End effector for crop harvesting, and crop harvesting system

Abstract

To provide an end effector for crop harvesting adaptable to the thickness and the length of various peduncles.SOLUTION: An end effector 1 for crop harvesting is configured to harvest a harvest target 90 that fruits on a main stem 92 or a branch. The end effector 1 for crop harvesting includes: a base member 11 attached to a fingertip of a robot arm 64; an upper claw member 13 touchable with a surface of a peduncle 91 side in the harvest target; a lower claw member 14 configured to be movable in a leaving direction and an approaching direction with respect to the upper claw member, and capable of gripping the harvest target, in a manner of coming into contact with a surface of a side opposite to the peduncle, of the harvest target at a position having approached to the upper claw member side to sandwich with the upper claw member; and a pressing member 15 configured to be movable in a leaving direction and an approaching direction with respect to the base member, and when moving in the leaving direction from the base member, pressed against the peduncle.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Embodiments of the present invention relate to a crop harvesting end effector and crop harvesting system for harvesting crops bearing fruit on main stems or branches. [Background technology]

[0002] In recent years, in order to realize the automation of agricultural work, end effectors and crop harvesting systems for automatic harvesting of agricultural products have been proposed. For example, a configuration has been considered in which an end effector with a scissors-shaped blade is attached to the tip of a robot arm, and the end effector is used to cut the fruit stalk, separating the fruit from the main stem or branches and harvesting it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-37214 Summary of the Invention [Problem to be solved by the invention]

[0004] When cutting fruit stalks with a blade such as scissors, it is easy to cut them if they are thin and long. However, if the fruit stalk is thick, cutting with scissors requires a lot of force, increasing the possibility of failure. Furthermore, if the fruit stalk is short, there is little space to insert the scissors, so there is a risk that the scissors will damage the harvested fruit and reduce its market value. Thus, when harvesting with an end effector equipped with scissors, it is difficult to handle individuals and varieties with different thicknesses and lengths of fruit stalks.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a crop harvesting end effector and a crop harvesting system that can accommodate various thicknesses and lengths of fruit stalks. [Means for solving the problem]

[0006] The crop harvesting end effector 1 according to the present disclosure is an end effector 1 for harvesting crops 90 that have fruit on a main stem 92 or branches, and comprises a base member 11 attached to the end of the robot arm 64, an upper claw member 13 that can contact the surface of the harvest object on the side of the stalk 91, a lower claw member 14 that is configured to be movable in directions away from and towards the upper claw member, and that can contact the surface of the harvest object opposite the stalk when close to the upper claw member, thereby clamping and grasping the harvest object between the upper claw member and the lower claw member, and a pressing member 15 that is configured to be movable in directions away from and towards the base member, and that is pressed against the stalk when moved away from the base member.

[0007] A crop harvesting system 50 according to the present disclosure includes the crop harvesting end effector 1, a robot arm 64 to which the crop harvesting end effector is attached, and a control device 70 that controls the operation of the crop harvesting end effector and the robot arm. The control device can execute the following steps: an approaching step of operating the robot arm to move the crop harvesting end effector to a position where the upper and lower jaw members are separated from each other and the harvested object is placed between the upper and lower jaw members; a gripping step of moving the lower jaw members toward the upper jaw members to sandwich and grip the harvested object between the upper and lower jaw members; and a plucking step of moving the pressing member away from the base member while holding the harvested object and pressing it against the stalk of the harvested object, and operating the robot arm to tilt the crop harvesting end effector. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a rear perspective view of an example of an end effector for harvesting agricultural produce, in accordance with one embodiment; [Figure 2] FIG. 1 is a front perspective view of an example of an end effector for harvesting agricultural produce, in accordance with one embodiment; [Figure 3] FIG. 1 is a right side view showing the configuration of a lower jaw drive mechanism and its surroundings in an example of an end effector for harvesting agricultural products according to an embodiment. [Figure 4] FIG. 4 is a right side view showing the configuration of the lower jaw drive mechanism and its surroundings in an example of an end effector for harvesting agricultural products according to an embodiment, in which the third lower jaw link in FIG. 3 is shown in imaginary lines. [Figure 5] FIG. 4 is a right side view showing the configuration of the lower jaw drive mechanism and its surroundings in an example of an end effector for harvesting agricultural products according to an embodiment, in which the third lower jaw link and the fourth lower jaw link in FIG. 3 are shown in imaginary lines. [Figure 6] FIG. 4 is a right side view showing the configuration of the lower jaw drive mechanism and its surroundings in an example of an end effector for harvesting agricultural products according to an embodiment, showing a state in which the lower jaw drive wire has been retracted from the state shown in FIG. [Figure 7] FIG. 7 is a right side view showing the configuration of the lower jaw drive mechanism and its surroundings in an example of an end effector for harvesting agricultural products according to an embodiment, in which the lower jaw drive wire is further retracted from the state shown in FIG. [Figure 8] FIG. 1 is a left side view showing the configuration of the pressing drive mechanism and its surroundings in an example of an end effector for harvesting agricultural products according to an embodiment. [Figure 9] FIG. 1 is a left side view showing a configuration around a pressing drive mechanism of an example of an end effector for harvesting agricultural products according to an embodiment, in which a second push-out link is shown in imaginary lines. [Figure 10] 1A is a plan view showing an example of an end effector for harvesting agricultural products according to one embodiment, in which (A) is a plan view showing a state before a pusher member advances, and (B) is a plan view showing (A) without a scissors member. [Figure 11] 9 is a left side view showing the configuration of the pressing drive mechanism and its surroundings in an example of an end effector for harvesting agricultural products according to one embodiment, showing a state in which the extrusion drive wire is retracted from the state shown in FIG. 8. [Figure 12] 12A shows an example of an end effector for harvesting agricultural produce according to one embodiment, in which (A) is a plan view of FIG. 11, and (B) is a plan view showing (A) without a scissors member. [Figure 13]12 is a left side view showing the configuration of the pressing drive mechanism and its surroundings in an example of an end effector for harvesting agricultural products according to one embodiment, showing a state in which the extrusion drive wire is further retracted from the state shown in FIG. 11. [Figure 14] 14 is a left side view showing the configuration of the pressing drive mechanism and its surroundings in an example of an end effector for harvesting agricultural products according to an embodiment, in which the extrusion drive wire is further retracted from the state shown in FIG. 13. [Figure 15] 15A is a plan view of FIG. 14 showing an example of an end effector for harvesting agricultural produce according to one embodiment, and FIG. 15B is a plan view showing the end effector from FIG. 14 with the scissors member removed. [Figure 16] 16A is a plan view showing an example of an end effector for harvesting agricultural products according to one embodiment, in which (A) is a plan view showing a state in which the scissors members are closed from the state shown in FIG. 15, and (B) is a plan view showing (A) with the scissors members removed. [Figure 17] FIG. 1 is a diagram illustrating an example of the configuration of a crop harvesting system according to an embodiment. [Figure 18] FIG. 1 shows an example of a separation layer of a harvested object. [Figure 19] A flowchart showing an example of the control content of harvesting work executed in a crop harvesting system according to one embodiment. [Figure 20] FIG. 10 is a diagram illustrating a state immediately before a tilting operation is performed in a crop harvesting system according to an embodiment. [Figure 21] FIG. 10 illustrates a state immediately after a tilting operation is performed in a crop harvesting system according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a crop harvesting end effector and a crop harvesting system according to several embodiments will be described with reference to the drawings.

