A strain foot structure and a torque measurement platform

Abstract

The present invention discloses a strain foot structure and a torque measurement platform. The torque measurement platform includes a plurality of strain foot structures and a placement table. The placement table is supported by the plurality of strain foot structures, improving the load capacity of the placement table. Each strain foot structure includes a loading block, a connecting block, and a fixing block; the connecting block includes a horizontal connecting portion and a vertical connecting portion, the horizontal connecting portion and the vertical connecting portion are perpendicularly arranged, and the horizontal connecting portion is connected to one side of the loading block through a horizontal strain beam; the fixing block is arranged below the vertical connecting portion and is connected to the bottom surface of the vertical connecting portion through a vertical strain beam. By means of the horizontal strain beam and the vertical strain beam provided in the strain foot structure, the inter-dimensional coupling is reduced, improving the measurement accuracy of the torque measurement platform. Strain gauges are respectively arranged on the horizontal strain beam and the vertical strain beam, enabling the torque measurement platform to have good low-frequency dynamic characteristics.

Description

Technical Field

[0001] The present invention relates to the field of micro-vibration measurement, and in particular to a strain foot structure and a torque measurement platform. Background Art

[0002] With the continuous development of space telescope technology, higher requirements are imposed on its pointing stability, and thus more stringent requirements are also placed on the micro-vibration index. In order to explore the influence of micro-vibration on large-scale equipment such as telescope systems, it is particularly important to study the disturbance characteristics of its vibration sources. The mass of a space telescope together with its tooling can reach more than one ton, so a torque measurement platform is required to meet the requirements of measuring the vibration sources of large-scale aerospace equipment in terms of accuracy, size, and load capacity.

[0003] At present, for ground measurement of vibration sources, piezoelectric structures are mostly used for disturbance force testing, among which the Stewart configuration is the most commonly used. However, its loose structure will significantly reduce the stiffness of the platform. In addition, the dynamic characteristics of piezoelectric ceramics are very poor at low frequencies, making it difficult to measure low-frequency vibrations well. Moreover, the Stewart configuration has coupling for torque, and decoupling is required during the measurement process, which will inevitably introduce inter-dimensional coupling errors.

[0004] Therefore, how to improve the load capacity and stiffness of the measurement platform, reduce the inter-dimensional coupling of forces, and have good dynamic characteristics at low frequencies is an urgent problem to be solved in the current field of micro-vibration measurement. Summary of the Invention

[0005] In order to overcome the above-mentioned defects in the prior art, the present invention proposes a strain foot structure and a torque measurement platform. The measurement platform has low inter-dimensional coupling and high sensitivity, can largely reduce measurement errors, improve measurement reliability, and can measure the low-frequency disturbance force of large-mass equipment with good characteristics. It can be applied to ground vibration detection of equipment with large mass and high precision requirements such as space telescopes.

[0006] To achieve the above object, the present invention provides the following specific technical solutions:

[0007] In a first aspect, the present invention provides a strain foot structure, including a loading block, a connecting block, a fixing block, and a base;

[0008] At least one first positioning hole is provided on the top surface of the loading block;

[0009] The connecting block is in an L shape, including a horizontal connecting portion and a vertical connecting portion. The horizontal connecting portion and the vertical connecting portion are perpendicularly arranged. The horizontal connecting portion is connected to one side of the loading block through a horizontal strain beam; first strain gauges are respectively provided on the upper and lower sides of the horizontal strain beam;

[0010] The fixed block is arranged below the vertical connecting part and is connected to the bottom surface of the vertical connecting part through a vertical strain beam; second strain gauges are respectively arranged on both sides of the vertical strain beam in the thickness direction; a second positioning hole is also arranged on the fixed block;

[0011] A third positioning hole adapted to the second positioning hole is arranged on the base, and the position of the third positioning hole corresponds to the position of the second positioning hole.

[0012] As an alternative embodiment, the numbers of the connecting blocks, the horizontal strain beams, the vertical strain beams, and the fixed blocks are 4 respectively;

[0013] The 4 connecting blocks are annularly arranged around the loading block. The horizontal connecting part of each connecting block is connected to one side edge of the loading block through a horizontal strain beam, and the included angle between adjacent horizontal strain beams in their length directions is 90°;

[0014] Each fixed block is connected to the vertical connecting part of a connecting block through a vertical strain beam in the vertical direction, and the included angle between adjacent vertical strain beams in their length directions is 90°.

[0015] As an alternative embodiment, the thickness of the horizontal strain beam is less than the thickness of the horizontal connecting part, and / or the thickness of the vertical strain beam is less than the thickness of the vertical connecting part.

[0016] As an alternative embodiment, the first strain gauge is arranged at the midpoint position of the horizontal strain beam in its length direction, and / or the second strain gauge is arranged at the midpoint position of the vertical strain beam in its length direction.

[0017] As an alternative embodiment, an overload protection structure is further included;

[0018] The overload protection structure includes a support column and a circular protection structure. The support column is arranged on the top surface of the base, the circular protection structure is arranged on the support column, and the circular protection structure has a clearance fit with the loading block, the connecting blocks, the fixed blocks, the horizontal strain beams, and the vertical strain beams.

[0019] In a second aspect, the present invention further provides a torque measurement platform, including at least two strain foot structures and a placement table;

[0020] At least two strain foot structures are the strain foot structures as in the first aspect of the present invention;

[0021] The placement table is arranged above the two strain foot structures, and a fourth positioning hole is arranged at the corresponding position of the bottom surface of the placement table to the first positioning hole.

[0022] As an alternative embodiment, the number of the strain foot structures is 4, and the shape of the placement table is rectangular; the 4 strain foot structures are respectively arranged at the 4 corner positions of the placement table.

[0023] As an alternative embodiment, a weight reduction groove is further provided on the bottom surface of the placement table, and a plurality of reinforcing ribs perpendicular to the bottom surface of the placement table are further provided in the weight reduction groove.

[0024] As an alternative embodiment, a counterbore penetrating the placement table in the thickness direction is further provided at the central position of the placement table, and the shape of the counterbore is circular.

[0025] As an alternative embodiment, a fifth positioning hole for fixing the vibration source is further provided on the top surface of the placement table.

[0026] The present invention can achieve the following technical effects:

[0027] The present invention provides a strain foot structure and a torque measurement platform. The torque measurement platform includes a plurality of strain foot structures and a placement table. The placement table is supported by the plurality of strain foot structures, improving the load capacity of the placement table. Each strain foot structure includes a loading block, a connecting block, and a fixing block; the connecting block includes a horizontal connecting portion and a vertical connecting portion, the horizontal connecting portion and the vertical connecting portion are perpendicularly arranged, the horizontal connecting portion is connected to one side of the loading block through a horizontal strain beam; the fixing block is arranged below the vertical connecting portion and is connected to the bottom surface of the vertical connecting portion through a vertical strain beam. By means of the horizontal strain beam and the vertical strain beam provided in the strain foot structure, the inter-dimensional coupling is reduced, improving the measurement accuracy of the torque measurement platform. Strain gauges are respectively arranged on the horizontal strain beam and the vertical strain beam, enabling the torque measurement platform to have good low-frequency dynamic characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of a torque measurement platform according to an embodiment of the present invention;

[0029] Figure 2 is a schematic structural diagram of a strain foot structure according to an embodiment of the present invention;

[0030] Figure 3 is a top view of a placement table according to an embodiment of the present invention;

[0031] Figure 4 is a bottom view of a placement table according to an embodiment of the present invention;

[0032] Figure 5 is a schematic structural diagram of a strain foot structure according to another embodiment of the present invention;

[0033] Figure 6 is a bottom view structural schematic diagram of a strain foot structure according to an embodiment of the present invention;

[0034] Figure 7 is a schematic structural diagram of an overload protection structure according to an embodiment of the present invention;

[0035] Figure 8 It is a schematic structural diagram of a base according to an embodiment of the present invention;

[0036] Figure 9 It is a schematic diagram of the distribution of strain gauges on a certain strain foot structure according to an embodiment of the present invention;

[0037] Figure 10 It is a schematic diagram of a full-bridge circuit according to an embodiment of the present invention;

[0038] Figure 11 It is a finite element analysis diagram of a certain strain foot structure under the force in the first direction according to an embodiment of the present invention;

[0039] Figure 12 It is a finite element analysis diagram of a certain strain foot structure under the force in the second direction according to an embodiment of the present invention;

[0040] Figure 13 It is a finite element analysis diagram of a certain strain foot structure under the force in the third direction according to an embodiment of the present invention.

[0041] Reference numerals:

[0042] 1, placement table;

[0043] 11, counterbore;

[0044] 12, fifth positioning hole;

[0045] 13, fourth positioning hole;

[0046] 14, weight reduction groove;

[0047] 15, reinforcing rib;

[0048] 2, strain foot structure;

[0049] 21, cross strain unit;

[0050] 211, loading block;

[0051] 2110, first vertical strain beam;

[0052] 2111, second vertical strain beam;

[0053] 2112, third vertical strain beam;

[0054] 2113, fourth vertical strain beam;

[0055] 2114, first fixing block;

[0056] 2115, second fixing block;

[0057] 2116, third fixing block;

[0058] 2117, Fourth fixing block;

[0059] 2118, First positioning hole;

[0060] 21141, Second positioning hole;

[0061] 212, First horizontal strain beam;

[0062] 213, Second horizontal strain beam;

[0063] 214, Third horizontal strain beam;

[0064] 215, Fourth horizontal strain beam;

[0065] 216, First connecting block;

[0066] 217, Second connecting block;

[0067] 218, Third connecting block;

[0068] 219, Fourth connecting block;

[0069] 221, Support positioning hole;

[0070] 222, Circular protection structure;

[0071] 231, Third positioning hole;

[0072] 232, Sixth positioning hole;

[0073] 233, Seventh positioning hole;

[0074] 22, Overload protection structure;

[0075] 23, Base;

[0076] 24, Strain gauge;

[0077] 241, First strain gauge;

[0078] 242, Second strain gauge;

[0079] 243, Third strain gauge;

[0080] 244, Fourth strain gauge;

[0081] 245, Fifth strain gauge;

[0082] 246, Sixth strain gauge;

[0083] 247, Seventh strain gauge;

[0084] 248, Eighth strain gauge;

[0085] 249, Ninth strain gauge;

[0086] 2410. Tenth strain gauge;

[0087] 2411. Eleventh strain gauge;

[0088] 2412. Twelfth strain gauge;

[0089] 2413. Thirteenth strain gauge;

[0090] 2414. Fourteenth strain gauge;

[0091] 2415. Fifteenth strain gauge;

[0092] 2416. Sixteenth strain gauge. Specific implementation mode

[0093] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0094] As Figure 2 、 Figure 5 and Figure 6 shown, in the first aspect, the present invention provides a strain foot structure 2, including a loading block 211, a connecting block, a fixing block and a base 23.

[0095] At least one first positioning hole 2118 is provided on the top surface of the loading block 211;

[0096] The connecting block is in an L shape, including a horizontal connecting portion and a vertical connecting portion. The horizontal connecting portion and the vertical connecting portion are perpendicularly arranged. The horizontal connecting portion is connected to one side of the loading block 211 through a horizontal strain beam; first strain gauges are respectively provided on the upper and lower sides of the horizontal strain beam;

[0097] The fixing block is arranged below the vertical connecting portion and is connected to the bottom surface of the vertical connecting portion through a vertical strain beam; second strain gauges are respectively provided on both sides of the vertical strain beam in the thickness direction; a second positioning hole 21141 is further provided on the fixing block;

[0098] A third positioning hole 231 adapted to the second positioning hole 21141 is provided on the base 23, and the position of the third positioning hole 231 corresponds to the position of the second positioning hole 21141.

[0099] In this implementation mode, the number of the first positioning holes 2118 is multiple and they are evenly distributed on the top surface of the loading block 211. For example, the shape of the top surface of the loading block 211 is rectangular, and the number of the first positioning holes 2118 is 4, which are respectively arranged at the 4 corner positions of the top surface of the loading block 211.

[0100] In this embodiment, the thickness direction of the horizontal strain beam and the vertical strain beam within the same strain foot structure 2 are perpendicular to each other in the thickness direction. By arranging the mutually perpendicular strain beams, the effect of reducing the inter-dimensional coupling is achieved, and the measurement accuracy is improved.

[0101] During use, the strain foot structure 2 can be placed at the bottom of the placement table to support the placement table, and the first positioning hole on the top surface of the loading block 211 is matched with the bottom surface of the placement table to achieve the fixation between the two. A vibration source can be placed on the placement table, and strain gauges are provided on the strain beams (horizontal strain beams or vertical strain beams) so that the measurement platform has good low-frequency dynamic characteristics.

[0102] In some embodiments, the numbers of the connecting blocks, horizontal strain beams, vertical strain beams, and fixing blocks are 4 respectively; the 4 connecting blocks are annularly arranged around the loading block, the horizontal connecting part of each connecting block is connected to one side of the loading block through a horizontal strain beam, and the included angle between adjacent horizontal strain beams in their length directions is 90°; each fixing block is connected to the vertical connecting part of a connecting block through a vertical strain beam in the vertical direction, and the included angle between adjacent vertical strain beams in their length directions is 90°. By arranging multiple strain beams, at least two strain gauges are arranged on each strain beam. When external forces in different directions are applied, the strain beams at the corresponding positions are deformed, and accurate judgment can be made by collecting the signal changes output by the strain gauges on the strain beams, thereby improving the measurement progress.

[0103] Preferably, as Figure 8 shown, the shape of the base is a cuboid, and third positioning holes 231 are provided on the 4 side surfaces of the cuboid base, which are respectively matched and fixed with the second positioning holes on the 4 fixing blocks, so as to fix the 4 fixing blocks through one base and prevent relative sliding between the base and the 4 fixing blocks. The fixing method can adopt bolt locking, etc.

[0104] In some embodiments, the thickness of the horizontal strain beam is less than the thickness of the horizontal connecting part, and / or the thickness of the vertical strain beam is less than the thickness of the vertical connecting part. The horizontal strain beam and the vertical strain beam are preferably in the shape of thin plates, so that the small deformation of the strain beam can be made easier, and the measurement accuracy is improved.

[0105] In actual application scenarios, the strain effect of the strain beam can be changed by designing the thickness, height, and width dimensions of the strain beam, thereby affecting the sensitivity of the strain foot. Generally, the smaller the width and thickness of the strain beam and the greater the height, the higher the sensitivity to the deformation change after being stressed. However, since the placement platform for the vibration source needs to be supported by the strain foot structure, a relatively high height and relatively small width and thickness of the strain beam will result in a decrease in the overall stiffness of the measurement platform, that is, a decrease in the load capacity. Therefore, the design dimensions of the strain beam need to be obtained through simulation calculations according to the requirements of stiffness and the resolution of the measurement platform.

[0106] Preferably, the first strain gauge is disposed at the midpoint position of the horizontal strain beam along its length direction, and / or the second strain gauge is disposed at the midpoint position of the vertical strain beam along its length direction. By disposing the first strain gauge at the center position of the horizontal strain beam and the second strain gauge at the center position of the vertical strain beam, the signal changes collected by the strain gauges can be made more uniform when the corresponding strain beam deforms at any position, improving the measurement accuracy.

[0107] In some embodiments, such as Figure 7 , Figure 8 shown, the strain foot structure further includes an overload protection structure 22. The overload protection structure 22 includes a support column and a circular protection structure. The support column is disposed on the top surface of the base, and the circular protection structure is disposed on the support column. There is a clearance fit between the circular protection structure and the loading block, the connecting block, the fixing block, the horizontal strain beam, and the vertical strain beam. Clearance fit means that there is no direct contact during the setting process. The circular protection structure can be a circular disk-shaped, cylindrical, or frustum-shaped structure. For example, Figure 7 the circular protection structure in

[0108] is a circular disk-shaped structure. When a placement platform is installed above the strain foot structure, the overload protection structure 22 of the strain foot structure can play a limiting and protecting role to prevent damage to the strain foot structure due to excessive load. The working principle is as follows: When there is no object placed on the placement platform or the weight of the object placed does not reach the overload requirement, at this time, the top surface or side surface of the circular protection structure 222 does not contact the loading block 211, the connecting block, the fixing block, the horizontal strain beam, and the vertical strain beam. When the object placed on the placement platform is overloaded, the top surface and side surface of the circular protection structure 222 will contact the loading block 211 and the connecting block, playing a limiting and protecting role to prevent damage to the strain foot due to excessive load. To achieve a better protection effect, when the placement platform is not overloaded, the distance between the circular protection structure and the loading block, the connecting block, the fixing block, the horizontal strain beam, and the vertical strain beam is less than the displacement amount that the strain beam can move during the maximum deformation.

[0109] The end face of the support column is provided with a support positioning hole 221, and the top face of the base 23 is further provided with a seventh positioning hole 233. The position where the seventh positioning hole 233 is set corresponds to the position of the support positioning hole 221, and the two can be locked by bolts, so that the overload protection structure 22 can be fixed on the base 23. To enhance the firmness of the overload protection structure, the number of the support positioning hole 221 and the seventh positioning hole 233 is preferably multiple.

[0110] In some embodiments, the top face of the base 23 is further provided with a sixth positioning hole 232. The sixth positioning hole 232 is arranged at the outer edge position of the seventh positioning hole 233 and does not overlap with the seventh positioning hole 233. The sixth positioning hole 232 can be used to fix the strain foot structure 2 on the vibration isolation table.

[0111] As Figure 2 、 Figures 5 - 9 shown, assuming that the direction where the x-axis is located is the first direction, the direction where the y-axis is located is the second direction, and the direction where the z-axis is located is the third direction, and the z-axis is orthogonal to the x-axis and the y-axis.

[0112] The strain foot structure 2 includes a cross strain unit 21, an overload protection structure 22, a base 23, and a strain gauge 24.

[0113] Among them, the cross strain unit 21 includes a loading block 211, a horizontal strain beam, a connecting block, a vertical strain beam, and a fixing block. The horizontal strain beam includes a first horizontal strain beam 212, a second horizontal strain beam 213, a third horizontal strain beam 214, and a fourth horizontal strain beam 215; the connecting block includes a first connecting block 216, a second connecting block 217, a third connecting block 218, and a fourth connecting block 219; the vertical strain beam includes a first vertical strain beam 2110, a second vertical strain beam 2111, a third vertical strain beam 2112, and a fourth vertical strain beam 2113; the fixing block includes a first fixing block 2114, a second fixing block 2115, a third fixing block 2116, and a fourth fixing block 2117.

[0114] Among them, the first positioning hole 2118 is provided on the loading block 211, which is matched with the fourth positioning hole 13 on the placement table 1 and is fixedly connected by bolts. The support positioning hole 221 of the overload protection structure 22 is matched with the seventh positioning hole 233 of the base 23, and the second positioning hole 21141 of the cross strain unit 21 is matched with the third positioning hole 231 of the base 23, and all are fixedly connected by bolts.

[0115] The first horizontal strain beam 212, the second horizontal strain beam 213, the third horizontal strain beam 214, and the fourth horizontal strain beam 215 are annularly distributed around the loading block 211. The first horizontal strain beam 212 is connected between the first side of the loading block 211 and the first connection block 216, the second horizontal strain beam 213 is connected between the second side of the loading block 211 and the second connection block 217, the third horizontal strain beam 214 is connected between the third side of the loading block 211 and the third connection block 218, and the fourth horizontal strain beam 215 is connected between the fourth side of the loading block 211 and the fourth connection block 219. Among them, the first horizontal strain beam 212 and the third horizontal strain beam 214 are distributed in the first direction, and the second horizontal strain beam 213 and the fourth horizontal strain beam 215 are distributed in the second direction.

[0116] The first vertical strain beam 2110 is connected between the first connection block 216 and the first fixed block 2114, the second vertical strain beam 2111 is connected between the second connection block 217 and the second fixed block 2115, the third vertical strain beam 2112 is connected between the third connection block 218 and the third fixed block 2116, and the fourth vertical strain beam 2113 is connected between the fourth connection block 219 and the fourth fixed block 2117.

[0117] Specifically, the first horizontal strain beam 212, the second horizontal strain beam 213, the third horizontal strain beam 214, the fourth horizontal strain beam 215, the first vertical strain beam 2110, the second vertical strain beam 2111, the third vertical strain beam 2112, and the fourth vertical strain beam 2113 in each cross strain unit 21 are all in the shape of thin plates, making it easier for the strain beams to have small deformations. Among them, the first horizontal strain beam 212, the second horizontal strain beam 213, the third horizontal strain beam 214, and the fourth horizontal strain beam 215 will have large strains when subjected to forces in the third direction, the first vertical strain beam 2110 and the third vertical strain beam 2112 will have large strains when subjected to forces in the first direction, and the second vertical strain beam 2111 and the fourth vertical strain beam 2113 will have large strains when subjected to forces in the second direction.

[0118] Specifically, the first strain gauge 241 and the third strain gauge 243 are attached to the first horizontal strain beam 212, the sixth strain gauge 246 and the eighth strain gauge 248 are attached to the second horizontal strain beam 213, the second strain gauge 242 and the fourth strain gauge 244 are attached to the third horizontal strain beam 214, and the fifth strain gauge 245 and the seventh strain gauge 247 are attached to the fourth horizontal strain beam 215. The two strain gauges on each horizontal strain beam are symmetrically distributed with respect to the central plane of the horizontal strain beam in the third direction. Figure 13It can be obtained that when the strain foot structure is subjected to a force in the third direction, the strain of the four horizontal strain beams is the largest and the deformation is the same, and the strain at the position where the strain gauges are attached to the vertical strain beam can be ignored, that is, the coupling in other dimensions is small. In addition, the positions of the strain gauges on the four horizontal strain beams are preferably at the positions with the largest deformation.

[0119] Specifically, a ninth strain gauge 249 and an eleventh strain gauge 2411 are attached to the first vertical strain beam 2110, and a tenth strain gauge 2410 and a twelfth strain gauge 2412 are attached to the third vertical strain beam 2112. The two strain gauges on each vertical strain beam are symmetrically distributed with respect to the central plane of each vertical strain beam in the first direction. From Figure 11 It can be obtained that when the strain foot structure is subjected to a force in the first direction, the strain of the first vertical strain beam 2110 and the third vertical strain beam 2112 is the largest and the deformation is the same, and the strain at the positions where the strain gauges are attached to the four horizontal strain beams, the second vertical strain beam 2111, and the fourth vertical strain beam 2113 can be ignored, that is, the coupling in other dimensions is small. In addition, the positions of the strain gauges on the two vertical strain beams should be at the positions with the largest deformation.

[0120] Specifically, a fourteenth strain gauge 2414 and a sixteenth strain gauge 2416 are attached to the second vertical strain beam 2111, and a thirteenth strain gauge 2413 and a fifteenth strain gauge 2415 are attached to the fourth vertical strain beam 2113. The two strain gauges on each vertical strain beam are symmetrically distributed with respect to the central plane of each vertical strain beam in the second direction. From Figure 12 It can be obtained that when the strain foot is subjected to a force in the second direction, the strain of the second vertical strain beam 2111 and the fourth vertical strain beam 2113 is the largest and the deformation is the same, and the strain at the positions where the strain gauges are attached to the four horizontal strain beams, the first vertical strain beam 2110, and the third vertical strain beam 2112 can be ignored, that is, the coupling in other dimensions is small. In addition, the positions of the strain gauges on the two vertical strain beams should be at the positions with the largest deformation.

[0121] In some embodiments, the first strain gauge 241, the second strain gauge 242, the third strain gauge 243, and the fourth strain gauge 244 form a Figure 10 strain bridge circuit A as shown, and the strain bridge circuit A is used to measure Fz, where Fz represents the force condition in the third direction. The first strain gauge 241, the second strain gauge 242, the third strain gauge 243, and the fourth strain gauge 244 respectively correspond to R1, R2, R3, and R4 in the bridge circuit A.

[0122] The fifth strain gauge 245, the sixth strain gauge 246, the seventh strain gauge 247, and the eighth strain gauge 248 form a Figure 10The shown bridge circuit B, the strain bridge circuit B is used to measure Fz. The fifth strain gauge 245, the sixth strain gauge 246, the seventh strain gauge 247, and the eighth strain gauge 248 respectively correspond to R1, R2, R3, and R4 in the bridge circuit B. The strain bridge circuit B is also used to measure Fz, and Fz represents the force condition in the third direction.

[0123] The ninth strain gauge 249, the tenth strain gauge 2410, the eleventh strain gauge 2411, and the twelfth strain gauge 2412 form the Figure 10 shown strain bridge circuit C. The strain bridge circuit C is used to measure Fx, and Fx represents the force condition in the first direction. The ninth strain gauge 249, the tenth strain gauge 2410, the eleventh strain gauge 2411, and the twelfth strain gauge 2412 respectively correspond to R1, R2, R3, and R4 in the bridge circuit C.

[0124] The thirteenth strain gauge 2413, the fourteenth strain gauge 2414, the fifteenth strain gauge 2415, and the sixteenth strain gauge 2416 form the Figure 10 shown strain bridge circuit D. The strain bridge circuit D is used to measure Fy, and Fy represents the force condition in the second direction. The thirteenth strain gauge 2413, the fourteenth strain gauge 2414, the fifteenth strain gauge 2415, and the sixteenth strain gauge 2416 respectively correspond to R1, R2, R3, and R4 in the bridge circuit D.

[0125] Based on the above embodiments, the cross-shaped strain unit 21 can be an integrally formed structure. For example, it can be integrally machined from a whole piece of material, which can avoid the gaps and hysteresis phenomena caused by combined assembly, and improve the service life and measurement accuracy of the strain foot.

[0126] Based on the above embodiments, each strain foot structure 2 can measure two Fz, one Fx, and one Fy through the 4 horizontal strain beams and 4 vertical strain beams provided thereon (if it is a dynamic disturbing force, the force is a function of time, and it is discrete data points after sampling). In the actual application process, 4 strain foot structures 2 can be set to sample data simultaneously to obtain 8 Fz, 4 Fx, and 4 Fy. Then, through experimental data acquisition and optimization algorithms, several optimal force combinations can be selected from 8 Fz, 4 Fx, and 4 Fy to solve the disturbing force of the vibration source, so that the calculated disturbing force has the smallest error with the actual vibration. The calculation formula is as follows:

[0127] F(ω) = D(ω)V(ω);

[0128] This equation is for solving the six - dimensional force in space. It is necessary to calibrate D(ω) through experiments. During calibration, F(ω) and V(ω) are known. F(ω) is the input six - dimensional force in space, and V(ω) is the output of 6 selected channels (more than six is also possible, but it will introduce systematic errors). Now there are 12 redundant output forces. Selecting different combinations of 6 channels will result in different calculation accuracies. The criteria for judging accuracy are as follows: When the error between F(ω) obtained by substituting D(ω) and V(ω) into the equation and the original input force is minimized, the output of these 6 channels is the optimal combination. Thereafter, the output of these six channels will be used for the calculation of the six - dimensional force.

[0129] In a second aspect, as Figure 1 、 Figure 3 and Figure 4 shown, the present invention also provides a torque measurement platform, including at least two strain foot structures 2 and a placement table 1; at least two strain foot structures are the strain foot structures 2 as in the first aspect of the present invention; the placement table 1 is arranged above the two strain foot structures, and a fourth positioning hole 13 is provided at the corresponding position of the bottom surface of the placement table 1. The fourth positioning hole 13 is used to cooperate with the first positioning hole 2118 on the loading block 211 of the strain foot structure 2 to fix the strain foot structure 2 to the bottom of the placement table 1, so as to support the placement table 1.

[0130] Preferably, the number of strain foot structures is 4, and the shape of the placement table is rectangular; the 4 strain foot structures are respectively arranged at the 4 corner positions of the placement table. Such a distribution method can effectively improve the fundamental frequency (stiffness) of the measurement platform.

[0131] As Figure 4 shown, a weight - reducing groove 14 is further provided on the bottom surface of the placement table 1, and multiple reinforcing ribs 15 perpendicular to the bottom surface of the placement table 1 are further provided in the weight - reducing groove 14. Preferably, a counterbore 11 penetrating the placement table in the thickness direction is further provided at the center position of the placement table 1, and the shape of the counterbore 11 is circular. The reinforcing ribs 15 can be arranged between the two groove walls of the weight - reducing groove 14, or can be arranged between the groove wall of the weight - reducing groove 14 and the outer edge of the counterbore 11. The multiple reinforcing ribs 15 can be arranged in an array or staggered, effectively reducing the overall mass of the measurement platform while enhancing the overall stiffness of the measurement platform.

[0132] In some embodiments, a fifth positioning hole 12 for fixing a vibration source is further provided on the top surface of the placement table 1. The number of the fifth positioning holes 12 is preferably multiple, distributed around the counterbore 11. The set position of the positioning hole 12 corresponds to the position of the positioning hole on the vibration source, and the two can be locked by bolts. The vibration source can be a vibration source such as a momentum wheel or a flywheel.

