A manipulator suitable for picking citrus fruits using the one-fruit-two-cut method

Abstract

The invention discloses a manipulator suitable for picking citrus fruits by a one-fruit two-cut method, and relates to the field of fruit picking. The manipulator is used as an end effector of an automated citrus picking manipulator based on machine vision, and comprises a finger-shaped blade mechanism, a blade pushing and rotating mechanism, and a manipulator palm body. The finger-shaped blade mechanism can rotate up and down relative to the manipulator palm body to complete the combing and positioning action of target fruits. The finger-shaped blade mechanism is composed of a main blade group and an auxiliary blade group stacked together. When the two are separated, the shearing action of branches at two places, the fruit stalk and the top tip, can be completed simultaneously. The fruit shearing method of the invention can realize one-fruit two-cut method, reduce the excessively high requirements for the positioning accuracy of machine vision, do not need compressed air, and control objects with only two electric push rods, thereby reducing the bloatedness and complexity of automated picking equipment, and facilitating popularization and application.

Description

Technical Field

[0001] The invention relates to a manipulator for picking citrus, in particular to a citrus picking manipulator which can cooperate with a citrus one-fruit two-cutter picking agronomic technology, and belongs to the field of fruit picking. Background Art

[0002] In terms of citrus harvesting, many planting experts advocate the use of the two-pruning method to harvest citrus, which is conducive to the accelerated growth of the fruit on the tree, from small fruit to large fruit, and is also conducive to the recovery of tree vigor and the promotion of flower bud differentiation to avoid the growth of spring shoots and affect the quality of future fruiting; the agronomic technology of one fruit and two prunes requires that while the fruit stalk is pruned along the root, the fruit branches with 3-4 leaves should be cut 5-10 cm upward from the root of the fruit stalk. In terms of intelligent harvesting of citrus, there are currently many citrus picking robots based on machine vision in the process of research and development, but there are no citrus picking robots that have been promoted and applied on a large scale. The reasons include: 1. The operating goal of the end effector of most citrus picking robots is only to pick the citrus fruit from the fruit stalk by shearing or twisting, without considering the "one fruit and two prunes" agronomic technology of pruning the top of the fruit-bearing branches at the same time, resulting in the need for manual top pruning after the robot is used to harvest citrus to meet the "one fruit and two prunes" to ensure future production. 1. The amount of citrus fruits picked by robots is not necessary; 2. High-precision machine vision technology often requires a high cost, while low-precision machine vision technology cannot accurately find the location of the fruit stalk, resulting in most shearing end effectors being unable to accurately cut the fruit along the root of the fruit stalk, which will leave longer fruit branches on the cut fruit and cause mutual damage to the peel when the fruit is piled and transported; 3. Although the use of airbag picking end effectors to pick citrus fruits can avoid the fruit stalk from being too long, it needs to be equipped with air sources such as air pumps, which makes the overall picking robot larger and more complex and difficult to use in practice. Therefore, a shearing citrus picking end effector that can fully combine the "one fruit, two shears" agronomic technology, while using the "combing fruit" method to assist in finding the fruit stalk, thereby reducing the high-precision requirements for machine vision technology, has become a necessary part of promoting citrus intelligent picking technology. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a manipulator suitable for picking citrus with the one-fruit, two-cut method as the end effector of an intelligent citrus picking manipulator based on machine vision. The manipulator can simultaneously cut off the top of the branch with fruits and the root of the fruit stalk, thereby realizing the automated one-fruit, two-cut method of citrus fruits. At the same time, the fruit combing method is used to accurately locate the cutting position of the fruit stalk, reducing the excessively high requirements for the positioning accuracy of machine vision. The shearing method is used to pick fruits, avoiding the integration of a compressed air source in the equipment, so as to greatly improve the possibility of popularizing and applying robot automated citrus picking technology.

[0004] The purpose and effect of the present invention are achieved through the following technical solutions:

[0005] A robot suitable for picking citrus fruits using the one-fruit, two-cut method, characterized in that it is installed as an end effector on a six-degree-of-freedom robot arm, comprises a finger-like blade mechanism, a blade pushing and rotating mechanism and a robot palm body, the finger-like blade mechanism can rotate upward or downward relative to the robot palm body around a hinge shaft located at the front end of the robot palm body, when rotated downward to the extreme position, the finger-like blade mechanism and the robot palm body are located in the same plane, which is equivalent to the unfolding posture, and after rotating upward so that the finger-like blade mechanism and the robot palm body form an angle of 90°, the fruit-cutting posture can be entered; the finger-like blade mechanism is composed of a main blade group and an auxiliary blade group superimposed under the guiding and clamping action of two blade guide sleeves, after entering the fruit-cutting posture, the auxiliary blade group can move relative to the main blade group along the axial direction of the blade guide sleeve Separated from the overlapping state to a positional relationship having the spacing requirement of two pruning points that meets the agronomic requirement of "one fruit, two cuts"; each blade guide sleeve includes a main guide sleeve, a secondary guide sleeve and a guide sleeve spring; the main blade group is composed of a front main blade and a rear main blade in the shape of four fingers opened and overlapped under the clamping of two main guide sleeves, and the secondary blade group is composed of a front secondary blade and a rear secondary blade in the shape of four fingers opened and overlapped under the clamping of two secondary guide sleeves; when cutting fruit, the front main blade can slide relative to the rear main blade in a direction perpendicular to its four-finger length under the common guidance of the two main guide sleeves to complete the cutting of branches at the fruit stalk, and at the same time, the front secondary blade can slide relative to the rear secondary blade in a direction perpendicular to its four-finger length under the common guidance of the two secondary guide sleeves to complete the pruning of the top of the fruit branch, thereby completing one fruit and two cuts.

[0006] The four front main blade fingers of the front main blade are bent upward, and the width between the fingers is slightly larger than the maximum possible diameter of the branch at the stalk of the citrus fruit to be picked. The two opposite edges of two adjacent fingers are chamfered along the finger length direction to form a front main blade, and the fingertips are provided with arc chamfers to guide the fruit stalk branches. A rectangular front main gear ring hole is provided in the center below the four fingers, and a row of front main tooth bars is provided on the hole wall on one side perpendicular to the length direction of the front main blade fingers. There is a front main waist hole on each side of the front main gear ring hole, and a circular front main shallow pit is provided on the outer surface of the middle section in the length direction of each front main waist hole. The distance between the arc centers of the two ends of the front main waist hole is larger than the width between the adjacent fingers of the four front main blade fingers; the main shape of the rear main blade is consistent with the main front blade, so that the rear main blade and the main front blade can just overlap and stick to each other. The main blade group is formed by the four rear main blade fingers on the rear main blade, and the shapes of the inter-finger and fingertip formed by the four front main blade fingers are exactly the same as the shapes of the inter-finger and fingertip formed by the four front main blade fingers. The rear main blade edge formed by the two opposite edges of the adjacent two fingers of the rear main blade finger being chamfered along the finger length direction is exactly opposite to the cutting edge of the front main blade, so that a seamless blade edge is formed on the opposite edges of each adjacent two fingers along the finger length direction. The rear main gear ring hole arranged at the center below the rear main blade finger is exactly coincident with the front main gear ring hole, but the rear main rack arranged on the hole wall on one side of the rear main gear ring hole is exactly opposite to the hole wall where the front main rack is located, and the two rear main waist-shaped holes arranged on both sides of the rear main gear ring hole are exactly coincident with the two front main waist-shaped holes, and the rear main shallow pit on the rear main waist-shaped hole is exactly symmetrical with the front main shallow pit relative to the fitting surface of the front main blade and the rear main blade;

[0007] The square hole side length of the front auxiliary gear ring hole on the front auxiliary blade in the direction parallel to the length direction of the front auxiliary blade finger on the front auxiliary blade is shorter than the square hole side length of the corresponding front main gear ring hole in the direction parallel to the length direction of the front main blade finger, and the module of the front auxiliary rack arranged on the hole wall on one side of the front auxiliary gear ring hole is smaller than the module of the corresponding front main rack. In addition, the structure and shape of the front auxiliary blade are exactly the same as the front main blade; the rear auxiliary gear ring hole on the rear auxiliary blade just coincides with the front auxiliary gear ring hole, but the rear auxiliary rack arranged on the hole wall on one side of the rear auxiliary gear ring hole is just opposite to the hole wall where the front auxiliary rack is located, and the rear auxiliary gear ring hole is fixedly connected with a strip baffle parallel to the rear auxiliary rack in the middle of an end face away from the front auxiliary blade, and a sliding groove is provided on the side surface of the strip baffle facing the rear auxiliary gear ring hole along its own length direction. In addition, the structure and shape of the rear auxiliary blade are exactly the same as the rear main blade; the front auxiliary blade and the rear auxiliary blade just completely overlap and fit together to form an auxiliary blade group;

[0008] The main guide sleeve is composed of a main guide sleeve core and a main guide sleeve box; the main guide sleeve core includes a main guide hollow male shaft, a main hollow externally threaded shaft and a circular main guide sleeve core flange, the main guide hollow male shaft and the main hollow externally threaded shaft are coaxially arranged, one end of which is coaxially fixedly connected to the main guide sleeve core flange, the outer cylindrical surface of the other end of the main guide hollow male shaft is an outer cone, the length of the main guide hollow male shaft is longer than that of the main hollow externally threaded shaft, and the outer diameter is smaller than the inner diameter of the main hollow externally threaded shaft, the gap between the outer cylindrical surface of the main guide hollow male shaft and the inner cylindrical surface of the main hollow externally threaded shaft can accommodate the guide sleeve spring, the inner hole of the guide main sleeve core flange is consistent with the inner hole diameter of the main guide hollow male shaft, and a front main circular convex bulge gradually bulging from the edge to the center is provided on the same side of the flange surface and the fixed main guide hollow male shaft, and the convex bulge just complements the front main shallow pit; the main guide sleeve box includes a main hollow inner The threaded shaft and a circular main sleeve box flange, one end of the main hollow internally threaded shaft is coaxially fixedly connected to the main sleeve box flange, and the inner hole of the main sleeve box flange is consistent with the inner hole diameter of the main hollow internally threaded shaft, and on the same side of the flange surface and the fixed main hollow internally threaded shaft, a rear main circular convex bump is provided which gradually bulges from the edge to the center, and the convex bump just complements the described rear main shallow pit; the external thread on the main hollow externally threaded shaft can be completely screwed into the internal thread of the main hollow internally threaded shaft, at this time, the front main circular convex bump and the rear main circular convex bump are just opposite to each other, and the outer cylindrical diameter of the main hollow internally threaded shaft is slightly larger than the width of the described front main waist-shaped hole, so that its outer cylindrical surface can be inserted into the waist-shaped hole and the relative disk surfaces of the main sleeve core flange and the main sleeve box flange can just clamp the described main blade assembly; the two screwed-in main sleeves are respectively inserted into the two front main waist-shaped holes to jointly clamp the main blade assembly;

[0009] The auxiliary guide sleeve is composed of an auxiliary guide sleeve core and an auxiliary guide sleeve box; the auxiliary guide sleeve core includes a auxiliary guide hollow female shaft, a auxiliary hollow externally threaded shaft and a circular auxiliary guide sleeve core flange, and the auxiliary guide sleeve box includes a auxiliary hollow internally threaded shaft and a circular auxiliary guide sleeve box flange; one end of the auxiliary guide hollow female shaft is coaxially fixed to the auxiliary guide sleeve core flange, and the inner cylindrical surface of the other end thereof is an inner cone, which can be precisely matched and positioned with the outer cone section on the outer cylindrical surface of one end of the main guide hollow male shaft. In addition, the structure and shape of the auxiliary guide sleeve are exactly the same as those of the main sleeve. The two screwed-on auxiliary guide sleeves are respectively inserted into the two front auxiliary waist holes on the front auxiliary blade located on both sides of the front auxiliary gear ring hole to jointly clamp the auxiliary blade assembly. ; The inner holes of the two main guide hollow male shafts are exactly aligned with the inner holes of the two secondary guide hollow female shafts, and the inner conical surface of one end of the secondary guide hollow female shaft is also exactly opposite to the outer conical surface of one end of the main guide hollow male shaft; the guide sleeve spring is a tension spring, which is installed in the gap outside the outer cylindrical surface of the main guide hollow male shaft and the secondary guide hollow female shaft and inside the inner cylindrical surface of the main hollow externally threaded shaft and the secondary hollow externally threaded shaft, one end is fixedly connected to the main guide sleeve core flange, and the other end is fixedly connected to the secondary guide sleeve core flange. When the main blade group and the secondary blade group are superimposed together, the outer conical surface of one end of the main guide hollow male shaft is inserted into the inner conical surface of one end of the secondary guide hollow female shaft, and the guide sleeve spring is in a contracted state with a certain pre-stretching force.

[0010] The mechanical palm body comprises a palm body, a front palm push rod, a push-turn hinge and two guide rod supports; the two guide rod supports are symmetrically fixed to the upper surface of the palm body on both sides parallel to the length direction of the palm body, a hinge shaft is installed perpendicular to the length direction of the palm body at the front end of the palm body, the front palm push rod is an electric push rod, the motor end housing of which is connected to a hinge shaft below the palm body through a hinge, and the telescopic end head thereof has a hinge hole, the axis of the hole is parallel to the axis of the hinge shaft; the push-turn hinge comprises a hinge shaft sleeve and a push rod. The rod shaft, the axes of the two are parallel to each other and fixedly connected to each other, the finger-shaped blade mechanism as a whole is fixedly connected to the push-turn hinge through the two main guide sleeve core flanges, and the axis of the hinge shaft sleeve is perpendicular to the axis direction of the inner hole of the main guide hollow male shaft, the hinge shaft is inserted into the hinge shaft sleeve to form the rotation axis of the finger-shaped blade mechanism relative to the robot palm body, the push rod shaft is inserted into the hinge hole of the telescopic end of the forepalm push rod, and when the telescopic end of the forepalm push rod is extended or shortened, the entire finger-shaped blade mechanism can be driven to rotate around the axis of the hinge shaft relative to the robot palm body through the push-turn hinge.

[0011] The blade pushing and rotating mechanism includes a blade pushing rod, a double gear shaft, a pushing rod spring and two guide rods; the blade pushing rod is modified from an electric pushing rod, and its motor end housing and outer sleeve are fixedly connected to the middle of the upper surface of the palm body, and its telescopic rod can only telescopically move relative to the outer sleeve but cannot rotate, and the axis of the telescopic rod is parallel to the upper surface of the palm body and perpendicular to the axis of the hinge shaft, and two connecting rods are respectively fixedly connected to the two connecting rods on both sides of the rear of the telescopic rod, and the two guide rods are respectively fixedly connected to the two connecting rods, and the axes of the two guide rods are parallel to each other and respectively pass through the guide holes of the two guide rod supports. When the finger-shaped blade mechanism and the mechanical palm body are When the body is at an angle of 90° and is ready to start cutting the fruit, the axes of the two guide rods coincide with the axes of the two main guide hollow male shafts but are separated from the finger-shaped blade mechanism. The outer diameter of the guide rod is consistent with the inner hole diameter of the main guide hollow male shaft and can be inserted smoothly; the front end of the telescopic rod is provided with a coaxial thin shaft therewith, and the front part of the telescopic rod adjacent to the thin shaft is provided with a cylindrical pin, and the axis of the cylindrical pin is perpendicular to the axis of the telescopic rod; the double gear shaft is a stepped shaft with a stepped hole, the front end of which is a hollow small gear shaft, and the rear end is a coaxial hollow large gear shaft. The outer diameter and inner hole diameter of the small gear shaft are smaller than those of the large gear shaft, and the thin shaft is just inserted into the inner hole of the small gear shaft, and the push rod The spring is a compression spring, which is installed in the gap between the front end of the thin shaft and the bottom of the inner hole of the small gear shaft. Its stiffness coefficient is at least twice the stiffness coefficient of the guide sleeve spring. There is a pin groove on the cylindrical wall of the large gear shaft. The section with the cylindrical pin at the front of the telescopic rod is just inserted into its inner hole from the tail of the large gear shaft, and the cylindrical pin is just inserted into the pin groove and can slide in the groove along its entire length. The pin groove is a straight groove parallel to the axis of the large gear shaft near the tail of the large gear shaft, and gradually transitions forward to a spiral groove with the axis of the large gear shaft as the rotation axis; the front end of the small gear shaft is fixedly connected to a small gear, and its module is the same as that of the front auxiliary rack. The modulus is consistent and can mesh with it normally. A large gear is fixedly connected at the junction of the front end of the large gear shaft and the small gear shaft, and its modulus is consistent with the modulus of the front main rack and can mesh with it normally. When the finger-shaped blade mechanism and the main body of the manipulator palm are at an angle of 90° and are ready to start cutting fruits, the large gear and the small gear are separated from the finger-shaped blade mechanism. The pitch circle of the large gear is exactly tangent to the pitch lines of the front main rack and the rear main rack on the upper and lower sides, respectively, when viewed along the axis of the double gear shaft. The pitch circle of the small gear is exactly tangent to the pitch lines of the front auxiliary rack and the rear auxiliary rack on the upper and lower sides, respectively, when viewed along the axis of the double gear shaft.The end face of the large gear away from the finger-like blade mechanism is fixedly connected to a retaining ring with an outer diameter larger than the width of the front main gear ring hole in a direction parallel to the length direction of the front main blade finger. When the large gear moves along with the blade push rod toward the finger-like blade mechanism until it is meshed with the front main rack and the rear main rack, the front end face of the retaining ring contacts the end face of the front main gear ring hole to prevent the large gear and the double gear shaft connected to it from continuing to move forward and allow the retaining ring to slide relative to the front main blade in a direction perpendicular to the length direction of the front main blade finger. At the same time, the small gear has passed through the front main gear ring hole and the rear main gear ring hole The pinion gear meshes with both the front auxiliary rack and the rear auxiliary rack. The raised spherical crown surface on the outer end face of the pinion gear matches the cross section of the slide groove of the strip baffle. This allows the auxiliary blade group to be separated from the main blade group under the action of the pinion gear end face pushing the strip baffle, and also allows the pinion gear end face to slide relative to the rear auxiliary blade along the slide groove direction of the strip baffle. The lengths of the two guide rods are such that when the auxiliary blade group just separates from the main blade group from the original overlapping state, the two guide rods have been inserted into and passed through the inner holes of the two auxiliary guide hollow female shafts. ;

[0012] The working principle of the above scheme is: the whole device is fixedly installed on a six-degree-of-freedom robot arm as an end effector, and the fixed connection with the end of the robot arm is located at the tail of the robot palm body. In the initial state, the finger blade mechanism and the robot palm body are located in the same plane and are in an unfolded posture, and a flexible pipe for receiving fallen fruits is installed at an appropriate position behind the "palm" to lead to the fruit basket; the machine vision technology is used to determine the center point position coordinates and maximum radius of the target fruit, and the position coordinates of the fruit handle are predicted. According to these parameters, the robot arm drives the unfolded device to go around from the bottom of the target fruit to the back of the fruit with the initial posture of the "palm" facing up, and then the fingertips are slowly moved upward until the entire target fruit is separated from other branches or fruits; After the four "fingers" of the finger-like blade mechanism exceed the predicted fruit handle position coordinates by a certain distance upward, the telescopic end of the forefoot push rod extends to drive the finger-like blade mechanism as a whole to rotate around the hinge axis. At the same time, the robotic arm can still drive the entire device to slowly move and fine-tune upward until the position of the hinge axis is basically the same height as the fruit handle position. As the finger-like blade mechanism as a whole rotates around the hinge axis, the branches connected to the fruit handle will be "combed" into the gaps between the four fingers. Since there are three side-by-side gaps between the fingers, even if there is a certain error in the calculation of the fruit handle position, it can be ensured that the branches at the fruit handle enter at least one of the gaps between the fingers. When the finger-like blade mechanism rotates to a 90° angle relative to the main body of the robotic palm, the position of the entire device is fine-tuned downward by using machine vision and the robotic arm. The four fingers are positioned so that the inner surfaces just touch the skin of the fruit stalk, and then the posture of the whole device is fine-tuned by machine vision and mechanical arms so that the fruit is basically aligned with the entrance of the flexible pipe arranged in advance for receiving the fallen fruit. At this time, the whole device has entered the posture ready to cut the fruit; the blade push rod begins to extend, thereby driving the two guide rods fixed thereto and the double gear shaft coaxial therewith to move in a translational direction close to the finger blade mechanism, and when the front end face of the small gear at the front end of the double gear shaft just touches the strip baffle slide groove fixed on the rear auxiliary blade, the two guide rods have been inserted into and passed through the inner holes of the two blade guide sleeves, thereby becoming the translation guide rails when the main sleeve and the auxiliary sleeve are separated, and the small gear has entered into a meshing state with the front auxiliary rack and the rear auxiliary rack at the same time; As the blade push rod continues to extend, the small gear will push the entire auxiliary blade group and the main blade group to begin to separate. At this time, the two guide sleeve springs in the two blade guide sleeves are stretched, and the push rod spring located in the gap between the front end of the thin shaft and the bottom of the inner hole of the small gear shaft is compressed. This will cause the cylindrical pin at the front of the telescopic rod to start sliding in the column pin groove on the wall of the large gear shaft. However, since the stiffness of the push rod spring is greater than the stiffness of the two guide sleeve springs in parallel, when the two guide sleeve springs are stretched to the longest (at this time, the retaining ring fixed to the rear of the large gear has contacted the front main blade), the sliding stroke of the cylindrical pin in the column pin groove is still within the straight groove range close to the tail of the large gear shaft. Therefore, during this period, the double gear shaft will not rotate relative to the telescopic rod, and the large gear and the small gear will not rotate either.After the retaining ring fixed to the rear of the large gear has contacted the front main blade, the double-gear shaft can no longer move forward relative to the finger-shaped blade mechanism. At this time, as the telescopic rod continues to extend, the push rod spring will be further compressed, causing the cylindrical pin to slide into the spiral groove range in the cylindrical pin groove. Since the telescopic rod cannot rotate relative to the main body of the robot palm, the double-gear shaft and the large gear and small gear fixed thereon will rotate and respectively drive the front main rack, rear main rack and front auxiliary rack, rear auxiliary rack engaged therewith to translate. As long as the front palm push rod does not extend or retract at this time, the positions of the two main guide sleeves relative to the main body of the robot palm will not change, and the two auxiliary guide sleeves will only be left along the guide rod shaft The front main blade and the rear main blade will move in opposite directions respectively with the front main rack and the rear main rack under the common guiding action of the two main guide sleeves, and the previously overlapped front main blade fingers and the rear main blade fingers will move relatively to form a shearing effect on the branches at the fruit stalk located in a certain gap between the fingers, cutting off the branches of the fruit stalk, and the fruits fall into the flexible pipe. Similarly, the front auxiliary blade and the rear auxiliary blade will move in opposite directions respectively with the front auxiliary rack and the rear auxiliary rack under the common action of the two auxiliary guide sleeves, thereby cutting off the fruit branches at a certain distance in front of the fruit stalk, thereby achieving the effect of pruning the top tip; when the cylindrical pin moves forward through the entire stroke of the cylindrical pin slot, The gaps between the four fingers are completely closed to complete the two shearing operations, and then the blade push rod retracts backwards. Under the action of the push rod spring, the double gear shaft will not retract immediately, but will rotate in the opposite direction as the cylindrical pin slides in the opposite direction in the cylindrical pin groove. The reverse rotation of the large gear and the small gear respectively drives the front main blade, the rear main blade and the front auxiliary blade, and the rear auxiliary blade to reset. When the four fingers are about to overlap, the front main shallow pit, the rear main shallow pit and the front main circular convex bulge and the rear main circular convex bulge cooperate with each other to reset, so that the main blade group can be completely reset until the four fingers of the front main blade fingers and the rear main blade fingers completely overlap, so as to avoid the gear rack from being unable to mesh when cutting the fruit next time. Similarly, the secondary blade assembly will be completely reset; when the cylindrical pin slides back into the straight groove range in the cylindrical pin groove, the push rod spring is close to the natural state, and the tension generated by the two guide sleeve springs will play a major role. At this time, the double gear shaft retreats with the telescopic rod, and the secondary blade assembly approaches the main blade assembly again along the axis direction of the two guide rods until the outer cone surface of the main guide hollow male shaft is inserted into the inner cone surface of the secondary guide hollow female shaft, and the secondary blade assembly and the main blade assembly are re-overlapped together, and then the pinion and the two guide rods are successively withdrawn from the finger blade mechanism; finally, the finger blade mechanism and the main body of the manipulator palm are reset to the unfolded posture, and the manipulator is ready for the next fruit picking. ;

[0013] The beneficial effects of the present invention are as follows: the top of the branch with fruits and the root of the fruit stalk can be cut off at the same time, thereby realizing the automated one-fruit-two-cutting of citrus fruits, thereby avoiding the problem of manual top pruning after the citrus is harvested by robots; at the same time, the fruit combing method is used to find the cutting position of the fruit stalk, reducing the excessive requirements for the machine vision positioning accuracy; the shearing method is used to pick fruits, avoiding the integration of compressed air source in the equipment; the entire device, as the end effector of the robotic arm, only needs to control the extension and retraction of two electric push rods to minimize the control complexity of the fruit picking device; based on the above advantages, the present device is expected to play an important role in the promotion and application of robot automated citrus picking. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the present invention when it is in a posture ready to cut fruit, as viewed from above the "palm".

[0015] Figure 2 It is a schematic diagram of the structure of the present invention when the posture of preparing to cut fruit is observed from the bottom of the "back of the hand".

[0016] Figure 3 The schematic diagram is a side view of the running position of the present invention equipped with a fruit-dropping flexible pipe when the present invention is in an unfolded posture with the palm facing upward and is about to go around from under the target fruit to the rear of the fruit.

[0017] Figure 4 It is a schematic diagram of the operating position when the present invention equipped with the fruit-dropping flexible pipe is observed from the side and moves upward in an unfolded posture with fingertips upward until the target fruit is separated from other branches or fruits.

[0018] Figure 5 The present invention is a schematic diagram of the position when the present invention equipped with a fruit-dropping flexible pipe is observed from the side and the branches connected to the fruit stalk of the target fruit are just "combed" into the gap between the fingers.

[0019] Figure 6 It is a schematic diagram of the structure of the main blade group and the auxiliary blade group observed from the front.

[0020] Figure 7 It is a schematic diagram of the structure of the main blade group and the auxiliary blade group observed from the back.

[0021] Figure 8 It is a schematic diagram of the structure of two blade guide sleeves.

[0022] Fig. 9 It is a partial cross-sectional structural diagram of the present invention in a posture ready to cut fruit, looking down from the "palm".

[0023] Fig.10 yes Fig. 9 The detailed diagram at A is also a diagram of the installation structure of the blade guide sleeve in the present invention.

[0024] Fig.11 It is a partial cross-sectional structural diagram of the present invention when the pinion gear is just meshed with the front auxiliary rack and the rear auxiliary rack when the fruit is just being cut, as viewed from the "palm" above.

[0025] Fig.12 It is a partial cross-sectional structural diagram when the present invention is viewed from above the "palm" when the large gear is just meshing with the front main rack and the rear main rack at the beginning of fruit cutting.

[0026] Fig.13 It is a partial cross-sectional structural diagram of the present invention when the fruit stalk and the top branches are cut off when the fruit is cut off, looking down from the "palm" directly above.

[0027] Fig.14 The present invention is a schematic diagram of the structure when the fruit stalk and the top branches are cut off when the fruit is cut off from the upper side of the "palm". Fig.13 Schematic diagram of the entire device structure when viewed along the direction of view arrow B.

[0028] Fig.15 The schematic diagram of the local structure of the present invention when the fruit stalk and the top branch are cut off when the fruit is cut off is observed from the bottom of the "back of the hand". Fig.13 Schematic diagram of the local structure when viewed along the direction of view arrow E.

[0029] Fig.16 It is a structural diagram of a push-turn hinge.

[0030] Markings in the figure are: 00-target fruit, 01-flexible pipe, 1-finger blade mechanism, 2-blade push-turn mechanism, 3-manipulator palm body, 11-main blade group, 12-auxiliary blade group, 13-blade guide sleeve, 111-front main blade, 112-rear main blade, 121-front auxiliary blade, 122-rear auxiliary blade, 1111-front main blade finger, 1112-front main blade edge, 1113-front main gear ring hole, 1114-front main rack, 1115-front main waist hole, 1116-front main shallow pit, 1121-rear main blade Finger, 1122-rear main blade, 1123-rear main gear ring hole, 1124-rear main rack, 1125-rear main waist hole, 1126-rear main shallow pit, 1213-front auxiliary gear ring hole, 1211-front auxiliary blade finger, 1214-front auxiliary rack, 1223-rear auxiliary gear ring hole, 1224-rear auxiliary rack, 1227-strip baffle, 131-main guide sleeve, 132-auxiliary guide sleeve, 133-guide sleeve spring, 1311-main guide sleeve core, 1312-main guide sleeve box, 13111-main guide hollow male shaft, 131 12-main hollow external threaded shaft, 13113-main sleeve core flange, 13114-front main circular convex bulge, 13121-main hollow internal threaded shaft, 13122-main sleeve box flange, 13123-rear main circular convex bulge, 1321-secondary guide sleeve core, 1322-secondary guide sleeve box, 13211-secondary guide hollow female shaft, 13212-secondary hollow external threaded shaft, 13213-secondary guide sleeve core flange, 13221-secondary hollow internal threaded shaft, 13222-secondary guide sleeve box flange, 1215-front secondary waist hole, 31 -palm body, 32-forepalm push rod, 33-push-turn hinge, 34-guide rod support, 311-hinge shaft, 312-hinge shaft, 331-hinge shaft sleeve, 332-push rod shaft, 21-blade push rod, 22-double gear shaft, 23-push rod spring, 24-guide rod, 211-telescopic rod, 212-connecting rod, 213-thin shaft, 214-cylindrical pin, 221-small gear shaft, 222-large gear shaft, 223-pinion pin groove, 224-small gear, 225-large gear, 226-retaining ring, 227-spherical crown surface. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings.

[0032] This embodiment provides a manipulator suitable for picking citrus fruits using the one-fruit-two-cut method, which is installed on a six-degree-of-freedom manipulator as an end effector. Figure 1 , 2, 3, it comprises a finger-shaped blade mechanism 1, a blade pushing and rotating mechanism 2 and a manipulator palm body 3. The finger-shaped blade mechanism 1 can rotate upward or downward relative to the manipulator palm body 3 around a hinge shaft 311 located at the front end of the manipulator palm body 3. When the finger-shaped blade mechanism 1 rotates downward to the limit position, the manipulator palm body 3 and the manipulator palm body 3 are located in the same plane ( Figure 3 ), which is equivalent to the unfolding posture, and then the finger blade mechanism 1 and the robot palm body 3 are rotated upward to form a 90° angle to enter the fruit cutting posture ( Figure 1 );like Figure 6-Figure 10 As shown, the finger blade mechanism 1 is composed of a main blade group 11 and an auxiliary blade group 12 which are overlapped under the guiding and clamping action of two blade guide sleeves 13. After entering the fruit cutting posture, the auxiliary blade group 12 can be separated from the overlapping state relative to the main blade group 11 along the axial direction of the blade guide sleeve 13 to a position relationship having a spacing requirement between two pruning points that meets the agronomic requirement of "one fruit, two prunings" ( Fig.12 ); Each blade guide sleeve 13 includes a main guide sleeve 131, a secondary guide sleeve 132 and a guide sleeve spring 133; the main blade set 11 is composed of a front main blade 111 and a rear main blade 112 in the shape of four open fingers overlapped under the clamping of two main guide sleeves 131, and the secondary blade set 12 is composed of a front secondary blade 121 and a rear secondary blade 122 in the shape of four open fingers overlapped under the clamping of two secondary guide sleeves 132; Figure 13-Figure 15 As shown, when cutting the fruit, the front main blade 111 can slide relative to the rear main blade 112 in a direction perpendicular to its four-finger length under the common guidance of the two main guide sleeves 131 to complete the cutting of the branches at the fruit stalk. At the same time, the front auxiliary blade 121 can slide relative to the rear auxiliary blade 122 in a direction perpendicular to its four-finger length under the common guidance of the two auxiliary guide sleeves 132 to complete the pruning of the top of the fruit branch, thereby completing one fruit and two cuts.

[0033] like Figure 6 , Figure 7As shown, the four front main blade fingers 1111 of the front main blade 111 are bent upward (toward the palm center), the width between the fingers is slightly larger than the maximum possible diameter of the branch at the stalk of the citrus fruit to be picked, the two opposite edges of the two adjacent fingers are chamfered along the finger length direction to form a front main blade 1112, the fingertips are provided with arc chamfers to guide the fruit stalk branches, a rectangular front main tooth ring hole 1113 is provided in the center below the four fingers, and a row of front teeth are provided on the hole wall on one side perpendicular to the length direction of the front main blade fingers 1111. The main rack 1114, the front main gear ring hole 1113 has a front main waist hole 1115 on both sides, and each front main waist hole 1115 has a circular front main shallow pit 1116 on the outer surface of the middle section in the length direction, and the distance between the centers of the arcs at both ends of the front main waist hole 1115 is greater than the width between the adjacent fingers of the four front main blade fingers 1111; the main shape of the rear main blade 112 is consistent with the main front blade 111, so that the rear main blade 112 and the main front blade 111 can just overlap and fit together to form a main blade set 11. The inter-finger and fingertip shapes formed by the four rear main blade fingers 1121 on the rear main blade 112 are exactly the same as the inter-finger and fingertip shapes formed by the four front main blade fingers 1111. The rear main blade edges 1122 formed by chamfering the two opposite edges of the adjacent two fingers of the rear main blade finger 1121 along the finger length direction are exactly opposite to the cutting edges of the front main blade edge 1112, so that a seamless blade edge is formed along the finger length direction at the opposite edges of each adjacent two fingers. The rear main blade finger 1121 provided at the center below the rear main blade finger 1121 is provided with a plurality of rear main blade fingers 1122, and the rear main blade finger 1122 is provided with a plurality of rear main blade fingers 1121 ... The gear ring hole 1123 coincides with the front main gear ring hole 1113, but the rear main rack 1124 provided on the hole wall on one side of the rear main gear ring hole 1123 coincides with the hole wall where the front main rack 1114 is located, and the two rear main waist-shaped holes 1125 provided on both sides of the rear main gear ring hole 1123 coincide with the two front main waist-shaped holes 1115, and the rear main shallow pits 1126 on the rear main waist-shaped holes 1125 coincide with the front main shallow pits 1116 relative to the fitting surface of the front main blade 111 and the rear main blade 112.

[0034] The square hole side length of the front auxiliary gear ring hole 1213 on the front auxiliary blade 121 in the direction parallel to the length of the front auxiliary blade finger 1211 on the front auxiliary blade 121 is shorter than the square hole side length of the corresponding front main gear ring hole 1113 in the direction parallel to the length of the front main blade finger 1111, and the module of the front auxiliary rack 1214 arranged on the hole wall on one side of the front auxiliary gear ring hole 1213 is smaller than the module of the corresponding front main rack 1114. Apart from this, the structure and shape of the front auxiliary blade 121 are exactly the same as those of the front main blade 111; the rear auxiliary gear ring hole 1223 on the rear auxiliary blade 122 is similar to the front auxiliary gear ring hole 1213 The rear auxiliary rack 1224 is exactly overlapped, but the rear auxiliary rack 1224 arranged on the hole wall on one side of the rear auxiliary gear ring hole 1223 is just opposite to the hole wall where the front auxiliary rack 1214 is located. The rear auxiliary gear ring hole 1223 is fixedly connected with a strip baffle 1227 parallel to the rear auxiliary rack 1224 in the middle of an end surface away from the front auxiliary blade 121. The strip baffle 1227 has a sliding groove along its own length direction on the surface of the side facing the rear auxiliary gear ring hole 1223. In addition, the structure and shape of the rear auxiliary blade 122 are exactly the same as those of the rear main blade 112; the front auxiliary blade 121 and the rear auxiliary blade 122 are just completely overlapped and fitted to form the auxiliary blade set 12;

[0035] like Figure 8 , Fig. 9 , Fig.10As shown, the main guide sleeve 131 is composed of a main guide sleeve core 1311 and a main guide sleeve box 1312; the main guide sleeve core 1311 includes a main guide hollow male shaft 13111, a main hollow externally threaded shaft 13112 and a circular main guide sleeve core flange 13113, the main guide hollow male shaft 13111 and the main hollow externally threaded shaft 13112 are coaxially arranged, one end of each of them is coaxially fixedly connected to the main guide sleeve core flange 13113, the other end of the main guide hollow male shaft 13111 has an outer cone shape, and the length of the main guide hollow male shaft 13111 is longer than the main hollow externally threaded shaft 1311. 2 is longer, and the outer diameter is smaller than the inner diameter of the main hollow external threaded shaft 13112. The gap between the outer cylindrical surface of the main guide hollow male shaft 13111 and the inner cylindrical surface of the main hollow external threaded shaft 13112 can accommodate the guide sleeve spring 133. The inner hole of the guide sleeve core flange 13113 is consistent with the inner hole diameter of the main guide hollow male shaft 13111. On the same side of the flange surface and the main guide hollow male shaft 13111, a front main circular convex bulge 13114 is provided which gradually bulges from the edge to the center. The convex bulge is just complementary to the front main shallow pit 1116. The main guide sleeve box 1312 includes a The main hollow internal threaded shaft 13121 and a circular main guide sleeve flange 13122, one end of the main hollow internal threaded shaft 13121 is coaxially fixedly connected to the main guide sleeve flange 13122, and the inner hole of the main guide sleeve flange (13122) is consistent with the inner hole of the main hollow internal threaded shaft (13121) The aperture, a rear main circular convex bulge 13123 that gradually bulges from the edge to the center is provided on the same side of the flange surface and the main hollow internal threaded shaft 13121 that is fixedly connected, and the convex bulge is just complementary to the rear main shallow pit 1126; the external thread on the main hollow external threaded shaft 13112 can be It is completely screwed into the internal thread of the main hollow internal threaded shaft 13121. At this time, the front main circular convex bump 13114 is exactly opposite to the rear main circular convex bump 13123. The outer cylindrical diameter of the main hollow internal threaded shaft 13121 is slightly larger than the width of the front main waist-shaped hole 1115, so that its outer cylindrical surface can be inserted into the waist-shaped hole and the relative disk surfaces of the main sleeve core flange 13113 and the main sleeve box flange 13122 can just clamp the main blade group 11; the two screwed-in main sleeves 131 are respectively inserted into the two front main waist-shaped holes 1115 to clamp the main blade group 11 together.Auxiliary guide sleeve 132 The auxiliary guide sleeve core 1321 and the auxiliary guide sleeve box 1322 are composed of a secondary guide sleeve core 1321 and a secondary guide sleeve box 1322; the secondary guide sleeve core 1321 includes a secondary guide hollow female shaft 13211, a secondary hollow externally threaded shaft 13212 and a circular secondary guide sleeve core flange 13213, and the secondary guide sleeve box 1322 includes a secondary hollow internally threaded shaft 13221 and a circular secondary guide sleeve box flange 13222; one end of the secondary guide hollow female shaft 13211 is coaxially fixedly connected to the secondary guide sleeve core flange 13213, and the inner cylindrical surface of the other end thereof is an inner cone, which can be positioned with the outer cone section on the outer cylindrical surface of one end of the main guide hollow male shaft 13111. In addition, the structure and shape of the auxiliary guide sleeve 132 are exactly the same as those of the main sleeve 131. The two screwed-on auxiliary guide sleeves 132 are respectively inserted into the two front auxiliary waist holes 1215 on the front auxiliary blade 121 located on both sides of the front auxiliary gear ring hole 1213 to jointly clamp the auxiliary blade group 1 2; The inner holes of the two main guide hollow male shafts 13111 are exactly aligned with the inner holes of the two auxiliary guide hollow female shafts 13211, and the inner conical surface of one end of the auxiliary guide hollow female shaft 13211 is also exactly opposite to the outer conical surface of one end of the main guide hollow male shaft 13111; the guide sleeve spring 133 is a tension spring, which is installed outside the outer cylindrical surface of the main guide hollow male shaft 13111 and the auxiliary guide hollow female shaft 13211, and the main hollow external threaded shaft 1311 2 and the gap within the inner cylindrical surface of the auxiliary hollow externally threaded shaft 13212, one end is fixedly connected to the main guide sleeve core flange 13113, and the other end is fixedly connected to the auxiliary guide sleeve core flange 13213. When the main blade group 11 and the auxiliary blade group 12 are superimposed together, the outer conical surface of one end of the main guide hollow male shaft 13111 is inserted into the inner conical surface of one end of the auxiliary guide hollow female shaft 13211 and the guide sleeve spring 133 is in a contracted state with a certain pre-stretching force.

[0036] like Figure 1 , Figure 2 , Figure 3 , Fig.16 As shown, the robot palm body 3 includes a palm body 31, a front palm push rod 32, a push-turn hinge 33 and two guide rod supports 34; the two guide rod supports 34 are symmetrically fixed to the upper surface of the palm body 31 on both sides parallel to the length direction of the palm body 31, and the front end of the palm body 31 has a hinge shaft 311 installed perpendicular to the length direction of the palm body 31. The front palm push rod 32 is an electric push rod, and its motor end housing is connected to a hinge shaft 312 below the palm body 31 through a hinge, and its telescopic end head has a hinge hole, and the hole axis is parallel to the axis of the hinge shaft 311; the push-turn hinge 33 includes a hinge shaft sleeve 331 and a push rod shaft 332 ( Fig.16), the axes of the two are parallel to each other and fixedly connected to each other, the finger-shaped blade mechanism 1 as a whole is fixedly connected to the push-turn hinge 33 through two main guide sleeve core flanges 13113, and the axis of the hinge shaft sleeve 331 is perpendicular to the axis direction of the inner hole of the main guide hollow male shaft 13111, the hinge shaft 311 is inserted into the hinge shaft sleeve 331 to form the rotation axis of the finger-shaped blade mechanism 1 relative to the robot palm body 3, and the push rod shaft 332 is inserted into the hinge hole of the telescopic end of the forepalm push rod 32. When the telescopic end of the forepalm push rod 32 is extended or shortened, the entire finger-shaped blade mechanism 1 can be driven by the push-turn hinge 33 to rotate around the axis of the hinge shaft 311 relative to the robot palm body 3.

[0037] like Figure 1 , Fig.11 , Fig.12 , Fig.13 , Fig.14 , Fig.15 As shown, the blade pushing mechanism 2 includes a blade push rod 21, a double gear shaft 22, a push rod spring 23 and two guide rods 24; the blade push rod 21 is modified from an electric push rod, and its motor end housing and outer sleeve are fixedly connected to the middle of the upper surface of the palm body 31, and its telescopic rod 211 can only telescopically move relative to the outer sleeve but cannot rotate, and the axis of the telescopic rod 211 is parallel to the upper surface of the palm body 31 and perpendicular to the axis of the hinge shaft 311, and two connecting rods 212 are fixedly connected to the two connecting rods 212 on both sides of the rear part of the telescopic rod 211, and the two guide rods 24 are fixedly connected to the two connecting rods 212, respectively. The axes of the two guide rods 24 are parallel to each other and pass through the guide holes of the two guide rod supports 34, respectively. When the finger-shaped blade mechanism 1 and the mechanical palm body 3 are at an angle of 90° and are ready to start cutting the fruit, the axes of the two guide rods 24 just coincide with the axes of the two main guide hollow male shafts 13111, respectively, but are separated from the finger-shaped blade mechanism 1 ( Figure 1 , Fig. 9), the outer diameter of the guide rod 24 is consistent with the inner diameter of the main guide hollow male shaft 13111, and can be smoothly inserted; the front end of the telescopic rod 211 has a coaxial thin shaft 213, and the front part of the telescopic rod 211 adjacent to the thin shaft 213 has a cylindrical pin 214, and the axis of the cylindrical pin 214 is perpendicular to the axis of the telescopic rod 211; the double gear shaft 22 is a step shaft with a step hole, the front end of which is a hollow small gear shaft 221, and the rear end is a coaxial hollow large gear shaft 222, and the outer diameter and inner hole diameter of the small gear shaft 221 are larger than those of the large gear shaft 222. The thin shaft 213 is just inserted into the inner hole of the small gear shaft 221. The push rod spring 23 is a compression spring installed in the gap between the front end of the thin shaft 213 and the bottom of the inner hole of the small gear shaft 221. Its stiffness coefficient is at least twice the stiffness coefficient of the guide sleeve spring 133. There is a column pin groove 223 on the cylindrical wall of the large gear shaft 222. The section of the front part of the telescopic rod 211 with the cylindrical pin 214 is just inserted into the inner hole of the large gear shaft 222 from the tail end, and the cylindrical pin 214 is just inserted into the column pin groove 223 and can slide in the groove along its entire length. The pin groove 223 is a straight groove parallel to the axis of the large gear shaft 222 near the tail of the large gear shaft 222, and gradually transitions forward to a spiral groove with the axis of the large gear shaft 222 as the rotation axis; the front end of the pinion shaft 221 is fixedly connected to a small gear 224, whose modulus is consistent with the modulus of the front auxiliary rack 1214 and can be normally meshed with it, and the front end of the large gear shaft 222 and the small gear shaft 221 are fixedly connected to a large gear 225, whose modulus is consistent with the modulus of the front main rack 1114 and can be normally meshed with it. When the finger blade mechanism 1 and the robot palm body (3) are at an angle of 90° and are ready to start cutting the fruit, the large gear 225 and the small gear 224 are both separated from the finger blade mechanism 1. The pitch circle of the large gear 225 is exactly tangent to the pitch lines of the front main rack 1114 and the rear main rack 1124 on the upper and lower sides when viewed along the axis of the dual gear shaft 22. The pitch circle of the small gear 224 is exactly tangent to the pitch lines of the front auxiliary rack 1214 and the rear auxiliary rack 1224 on the upper and lower sides when viewed along the axis of the dual gear shaft 22.The end face of the large gear 225 away from the finger-shaped blade mechanism 1 is fixedly connected to a retaining ring 226 with an outer diameter larger than the width of the front main gear ring hole 1113 in a direction parallel to the length of the front main blade finger 1111. When the large gear 225 moves along with the blade push rod 21 in the direction close to the finger-shaped blade mechanism 1 until it is meshed with the front main rack 1114 and the rear main rack 1124, the front end face of the retaining ring 226 contacts the end face of the front main gear ring hole 1113 to prevent the large gear 225 and the double gear shaft 22 connected thereto from continuing to move forward and allow the retaining ring 226 to slide relative to the front main blade 111 in a direction perpendicular to the length of the front main blade finger 1111. At the same time, the small gear 224 has passed through the front main gear ring hole 1113 and the rear main gear ring hole 1123 and meshes with both the front auxiliary rack 1214 and the rear auxiliary rack 1224. The convex spherical crown surface 227 on the outer end surface of the pinion gear 224 just matches the cross section of the slide groove of the strip baffle 1227, which can not only make the auxiliary blade group 12 separate from the main blade group 11 under the action of the strip baffle 1227 pushed by the end surface of the pinion gear 224, but also make the end surface of the pinion gear 224 slide relative to the rear auxiliary blade 122 along the slide groove direction of the strip baffle 1227; the length of the two guide rods 24 is sufficient when the auxiliary blade group 12 just separates from the main blade group 11 from the original overlapping state, the two guide rods 24 have been inserted into and passed through the inner holes of the two auxiliary guide hollow female shafts 13211. ;

[0038] The working principle of the above embodiment is: the whole device is fixedly installed on a six-degree-of-freedom robot arm as an end effector, and the fixed connection with the end of the robot arm is located at the tail of the robot palm body 3. In the initial state, the finger blade mechanism 1 and the robot palm body 3 are located in the same plane and are in an unfolded posture, and a flexible pipe 01 for receiving fallen fruits is installed at an appropriate position at the rear of the "palm" to lead to the fruit basket, such as Figure 3 , using machine vision technology to determine the center point position coordinates and maximum radius of the target fruit 00, and predict the position coordinates of its fruit stem. Based on these parameters, the robotic arm drives the unfolded device to an initial position with the "palm" facing upwards, in a similar Figure 3 Follow the dotted arrow in the figure, go around from the bottom of the target fruit 00 to the back of the fruit, and then slowly move your fingertips upward until the entire target fruit 00 is separated from other branches or fruits ( Figure 4 When the four "fingers" of the finger-shaped blade mechanism 1 exceed the predetermined fruit handle position coordinates by a certain distance upward, the telescopic end of the forefoot push rod 32 extends to drive the finger-shaped blade mechanism 1 to rotate around the hinge shaft 311 as a whole (such as Figure 4The dotted arrow track in the figure), at the same time, the robotic arm can still drive the entire device to slowly move and fine-tune upwards so that the position of the axis of the hinge shaft 311 is basically the same height as the position of the fruit stalk; as the finger-shaped blade mechanism 1 rotates around the hinge shaft 311 as a whole, the branches connected to the fruit stalk will be "combed" into the gaps between the four fingers. Since there are three inter-finger gaps side by side, even if there is a certain error in the calculation of the position of the fruit stalk, it can be ensured that the branches at the fruit stalk enter at least one of the inter-finger gaps; when the finger-shaped blade mechanism 1 is rotated to an angle of 90° relative to the main body of the robotic palm, the position of the entire device is fine-tuned downwards by using machine vision and the robotic arm, so that the inner surfaces of the four fingers just contact the epidermis of the fruit stalk, and then the posture of the entire device is fine-tuned by using machine vision and the robotic arm, so that the fruit is basically aligned with the entrance of the flexible pipe 01 arranged in advance for receiving the fallen fruit. At this time, the entire device has entered a posture ready to cut the fruit (such as Figure 5 as shown); Fig. 9 , the blade push rod 21 begins to extend, thereby driving the two guide rods 24 fixed thereto and the coaxial double gear shaft 22 to translate toward the direction close to the finger blade mechanism 1; Fig.11 When the front end face of the pinion 224 at the front end of the double gear shaft 22 just contacts the slide groove of the strip baffle 1227 fixed to the rear auxiliary blade, the two guide rods 24 have been inserted into and passed through the inner holes of the two blade guide sleeves 13, thereby becoming the translation guide rails when the main sleeve 131 and the auxiliary guide sleeve 132 are separated, and the pinion 224 has entered into a meshing state with the front auxiliary rack 1214 and the rear auxiliary rack 1224 at the same time; as the blade push rod 21 continues to extend, the pinion 224 will push the entire auxiliary blade group 12 to align with the main guide sleeve 131, and the pinion 224 will enter into a meshing state with the front auxiliary rack 1214 and the rear auxiliary rack 1224. The blade assembly 11 begins to separate, and at this time, the two guide sleeve springs 133 in the two blade guide sleeves 13 are stretched, and the push rod spring 23 located in the gap between the front end of the thin shaft 213 and the bottom of the inner hole of the small gear shaft 221 is compressed, which will cause the cylindrical pin 214 at the front of the telescopic rod 211 to start sliding in the cylindrical pin groove 223 on the wall of the large gear shaft 222. However, since the stiffness of the push rod spring 23 is greater than that of the two guide sleeve springs 133 in parallel, when the two guide sleeve springs 133 are stretched to the Fig.12When the retaining ring 226 fixedly connected to the rear of the large gear 225 has been in contact with the front main blade 111, the sliding stroke of the cylindrical pin 214 in the pin groove 223 is still within the straight groove range close to the tail of the large gear shaft 222. Therefore, during this period, the double gear shaft 22 will not rotate relative to the telescopic rod 211, and the large gear 225 and the small gear 224 will not rotate either; after the retaining ring 226 fixedly connected to the rear of the large gear 225 has been in contact with the front main blade 111, the double gear shaft 22 can no longer move forward relative to the finger blade mechanism 1. At this time, as the telescopic rod 211 continues to extend, the push rod spring 23 will be further compressed, causing the cylindrical pin 214 to slide into the spiral groove range in the pin groove 223. 211 cannot rotate relative to the robot palm body 3, so the double-gear shaft 22 and the large gear 225 and the small gear 224 fixed thereon will rotate and respectively drive the front main rack 1114, the rear main rack 1124 and the front auxiliary rack 1214, the rear auxiliary rack 1224 meshing therewith to translate. As long as the forefoot push rod 32 does not extend or retract at this time, the positions of the two main guide sleeves 131 relative to the robot palm body 3 will not change, and the two auxiliary guide sleeves 132 will only have one degree of freedom of movement along the axial direction of the guide rod 24. Therefore, the front main blade 111 and the rear main blade 112 will translate in opposite directions respectively with the front main rack 1114 and the rear main rack 1124 under the common guiding action of the two main guide sleeves 131, as shown in FIG. Fig.13 , Fig.14 , Fig.15As shown; the previously overlapped front main blade finger 1111 and the rear main blade finger 1121 will translate relative to each other to form a shearing effect on the branches at the fruit stalk located in a certain gap between the fingers, cutting off the branches at the fruit stalk, and the target fruit 00 falls into the flexible pipe 01. Similarly, the front auxiliary blade 121 and the rear auxiliary blade 122 will translate in opposite directions respectively along with the front auxiliary rack 1214 and the rear auxiliary rack 1224 under the joint action of the two auxiliary guide sleeves 132, thereby cutting off the fruit branches at a certain distance in front of the fruit stalk, thereby achieving the effect of pruning the top tip; when the cylindrical pin 214 moves to When the front main blade 111 and the rear main blade 112 are completely moved, the gaps between the four fingers are completely closed and the two shearing operations are completed. Then, the blade push rod 21 retracts backwards. Under the action of the push rod spring 23, the double gear shaft 22 does not retract immediately, but rotates in the opposite direction as the cylindrical pin 214 slides in the opposite direction in the pin groove 223. The large gear 225 and the small gear 224 rotate in the opposite direction to respectively drive the front main blade 111, the rear main blade 112 and the front auxiliary blade 121, and the rear auxiliary blade 122 to reset. When the four fingers are about to overlap, the front main shallow pit 1116 and the rear auxiliary pit 1117 are in the front main shallow pit 1118 and the rear auxiliary pit 1119. Under the action of mutual reset of the main shallow pit 1126, the front main circular convex bump 13114 and the rear main circular convex bump 13123, the main blade assembly 11 can be completely reset to the point where the four fingers of the front main blade finger 1111 and the rear main blade finger 1121 completely overlap, so as to avoid the problem that the gear rack cannot be engaged when cutting the fruit next time. Similarly, the auxiliary blade assembly 12 will also be completely reset; when the cylindrical pin 214 slides backwards into the straight groove range in the cylindrical pin groove 223 again, the push rod spring 23 is close to the natural state, and the tension generated by the two guide sleeve springs 133 will The double gear shaft 22 retreats with the telescopic rod 211, and the auxiliary blade group 12 approaches the main blade group 11 again along the axial direction of the two guide rods 24 until the outer conical surface of the main guide hollow male shaft 13111 is inserted into the inner conical surface of the auxiliary guide hollow female shaft 13211, and the auxiliary blade group 12 and the main blade group 11 are overlapped together again, and then the small gear 224 and the two guide rods 24 are successively withdrawn from the finger-shaped blade mechanism 1; finally, the finger-shaped blade mechanism 1 and the robot palm body 3 are reset to the unfolded posture, and the robot arm is ready for the next fruit picking.

Claims

1. A manipulator suitable for picking citrus fruits using the one-fruit-two-cut method, characterized in that: It is installed on a six-degree-of-freedom robot arm as an end effector, and comprises a finger-shaped blade mechanism (1), a blade pushing and rotating mechanism (2) and a robot palm body (3). The finger-shaped blade mechanism (1) can rotate upward or downward relative to the robot palm body (3) around a hinge shaft (311) located at the front end of the robot palm body (3). When the finger-shaped blade mechanism (1) rotates downward to the limit position, the robot palm body (3) and the robot palm body (3) are located in the same plane, which is equivalent to the unfolding posture. After the finger-shaped blade mechanism (1) and the robot palm body (3) are rotated upward so that the finger-shaped blade mechanism (1) and the robot palm body (3) form an angle of 90°, the robot palm body (3) can enter the fruit cutting posture. The finger-shaped blade mechanism (1) is composed of a main blade group (11) and an auxiliary blade group (12) overlapped under the guiding and clamping action of two blade guide sleeves (13). After entering the fruit cutting posture, the auxiliary blade group (12) can move relative to the main blade group (11) along the axis of the blade guide sleeve (13). The present invention relates to a method for separating the blades from a superimposed state to a positional relationship having a spacing requirement between two pruning points that meets the agronomic requirement of "one fruit, two prunings"; each blade guide sleeve (13) comprises a main guide sleeve (131), a secondary guide sleeve (132) and a guide sleeve spring (133); the main blade group (11) is composed of a front main blade (111) and a rear main blade (112) in the shape of four fingers opened and overlapped under the clamping of two main guide sleeves (131); the secondary blade group (12) is composed of a front secondary blade (121) and a rear secondary blade (122) in the shape of four fingers opened and overlapped under the clamping of two secondary guide sleeves (132); when pruning the fruit, the front main blade (111) can slide relative to the rear main blade (112) in a direction perpendicular to its four-finger length under the common guidance of the two main guide sleeves (131) to complete the pruning of the branches at the fruit stalk, and at the same time, the front secondary blade (121) can slide relative to the rear secondary blade (122) Under the common guidance of the two auxiliary guide sleeves (132), the guide sleeve slides in a direction perpendicular to the length of four fingers to complete the pruning of the top of the fruit branch, thereby completing two prunings for one fruit; The four front main blade fingers (1111) of the front main blade (111) are all bent upwards, and the width between the fingers is slightly larger than the maximum possible diameter of the branches at the stalk of the citrus fruit to be picked. The two opposite edges of two adjacent fingers are chamfered along the finger length direction to form a front main blade (1112), and the fingertips are provided with arc chamfers to guide the fruit stalk branches. A rectangular front main tooth ring hole (1113) is provided in the center below the four fingers, and a row of front main tooth racks (1114) are provided on the hole wall on one side perpendicular to the length direction of the front main blade fingers (1111). There is a front main waist-shaped hole (1115) on each side of the circle hole (1113), and each front main waist-shaped hole (1115) has a circular front main shallow pit (1116) on the outer surface of the middle section in the length direction, and the distance between the arc centers of the two ends of the front main waist-shaped hole (1115) is greater than the width between the adjacent fingers of the four front main blade fingers (1111); the main body shape of the rear main blade (112) is consistent with the main front blade (111), so that the rear main blade (112) and the main front blade (111) can just overlap and fit together to form the main blade group (11), and the rear main blade The shapes of the inter-finger and fingertips formed by the four rear main blade fingers (1121) on the sheet (112) are exactly the same as the shapes of the inter-finger and fingertips formed by the four front main blade fingers (1111). The rear main blade edges (1122) formed by chamfering the two opposite edges of the adjacent two fingers of the rear main blade fingers (1121) along the finger length direction are exactly opposite to the cutting edges of the front main blade edges (1112), so that seamless blade edges are formed along the finger length direction at the opposite edges of each adjacent two fingers. The rear main gear ring hole (1123) is arranged at the center below the rear main blade fingers (1121). The rear main gear ring hole (1123) is exactly coincident with the front main gear ring hole (1113), but the rear main rack (1124) arranged on the hole wall on one side of the rear main gear ring hole (1123) is exactly opposite to the hole wall where the front main rack (1114) is located, and the two rear main waist-shaped holes (1125) arranged on both sides of the rear main gear ring hole (1123) are exactly coincident with the two front main waist-shaped holes (1115), and the rear main shallow pit (1126) on the rear main waist-shaped hole (1125) is exactly symmetrical with the front main shallow pit (1116) relative to the fitting surface of the front main blade (111) and the rear main blade (112); The square hole side length of the front auxiliary gear ring hole (1213) on the front auxiliary blade (121) in the direction parallel to the length of the front auxiliary blade finger (1211) on the front auxiliary blade (121) is shorter than the square hole side length of the corresponding front main gear ring hole (1113) in the direction parallel to the length of the front main blade finger (1111), and the module of the front auxiliary rack (1214) arranged on the hole wall on one side of the front auxiliary gear ring hole (1213) is smaller than the module of the corresponding front main rack (1114). Apart from this, the structure and shape of the front auxiliary blade (121) are completely consistent with those of the front main blade (111); the rear auxiliary gear ring hole (1223) on the rear auxiliary blade (122) is similar to the front auxiliary gear ring hole (1213). ), but the rear auxiliary rack (1224) arranged on the hole wall of one side of the rear auxiliary gear ring hole (1223) is just opposite to the hole wall where the front auxiliary rack (1214) is located, and the rear auxiliary gear ring hole (1223) is fixedly connected with a strip baffle (1227) parallel to the rear auxiliary rack (1224) in the middle of an end surface away from the front auxiliary blade (121), and a slide groove along its own length direction is provided on the surface of the side of the strip baffle (1227) facing the rear auxiliary gear ring hole (1223). In addition, the structure and shape of the rear auxiliary blade (122) are completely consistent with the rear main blade (112); the front auxiliary blade (121) and the rear auxiliary blade (122) are just completely overlapped and fitted to form an auxiliary blade group (12); The main guide sleeve (131) is composed of a main guide sleeve core (1311) and a main guide sleeve box (1312); the main guide sleeve core (1311) includes a main guide hollow male shaft (13111), a main hollow externally threaded shaft (13112) and a circular main guide sleeve core flange (13113); the main guide hollow male shaft (13111) and the main hollow externally threaded shaft (13112) are coaxially arranged, one end of each of them is coaxially fixedly connected to the main guide sleeve core flange (13113); the outer cylindrical surface of the other end of the main guide hollow male shaft (13111) is in an external cone shape; the length of the main guide hollow male shaft (13111) is longer than the main hollow externally threaded shaft (13112); 13112) is longer and has an outer diameter smaller than the inner diameter of the main hollow externally threaded shaft (13112); the gap between the outer cylindrical surface of the main guide hollow male shaft (13111) and the inner cylindrical surface of the main hollow externally threaded shaft (13112) can accommodate the guide sleeve spring (133); the inner hole of the guide sleeve core flange (13113) is consistent with the inner hole diameter of the main guide hollow male shaft (13111); on the same side of the flange surface and the main guide hollow male shaft (13111) fixedly connected, a front main circular convex bulge (13114) is provided which gradually bulges from the edge to the center, and the convex bulge just complements the front main shallow pit (1116); the main guide sleeve box (1312) The invention comprises a main hollow internally threaded shaft (13121) and a circular main guide sleeve flange (13122), one end of the main hollow internally threaded shaft (13121) is coaxially fixedly connected to the main guide sleeve flange (13122), and the inner hole of the main guide sleeve flange (13122) has the same diameter as the inner hole of the main hollow internally threaded shaft (13121), and a rear main circular convex bulge (13123) which gradually bulges from the edge to the center is provided on the same side of the flange surface and the main hollow internally threaded shaft (13121) fixedly connected, and the convex bulge just complements the rear main shallow concave pit (1126); the external thread on the main hollow externally threaded shaft (13112) can be The main hollow internal threaded shaft (13121) is completely screwed into the internal thread. At this time, the front main circular convex bump (13114) and the rear main circular convex bump (13123) are just opposite to each other. The outer cylindrical diameter of the main hollow internal threaded shaft (13121) is slightly larger than the width of the front main waist-shaped hole (1115), so that the outer cylindrical surface can be inserted into the waist-shaped hole and the relative disk surfaces of the main sleeve core flange (13113) and the main sleeve box flange (13122) can just clamp the main blade assembly (11); the two screwed main sleeves (131) are respectively inserted into the two front main waist-shaped holes (1115) to clamp the main blade assembly (11) together. The auxiliary guide sleeve (132) is composed of an auxiliary guide sleeve core (1321) and an auxiliary guide sleeve box (1322); the auxiliary guide sleeve core (1321) includes an auxiliary guide hollow female shaft (13211), an auxiliary hollow external threaded shaft (13212) and a circular auxiliary guide sleeve core flange (13213), and the auxiliary guide sleeve box (1322) includes an auxiliary hollow internal threaded shaft (13221) and a circular auxiliary guide sleeve box flange (13222); one end of the auxiliary guide hollow female shaft (13211) is coaxially fixedly connected to the auxiliary guide sleeve core flange (13213), and the inner cylindrical surface of the other end thereof is in an inner conical shape, which can be exactly aligned with the main guide hollow male shaft. The outer conical section on the outer cylindrical surface of one end of the auxiliary guide sleeve (13111) cooperates for positioning. In addition, the structure and shape of the auxiliary guide sleeve (132) are completely consistent with those of the main guide sleeve (131). The two screwed auxiliary guide sleeves (132) are respectively inserted into the two front auxiliary waist holes (1215) located on both sides of the front auxiliary gear ring hole (1213) on the front auxiliary blade (121) to jointly clamp the auxiliary blade group (12); the inner holes of the two main guide hollow male shafts (13111) are exactly divided The guide sleeve spring (133) is a tension spring, which is installed outside the outer cylindrical surface of the main guide hollow male shaft (13111) and the auxiliary guide hollow female shaft (13211), and the main hollow externally threaded shaft (13112) and the auxiliary hollow externally threaded shaft (13111). 3212), one end is fixedly connected to the main guide sleeve core flange (13113), and the other end is fixedly connected to the secondary guide sleeve core flange (13213). When the main blade group (11) and the secondary blade group (12) are superimposed together, the outer conical surface of one end of the main guide hollow male shaft (13111) is inserted into the inner conical surface of one end of the secondary guide hollow female shaft (13211), and the guide sleeve spring (133) is in a contracted state with a certain pre-tensioning force.

2. The manipulator for picking citrus fruits using the one-fruit, two-cut method according to claim 1, characterized in that: The mechanical palm body (3) comprises a palm body (31), a front palm push rod (32), a push-turn hinge (33) and two guide rod supports (34); the two guide rod supports (34) are symmetrically fixed to the upper surface of the palm body (31) on both sides parallel to the length direction of the palm body (31); the front end of the palm body (31) has a hinge shaft (311) installed perpendicular to the length direction of the palm body (31); the front palm push rod (32) is an electric push rod, the motor end housing of which is connected to a hinge shaft (312) below the palm body (31) through a hinge, and the telescopic end head thereof has a hinge hole, the axis of the hole is parallel to the axis of the hinge shaft (311); the push-turn hinge (33) comprises a hinge shaft sleeve (331) and a push rod shaft (332), the axes of the two are parallel to each other and fixed to each other, and the finger blade mechanism (1) The whole is fixedly connected to the push-turn hinge (33) through the two main guide sleeve core flanges (13113), and the axis of the hinge shaft sleeve (331) is perpendicular to the axis of the inner hole of the main guide hollow male shaft (13111). The hinge shaft (311) is inserted into the hinge shaft sleeve (331) to form the rotation axis of the finger-shaped blade mechanism (1) relative to the robot palm body (3). The push rod shaft (332) is inserted into the hinge hole of the telescopic end of the forepalm push rod (32). When the telescopic end of the forepalm push rod (32) is extended or shortened, the push-turn hinge (33) can drive the entire finger-shaped blade mechanism (1) to rotate around the axis of the hinge shaft (311) relative to the robot palm body (3).

3. The manipulator for picking citrus fruits using the one-fruit, two-cut method according to claim 1, characterized in that: The blade pushing mechanism (2) comprises a blade pushing rod (21), a double gear shaft (22), a pushing rod spring (23) and two guide rods (24); the blade pushing rod (21) is modified from an electric pushing rod, the motor end housing and the outer sleeve are fixedly connected to the middle of the upper surface of the palm body (31), the telescopic rod (211) can only move telescopically relative to the outer sleeve but cannot rotate, the axis of the telescopic rod (211) is parallel to the upper surface of the palm body (31) and perpendicular to the axis of the hinge shaft (311), two connecting rods (212) are respectively fixedly connected to the two connecting rods (212), and the two guide rods (24) are respectively fixedly connected to the two connecting rods (212), and the axes of the two guide rods (24) are mutually parallel. The guide holes of the two guide rod supports (34) are parallel and pass through them respectively. When the finger-shaped blade mechanism (1) and the mechanical palm body (3) are at an angle of 90° and are ready to start cutting the fruit, the axes of the two guide rods (24) just coincide with the axes of the two main guide hollow male shafts (13111) but are separated from the finger-shaped blade mechanism (1). The outer diameter of the guide rod (24) is consistent with the inner hole diameter of the main guide hollow male shaft (13111) and can be smoothly inserted. The front end of the telescopic rod (211) has a coaxial thin shaft (213). The front part of the telescopic rod (211) adjacent to the thin shaft (213) has a cylindrical pin (214), and the axis of the cylindrical pin (214) is perpendicular to the axis of the telescopic rod (211). The double gear shaft (22) is A stepped shaft with a stepped hole, the front end of which is a hollow pinion shaft (221) and the rear end of which is a coaxial hollow large gear shaft (222). The outer diameter and inner hole diameter of the pinion shaft (221) are smaller than those of the large gear shaft (222). The thin shaft (213) is just inserted into the inner hole of the pinion shaft (221). The push rod spring (23) is a compression spring installed in the gap between the front end of the thin shaft (213) and the bottom of the inner hole of the pinion shaft (221). The stiffness coefficient of the push rod spring (23) is at least twice the stiffness coefficient of the guide sleeve spring (133). A column pin groove (223) is provided on the cylindrical wall of the large gear shaft (222). The section of the front part of the telescopic rod (211) with the cylindrical pin (214) is just inserted from the rear end of the large gear shaft (222). The cylindrical pin (214) is inserted into the inner hole thereof, and the cylindrical pin (214) is just inserted into the cylindrical pin groove (223) and can slide in the groove along its entire length. The cylindrical pin groove (223) is a straight groove parallel to the axis of the large gear shaft (222) near the tail of the large gear shaft (222), and gradually transitions forward to a spiral groove with the axis of the large gear shaft (222) as the rotation axis; the front end of the pinion shaft (221) is fixedly connected to a small gear (224), whose modulus is consistent with the modulus of the front auxiliary rack (1214) and can mesh with it normally; the front end of the large gear shaft (222) and the intersection of the pinion shaft (221) are fixedly connected to a large gear (225), whose modulus is consistent with the modulus of the front main rack (1114) and can mesh with it normally;When the finger-shaped blade mechanism (1) and the mechanical palm body (3) are at an angle of 90° and are ready to start cutting the fruit, the large gear (225) and the small gear (224) are both separated from the finger-shaped blade mechanism (1), and the pitch circle of the large gear (225) is exactly tangent to the pitch lines of the front main rack (1114) and the rear main rack (1124) on both sides, as viewed along the axis of the double gear shaft (22), and the pitch circle of the small gear (224) is exactly tangent to the pitch lines of the front auxiliary rack (1214) and the rear auxiliary rack (1224) on both sides, as viewed along the axis of the double gear shaft (22); an end face of the large gear (225) away from the finger-shaped blade mechanism (1) is fixedly connected to a hole (1113) having an outer diameter larger than that of the front main gear ring hole (1113) The retaining ring (226) has a width parallel to the length direction of the front main blade finger (1111). When the large gear (225) moves along with the blade push rod (21) in the direction close to the finger blade mechanism (1) and meshes with the front main rack (1114) and the rear main rack (1124), the front end surface of the retaining ring (226) contacts the end surface of the front main gear ring hole (1113) to prevent the large gear (225) and the double gear shaft (22) connected thereto from continuing to move forward and allow the retaining ring (226) to move relative to the front main blade (111). Sliding in a direction perpendicular to the length of the front main blade finger (1111), at the same time, the pinion (224) has passed through the front main gear ring hole (1113) and the rear main gear ring hole (1123) and is meshed with the front auxiliary rack (1214) and the rear auxiliary rack (1224), and the raised spherical crown surface (227) on the outer end surface of the pinion (224) is exactly matched with the cross section of the slide groove of the strip baffle (1227), which can make the auxiliary blade group (12) on the pinion (224) The end surface pushes the strip baffle (1227) to separate from the main blade assembly (11), and the end surface of the pinion gear (224) can also slide relative to the rear auxiliary blade (122) along the direction of the slide groove of the strip baffle (1227); the lengths of the two guide rods (24) are such that when the auxiliary blade assembly (12) and the main blade assembly (11) just start to separate from the original overlapping state, the two guide rods (24) are respectively inserted into and passed through the inner holes of the two auxiliary guide hollow female shafts (13211).

Images