CN117109804A

CN117109804A - Calibration device and calibration method for large-deformation six-dimensional force sensor

Info

Publication number: CN117109804A
Application number: CN202311052489.2A
Authority: CN
Inventors: 尹忠俊; 黄小明; 韩天; 陈兵; 李明各; 刘泉
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2023-08-21
Filing date: 2023-08-21
Publication date: 2023-11-24
Anticipated expiration: 2043-08-21
Also published as: CN117109804B

Abstract

The invention provides a calibration device and a calibration method for a large-deformation six-dimensional force sensor. The eighth straight notch of the sensor base is connected with the lower end of the six-dimensional force sensor, the upper end of the six-dimensional force sensor is connected with the second through hole of the circular mounting plate in the stress rod assembly, the seventh threaded hole in the stress rod assembly is connected with the first end of the miniature tension-compression sensor, the second end of the miniature tension-compression sensor is connected with the fixed end of the ring nut, and the working end of the ring nut passes through the small hole in the gravity compensation wheel assembly through the first steel wire rope and is connected with the lock catch. The invention is not only used for calibrating the large-deformation six-dimensional force sensor, but also ensures that the loaded position can be automatically adjusted when each dimension is loaded and deformed by adjusting the rolling contact of the elliptical surface in the seat assembly, so that the loading direction and moment are kept unchanged, the coupling caused by loading force is eliminated, and the calibration precision of each dimension is ensured.

Description

Calibration device and calibration method for large-deformation six-dimensional force sensor

Technical Field

The invention relates to the field of calibration of multidimensional force sensors, in particular to a calibration device and a calibration method for a large-deformation six-dimensional force sensor.

Background

The calibration of the six-dimensional force sensor means that after the sensor is prepared, the detection of each dimension is independently calibrated, namely, the load is independently applied to the channel of each dimension, the signal output value of the corresponding channel is collected, and then a calibration matrix between the load and the signal output value is solved. In order to enable the six-dimensional force sensor to meet the requirement of accurate measurement function, calibration work is necessary.

Researchers at home and abroad develop various forms of research and design work on the calibration device, more commonly, a hanging weight type force applying device is adopted, and the precision of the calibration device determines the precision of the six-dimensional force sensor, so that the calibration device plays a very important role in the design and development of the six-dimensional force sensor. The existing six-dimensional force sensor calibration devices are designed and developed for high-rigidity six-dimensional force sensors, if the six-dimensional force sensors with large strain are calibrated by the six-dimensional force sensor calibration devices, the coupling of loading force/moment to other dimensions is necessarily caused, and the accuracy of the large-deformation six-dimensional force sensors is seriously influenced, wherein the large deformation is relative to the conventional strain gauge, piezoelectric/piezoresistive materials and the like, the deformation of the six-dimensional force sensors based on the strain gauge is generally in a micron level, and the deformation of the sensors calibrated by the calibration devices reaches a millimeter level.

In the fields of medical rehabilitation apparatuses and wearable equipment, a large-deformation six-dimensional force sensor with compliance advantages is more and more valued and researched, and a calibration device suitable for the large-deformation six-dimensional force sensor is rarely reported. In addition, the existing calibration device for the high-rigidity six-dimensional force sensor cannot realize the one-time clamping of the six-dimensional force sensor so as to meet the calibration of six-dimensional force/moment, the pose of the six-dimensional force sensor is required to be adjusted secondarily or the position of a force source is required to be adjusted so as to realize the calibration of each dimension, and the whole calibration work is complex.

Disclosure of Invention

The invention provides a calibration device and a calibration method for a large-deformation six-dimensional force sensor, aiming at the problems existing in the prior art, the adjustment wheel assembly at the end part of the force rod assembly is utilized to automatically adjust the force position in a rolling contact manner in an elliptical curved surface of an adjustment seat, so that the calibration device has the characteristic of keeping the direction of loading force/moment of each dimension unchanged with the force arm, the coupling of the loading force/moment of the six-dimensional force sensor is eliminated when the force sensor is large deformed, in addition, the rolling adjustment in a guide groove of an upper cross beam by virtue of a gravity compensation wheel assembly can meet the condition that the gravity of the force rod assembly is always kept to be counteracted in different loaded states, thereby ensuring that the calibration device has higher calibration precision, and simultaneously meeting the one-time positioning installation of the six-dimensional force sensor, and realizing all calibration of the six-dimensional force/moment.

The invention provides a calibration device for a large-deformation six-dimensional force sensor, which comprises a mounting platform, a guide wheel mounting frame, an upper cross beam, a stress rod assembly, a sensor base, a miniature tension-compression sensor, a ring nut, a gravity compensation wheel assembly, a lock catch, a notch transition plate, a guide wheel assembly and a bottom frame. The positioning groove of the mounting platform is connected with the mounting end of the vertical beam of the underframe, the sixth straight notch of the guide wheel mounting frame and the second mounting hole of the sensor base are respectively connected with the first threaded hole and the second threaded hole of the mounting platform, the second positioning hole of the sensor base and the first positioning hole of the mounting platform are connected, the six-dimensional force sensor is positioned in the circular groove of the sensor base, the eighth straight notch of the sensor base and the lower end of the six-dimensional force sensor are connected, the upper end of the six-dimensional force sensor is connected with the second through hole of the circular mounting plate in the stress rod assembly, the seventh threaded hole in the stress rod assembly is connected with the first end of the miniature tension sensor, the second end of the miniature tension sensor is connected with the fixed end of the ring nut, the working end of the ring nut passes through the first steel wire rope and is connected with the lock catch in the small hole of the gravity compensation wheel assembly, the step hole of the upper cross beam is connected with the fourth threaded hole of the guide wheel base, the upper cross beam is connected with the fourth through hole of the guide wheel assembly, and the guide wheel assembly is positioned in the fourth through hole of the guide wheel assembly. The bearing rod assembly comprises a bearing rod, a support frame, an adjusting seat assembly, a T-shaped shaft sleeve, a set screw and a bolt, wherein an end flange of the bearing rod is connected with an installation threaded hole of the support frame through the bolt, a round shaft of the adjusting seat assembly is respectively connected with a first shaft hole of the bearing rod and a second shaft hole of the support frame through the T-shaped shaft sleeve, and the set screw is positioned in a limit threaded hole of the support frame; the stress rod comprises a cross beam, an end flange, a first through hole, a seventh threaded hole, a first shaft hole, a positioning flange, a circular mounting plate and a second through hole, wherein the end flange is arranged at the end of the cross beam, the first through hole and the positioning flange are arranged around the end flange, the first shaft hole is arranged in the middle of the end flange, the seventh threaded hole is formed in the first end of the middle of the cross beam, the circular mounting plate is arranged at the second end of the middle of the cross beam, and the second through hole is formed in the circular mounting plate. The adjusting seat assembly comprises an adjusting seat, an end cover, an adjusting wheel assembly and a screw, wherein a screw hole of the adjusting seat is connected with a third through hole of the end cover through the screw, a columnar long arm of a transition piece in the adjusting wheel assembly is positioned in a seventh straight notch of the adjusting seat, and a first bearing in the adjusting wheel assembly is in contact with a curved surface through hole of the adjusting seat. The gravity compensation wheel assembly comprises a second pin shaft, a second clamp spring, a transition ring and a second bearing, wherein the second bearing is symmetrically distributed at two ends of the transition ring, and clamp spring grooves of the second pin shaft sequentially penetrate through an inner ring of the second bearing and an inner ring of the transition ring to be connected with the second clamp spring; the guide wheel assembly comprises a third pin shaft, a third clamp spring, a guide wheel and a guide wheel seat, wherein the guide wheel is connected with a mounting hole of the guide wheel seat through the third pin shaft and the third clamp spring, a wire passing through hole is formed in the middle of the guide wheel seat, straight slot holes are symmetrically formed in the periphery of the guide wheel seat, and the straight slot holes are respectively connected with a third threaded hole and a fourth threaded hole of the guide wheel mounting frame.

Preferably, the support frame comprises a first base, a second shaft hole, a protrusion, a mounting threaded hole and a limiting threaded hole, wherein the second shaft hole is formed in the middle of the first base, protrusions are uniformly formed in the periphery of the first base, the mounting threaded hole is formed in the protruding hanging end of the first base, and the limiting threaded hole is symmetrically formed in the protruding side wall of the support frame.

Preferably, the adjusting seat comprises a second base, a curved surface through hole, a round shaft, a screw hole and a seventh straight slot, the curved surface through hole is arranged in the middle of the second base, the screw hole is symmetrically arranged around the second base, the seventh straight slot is symmetrically distributed at the side face end of the second base along the length direction, and the round shaft is symmetrically distributed at the side face end of the second base along the width direction.

Preferably, the end cover comprises a rectangular panel, an annular boss and a third through hole, wherein the annular boss is arranged in the middle of the rectangular panel, and the third through hole is symmetrically arranged around the rectangular panel.

Preferably, the transition piece comprises a sleeve, a columnar long arm and a fourth through hole, wherein the columnar long arm is symmetrically arranged on two side surfaces of the sleeve, and the fourth through hole is formed in the suspension end of the columnar long arm.

Preferably, the adjusting wheel assembly comprises a first pin shaft, a first clamp spring, a first bearing and a transition piece, wherein the first bearing is symmetrically distributed at two ends of the sleeve in the transition piece, and the clamp spring groove of the first pin shaft sequentially penetrates through the inner ring of the first bearing and the inner ring of the sleeve in the transition piece to be connected with the first clamp spring.

In another aspect of the present invention, a calibration method for a large deformation six-dimensional force sensor is provided, comprising the steps of:

the method comprises the steps of defining coordinates of the six-dimensional force sensor in a calibration device and calibrating each dimension of the six-dimensional force sensor to be calibrated:

s1, using a first steel wire rope connected with a miniature tension-compression sensor through a ring nut, enabling the force value of the miniature tension-compression sensor to be equal to the gravity of a stress rod assembly, and locking the first steel wire rope by using a lock catch;

s2, respectively selecting and adjusting the state of the cross beam, the position of the guide wheel assembly, the position of the adjusting seat assembly, the positions of the notch transition plate and the gravity compensation wheel assembly according to the calibration of the six-dimensional force sensor along different directions;

s3, according to calibration of the six-dimensional force sensor along different directions, connecting two ends of the second steel wire rope with different positions in the calibration device respectively;

And S4, calibrating the six-dimensional force sensor.

Preferably, the specific implementation process of the step S2 is as follows:

if the six-dimensional force sensor is required to be calibrated along the x-axis direction, adjusting an adjusting seat assembly in two branches of a cross beam in a stress rod assembly, which are perpendicular to the x-axis, to be in a horizontal state, and adjusting a set screw on a support frame in the branch to prop against the surface of the adjusting seat assembly so as to keep a columnar long arm in an adjusting wheel assembly in a horizontal posture, and adjusting the position of a guide wheel assembly in a side end limiting groove of a guide wheel mounting frame;

if the six-dimensional force sensor is required to be calibrated along the y-axis direction, adjusting an adjusting seat assembly in two branches of a cross beam in a stress rod assembly, which are perpendicular to the y-axis, to be in a horizontal state, and propping against the surface of the adjusting seat assembly through a set screw on a support frame in the branch so as to keep a columnar long arm in an adjusting wheel assembly in a horizontal posture, adjusting the position of the guiding wheel assembly in a side end limiting groove of a guiding wheel mounting frame, and simultaneously respectively indexing a gap transition plate and a gravity compensation wheel assembly which are symmetrically arranged in the guiding groove by 90 degrees;

if the six-dimensional force sensor is required to be calibrated along the positive direction of the z axis, adjusting the adjusting seat assemblies in two branches of the cross beam positioned on the same axis in the stress rod assembly to be in a vertical state, and propping against the surface of the adjusting seat assembly through a set screw on a support frame in the branch so as to keep a columnar long arm in the adjusting wheel assembly in a vertical posture, and respectively adjusting the positions of the guide wheel assemblies in a limit groove of the guide wheel mounting frame;

If the six-dimensional force sensor is required to be calibrated around the x-axis direction, adjusting the adjusting seat assembly in two branches of the cross beam on the same axis in the stress rod assembly to be in a vertical state, and propping against the surface of the adjusting seat assembly through a set screw on a support frame in the branch so as to keep a columnar long arm in the adjusting wheel assembly in a vertical posture, and adjusting the position of the guide wheel assembly in a top limit groove of the guide wheel mounting frame;

if the six-dimensional force sensor is required to be calibrated around the z-axis direction, adjusting seat assemblies in two branches of a cross beam on the x-axis in the stress rod assembly are adjusted to be in a horizontal state, and a set screw on a support frame in the branch is adjusted to prop against the surface of the adjusting seat assembly so as to keep a columnar long arm in the adjusting wheel assembly in a horizontal posture, and the position of the guide wheel assembly in a side end limiting groove of the guide wheel mounting frame is adjusted.

Preferably, the specific implementation process of the step S3 is as follows:

if the six-dimensional force sensor is required to be calibrated along the positive direction of the x-axis, connecting the first ends of two identical second steel wire ropes with fourth through holes symmetrically distributed on transition pieces in adjusting wheel assemblies at two ends of a stress rod assembly, respectively enabling the second ends of the two identical second steel wire ropes to pass through fifth straight notches of corresponding guide wheel mounting frames along the positive direction of the x-axis, steering downwards by 90 degrees through guide wheels, and connecting the guide wheel mounting frames with the balancing weights through the notches of the corresponding guide wheel mounting frames and the first straight notches of the mounting platforms;

If the six-dimensional force sensor is required to be calibrated along the negative x-axis direction, connecting the first ends of two identical second steel wire ropes with fourth through holes symmetrically distributed on transition pieces in adjusting wheel assemblies at two ends of a stress rod assembly, respectively enabling the second ends of the two identical second steel wire ropes to pass through fifth straight notches of corresponding guide wheel mounting frames along the negative x-axis direction, steering the six-dimensional force sensor downwards by 90 degrees through guide wheels, and connecting the six-dimensional force sensor with a balancing weight through the notches of the corresponding guide wheel mounting frames and the first straight notches of a mounting platform;

if the six-dimensional force sensor is required to be calibrated along the positive direction of the y axis, connecting the first ends of two identical second steel wire ropes with fourth through holes symmetrically distributed on transition pieces in adjusting wheel assemblies at two ends of a stress rod assembly, respectively enabling the second ends of the two identical second steel wire ropes to pass through fifth straight notches of corresponding guide wheel mounting frames along the positive direction of the y axis, steering the six-dimensional force sensor downwards by 90 degrees through guide wheels, and connecting the six-dimensional force sensor with a balancing weight through the notches of the corresponding guide wheel mounting frames and the first straight notches of a mounting platform;

if the six-dimensional force sensor is required to be calibrated along the negative y-axis direction, connecting the first ends of two identical second steel wire ropes with fourth through holes symmetrically distributed on transition pieces in adjusting wheel assemblies at two ends of a stress rod assembly, respectively enabling the second ends of the two identical second steel wire ropes to pass through fifth straight notches of corresponding guide wheel mounting frames along the negative y-axis direction, steering the six-dimensional force sensor downwards by 90 degrees through guide wheels, and connecting the six-dimensional force sensor with a balancing weight through the notches of the corresponding guide wheel mounting frames and the first straight notches of a mounting platform;

If the six-dimensional force sensor is required to be calibrated along the positive direction of the z axis, connecting the first ends of two identical second steel wire ropes with fourth through holes symmetrically distributed on transition pieces in adjusting wheel assemblies at two ends of a stress rod assembly, respectively enabling the second ends of the two identical second steel wire ropes to pass through first and fourth straight notch openings in top limit grooves in corresponding guide wheel mounting frames along the positive direction of the z axis, steering the six-dimensional force sensor to the right by 90 degrees through the first guide wheels at the top ends of the guide wheel mounting frames, steering the six-dimensional force sensor to the lower by 90 degrees through second guide wheels at the top ends of the guide wheel mounting frames, and connecting the two identical second steel wire ropes with a balancing weight through second and fourth straight notch openings in top limit grooves in the corresponding guide wheel mounting frames and first and second straight notch openings of mounting platforms;

if the six-dimensional force sensor is required to be calibrated along the negative direction of the z axis, connecting the first ends of two identical second steel wire ropes with fourth through holes symmetrically distributed on transition pieces in the adjusting wheel assemblies at the two ends of the stress rod assembly, and respectively connecting the second ends of the two identical second steel wire ropes with the balancing weights by penetrating through third straight notch corresponding to the mounting platform along the negative direction of the z axis;

if the six-dimensional force sensor is required to be calibrated around the x axis or the y axis, connecting the first end of a first second steel wire rope with fourth through holes symmetrically distributed on transition pieces in first adjusting wheel assemblies at two ends of a stress rod assembly, respectively enabling the second end of the first second steel wire rope to pass through a first straight notch in a top limit groove in a corresponding guide wheel mounting frame along the positive direction of the z axis, steering the six-dimensional force sensor to the left by 90 degrees through a first guide wheel positioned at the top end of the guide wheel mounting frame, steering the six-dimensional force sensor to the right by 90 degrees through a third guide wheel positioned at the top end of the guide wheel mounting frame, and connecting the six-dimensional force sensor with a balancing weight through a third straight notch in a top limit groove in the corresponding guide wheel mounting frame and a second straight notch of a mounting platform; connecting the first end of a second steel wire rope with a fourth through hole symmetrically distributed on a transition piece in a second adjusting wheel assembly at two ends of the stress rod assembly, and connecting the second end of the second steel wire rope with a balancing weight by penetrating through a third straight notch of a corresponding mounting platform along the negative direction of the z-axis;