[0133] The present invention provides a strain foot structure and a torque measurement platform. The torque measurement platform mainly includes a placement table and 4 strain foot structures; the strain foot structure includes a cross strain unit, an overload protection structure, a base, and strain gauges; the cross strain unit includes a loading block, a horizontal strain beam, a connecting block, a vertical strain beam, and a fixing block; the strain foot structure is fixedly connected to the placement table; the overload protection structure and the cross strain unit are fixedly connected to the base; the loading block is used to connect the placement table and the strain foot structure, the horizontal strain beam is connected between the loading block and the connecting block, the vertical strain beam is connected between the connecting block and the fixing block, and the fixing block is connected to the base; the placement table is supported by 4 strain foot structures, improving the load capacity of the measurement platform; by setting strain beams perpendicular to each other, the effect of reducing inter-dimensional coupling is achieved, improving the measurement accuracy of the platform. Strain gauges are provided on the strain beams, enabling the platform to have good low-frequency dynamic characteristics; the strain beams are designed as thin plates, and the installation positions of the strain gauges are set as the regions with the largest deformation when the strain foot structure is stressed in three directions. In addition, a Wheatstone full-bridge circuit is used for subsequent processing, improving the measurement sensitivity of the platform. Through experiments and optimization algorithms, several optimal forces are selected from the redundant output forces of the 4 strain foot structures for the calculation of the vibration source disturbing force, improving the measurement accuracy of the platform; the overload protection structure ensures the overall safety of the measurement platform during the measurement process.

[0134] In the description of this specification, the descriptions referring to terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0135] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0136] The above specific embodiments of the present invention do not constitute a limitation to the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A strain foot structure, characterized in that, Comprising: A loading block, on the top surface of which there is provided at least one first positioning hole; A connecting block, shaped like an L, including a horizontal connecting portion and a vertical connecting portion, the horizontal connecting portion and the vertical connecting portion are perpendicularly arranged, the horizontal connecting portion is connected to one side of the loading block through a horizontal strain beam; on the upper and lower sides of the horizontal strain beam, there are respectively provided first strain gauges; A fixing block, arranged below the vertical connecting portion and connected to the bottom surface of the vertical connecting portion through a vertical strain beam; on the two sides of the vertical strain beam along the thickness direction, there are respectively provided second strain gauges; on the fixing block, there is also provided a second positioning hole; A base, on which there is provided a third positioning hole adapted to the second positioning hole, and the position of the third positioning hole corresponds to the position of the second positioning hole; The thickness of the horizontal strain beam is less than the thickness of the horizontal connecting portion, and / or the thickness of the vertical strain beam is less than the thickness of the vertical connecting portion.

2. The strain foot structure according to claim 1, wherein, The number of the connecting blocks, horizontal strain beams, vertical strain beams, and fixing blocks is 4 respectively; The 4 connecting blocks are annularly arranged around the loading block, the horizontal connecting portion of each connecting block is connected to one side edge of the loading block through one horizontal strain beam, and the included angle between adjacent horizontal strain beams in their length direction is 90°; Each fixing block is connected to the vertical connecting portion of a connecting block through one vertical strain beam in the vertical direction, and the included angle between adjacent vertical strain beams in their length direction is 90°.

3. The strain foot structure according to claim 1 or 2, characterized in that, The first strain gauge is arranged at the midpoint position of the horizontal strain beam along its length direction, and / or the second strain gauge is arranged at the midpoint position of the vertical strain beam along its length direction.

4. The strain foot structure according to claim 1, wherein Further comprising: An overload protection structure, including a support column and a circular protection structure, the support column is arranged on the top surface of the base, the circular protection structure is arranged on the support column, and there is a clearance fit between the circular protection structure and the loading block, the connecting block, the fixing block, the horizontal strain beam, and the vertical strain beam.

5. A torque measurement platform, characterized in that, Comprising: At least two strain foot structures, which are the strain foot structures as described in any one of claims 1 to 4; A placement table, arranged above the two strain foot structures, and at the corresponding position of the first positioning hole on the bottom surface of the placement table, there is provided a fourth positioning hole.

6. The torque measurement platform according to claim 5, wherein, The number of the strain foot structures is 4, and the shape of the placement table is rectangular; the 4 strain foot structures are respectively arranged at the 4 corner positions of the placement table.

7. The torque measurement platform according to claim 5, wherein On the bottom surface of the placement table, there is also provided a weight reduction groove, and in the weight reduction groove, there are also provided multiple reinforcing ribs perpendicular to the bottom surface of the placement table.

8. The torque measurement platform according to any one of claims 5 to 7, characterized in that At the center position of the placement table, there is also provided a counterbore penetrating the placement table along the thickness direction, and the shape of the counterbore is circular.

9. The torque measurement platform according to any one of claims 5 to 7, characterized in that On the top surface of the placement table, there is also provided a fifth positioning hole for fixing a vibration source.

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