CN115389081A - Decoupling-free micro-space force accurate measurement device and measurement method based on double-freedom-degree air-floating guide rail and air-floating bearing - Google Patents
Decoupling-free micro-space force accurate measurement device and measurement method based on double-freedom-degree air-floating guide rail and air-floating bearing Download PDFInfo
- Publication number
- CN115389081A CN115389081A CN202210840947.8A CN202210840947A CN115389081A CN 115389081 A CN115389081 A CN 115389081A CN 202210840947 A CN202210840947 A CN 202210840947A CN 115389081 A CN115389081 A CN 115389081A
- Authority
- CN
- China
- Prior art keywords
- air
- guide rail
- floating
- bearing
- force
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000005259 measurement Methods 0.000 title claims abstract description 24
- 238000000691 measurement method Methods 0.000 title abstract description 3
- 238000000034 method Methods 0.000 claims abstract description 19
- 238000005461 lubrication Methods 0.000 claims abstract description 8
- 239000000523 sample Substances 0.000 claims description 21
- 230000003287 optical effect Effects 0.000 claims description 16
- 238000012360 testing method Methods 0.000 claims description 11
- 238000006073 displacement reaction Methods 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 5
- 238000013461 design Methods 0.000 claims description 3
- 238000007789 sealing Methods 0.000 claims description 3
- 239000007787 solid Substances 0.000 claims description 3
- 230000003068 static effect Effects 0.000 claims description 3
- 230000000149 penetrating effect Effects 0.000 claims 1
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 230000002349 favourable effect Effects 0.000 abstract description 2
- 238000009434 installation Methods 0.000 description 5
- 238000013016 damping Methods 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 235000001968 nicotinic acid Nutrition 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/16—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for measuring several components of force
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Magnetic Bearings And Hydrostatic Bearings (AREA)
Abstract
The invention belongs to the field of force value measurement, and particularly relates to a decoupling-free micro-space force accurate measurement device and a measurement method based on a two-degree-of-freedom air-floating guide rail and an air-floating bearing. The device uses a two-degree-of-freedom air-floating guide rail and an air-floating bearing to measure micro-space force, wherein the air-floating guide rail consists of a guide rail and a sliding block, and the air-floating bearing consists of a rotor at the center and a stator at the outer ring. The air-floating guide rail injects high-pressure gas into gaps between four surfaces of the guide rail and the sliding block through the quick connectors, so that uniform gas films with extremely strong bearing capacity can be formed in the gaps, the guide rail and the sliding block can be considered to be assembled in a non-contact manner under the condition of gas lubrication, and the air-floating bearing is the same. Therefore, the air-float force measuring method can lead the internal resistance to be extremely low and approximate to zero, and the provided measuring environment is very favorable for realizing high-resolution force measurement. In the measuring process, the air film in the air-float guide rail and the air film in the air-float bearing can isolate vibration to a certain extent, which is beneficial to improving the precision of the measuring device.
Description
Technical Field
The invention belongs to the field of force value measurement, and particularly relates to a decoupling-free micro-space force accurate measurement device based on a two-degree-of-freedom air-floating guide rail and an air-floating bearing.
Background
Spatial force refers to a force directed in any direction in three-dimensional space and can be resolved into three orthogonal directions. The accurate measurement of the magnitude and direction of the space force has important requirements in the fields of aviation, pneumatics, bionics, biology and the like, and has important significance for guiding basic research and design optimization of related fields. One of the difficulties is to simultaneously realize accurate measurement of the magnitude and direction of the spatial force value. In the past, in order to realize measurement of spatial force, researchers select a mechanical structure specially designed and processed, strain gauges are pasted on certain positions of the surface of the mechanical structure, force calibration is carried out in a plurality of orthogonal directions, strain gauge data are analyzed and decoupled when the spatial force is applied to obtain stress in the orthogonal directions, and finally the spatial force is synthesized, so that the size and the direction of resultant force are determined; researchers also use indirect methods such as air pressure and hydraulic pressure to calculate and obtain force values in a plurality of orthogonal directions. In summary, the synthesis of spatial forces by multiple orthogonal forces is popular and reasonable. According to the method for converting the force value through the strain signal, better measurement accuracy can be realized in the calibration direction of the strain gauge, particularly when the force is applied along the calibration direction, but accurate measurement is difficult to realize in other directions with a larger range outside the calibration direction, and meanwhile, the measurement results in the orthogonal directions have mutual interference, so that system errors are easily introduced; the method for indirectly calculating the resultant force by using signals such as air pressure, hydraulic pressure and the like can realize better orthogonal independence, namely the interference of measurement results between orthogonal directions is small, the method can even omit a decoupling process, but the measurement precision is difficult to improve due to the principle, and the measurement uncertainty can be increased by the fluctuation of the air pressure and the hydraulic pressure.
Disclosure of Invention
The invention aims to provide a novel decoupling-free micro-space force accurate measuring device based on a two-degree-of-freedom air-floating guide rail and an air-floating bearing, which has a simple structure and is convenient and fast to operate, and the space force is finally synthesized by independently measuring the stress of a test object in three orthogonal directions. The invention can realize the accurate measurement of the force value and the direction of the micro-space, the force values in the orthogonal directions are not interfered with each other, the measurement result does not need to be decoupled, and the data processing is greatly simplified.