If the six-dimensional force sensor is required to be calibrated around the z-axis direction, the first ends of the two identical second steel wire ropes are connected with fourth through holes in transition pieces in adjusting wheel assemblies symmetrically distributed at two ends of a stress rod assembly on the x-axis, the second ends of the two identical second steel wire ropes respectively penetrate through fifth straight notches of corresponding guide wheel mounting frames along the positive direction and the negative direction of the x-axis, then the guide wheels are used for steering downwards by 90 degrees, and the guide wheels penetrate through the notches of the corresponding guide wheel mounting frames and the two first straight notches of the mounting platform to be connected with balancing weights.

Preferably, the specific implementation process of the step S4 is as follows:

if the six-dimensional force sensor is calibrated along the x-axis or the y-axis, a gravity compensation wheel assembly connected with a force-bearing rod assembly through a second steel wire rope is subjected to component force along the x-axis or the y-axis through a locking lock catch, and then the gravity compensation wheel assembly rolls for a certain distance along a guide groove in an upper cross beam, so that the gravity of the force-bearing rod assembly is eliminated when the six-dimensional force sensor is stressed and deformed along the x-axis or the y-axis, the step length is defined according to the measuring range of the six-dimensional force sensor along the x-axis or the y-axis, the load is gradually loaded, the output signal quantity of the six-dimensional force sensor along the x-axis or the y-axis is read, and the calibration of the six-dimensional force sensor along the x-axis or the y-axis is completed by repeatedly measuring a plurality of groups of electric signal parameters output by the balancing weights and the six-dimensional force sensor and taking an average value; if the six-dimensional force sensor is calibrated along the z-axis direction, the step length is defined according to the measuring range of the six-dimensional force sensor along the z-axis direction, the load is gradually loaded, after the load is loaded each time, when the force value monitored by the miniature tension-compression sensor is equal to the gravity of the stress rod assembly, the output signal quantity of the six-dimensional force sensor along the z-axis direction is read, and the calibration of the six-dimensional force sensor along the z-axis direction is completed by repeatedly measuring the electric signal parameters output by a plurality of groups of balancing weights and the six-dimensional force sensor and taking an average value;

If the six-dimensional force sensor is calibrated around the x-axis, the y-axis or the z-axis, the sum of the moments obtained by multiplying the weights on the two sides of the cross beam by the corresponding moment arms is the action moment on the six-dimensional force sensor around the x-axis, the y-axis or the z-axis, the load is gradually loaded according to the step length defined by the six-dimensional force sensor, after the six-dimensional force sensor is loaded according to the step length each time and is regulated and stabilized, the signal quantity output by the six-dimensional force sensor is read, and the calibration of the six-dimensional force sensor around the x-axis, the y-axis or the z-axis is completed by repeating a plurality of groups of measurement and averaging.

Compared with the prior art, the invention has the following advantages:

1. the invention is suitable for calibrating the six-dimensional force sensor with large deformation, and can automatically adjust the loaded position when each dimension of the sensor is loaded and deformed through the rolling contact of the elliptical surface of the adjusting seat assembly arranged at the end part of the stress rod assembly, so that the loading direction and the moment are kept unchanged, the loading coupling is eliminated, and the calibration precision of each dimension is ensured.

2. The stress rod assembly of the structure is connected with the gravity compensation wheel assembly, and the influence of the gravity of the stress rod assembly on calibration can be eliminated when the calibration is carried out in different directions.

3. The invention can realize one-time clamping of the six-dimensional force sensor and complete calibration of six-dimensional force/moment components. The calibration method solves the calibration problem of the large-deformation six-dimensional force sensor, and simplifies the calibration work.

Drawings

FIG. 1 is an overall block diagram of a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 2 is a block diagram of a guide wheel mounting bracket in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 3 is a block diagram of an upper cross beam in the calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 4 is a block diagram of an adjustment seat assembly for a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 5 is a block diagram of a force lever in the calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 6 is a block diagram of a support frame in the calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 7 is a block diagram of a force lever assembly in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 8 is a block diagram of an adjustment seat in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 9 is a schematic diagram of automatic adjustment of loading action points in a calibration device for a large deformation six-dimensional force sensor according to the present invention;

FIG. 10 is a block diagram of an end cap in the calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 11 is a block diagram of a transition piece in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 12 is a block diagram of an adjustment wheel assembly for use in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 13 is a block diagram of a gravity compensation wheel assembly for use in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 14 is a block diagram of a mounting platform in the calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 15 is a block diagram of a sensor base in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 16 is a block diagram of a transition ring in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 17 is a block diagram of a second pin in the calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 18 is a block diagram of a guide wheel assembly in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 19 is a block diagram of a chassis in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 20 is a block diagram of a notch transition plate in a calibration apparatus for a large deformation six-dimensional force sensor of the present invention;

FIG. 21 is a schematic illustration of a calibration device for a large deformation six-dimensional force sensor according to the present invention, calibrated in the positive x-axis direction;

FIG. 22 is a schematic illustration of a calibration device for a large deformation six-dimensional force sensor according to the present invention calibrated forward along the z-axis;

FIG. 23 is a negative calibration schematic along the z-axis in a calibration device for a large deformation six-dimensional force sensor according to the present invention;

FIG. 24 is a schematic illustration of calibration about the x-axis in a calibration device for a large deformation six-dimensional force sensor of the present invention;

FIG. 25 is a schematic illustration of a positive calibration about the z-axis in a calibration device for a large deformation six-dimensional force sensor according to the present invention.

The main reference numerals:

mounting platform 1, first straight slot 101, second straight slot 102, third straight slot 103, first threaded hole 104, first mounting hole 105, second threaded hole 106, first positioning hole 107, positioning groove 108, guide wheel mount 2, fourth straight slot 201, third threaded hole 202, limit slot 203, fourth threaded hole 204, fifth straight slot 205, fifth threaded hole 206, connecting flange 207, sixth straight slot 208, notch 209, upper cross beam 3, groove 301, guide slot 302, large round hole 303, sixth threaded hole 304, stepped hole 305, force bar assembly 4, force bar 41, cross beam 411, end flange 412, first through hole 413, seventh threaded hole 414, first shaft hole 415, positioning flange 416, circular mounting plate 417, second through hole 418, support frame 42, first base 421, second shaft hole 422, boss 423, mounting threaded hole 424, limit screw hole 425, adjustment seat assembly 43, adjustment seat 431, the second base 4311, the curved through hole 4312, the round shaft 4313, the screw hole 4314, the seventh straight slot 4315, the end cover 432, the rectangular panel 4321, the annular boss 4322, the third through hole 4323, the screw 433, the adjusting wheel assembly 434, the transition piece 4341, the sleeve 43411, the columnar long arm 43412, the fourth through hole 43413, the first pin shaft 4342, the first clamp spring 4343, the first bearing 4344, the t-shaped shaft sleeve 44, the set screw 45, the bolt 46, the sensor base 5, the round groove 501, the eighth straight slot 502, the rib plate 503, the second mounting hole 504, the second positioning hole 505, the micro tension and compression sensor 6, the ring nut 7, the gravity compensation wheel assembly 8, the second pin 81, the cap end 8101, the pin body 8102, the first small hole 8103, the clamp spring slot 8104, the second clamp spring 82, the transition ring 83, the second small hole 01, the second bearing 84, the lock catch 9, the notch transition plate 10, the inclined end 1001, the end 1002, the first hole 1003, chamfer 1004, balancing weight 11, leading wheel subassembly 12, third round pin axle 121, leading wheel 122, guide pulley seat 123, cross line through-hole 1231, straight slot 1232, third jump ring 124, chassis 13, vertical beam 1301, crossbeam 1302, connecting piece 1303, first wire rope 18, second wire rope 19.

