Large-mass weighing sensing device and method for detecting micro displacement based on capacitive sensor

Abstract

The invention belongs to the technical field of precision measurement, and discloses a large-mass weighing sensing device and method for detecting micro displacement based on a capacitive sensor, and the device comprises an elastic body which is provided with a first elastic groove, a second elastic groove and a third elastic groove, the first elastic groove is communicated with the left side surface of the elastomer, the second elastic groove is communicated with the right side surface of the elastomer, the third elastic groove comprises an upper sub-groove, a middle sub-groove and a lower sub-groove, and a first displacement part and a second displacement part are respectively formed on the left and right sides of the middle sub-groove; the first cantilever is connected with the first displacement part; the second cantilever is connected with the second displacement part; the capacitive displacement sensor is located between the first cantilever and the second cantilever in the vertical direction. According to the embodiment of the invention, the large-mass weighing sensing equipment for detecting the micro displacement based on the capacitive sensor has the advantages of high resolution, wide range and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of precision measurement, and in particular, to a large-mass weighing sensing device and method for detecting micro-displacement based on a capacitive sensor. Background Art

[0002] In scenarios such as transportation and large equipment assembly, it is necessary to weigh relatively large masses with high sensitivity.

[0003] The weighing sensors in the related art include piezoelectric, piezomagnetic, and resistive strain sensors. The resistive strain sensor is used in the large-mass weighing scenario. The resistive strain sensor utilizes the strain resistance effect, that is, the resistance of the material changes under the action of an external force. By detecting the change in the resistance of the material, the measurement of the mass can be achieved. However, the sensitivity of the resistive strain sensor is poor. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a large-mass weighing sensing device for detecting micro-displacement based on a capacitive sensor. The large-mass weighing sensing device for detecting micro-displacement based on a capacitive sensor has the advantages of high resolution and wide range.

[0005] The present invention also proposes a large-mass weighing sensing method for detecting micro-displacement based on a capacitive sensor.

[0006] To achieve the above object, according to an embodiment of the first aspect of the present invention, a large-mass weighing sensing device for detecting micro-displacement based on a capacitive sensor is proposed. The large-mass weighing sensing device for detecting micro-displacement based on a capacitive sensor includes: an elastic body, on which a first elastic groove, a second elastic groove, and a third elastic groove are provided. The first elastic groove, the second elastic groove, and the third elastic groove all penetrate the elastic body in the front-rear direction. The third elastic groove is located between the first elastic groove and the second elastic groove in the up-down direction. The first elastic groove communicates with the left surface of the elastic body, and the second elastic groove communicates with the right surface of the elastic body. The third elastic groove includes an upper sub-groove, a middle sub-groove, and a lower sub-groove. The upper sub-groove and the lower sub-groove both extend in the left-right direction. The lower sub-groove is located below the upper sub-groove. The middle sub-groove extends in the up-down direction and communicates with the upper sub-groove and the lower sub-groove respectively. First displacement portions and second displacement portions are respectively formed on the left and right sides of the middle sub-groove; a first cantilever connected to the first displacement portion; a second cantilever connected to the second displacement portion; and a capacitive displacement sensor located between the first cantilever and the second cantilever in the up-down direction.

[0007] The large-mass weighing and sensing device for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention has advantages such as high resolution and wide range.

[0008] In addition, the large-mass weighing and sensing device for detecting micro-displacement based on a capacitance sensor according to the above embodiment of the present invention may further have the following additional technical features:

[0009] According to an embodiment of the present invention, circular grooves are provided at the right end of the first elastic groove, the left end of the second elastic groove, the left and right ends of the upper sub-groove, and the left and right ends of the lower sub-groove.

[0010] According to an embodiment of the present invention, when a load is applied to the upper surface of the elastic body, the location of the maximum stress in the elastic body is at the right end of the lower sub-groove and the maximum stress value is less than or equal to half of the yield limit of the elastic body material.

