving link (311) is matched with the inner side surface of the second driving link (312), and the outer side surface of the second driving link (312) is matched with the inner side surface of the third driving link (313).
4. The dragon fruit picking end effector of claim 2, wherein, The driven arm (11) includes sequentially connected first driven link (111) and second driven link (112), and the first driven link (111) and the second driven link (112) have a preset included angle, and the outer side surface of the first driven link (111) is matched with the inner side surface of the second driven link (112).
5. The dragon fruit picking end effector of claim 2, wherein, The fixed disc (1) is provided with an arc-shaped groove (13), and the driving disc (3) is connected with a limiting sheet (33) on the side facing the fixed disc (1), and the limiting sheet (33) extends into the arc-shaped groove (13).
6. The dragon fruit picking end effector of claim 1, wherein, The clamping piece (5) is made of flexible material, and includes two connecting ends connected to two adjacent limiting rods (4), respectively, and includes a clamping surface (51) facing the central axis of the driving disc (3).
7. The dragon fruit picking end effector of claim 6, wherein, The clamping surface (51) is provided with an arch-shaped body (52).
8. The dragon fruit picking end effector of claim 6, wherein, A plurality of clamping pieces (5) are equidistantly arranged along the axis of the limiting rod (4).
9. The dragon fruit picking end effector of claim 8, wherein, The clamping pieces (5) on the adjacent limiting rods (4) are arranged in a staggered manner, and a staggered gap is formed between the two adjacent clamping pieces (5) on the limiting rod (4), and the staggered gap is greater than the width of the clamping piece (5).
10. The dragon fruit picking end effector of claim 7, wherein, The arch-shaped body (52) is provided with a strain sheet (6) for detecting the deformation amount of the clamping piece (5).