Miniature strain type six-dimensional force sensor and calibration device thereof

Abstract

The application discloses a micro strain type six-dimensional force sensor and a calibration device thereof. The sensor comprises an elastic body, three groups of moment measuring strain gauges, three groups of force measuring strain gauges and a circuit board. The elastic body comprises a fixing stud, a base, four inverted L-shaped sensitive beams and a force guide column which are sequentially connected in an integrated manner from bottom to top. The four inverted L-shaped sensitive beams are evenly distributed along the circumference of the base. Each inverted L-shaped sensitive beam comprises a vertical floating beam and a horizontal cross beam which are connected in an integrated manner. The three groups of moment measuring strain gauges are respectively attached to the upper and lower sides and the left and right sides of the horizontal cross beam. The three groups of force measuring strain gauges are respectively attached to the inner and outer sides of the vertical floating beam. The circuit board is clamped on the base and located between the four vertical floating beams. The three groups of moment measuring strain gauges and the three groups of force measuring strain gauges are respectively electrically connected with the circuit board. The application has the advantages of high sensitivity, good isotropy and low inter-dimension coupling and is suitable for six-dimensional force measurement of a mechanical finger tip or a small robot wrist.

Description

Technical Field

[0001] This invention relates to the field of multidimensional force sensors and static calibration technology, and more specifically to a miniature strain-type six-dimensional force sensor and its calibration device. Background Technology

[0002] As the end effector of robots, robotic arms play a crucial role in upper body manipulation and grasping tasks, and are widely used in industrial production, medical and health care, military and other fields. With the continuous expansion of robotic arm applications, the demand for its precise control and sensitive perception capabilities is also increasing.

[0003] Robotic arms perform complex and diverse tasks, requiring flexible and accurate motion control depending on the situation. Force is a crucial parameter in the interaction between the robotic arm and external objects; accurately sensing the forces applied to the robotic arm is essential for its motion control. Multidimensional force sensors, as a vital component of robotic arms, can accurately measure forces and torques in various directions, providing necessary information for precise control. Among these, the six-dimensional force / torque sensor, a type of multidimensional force sensor, can comprehensively measure forces and torques in the X, Y, and Z directions within a Cartesian coordinate system.

[0004] However, the current trend of miniaturization in humanoid robots, medical robots, and other types of robots has created an urgent need for research on the performance and application of small multidimensional force sensors. Currently, small six-dimensional force sensors cannot guarantee their static and dynamic performance while achieving miniaturization. For example, Chinese invention patent CN116337323A discloses a loading mechanism for dynamic calibration of a six-dimensional force sensor, which uses four square columns to apply force and torque. This complex structure makes calibration difficult and costly for micro-six-dimensional force sensors, and it cannot accurately position a micro-sensor with only one fixing bolt. Similarly, Chinese invention patent CN116046257A discloses a simplified calibration device and method for a six-dimensional force sensor, requiring multiple bolts to position the multidimensional force sensor, which cannot meet the requirements of micro-sensors. Furthermore, Chinese utility model patent CN205449351U discloses a small three-dimensional force sensor that uses two cantilevered double-hole parallel beam elastic bodies to measure force, but it cannot measure torque.

[0005] Therefore, providing a miniature strain-type six-dimensional force sensor and its calibration device is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a miniature strain-type six-dimensional force sensor and its calibration device, which has the advantages of high sensitivity, good isotropy and low interdimensional coupling, and is suitable for six-dimensional force measurement of mechanical fingertips or small robot wrists.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A miniature strain-type six-dimensional force sensor, comprising:

[0009] An elastomer includes, from bottom to top, a fixed stud, a base, four inverted L-shaped sensitive beams, and a force guide column connected as a single unit. The four inverted L-shaped sensitive beams are evenly distributed around the circumference of the base. Each inverted L-shaped sensitive beam includes a vertical floating beam and a horizontal cross beam connected as a single unit. The vertical floating beam is connected to the base as a single unit. The force guide column is located between the four horizontal cross beams.

[0010] Three sets of torque measurement strain gauges and three sets of force measurement strain gauges are attached to the top, bottom and left and right sides of the horizontal cross beam, respectively, and the three sets of force measurement strain gauges are attached to the inner and outer sides of the vertical floating beam, respectively, to form six Wheatstone bridges.

[0011] A circuit board is snapped onto the base and located between the four vertical floating beams; three sets of torque measuring strain gauges and three sets of force measuring strain gauges are electrically connected to the circuit board.

[0012] By adopting the above technical solutions, the beneficial effects of the present invention are as follows:

[0013] By employing a combination of a horizontal cross beam and a vertical floating beam, three sets of torque measurement strain gauges are attached to the horizontal cross beam, and three sets of force measurement strain gauges are attached to the vertical floating beam. This enables full-bridge measurement of all forces and moments in the X, Y, and Z directions. Furthermore, the horizontal cross beam and the vertical floating beam intersect perpendicularly in space, which can reduce interdimensional coupling between forces and moments.

