Clamping-direction-adjustable mechanical gripper and control method thereof

Abstract

The invention provides a mechanical claw with an adjustable clamping direction and a control method thereof, and belongs to the technical field of mechanical claws, the mechanical claw is characterized in that a plurality of rotating blocks are rotatably mounted on a mounting seat, and mechanical finger assemblies are rotatably mounted on the rotating blocks and are perpendicular to rotating shafts of the rotating blocks. The second transmission assembly is used for driving the rotating shafts of the multiple sets of mechanical finger assemblies to rotate relatively, so that two clamping directions of the multiple sets of mechanical finger assemblies are switched; and the spherical and cuboid objects are respectively adapted. Before clamping, the clamping positions of the multiple sets of mechanical finger assemblies are switched through the second transmission assembly so as to adapt to the shape of the object. And the first transmission assembly is used for driving the multiple sets of mechanical finger assemblies to get close to one another, and the object clamping function is achieved. Based on the structural design, the mechanical claw can freely switch the clamping direction according to the shape of an object, stable clamping can be achieved when objects of different shapes are clamped, the mechanical claw does not need to be replaced, and the convenience of the mechanical claw is improved.

Description

Technical Field

[0001] The present invention generally relates to the technical field of robotic grippers, and particularly to a robotic gripper with adjustable clamping direction and its control method. Background Art

[0002] Robotic grippers have been widely applied in various fields. In the prior art, when grasping objects of various shapes, different models of robotic grippers are used respectively.

[0003] In the first case, when grasping a spherical object, a robotic gripper with 3 sets of robotic fingers is generally used, and there is an included angle of 120 degrees between the rotation axes of the 3 sets of robotic fingers in pairs. Thus, stable clamping of the spherical object is achieved. The robotic gripper in the first case can only grasp spherical objects; since the rotation axes of multiple robotic fingers are not parallel, it is difficult to stably clamp a cuboid object.

[0004] In the second case, when grasping a cuboid object, the robotic gripper used has multiple rotation axes of multiple robotic fingers that are all parallel to each other. The robotic gripper in the second case can only grasp cuboid objects; since the rotation axes of multiple robotic fingers are all parallel to each other, it is difficult to stably clamp a spherical object.

[0005] Based on the above situations, in the prior art, when it is necessary to clamp objects of different shapes, it is necessary to replace different models of robotic grippers, or install multiple models of robotic grippers simultaneously, which is very inconvenient. Therefore, there is an urgent need for a robotic gripper structure that can stably clamp objects of different shapes. Summary of the Invention

[0006] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a robotic gripper with adjustable clamping direction and its control method.

[0007] On the one hand, the present invention provides a robotic gripper with adjustable clamping direction, including: A mounting base; Rotating blocks, there are multiple rotating blocks, and they are all rotatably mounted on the mounting base with the parallel lines in the first direction as the axes; Robotic finger assemblies, there are multiple groups of robotic finger assemblies, and they are respectively rotatably mounted on multiple rotating blocks; there is a first rotation axis between the robotic finger assembly and the connected rotating block; multiple first rotation axes are all perpendicular to the first direction; Multiple groups of robotic finger assemblies have a first state and a second state; When in the first state, the extension lines of adjacent two first rotation axes intersect; When in the second state, all the first rotation axes are parallel to each other; The first transmission assembly is mounted on the mounting seat and connected to multiple groups of the mechanical finger assemblies, and is configured to drive the multiple groups of the mechanical finger assemblies to approach or move away from each other. The second transmission assembly is mounted on the mounting seat and is respectively connected to the multiple rotating blocks, and is configured to drive the multiple rotating blocks and the mechanical finger assemblies to rotate about an axis parallel to the first direction, so as to switch the multiple groups of the mechanical finger assemblies between a first state and a second state.

[0008] According to the technical solution provided by the present invention, the first transmission assembly includes: A first driving device, which is mounted on the mounting seat; A first transmission member, which is connected to the first driving device and is configured to move along the first direction under the drive of the first driving device; Multiple second transmission members, all of the multiple second transmission members are rotatably connected to the first transmission member, and the rotation axes are parallel to the first direction; Multiple third transmission members, one ends of the multiple third transmission members are respectively rotatably connected to the multiple second transmission members, and the rotation axes are perpendicular to the first direction; the other ends are respectively rotatably connected to multiple groups of the mechanical finger assemblies, and the rotation axes are perpendicular to the first direction; When the first transmission member moves along the first direction under the drive of the first driving device, it drives the second transmission members and the third transmission members to move, and drives the mechanical finger assemblies to approach or move away from each other.

[0009] According to the technical solution provided by the present invention, the first driving device includes: A mounting post, which is fixedly mounted on the mounting seat along the first direction; and multiple permanent magnets are mounted on the outer sidewall along the first direction; the magnetic poles between adjacent permanent magnets are different in the direction perpendicular to the sidewall of the mounting post; A moving cylinder, which is slidably mounted on the mounting seat along the first direction and sleeved outside the mounting post; the first transmission member is fixedly connected to the moving cylinder; A coil, which is mounted on the inner sidewall of the moving cylinder close to the mounting post and is configured to interact with the multiple permanent magnets after being connected to an alternating current, so as to drive the moving cylinder and the first transmission member to move along the first direction.

[0010] According to the technical solution provided by the present invention, the mechanical finger assembly includes: A first connecting block, which is rotatably connected to the rotating block, and the rotation axis is perpendicular to the first direction; Multiple first connecting rods, one ends of all the multiple first connecting rods are rotatably connected to the first connecting block; A second connecting block, the second connecting block is rotatably connected to the other ends of the plurality of first link rods respectively; the first transmission assembly is rotatably connected to the second connecting block; A plurality of second link rods, one ends of the plurality of second link rods are rotatably connected to the second connecting block; An abutting member, the abutting member is rotatably connected to the other ends of the plurality of second link rods respectively; the abutting member is used for abutting against an object.

[0011] According to the technical solution provided by the present invention, there are three rotating blocks; there are three sets of mechanical finger assemblies; The second transmission assembly includes: A second driving device, the second driving device is fixedly installed on the mounting seat; A first gear, the first gear is fixedly installed on the driving shaft of the second driving device; A second gear and a third gear that mesh with each other, the second gear and the third gear are rotatably installed on the mounting seat; the first gear meshes with the second gear; Two fourth gears, the two fourth gears are respectively fixedly installed on the two rotating blocks; Two first toothed belts, one of the first toothed belts meshes with the second gear and one of the fourth gears respectively; the other first toothed belt meshes with the third gear and the other fourth gear respectively; The second driving device drives the second gear and the third gear to rotate through the first gear, and respectively drives the two fourth gears and the two rotating blocks fixedly connected to the two fourth gears to rotate along axes parallel to the first direction in different directions through the two first toothed belts.

[0012] According to the technical solution provided by the present invention, there are three rotating blocks; there are three sets of mechanical finger assemblies; the second transmission assembly includes: Three sets of transmission mechanisms, the transmission mechanisms are installed on the mounting seat and are connected to the rotating blocks for driving the rotating blocks to rotate; The transmission mechanism includes: A third driving device, the third driving device is fixedly installed on the mounting seat; A fifth gear, the fifth gear is fixedly installed on the driving shaft of the third driving device; A sixth gear, the sixth gear is fixedly installed on the rotating block; A second toothed belt, the second toothed belt meshes with the fifth gear and the sixth gear respectively; The third driving device drives the second toothed belt to move through the fifth gear, and drives the sixth gear and the rotating block to rotate about an axis parallel to the first direction.

[0013] According to the technical solution provided by the present invention, there are four rotating blocks; there are four groups of mechanical finger assemblies; the second transmission assembly includes: A fourth driving device, which is fixedly installed on the mounting seat; A seventh gear, which is fixedly connected to the driving shaft of the fourth driving device; Two eighth gears, which are rotatably installed on the mounting seat and are both meshed with the seventh gear; Two ninth gears, which are rotatably installed on the mounting seat and are respectively meshed with the two eighth gears; Four tenth gears, which are respectively fixedly installed on the four rotating blocks; Four third toothed belts, wherein two of the third toothed belts are respectively meshed with the two eighth gears and are meshed with two alternately arranged tenth gears; the other two third toothed belts are respectively meshed with the two ninth gears and are meshed with the other two alternately arranged tenth gears; The fourth driving device drives the two eighth gears to rotate through the seventh gear, and drives the two ninth gears to rotate; and then drives the four tenth gears and the four rotating blocks to rotate through the four third toothed belts.

[0014] On the other hand, the present invention provides a control method for a mechanical claw with an adjustable clamping direction, which is applied to a mechanical claw with an adjustable clamping direction as described above; The mechanical claw is rotatably installed on a robotic arm; The method includes: Switching multiple mechanical finger assemblies to the second state; The first transmission assembly drives multiple groups of the mechanical finger assemblies to move away from each other; Obtaining the shape of a cross-section of an object perpendicular to the first direction; If the shape of the cross-section of the object is spherical, translating the mechanical claw so that the object is located between multiple groups of the mechanical finger assemblies, and the first transmission assembly drives multiple groups of the mechanical finger assemblies to move closer to each other to clamp the object; If the shape of the cross-section of the object is rectangular, obtaining the length direction of the object; Rotating the mounting seat so that one of the first rotating axes is parallel to the length direction; Switching multiple mechanical finger assemblies to the second state; making all the first rotating axes parallel to the length direction; Translate the mechanical claw so that the object is between multiple groups of the mechanical finger assemblies. The first transmission assembly drives the multiple groups of the mechanical finger assemblies to approach each other and clamp the object.

[0015] According to the technical solution provided by the present invention, rotate the mounting base so that one of the first rotating shafts is parallel to the length direction, including: Calculate the angles between the length direction and the multiple first rotating shafts; Take the first rotating shaft with the smallest angle with the length direction as the first reference direction; Obtain the rotation direction of the mounting base to get the first rotation direction; Control the mounting base to rotate by a first angle along the first rotation direction; make the first rotating shaft serving as the first reference direction parallel to the length direction; the first angle is the angle between the first reference direction and the length direction.

[0016] According to the technical solution provided by the present invention, obtaining the rotation direction of the mounting base to get the first rotation direction includes: Take, among the two first rotating shafts adjacent to the first reference direction, the one with the smaller angle with the length direction as the second reference direction; Take the direction from the first reference direction to the second reference direction as the first rotation direction.

[0017] The beneficial effects of the present invention are as follows: A plurality of rotating blocks can be rotatably mounted on the mounting base of the mechanical claw. Multiple groups of mechanical finger assemblies can be rotatably mounted on the rotating blocks and are perpendicular to the rotating shafts of the rotating blocks. The first transmission assembly is connected to the mechanical finger assemblies to drive the multiple groups of mechanical finger assemblies to approach or separate from each other to clamp or release the object. The second transmission assembly drives the rotating shafts of the multiple groups of mechanical finger assemblies to rotate relative to each other to switch between two states of the multiple groups of mechanical finger assemblies. In the two states, the clamping directions of the mechanical finger assemblies are different. The two clamping directions are respectively used to adapt to spherical and cuboid-shaped objects. Before clamping objects of different shapes, the state of the multiple groups of mechanical finger assemblies is switched through the second transmission assembly to adapt to the shape of the object; and the first transmission assembly is used to drive the multiple groups of mechanical finger assemblies to approach each other to complete the function of clamping the object. Based on the above structural design, the mechanical claw can freely switch states according to the shape of the object to adjust the clamping direction, and can achieve stable clamping when clamping objects of different shapes without replacing the mechanical claw, improving the convenience of the mechanical claw. Description of the Drawings

[0018] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, objects and advantages of the present invention will become more obvious: Figure 1Schematic diagram of the mechanical claw structure; Figure 2 Front view of the mechanical claw; Figure 3 Another schematic diagram of the mechanical claw structure; Figure 4 Schematic diagram of the structure of the first driving device; Figure 5 Schematic diagram of the structure of the second transmission component in the first implementation manner; Figure 6 Schematic diagram of the structure of the second transmission component in the second implementation manner; Figure 7 Schematic diagram of the structure of the second transmission component in the third implementation manner; Figure 8 Schematic diagram when the mechanical finger assembly is in the first state; Figure 9 Schematic diagram when the mechanical finger assembly is in the second state; Wherein: 1. Mounting base; 2. Rotating block; 3. Mechanical finger assembly; 4. First driving device; 5. First transmission member; 6. Second transmission member; 7. Third transmission member; 8. Mounting column; 9. Permanent magnet; 10. Moving cylinder; 11. First connecting block; 12. First connecting rod; 13. Second connecting block; 14. Second connecting rod; 15. Contact member; 16. Second driving device; 17. First gear; 18. Second gear; 19. Third gear; 20. Fourth gear; 21. First toothed belt; 22. Fifth gear; 23. Sixth gear; 24. Second toothed belt; 25. Seventh gear; 26. Eighth gear; 27. Ninth gear; 28. Tenth gear; 29. Third toothed belt; 30. Mounting base plate; 31. Mounting top plate; 32. Mounting beam; 33. Elastic member. Specific implementation manner

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention, rather than limiting the invention. In addition, it should be noted that for the convenience of description, only the parts related to the invention are shown in the drawings.

[0020] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and embodiments.

[0021] Embodiment 1 Refer to Figure 1 , the present invention provides a mechanical claw with adjustable clamping direction, including: Mounting base 1; Refer to Figure 3, the mounting base 1 includes a mounting bottom plate 30, a disc-shaped mounting top plate 31, and a plurality of mounting beams 32 with both ends fixedly connected to the mounting top plate and the mounting bottom plate respectively; the mounting beams 32 are arranged along the first direction; Rotating blocks 2, there are a plurality of the rotating blocks 2, and they are all rotatably mounted on the mounting top plate 31 of the mounting base 1 with the parallel lines of the first direction as the axis; Mechanical finger assemblies 3, there are multiple groups of the mechanical finger assemblies 3, and they are respectively rotatably mounted on a plurality of the rotating blocks 2; there is a first rotating axis between the mechanical finger assembly 3 and the connected rotating block 2; all the plurality of first rotating axes are perpendicular to the first direction; Multiple groups of the mechanical finger assemblies 3 have a first state and a second state; Reference Figure 8 , when in the first state, the extension lines of two adjacent first rotating axes intersect; Reference Figure 9 , when in the second state, all the plurality of first rotating axes are parallel to each other; Figures 8 - 9 The perspective view in is the top view of the mounting top plate 31, the dotted line represents the first rotating axis, and the arrow represents the movement direction in the perspective view of the figure when the mechanical finger assembly rotates relative to the rotating block 2.

[0022] The first transmission assembly is mounted on the mounting bottom plate 30 and the mounting beams 32 of the mounting base 1, and is connected to multiple groups of the mechanical finger assemblies 3 for driving multiple groups of the mechanical finger assemblies 3 to approach or separate from each other; The second transmission assembly is mounted on the mounting top plate 31 of the mounting base 1, and is respectively connected to a plurality of the rotating blocks 2 for respectively driving a plurality of the rotating blocks 2 and the mechanical finger assemblies 3 to rotate with the parallel lines of the first direction as the axis, so that multiple groups of the mechanical finger assemblies 3 switch between the first state and the second state.

[0023] Specifically, the first direction is Figure 2 the up and down direction in

[0024] When there are three groups of mechanical finger assemblies, there are also three first rotating axes; When in the first state, the three first rotating axes form an equilateral triangle, and the three groups of mechanical finger assemblies rotate along their respective first rotating axes and approach each other to realize the function of clamping a spherical object.

[0025] When in the second state, the three first rotating axes are all parallel to each other. Among the three groups of mechanical finger assemblies, two of them rotate synchronously towards the third group of mechanical finger assemblies and finally abut against the side wall of one side of the cuboid object, and the third group of mechanical finger assemblies rotates towards the other two groups and finally abuts against the side wall of the other side of the cuboid object to realize the function of approaching each other to clamp the cuboid object.

[0026] When the mechanical finger assembly has four groups, there are also four first rotating shafts; When in the first state, two adjacent first rotating shafts are perpendicular to each other, and two opposite first rotating shafts are parallel to each other. The four first rotating shafts form a square; when clamping a spherical object by approaching each other, the rotation directions of two opposite groups of mechanical finger assemblies are opposite, and finally the function of clamping the spherical object is realized; When in the second state, the four first rotating shafts are divided into two groups. The two first rotating shafts in the same group coincide, and the rotating shafts in different groups are parallel to each other but do not coincide. When clamping a cuboid object, the mechanical finger assemblies in the same group rotate in opposite directions and are respectively abutted against the side walls on both sides of the object to realize the function of clamping the cuboid object.

[0027] Based on the above structural design, the working process of the mechanical claw includes: According to the shape of the object, use the second transmission component to switch between the first state and the second state, so that the clamping directions of multiple groups of mechanical finger assemblies can adapt to the shape of the object; during the process of switching between the two states, the directions of the first rotating shafts between each mechanical finger assembly and the rotating block 2 will also change, but always perpendicular to the first direction; Furthermore, use the first transmission component to drive multiple groups of mechanical finger assemblies to approach each other to clamp the object.

[0028] With the above structural design, the mechanical claw can freely switch the clamping direction according to the shape of the object. When clamping objects of different shapes, stable clamping can be achieved without replacing the mechanical claw, improving the convenience of the mechanical claw.

[0029] Specifically, since the direction of the first rotating shaft of the mechanical finger assembly in this embodiment needs to be changed according to the shape of the object, and the existing transmission structure for driving multiple groups of mechanical finger assemblies can only complete the transmission in one of the states, it is difficult to realize the transmission function after the direction of the first rotating shaft changes.

[0030] To solve the above problems, the present invention also designs the following structure: Furthermore, the first transmission component includes: The first driving device 4, and the first driving device 4 is installed on the mounting base plate 30 of the mounting seat 1; The first transmission member 5, and the first transmission member 5 is connected to the first driving device 4 and is used to move along the first direction under the drive of the first driving device 4; Multiple second transmission members 6, and multiple second transmission members 6 are all rotatably connected to the first transmission member 5, and the rotating shafts are parallel to the first direction; A plurality of third transmission members 7, one ends of the plurality of third transmission members 7 are respectively rotatably connected to the plurality of second transmission members 6, and the rotation axes are perpendicular to the first direction; the other ends are respectively rotatably connected to multiple groups of the mechanical finger assemblies 3, and the rotation axes are perpendicular to the first direction; When the first transmission member 5 moves along the first direction driven by the first driving device 4, it drives the second transmission member 6 and the third transmission member 7 to move, and drives the mechanical finger assemblies 3 to approach or separate from each other.

[0031] Specifically, since the direction of the rotation axis between the second transmission member 6 and the first transmission member 5 is parallel to the first direction. Therefore, when the direction of the first rotation axis of the mechanical finger assembly changes, the second transmission member 6 and the third transmission member 7 can rotate along with the mechanical finger assembly; and the second transmission member 6 can still be connected to the first transmission member 5 to achieve transmission along the first direction.

[0032] Specifically, generally, motors are used as the driving devices of the mechanical claws. For example, the driving shaft of the motor is fixed to the lead screw, and the first transmission member 5 is threadedly connected to the lead screw; the motor drives the lead screw to rotate, and through the threaded action, the torque is converted into a thrust along the first direction, and finally the transmission is realized.

[0033] However, the friction between the threads in this transmission method and the friction when the driving shaft of the motor rotates relative to the motor housing will both generate resistance, resulting in a large error between the thrust along the first direction and the actually required thrust. In order to reduce the resistance or error caused by the transmission of the driving device, the present invention also has the following design: Further, referring to Figure 4 , the first driving device 4 includes: A mounting post 8, the mounting post 8 is fixedly mounted on the mounting base plate 30 of the mounting seat 1 along the first direction; and a plurality of permanent magnets 9 are mounted on the outer side wall along the first direction; the magnetic poles between adjacent permanent magnets 9 are different in the direction perpendicular to the side wall of the mounting post 8; A moving cylinder 10, the moving cylinder 10 is slidably mounted on the mounting beam 32 of the mounting seat 1 along the first direction, and is sleeved outside the mounting post 8, and there is a moving gap therebetween; the first transmission member 5 is fixedly connected to the moving cylinder 10; A coil, the coil is mounted on the inner side wall of the moving cylinder 10 close to the mounting post 8, and is used to interact with the plurality of permanent magnets 9 after being connected to an alternating current, so as to drive the moving cylinder 10 and the first transmission member 5 to move along the first direction.

[0034] Specifically, by applying alternating current to the coil, an electromagnetic interaction is generated between the coil and the permanent magnet 9. Since the position of the mounting post 8 is fixed, the electromagnetic force generated between them will drive the moving cylinder 10 to move in the first direction. Since the moving cylinder 10 is slidably mounted on the mounting beam 32 of the mounting seat 1 in the first direction and does not directly contact the mounting post 8, the resistance caused by friction will be significantly less than the common transmission methods introduced above.

[0035] In this embodiment, the structural design of the first driving device 4 can more precisely control the acting force in the first direction. Then, by using the first transmission component, when driving multiple groups of mechanical finger components to clamp an object, an accurate clamping force can be provided. It will not make the clamping force too small, resulting in difficulty in clamping the object, or make the clamping force too large to damage the object in order to offset the transmission resistance.

[0036] Further, referring to Figure 2 , the mechanical finger component 3 includes: A first connecting block 11, the first connecting block 11 is rotatably connected to the rotating block 2, and the rotation axis is perpendicular to the first direction; A plurality of first connecting rods 12, one end of each of the plurality of first connecting rods 12 is rotatably connected to the first connecting block 11; A second connecting block 13, the second connecting block 13 is respectively rotatably connected to the other ends of the plurality of first connecting rods 12; the first transmission component is rotatably connected to the second connecting block 13; A plurality of second connecting rods 14, one end of each of the plurality of second connecting rods 14 is rotatably connected to the second connecting block 13; An abutting member 15, the abutting member 15 is respectively rotatably connected to the other ends of the plurality of second connecting rods 14; the abutting member 15 is used to abut against an object.

[0037] In some embodiments, an elastic member 33 is further connected between the first connecting block 11 and the rotating block 2, which is used to reduce the degree of freedom of the mechanical finger component 3, so that when it is not subjected to external force, it will not move to an unnecessary posture due to looseness.

[0038] A pressure sensor is further provided on the side of the abutting member 15 close to the object. When the pressure sensors installed on all the abutting members 15 of the mechanical finger components detect pressure, it means that the object has been successfully grasped.

[0039] Specifically, the mechanical finger component is formed by connecting multiple groups of connecting rods and connecting blocks. When abutting against an object, rotation occurs between the connecting block and the connecting rod, enabling the abutting member 15 to adapt to the inclined side wall of the object; ensuring that the abutting member 15 stably abuts against the side wall of the object, and thus stably clamping the object.

[0040] For the structural design of the second transmission component, it needs to be designed separately according to the number of groups of the mechanical finger components. In the present invention, there are three implementation manners: In the first implementation manner, referring to Figure 5 , there are three rotating blocks 2; there are three groups of mechanical finger components 3; The second transmission component includes: A second driving device 16, which is fixedly installed on the installation top plate 31 of the installation seat 1; A first gear 17, which is fixedly installed on the driving shaft of the second driving device 16; A second gear 18 and a third gear 19 that mesh with each other, and the second gear 18 and the third gear 19 are both rotatably installed on the installation top plate 31 of the installation seat 1; the first gear 17 meshes with the second gear 18; Two fourth gears 20, and the two fourth gears 20 are respectively fixedly installed on the two rotating blocks 2; Two first toothed belts 21, one of the first toothed belts 21 meshes with the second gear 18 and one of the fourth gears 20 respectively; the other first toothed belt 21 meshes with the third gear 19 and the other fourth gear 20 respectively; The second driving device 16 drives the second gear 18 and the third gear 19 to rotate through the first gear 17, and respectively drives the two fourth gears 20 and the two rotating blocks 2 fixedly connected to the two fourth gears 20 to rotate along axes parallel to the first direction in different directions.

[0041] Among them, the second driving device 16 is a motor. The purpose of the above structural design is: to make two of the mechanical finger components rotate in opposite directions to realize the switching between the first state and the second state.

[0042] Among the three rotating blocks 2, two are fixedly installed with fourth gears 20, and the third rotating block 2 is rotatably installed on the installation top plate 31 of the installation seat 1. Initially, the direction of the first rotation axis of the mechanical finger component connected to the rotatable rotating block 2 is perpendicular to the first direction and perpendicular to the radial direction of the installation top plate 31 of the installation seat 1. Therefore, when observing from the perspective of the first direction, the mechanical finger component rotationally connected thereto can move along the radial direction of the installation top plate 31.

[0043] The two rotating blocks 2 installed with the fourth gear 20 are respectively connected to the second gear 18 and the third gear 19 through two first toothed belts 21. Since the first gear 17 meshes with the second gear 18, during rotation, the rotation directions of the second gear 18 and the third gear 19 are opposite. Through the transmission of the first toothed belt 21 and the fourth gear 20, the two rotating blocks 2 can rotate around the axis parallel to the first direction and in different rotation directions; finally, the function of switching the first state and the second state of multiple groups of mechanical finger assemblies is realized.

[0044] During the process of abutting against the object, due to the mechanical finger assembly that can rotate freely; when there is a small inclination on the side wall of the object, the freely rotatable mechanical finger assembly will rotate slightly during the process of abutting against the object, so that the surfaces of the abutting member 15 in contact with the object are parallel to each other, which can make the clamping of the object by the mechanical claw more stable.

[0045] In the second embodiment, referring to Figure 6 , there are three rotating blocks 2; there are three groups of mechanical finger assemblies 3; the second transmission assembly includes: Three groups of transmission mechanisms, the transmission mechanisms are installed on the installation top plate 31 of the installation seat 1 and are connected to the rotating blocks 2 for driving the rotating blocks 2 to rotate; The transmission mechanism includes: A third driving device, the third driving device is fixedly installed on the installation top plate 31 of the installation seat 1; A fifth gear 22, the fifth gear 22 is fixedly installed on the driving shaft of the third driving device; A sixth gear 23, the sixth gear 23 is fixedly installed on the rotating block 2; A second toothed belt 24, the second toothed belt 24 meshes with the fifth gear 22 and the sixth gear 23 respectively; The third driving device drives the second toothed belt 24 to move through the fifth gear 22 and drives the sixth gear 23 and the rotating block 2 to rotate around the axis parallel to the first direction.

[0046] Specifically, the third driving device is a motor.

[0047] The three groups of mechanical finger assemblies are separately controlled by three groups of transmission mechanisms, and the driving shafts of the motors can be respectively controlled to rotate, so that the first rotation axes of the three groups of mechanical finger assemblies form an arbitrary triangle. When facing an object with a special shape, for example, when the cross-sectional shape of the object perpendicular to the first direction is a right triangle, the three first rotation axes can be controlled to be respectively parallel to the three sides of the right triangle to achieve the effect of stable clamping.

[0048] In the third embodiment, referring to Figure 7, there are four of the rotating blocks 2; there are four sets of the mechanical finger assemblies 3; the second transmission assembly includes: A fourth driving device fixedly installed on the installation top plate 31 of the mounting seat 1; A seventh gear 25 fixedly connected to the driving shaft of the fourth driving device; Two eighth gears 26 rotatably installed on the installation top plate 31 of the mounting seat 1 and both meshing with the seventh gear 25; Two ninth gears 27 rotatably installed on the installation top plate 31 of the mounting seat 1 and respectively meshing with the two eighth gears 26; Four tenth gears 28 respectively fixedly installed on the four rotating blocks 2; Four third toothed belts 29, two of the third toothed belts 29 respectively meshing with the two eighth gears 26 and meshing with two of the tenth gears 28 arranged alternately; the other two third toothed belts 29 respectively meshing with the two ninth gears 27 and meshing with the other two tenth gears 28 arranged alternately; The fourth driving device drives the two eighth gears 26 to rotate through the seventh gear 25 and drives the two ninth gears to rotate; and then drives the four tenth gears 28 and the four rotating blocks 2 to rotate through the four third toothed belts 29.

[0049] Specifically, the four sets of mechanical finger assemblies have four first rotating shafts. The fourth driving device is a motor.

[0050] Through the above design of the second transmission assembly, when the driving shaft of the fourth driving device rotates, the first rotating shafts of the two relatively arranged mechanical finger assemblies can rotate in the same direction, and the first rotating shafts of the two adjacent mechanical finger assemblies can rotate in opposite directions. This control method is simple and only requires one motor to realize the control of the clamping directions of multiple mechanical finger assemblies.

[0051] In some other embodiments, when there are four of the rotating blocks 2 and four sets of the mechanical finger assemblies 3, it is also possible to control them separately in the same way as the second transmission assembly in the second embodiment, so that multiple sets of mechanical finger assemblies can adapt to the special shape of the object. For example, when clamping an object with an irregular shape and the first rotating shafts of the four sets of mechanical finger assemblies need to face different directions respectively, the independent control method can fully adapt to this situation.

[0052] Embodiment 2 The present invention also provides a control method for a mechanical claw with adjustable clamping direction, which is applied to a mechanical claw with adjustable clamping direction as described in the above embodiments; The mounting base 1 of the mechanical claw is rotatably mounted on the robotic arm; wherein, the mounting base plate 30 is rotatably connected to the robotic arm; a motor and a camera are installed inside the robotic arm, and the driving shaft of the motor is fixedly connected to the mounting base plate 30; the camera captures an image of the object and uses an image recognition model loaded in the processor inside the camera to recognize the shape of the object. Capturing an image by the camera and detecting the shape of the object using the image recognition model are prior arts.

[0053] The method includes: Switching multiple mechanical finger assemblies to the second state; The first transmission assembly drives multiple groups of the mechanical finger assemblies to move away from each other; Obtaining the shape of the cross-section of the object along a direction perpendicular to the first direction; in this embodiment, an image of the object is captured by a camera mounted on the robotic arm, and the shape of the object is detected using an image recognition model; Case 1: If the shape of the cross-section of the object is spherical, then translate the mechanical claw so that the object is located between multiple groups of the mechanical finger assemblies, and the first transmission assembly drives multiple groups of the mechanical finger assemblies to move closer to each other to clamp the object.

[0054] For a spherical object, the mechanical claw can be directly moved to complete the clamping.

[0055] Specifically, if a cuboid object is not aligned with the mechanical claw, that is, the length direction of the rectangular object is not parallel to any of the multiple first rotation axes, it may cause the mechanical claw to fail to grasp. Therefore, it is necessary to make the direction of one of the first rotation axes of the mechanical claw parallel to the length direction of the object before grasping.

[0056] Case 2: If the shape of the cross-section of the object is rectangular, then it includes: Step 1: Obtaining the length direction of the object, specifically including: establishing a coordinate system, capturing an image using the camera, and recognizing a straight line parallel to the length direction of the object. Arbitrarily taking two points on the straight line parallel to the length direction, and calculating the vector coordinates representing the length direction; Step 2: Rotating the mounting base 1 so that one of the first rotation axes is parallel to the length direction, including: Step 2-1: Calculating the angles between the length direction and multiple first rotation axes, specifically including: obtaining the vector coordinates representing the directions of the respective first rotation axes from the database; and then calculating the angles between the length direction and multiple first rotation axes based on the respective vector coordinates. After the structural design of the mechanical claw is completed, the vector coordinates representing multiple first rotation axes when each mechanical finger assembly is in the first state are measured and calculated, and then stored in the database.

[0057] Step 2-2: Take the first rotation axis with the smallest angle with the length direction as the first reference direction; the first rotation axis corresponding to the first reference direction needs to be parallel to the length direction after rotating the robotic gripper.

[0058] Specifically, to achieve the above goals and minimize the time consumption during the adjustment process as much as possible, the following steps need to be carried out: Step 2-3: Obtain the rotation direction of the mounting base 1 to get the first rotation direction, including: Take the one with a smaller angle between the two first rotation axes adjacent to the first reference direction and the length direction as the second reference direction; Take the direction from the first reference direction to the second reference direction as the first rotation direction.

[0059] The principle is: The length direction must be between the directions corresponding to the two first rotation axes with the smallest angles with the length direction; therefore, when the first rotation axis corresponding to the first reference direction rotates from the first reference direction towards the second reference direction, it will definitely pass through the length direction. Based on the above principle, knowing the rotation direction and the angle to be rotated, the adjustment of the robotic gripper can be completed to make the length direction parallel to one of the first rotation axes.

[0060] Step 2-4: Control the mounting base 1 to rotate by a first angle along the first rotation direction; make the first rotation axis serving as the first reference direction parallel to the length direction; the first angle is the angle between the first reference direction and the length direction.

[0061] Rotating the robotic gripper according to the above steps can reduce the angle required to rotate the robotic gripper to align with the object and reduce the time consumption during the movement process.

[0062] Step 3: Switch multiple mechanical finger assemblies to the second state; make all the first rotation axes parallel to the length direction; Step 4: Translate the robotic gripper to place the object between multiple groups of mechanical finger assemblies, and the first transmission assembly drives multiple groups of mechanical finger assemblies to approach each other to clamp the object.

[0063] Specifically, in this embodiment, only the control methods corresponding to two shapes of objects are listed. When the object is of other shapes, according to the structural design of the second embodiment, the directions of multiple first rotation axes are adjusted specifically so that the robotic gripper can stably clamp objects of various shapes.

[0064] The above description is only a preferred embodiment of the present invention and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present invention is not limited to the technical solution formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the technical solution formed by mutually replacing the above features with the technical features (but not limited to) disclosed in the present invention that have similar functions.

Claims

1. A mechanical gripper with adjustable clamping direction, characterized in that: include: Mounting seat (1); A rotating block (2), the rotating block (2) comprising a plurality of rotating blocks (2), each of which is rotatably mounted on the mounting seat (1) with a parallel line in the first direction as an axis; A mechanical finger assembly (3), the mechanical finger assembly (3) comprising a plurality of groups, each of which is rotatably mounted on a plurality of the rotating blocks (2); a first rotation axis is provided between the mechanical finger assembly (3) and the rotating blocks (2) to which it is connected; the plurality of first rotation axes are all perpendicular to the first direction; The plurality of sets of mechanical finger assemblies (3) have a first state and a second state; When in the first state, the extension lines of two adjacent first rotation axes intersect; When in the second state, the plurality of first rotation axes are parallel to each other; A first transmission assembly, the first transmission assembly being mounted on the mounting seat (1) and connected to the plurality of sets of mechanical finger assemblies (3), and being used to drive the plurality of sets of mechanical finger assemblies (3) to move closer to or further away from each other; The second transmission assembly is mounted on the mounting seat (1) and is respectively connected to the plurality of rotating blocks (2) and is used to respectively drive the plurality of rotating blocks (2) and the mechanical finger assemblies (3) to rotate about parallel lines in the first direction as axes, so that the plurality of sets of the mechanical finger assemblies (3) switch between the first state and the second state.

2. A mechanical gripper with adjustable clamping direction according to claim 1, characterized in that: The first transmission assembly comprises: A first driving device (4), the first driving device (4) being mounted on the mounting seat (1); A first transmission member (5), the first transmission member (5) being connected to the first driving device (4) and being used for moving along a first direction under the drive of the first driving device (4); a plurality of second transmission members (6), each of the plurality of second transmission members (6) being rotatably connected to the first transmission member (5), and having a rotation axis parallel to the first direction; a plurality of third transmission members (7), wherein one end of the plurality of third transmission members (7) is rotatably connected to the plurality of second transmission members (6), and the rotation axis is perpendicular to the first direction; and the other end of the plurality of third transmission members (7) is rotatably connected to the plurality of mechanical finger assemblies (3), and the rotation axis is perpendicular to the first direction; When the first transmission member (5) is driven by the first driving device (4) to move along the first direction, it drives the second transmission member (6) and the third transmission member (7) to move, and drives the mechanical finger components (3) to move closer to or farther from each other.

3. A mechanical claw with adjustable clamping direction according to claim 2, characterized in that: The first driving device (4) comprises: A mounting column (8), the mounting column (8) being fixedly mounted on the mounting seat (1) along a first direction; and a plurality of permanent magnets (9) being mounted on the outer side wall along the first direction; and adjacent permanent magnets (9) having different magnetic poles along a direction perpendicular to the side wall of the mounting column (8); A moving cylinder (10), the moving cylinder (10) being slidably mounted on the mounting seat (1) along a first direction and sleeved on the outside of the mounting column (8); the first transmission member (5) being fixedly connected to the moving cylinder (10); A coil, the coil being mounted on the inner side wall of the moving cylinder (10) close to the mounting column (8), and being used for interacting with the plurality of permanent magnets (9) after being connected to alternating current, thereby driving the moving cylinder (10) and the first transmission member (5) to move in a first direction.

4. The mechanical gripper with adjustable clamping direction according to claim 1, characterized in that: The mechanical finger assembly (3) comprises: a first connecting block (11), the first connecting block (11) being rotatably connected to the rotating block (2), and the rotating axis being perpendicular to the first direction; A plurality of first connecting rods (12), each of the plurality of first connecting rods (12) having one end rotatably connected to the first connecting block (11); a second connecting block (13), the second connecting block (13) being rotatably connected to the other ends of the plurality of first connecting rods (12) respectively; the first transmission assembly being rotatably connected to the second connecting block (13); A plurality of second connecting rods (14), each of the plurality of second connecting rods (14) having one end rotatably connected to the second connecting block (13); An abutment member (15), wherein the abutment member (15) is rotatably connected to the other ends of the plurality of second connecting rods (14) respectively; the abutment member (15) is used to abut against an object.

5. The mechanical gripper with adjustable clamping direction according to claim 1, characterized in that: The number of the rotating blocks (2) is three; the number of the mechanical finger components (3) is three; The second transmission assembly comprises: A second driving device (16), the second driving device (16) being fixedly mounted on the mounting seat (1); a first gear (17), the first gear (17) being fixedly mounted on a drive shaft of the second drive device (16); a second gear (18) and a third gear (19) meshing with each other, wherein the second gear (18) and the third gear (19) are both rotatably mounted on the mounting seat (1); the first gear (17) is meshing with the second gear (18); Two fourth gears (20), the two fourth gears (20) being fixedly mounted on the two rotating blocks (2) respectively; two first toothed belts (21), wherein one of the first toothed belts (21) is respectively meshed with the second gear (18) and one of the fourth gears (20); and the other of the first toothed belts (21) is respectively meshed with the third gear (19) and the other of the fourth gears (20); The second driving device (16) drives the second gear (18) and the third gear (19) to rotate via the first gear (17), and drives the two fourth gears (20) and the two rotating blocks (2) fixedly connected to the two fourth gears (20) via the two first toothed belts (21) to rotate in different directions with the parallel lines in the first direction as axes.

6. The mechanical claw with adjustable clamping direction according to claim 1, characterized in that: The number of the rotating blocks (2) is three; the number of the mechanical finger components (3) is three; the second transmission component comprises: three sets of transmission mechanisms, wherein the transmission mechanisms are mounted on the mounting seat (1) and connected to the rotating block (2) to drive the rotating block (2) to rotate; The transmission mechanism comprises: a third driving device, the third driving device being fixedly mounted on the mounting seat (1); a fifth gear (22), the fifth gear (22) being fixedly mounted on a drive shaft of the third drive device; a sixth gear (23), the sixth gear (23) being fixedly mounted on the rotating block (2); a second toothed belt (24), the second toothed belt (24) being meshed with the fifth gear (22) and the sixth gear (23) respectively; The third driving device drives the second toothed belt (24) to move via the fifth gear (22), and drives the sixth gear (23) and the rotating block (2) to rotate about a line parallel to the first direction as an axis.

7. The mechanical claw with adjustable clamping direction according to claim 1, characterized in that: The number of the rotating blocks (2) is four; the number of the mechanical finger assemblies (3) is four; the second transmission assembly comprises: a fourth driving device, the fourth driving device being fixedly mounted on the mounting seat (1); a seventh gear (25), the seventh gear (25) being fixedly connected to the drive shaft of the fourth drive device; Two eighth gears (26), the two eighth gears (26) being rotatably mounted on the mounting seat (1) and both meshing with the seventh gear (25); Two ninth gears (27), the two eighth gears (26) are rotatably mounted on the mounting seat (1), and are respectively meshed with the two eighth gears (26); Four tenth gears (28), the four tenth gears (28) being fixedly mounted on the four rotating blocks (2) respectively; four third toothed belts (29), wherein two of the third toothed belts (29) are respectively meshed with the two eighth gears (26) and are meshed with the two tenth gears (28) disposed alternately; the other two third toothed belts (29) are respectively meshed with the two ninth gears (27) and are meshed with the other two tenth gears (28) disposed alternately; The fourth driving device drives the two eighth gears (26) to rotate through the seventh gear (25), and drives the two ninth gears to rotate; and further drives the four tenth gears (28) and the four rotating blocks (2) to rotate through the four third toothed belts (29).

8. A control method for a mechanical gripper with adjustable clamping direction, characterized in that: A mechanical claw with adjustable clamping direction as described in any one of claims 1-4, 6-7; The mechanical claw can be rotatably mounted on the mechanical arm; Methods include: Switching the plurality of mechanical finger components to a second state; The first transmission assembly drives the plurality of groups of mechanical finger assemblies to move away from each other; Acquire the shape of a cross section of the object along a direction perpendicular to the first direction; If the cross-section of the object is spherical, the mechanical claw is translated so that the object is located between the multiple sets of mechanical finger assemblies, and the first transmission assembly drives the multiple sets of mechanical finger assemblies to approach each other to clamp the object; If the shape of the cross section of the object is a rectangle, obtain the length direction of the object; Rotating the mounting seat (1) so that one of the first rotation axes is parallel to the length direction; Switching the plurality of mechanical finger components to a second state; making the plurality of the first rotation axes parallel to the length direction; The mechanical claw is translated to place the object between the multiple groups of mechanical finger assemblies, and the first transmission assembly drives the multiple groups of mechanical finger assemblies to approach each other to clamp the object.

9. A control method for a mechanical gripper with adjustable clamping direction according to claim 8, characterized in that: Rotating the mounting seat (1) so that one of the first rotation axes is parallel to the length direction, comprising: Calculating the angles between the length direction and the plurality of first rotation axes; Taking the first rotation axis with the smallest angle with the length direction as the first reference direction; Obtaining the rotation direction of the mounting seat (1) to obtain a first rotation direction; The mounting seat (1) is controlled to rotate along the first rotation direction at a first angle; a first rotation axis serving as the first reference direction is made parallel to the length direction; the first angle is the angle between the first reference direction and the length direction.

10. A control method for a mechanical gripper with adjustable clamping direction according to claim 9, characterized in that: Obtaining the rotation direction of the mounting seat (1) to obtain a first rotation direction includes: Of the two first rotation axes adjacent to the first reference direction, the one with the smaller angle with the length direction is used as the second reference direction; A direction rotated from the first reference direction to the second reference direction is referred to as a first rotation direction.

Images