[0010] <Configuration of end effector for harvesting crops> First, the configuration of a crop harvesting end effector 1 will be described mainly with reference to Figures 1 to 16. The crop harvesting end effector 1 of this embodiment (hereinafter referred to as end effector 1) can harvest fruit vegetables that grow drooping from the main stem, such as tomatoes and eggplants, and fruit trees that grow drooping from the branches of trees, such as apples and pears. In this embodiment, the harvested fruit is assumed to be, for example, a medium-sized or large tomato with a diameter of approximately 80 mm to 120 mm, but the harvested fruit of the end effector 1 is not limited to this.

[0011] The end effector 1 has a base member 11, side members 12, upper claw members 13, lower claw members 14, and a pressing member 15. In this embodiment, the side of the end effector 1 facing the object to be harvested 90 is referred to as the front side or tip side of the end effector 1, and the side opposite the object to be harvested 90 is referred to as the rear side or base side of the end effector 1. The direction in which the upper claw members 13 and the lower claw members 14 are arranged is referred to as the up-down direction of the end effector 1, and the direction perpendicular to the front-rear direction and the up-down direction is referred to as the left-right direction of the end effector 1.

[0012] The base member 11 and the side member 12 form a base to which the components of the end effector 1 are directly or indirectly attached. The base member 11 is made of, for example, a plate-shaped member and is provided on the rear side, i.e., the base end side, of the end effector 1. The base member 11 is a structure for attaching the end effector 1 to the tip of a robot arm. The side member 12 is made of, for example, a plate-shaped member and is provided on one side of the base member 11 in the left-right direction. The side member 12 is attached to the base member 11 so that the surface direction of the side member 12 is perpendicular to the base member 11.

[0013] The upper claw member 13 is configured to be able to come into contact with the upper surface of the harvest target 90, i.e., the surface on the stalk 91 side. The upper claw member 13 is provided on the side member 12 opposite the base member 11. The upper claw member 13 is configured to protrude forward from the tip of the side member 12. The upper claw member 13 is configured to be immovable relative to the base member 11 and the side member 12.

[0014] In this embodiment, the end effector 1 has two upper claw members 13. As shown in FIG. 10 , the two upper claw members 13 are arranged at a distance in the left-right direction of the end effector 1. The distance between the two upper claw members 13 is wider than the stalk 91 of the harvest target 90 and smaller than the outer diameter of the harvest target 90. The upper claw member 13 can be configured to have, for example, a contact portion 131. The contact portion 131 is a portion that comes into contact with the harvest target 90. The contact portion 131 can be configured, for example, from a rubber material with a Vickers hardness of approximately 40 to 60 so as not to damage the harvest target 90 when it comes into contact with the harvest target 90.

[0015] The lower claw member 14 is provided below the upper claw member 13. The lower claw member 14 is configured to be movable relative to the base member 11 and the side member 12. The lower claw member 14 is configured to be movable in directions away from and toward the upper claw member 13, i.e., in the up and down direction. By moving in a direction toward the upper claw member 13, the lower claw member 14 shortens the distance between itself and the upper claw member 13, closing the gap between the upper claw member 13 and the lower claw member 14. In addition, by moving in a direction away from the upper claw member 13, the lower claw member 14 increases the distance between itself and the upper claw member 13, opening the gap between the upper claw member 13 and the lower claw member 14.

