TWI404612B - Remote center compliance device - Google Patents

Abstract

The invention discloses an adaptability position correction device which is situable for remote of a mechanical arm. The correction device comprises a first flat plate and a second flat plate that are connected to a remote, a central assembly connected to the second flat plate, and a position adaptability assembly. The two ends of the position adaptability assembly are respectively connected to the first flat plate and the second flat plate. The position adaptability assembly is provided with at least a groove between the two ends. An acute angle is ormed between the opening direction of the groove and an on-line machine between the two ends. Therefore, the groove of the adaptability position correction device helps to effectively compensate the offset of the mechanical arm, caused by size errors, rigid factors or positioning errors.

Description

Compliance position correction device

This proposal is a compliant position correction device, in particular a compliant position correction device that is connected to the distal end of the robot arm to correct the error.

Industrial use of mechanical arms instead of manual work has become quite popular. Robotic arms are often used for taking and discharging materials, that is, using a robotic arm to take out pre-prepared materials and then move them to a predetermined position. When the robot arm performs the reclaiming or discharging operation, the accuracy of the reclaiming point and the discharging point is very important. When the position of the reclaiming point or the discharging point is wrong, the robot arm will not be able to complete the predetermined action correctly. The factors that affect the accuracy of the pick-and-place points include the dimensional error of each component in the robot arm, the rigidity of each component, and the positioning error.

In order to correct the offset caused by the above error, the industry has proposed a compliance correction device, for example, the US Patent "Remote center compliance device with measuring sensor" (No. 7748136, published on July 6, 2010). "Remediation device", "U.S. Patent No. 4,080,801, issued on July 4, 1978, "Remote center compliance system", and U.S. Patent No. 6,792,689, "Remote center compliance device", September 21, 2004 (Compliance Correction Device), these techniques are used to correct the above offset, and from the date of approval, it can be easily known that this offset problem has occurred for decades and is still the industry's continued desire The issue to be solved.

In view of the above offset problem, the present proposal proposes a compliant position correction device adapted to the distal end of a robot arm to correct the offset of the robot arm due to dimensional error, rigidity or positioning error, thereby solving the above problem.

According to an embodiment, the correction device comprises a first plate connected to the distal end, a second plate, a central element connected to the second plate, and a position compliant element, wherein the two ends of the position compliant element are respectively connected to the first plate and the second The flat plate and the position compliant member have at least one groove between the two ends, and the opening direction of the groove and the connecting line between the two ends are at an acute angle.

According to an embodiment, the compliant element has two grooves and the openings of the two grooves are oriented differently.

According to an embodiment, the compliant element has four grooves and the opening direction of the adjacent grooves is substantially at an angle of 90 degrees.

According to an embodiment, the correction device has three compliant elements, the compliant elements being disposed between the first plate and the second plate in an annular equiangular shape.

By virtue of the above-described compliant position correcting device, the compliant position correcting device can effectively correct the offset of the robot arm due to dimensional error, rigidity factor or positioning error by means of the groove.

Please refer to FIG. 1 , which is a perspective view of a first embodiment of a compliant position correction device according to the present invention. A compliant position correction device (or a remote center compliance device) is adapted to be coupled to a distal end of a robot arm (Remote End) to correct the mechanical arm error during positioning of the mechanical arm. The amount of offset caused by the stiffness factor or positioning error. This offset may occur in a single axial direction (such as one of the two horizontal axes or the vertical axis) or in three axial directions (two horizontal and vertical axes). The uniaxial or triaxial offset can be corrected by the compliant position correction device.

Please also refer to "FIG. 1" and "FIG. 2", which are perspective views of a first embodiment of a position compliant component of a compliant position correcting device in accordance with the present invention. As can be seen, the compliant position correction device includes a first plate 20, a second plate 25, a center member 50, and position compliant members 30a, 30b (also referred to as an elastic column). The first plate 20 is coupled to the distal end 90 of the robotic arm and the central member 50 is coupled to the second plate 25. The two ends 32a, 32b of the position compliant members 30a, 30b are connected to the first flat plate 20 and the second flat plate 25, respectively. As can be seen from the figure, the position compliant members 30a, 30b are cylindrical (like a thin-walled cylinder), and the end faces of the end faces are annular, but not limited thereto, and the position compliant members 30a, 30b can also be It is a solid cylinder, square, pentagon or hexagon, etc., and considering stress concentration and uniformity, it is preferably circular or equilateral. The position compliant components 30a, 30b are disposed between the first flat plate 20 and the second flat plate 25, and are arranged in an equiangular manner according to the top view thereof so as to obtain a better balance when the correction is made.

The lines connecting the two ends 32a, 32b of the position compliant members 30a, 30b are indicated in the "Fig. 2" as the Z axis, that is, the axial direction of the position compliant members 30a, 30b, and the position compliant members 30a, 30b at the ends 32a, 32b. Between the plurality of grooves 34a, 34b, 34c, 34d, the grooves 34a, 34b, 34c, 34d can be fabricated by any processing means such as, but not limited to, waterjet cutting, electric discharge wire cutting, laser cutting, sawing Sheet, wire cutting or saw blade cutting. The grooves 34a, 34b, 34c, 34d can be cut into a specific pattern in a metal cylinder (such as spring steel, stainless steel, tool steel, etc.) to make the metal cylinder a flexible part, taking the metal itself. The characteristics of good tensile strength enable it to achieve Z-axis tensile force and compensatory movement on the XY axis.

In order to further explain the structure and characteristics of the grooves 34a, 34b, 34c, 34d, please refer to "3", "4A", "4B", "4C", and "4D". "3D" is a side view of "Picture 2", and "4A", "4B", "4C" and "4D" are respectively "3". Cross-sectional views of positions 4A-4A, 4B-4B, 4C-4C, and 4D-4D. For the sake of convenience, the grooves 34a, 34b, 34c, 34d in "4A", "4B", "4C", and "4D" are respectively referred to as first grooves 34a. a second trench 34b, a third trench 34c, and a fourth trench 34d.

Here, only the wire cutting will be described as an example. As can be seen from "Fig. 4A", the first groove 34a is cut from the +Y direction to the -Y direction; it can be seen from "Fig. 4B" The second groove 34b is cut from the -Y direction toward the +Y direction; as can be seen from the "Cth 4C", the third groove 34c is cut from the -X direction toward the +X direction; As can be seen from "4D", the fourth groove 34d is cut from the +X direction toward the -X direction. Therefore, the position compliant member 30a has appropriate elasticity at the position where each of the grooves 34a, 34b, 34c, 34d is cut. Taking "4A" as an example, the position compliant member 30a is centered on the connecting portion 35. The elasticity of the swing along the X-axis direction, the magnitude of the swing amplitude (ie, the Z-axis correction width) is related to the width h of the first groove 34a (see "3"), and the wider the cut width h, The greater the amplitude of the swing, the greater the elasticity (or rigidity) of the swing is related to the depth of the cut h (see Figure 4A) and the area of the connecting section 35. Of course, the elasticity (or rigidity) of the swing is also The wall thickness t of the cylinder is related, and the deeper the cutting depth h, the smaller the rigidity and the greater the elasticity, and the larger the area and the wall thickness t of the connecting portion 35, the greater the rigidity and the smaller the elasticity.

In addition, from "4A", "4B", "4C" and "4D", it can be seen that the cutting direction (or opening direction) of each groove is also properly arranged (+Y, -Y, -X, +X), the purpose of which is that the correction of the position compliant element 30a for each axial direction is not concentrated on a certain area of the position (upper or lower in the axial direction), but is dispersed, so that It can maintain its rigidity and evenly disperse its stress. Although in this embodiment, the cutting direction is arranged in the order of +Y, -Y, -X, +X, but not limited to this, any arrangement, even Arranging in a random number manner does not affect the achievement of the object of the present invention.