Detailed Description

In order to make the technical content, the structural features, the achieved objects and the effects of the present invention more detailed, the following description will be taken in conjunction with the accompanying drawings.

The calibration device for the large-deformation six-dimensional force sensor comprises a mounting platform 1, a guide wheel mounting frame 2, an upper cross beam 3, a stress rod assembly 4, a sensor base 5, a miniature tension and compression sensor 6, a ring nut 7, a gravity compensation wheel assembly 8, a lock catch 9, a notch transition plate 10, a guide wheel assembly 12 and a bottom frame 13, as shown in fig. 1.

The positioning groove 108 of the mounting platform 1 is connected with the mounting end of the vertical beam 1301 of the underframe 13, the circumferential array of the guide wheel mounting frame 2 is arranged on the mounting platform 1, the sixth straight notch 208 of the guide wheel mounting frame 2 and the second mounting hole 504 of the sensor base 5 are respectively connected with the first threaded hole 104 and the second threaded hole 106 of the mounting platform 1, the horizontal and vertical intervals of the first threaded hole 104 on the mounting platform 1 are equal to the corresponding intervals of the sixth straight notch 208 of the guide wheel mounting frame 2, the second positioning hole 505 of the sensor base 5 is connected with the first positioning hole 107 of the mounting platform 1, and the horizontal and vertical intervals of the second threaded hole 106 are equal to the corresponding intervals of the 4 second mounting holes 504; the size of the first positioning hole 107 is equal to that of the second positioning hole 505, the horizontal and vertical distances of the first positioning hole 107 and the second positioning hole 505 are correspondingly equal, the six-dimensional force sensor is located in a circular groove 501 of the sensor base 5, an eighth straight notch 502 of the sensor base 5 is connected with the lower end of the six-dimensional force sensor, the upper end of the six-dimensional force sensor is connected with a second through hole 418 of a circular mounting plate 417 in the stress rod assembly 4, a seventh threaded hole 414 of the stress rod assembly 4 is connected with the first end of the miniature tension and compression sensor 6, the second end of the miniature tension and compression sensor 6 is connected with the fixed end of the ring nut 7, the working end of the ring nut 7 passes through a first steel wire rope 18 and penetrates through a small hole in the gravity compensation wheel assembly 8 to be connected with a lock catch 9, the force detected by the miniature tension and compression sensor 6 is equal to the gravity of the stress rod assembly 4, a step hole 305 of the upper cross beam 3 is coaxially matched with a fourth threaded hole 204 of the guide wheel mounting frame 2, a gap transition plate 10 and the gravity compensation wheel assembly 8 are respectively located in a guide groove 302 of the upper cross beam 3, the gap transition plate 10 is provided with a face of a chamfer 1004, the two gap transition plates 10 are symmetrically face upwards, the two gap transition plates 10 are symmetrically arranged in the guide grooves 302 of the upper cross beam 3 and the guide beam 10 are located in the guide groove 3 and the guide groove 2 is formed by the guide groove 3 and the guide groove 2 is connected with the guide groove 3 and the guide groove 2 through the gap bridge groove 3 and the guide groove 3 is located in the guide groove 2.

As shown in fig. 14, the mounting platform 1 is in a square plate structure, the side length of the mounting platform 1 is equal to the outline side length of the underframe 13, a third straight notch 103 is arranged on the central symmetry line of the mounting platform 1, the first straight notch 101 and the second straight notch 102 are symmetrically distributed on two sides of the third straight notch 103, the long axes of the first straight notch 101 and the second straight notch 102 are collinear and respectively parallel to the edge of the adjacent mounting platform 1, the distance between two first straight notches 101 which are concentric on each side of the mounting platform 1 along the central line direction is equal to the distance between the notches 209 on the guide wheel mounting frame 2, and the radii of the two first straight notches are equal; the first threaded hole 104 is located between the first straight notch 101 and the second straight notch 102, the first threaded hole 104 is symmetrically distributed along the central line of the mounting platform 1, the first mounting hole 105 is located between the second straight notch 102 and the third straight notch 103, the second threaded hole 106 and the first positioning hole 107 are located in the middle of the mounting platform 1, the positioning grooves 108 are symmetrically distributed at the four top corners of the mounting platform 1, and the length and width of the positioning grooves 108 are equal to the length and width of the vertical beams 1301 of the underframe 13.

As shown in fig. 2, the guide wheel mounting frame 2 has a U-shaped structure, a limit groove 203 is arranged in the middle of the mounting surface of the guide wheel mounting frame 2, and the width of the limit groove 203 is equal to that of the guide wheel seat 123 of the guide wheel assembly 12; the horizontal section of the limit groove 203 is respectively provided with a fourth straight notch 201 and a third threaded hole 202, the horizontal and vertical spacing of the third threaded hole 202 is equal to the spacing corresponding to the straight groove hole 1232 of the guide wheel assembly 12, the two sides of the limit groove 203 positioned at the upper end of the mounting surface of the guide wheel mounting frame 2 are symmetrically provided with fourth threaded holes 204, the spacing of the fourth threaded holes 204 along the long axis direction is equal to the spacing of the step holes 305 on the single side of the upper cross beam 3, the spacing of the step holes 305 on the two sides of the upper cross beam 3 is equal to the spacing of the fourth threaded holes 204 which are mounted on the mounting platform 1 in the same left and right postures as the two guide wheel mounting frames 2, the limit groove 203 positioned at the side end of the mounting surface of the guide wheel mounting frame 2 is respectively provided with a fifth straight notch 205 and a fifth threaded hole 206, the fixed end of the limit groove 203 positioned at the side end is provided with a connecting flange 207, and the connecting flange 207 is respectively provided with a sixth straight notch 208 and a notch 209.

The horizontal-vertical spacing of the threaded holes 206 in the vertical segment limiting slots 203 is equal to the corresponding spacing of the straight slot holes 1232 of the guide wheel assembly 12. 2 guide wheels 12 are arranged at designated positions of the horizontal section limiting grooves 203 of each guide wheel mounting frame 2, and one guide wheel 12 is respectively arranged at designated positions in the vertical limiting grooves 203 on the left side and the right side of the guide wheel mounting frame 2 and used for guiding the steel wire ropes in different directions.

As shown in fig. 3, grooves 301 are symmetrically arranged on the lower surfaces of two ends of the upper beam 3, stepped holes 305 are symmetrically arranged on two ends of the upper beam 3, a crossed guide groove 302 is arranged in the middle of the upper beam 3, a 45-degree chamfer is arranged at the crossed position of the guide groove 302, a large round hole 303 is arranged in the middle of the guide groove 302, the radius of the large round hole 303 is larger than the deformation amount generated by stress of the six-dimensional force sensor in a certain direction, and sixth threaded holes 304 are uniformly formed in the circumferential direction of the large round hole 303. The width and depth of the guide groove 302 are respectively equal to the width and thickness of the straight line end 1002 of the notch transition plate 10, the inclination angle of the inclined end 1001 is 45 degrees, the size of the inclined end 1001 is consistent with the chamfer size on the guide groove 302, and the width of the guide groove 302 is equal to the outer space of the second bearings 84 on two sides of the gravity compensation wheel assembly 8.

As shown in fig. 7, the stress rod assembly 4 comprises a stress rod 41, a support frame 42, an adjusting seat assembly 43, a T-shaped shaft sleeve 44, a set screw 45 and a bolt 46, wherein an end flange 412 of the stress rod 41 is connected with an installation threaded hole 424 of the support frame 42 through the bolt 46, the circular size of the inner side of a positioning flange 416 on the surface of the end flange 412 of the stress rod 41 is used for carrying out matching limiting on the outer edge of a protrusion 423 of the support frame 42, the positioning flange 416 on the stress rod 41 is used for limiting to ensure that a second shaft hole 422 of the support frame 42 is coaxial with a first shaft hole 415 on the stress rod 41, a circular shaft 4313 of the adjusting seat assembly 43 is respectively connected with the first shaft hole 413 of the stress rod 41 and the second shaft hole 422 of the support frame 42 through the T-shaped shaft sleeve 44, the outer diameter of the flange of the T-shaped shaft sleeve 44 is larger than the diameters of the first shaft hole 415 on the surface of the end flange 412 and the second shaft hole 422 of the support frame 42, and the set screw 45 is positioned in the limiting threaded hole 425 of the support frame 42; the adjusting seat assembly 43 can be rotated around the axis in the space formed by the support frame 42 and the end flange 412 of the force-receiving rod 41, and after being rotated to the target position, can be fixed by a set screw 45 arranged on the support frame 42.