[0011] According to an embodiment of the present invention, the upper surface of the elastic body has a loading boss protruding from the upper surface of the elastic body.

[0012] According to an embodiment of the present invention, the first cantilever includes a first vertical section and a first horizontal section, the first vertical section is connected to the first displacement portion, the second cantilever includes a second vertical section and a second horizontal section, the second vertical section is connected to the second displacement portion, and the capacitive displacement sensor is located between the first horizontal section and the second horizontal section.

[0013] According to an embodiment of the present invention, mounting holes are provided on both the first displacement portion and the second displacement portion, and the first cantilever and the second cantilever are respectively mounted on the first displacement portion and the second displacement portion by bolts fitted in the mounting holes.

[0014] According to an embodiment of the present invention, the large-mass weighing and sensing device for detecting micro-displacement based on a capacitance sensor further includes: a mounting base, which is provided on one of the first cantilever and the second cantilever located below; a protective sleeve, which is movably provided up and down on the mounting base, the capacitive displacement sensor is fitted in the protective sleeve and its upper end protrudes upward from the protective sleeve, and a wedge-shaped groove is provided at the connection between the bottom surface and the peripheral surface of the protective sleeve; an adjusting wedge, which is movably provided horizontally on the mounting base and is engaged with the wedge-shaped groove; and a threaded locking member, which is threadedly fitted on the mounting base and is adapted to abut against the protective sleeve.

[0015] According to an embodiment of the present invention, the large-mass weighing and sensing device for detecting micro-displacement based on a capacitance sensor further includes a ground electrode, which is electrically connected to one of the first displacement portion and the second displacement portion.

[0016] According to an embodiment of the present invention, the elastomer is a martensitic precipitation hardening stainless steel material piece.

[0017] According to an embodiment of the second aspect of the present invention, a large-mass weighing sensing method for detecting micro-displacement based on a capacitance sensor is proposed. The large-mass weighing sensing method for detecting micro-displacement based on a capacitance sensor uses the large-mass weighing sensing device for detecting micro-displacement based on a capacitance sensor according to the embodiment of the first aspect of the present invention, and includes the following steps:

[0018] Measure the basic output voltage of the capacitive displacement sensor;

[0019] Measure the gravitational acceleration value at the calibration position of the location where it is located. Load standard weights with different masses on the elastomer, respectively measure the calibration output voltage of the capacitive displacement sensor, calculate the calibration voltage output change value of the capacitive displacement sensor, and draw a relationship curve of the calibration voltage output change value of the capacitive displacement sensor changing with the mass of the standard weight according to the gravitational acceleration value at the calibration position, and fit to obtain the slope of the relationship curve;

[0020] Measure the gravitational acceleration value at the actual position of the location where it is located. Load the heavy object to be measured on the elastomer, measure the actual output voltage of the capacitive displacement sensor, calculate the actual voltage output change value of the capacitive displacement sensor before and after loading the heavy object to be measured, and calculate the mass of the heavy object to be measured according to the slope, the gravitational acceleration value at the actual position, and the actual voltage output change value.

[0021] The large-mass weighing sensing method for detecting micro-displacement based on a capacitance sensor according to the embodiment of the present invention, by using the large-mass weighing sensing device for detecting micro-displacement based on a capacitance sensor according to the embodiment of the first aspect of the present invention, has the advantages of high resolution, wide range, etc.

[0022] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0024] Figure 1 is a schematic structural diagram of a large-mass weighing sensing device for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention.

[0025] Figure 2 is a schematic structural diagram of a large-mass weighing sensing device for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention.

[0026] Figure 3 It is a schematic structural diagram of an elastomer of a large-mass weighing sensing device for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention.

[0027] Figure 4 It is a schematic structural diagram of an elastomer of a large-mass weighing sensing device for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention.

[0028] Figure 5 It is a schematic partial structural diagram of a large-mass weighing sensing device for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention.

[0029] Figure 6 It is a schematic partial structural diagram of a large-mass weighing sensing device for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention.

[0030] Figure 7 It is a schematic partial structural diagram of a large-mass weighing sensing device for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention.

[0031] Figure 8 It is a flowchart of a large-mass weighing sensing method for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention.

[0032] Figure 9 It is a schematic diagram showing the relationship between the load mass and the output voltage difference of a large-mass weighing sensing device for detecting micro-displacement based on a capacitance sensor according to a specific embodiment of the present invention.

[0033] Reference numerals: Large-mass weighing sensing device 1 for detecting micro-displacement based on a capacitance sensor, elastomer 10, first elastic groove 11, second elastic groove 12, third elastic groove 13, upper sub-groove 131, lower sub-groove 132, middle sub-groove 133, circular groove 14, loading boss 15, first displacement part 16, second displacement part 17, first cantilever 21, second cantilever 22, capacitive displacement sensor 30, mounting seat 40, protective sleeve 50, wedge-shaped groove 51, threaded fastener 52, adjusting wedge 60, threaded locking member 70, bolt 80. Detailed Description of the Invention

[0034] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0035] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0036] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0037] Next, a large-mass weighing and sensing device 1 for detecting micro-displacement based on a capacitive sensor according to an embodiment of the present invention will be described with reference to the drawings.

[0038] As Figures 1-8 shown, the large-mass weighing and sensing device 1 for detecting micro-displacement based on a capacitive sensor according to an embodiment of the present invention includes an elastomer 10, a first cantilever 21, a second cantilever 22, and a capacitive displacement sensor 30.

[0039] The elastomer 10 is provided with a first elastic groove 11, a second elastic groove 12, and a third elastic groove 13. The first elastic groove 11, the second elastic groove 12, and the third elastic groove 13 all penetrate the elastomer 10 in the front-rear direction (the up-down, left-right, and front-rear directions are shown by the arrows in the figure). The third elastic groove 13 is located between the first elastic groove 11 and the second elastic groove 12 in the up-down direction. The first elastic groove 11 communicates with the left side surface of the elastomer 10, and the second elastic groove 12 communicates with the right side surface of the elastomer 10. The third elastic groove 13 includes an upper sub-groove 131, a middle sub-groove 133, and a lower sub-groove 132. The upper sub-groove 131 and the lower sub-groove 132 both extend in the left-right direction. The lower sub-groove 132 is located below the upper sub-groove 131. The middle sub-groove 133 extends in the up-down direction and communicates with the upper sub-groove 131 and the lower sub-groove 132 respectively. First displacement portions 16 and second displacement portions 17 are respectively formed on the left and right sides of the middle sub-groove 133.

[0040] The first cantilever 21 is connected to the first displacement portion 16 , and the second cantilever 22 is connected to the second displacement portion 17 .

[0041] The capacitive displacement sensor 30 is located between the first cantilever 21 and the second cantilever 22 in the up-down direction.

[0042] Specifically, since the first elastic groove 11, the second elastic groove 12 and the third elastic groove 13 all penetrate the elastic body 10 in the front-to-back direction, the first elastic groove 11, the second elastic groove 12 and the third elastic groove 13 can make the elastic body 10 more easily elastically deformed. By making the first elastic groove 11 communicate with the left side surface of the elastic body 10 and the second elastic groove 12 communicate with the right side surface of the elastic body 10, the elastic body 10 can be formed into a substantially S-shaped structure. The upper sub-groove 131, the middle sub-groove 133 and the lower sub-groove 132 of the third elastic groove 13 can form an I-shaped groove and make the first displacement portion 16 and the second displacement portion 17 form a motion structure similar to a parallelogram mechanism.

[0043] In this way, after the load is loaded on the upper surface of the elastic body 10, elastic deformation occurs in different directions at the first elastic groove 11 and the second elastic groove 12, so that the force of the load is transmitted to the third elastic groove 13, and the upper sub-groove 131 and the lower sub-groove 132 produce deformation similar to a parallelogram mechanism. The upper sub-groove 131 and the lower sub-groove 132 remain parallel and undergo elastic deformation, so that the first displacement part 16 and the second displacement part 17 produce relative displacement in the up and down directions, and the displacement is related to the gravity of the loaded load. The mass of the loaded load can be calculated by detecting the displacement difference between the first displacement part 16 and the second displacement part 17.

[0044] By setting the first cantilever 21 and the second cantilever 22, the displacement of the first displacement part 16 and the second displacement part 17 can be transmitted to the first cantilever 21 and the second cantilever 22. By setting the capacitive displacement sensor 30 between the first cantilever 21 and the second cantilever 22, the relative displacement of the first cantilever 21 and the second cantilever 22 can be detected, thereby reflecting the relative displacement of the first displacement part 16 and the second displacement part 17, so as to calculate the mass of the loaded load through the detection value of the capacitive displacement sensor 30.

[0045] According to the large-mass weighing and sensing device 1 for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention, by providing an elastic body 10 and arranging a first elastic groove 11, a second elastic groove 12, and a third elastic groove 13 on the elastic body 10, the elastic body 10 can be more easily elastically deformed. When a heavy object to be measured is loaded on the elastic body 10, the gravity can be transmitted to the third elastic groove 13 through the deformation of the first elastic groove 11 and the second elastic groove 12, causing relative displacement in the up-and-down direction between a first displacement portion 16 and a second displacement portion 17 at the third elastic groove 13. By detecting the displacement difference between the first displacement portion 16 and the second displacement portion 17, the mass of the heavy object to be measured can be detected. Compared with the method of directly detecting the mass using a resistive sensor in the related art, the large-mass weighing and sensing device 1 for detecting micro-displacement based on a capacitance sensor does not directly detect the mass of the heavy object to be measured, but reflects the mass of the heavy object to be measured through the magnitude of the displacement generated by the local deformation of the elastic body 10, avoiding the limitation of the detection resolution by the resistive sensor.

[0046] Moreover, by providing a first cantilever 21, a second cantilever 22, and a capacitive displacement sensor 30, the displacement of the first displacement portion 16 and the second displacement portion 17 can be transmitted to the first cantilever 21 and the second cantilever 22 by using the first cantilever 21 and the second cantilever 22, and the relative displacement of the first cantilever 21 and the second cantilever 22 can be detected by the capacitive displacement sensor 30. Thus, the mass of the heavy object to be measured can be calculated based on the detection value of the capacitive displacement sensor 30. Compared with the method of directly detecting the gravity using a resistive sensor, the capacitive displacement sensor 30 has a higher resolution for detecting the deformation displacement of the elastic body 10, which can reach 10 - 7 FS, much higher than 10 -4 FS of the resistive sensor. It can break through the bottleneck of the low resolution of the resistive strain weighing sensor in the related art, improve the detection accuracy and detection accuracy, and has a wider range, a larger detection range, and better applicability.

[0047] Therefore, the large-mass weighing and sensing device 1 for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention has advantages such as high resolution and wide range.

[0048] Next, the large-mass weighing and sensing device 1 for detecting micro-displacement based on a capacitance sensor according to a specific embodiment of the present invention will be described with reference to the accompanying drawings.

[0049] In some specific embodiments of the present invention, as Figures 1-8 shown, the large-mass weighing and sensing device 1 for detecting micro-displacement based on a capacitance sensor according to an embodiment of the present invention includes an elastic body 10, a first cantilever 21, a second cantilever 22, and a capacitive displacement sensor 30.

[0050] Specifically, as Figure 3 andFigure 4 As shown, circular grooves 14 are provided at the right end of the first elastic groove 11, the left end of the second elastic groove 12, the left and right ends of the upper sub-groove 131, and the left and right ends of the lower sub-groove 132. This can further facilitate the elastic deformation of the elastic body 10.

[0051] More specifically, as Figure 4 shown, when a load is applied to the upper surface of the elastic body 10, the location a where the stress is maximum in the elastic body 10 is at the right end of the lower sub-groove 132 and the maximum stress value is less than or equal to half of the yield limit of the material of the elastic body 10. This can prevent the elastic body 10 from undergoing plastic deformation, keep the deformation of the elastic body 10 within the range of elastic deformation, and maintain the correlation between the relative displacement of the first displacement portion 16 and the second displacement portion 17 and the elastic force of the elastic body 10.

[0052] Advantageously, as Figure 3 and Figure 4 shown, the upper surface of the elastic body 10 has a loading boss 15 protruding from the upper surface of the elastic body 10. This can facilitate the application of a load above the elastic body 10, facilitate the downward transmission of the gravity of the heavy object to be measured through the loading boss 15, and avoid errors caused by different positions of the action of the gravity of the heavy object to be measured.

[0053] Even more advantageously, as Figure 1 and Figure 2 shown, the first cantilever 21 includes a first vertical section and a first horizontal section, the first vertical section is connected to the first displacement portion 16, the second cantilever 22 includes a second vertical section and a second horizontal section, the second vertical section is connected to the second displacement portion 17, and the capacitive displacement sensor 30 is located between the first horizontal section and the second horizontal section. This can facilitate the installation of the first cantilever 21 and the second cantilever 22 on the elastic body 10, facilitate the conversion of the relative displacement of the first displacement portion 16 and the second displacement portion 17 into the relative displacement of the first horizontal section and the second horizontal section, and thus facilitate the setting of the capacitive displacement sensor 30 for measurement.

[0054] Furthermore, as Figure 1 and Figure 2 shown, mounting holes are provided on both the first displacement portion 16 and the second displacement portion 17, and the first cantilever 21 and the second cantilever 22 are respectively mounted on the first displacement portion 16 and the second displacement portion 17 by bolts 80 fitted in the mounting holes. This can improve the connection reliability and stability between the cantilever and the elastic body 10.

[0055] Figures 5-7 Illustrated is a large-mass weighing sensing device 1 for detecting micro-displacements based on a capacitive sensor according to some examples of the present invention. As Figures 5-7As shown, the large-mass weighing and sensing device 1 for detecting micro-displacement based on a capacitance sensor further includes a mounting base 40, a protective sleeve 50, an adjusting wedge 60, and a threaded locking member 70. The mounting base 40 is provided on one of the first cantilever 21 and the second cantilever 22 that is located below. The protective sleeve 50 is movably provided up and down on the mounting base 40. The capacitive displacement sensor 30 is fitted inside the protective sleeve 50 and its upper end protrudes upward from the protective sleeve 50. A wedge-shaped groove 51 is provided at the connection between the bottom surface and the circumferential surface of the protective sleeve 50. The adjusting wedge 60 is movably provided horizontally on the mounting base 40 and is engaged with the wedge-shaped groove 51. The threaded locking member 70 is threadedly engaged with the mounting base 40 and is adapted to abut against the protective sleeve 50. In this way, the protective sleeve 50 can be driven to move up and down by moving the adjusting wedge 60, so as to adjust the height of the protective sleeve 50. After the adjustment is in place, the protective sleeve 50 can be locked by tightening the threaded locking member 70. The protective sleeve 50 can play a role in protecting the capacitive displacement sensor 30 and prevent the adjusting wedge 60 and the threaded locking member 70 from damaging the capacitive displacement sensor 30. Thus, it is convenient to adjust the capacitive displacement sensor 30 to a suitable height and ensure the detection accuracy and reliability.

[0056] Specifically, a threaded fastener 52 is threadedly engaged with the protective sleeve 50, and the threaded fastener 52 abuts against the capacitive displacement sensor 30. In this way, the stability of the capacitive displacement sensor 30 inside the protective sleeve 50 can be improved.

[0057] Specifically, the large-mass weighing and sensing device 1 for detecting micro-displacement based on a capacitance sensor further includes a ground electrode, and the ground electrode is electrically connected to one of the first displacement portion 16 and the second displacement portion 17. Specifically, when the ground electrode is electrically connected to the second displacement portion 17, the position of the protective sleeve 50 is adjusted so that the distance between the probe of the capacitive displacement sensor 30 and the second cantilever 22 reaches the maximum range value of the capacitive displacement sensor 30. When the ground electrode is electrically connected to the first displacement portion 16, the distance between the probe of the capacitive displacement sensor 30 and the first cantilever 21 is made close to 0. In this way, the detection accuracy and reliability can be further improved.

[0058] Optionally, the elastomer 10 is a maraging precipitation hardening stainless steel material part. In this way, the elastomer 10 can have good yield strength and is convenient for the elastomer 10 to maintain elastic deformation under load.

[0059] For example, the material used for the elastomer 10 is 17-4PH alloy steel, its Young's modulus is 197 GPa, Poisson's ratio is 0.247, and the yield limit is about 1518 MPa.

[0060] Such as Figure 3As shown, the length L of the elastomer 10 is 80 mm, the width T is 40 mm, and the height H is 68 mm. The radius R1 of the circular groove 14 at the ends of the first elastic groove 11 and the second elastic groove 12 is 5 mm, the radius R2 of the circular groove 14 of the third elastic groove 13 is 4 mm, the distance d1 between the circular groove 14 at the right end of the first elastic groove 11 and the right side of the elastomer 10 is 20 mm, and the distance d2 between the circular groove 14 of the third elastic groove 13 and the first elastic groove 11 is 5 mm. The distance d2 between the circular groove 14 of the third elastic groove 13 and the second elastic groove 12 is 5 mm.

[0061] When the load force is 10000 N, the maximum stress inside the elastomer 10 is about 400 MPa, and the maximum loading force that the large-mass weighing sensing device 1 based on the capacitive sensor for detecting micro-displacement can withstand is greater than 10000 N (about 1000 kg).

[0062] The diameter of the capacitive displacement sensor 30 is 20 mm, the measuring range is 400 μm, and the resolution is as high as 0.25 nm (6.25×10 -7 FS). After the output signal of the capacitive displacement sensor 30 passes through the digital circuit processor, the output voltage signal is in the range of -12 V to 12 V, that is, the corresponding relationship between the displacement of the capacitive displacement sensor 30 and the output voltage signal is 0.06 V per micrometer.

[0063] The linearity of the capacitive displacement sensor 30 is calibrated using standard weights of different masses. Standard weights of grade E1 of 5 g, 50 g, 500 g, and 1000 g are used respectively, and the value of the gravitational acceleration is taken as 9.8 m / s 2 . After the weights are loaded, the relationship between the weight mass and the average difference of the output voltage of the capacitive sensor is as Figure 9 shown.

[0064] It can be seen from the test results that the linearity of the capacitive displacement sensor 30 is good. According to the fitting results, its linear coefficient is 1.5569×10 -3 V / N. Since the measuring range of the large-mass weighing sensing device 1 based on the capacitive sensor for detecting micro-displacement is jointly determined by the characteristics of the elastomer 10 and the measuring range of the capacitive displacement sensor 30, and since the maximum load value that the elastomer 10 can withstand is higher than 10000 N, and according to the maximum measuring range of the capacitive displacement sensor 30, it can be deduced that the maximum load that the capacitive sensor can measure is greater than 15000 N. In summary, the maximum measuring range of the large-mass weighing sensing device 1 based on the capacitive sensor for detecting micro-displacement is greater than 10000 N (about 1000 kg).

[0065] In addition, the resolution of the capacitive displacement sensor 30 is 0.25 nm, and the resolution of the corresponding output voltage value is 1.5×10 -5V, it can be calculated that the resolution of the large-mass weighing sensor device 1 for detecting micro-displacement based on a capacitive sensor can reach 9.63×10 -3 N (9.63×10 -7 FS). It can be seen from this that the weighing sensing method proposed by the present invention can break through the bottleneck of the low resolution of traditional resistive strain weighing sensors.

[0066] The following describes the large-mass weighing sensing method based on capacitive sensor for detecting micro-displacement according to an embodiment of the present invention. The large-mass weighing sensing method based on capacitive sensor for detecting micro-displacement according to an embodiment of the present invention uses the large-mass weighing sensor device 1 for detecting micro-displacement based on capacitive sensor according to the above embodiment of the present invention, and includes the following steps:

[0067] Measure the basic output voltage of the capacitive displacement sensor;

[0068] Measure the gravitational acceleration value at the calibration position of the location, load standard weights with different masses on the elastic body, respectively measure the calibration output voltage of the capacitive displacement sensor, calculate the calibration voltage output change value of the capacitive displacement sensor, and according to the gravitational acceleration value at the calibration position, plot the relationship curve of the calibration voltage output change value of the capacitive displacement sensor changing with the mass of the standard weight, and fit to obtain the slope of the relationship curve;

[0069] Measure the gravitational acceleration value at the actual position of the location, load the measured heavy object on the elastic body, measure the actual output voltage of the capacitive displacement sensor, calculate the actual voltage output change value of the capacitive displacement sensor before and after loading the measured heavy object, and calculate the mass of the measured heavy object according to the slope, the gravitational acceleration value at the actual position and the actual voltage output change value.

[0070] Specifically, the voltage output change value of the capacitive sensor is △U, the slope of the relationship curve of △U changing with the gravity of the standard weight is k, and the gravitational acceleration is g, then the mass m of the loaded heavy object = △U / (kg).

[0071] The large-mass weighing sensing method based on capacitive sensor for detecting micro-displacement according to an embodiment of the present invention, by using the large-mass weighing sensor device 1 for detecting micro-displacement based on capacitive sensor according to the above embodiment of the present invention, has the advantages of high resolution, wide range, etc.

[0072] Specifically, after measuring the basic output voltage of the capacitive displacement sensor 30, it further includes adjusting the position of the capacitive displacement sensor 30 in the up and down directions. This includes using the adjusting wedge 60 to adjust the position of the protective sleeve 50. When the local electrode is electrically connected to the second displacement portion 17, the position of the protective sleeve 50 is adjusted so that the distance between the probe of the capacitive displacement sensor 30 and the second cantilever 22 reaches the maximum range value of the capacitive displacement sensor 30. When the local electrode is electrically connected to the first displacement portion 16, the distance between the probe of the capacitive displacement sensor 30 and the first cantilever 21 is made close to 0. Then, the protective sleeve 50 is fixed using the thread locking member 70.

[0073] For those of ordinary skill in the art, the other components and operations of the large-mass weighing sensing device 1 and method for detecting micro-displacement based on a capacitive sensor according to the embodiments of the present invention are known and will not be described in detail here.

[0074] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. means 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.

[0075] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A large mass weighing sensor device based on a capacitive sensor to detect micro displacement, characterized in that: include: An elastic body, wherein a first elastic groove, a second elastic groove and a third elastic groove are provided on the elastic body, wherein the first elastic groove, the second elastic groove and the third elastic groove all penetrate the elastic body in the front-to-back direction, wherein the third elastic groove is located between the first elastic groove and the second elastic groove in the up-down direction, wherein the first elastic groove is communicated with the left side surface of the elastic body, wherein the second elastic groove is communicated with the right side surface of the elastic body, wherein the third elastic groove comprises an upper sub-groove, a middle sub-groove and a lower sub-groove, wherein the upper sub-groove and the lower sub-groove both extend in the left-right direction, wherein the lower sub-groove is located below the upper sub-groove, wherein the middle groove extends in the up-down direction and is communicated with the upper sub-groove and the lower sub-groove respectively, wherein the left and right sides of the middle groove respectively form a first displacement portion and a second displacement portion; a first cantilever, the first cantilever being connected to the first displacement portion; a second cantilever, the second cantilever being connected to the second displacement portion; A capacitive displacement sensor is located between the first cantilever and the second cantilever in the up-down direction.

2. The large mass weighing sensor device based on a capacitive sensor for detecting micro-displacement according to claim 1 is characterized in that: The right end of the first elastic groove, the left end of the second elastic groove, the left and right ends of the upper sub-groove and the left and right ends of the lower sub-groove are all provided with circular grooves.

3. The large mass weighing sensor device based on a capacitive sensor for detecting micro-displacement according to claim 1 is characterized in that: The elastic body is constructed so that when a load is applied to the upper surface, the maximum stress in the elastic body is located at the right end of the lower sub-groove and the maximum stress is less than or equal to half of the yield limit of the elastic body material.

4. The large mass weighing sensor device based on a capacitive sensor for detecting micro-displacement according to claim 1 is characterized in that: The upper surface of the elastic body is provided with a loading boss protruding from the upper surface of the elastic body.

5. The large mass weighing sensor device based on a capacitive sensor for detecting micro-displacement according to claim 1 is characterized in that: The first cantilever includes a first vertical section and a first horizontal section, the first vertical section is connected to the first displacement portion, the second cantilever includes a second vertical section and a second horizontal section, the second vertical section is connected to the second displacement portion, and the capacitive displacement sensor is located between the first horizontal section and the second horizontal section.

6. The large mass weighing sensor device based on a capacitive sensor for detecting micro-displacement according to claim 1 is characterized in that: The first displacement part and the second displacement part are both provided with mounting holes, and the first cantilever and the second cantilever are respectively mounted on the first displacement part and the second displacement part by bolts fitted in the mounting holes.

7. The large mass weighing sensor device based on a capacitive sensor for detecting micro-displacement according to claim 1 is characterized in that: Also includes: A mounting seat, the mounting seat being disposed on a lower one of the first cantilever and the second cantilever; A protective sleeve, the protective sleeve is movably arranged on the mounting seat, the capacitive displacement sensor is fitted in the protective sleeve and the upper end protrudes upward from the protective sleeve, and a wedge-shaped groove is provided at the connection between the bottom surface and the peripheral surface of the protective sleeve; An adjusting wedge, the adjusting wedge being horizontally movably disposed on the mounting seat and cooperating with the wedge-shaped groove; A thread locking member is threadably engaged with the mounting seat and is adapted to abut against the protection sleeve.

8. The large mass weighing sensor device based on a capacitive sensor for detecting micro-displacement according to claim 1 is characterized in that: A ground electrode is also included, wherein the ground electrode is electrically connected to one of the first displacement portion and the second displacement portion.

9. The large mass weighing sensor device based on a capacitive sensor for detecting micro-displacement according to claim 1 is characterized in that: The elastomer is a martensitic precipitation hardened stainless steel material.

10. A large mass weighing sensing method based on a capacitive sensor to detect micro displacement, characterized in that: The large mass weighing sensor device based on a capacitive sensor for detecting micro-displacement according to any one of claims 1 to 9 comprises the following steps: Measuring a basic output voltage of the capacitive displacement sensor; Measuring the gravity acceleration value of the calibration position of the position, loading standard weights of different masses on the elastic body, measuring the calibration output voltage of the capacitive displacement sensor respectively, calculating the calibration voltage output change value of the capacitive displacement sensor, and drawing a relationship curve between the calibration voltage output change value of the capacitive displacement sensor and the change of the mass of the standard weight according to the gravity acceleration value of the calibration position, and fitting to obtain the slope of the relationship curve; Measure the actual position gravity acceleration value of the position, load the measured weight on the elastic body, measure the actual output voltage of the capacitive displacement sensor, calculate the actual voltage output change value of the capacitive displacement sensor before and after the measured weight is loaded, and calculate the mass of the measured weight according to the slope, the actual position gravity acceleration value and the actual voltage output change value.

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