[0016] The lower jaw members 14 come into contact with the surface of the harvest object 90 opposite the stalk 91, i.e., the bottom surface of the harvest object 90, at a position close to the upper jaw members 13. This allows the end effector 1 to grip the harvest object 90 by sandwiching it between the upper jaw members 13 and the lower jaw members 14, by moving the lower jaw members 14 toward the upper jaw members 13. The lower jaw members 14 can be made of a rubber material with a Vickers hardness of, for example, about 40 to 60, just like the contact portions 131 of the upper jaw members 13.

[0017] The pressing member 15 is configured to be movable in a direction away from and toward the base member 11. That is, the pressing member 15 is configured to be movable in the front-to-rear direction of the end effector 1. When the pressing member 15 moves in a direction away from the base member 11, it is pressed against the fruit stalk 91, as shown in FIG. 12 and other figures. The pressing member 15 has an opening 151 that opens toward the fruit stalk 91, i.e., forward, in a U- or V-shape. The pressing member 15 is configured so that the fruit stalk 91 can be positioned inside the opening 151. The pressing member 15 can be made of, for example, a resin that is harder than the contact portion 131.

[0018] 3 to 5, the end effector 1 is equipped with a lower claw drive mechanism 20 as a mechanism for moving the lower claw member 14. The lower claw drive mechanism 20 has a first lower claw link 21, a second lower claw link 22, a third lower claw link 23, a fourth lower claw link 24, a first lower claw spring 25, a second lower claw spring 26, a lower claw drive wire 27, and a lower claw sensor 28.

[0019] The first lower claw link 21 is attached to the side member 12 so as to be rotatable about the first lower claw shaft 201 as a fulcrum. The lower claw member 14 is provided at the tip end of the first lower claw link 21, i.e., at the end opposite the first lower claw shaft 201. The second lower claw link 22 connects the first lower claw link 21 and the third lower claw link 23.

[0020] The third lower claw link 23 is attached to the side member 12 so as to be rotatable around the second lower claw shaft 202 as a fulcrum. The first lower claw link 21 and the third lower claw link 23 are connected via the second lower claw link 22. The fourth lower claw link 24 is attached to the side member 12 so as to be rotatable around the second lower claw shaft 202 as a fulcrum. In other words, the third lower claw link 23 and the fourth lower claw link 24 are configured so as to be rotatable around the second lower claw shaft 202 as a fulcrum. In addition, the third lower claw link 23 and the fourth lower claw link 24 are connected to each other via a first lower claw spring 25. The first lower claw spring 25 is configured, for example, by a tension coil spring.

[0021] As shown in Fig. 5, one end of the second lower claw spring 26 is attached to the side member 12, and the other end is attached to the fourth lower claw link 24. The second lower claw spring 26 is formed, for example, by a tension coil spring, and pulls the fourth lower claw link 24 in a direction that rotates counterclockwise on the plane of the paper in Fig. 5. In other words, the second lower claw spring 26 applies a force to each of the lower claw links 21, 22, 23, 24 in a direction that opens the lower claw member 14, i.e., in a direction away from the upper claw member 13.

[0022] The lower jaw drive wire 27 has the function of moving the lower jaw member 14 by being pushed out and pulled in. The lower jaw drive wire 27 is preferably made of a material that is flexible enough to bend but not easily stretched. The lower jaw drive wire 27 has a tip connected to the fourth lower jaw link 24 and a base connected to a drive source such as a motor. By pulling the fourth lower jaw link 24, the lower jaw drive wire 27 applies a force that rotates the fourth lower jaw link 24 in the clockwise direction on the plane of the page in FIG. 5 with the second lower jaw shaft 202 as a fulcrum.

[0023] In this configuration, when the fourth lower claw link 24 is pulled by the lower claw drive wire 27, the fourth lower claw link 24 rotates clockwise on the page in Figure 4 around the second lower claw shaft 202. Then, as the fourth lower claw link 24 rotates, the first lower claw spring 25 pulls the third lower claw link 23, and in synchronization with the rotation of the fourth lower claw link 24, the third lower claw link 23 also rotates clockwise on the page around the second lower claw shaft 202.

[0024] When the first lower jaw link 21 is pulled by the second lower jaw link 22 in accordance with the rotation of the third lower jaw link 23, the first lower jaw link 21 rotates clockwise on the plane of the page in Fig. 4 around the first lower jaw shaft 201. As a result, the lower jaw member 14 moves in a direction approaching the upper jaw member 13, i.e., in a direction in which the upper jaw member 13 and the lower jaw member 14 close, as shown in Fig. 6. This allows the end effector 1 to grip the harvesting target 90 between the upper jaw member 13 and the lower jaw member 14.

[0025] Furthermore, when tension on the lower jaw drive wire 27 is released, the second lower jaw spring 26 shown in FIG. 5 causes the fourth lower jaw link 24 to rotate counterclockwise on the page of FIG. 5 around the second lower jaw shaft 202. The rotation of the fourth lower jaw link 24 is then transmitted to the first lower jaw link 21 via the third lower jaw link 23 and the second lower jaw link 22, causing the first lower jaw link 21 to rotate counterclockwise around the first lower jaw shaft 201. As a result, the lower jaw member 14 moves in a direction away from the upper jaw member 13, i.e., in a direction in which the upper jaw member 13 and the lower jaw member 14 open. This allows the end effector 1 to release its grip on the object to be harvested 90.

[0026] The lower jaw sensor 28 detects that the lower jaw member 14 has come into contact with the harvesting target 90 due to movement of the lower jaw member 14. The lower jaw sensor 28 can be configured with, for example, a photoelectric sensor. In this case, the lower jaw sensor 28 detects that the lower jaw member 14 has come into contact with the bottom of the harvesting target 90 based on, for example, the rotation of the fourth lower jaw link 24 by a predetermined angle relative to the third lower jaw link 23. In other words, the lower jaw sensor 28 detects that the third lower jaw link 23 does not rotate even when the fourth lower jaw link 24 is pulled by the lower jaw drive wire 27.

