Pressure sensor and method for adaptively adjusting force arm

Abstract

The invention discloses a pressure sensor and method for adaptively adjusting a force arm. The pressure sensor comprises a strain sensor, a driving unit and a control unit, the strain sensor is located between the first flange plate and the second flange plate, one end of the bottom of the strain sensor is connected with the second flange plate in a spaced mode, a strain gage is arranged on the side face of the strain sensor, the top of the strain sensor is connected with the bottom of the first flange plate through a reciprocating lead screw structure, and the reciprocating direction is the length direction of the strain gage. The driving unit is connected with a lead screw in the reciprocating lead screw structure; the control unit comprises a data processing unit and a digital-to-analog conversion unit, the input end of the data processing unit is connected with the output end of the strain gauge, the data processing unit is connected with the digital-to-analog conversion unit, and the output end of the data processing unit is connected with the signal input end of the driving unit. The arm of force of the pressure sensor can be changed, thereby controlling the range of output signals of the pressure sensor and improving the sensitivity of the pressure sensor.

Description

Technical Field

[0001] The invention belongs to the field of pressure detection, and relates to a pressure sensor and a method for adaptively adjusting a force arm. Background Art

[0002] As the demand for pressure sensors in the market gradually increases, higher requirements are also placed on pressure sensors. Traditional pressure sensors measure pressure by measuring the deformation of elastic elements, and due to the limitation of elasticity, the output signal pressure of the pressure sensor when it is under pressure is usually within a fixed range, and the sensitivity is a fixed value, which cannot meet the pressure measurement in various application scenarios. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a pressure sensor and method with adaptively adjustable force arm, which can change the force arm of the pressure sensor, thereby controlling the range of the pressure sensor output signal and improving the sensitivity of the pressure sensor.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A pressure sensor with an adaptively adjustable force arm comprises a first flange plate, a strain sensor, a second flange plate, a driving unit and a control unit; The strain sensor is located between the first flange plate and the second flange plate, one end of the bottom of the strain sensor is connected to the second flange plate and is arranged at intervals, a strain gauge is arranged on the side of the strain sensor, the top of the strain sensor is connected to the bottom of the first flange plate by a reciprocating screw structure, the reciprocating direction is the length direction of the strain gauge, and the driving unit is connected to the screw in the reciprocating screw structure; The control unit includes a data processing unit and a digital-to-analog conversion unit. The input end of the data processing unit is connected to the output end of the strain gauge, the data processing unit is connected to the digital-to-analog conversion unit, and the output end of the data processing unit is connected to the signal input end of the drive unit.

[0005] Preferably, the reciprocating screw structure includes a screw rod, a slider and a slide rail, the slide rail is located at the top of the strain sensor, the top of the slider is connected to the bottom of the first flange plate, the bottom of the slider is slidably connected to the slide rail, the screw rod is arranged outside the strain sensor, the end of the screw rod is connected to the drive unit, and the screw rod is threadedly connected to the slider, and the direction of the screw rod and the direction of the slide rail are both the length direction of the strain gauge.

[0006] Furthermore, the driving unit adopts an electric motor.

[0007] Furthermore, a screw flange plate is installed on the motor, the screw flange plate is fixed to the end of the strain sensor, the motor output shaft passes through the screw flange plate, and the free end of the motor output shaft is connected to the screw end by a coupling.

[0008] Furthermore, a first cushion block is arranged between the first flange plate and the sliding block.

[0009] Furthermore, the top of the first cushion block is fixed to the first flange plate by screws, and the bottom of the first cushion block is fixed to the sliding block by screws.

[0010] Furthermore, a second cushion block is arranged between one end of the bottom of the strain sensor and the second flange plate.

[0011] Furthermore, the digital-to-analog conversion unit adopts an ADC module.

[0012] Furthermore, the data processing unit adopts MCU.

[0013] A method for adaptively adjusting the force arm of the pressure sensor includes the following steps: The object to be measured is placed on the first flange plate, and the strain gauge collects the deformation variable generated by the current object and transmits it to the data processing unit. The data processing unit calculates the analog signal generated by the current deformation variable, and the digital-to-analog conversion unit converts the current output signal into a digital signal, which is the measured pressure data; At the same time, the data processing unit calculates the signal-to-noise ratio of the current output signal and determines whether the value of the current signal-to-noise ratio is within a normal range. If the signal-to-noise ratio exceeds the set range, the data processing unit controls the drive unit to drive the reciprocating screw structure to move the first flange plate toward the fixed end of the strain sensor, thereby reducing the force arm of the pressure sensor until the signal-to-noise ratio reaches within the set range. If the signal-to-noise ratio is less than the set range, the data processing unit controls the drive unit to drive the reciprocating screw structure to move the first flange plate toward the loading end of the strain sensor to reduce the force arm of the pressure sensor until the signal-to-noise ratio reaches the set range.

[0014] Compared with the prior art, the present invention has the following beneficial effects: In the present application, the top of the strain sensor is connected to the bottom of the first flange plate through a reciprocating screw structure, and the driving unit is connected to the screw in the reciprocating screw structure. The driving unit drives the reciprocating screw structure to move the first flange plate back and forth between the loading end and the fixed end on the strain sensor, thereby adjusting the size of the force arm of the pressure sensor. The strain gauge collects the deformation variable generated by the current object and transmits it to the data processing unit. The data processing unit calculates the analog signal generated by the current deformation variable, and the digital-to-analog conversion unit converts the current output signal into a digital signal, which is the measured pressure data; at the same time, the signal-to-noise ratio of the current output signal is calculated by the data processing unit, and it is determined whether the current signal-to-noise ratio value is within a normal range. If the signal-to-noise ratio is large, it will cause signal distortion and affect the measurement accuracy of the pressure sensor. It is necessary to change the signal-to-noise ratio of the pressure sensor by reducing the force arm of the pressure sensor. If the signal-to-noise ratio is small, the noise interference is too large, and it is necessary to increase the force arm of the pressure sensor to enhance the signal, thereby changing the output signal, thereby improving the sensitivity of the pressure sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a front view of the pressure sensor structure of the adaptively adjustable force arm of the present invention; Figure 2 It is a rear view of the pressure sensor structure of the adaptive adjustment lever arm of the present invention; Figure 3 It is a schematic diagram of the internal structure of the control unit of the present invention; Figure 4 It is a structural schematic diagram of the pressure sensor adjustment process of the present invention; Figure 5 FIG. 5 is a schematic diagram of the internal principle of the strain gauge 5 of the pressure sensor of the present invention during movement.

[0016] 1-first flange plate, 2-slider, 3-slide rail, 4-strain sensor, 5-strain gauge, 6-second flange plate, 7-first cushion block, 8-second cushion block, 9-motor, 10-screw flange plate, 11-control unit, 12-ADC module, 13-MCU. DETAILED DESCRIPTION

[0017] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0018] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are 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, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms "installed", "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, an electrical connection, or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" used in this article includes any and all combinations of one or more related listed items. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0020] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0021] The present application embodiment provides a schematic diagram of a pressure sensor structure for adaptively adjusting a force arm, such as Figure 1 , Figure 2Shown are the front view and rear view of a pressure sensor with an adaptively adjustable force arm. The pressure sensor mainly includes: a first flange plate 1, a slider 2, a slide rail 3, a strain sensor 4, a strain gauge 5, a second flange plate 6 and a driving structure.

[0022] The strain gauge 5 is attached to the side of the strain sensor 4 by adhesive bonding. A groove is provided in the strain sensor 4 corresponding to the strain gauge 5 , and the strain gauge 5 is arranged in the groove.

[0023] The slide rail 3 is arranged on the top of the strain sensor 4 and fixed by screws. The slider 2 is slidably connected above the slide rail 3. The first flange plate 1 and the second flange plate 6 are respectively arranged above and below the strain sensor 4 for placing the object to be measured.

[0024] A pad is provided in the pressure sensor for buffering the pressure when measuring an object, and includes a first pad 7 and a second pad 8. The first pad 7 is located between the first flange plate 1 and the slider 2. The top of the first pad 7 is fixed to the first flange plate 1 by screws, and the bottom is fixed to the slider 2 by screws. According to the above-mentioned fixed structure, the first flange plate 1, the first pad 7 and the slider 2 are connected as a whole. Since the slider 2 is slidably connected above the slide rail 3, the whole can be adjusted and moved through the slide rail 3. The position of the slider 2 on the strain sensor 4 is the loading end of the strain sensor 4.

[0025] The second pad 8 is located between the second flange plate 6 and the strain sensor 4, wherein the top screws of the second flange plate 6 are fixed to the bottom of the second pad 8, and the top of the second pad 8 is fixed to the bottom of one end of the strain sensor 4. The connection position serves as the fixed end of the strain sensor 4, and the top of the strain sensor 4 is fixedly connected to the slide rail 3. According to the above fixed structure, the second flange plate 6, the second pad 8, the strain sensor 4 and the slide rail 3 are connected as a whole.

[0026] The driving structure includes a driving unit and a control unit 11. In this embodiment, the driving unit is a motor 9, which is used to control the slider 2 to move on the slide rail 3. The control unit 11 is connected to the motor 9, and a screw flange plate 10 is installed on the motor 9. The screw flange plate 10 is fixed to the end of the strain sensor 4 and is not connected to the first flange plate 1, the first cushion block 7 and the slider 2. The output shaft of the motor 9 passes through the screw flange plate 10. The free end of the output shaft of the motor 9 is connected to a screw through a coupling. The screw is arranged outside the strain sensor 4, and the screw is threadedly connected to the slider 2. The direction of the screw is consistent with the direction of the slide rail 3. The screw, the slider 2 and the slide rail 3 form a reciprocating screw structure. The rotation of the motor 9 controls the slider 2 to move linearly along the slide rail 3, thereby changing the position of the slider 2 at the top of the strain sensor 4.

[0027] like Figure 3The figure shows the internal schematic diagram of the control unit 11. The control unit 11 includes a data processing unit and a digital-to-analog conversion unit. The digital-to-analog conversion unit is an ADC module 12 (Analog-to-digital converter) module, which is used to convert the output analog signal of the pressure sensor when it is under pressure into a digital signal. The data processing unit in this embodiment is an MCU 13 (Microcontroller Unit), which can also be a microcontroller, etc., which is not specifically limited in this embodiment. The input end of the MCU 13 is connected to the output end of the strain gauge 5, the MCU 13 is connected to the ADC module 12, and the output end of the MCU 13 is connected to the signal input end of the motor 9. The MCU 13 is used to control the movement of the motor 9 and is also used to process the output signal of the pressure sensor, so as to perform adaptive adjustment of the force arm. According to the pressure sensor with adaptive adjustment arm proposed in the above embodiment, the specific implementation principle includes: placing the object to be measured on the first flange plate 1 of the pressure sensor, the strain gauge 5 collects the deformation variable generated by the current object and transmits it to the control unit 11, the MCU13 in the control unit 11 calculates the analog signal generated by the current deformation variable, and the ADC module 12 converts the current output signal into a digital signal, which is the measured pressure data. At the same time, the signal-to-noise ratio of the current output signal is calculated by MCU13, and the signal-to-noise ratio is the ratio of the signal to the noise. And determine whether the value of the current signal-to-noise ratio is within the normal range. If the signal-to-noise ratio is large and exceeds the set range, it will cause signal distortion and affect the measurement accuracy of the pressure sensor. It is necessary to change the signal-to-noise ratio of the pressure sensor by reducing the arm of the pressure sensor. The MCU13 controls the motor 9 to rotate, and drives the slider 2 to move along the slide rail 3 toward the fixed end of the strain sensor 4 through the screw until the signal-to-noise ratio reaches the set range.

[0028] If the signal-to-noise ratio is small, less than the set range, the noise interference is too large, and the force arm of the pressure sensor needs to be increased to enhance the signal, thereby changing the output signal and improving the sensitivity of the pressure sensor. At this time, the MCU 13 controls the motor 9 to rotate, and drives the slider 2 to move along the slide rail 3 to the opposite end of the fixed end of the strain sensor 4 through the screw rod until the signal-to-noise ratio reaches the set range.

[0029] According to the above working principle, when the signal-to-noise ratio of the pressure sensor is not within the normal range, it is necessary to adjust the force arm of the pressure sensor. The specific adjustment process includes: controlling the motor 9 through the MCU13 in the control unit 11, and the motor 9 controls the movement of the slider 2. In this embodiment, the movement of the slider 2 will cause the force arm to change, thereby changing the signal-to-noise ratio of the pressure sensor when the same object is subjected to force, adjusting the output signal, and thereby improving the sensitivity of the pressure sensor during operation.

[0030] According to the working principle of the pressure sensor in the above embodiment, Figure 4The figure shows the structure of the sensor movement process. The motor 9 drives the slider 2, the first flange plate 1, and the first cushion block 7 to move along the slide rail 3. Figure 3 The current position shown, the force arm of the pressure sensor changes.

[0031] In this embodiment, move to Figure 4 When the position is Figure 5 The figure shows a schematic diagram of the specific internal principle of the strain gauge 5. The length of the strain gauge 5 of the pressure sensor is L, that is, when the slider 2 of the pressure sensor is in the initial position, the length of the strain gauge 5 is the force arm L1. A pressure F is applied to the pressure sensor. At this time, the deformation variable X1 of the strain gauge 5 caused by F is L1tanα, α is the angle between the strain gauge 5 before and after the deformation when the force arm length is L1, and the voltage value output by the pressure sensor under the current deformation can be obtained as V1; the slider 2 is moved from the original position by ΔL through the motor 9. At this time, the force arm length of the strain gauge 5 is L2, L2=L1-ΔL, and then a force F of the same magnitude is applied to the pressure sensor. At this time, the deformation variable X2 of the strain gauge 5 caused by F is L2tanβ, β is the angle between the strain gauge 5 before and after the deformation when the force arm length is L2, and the voltage value output by the pressure sensor under the current deformation can be obtained as V2.

[0032] According to the lever principle, if the same equilibrium condition needs to be achieved, according to the formula F×L1=F×L2, the vector product of the two forces and their lever arms should be the same. If the deformation of the strain gauge 5 is the same, then when the slider 2 moves and the lever arm decreases, a greater force must be applied. That is, in the above embodiment, the forces applied twice are both F, but the lever arm length L1>L2, so X1>X2 can be obtained, that is, the deformation under the same force becomes smaller after the slide rail 3 moves, so V1≠V 2， Therefore, when the same force is applied twice, the voltage signal transmitted by the pressure sensor in the present application is different, that is, the output signal is different after adjusting the force arm, thus achieving the purpose of changing the output signal range of the pressure sensor by adjusting the force arm.

[0033] In summary, the adaptively adjustable pressure sensor proposed in the present application controls the motor 9 to drive the slider 2 to move, thereby changing the force arm of the pressure sensor when the pressure sensor is subjected to the same pressure, thereby changing the range of the pressure sensor output signal and improving the sensitivity of the pressure sensor.

[0034] The present application proposes a pressure sensor with an adaptively adjustable force arm, wherein the strain gauge 5 is glued into the strain sensor 4; the slide rail 2 and the strain sensor 4 are fixed by screws; the slider 2 is located above the slide rail 3; a drive unit is installed on the slider 2, and the movement of the slider 2 on the slide rail 3 is controlled by the drive unit. When the pressure sensor is subjected to pressure, the digital-to-analog conversion unit is used to convert the analog signal output by the pressure sensor into a digital signal, and the data processing unit is used to control the drive unit and process the pressure sensor data, and adaptively change the force arm of the pressure sensor according to the signal output by the pressure sensor, thereby controlling the range of the pressure sensor output signal and improving the sensitivity of the pressure sensor.