In order to achieve the purpose, the invention adopts the following technical scheme:
a decoupling-free micro-space force accurate measurement device based on a two-degree-of-freedom air-floating guide rail and an air-floating bearing comprises the two-degree-of-freedom air-floating guide rail (1), a support (2), a working flat plate (3), a bearing (4), a bearing clamping block (5), a rotating shaft (6), a cross beam (7), a probe (8), a differential head (9), a differential head support (10), a cross beam stud (20), a mounting arm (21), the air-floating bearing (22), a force sensor (23), an air-floating bearing support (24), an air-floating bearing clamping block (25), a sensor support (26), a cantilever beam (27), an inter-beam support (28), an air-floating guide rail base (29) and an optical flat plate (30);
the two-degree-of-freedom air-floating guide rail (1) is installed on an optical flat plate (30) through an air-floating guide rail base (29), a support (2) and a working flat plate (3) are sequentially installed at the top of the air-floating guide rail (1), a pair of bearings (4) are clamped on the working flat plate (3) and fixed through bearing clamping blocks (5), a rotating shaft (6) penetrates through the bearings, a cross beam (7) is clamped on the rotating shaft, and the cross beam (7) can rotate freely in an unconstrained state.
The two-degree-of-freedom air floatation guide rail (1) comprises a lower air floatation guide rail (11), an upper air floatation guide rail (12) and a quick joint (13) for a pipe;
the lower-layer air-floating guide rail (11) comprises a guide rail (111), a sliding block (112), a sliding block (113), a sliding block (114) and a sliding block (115), wherein a rectangular open cavity is formed in the inner side of the installed sliding blocks (112) to (115), the guide rail (111) is inserted into the cavity, the upper-layer air-floating guide rail (12) comprises a guide rail (121), a sliding block (122), a sliding block (123), a sliding block (124) and a sliding block (125), the rectangular open cavity is formed in the inner side of the installed sliding blocks (122) to (125), the guide rail (121) is inserted into the cavity, and the distance between the guide rail (111) and the guide rail (121) and the sliding blocks installed on the periphery of the guide rail (111) is about 50-100 mu m.
The air guide hole with the diameter of d = 2-4 mm is vertically penetrated at the center (116) of the upper surface of a sliding block (112), two sealing grooves are machined at the upper surface (117) by taking the air guide hole as the center of a circle and used for filling a rubber gasket when a lower air-floating guide rail (11) and an upper air-floating guide rail (12) are installed, the sliding blocks (113) - (115) are all of a solid structure, a plurality of air guide holes with the diameter of d = 2-4 mm are machined in the guide rail (111), the air guide holes are led to an upper front surface, a lower front surface and a rear surface (a surface through which a z axis and a y axis penetrate) in a divergent mode by taking an inlet position as a starting point, the number of air guide hole outlets on each surface is not less than two, a quick joint (13) for pipes is tapped at the inlet position and installed at the outlet position, a small throttling hole with the diameter of a = 0.1-0.2 mm is installed at the outlet position, and an air guide hole with the diameter of d = 2-4 mm is machined at the center of the upper surface of the guide rail (111).
The inner parts of sliders (122) to (125) are provided with air holes with the diameter d, the shape of each air hole in the slider is in a 'well' shape, the 'well' shaped air holes can be communicated with each other after the sliders (122) to (125) are installed, each 'well' shaped air hole has four air hole intersection points, a through hole with the diameter d = 2-4 mm is opened on one side of a guide rail (121) at the position of the intersection point (126) and a throttling hole with the diameter a = 0.1-0.2 mm is installed at the tail end of the through hole, besides, a plurality of independent air holes with the diameter d = 2-4 mm are processed at the position of the center (127) of the lower surface of the slider (125), the air holes do not penetrate through the slider, besides the independent air holes for installing the throttling holes and the center processing of the slider (125), other air holes which have to be processed due to processing convenience, design convenience and the like but are exposed in the atmosphere environment are tapped and installed with studs, the guide rails (121) are not penetrated, and are used for drawing out the air holes as independent air holes, the guide holes in the slider (125), the guide rail (122) are reasonably distributed, the guide holes (111) are distributed in order to prevent the diffusion of the slider (122) and the slider (111) from being distributed according to limit the invention: .
The throttling small holes are mainly used for generating airflow with stable pressure and flow, and an air film is formed between the guide rail and the sliding block.
After the upper air-floating guide rail (12) is connected with the lower air-floating guide rail (11), an air guide hole in the center of the guide rail (111) and an air guide hole in the center of the sliding block (112) are basically located on the same axis, the air guide hole in the center of the sliding block (125) is connected with an air compressor through a quick joint (13), high-pressure air enters the air-floating guide rail (11) immediately after being introduced into the air-floating guide rail, the air pressure can be rapidly transmitted among the air guide holes, namely the two-degree-of-freedom air-floating guide rail (1) can realize that one fixed air inlet simultaneously supplies air to an upper air-floating guide rail system and a lower air-floating guide rail system to realize air lubrication, at the moment, the lower guide rail (111) is static on an optical flat plate (30), the sliding blocks (112) to (115) and parts assembled on the sliding blocks can do linear motion (x direction) relative to the guide rail (111), the upper guide rail (121) and parts assembled on the upper guide rail can do linear motion (y direction) relative to the sliding blocks (122) to (125) so that the upper guide rail (121) and the parts can do free motion (y) relative to the optical flat plate (30), and the resistance between the parts can be ignored.
