Self-cleaning end effector based on flexible joint force feeling

Abstract

The invention provides a self-cleaning end effector based on flexible joint force sense, which comprises a clamping device, a movable base and a cutting and removing device, the clamping device comprises a body and a flexible clamping structure, the flexible clamping structure is arranged on the body, the body is arranged above the movable base, and the body can move on the movable base; the flexible clamping structure can deform so that the flexible clamping structure can clamp a fruit stem, and the cutting and clearing device is arranged above the flexible clamping structure so that the fruit stem clamped by the flexible clamping structure can be cut and the flexible clamping structure can be cleared. The device is compact and small in structure and suitable for operation in a narrow space.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural machinery, and in particular to a self-cleaning end effector based on flexible joint force sensing. Background Art

[0002] At present, as the device for harvesting robots to directly contact the fruit stem, the existing end effectors usually have problems with the claw tip or the overall size being too large, making it difficult to perform precise operations in a small space. In addition, the existing harvesting end effectors have relatively single functions and lack accurate force measurement functions. They are unable to provide timely and effective feedback on dangerous situations such as collisions with the surrounding environment during operation, which increases the risk during the operation.

[0003] Therefore, there is an urgent need for a self-cleaning end effector based on flexible joint force sensing. Summary of the invention

[0004] The present invention provides a self-cleaning end effector based on flexible joint force sensing, which solves the problem that the claw tip of the current end effector is large in size and cannot provide accurate force measurement.

[0005] The present invention provides a self-cleaning end effector based on flexible joint force sensing, comprising a clamping device, a mobile base and a cutting and removing device, wherein the clamping device comprises a main body and a flexible clamping structure, the main body is provided with the flexible clamping structure, the main body is arranged above the mobile base, and the main body can move on the mobile base, the flexible clamping structure can be deformed to enable the flexible clamping structure to clamp a fruit handle, and the cutting and removing device is arranged above the flexible clamping structure to achieve cutting of the fruit handle clamped by the flexible clamping structure and cleaning of the flexible clamping structure.

[0006] The self-cleaning end effector based on flexible joint force sensing, preferably, the flexible clamping structure includes a left flexible joint, a right flexible joint, a left sharp claw, a right sharp claw, a left rubber-coated bearing, a right rubber-coated bearing and a precision force measuring device, the tail end of the left flexible joint is connected to the body, the top end of the left flexible joint is connected to the left sharp claw, the left rubber-coated bearing is arranged on the mobile base, the left rubber-coated bearing can fit with the outer side of the left flexible joint, and the outer side of the left flexible joint is an arc surface, the tail end of the right flexible joint is connected to the body, the top end of the right flexible joint is connected to the right sharp claw, the right rubber-coated bearing is arranged on the mobile base, the right rubber-coated bearing can fit with the outer side of the right flexible joint, and the outer side of the right flexible joint is an arc surface, the precision force measuring device is provided on the body, the left sharp claw is connected to the precision force measuring device through the left flexible joint, and the right sharp claw is connected to the precision force measuring device through the right flexible joint.

[0007] The self-cleaning end effector based on flexible joint force sensing is preferably provided with slots on both the left flexible joint and the right flexible joint.

[0008] In the self-cleaning end effector based on flexible joint force sensing, preferably, the slot is an I-shape.

[0009] The self-cleaning end effector based on flexible joint force sensing, preferably, the clamping device also includes a fiber optic counter-radiation sensor, and the fiber optic counter-radiation sensor is respectively arranged at the claw tip of the left sharp claw and the claw tip of the right sharp claw.

[0010] The self-cleaning end effector based on flexible joint force sensing, preferably, the precision force measuring device includes a first strain gauge, a second strain gauge and a third strain gauge, the first strain gauge is arranged above the main body, and an open groove is provided on the main body along the moving direction of the clamping device, the second strain gauge is provided in the open groove, and the third strain gauge is provided on the side of the main body.

[0011] The self-cleaning end effector based on flexible joint force sensing is preferably provided with a plurality of amplifying structures on the main body, and the first strain gauge, the second strain gauge and the third strain gauge are respectively installed in front of the amplifying structure, and the amplifying structure is a hollow figure-8 shape.

[0012] The self-cleaning end effector based on flexible joint force sensing, preferably, the mobile base includes a sleeve, a load-bearing slide rail, a slider and a bracket, the sleeve is provided with the load-bearing slide rail, the slider is provided on the load-bearing slide rail, the slider is connected to the bottom of the body through the bracket, the left rubber-coated bearing and the right rubber-coated bearing are respectively arranged on the sleeve, and the left rubber-coated bearing is arranged on the left side of the load-bearing slide rail, and the right rubber-coated bearing is arranged on the right side of the load-bearing slide rail.