Further, when moment calibration is performed on the six-dimensional force sensor with large deformation, as shown in fig. 9, the force rod assembly 4 is inclined, so that the curved surface of the adjusting seat 431 is matched with the adjusting wheel assembly 434, the adjusting wheel assembly 434 automatically adjusts the force acting point in the deformed state, specifically rolls to a new highest or lowest point position on the curved surface, the highest or lowest point position is always positioned on a straight line where the acting force of the six-dimensional force sensor to be calibrated in the undeformed state is positioned, the loading load direction is ensured to be unchanged, the moment is ensured to be unchanged, and the loading coupling influence generated by the deformation of the six-dimensional force sensor is effectively eliminated, so that the calibration precision of the six-dimensional force sensor with large deformation is ensured.

As shown in fig. 5, the stress rod 41 is in a cross structure, and comprises a cross beam 411, an end flange 412, a first through hole 413, a seventh threaded hole 414, a first shaft hole 415, a positioning flange 416, a circular mounting plate 417 and a second through hole 418, wherein the bottom surface of the circular mounting plate 417 is coplanar with the axis of the first shaft hole 415 at the center of the end flange 412, the end of the cross beam 411 is provided with the end flange 412, the periphery of the end flange 412 is provided with the first through hole 413 and the positioning flange 416, the middle part of the end flange 412 is provided with the first shaft hole 415, the first end of the middle part of the cross beam 411 is provided with the seventh threaded hole 414, the second end of the middle part of the cross beam 411 is provided with the circular mounting plate 417, and the circular mounting plate 417 is provided with the second through hole 418.

In one embodiment of the present invention, the moment arm of the force bar 41 is 250mm, and since the force bar 41 can keep the direction of the applied load and the moment arm unchanged when the force bar is deflected by different angles under load, a curved equation of the curved through hole 4312 is obtained, and the specific expression is:

y＝-2.466×10 ^-5 x ⁴ -4.157×10 ^-19 x ³ -0.01531x ² +2.207×10 ^-16 x+15

in the coordinate system using the central symmetry line as the coordinate axis, x represents the axis coordinate of the central symmetry line of the adjusting seat 431 in the length direction, and y represents the axis coordinate of the central symmetry line of the adjusting seat 431 in the width direction.

The support frame 42 is similar square structure, as shown in fig. 6, including first base 421, second axial hole 422, protruding 423, installation screw hole 424 and spacing screw hole 425, the middle part of first base 421 is equipped with second axial hole 422, evenly is equipped with protruding 423 around the first base 421, and the overhang of protruding 423 is equipped with installation screw hole 424, and the lateral wall symmetry of protruding 423 is equipped with spacing screw hole 425.

The adjusting seat assembly 43, as shown in fig. 4, comprises an adjusting seat 431, an end cover 432, an adjusting wheel assembly 434 and a screw 433, wherein the center line of the adjusting seat assembly 43 in the long axis direction is coplanar with the bottom surface of the circular mounting plate 417 on the force-bearing rod 41, the screw hole 4314 of the adjusting seat 431 is connected with the third through hole 4323 of the end cover 432 through the screw 433, the column-shaped long arm 43412 of the transition piece 4341 in the adjusting wheel assembly 434 is positioned in the seventh straight slot 4315 of the adjusting seat 431, and the first bearing 4344 in the adjusting wheel assembly 434 is in rolling contact with the cambered surface of the cambered surface through hole 4312 of the adjusting seat 431. The outer edge of the annular boss 4322 and the third through hole 4323 on the end cover 432 are correspondingly matched with the curved surface through hole 4312 and the screw hole 4314 in the adjusting seat 431 respectively, and the top surface interval of the annular boss 4322 of the end cover 432 is larger than the outer edge interval of the first bearings 4344 on two sides of the adjusting wheel assembly 434. Specifically, the spacing between the opposite faces of the annular bosses 4322 of the two end caps 432 at the two ends of the adjustment seat 431 is greater than the spacing between the outer lateral faces of the two bearings 8D of the adjustment wheel assembly 434 that are symmetrically disposed on the two sides of the transition piece 4341.

The adjusting seat 431, as shown in fig. 8, includes a second base 4311, a curved surface through hole 4312, a round shaft 4313, a screw hole 4314 and a seventh straight slot 4315, where the curved surface through hole 4312 is symmetrically formed by two curved surfaces, the long axis of the curved surface through hole 4312 coincides with the long axis of the second base 4311, the second base 4311 is in a chamfered cuboid structure, the curved surface through hole 4312 is arranged in the middle of the second base 4311, the screw hole 4314 is symmetrically arranged around the second base 4311, the through seventh straight slot 4315 is symmetrically distributed at the side end of the second base 4311 along the length direction, the length of the through seventh straight slot 4315 is equal to the long axis length of the curved surface through hole 4312, the width of the through seventh straight slot 4315 is greater than the thickness of the columnar long arm 43412 of the transition piece 4341, and the round shaft 4313 is symmetrically distributed at the side end of the second base 4311 along the width direction.

The end cover 432, as shown in fig. 10, comprises a chamfered rectangular panel 4321, an elliptical annular boss 4322 and a third through hole 4323, wherein the annular boss 4322 is arranged in the middle of the rectangular panel 4321, the third through hole 4323 is symmetrically arranged around the rectangular panel 4321, and the elliptical curvature of the annular boss 4322 is consistent with that of the curved surface through hole 4312.

The adjusting wheel assembly 434, as shown in fig. 12, comprises a first pin shaft 4342, a first clamp spring 4343, a first bearing 4344 and a transition piece 4341, wherein the appearance structure of the first pin shaft 4342 is the same as that of the second pin shaft 81, the first bearing 4344 is symmetrically distributed at two ends of a sleeve 43411 in the transition piece 4341, a clamp spring groove of the first pin shaft 4342 sequentially penetrates through an inner ring of the first bearing 4344 and an inner ring of a sleeve 43411 in the transition piece 4341 to be connected with the first clamp spring 4343, and the first clamp spring 4343 limits parts on the first pin shaft 4342 to move along the axial direction; the annular inner diameter of the transition piece 4341 and the inner diameter of the first bearing 4344 are respectively matched with the outer diameter of the first pin 4342.

The transition piece 4341 is widest at the position of the sleeve 43411, as shown in fig. 11, and comprises a sleeve 43411, a cylindrical long arm 43412 and a fourth through hole 43413, wherein cylindrical long arms 43412 are symmetrically arranged on two side surfaces of the sleeve 43411, and the suspending end of the cylindrical long arm 43412 is provided with the fourth through hole 43413. Specifically, the width of the sleeve 43411 is equal to the width of the seventh straight slot 4315, the thickness of the long cylindrical arm 43412 along the axial direction of the sleeve 43411 is smaller than the thickness of the sleeve 43411, and after the sleeve 43411 is mounted on the adjusting seat assembly 43, the long cylindrical arm 43412 is not in contact with the seventh straight slot 4315 and the two side distances are equal.

The gravity compensation wheel assembly 8, as shown in fig. 13, comprises a second pin shaft 81, a second clamp spring 82, a transition ring 83 and a second bearing 84, wherein the second bearing 84 is symmetrically distributed at two ends of the transition ring 83, and a clamp spring groove 8104 of the second pin shaft 81 sequentially penetrates through an inner ring of the second bearing 84 and an inner ring of the transition ring 83 to be connected with the second clamp spring 82; the outer diameter of the shackle 9 is smaller than the inner distance of the second bearings 84 on both sides of the weight compensation wheel assembly 8.

The second pin shaft 81, as shown in fig. 17, includes a cap end 8101, a pin body 8102, a first small hole 8103 and a clamp spring groove 8104, wherein the cap end 8101 is disposed at the first end of the pin body 8102, the clamp spring groove 8104 is disposed at the second end of the pin body 8102, the first small hole 8103 is disposed in the middle of the pin body 8102, as shown in fig. 16, a second small hole 8301 is disposed in the middle of the transition ring 83, centers of the first small hole 8103 and the second small hole 8301 are overlapped, and diameters of the first small hole 8103 and the second small hole 8301 are equal.

The guide wheel assembly 12, as shown in fig. 18, comprises a third pin shaft 121, a third clamp spring 124, a guide wheel 122 and a guide wheel seat 123, wherein the appearance structure of the third pin shaft 121 is the same as that of the second pin shaft 81, the guide wheel 122 is connected with a mounting hole of the guide wheel seat 123 through the third pin shaft 121 and the third clamp spring 124, a wire passing through hole 1231 is formed in the middle of the guide wheel seat 123, straight slot holes 1232 are symmetrically formed in the periphery of the guide wheel seat 123, and the straight slot holes 1232 are respectively connected with a third threaded hole 202 and a fourth threaded hole 204 of the guide wheel mounting frame 2.

As shown in fig. 15, the sensor base 5 is in a U-shaped flanging structure, a circular groove 501 is formed in the middle of the U-shaped top surface of the sensor base 5, eighth straight notches 502 are uniformly formed in the circumference of the inside of the circular groove 501, and rib plates 503, second mounting holes 504 and second positioning holes 505 are symmetrically formed in the U-shaped side surface of the sensor base 5.

As shown in fig. 20, a fourth through hole 1003 is formed in the middle of the intersection of the inclined end 1001 and the straight end 1002 of the notch transition plate 10, a chamfer 1004 is formed in the straight end, and the distance from the end surface of the inclined end 1001 to the fourth through hole 1003 is equal to the distance from the edge of the guide groove 302 of the upper beam 3 to the sixth threaded hole 304 on the same side.

The underframe 13, as shown in fig. 19, comprises a vertical beam 1301, a cross beam 1302 and a connecting piece 1303, wherein the vertical beam is connected with the cross beam through the connecting piece, the vertical beam 1301 is clamped into a positioning groove 108 of the mounting platform 1 for limiting assembly, and meanwhile, the top surface of the cross beam 1302 is contacted with the bottom surface of the mounting platform 1 for reinforcing support.

The calibration device and the calibration method for the large-deformation six-dimensional force sensor are further described by combining the following embodiments:

in this specific embodiment, the calibration method for the large deformation six-dimensional force sensor is implemented as follows:

the method comprises the steps of defining coordinates of the six-dimensional force sensor in a calibration device, calibrating each dimension of the six-dimensional force sensor to be calibrated, and calibrating each dimension of the six-dimensional force sensor to be calibrated, wherein the calibration comprises positive and negative directions along coordinate axes and positive and negative directions around three axes. Dividing the six-dimensional force sensor to be calibrated into a plurality of loading steps according to the maximum range of each dimension, gradually loading according to the step load, gradually unloading, respectively recording output signals corresponding to the six-dimensional force sensor after stabilizing the device to be calibrated each time, and carrying out multi-group averaging on each dimension calibration according to the same method so as to improve the calibration precision.

S1, using a first steel wire rope 18 connected with the miniature tension-compression sensor 6 through a ring nut 7, enabling the force value of the miniature tension-compression sensor 6 to be equal to the gravity of the stressed rod assembly 4, locking the first steel wire rope 18 by using a lock catch 9, acquiring the gravity of the stressed rod assembly 4, and eliminating or compensating for the subsequent calibration process.

And installing the six-dimensional force sensor to be calibrated, installing the bottom surface of the six-dimensional force sensor in the circular groove 501 of the sensor fixing seat 5, adjusting the bottom surface installation hole of the six-dimensional force sensor to be calibrated to correspond to the eighth straight notch 502, and connecting and fixing the six-dimensional force sensor from the lower part by adopting a connecting bolt. The top surface of the six-dimensional force sensor to be calibrated is in contact connection with the bottom surface of the circular mounting plate 417 of the force rod 41 on the force rod assembly 4, the top surface mounting holes of the six-dimensional force sensor to be calibrated are adjusted to correspond to the second through holes 418 of the circular mounting plate 417 respectively, and the six-dimensional force sensor to be calibrated is fixedly connected from the upper side through bolts.

S2, if calibration of the six-dimensional force sensor along the x-axis direction is required, as shown in FIG. 21, connecting a miniature tension and compression sensor 6 on a seventh threaded hole 414 of a cross beam 411 of a force rod assembly 4, connecting a ring nut 7 on a stud at the upper end of the miniature tension and compression sensor 6, connecting the ring nut 7 with a first steel wire rope 18, penetrating the other end of the first steel wire rope 18 through a large round hole 303 of an upper cross beam 3, penetrating a first small hole 8103 and a second small hole 8301 which are coaxial with a transition ring 83 of a second pin shaft 81 in a gravity compensation wheel assembly 8 arranged in a guide groove 302 parallel to the x-axis in the upper cross beam 3, and further penetrating a lock catch 9, gradually tensioning the first steel wire rope 18 at the moment, observing the magnitude of the force value monitored by the miniature tension and compression sensor 6, keeping stable when the magnitude of the monitored force value is equal to the gravity of the force rod assembly 4, and locking the first steel wire rope 18 by the lock catch 9, so that the influence of the gravity of the force rod assembly 4 itself on the six-dimensional force sensor to be calibrated is eliminated; then, the adjusting seat assembly 43 in the two branches of the cross beam 411 perpendicular to the x axis in the stress rod assembly 4 is adjusted to be in a horizontal state, and the set screw 45 on the supporting frame 42 in the branch is adjusted to prop against the surface of the adjusting seat assembly 43 so as to keep the column-shaped long arm 43412 in the adjusting wheel assembly 434 in a horizontal posture, and the position of the guiding wheel assembly 12 in the limit groove 203 at the side end of the guiding wheel mounting frame 2 is adjusted to ensure that the central axis of the adjusting seat assembly 43 is in the upper edge horizontal section of the minimum diameter of the rope groove of the guiding wheel 122.

If calibration of the six-dimensional force sensor along the y-axis direction is required, firstly, a method of calibrating the x-axis direction is adopted, the gravity influence of the stress rod assembly 4 is eliminated by utilizing the miniature tension pressure sensor 6, then the adjusting seat assembly 43 in two branches of the cross beam 411 vertical to the y-axis in the stress rod assembly 4 is adjusted to be in a horizontal state, the surface of the adjusting seat assembly 43 is propped against by the set screw 45 on the support frame 42 in the branch so as to keep the columnar long arm 43412 in the adjusting wheel assembly 434 in a horizontal posture, and the position of the guide wheel assembly 12 in the limit groove 203 at the side end of the guide wheel mounting frame 2 is adjusted, so that the central axis of the adjusting seat assembly 43 is ensured to be in the upper edge horizontal section of the minimum diameter of the rope groove of the guide wheel 122; simultaneously, the notch transition plates 10 and the gravity compensation wheel assemblies 8 which are symmetrically arranged in the guide grooves 302 are respectively subjected to 90-degree transposition.

If calibration of the six-dimensional force sensor along the z-axis direction is required, as shown in fig. 22 and 23, the method of calibrating the x-axis direction is firstly adopted to eliminate the gravity influence of the force-bearing rod assembly 4 by utilizing the miniature pulling pressure sensor 6, then the adjusting seat assembly 43 in two branches of the cross beam 411 on the same axis in the force-bearing rod assembly 4 is adjusted to be vertical, and the surface of the adjusting seat assembly 43 is propped against the surface of the adjusting seat assembly 43 by the set screw 45 on the support frame 42 in the branch so as to keep the column-shaped long arm 43412 in the adjusting wheel assembly 434, and the positions of the guide wheel assembly 12 in the limit groove 203 of the guide wheel mounting frame 2 are respectively adjusted, so that the central axis of the adjusting seat assembly 43 is ensured to be in the vertical section of the left edge of the minimum diameter of the rope groove of the guide wheel 122 in the limit groove 203 at the side end, and the vertical section of the right edge of the minimum diameter of the rope groove of the guide wheel 122 in the limit groove 203 at the top is ensured to pass through the fourth vertical notch 201 on the right side in the limit groove 203 at the top, and the vertical notch 102 on the right side of the corresponding edge on the mounting platform 1 is ensured to pass through the vertical notch 102 on the right side of the corresponding edge on the mounting platform 1.

If calibration of the six-dimensional force sensor around the x-axis direction is required, as shown in fig. 24, the method of calibrating the x-axis direction is firstly adopted to eliminate the gravity influence of the force-bearing rod assembly 4 by utilizing the miniature tension pressure sensor 6, then the adjusting seat assembly 43 in two branches of the cross beam 411 on the same axis in the force-bearing rod assembly 4 is adjusted to be in a vertical state, and the surface of the adjusting seat assembly 43 is propped against the surface of the adjusting seat assembly 43 by the set screw 45 on the supporting frame 42 in the branch so as to keep the column-shaped long arm 43412 in the adjusting wheel assembly 434 in a vertical posture, and the position of the guide wheel assembly 12 in the limit groove 203 at the top end of the guide wheel mounting frame 2 is adjusted, so that the right edge vertical section of the minimum diameter of the rope groove of the guide wheel 122 in the limit groove 203 at the top end passes through the fourth straight notch 201 near the right side in the limit groove 203 at the top end.

If calibration of the six-dimensional force sensor around the z-axis direction is required, the gravity influence of the force-bearing rod assembly 4 is eliminated by the miniature tension pressure sensor 6 by adopting a method of calibrating the x-axis direction, then the adjusting seat assembly 43 in two branches of the cross beam 411 on the x-axis in the force-bearing rod assembly 4 is adjusted to be in a horizontal state, the set screw 45 on the support frame 42 in the branch is adjusted to bear against the surface of the adjusting seat assembly 43 so as to keep the columnar long arm 43412 in the adjusting wheel assembly 434 in a horizontal posture, and the position of the guide wheel assembly 12 in the limit groove 203 at the side end of the guide wheel mounting frame 2 is adjusted, so that the central axis of the adjusting seat assembly 43 is ensured to be in the upper edge horizontal section of the minimum diameter of the rope groove of the guide wheel 122.

S3, if calibration of the six-dimensional force sensor along the positive x-axis direction is required, as shown in FIG. 21, the first ends of the two identical second steel wire ropes 19 are connected with fourth through holes 43413 symmetrically distributed on transition pieces 4341 in adjusting wheel assemblies 434 at two ends of the stress rod assembly 4, the second ends of the two identical second steel wire ropes 19 respectively pass through fifth straight notches 205 of corresponding guide wheel mounting frames 2 along the positive x-axis direction, then turn downwards by 90 degrees through guide wheels 122, and pass through notches 209 of corresponding guide wheel mounting frames 2 and first straight notches 101 of mounting platforms 1 to be connected with balancing weights 11.

If calibration of the six-dimensional force sensor along the negative x-axis direction is required, the first ends of the two identical second steel wire ropes 19 are connected with fourth through holes 43413 symmetrically distributed on transition pieces 4341 in adjusting wheel assemblies 434 at two ends of the stress rod assembly 4, the second ends of the two identical second steel wire ropes 19 respectively pass through fifth straight notches 205 of corresponding guide wheel mounting frames 2 along the negative x-axis direction, then are turned downwards by 90 degrees through guide wheels 122, and pass through notches 209 of corresponding guide wheel mounting frames 2 and first straight notches 101 of mounting platforms 1 to be connected with balancing weights 11.

If calibration of the six-dimensional force sensor along the positive y-axis is required, the first ends of the two identical second steel wire ropes 19 are connected with fourth through holes 43413 symmetrically distributed on transition pieces 4341 in adjusting wheel assemblies 434 at two ends of the stress rod assembly 4, the second ends of the two identical second steel wire ropes 19 respectively pass through fifth straight notches 205 of corresponding guide wheel mounting frames 2 along the positive y-axis direction, then are turned downwards by 90 degrees through guide wheels 122, and pass through notches 209 of corresponding guide wheel mounting frames 2 and first straight notches 101 of mounting platforms 1 to be connected with balancing weights 11.

If calibration of the six-dimensional force sensor along the negative y-axis direction is required, as shown in fig. 23, the first ends of the two identical second steel wire ropes 19 are connected with fourth through holes 43413 symmetrically distributed on transition pieces 4341 in adjusting wheel assemblies 434 at two ends of the stress rod assembly 4, the second ends of the two identical second steel wire ropes 19 respectively pass through fifth straight notches 205 of the corresponding guide wheel mounting frame 2 along the negative y-axis direction, then turn downwards by 90 degrees through guide wheels 122, and pass through notches 209 of the corresponding guide wheel mounting frame 2 and first straight notches 101 of the mounting platform 1 to be connected with the balancing weights 11.

If calibration of the six-dimensional force sensor along the positive z-axis direction is required, as shown in fig. 22, the first ends of the two identical second steel wire ropes 19 are connected with fourth through holes 43413 symmetrically distributed on the transition pieces 4341 in the adjusting wheel assemblies 434 at two ends of the stress rod assembly 4, the second ends of the two identical second steel wire ropes 19 respectively pass through the first fourth straight notch 201 in the limit groove 203 at the top end of the corresponding guide wheel mounting frame 2 along the positive z-axis direction, then turn to the right 90 ° through the first guide wheel 122 at the top end of the guide wheel mounting frame 2, turn to the right 90 ° through the second guide wheel 122 at the top end of the guide wheel mounting frame 2, and pass through the second fourth straight notch 201 in the limit groove 203 at the top end of the corresponding guide wheel mounting frame 2 and the first second straight notch 102 of the mounting platform 1 to be connected with the balancing weight 11. On the opposite side of the guide wheel mounting frame 2, two guide wheel assemblies 12 and a second wire rope 19 are run, with a circular axis array of 180 ° centered on the z-axis.

If calibration of the six-dimensional force sensor along the negative z-axis direction is required, as shown in fig. 23, the first ends of the two identical second steel wire ropes 19 are connected with fourth through holes 43413 symmetrically distributed on transition pieces 4341 in adjusting wheel assemblies 434 at two ends of the stress rod assembly 4, and the second ends of the two identical second steel wire ropes 19 respectively pass through third straight notches 103 of the corresponding mounting platform 1 along the negative z-axis direction to be connected with the balancing weights 11.

If calibration of the six-dimensional force sensor is required around the x-axis or y-axis, connecting the first end of the first second wire rope 19 with the fourth through hole 43413 symmetrically distributed on the transition piece 4341 in the first adjusting wheel assembly 434 at both ends of the stress rod assembly 4, respectively passing the second end of the first second wire rope 19 through the first fourth straight notch 201 in the limit groove 203 at the top end of the corresponding guide wheel mounting frame 2 along the positive z-axis direction, steering left by 90 degrees through the first guide wheel 122 at the top end of the guide wheel mounting frame 2, steering down by 90 degrees through the third guide wheel 122 at the top end of the guide wheel mounting frame 2, and connecting the third fourth straight notch 201 in the limit groove 203 at the top end of the corresponding guide wheel mounting frame 2 and the second straight notch 102 of the mounting platform 1 with the balancing weight 11; the first end of the second steel wire rope 19 is connected with a fourth through hole 43413 symmetrically distributed on a transition piece 4341 in a second adjusting wheel assembly 434 at two ends of the stress rod assembly 4, and the second end of the second steel wire rope 19 passes through a third straight notch 103 corresponding to the mounting platform 1 along the negative direction of the z axis to be connected with the balancing weight 11.

If calibration of the six-dimensional force sensor around the z-axis direction is required, as shown in fig. 25, the first ends of the two identical second steel wire ropes 19 are connected with fourth through holes 43413 on the transition piece 4341 in the adjusting wheel assemblies 434 symmetrically distributed on the two ends of the stress rod assembly 4 on the x-axis, the second ends of the two identical second steel wire ropes 19 respectively pass through the fifth straight notch 205 of the corresponding guide wheel mounting frame 2 along the positive direction and the negative direction of the x-axis, then turn downwards by 90 degrees through the guide wheel 122, and pass through the notch 209 of the corresponding guide wheel mounting frame 2 and the two first straight notches 101 of the mounting platform 1 to be connected with the balancing weight 11.

S4, if the six-dimensional force sensor is calibrated along the x-axis or the y-axis, the same balancing weights 11 are mounted on the second steel wire ropes 19 at the two sides, and the sum of the gravity of the balancing weights 11 at the two sides is the acting force of the six-dimensional force sensor to be calibrated along the x-axis or the y-axis; the calibration process is that along with the increase of the load, the force-bearing rod assembly 4 transmits acting force to the six-dimensional force sensor to be calibrated, the gravity compensation wheel assembly 8 connected with the force-bearing rod assembly 4 through the second steel wire rope 19 receives component force along the x axis or the y axis, at the moment, the gravity compensation wheel assembly 8 rolls along the guide groove 302 in the upper cross beam 3 for a distance which is equal to the deformation of the six-dimensional force sensor to be calibrated, so that the gravity of the force-bearing rod assembly when the six-dimensional force sensor is stressed and deformed in the x axis or the y axis direction is eliminated, the step length is defined according to the measuring range of the six-dimensional force sensor in the x axis or the y axis direction, the load is gradually loaded, the output signal quantity of the six-dimensional force sensor along the x axis or the y axis direction is read, the electric signal parameters output by a plurality of groups of balancing weights 11 and the six-dimensional force sensor are repeatedly measured, and the calibration of the six-dimensional force sensor in the x axis or the y axis direction is completed by taking an average value.