The two air bearing (22) are arranged, the first air bearing is clamped by an air bearing support (24) and an air bearing clamping block (25) and then is installed between a pair of cantilever beams (27), the second air bearing is installed on an optical flat plate (30) in the same clamping mode, a pair of installation arms (21) clamp the rotor of the air bearing (22) from the upper position and the lower position and are fixed with each other, a differential head support (10) is connected with the installation arms (21) after combination, two differential heads (9) are installed at the end part of the differential head support (10) in an opposite-propping mode, the length of the differential heads is adjusted to enable the differential heads to be just clamped with the probes (8) in an opposite-propping mode, and the shortest distance between the axis of the rotor of the previous air bearing and the axis of the differential head is D y The shortest distance between the rotor axis of the last air bearing and the axis of the differential head is D x When high-pressure gas is introduced into the air bearing (22), gas lubrication is formed inside the air bearing, the inner rotor can rotate around the shell with extremely low friction, and correspondingly, the mounting arm (21) and the differential head support (10) which are connected with the rotor can also rotate around the shell.
The two probes (8) are arranged, one of the probes is arranged on the sliding block (114) or other structures fixedly connected with the sliding block (114), the other probe is arranged on the cantilever beam (27) in the drawing, the other probe is arranged on the upper-layer guide rail (121) or other structures fixedly connected with the upper-layer guide rail (121), the probes are arranged on the side surface of the working flat plate (3) in the drawing, and a plurality of inter-beam supports (28) are arranged between the cantilever beams (27) to increase the rigidity of the cantilever beams;
the number of the force sensors (23) is 3, the mounting modes of the first two force sensors are the same, one end of each force sensor is mounted on the sensor support (26), the other end of each force sensor is mounted on the outer side of the mounting arm (21) through a stud, and the shortest distances between the axle centers of the two studs and the axle center of the air bearing rotor are d respectively x ，d y One end of a third force sensor is arranged on the upper surface of the working flat plate (3), the other end of the third force sensor is provided with a cross beam stud (20), the cross beam stud (20) is propped against the lower part of the outer side of the cross beam rotating shaft (6), and the shortest distance between the axis of the cross beam stud (20) and the axis of the cross beam rotating shaft (6) is d z The sensor bracket (26) is clamped on the outer shaft surface of the air bearing;
the testing device is characterized in that through holes are machined in the front end and the tail end of the cross beam (7), a testing object is installed or an auxiliary tool convenient for clamping the testing object is installed in the through hole in the front end, a balance weight is installed in the through hole in the tail end and used for balancing moment on the cross beam, the phenomenon that the stress on a force sensor below the cross beam (7) is too large and exceeds a measuring range is avoided, a space force f is applied to the cross beam by the testing object installed at the front end of the cross beam (7), and the shortest distance between the acting point of the space force f and a rotating shaft of the cross beam (7) is D z 。
The method for accurately measuring the space force based on the device comprises the following processes:
when the space force f is applied to the front end of the cross beam (7), three opposite directions of xyz can be resolved, wherein the component force f in the x direction x The upper guide rail (121) has the tendency of moving in the x direction and generates a tiny displacement, the tiny displacement can make a differential head bracket (10) and a mounting arm (21) which are connected with a differential head (9) generate tiny deflection by taking an air bearing rotor as an axis, and a force sensor (23) at the other side of the mounting arm (21) is stretched or compressed due to the deflection so as to feed back a force F applied on the force sensor x According to the lever principle, the real stress f in the x direction under the balanced state x Calculated by the following method:
the change of the magnitude of the true force value in the x direction before and after f is applied is:
wherein f is x1 And f x0 The actual stress in the x direction before and after F is applied is respectively the value of the stress read by the force sensor before and after F is applied x1 And F x0 Calculating;
similarly, the magnitude of the force value change in the y and z directions is Δ f y And Δ f z ，
Therefore, the resultant force f is:
the angle between the resultant force and the x direction is:
calculating the included angle between the resultant force and the other directions in the same way;
the resolution ratio of the force sensor (23) is delta, and the resolution ratio of the force value of the measuring device in the x direction after the force sensor is amplified by the lever is as follows:
the resolution conversion in the y direction and the z direction is the same, and the leverage further improves the resolution of the measuring device compared with the resolution of the sensor.
The invention has the beneficial effects that: 1. the accurate measurement of the magnitude and the direction of the micro-space force can be realized. The invention provides a measuring method based on a two-degree-of-freedom air-floating guide rail and an air-floating bearing, which decomposes a space force into three orthogonal degrees of freedom, does not influence each other after decomposition, can independently and accurately measure the components, and avoids complicated calibration and decoupling processes.
2. The micro-space force is measured by using a two-degree-of-freedom air-floating guide rail and an air-floating bearing, wherein the air-floating guide rail consists of a guide rail and a sliding block, and the air-floating bearing consists of a rotor at the center and a stator at the outer ring. The air supporting guide rail injects high-pressure gas into gaps between four surfaces of the guide rail and the sliding block through the quick connectors, so that an even air film with extremely strong bearing capacity can be formed in the gaps, the guide rail and the sliding block can be considered to be assembled without contact under the condition of gas lubrication, the direct contact resistance of the guide rail and the sliding block can be ignored, only the pneumatic damping force formed by the air film exists, and the damping force can also be ignored in the low-speed motion process, and the air supporting bearing is the same. Therefore, the air-float force measuring method can make the internal resistance extremely low and approximately zero, and the provided measuring environment is very favorable for realizing high-resolution force measurement.
