Tomato picking head based on negative pressure adsorption and laser cutting

Abstract

The invention discloses a tomato picking head based on negative pressure adsorption and laser cutting, and relates to the field of agricultural picking equipment, and the tomato picking head is configured to be an end effector which is based on cooperation of a control system and a mechanical arm and integrates adsorption, positioning and cutting. The end effector comprises a picking head module, a self-adaptive negative pressure adsorption module, an integrated laser cutting module and a machine vision module, the picking head module comprises a shell, a mounting base and an auxiliary supporting frame, and the self-adaptive negative pressure adsorption module comprises a plurality of suction cup units evenly distributed in the circumferential direction of an opening of the shell; according to the tomato picking head, flexible negative pressure adsorption with multiple independent air cavities, reflective laser non-contact cutting, RGB-D visual positioning and closed-loop control are integrated, and a multifunctional end effector integrating adsorption fixation, precise positioning, energy separation and intelligent decision making is constructed; lossless, efficient and self-adaptive picking requirements of thin-skin, high-juice and vulnerable tomatoes in a complex field environment can be met.

Description

Technical Field

[0001] This invention relates to the field of agricultural harvesting equipment technology, specifically to a tomato harvesting head based on negative pressure adsorption and laser cutting. Background Technology

[0002] Tomatoes, a widely cultivated cash crop, are rich in vitamins, minerals, and various antioxidants, holding a significant position in the global consumer market. In both greenhouse and open-field large-scale cultivation models, the tomato harvest season is often concentrated, with large harvest volumes and short operating cycles. The labor-intensive nature of the harvesting process and seasonal fluctuations in labor demand mean that manual harvesting costs constitute a high proportion of the overall production input. Industry statistics show that labor costs in tomato harvesting can account for 30% to 45% of total production costs, and this proportion is even higher in some regions during peak harvest season. Therefore, developing efficient and reliable automated harvesting equipment has become a key direction for reducing operating costs, improving the marketability of fruits and vegetables, and promoting the intelligent development of agriculture.

[0003] In the field of fruit and vegetable harvesting robots, the performance of the end effector directly determines the harvesting quality and efficiency. Tomatoes, due to their thin skin, high juice content, soft texture, and susceptibility to external damage, place stringent requirements on the non-destructive operation capabilities of the end effector. Existing harvesting robot end effectors generally employ mechanical contact operation mechanisms and can be mainly classified as follows: Rigid gripper harvesting heads: These devices use rigid grippers or parallel clamps similar to industrial robotic arms, with a motor or cylinder driving the grippers to close and grasp the fruit. While structurally robust and possessing strong gripping force, they have significant drawbacks: the tomato skin lacks a protective layer, the gripper's contact area is limited, and the contact force is concentrated, easily causing indentations and dents on the fruit surface, and even cracking and juice loss in overripe fruit, significantly reducing post-harvest marketability. Furthermore, rigid grippers are poorly adaptable to fruits of different sizes and shapes, requiring complex size detection and force feedback control; otherwise, missed harvests or damage are likely.

[0004] Flexible clamping harvesting heads: To reduce damage caused by rigid clamping, some studies have covered the gripper surface with flexible materials such as silicone, rubber, or fabric to reduce contact stress; other designs introduce multi-point flexible contact pads or airbag structures to achieve a near-wrapped grip. Although such designs can disperse pressure to some extent, they still rely on mechanical clamping force to fix the fruit, posing an irreversible risk of damage to overripe, softened, or already damaged tomatoes. Meanwhile, the durability of flexible materials, the difficulty of cleaning and maintenance, and their reliability in humid, dusty field environments still face challenges.

[0005] Single-cavity air-suction harvesting head: This type of device uses a vacuum generator to create negative pressure within a single suction cup cavity, using atmospheric pressure difference to adsorb and fix the fruit. Its advantage lies in avoiding direct mechanical clamping, but it has significant limitations: it requires a high degree of flatness and sealing of the fruit surface; when the tomato surface is uneven or the structure near the stem is complex, air leakage can easily occur, leading to adsorption failure; a single cavity cannot adapt to irregular curved surfaces, and poor adhesion between the suction cup and the fruit reduces adsorption stability; if the negative pressure value is not properly controlled, a large pressure difference may form inside the fruit, causing the flesh to collapse or internally damage, posing a higher risk to thin-skinned varieties.

[0006] Because the aforementioned mechanical contact harvesting methods suffer from fruit damage or rely on complex mechanisms during both the fixing and separation stages, the following solutions have been disclosed in the prior art to address issues such as direct squeezing, clamping damage, and blade collisions during the harvesting process: 1) Patent application CN116548180A discloses a tomato harvesting end effector with an adsorption system. This patent application includes a drive mechanism, a harvesting mechanism, an adsorption system, and a housing. A cylinder in the adsorption system is connected to a fixed base inside the housing. The linear motion of the cylinder drives the suction cup to move forward and backward, thus enabling the suction cup to extract and separate the tomato from the fruit bunch. The drive mechanism is installed inside the housing and controls the linear motion of the lead screw nut via a stepper motor, causing the gripper of the harvesting mechanism to rotate and clamp the tomato fruit. The housing includes a sleeve, a fixed base, and a flange. The bottom of the sleeve is connected to the flange, and the flange is fixed to the end motor of the robotic arm, allowing the housing to rotate. This invention employs a harvesting method that first suctions the fruit and pulls it a certain distance before clamping it, reducing damage to adjacent tomatoes or branches during harvesting and improving the success rate of tomato harvesting.

[0007] 2) Patent application CN218007085U discloses a vacuum suction mechanism for tomato harvesting. This patent application includes a harvesting arm with a harvesting cavity at one end. A rotating ring is rotatably mounted inside the harvesting arm, and an outer cylinder slides inside the rotating ring. Suction cups and an air pump are respectively installed at both ends of a ventilation pipe. An electric telescopic rod is fixedly mounted at the end of the harvesting arm away from the harvesting cavity, and a mounting base is rotatably mounted at the end of the electric telescopic rod near the air pump. The harvesting arm contains a drive assembly, an auxiliary assembly, and a transmission assembly that cooperates with the auxiliary assembly. This invention utilizes an air pump to use a suction cup to suck up the tomato, and then uses an electric telescopic rod to move the tomato into the harvesting cavity. Under the action of the drive assembly, the suction cup rotates, causing the tomato to rotate and twist off the stem. The harvested tomato is stemless, which is beneficial for improving automation.

[0008] 3) Publication No. CN111758380A discloses a fruit and vegetable harvesting robot, a harvesting robot, and a harvesting method thereof. This patent application includes: a gripping part with a gripping surface for gripping the outer surface of fruits and vegetables; a separating part with a cutting tool for cutting the stems of fruits and vegetables; and a positioning part for collecting the position information of fruits and vegetables and communicating with the gripping part and the separating part. This invention effectively reduces interference and disturbance during the harvesting process, ensures accurate positioning of fruits and vegetables, and improves the quality and success rate of harvesting. It is particularly suitable for harvesting fruits and vegetables with high stem strength and no obvious abscission layer, such as cucumbers, loofahs, and bunch tomatoes.

[0009] The above-mentioned solutions have made beneficial explorations in reducing mechanical damage and improving harvesting success rates. For example, by introducing adsorption pre-fixation, twisting separation, or combining positioning and cutting methods, they have reduced interference with adjacent fruits and branches, and to a certain extent achieved semi-automation of the harvesting process. However, the following technical problems still exist: The fixing process still involves mechanical contact or single negative pressure adsorption. Although CN116548180A first uses a suction cup to adsorb and then clamps, the clamping process still relies on rigid or semi-rigid grippers, which inevitably generates contact stress. CN218007085U relies on a single suction cup to vacuum pick up and twist to separate the fruit stem. It has high requirements for the flatness and sealing of the fruit surface. When the adsorption is unstable, it is easy to fall off or cause internal damage. Moreover, the twisting process may generate torsional stress on the fruit skin.

[0010] The separation methods are mostly mechanical force or additional rotation mechanism. Whether it is shearing after gripping by hand or twisting the stem with suction cup, it is a mechanical separation, which has the risks of blade wear, uneven breakage of fruit stem, juice splashing and secondary contamination. The cutting blade of CN111758380A needs to be close to the fruit stem for physical cutting, and there is still a possibility of accidental collision with fruit or branches.

[0011] With limited adaptability, existing solutions rely on fixed structures or single cavities for the adhesion and sealing of irregularly curved fruits, making it difficult to maintain uniform adsorption when the fruit size and shape vary greatly. When faced with obstruction by branches and leaves or changes in fruit posture, the posture adjustment capability depends on the overall robotic arm path correction, which limits the response speed and accuracy.

[0012] In summary, although existing technologies have reduced the risk of damage or improved the success rate of operations in some aspects, they have not yet made breakthroughs in completely eliminating mechanical contact damage, achieving non-contact energy cutting, and highly adaptive and closed-loop control. As a result, they are still unable to meet the comprehensive needs of thin-skinned, juicy, and easily damaged tomatoes for non-destructive, efficient, and intelligent harvesting in complex field environments. Summary of the Invention

[0013] The purpose of this invention is to provide a tomato picking head based on negative pressure adsorption and laser cutting, so as to solve the problems of mechanical contact picking that easily damages the fruit, poor adsorption adaptability and collision during the cutting process in the prior art.

[0014] To achieve the above objectives, the present invention provides the following technical solution: a tomato harvesting head based on negative pressure adsorption and laser cutting, wherein the tomato harvesting head is configured as an end effector integrating adsorption, positioning, and cutting, based on a control system and a robotic arm in collaboration. The end effector includes a harvesting head module, an adaptive negative pressure adsorption module, an integrated laser cutting module, and a machine vision module, wherein: The harvesting head module includes a shell, a mounting base, and auxiliary support frames. The shell is a conical cylindrical structure with a large opening at the top and a small opening at the bottom. The mounting base is located at the lower end of the opening of the shell. The mounting base is a ring structure made of rigid metal. Multiple auxiliary support frames are installed on the outside of the mounting base in a ring shape. These auxiliary support frames are used to connect the mounting base and the shell. The adaptive negative pressure adsorption module includes multiple suction cup units evenly distributed circumferentially along the opening of the shell, each suction cup unit being made of a flexible material (such as silicone or medical-grade TPU). The integrated laser cutting module includes a servo motor and a micro laser. The servo motor is installed in the mounting base, and the servo motor shaft passes through the opening at the bottom of the housing and connects to the micro laser. The machine vision module is located on the outside of the housing. The machine vision module is used to identify mature tomato fruits and locate the three-dimensional spatial position of their stems, as well as to verify whether the stems are completely separated after laser cutting.

[0015] Furthermore, the auxiliary support frame includes a damping rod and a support arm. The damping rod and the support arm are respectively hinged to the upper and middle sides of the outer side of the mounting base. The front end of the damping rod is hinged to the lower side of the support arm, and the upper end of the support arm is connected to the top edge of the housing.

[0016] Furthermore, each suction cup unit is equipped with a pressure-sensing patch on its outer side. This pressure-sensing patch is a thin-film flexible pressure sensor (such as an FSR flexible patch based on the piezoresistive effect or a MEMS micro pressure sensing element). The pressure-sensing patch can detect in real time the change in adsorption pressure generated after the corresponding air cavity adheres to the tomato surface, and convert the pressure signal into an electrical signal output to the control system. In practical applications, this pressure-sensing patch is attached to the outer surface of the flexible substrate of the suction cup unit or embedded in the sealing area near the air cavity inlet. During the negative pressure establishment process, it can monitor the local sealing status and the distribution of adsorption force. Once the pressure is detected to be lower than a set threshold, it feeds back to the control system for negative pressure compensation, ensuring that each air cavity can obtain uniform and sufficient adsorption force under different curved surface adhesion conditions, thereby achieving adaptive sealing and stable adsorption on irregularly shaped tomato surfaces.

[0017] Furthermore, each suction cup unit has an independent air chamber, and each air chamber is connected to a negative pressure control channel. The control system independently adjusts the negative pressure according to the adhesion, thereby achieving adaptive sealing and adsorption fixation of irregularly shaped tomato surfaces.

[0018] Furthermore, the integrated laser cutting module also includes a first reflective element and a second reflective element, which are respectively disposed on the upper part and the middle part of the inner wall of the housing.

[0019] Furthermore, the first and second reflective elements, together with the optical path of the microlaser, form a folded transmission path. The laser beam emitted by the microlaser is guided after two reflections, ultimately illuminating the fruit stalk vertically or at an angle, achieving non-contact cutting. On the one hand, this folded optical path design avoids the laser emitter head being directly exposed to areas where the fruit or branches may collide, reducing the risk of mechanical damage. On the other hand, compared with direct penetrating laser emission, this folded transmission path, combined with the design of the through hole in the center of the suction cup, not only solves the problem of potential mutual obstruction between the laser emission and the suction cup adsorption structure, but also utilizes the adjustable angle of the reflective elements to achieve multi-pose cutting, reducing the probability of laser head contamination or damage, and improving the reliability and service life of the system in complex field environments.

[0020] Furthermore, the machine vision module consists of at least one RGB-D camera that integrates color and depth information. This RGB-D camera can simultaneously acquire color images (RGB information) and depth images (Depth information) of the target area. The color images can provide features such as the color and texture of the fruit skin for ripeness determination, while the depth images can reflect the three-dimensional spatial position and contour information of the fruit and its stem, facilitating accurate positioning and attitude estimation.

[0021] Furthermore, the control system is configured inside the housing or connected externally to a host controller, including a microcontroller or a small PLC, and integrates a signal acquisition and processing unit, a negative pressure drive control unit, a laser drive control unit, and a vision data processing unit. The control system receives RGB-D image data and depth information from the machine vision module, and adsorption force feedback signals from the pressure-sensing patches of each suction cup unit. According to a preset algorithm, it performs fruit maturity determination, fruit stem spatial positioning, adaptive adjustment of adsorption parameters, and control of laser cutting timing and power. It also coordinates the movement of the robotic arm, the start and stop of negative pressure adsorption, the adjustment of attitude of the micro laser driven by the servo motor, and the laser pulse emission in sequence to realize a closed-loop operation process of positioning—adsorption—cutting—verification—collection.

[0022] Compared with existing technologies, this invention provides a tomato harvesting head based on negative pressure adsorption and laser cutting. It integrates multi-independent air-cavity flexible negative pressure adsorption, reflective laser non-contact cutting, RGB-D visual positioning, and closed-loop control, constructing a multi-functional end effector that combines adsorption fixation, precise positioning, energy separation, and intelligent decision-making. This meets the needs of non-destructive, efficient, and adaptive harvesting of thin-skinned, juicy, and easily damaged tomatoes in complex field environments, while significantly reducing the risk of mechanical damage and improving post-harvest marketability and operational continuity. Specific technical effects include the following: 1. Achieve fixation and separation without any mechanical contact throughout the process, eliminating fruit damage caused by clamping marks, punctures, and knife collisions at the source.

[0023] 2. The multi-independent air chamber flexible suction cup can adaptively fit various irregular curved fruits, and with the help of pressure sensing, it can achieve precise control of adsorption force, greatly improving the adsorption success rate and field adaptability.

[0024] 3. Laser cutting is fast, precise, and has no physical wear. The reflective optical path design avoids obstruction and ensures multi-angle cutting capability. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0026] Figure 1 This is a schematic diagram illustrating the application of the present invention; Figure 2 This is a schematic diagram of the end effector structure in Embodiment 1 of the present invention. Figure 1 ; Figure 3 This is a schematic diagram of the end effector structure in Embodiment 1 of the present invention. Figure 2 ; Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0027] Explanation of reference numerals in the attached figures: 1. Robotic arm; 2. Harvesting head module; 201. Housing; 202. Mounting base; 203. Auxiliary support frame; 3. Adaptive negative pressure adsorption module; 4. Integrated laser cutting module; 401. Servo motor; 402. Miniature laser; 403. First reflective element; 404. Second reflective element; 5. Machine vision module. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] As attached Figure 1 To be continued Figure 3 As shown: Example

[0030] This invention provides a tomato picking head based on negative pressure adsorption and laser cutting. The tomato picking head is configured as an end effector that integrates adsorption, positioning and cutting in collaboration with a control system and a robotic arm 1. The end effector includes a picking head module 2, an adaptive negative pressure adsorption module 3, an integrated laser cutting module 4 and a machine vision module 5.

[0031] 1. In one embodiment of the present invention, the harvesting head module 2 includes a housing 201, a mounting base 202, and an auxiliary support frame 203. The housing 201 is a conical cylindrical structure with a large opening at the upper end and a small opening at the lower end. The mounting base 202 is provided at the lower end of the opening of the housing 201. The mounting base 202 is a ring structure made of rigid metal. Multiple auxiliary support frames 203 are installed on the outside of the mounting base 202 in a ring arrangement. The auxiliary support frames 203 are used to connect the mounting base 202 and the housing 201. The auxiliary support frame 203 includes a damping rod and a support arm. The damping rod and the support arm are respectively hinged to the upper end and the middle of the outside of the mounting base 202. The front end of the damping rod is hinged to the lower side of the support arm, and the upper end of the support arm is connected to the top edge of the housing 201.

[0032] 2. In one embodiment of the present invention, the adaptive negative pressure adsorption module 3 includes multiple suction cup units uniformly distributed circumferentially along the opening of the housing 201. Each suction cup unit is made of a flexible material (such as silicone or medical-grade TPU); each suction cup unit has a pressure-sensing patch (not shown in the figure) on its outer side. The pressure-sensing patch is a thin-film flexible pressure sensor (such as an FSR flexible patch based on the piezoresistive effect or a MEMS micro pressure sensing element). The pressure-sensing patch can detect the change in adsorption pressure generated after the corresponding air cavity is attached to the tomato surface in real time, and convert the pressure signal into an electrical signal and output it to the control system. In specific applications, the pressure-sensing patch is attached to the outer surface of the flexible substrate of the suction cup unit or embedded in the sealing area near the air cavity inlet. During the negative pressure establishment process, it can monitor the local sealing state and the distribution of adsorption force. Once the pressure is detected to be lower than the set threshold, it is fed back to the control system for negative pressure compensation, ensuring that each air cavity can obtain uniform and sufficient adsorption force under different curved surface attachment conditions, thereby achieving adaptive sealing and stable adsorption of irregularly shaped tomato surfaces. Each suction cup unit has an independent air chamber, and each air chamber is connected to a negative pressure control channel. The control system independently adjusts the negative pressure according to the adhesion, thereby achieving adaptive sealing and adsorption fixation of irregularly shaped tomato surfaces.

[0033] 3. In one embodiment of the present invention, the integrated laser cutting module 4 includes a servo motor 401 and a micro laser 402, wherein the servo motor 401 is installed in the mounting base 202, and the shaft end of the servo motor 401 passes through the opening at the lower end of the housing 201 and is connected to the micro laser 402.

[0034] 4. In one embodiment of the present invention, the machine vision module 5 is disposed on the outside of the housing 201. The machine vision module 5 is used to identify mature tomato fruits and locate the three-dimensional spatial position of their stems, and to verify whether the stems are completely separated after laser cutting. The machine vision module 5 is at least one RGB-D camera integrating color and depth information. The RGB-D camera can simultaneously acquire color images (RGB information) and depth images (Depth information) of the target area. The color images can provide features such as the color and texture of the fruit skin for maturity determination, while the depth images can reflect the three-dimensional spatial position and contour information of the fruit and stems, facilitating accurate positioning and attitude estimation.

[0035] 5. In one embodiment of the present invention, the control system (not shown in the figure) is configured inside the housing 201 or connected to the host controller, including a microcontroller or a small PLC, and integrates a signal acquisition and processing unit, a negative pressure drive control unit, a laser drive control unit, and a vision data processing unit. The control system receives RGB-D image data and depth information from the machine vision module 5, and adsorption force feedback signals from the pressure sensing patches of each suction cup unit. According to a preset algorithm, it performs fruit maturity judgment, fruit stem spatial positioning, adaptive adjustment of adsorption parameters, and laser cutting timing and power control. It also sequentially coordinates the movement of the robotic arm 1, the start and stop of negative pressure adsorption, the adjustment of the attitude of the micro laser 402 driven by the servo motor 401, and the laser pulse emission, to realize a closed-loop operation process of positioning—adsorption—cutting—verification—collection.

[0036] Working Principle: Example 1 discloses a tomato harvesting head integrating adsorption, positioning, and laser cutting functions. Through the collaboration of a robotic arm 1 and a control system, it organically combines multi-suction cup flexible negative pressure adsorption, servo motor 401-driven micro-laser cutting, and RGB-D visual positioning to form an end effector that can adapt to irregular fruit surfaces and complete non-contact stem cutting. The harvesting head uses a conical shell 201 and an annular auxiliary support frame 203 to achieve stable support and posture connection. The suction cup unit has an independent air chamber and pressure sensing feedback, which can dynamically adjust the negative pressure under control to achieve stable and evenly distributed adsorption and fixation. Laser cutting is achieved by the servo motor 401 adjusting the laser posture and directly irradiating the fruit stem through the central through-hole of the suction cup, avoiding mechanical contact damage. The vision module is responsible for mature fruit identification, stem positioning, and cutting verification. This embodiment achieves non-destructive, efficient, and intelligent tomato harvesting, significantly improving post-harvest quality and operational adaptability.

[0037] As attached Figure 1 To be continued Figure 4 As shown: Example

[0038] This embodiment is basically the same as the previous embodiment, except that the integrated laser cutting module 4 also includes a first reflective element 403 and a second reflective element 404, which are respectively disposed on the upper part and the middle part of the inner wall of the housing 201. The optical path of the first reflective element 403, the second reflective element 404 and the micro laser 402 forms a folded transmission path, and guides the laser beam emitted by the micro laser 402 after two reflections, finally irradiating the fruit stalk part vertically or obliquely, realizing non-contact cutting. On the one hand, this folded optical path design can avoid the laser emitter head being directly exposed to the area where the fruit or branches may collide, reducing the risk of mechanical damage. On the other hand, compared with direct penetrating laser emission, this folded transmission path, combined with the design of the suction cup central through hole, not only solves the problem that the laser emission and suction cup adsorption may block each other structurally, but also utilizes the adjustable angle of the reflective element to realize multi-posture cutting, and reduces the probability of laser head contamination or damage, improving the reliability and service life of the system in complex field environments.

[0039] Working Principle: Compared to Embodiment 1, Embodiment 2, while maintaining the core solutions such as multi-cavity adaptive adsorption, RGB-D visual positioning, and closed-loop control, adds a first reflective element 403 and a second reflective element 404 to the integrated laser cutting module 4. This allows the laser beam emitted by the micro-laser 402 to be reflected twice by the inner wall of the housing 201, forming a folded transmission path before being guided to the central through-hole of the suction cup to irradiate the fruit stalk for non-contact cutting. This folded optical path design avoids the laser emitter head being directly exposed to areas where the fruit or branches may collide, thus reducing the risk of mechanical damage. It also solves the problem of potential mutual obstruction between laser emission and suction cup adsorption, and utilizes the adjustable angle of the reflective elements to achieve multi-pose cutting, broadening the cutting capability to adapt to different fruit stalk growth directions. Furthermore, because the laser head is relatively elevated and not affected by direct contact, the probability of contamination and damage is reduced, improving the system's reliability and service life in complex field environments. This allows the harvesting head to maintain non-destructive operation while also possessing higher structural safety and operational flexibility.

[0040] In conjunction with Embodiments 1 and 2 above, the present invention also provides a method for using the tomato harvesting head based on negative pressure adsorption and laser cutting, comprising the following steps: Step 1: The machine vision module 5 acquires images of the work area, uses color information obtained by the RGB-D camera to determine the ripeness of the tomato fruit, and combines depth information to calculate the three-dimensional spatial position of the fruit and stem. The positioning data is then transmitted to the control system to complete the identification and precise positioning of ripe tomatoes and stems.

[0041] Step 2: The control system plans the motion path of the robotic arm 1 based on the positioning information, drives the picking head to move near the target tomato, and makes the suction cup unit of the adaptive negative pressure adsorption module 3 contact the fruit surface.

[0042] Step 3: Activate the adaptive negative pressure adsorption module 3. Each suction cup unit generates adsorption force under the action of the negative pressure control channel. The pressure sensing patch monitors the bonding pressure and sealing status of each air cavity in real time and feeds the signal back to the control system. The control system independently adjusts and compensates the negative pressure of each air cavity to ensure that the suction cup unit forms a uniform seal on the irregular curved surface, achieving stable and adaptive adsorption fixation.

[0043] Step 4: After confirming that the adsorption is stable, the control system controls the integrated laser cutting module 4 to work according to the spatial position of the fruit stem. The servo motor 401 adjusts the attitude of the micro laser 402 so that the laser beam is guided through the folding transmission path formed by the first reflective element 403 and the second reflective element 404 to the central through hole of the suction cup and irradiates the fruit stem vertically or obliquely; non-contact cutting of the fruit stem is achieved through short-time high-energy laser pulses.

[0044] Step 5: The machine vision module 5 acquires images of the cut area again, uses the visual data processing unit to determine whether the fruit stem has been completely separated, and feeds back the verification results to the control system.

[0045] Step 6: After confirming the separation of the fruit stalk, the control system drives the robotic arm 1 to move the picking head to the collection position.

[0046] Step 7: The control system shuts off the negative pressure to release the suction force of each suction cup unit. The tomato detaches from the picking head under the action of gravity and falls into the collection container, completing one picking operation.

[0047] It should be noted that the robotic arm 1 involved in the present invention is existing technology. It can be mounted on a wheeled or tracked vehicle, a rail-mounted mobile platform or other mobile working carrier to carry and realize the spatial positioning and attitude adjustment of the picking head of the present invention. The structural form, driving method and control method of the robotic arm 1 are not the contents of the present invention. Therefore, no matter what kind of existing robotic arm 1 is used, it will not affect the functional realization of the picking head of the present invention.

[0048] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A tomato picking head based on negative pressure adsorption and laser cutting, the tomato picking head is configured to be based on a control system, a mechanical arm (1) cooperates and integrates adsorption, positioning and cutting in an end effector, the end effector includes a picking head module (2), an adaptive negative pressure adsorption module (3), an integrated laser cutting module (4) and a machine vision module (5), characterized in that: the picking head module (2) includes a shell (201), a mounting seat (202) and an auxiliary support frame (203), the shell (201) is a tapered cylindrical structure with a large upper opening and a small lower opening, the mounting seat (202) is arranged at the lower opening of the shell (201), the mounting seat (202) is a rigid metal ring structure, a plurality of auxiliary support frames (203) are arranged on the outer side of the mounting seat (202) in a ring shape, and the auxiliary support frames (203) are used to connect the mounting seat (202) and the shell (201); the adaptive negative pressure adsorption module (3) includes a plurality of suction cup units uniformly distributed along the opening circumference of the shell (201), each suction cup unit is made of flexible material; the integrated laser cutting module (4) includes a rudder (401) and a micro laser (402), wherein the rudder (401) is arranged in the mounting seat (202), the shaft end of the rudder (401) penetrates the opening at the lower end of the shell (201) and is connected with the micro laser (402); the machine vision module (5) is arranged on the outer side of the shell (201), and is used to identify mature tomato fruits and locate the three-dimensional spatial position of the fruit stem, and verify whether the fruit stem is completely separated after laser cutting.

2. A tomato picking head based on negative pressure adsorption and laser cutting according to claim 1, characterized in that, The auxiliary support frame (203) includes a damping rod and a support arm, the damping rod and the support arm are respectively hinged to the outer side of the mounting seat (202) at the upper end and the middle, the front end of the damping rod is hingedly connected to the lower side of the support arm, and the upper end of the support arm is connected to the top edge of the shell (201).

3. The tomato picking head based on negative pressure adsorption and laser cutting according to claim 1, characterized in that, Each suction cup unit is provided with a pressure sensing patch on the outer side.

4. The tomato picking head based on negative pressure adsorption and laser cutting according to claim 1, characterized in that, Each suction cup unit has an independent air cavity, and each air cavity is connected with a negative pressure control channel.

5. The tomato picking head based on negative pressure adsorption and laser cutting according to claim 1, characterized in that, The integrated laser cutting module (4) further includes a first reflecting element (403) and a second reflecting element (404), and the first reflecting element (403) and the second reflecting element (404) are arranged on the inner wall of the shell (201) at the upper part and the middle part, respectively.

6. A tomato picking head based on negative pressure adsorption and laser cutting according to claim 5, characterized in that, The light path of the first reflecting element (403), the second reflecting element (404) and the micro laser (402) forms a turn-back type transmission path, and the laser beam emitted by the micro laser (402) is guided after being reflected twice, and finally vertically or obliquely irradiated to the fruit stem part.

7. The tomato picking head based on negative pressure adsorption and laser cutting according to claim 1, characterized in that, The machine vision module (5) is at least one RGB-D camera integrating color and depth information.

8. The tomato picking head based on negative pressure adsorption and laser cutting according to claim 1, characterized in that, The control system is arranged in the shell (201), and the control system is a microcontroller or a small PLC, and integrates a signal acquisition and processing unit, a negative pressure driving control unit, a laser driving control unit and a vision data processing unit.

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