If the six-dimensional force sensor is calibrated along the z-axis direction, the same balancing weights 11 are mounted on the second steel wire ropes 19 on the two sides, and the sum of the gravity of the balancing weights 11 on the two sides is the acting force of the six-dimensional force sensor to be calibrated in the positive z-axis direction. The method is divided into a plurality of loading steps according to the maximum range in the z direction, the loading step by step is carried out according to the step load, then the loading step by step is carried out, and each step of loading or unloading is carried out, so that the gravity of the force rod assembly 4 is eliminated and is invalid initially due to the fact that the six-dimensional force sensor to be calibrated is loaded and deformed in the z direction, the gravity of the force rod assembly 4 is required to be eliminated again, specifically, the lock catch 9 is released, the first steel wire rope 18 is gradually tensioned, the magnitude of the force value monitored by the miniature tension-compression sensor 6 is observed, the stability is kept when the magnitude of the monitored force value is equal to the gravity of the force rod assembly 4 again, the second steel wire rope 18 is locked by the lock catch 9, and the influence of the gravity of the force rod assembly 4 to be calibrated on the six-dimensional force sensor is eliminated. After each stabilization, the signal quantity output by the six-dimensional force sensor is read, and the calibration of each dimension is performed with multiple groups of average value taking according to the same method so as to improve the calibration precision.

If the six-dimensional force sensor is calibrated around the x-axis, the y-axis or the z-axis, the sum of the moments obtained by multiplying the gravity of the balancing weights 11 on the two symmetrical sides of the cross beam 411 by the corresponding moment arms is the acting moment on the six-dimensional force sensor around the x-axis, the y-axis or the z-axis, the load is gradually loaded according to the step length defined by the six-dimensional force sensor, after the six-dimensional force sensor is loaded according to the step length each time and regulated stably, the signal quantity output by the six-dimensional force sensor is read, and the calibration of each dimension is carried out by taking the average value of multiple groups according to the same method so as to improve the calibration precision.

The above examples are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solution of the present invention should fall within the scope of protection defined by the claims of the present invention without departing from the spirit of the present invention.

Claims

1. The calibration device for the large-deformation six-dimensional force sensor comprises a mounting platform, a guide wheel mounting frame, an upper cross beam, a stress rod assembly, a sensor base, a miniature tension-compression sensor, a ring nut, a gravity compensation wheel assembly, a lock catch, a notch transition plate, a guide wheel assembly and a chassis, and is characterized in that,

the positioning groove of the mounting platform is connected with the mounting end of the vertical beam of the underframe, the sixth straight notch of the guide wheel mounting frame and the second mounting hole of the sensor base are respectively connected with the first threaded hole and the second threaded hole of the mounting platform, the second positioning hole of the sensor base and the first positioning hole of the mounting platform are connected, the six-dimensional force sensor is positioned in the circular groove of the sensor base, the eighth straight notch of the sensor base and the lower end of the six-dimensional force sensor are connected, the upper end of the six-dimensional force sensor is connected with the second through hole of the circular mounting plate in the stress rod assembly, the seventh threaded hole in the stress rod assembly is connected with the first end of the miniature tension and compression sensor, the second end of the miniature tension and compression sensor is connected with the fixed end of the ring nut, the working end of the ring nut passes through the first steel wire rope and is connected with the lock catch in the small hole of the gravity compensation wheel assembly, the step hole of the upper cross beam is connected with the fourth threaded hole of the guide wheel base, the upper cross beam passes through the gap of the guide wheel assembly and the fourth through hole of the guide wheel assembly, and the guide wheel assembly is positioned in the gap of the guide wheel assembly;

The bearing rod assembly comprises a bearing rod, a support frame, an adjusting seat assembly, a T-shaped shaft sleeve, a set screw and a bolt, wherein an end flange of the bearing rod is connected with an installation threaded hole of the support frame through the bolt, a round shaft of the adjusting seat assembly is respectively connected with a first shaft hole of the bearing rod and a second shaft hole of the support frame through the T-shaped shaft sleeve, and the set screw is positioned in a limit threaded hole of the support frame; the stress rod comprises a cross beam, an end flange, a first through hole, a seventh threaded hole, a first shaft hole, a positioning flange, a circular mounting plate and a second through hole, wherein the end flange is arranged at the end part of the cross beam, the first through hole and the positioning flange are arranged around the end flange, the first shaft hole is arranged in the middle of the end flange, the seventh threaded hole is formed in the first end of the middle of the cross beam, the circular mounting plate is arranged at the second end of the middle of the cross beam, and the second through hole is formed in the circular mounting plate;

the adjusting seat assembly comprises an adjusting seat, an end cover, an adjusting wheel assembly and a screw, wherein a screw hole of the adjusting seat is connected with a third through hole of the end cover through the screw, a columnar long arm of a transition piece in the adjusting wheel assembly is positioned in a seventh straight notch of the adjusting seat, and a first bearing in the adjusting wheel assembly is in contact with a curved surface through hole of the adjusting seat;

The gravity compensation wheel assembly comprises a second pin shaft, a second clamp spring, a transition ring and a second bearing, wherein the second bearing is symmetrically distributed at two ends of the transition ring, and clamp spring grooves of the second pin shaft sequentially penetrate through an inner ring of the second bearing and an inner ring of the transition ring to be connected with the second clamp spring; the guide wheel assembly comprises a third pin shaft, a third clamp spring, a guide wheel and a guide wheel seat, wherein the guide wheel is connected with a mounting hole of the guide wheel seat through the third pin shaft and the third clamp spring, a wire passing through hole is formed in the middle of the guide wheel seat, straight slot holes are symmetrically formed in the periphery of the guide wheel seat, and the straight slot holes are respectively connected with a third threaded hole and a fourth threaded hole of the guide wheel mounting frame.

2. The calibration device for the large-deformation six-dimensional force sensor according to claim 1, wherein the support frame comprises a first base, a second shaft hole, a protrusion, a mounting threaded hole and a limiting threaded hole, the second shaft hole is formed in the middle of the first base, protrusions are uniformly formed in the periphery of the first base, the mounting threaded hole is formed in the protruding overhanging end of the first base, and the limiting threaded hole is symmetrically formed in the side wall of the protrusion.

3. The calibration device for the large-deformation six-dimensional force sensor according to claim 1, wherein the adjusting seat comprises a second base, a curved surface through hole, a round shaft, a screw hole and a seventh straight notch, the curved surface through hole is arranged in the middle of the second base, the screw hole is symmetrically arranged around the second base, the seventh straight notch is symmetrically distributed at the side face end of the second base along the length direction, and the round shaft is symmetrically distributed at the side face end of the second base along the width direction.

4. The calibration device for the large-deformation six-dimensional force sensor according to claim 1, wherein the end cover comprises a rectangular panel, an annular boss and a third through hole, the annular boss is arranged in the middle of the rectangular panel, and the third through hole is symmetrically arranged around the rectangular panel.

5. The calibration device for a large deformation six-dimensional force sensor according to claim 1, wherein the transition piece comprises a sleeve, a columnar long arm and a fourth through hole, the columnar long arm is symmetrically arranged on two side surfaces of the sleeve, and a fourth through hole is arranged at the overhanging end of the columnar long arm.

6. The calibration device for the large-deformation six-dimensional force sensor according to claim 1, wherein the adjusting wheel assembly comprises a first pin shaft, a first clamp spring, a first bearing and a transition piece, the first bearing is symmetrically distributed at two ends of a sleeve in the transition piece, and clamp spring grooves of the first pin shaft sequentially penetrate through an inner ring of the first bearing and an inner ring of the sleeve in the transition piece to be connected with the first clamp spring.

7. A calibration method for a large deformation six-dimensional force sensor according to one of claims 1-6, characterized in that it comprises the steps of:

and S4, calibrating the six-dimensional force sensor.

8. The calibration method for a large deformation six-dimensional force sensor according to claim 7, wherein the specific implementation process of step S2 is as follows:

9. The calibration method for a large deformation six-dimensional force sensor according to claim 7, wherein the specific implementation process of step S3 is as follows:

10. The calibration method for a large deformation six-dimensional force sensor according to claim 7, wherein the specific implementation process of step S4 is as follows: