Fruit picking manipulator control method and picking manipulator

Abstract

The invention belongs to the technical field of picking manipulators, and particularly discloses a fruit picking manipulator control method and a picking manipulator. Obtaining mechanical parameters of the fruits; according to the appearance parameters and the mechanical parameters, the clamping position and the clamping force of the picking manipulator on the fruits are calibrated; mechanical parameters between the fruit stems and the branches are obtained; and calibrating the moving track and the loading force of the picking manipulator according to the mechanical parameters between the fruit stems and the branches. According to the control method of the fruit picking manipulator, the clamping force can be set in advance before the fruits are picked, the damage rate of the fruits is reduced, and the picking efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of picking manipulators, and in particular relates to a fruit picking manipulator control method and a picking manipulator. Background Art

[0002] In most areas of my country, fruit picking still relies mainly on manual labor. In related technologies, a variety of fruit picking robots have been developed to assist manual fruit picking and improve work efficiency. Although the picking robots in related technologies can adjust the clamping force when picking fruits, the clamping force is adjusted during the picking process, and the clamping force cannot be set in advance before picking, resulting in some fruits being damaged or unable to be picked smoothly. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, an embodiment of the present invention proposes a fruit picking robot control method, which can set the clamping force in advance before picking the fruit, reduce the breakage rate of the fruit, and improve the picking efficiency.

[0004] An embodiment of the present invention further provides a fruit picking robot.

[0005] The fruit picking robot control method of the embodiment of the present invention comprises the following steps:

[0006] Obtain fruit shape parameters;

[0007] Obtain fruit mechanical parameters;

[0008] Calibrate the gripping position and gripping force of the picking manipulator on the fruit according to the shape parameters and the mechanical parameters;

[0009] Obtain the mechanical parameters between the fruit stalk and the branch;

[0010] The running track and loading force of the picking manipulator are calibrated according to the mechanical parameters between the fruit stalk and the branch.

[0011] The embodiment of the present invention provides a fruit picking robot control method, which can set the clamping force in advance before picking the fruit, thereby reducing the breakage rate of the fruit and the picking efficiency.

[0012] In some embodiments, obtaining the fruit shape parameters comprises:

[0013] Using an image recognition system to obtain fruit image information;

[0014] The height, diameter, stalk length and stalk diameter of the fruit are acquired according to the fruit image information.

[0015] In some embodiments, obtaining the fruit mechanical parameters comprises:

[0016] obtaining the mass of the fruit using a weighing sensor;

[0017] The bearing limit force at different positions in the height direction of the fruit is measured.

[0018] In some embodiments, calibrating the gripping position and gripping force of the picking manipulator on the fruit according to the shape parameters and the mechanical parameters includes:

[0019] The maximum limit force is used as the maximum threshold of the clamping force of the picking manipulator;

[0020] The position corresponding to the maximum limit force is used as the clamping position of the picking robot.

[0021] The minimum threshold of the gripping force of the picking robot is calculated according to the mass of the fruit and the average load-bearing limit force at different positions.

[0022] In some embodiments, the method further comprises calculating the air pressure inside the airbag based on the calibrated clamping force of the picking robot.

[0023] In some embodiments, calibrating the running trajectory of the picking manipulator according to the mechanical parameters of the fruit stalk and the branch includes:

[0024] Driving the picking robot to move to a first position upward and away from the fruit;

[0025] After the picking robot moves to the first position, it moves to the second position toward the lower side close to the fruit.

[0026] In some embodiments, calibrating the loading force of the picking robot according to the mechanical parameters of the fruit stalk and the branch includes: setting the loading force of the picking robot according to the maximum bearing capacity between the fruit stalk and the branch.

[0027] The fruit picking robot according to the embodiment of the present invention comprises:

[0028] An image recognition device for obtaining fruit appearance parameters;

[0029] Weighing sensor, used to obtain the weight of the fruit;

[0030] A clamping unit, wherein the clamping unit has a clamping state and an unfolding state, wherein the clamping unit clamps the fruit in the clamping state, and wherein the clamping unit releases the fruit in the unfolding state;

[0031] A driving unit, the driving unit is connected to the clamping unit, and the driving unit is used to drive the clamping unit to switch between the unfolded state and the clamping state;

[0032] An adjusting unit is used to adjust the angle, height and extension length of the clamping unit.

[0033] In some embodiments, the clamping unit includes a plurality of clamping components, which are distributed in a ring shape and enclose a clamping space, and the clamping components include a clamping claw and a clamping airbag, and the clamping airbag is installed on the inner side of the clamping claw, and the clamping airbag is connected to the air source through an air pipe.

[0034] In some embodiments, the driving unit includes a telescopic driver and a connecting rod component, the driving end of the telescopic driver is connected to one end of the connecting rod component, and the other end of the connecting rod component is respectively connected to the plurality of clamping components. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flow chart of the control method of the fruit picking robot according to an embodiment of the present invention.

[0036] Figure 2 It is a structural schematic diagram of a fruit picking robot according to an embodiment of the present invention.

[0037] Figure 3 It is a schematic structural diagram of a clamping unit and a driving unit according to an embodiment of the present invention.

[0038] Figure 4 It is a structural schematic diagram of the clamping unit and the driving unit of an embodiment of the present invention from another perspective.

[0039] Figure 5 These are the tensile force curves of the fruit-stalk-branch and the fruit-stalk according to the embodiment of the present invention.

[0040] Figure 6 Schematic diagram of different operation trajectories of the picking robot according to an embodiment of the present invention.

[0041] Reference numerals:

[0042] Weighing sensor 100, clamping unit 200, driving unit 300, adjusting unit 400,

[0043] Clamping part 1, clamping claw 11,

[0044] Telescopic drive 2, lead screw 21, drive 22,

[0045] Connecting rod component 3, connecting rod 31, connecting plate 32,

[0046] The first adjustment component 4, the telescopic joint 41, the first telescopic member 42,

[0047] The second adjustment component 5, the second telescopic member 51,

[0048] The third adjustment component 6, the third telescopic member 61,

[0049] Rotating platform 7, rotating table 71, driving component 72, driving motor 721, driving gear 722, driven gear 723. DETAILED DESCRIPTION

[0050] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0051] The fruit picking robot control method of the embodiment of the present invention comprises the following steps:

[0052] S100, obtaining fruit appearance parameters.

[0053] For example, the shape parameters of the fruit can be obtained through image recognition technology. It should be noted that the image recognition technology for identifying the shape parameters of the fruit includes obtaining the fruit image information and preprocessing the fruit image, for example, grayscale processing, binarization and denoising of the image, and then extracting the edge of the fruit, and calculating the shape parameters of the fruit based on the result that is easy to extract.

[0054] S200, obtaining mechanical parameters of the fruit.

[0055] It should be noted that some mechanical parameters of the fruit are measured, calibrated and recorded in advance into the controller of the picking robot. For example, a hardness tester is used to measure the hardness of the fruit with skin. 100 fragrant pears are taken for measurement. A measurement point is selected in the middle and on both sides of the fruit. The measured data is analyzed and the average value is taken as the calibrated hardness and recorded into the controller of the picking robot. For example, the calibrated hardness can be the maximum hardness of the fruit. When the maximum hardness of the fruit is known, the bearing limit force that the fruit can withstand can be determined.

[0056] S300: calibrate the gripping position and gripping force of the picking robot on the fruit according to the shape parameters and mechanical parameters.

[0057] It should be noted that the gripping position and gripping force of the picking robot on the fruit can be set according to the shape parameters and mechanical parameters of the fruit before picking the fruit, thereby ensuring the position accuracy and strength of the fruit gripping, reducing the breakage rate of the fruit and improving the picking efficiency.

[0058] S400: Obtain mechanical parameters between the fruit stalk and the branch.

[0059] It should be noted that the branch is the fruit branch, and the fruit stalk is the branch stalk connected to the fruit.

[0060] For example, the mechanical parameters between the fruit stalk and the branch are measured in advance and entered into the picking robot controller, that is, when the picking robot picks the fruit, it only needs to retrieve the relevant data from the control module.

[0061] Obtaining the mechanical parameters between the fruit and the branches includes:

[0062] For the overall tensile test of the fruit, the fruit and the connected stalk and branch are retained. When doing the overall tensile test of the fruit-stalk-branch, the branch part of the fruit is fixed on the fixture of the universal testing machine to ensure that the stretching direction is consistent with the natural hanging direction of the fruit. Stretch at a constant speed of 5mm / min until the connection between the branch and the stalk breaks. Record the maximum tensile force (Fzt) at the time of fracture. This test is designed to evaluate the maximum load-bearing capacity and fracture characteristics of the branch-stalk connection.

[0063] Fruit-pedicel tensile separation test, that is, only the fruit and pedicel parts are retained. The fruit and pedicel parts of the fruit are fixed on the fixture of the universal testing machine, and stretched at a constant speed of 5mm / min until the pedicel is separated from the fruit. The maximum tensile force (Fgb) when the fruit is separated from the pedicel is recorded. This test is used to analyze the bonding strength and separation mechanism between the fruit and the pedicel. During the test, the loading force and displacement data are monitored and recorded in real time to capture the mechanical response of the connection part. To ensure the reliability of the test results, each test was repeated multiple times to evaluate the repeatability and stability of the results.

[0064] Both the integral tensile test and the separate tensile test show obvious load-displacement curves, reflecting the entire process of elasticity, yielding and fracture of the connection. Figure 5 As shown in the figure, the load-displacement curves of 5 representative samples were selected to show the typical characteristics of the experimental results. In the overall tensile test, it was observed that the connection showed linear elastic behavior before reaching the maximum load, and then entered a nonlinear stage until the branch-stalk fruit stalk connection broke. The determination of the maximum load provides an important indicator for evaluating the bearing capacity of this part. In the separation tensile test, the connection between the fruit and the stalk separated at a lower load, and the load-displacement curve showed a lower yield point and a gentler nonlinear stage. This phenomenon indicates that the bonding strength between the fruit and the stalk is lower than that of the overall connection.

[0065] By testing the separation mechanical properties of the fruit "branch-stalk-fruit", the following results were obtained: the results of the overall tensile test of fruit-stalk-branch showed that the fracture mainly occurred at the connection between the branch and the stalk, and the average maximum tensile force (Fzt) was 26.18±9.21N (n=10). This tensile force was used as the loading force basis of the picking robot. For example, the maximum tensile force at the connection between the branch and the stalk was used as the minimum loading force of the picking robot. That is, when the loading force of the picking robot was greater than the maximum tensile force at the connection between the branch and the stalk, the connection between the branch and the stalk would fracture.

[0066] This indicates that during the picking process, the connection between the branch and the pedicel is a mechanically weak link and is prone to breakage. The results of the fruit-pedicel tensile separation test showed that the average maximum tensile force (Fgb) was 23.35±9.46N (n=10). Compared with the overall tensile test, the maximum tensile force of the pedicel was significantly lower than that of the whole, indicating that the force required to separate the fruit from the pedicel was less than the breaking force at the connection between the branch and the pedicel. By performing an independent sample t-test on the two groups of experimental data, we found that at the significance level of α=0.05, there was a significant difference between the "branch-pedicel-fruit" as a whole (Fzt) and the fruit-pedicel (Fgb) (t=2.83, df=18, p<0.05).

[0067] By measuring the mechanical parameters between the fruit stalk and the branch, data support can be provided for the control of the loading force of the picking robot, so as to reduce the damage rate during the picking process and improve the picking efficiency.

[0068] S500, calibrating the running trajectory and loading force of the picking robot according to the mechanical parameters between the fruit stalk and the branch.

[0069] It should be noted that after the picking robot grabs the fruit, it needs to pick it down. The picking methods include horizontal pulling, horizontal rotation, vertical pulling and bending and breaking. Through the analysis of the four picking methods, the bending and breaking picking method has lower force requirements and precise operating characteristics, which can improve the flexibility and safety of the picking operation at the same time.

[0070] An embodiment of the present invention proposes a fruit picking robot control method. According to the shape parameters and mechanical parameters of the fruit, the gripping position and gripping force of the fruit by the picking robot can be set before picking the fruit, thereby ensuring the position accuracy and gripping force of the fruit, reducing the breakage rate of the fruit, and improving the picking efficiency.

[0071] In some embodiments, obtaining the fruit appearance parameters comprises:

[0072] S101, obtaining fruit image information using an image recognition system.

[0073] For example, fruit image information is obtained through an image collector. It should be noted that the image recognition system is an existing mature technology, and how to collect fruit information will not be elaborated here.

[0074] S102, acquiring the height, diameter, stalk length and stalk diameter of the fruit according to the fruit image information.

[0075] It should be noted that the height of the fruit refers to the dimension along the length of the fruit minus the length of the stalk, and the diameter of the fruit refers to the maximum diameter of the fruit.

[0076] After the image recognition system collects the fruit image information, it processes the image and obtains the information of the fruit height, diameter, stalk length and stalk diameter.

[0077] In some embodiments, obtaining the fruit mechanical parameters comprises:

[0078] S201. Obtain the mass of the fruit using a weighing sensor.

[0079] For example, a weighing sensor is installed in the clamping space, and the weight of the fruit is measured using the weighing sensor.

[0080] S202. Measure the ultimate bearing capacity at different positions along the height direction of the fruit.

[0081] It should be noted that the bearing limit force at different positions in the height direction of the fruit is measured and calibrated in advance and entered into the controller of the picking robot. For example, the hardness of the fruit with skin is measured using a hardness tester. 100 fragrant pears are taken for measurement. A measurement point is selected in the middle and on both sides of the fruit. The measured data is analyzed and the average value is taken as the calibrated hardness and entered into the controller of the picking robot. The calibrated hardness can be the maximum hardness of the fruit. When the maximum hardness of the fruit is known, the bearing limit force at different positions of the fruit can be determined.

[0082] In some embodiments, calibrating the gripping position and gripping force of the picking manipulator on the fruit according to the shape parameters and mechanical parameters includes:

[0083] S301. The maximum limit force is used as the maximum threshold of the gripping force of the picking robot.

[0084] It should be noted that the maximum bearing limit force of the fruit is the maximum clamping force that the fruit can bear. When this value is exceeded, the fruit will break. Therefore, the maximum limit force is used as the maximum threshold of the clamping force of the picking robot.

[0085] S302: The position corresponding to the maximum limit force is used as the clamping position of the picking robot.

[0086] It should be noted that the position corresponding to the maximum limit force is the position where the fruit can bear the maximum clamping force. The picking robot clamps this position to minimize the chance of fruit breakage, thereby reducing the fruit breakage rate.

[0087] S303, calculating the minimum threshold of the gripping force of the picking robot according to the mass of the fruit and the average load-bearing limit force at different positions.

[0088] For example, the following formula is used to calculate the minimum threshold of the gripping force of the picking robot according to the weight of the fruit and the average load-bearing limit force at different positions:

[0089]

[0090] Where, μ is the friction coefficient between the fruit and the air bag;

[0091] f——average bearing limit, N;

[0092] m——fruit mass, g;

[0093] g——acceleration due to gravity, 9.8N / Kg;

[0094] F j ——Minimum clamping force required by the picking robot, N.

[0095] It should be noted that in order to ensure the stability of the picking robot's grip on the fruit, the gripping force of the picking robot should be greater than or equal to the minimum gripping force and less than or equal to the maximum gripping force, that is, the gripping force of the picking robot should be greater than or equal to the minimum threshold of the gripping force and less than or equal to the maximum threshold of the gripping force.

[0096] In some embodiments, the method also includes calculating the air pressure inside the airbag based on the calibrated clamping force of the picking robot.

[0097] After the picking robot's clamping force on the fruit is calibrated, the pressure inside the airbag is controlled according to the calibrated clamping force. That is, the greater the clamping force, the greater the air pressure inside the airbag. Conversely, the smaller the clamping force, the smaller the air pressure inside the airbag.

[0098] It should be noted that since the clamping force on the fruit is the combined force between the picking robot and the airbag, and the airbag is a flexible structure that can reduce the extrusion damage rate of the outer surface of the fruit, the force generated by the picking robot can be appropriately reduced and the pressure generated by the airbag can be increased. In other words, under the premise of ensuring that the total clamping force is greater than or equal to the minimum threshold of the fruit clamping force, the relationship between the force generated by the robot and the force generated by the airbag can be adjusted and distributed according to actual conditions.

[0099] In some embodiments, calibrating the running trajectory of the picking robot according to the mechanical parameters of the fruit stalk and the branch includes:

[0100] S501, driving the picking robot to move to a first position upward and away from the fruit.

[0101] S502: After the picking robot moves to the first position, it moves to the second position toward the lower side close to the fruit.

[0102] like Figure 6 As shown, the motion trajectory of the picking robot is a curved upward trajectory, that is, the rear end of the picking robot first moves to the upper side and then the top end of the picking robot moves to the lower side, forming a curved upward arc trajectory.

[0103] It should be noted that the operation trajectory of the picking robot is set in advance, that is, during the fruit picking process, the robot moves according to the pre-set operation trajectory.

[0104] The process of setting the trajectory of the picking robot includes:

[0105] Pressure sensors and acceleration sensors are installed on different fingers of the picking manipulator. After a detailed study of the force analysis data of the finger pressure sensors in different picking modes, the following conclusions can be drawn: There are significant differences in the gripping force applied by the fingers in the four different picking modes. As can be seen from Table 1, the average gripping force is the highest under the horizontal pulling trajectory, reaching 839.42N, indicating that under this trajectory, the fingers need to exert a large force to complete the picking action. Under the vertical pulling trajectory, the average gripping force is 703.13N, which is lower than the horizontal pulling. The average gripping force under the horizontal rotation and bending and bending trajectories is 585.85N and 365.24N, respectively, which is significantly lower than the first two trajectories. By comparing the force of each finger under different trajectories, we found that finger 1 bears a large force in horizontal pulling and vertical pulling, which is 930.16N and 751.94N, respectively. This may be because finger 1 plays a major supporting role in the picking process, while the forces on fingers 2 and 3 are relatively small. However, in the horizontal rotation trajectory, the forces on finger 3 are higher than those on fingers 1 and 2, indicating that in this trajectory, the role of finger 3 is more important. In addition, it can be seen from the statistical data that the average gripping force of the three fingers in different trajectories shows a certain regularity: the average gripping force of horizontal pulling and vertical pulling is higher, followed by horizontal rotation, and the average gripping force of bending upward is the lowest.

[0106] The influence of different operation trajectories on the force on the fingers of the manipulator is multi-dimensional. When designing and optimizing picking tools, factors such as the direction, magnitude, distribution, stability, labor intensity, picking efficiency and safety of the force should be comprehensively considered to achieve efficient, safe and moderately labor-intensive picking operations. The complexity and difficulty of the picking action are closely related to the gripping force applied by the fingers. The bending and bending mode is more suitable for the operation trajectory of the picking manipulator due to its lower force requirements and precise operating characteristics. This operation trajectory helps to reduce the complexity of the mechanical structure while improving the flexibility and safety of the picking operation.

[0107] Table 1 Force analysis under different picking modes

[0108]

[0109] In some embodiments, calibrating the loading force of the picking manipulator according to the mechanical parameters of the fruit stalk and the branch includes:

[0110] S503: setting the loading force of the picking robot according to the maximum bearing capacity between the fruit stalk and the branch.

[0111] It should be noted that the loading force of the picking robot is greater than the maximum bearing capacity between the fruit stalk and the branch, that is, the loading force of the picking robot is greater than the maximum tensile force between the fruit stalk and the branch. From the above content, it can be seen that the force required to separate the fruit from the stalk is less than the breaking force at the connection between the branch and the stalk. Therefore, when the loading force is greater than the maximum bearing capacity between the branch and the stalk, the fruit can be picked to improve the efficiency of fruit picking.

[0112] like Figures 2 to 4 As shown, the fruit picking robot of the embodiment of the present invention comprises

[0113] An image recognition device is used to obtain fruit appearance parameters.

[0114] It should be noted that the image recognition device can be installed on a rack, and the image recognition device can be a high-definition image collector or other existing image recognition devices.

[0115] The weighing sensor 100 is used to obtain the weight of the fruit.

[0116] Specifically, Figure 2As shown, the weighing sensor 100 is installed on the clamping unit 200, and the weighing sensor 100 can obtain the weight of the fruit. The weighing sensor 100 is located in the clamping space. It should be noted that the weighing sensor 100 can not only obtain the weight of the fruit, but also monitor whether the fruit is clamped when the clamping unit 200 clamps the fruit. For example, when the clamping unit 200 is empty, there is no fruit in the clamping space. At this time, the data collected by the weighing sensor 100 is a null value, which means that the clamping unit 200 is empty. At this time, it is necessary to re-control the clamping unit 200 to clamp the fruit, so as to improve the fruit picking efficiency.

[0117] The clamping unit 200 has a clamping state and an unfolding state. In the clamping state, the clamping unit 200 clamps the fruit. In the unfolding state, the clamping unit 200 releases the fruit.

[0118] Specifically, Figure 2 As shown, the clamping unit 200 is installed at the top of the frame. When the clamping unit 200 is in the clamping state, it can clamp the fruit, and when it is in the unfolded state, it can release the fruit.

[0119] The driving unit 300 is connected to the clamping unit 200 and is used to drive the clamping unit 200 to switch between the unfolded state and the clamping state.

[0120] Specifically, Figure 2 As shown, the driving unit 300 is located below the clamping unit 200, and the driving unit 300 can drive the clamping unit 200 to transform between the unfolded state and the clamping state.

[0121] The adjusting unit 400 is used to adjust the angle, height and extension length of the clamping unit 200 .

[0122] Specifically, Figure 2 As shown, the adjusting unit 400 is connected to the driving unit 300 , and the adjusting unit 400 is located below the driving unit 300 . The adjusting unit 400 is used to adjust the angle, height and extension length of the clamping unit 200 .

[0123] In some embodiments, the adjustment unit 400 includes a first adjustment component 4, a second adjustment component 5 and a third adjustment component 6, the first adjustment component 4 is used to adjust the length of the clamping unit 200, the second adjustment component 5 is used to adjust the angle of the clamping unit 200, and the third adjustment component 6 is used to adjust the height of the clamping unit 200.

[0124] Specifically, Figures 2 to 4As shown, the first adjustment component 4 includes a plurality of telescopic joints 41 and a plurality of first telescopic members 42 which are nested with each other. A first telescopic member 42 is provided between two adjacent telescopic joints 41. The top of the telescopic joint 41 located at the top is connected to the clamping unit 200. It should be noted that when the first telescopic member 42 is extended, the extended length of the clamping unit 200 increases. Conversely, when the first telescopic member 42 is contracted, the extended length of the clamping unit 200 decreases.

[0125] The second adjustment component 5 includes a second telescopic member 51, the telescopic end of the second telescopic member 51 is connected to a telescopic joint 41 located at the bottom. When the second telescopic member 51 is extended, the angle of the clamping unit 200 increases. Conversely, when the second telescopic member 51 is contracted, the angle of the clamping unit 200 decreases.

[0126] The third adjustment assembly 6 includes a third telescopic member 61, the telescopic end of which is connected to a telescopic section 41 located at the bottom. When the third telescopic member 61 is extended, the second telescopic member 51 is extended at the same time, and the height of the telescopic section 41 located at the bottom is increased. Conversely, when the third telescopic member 61 is retracted, the second telescopic member 51 is retracted at the same time, and the height of the telescopic section 41 located at the bottom is decreased.

[0127] Optionally, the adjustment unit 400 may further include a rotating platform 7, which includes a rotating table 71 and a driving component 72. The fixed end of the third telescopic member 61 is connected to the rotating table 71. The driving component 72 is located below the rotating table 71. The driving component 72 drives the rotating table 71 to rotate 360°. When the rotating table 71 rotates, it can drive the clamping unit 200 to rotate, thereby adjusting the position of the clamping unit 200.

[0128] Specifically, Figure 4 As shown, the driving component 72 includes a driving motor 721, a driving gear 722 and a driven gear 723. The driving gear 722 is connected to the output shaft of the driving motor 721. The driven gear 723 meshes with the driving gear 722. The driven gear 723 is connected to the rotating platform 71.

[0129] The fruit picking robot of the embodiment of the present invention can realize automatic picking of fruits by using the clamping unit 200, the driving unit 300 and the adjusting unit 400, obtains the weight of the fruit by using the weighing sensor 100, and collects the shape parameters of the fruit by using the image recognition device to provide support for the setting of the clamping position, clamping force and loading force of the picking robot, thereby ensuring the picking efficiency and quality of the fruit.

[0130] In some embodiments, the clamping unit 200 includes a plurality of clamping components 1, which are distributed in a ring shape and enclose a clamping space. The clamping component 1 includes a clamping claw 11 and a clamping airbag. The clamping airbag is installed on the inner side of the clamping claw 11, and the clamping airbag is connected to the air source through an air pipe.

[0131] Specifically, Figure 3 As shown, there are three clamping parts 1, which are distributed in a ring shape. The inner sides of the three clamping parts 1 form a clamping space. The clamping claw 11 includes a plurality of clamping sections hinged in sequence. The clamping airbag is installed on the inner side of the clamping claw 11. The clamping airbag is connected to an air source through an air pipe. For example, the air source can be compressed gas or a compressor.

[0132] It should be noted that a solenoid valve is installed on the air pipe and a pressure sensor is installed inside the airbag. When the preset air pressure value is reached, the solenoid valve can stop supplying air to the inside of the airbag.

[0133] It should be noted that after the picking robot calibrates the clamping force of the fruit, the pressure inside the airbag is controlled according to the calibrated clamping force, that is, the greater the clamping force, the greater the air pressure inside the airbag, and conversely, the smaller the clamping force, the smaller the air pressure inside the airbag.

[0134] In some embodiments, the driving unit 300 includes a telescopic driver 2 and a connecting rod component 3, the driving end of the telescopic driver 2 is connected to one end of the connecting rod component 3, and the other end of the connecting rod component 3 is respectively connected to the plurality of clamping components 1.

[0135] Specifically, Figures 2 to 4 As shown, the connecting rod component 3 includes a plurality of connecting rods 31 and a connecting disk 32, the plurality of connecting rods 31 are distributed in a ring shape, the plurality of connecting rods 31 are connected to the plurality of clamping components 1 in a one-to-one correspondence, the lower ends of the plurality of connecting rods 31 are hinged to the connecting disk 32, the telescopic driver 2 includes a lead screw 21 and a driver 22, the output shaft of the driver 22 is connected to the lead screw 21, the connecting disk 32 is sleeved on the lead screw 21, and the connecting disk 32 is movable in the length direction of the lead screw 21 when the lead screw 21 rotates. For example, when the lead screw rotates forward, the connecting disk 32 moves upward, driving the connecting rod 31 to move upward, and the plurality of clamping components 1 gather to the middle to hold the fruit tightly, and vice versa, when the lead screw 21 rotates reversely, the connecting disk 32 moves downward, driving the connecting rod 31 to move downward, and the plurality of clamping components 1 move away from each other to place the fruit.

[0136] It should be noted that in the process of multiple clamping components 1 gripping and releasing the fruit, the threaded connection between the screw 21 and the connecting plate 32 has a self-locking function. For example, when the screw 21 is a trapezoidal thread and the thread lead angle is smaller than the static friction angle, self-locking can be achieved. The self-locking ability prevents the clamping components 1 from opening due to the gravity of the pear.

[0137] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0138] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0139] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0140] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0141] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0142] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A fruit picking robot control method, characterized in that: The steps include: Obtain fruit shape parameters; Obtain fruit mechanical parameters; Calibrate the gripping position and gripping force of the picking manipulator on the fruit according to the shape parameters and the mechanical parameters; Obtain the mechanical parameters between the fruit stalk and the branch; The running track and loading force of the picking manipulator are calibrated according to the mechanical parameters between the fruit stalk and the branch.

2. The fruit picking robot control method according to claim 1, characterized in that: The obtaining of fruit shape parameters comprises: Using an image recognition system to obtain fruit image information; The height, diameter, stalk length and stalk diameter of the fruit are acquired according to the fruit image information.

3. The fruit picking robot control method according to claim 1 is characterized in that: The obtaining of fruit mechanical parameters comprises: obtaining the mass of the fruit using a weighing sensor; The bearing limit force at different positions in the height direction of the fruit is measured.

4. The fruit picking robot control method according to claim 3, characterized in that: Calibrating the gripping position and gripping force of the picking manipulator on the fruit according to the shape parameters and the mechanical parameters includes: The maximum limit force is used as the maximum threshold of the clamping force of the picking manipulator; The position corresponding to the maximum limit force is used as the clamping position of the picking robot. The minimum threshold of the gripping force of the picking robot is calculated according to the mass of the fruit and the average load-bearing limit force at different positions.

5. The fruit picking robot control method according to claim 1, characterized in that: The method further comprises: The air pressure inside the airbag is calculated according to the calibrated clamping force of the picking manipulator.

6. The fruit picking robot control method according to claim 5, characterized in that: The operation trajectory of the picking manipulator is calibrated according to the mechanical parameters of the fruit stalk and the branch, including: Driving the picking robot to move to a first position upward and away from the fruit; After the picking robot moves to the first position, it moves to the second position toward the lower side close to the fruit.

7. The fruit picking robot control method according to claim 6, characterized in that: Calibrating the loading force of the picking robot according to the mechanical parameters of the fruit stalk and the branch includes: setting the loading force of the picking robot according to the maximum bearing capacity between the fruit stalk and the branch.

8. A fruit picking robot, characterized in that: include: An image recognition device for obtaining fruit appearance parameters; Weighing sensor, used to obtain the weight of the fruit; A clamping unit, wherein the clamping unit has a clamping state and an unfolding state, wherein the clamping unit clamps the fruit in the clamping state, and wherein the clamping unit releases the fruit in the unfolding state; A driving unit, the driving unit is connected to the clamping unit, and the driving unit is used to drive the clamping unit to switch between the unfolded state and the clamping state; An adjusting unit is used to adjust the angle, height and extension length of the clamping unit.

9. The fruit picking robot according to claim 8, characterized in that: The clamping unit includes a plurality of clamping components, which are distributed in a ring shape and enclose a clamping space. The clamping components include clamping claws and a clamping airbag, which is installed on the inner side of the clamping claws and is connected to an air source through an air pipe.

10. The fruit picking robot according to claim 8, characterized in that: The driving unit comprises a telescopic driver and a connecting rod component, wherein the driving end of the telescopic driver is connected to one end of the connecting rod component, and the other end of the connecting rod component is respectively connected to the plurality of clamping components.

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