Self-adaptive force controlled industrial robot end effector

Abstract

The invention relates to a self-adaptive force control industrial robot end effector applied to the field of robots, which is characterized in that through the arrangement of a plurality of groups of clamping jaws, a whole-surface plate-shaped clamp in the prior art is divided into a plurality of small-unit clamping fingers, so that single-surface multi-point clamping can be realized when the clamping is hard and the surface profile fluctuates relatively; compared with single-point clamping on a certain side, the clamping stability can be greatly improved, meanwhile, the clamping force can be reduced, and damage to a clamped object and the clamping jaw is reduced; in addition, in cooperation with the arrangement of the single rotating strips, when the end effector executes a clamping command, after the multiple clamping jaws adapt to the surface contour of the hard to-be-clamped object, the multiple single rotating strips on the surface of the single clamping jaw can be attached to the surface contour of the object in a self-adaptive mode, and then the clamping stability is further improved.

Description

Technical Field

[0001] The present invention relates to a robot end effector, and in particular to an industrial robot end effector with adaptive force control applied in the field of robotics. Background Art

[0002] For industrial robots in complex operations such as assembly, polishing, deburring, and precision inspection, precise force control is a core requirement for ensuring process quality. Traditional robot end effectors include grippers, grinding heads, and suction cups, which typically perform tasks such as gripping, grinding, and suction under the control of the robot's control program.

[0003] The clamps at the end of existing industrial robots are often two hard clamps, such as the industrial robot clamp disclosed in the Chinese patent specification with publication number CN117841034B, which results in the inability to completely fit the object to be clamped during clamping. When the surface of the object to be clamped is elastic or flexible, it can deform itself to fit the surface of the clamp, making the clamping more stable. However, for hard objects to be clamped, it is difficult for them to adapt to the surface of the clamp. When there are local protrusions or depressions on the surface of the object to be clamped, the clamp and the object will be clamped at points instead of at surfaces, resulting in lower clamping stability. In order to improve stability, the required clamping force is relatively large, which is not only easy to damage the object to be clamped, but also easy to damage the end clamp.

[0004] Although there are adaptive clamps, most of the adaptive clamps in the existing technology only have an elastic pad layer set on the clamp surface. For example, the industrial robot clamp disclosed in the Chinese patent specification with publication number CN111390952B has limited adaptability to the surface contour of hard objects and is still difficult to clamp stably. Summary of the Invention

[0005] In view of the above-mentioned existing technologies, the technical problem to be solved by the present invention is that the end clamps of existing robots are often difficult to adapt to hard objects with undulating surface contours. When clamping, there is often point contact, which affects stability and is easy to damage the surface of the object.

[0006] In order to solve the above problems, the present invention provides an industrial robot end effector with adaptive force control, comprising a mounting back plate, a top plate fixedly connected to the right end of the mounting back plate, a plurality of gripper units mounted on the lower end of the top plate, the gripper unit comprising a connecting plate fixedly connected to the top plate, an H-shaped slot plate fixedly mounted on the lower end of the connecting plate, two grippers symmetrical to each other are provided below the H-shaped slot plate, two active slides are slidably connected in the upper track slot of the H-shaped slot plate, two passive slides are slidably connected in the lower track slot of the H-shaped slot plate, and the two passive slides are They correspond to the two active slides respectively, and a connecting rod is fixedly connected between the two. Compensation bars are fixedly connected to the left and right ends of the lower track groove of the H-shaped groove plate. Pressure sensors are installed between the ends of the two compensation bars close to each other and the corresponding follower slides. The ends of the two compensation bars extend outside the H-shaped groove plate, and the upper ends of the compensation bars outside the H-shaped groove plate are fixedly connected to the air pipe, which is connected to the external air source through an air pump. Two follower slides are slidably connected in the track groove at the lower end of the H-shaped groove plate, and the follower slide is fixedly connected to the clamping claw.

[0007] In the above-mentioned adaptive force-controlled industrial robot end effector, multiple groups of grippers are provided to divide the entire plate-shaped clamp in the prior art into multiple small units of grippers, so that when the clamping is hard and the surface contour is relatively undulating, single-sided multi-point clamping can be achieved. Compared with single-point clamping on a certain side, the clamping stability can be greatly improved, and at the same time the clamping force can be reduced, thereby reducing the damage to the clamped object and the gripper itself.