[0035] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0036] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0037] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0038] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0039] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

[0040] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this patent should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A pressure sensor with an adaptively adjustable lever arm, characterized in that: It comprises a first flange plate (1), a strain sensor (4), a second flange plate (6), a drive unit and a control unit (11); The strain sensor (4) is located between the first flange plate (1) and the second flange plate (6); one end of the bottom of the strain sensor (4) is connected to the second flange plate (6) and is arranged at an interval; a strain gauge (5) is arranged on the side of the strain sensor (4); the top of the strain sensor (4) is connected to the bottom of the first flange plate (1) by a reciprocating screw structure, the reciprocating direction is the length direction of the strain gauge (5); and the drive unit is connected to the screw in the reciprocating screw structure; The control unit (11) comprises a data processing unit and a digital-to-analog conversion unit, the input end of the data processing unit is connected to the output end of the strain gauge (5), the data processing unit is connected to the digital-to-analog conversion unit, and the output end of the data processing unit is connected to the signal input end of the drive unit.

2. The pressure sensor with adaptively adjustable force arm according to claim 1, characterized in that: The reciprocating screw structure comprises a screw, a slider (2) and a slide rail (3), wherein the slide rail (3) is located at the top of the strain sensor (4), the top of the slider (2) is connected to the bottom of the first flange plate (1), the bottom of the slider (2) is slidably connected to the slide rail (3), the screw is arranged outside the strain sensor (4), the end of the screw is connected to the drive unit, and the screw is threadedly connected to the slider (2), and the direction of the screw and the direction of the slide rail (3) are both the length direction of the strain gauge (5).

3. The pressure sensor for adaptively adjusting the force arm according to claim 2, characterized in that: The driving unit adopts a motor (9).

4. The pressure sensor for adaptively adjusting the force arm according to claim 3, characterized in that: A screw flange plate (10) is mounted on the motor (9), the screw flange plate (10) is fixed to the end of the strain sensor (4), the output shaft of the motor (9) passes through the screw flange plate (10), and the free end of the output shaft of the motor (9) is connected to the end of the screw by a coupling.

5. The pressure sensor with adaptively adjustable force arm according to claim 2, characterized in that: A first cushion block (7) is arranged between the first flange plate (1) and the sliding block (2).

6. The pressure sensor with adaptively adjustable force arm according to claim 5, characterized in that: The top of the first cushion block (7) is fixed to the first flange plate (1) by means of screws, and the bottom of the first cushion block (7) is fixed to the sliding block (2) by means of screws.

7. The pressure sensor with adaptively adjustable force arm according to claim 1, characterized in that: A second cushion block (8) is provided between one end of the bottom of the strain sensor (4) and the second flange plate (6).

8. The pressure sensor with adaptively adjustable force arm according to claim 1, characterized in that: The digital-to-analog conversion unit adopts an ADC module (12).

9. The pressure sensor with adaptively adjustable force arm according to claim 1, characterized in that: The data processing unit adopts MCU (13).

10. A method for adaptively adjusting the force arm of a pressure sensor according to any one of claims 1 to 9, characterized in that: The process includes: The object to be measured is placed on the first flange plate (1), the strain gauge (5) collects the deformation variable generated by the current object and transmits it to the data processing unit, the data processing unit calculates the analog signal generated by the current deformation variable, and the digital-to-analog conversion unit converts the current output signal into a digital signal, which is the measured pressure data; At the same time, the data processing unit calculates the signal-to-noise ratio of the current output signal and determines whether the value of the current signal-to-noise ratio is within a normal range. If the signal-to-noise ratio exceeds the set range, the data processing unit controls the drive unit to drive the reciprocating screw structure to move the first flange plate (1) toward the fixed end of the strain sensor (4) to reduce the force arm of the pressure sensor until the signal-to-noise ratio reaches within the set range. If the signal-to-noise ratio is less than a set range, the data processing unit controls the drive unit to drive the reciprocating screw structure to move the first flange plate (1) toward the loading end of the strain sensor (4) to reduce the force arm of the pressure sensor until the signal-to-noise ratio reaches within the set range.

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