Strawberry picking manipulator integrating clamping, touch detection and shearing functions

Abstract

The invention discloses a strawberry picking manipulator integrating clamping, touch detection and shearing functions. An end effector is arranged at the tail end of a mechanical arm, and a touch sensor is installed on the end effector; according to the end effector, a mechanism carrying plane is arranged at the tail end of the mechanical arm, the upper side and the lower side of the mechanism carrying plane are each provided with a linear sliding rail, the two linear sliding rails are each provided with a fruit stem traction and shearing unit and a fruit clamping and detecting unit, and the fruit stem traction and shearing unit is used for hooking and shearing strawberry fruit stems; the fruit clamping detection unit is used for clamping strawberry fruits, and a touch sensor is mounted on the fruit clamping detection unit; the mechanism carrying plane is fixedly connected with the mechanical arm, and the mechanism carrying plane is fixedly connected with the linear sliding rail. Through the synergistic effect of the hook-shaped fruit stem hooking mechanism and the touch sensor which are innovatively designed, the technical bottleneck of accurate separation of cluster-shaped fruits is broken through, and meanwhile, the problem of mechanical damage to the fruits caused by rigid clamping is avoided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of agricultural machinery, and specifically relates to a strawberry picking manipulator integrating clamping, tactile detection and shearing functions, which is suitable for automatic picking operation of strawberries in facility agriculture. BACKGROUND

[0002] As an economic crop with high nutritional value, strawberries play an important role in facility agriculture in China. The yield has broken through 3.5 million tons in 2023, with an average yield per mu of 48,000 yuan. The market demand is continuously strong, and China is the largest producer and consumer of strawberries. However, the thin and soft nature of strawberry fruit poses a serious challenge in the picking process. During manual picking, damage caused by bumps and squeezing shortens the shelf life of damaged fruit and easily leads to cross-infection of bacteria, resulting in economic losses every year. The current strawberry industry faces a double dilemma: on the one hand, labor shortage and aging exacerbate the increase in labor costs; on the other hand, the traditional row planting mode (plant spacing ≤ 30 cm) forms a complex field environment, and workers need to bend frequently, while large agricultural machinery is difficult to adapt to such scenarios, hindering the advancement of mechanization. In contrast, the high cultivation mode creates conditions for mechanized picking by agricultural innovation, as fruits naturally droop after ripening, but existing technologies still cannot meet the needs of precision operations.

[0003] Existing strawberry picking devices generally have functional limitations and technical bottlenecks. Traditional clamps lack fruit stem positioning in dense planting scenarios, and when facing cluster fruits with overlapping stems (spacing < 2 cm), they cannot separate individual strawberries growing in clusters, resulting in high collateral damage. Especially for overhanging fruits in high cultivation mode, rigid clamps are prone to collide with adjacent unripe fruits, causing hidden damage due to the lack of tactile feedback. For high cultivation mode, existing devices have not optimized the fruit stem hooking mechanism, and direct clamping of fruits can easily cause slipping or damage, making it difficult to meet the needs of commercial picking.

[0004] Therefore, there is an urgent need for an innovative solution that integrates precise tactile control, rapid adaptation, and agricultural adaptation to break through the technical barriers of strawberry mechanized picking. SUMMARY

[0005] To address the problems of cluster fruit separation and mechanical damage caused by rigid clamping without tactile feedback in existing technologies for greenhouse cultivation mode strawberry mechanized picking, the present application provides a strawberry picking manipulator integrating clamping, tactile detection and shearing functions. The device breaks through the technical bottleneck of precise separation of cluster fruits while reducing manual labor intensity, avoiding the problem of mechanical damage to fruits caused by traditional rigid clamping without tactile feedback.

[0006] To achieve the above-mentioned purposes, the present application provides the following technical solutions: 1. A strawberry picking manipulator integrating clamping, tactile detection and shearing functions.

[0007] The strawberry picking manipulator comprises a mechanical arm, a tactile sensor and an end effector; the end of the mechanical arm is arranged with the end effector, and the tactile sensor is mounted on the end effector; the end effector comprises a fruit stem traction shearing unit, a fruit clamping detection unit, a linear slide rail and a mechanism mounting plane; the mechanism mounting plane is arranged at the end of the mechanical arm, and one linear slide rail is arranged on each of the upper and lower sides of the mechanism mounting plane; the fruit stem traction shearing unit and the fruit clamping detection unit are respectively arranged on the two linear slide rails; the fruit stem traction shearing unit is used for hooking and shearing the strawberry stem; the fruit clamping detection unit is used for clamping the strawberry fruit body; the tactile sensor is mounted on the fruit clamping detection unit; the mechanism mounting plane is arranged in a spaced manner with the end face of the end of the mechanical arm and is fixedly connected; and the mechanism mounting plane is fixedly connected with the linear slide rails.