[0008] As a further improvement of the present application, the passive slider is made of electromagnetic material, the follower slider is made of ferromagnetic metal material, and the passive slider generates magnetic attraction to the follower slider after being energized.

[0009] As a further improvement of the present application, the compensation strip includes a positioning section fixedly connected to the inner wall of the track groove at the lower end of the H-shaped groove plate near the edge, a sliding section slidably connected to the track groove at the lower end of the H-shaped groove plate, and an adaptive section fixedly connected between the sliding section and the positioning section. The pressure sensor is installed on the sliding section, and an L-shaped air hole is opened inside the positioning section, and the L-shaped air hole connects the air pipe and the adaptive section.

[0010] As a further improvement of the present application, the adaptive section is made of elastic material, and the adaptive section is always in a saturated and inflated state.

[0011] As a further improvement of the present application, a supporting base plate is fixedly connected to the lower end of the sliding section, the supporting base plate spans the adaptive section and is slidably connected to the lower end of the positioning section, and the overlapping area between the end of the supporting base plate and the positioning section is not less than half of the bottom area of the positioning section.

[0012] As another improvement of the present application, multiple inward-rotating grooves are excavated inside the clamping jaws, and single-rotating bars are rotatably connected inside the multiple inward-rotating grooves. An inner pad is also fixedly connected between the inner wall of the inward-rotating groove and the middle of the outer wall of the single-rotating bar.

[0013] As another improved supplement to the present application, the single-rotation bar is crescent-shaped with double corners, and the edges of the two corners of the single-rotation bar are rounded. One corner of the single-rotation bar is located in the inner rotation groove and serves as a rotation point. The other corner of the single-rotation bar passes through the inner rotation groove and extends to the outside of the clamping jaw. When the single-rotation bar is not subject to force, the part of the single-rotation bar located outside the clamping jaw is not less than 1 / 2-2 / 3 of the volume of the single-rotation bar.

[0014] As another improved supplement of the present application, the inner pad is made of a high-resilience material, and the distribution span of the inner pad is no more than half of the span of the inner wall of the inner rotation groove.

[0015] In summary, in the above-mentioned adaptive force-controlled industrial robot end effector, through the setting of multiple groups of grippers, the whole surface of the plate-like clamp in the prior art is divided into multiple small units of grippers, so that when the clamping is hard and the surface contour is relatively undulating, single-sided multi-point clamping can be achieved. Compared with the single-point clamping on a certain side, the clamping stability can be greatly improved, and the clamping force can be reduced, reducing the damage to the clamped object and the gripper itself; in addition, in conjunction with the single-rotating bar setting, when this end effector executes the clamping command, after the multiple grippers adapt to the surface contour of the hard object to be clamped, the multiple single-rotating bars on the surface of a single gripper can adapt to the contour of the surface of the object, thereby further improving the clamping stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a right side perspective view of the first embodiment of the present application; Figure 2 This is a left side perspective view of the first embodiment of the present application; Figure 3 A side view of the first embodiment of the present application; Figure 4 A perspective view of a clamping jaw unit according to a first embodiment of the present application; Figure 5 This is a front view of the clamping unit according to the first embodiment of the present application; Figure 6 This is a schematic cross-sectional view of a compensation strip according to a first embodiment of the present application; Figure 7 This is a schematic diagram of the first embodiment of the present application when the clamping jaw unit is opened and ready to clamp an object; Figure 8 This is a front view of a single gripper of the gripper unit according to the first embodiment of the present application, when adapting to the surface contour of the object to perform unilateral compensation; Figure 9This is a schematic diagram comparing the first embodiment of the present application with the prior art during clamping; Figure 10 This is a front view of the second embodiment of the present application; Figure 11 This is a top cross-sectional view of a clamping jaw according to a second embodiment of the present application; Figure 12 This is a top cross-sectional view of the second embodiment of the present application after the clamping jaw is partially subjected to force; Figure 13 This is a schematic diagram of the clamping unit of the second embodiment of the present application clamping an object.

[0017] Description of the numbers in the figure: 1 Install back plate, 2 Top plate, 3 Connecting plate, 4 H-shaped slot plate, 41 Active slide, 42 Passive slide, 43 Follower slide, 5 Clamp, 501 Inner rotation groove, 6 Compensation bar, 61 Sliding section, 62 Adaptive section, 63 Positioning section, 64 Supporting and removing bottom plate, 601 Pressure sensor, 7 Air pipe, 8 Single rotation bar, 81 Inner pad. DETAILED DESCRIPTION

[0018] Two implementation modes of the present application are described in detail below with reference to the accompanying drawings.