3. In the measuring process, the air film in the air floatation guide rail and the air film in the air floatation bearing can isolate vibration to a certain extent, and the precision of the measuring device is favorably improved.
Drawings
FIG. 1 is an isometric view of a device of the present invention;
FIG. 2 is a front view of the apparatus of the present invention;
FIG. 3 is a left side view of the apparatus of the present invention;
FIG. 4 is a top view of the apparatus of the present invention;
in the figure, 1, a double-freedom-degree air-floating guide rail, 2, a bracket, 3, a working flat plate, 4, a bearing, 5, a bearing fixture block, 6, a rotating shaft, 7, a cross beam, 8, a probe, 9, a differential head, 10, a differential head bracket, 20, a cross beam stud, 21, a mounting arm, 22, an air-floating bearing, 23, a force sensor, 24, an air-floating bearing bracket, 25, an air-floating bearing fixture block, 26, a sensor bracket, 27, a cantilever beam, 28, an inter-beam bracket, 29, an air-floating guide rail base 30 and an optical flat plate are arranged.
FIG. 5 is an isometric view of a two degree of freedom air bearing rail 1;
FIG. 6 is a partially cut-away isometric view of a two degree-of-freedom air bearing rail 1;
FIG. 7 is a 1/4 cut-away isometric view of upper track 12;
fig. 8 is an isometric view of the lower track 11 from a bottom perspective;
in the figure, 11 is a lower air bearing rail, 12 is an upper air bearing rail, 13 is a quick connector for a tube, 111 is a lower rail, 112 is a slider, 113 is a slider, 114 is a slider, 115 is a slider, 121 is an upper rail, 122 is a slider, 123 is a slider, 124 is a slider, and 125 is a slider.
The specific implementation scheme is as follows:
in the decoupling-free micro-space force accurate measurement device based on the two-degree-of-freedom air-floating guide rail and the air-floating bearing in the embodiment, the whole size of the device is 35cm multiplied by 35cm, the device comprises the two-degree-of-freedom air-floating guide rail, the size of the device is 35cm multiplied by 35cm, a bracket, a working flat plate, a bearing clamping block, a rotating shaft, a cross beam, a probe, a differential head bracket, a cross beam stud, a mounting arm, the air-floating bearing, a force sensor, an air-floating bearing bracket, an air-floating bearing clamping block, a sensor bracket, a cantilever beam, an inter-beam bracket, an air-floating guide rail base and an optical flat plate;
the air-floating guide rail is arranged on the optical flat plate through the air-floating guide rail base, the top of the air-floating guide rail is sequentially provided with the support and the working flat plate, the working flat plate can be clamped with a pair of bearings and fixed through the bearing clamping blocks, the rotating shaft penetrates through the bearings, the cross beam is clamped on the rotating shaft, and the cross beam can freely rotate in an unconstrained state.
The double-freedom-degree air floatation guide rail comprises a lower-layer air floatation guide rail, an upper-layer air floatation guide rail and a quick connector for a pipe;
the lower air-floating guide rail comprises a lower guide rail and four sliding blocks assembled with the lower guide rail, a rectangular open cavity is formed on the inner side of the installed sliding blocks, the lower guide rail can be inserted into the cavity, the upper air-floating guide rail comprises an upper guide rail and another four sliding blocks assembled with the upper guide rail, the rectangular open cavity is formed on the inner side of the installed sliding blocks, the upper guide rail can be inserted into the cavity, and the distance between the two guide rails and the sliding blocks arranged on the periphery of the two guide rails is about 100 mu m.
The center of the upper surface of the upper sliding block of the lower guide rail is provided with a vertically-penetrating air guide hole with the diameter of 3mm, the upper surface of the upper sliding block is provided with two sealing grooves by taking the air guide hole as the center of a circle, the lower air-floating guide rail and the upper air-floating guide rail are filled with a rubber gasket when being installed, the inside of other sliding blocks of the lower guide rail is of a solid structure, a plurality of air guide holes with the diameter of 3mm are processed inside the lower guide rail, the air guide holes are led to the upper front surface and the lower front surface (the surfaces penetrated by the z axis and the y axis) in a divergent mode by taking the inlet position as a starting point, the number of the outlets of the air guide holes on each surface is not less than two, the inlet position is provided with a quick connector for tapping and installing a pipe, the outlet position is provided with a throttling hole with the diameter of a, and besides, the center of the upper surface of the lower guide rail is provided with a vertically-penetrating guide hole with the diameter of 3 mm.
The upper air-floating guide rail is characterized in that air guide holes with the diameter of 3mm are machined in the sliding blocks of the upper air-floating guide rail, the air guide holes in each sliding block are in a shape like a Chinese character 'jing', the air guide holes in the shape like the Chinese character 'jing' can be communicated with each other after the sliding blocks are installed, each air guide hole in the shape like the Chinese character 'jing' is provided with four air hole intersection points, a through hole is formed in one side of the upper air-floating guide rail at the intersection point position, and a throttling small hole with the diameter of 0.16mm is installed at the tail end of the through hole.