[0014] Furthermore, it also includes a housing and fixing bolts. The bottom of the housing has an overload protection groove adapted to the shape of the base, and the top of the housing has a square positioning groove with a mounting hole in the center of the square positioning groove. The housing is fitted onto the elastic body so that the base is fitted into the overload protection groove and the force guide column is fitted into the square positioning groove. The fixing bolt passes through the mounting hole and is screwed onto the force guide column.

[0015] Furthermore, the three sets of force measurement strain gauges are respectively an X-direction force measurement strain gauge group, a Y-direction force measurement strain gauge group, and a Z-direction force measurement strain gauge group. The X-direction force measurement strain gauge group is attached to the inner and outer sides of the two vertical floating beams located in the X direction near the base; the Y-direction force measurement strain gauge group is attached to the inner and outer sides of the two vertical floating beams located in the Y direction near the base; the Z-direction force measurement strain gauge group is attached to the inner and outer sides of the two vertical floating beams located in the X direction away from the base. Similarly, the three sets of torque measurement strain gauges are respectively an X-direction torque measurement strain gauge group, a Y-direction torque measurement strain gauge group, and a Z-direction torque measurement strain gauge group. The X-direction torque measurement strain gauge group is attached to the upper and lower surfaces of the two horizontal cross beams located in the Y direction away from the guide column; the Y-direction torque measurement strain gauge group is attached to the upper and lower surfaces of the two horizontal cross beams located in the X direction away from the guide column; the Z-direction torque measurement strain gauge group is attached to the left and right sides of the two horizontal cross beams located in the Y direction near the guide column.

[0016] Furthermore, the four vertical floating beams are designated as a first vertical floating beam, a second vertical floating beam, a third vertical floating beam, and a fourth vertical floating beam, wherein the first and second vertical floating beams are distributed along the X-direction, and the third and fourth vertical floating beams are distributed along the Y-direction; the four horizontal cross beams are designated as a first horizontal cross beam, a second horizontal cross beam, a third horizontal cross beam, and a fourth horizontal cross beam, wherein the first and second horizontal cross beams are distributed along the X-direction, and the third and fourth horizontal cross beams are distributed along the Y-direction; the X-direction force measurement strain gauge assembly The system includes strain gauges Rx1, Rx2, Rx3, and Rx4. The Rx1 strain gauge is attached to the outer side of the first vertical floating beam near the base; the Rx3 strain gauge is attached to the inner side of the first vertical floating beam near the base; the Rx2 strain gauge is attached to the inner side of the second vertical floating beam near the base; and the Rx4 strain gauge is attached to the outer side of the second vertical floating beam near the base. These strain gauges form a Wheatstone bridge for measuring the force in the x-direction; the force in the y-direction is measured... The strain gauge assembly includes strain gauges Ry1, Ry2, Ry3, and Ry4. Strain gauge Ry1 is attached to the outer side of the third vertical floating beam near the base; strain gauge Ry3 is attached to the inner side of the third vertical floating beam near the base; strain gauge Ry2 is attached to the inner side of the fourth vertical floating beam near the base; and strain gauge Ry4 is attached to the outer side of the fourth vertical floating beam near the base. The strain gauges Ry1, Ry2, Ry3, and Ry4 form a Wheatstone bridge for measuring the force in the y-direction. The strain gauge assembly for force measurement includes strain gauges Rz1, Rz2, Rz3, and Rz4. Strain gauge Rz1 is attached to the outer side of the first vertical floating beam away from the base, and strain gauge Rz3 is attached to the inner side of the first vertical floating beam away from the base. Strain gauge Rz2 is attached to the outer side of the second vertical floating beam away from the base, and strain gauge Rz4 is attached to the inner side of the second vertical floating beam away from the base. Strain gauges Rz1, Rz2, Rz3, and Rz4 form a Wheatstone bridge for measuring the force in the z-direction.The X-direction torque measurement strain gauge group includes an Rmx1 strain gauge, an Rmx2 strain gauge, an Rmx3 strain gauge, and an Rmx4 strain gauge. The Rmx1 strain gauge is attached to the top surface of the third horizontal cross beam away from the guide column, the Rmx3 strain gauge is attached to the bottom surface of the third horizontal cross beam away from the guide column, the Rmx2 strain gauge is attached to the bottom surface of the fourth horizontal cross beam away from the guide column, and the Rmx4 strain gauge is attached to the top surface of the fourth horizontal cross beam away from the guide column. The Rmx1 strain gauge, Rmx2 strain gauge, Rmx3 strain gauge, and Rmx4 strain gauge form a Wheatstone bridge for measuring the torque in the x-direction; the strain gauge group for measuring the torque in the y-direction includes Rmy1 strain gauge, Rmy2 strain gauge, Rmy3 strain gauge, and Rmy4 strain gauge. The Rmy1 strain gauge is attached to the top surface of the first horizontal cross beam away from the guide column, the Rmy3 strain gauge is attached to the bottom surface of the first horizontal cross beam away from the guide column, and the Rmy2 strain gauge... The strain gauge is attached to the bottom surface of the second horizontal cross beam away from the guide column, and the Rmy4 strain gauge is attached to the top surface of the second horizontal cross beam away from the guide column; the Rmy1, Rmy2, Rmy3, and Rmy4 strain gauges form a Wheatstone bridge for measuring the torque in the y-direction; the strain gauge group for measuring the torque in the Z-direction includes Rmz1, Rmz2, Rmz3, and Rmz4 strain gauges, and the Rmz1 strain gauge is attached to the bottom surface of the second horizontal cross beam away from the guide column. The third horizontal cross beam is located on the right side near the guide column. The Rmz3 strain gauge is attached to the left side of the third horizontal cross beam near the guide column. The Rmz2 strain gauge is attached to the left side of the fourth horizontal cross beam near the guide column. The Rmz4 strain gauge is attached to the right side of the fourth horizontal cross beam near the guide column. The Rmz1, Rmz2, Rmz3, and Rmz4 strain gauges form a Wheatstone bridge for measuring the torque in the z-direction.