[0019] The first implementation method: Figure 1-3 As shown, an industrial robot end effector with adaptive force control includes a mounting back plate 1, a top plate 2 is fixedly connected to the right end of the mounting back plate 1, and a plurality of gripper units are mounted on the lower end of the top plate 2, such as Figure 4 The clamping jaw unit includes a connecting plate 3 fixedly connected to the top plate 2, an H-shaped groove plate 4 is fixedly installed on the lower end of the connecting plate 3, and two mutually symmetrical clamping jaws 5 are provided below the H-shaped groove plate 4.

[0020] like Figure 5, There are two active slides 41 slidingly connected in the upper track groove of the H-shaped groove plate 4, and two passive slides 42 slidingly connected in the lower track groove of the H-shaped groove plate 4. The two passive slides 42 correspond to the two active slides 41 respectively, and a connecting rod is fixedly connected between the two. The left and right ends of the lower track groove of the H-shaped groove plate 4 are fixedly connected with compensation bars 6. A pressure sensor 601 is installed between the end of the two compensation bars 6 close to each other and the corresponding follower slide 43. The ends of the two compensation bars 6 extend to the H-shaped groove plate 4, and the upper end of the compensation bar 6 outside the H-shaped groove plate 4 is fixedly connected to an air pipe 7, and the air pipe 7 is communicated with the external air source through an air pump. Two follower slides 43 are slidably connected in the track groove at the lower end of the H-shaped groove plate 4. The follower slide 43 is fixedly connected to the clamping claw 5. When clamping an object, multiple passive slides 42 are controlled to be energized to adsorb the follower slide 43, and then when the active slide 41 moves along the H-shaped groove plate 4 under electric drive, the magnetic attraction force can make the clamping claw 5 move accordingly, thereby driving the clamping claw 5 to clamp or put down the object. Figure 9 , for a single clamping unit, such as Figure 7 When the two clamping jaws 5 first move away from each other and then move closer to each other to clamp the object, the friction between the clamping jaws 5 will trigger the pressure sensor 601 to generate force data, causing the data of multiple pressure sensors 601 to increase first and then decrease, and even the force data on some pressure sensors 601 will disappear. When the surface contour of the object is greatly undulating, after clamping, the force data of multiple pressure sensors 601 will be inconsistent, or when only one of the two pressure sensors 601 on the same clamping jaw assembly still has force data, it means that in the same group of clamping jaw units, one clamping jaw 5 has failed to establish a clamping relationship with the surface of the clamped object, such as Figure 8 At this time, the robot can control the passive slide 42 corresponding to the pressure sensor 601 whose data is too small or disappears to cut off the power, so that the corresponding clamping claw 5 is separated from the active slide 41. At this time, air is inflated into the compensation bar 6 on this side through the air pipe 7, thereby stretching the compensation bar 6, thereby pushing the clamping claw 5 on this side to move toward the surface of the clamped object, realizing unilateral local compensation, and then making the two clamping claws 5 in each group of clamping claw units can play a corresponding clamping role, effectively ensuring the uniformity of the force on the object to be clamped, making the clamping more stable, and not prone to single-point concentrated force, effectively protecting the surface of the object and the clamping claw 5 itself from damage.

[0021] The passive slide 42 is made of electromagnetic material, and the follower slide 43 is made of ferromagnetic metal material. When the passive slide 42 is energized, it generates a magnetic attraction force on the follower slide 43. By controlling the power on and off of the passive slide 42, the driving mode of the movement of the clamp 5 can be changed. When preparing for clamping, the electromagnetic adsorption force can be driven by the active slide 41, so that multiple clamps 5 can be opened and closed synchronously. After clamping, it can be pneumatically driven separately according to the surface contour of the object, thereby achieving the effect of adaptive clamping.

[0022] The compensation bar 6 includes a positioning section 63 fixedly connected to the inner wall of the track groove at the lower end of the H-shaped groove plate 4 near the edge, a sliding section 61 slidably connected to the track groove at the lower end of the H-shaped groove plate 4, and an adaptive section 62 fixedly connected between the sliding section 61 and the positioning section 63. The pressure sensor 601 is installed on the sliding section 61. An L-shaped air hole is drilled inside the positioning section 63. The L-shaped air hole connects the air pipe 7 and the adaptive section 62. The adaptive section 62 is made of elastic material, and the adaptive section 62 is always in a saturated and inflated state, effectively ensuring that when the follower slide 43 moves outward, the compensation bar 6 has good load-bearing performance, and effectively ensuring that the pressure sensor 601 can generate force data. When the compensation bar 6 is inflated through the air pipe 7, the gas enters the adaptive section 62 along the L-shaped air hole, causing it to expand laterally, and then independently push the clamping jaw 5 on this side to compensate for the clamping force of the clamping jaw 5 on the surface of the object, so that the adaptive effect of this end effector is better.

[0023] The lower end of the sliding section 61 is fixedly connected to a supporting base plate 64, which spans the adaptive section 62 and is slidably connected to the lower end of the positioning section 63, and the overlapping area between the end of the supporting base plate 64 and the positioning section 63 is not less than half of the bottom area of the positioning section 63. The setting of the supporting base plate 64 can effectively limit the adaptive section 62, so that when it is inflated, its main lateral deformation is limited and longitudinal deformation is not easy to occur, thereby making its drive to the clamping jaw 5 more controllable.

[0024] like Figure 9 By setting up multiple groups of clamping jaws 5, the entire plate-shaped clamp in the existing technology is divided into multiple small units of clamping fingers, so that when clamping hard objects with relatively undulating surface contours, multiple groups of clamping jaws 5 can work independently, thereby realizing multi-point clamping on a single side. Compared with single-point clamping on a certain side, the clamping stability can be greatly improved, and at the same time the clamping force can be reduced, thereby reducing the damage to the clamped object and the clamping jaw 5 itself.

[0025] Second implementation method: Based on the first embodiment, this embodiment adds a single twist bar 8 and related structures, and the rest of the structure remains the same as the first embodiment.

[0026] Figure 10-11 As shown, the inside of the clamping jaw 5 is excavated with multiple inward-rotating grooves 501, and the inside of the multiple inward-rotating grooves 501 is rotatably connected to a single-rotating bar 8. An inner pad 81 is fixedly connected between the inner wall of the inward-rotating groove 501 and the middle of the outer wall of the single-rotating bar 8. The single-rotating bar 8 is a crescent-shaped bar with two corners, and the two corner edges of the single-rotating bar 8 are arc-shaped and rounded. One corner of the single-rotating bar 8 is located in the inward-rotating groove 501 and serves as a rotation point. The other corner of the single-rotating bar 8 passes through the inward-rotating groove 501 and extends to the outside of the clamping jaw 5. Figure 12-13During clamping, the corners of the single-rotating bars 8 that protrude from the surface of the clamping jaws 5 will contact the surface of the object. As the clamping force increases, the corners of the single-rotating bars 8 will rotate accordingly. At the same time, the single-rotating bars 8 that do not contact the surface of the clamped object due to the large contour fluctuations will gradually approach the surface of the object to be clamped. Compared with the first embodiment, the adaptability of the single clamping jaw 5 itself to the surface contour of the object is effectively improved.

[0027] When no force is applied, the portion of the single-rotation bar 8 located outside the clamping jaw 5 is not less than 1 / 2-2 / 3 of the volume of the single-rotation bar 8, so that the portion extending outward is not too small, effectively ensuring its adaptability to the surface contour of the clamped object. The inner pad 81 is made of a high-elasticity material, and the distribution span of the inner pad 81 is not greater than half of the span of the inner wall of the inner-rotation groove 501. If the span is too large, it will easily occupy too much space inside the inner-rotation groove 501, affecting the rotation amplitude of the single-rotation bar 8, and thus having an adverse effect on the adaptability of the single-rotation bar 8 to the surface contour of the object.

[0028] In summary, in the above-mentioned adaptive force-controlled industrial robot end effector, through the setting of multiple groups of grippers 5, the whole surface of the plate-like clamp in the prior art is divided into multiple small units of grippers, so that when the clamping is hard and the surface contour is relatively undulating, single-sided multi-point clamping can be achieved. Compared with the single-point clamping on a certain side, the clamping stability can be greatly improved, and at the same time the clamping force can be reduced, reducing the damage to the clamped object and the gripper 5 itself; in addition, in conjunction with the setting of the single rotating bar 8, when this end effector executes the clamping command, after the multiple grippers 5 adapt to the surface contour of the hard object to be clamped, the multiple single rotating bars 8 on the surface of a single gripper 5 can adapt to the contour of the surface of the object, thereby further improving the clamping stability.

