Size classification method and device for sphere-like fruits and vegetables based on flexible mechanical claw

Abstract

The invention relates to the technical field of fruit and vegetable picking, and provides a size classification method and device for sphere-like fruits and vegetables based on a flexible mechanical claw. The size classification method comprises the following steps: determining set positions of the sphere-like fruits and vegetables in a clamping interval of a flexible mechanical claw; a flexible mechanical claw is controlled to clamp the sphere-like fruits and vegetables, and pressure information collected by the corresponding flexible pressure sensors on the flexible clamping fingers is obtained; according to the pressure information of the flexible pressure sensors, pressure distribution information of the flexible clamping fingers in the extending direction of the flexible clamping fingers is determined; and according to the pressure distribution information, determining the size category of the sphere-like fruits and vegetables. The method is generally suitable for lossless classification of the size categories of the spheroidal fruits and vegetables of various specifications, is convenient to operate and high in efficiency, ensures the classification accuracy of the spheroidal fruits and vegetables, and reduces the influence of the surrounding environment on the standardized classification precision of the spheroidal fruits and vegetables.

Description

Technical Field

[0001] The invention relates to the technical field of fruit and vegetable picking, and in particular to a method and device for classifying spherical fruits and vegetables by size based on flexible mechanical claws. Background Art

[0002] Fruit specifications are generally classified according to the size of the fruit, which refers to the diameter of the fruit. At present, there are many methods for the classification of the fruit diameter of spherical fruits and vegetables. There are many research results on the algorithm of visual detection of fruit diameter, mainly including the minimum circumscribed rectangle method, the projection area calculation method and the contour fitting method. One of the methods for measuring fruit diameter is to use a grade card or a vernier caliper. The grade card is a cardboard or other material board with holes dug out according to the specified diameter size. When using it, spherical fruits and vegetables are placed in the holes to estimate the size of the fruit diameter. Machine vision technology can quickly and non-destructively obtain parameters such as the size, color and surface defects of spherical fruits and vegetables, and combine feature information extraction and processing algorithms to identify the quality of fruits. These methods have their own characteristics and are suitable for different scenarios and needs, providing important technical support for the standardized production and sales of spherical fruits and vegetables.

[0003] However, machine vision technology has certain limitations in the classification of spherical fruits and vegetables. When using machine vision technology to classify spherical fruits and vegetables, it is easily affected by the occlusion of branches and leaves on the tree, making it difficult to accurately obtain the image of spherical fruits and vegetables, resulting in the inability to classify spherical fruits and vegetables. When using a grade card or a vernier caliper to measure the fruit diameter, due to the irregularity of the shape of spherical fruits and vegetables, there may be a large gap between the maximum and minimum fruit diameters of the same type of spherical fruits and vegetables, resulting in measurement errors. Some of the designed classification mechanisms are only suitable for fruits of specific shapes and sizes, and cannot sort irregularly shaped fruits, and are less popular. These defects limit the accuracy and efficiency of the classification of the size of spherical fruits and vegetables, and also affect the market competitiveness of spherical fruit and vegetable products. Summary of the invention

[0004] The present invention provides a method and device for classifying spherical fruits and vegetables by size based on a flexible mechanical claw, which are used to at least solve or improve the problem that the existing detection method is not convenient for accurately classifying spherical fruits and vegetables by size.

[0005] The present invention provides a size classification method for spherical fruits and vegetables based on a flexible mechanical claw, wherein the flexible mechanical claw comprises a driving member and a plurality of flexible clamping fingers, wherein the driving member is connected to the plurality of flexible clamping fingers to drive the plurality of flexible clamping fingers to move closer to each other or separate from each other, and a plurality of flexible pressure sensors are provided on a clamping surface of at least one of the flexible clamping fingers, and the plurality of flexible pressure sensors are sequentially arranged along the extension direction of the flexible clamping fingers; the method comprises: Determine that the spherical fruit and vegetable is located at a set position in the clamping interval of the flexible mechanical claw; Controlling the flexible mechanical claw to clamp the spherical fruits and vegetables, and obtaining pressure information collected by each of the flexible pressure sensors corresponding to the flexible clamping fingers; Determining pressure distribution information of the flexible clamping finger along its extension direction according to pressure information of each of the flexible pressure sensors; The size category of the spherical fruits and vegetables is determined according to the pressure distribution information.

[0006] According to a method for classifying spherical fruits and vegetables by size based on a flexible mechanical claw provided by the present invention, before determining that the spherical fruits and vegetables are located at a set position of the clamping interval of the flexible mechanical claw, the method further includes: acquiring image information of the flexible mechanical claw; Determining the position information of the spherical fruits and vegetables according to the image information; According to the position information, the clamping posture of the flexible mechanical claw relative to the spherical fruits and vegetables is controlled to change, so as to ensure that the flexible mechanical claw clamps the peripheral wall of the spherical fruits and vegetables.

[0007] According to a method for classifying spherical fruits and vegetables by size based on a flexible mechanical claw provided by the present invention, the driving member includes a base, a linear driving part and a plurality of connecting rod assemblies; A plurality of the flexible clamping fingers are circumferentially arranged at the first end of the base, and each of the flexible clamping fingers is rotatably connected to the base; The linear drive unit is disposed on the base and connected to the first ends of the plurality of connecting rod assemblies, and the second ends of the plurality of connecting rod assemblies are rotatably connected to the plurality of flexible clamping fingers in a one-to-one correspondence; The linear drive unit is used to drive the first ends of the multiple sets of connecting rod assemblies to move along the central axis of the base, and then the multiple sets of connecting rod assemblies drive the multiple flexible clamping fingers to rotate toward or away from the central axis at the same time.

[0008] According to a method for classifying spherical fruits and vegetables by size based on a flexible mechanical claw provided by the present invention, the connecting rod assembly includes a first connecting rod and a second connecting rod; The base has a receiving cavity and a plurality of openings communicating with the receiving cavity, the linear drive unit is arranged in the receiving cavity, and the plurality of openings are arranged in sequence along the circumference of the base; The output end of the linear drive unit is connected to the first end of the first connecting rod, and the first connecting rods corresponding to each set of the connecting rod assemblies are inserted into each of the openings one by one, the second end of the first connecting rod is rotatably connected to the first end of the second connecting rod, and the second end of the second connecting rod is rotatably connected to the flexible clamping finger.

[0009] According to a method for classifying spherical fruits and vegetables by size based on a flexible mechanical claw provided by the present invention, the flexible clamping finger comprises a clamping finger body and a flexible pad; The clamping finger body comprises a first side, a second side and a third side connected in sequence to form a triangular structure, the first side is located on a side facing the central axis of the base, and the second side is located on a side away from the central axis of the base; The flexible pad is arranged on the first side, and a plurality of the flexible pressure sensors are arranged on the surface of the flexible pad in sequence and at intervals along the extension direction of the first side. The third side is rotatably connected to the first end of the base and the second end of the connecting rod assembly respectively.

[0010] According to a method for classifying spherical fruits and vegetables by size based on a flexible mechanical claw provided by the present invention, the step of determining that the spherical fruits and vegetables are located at a set position in the clamping interval of the flexible mechanical claw includes: determining that the spherical fruits and vegetables are located in the clamping interval formed by a plurality of flexible clamping fingers, and that the bottom end of the spherical fruits and vegetables is in contact with the first end of the base; wherein the bottom end of the spherical fruits and vegetables is arranged opposite to the handle end of the spherical fruits and vegetables.

[0011] According to a method for classifying spherical fruits and vegetables by size based on a flexible mechanical claw provided by the present invention, the step of controlling the flexible mechanical claw to clamp the spherical fruits and vegetables comprises: During the detection of different spherical fruits and vegetables, the linear drive unit is controlled to drive the first ends of multiple sets of connecting rod assemblies to move a set distance, so that multiple flexible clamping fingers are simultaneously rotated toward a side close to the central axis by a set angle.

[0012] According to a method for classifying spherical fruits and vegetables based on a flexible mechanical claw provided by the present invention, the step of determining the size category of the spherical fruits and vegetables according to the pressure distribution information comprises: comparing the pressure distribution information with information in a database, and determining the size category of the spherical fruits and vegetables according to the comparison result; The database represents the matching relationship between the diameter and pressure distribution information of spherical fruits and vegetables of different sizes.

[0013] The present invention also provides a size classification device for spherical fruits and vegetables based on a flexible mechanical claw, wherein the flexible mechanical claw comprises a driving member and a plurality of flexible clamping fingers, wherein the driving member is connected to the plurality of flexible clamping fingers to drive the plurality of flexible clamping fingers to move closer to each other or separate from each other, and a plurality of flexible pressure sensors are provided on the clamping surface of at least one of the flexible clamping fingers, and the plurality of flexible pressure sensors are sequentially arranged along the extension direction of the flexible clamping fingers; the device comprises the following modules: A determination module, used to determine the set position of the spherical fruit and vegetable in the clamping interval of the flexible mechanical claw; An acquisition module, used to control the flexible mechanical claw to clamp the spherical fruits and vegetables, and to acquire pressure information collected by each of the flexible pressure sensors corresponding to the flexible clamping fingers; A calculation module, used to determine the pressure distribution information of the flexible clamping finger along its extension direction according to the pressure information of each of the flexible pressure sensors; A classification module is used to determine the size category of the spherical fruits and vegetables according to the pressure distribution information.

[0014] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for size classification of spherical fruits and vegetables based on a flexible mechanical claw as described in any one of the above is implemented.

[0015] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the size classification method of spherical fruits and vegetables based on a flexible mechanical claw as described in any one of the above is implemented.

[0016] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the method for size classification of spherical fruits and vegetables based on a flexible mechanical claw as described above is implemented.

[0017] The method and device for classifying spherical fruits and vegetables based on a flexible mechanical claw provided by the present invention control the flexible mechanical claw to clamp the spherical fruits and vegetables when it is determined that the spherical fruits and vegetables are located at a set position in the clamping interval of the flexible mechanical claw, and obtain pressure information collected by corresponding flexible pressure sensors on the flexible clamping fingers; since the flexible clamping fingers are provided with a plurality of flexible pressure sensors arranged along the extension direction thereof, when the diameters of the spherical fruits and vegetables are different, the number and pressure of the flexible pressure sensors on the same flexible clamping fingers in contact with the spherical fruits and vegetables of different diameters are different, so that the pressure distribution information of the flexible clamping fingers along the extension direction thereof can be determined according to the pressure information of each flexible pressure sensor on the same flexible clamping finger; and then the size category of the spherical fruits and vegetables clamped by the flexible mechanical claw is determined according to the pressure distribution information. This size classification method for spherical fruits and vegetables is realized based on the clamping of the flexible mechanical claw, and the influence of environmental shielding on the detection result is reduced as much as possible during the detection process, and the method has good versatility and can be applied to the classification of spherical fruits and vegetables in various complex environments.

[0018] As can be seen from the above, the present invention is generally applicable to non-destructive classification of the size categories of spherical fruits and vegetables of various specifications. It is not only convenient to operate and efficient, but also ensures the accuracy of the classification of spherical fruits and vegetables, and reduces the influence of the surrounding environment on the accuracy of the standardized classification of spherical fruits and vegetables. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a schematic structural diagram of the flexible mechanical claw provided by the present invention.

[0021] Figure 2 It is a schematic structural diagram of the flexible clamping finger provided by the present invention.

[0022] Figure 3 It is a schematic diagram of the exploded structure of the flexible pressure sensor provided by the present invention.

[0023] Figure 4 It is a structural schematic diagram of a method for classifying spherical fruits and vegetables by size based on a flexible mechanical claw provided by the present invention.

[0024] Figure 5 It is a schematic structural diagram of a device for classifying spherical fruits and vegetables based on flexible mechanical claws provided by the present invention.

[0025] Figure 6 It is a structural schematic diagram of the electronic device provided by the present invention.

[0026] Reference numerals: 1. Flexible mechanical claw; 11. Driving member; 111. Base; 1110. Opening; 112. Link assembly; 1121. First link; 1122. Second link; 12. Flexible clamping finger; 121. Clamping finger body; 122. Flexible pad; 13. Flexible pressure sensor; 131. First shell; 132. Second shell; 133. Pressure sensitive element; 134. Wire. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Combine the following Figure 1-Figure 6 The method and device for classifying the size of spherical fruits and vegetables based on flexible mechanical claws provided in the embodiments of the invention are described in detail through specific embodiments and application scenarios.

[0029] In some embodiments, Figure 1 As shown, an embodiment of the present invention provides a flexible mechanical claw 1, which is applied to a picking machine. For example, the picking machine is connected to the flexible mechanical claw 1 through a mechanical arm. The flexible mechanical claw 1 includes: a driving member 11 and a plurality of flexible clamping fingers 12. The driving member 11 is connected to the plurality of flexible clamping fingers 12 to drive the plurality of flexible clamping fingers 12 to move closer to or separate from each other. A plurality of flexible pressure sensors 13 are provided on the clamping surface of at least one flexible clamping finger 12, and the plurality of flexible pressure sensors 13 are arranged in sequence along the extension direction of the flexible clamping finger 12.

[0030] It is understandable that all or part of the flexible clamping fingers 12 are made of a material with a certain elasticity, for example, the flexible clamping fingers 12 are made of plastic material, or part of the flexible clamping fingers 12 are made of plastic material and the other part is made of silicone material. This design can prevent the flexible clamping fingers 12 from causing clamping damage to spherical fruits and vegetables.

[0031] The multiple flexible clamping fingers 12 are evenly arranged along the circumferential direction, and the driving member 11 can control the multiple flexible clamping fingers 12 to switch between a first state and a second state. In the first state, the multiple flexible clamping fingers 12 are close to each other, and the clamping interval formed between the multiple flexible clamping fingers 12 becomes smaller to achieve clamping of spherical fruits and vegetables. In the second state, the multiple flexible clamping fingers 12 are separated from each other, and the clamping interval formed between the multiple flexible clamping fingers 12 becomes larger to achieve separation from the spherical fruits and vegetables.

[0032] For example, Figure 1 As shown, the flexible clamping finger 12 is generally in a strip shape, and the clamping surface of the flexible clamping finger 12 is a plane and extends along the length direction of the flexible clamping finger 12 .

[0033] For example, Figure 1 As shown, the flexible mechanical gripper 1 is provided with four flexible clamping fingers 12 , two of the four flexible clamping fingers 12 are arranged opposite to each other, and the other two are also arranged opposite to each other.

[0034] Among them, a plurality of flexible pressure sensors 13 are provided on the clamping surfaces of two of the four flexible clamping fingers 12 that are arranged opposite to each other, and the plurality of flexible pressure sensors 13 on each flexible clamping finger 12 are arranged in sequence along the extension direction of the flexible clamping finger 12 .

[0035] In some embodiments, Figure 2 and Figure 3As shown, the flexible pressure sensor 13 includes a first shell 131, a second shell 132, a pressure-sensitive element 133 and a wire 134. The first shell 131 and the second shell 132 are both in sheet form and are configured as a stacked arrangement. The first shell 131 and the second shell 132 can be made of flexible materials. The pressure-sensitive element 133 is sandwiched between the first shell 131 and the second shell 132. The pressure-sensitive element 133 includes a strain gauge and a bridge circuit. The strain gauge and the bridge circuit are electrically connected, and the bridge circuit and the wire 134 are electrically connected. The strain gauge is made of metal foil or semiconductor material, and the bridge circuit adopts a Wheatstone bridge.

[0036] Among them, each flexible pressure sensor 13 has two signal feedback ports, and the two signal feedback ports corresponding to each flexible pressure sensor 13 are connected to the signal acquisition module on the circuit board through two corresponding wires 134. The signal acquisition module is connected to the control module, and the control module processes the pressure information fed back by each flexible pressure sensor 13.

[0037] The first shell 131 is connected to the clamping surface of the flexible clamping finger 12, and the second shell 132 is configured to bear the pressure from the spherical fruits and vegetables. In practical applications, according to the different spherical fruits and vegetables grasped by the flexible mechanical claw 1, the deformation produced by the strain gauge is different, which makes the strain gauge produce different resistance values, and the current obtains different voltage signals after passing through the bridge circuit. According to the different distribution positions of each flexible pressure sensor 13 on the flexible clamping finger 12, the size of the spherical fruits and vegetables grasped by the flexible mechanical claw 1 can be obtained, thereby realizing the size classification of the spherical fruits and vegetables.

[0038] In some embodiments, Figure 1 and Figure 2 As shown, the driving member 11 includes a base 111, a linear driving portion and a plurality of connecting rod assemblies 112; A plurality of flexible clamping fingers 12 are circumferentially arranged at a first end of the base 111, and each flexible clamping finger 12 is rotatably connected to the base 111; a linear drive unit is arranged at the base 111, and is connected to the first ends of a plurality of connecting rod assemblies 112, and the second ends of the plurality of connecting rod assemblies 112 are rotatably connected to the plurality of flexible clamping fingers 12 in a one-to-one correspondence; The linear drive unit is used to drive the first ends of the multiple sets of connecting rod assemblies 112 to move along the central axis of the base 111, and then the multiple sets of connecting rod assemblies 112 drive the multiple flexible clamping fingers 12 to rotate toward or away from the central axis at the same time.

[0039] It can be understood that the base 111 is a columnar structure, and the plurality of flexible fingers 12 are evenly distributed around the circumference relative to the central axis of the base 111. The linear drive unit may be a telescopic rod or a linear motor.

[0040] The linear drive unit has a drive end that can reciprocate along the central axis of the base 111, and the drive ends of the linear drive unit are respectively connected to the first ends of multiple sets of connecting rod assemblies 112. The multiple sets of connecting rod assemblies 112 are evenly distributed around the central axis of the base 111 and are arranged one by one with the multiple flexible clamping fingers 12.

[0041] In actual application, a first hinge hole and a second hinge hole are provided at one end of the flexible clamping finger 12 close to the base 111. The flexible clamping finger 12 is rotatably connected to the first end of the base 111 through a first hinge shaft passing through the first hinge hole, and the flexible clamping finger 12 is rotatably connected to the second end of the connecting rod assembly 112 through a second hinge shaft passing through the second hinge hole.

[0042] In some embodiments, Figure 1 As shown, the connecting rod assembly 112 includes a first connecting rod 1121 and a second connecting rod 1122; the base 111 has a receiving cavity and a plurality of openings 1110 communicating with the receiving cavity, the linear driving part is arranged in the receiving cavity, and the plurality of openings 1110 are arranged in sequence along the circumference of the base 111; The output end of the linear drive unit is connected to the first end of the first connecting rod 1121, and the first connecting rod 1121 corresponding to each set of connecting rod assemblies 112 is inserted into each opening 1110 one by one. The second end of the first connecting rod 1121 is rotatably connected to the first end of the second connecting rod 1122, and the second end of the second connecting rod 1122 is rotatably connected to the flexible clamping finger 12.

[0043] In some embodiments, Figure 2 As shown, the flexible clamping finger 12 includes a clamping finger body 121 and a flexible pad 122; the clamping finger body 121 includes a first side, a second side and a third side connected in sequence to form a triangular structure, the first side is located on the side facing the central axis of the base 111, and the second side is located on the side away from the central axis of the base 111; the flexible pad 122 is arranged on the first side, and a plurality of flexible pressure sensors 13 are arranged on the surface of the flexible pad 122 in sequence along the extension direction of the first side, and the third side is rotatably connected to the first end of the base 111 and the second end of the connecting rod assembly 112 respectively.

[0044] It is understandable that the clamping finger body 121 can be made of plastic material, the lengths of the first side and the second side corresponding to the clamping finger body 121 are equal, and both are greater than the length of the third side, and multiple beams can be set between the first side and the second side corresponding to the clamping finger body 121 to increase the structural rigidity of the clamping finger body 121 to a certain extent.

[0045] Meanwhile, the flexible pad 122 may be a rubber pad or a silicone pad to achieve flexible contact with spherical fruits and vegetables.

[0046] In some embodiments, Figure 4 As shown, an embodiment of the present invention provides a method for classifying the size of spherical fruits and vegetables based on a flexible mechanical claw. The execution subject of the method can be a control module on a server or a picking machine. The method includes the following steps: Step 410, determining that the spherical fruit and vegetable is located at a set position in the clamping interval of the flexible mechanical claw.

[0047] In practical applications, visual detection can be used to determine whether the spherical fruits and vegetables are located at the set position of the clamping interval. Only when the spherical fruits and vegetables are located at the set position of the clamping interval are the flexible mechanical claws used to clamp the spherical fruits and vegetables, thereby avoiding the accuracy of the detection results being affected by the different distribution positions of the spherical fruits and vegetables relative to the flexible mechanical claws.

[0048] Among them, spherical fruits and vegetables can be apples, oranges, tangerines, kiwis, etc.

[0049] Step 420, controlling the flexible mechanical claw to clamp the spherical fruits and vegetables, and obtaining pressure information collected by the corresponding flexible pressure sensors on the flexible gripping fingers.

[0050] It can be understood that when the flexible mechanical claw is performing clamping work, the strain gauge corresponding to the flexible pressure sensor is deformed and generates a voltage signal. Through the analysis of the voltage waveform signal, it can be known that the flexible mechanical claw is performing a picking operation at this time.

[0051] In practical applications, it should be ensured that the flexible robotic claw maintains consistent gripping force on different spherical fruits and vegetables to ensure the validity of the pressure information collected by each flexible pressure sensor.

[0052] Step 430: Determine the pressure distribution information of the flexible clamping finger along its extension direction according to the pressure information of each flexible pressure sensor.

[0053] It is understandable that, since the force is mutual, the pressure exerted on the flexible clamp finger at the location of the flexible pressure sensor can be detected by the flexible pressure sensor. Since the plurality of flexible pressure sensors are arranged in sequence along the extension direction of the flexible clamp finger, the pressure distribution information of the flexible clamp finger along the extension direction thereof can be determined based on the pressure information of each flexible pressure sensor.

[0054] When the clamping force applied by the flexible mechanical claw to different spherical fruits and vegetables is roughly the same, for spherical fruits and vegetables with smaller diameters, the flexible pressure sensors near the middle of the flexible clamping fingers are subjected to greater pressure, while the flexible pressure sensors at other positions are subjected to relatively smaller pressure, especially the flexible pressure sensors near the top of the flexible clamping fingers may not be subjected to pressure, so that the sensors do not generate voltage signals.

[0055] However, for spherical fruits and vegetables with larger diameters, when the flexible mechanical claw maintains the same clamping force, the flexible pressure sensors at various positions of the flexible clamping fingers can all be subjected to pressure, and the pressure feedback from each flexible pressure sensor is more uniform in comparison. However, the flexible pressure sensor near the middle of the flexible clamping fingers is still subjected to the greatest pressure. However, the pressure detected by the flexible pressure sensors at other positions is significantly improved compared with the pressure received by the flexible pressure sensors with smaller fruit diameters.

[0056] It can be seen that for the same type of spherical fruits and vegetables, the pressure information fed back by each flexible pressure sensor on the same flexible clamp finger is different; for spherical fruits and vegetables with different diameters, the pressure information fed back by each flexible pressure sensor on the same flexible clamp finger also has significant differences. However, according to the increase or decrease in the diameter of the spherical fruits and vegetables, the pressure information fed back by each flexible pressure sensor on the same flexible clamp finger shows regular changes. Therefore, by determining the pressure distribution information of the flexible clamp finger along its extension direction, it is helpful to judge the size category of the spherical fruits and vegetables.

[0057] Step 440: Determine the size category of the spherical fruits and vegetables based on the pressure distribution information.

[0058] It can be understood that the pressure distribution information can not only characterize the pressure information of each position of the clamping surface of the flexible clamping fingers along the extension direction of the flexible clamping fingers, but also characterize the pressure change gradient of the clamping surface of the flexible clamping fingers along the extension direction of the flexible clamping fingers. Since the pressure distribution information of the flexible clamping fingers along the extension direction is available for spherical fruits and vegetables of different diameters, the spherical fruits and vegetables can be classified by size according to the pressure distribution information on the flexible clamping fingers.

[0059] For the size classification method shown in the embodiment of the present invention, when it is determined that the spherical fruits and vegetables are located at the set position of the clamping interval of the flexible mechanical claw, the flexible mechanical claw is controlled to clamp the spherical fruits and vegetables, and the pressure information collected by the corresponding flexible pressure sensors on the flexible clamping fingers is obtained; because the flexible clamping fingers are provided with a plurality of flexible pressure sensors arranged along the extension direction thereof, when the diameters of the spherical fruits and vegetables are different, the number and pressure of the flexible pressure sensors on the same flexible clamping fingers in contact with the spherical fruits and vegetables of different diameters are different, so that the pressure distribution information of the flexible clamping fingers along the extension direction thereof can be determined according to the pressure information of each flexible pressure sensor on the same flexible clamping finger; and then the size category of the spherical fruits and vegetables clamped by the flexible mechanical claw is determined according to the pressure distribution information. This size classification method for spherical fruits and vegetables is realized based on the clamping of the flexible mechanical claw, and the influence of environmental occlusion on the detection result is reduced as much as possible during the detection process. It has good versatility and can be applied to the classification of spherical fruits and vegetables in various complex environments.

[0060] As can be seen from the above, the present invention is generally applicable to non-destructive classification of the size categories of spherical fruits and vegetables of various specifications. It is not only convenient to operate and efficient, but also ensures the accuracy of the classification of spherical fruits and vegetables, and reduces the influence of the surrounding environment on the accuracy of the standardized classification of spherical fruits and vegetables.

[0061] In some embodiments, before determining that the spherical fruit or vegetable is located at a set position in the clamping interval of the flexible mechanical claw as shown in this embodiment, the steps include but are not limited to the following: Acquire image information of the flexible mechanical claw; Determine the position information of the spherical fruits and vegetables according to the image information; According to the position information, the clamping posture of the flexible mechanical claw relative to the spherical fruits and vegetables is controlled to change, so as to ensure that the flexible mechanical claw clamps the surrounding wall of the spherical fruits and vegetables.

[0062] It is understandable that spherical fruits and vegetables are distributed at different positions on the tree. If the flexible mechanical claw selects an inappropriate clamping posture, the flexible mechanical claw may clamp at the bottom or the stalk end of the spherical fruits and vegetables. Considering that the bottom or the stalk end of the spherical fruits and vegetables have uneven shapes and depressions, it is bound to cause the data detected by each flexible pressure sensor on the flexible clamping finger to be not true and valid, thereby affecting the accuracy of the detection results.

[0063] In practical applications, the camera module on the picking robot can be used to obtain image information of the flexible mechanical claw. After the image information is transmitted to the control module of the picking robot, the control module uses an image processing algorithm known in the art to process the image information to obtain position information such as the spatial coordinates of spherical fruits and vegetables. Then, the control module controls the mechanical arm connected to the flexible mechanical claw to adjust its posture, change the clamping posture of the flexible mechanical claw relative to the spherical fruits and vegetables, and ensure that the flexible mechanical claw can clamp the surrounding walls of the spherical fruits and vegetables.

[0064] In some embodiments, in order to avoid the accuracy of the detection result being affected by the different clamping positions of the flexible mechanical claws for different spherical fruits and vegetables, the setting position of determining the spherical fruits and vegetables in the clamping interval of the flexible mechanical claws shown in this embodiment includes but is not limited to the following steps: It is determined that the spherical fruits and vegetables are located in the clamping area formed by the multiple flexible clamping fingers, and the bottom end of the spherical fruits and vegetables is in contact with the first end of the base; wherein the bottom end of the spherical fruits and vegetables is arranged opposite to the fruit handle end of the spherical fruits and vegetables.

[0065] In some embodiments, in order to ensure that the flexible mechanical claw maintains a consistent gripping force on spherical fruits and vegetables of different diameters, the control of the flexible mechanical claw to grip the spherical fruits and vegetables shown in this embodiment includes but is not limited to the following steps: During the inspection of different spherical fruits and vegetables, the linear drive unit is controlled to drive the first ends of the multiple sets of connecting rod assemblies to move a set distance, so that the multiple flexible clamping fingers simultaneously rotate toward the side close to the central axis at a set angle.

[0066] In some embodiments, the method of determining the size category of spherical fruits and vegetables according to the pressure distribution information shown in this embodiment includes but is not limited to the following steps: Compare the pressure distribution information with the information in the database, and determine the size category of the spherical fruits and vegetables based on the comparison results; Among them, the database represents the matching relationship between the diameter and pressure distribution information of spherical fruits and vegetables of different sizes.

[0067] It can be understood that before spherical fruits and vegetables are classified by size, the flexible mechanical claw is controlled to clamp spheres of different diameters. This simulation test method is used to obtain the database shown in this embodiment based on the diameter of the sphere and the pressure distribution information obtained when the sphere is clamped.

[0068] In practical applications, the solution shown in this embodiment is specifically described by taking apple as an example. It should be pointed out that the spherical fruits and vegetables shown in this embodiment should not be limited to apples.

[0069] When apples are classified by diameter (i.e., the diameter of the apple), the usual classification standard is mainly based on the size of the apple's diameter, and is graded according to a certain size range. Generally speaking, the diameter of apples can be classified into the following categories: large fruit: usually refers to apples with a diameter of more than 80 mm, medium fruit: the diameter is approximately between 70 mm and 80 mm, small fruit: the diameter is usually between 60 mm and 70 mm, or smaller. First, the three types of apples are simulated for picking within a range according to this classification standard. However, considering the different diameters of apples, some voltage signals near the interval need to be considered during simulated picking, that is, the voltage signals near the interval allow the existence of picking errors. According to the voltage signals obtained from the simulated picking, a relatively complete apple picking voltage signal system is formed in this interval. According to the voltage signals obtained from the simulation, during actual picking, the voltage signals obtained from the actual picking are compared with the voltage signals obtained from the simulation. After the comparison is completed, the apples that generate similar voltage signals are grouped together to complete the classification work.

[0070] The following is a description of the size classification device for spherical fruits and vegetables based on a flexible mechanical claw provided by the present invention. The size classification device for spherical fruits and vegetables based on a flexible mechanical claw described below and the size classification method for spherical fruits and vegetables based on a flexible mechanical claw described above can correspond to each other.

[0071] In some embodiments, Figure 5As shown, an embodiment of the present invention further provides a size classification device for spherical fruits and vegetables based on a flexible mechanical claw, comprising the following modules: A determination module 510 is used to determine the set position of the spherical fruit and vegetable in the clamping interval of the flexible mechanical claw; The acquisition module 520 is used to control the flexible mechanical claw to clamp the spherical fruits and vegetables, and obtain the pressure information collected by each flexible pressure sensor corresponding to the flexible clamping finger; A calculation module 530, for determining pressure distribution information of the flexible clamping finger along its extension direction according to pressure information of each flexible pressure sensor; The classification module 540 is used to determine the size category of the spherical fruits and vegetables according to the pressure distribution information.

[0072] Since the size classification device described in the embodiment of the present invention includes all the technical solutions of the size classification method shown in the above embodiment, it at least has all the beneficial effects achieved by all the technical solutions of the above embodiment, which will not be described one by one here.

[0073] Figure 6 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 6 As shown, the electronic device may include: a processor 610, a communications interface 620, a memory 630 and a communication bus 640, wherein the processor 610, the communications interface 620 and the memory 630 communicate with each other through the communication bus 640. The processor 610 may call the logic instructions in the memory 630 to execute the size classification method of spherical fruits and vegetables based on the flexible mechanical claw, and the method includes: Determine that the spherical fruit and vegetable is located at a set position in the clamping interval of the flexible mechanical claw; Controlling the flexible mechanical claw to clamp the spherical fruits and vegetables, and obtaining pressure information collected by each of the flexible pressure sensors corresponding to the flexible clamping fingers; Determining pressure distribution information of the flexible clamping finger along its extension direction according to pressure information of each of the flexible pressure sensors; The size category of the spherical fruits and vegetables is determined according to the pressure distribution information.

[0074] In addition, the logic instructions in the above-mentioned memory 630 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0075] On the other hand, an embodiment of the present invention further provides a computer program product, the computer program product includes a computer program, the computer program can be stored in a non-transitory computer-readable storage medium, when the computer program is executed by a processor, the computer can execute the size classification method of spherical fruits and vegetables based on flexible mechanical claws provided by the above methods, the method includes: Determine that the spherical fruit and vegetable is located at a set position in the clamping interval of the flexible mechanical claw; Controlling the flexible mechanical claw to clamp the spherical fruits and vegetables, and obtaining pressure information collected by each of the flexible pressure sensors corresponding to the flexible clamping fingers; Determining pressure distribution information of the flexible clamping finger along its extension direction according to pressure information of each of the flexible pressure sensors; The size category of the spherical fruits and vegetables is determined according to the pressure distribution information.

[0076] In another aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for classifying the size of spherical fruits and vegetables based on a flexible mechanical claw provided by the above methods is implemented, and the method includes: Determine that the spherical fruit and vegetable is located at a set position in the clamping interval of the flexible mechanical claw; Controlling the flexible mechanical claw to clamp the spherical fruits and vegetables, and obtaining pressure information collected by each of the flexible pressure sensors corresponding to the flexible clamping fingers; Determining pressure distribution information of the flexible clamping finger along its extension direction according to pressure information of each of the flexible pressure sensors; The size category of the spherical fruits and vegetables is determined according to the pressure distribution information.

[0077] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0078] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for classifying spherical fruits and vegetables by size based on a flexible mechanical claw, characterized in that: The flexible mechanical claw comprises a driving member and a plurality of flexible clamping fingers, wherein the driving member is connected to the plurality of flexible clamping fingers to drive the plurality of flexible clamping fingers to move closer to each other or separate from each other, and a plurality of flexible pressure sensors are provided on a clamping surface of at least one of the flexible clamping fingers, and the plurality of flexible pressure sensors are sequentially arranged along an extension direction of the flexible clamping fingers; the method comprises: Determine that the spherical fruit and vegetable is located at a set position in the clamping interval of the flexible mechanical claw; Controlling the flexible mechanical claw to clamp the spherical fruits and vegetables, and obtaining pressure information collected by each of the flexible pressure sensors corresponding to the flexible clamping fingers; Determining pressure distribution information of the flexible clamping finger along its extension direction according to pressure information of each of the flexible pressure sensors; The size category of the spherical fruits and vegetables is determined according to the pressure distribution information.

2. The method for classifying spherical fruits and vegetables by size based on flexible mechanical claws according to claim 1, characterized in that: Before determining that the spherical fruit and vegetable is located at the set position of the clamping interval of the flexible mechanical claw, the method further includes: Acquiring image information of the flexible mechanical claw; Determining the position information of the spherical fruits and vegetables according to the image information; According to the position information, the clamping posture of the flexible mechanical claw relative to the spherical fruits and vegetables is controlled to change, so as to ensure that the flexible mechanical claw clamps the peripheral wall of the spherical fruits and vegetables.

3. The method for classifying spherical fruits and vegetables by size based on flexible mechanical claws according to claim 1, characterized in that: The driving member includes a base, a linear driving part and a plurality of connecting rod assemblies; A plurality of the flexible clamping fingers are circumferentially arranged at the first end of the base, and each of the flexible clamping fingers is rotatably connected to the base; The linear drive unit is disposed on the base and connected to the first ends of the plurality of connecting rod assemblies, and the second ends of the plurality of connecting rod assemblies are rotatably connected to the plurality of flexible clamping fingers in a one-to-one correspondence; The linear drive unit is used to drive the first ends of the multiple sets of connecting rod assemblies to move along the central axis of the base, and then the multiple sets of connecting rod assemblies drive the multiple flexible clamping fingers to rotate toward or away from the central axis at the same time.

4. The method for classifying spherical fruits and vegetables by size based on flexible mechanical claws according to claim 3, characterized in that: The connecting rod assembly includes a first connecting rod and a second connecting rod; The base has a receiving cavity and a plurality of openings communicating with the receiving cavity, the linear drive unit is arranged in the receiving cavity, and the plurality of openings are arranged in sequence along the circumference of the base; The output end of the linear drive unit is connected to the first end of the first connecting rod, and the first connecting rods corresponding to each set of the connecting rod assemblies are inserted into each of the openings one by one, the second end of the first connecting rod is rotatably connected to the first end of the second connecting rod, and the second end of the second connecting rod is rotatably connected to the flexible clamping finger.

5. The method for classifying spherical fruits and vegetables by size based on flexible mechanical claws according to claim 3, characterized in that: The flexible clamping finger comprises a clamping finger body and a flexible pad; The clamping finger body comprises a first side, a second side and a third side connected in sequence to form a triangular structure, the first side is located on a side facing the central axis of the base, and the second side is located on a side away from the central axis of the base; The flexible pad is arranged on the first side, and a plurality of the flexible pressure sensors are arranged on the surface of the flexible pad in sequence and at intervals along the extension direction of the first side. The third side is rotatably connected to the first end of the base and the second end of the connecting rod assembly respectively.

6. The method for classifying spherical fruits and vegetables by size based on flexible mechanical claws according to claim 3, characterized in that: The step of determining the set position of the spherical fruit and vegetable in the clamping interval of the flexible mechanical claw includes: Determining that the spherical fruit and vegetable is located in a clamping interval formed by the plurality of flexible clamping fingers, and the bottom end of the spherical fruit and vegetable is in contact with the first end of the base; Wherein, the bottom end of the spherical fruit and vegetable is arranged opposite to the fruit handle end of the spherical fruit and vegetable.

7. The method for classifying spherical fruits and vegetables by size based on flexible mechanical claws according to claim 3, characterized in that: The step of controlling the flexible mechanical claw to clamp the spherical fruits and vegetables comprises: During the detection of different spherical fruits and vegetables, the linear drive unit is controlled to drive the first ends of multiple sets of connecting rod assemblies to move a set distance, so that multiple flexible clamping fingers are simultaneously rotated toward a side close to the central axis by a set angle.

8. The method for classifying spherical fruits and vegetables by size based on a flexible mechanical claw according to any one of claims 1 to 7, characterized in that: The step of determining the size category of the spherical fruits and vegetables according to the pressure distribution information comprises: Comparing the pressure distribution information with the information in the database, and determining the size category of the spherical fruits and vegetables according to the comparison result; The database represents the matching relationship between the diameter and pressure distribution information of spherical fruits and vegetables of different sizes.

9. A device for classifying spherical fruits and vegetables based on flexible mechanical claws, characterized in that: The flexible mechanical claw comprises a driving member and a plurality of flexible clamping fingers, wherein the driving member is connected to the plurality of flexible clamping fingers to drive the plurality of flexible clamping fingers to move closer to each other or separate from each other, and a plurality of flexible pressure sensors are arranged on a clamping surface of at least one of the flexible clamping fingers, and the plurality of flexible pressure sensors are arranged in sequence along the extension direction of the flexible clamping fingers; the device comprises: A determination module, used to determine the set position of the spherical fruit and vegetable in the clamping interval of the flexible mechanical claw; An acquisition module, used to control the flexible mechanical claw to clamp the spherical fruits and vegetables, and to acquire pressure information collected by each of the flexible pressure sensors corresponding to the flexible clamping fingers; A calculation module, used to determine the pressure distribution information of the flexible clamping finger along its extension direction according to the pressure information of each of the flexible pressure sensors; A classification module is used to determine the size category of the spherical fruits and vegetables according to the pressure distribution information.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for classifying the size of spherical fruits and vegetables based on a flexible mechanical claw as described in any one of claims 1 to 8 is implemented.

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