CN206648770U - A kind of six-dimension force sensor of flexible body structure - Google Patents

Abstract

The utility model discloses a six-dimensional force sensor with an elastic body structure, which comprises a horizontal elastic beam, a central vertical elastic beam, a loading shaft and an outer ring fixing table, the horizontal elastic beam is a cross-shaped structure, and the horizontal elastic beam includes four etc. For long branches, one end of the central vertical elastic beam is fixed at the center of the cross-shaped structure of the horizontal elastic beam, and is perpendicular to the surface where the cross-shaped structure is located, the loading shaft is installed at the other end of the central vertical elastic beam, and the outer ring fixed platform is sleeved The ring-shaped part on the outside of the horizontal elastic beam, the ends of the four branches of the horizontal elastic beam are fixed on the inner side of the outer ring fixing platform, the ends of the four branches of the horizontal elastic beam are in an S-shaped structure, and the horizontal elastic beam and/or the center are vertical The elastic beam is also pasted with a strain gauge. The S-shaped structure in the utility model makes it a flexible link when it is subjected to the force in the corresponding direction; the design of the central vertical elastic beam reduces the coupling between dimensions, thereby simplifying the decoupling algorithm and improving the measurement accuracy.

Description

A six-dimensional force sensor with an elastic body structure

technical field

The utility model belongs to the technical field of sensors, in particular to a six-dimensional force sensor with an elastic body structure.

Background technique

The six-dimensional force sensor measures the three-dimensional orthogonal force (Fx, Fy, Fz) and three-dimensional orthogonal moment (Mx, My, Mz) in the three-dimensional space of the Cartesian coordinate system. Due to its rich force measurement information and high measurement accuracy, It is mainly used in force and force-position control occasions, such as robot end effectors, wheel force detection during vehicle driving, contour tracking, precision assembly, hand coordination, etc., especially in aerospace robots, space station docking simulations, etc. It plays an extremely important role effect.

The cross-beam structure is the most widely used form of the six-dimensional force sensor at present, and the principle of resistance strain force measurement is the most widely used one in the current six-dimensional force sensor. Patent CN103528746A discloses a cross-beam type six-dimensional force sensor elastic body, which is composed of four inner beams, four outer beams and four overload protection beams, which can improve sensitivity and reduce inter-dimensional coupling, but the structure is relatively complex. Patent CN205333238U discloses a strain-type six-dimensional force sensor with a compact structure, which includes a base elastic body, a cross beam elastic body, etc., the base elastic body has a cavity, and the cross beam elastic body is arranged in the cavity, and the overall structure is relatively compact .

The research hotspots of multi-dimensional force/torque sensors in the world are mostly in the aspects of detection principle, method innovation and new elastic body structure design. However, the unique inter-dimensional coupling of multi-dimensional force/torque sensors has become the main problem of multi-dimensional force/torque sensors, which restricts the measurement accuracy and directly affects the subsequent force feedback and force control performance.

Utility model content

Purpose of the utility model: In order to reduce the measurement error of the six-dimensional force sensor, the utility model provides a six-dimensional force sensor with an elastic body structure.

Technical solution: A six-dimensional force sensor with an elastic body structure, including a horizontal elastic beam, a central vertical elastic beam, a loading shaft and an outer ring fixing table, the horizontal elastic beam is a cross-shaped structure, and the horizontal elastic beam includes four etc. For the long branch, one end of the central vertical elastic beam is fixed at the center of the cross-shaped structure of the horizontal elastic beam, and is perpendicular to the surface where the cross-shaped structure is located, the loading shaft is installed at the other end of the central vertical elastic beam, and the outer The ring fixing platform is a ring-shaped part sleeved on the outside of the horizontal elastic beam. The outer ring fixing platform includes the inner surface. The ends of the four branches of the horizontal elastic beam are fixed on the inner surface of the outer ring fixing platform. The four branches of the horizontal elastic beam The ends of the branches are all S-shaped structures, and the horizontal elastic beams and/or the central vertical elastic beams are also covered with strain gauges.

Working principle: When the sensor is subjected to the force Fy in the Y direction, the two X-direction elastic beam branches undergo bending deformation, and the two Y-direction elastic beam branches undergo tension-compression deformation and the change is small and negligible. At this time, the S-shaped The structure can be regarded as a flexible link, and Fy can be measured by the Wheatstone full-bridge circuit composed of strain gauges pasted on the left and right sides of the X-direction elastic beam; when the sensor is subjected to the Z-direction acting torque Mz, the two X-direction elastic beams branch Bending deformation occurs, and the deformations produced at the same position on the left and right side of the two X-direction elastic beam branches are equal in size and opposite in direction, Mz can pass the whole Wheatstone composed of strain gauges pasted on the left and right sides of the X-direction elastic beam bridge circuit measured.

When the sensor is subjected to the force Fz in the Z direction, the two Y-direction elastic beam branches are bent and deformed, and the deformations at the same position on the upper and lower surfaces of the two Y-direction elastic beam branches are equal in magnitude and opposite in direction, and Fz can be passed through Measured by a full-bridge circuit composed of strain gauges pasted on the upper and lower surfaces of two Y-direction elastic beam branches; when the sensor is subjected to X-direction torque Mx, the two Y-direction elastic beam branches undergo bending deformation, and the two X-direction elastic beams The branch is twisted and deformed, and the deformation is very small and can be ignored. Mx can be measured by a full-bridge circuit composed of strain gauges pasted on the upper and lower surfaces of the two Y-direction elastic beam branches.

When the sensor is subjected to the force Fx in the X direction or the moment My in the Y direction, the central vertical elastic beam undergoes a large bending deformation, and the strains generated at the same position on the front and rear sides of the central vertical elastic beam are equal in size and opposite in direction, Fx and My can be measured through a bridge composed of strain gauges pasted on the front and rear sides of the central vertical elastic beam.

Beneficial effects: the utility model provides a six-dimensional force sensor with an elastic body structure. The end of the horizontal elastic beam branch is designed as an S-shaped structure, so that it acts as a flexible link when it is subjected to a force in the corresponding direction; compared with the existing The cross-beam type six-dimensional force sensor has a central vertical elastic beam to feel the force Fx in the X direction and the torque My in the Y direction; in addition to pasting the strain gauges on the four horizontal elastic beam branches, the center The two sides of the vertical elastic beam facing the Y-direction elastic beam branch are also covered with two pairs of strain gauges, which reduces the measurement error; the existing cross-beam type six-dimensional force sensor has coupling between three and more than three directions ( Such as between Fy, Mz, Fx, between Fz, Mx, My), while the six-dimensional force sensor with an elastic body structure in this patent only has coupling between two directions (such as between Fy, Mz, between Fz, Mx Between, between Fx, My), reduce the inter-dimensional coupling, thereby simplifying the decoupling algorithm and improving the measurement accuracy.

Description of drawings

FIG. 1 is a schematic diagram of the overall structure of a six-dimensional force sensor with an elastic body structure of the present invention.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the utility model is further described.

As shown in Figure 1, in order to facilitate the description of the direction, a spatial Cartesian coordinate system is established as shown in the figure.

As shown in Figure 1, a six-dimensional force sensor with an elastic body structure includes a horizontal elastic beam 1, a central vertical elastic beam 2, a loading shaft 3 and an outer ring fixing platform 4, the horizontal elastic beam 1 is a cross-shaped structure, and the horizontal elastic The beam 1 includes four equal-length branches, one end of the central vertical elastic beam 2 is fixed at the center of the cross-shaped structure of the horizontal elastic beam 1, and is perpendicular to the surface where the cross-shaped structure is located, and the loading shaft 3 is installed in the center vertical The other end of the elastic beam 2, the outer ring fixing table 4 is an annular component sleeved on the outside of the horizontal elastic beam 1, the outer ring fixing table 4 includes an inner surface 41, and the ends of the four branches of the horizontal elastic beam 1 are fixed On the inner surface 41 of the outer ring fixing platform 4 , the ends of the four branches of the horizontal elastic beam 1 are all S-shaped structures, and the horizontal elastic beam and/or the central vertical elastic beam are also covered with strain gauges. The thickness of the S-shaped structure is 1 mm. The end of the branch of the horizontal elastic beam is designed as an S-shaped structure, so that it acts as a flexible link when it is subjected to a force in the corresponding direction, that is, it acts as a floating beam. Compared with the existing cross-beam type six-dimensional force sensor, this embodiment has an additional central vertical elastic beam 2 for sensing the force Fx in the X direction and the torque My in the Y direction.