[0029] In view of current actual needs, the protection scope of the above-mentioned implementation mode adopted in this application is not limited to this. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the protection scope of the present invention.

Claims

1. An industrial robot end effector with adaptive force control, characterized by: The invention comprises a mounting back plate (1), wherein the right end of the mounting back plate (1) is fixedly connected to a top plate (2), a plurality of clamping claw units are installed at the lower end of the top plate (2), the clamping claw unit comprises a connecting plate (3) fixedly connected to the top plate (2), an H-shaped slot plate (4) is fixedly installed at the lower end of the connecting plate (3), two mutually symmetrical clamping claws (5) are provided below the H-shaped slot plate (4), two active slides (41) are slidably connected in the upper track groove of the H-shaped slot plate (4), and two passive slides (42) are slidably connected in the lower track groove of the H-shaped slot plate (4), and the two passive slides (42) correspond to the two active slides (41) respectively. A connecting rod is fixedly connected between the two, and the left and right ends of the lower track groove of the H-shaped groove plate (4) are fixedly connected with compensation bars (6), and a pressure sensor (601) is installed between the ends of the two compensation bars (6) close to each other and the corresponding follower slide (43). The ends of the two compensation bars (6) extend outside the H-shaped groove plate (4), and the upper end of the compensation bar (6) outside the H-shaped groove plate (4) is fixedly connected with an air pipe (7), and the air pipe (7) is communicated with an external air source through an air pump. Two follower slides (43) are slidably connected in the lower track groove of the H-shaped groove plate (4), and the follower slide (43) is fixedly connected to the clamping claw (5).

2. The industrial robot end effector with adaptive force control according to claim 1, characterized in that: The passive slide (42) is made of electromagnetic material, the follower slide (43) is made of ferromagnetic metal material, and the passive slide (42) generates magnetic attraction on the follower slide (43) when energized.

3. The industrial robot end effector with adaptive force control according to claim 1, characterized in that: The compensation bar (6) comprises a positioning section (63) fixedly connected to the inner wall of the track groove at the lower end of the H-shaped groove plate (4) near the edge, a sliding section (61) slidably connected to the track groove at the lower end of the H-shaped groove plate (4), and an adaptive section (62) fixedly connected between the sliding section (61) and the positioning section (63). The pressure sensor (601) is mounted on the sliding section (61). An L-shaped air hole is bored inside the positioning section (63), and the L-shaped air hole communicates with the air pipe (7) and the adaptive section (62).

4. The industrial robot end effector with adaptive force control according to claim 3, characterized in that: The adaptive section (62) is made of elastic material, and the adaptive section (62) is always in a saturated and inflated state.

5. The industrial robot end effector with adaptive force control according to claim 4, characterized in that: The lower end of the sliding section (61) is fixedly connected to a supporting base plate (64), the supporting base plate (64) spans the adaptive section (62) and is slidably connected to the lower end of the positioning section (63), and the overlapping area between the end of the supporting base plate (64) and the positioning section (63) is not less than half the bottom area of the positioning section (63).

6. The industrial robot end effector with adaptive force control according to claim 5, characterized in that: A plurality of inward-rotating grooves (501) are bored inside the clamping jaw (5), and a single-rotating bar (8) is rotatably connected inside each of the plurality of inward-rotating grooves (501). An inner pad (81) is also fixedly connected between the inner wall of the inward-rotating groove (501) and the middle of the outer wall of the single-rotating bar (8).

7. The industrial robot end effector with adaptive force control according to claim 6, characterized in that: The single-rotation bar (8) is crescent-shaped with two corners, and the edges of the two corners of the single-rotation bar (8) are arc-shaped and rounded. One corner of the single-rotation bar (8) is located in the inner rotation groove (501) and serves as a rotation point. The other corner of the single-rotation bar (8) passes through the inner rotation groove (501) and extends to the outside of the clamping jaw (5). When the single-rotation bar (8) is not subjected to force, the portion of the single-rotation bar (8) located outside the clamping jaw (5) is not less than 1 / 2-2 / 3 of the volume of the single-rotation bar (8).

8. The industrial robot end effector with adaptive force control according to claim 7, characterized in that: The inner pad (81) is made of a high-resilience material, and the distribution span of the inner pad (81) is no greater than half the span of the inner wall of the inner rotation groove (501).

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