Then, the cutting direction (opening direction) of the grooves 34a, 34b, 34c, 34d may be a specific angle with the X axis or the Y axis, in addition to the +Y, -Y, -X, +X directions. For example, but not limited to 30 degrees, 45 degrees, 60 degrees, and the like. The opening direction of the grooves 34a, 34b, 34c, 34d can be regarded as the opposite direction of the cutting of the grooves 34a, 34b, 34c, 34d. Taking "4A" as an example, the groove 34a is from the +Y direction to the -Y direction. It is cut, so its opening direction is +Y direction. In the present embodiment, the opening directions of all the grooves 34a, 34b, 34c, 34d are at an angle of about 90 degrees with the axial direction (Z-axis) of the position compliant member 30a, but the invention is not limited thereto, and the groove is not limited thereto. The opening directions of 34a, 34b, 34c, 34d may be at an acute angle to the axial direction (Z-axis) of the position compliant member 30a, so that the offset of the single grooves 34a, 34b, 34c, 34d can be corrected. Limited to a single axial direction. Further, the opening directions of the respective grooves 34a, 34b, 34c, 34d may be the same or different.

Furthermore, it can be seen from "Fig. 3" that the position compliant element 30a has a plurality of grooves 34a, 34b, 34c, 34d, and the number of grooves 34a, 34b, 34c, 34d also affects the offset that can be corrected. When the number of the grooves 34a, 34b, 34c, 34d is larger, the wider the total width, the larger the total offset that can be corrected. Further, the pitch p (Pitch) between the grooves also affects the rigidity of the position compliant member 30a as a whole. Therefore, in design, the design can be designed with reference to the required correction amount of the robot arm, for example, the grooves 34a, 34b, 34c are designed according to the respective offsets of the X, Y, and Z axes to be corrected. , the width h of the 34d, the depth d and the pitch p, and the wall thickness t of the position compliant element 30a, and when the distance between the first flat plate 20 and the second flat plate 25 is fixed, in addition to the proper adjustment of the grooves 34a, 34b, In addition to the width h, the depth d and the pitch p of the 34c, 34d, and the wall thickness t of the position compliant element 30a, different materials may be selected to achieve the offset of the desired correction.

The Z-axis correction width is related to the number of grooves 34a, 34b, 34c, 34d and the width h of the groove cut ("Fig. 3"), that is, the wider the cutting width h, the more the number of grooves 34a, 34b, 34c, 34d If there are many, the larger the amplitude of the swing is, and the amount of the left and right swing is the same as the number of the grooves 34a, 34b, 34c, 34d, the distance between the grooves 34a, 34b, 34c, 34d, and the depth of the cut h (" 4A") and the width of the connecting section and the wall thickness t of the cylinder, the deeper the cutting depth h, the smaller the width and wall thickness t of the connecting section, the smaller the rigidity and the greater the elasticity, and vice versa. The less elasticity.

Next, please refer to "5A" and "5B", which is a schematic diagram of the use of the compliant position correcting device, which is a schematic diagram of the distal end 90 of the simulated robot arm to align the central member 50 with the concave hole 92. As can be seen in "Fig. 5A", when the robot arm moves the center member 50 to the recessed hole 92, the center member 50 and the recessed hole 92 are offset by an amount. At this time, when the robot arm views the center member 50 toward the figure. When the lower surface (ie, the -Z direction) moves, the center member 50 first contacts the lead angle above the recess 92, and then, because the position compliant member 30b has the offset correction capability on the X, Y, and Z axes. Therefore, the center member 50 can be smoothly placed in the recessed hole 92.

Furthermore, please refer to "FIG. 6", which is a second embodiment of the compliant position correction device according to the present invention. As can be seen from the figure, there is only a single between the first plate 20 and the second plate 25. The position compliant member 30c has an outer diameter which is only slightly smaller than the first flat plate 20 and the second flat plate 25. At the same time, the position compliant member 30c has only one groove 34e, and the opening direction and position of the groove 34e are compliant. The angle between the axial direction (long axis or Z axis) of the element 30c is not a right angle but an acute angle, which is, for example, about 30 degrees.

Please refer to "Figure 7" and "Figure 8" at the same time. The former is a schematic diagram of another embodiment of the position compliant component, and the latter is the third of the compliant position correction device of the position compliant component 30e according to the "Fig. 7". A top plan view of an embodiment. As can be seen from the figure, the position compliant member 30e has a plate shape and has a plurality of grooves 34f. When applied to the compliant position correcting device, an arrangement as shown in "Fig. 8" can be employed. The arrangement of the corner triangles can make the offset correction effect between the grooves 34f more balanced and there is no stress concentration phenomenon.

According to the technology of this proposal, the position compliant component can be corrected to 2.6 cm (mm) in the XY direction, the bending range can be up to 5 degrees, and the rotation range (with the Z axis as the axis) can reach 2 degrees. The shaft can withstand a pressure of 5,000 Newtons and can reach a tensile force of 300 Newtons. However, the above-mentioned positional compliance capability (or correction capability) is not intended to limit the proposal. The groove of the position-adapting component is properly designed and matched. Depending on the rigidity and elasticity of the component body, different position compliance capabilities can be obtained.

In summary, the compliant position correcting device can effectively correct the offset of the robot arm due to dimensional error, rigidity factor, or positioning error by the configuration of the position compliant component.

While the present invention has been described above in terms of the preferred embodiments described above, it is not intended to limit the present invention, and anyone skilled in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of patent protection of this proposal shall be subject to the definition of the scope of the patent application attached to this specification.

20. . . First tablet

25. . . Second tablet

30a, 30b, 30c. . . Position compliant component

32a, 32b. . . Two ends

34a, 34b, 34c, 34d, 34e, 34f. . . Trench

35. . . Connection segment

50. . . Central component

90. . . remote

92. . . Concave hole

Fig. 1 is a perspective view showing a first embodiment of a compliant position correcting device according to the present proposal.

Figure 2 is a perspective view of a first embodiment of a position compliant component of a compliant position correcting device in accordance with the present disclosure.

Figure 3 is a side view of "Figure 2".

4A, 4B, 4C, and 4D are cross-sectional views of "3rd" at positions 4A-4A, 4B-4B, 4C-4C, and 4D-4D, respectively.

Figures 5A and 5B are schematic views of the use of a compliant position correction device.

Figure 6 is a second embodiment of a compliant position correcting device in accordance with the present invention.

Figure 7 is a schematic illustration of another embodiment of a position compliant element.

Figure 8 is a top plan view showing a third embodiment of the compliant position correcting device of the position compliant element according to the "Fig. 7".

20. . . First tablet

25. . . Second tablet

30a, 30b. . . Position compliant component

50. . . Central component

90. . . remote

Claims (7)

A compliant position correcting device is adapted to be distal to a robot arm, the correcting device comprising: a first plate coupled to the distal end; a second plate; a central member coupled to the second plate; a position compliant component, the two ends of the position compliant component are respectively connected to the first flat plate and the second flat plate, and the position compliant component has at least one groove between the two ends, the opening direction of the groove and the second The end of the line is sandwiched by an acute angle, the depth of the groove being greater than one-half of the outer diameter of the position compliant element. The compliant position correcting device of claim 1, wherein the position compliant member has two such grooves, and the opening directions of the two grooves are different. The compliant position correcting device of claim 1, wherein the position compliant member has four such grooves, and wherein the opening directions of the two adjacent grooves are substantially at an angle of 90 degrees. The compliant position correcting device of claim 1, wherein the position compliant member is a cylinder, and the two ends are axially circular end faces of the cylinder. The compliant position correcting device of claim 1, wherein the position compliant member is a cylinder, and the two ends are axial annular end faces of the cylinder. The compliant position correcting device of claim 1, wherein the correcting device has three position compliant members, and the position compliant members are disposed between the first flat plate and the second flat plate at an annular equiangular shape. The compliant position correcting device of claim 6, wherein the position compliant members have four such grooves, and wherein the adjacent openings of the plurality of grooves are substantially at an angle of 90 degrees.