An adaptive fruit picking end effector

Abstract

The application provides an adaptive fruit picking end effector, and relates to the technical field of agricultural product picking; the end effector comprises an end effector base, a driving assembly, a clamping assembly and a pressure sensing assembly; the clamping assembly comprises a clamping support, a main transmission assembly, a driving finger and an underactuated finger; the main transmission finger driving assembly is connected with the pulley shaft through the main transmission finger transmission assembly and is used for driving the fruit gripping transmission belt to rotate, and then the fruit is transmitted to the palm center; after the pressure value of the pressure sensing assembly reaches a threshold value, the main transmission finger and the underactuated finger stop folding, and then the fruit of different shapes and sizes can be fully gripped, and the gripping stability and low damage property of the fruit are improved.

Description

Technical Field

[0001] This invention relates to the field of agricultural product harvesting technology, specifically to an adaptive fruit harvesting end effector. Background Technology

[0002] Apple cultivation and harvesting are particularly widespread in China, but the apple picking process is tedious, time-consuming, and labor-intensive, requiring the most manpower. When an apple picking end effector works in conjunction with a robotic arm, ripe apples can be picked continuously, filling this labor gap and enabling continuous and efficient picking operations without being limited by weather, time, or other factors.

[0003] In unstructured orchard environments, apples vary greatly in size and shape. Existing apple picking end effectors struggle to balance gripping stability and low damage, often resulting in gripping failure when picking apples in different growth conditions. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive fruit picking end effector to solve the problem that existing apple picking end effectors are difficult to balance gripping stability and low damage, and are prone to gripping failure when picking apples in different growth conditions.

[0005] For the purposes described above, this application provides an adaptive fruit-picking end effector, including an end effector base, a drive assembly, a clamping assembly, and a pressure sensing assembly;

[0006] The clamping assembly includes a clamping bracket, a main drive assembly, an active drive finger, and an underdriven finger;

[0007] The bottom of the clamping bracket is connected to the end of the end effector base. The clamping bracket has an assembly cavity inside, and the drive assembly is disposed in the assembly cavity. The output end of the drive assembly is connected to the main drive assembly.

[0008] The main drive finger is connected to the main drive assembly through the first driven assembly, and the two underdriven fingers are connected to the main drive assembly through the second drive assembly. Furthermore, the underdriven fingers are hinged to the clamping bracket via a shaft. The drive assembly is used to drive the active drive finger and the underdriven finger to retract or open to pick the fruit through the main drive assembly.

[0009] The active transmission finger includes a transmission finger base, a transmission finger support, a main transmission finger drive assembly, a main transmission finger transmission assembly, and a fruit gripping transmission belt.

[0010] The transmission finger base is connected to the first driven component, the transmission finger bracket is fixed on the transmission finger base, the fruit gripping transmission belt is connected to the transmission finger bracket through the pulley shaft, the main transmission finger drive component is set inside the transmission finger base, and the main transmission finger drive component is connected to the pulley shaft through the main transmission finger transmission component to drive the fruit gripping transmission belt to rotate.

[0011] The pressure sensing component is located at the palm position on the top of the gripping bracket and is used to detect the pressure value applied to the pressure sensing component during the grasping and moving of the fruit.

[0012] Furthermore, the clamping bracket is cylindrical, and the side walls of the clamping bracket are respectively provided with grooves for accommodating the first driven component and the second driven component, and mounting brackets are provided on both sides of each groove;

[0013] The first driven component, the second driven component, and the underdriven finger are rotatably connected to their respective mounting brackets via shafts.

[0014] Furthermore, the main drive assembly adopts a worm gear;

[0015] The first driven component includes a first turbine and a turbine bracket. The first turbine is rotatably connected to the mounting bracket via a shaft, and the first turbine meshes with a worm gear. The first turbine is connected to the transmission finger base via the turbine bracket.

[0016] The second driven component includes a second turbine, the first turbine is rotatably connected to the mounting bracket via a shaft, the worm gear end of the second turbine meshes with a worm, and the connecting end of the second turbine is rotatably connected to an underdriven finger via a shaft.

[0017] Furthermore, the underactuated finger includes a proximal phalanx, a middle phalanx, a distal phalanx, a straight link, and an L-link;

[0018] One end of the proximal phalanx is rotatably connected to the mounting bracket via a shaft. The two ends of the middle phalanx are rotatably connected between the proximal and distal phalanxes via shafts with torsion springs, respectively. One end of the L-link is rotatably connected to the middle of the proximal phalanx via a shaft, and the other end of the L-link is rotatably connected to the distal phalanx via a shaft. One end of the straight link is rotatably connected to the connection end of the second turbine via a shaft, and the other end of the straight link is rotatably connected to the right-angle end of the L-link via a shaft.

[0019] Furthermore, the sides of the proximal, middle, and distal phalanges used for gripping the apple are each rotatably connected to several rollers.

[0020] Furthermore, the pressure sensing component includes a palm base, palm software, and a pressure sensor;

[0021] The palm base is fixedly installed on the top of the clamping bracket, the palm software is fixed on the palm base, and the pressure sensor is located inside the palm software.

[0022] Furthermore, the palm soft body is made of soft silicone material, and the pressure sensor is a piezoresistive flexible pressure sensor.

[0023] Furthermore, it also includes a shearing assembly, which includes a first base, a second base, a first bevel gear, a second bevel gear, a first drive motor, a universal joint, and a shearing blade;

[0024] The first base is fixed to the side wall of the clamping bracket;

[0025] Two first drive motors are symmetrically arranged on both sides of the first base, and the output end of each first drive motor is connected to a first bevel gear;

[0026] The bottom fixed end of the universal joint is rotatably connected to the middle of the first base via a rotating shaft. The second bevel gear is sleeved on the upper movable joint of the universal joint, and the second bevel gear meshes with the two first bevel gears respectively.

[0027] The second base is connected to the movable joint of the universal joint;

[0028] The shearing blade is connected to the second base.

[0029] Furthermore, it also includes a vision component, which includes a depth camera and a camera mount. The depth camera is fixed to the side of the end effector base via the camera mount. The depth camera is used to acquire RGB images and depth images of the fruit stalk.

[0030] Furthermore, it also includes a data processing module for acquiring the RGB and depth images of the fruit stalk, calling the YOLOv8-SEG model to segment the fruit stalk and fruit, and then using the YOLOv8 Pose model to detect key points of the fruit shoulder and stem. A straight line is formed from the fruit shoulder to the stem as the reference direction for shearing pose estimation. The distance h between the perpendicular line of the fruit stalk midline and the fruit surface is set, and the final shearing pose point is obtained by translating along the fruit stalk midline away from the fruit in a direction away from the fruit.

[0031] By adopting the above technical solution, the adaptive fruit-picking end effector provided in this application has the following technical advantages compared with the prior art:

[0032] In this scheme, the main drive finger is connected to the main drive assembly through the first driven assembly, the two underdriven fingers are connected to the main drive assembly through the second drive assembly, and the underdriven fingers are hinged to the clamping bracket by a shaft. The drive assembly is used to drive the active drive finger and the underdriven finger to retract or open to pick the fruit through the main drive assembly.

[0033] In the active transmission finger, the transmission finger base is connected to the first driven component, the transmission finger bracket is fixed on the transmission finger base, the fruit gripping transmission belt is connected to the transmission finger bracket through the pulley shaft, the main transmission finger drive component is set inside the transmission finger base, and the main transmission finger drive component is connected to the pulley shaft through the main transmission finger transmission component to drive the fruit gripping transmission belt to rotate, thereby transmitting the fruit to the palm until the pressure value of the pressure sensing component reaches the threshold, at which point the main transmission finger and the underdriven finger stop retracting, thereby achieving the function of fully gripping fruits of different shapes and sizes, improving the gripping stability and minimizing damage to the fruit. Attached Figure Description

[0034] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a front view of the adaptive fruit-picking end effector provided in the embodiments of this application;

[0036] Figure 2 This is a perspective view of the adaptive fruit-picking end effector provided in the embodiments of this application;

[0037] Figure 3 This is a schematic diagram of the assembly of the drive assembly, main transmission assembly, first driven assembly, and second driven assembly provided in the embodiments of this application;

[0038] Figure 4 This is a schematic diagram of the clamping bracket provided in an embodiment of this application;

[0039] Figure 5 This is a schematic diagram of the active transmission finger provided in an embodiment of this application;

[0040] Figure 6 This is a schematic diagram of the underdriven finger provided in an embodiment of this application;

[0041] Figure 7 This is a schematic diagram of the pressure sensing component provided in an embodiment of this application;

[0042] Figure 8 yes Figure 1 Enlarged view of point A in the image.

[0043] Icons: 100 - End effector base; 200 - Drive assembly; 300 - Clamping assembly; 310 - Clamping bracket; 311 - Mounting bracket; 320 - Main drive assembly; 330 - Active drive finger; 331 - Drive finger base; 332 - Drive finger bracket; 333 - Main drive finger drive assembly; 334 - Main drive finger drive assembly; 335 - Fruit gripping drive belt; 340 - Underactuated finger; 341 - Proximal phalanx; 342 - Middle phalanx; 343 - Distal phalanx; 344 - Straight link; 345 - L-link; 346-roller; 350-first driven assembly; 351-first turbine; 352-turbine bracket; 360-second driven assembly; 400-pressure sensing assembly; 410-palm base; 420-palm software; 430-pressure sensor; 500-shearing assembly; 510-first base; 520-second base; 530-first bevel gear; 540-second bevel gear; 550-first drive motor; 570-universal joint; 580-shearing tool; 600-depth camera. Detailed Implementation

[0044] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] The embodiments of this application provide an adaptive fruit picking end effector, whose overall structural design revolves around improving the gripping adaptability to fruits of different sizes and shapes and minimizing damage during the picking process.

[0048] like Figures 1-8 As shown, the end effector mainly includes an end effector base 100, a drive assembly 200, a clamping assembly 300, and a pressure sensing assembly 400. The clamping assembly 300, as the core actuation unit, further includes a clamping bracket 310, a main drive assembly 320, an active drive finger 330, and an underactuated finger 340.

[0049] The bottom of the clamping bracket 310 is fixedly connected to the end of the end effector base 100 to support the entire clamping mechanism. The clamping bracket 310 has an assembly cavity inside, and the drive assembly 200, which is a motor, is installed in this cavity. The output end of the drive assembly 200 is connected to the main transmission assembly 320 to provide power for the entire clamping action. Through this structural arrangement, the drive assembly 200 can simultaneously control the active transmission finger 330 and the two underactuated fingers 340 to retract or open via the main transmission assembly 320, thereby achieving the grasping and release of the fruit.

[0050] Considering that when grasping fruits of different sizes, it is difficult for fingers in a fixed posture to ensure uniform contact with the surface of the fruit, the active transmission finger 330 in this embodiment adopts a belt drive structure design.

[0051] Specifically, refer to Figure 2 and Figure 5 The active drive finger 330 includes a drive finger base 331, a drive finger support 332, a main drive finger drive assembly 333, a main drive finger transmission assembly 334, and a fruit-gripping transmission belt 335. The drive finger base 331 is connected to a first driven assembly 350, which drives the active drive finger 330 to move. The drive finger support 332 is fixed to the drive finger base 331, and the fruit-gripping transmission belt 335 is mounted on the drive finger support 332 via a pulley shaft. The main drive finger drive assembly 333 is located inside the drive finger base 331, and its output end is connected to the pulley shaft via the main drive finger transmission assembly 334, allowing it to independently drive the fruit-gripping transmission belt 335 to rotate along the length of the finger (i.e., towards the palm). When the fingers close and contact the fruit, the rotation of the fruit-gripping transmission belt 335 can slightly roll or push the fruit towards the palm, helping to adjust the fruit's posture and make it fit the palm, improving the reliability and stability of the grip. At the same time, this flexible contact method also helps to reduce mechanical damage to the fruit peel.

[0052] The pressure sensing component 400 is located at the top of the gripping bracket 310, i.e., at the palm position. This pressure sensing component 400 is used to detect in real time the pressure value applied to the palm as the fruit is grasped and moved towards the palm. When the pressure value reaches a preset threshold, the control system can issue a command to stop the fingers from further closing, thereby realizing closed-loop control of the gripping force and avoiding damage to the fruit due to excessive gripping force. This design takes into account both the stability of the grip and the requirements of low damage.

[0053] Furthermore, referring to Figure 4 In order to optimize the structural layout and transmission efficiency of the clamping bracket 310, the clamping bracket 310 in this embodiment is generally cylindrical, and its side walls are respectively provided with grooves for accommodating the first driven component 350 and the second driven component 360. Each groove is provided with a mounting bracket 311 on both sides.

[0054] The first driven component 350, the second driven component 360, and the underdriven finger 340 are respectively connected to the corresponding mounting bracket 311 via shaft rotation. This structural design not only makes the overall layout compact and easy to assemble and maintain, but also ensures the relative positional accuracy between the moving parts and improves the transmission reliability.

[0055] Reference Figure 2 and Figure 3 In terms of the specific transmission implementation, this embodiment uses a worm gear as the main transmission component 320. Correspondingly, the first driven component 350 includes a first turbine 351 and a turbine bracket 352. The first turbine 351 is rotatably connected to the mounting bracket 311 via a shaft and meshes with the worm gear. The first turbine 351 is connected to the transmission finger base 331 via the turbine bracket 352, thereby converting the rotation of the worm gear into the oscillating motion of the active transmission finger 330.

[0056] The second driven component 360 includes a second turbine, the end of which meshes with a worm gear, and the connecting end is rotatably connected to the underdriven finger 340 via a shaft. The worm gear transmission method has advantages such as compact structure, large transmission ratio, and good self-locking, effectively maintaining the finger position during clamping and preventing loosening due to external disturbances.

[0057] Reference Figure 6 In order to achieve adaptive wrapping of the fruit shape by the underactuated finger 340, the underactuated finger 340 in this embodiment adopts a multi-link structure design, specifically including a proximal phalanx 341, a middle phalanx 342, a distal phalanx 343, a straight link 344, and an L-link 345.

[0058] One end of the proximal phalanx 341 is rotatably connected to the mounting bracket 311 via a shaft. The two ends of the middle phalanx 342 are rotatably connected between the proximal phalanx 341 and the distal phalanx 343 via shafts with torsion springs. The torsion springs maintain the natural bending posture of the fingers in the absence of external force, facilitating contact with the fruit surface. One end of the L-link 345 is rotatably connected to the middle of the proximal phalanx 341 via a shaft, and the other end is rotatably connected to the distal phalanx 343 via a shaft. One end of the straight link 344 is rotatably connected to the connection end of the second turbine, and the other end is connected to the right-angle end of the L-link 345. When the second turbine rotates, the straight link 344 drives the L-link 345 to move, thereby causing the proximal phalanx 341, middle phalanx 342, and distal phalanx 343 to move sequentially, achieving the bending posture of the fingers. Because this structure is underactuated, the fingers can passively adjust their contact posture according to the shape of the fruit, achieving multi-point contact, improving grip stability while reducing local stress concentration.

[0059] To further reduce mechanical damage to the fruit and decrease friction, this embodiment of the application has a plurality of rollers 346 rotatably connected to the gripping sides of the proximal phalanx 341, middle phalanx 342 and distal phalanx 343 respectively. The surface of the rollers 346 is covered with soft silicone material. When the fruit is grasped or its posture is adjusted, the rollers 346 can roll with the surface of the fruit, avoiding the scratching of the peel by sliding friction. This is especially suitable for fruits such as fresh apples with fragile peels.

[0060] Reference Figure 7 In the specific implementation of the pressure sensing component 400, this embodiment includes a palm base 410, a palm soft body 420, and a pressure sensor 430. The palm base 410 is fixedly installed on the top of the clamping bracket 310, the palm soft body 420 is fixed on the palm base 410, and the pressure sensor 430 is embedded inside the palm soft body 420. The palm soft body 420 is made of soft silicone material, which has good elasticity and cushioning performance, and can play a cushioning role when in contact with fruit. The pressure sensor 430 is a piezoresistive flexible pressure sensor 430, which can sense the contact force in real time and output an electrical signal for closed-loop control of the gripping force. This structure ensures both the sensitivity of the sensing and improves the flexibility of contact with fruit.

[0061] Considering that the fruit stems also need to be cut during harvesting, this application embodiment also provides a cutting component 500. (Refer to...) Figure 1 , Figure 2 and Figure 8 The shearing assembly 500 includes a first base 510, a second base 520, a first bevel gear 530, a second bevel gear 540, a first drive motor 550, a universal joint 570, and a shearing blade 580.

[0062] The first base 510 is fixed to the side wall of the clamping bracket 310. Two first drive motors 550 are symmetrically arranged on both sides of the first base 510. The output end of each motor is connected to the first bevel gear 530. The bottom fixed end of the universal joint 570 is rotatably connected to the middle of the first base 510 through a rotating shaft. The second bevel gear 540 is sleeved on the upper movable joint of the universal joint 570 and meshes with the two first bevel gears 530 respectively.

[0063] The second base 520 is connected to the movable joint of the universal joint 570, and the shearing blade 580 is mounted on the second base 520. When the two lower first bevel gears 530 rotate in the same direction, the upper second bevel gear 540 and the second base 520 rotate around the axis of the lower first bevel gear 530. When the two lower first bevel gears 530 rotate in opposite directions, the upper bevel gear and the second base 520 rotate around the axis of the upper second bevel gear 540. This allows for angle adjustment of the second bevel gear 540 and the universal joint 570, thereby changing the orientation of the shearing blade 580 and achieving precise shearing of fruit stalks in different orientations. This design improves the spatial adaptability of the shearing mechanism and can handle situations where fruit stalks grow in different directions.

[0064] It should be noted that the shearing blade 580 is existing technology, and its structure will not be described in detail in this embodiment.

[0065] To achieve accurate identification of the fruit stalk position and planning of the cutting path, this embodiment also includes a vision component. The vision component consists of a depth camera 600 and a camera bracket. The depth camera 600 is fixed to the side of the end effector base 100 via the camera bracket and is used to acquire RGB images and depth images of the fruit stalk and fruit. The acquisition of visual information provides a data foundation for subsequent estimation of the cutting pose.

[0066] To further improve the automation and accuracy of the shearing operation, this application embodiment also includes a data processing module. The data processing module acquires RGB and depth images from a depth camera 600, calls the YOLOv8-SEG model to segment the fruit stalk and fruit in the images, and then uses the YOLOv8 Pose model to detect key points such as the fruit shoulder and stem. A straight line from the fruit shoulder to the stem is formed as a reference direction for shearing pose estimation. Based on this, the distance h from the perpendicular line of the fruit stalk centerline to the fruit surface is set, and the distance is translated 2h away from the fruit along the fruit stalk centerline to obtain the final shearing tool pose position 580. This algorithm design fully considers the spatial relationship between the fruit stalk and the fruit, enabling effective shearing of the fruit stalk while avoiding damage to the fruit.

[0067] The following describes the harvesting method of the adaptive fruit-harvesting end effector provided in this embodiment:

[0068] After the end effector reaches the picking point, the drive assembly 200 drives the worm to rotate. Through the meshing transmission between the worm and the first turbine 351 and the second turbine, the active drive finger 330 and the under-driven finger 340 close towards the palm. At the same time, the fruit gripping transmission belt 335 on the active drive finger 330 is driven by the main drive finger drive assembly 333 (using a motor), and works with several rollers 346 on the under-driven finger 340 to transmit the apple towards the palm.

[0069] Under the constraint of the torsion spring installed between the proximal phalanx 341, the middle phalanx 342 and the distal phalanx 343, the underactuated finger 340 fits against the surface of the apple and presses against the palm soft body 420. When the pressure sensor 430 installed in the palm soft body 420 detects the pressure threshold, the first motor and the second motor stop driving, forming a "wrap-around" grasping posture.

[0070] The depth camera 600 begins to acquire RGB and depth images of the fruit stalk. The data processing module acquires the RGB and depth images of the fruit stalk and calls the YOLOv8-SEG model to segment the fruit stalk and fruit, further improving the detection accuracy of individual fruits and fruit stalks and reducing the interference of the background on the detection of the fruit stalk. Then, the YOLOv8 Pose model is used to detect key points of the fruit shoulder and fruit stem. A straight line is formed from the fruit shoulder to the fruit stem as the reference direction for shearing pose estimation. The distance h between the perpendicular line of the fruit stalk midline and the fruit surface is set. The final shearing pose point is obtained by translating along the fruit stalk midline away from the fruit in a direction away from the fruit.

[0071] Based on the shearing posture, the two sets of first drive motors 550 drive the first bevel gear 530 to adjust the cutter base, and finally the apple stem is cut off by the shearing device to complete the apple picking operation.

[0072] In summary, the adaptive fruit-picking end effector provided in this application embodiment drives the main transmission component 320 through the drive component 200, enabling the active transmission finger 330 and the underactuated finger 340 to work together to achieve the closing and opening of the fingers. The transmission belt structure built into the active transmission finger 330 can roll and push the fruit towards the palm, and together with the pressure sensing component 400, it realizes closed-loop control of the grasping force, ensuring stable clamping of fruits of different sizes and shapes.

[0073] The underactuated finger 340 multi-link design, combined with the roller 346 structure, can adaptively envelop the shape of the fruit, further reducing clamping damage.

[0074] The shearing assembly 500 uses a dual-motor driven universal joint 570 structure to achieve flexible shearing of fruit stalks in different orientations, while the vision assembly and data processing module provide precise positional guidance for shearing.

[0075] Overall, the embodiments of this application have significantly improved in terms of grip adaptability, low damage, shearing flexibility and intelligence level, and can effectively solve the problems of grip failure and high damage rate of existing apple picking end effectors in unstructured environments, and are suitable for the automated picking needs of modern orchards.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive fruit-picking end effector, characterized in that, Includes end effector base, drive assembly, clamping assembly and pressure sensing assembly; The clamping assembly includes a clamping bracket, a main drive assembly, an active drive finger, and an underdriven finger; The bottom of the clamping bracket is connected to the end of the end effector base. The clamping bracket has an assembly cavity inside, and the drive assembly is disposed in the assembly cavity. The output end of the drive assembly is connected to the main drive assembly. The main drive finger is connected to the main drive assembly through the first driven assembly, and the two underdriven fingers are connected to the main drive assembly through the second drive assembly. Furthermore, the underdriven fingers are hinged to the clamping bracket via a shaft. The drive assembly is used to drive the active drive finger and the underdriven finger to retract or open to pick the fruit through the main drive assembly. The active transmission finger includes a transmission finger base, a transmission finger support, a main transmission finger drive assembly, a main transmission finger transmission assembly, and a fruit gripping transmission belt. The transmission finger base is connected to the first driven component, the transmission finger bracket is fixed on the transmission finger base, the fruit gripping transmission belt is connected to the transmission finger bracket through the pulley shaft, the main transmission finger drive component is set inside the transmission finger base, and the main transmission finger drive component is connected to the pulley shaft through the main transmission finger transmission component to drive the fruit gripping transmission belt to rotate. The pressure sensing component is located at the palm position on the top of the gripping bracket and is used to detect the pressure value applied to the pressure sensing component during the grasping and moving of the fruit.

2. The adaptive fruit-picking end effector according to claim 1, characterized in that, The clamping bracket is cylindrical, and the side walls of the clamping bracket are respectively provided with slots for accommodating the first driven component and the second driven component. Each slot is provided with a mounting bracket on both sides. The first driven component, the second driven component, and the underdriven finger are rotatably connected to their respective mounting brackets via shafts.

3. The adaptive fruit-picking end effector according to claim 2, characterized in that, The main drive assembly uses a worm gear; The first driven component includes a first turbine and a turbine bracket. The first turbine is rotatably connected to the mounting bracket via a shaft, and the first turbine meshes with a worm gear. The first turbine is connected to the transmission finger base via the turbine bracket. The second driven component includes a second turbine, the first turbine is rotatably connected to the mounting bracket via a shaft, the worm gear end of the second turbine meshes with a worm, and the connecting end of the second turbine is rotatably connected to an underdriven finger via a shaft.

4. The adaptive fruit-picking end effector according to claim 1, characterized in that, The underactuated finger includes a proximal phalanx, a middle phalanx, a distal phalanx, a straight link, and an L-link; One end of the proximal phalanx is rotatably connected to the mounting bracket via a shaft. The two ends of the middle phalanx are rotatably connected between the proximal and distal phalanxes via shafts with torsion springs, respectively. One end of the L-link is rotatably connected to the middle of the proximal phalanx via a shaft, and the other end of the L-link is rotatably connected to the distal phalanx via a shaft. One end of the straight link is rotatably connected to the connection end of the second turbine via a shaft, and the other end of the straight link is rotatably connected to the right-angle end of the L-link via a shaft.

5. The adaptive fruit-picking end effector according to claim 4, characterized in that, The proximal, middle, and distal phalanges are each rotatably connected to a number of rollers on the side used to hold the apple.

6. The adaptive fruit-picking end effector according to claim 1, characterized in that, The pressure sensing component includes a palm base, palm software, and a pressure sensor. The palm base is fixedly installed on the top of the clamping bracket, the palm software is fixed on the palm base, and the pressure sensor is located inside the palm software.

7. The adaptive fruit-picking end effector according to claim 6, characterized in that, The palm-shaped soft body is made of soft silicone material, and the pressure sensor is a piezoresistive flexible pressure sensor.

8. The adaptive fruit-picking end effector according to claim 1, characterized in that, It also includes a shearing assembly, which includes a first base, a second base, a first bevel gear, a second bevel gear, a first drive motor, a universal joint, and a shearing blade; The first base is fixed to the side wall of the clamping bracket; Two first drive motors are symmetrically arranged on both sides of the first base, and the output end of each first drive motor is connected to a first bevel gear; The bottom fixed end of the universal joint is rotatably connected to the middle of the first base via a rotating shaft. The second bevel gear is sleeved on the upper movable joint of the universal joint, and the second bevel gear meshes with the two first bevel gears respectively. The second base is connected to the movable joint of the universal joint; The shearing blade is connected to the second base.

9. The adaptive fruit-picking end effector according to claim 8, characterized in that, It also includes a vision component, which includes a depth camera and a camera mount. The depth camera is fixed to the side of the end effector base via the camera mount. The depth camera is used to acquire RGB images and depth images of the fruit stalk.

10. The adaptive fruit-picking end effector according to claim 9, characterized in that, It also includes a data processing module, which is used to acquire the RGB image and depth image of the fruit stalk, call the yolov8-seg model to segment the fruit stalk and fruit, and then use the YOLOv8 Pose model to detect key points of the fruit shoulder and stem. A straight line is formed from the fruit shoulder to the stem as the reference direction for shearing pose estimation. The distance h between the perpendicular line of the fruit stalk midline and the fruit surface is set, and the final shearing pose point is obtained by translating along the fruit stalk midline away from the fruit in a direction away from the fruit.

Images