[0027] 4 and 5, the lower jaw sensor 28 is attached to the third lower jaw link 23 and rotates integrally with the third lower jaw link 23. Here, as shown in FIG. 6, the fourth lower jaw link 24 has a lower jaw cam groove 241, and the third lower jaw link 23 has a lower jaw connecting shaft 231.

[0028] The lower claw cam groove 241 is a hole formed through the fourth lower claw link 24 or a groove formed by digging, and is formed long and narrow along the circumference of a circle centered on the second lower claw shaft 202. The lower claw connecting shaft 231 is fixed to the third lower claw link 23 and inserted into the lower claw cam groove 241. The third lower claw link 23 and the fourth lower claw link 24 can move relatively within the range of the lower claw cam groove 241.

[0029] In this configuration, as shown in Figure 6, when the lower jaw member 14 comes into contact with the harvesting object 90, the movement of the lower jaw member 14 stops, and therefore the rotation of the first lower jaw link 21 and the third lower jaw link 23 also stops. If the lower jaw drive wire 27 is further retracted while the lower jaw member 14 is in contact with the harvesting object 90, the fourth lower jaw link 24 rotates relative to the third lower jaw link 23 until the lower jaw connecting shaft 231 comes into contact with the end of the lower jaw cam groove 241, as shown in Figures 6 and 7. Then, when the lower jaw connecting shaft 231 comes into contact with the end of the lower jaw cam groove 241, the third lower jaw link 23 again rotates integrally with the fourth lower jaw link 24 in synchronization with it.

[0030] The fourth lower jaw link 24 has a lower jaw detector 242. The lower jaw detector 242 is set so as to interrupt the optical axis of the lower jaw sensor 28 when the lower jaw drive wire 27 is retracted and the lower jaw connecting shaft 231 comes into contact with the end of the lower jaw cam groove 241 and starts rotating integrally with the fourth lower jaw link 24 again in synchronization with the fourth lower jaw link 24. In other words, the lower jaw sensor 28 can detect that the lower jaw member 14 has come into contact with the harvesting target 90 and stopped moving. The end effector 1 can grip the harvesting target 90 with a constant force regardless of the size of the harvesting target 90 by retracting the lower jaw drive wire 27 by a predetermined amount after the lower jaw sensor 28 detects the lower jaw detector 242.

[0031] 8 and 9, the end effector 1 includes a pressing drive mechanism 30 as a mechanism for moving the pressing member 15. As shown in, for example, FIGS. 3 and 8, the pressing drive mechanism 30 includes a rail 31, a slider 32, a connecting member 33, a first pressing link 34, a second pressing link 35, a first pressing spring 36, a second pressing spring 37, a pressing drive wire 38, and a pressing sensor 39.

[0032] As shown in Figures 3 and 8, the rail 31 is provided on the side member 12 and extends in the front-rear direction. The rail 31 has a function of guiding the movement of the slider 32 in the front-rear direction, i.e., in the direction toward and away from the base member 11. The slider 32 is configured to be movable along the extension direction of the rail 31. The connecting member 33 connects the slider 32 and the pressing member 15 and has a function of transmitting the movement of the slider 32 to the pressing member 15. In other words, the pressing member 15 moves in the front-rear direction integrally with the slider 32 as the slider 32 moves.

[0033] 8, the slider 32 is provided with a pressing cam groove 421. The pressing cam groove 421 is a groove formed by penetrating or digging through the slider 32, and is formed long in a direction perpendicular to the extension direction of the rail 31. In other words, the pressing cam groove 421 is formed long in the vertical direction.

[0034] The first pressing link 34, the second pressing link 35, the first pressing spring 36, and the second pressing spring 37 are a mechanism for converting the pushing and pulling movement of the pressing drive wire 38 into movement in the front-rear direction and transmitting the movement to the slider 32. The first pressing link 34 and the second pressing link 35 are arranged one on top of the other in the width direction of the end effector 1 and are attached to the side member 12 so as to be rotatable around a pressing shaft 301 as a fulcrum. A transmission member 341, such as a cam follower, is provided at the end of the first pressing link 34. The transmission member 341 passes through the side member 12 and is inserted into the pressing cam groove 421 of the slider 32. As a result, the movement of the first pressing link 34 in the rotational direction is converted into movement in the front-rear direction and transmitted to the slider 32.

[0035] The first pressing link 34 and the second pressing link 35 are configured to be rotatable relative to each other with the pressing shaft 301 as a fulcrum. The first pressing link 34 and the second pressing link 35 are connected to each other via a first pressing spring 36. The first pressing spring 36 is configured, for example, by a tension coil spring, and pulls the first pressing link 34 in a direction that rotates clockwise on the plane of FIG. 9. In other words, the first pressing spring 36 pulls the second pressing link 35 in a direction that rotates counterclockwise on the plane of FIG. 9. The second pressing spring 37 is configured, for example, by a tension coil spring, and connects the second pressing link 35 and the side member 12. The second pressing spring 37 pulls the second pressing link 35 in a direction that rotates counterclockwise on the plane of FIG. 9.

[0036] The first pressing link 34 and the second pressing link 35 are connected by a pressing connecting shaft 342. In this case, the pressing connecting shaft 342 is fixed to the first pressing link 34. The second pressing link 35 has a pressing elongated hole 451 through which the pressing connecting shaft 342 passes. The pressing elongated hole 451 is, for example, an elongated hole formed along the circumference of a circle centered on the pressing shaft 301. As a result, the first pressing link 34 and the second pressing link 35 are configured to be rotatable relative to each other within a range in which the pressing connecting shaft 342 engages with the end of the pressing elongated hole 451.

[0037] The pressing drive wire 38 has the function of moving the pressing member 15 by being pushed out and pulled in. Like the lower jaw drive wire 27, the pressing drive wire 38 is preferably made of a material that is flexible enough to bend but not easily stretched. The tip end of the pressing drive wire 38 is connected to the second pressing link 35, and the base end is connected to a drive source such as a motor. By pulling the second pressing link 35, the pressing drive wire 38 applies a force that rotates the second pressing link 35 in the clockwise direction on the paper of FIGS. 8 and 9 around the pressing shaft 301 as a fulcrum.

[0038] In this configuration, when the second pressing link 35 is pulled by the pressing drive wire 38, the second pressing link 35 rotates clockwise on the page in Fig. 8 around the pressing shaft 301. Then, as the second pressing link 35 rotates, the first pressing spring 36 pulls the first pressing link 34, and as shown in Fig. 11, the first pressing link 34 also rotates clockwise on the page around the pressing shaft 301. As a result, the rotation of the first pressing link 34 is converted into movement in the front-to-rear direction via the slider 32 and the connecting member 33, and the pressing member 15 moves forward, that is, in a direction away from the base member 11, as shown in Fig. 12.

[0039] Furthermore, when tension on the pressing drive wire 38 is released, the second pressing spring 37 shown in Fig. 11 causes the second pressing link 35 to rotate counterclockwise on the plane of the paper in Fig. 11 around the pressing shaft 301. Then, when the pressing connecting shaft 342 engages with the end of the pressing elongated hole 451 due to the rotation of the second pressing link 35, the first pressing link 34 also rotates counterclockwise together with the second pressing link 35. As a result, the pressing member 15 is pulled back toward the base member 11, as shown in Fig. 8.

[0040] The pressing sensor 39 detects that the pressing member 15 has come into contact with the stalk 91 of the harvest target 90 as the pressing member 15 moves. The pressing sensor 39 can be configured, for example, with a photoelectric sensor, similar to the lower jaw sensor 28. In this case, the pressing sensor 39 detects that the pressing member 15 has come into contact with the stalk 91 based on, for example, the second pressing link 35 having rotated a predetermined angle relative to the first pressing link 34. In other words, the pressing sensor 39 detects that the first pressing link 34 does not rotate even when the second pressing link 35 is pulled by the pressing drive wire 38.

[0041] As shown in FIG. 8 and other figures, the pressing sensor 39 is attached to the first pressing link 34 and rotates integrally with the first pressing link 34. When the pressing member 15 comes into contact with the fruit stalk 91, as shown in FIGS. 11 and 12 , the movement of the pressing member 15 stops, which in turn stops the forward movement of the slider 32 and the rotation of the first pressing link 34. If the pressing drive wire 38 is further retracted while the pressing member 15 is in contact with the fruit stalk 91, the second pressing link 35 rotates relative to the first pressing link 34, as shown in FIG. 13 . When the second pressing link 35 rotates a predetermined angle relative to the first pressing link 34, the pressing detection portion 452 of the second pressing link 35 interrupts the optical axis of the pressing sensor 39. This allows the pressing sensor 39 to detect that the second pressing link 35 has rotated relative to the first pressing link 34, i.e., that the pressing member 15 has come into contact with the fruit stalk 91.

[0042] 13, when the pressing drive wire 38 is further pulled in, the second pressing link 35 rotates relative to the first pressing link 34, and then the end of the pressing elongated hole 451 of the second pressing link 35 engages with the pressing connecting shaft 342, causing the first pressing link 34 to rotate again integrally with the second pressing link 35. As a result, the pressing member 15 moves further forward, as shown in FIGS.

[0043] As shown in Figures 1, 2, and 10, the end effector 1 further includes a scissors member 16 and a scissors drive mechanism 40. The scissors member 16 is a pair of scissors having two blades 161 that can be opened and closed, and is configured to be able to cut the fruit stalk 91 by closing it from an open state. The scissors member 16 is configured to be movable integrally with the pressing member 15, that is, in the front-to-rear direction along the rail 31. The scissors member 16 is also arranged overlapping the pressing member 15.

[0044] In this case, the scissors member 16 is disposed above the pressing member 15 and is attached to the connecting member 33 via the scissors shaft 401 so as to be able to open and close. The angle of the two blades 161 when the scissors member 16 is open is set to be equal to or greater than the opening angle of the opening portion 151 of the pressing member 15. In other words, when the scissors member 16 is open, the blades 161 overlap the pressing member 15. For this reason, when the scissors member 16 is open, the blades 161 of the scissors member 16 are not positioned inside the opening portion 151 of the pressing member 15. Therefore, when the scissors member 16 is open, the blades 161 of the scissors member 16 are prevented from coming into contact with and damaging the harvest target 90.

[0045] The scissors drive mechanism 40 is a mechanism for opening and closing the scissors members 16. As shown in, for example, Figures 1, 2, and 10, the scissors drive mechanism 40 has a scissors drive source 41 and a gear unit 42. Note that the gear unit 42 may be covered by, for example, a cover 43, as shown in Figures 1 and 2. The scissors drive source 41 and the gear unit 42 are attached to the slider 32 and configured to be movable in the front-rear direction along the rail 31 together with the pressing member 15. The scissors drive source 41 can be configured by, for example, an electric motor. The gear unit 42 transmits the rotation of the scissors drive source 41 to the scissors members 16 to open and close the scissors members 16.