The throttling small hole mainly has the function of generating airflow with stable pressure and flow, and an air film is formed between the guide rail and the sliding block.
After the upper air-floating guide rail and the lower air-floating guide rail are connected, an air guide hole in the center of the lower guide rail, an air guide hole in the center of an upper sliding block of the lower air-floating guide rail and an air guide hole in the center of a lower sliding block of the upper air-floating guide rail are basically located on the same axis, a quick joint is used for connecting an air compressor, high-pressure air enters the air-floating guide rail immediately after being introduced into the air-floating guide rail, and the air pressure can be transferred rapidly among the air guide holes, namely the two-degree-of-freedom air-floating guide rail can realize that a fixed air inlet simultaneously supplies air to an upper air-floating guide rail system and a lower air-floating guide rail system to realize air lubrication, at the moment, the lower guide rail is static on an optical flat plate, a sliding block of the lower guide rail and parts assembled on the sliding block of the lower guide rail can do linear motion (x direction) relative to the lower guide rail, the upper guide rail and the parts assembled on the upper guide rail can do free motion in a horizontal plane (x-y) relative to the optical flat plate, and the resistance among the parts which move relative to each other can be ignored under the action of the air-floating guide rail.
The air bearing comprises two air bearing bodies, the first air bearing body is clamped by an air bearing support and an air bearing clamping block and then installed between a pair of cantilever beams, the second air bearing body is installed on the optical flat plate in the same clamping mode, a pair of installation arms clamp rotors of the air bearing bodies from the upper position and the lower position and fix the rotors, a differential head support is connected with the installation arms after combination, two differential heads are installed on the end portions of the differential head support in an opposite mode, the length of the differential heads is adjusted to enable the differential heads to be capable of clamping probes in an opposite mode, and the shortest distance between the axis of the rotor of the previous air bearing body and the axis of the differential head is D y =203mm, and the shortest distance between the rotor axis of the last air bearing and the axis of the differential head is D x =203mm, when high-pressure gas is introduced into the gas bearing, gas lubrication is formed inside the gas bearing, the internal rotor can rotate around the housing with extremely low friction, and correspondingly, the mounting arm and the differential head bracket connected with the rotor can also rotate around the housing.
The two probes are arranged, one of the two probes is arranged on the side sliding block of the lower layer guide rail or other structures fixedly connected with the side sliding block, the other probe is arranged on the cantilever beam in the attached drawing, the other probe is arranged on the upper layer guide rail or other structures fixedly connected with the upper layer guide rail, the side surface of the working flat plate is arranged in the attached drawing, and a plurality of inter-beam supports are arranged between the cantilever beams to increase the rigidity of the cantilever beam.
The number of the force sensors is 3, the first two force sensors are installed in the same mode, one end of each force sensor is installed on the sensor support, the other end of each force sensor is installed on the outer side of the installation arm through a stud, and the shortest distances between the axle centers of the two studs and the axle center of the air bearing rotor are d respectively x ＝9mm，d y =9mm, one end of a third force sensor is arranged on the upper surface of the working flat plate, the other end of the third force sensor is provided with a beam stud, and the beam stud is propped against the lower part of the outer side of the beam rotating shaftThe shortest distance between the axle center of the cross beam stud and the axle center of the cross beam rotating shaft is d z =17mm, the sensor bracket is clamped on the outer axial surface of the air bearing;
through holes are machined in the front end and the tail end of the cross beam, a test object or an auxiliary tool convenient for clamping the test object is installed in the through hole in the front end, a balance weight is installed in the through hole in the tail end and used for balancing the moment on the cross beam, and the phenomenon that the force sensor below the cross beam is excessively stressed is avoided. The test object arranged at the front end of the cross beam applies a space force f to the cross beam, and the shortest distance between the action point of the space force f and the rotating shaft of the cross beam is D z ＝300mm。
When the space force f is applied to the front end of the cross beam, the space force f can be decomposed into three opposite directions of xyz, wherein the component force f in the x direction x The upper guide rail has the tendency of moving in the x direction and generates micro displacement, the micro displacement can cause the differential head bracket and the mounting arm which are connected with the differential head to generate micro deflection by taking the air bearing rotor as the axis, and the force sensor at the other side of the mounting arm can be stretched or compressed due to deflection so as to feed back the stress F on the force sensor x The size of (a) is smaller than (b),
according to the lever principle, the real stress f in the x direction under the balanced state x Can be calculated by the following method:
the change in the magnitude of the true force value in the x direction before and after f is applied is:
wherein f is x1 And f x0 The actual force in the x direction before and after F is applied is respectively obtained by reading F through the force sensor before and after F is applied x1 And F x0 Calculating, similarly, the magnitude of the force value change in the y and z directions is Δ f y And Δ f z ，
Therefore, the resultant force f is:
the angle between the resultant force and the x direction is:
calculating the included angle between the resultant force and the other directions in the same way;
the resolution ratio of the force sensor (23) is delta, and the resolution ratio of the force value of the measuring device in the x direction after the force sensor is amplified by the lever is as follows:
the resolution of the commercial sensor used in the present invention is δ =0.002N, and the resolution of the present invention in the x direction is δ by lever amplification mx ＝0.000088N。
And the resolution in the y direction and the z direction is converted in the same way, and the leverage enables the resolution of the measuring device to be further improved compared with the resolution of the sensor.
Claims (2)
1. A decoupling-free micro-space force accurate measurement device based on a two-degree-of-freedom air-floating guide rail and an air-floating bearing is characterized by comprising the two-degree-of-freedom air-floating guide rail (1), a support (2), a working flat plate (3), a bearing (4), a bearing clamping block (5), a rotating shaft (6), a cross beam (7), a probe (8), a differential head (9), a differential head support (10), a cross beam stud (20), a mounting arm (21), the air-floating bearing (22), a force sensor (23), an air-floating bearing support (24), an air-floating bearing clamping block (25), a sensor support (26), a cantilever beam (27), an inter-beam support (28), an air-floating guide rail base (29) and an optical flat plate (30);
the double-freedom-degree air-floating guide rail (1) is installed on an optical flat plate (30) through an air-floating guide rail base (29), a support (2) and a working flat plate (3) are sequentially installed at the top of the air-floating guide rail (1), a pair of bearings (4) are clamped on the working flat plate (3) and fixed through bearing clamping blocks (5), a rotating shaft (6) penetrates through the bearings, a cross beam (7) is clamped on the rotating shaft, and the cross beam (7) can freely rotate in an unconstrained state;
the two-degree-of-freedom air-floating guide rail (1) comprises a lower air-floating guide rail (11), an upper air-floating guide rail (12) and a quick joint (13) for a pipe;
the lower-layer air-floating guide rail (11) comprises a guide rail (111), a sliding block (112), a sliding block (113), a sliding block (114) and a sliding block (115), wherein a rectangular open cavity is formed in the inner side of the installed sliding blocks (112) to (115), the guide rail (111) is inserted into the cavity, the upper-layer air-floating guide rail (12) comprises a guide rail (121), a sliding block (122), a sliding block (123), a sliding block (124) and a sliding block (125), the rectangular open cavity is formed in the inner side of the installed sliding blocks (122) to (125), the guide rail (121) is inserted into the cavity, and the distance between the guide rail (111) and the guide rail (121) and the sliding blocks installed on the periphery of the guide rail (111) is about 50-100 mu m;
a vertically penetrating air guide hole with the diameter of d = 2-4 mm is processed at the center (116) of the upper surface of a sliding block (112), two sealing grooves are processed at the upper surface (117) by taking the air guide hole as the center of a circle and used for filling a rubber gasket when a lower-layer air-floating guide rail (11) and an upper-layer air-floating guide rail (12) are installed, the sliding blocks (113) to (115) are all of a solid structure, a plurality of air guide holes with the diameter of d = 2-4 mm are processed inside a guide rail (111), the air guide holes are divergently led to the upper front surface, the lower front surface, the upper rear surface and the lower front surface (the surface through which a z axis and a y axis penetrate) by taking an inlet position as a starting point, the number of air guide hole outlets on each surface is not less than two, a quick connector (13) for pipes is tapped at the inlet position and installed at the outlet position, a small throttling hole with the diameter of a = 0.1-0.2.2 mm is installed at the outlet position, and an air guide hole with the diameter of d = 2-4 mm is processed at the center of the upper surface of the guide rail (111);
the inner parts of the sliding blocks (122) to (125) are provided with air guide holes with the diameter d, the shape of each air guide hole in the sliding block is in a shape of a Chinese character 'jing', the air guide holes in the Chinese character 'jing' can be communicated with each other after the sliding blocks (122) to (125) are installed, each air guide hole in the Chinese character 'jing' is provided with four air guide hole intersection points, a through hole with the diameter d = 2-4 mm is opened on one side of a guide rail (121) at the position of the intersection point (126 and the like), a throttling small hole with the diameter a = 0.1-0.2 mm is installed at the tail end of the through hole, besides, a single air guide hole with the diameter d = 2-4 mm communicated with the air guide holes in the Chinese character 'jing' is additionally processed at the center (127) of the lower surface of the sliding block (125), the air guide holes do not penetrate through the sliding block, besides the single air guide holes for installing the throttling small hole and the center processing of the sliding block (125), other air guide holes which have to be processed due to the processing convenience, the design convenience, but exposed in the atmosphere are all tapped and installed and are blocked, the tail ends (128 and the guide holes are distributed as the air guide holes (122) which are reasonably distributed according to the invention, the guide holes are distributed as the guide holes are distributed in the guide holes (111) to be reasonably distributed in the guide rail (111) and the invention, the guide holes are distributed as the guide holes, the invention, the guide holes are distributed in the invention, and can not distributed in the invention: (ii) a
The throttling small hole is mainly used for generating airflow with stable pressure and flow, and an air film is formed between the guide rail and the sliding block;
after the upper-layer air-floating guide rail (12) is connected with the lower-layer air-floating guide rail (11), an air guide hole in the center of the guide rail (111) and an air guide hole in the center of the sliding block (112) are basically positioned on the same axis, a quick joint (13) is used for connecting an air compressor, high-pressure air is introduced into the air-floating guide rail (11) and then enters the air-floating guide rail (12), the air pressure can be rapidly transmitted among the air guide holes, namely the two-degree-of-freedom air-floating guide rail (1) can realize that one fixed air inlet simultaneously supplies air to an upper air-floating guide rail system and a lower air-floating guide rail system to realize air lubrication, at the moment, the lower-layer guide rail (111) is static on an optical flat plate (30), the sliding blocks (112) to (115) and parts assembled on the sliding blocks can do linear motion (x direction) relative to the guide rail (111), the upper-layer guide rail (121) and parts assembled on the upper-layer guide rail can do linear motion (y direction) relative to the sliding blocks (122) to (125), so that the upper-floating guide rail (121) and the parts can do free motion in the horizontal plane (x-y) relative to the optical flat plate (30), and the action of the air-floating guide rail (11) can be ignored;
the two air bearing (22) are arranged, the first one is clamped by an air bearing frame (24) and an air bearing clamping block (25) and then is arranged between a pair of cantilever beams (27), the second one is arranged on an optical flat plate (30) in the same clamping mode, a pair of mounting arms (21) clamp the rotor of the air bearing (22) from the upper position and the lower position and are fixed with each other, a differential head bracket (10) is connected with the combined mounting arm (21), two differential heads (9) are arranged on the end part of the differential head bracket (10) in an opposite-pushing mode, the length of the differential heads is adjusted to enable the differential heads to be just capable of clamping a probe (8) in an opposite-pushing mode, and the shortest distance between the axis of the rotor of the previous air bearing and the axis of the differential head is D y The shortest distance between the rotor axis of the last air bearing and the axis of the differential head is D x When high-pressure gas is introduced into the air bearing (22), gas lubrication is formed inside the air bearing, an internal rotor can rotate around the shell with extremely low friction, and correspondingly, a mounting arm (21) connected with the rotor and the differential head bracket (10) can also rotate around the shell;
the two probes (8) are arranged, one of the probes is arranged on the sliding block (114) or other structures fixedly connected with the sliding block (114), the other probe is arranged on the cantilever beam (27) in the drawing, the other probe is arranged on the upper-layer guide rail (121) or other structures fixedly connected with the upper-layer guide rail (121), the probes are arranged on the side surface of the working flat plate (3) in the drawing, and a plurality of inter-beam supports (28) are arranged between the cantilever beams (27) to increase the rigidity of the cantilever beams;
the number of the force sensors (23) is 3, the mounting modes of the first two force sensors are the same, one end of each force sensor is mounted on the sensor support (26), the other end of each force sensor is mounted on the outer side of the mounting arm (21) through a stud, and the shortest distances between the axle centers of the two studs and the axle center of the air bearing rotor are d respectively x ，d y One end of a third force sensor is arranged on the upper surface of the working flat plate (3), the other end of the third force sensor is provided with a cross beam stud (20), the cross beam stud (20) is propped against the lower part of the outer side of the cross beam rotating shaft (6), and the shortest distance between the axle center of the cross beam stud (20) and the axle center of the cross beam rotating shaft (6) is d z The sensor bracket (26) is clamped on the outer shaft surface of the air bearing;
the front end of the cross beam (7) isThe tail ends of the cross beams are all provided with through holes, the through holes at the front ends of the cross beams are used for installing test objects or auxiliary tools which are convenient for clamping the test objects, the through holes at the front ends of the cross beams are provided with balance weights which are used for balancing the moment on the cross beams, the phenomenon that the stress on a force sensor below the cross beam (7) is too large and exceeds the measuring range is avoided, the test objects installed at the front ends of the cross beams (7) exert a space force f on the cross beams, and the shortest distance from the action points of the space force f to the rotating shaft of the cross beams (7) is D z 。
2. Method for the accurate measurement of spatial forces based on the device according to claim 1, characterized in that the procedure is as follows:
when the space force f is applied to the front end of the cross beam (7), three opposite directions of xyz can be resolved, wherein the component force f in the x direction x The upper layer guide rail (121) has the tendency of moving in the x direction and generates micro displacement, the micro displacement can enable a differential head bracket (10) and a mounting arm (21) which are connected with a differential head (9) to generate micro deflection by taking an air bearing rotor as an axis, and a force sensor (23) at the other side of the mounting arm (21) is stretched or compressed due to deflection so as to feed back a force F on the force sensor x According to the lever principle, the real stress f in the x direction under the equilibrium state x Calculated by the following method:
the change in the magnitude of the true force value in the x direction before and after f is applied is:
wherein f is x1 And f x0 The actual stress in the x direction before and after F is applied is respectively measured, and the value is read by the sensor after F is applied x1 And F x0 Calculating;
similarly, the magnitude of the force value change in the y and z directions is Δ f y And Δ f z ，
Therefore, the resultant force f is:
the angle between the resultant force and the x direction is:
the included angle between the resultant force and the other directions is calculated in the same way.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210840947.8A CN115389081B (en) | 2022-07-18 | 2022-07-18 | Decoupling-free micro-space force accurate measurement device and method based on double-degree-of-freedom air floatation guide rail and air floatation bearing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210840947.8A CN115389081B (en) | 2022-07-18 | 2022-07-18 | Decoupling-free micro-space force accurate measurement device and method based on double-degree-of-freedom air floatation guide rail and air floatation bearing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115389081A true CN115389081A (en) | 2022-11-25 |
| CN115389081B CN115389081B (en) | 2024-04-12 |
Family
ID=84117001
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210840947.8A Active CN115389081B (en) | 2022-07-18 | 2022-07-18 | Decoupling-free micro-space force accurate measurement device and method based on double-degree-of-freedom air floatation guide rail and air floatation bearing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115389081B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103062301A (en) * | 2012-12-19 | 2013-04-24 | 哈尔滨工业大学 | Magnetic suspension vibration isolator of double-layer air-flotation orthogonal decoupling and air-flotation ball bearing angle decoupling |
| CN110836743A (en) * | 2019-10-31 | 2020-02-25 | 南京理工大学 | Thrust vector test bench for main side thrust decoupling |
| WO2021051950A1 (en) * | 2019-09-18 | 2021-03-25 | 马洪文 | Load platform micro displacement measurement method of multi-dimensional force sensor, and measurement sensitive element mounting method |
| CN112576622A (en) * | 2020-11-19 | 2021-03-30 | 西北工业大学 | Air-floating type moving device for short-stroke guide rail air supply |
| CN113029416A (en) * | 2021-04-08 | 2021-06-25 | 哈尔滨工业大学 | Six-dimensional force measuring device based on gas lubrication mechanical decoupling |
-
2022
- 2022-07-18 CN CN202210840947.8A patent/CN115389081B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103062301A (en) * | 2012-12-19 | 2013-04-24 | 哈尔滨工业大学 | Magnetic suspension vibration isolator of double-layer air-flotation orthogonal decoupling and air-flotation ball bearing angle decoupling |
| WO2021051950A1 (en) * | 2019-09-18 | 2021-03-25 | 马洪文 | Load platform micro displacement measurement method of multi-dimensional force sensor, and measurement sensitive element mounting method |
| CN110836743A (en) * | 2019-10-31 | 2020-02-25 | 南京理工大学 | Thrust vector test bench for main side thrust decoupling |
| CN112576622A (en) * | 2020-11-19 | 2021-03-30 | 西北工业大学 | Air-floating type moving device for short-stroke guide rail air supply |
| CN113029416A (en) * | 2021-04-08 | 2021-06-25 | 哈尔滨工业大学 | Six-dimensional force measuring device based on gas lubrication mechanical decoupling |
Non-Patent Citations (3)
| Title |
|---|
| 丁光辉;马炳和;邓进军;苑伟政;: "浮动电容式剪应力微传感器结构设计解析模型", 实验流体力学, no. 03, 15 June 2017 (2017-06-15) * |
| 周欢伟;: "超精密机床气浮导轨的气体润滑研究", 润滑与密封, no. 08, 15 August 2013 (2013-08-15) * |
| 杨洪涛;刘勇;费业泰;陈晓怀;: "三坐标测量机气浮导轨引起的动态误差", 沈阳工业大学学报, no. 01, 18 January 2011 (2011-01-18) * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115389081B (en) | 2024-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108645562B (en) | Three-axis Hopkinson rod synchronous dynamic calibration device and method for three-dimensional impact force sensor | |
| US7010970B2 (en) | Embedded-sensor multi-hole probes | |
| CN108548942A (en) | Hopkinson pressure bar systems and method with true triaxial dynamic load and test function | |
| CN109115510B (en) | Six-component force test bed and error determination method thereof | |
| CN111811817B (en) | High-precision fluid dynamic pressure sliding bearing comprehensive performance test platform | |
| CN109084982A (en) | A kind of high-thrust rocket three axis force measuring device and measuring method | |
| JPH01209301A (en) | Coordinate measuring machine having prove shaft balancing mechanism | |
| CN108592839A (en) | A kind of three coordinate test platform of ultraprecise | |
| US10215675B2 (en) | Universal material tester with quick-release test probe and with reduced cross-talk between the sensors | |
| CN208671936U (en) | A kind of large scale articulated arm coordinate measuring machine | |
| CN109104909B (en) | Guided missile adapter static pressure test apparatus | |
| CN115389081A (en) | Decoupling-free micro-space force accurate measurement device and measurement method based on double-freedom-degree air-floating guide rail and air-floating bearing | |
| CN109613889B (en) | Comprehensive error compensation method of numerical control machine tool on-machine measurement system based on differential transformation | |
| He et al. | Novel compensation method of volumetric errors for micro-coordinate measuring machines using Abbe and Bryan principles | |
| CN108458854B (en) | Three-dimensional stern flow field testing device | |
| CN212806802U (en) | Small-range comparator for measuring space size of precise spherical surface | |
| CN109596295B (en) | Laser absolute calibration device for linear vibration of multi-axial vibration table | |
| CN115855477A (en) | Device and method for testing robot joint performance | |
| US5533380A (en) | Automatic force balance calibration system | |
| CN111623817B (en) | High-precision turntable without magnetic speed | |
| CN108955997A (en) | Inertia force method gas-dynamic pressure laser interferometry system and method | |
| CN214121216U (en) | Inertial measurement unit calibration tool based on three-axis turntable | |
| CN110470416B (en) | Micro-propulsion force measuring system and method for micro-miniature underwater movement device | |
| Nyilas | Transducers for Sub‐Micron Displacement Measurements at Cryogenic Temperatures | |
| US5659141A (en) | Apparatus for measuring minute forces |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |