In-situ calibration device and method for thin film pressure sensor

Abstract

The invention discloses an in-situ calibration device and method for a thin film pressure sensor. The device comprises a sacculus assembly, wherein the sacculus assembly comprises an upper semispherical shell, a lower semispherical shell and a sacculus positioned in the upper semispherical shell and the lower semispherical shell; the hydraulic source is connected with the balloon through a pipeline and used for injecting liquid into the balloon; the detection unit comprises at least one pressure measuring device and a temperature sensor and is used for measuring the pressure and the temperature in the balloon; and the control system is used for controlling operation of the hydraulic source, receiving measurement data of the detection unit and analyzing the measurement data so as to complete calibration of the thin film pressure sensor attached to the inner wall of the lower hemispherical shell. The device can be accurately matched with contact surfaces or mounting positions of film sensors with different shapes and sizes by utilizing the flexibility and self-adaptive deformation capability of the inflatable balloon, so that high-precision in-situ pressure application and calibration are realized.

Description

Technical Field

[0001] This invention relates to the field of in-situ calibration technology for sensors, and specifically to an in-situ calibration device and method for a thin-film pressure sensor. Background Technology

[0002] Thin-film pressure sensors are widely used in wearable devices, robotics, and other fields due to their flexibility and high sensitivity. However, their pressure response is prone to deviation due to material properties, manufacturing process differences, and temperature variations, requiring periodic calibration.

[0003] Traditional calibration methods have significant drawbacks: static methods are suitable for linear sensors, but nonlinear calibration suffers from low accuracy and is difficult to perform on-site; dynamic methods involve bulky equipment, high costs, and may damage the thin film. Existing devices are mostly designed for traditional sensors, with rigid structures that easily damage flexible thin films, and they have low levels of automation, failing to meet the requirements for non-destructive in-situ calibration of thin film sensors. Therefore, a new type of in-situ calibration device is urgently needed. Summary of the Invention

[0004] To address the shortcomings of the aforementioned technologies, this invention first discloses an in-situ calibration device for a thin-film pressure sensor, comprising: A balloon assembly, comprising an upper hemispherical shell, a lower hemispherical shell, and a balloon located within the shell; A hydraulic power source, which is connected to the balloon via a pipe, is used to inject liquid into the balloon; The detection unit includes at least one pressure measuring device and a temperature sensor for measuring the pressure and temperature inside the balloon. The control system controls the operation of the hydraulic source, receives measurement data from the detection unit, and analyzes it to calibrate the thin-film pressure sensor attached to the inner wall of the lower hemispherical shell.

[0005] Furthermore, it also includes a base having mounting holes for securing the balloon assembly to the working surface.

[0006] Furthermore, the upper and lower hemispheres are connected and fixed by bolts, forming a spherical cavity space to ensure that the pressure of the balloon on all parts of the inner wall of the device is basically the same.

[0007] Furthermore, the balloon is made of a high-strength, highly elastic material, which can remain unruptured under certain pressure and ensure uniform pressure distribution.

[0008] Furthermore, the upper hemispherical shell has a pressure gauge mounting hole and a liquid inlet, which is connected to a hydraulic power source via a pipe.

[0009] Further, the control system controls the amount of liquid entering the balloon according to the set test pressure value to achieve accurate calibration of the diaphragm pressure sensor.

[0010] The application also discloses a diaphragm pressure sensor in-situ calibration method, comprising the following steps: Step 1: start the control system and initialize the system, set calibration parameters in the control system according to calibration requirements, set the parameters, turn on the hydraulic source button through the control system, and inject water into the balloon.

[0011] Step 2: the water flow enters the balloon to increase the pressure, at this time the diaphragm sensor and the pressure measuring device will display data; collect the pressure gauge data and the signal output by the diaphragm sensor and deliver the data to the control system for result checking.

[0012] If the result is out of the allowable error range, the calibration result is wrong; if the result is within the allowable error range, the next pressure value calibration operation is entered.

[0013] Step 3: repeat the calibration test under multiple liquid pressure conditions to ensure the accuracy of the calibration result.

[0014] Step 4: the control system adjusts the automatic pressure relief of the balloon and closes the hydraulic source to end the calibration test.

[0015] Further, before starting the control system, the step of checking whether the balloon leaks is further included.

[0016] Further, before the signal is collected, the diaphragm sensor is used to detect whether the pressure increasing process is stable.

[0017] The application has the following beneficial effects: (1) The pressure sensor with calibration is not damaged, and in-situ calibration is realized.

[0018] (2) The balloon assembly adopts a flexible capsule structure, which can be self-adaptively expanded according to the cross-sectional shape of the to-be-calibrated part, avoids local stress concentration, and protects the surface of the part.

[0019] (3) The control system accurately adjusts the in-out pressure source button through real-time feedback of the detection unit.

[0020] (4) The flexible and self-adaptive deformation ability of the inflatable balloon can accurately match the contact surface or installation position of diaphragm sensors of different shapes and sizes, realize high-precision in-situ pressure application and calibration, significantly reduce the cost of purchasing multiple special calibration devices due to the variable installation position and different shapes of diaphragm sensors, and meet the diversified in-situ calibration requirements in complex application scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Structure diagram of a thin-film pressure sensor in-situ calibration device; Figure 2 Top view of a thin-film pressure sensor in-situ calibration base; Figure 3 Flow chart of a thin-film pressure sensor in-situ calibration procedure. DETAILED DESCRIPTION

[0022] The application will be further described in detail with reference to the accompanying drawings and embodiments, which are all simplified schematic diagrams and only show the basic structure of the application in view, thus only show the components related to the application.

[0023] As shown in Figure 1 , the application provides a thin-film pressure sensor in-situ calibration device, mainly including a balloon assembly, a hydraulic source, a detection unit and a control system; the balloon assembly includes a base 1, an upper hemispherical shell 2, a lower hemispherical shell 3, a balloon 7 located in the shell and a fixing device 11, the hydraulic source 4 is connected to the balloon 7 through a pipeline 10, and the balloon 7 is injected with liquid by controlling the pressure source button 9, the detection unit includes a pressure gauge 5 and a temperature sensor 12, and the detection results of the pressure gauge 5 and the temperature sensor 12 are transmitted to the control system for processing and analysis. The hydraulic source 4 injects liquid into the balloon 7 through the pipeline 10, and the control system controls the amount of liquid entering the balloon 7 according to the set test pressure value, so as to realize accurate calibration of the thin-film pressure sensor.

[0024] The upper hemispherical shell 2 and the lower hemispherical shell 3 are fixed by bolts, and form a spherical cavity space, which ensures that the balloon pressure on the inner wall of the device is basically uniform. The upper hemispherical shell 2 is provided with a pressure gauge 5 mounting hole and a liquid inlet 6, and the liquid inlet 6 is connected to the hydraulic source 4 through the pipeline 10.

[0025] As shown in Figure 2 , in some embodiments, the base 1 is provided with a mounting hole 13, which is fixedly connected to the outer side wall of the lower hemispherical shell 3, so as to ensure the stability of the entire calibration device.

[0026] In some embodiments, the balloon 7 is a flexible spherical structure made of high-strength and high-elasticity rubber material, which does not break under a pressure of 2 MPa, and the pressure is uniformly distributed, and has good sealing performance. The measured sensor 8 (thin-film pressure sensor) is tightly attached to the inner wall of the lower hemisphere.

[0027] As shown in Figure 3 , the application provides a thin-film pressure sensor in-situ calibration method, mainly including the following steps: Step 1: When the calibration test starts, tighten the hydraulic source valve, check the balloon air leakage according to the display of the pressure gauge, if the balloon air leakage, replace the balloon, otherwise continue the test.

[0028] Step 2: Start the control system, and set the system initialization, set calibration parameters in the control system according to calibration requirements, complete parameter setting, open the hydraulic source button through the control system, and inject water into the balloon.

[0029] Step 3: Water flow enters the balloon to make the pressure reach 0.1 MPa, at this time, the display of the measured film sensor and the pressure gauge on the balloon will obtain pressure data respectively, and the measured film sensor can detect whether the increasing process of the balloon pressure is stable. Collect the pressure gauge data and the signal output by the film sensor, and deliver the data to the control system for result checking.

[0030] If the measurement error of the sensor exceeds 0.1%, it indicates that the calibration result is wrong; if the result is within the allowable error range, the next calibration operation of the pressure value is entered.

[0031] Step 4: Repeat the calibration test of 0.2 MPa, 0.4 MPa, 0.6 MPa, 0.8 MPa, and 1.0 MPa liquid pressure conditions to ensure the accuracy of the calibration result.

[0032] Step 5: The control system adjusts the automatic pressure relief of the balloon, and closes the hydraulic source, and ends the calibration test.

[0033] The above is the preferred specific embodiment of the present application; however, the protection scope of the present application is not limited to this. Any skilled person in the art can make equivalent replacement or change according to the technical scheme and the improvement concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A thin film pressure sensor in-situ calibration apparatus, characterized by, It comprises: a balloon assembly, which comprises an upper half-sphere shell, a lower half-sphere shell and a balloon located in the sphere shell; a hydraulic source, which is connected with the balloon through a pipeline for injecting liquid into the balloon; a detection unit, which comprises at least one pressure measuring device and a temperature sensor for measuring the pressure and temperature in the balloon; a control system, which is used for controlling the operation of the hydraulic source, receiving the measurement data of the detection unit and analyzing to complete the calibration of the film pressure sensor attached to the inner wall of the lower half-sphere shell.

2. A thin film pressure sensor in-situ calibration device according to claim 1, wherein, It also comprises a base with a mounting hole for fixing the balloon assembly on a working plane.

3. A thin film pressure sensor in-situ calibration device according to claim 1 or 2, characterised in that, The upper half-sphere shell and the lower half-sphere shell are connected and fixed by bolts, forming a spherical cavity space to ensure that the balloon pressure on the inner wall of the device is basically uniform.

4. A thin film pressure sensor in-situ calibration apparatus as claimed in claim 3, wherein, The balloon is made of high-strength and high-elasticity material, which can maintain no rupture under certain pressure and uniform pressure distribution.

5. A thin film pressure sensor in-situ calibration device according to claim 4, wherein, The upper half-sphere shell is provided with a pressure gauge mounting hole and a liquid inlet, and the liquid inlet is connected with the hydraulic source through a pipeline.

6. A thin film pressure sensor in-situ calibration device according to claim 1, wherein, The control system controls the amount of liquid entering the balloon according to the set test pressure value to realize accurate calibration of the film pressure sensor.

7. A method for in-situ calibration of a thin film pressure sensor using the device of any one of claims 1 to 6, characterized in that, It comprises the following steps: Step 1: start the control system and initialize the system, set the calibration parameters in the control system according to the calibration requirements, set the parameters, turn on the hydraulic source button through the control system to inject water into the balloon; Step 2: the water flow enters the balloon to increase the pressure, at this time the film sensor and the pressure measuring device will display the data; collect the pressure gauge data and the signal output by the film sensor and deliver the data to the control system for result checking; If the result is out of the allowable error range, the calibration result is wrong; if the result is within the allowable error range, proceed to the next pressure value calibration operation; Step 3: repeat the calibration test under multiple liquid pressure conditions to ensure the accuracy of the calibration result; Step 4: the control system adjusts the automatic pressure relief of the balloon and closes the hydraulic source to end the calibration test.

8. A method of in-situ calibration of a thin film pressure sensor according to claim 7, wherein, Before starting the control system, it also includes the step of checking whether the balloon leaks.

9. A method of in-situ calibration of a thin film pressure sensor according to claim 7, wherein, Before collecting the signal, the film sensor detects whether the pressure increase process is stable.

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