[0046] <Crop harvesting system> Next, an example of a crop harvesting system using the end effector 1 will be described with reference to Figure 17 and subsequent figures. The crop harvesting system 50 shown in Figure 17 is an example in which medium or large tomatoes are set as the crop to be harvested 90. In this embodiment, the entire bunch made up of multiple fruits is set as the crop to be harvested 90. The crop harvesting system 50 of this embodiment can harvest multiple tomatoes individually.

[0047] A harvest object 90 such as a tomato bears fruit in a drooping state from a main stem 92 via a stalk 91. Tomatoes for sale at market are often grown in greenhouses. In this case, the tip of the main stem 92 is hung from a rail located near the ceiling of the greenhouse. This causes the main stem 92 to extend obliquely upward from the ground toward the ceiling.

[0048] In addition to the end effector 1, the crop harvesting system 50 further includes a lower jaw drive source 51, a pressing drive source 52, a visual device 53, a robot arm 54, a transport device 55, a collection box 56, and a control device 60. The lower jaw drive source 51 is configured to retract the lower jaw drive wire 27 and can be configured, for example, by an electric motor. The pressing drive source 52 is configured to retract the pressing drive wire 38 and, like the lower jaw drive source 51, can be configured, for example, by an electric motor. The lower jaw drive source 51 and the pressing drive source 52 are not attached to the end effector 1. The lower jaw drive source 51 and the pressing drive source 52 are provided closer to the base of the robot arm 54 than the tip of the robot arm 54, i.e., closer to the base of the robot arm 54.

[0049] The visual device 53 is a device capable of acquiring visual information including position information of the harvest target object 90. The visual device 53 is a device capable of measuring three-dimensional space and objects, such as a stereo camera, a ToF (Time of Flight) camera, or a structured light scanner.

[0050] The robot arm 54 is, for example, a six-axis vertical articulated robot having multiple drive axes, six drive axes in this case. The end effector 1 is, for example, a base member 11 attached to the tip of the robot arm 54. The robot arm 54 moves the end effector 1 to any position.

[0051] The transport device 55 is configured to transport the robot arm 54 equipped with the end effector 1 and the collection box 56 to the harvest target 90. The transport device 55 has, for example, a motor (not shown) for driving tires 551, and can be moved to any position by external control or the like. The collection box 56 is a box for storing and collecting the harvest target 90 harvested by cutting the stalk 91 with the end effector 1. The collection box 56 is formed, for example, in the shape of a container with an open top, and is installed on the transport device 55. Note that if a facility such as a greenhouse is equipped with a device for transporting the harvest target 90, such as a belt conveyor, the collection box 56 can be eliminated.

[0052] The crop harvesting system 50 also includes an end effector control unit 501, a vision device control unit 502, a robot arm control unit 503, and a transport device control unit 504. The end effector control unit 501 is a device that receives information from the sensors 28 and 39 and controls the drive sources 41, 51, and 52 for the end effector 1. The vision device control unit 502, the robot arm control unit 503, and the transport device control unit 504 are devices associated with the vision device 53, the robot arm 54, and the transport device 55, respectively. The end effector control unit 501, the vision device control unit 502, the robot arm control unit 503, and the transport device control unit 504 are provided in the transport device 55, for example.

[0053] The end effector control unit 501, the visual device control unit 502, the robot arm control unit 503, and the transport device control unit 504 are each mainly composed of a microcomputer having a storage area such as a CPU, ROM, RAM, and rewritable flash memory (not shown), and a power circuit for supplying power as a driving force to the drive sources 41, 51, and 52 of the end effector 1, the visual device 53, the robot arm 54, and the transport device 55. The drive sources 41, 51, and 52 of the end effector 1, the visual device 53, the robot arm 54, and the transport device 55 are driven and controlled based on commands from the end effector control unit 501, the visual device control unit 502, the robot arm control unit 503, and the transport device control unit 504, respectively.

[0054] The control device 60 controls the end effector 1, the visual device 53, the robot arm 54, and the transport device 55 via an end effector control unit 501, a visual device control unit 502, a robot arm control unit 503, and a transport device control unit 504, respectively. The control device 60 is communicably connected to each of the end effector control unit 501, the visual device control unit 502, the robot arm control unit 503, and the transport device control unit 504 by wire or wirelessly. In this case, the control device 60 may be connected to the end effector control unit 501, the visual device control unit 502, the robot arm control unit 503, and the transport device control unit 504 via a telecommunications line such as a LAN or WAN, the Internet, or a mobile phone line.

[0055] The control device 60 is mainly composed of a microcomputer having, for example, a CPU 61 and a storage area 62 such as a ROM, a RAM, and a rewritable flash memory. The control device 60 issues drive commands to the end effector 1, the visual device 53, the robot arm 54, and the transport device 55, and receives feedback from the end effector 1, the visual device 53, the robot arm 54, and the transport device 55. The control device 60 is a general-purpose control device that is not associated with any of the end effector 1, the visual device 53, the robot arm 54, and the transport device 55. In other words, the control device 60 is a higher-level device that issues commands to the end effector control unit 501, the visual device control unit 502, the robot arm control unit 503, and the transport device control unit 504. The control device 60 can be composed of, for example, a personal computer, a server, etc.

[0056] The memory area 62 stores a program for the crop harvesting system. By executing the program for the crop harvesting system in the CPU 61, the control device 60 can control the end effector 1, the visual device 53, the robot arm 54, and the transport device 55 to execute each process for harvesting the harvest object 90.

[0057] For example, in the case of tomatoes, as the fruit ripens, a separation layer 911 forms in part of the stalk, as shown in Figure 18. The separation layer 911 is a slightly swollen part in which specially differentiated small meristem cells cross the axis and have no fibers, resulting in a weak structure. Therefore, the crop harvesting system 50 of this embodiment is capable of executing a plucking process in which the harvest object 90 is separated at the separation layer 911 by twisting the end effector 1 while holding the harvest object 90 with the end effector 1.

[0058] Specifically, when the control device 60 performs a harvesting operation to harvest the harvest object 90, it sequentially performs an approaching process, a gripping process, a plucking process, a cutting process, and a detaching process, as shown in Fig. 19. At the start of the harvesting operation, the lower jaw members 14 of the end effector 1 are in an open state.

[0059] When the harvesting operation starts, the control device 60 executes the approaching process in step S11. When the control device 60 executes the approaching process, the control device 60 operates the robot arm 54 based on the visual information of the harvesting object 90 acquired by the vision device 53, and moves the end effector 1 closer to the harvesting object 90 so that the fruit stalk 91 is positioned between the two upper claw members 13.

[0060] Next, the control device 60 executes the gripping process of steps S12 to S14. First, in step S12, the control device 60 operates the lower claw drive source 51 to retract the lower claw drive wire 27. As a result, the control device 60 starts moving the lower claw members 14, that is, starts gripping the harvesting target 90. Then, when the lower claw members 14 come into contact with the bottom of the harvesting target 90 and the lower claw sensor 28 detects the lower claw detection unit 242 (YES in step S13), the control device 60 proceeds to step S14. In step S14, the control device 60 further retracts the lower claw drive wire 27 by a predetermined amount, thereby gripping the harvesting target 90. This completes the gripping process.

[0061] Next, the control device 60 executes the picking process of steps S15 to S18. First, in step S15, the control device 60 operates the pressing drive source 52 to retract the pressing drive wire 38. As a result, the control device 60 starts moving the pressing member 15 in the forward direction, that is, in the direction in which it presses against the fruit stalk 91. Then, when the pressing member 15 comes into contact with the fruit stalk 91 and the pressing sensor 39 detects the pressing detection unit 452 (YES in step S16), the control device 60 executes step S17.

[0062] In step S17, the control device 60 further retracts the pressing drive wire 38 by a predetermined amount, and continues to advance the pressing member 15, i.e., to press the pressing member 15 against the stalk 91, while operating the robot arm 54 to tilt the end effector 1 while gripping the harvest object 90, as shown in Figures 20 and 21. This separates many of the delaminating portions 911 of the harvest object 90.

[0063] Here, as shown in Figure 18, the stalk 91 is often bent in an "U" shape with the delamination portion 911 as a fulcrum. In this case, when a force is applied to the delamination portion 911 in a direction that opens the "U" shape, the delamination portion 911 is separated with a small force. Therefore, in the tilting operation of step S17, the control device 60 may recognize the bending direction of the delamination portion 911 from the visual information acquired by the visual device 53, and tilt the end effector 1 in a direction that makes it easier for the delamination portion 911 to separate.

[0064] Next, in step S18, the control device 60 operates the scissors drive source 41 to close the scissors members 16 as shown in Fig. 16. This ensures that the stalk 91 can be cut even for harvest objects 90 from which the abscission portion 911 was not separated during the picking process of steps S15 to S17.

[0065] Then, the control device 60 executes a detachment step in step S19. In the detachment step, the control device 60 operates the robot arm 54 to detach the end effector 1 from its current position and place the harvested objects 90 into the collection box 56. This completes the series of harvesting operations.

[0066] According to the embodiment described above, the end effector 1 harvests the harvest target 90 that has fruit on the main stem 92 or branches. The end effector 1 includes a base member 11, upper jaw members 13, lower jaw members 14, and a pressing member 15. The base member 11 is attached to the tip of the robot arm 54. The upper jaw members 13 are configured to be able to contact the surface of the harvest target 90 that faces the stalk 91.

[0067] The lower claw members 14 are configured to be movable toward and away from the upper claw members 13, and when they are close to the upper claw members 13, they come into contact with the surface of the harvest object 90 opposite the stalk 91, i.e., the bottom, so that they can pinch and grip the harvest object 90 between themselves and the upper claw members 13. The pressing member 15 is configured to be movable toward and away from the base member 11, and is pressed against the fruit stalk 91 when it moves away from the base member 11.

[0068] Moreover, the crop harvesting system 50 of the embodiment includes an end effector 1, a robot arm 54 to which the end effector 1 is attached, and a control device 60 that controls the operation of the end effector 1 and the robot arm 54. The control device 60 can execute an approaching step, a gripping step, and a plucking step. The approaching step is a step of operating the robot arm 54 to move the end effector 1 to a position where the harvest target 90 is positioned between the upper claw member 13 and the lower claw member 14 with the upper claw member 13 and the lower claw member 14 separated from each other.

[0069] The gripping process is a process of moving the lower claw members 14 toward the upper claw members 13 to pinch and grip the harvest target 90 between the upper claw members 13 and the lower claw members 14. The plucking process is a process of moving the pressing member 15 away from the base member 11 while the end effector 1 is gripping the harvest target 90 to press it against the stalk 91 of the harvest target 90, and operating the robot arm 54 to tilt the end effector 1.

[0070] According to this, the crop harvesting system 50 can separate the desquamated portion 911 of the fruit stalk 91 by twisting the end effector 1 while the end effector 1 holds the object to be harvested 90 with the upper jaw member 13 and the lower jaw member 14 and presses the pressing member 15 against the fruit stalk 91. Therefore, the end effector 1 and the crop harvesting system 50 can harvest the object to be harvested 90 without using a blade, and can accommodate various changes in the thickness and length of fruit stalks. In other words, many varieties of object to be harvested 90 can be harvested with a single end effector 1.

[0071] The end effector 1 is configured so that the lower jaw members 14 and the pressing member 15 are connected via wires 27 and 38 to drive sources 51 and 52 provided closer to the base of the robot arm 54 than the tip of the robot arm 54, and are wire-driven by pushing and pulling the wires 27 and 38. This eliminates the need to mount the drive sources 51 and 52 for operating the lower jaw members 14 and the pressing member 15 on the end effector 1, allowing the end effector 1 to be made smaller. This allows the end effector 1 to enter even narrow spaces, thereby preventing the harvest object 90 from coming into contact with the end effector 1 and being damaged.

[0072] The end effector 1 further includes a lower claw sensor 28 that detects when the lower claw members 14 come into contact with the harvest object 90 as the lower claw members 14 move. This allows the end effector 1 to grip the harvest object 90 with a constant force regardless of its size by further moving the lower claw members 14 a predetermined amount after the lower claw sensor 28 detects contact. This allows harvest objects 90 of various sizes to be gripped with an appropriate force. As a result, it is possible to prevent the end effector 1 from gripping the harvest object 90 with excessive force, crushing the harvest object 90 and reducing its commercial value.

[0073] The end effector 1 further includes a pressing sensor 39 that detects when the pressing member 15 comes into contact with the fruit stalk 91 as the pressing member 15 moves. This allows the end effector 1 to detect when the pressing member 15 comes into contact with the fruit stalk 91, so that after the pressing member 15 comes into contact with the fruit stalk 91, the pressing member 15 can be further pressed in while tilting the end effector 1. This allows the delamination portion 911 to be cut efficiently.

[0074] The end effector 1 further includes a scissors member 16. The scissors member 16 is disposed on top of the pressing member 15, and in the open state, the blade 161 overlaps the pressing member 15. This allows the end effector 1 to reliably cut the fruit stalk 91 using the scissors member 16 even in fruit whose delamination portion 911 was not cut off during the picking process.

[0075] In this case, the crop harvesting system 50 performs the cutting process after the picking process. In this way, the fruit stalk 91 is weakened by the picking process, so the force required to close the scissors 16 is small, and the fruit stalk 91 can be easily cut even with a small scissors 16. As a result, the size and weight of the end effector 1 can be prevented from increasing due to the incorporation of the scissors 16.

[0076] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0077] 1...Crop harvesting end effector, 11...base member, 13...upper jaw member, 14...lower jaw member, 15...pressing member, 16...scissor member, 27...lower jaw drive wire, 28...lower jaw sensor, 38...pressing drive wire, 39...pressing sensor, 50...crop harvesting system, 51...lower jaw drive source, 52...pressing drive source, 60...control device, 64...robot arm, 70...control device

Claims

1. An end effector (1) for harvesting agricultural crops that harvests harvesting objects (90) bearing fruit on main stems (92) or branches, a base member (11) attached to the tip of a robot arm (64); an upper claw member (13) capable of contacting a surface of the harvesting object on the side of the fruit stem (91); a lower claw member (14) configured to be movable in a direction away from and toward the upper claw member, and which, when approaching the upper claw member, contacts the surface of the harvest object opposite the stalk and can pinch and grasp the harvest object between the upper claw member and the lower claw member; a pressing member (15) configured to be movable in a direction away from and toward the base member, and pressed against the fruit stalk when moved in a direction away from the base member; An end effector (1) for harvesting agricultural crops, comprising:

2. The lower jaw member and the pressing member are connected by wires (27, 38) to a drive source provided closer to the base of the robot arm than the tip of the robot arm, and are configured to be wire-drivable by pushing and pulling the wires.

10. The crop harvesting end effector of claim 1.

3. The harvesting device further includes a lower claw sensor (28) that detects that the lower claw member has come into contact with the harvesting object due to the movement of the lower claw member.

10. The crop harvesting end effector of claim 1.

4. The pressing member further includes a pressing sensor (39) for detecting contact of the pressing member with the fruit stem due to movement of the pressing member.

10. The crop harvesting end effector of claim 1.

5. The scissors member (16) is arranged on top of the pressing member and has a blade (161) that overlaps the pressing member when opened.

10. The crop harvesting end effector of claim 1.

6. An end effector (1) for harvesting agricultural crops according to any one of claims 1 to 5; a robotic arm (64) to which the crop harvesting end effector is attached; a control device (70) for controlling the operation of the crop harvesting end effector and the robotic arm; The control device an approaching step of operating the robot arm to move the crop harvesting end effector to a position where the harvesting target is placed between the upper claw members and the lower claw members while the upper claw members and the lower claw members are spaced apart from each other; a gripping step of moving the lower claw member toward the upper claw member to sandwich and grip the harvest object between the upper claw member and the lower claw member; a picking step of moving the pressing member away from the base member while holding the harvest object to press it against a fruit stalk of the harvest object and operating the robot arm to tilt the crop harvesting end effector; can be performed, A crop harvesting system (60).

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