The four branches of the central vertical elastic beam 2 and the horizontal elastic beam 1 are all quadrangular prisms with a square cross section. The loading shaft 3 is a cylindrical structure. The outer ring fixing table 4 is provided with 8 upper and lower through holes for fixing the sensor.

The four branches of the horizontal elastic beam 1 include two X-direction elastic beam branches 11 and two Y-direction elastic beam branches 12, the two X-direction elastic beam branches 11 are on a straight line, and the two Y-direction elastic beam branches 12 On a straight line, the opening directions of the S-shaped structures on the two X-direction elastic beam branches 11 are the same, and the opening directions of the S-shaped structures on the two Y-direction elastic beam branches 12 are the same as those on the X-direction elastic beam branches 11. The opening direction of the S-shaped structure is vertical. In this embodiment, the opening direction of the S-shaped structure at the end of the X-direction elastic beam branch 11 is the left-right direction; the opening direction of the S-shaped structure at the end of the Y-direction elastic beam branch 12 is the up-down direction.

In addition, this embodiment also has a design for the sticking position of the strain gauge.

The two X-direction elastic beam branches 11 have identical structures and are covered with the same strain gauges at symmetrical positions; one of the X-direction elastic beam branches 11 includes a left side 111 and a right side (blocked in the figure, not shown), the central axis of the left side 111 is pasted with the first strain gauge 01 and the second strain gauge 02, and the positions corresponding to the first strain gauge 01 and the second strain gauge 02 on the right side are respectively pasted with The third strain gauge and the fourth strain gauge (blocked in the figure, not shown); the other X-direction elastic beam branch 11' is respectively connected with the first strain gauge 01, the second strain gauge 02, the third strain gauge, the first strain gauge The four strain gauges corresponding to the four strain gauges are denoted as the thirteenth strain gauge 013 , the fourteenth strain gauge 014 , the fifteenth strain gauge, and the sixteenth strain gauge.

The two Y-direction elastic beam branches have identical structures and are covered with the same strain gauges at symmetrical positions; one of the Y-direction elastic beam branches 12 includes an upper surface 121 and a lower surface (blocked in the figure, not shown) The fifth strain gauge 05 and the sixth strain gauge 06 are pasted on the central axis of the upper surface 121, and the seventh strain gauge and the sixth strain gauge 06 are pasted on the lower surface corresponding to the fifth strain gauge 05 and the sixth strain gauge 06 respectively. The eighth strain gauge (blocked among the figure, not shown); On the other Y-direction elastic beam branch 12', it is respectively connected with the fifth strain gauge 05, the sixth strain gauge 06, the seventh strain gauge, and the eighth strain gauge (figure The corresponding four strain gauges are marked as the seventeenth strain gauge 017, the eighteenth strain gauge 018, the nineteenth strain gauge, and the twentieth strain gauge (covered in the figure, not shown out).

The central vertical elastic beam 2 includes a front side 21, a rear side (blocked in the figure, not shown), a left side 22 and a right side (blocked in the figure, not shown), the front side 21 and the rear side Facing the two X-direction elastic beam branches 11 respectively, the ninth strain gauge 09 and the tenth strain gauge 010 are pasted on the central axis of the front side 21, and the corresponding ninth strain gauge 09 and tenth strain gauge 010 are on the rear side. An eleventh strain gauge and a twelfth strain gauge (blocked in the figure, not shown) are pasted on the positions respectively.

All strain gauges are the same strain gauge. Set the distance from the first strain gauge 01 to the Y-direction elastic beam branch 12 as d1, set the distance from the fifth strain gauge 05 to the central vertical elastic beam 2 as d2, and set the distance from the ninth strain gauge 09 to the X-direction elastic beam branch 11 It is d3, where d1=d2=d3; the distance from the second strain gauge 02 to the Y-direction elastic beam branch 12 is d4, the distance from the sixth strain gauge 06 to the central vertical elastic beam 2 is d5, and the tenth strain gauge The distance from 10 to the X-direction elastic beam branch 11 is d6, where d4=d5=d6; and the distance from the first strain gauge 01 to the Y-direction elastic beam branch 12 is the same as the distance from the second strain gauge 02 to the Y-direction elastic beam branch 12 Not equal, that is, d1≠d4.

The 20 strain gauges constitute a total of six sets of strain gauges. Each strain gauge group is electrically connected to form a Wheatstone full-bridge or half-bridge circuit for measuring force or moment in one dimension of space.

The first strain gauge 01, the third strain gauge, the thirteenth strain gauge 013 and the fifteenth strain gauge form the first strain gauge group; the second strain gauge 02, the fourth strain gauge, the fourteenth strain gauge 014 and the tenth strain gauge Six strain gauges form the second strain gauge group. When the sensor is subjected to a force in the Y direction or a moment in the Z direction, the horizontal elastic beam in the X direction will have a large deformation. Therefore, the Wheatstone bridge circuit composed of the first and second strain gauge groups is used to measure the effect in the Y direction The magnitude of the force Fy and the moment Mz in the Z direction.

The fifth strain gauge 05, the seventh strain gauge, the seventeenth strain gauge 017 and the nineteenth strain gauge form the third strain gauge group; the sixth strain gauge 06, the eighth strain gauge, the eighteenth strain gauge 018 and the second The ten strain gauges make up the fourth strain gauge group. When the sensor is subjected to a force in the Z direction or a moment in the X direction, the horizontal elastic beam in the Y direction will have a large deformation. Therefore, the Wheatstone bridge circuit composed of the third and fourth strain gauge groups is used to measure the Z direction force Fz and The magnitude of the moment Mx in the X direction.

The ninth strain gauge 09 and the eleventh strain gauge on the back form the fifth strain gauge group, and the tenth strain gauge 10 and the twelfth strain gauge on the back form the sixth strain gauge group. When the sensor is subjected to the force in the X direction or the moment in the Y direction, the central vertical elastic beam will have a large deformation. Therefore, the Wheatstone bridge circuit composed of the fifth and sixth strain gauge groups is used to measure the force Fx in the X direction and the Y direction The magnitude of the moment My.

In addition to sticking strain gauge groups on the corresponding positions of the four horizontal elastic beam branches, this structure also has two pairs of strain gauges pasted on the two sides of the central vertical elastic beam 2 facing the X-direction elastic beam branch, and the measurement error is relatively small. . The sensor structure has coupling between two directions (such as between Fy and Mz, between Fz and Mx, between Fx and My), which can simplify the decoupling algorithm and make decoupling easier.

Claims (10)

1. a kind of six-dimension force sensor of flexible body structure, it is characterised in that vertical including horizontal resiliency beam (1), center Spring beam (2), loading axis (3) and outer ring fixed station (4), the horizontal resiliency beam (1) are decussate texture, horizontal resiliency beam (1) four isometric branches are included, one end of the vertical spring beam in center (2) is fixed on horizontal resiliency beam (1) decussate texture Center, and vertical with the face where decussate texture, the loading axis (3) is arranged on the vertical spring beam in center (2) The other end, the outer ring fixed station (4) are to be set in the circle shape part on the outside of horizontal resiliency beam (1), outer ring fixed station (4) bag Medial surface (41) is included, the end of four branches of horizontal resiliency beam (1) is fixed on the medial surface (41) of outer ring fixed station (4), The end of four branches of horizontal resiliency beam (1) is S type structures, the horizontal resiliency beam (1) and/or the vertical spring beam in center (2) foil gauge is also covered with.

2. the six-dimension force sensor of flexible body structure according to claim 1, it is characterised in that the center is vertical Four branches of spring beam (2) and horizontal resiliency beam (1) are the quadrangular that cross section is square.

3. the six-dimension force sensor of flexible body structure according to claim 1 or 2, it is characterised in that the level Four branches of spring beam (1) include two X to spring beam branch (11) and Liang GeYXiang spring beams branch (12), and two X are to bullet Point-blank, point-blank, two X are to spring beam branch for Liang GeYXiang spring beams branch (12) for Xing Liang branches (11) (11) opening direction of the S type structures on is identical, and the opening direction of the S type structures in Liang GeYXiang spring beams branch (12) is identical It is and vertical to the opening direction of the S type structures in spring beam branch (11) with X.

4. the six-dimension force sensor of flexible body structure according to claim 3, it is characterised in that described two X to Spring beam branch (11) structure is identical and is covered with identical foil gauge in symmetrical position；X is to spring beam branch (11) Including left surface (111) and right flank, the first foil gauge (01) and the second strain are covered with the central axis of left surface (111) Piece (02), position corresponding with the first foil gauge (01) and the second foil gauge (02) is covered with the 3rd foil gauge respectively on right flank With the 4th foil gauge；

Described two Y-direction spring beam branched structures are identical and are covered with identical foil gauge in symmetrical position；Y-direction elasticity Beam branch (12) includes upper surface (121) and lower surface, the 5th foil gauge (05) being covered with the central axis of upper surface (121) With the 6th foil gauge (06), position corresponding with the 5th foil gauge (05) and the 6th foil gauge (06) is covered with respectively on lower surface 7th foil gauge and the 8th foil gauge；

The vertical spring beam in center (2) includes leading flank (21), trailing flank, left surface (22) and right flank, leading flank (21) Two X are respectively facing to spring beam branch (11) with trailing flank, and the 9th foil gauge is covered with the central axis of leading flank (21) (09) and the tenth foil gauge (10), position corresponding with the 9th foil gauge (09) and the tenth foil gauge (10) is pasted respectively on trailing flank It is covered with the 11st foil gauge and the 12nd foil gauge.

5. the six-dimension force sensor of flexible body structure according to claim 4, it is characterised in that the first foil gauge (01), the second foil gauge (02), the 3rd foil gauge, the 4th foil gauge, the 5th foil gauge (05), the 6th foil gauge (06), the 7th Foil gauge, the 8th foil gauge, the 9th foil gauge (09), the tenth foil gauge (10), the 11st foil gauge and the 12nd foil gauge are equal For identical foil gauge.

6. the six-dimension force sensor of flexible body structure according to claim 4, it is characterised in that set the first foil gauge (01) it is d1 to the distance of Y-direction spring beam branch (12), if the distance of the 5th foil gauge (05) to the vertical spring beam in center (2) is D2, if the 9th foil gauge (09) to X to the distance of spring beam branch (11) be d3, wherein d1=d2=d3；If the second foil gauge (02) it is d4 to the distance of Y-direction spring beam branch (12), if the distance of the 6th foil gauge (06) to the vertical spring beam in center (2) is D5, if the tenth foil gauge (10) to X to the distance of spring beam branch (11) be d6, wherein d4=d5=d6；And d1 ≠ d4.

7. the six-dimension force sensor of flexible body structure according to claim 1 or 2, it is characterised in that the S types knot The thickness of structure is 1mm.

8. the six-dimension force sensor of flexible body structure according to claim 1 or 2, it is characterised in that the loading Axle (3) is cylindrical structure.

9. the six-dimension force sensor of flexible body structure according to claim 1 or 2, it is characterised in that the outer ring Fixed station (4) is provided with multiple upper lower through-holes, for fixing sensor.

10. the six-dimension force sensor of flexible body structure according to claim 4, it is characterised in that the X is to elasticity The opening direction of the S type structures of beam branch (11) end is left and right directions；The S type knots of Y-direction spring beam branch (12) end The opening direction of structure is above-below direction.