[0013] The self-cleaning end effector based on flexible joint force sensing is preferably provided with a groove on the sleeve, and the load-bearing slide rail and the slider are both arranged in the groove.

[0014] The self-cleaning end effector based on flexible joint force sensing, preferably, the cutting and removing device includes a cover plate, an inclined block, a blade and a high-pressure air pipe, the cover plate is arranged at the front part of the sleeve, the cover plate is provided with the inclined block, the inclined block is provided with the blade, and the blade is located above the left claw and the right claw, a circular hole is provided in the center of the cover plate, the high-pressure air pipe is located in the circular hole, and the extension direction of the pipe hole of the high-pressure air pipe is parallel to the inclined surface of the inclined block.

[0015] The beneficial effects are: A set of optical fiber sensors is installed at the front of the claw tip to detect whether the fruit stalk enters the clamping range of the claw tip; The flexible joint adopts a parallel soft connection design, which has the advantages of being small and easy to connect; The arc surface on the outside of the flexible joint cooperates with the rubber-coated bearing to form a linear cam structure to ensure smooth movement; The precision force measuring device is used to measure the three-dimensional force in the forward, lateral and vertical directions, mainly through three strain gauges and corresponding amplification structures, to ensure accurate feedback of the real-time changes in the three-dimensional force during operation. The precision force measuring device can also measure the weight of the fruit and avoid collisions with surrounding obstacles, ensuring the accuracy and safety of the device during operation. The air pipe of the cutting and removing device delivers high-pressure gas to the front end of the claw tip to clean the fruit stem residue, ensuring the cleaning effect when the device continues to work.

[0016] The invention has a compact and small structure and is suitable for operations in narrow spaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is an exploded view of the structure of the present invention; Figure 3 is a top view schematic diagram of the clamping device; Figure 4 is a three-dimensional diagram of the clamping device; Figure 5 It is a schematic diagram of the structure of the cutting and removing device; In the figure: 1. Mobile base; 1-1. Sleeve; 1-2. Load-bearing slide rail; 1-3. Slider; 1-4. Bracket; 1-5. Groove; 2. Gripping device; 2-1. Left flexible joint; 2-2. Main body; 2-3. Right flexible joint; 2-4. Left sharp claw; 2-5, right sharp claw; 2-6, left rubber-coated bearing; 2-7, right rubber-coated bearing; 2-8, slot; 3-1, first strain gauge; 3-2, second strain gauge; 3-3, third strain gauge; 3-4, first amplification structure; 3-5, second amplification structure; 3-6, third amplification structure; 4. Cutting and clearing device; 4-1. Cover plate; 4-2. Bevel block; 4-3. Blade; 4-4. High-pressure air pipe; 5. Fiber optic beam sensor; 6. Open slot. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the system or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used to define components only for the convenience of distinguishing the above components. If not otherwise stated, the above terms have no special meanings and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "setting" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] The present invention provides a self-cleaning end effector based on flexible joint force sense, including a clamping device, a mobile base and a cutting and clearing device, wherein the clamping device includes a body and a flexible clamping structure, the body is provided with the flexible clamping structure, the body is arranged above the mobile base, and the body can move on the mobile base, the flexible clamping structure can be deformed to achieve the flexible clamping structure clamping the fruit handle, and the cutting and clearing device is arranged above the flexible clamping structure to achieve cutting of the fruit handle clamped by the flexible clamping structure and cleaning of the flexible clamping structure. The present invention has a compact and small structure and is suitable for operations in narrow spaces.

[0022] The entire technical process is explained in detail below using a self-cleaning end effector based on flexible joint force sensing as an example.

[0023] Reference Figure 1 and Figure 2As shown, a self-cleaning end effector based on flexible joint force sensing includes a clamping device 2, a mobile base 1 and a cutting and removing device 4, the clamping device 2 includes a main body 2-2 and a flexible clamping structure, the flexible clamping structure is provided on the main body 2-2, and an optical fiber corresponding sensor 5 is provided at the end of the flexible clamping structure, the main body 2-2 is arranged above the mobile base 1, and the main body 2-2 can move on the mobile base 1, the flexible clamping structure can be deformed to enable the flexible clamping structure to clamp the fruit handle, and the cutting and removing device 4 is arranged above the flexible clamping structure to achieve cutting of the fruit handle clamped by the flexible clamping structure and cleaning of the flexible clamping structure.

[0024] Continue to refer to Figure 1 and Figure 2 As shown, the movable base 1 includes a sleeve 1-1, a bearing slide rail 1-2, a slider 1-3 and a bracket 1-4. The bearing slide rail 1-2 is provided on the sleeve 1-1, and the slider 1-3 is provided on the bearing slide rail 1-2. The slider 1-3 is connected to the bottom of the body 2-2 through the bracket 1-4. The left rubber-coated bearing 2-6 and the right rubber-coated bearing 2-7 are respectively arranged on the sleeve 1-1, and the left rubber-coated bearing 2-6 is arranged on the left side of the bearing slide rail 1-2, and the right rubber-coated bearing 2-7 is arranged on the right side of the bearing slide rail 1-2. In the initial position, the left rubber-coated bearing 2-6 does not contact the left flexible joint 2-1, and the right rubber-coated bearing 2-7 does not contact the right flexible joint 2-3.

[0025] The sleeve 1-1 is also provided with a groove 1-5, and the bearing slide rail 1-2 and the slider 1-3 are both arranged in the groove 1-5. The slider 1-3 is driven by a driver to perform linear motion, and the driver can be a motor.

[0026] like Figure 5 As shown, the cutting and removing device 4 includes a cover plate 4-1, an inclined block 4-2, a blade 4-3 and a high-pressure air pipe 4-4. The cover plate 4-1 is arranged at the front of the sleeve 1-1, the cover plate 4-1 is provided with an inclined block 4-2, the inclined block 4-2 is provided with a blade 4-3, and the blade 4-3 is located above the left sharp claw 2-4 and the right sharp claw 2-5, refer to Figure 5 As shown, a central circular hole is provided on the inclined block 4-2, and a high-pressure air pipe 4-4 is arranged in the central circular hole. The extension direction of the tube hole of the high-pressure air pipe 4-4 is parallel to the inclined surface of the inclined block 4-2. The high-pressure air pipe 4-4 is used to transport high-pressure gas to the laser emission hole of the optical fiber counter-shooting sensor 5, which can remove debris such as fruit stalk residues to prevent clogging of the sensor.

[0027] Among them, the main body 2-2 and the cover plate 4-1 are made of stainless steel, and the material of the mobile base 1 is aluminum alloy, which ensures the durability and strength of the equipment.

[0028] Reference Figure 2 ,3 As shown in Figure 4, the flexible clamping structure includes a left flexible joint 2-1, a right flexible joint 2-3, a left sharp claw 2-4, a right sharp claw 2-5, a left rubber-coated bearing 2-6, a right rubber-coated bearing 2-7 and a precision force measuring device. The tail end of the left flexible joint 2-1 is connected to the main body 2-2, the top of the left flexible joint 2-1 is connected to the left sharp claw 2-4, the left rubber-coated bearing 2-6 is arranged on the mobile base 1, the left rubber-coated bearing 2-6 can fit with the outer side of the left flexible joint 2-1, and the outer side of the left flexible joint 2-1 is an arc surface, the tail end of the right flexible joint 2-3 is connected to the main body 2-2, the top of the right flexible joint 2-3 is connected to the right sharp claw 2-5, and the right rubber-coated bearing 2-7 is arranged on the mobile base 1, the right rubber-coated bearing 2-7 can fit with the outer side of the right flexible joint 2-3, and the outer side of the right flexible joint 2-3 is an arc surface. That is, the outer side of the left flexible joint 2-1 cooperates with the left rubber-coated bearing 2-6, and the outer side of the right flexible joint 2-3 cooperates with the right rubber-coated bearing 2-7, respectively, to form a linear cam structure to ensure smooth movement. Taking the left flexible joint 2-1 as an example, when working, in the initial position, the left rubber-coated bearing 2-6 does not contact the left flexible joint 2-1. As the slider 1-3 moves backward, the left rubber-coated bearing 2-6 fits the arc surface of the outer side of the left flexible joint 2-1 and moves along the arc surface. The left rubber-coated bearing 2-6 squeezes the left flexible joint 2-1 to deform the left flexible joint 2-1. During the working process of the right flexible joint 2-3, the left flexible joint 2-1, the left flexible joint 2-1 and the right flexible joint 2-3 are deformed to achieve the clamping of the left sharp claw 2-4 and the right sharp claw 2-5.

[0029] Among them, the material of the left flexible joint 2-1 and the right flexible joint 2-3 is 304 stainless steel.

[0030] Among them, the left sharp claw 2-4 and the right sharp claw 2-5, the left flexible joint 2-1 and the right flexible joint 2-3 are arranged symmetrically, and have the same function and structure.

[0031] Among them, the front part of the left sharp claw 2-4 and the front part of the right sharp claw 2-5 are respectively provided with grooves for installing the optical fiber counter-radiation sensor 5, and the optical fiber counter-radiation sensor 5 is used to detect whether the fruit handle enters the clamping range of the left sharp claw 2-4 and the right sharp claw 2-5.

[0032] The left flexible joint 2-1 and the right flexible joint 2-3 are both provided with a slot 2-8, which is an I-shaped slot to create a physical space for the left flexible joint 2-1 and the right flexible joint 2-3 to deform. The flexible joints are softly connected to achieve flexibility.

[0033] Continue to refer to Figure 2 , 3As shown in Figure 4, the precision force measuring device is arranged on the main body 2-2, and the precision force measuring device includes a first strain gauge 3-1, a second strain gauge 3-2 and a third strain gauge 3-3. The first strain gauge 3-1 is arranged on the upper surface of the main body 2-2, and an open groove 6 is provided on the main body 2-2 along the moving direction of the clamping device 2. The second strain gauge 3-2 is provided in the open groove 6, and the third strain gauge 3-3 is provided on the side of the main body 2-2.

[0034] in, The function of the first strain gauge 3-1 is the weight of the fruit; The function of the second strain gauge 3-2 is to prevent the front and rear obstacles from colliding when the clamping device 2 moves forward and backward; The function of the third strain gauge 3-3 is to avoid collision with left and right obstacles; The left claw tip 2-4 is indirectly connected to the precision force measuring device at the rear through the left flexible joint 2-1, and the right claw 2-5 is indirectly connected to the precision force measuring device at the rear through the right flexible joint 2-3.

[0035] Continue to refer to Figure 2 , 3 As shown in FIG. 4 , the main body 2-2 is further provided with a first amplifying structure 3-4, a second amplifying structure 3-5 and a third amplifying structure 3-6, and the first amplifying structure 3-4, the second amplifying structure 3-5 and the third amplifying structure 3-6 are all hollow 8-shaped, further enhancing the sensitivity of the first strain gauge 3-1, the second strain gauge 3-2 and the third strain gauge 3-3; The first amplifying structure 3-4 is arranged on the side of the body 2-2, and the first strain gauge 3-1 is arranged in front of the first amplifying structure 3-4; The second amplifying structure 3-5 is disposed on the upper surface of the body 2-2, and the second amplifying structure 3-5 is located above the second strain gauge 3-2, that is, the second strain gauge 3-2 is installed directly in front of the second amplifying structure 3-5; The third amplifying structure 3-6 is arranged on the upper surface of the main body 2-2, and the third amplifying structure 3-6 is located above the third strain gauge 3-3, that is, the third strain gauge 3-3 is installed directly in front of the third amplifying structure 3-6.

[0036] The driver, the optical fiber corresponding sensor 5, the first strain gauge 3-1, the second strain gauge 3-2 and the third strain gauge 3-3 are respectively connected to the controller to realize electrical control.

[0037] Working process: Taking strawberries as an example, when the end effector gradually approaches the strawberry and the strawberry stem enters the opening range of the left sharp claw 2-4 and the right sharp claw 2-5, the optical fiber beam sensor 5 transmits a signal to the controller. At this time, the gripping device 2 is driven to move backward (such as Figure 1As the left rubber-coated bearing 2-6 and the right rubber-coated bearing 2-7 exert pressure on the left flexible joint 2-1 and the right flexible joint 2-3 respectively, the left flexible joint 2-1 and the right flexible joint 2-3 are deformed, so that the left sharp claw 2-4 and the right sharp claw 2-5 approach each other and close, thereby firmly clamping the fruit stalk. Subsequently, the clamping device 2 continues to move backward on the load-bearing slide rail 1-2 through the slider 1-3, and the left sharp claw 2-4 and the right sharp claw 2-5 carry the fruit stalk further backward to the blade 4-3, and the blade 4-3 completes the cutting of the fruit stalk. When the end effector moves the separated strawberry to the specified position, the dynamic clamping device 2 moves forward (with the movement direction shown in the figure). Figure 1 The left claw 2-4 and the right claw 2-5 automatically return to the open state under the elastic force of the left claw 2-4 and the right claw 2-5. At the same time, the high-pressure airflow is sprayed to the laser emission hole of the optical fiber counter-shooting sensor 5 through the high-pressure air pipe 4-4 to remove residual debris and ensure that the optical fiber counter-shooting sensor 5 continues to work normally. Under the rapid action of the motor, the entire strawberry stalk separation process can be completed instantly, greatly improving the picking efficiency.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-cleaning end effector based on flexible joint force sensing, characterized in that: It includes a clamping device, a mobile base and a cutting and cleaning device. The clamping device includes a main body and a flexible clamping structure. The flexible clamping structure is provided on the main body. The main body is arranged above the mobile base and the main body can move on the mobile base. The flexible clamping structure can be deformed to enable the flexible clamping structure to clamp the fruit stalk. The cutting and cleaning device is arranged above the flexible clamping structure to cut the fruit stalk clamped by the flexible clamping structure and clean the flexible clamping structure.

2. The self-cleaning end effector based on flexible joint force sensing according to claim 1 is characterized in that: The flexible clamping structure includes a left flexible joint, a right flexible joint, a left sharp claw, a right sharp claw, a left rubber-coated bearing, a right rubber-coated bearing and a precision force measuring device. The tail end of the left flexible joint is connected to the body, the top end of the left flexible joint is connected to the left sharp claw, the left rubber-coated bearing is arranged on the movable base, the left rubber-coated bearing can fit with the outer side of the left flexible joint, and the outer side of the left flexible joint is an arc surface, the tail end of the right flexible joint is connected to the body, the top end of the right flexible joint is connected to the right sharp claw, the right rubber-coated bearing is arranged on the movable base, the right rubber-coated bearing can fit with the outer side of the right flexible joint, and the outer side of the right flexible joint is an arc surface, the precision force measuring device is provided on the body, the left sharp claw is connected to the precision force measuring device through the left flexible joint, and the right sharp claw is connected to the precision force measuring device through the right flexible joint.

3. The self-cleaning end effector based on flexible joint force sensing according to claim 2 is characterized in that: The left flexible joint and the right flexible joint are both provided with slots.

4. The self-cleaning end effector based on flexible joint force sensing according to claim 3 is characterized in that: The slot is I-shaped.

5. The self-cleaning end effector based on flexible joint force sensing according to claim 4 is characterized in that: The clamping device also includes an optical fiber counter-radiation sensor, which is respectively arranged at the claw tip of the left sharp claw and the claw tip of the right sharp claw.

6. The self-cleaning end effector based on flexible joint force sensing according to claim 5 is characterized in that: The precision force measuring device includes a first strain gauge, a second strain gauge and a third strain gauge. The first strain gauge is arranged above the main body. An open groove is provided on the main body along the moving direction of the clamping device. The second strain gauge is provided in the open groove. The third strain gauge is provided on the side of the main body.

7. The self-cleaning end effector based on flexible joint force sensing according to claim 6 is characterized in that: The main body is also provided with a plurality of amplifying structures, and the first strain gauge, the second strain gauge and the third strain gauge are respectively installed in front of the amplifying structures, and the amplifying structures are hollow 8-shaped.

8. The self-cleaning end effector based on flexible joint force sensing according to any one of claims 2 to 7, characterized in that: The movable base includes a sleeve, a load-bearing slide rail, a slider and a bracket. The sleeve is provided with the load-bearing slide rail, the slider is provided on the load-bearing slide rail, the slider is connected to the bottom of the body through the bracket, the left-side rubber-coated bearing and the right-side rubber-coated bearing are respectively arranged on the sleeve, and the left-side rubber-coated bearing is arranged on the left side of the load-bearing slide rail, and the right-side rubber-coated bearing is arranged on the right side of the load-bearing slide rail.

9. The self-cleaning end effector based on flexible joint force sensing according to claim 8, characterized in that: The sleeve is also provided with a groove, and the bearing slide rail and the sliding block are both arranged in the groove.

10. The self-cleaning end effector based on flexible joint force sensing according to claim 9, characterized in that: The cutting and removing device includes a cover plate, an inclined block, a blade and a high-pressure air pipe. The cover plate is arranged at the front part of the sleeve, the inclined block is provided on the cover plate, the blade is provided on the inclined block, and the blade is located above the left claw and the right claw. A circular hole is provided at the center of the cover plate, the high-pressure air pipe is located in the circular hole, and the extension direction of the pipe hole of the high-pressure air pipe is parallel to the inclined surface of the inclined block.

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