A flipping type high-efficiency pear picking robotic arm

Abstract

The present invention relates to a flip - type high - efficiency pear picking robotic arm, which includes a clamping mechanism, a flipping mechanism, a lifting and harvesting mechanism, a number of limit support frames and a housing. By combining gear transmission, cam transmission, and rack - and - pinion transmission, and driven by one motor, it realizes three actions of clamping, picking, and harvesting, reduces costs. Compared with the traditional six - degree - of - freedom robotic arm, only three degrees of freedom of the robotic arm in space x, y, z need to be given, simplifying the complexity of the control system, improving the picking efficiency, and the picking trajectory is an upward circular arc. At the same time, a pressure - control spring is provided to reduce the damage to the pears during the picking process. In addition, the harvesting device adopts a lifting structure, which can avoid blocking the camera's line of sight and colliding with branches before picking, and also avoid damage caused by too large a dropping height of the pears.

Description

Technical Field

[0001] The present invention relates to a flip - type high - efficiency pear picking robotic arm, belonging to the technical field of picking robotic arms. Background Art

[0002] Pears are one of the fruit trees with the widest planting range in China. However, at present, the picking and harvesting of pears are mainly carried out manually. With the development of technology, the production mode is gradually moving from labor - intensive to mechanized, simplified, standardized and modernized. In terms of cultivation patterns, the gradual popularization of new high - light - efficiency tree forms such as "slender cylindrical shape", "inverted umbrella shape", "inverted shape", "Y - shape", and horizontal trellis type has formed a new cultivation mode that is simple, labor - saving and efficient. Compared with the traditional large - crown and sparse - planting traditional cultivation patterns such as the dispersed hierarchical shape, it has the outstanding advantages of simple tree structure, simplified shaping and pruning, good ventilation and light transmission conditions, excellent quality, and being more suitable for mechanized operation.

[0003] At present, most of the existing picking robots are six - degree - of - freedom robotic arms, and their end - effectors require independent drive and control. The picking action is completed by a six - degree - of - freedom robotic arm. However, the six - degree - of - freedom robotic arm has problems such as complex control systems, long pose - solving time, low execution efficiency, easy occurrence of pose - solving errors, and high costs. At present, most pear orchards are mainly semi - structured, using a trellis planting method, and the pears basically grow at the same height, and the fruit axis direction is basically vertically downward. In addition, the picking characteristics of pears are different from most fruits. Pears cannot be picked by pulling, which easily causes the fruit stalk to separate from the pear and requires a large force, accelerating the decay of the pear. Currently, the upward - lifting method is mostly used, which can better retain the fruit stalk and the fruit stalk is easy to separate from the branch. Therefore, in order to improve the picking efficiency and reduce the damage to pears, a more efficient picking robotic arm is needed. Summary of the Invention

[0004] In order to overcome the deficiencies of existing research, the present invention provides a flip - type high - efficiency pear picking robotic arm, which has the characteristics of simple control, high picking efficiency, low cost, and low picking damage.

[0005] A flip - type high - efficiency pear picking robotic arm includes a clamping mechanism, a flipping mechanism, a lifting and harvesting mechanism, a number of limit support frames and a housing;

[0006] The clamping mechanism includes a mechanical claw mechanism and a cam mechanism connected to the mechanical claw mechanism. The mechanical claw mechanism includes multiple mechanical claws, a second mechanical claw pull rod, a first mechanical claw mounting seat, and a second mechanical claw mounting seat. One end of the mechanical claw is hinged to the first mechanical claw mounting seat through a connecting rod, and the other end is hinged to the second mechanical claw mounting seat. The second mechanical claw pull rod passes through the first mechanical claw mounting seat and is fixedly connected to the second mechanical claw mounting seat. A return spring sleeved on the second mechanical claw pull rod is installed between the first mechanical claw mounting seat and the second mechanical claw mounting seat. The interior of the mechanical claw is hollowed out and is made of flexible silicone material;

[0007] The cam mechanism includes a cam, a cam push rod in contact with the cam, and a first mechanical claw pull rod. The upper end of the first mechanical claw pull rod passes through the second mechanical claw pull rod and is sleeved with a pressure control spring for controlling the pressure between the mechanical claw and the pear. The lower end is fixedly connected to the cam push rod. The stiffness of the return spring is less than the stiffness of the pressure control spring. The return spring is installed between the first mechanical claw mounting seat and the second mechanical claw mounting seat. The pressure control spring is installed between the first mechanical claw pull rod and the second mechanical claw pull rod. The middle of the second mechanical claw pull rod is a through hole;

[0008] The flipping mechanism includes a driving gear, an intermediate gear, a driven gear, a driving shaft, an intermediate gear shaft, and a first driven shaft in interference fit with the cam. The driving gear, the intermediate gear, and the driven gear are respectively installed on the driving shaft and the intermediate gear shaft. The driving gear and the driven gear are respectively installed on both sides of the intermediate gear and are meshed with each other. The gears are respectively installed on the large outer housing through the driving shaft, the intermediate gear shaft, and the driven shaft. The shafts are installed on the housing through bearings, and bearing end covers are provided outside the bearings;

[0009] The lifting and harvesting mechanism includes a harvesting device, a mounting bracket, and a gear-rack transmission mechanism. The harvesting device includes a harvesting pipe and a connecting bracket. The mounting bracket includes a limit support frame, a support frame, and a first small outer housing. The gear-rack transmission mechanism includes a second driving gear, a second driven gear, and a linear rack. The second driving gear is installed on the driving shaft through a key and is meshed with the second driven gear. The second driven gear is meshed with the linear rack. The second driving gear and the second driven gear are provided with a locking structure.

[0010] The cam push rod has a convex left side and remains in contact with the cam push rod.

[0011] The first driven shaft is installed on the first large outer housing and the second large outer housing through bearings. The driving shaft and the intermediate gear shaft are rotatable relative to the first large outer housing. There is a circular groove at the upper left corner of the circular hole on the right side of the first large outer housing. There is a key-shaped protrusion on the shaft of the first driven shaft in contact with the circular hole. The first large outer housing is fixedly connected to the cam housing, and the cam housing is fixedly connected to the first mechanical claw mounting seat. There is a 90° circular groove at the upper left corner of the circular hole on the right side of the first large outer housing. There is a key-shaped protrusion on the shaft of the driven shaft in contact with the circular hole for limiting by the circular groove;

[0012] The gear shaft is connected to the small outer housing through a bearing. The first small outer housing is fixedly connected to the limit support frame and the support frame by screws. The limit support frame and the support frame are fixedly installed on the robotic arm. The harvesting pipe is fixedly connected to the linear rack through a connecting bracket for synchronous movement.

[0013] It further includes a driving motor housing. A reduction servo motor is installed inside the driving motor housing. The second large outer housing and the cam housing are fixedly connected through a first connecting frame to maintain synchronous movement. The second large outer housing is connected to the first small outer housing through a second connecting frame, and the second large outer housing and the first small outer housing can rotate relative to each other. The servo reduction motor is installed inside the motor housing, and the servo reduction motor is connected to the driving shaft through a coupling.

[0014] A working method of a flip-type high-efficiency pear picking robotic arm includes the following steps:

[0015] The mechanical claw is vertically upward in an open state, and the flipping mechanism is horizontally placed. The whole robotic arm moves so that the mechanical claw is directly below the target pear. After the movement is completed, the reduction servo motor starts to rotate forward 180°. In the first 90°, the flipping mechanism remains horizontal and stationary. The motor drives the driving shaft to rotate, drives the first driven shaft to rotate through gear transmission. The first driven shaft drives the cam to rotate and push the cam push rod downward to make the mechanical claw achieve the clamping action. In this process, since the stiffness of the pressure control spring is greater than that of the return spring, when the mechanical claw starts to pull the rod downward, the deformation of the return spring is greater than that of the pressure control spring, and the second mechanical claw mounting seat moves downward to achieve clamping. When the pulling force further increases, the pressure control spring is further compressed and deformed, and the second mechanical claw mounting seat remains stationary to achieve clamping force control and avoid damaging the fruit due to excessive clamping force.

[0016] Meanwhile, the driving shaft drives the second driving gear to rotate, and through the rack and pinion transmission, the lifting harvesting mechanism is driven to rise. When it rotates 90°, the circular groove limit of the large outer casing restricts the relative rotation of the first driven shaft, making the first driven shaft and the large outer casing relatively fixed. The driving shaft continues to rotate 90° to drive the flipping mechanism to flip upward by 90°. At the same time, the gear of the lifting harvesting mechanism enters the locked state and stops rotating, and the lifting harvesting mechanism remains stationary. When the driving shaft rotates 180° and then starts to reverse, the driving shaft drives the first driven shaft to flip, and at the same time drives the cam to reverse. Due to the action of the reset spring force, the mechanical claw opens, and the fruit falls into the harvesting pipe to achieve harvesting at its position. After reversing 90°, the circular groove limit of the outer casing restricts the relative rotation of the first driven shaft again, making the flipping mechanism return to the horizontal position. At the same time, the locking of the second driven gear and the second driving gear ends, and the lifting harvesting mechanism descends to return to the initial position, realizing one round of picking.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The present invention combines gear transmission, cam transmission, and rack and pinion transmission, and is driven by one motor to realize three actions of clamping, picking, and harvesting, reducing costs. Compared with the traditional six-degree-of-freedom robotic arm, only three degrees of freedom of the robotic arm in the space x, y, and z need to be given, simplifying the complexity of the control system, improving the picking efficiency, and the picking trajectory is an upward circular arc. At the same time, a pressure control spring is provided to reduce the damage to the pears during the picking process. In addition, the harvesting device adopts a lifting structure, which can avoid blocking the camera's line of sight and colliding with branches before picking, and also avoid damage caused by the large falling height of the pears. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 It is the initial orthographic axonometric drawing of a flipping type high-efficiency pear picking robotic arm of the present invention;

[0021] Figure 2 It is the schematic diagram of the flipping mechanism of the present invention;

[0022] Figure 3 It is the schematic diagram of the limit structure of the flipping mechanism of the present invention;

[0023] Figure 4 It is the schematic diagram of the clamping mechanism of the present invention;

[0024] Figure 5Cross-sectional view of the clamping mechanism of the present invention;

[0025] Figure 6 Schematic diagram of the lifting and harvesting mechanism of the present invention;

[0026] Figure 7 Schematic diagram of the limit support frame of the present invention;

[0027] Figure 8 Isometric view of the end position of the present invention;

[0028] In the figure, 1 - clamping mechanism, 2 - flipping mechanism, 3 - lifting and harvesting mechanism, 4 - housing, 100 - driving shaft, 101 - first driving gear, 102 - intermediate gear shaft, 103 - intermediate gear, 104 - first driven gear, 105 - first large outer housing, 106 - first driven shaft, 200 - cam push rod, 201 - driving cam, 202 - connecting rod, 203 - mechanical claw, 204 - return spring, 205 - first mechanical claw mounting seat, 206 - second mechanical claw mounting seat, 207 - first mechanical claw pull rod, 208 - pressure control spring, 209 - second mechanical claw pull rod, 300 - harvesting pipe, 301 - connecting bracket, 302 - linear rack, 304 - second driven gear, 305 - second driving gear, 307 - first small outer housing, 308 - limit support frame, 309 - robotic arm, 310 - support frame, 400 - first end cover, 401 - second large outer housing, 402 - first connecting frame, 403 - cam housing, 404 - second small outer housing, 405 - second connecting frame, 406 - driving motor housing. Detailed implementation

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] As Figure 1-7 shown, a flip - type high - efficiency picking robotic arm includes a clamping mechanism 1, a flipping mechanism 2, a lifting and harvesting mechanism 3, several limit support frames and a housing 4. The clamping mechanism 1 is installed on the left half of the flipping mechanism 2 through a connecting frame 1. The clamping mechanism is used to clamp fruits. The lifting and harvesting mechanism 3 is installed on the right half of the flipping mechanism through a connecting frame and can perform lifting and harvesting of fruits. The flipping mechanism is arranged on the limit support frame, and the limit support frame is used to support the flipping mechanism and ensure that the flipping mechanism is in a horizontal posture.

[0031] As Figure 2, as shown in Fig. 3, the clamping mechanism 1 includes a mechanical claw mechanism, a cam mechanism, and a spring. The mechanical claw mechanism is connected to the cam mechanism, and a spring is installed inside the mechanical claw. The mechanical claw mechanism includes a mechanical claw 203, a first mechanical claw mounting seat 205, a second mechanical claw mounting seat 206, and a connecting rod 202. One end of the mechanical claw 203 is rotatably mounted on the first mechanical claw mounting seat 205 through the connecting rod 202, and the other end is rotatably mounted on the second mechanical claw mounting seat 206. The second mechanical claw mounting seat 206 is provided with a thread and fixedly connected to the second mechanical claw pull rod 209. The first mechanical claw mounting seat 205 is provided with a through hole, and the second mechanical claw pull rod 209 passes through the through hole to form a moving pair, and a return spring 204 is provided to ensure a certain distance between the two mounting seats, so that the mechanical claw 203 is in an open state under normal circumstances, and at the same time ensure that the cam push rod 200 and the driving cam 201 can remain in contact. The second mechanical claw pull rod 209 is provided with a through hole inside, and the first mechanical claw pull rod 207 passes through the through hole of the second mechanical claw pull rod 209 and a pressure control spring 208 is arranged in the middle. The pressure control spring 208 is used to control the pressure between the mechanical claw 203 and the pear, and the stiffness of the pressure control spring 208 is greater than that of the return spring 204. When the second mechanical claw pull rod 209 is pulled downward, the deformation of the return spring 204 is greater than that of the pressure control spring 208, and the second mechanical claw mounting seat 206 moves downward to achieve clamping. When the pulling force further increases, the pressure control spring 208 is further compressed and deformed, and the second mechanical claw mounting seat 206 basically remains stationary to achieve clamping force control. The cam mechanism includes a cam 201, a cam push rod 200, and a first mechanical claw pull rod 207. The cam push rod 201 has a convexity on the left side and remains in contact with the cam push rod 200. The first mechanical claw pull rod 207 is provided with a thread below and is fixedly connected to the cam push rod 200 through the thread,

[0032] The cam 201 and the first driven shaft 106 are in interference connection and move synchronously. During operation, the rotation of the driven shaft 106 drives the rotation of the cam 201, and the cam 201 pushes the cam push rod 200 downward, so that the second mechanical claw mounting seat 206 moves downward relative to the first mechanical claw mounting seat 205 to achieve the clamping action.

[0033] As Figure 4, as shown in Figures 5 and 7, the flipping mechanism includes a gear transmission mechanism and a large outer housing. The gear transmission mechanism includes a first driving gear 101, an intermediate gear 103, a driven gear 104, a driving shaft 100, an intermediate gear shaft 102, and a first driven shaft 106. The driving gear 101, the intermediate gear 103, and the driven gear 104 are respectively installed on the driving shaft 100 and the intermediate gear shaft 102. The first driven shaft 106 is connected to the driving shaft 100 and the intermediate gear shaft 102 by keys. The first driven shaft 106 is installed on the first large outer housing 105 and the second large outer housing 401 through bearings. The driving shaft 100 and the intermediate gear shaft 102 can rotate relative to the first large outer housing 105. There is a 90° circular groove at the upper left corner of the right circular hole of the first large outer housing 105. There is a key-shaped protrusion on the shaft of the first driven shaft 106 that contacts the circular hole for positioning. The initial position of the key-shaped protrusion is vertically upward and close to the upper surface of the circular groove. When starting to work, the first driven shaft 106 rotates, and the key-shaped protrusion rotates towards the other end and approaches. When the transmission angle is 90°, it contacts the other end surface of the circular groove. At this time, when the first driven shaft 106 continues to rotate, due to the limiting effect of the circular groove, the first driven shaft 106 drives the entire large outer housing 105 to rotate upward. The first large outer housing 105 is fixedly connected to the cam housing 403, and the cam housing 403 is fixedly connected to the first robotic arm mounting seat 205. Therefore, it drives the entire robotic arm to flip upward to form a picking trajectory.

[0034] As Figure 6 shown, the lifting and harvesting mechanism includes a harvesting device, a mounting bracket, and a gear-rack transmission mechanism. The harvesting device includes a harvesting pipe 300 and a connecting bracket 301. The mounting bracket includes a limit support frame 308, a support frame 310, and a first small outer housing 307. The gear-rack transmission mechanism includes a second driving gear 305, a second driven gear 304, and a linear rack 302. The second driving gear 305 is installed on the driving shaft 100 by a key and meshes with the second driven gear 304. The second driven gear 304 meshes with the linear rack 302. One-fourth of the teeth of the second driving gear 305 are cut off. The second driving gear 305 and the second driven gear 304 are provided with a locking structure. When the driving shaft 100 drives the second driving gear 305 to rotate 90°, it enters the locked state, and the second driven gear 304 remains stationary, causing the linear rack to rise to a certain height and stop rising. The gear shaft is connected to the small outer housing through a bearing. The first small outer housing 307 is fixedly connected to the limit support frame 308 and the support frame 310 by screws. The limit support frame 308 and the support frame 310 are fixedly installed on the robotic arm 309 to support the entire lifting and harvesting mechanism. The harvesting pipe 300 is fixedly connected to the linear rack 302 through the connecting bracket 301 and moves synchronously.

[0035] As Figure 7As shown in the figure, a reduction servo motor is installed inside the drive motor housing 406. As a driving device, a bearing end cover is provided outside the bearing where the shaft is connected to the housing. The second large housing body 401 and the cam housing 403 are fixedly connected by a first connecting frame 402 to maintain synchronous movement. The second large housing body 401 is connected to the first small housing body 307 by a second connecting frame 405. The second large housing body 401 and the small housing 307 can rotate relative to each other. A first end cover is installed under the second large housing body 401, and a second small housing body 404 is on the second connecting frame 405.

[0036] This example takes the picking of pergola pears as an example to introduce the specific movement process of the picking robotic arm as follows:

[0037] Since the growth postures of pergola pears are mostly vertically drooping, the initial state of the end effector in this example is as Figure 1 shown. The mechanical claws are vertically upward and in an open state, and the flipping mechanism 2 is horizontally placed. When the vision system of the pear picking robot locates the position of the target pear, according to the branch direction recognized by the vision system, the flipping direction is adjusted to avoid collision with the branches. Then the whole robotic arm moves so that the mechanical claws are directly below the target pear. After the movement is completed, the reduction servo motor starts to rotate forward by 180°. In the first 90°, the flipping mechanism 2 remains horizontally stationary. The motor drives the driving shaft 100 to rotate, drives the first driven shaft 106 to rotate through gear transmission, and the first driven shaft 106 drives the cam 201 to rotate and push the cam push rod 200 downward to make the mechanical claws 203 achieve the clamping action. In this process, since the stiffness of the pressure control spring 208 is greater than that of the return spring 204, when the mechanical claws start to pull the rod 2209 downward, the deformation of the return spring 204 is greater than that of the pressure control spring 208, and the second mechanical claw mounting seat 206 moves downward to achieve clamping. When the pulling force further increases, the pressure control spring 208 is further compressed and deformed, and the second mechanical claw mounting seat 206 basically remains stationary to achieve clamping force control, avoiding excessive clamping force from damaging the fruit. At the same time, the driving shaft 100 drives the second driving gear 305 to rotate and drives the lifting harvesting mechanism to rise through a rack and pinion transmission. When it rotates 90° later, the circular groove limit of the large housing body 105 restricts the relative rotation of the first driven shaft 106, making the first driven shaft 106 and the large housing body 105 relatively fixed. The driving shaft 100 continues to rotate 90° to drive the flipping mechanism 2 to flip upward by 90°. At the same time, the gears of the lifting harvesting mechanism enter the locked state and stop rotating, and the lifting harvesting mechanism remains stationary. When the driving shaft 100 rotates 180° and then starts to reverse, the driving shaft 100 drives the first driven shaft 106 to flip, and at the same time drives the cam 201 to reverse. Due to the action of the force of the return spring 204, the mechanical claws open, and the fruit falls into the harvesting pipe 300 to achieve harvesting. Its position is as Figure 8As shown, after being reversed by 90°, the circular groove limit of the outer housing 105 restricts the relative rotation of the first driven shaft 106 again, causing the flipping mechanism to return to the horizontal position. At the same time, the locking of the second driven gear 304 and the second driving gear 305 ends, and the lifting and harvesting mechanism descends to return to the initial position, realizing one round of picking.

[0038] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions, and variations made to these embodiments still fall within the protection scope of the present invention.

Claims

1. A flip - type high - efficiency pear - picking robotic arm, characterized in that: It includes a clamping mechanism, a flipping mechanism, a lifting and harvesting mechanism, several limit support frames and a housing; The clamping mechanism includes a mechanical claw mechanism and a cam mechanism connected to the mechanical claw mechanism. The mechanical claw mechanism includes multiple mechanical claws, a second mechanical claw pull rod, a first mechanical claw mounting seat and a second mechanical claw mounting seat. One end of the mechanical claw is hinged to the first mechanical claw mounting seat through a connecting rod, and the other end is hinged to the second mechanical claw mounting seat. The second mechanical claw pull rod passes through the first mechanical claw mounting seat and is fixedly connected to the second mechanical claw mounting seat. A return spring sleeved on the second mechanical claw pull rod is installed between the first mechanical claw mounting seat and the second mechanical claw mounting seat; The cam mechanism includes a cam, a cam push rod connected to the cam and a first mechanical claw pull rod. The upper end of the first mechanical claw pull rod passes through the second mechanical claw pull rod and is sleeved with a pressure control spring for controlling the pressure between the mechanical claw and the pear. The lower end is fixedly connected to the cam push rod, and the stiffness of the pressure control spring is greater than that of the return spring; The flipping mechanism includes a driving gear, an intermediate gear, a driven gear, a driving shaft, an intermediate gear shaft and a first driven shaft in interference connection with the cam. The driving gear, the intermediate gear and the driven gear are respectively installed on the driving shaft and the intermediate gear shaft; The lifting and harvesting mechanism includes a harvesting device, a mounting bracket and a gear-rack transmission mechanism. The harvesting device includes a harvesting pipe and a connecting bracket. The mounting bracket includes a limit support frame, a support frame and a first small housing. The gear-rack transmission mechanism includes a second driving gear, a second driven gear and a linear rack. The second driving gear is installed on the driving shaft through a key and meshes with the second driven gear. The second driven gear meshes with the linear rack. The second driving gear and the second driven gear are provided with a locking structure, The first driven shaft is installed on the first large housing and the second large housing through bearings. The driving shaft and the intermediate gear shaft are rotatable relative to the first large housing. There is a circular groove at the upper left corner of the right circular hole of the first large housing. There is a key-shaped protrusion on the shaft of the first driven shaft in contact with the circular hole. The first large housing is fixedly connected to the cam housing, and the cam housing is fixedly connected to the first mechanical claw mounting seat.

2. The flip - type high - efficiency pear picking robotic arm according to claim 1, wherein: The cam push rod has a left-side protrusion and remains in contact with the cam push rod.

3. The flip - type high - efficiency pear picking robotic arm according to claim 1, wherein: The gear shaft is connected to the small housing through a bearing. The first small housing is fixedly connected to the limit support frame and the support frame through screws. The limit support frame and the support frame are fixedly installed on the robotic arm. The harvesting pipe is fixedly connected to the linear rack through the connecting bracket and moves synchronously.

4. The flip - type high - efficiency pear - picking robotic arm according to claim 1, wherein: It also includes a driving motor housing. A reduction servo motor is installed inside the driving motor housing. The second large housing is fixedly connected to the cam housing through a first connecting frame to move synchronously. The second large housing is connected to the first small housing through a second connecting frame, and the second large housing and the first small housing can rotate relative to each other.

5. A working method of a flip - type high - efficiency pear picking robotic arm according to any one of claims 1 - 4, characterized in that: It includes the following steps: The mechanical claw is in an open state vertically upward, and the flipping mechanism is placed horizontally. The overall movement of the robotic arm positions the mechanical claw directly below the target pear. After the movement is completed, the deceleration servo motor starts to rotate forward by 180°. In the first 90°, the flipping mechanism remains horizontal and stationary. The motor drives the rotation of the drive shaft, which drives the rotation of the first driven shaft through gear transmission. The first driven shaft drives the rotation of the cam, which pushes the cam push rod downward to make the mechanical claw perform the clamping action. During this process, since the stiffness of the pressure control spring is greater than that of the return spring, when the mechanical claw starts to pull the rod downward, the deformation of the return spring is greater than that of the pressure control spring, and the second mechanical claw mounting seat moves downward to achieve clamping. When the pulling force further increases, the pressure control spring is further compressed and deformed, and the second mechanical claw mounting seat remains stationary to achieve clamping force control and avoid damaging the fruit due to excessive clamping force. At the same time, the drive shaft drives the rotation of the second drive gear, which drives the lifting harvesting mechanism to rise through the rack and pinion transmission. When it rotates 90° later, the circular groove limit of the large outer housing restricts the relative rotation of the first driven shaft, making the first driven shaft and the large outer housing relatively fixed. The drive shaft continues to rotate 90° to drive the flipping mechanism to flip upward by 90°. At the same time, the gears of the lifting harvesting mechanism enter the locked state and stop rotating, and the lifting harvesting mechanism remains stationary. When the drive shaft rotates 180° and then starts to reverse, the drive shaft drives the first driven shaft to flip and at the same time drives the cam to reverse. Due to the action of the return spring force, the mechanical claw opens, and the fruit falls into the harvesting pipe to achieve harvesting at its position. After reversing 90°, the circular groove limit of the outer housing restricts the relative rotation of the first driven shaft again, causing the flipping mechanism to return to the horizontal position. At the same time, the locking of the second driven gear and the second drive gear ends, and the lifting harvesting mechanism descends to return to the initial position, completing one round of picking.

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