[0008] Specifically, the fruit stem traction shearing unit comprises a closed-loop control motor, a blade mounting piece, a hook-shaped fruit stem hooking mechanism, a gear and rack set, a fixed slide block and a first movable slide block; the closed-loop control motor is in transmission connection with the first movable slide block through the gear and rack set; the first movable slide block is slidingly arranged on the linear slide rail above the mechanism mounting plane; the fixed slide block is arranged on one side of the first movable slide block; the hook-shaped fruit stem hooking mechanism is mounted on the first movable slide block; and the blade mounting piece is mounted on the fixed slide block, and the blade mounting piece is used for mounting a blade.

[0009] Specifically, the hook-shaped fruit stem hooking mechanism is provided in a circular arc shape at the end away from the linear slide rail.

[0010] Further, the strawberry picking manipulator further comprises a control system, and the mechanical arm, the tactile sensor and the closed-loop control motor are in communication connection with the control system.

[0011] Specifically, the fruit clamping detection unit comprises a transmission mechanism, two second movable slide blocks and two sensor clamping pieces; the driving part of the transmission mechanism is connected with the output shaft of the end of the mechanical arm, and the output part is connected with the two second movable slide blocks; the second movable slide blocks are slidingly arranged on the linear slide rails below the mechanism mounting plane; one sensor clamping piece is mounted on each of the two second movable slide blocks; and the sensor clamping pieces are used for fixing the tactile sensor.

[0012] Specifically, the transmission mechanism comprises a first driving wheel, a first driven wheel, a second gear set and two connecting rods; the first driving wheel is connected with the output shaft of the mechanical arm, and a first driven wheel is arranged on one side of the first driving wheel and is in meshing connection with the first driven wheel; a second gear set is arranged above the first driven wheel, the second gear set comprises a second driving wheel and a second driven wheel, the second driving wheel is coaxially arranged with the first driven wheel, the second driving wheel is arranged on one side of the second driving wheel, the second driving wheel is fixedly connected with the first driven wheel, and the second driving wheel is in meshing connection with the second driven wheel; the cross-sectional shape of the second driving wheel and the second driven wheel is a non-complete circle with a notch, and one connecting rod is arranged at the notch; the connecting rod, the connecting rod and the second movable slider correspond one by one, each connecting rod is hingedly connected with one end of the corresponding connecting rod, and the other end of the connecting rod is hingedly connected with the second movable slider.

[0013] Two, a strawberry picking robot.

[0014] Three, a strawberry picking method using the strawberry picking robot.

[0015] The strawberry picking method comprises the following steps: S1: using the mechanical arm to move the end effector close to the target strawberry, using the hook-shaped fruit stem hooking mechanism to hook the fruit stem of the target strawberry, even if the fruit stem of the target strawberry is located on the inside of the hook-shaped fruit stem hooking mechanism; using the closed-loop control motor to drive the first movable slider to move along the linear slide rail located above the mechanism mounting plane to the fixed slider, the first movable slider drives the hook-shaped fruit stem hooking mechanism to move synchronously by a preset distance, realizing the hooking and guiding of the strawberry fruit stem, and then separating the target strawberry from the strawberry fruit cluster; In the step S1, the preset distance is 1-2 cm; S2: using the output shaft of the mechanical arm to drive the two second movable sliders to move towards each other along the linear slide rail located below the mechanism mounting plane, the two second movable sliders drive the corresponding sensor holders to move synchronously, the tactile sensor transmits the collected signals to the control system, realizing the dynamic stable clamping of the strawberry fruit body and the tactile information collection; S3: using the closed-loop control motor to drive the first movable slider to move along the linear slide rail located above the mechanism mounting plane to the fixed slider, the first movable slider drives the hook-shaped fruit stem hooking mechanism to move synchronously until the hook-shaped fruit stem hooking mechanism contacts with the blade on the blade adding piece, realizing the shearing of the strawberry fruit stem; S4: using the mechanical arm to move the end effector to the collection container, using the output shaft of the mechanical arm to drive the two second movable sliders to move away along the linear slide rail located below the mechanism mounting plane, canceling the clamping of the strawberry fruit body, so that the strawberry fruit body enters the collection container under the action of gravity and is stored; S5: repeat steps S1-S4 until the end of picking.

[0016] Four, the application of a strawberry picking manipulator in a strawberry picking robot.

[0017] The present application has the following technical effects relative to the prior art: 1. The hierarchical modular and compact structure design adopted by the present application is compatible with the mechanical arm mounting scheme, which effectively avoids mechanical damage to adjacent fruits through spatial layout optimization while achieving efficient strawberry harvesting, significantly improving the environmental adaptability of the harvesting operation.

[0018] 2. The present application addresses the problem of separating cluster fruits, and uses a acrylic hook structure (curvature radius 1.5mm) to overcome the precision separation technology bottleneck of fruit stem spacing <2cm. Compared with the traditional rigid jaw scheme, the associated damage rate is significantly reduced.

[0019] 3. The tactile sensor used in the present application can be combined with the control system to realize adaptive clamping force closed-loop control, and through real-time sensing of the differences in the biomechanical properties of fruits, the clamping force (typical working range 3~7N) is dynamically adjusted, which eliminates the risk of hidden damage to the fruit skin under the premise of ensuring stable clamping.

[0020] 4. Based on the lightweight design of the physical properties of strawberry fruits (clamping force requirement ≤7N), small driving motors and compact transmission mechanisms are used to ensure the reliability of the function under the premise of realizing the overall quality of the device ≤1.2kg, meeting the dynamic performance requirements of the mechanical arm end effector. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a structural schematic diagram of a strawberry picking manipulator; Figure 2 is a structural schematic diagram of the end of a strawberry picking manipulator; Figure 3 is a structural schematic diagram of the upper layer of the end of a strawberry picking manipulator (top view); Figure 4 is a structural schematic diagram of the lower layer of the end of a strawberry picking manipulator (bottom view); Figure 5 is a structural schematic diagram of the lower layer of the end of a strawberry picking manipulator (front isometric view).

[0022] In the figure: 1-mechanical arm; 2-tactile sensor; 3-end effector; 31-fruit stem traction shearing unit; 32-fruit clamping detection unit; 33-closed-loop control motor; 34-linear slide rail; 35-mechanism carrying plane; 36-sensor clamping piece; 37-blade add-on; 38-hook-shaped fruit stem hooking mechanism; 311-gear and rack set; 312-fixed slide block; 313-first movable slide block; 321-first level driving wheel; 322-first level driven wheel; 323-second level gear set; 324-connecting rod; 325-first shaft hole; 326-gear fixed connection; 327-second shaft hole; 328-second movable slide block. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0024] The present application provides a strawberry picking manipulator integrating clamping, tactile detection and shearing functions.

[0025] The strawberry picking manipulator comprises a mechanical arm 1, a tactile sensor 2 and an end effector 3. The end of the mechanical arm 1 is arranged with the end effector 3, and the end effector 3 is installed with the tactile sensor 2. The end effector 3 adopts a hierarchical modular design and a compact structure design. The upper mechanism (fruit stem traction shearing unit 31) and the lower mechanism (fruit clamping detection unit 32) realize cooperative movement through the linear slide rail.

[0026] The hierarchical modular and compact structure design of the end effector 3 specifically refers to that the end effector 3 comprises a fruit stem traction shearing unit 31, a fruit clamping detection unit 32, a linear slide rail 34 and a mechanism carrying plane 35. The mechanism carrying plane 35 is arranged at the end of the mechanical arm 1. The upper and lower sides of the mechanism carrying plane 35 are each arranged with a linear slide rail 34. The fruit stem traction shearing unit 31 and the fruit clamping detection unit 32 are respectively arranged on the two linear slide rails 34. The fruit stem traction shearing unit 31 is used for hooking and shearing the strawberry stem. The fruit clamping detection unit 32 is used for clamping the strawberry fruit body. The fruit clamping detection unit 32 is installed with the tactile sensor 2. The mechanism carrying plane 35 is arranged and fixedly connected with the end face of the mechanical arm 1. The mechanism carrying plane 35 is fixedly connected with the linear slide rail 34.

[0027] As a preferred embodiment of the present application, the fruit stem pulling and cutting unit 31 comprises a closed-loop control motor 33, a blade mounting piece 37, a hook-shaped fruit stem hooking mechanism 38, a gear and rack set 311, a fixed sliding block 312 and a first movable sliding block 313; the closed-loop control motor 33 is installed on one side of the end of the mechanical arm 1, the closed-loop control motor 33 is in transmission connection with the first movable sliding block 313 through the gear and rack set 311, the first movable sliding block 313 is slidingly arranged on the linear slide rail 34 above the mechanism mounting plane 35, a fixed sliding block 312 is arranged on one side of the first movable sliding block 313 in the moving direction of the linear slide rail 34, the hook-shaped fruit stem hooking mechanism 38 is installed on the first movable sliding block 313, and the blade mounting piece 37 is installed on the fixed sliding block 312, and the blade mounting piece 37 is used for mounting a blade.

[0028] In the above preferred embodiment, the hooking end of the hook-shaped fruit stem hooking mechanism 38 is provided in a circular arc shape. The hooking end of the hook-shaped fruit stem hooking mechanism 38 refers to the end away from the linear slide rail 34. When the strawberry picking mechanical hand approaches the strawberry cluster, because the length of the hook-shaped fruit stem hooking mechanism 38 in the direction perpendicular to the parallel slide rail is greater than that of the tactile sensor 2, the hook-shaped fruit stem hooking mechanism 38 touches the strawberry cluster first, and separates the target strawberry by hooking the fruit stem first, so that the reasonable spatial layout of the strawberry picking mechanical hand effectively avoids mechanical damage to the adjacent fruits.

[0029] It should be noted that the reason for providing the hooking end of the hook-shaped fruit stem hooking mechanism 38 in a circular arc shape in the present application is as follows: 1. Path trajectory: the circular arc path meets the dynamic requirements of fruit stem separation. In the cutting process, the fruit stem is controlled by the mechanical arm 1 to enter the hooking end, the first movable sliding block 313 drives the hook to slide 1-2 cm along the fruit stem in the transverse direction (parallel to the linear slide rail 34), at the same time, the circular arc surface guides the fruit stem to smoothly enter the blade opening in the longitudinal direction (perpendicular to the linear slide rail) through continuous curvature change, avoiding the "stuck" phenomenon of the transverse line movement of the rectangular structure, and the sliding resistance of the circular arc hook is lower than that of the rectangular structure, which can improve the separation success rate.

[0030] 2. Avoid stress concentration: the contact point pressure of the circular arc is low, while the contact point pressure of the rectangular or triangular hook structure is high due to the sharp corners, which easily leads to the rupture of epidermal cells and a large increase in the damage rate compared with the circular arc hook.

[0031] 3. Balance between manufacturing and reliability: the circular arc structure has no stress concentration point and high fatigue life. At the same time, the uniform wear characteristics of the circular arc edge can prolong the maintenance period, while the corner structure needs to be polished multiple times due to local wear.

[0032] In the above preferred embodiment, the hook-shaped fruit stem hooking mechanism 38 is preferably made of acrylic material.

[0033] In the preferred embodiment described above, the curvature radius of the hook end of the hook-shaped fruit stalk hooking mechanism 38 is preferably 1.5 mm, which can accurately separate the cluster fruit stalks.

[0034] In the preferred embodiment described above, the closed-loop control motor 33 is connected to the first movable slider 313 through the gear and rack set 311. The gear and rack set 311 includes a gear and a rack, which are connected in meshing engagement. The gear is connected to the output shaft of the closed-loop control motor 33, and the rack is fixedly connected to the first movable slider 313.

[0035] Further, the strawberry picking manipulator further includes a control system, and the mechanical arm 1, the tactile sensor 2, and the closed-loop control motor 33 are all in communication connection with the control system.

[0036] In specific implementation, the control system can perform real-time feedback control on the output power of the output shaft at the end of the mechanical arm 1 according to the real-time pressure signals fed back by the tactile sensor 2.

[0037] As a preferred embodiment of the present application, the fruit clamping detection unit 32 includes a transmission mechanism, two second movable sliders 328, and two sensor clamping pieces 36. The driving part of the transmission mechanism is connected to the output shaft at the end of the mechanical arm 1, and the output part is connected to the two second movable sliders 328. The second movable sliders 328 are slidingly arranged on the linear slide rail 34 below the mechanism mounting plane 35. Each of the two second movable sliders 328 is provided with a sensor clamping piece 36, and the sensor clamping piece 36 is used to fix the tactile sensor 2.

[0038] In the preferred embodiment described above, the transmission mechanism includes a primary driving wheel 321, a primary driven wheel 322, a secondary gear set 323, and two connecting rods 324. The primary driving wheel 321 is connected to the output shaft at the end of the mechanical arm 1. The primary driving wheel 321 is provided on one side with the primary driven wheel 322, which is connected in meshing engagement with the primary driving wheel 321. The secondary gear set 323 is arranged above the primary driven wheel 322. The secondary gear set 323 includes a secondary driving wheel and a secondary driven wheel. The secondary driving wheel is coaxially arranged with the primary driven wheel 322. The secondary driving wheel is provided on one side with the secondary driven wheel, which is fixedly connected to the secondary driving wheel. The secondary driving wheel and the secondary driven wheel are both in the shape of an incomplete circle with a notch, and each notch is provided with a connecting rod. The connecting rod, the connecting rod 324, and the second movable slider 328 are in one-to-one correspondence. Each connecting rod is hingedly connected to one end of the corresponding connecting rod 324, and the other end of the connecting rod 324 is hingedly connected to the second movable slider 328.

[0039] It should be noted that, in a specific implementation, the transmission ratio of the gear rack set 311 and the multi-stage gear set (the first-stage driving wheel 321, the first-stage driven wheel 322 and the second-stage gear set 323) is adjustable to adapt to different fruit handle hardness and clamping force requirements.

[0040] It should be noted that in specific implementations, the output power is positively correlated to the clamping force. The output power (P) at the end of the robot arm determines the output torque (T): T∝P / ω, where ω is the angular velocity of the output shaft. The relationship between clamping force (F) and torque (T): F=(T×i gear ×η) / r i gear : Total transmission ratio of the gear set (adjustable to suit different fruit stem hardness); η: transmission efficiency; r: Equivalent force arm from the clamping force application point to the rotation center.

[0041] The present invention also provides a strawberry picking robot using the strawberry picking manipulator.

[0042] The present invention also provides a strawberry picking method using the strawberry picking manipulator or the strawberry picking robot.

[0043] The strawberry picking method of the present invention comprises the following steps: S1: Use the robotic arm 1 to move the end effector 3 close to the target strawberry, and use the hook-shaped fruit stem hooking mechanism 38 to hook the fruit stem of the target strawberry, even if the fruit stem of the target strawberry is located inside the hook-shaped fruit stem hooking mechanism 38; use the closed-loop control motor 33 to drive the first movable slider 313 to move along the linear slide rail 34 located above the mechanism mounting plane 35 toward the fixed slider 312, and the first movable slider 313 drives the hook-shaped fruit stem hooking mechanism 38 to move synchronously by a preset distance, thereby hooking and guiding the strawberry fruit stem, and then separating the target strawberry from the strawberry cluster; Among them, the preset distance is preferably 1~2cm; S2: Use the end output shaft of the robotic arm 1 to drive the two second movable sliders 328 to move toward each other along the linear slide 313 track 34 located below the mechanism mounting plane 35. The two second movable sliders 328 drive their corresponding sensor clamps 36 to move synchronously. The tactile sensor 2 transmits the collected signal to the control system, realizing dynamic and stable clamping of the strawberry fruit and collection of tactile information; S3: Using the closed-loop control motor 33, the first movable slider 313 is driven to move along the linear slide rail 34 located above the mechanism mounting plane 35 toward the fixed slider 312. The first movable slider 313 drives the hook-shaped fruit stem hooking mechanism 38 to move synchronously until the hook-shaped fruit stem hooking mechanism 38 contacts the blade on the blade attachment 37, thereby shearing the strawberry stem. S4: using the mechanical arm 1 to move the end effector 3 to the collection container, using the end output shaft of the mechanical arm 1 to drive the two second movable sliders 328 to move back along the linear slide rail 34 located below the mechanism mounting plane 35, cancel the clamping of the strawberry fruit body, and make the strawberry fruit body enter the collection container under the action of gravity; S5: repeat steps S1-S4 until the picking is completed.

[0044] The application also provides an application of the strawberry picking mechanical hand in a strawberry picking robot.

[0045] The specific embodiments of the application are as follows: Please refer to Figure 1 The strawberry picking mechanical hand device in the embodiment includes a mechanical arm 1, a tactile sensor 2 and an end effector 3.

[0046] Please refer to Figure 2 The end effector 3 is shown in detail, which includes a fruit stem traction shearing unit 31 for hooking and shearing the strawberry stem, a fruit clamping detection unit 32 for closing the tactile sensor 2 and clamping the strawberry fruit body. A closed-loop control motor 33 is fixed to the side of the mechanical arm 1, and two linear slide rails 34 are respectively fixed to the upper and lower sides of the mechanism mounting plane 35, which are respectively an upper linear slide rail and a lower linear slide rail. Two second movable sliders 328 are arranged on the lower linear slide rail, and a fixed slider 312 and a first movable slider 313 are arranged on the upper linear slide rail. A sensor clamping piece 36 is fixed to the second movable slider 328 for clamping the tactile sensor 2, a blade mounting piece 37 is fixed to the fixed slider 312 for mounting the blade, and a hook-shaped fruit stem hooking mechanism 38 is fixed to the first movable slider 313.

[0047] In the embodiment, the hook-shaped fruit stem hooking mechanism 38 is made of acrylic material.

[0048] Please refer to Figure 3 The fruit stem traction shearing unit 31 in the end effector 3 is shown in detail, and the view angle is top view. In the fruit stem traction shearing unit 31: a gear and rack set 311, the gear is connected with the closed-loop control motor 33, the rack is fixed on the first movable slider 313 together with the hook-shaped fruit stem hooking mechanism 38, the fixed slider 312 is fixed on the upper linear slide rail and cannot move along the upper linear slide rail. The first movable slider 313 can move along the upper linear slide rail.

[0049] Figure 3 The transmission principle of the fruit stem traction shearing unit 31 shown in the figure is: The closed-loop control motor 33 controls the rotation of the gear in the gear rack set 311. After the transmission of the gear rack set 311, the first movable slider 313 can move horizontally along the upper straight rail, and the hook-shaped fruit stem hooking mechanism 38 is also moved. The hook-shaped fruit stem hooking mechanism 38 is similar to a hook, and the strawberry fruit stem enters the inside of the hook and moves horizontally with the hook. Finally, it contacts the blade arranged on the fixed slider 312 and is cut off under the action of pressure or shearing force.

[0050] Please refer to Figure 4 , the detailed diagram of the fruit clamping detection unit 32 in the end effector 3 is shown. In the fruit clamping detection unit 32: the primary driving wheel 321 is fixedly connected with the output shaft of the mechanical arm 1, the primary driven wheel 322 is fixedly connected with the driving wheel in the secondary gear set 323, i.e., the secondary driving wheel, both gears in the secondary gear set 323 are non-complete circumferences, the gap is an integral connecting rod extending out, the connecting rod is hingedly connected with a connecting rod 324, and the two connecting rods 324 are respectively fixedly connected with two second movable sliders 328.

[0051] Please refer to Figure 5 , the front isometric view of the fruit clamping detection unit 32 in the end effector 3 is shown. The primary driven wheel 322 and the first shaft hole 325 of the secondary driving wheel, and the first shaft hole 325 of the secondary driven wheel are respectively provided with an optical axis, which passes through the corresponding first shaft hole 325 and the hole position at the same position on the mechanism mounting plane 35 in sequence. The first shaft hole 325 allows the primary driven wheel 322 and the secondary gear set 323 to freely rotate relative to the mechanism mounting plane 35. The implementation of the gear connection 326 is that the primary driven wheel and the secondary driving wheel are fixedly connected by bolts. The hinge connection between the connecting rod and the connecting rod 324 is provided with a second shaft hole 327, and an optical axis is arranged in the second shaft hole 327, so that the connecting rod and the connecting rod 324 can rotate relative to each other.

[0052] Figure 4 and Figure 5 The transmission principle of the fruit clamping detection unit 32 shown in The primary driving wheel 321 rotates under the driving of the output shaft of the mechanical arm 1, and transmits power to the primary driven wheel 322. Since the primary driven wheel 322 is fixedly connected with the driving wheel (left) of the secondary gear set 323, power is transmitted to the secondary driving wheel, which rotates clockwise, and the secondary driven wheel (right) rotates counterclockwise. The connecting rod at the gap is closed and transmits power to the connecting rod 324. The left and right connecting rods 324 move towards the center, drive the second movable sliders 328 to move towards the center, and the sensor clamping part 36 moves towards the center synchronously, so that the left and right tactile sensors 2 are closed, the strawberry fruit body is clamped and the tactile information is collected, and the strawberry fruit body is prevented from falling.

[0053] Figure 4Need to be particularly pointed out, the invention mechanism has been through the degree of freedom accounting error, the output shaft of the mechanical arm 1 the angle directly determines the distance between the left and right two tactile sensors 2, can provide the accurate control on the distance for the tactile sensor to collect data. In addition, the larger the gear ratio of the gear set, the higher the resolution of the sensor spacing.

[0054] Figure 4 Need to be particularly declared, compared with the traditional unilateral input bilateral folding clamping mechanism, the input shaft of the mechanism is located in the center of the whole mechanism, adopts center input, and matches multi-stage gear to transmit power to both sides. It can be well adapted to the mechanical arm on the market (the output shaft is in the center of the end), and the multi-stage gear amplifies the output torque, ensuring reliable clamping.

[0055] The complete working principle of the embodiment of the application is: When the device is used for picking strawberries, the mechanical arm 1 drives the end to be close to the target strawberry, cooperates with the hook-shaped fruit stem hooking mechanism 38 to hook the fruit stem of the target strawberry, and the process can avoid cutting off the fruit stem of the non-target strawberry in the cutting process (the strawberry fruit stem is usually in clusters). The mechanical arm 1 pulls outwards (perpendicular to the direction of the straight line slide rail 34), separates the target strawberry from the strawberry fruit cluster, the output shaft of the mechanical arm 1 starts to rotate, drives the fruit clamping detection unit 32 of the end effector 3 to work, clamps the strawberry fruit stem, and the tactile sensor 2 collects data. After collecting data, the output shaft of the closed-loop control motor 33 starts to rotate, drives the fruit stem traction shearing unit 31 of the end effector 3 to work, and cuts off the strawberry fruit stem. The picking of the strawberry is completed.

[0056] The above specific embodiments are used to explain and illustrate the application, rather than limit the application, and any modification and change made to the application within the spirit and protection scope of the claims of the application, falls within the protection scope of the application.

[0057] The above is only the preferred embodiment of the application, therefore, any equivalent change or modification made to the structure, features and principles described in the scope of the application patent application, is included in the scope of the application patent application.

Claims

1. A strawberry picking robot integrating gripping, tactile detection and shearing functions, characterized by: The strawberry picking robot comprises a robot arm (1), a tactile sensor (2) and an end effector (3); the end effector (3) is arranged at the end of the robot arm (1), and the tactile sensor (2) is installed on the end effector (3); the end effector (3) comprises a fruit stalk pulling and shearing unit (31), a fruit clamping detection unit (32), a linear slide rail (34) and a mechanism mounting plane (35); the mechanism mounting plane (35) is arranged at the end of the robot arm (1), and the upper and lower sides of the mechanism mounting plane (35) are respectively A linear slide rail (34) is arranged, and a fruit stem pulling and shearing unit (31) and a fruit clamping detection unit (32) are respectively arranged on the two linear slide rails (34). The fruit stem pulling and shearing unit (31) is used to hook and shear the strawberry stem, and the fruit clamping detection unit (32) is used to clamp the strawberry fruit body. A tactile sensor (2) is installed on the fruit clamping detection unit (32); the mechanism carrying plane (35) is fixedly connected to the mechanical arm (1), and the mechanism carrying plane (35) is fixedly connected to the linear slide rail (34).

2. The strawberry picking robot integrating gripping, tactile detection and shearing functions according to claim 1, characterized in that: The fruit stem traction and shearing unit (31) comprises a closed-loop control motor (33), a blade attachment (37), a hook-shaped fruit stem hooking mechanism (38), a gear rack assembly (311), a fixed slider (312) and a first movable slider (313); the closed-loop control motor (33) is transmission-connected to the first movable slider (313) via the gear rack assembly (311); the first movable slider (313) is slidably arranged on a linear slide rail (34) located above a mechanism mounting plane (35); a fixed slider (312) is arranged on one side of the first movable slider (313); the first movable slider (313) is equipped with a hook-shaped fruit stem hooking mechanism (38); the fixed slider (312) is equipped with a blade attachment (37); and the blade attachment (37) is used to install a blade.

3. The strawberry picking robot integrating gripping, tactile detection and shearing functions according to claim 2, characterized in that: The end of the hook-shaped fruit stem hooking mechanism (38) away from the linear slide rail (34) is configured to be in an arc shape.

4. The strawberry picking robot integrating gripping, tactile detection and shearing functions according to claim 2, characterized in that: The strawberry picking robot further comprises a control system, and the robot arm (1), the tactile sensor (2) and the closed-loop control motor (33) are all communicatively connected to the control system.

5. The strawberry picking robot integrating gripping, tactile detection and shearing functions according to claim 1 is characterized in that: The fruit clamping detection unit (32) includes a transmission mechanism, two second movable sliders (328) and two sensor clamps (36); the driving part of the transmission mechanism is connected to the end output shaft of the mechanical arm (1), and the output part is connected to the two second movable sliders (328), the second movable sliders (328) are slidably arranged on a linear slide rail (34) located below the mechanism mounting plane (35), and a sensor clamp (36) is installed on each of the two second movable sliders (328), and the sensor clamp (36) is used to fix the tactile sensor (2).

6. The strawberry picking robot integrating gripping, tactile detection and shearing functions according to claim 5, characterized in that: The transmission mechanism comprises a primary driving wheel (321), a primary driven wheel (322), a secondary gear set (323) and two connecting rods (324); the primary driving wheel (321) is connected to the terminal output shaft of the mechanical arm (1); a primary driven wheel (322) is arranged on one side of the primary driving wheel (321) and is meshed with the primary driven wheel (322); a secondary gear set (323) is arranged above the primary driven wheel (322), the secondary gear set (323) comprises a secondary driving wheel and a secondary driven wheel, the secondary driving wheel and the primary driven wheel (322) are meshed with each other. 22) are coaxially arranged, a secondary driven wheel is arranged on one side of the secondary driving wheel, the secondary driving wheel is fixedly connected to the primary driven wheel (322), and the secondary driving wheel is meshed with the secondary driven wheel; the cross-sectional shapes of the secondary driving wheel and the secondary driven wheel are both incomplete circles with a notch, and a connecting rod is provided at each notch, the connecting rod, the connecting rod (324) and the second movable slider (328) are in one-to-one correspondence, each connecting rod is hingedly connected to one end of the corresponding connecting rod (324), and the other end of the connecting rod (324) is hingedly connected to the second movable slider (328).

7. A strawberry picking robot using the strawberry picking manipulator according to any one of claims 1 to 6.

8. A strawberry picking method using the strawberry picking manipulator according to any one of claims 1 to 6 or the strawberry picking robot according to claim 8, characterized in that: The following steps are involved: S1: Using a robotic arm (1), the end effector (3) is brought close to the target strawberry, and the hook-shaped fruit stem hooking mechanism (38) is used to hook the fruit stem of the target strawberry; using a closed-loop control motor (33), the first movable slider (313) is driven to move along a linear slide rail (34) located above the mechanism mounting plane (35) toward the fixed slider (312), and the first movable slider (313) drives the hook-shaped fruit stem hooking mechanism (38) to move synchronously by a preset distance, thereby hooking and guiding the strawberry fruit stem, and then separating the target strawberry from the strawberry cluster; S2: using the output shaft at the end of the robotic arm (1) to drive two second movable sliders (328) to move toward each other along a linear slide rail (34) located below the mechanism mounting plane (35), the two second movable sliders (328) drive their respective corresponding sensor clamps (36) to move synchronously, and the tactile sensor (2) transmits the collected signal to the control system, thereby achieving the clamping of the strawberry fruit and the collection of tactile information; S3: Using a closed-loop control motor (33), the first movable slider (313) is driven to move along a linear slide rail (34) located above the mechanism mounting plane (35) toward the fixed slider (312), and the first movable slider (313) drives the hook-shaped fruit stem hooking mechanism (38) to move synchronously until the hook-shaped fruit stem hooking mechanism (38) contacts the blade on the blade attachment (37), thereby achieving shearing of the strawberry fruit stem; S4: using the robotic arm (1) to move the end effector (3) to the collection container, and using the end output shaft of the robotic arm (1) to drive the two second movable sliders (328) to move in reverse along the linear slide rail (34) located below the mechanism mounting plane (35), thereby releasing the clamping of the strawberry fruit body and allowing the strawberry fruit body to enter the collection container for storage; S5: Repeat steps S1 to S4 until the picking is completed.

9. The strawberry picking method according to claim 8, wherein: In step S1, the preset distance is 1-2 cm.

10. Use of the strawberry picking manipulator according to any one of claims 1 to 6 in a strawberry picking robot.

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