A sensor calibration device and method based on three-dimensional pressure decoupling

Abstract

This invention discloses a sensor calibration device and method based on three-dimensional pressure decoupling. It solves the problem that traditional impact calibration devices can only provide impact loads in a single direction and cannot simulate the complex stress state of sensors under the combined action of normal pressure, tangential pressure and confining pressure in real working conditions. This invention uses multiple three-dimensional decoupling components with adjustable tilt angles and a standard force sensor at the bottom to accurately decompose the single axial impact force provided by systems such as drop hammers into normal and tangential forces acting on the sensitive surface of the pressure sensor to be calibrated. Combined with the confining pressure provided by the three-dimensional pressure chamber, it can simultaneously reproduce the multi-dimensional stress state of the pressure sensor in a real soil and rock environment in one system, realizing the performance calibration of one-dimensional sensors under multi-dimensional force coupling.

Description

Technical Field

[0001] This invention relates to a sensor calibration device and method, specifically to a sensor calibration device and method based on three-dimensional pressure decoupling. Background Technology

[0002] In geotechnical engineering, structural health monitoring, and dynamic load testing, sensors are frequently used to measure dynamic responses under complex stress states. Especially under transient loads such as explosions and impacts, sensors are subjected not only to the normal (sensitive axis) impact force but also to the combined effects of tangential force and confining pressure, resulting in significant inter-axis coupling interference in the measurement signal. This multi-dimensional force coupling effect severely impacts the accuracy and reliability of the sensor output, particularly for one-dimensional force sensors, whose output signal struggles to accurately reflect the actual load in a single direction.

[0003] Currently, calibration and decoupling methods for multidimensional force sensors mainly include synchronous loading systems based on Hopkinson bars and static calibration systems. For example, existing technologies use a combination of Hopkinson bars and artificial neural networks to apply triaxial impact forces in different directions to the sensor, achieving synchronous decoupling calibration of multidimensional forces. However, these methods are complex, costly, and difficult to assess multidimensional force interference in one-dimensional sensors under real confining pressure environments. Furthermore, traditional impact calibration devices often only provide impact loads in a single direction, failing to simulate the complex stress state of sensors under the combined effects of normal pressure, tangential pressure, and confining pressure in real-world conditions. Especially in soil and rock media, the sensor's measurement surface is often subjected to asymmetric, multi-directional stress waves, and existing calibration systems struggle to effectively reproduce such multidimensional coupled load environments, leading to significant errors and insufficient reliability in practical applications.

[0004] Therefore, there is an urgent need for a three-dimensional pressure decoupling device that is compact in structure, easy to operate, and capable of simulating real multidimensional stress states. Summary of the Invention

[0005] To address the technical problem that traditional impact calibration devices can only provide impact loads in a single direction and cannot simulate the complex stress state of sensors under the combined action of normal pressure, tangential pressure, and confining pressure in real working conditions, this invention provides a sensor calibration device and method based on three-dimensional pressure decoupling.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A sensor calibration device based on three-dimensional pressure decoupling is characterized by comprising a three-dimensional pressure chamber, a standard confining pressure sensor, an axial pressure rod, a three-dimensional decoupling assembly, a standard force sensor, and a water supply unit.

[0008] The three-dimensional pressure chamber is provided with a first threading hole, an exhaust hole, a water injection hole and a pressure transmission hole, with the exhaust hole located at the top of the three-dimensional pressure chamber;

[0009] The standard confining pressure sensor is installed on the side wall of the three-dimensional pressure chamber, and its sensitive surface is located inside the three-dimensional pressure chamber.

[0010] One end of the axial pressure rod is located outside the three-dimensional pressure chamber, and the other end is slidably inserted vertically through the top of the three-dimensional pressure chamber into the three-dimensional pressure chamber.

[0011] The three-dimensional decoupling assembly comprises multiple sets; in use, one set is installed in the middle of the bottom of the three-dimensional pressure chamber; each set of three-dimensional decoupling assemblies includes a lower force decoupling block and an upper force decoupling block arranged sequentially from bottom to top; the upper end of the upper force decoupling block is fitted onto the bottom end of the axial pressure rod; the pressure sensor to be calibrated is placed between the lower force decoupling block and the upper force decoupling block; the angle between the top surface of the lower force decoupling block and the horizontal plane is the same as the angle between the bottom surface of the upper force decoupling block and the horizontal plane, denoted as angle θ, which ranges from [0°, 90°); the angle θ corresponding to different three-dimensional decoupling assemblies is different;

[0012] The standard force sensor is located between the bottom surface of the lower force decoupling block and the bottom of the three-dimensional pressure chamber. The cables of the standard force sensor and the pressure sensor to be calibrated both pass through the first wire hole and exit the three-dimensional pressure chamber.

[0013] The water supply unit is connected to the three-dimensional pressure chamber through a water injection hole and is used to supply water into the three-dimensional pressure chamber.

[0014] Furthermore, the bottom surface of the lower force decoupling block is provided with an upwardly recessed first groove and a first wire groove that are interconnected;

[0015] The standard force sensor is set in the first groove, and its cable is led out from the bottom surface of the lower force decoupling block through the first wire groove.

[0016] The depth of the first groove is less than the thickness of the standard force sensor, so that the bottom surface of the standard force sensor protrudes from the bottom surface of the lower force decoupling block.

[0017] Furthermore, the top surface of the lower force decoupling block is provided with a second groove and a second line groove that are recessed downward and interconnected;

[0018] The bottom surface of the upper force decoupling block is provided with an upwardly recessed third groove;

[0019] The sum of the depths of the second groove and the third groove is less than the thickness of the pressure sensor to be calibrated, so that when the pressure sensor to be calibrated is installed between the second groove and the third groove, there is a gap between the top surface of the lower force decoupling block and the bottom surface of the upper force decoupling block.

[0020] The second cable groove is provided in multiple ways to lead out the cable of the pressure sensor to be calibrated from between the lower force decoupling block and the upper force decoupling block in different directions.

[0021] Furthermore, the three-dimensional pressure chamber includes a cylindrical pressure chamber body, a base disposed at the bottom of the pressure chamber body, and a top cover disposed at the top of the pressure chamber body;

[0022] The first wire hole is located on the top cover, and a first cable seal is provided inside the first wire hole;

[0023] The pressure transmission hole is located on the base;

[0024] The cables of the standard force sensor and the pressure sensor to be calibrated are sealed and led out to the outside of the three-dimensional pressure chamber through the first cable sealer;

[0025] The top cover is also provided with a central hole, and the other end of the axial pressure rod passes through the central hole into the three-dimensional pressure chamber.

[0026] Furthermore, it also includes an image acquisition module located within a three-dimensional pressure chamber;

[0027] The top cover is provided with a second wire hole, and a second cable seal is provided in the second wire hole;

[0028] The image acquisition module is installed at the bottom of the top cover, and its working end corresponds to the gap between the top surface of the lower force decoupling block and the bottom surface of the upper force decoupling block. Its cable is sealed and led out to the outside of the three-dimensional pressure chamber through the second cable sealer.

[0029] Furthermore, it also includes bushings and snap rings;

[0030] The bottom of the top cover is provided with a first annular groove around the central hole;

[0031] The outer diameter of the bushing matches the diameter of the central hole. The outer wall of the bushing is provided with a convex ring and a second annular groove. The convex ring is located near the bottom end of the bushing. The bushing passes through the central hole, so that the convex ring and the first annular groove engage with each other, and the second annular groove is located outside the top cover.

[0032] The snap ring is engaged in the second annular groove, and its outer diameter is larger than the diameter of the central hole, so that the top cover is confined between the snap ring and the convex ring.

[0033] The axial compression rod passes through the bushing tube.

[0034] Furthermore, the inner hole of the bushing is a two-stage stepped hole, which includes a small hole, a tapered hole and a large hole arranged sequentially from bottom to top, with the small end of the tapered hole facing downwards;

[0035] A preload nut and a first sealing ring are fitted between the large hole and the axial pressure rod. The preload nut is threaded to the bushing tube, and the first sealing ring is located in the large hole and / or tapered hole at the bottom of the preload nut.

[0036] The outer wall of the axial compression rod is provided with a third annular groove, and a second sealing ring is provided in the third annular groove.

[0037] Furthermore, the second groove includes four grooves, which are respectively arranged around the edge of the second groove, and the included angle α between two adjacent second grooves is 30°.

[0038] Furthermore, the three-dimensional pressure chamber, the axial pressure rod, and the three-dimensional decoupling assembly are all made of the same material.

[0039] A sensor calibration method based on three-dimensional pressure decoupling, employing the aforementioned sensor calibration device based on three-dimensional pressure decoupling, is characterized by including the following steps:

[0040] Step 1: Place a set of three-dimensional decoupling components into the three-dimensional pressure chamber, place the pressure sensor to be calibrated between the lower force decoupling block and the upper force decoupling block, and seal its cable through the first wire hole.

[0041] Step 2: Inject water into the three-dimensional pressure chamber through the water supply unit until water overflows from the vent hole. Then, close the water supply unit and seal the water injection hole and vent hole.

[0042] Step 3: Apply pressure to the water in the three-dimensional pressure chamber through the pressure transmission hole in the three-dimensional pressure chamber, and monitor the confining pressure in real time through a standard confining pressure sensor to maintain the preset confining pressure value.

[0043] Step 4: Apply a vertically downward axial impact force to the axial compression rod at a preset impact height. The axial impact force is transmitted to the pressure sensor to be calibrated through the axial compression rod and the upper force decoupling block, and then to the standard force sensor through the lower force decoupling block.

[0044] Step 5: Obtain the peak force output from the standard force sensor. Calculate the sensitivity C of the pressure sensor to be calibrated using the peak voltage V output by the pressure sensor to be calibrated:

[0045]

[0046] Where S is the sensitive surface area of ​​the pressure sensor to be calibrated;

[0047] Step 6: Establish a set of parameters including included angle θ, preset impact height, preset confining pressure, and peak force. The data correspondence between the sensitivity C and the sensitivity C;

[0048] Step 7: Replace the next set of three-dimensional decoupling components to change the included angle θ, and / or change the preset confining pressure value, and / or change the preset impact height, and return to step 1 until a preset number of data correspondences are established, thus completing the calibration of the pressure sensor to be calibrated.

[0049] The beneficial effects of this invention are:

[0050] 1. The present invention provides a sensor calibration device and method based on three-dimensional pressure decoupling. Through multiple three-dimensional decoupling components with adjustable tilt angles and a standard force sensor at the bottom, the single axial impact force provided by the drop hammer and other systems is accurately decomposed into normal force and tangential force acting on the sensitive surface of the pressure sensor to be calibrated. Combined with the confining pressure provided by the three-dimensional pressure chamber, the multi-dimensional stress state of the pressure sensor in the real soil and rock environment can be reproduced simultaneously in one system, realizing the performance calibration of one-dimensional sensor under multi-dimensional force coupling.

[0051] 2. The present invention provides a sensor calibration device and method based on three-dimensional pressure decoupling. The entire three-dimensional decoupling component is integrated in a three-dimensional pressure chamber, which is compact in structure. Multiple sets of three-dimensional decoupling components are set based on different included angles θ, so that the entire calibration device can be flexibly switched to suit different calibration requirements.

[0052] 3. The present invention provides a sensor calibration device and method based on three-dimensional pressure decoupling. Multiple second grooves are provided on the top surface of the lower force decoupling block, so that the pressure sensor to be calibrated can be installed between the lower force decoupling block and the upper force decoupling block at different angles according to the requirements, so that the calibration environment is more consistent with the actual environment and the accuracy of the calibration results is improved.

[0053] 4. The present invention provides a sensor calibration device based on three-dimensional pressure decoupling. An image acquisition module is also set in the three-dimensional pressure chamber. It can monitor the pressure sensor to be calibrated in real time when impact testing is carried out under confining pressure of 0-2MPa or even higher. This more realistically simulates the working state of the pressure sensor in deep rock and soil or underwater environment, and the calibration results are more meaningful for engineering guidance.

[0054] 5. The present invention provides a sensor calibration device based on three-dimensional pressure decoupling, wherein a bushing and a retaining ring are provided on the top cover, and a convex ring and a second annular groove are provided on the outer wall of the bushing. The retaining ring is engaged in the second annular groove, thereby limiting the top cover between the retaining ring and the convex ring, so that the relative position of the bushing and the top cover is fixed, and the bushing can provide interference-free guidance for the axial pressure rod, making the pressure decoupling more accurate and improving the accuracy of the calibration results. Attached Figure Description

[0055] Figure 1 This is a cross-sectional view of an embodiment of a three-dimensional pressure decoupling sensor calibration device according to the present invention;

[0056] Figure 2 This is a schematic diagram of the lower force decoupling block in an embodiment of the present invention.

[0057] The attached figures are labeled as follows:

[0058] 1. Three-dimensional pressure chamber; 11. First through hole; 12. Pressure transmission hole; 13. Pressure chamber body; 14. Base; 15. Top cover; 151. Center hole; 16. First cable seal; 17. Second through hole; 18. Second cable seal; 19. First annular groove; 2. Standard confining pressure sensor; 3. Axial pressure rod; 31. Third annular groove; 4. Three-dimensional decoupling assembly; 41. Lower force decoupling block; 411. Second groove; 412. Second cable groove; 42. Upper force decoupling block; 5. Standard force sensor; 6. Water supply unit; 7. Pressure sensor to be calibrated; 8. Image acquisition module; 9. Bushing; 91. Convex ring; 92. Second annular groove; 93. Preload nut; 94. First sealing ring; 10. Snap ring. Detailed Implementation

[0059] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] This invention provides a sensor calibration device based on three-dimensional pressure decoupling, such as... Figure 1 As shown, the sensor calibration device includes a three-dimensional pressure chamber 1, a standard confining pressure sensor 2, an axial pressure rod 3, a three-dimensional decoupling assembly 4, a standard force sensor 5, and a water supply unit 6; the three-dimensional pressure chamber 1, the axial pressure rod 3, and the three-dimensional decoupling assembly 4 are made of the same material.

[0061] The three-dimensional pressure chamber 1 includes a cylindrical pressure chamber body 13, a base 14 disposed at the bottom of the pressure chamber body 13, and a top cover 15 disposed at the top of the pressure chamber body 13. The top cover 15 is provided with a first wire through hole 11, a vent hole, and a central hole 151. A first cable seal 16 is provided in the first wire through hole 11. A first annular groove 19 is provided around the bottom of the top cover 15 around the central hole 151. A bushing 9 is provided in the central hole 151. The outer diameter of the bushing 9 matches the diameter of the central hole 151, and a protruding ring 91 is provided on the outer wall of the bushing 9. The second annular groove 92 and the convex ring 91 are located near the bottom end of the bushing tube 9. The bushing tube 9 passes through the central hole 151, so that the convex ring 91 engages with the first annular groove 19, and the second annular groove 92 is located outside the top cover 15. A retaining spring 10 is provided in the second annular groove 92. The outer diameter of the retaining spring 10 is larger than the diameter of the central hole 151, so that the top cover 15 is limited between the retaining spring 10 and the convex ring 91. The inner hole of the bushing tube 9 is a two-stage stepped hole, which includes a small hole, a tapered hole and a large hole arranged sequentially from bottom to top, with the small end of the tapered hole facing downward.

[0062] The base 14 is provided with a pressure transmission hole 12; the pressure chamber body 13 is provided with a water injection hole.

[0063] An image acquisition module 8 is installed inside the three-dimensional pressure chamber 1; a second wiring hole 17 is provided on the top cover 15, and a second cable sealer 18 is provided inside the second wiring hole 17; the image acquisition module 8 is installed at the bottom of the top cover 15, and its cable is sealed and led out to the outside of the three-dimensional pressure chamber 1 through the second cable sealer 18. In this embodiment, the image acquisition module 8 is a waterproof camera, and an acrylic plate protective cover is provided outside the waterproof camera to prevent the camera from being damaged by the pressure and to ensure normal operation under a pressure of 2MPa.

[0064] Both the first cable seal 16 and the second cable seal 18 are tubular cable seals to ensure no leakage under a confining pressure of 2 MPa. The tubular cable harness seal achieves cable sealing by tightening the rubber sealing gasket with threads, facilitating quick replacement of the corresponding sensor.

[0065] The standard confining pressure sensor 2 is installed on the side wall of the pressure chamber body 13, and its sensitive surface is located inside the three-dimensional pressure chamber 1.

[0066] One end of the axial pressure rod 3 is located outside the three-dimensional pressure chamber 1, and the other end is slidably inserted into the three-dimensional pressure chamber 1 in a vertical direction through the bushing tube 9; a preload nut 93 and a first sealing ring 94 are fitted between the large hole in the bushing tube 9 and the axial pressure rod 3. The preload nut 93 is threadedly connected to the bushing tube 9, and the first sealing ring 94 is located in the large hole and / or tapered hole at the bottom of the preload nut 93; a third annular groove 31 is provided on the outer wall of the axial pressure rod 3, and a second sealing ring is provided in the third annular groove 31.

[0067] The three-dimensional decoupling assembly 4 includes multiple sets; in use, one set is installed in the middle of the inner bottom of the three-dimensional pressure chamber 1; each set of three-dimensional decoupling assembly 4 includes a lower force decoupling block 41 and an upper force decoupling block 42 arranged sequentially from bottom to top; the upper end of the upper force decoupling block 42 is fitted outside the bottom end of the axial pressure rod 3 to ensure a stable force transmission path; the bottom surface of the lower force decoupling block 41 has an upwardly recessed and interconnected first groove and a first wire groove; the standard force sensor 5 is set in the first groove, and its cable is led out from the bottom surface of the lower force decoupling block 41 through the first wire groove and sealed to the outside of the three-dimensional pressure chamber 1 by the first cable sealer 16; the depth of the first groove is less than the thickness of the standard force sensor 5, so that the bottom surface of the standard force sensor 5 protrudes from the bottom surface of the lower force decoupling block 41; the standard force sensor 5 is set between the bottom surface of the lower force decoupling block 41 and the inner bottom of the three-dimensional pressure chamber 1, and its cable passes through the first wire hole 11 to the outside of the three-dimensional pressure chamber 1. Figure 2 As shown, the top surface of the lower force decoupling block 41 is provided with a downwardly recessed and interconnected second groove 411 and a second groove 412. The lower force decoupling block 41 is also provided with four countersunk holes for fixing to the base 14 by bolts. The bottom surface of the upper force decoupling block 42 is provided with an upwardly recessed third groove. The second groove 411 and the third groove correspond to each other and are used to place the pressure sensor 7 to be calibrated. Therefore, their shapes match the shape of the pressure sensor 7 to be calibrated, ensuring effective transmission of impact force. The sum of the depths of the second groove 411 and the third groove is less than the thickness of the pressure sensor 7 to be calibrated, so that when the pressure sensor 7 to be calibrated is installed between the second groove and the third groove, there is a gap between the top surface of the lower force decoupling block 41 and the bottom surface of the upper force decoupling block 42, which facilitates effective transmission of force. The angle between the top surface of the lower force decoupling block 41 and the horizontal plane is the same as the angle between the bottom surface of the upper force decoupling block 42 and the horizontal plane, denoted as angle θ, which ranges from [0° to 90°].

[0068] To adapt the testing environment to more real-world scenarios, different angles θ are used for the different three-dimensional decoupling components 4, and multiple second grooves 412 are provided to lead out the cable of the pressure sensor 7 to be calibrated from between the lower force decoupling block 41 and the upper force decoupling block 42 in different directions. In this embodiment, three three-dimensional decoupling components 4 are provided, with included angles θ of 0°, 30°, and 60°, respectively, to study the influence of 30° and 60° on the three-dimensional force decoupling results. The material is machined stainless steel. Four second grooves 412 are provided, respectively arranged around the edge of the second groove 411, and the included angle α between any two adjacent second grooves 412 is 30°, to change the arrangement direction and study the influence of different tangential force components. The cable of the pressure sensor 7 to be calibrated is led out from between the lower force decoupling block 41 and the upper force decoupling block 42 through the second cable groove 412, and sealed to the outside of the three-dimensional pressure chamber 1 through the first cable sealer 16; in addition, the second cable groove 412 is provided with an M3 threaded hole, which, together with the copper pressure plate, presses the cable of the pressure sensor 7 to be calibrated to prevent it from loosening during impact.

[0069] The water supply unit 6 is connected to the three-dimensional pressure chamber 1 through a water injection hole and is used to supply water to the three-dimensional pressure chamber 1.

[0070] This invention provides a sensor calibration method based on three-dimensional pressure decoupling, employing the aforementioned sensor calibration device based on three-dimensional pressure decoupling, and specifically includes the following steps:

[0071] Step 1: Assemble the three-dimensional pressure chamber and the three-dimensional force decoupling assembly: Place a set of three-dimensional decoupling assemblies 4 into the three-dimensional pressure chamber 1, place the pressure sensor 7 to be calibrated between the lower force decoupling block 41 and the upper force decoupling block 42, and seal its cable through the first wire hole 11.

[0072] Step 2, Water injection and air release: Inject water into the three-dimensional pressure chamber 1 through the water supply unit 6 until water overflows from the air release hole, then close the water supply unit 6 to seal the water injection hole and the air release hole;

[0073] Step 3: Apply confining pressure: Apply pressure to the water in the three-dimensional pressure chamber 1 through the pressure transmission hole 12 in the three-dimensional pressure chamber 1, and monitor the confining pressure in real time through the standard confining pressure sensor 2 to keep it at the preset confining pressure value F. In this embodiment, the preset confining pressure value F is 2MPa.

[0074] Step 4: Conduct an impact test: Apply a vertically downward axial impact force to the axial compression rod 3 at a preset impact height h. The axial impact force is transmitted to the pressure sensor 7 to be calibrated through the axial compression rod 3 and the upper force decoupling block 42, and then to the standard force sensor 5 through the lower force decoupling block 41.

[0075] Step 5: Obtain the peak force output by standard force sensor 5. Based on the peak voltage V output by the pressure sensor 7 to be calibrated, the theoretical normal force acting on the pressure sensor 7 to be calibrated is calculated according to the principle of vector decomposition. Then, the sensitivity C of the pressure sensor 7 to be calibrated is calculated:

[0076]

[0077] Where S is the area of ​​the sensitive surface of the pressure sensor 7 to be calibrated;

[0078] Step 6, Data Acquisition and Processing: Establish a set of data regarding the included angle θ, included angle α, preset impact height h, preset confining pressure F, and peak force. The data correspondence between the sensitivity C and the sensitivity C;

[0079] Step 7: Change the experimental parameters: Replace the next set of three-dimensional decoupling components 4 to change the included angle θ, and / or change the preset confining pressure value F, and / or change the preset impact height h, and / or change the installation orientation of the pressure sensor 7 to be calibrated to change the included angle α, and return to step 1 until a preset number of data correspondences are established. The specific preset number is determined according to the actual application scenario and the pressure bearing range of the pressure sensor 7 to be calibrated, and the calibration of the pressure sensor 7 to be calibrated is completed.

[0080] In practical applications, the required data can be obtained from the calibrated data correspondence based on the actual working conditions.

[0081] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A sensor calibration device based on three-dimensional pressure decoupling, characterized in that: It includes a three-dimensional pressure chamber (1), a standard confining pressure sensor (2), an axial pressure rod (3), a three-dimensional decoupling assembly (4), a standard force sensor (5), and a water supply unit (6); The three-dimensional pressure chamber (1) is provided with a first threading hole (11), an exhaust hole, a water injection hole and a pressure transmission hole (12), with the exhaust hole located at the top of the three-dimensional pressure chamber (1); The standard confining pressure sensor (2) is installed on the side wall of the three-dimensional pressure chamber (1), and its sensitive surface is located inside the three-dimensional pressure chamber (1); One end of the axial pressure rod (3) is located outside the three-dimensional pressure chamber (1), and the other end is slidably inserted into the three-dimensional pressure chamber (1) from the top of the three-dimensional pressure chamber (1) in a vertical direction; The three-dimensional decoupling assembly (4) includes multiple sets; in use, one set is installed in the middle of the bottom of the three-dimensional pressure chamber (1); each set of three-dimensional decoupling assembly (4) includes a lower force decoupling block (41) and an upper force decoupling block (42) arranged sequentially from bottom to top; the upper end of the upper force decoupling block (42) is fitted outside the bottom end of the axial pressure rod (3); the lower force decoupling block (41) and the upper force decoupling block (42) are used to set the pressure sensor (7) to be calibrated; the angle between the top surface of the lower force decoupling block (41) and the horizontal plane is the same as the angle between the bottom surface of the upper force decoupling block (42) and the horizontal plane, and is denoted as the angle θ, which ranges from [0°, 90°); the angle θ corresponding to different three-dimensional decoupling assemblies (4) is different; The standard force sensor (5) is located between the bottom surface of the lower force decoupling block (41) and the inner bottom of the three-dimensional pressure chamber (1). The cables of the standard force sensor (5) and the pressure sensor (7) to be calibrated both pass through the first wire hole (11) and out of the three-dimensional pressure chamber (1). The water supply unit (6) is connected to the three-dimensional pressure chamber (1) through a water injection hole and is used to supply water to the three-dimensional pressure chamber (1).

2. The sensor calibration device based on three-dimensional pressure decoupling according to claim 1, characterized in that: The bottom surface of the lower force decoupling block (41) is provided with an upwardly recessed first groove and a first line groove that are interconnected; The standard force sensor (5) is set in the first groove, and its cable is led out from the bottom surface of the lower force decoupling block (41) through the first wire groove; The depth of the first groove is less than the thickness of the standard force sensor (5), so that the bottom surface of the standard force sensor (5) protrudes from the bottom surface of the lower force decoupling block (41).

3. The sensor calibration device based on three-dimensional pressure decoupling according to claim 2, characterized in that: The top surface of the lower force decoupling block (41) is provided with a second groove (411) that is recessed downward and interconnected with each other, and a second line groove (412). The bottom surface of the upper force decoupling block (42) is provided with an upwardly recessed third groove; The sum of the depth of the second groove (411) and the depth of the third groove is less than the thickness of the pressure sensor (7) to be calibrated, so that when the pressure sensor (7) to be calibrated is installed between the second groove and the third groove, there is a gap between the top surface of the lower force decoupling block (41) and the bottom surface of the upper force decoupling block (42). The second cable groove (412) is provided with multiple cables for leading out the pressure sensor (7) to be calibrated from between the lower force decoupling block (41) and the upper force decoupling block (42) in different directions.

4. The sensor calibration device based on three-dimensional pressure decoupling according to claim 3, characterized in that: The three-dimensional pressure chamber (1) includes a cylindrical pressure chamber body (13), a base (14) disposed at the bottom of the pressure chamber body (13), and a top cover (15) disposed at the top of the pressure chamber body (13). The first wire hole (11) is provided on the top cover (15), and the first wire hole (11) is provided with a first cable sealer (16). The pressure transmission hole (12) is provided on the base (14); The cables of the standard force sensor (5) and the pressure sensor to be calibrated (7) are sealed and led out to the outside of the three-dimensional pressure chamber (1) through the first cable sealer (16); The top cover (15) is also provided with a central hole (151), and the other end of the axial pressure rod (3) passes through the central hole (151) into the three-dimensional pressure chamber (1).

5. The sensor calibration device based on three-dimensional pressure decoupling according to claim 4, characterized in that: It also includes an image acquisition module (8) located in the three-dimensional pressure chamber (1); The top cover (15) is provided with a second wire hole (17), and a second cable sealer (18) is provided inside the second wire hole (17). The image acquisition module (8) is installed at the bottom of the top cover (15). Its working end corresponds to the gap between the top surface of the lower force decoupling block (41) and the bottom surface of the upper force decoupling block (42). Its cable is sealed and led out to the outside of the three-dimensional pressure chamber (1) through the second cable sealer (18).

6. The sensor calibration device based on three-dimensional pressure decoupling according to claim 5, characterized in that: It also includes a bushing (9) and a snap ring (10); The bottom of the top cover (15) is provided with a first annular groove (19) around the center hole (151); The outer diameter of the bushing (9) matches the diameter of the central hole (151). The outer wall of the bushing (9) is provided with a convex ring (91) and a second annular groove (92). The convex ring (91) is located near the bottom end of the bushing (9). The bushing (9) passes through the central hole (151), so that the convex ring (91) engages with the first annular groove (19), and the second annular groove (92) is located outside the top cover (15). The snap ring (10) is engaged in the second annular groove (92), and its outer diameter is larger than the diameter of the central hole (151), so that the top cover (15) is confined between the snap ring (10) and the convex ring (91); The axial compression rod (3) is inserted inside the bushing (9).

7. The sensor calibration device based on three-dimensional pressure decoupling according to claim 6, characterized in that: The inner hole of the bushing (9) is a two-stage stepped hole, which includes a small hole, a tapered hole and a large hole arranged sequentially from bottom to top, with the small end of the tapered hole facing downwards; A preload nut (93) and a first sealing ring (94) are fitted between the large hole and the shaft pressure rod (3). The preload nut (93) is threaded to the shaft sleeve (9), and the first sealing ring (94) is located in the large hole and / or tapered hole at the bottom of the preload nut (93). The outer wall of the axial compression rod (3) is provided with a third annular groove (31), and a second sealing ring is provided in the third annular groove (31).

8. The sensor calibration device based on three-dimensional pressure decoupling according to any one of claims 2-7, characterized in that: The second groove (412) includes four grooves, which are respectively arranged around the edge of the second groove (411), and the included angle α between two adjacent second grooves (412) is 30°.

9. The sensor calibration device based on three-dimensional pressure decoupling according to claim 8, characterized in that: The three-dimensional pressure chamber (1), the axial pressure rod (3), and the three-dimensional decoupling component (4) are all made of the same material.

10. A sensor calibration method based on three-dimensional pressure decoupling, employing the sensor calibration device based on three-dimensional pressure decoupling as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Place a set of three-dimensional decoupling components (4) into the three-dimensional pressure chamber (1), place the pressure sensor (7) to be calibrated between the lower force decoupling block (41) and the upper force decoupling block (42), and seal its cable through the first wire hole (11); Step 2: Inject water into the three-dimensional pressure chamber (1) through the water supply unit (6) until water overflows from the vent hole, then close the water supply unit (6) and seal the water injection hole and vent hole; Step 3: Pressurize the water in the three-dimensional pressure chamber (1) through the pressure transmission hole (12) in the three-dimensional pressure chamber (1), and monitor the confining pressure in real time through the standard confining pressure sensor (2) to keep it at the preset confining pressure value; Step 4: Apply a vertically downward axial impact force to the axial pressure rod (3) at a preset impact height. The axial impact force is transmitted to the pressure sensor to be calibrated (7) through the axial pressure rod (3) and the upper force decoupling block (42), and then to the standard force sensor (5) through the lower force decoupling block (41). Step 5: Obtain the peak force output by the standard force sensor (5) Calculate the sensitivity C of the pressure sensor (7) to be calibrated based on the peak voltage V output by the pressure sensor (7) to be calibrated: ； Where S is the area of ​​the sensitive surface of the pressure sensor (7) to be calibrated; Step 6: Establish a set of parameters including included angle θ, preset impact height, preset confining pressure, and peak force. The data correspondence between the sensitivity C and the sensitivity C; Step 7: Replace the next set of three-dimensional decoupling components (4) to change the included angle θ, and / or change the preset confining pressure value, and / or change the preset impact height, and return to step 1 until a preset number of data correspondences are established, and complete the calibration of the pressure sensor (7) to be calibrated.

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