[0017] A calibration device for calibrating a miniature strain-type six-dimensional force sensor as described above includes a fixed block, a sliding block, a positioning plate, and calibration fasteners. The fixed block has a notch on one side of its top and a first vertically downward through-hole on the other side. A second vertically downward through-hole is formed in the notch. The sliding block is mounted on the notch, thereby forming a stud placement hole, a third through-hole, and a fourth through-hole between the fixed block and the sliding block. The stud is placed in the stud placement hole. The sliding block has a second through-hole corresponding to the position of the second through-hole. The first through-hole... The second, third, and fourth line through holes are evenly distributed; the positioning plate is installed on the top of the fixing block and the sliding block; the positioning plate has a base positioning hole in the middle that matches the shape of the base, and the base is located in the base positioning hole; the positioning plate has line through holes that correspond to the positions of the first, second, third, and fourth line through holes respectively; the middle part of the calibration firmware is connected to the guide column; the two ends of the calibration firmware have fixing holes; the two long sidewalls of the calibration firmware have four triangular grooves, and the four triangular grooves are all equidistant from the middle of the calibration firmware.

[0018] By adopting the above technical solutions, the beneficial effects of the present invention are as follows:

[0019] It can achieve rapid static calibration of miniature multidimensional force sensors and has the characteristics of small size, simple structure and easy use.

[0020] Furthermore, the top plane of the fixed block has two first upper threaded holes, and the bottom plane of the notch has two first lower threaded holes; the side wall of the notch has two second threaded holes; the top of the sliding block has two third threaded holes corresponding to the positions of the first lower threaded holes, and the two first upper threaded holes and the two third threaded holes are evenly distributed; the side wall of the sliding block has two first through holes corresponding to the positions of the second threaded holes; the positioning plate has two evenly distributed second through holes and two sliding grooves, the two second through holes corresponding to the positions of the two first upper threaded holes, and the two sliding grooves corresponding to the positions of the two third threaded holes; two first bolts pass through the two first through holes and are threadedly connected to the two second threaded holes; two second bolts pass through the two second through holes and are threadedly connected to the two first upper threaded holes; two third bolts pass through the two sliding grooves and are threadedly connected to the two third threaded holes and the two first lower threaded holes. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 The attached figure is an exploded view of a miniature strain-type six-dimensional force sensor provided by the present invention;

[0023] Figure 2 The attached figure is a schematic diagram of the structure of the elastomer provided by the present invention;

[0024] Figure 3 The attached figure is a schematic diagram of the structure of the outer shell provided by the present invention;

[0025] Figure 4 The attached figure is a schematic diagram of the structure of the xz projection surface of the elastomer provided by the present invention;

[0026] Figure 5 The attached figure is a schematic diagram of the yz projection surface of the elastomer provided by the present invention;

[0027] Figure 6 The attached figure is a schematic diagram of the structure of the xy projection plane of the elastomer provided by the present invention;

[0028] Figure 7 The attached figure is a circuit diagram of the Wheatstone bridge for measuring the force in the x-direction provided by the present invention;

[0029] Figure 8 The attached figure is a circuit diagram of the Wheatstone bridge for measuring the force in the y-direction provided by the present invention;

[0030] Figure 9 The attached figure is a circuit diagram of the Wheatstone bridge for measuring the force in the z-direction provided by the present invention;

[0031] Figure 10 The attached figure is a circuit diagram of the Wheatstone bridge for measuring the torque in the x-direction provided by the present invention;

[0032] Figure 11 The attached figure is a circuit diagram of the Wheatstone bridge for measuring the torque in the y-direction provided by the present invention;

[0033] Figure 12 The attached figure is a circuit diagram of the Wheatstone bridge for measuring the torque in the z-direction provided by the present invention;

[0034] Figure 13 The attached figure is a schematic diagram of the structure of a calibration device provided by the present invention;

[0035] Figure 14The attached figure is an exploded view of a calibration device provided by the present invention;

[0036] Figure 15 The attached figure is a schematic diagram of the structure of a calibration device provided by the present invention when measuring force in the z-direction;

[0037] Figure 16 The attached figure is a schematic diagram of the structure of a calibration device provided by the present invention for measuring torque in the z-direction. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] like Figure 1-16 As shown, this invention discloses a miniature strain gauge six-dimensional force sensor, including an elastic body 1, three sets of torque measuring strain gauges 2, three sets of force measuring strain gauges 3, and a circuit board 4. The elastic body 1 includes a fixed stud 11, a base 12, four inverted L-shaped sensitive beams 13, and a force guide column 14 connected as a single unit from bottom to top. The fixed stud 11 and the base 12 have through holes for interconnected wires. The four inverted L-shaped sensitive beams 13 are evenly distributed around the circumference of the base 12. Each inverted L-shaped sensitive beam 13 includes a vertical floating beam 131 and a horizontal cross beam 132 connected as a single unit. Both the vertical floating beam 131 and the horizontal cross beam 132 are sensitive beams. 1. It is integrated with the base 12; the force guide column 14 is located between the four horizontal cross beams 132; three sets of torque measuring strain gauges 2 are respectively pasted on the top, bottom and left and right sides of the horizontal cross beams 132 to measure the torque in the X, Y and Z directions; three sets of force measuring strain gauges 3 are respectively pasted on the inner and outer sides of the vertical floating beam 131 to measure the force in the X, Y and Z directions, so as to form six sets of Wheatstone bridges; the circuit board 4 is snapped onto the base 12 and located between the four vertical floating beams 131; the three sets of torque measuring strain gauges 2 and the three sets of force measuring strain gauges 3 are electrically connected to the circuit board 4 to realize the strain gauge bridge connection and the connection of the input and output signals with the external wiring terminals. This invention employs a combination of a horizontal cross beam 132 and a vertical floating beam 131. Three sets of torque measuring strain gauges 2 are attached to the horizontal cross beam 132, and three sets of force measuring strain gauges 3 are attached to the vertical floating beam 131. This enables full-bridge measurement of all forces and moments in the X, Y, and Z directions. Furthermore, the horizontal cross beam 132 and the vertical floating beam 131 intersect perpendicularly in space, which can reduce interdimensional coupling between forces and moments.

[0040] To further optimize the technical solution of the present invention, it also includes a housing 5 and a fixing bolt 6. The housing 5 is a cylinder with a height of 21.8 mm and a bottom diameter of 24 mm. The bottom of the housing 5 has an overload protection groove 51 that matches the shape of the base 12. In this embodiment, the base 12 is octagonal, and correspondingly, the overload protection groove 51 is also octagonal. The top of the housing 5 has a square positioning groove 52, and a mounting hole 53 is opened in the middle of the square positioning groove 52. The housing 5 is fitted onto the elastic body 1, so that the base 12 is fitted into the overload protection groove 51, and the guide column 14 is fitted into the square positioning groove 52 to form a shape positioning. The fixing bolt 6 passes through the mounting hole 53 and is screwed onto the guide column 14.

[0041] Specifically, the three sets of force measurement strain gauges 3 are: X-direction force measurement strain gauge set 31, Y-direction force measurement strain gauge set 32, and Z-direction force measurement strain gauge set 33. The X-direction force measurement strain gauge set 31 is attached to the inner and outer sides of the two vertical floating beams 131 located in the X direction near the base 12; the Y-direction force measurement strain gauge set 32 ​​is attached to the inner and outer sides of the two vertical floating beams 131 located in the Y direction near the base 12; and the Z-direction force measurement strain gauge set 33 is attached to the inner and outer sides of the two vertical floating beams 131 located in the X direction away from the base 12. The torque measurement strain gauges 2 are respectively X-direction torque measurement strain gauge group 21, Y-direction torque measurement strain gauge group 22 and Z-direction torque measurement strain gauge group 23. X-direction torque measurement strain gauge group 21 is attached to the upper and lower surfaces of the two horizontal cross beams 132 in the Y direction away from the guide column 14; Y-direction torque measurement strain gauge group 22 is attached to the upper and lower surfaces of the two horizontal cross beams 132 in the X direction away from the guide column 14; Z-direction torque measurement strain gauge group 23 is attached to the left and right sides of the two horizontal cross beams 132 in the Y direction near the guide column 14.

[0042] Specifically, the four vertical floating beams 131 are designated as the first vertical floating beam 1311, the second vertical floating beam 1312, the third vertical floating beam 1313, and the fourth vertical floating beam 1414. The first and second vertical floating beams 1311 and 1312 are distributed along the X-direction, while the third and fourth vertical floating beams 1313 and 1414 are distributed along the Y-direction. The four horizontal cross beams 132 are designated as the first horizontal cross beam 1321, the second horizontal cross beam 1322, the third horizontal cross beam 1323, and the fourth horizontal cross beam 1324. The first and second horizontal cross beams 1321 and 1322 are distributed along the X-direction, while the third and fourth horizontal cross beams 1323 and 1324 are distributed along the Y-direction. Directional distribution; the strain gauge group 31 for measuring force in the X direction includes Rx1 strain gauge 311, Rx2 strain gauge 312, Rx3 strain gauge 313, and Rx4 strain gauge 314. Rx1 strain gauge 311 is attached to the outer side of the first vertical floating beam 1311 near the base 12; Rx3 strain gauge 313 is attached to the inner side of the first vertical floating beam 1311 near the base 12; Rx2 strain gauge 312 is attached to the inner side of the second vertical floating beam 1312 near the base 12; and Rx4 strain gauge 314 is attached to the outer side of the second vertical floating beam 1312 near the base 12. The Rx1 strain gauge 311, Rx2 strain gauge 312, Rx3 strain gauge 313, and Rx4 strain gauge 314 constitute a Wheatstone for measuring force in the X direction. The bridge circuit; the strain gauge group 32 for measuring force in the Y direction includes strain gauges Ry1 321, Ry2 322, Ry3 323, and Ry4 324. Ry1 strain gauge 321 is attached to the outer side of the third vertical floating beam 1313 near the base 12; Ry3 strain gauge 323 is attached to the inner side of the third vertical floating beam 1313 near the base 12; Ry2 strain gauge 322 is attached to the inner side of the fourth vertical floating beam 1414 near the base 12; and Ry4 strain gauge 324 is attached to the outer side of the fourth vertical floating beam 1414 near the base 12. The strain gauges Ry1 321, Ry2 322, Ry3 323, and Ry4 324 form a Wheatstone bridge for measuring force in the Y direction. The bridge; the strain gauge group 33 for measuring force in the Z direction includes strain gauges Rz1 331, Rz2 332, Rz3 333 and Rz4 334. Strain gauge Rz1 331 is attached to the outer side of the first vertical floating beam 1311 away from the base 12, and strain gauge Rz3 333 is attached to the inner side of the first vertical floating beam 1311 away from the base 12. Strain gauge Rz2 332 is attached to the outer side of the second vertical floating beam 1312 away from the base 12, and strain gauge Rz4 334 is attached to the inner side of the second vertical floating beam 1312 away from the base 12. Strain gauges Rz1 331, Rz2 332, Rz3 333 and Rz4 334 form a Wheatstone bridge for measuring force in the Z direction.X-direction torque measurement strain gauge group 21 includes Rmx1 strain gauge 211, Rmx2 strain gauge 212, Rmx3 strain gauge 213, and Rmx4 strain gauge 214. Rmx1 strain gauge 211 is attached to the top surface of the third horizontal cross beam 1323 away from the guide column 14; Rmx3 strain gauge 213 is attached to the bottom surface of the third horizontal cross beam 1323 away from the guide column 14; Rmx2 strain gauge 212 is attached to the bottom surface of the fourth horizontal cross beam 1324 away from the guide column 14; and Rmx4 strain gauge 214 is attached to the fourth horizontal cross beam 1324 away from the guide column 14. Top surface; Rmx1 strain gauge 211, Rmx2 strain gauge 212, Rmx3 strain gauge 213 and Rmx4 strain gauge 214 form a Wheatstone bridge for measuring the torque in the x-direction; the strain gauge group 22 for measuring the torque in the Y-direction includes Rmy1 strain gauge 221, Rmy2 strain gauge 222, Rmy3 strain gauge 223 and Rmy4 strain gauge 224, Rmy1 strain gauge 221 is attached to the top surface of the first horizontal cross beam 1321 away from the guide column 14, Rmy3 strain gauge 223 is attached to the bottom surface of the first horizontal cross beam 1321 away from the guide column 14, Rmy... Strain gauge 222 is attached to the bottom surface of the second horizontal cross beam 1322 away from the guide column 14, and strain gauge 224 is attached to the top surface of the second horizontal cross beam 1322 away from the guide column 14; strain gauges 221, 222, 223, and 224 form a Wheatstone bridge for measuring the torque in the y-direction; strain gauge group 23 for measuring the torque in the Z-direction includes strain gauge 231, 232, 233, and 234, and strain gauge 231, 232, 233, and 234. 1. An Rmz1 strain gauge 231 is attached to the right side of the third horizontal cross beam 1323 near the guide column 14; 2. An Rmz2 strain gauge 232 is attached to the left side of the third horizontal cross beam 1323 near the guide column 14; 3. An Rmz3 strain gauge 233 is attached to the left side of the fourth horizontal cross beam 1324 near the guide column 14; 4. An Rmz4 strain gauge 234 is attached to the right side of the fourth horizontal cross beam 1324 near the guide column 14. These three strain gauges form a Wheatstone bridge for measuring the torque in the z-direction.

[0043] The elastic body 1 of this invention will produce slight deformation under the action of multidimensional forces. The strain gauges on the vertical floating beam 131 and the horizontal cross beam 132 can measure the surface deformation in real time and convert it into a millivolt-level voltage signal output through the Wheatstone full-bridge circuit. The strain gauge on the vertical floating beam 131 measures the force load, and the strain gauge on the horizontal cross beam 132 measures the torque load, which effectively reduces the interdimensional coupling interference between force and torque.

[0044] This invention also discloses a calibration device for calibrating a miniature strain-type six-dimensional force sensor as described above. The device includes a fixed block 7, a sliding block 8, a positioning plate 9, and a calibration fixture 10. The fixed block 7 has a notch 71 on one side of its top (the fixed block 7 is a cuboid, with a certain thickness of cuboid removed from its top along the centerline, thus forming a stepped structure on the top of the fixed block 7). The other side of the fixed block 7 has a vertically downward first through-hole 72, and the notch 71 has a vertically downward second through-hole 73. The sliding block 8 is mounted on the notch 71 (the sliding block 8 is a cuboid, its size corresponding to the stepped structure of the fixed block 7, and the two together form a complete cuboid), thus forming a fixing stud placement hole 74, a third through-hole 75, and a fourth through-hole 76 between the fixed block 7 and the sliding block 8. The fixing stud 11 is placed in the fixing stud placement hole 74. The sliding block 8 has a position corresponding to the second through-hole 73. The second line has a through hole 81; the first line has a through hole 72, the second line has a through hole 81, the third line has a through hole 75, and the fourth line has a through hole 76, which are evenly distributed; the positioning plate 9 is installed on the top of the fixing block 7 and the sliding block 8, and the positioning plate 9 is a square thin plate; the center of the positioning plate 9 has a base positioning hole 91 that matches the shape of the base 12, and the base 12 is located in the base positioning hole 91; the positioning plate 9 has through holes 92 that correspond to the positions of the first line through hole 72, the second line through hole 81, the third line through hole 75, and the fourth line through hole 78, respectively; the calibration fastener 10 is long and narrow; the center of the calibration fastener 10 is connected to the guide column 14; the two ends of the calibration fastener 10 have fixing holes 101 for suspending the calibration weight; the two long side walls of the calibration fastener 10 have four triangular grooves 102 for suspending the calibration weight when applying torque, and the four triangular grooves 102 are all equidistant from the center of the calibration fastener 10, each being 20mm. This invention enables rapid static calibration of miniature multidimensional force sensors and features small size, simple structure, and ease of use.

[0045] Specifically, the top plane of the fixed block 7 has two first upper threaded holes 77, and the bottom plane of the notch 71 has two first lower threaded holes 711; the side wall of the notch 71 has two second threaded holes 712; the top of the sliding block 8 has two third threaded holes 82 corresponding to the positions of the first lower threaded holes 711, and the two first upper threaded holes 77 and the two third threaded holes 82 are evenly distributed; the side wall of the sliding block 8 has two first through holes 83 corresponding to the positions of the second threaded holes 712; the positioning plate 9 has two evenly distributed second through holes 93 and two sliding grooves 94, the two second through holes 93 correspond to the positions of the two first upper threaded holes 77, and the two sliding grooves 94 correspond to the positions of the two third threaded holes 82; two first bolts pass through the two first through holes 83 and are threaded to the two second threaded holes 712 respectively; two second bolts pass through the two second through holes 93 and are threaded to the two first upper threaded holes 77 respectively; two third bolts pass through the two sliding grooves 94 and are threaded to the two third threaded holes 82 and the two first lower threaded holes 711 respectively.

[0046] During calibration, the calibration fixture 10 is assembled with the elastomer 1. The base 12 of the elastomer 1 is located in the base positioning hole 91, and the fixing stud 11 is located in the fixing stud placement hole 74. The sliding block 8 is tightened to fix and position the elastomer 1. The calibration weight is connected to the calibration fixture 10 through a thin rope.

[0047] When calibrating the force Fx in the x direction, assemble the calibration fastener 10 with the elastic body 1 along the X direction, rotate the calibration device 90 degrees along the Y axis direction for clamping, and suspend the calibration weight in the fixing hole 101 at one end of the calibration fastener 10.

[0048] When calibrating the force Fy in the y direction, calibrate the calibration fastener 10 along the y direction and assemble it with the elastic body 1. Rotate the calibration device 90 degrees along the X-axis and clamp it. Suspend the calibration weight in the fixing hole 101 at one end of the calibration fastener 10.

[0049] When calibrating the force Fz in the z direction, calibrate the calibrating fastener 10 along the X or Y direction to assemble it with the elastic body 1, clamp the calibrating device directly, and suspend the calibrating weight through the hole in the two fixing holes 101 at both ends of the calibrating fastener 10, and apply 1 / 2 force respectively or divide the force into two 1 / 2 forces through the pulley.

[0050] When calibrating the torque Mx in the x direction, assemble the calibration fixture 10 with the elastic body 1 along the X direction, clamp the calibration device directly, and suspend the calibration weight in the triangular groove 102 at one end of the calibration fixture 10 through the wire through the hole.

[0051] When calibrating the torque My in the y direction, calibrate the calibration fixture 10 along the y direction to the elastic body 1, clamp the calibration device directly, and suspend the calibration weight through the wire through the hole in the triangular groove 102 at one end of the calibration fixture 10.

[0052] When calibrating the torque Mz in the z-direction, assemble the calibration fixture 10 with the elastic body 1 along the X-direction, rotate the calibration device 90 degrees along the X-axis for clamping, and suspend the calibration weight in the triangular groove 102 at one end of the calibration fixture 10 through the wire through hole; or assemble the calibration fixture 10 with the elastic body 1 along the Y-direction, rotate the calibration device 90 degrees along the Y-axis for clamping, and suspend the calibration weight in the triangular groove 102 at one end of the calibration fixture 10 through the wire through hole.

[0053] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0054] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A calibration device for calibrating a miniature strain gauge six-dimensional force sensor, characterized in that, Includes fixed blocks, sliding blocks, positioning plates, and calibration fasteners. The micro-strain type six-dimensional force sensor includes: An elastomer includes, from bottom to top, a fixed stud, a base, four inverted L-shaped sensitive beams, and a force guide column connected as a single unit. The four inverted L-shaped sensitive beams are evenly distributed around the circumference of the base. Each inverted L-shaped sensitive beam includes a vertical floating beam and a horizontal cross beam connected as a single unit. The vertical floating beam is connected to the base as a single unit. The force guide column is located between the four horizontal cross beams. Three sets of torque measurement strain gauges and three sets of force measurement strain gauges are attached to the top, bottom and left and right sides of the horizontal cross beam, respectively, and the three sets of force measurement strain gauges are attached to the inner and outer sides of the vertical floating beam, respectively, to form six Wheatstone bridges. A circuit board is snapped onto the base and located between the four vertical floating beams; three sets of torque measuring strain gauges and three sets of force measuring strain gauges are electrically connected to the circuit board. The fixing block has a notch on one side of its top and a first vertically downward through hole on the other side. A second vertically downward through hole is formed in the notch. A sliding block is mounted on the notch, thus forming a stud placement hole, a third through hole, and a fourth through hole between the fixing block and the sliding block. The stud is placed in the stud placement hole. The sliding block has a second through hole corresponding to the position of the second through hole. The first, second, third, and fourth through holes are evenly distributed. The positioning plate is installed on top of the fixing block and the sliding block; the positioning plate has a base positioning hole in the middle that matches the shape of the base, and the base is located in the base positioning hole; the positioning plate has wire through holes that correspond to the positions of the first wire through hole, the second wire through hole, the third wire through hole and the fourth wire through hole respectively; the middle part of the calibration fastener is connected to the guide column; the two ends of the calibration fastener have fixing holes; the two long sidewalls of the calibration fastener have four triangular grooves, and the four triangular grooves are all equidistant from the middle part of the calibration fastener.

2. The calibration device according to claim 1, characterized in that, The top plane of the fixed block has two first upper threaded holes, and the bottom plane of the notch has two first lower threaded holes; the side wall of the notch has two second threaded holes; the top of the sliding block has two third threaded holes corresponding to the positions of the first lower threaded holes, and the two first upper threaded holes and the two third threaded holes are evenly distributed; the side wall of the sliding block has two first through holes corresponding to the positions of the second threaded holes; the positioning plate has two evenly distributed second through holes and two sliding grooves, the two second through holes corresponding to the positions of the two first upper threaded holes, and the two sliding grooves corresponding to the positions of the two third threaded holes; two first bolts pass through the two first through holes and are threadedly connected to the two second threaded holes; two second bolts pass through the two second through holes and are threadedly connected to the two first upper threaded holes; two third bolts pass through the two sliding grooves and are threadedly connected to the two third threaded holes and the two first lower threaded holes.

3. The calibration device according to claim 1, characterized in that, The miniature strain-type six-dimensional force sensor also includes a housing and a fixing bolt. The bottom of the housing has an overload protection groove adapted to the shape of the base, and the top of the housing has a square positioning groove with a mounting hole in the center. The housing is fitted onto the elastic body, so that the base is embedded in the overload protection groove and the force guide column is embedded in the square positioning groove. The fixing bolt passes through the mounting hole and is screwed onto the force guide column.

4. The calibration device according to claim 1, characterized in that, The three sets of force measurement strain gauges are: an X-direction force measurement strain gauge group, a Y-direction force measurement strain gauge group, and a Z-direction force measurement strain gauge group. The X-direction force measurement strain gauge group is attached to the inner and outer sides of the two vertical floating beams located in the X direction near the base; the Y-direction force measurement strain gauge group is attached to the inner and outer sides of the two vertical floating beams located in the Y direction near the base; and the Z-direction force measurement strain gauge group is attached to the inner and outer sides of the two vertical floating beams located in the X direction away from the base. Similarly, the three sets of torque measurement strain gauges are: an X-direction torque measurement strain gauge group, a Y-direction torque measurement strain gauge group, and a Z-direction torque measurement strain gauge group. The X-direction torque measurement strain gauge group is attached to the upper and lower surfaces of the two horizontal cross beams located in the Y direction away from the guide column; the Y-direction torque measurement strain gauge group is attached to the upper and lower surfaces of the two horizontal cross beams located in the X direction away from the guide column; and the Z-direction torque measurement strain gauge group is attached to the left and right sides of the two horizontal cross beams located in the Y direction near the guide column.

5. A calibration device according to claim 4, characterized in that, The four vertical floating beams are designated as a first, second, third, and fourth vertical floating beam, wherein the first and second vertical floating beams are distributed along the X-direction, and the third and fourth vertical floating beams are distributed along the Y-direction; the four horizontal cross beams are designated as a first, second, third, and fourth horizontal cross beam, wherein the first and second horizontal cross beams are distributed along the X-direction, and the third and fourth horizontal cross beams are distributed along the Y-direction; the X-direction force measurement strain gauge group includes Rx. Strain gauges Rx1, Rx2, Rx3, and Rx4 are provided. Strain gauge Rx1 is attached to the outer side of the first vertical floating beam near the base; strain gauge Rx3 is attached to the inner side of the first vertical floating beam near the base; strain gauge Rx2 is attached to the inner side of the second vertical floating beam near the base; and strain gauge Rx4 is attached to the outer side of the second vertical floating beam near the base. These strain gauges form a Wheatstone bridge for measuring forces in the x-direction. A strain gauge is also provided for measuring forces in the y-direction. The group includes strain gauges Ry1, Ry2, Ry3, and Ry4. Strain gauge Ry1 is attached to the outer side of the third vertical floating beam near the base; strain gauge Ry3 is attached to the inner side of the third vertical floating beam near the base; strain gauge Ry2 is attached to the inner side of the fourth vertical floating beam near the base; and strain gauge Ry4 is attached to the outer side of the fourth vertical floating beam near the base. Strain gauges Ry1, Ry2, Ry3, and Ry4 form a Wheatstone bridge for measuring the force in the y-direction; the force in the Z-direction... The force measurement strain gauge group includes strain gauges Rz1, Rz2, Rz3, and Rz4. Strain gauge Rz1 is attached to the outer side of the first vertical floating beam away from the base, and strain gauge Rz3 is attached to the inner side of the first vertical floating beam away from the base. Strain gauge Rz2 is attached to the outer side of the second vertical floating beam away from the base, and strain gauge Rz4 is attached to the inner side of the second vertical floating beam away from the base. Strain gauges Rz1, Rz2, Rz3, and Rz4 form a Wheatstone bridge for measuring forces acting in the z-direction.The X-direction torque measurement strain gauge group includes an Rmx1 strain gauge, an Rmx2 strain gauge, an Rmx3 strain gauge, and an Rmx4 strain gauge. The Rmx1 strain gauge is attached to the top surface of the third horizontal cross beam away from the guide column, the Rmx3 strain gauge is attached to the bottom surface of the third horizontal cross beam away from the guide column, the Rmx2 strain gauge is attached to the bottom surface of the fourth horizontal cross beam away from the guide column, and the Rmx4 strain gauge is attached to the top surface of the fourth horizontal cross beam away from the guide column. The Rmx1 strain gauge, Rmx2 strain gauge, Rmx3 strain gauge, and Rmx4 strain gauge form a Wheatstone bridge for measuring the torque in the x-direction; the strain gauge group for measuring the torque in the y-direction includes Rmy1 strain gauge, Rmy2 strain gauge, Rmy3 strain gauge, and Rmy4 strain gauge. The Rmy1 strain gauge is attached to the top surface of the first horizontal cross beam away from the guide column, the Rmy3 strain gauge is attached to the bottom surface of the first horizontal cross beam away from the guide column, and the Rmy2 strain gauge... The strain gauge is attached to the bottom surface of the second horizontal cross beam away from the guide column, and the Rmy4 strain gauge is attached to the top surface of the second horizontal cross beam away from the guide column; the Rmy1, Rmy2, Rmy3, and Rmy4 strain gauges form a Wheatstone bridge for measuring the torque in the y-direction; the strain gauge group for measuring the torque in the Z-direction includes Rmz1, Rmz2, Rmz3, and Rmz4 strain gauges, and the Rmz1 strain gauge is attached to the bottom surface of the second horizontal cross beam away from the guide column. The third horizontal cross beam is located on the right side near the guide column. The Rmz3 strain gauge is attached to the left side of the third horizontal cross beam near the guide column. The Rmz2 strain gauge is attached to the left side of the fourth horizontal cross beam near the guide column. The Rmz4 strain gauge is attached to the right side of the fourth horizontal cross beam near the guide column. The Rmz1, Rmz2, Rmz3, and Rmz4 strain gauges form a Wheatstone bridge for measuring the torque in the z-direction.

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