Piston detection method and system for a piston pressure gauge

Abstract

The application provides a piston detection method and system of a piston pressure gauge, and relates to the technical field of laser measurement. The system comprises a laser light source for emitting a laser beam; a first reflector arranged on a bearing disc of a standard piston pressure gauge; a second reflector arranged on a bearing disc of a detected piston pressure gauge; an optical system for splitting the laser light source into a first transmitted beam and a first reflected beam, so that the first transmitted beam irradiates the first reflector and the first reflected beam irradiates the second reflector, and combining the light beams reflected by the first reflector and the second reflector to generate interference fringes; and a signal processing system for acquiring the interference fringes, and analyzing the running condition of a detected piston of the detected piston pressure gauge based on the displacement of the interference fringes. Through the implementation of the application, direct contact with the measured object is not needed, and errors and damages caused by contact measurement can be avoided. Moreover, the change of piston displacement can be monitored in real time, and the measurement time is significantly shortened.

Description

Technical Field

[0001] The present invention relates to the field of laser measurement technology, and in particular to a piston detection method and system for a piston pressure gauge. Background Art

[0002] The piston descent velocity of a piston pressure gauge refers to the speed at which the piston descends due to fluid leakage through the piston gap under a specified pressure. It is a key indicator of the piston pressure gauge's sealing performance, directly affecting the accuracy and reliability of pressure measurements. It is also a necessary item in calibration. Excessively rapid piston descent typically indicates leakage, friction between the piston and the cylinder, or wear or damage to the seal. By measuring the piston descent velocity, these issues can be identified promptly, allowing appropriate maintenance measures to be implemented to ensure that the equipment's sealing performance meets standard requirements. Summary of the Invention

[0003] In view of this, the present invention provides a piston detection method and system for a piston pressure gauge.

[0004] In the first aspect, an embodiment of the present invention proposes a piston detection system for a piston pressure gauge, comprising: a laser light source for emitting a laser beam; a first reflector, arranged on the load-bearing plate of a standard piston pressure gauge; a second reflector, arranged on the load-bearing plate of the piston pressure gauge to be tested; an optical system, for splitting the laser light source into a first transmitted beam and a first reflected beam, so that the first transmitted beam is irradiated to the first reflector, and the first reflected beam is irradiated to the second reflector, and the beam reflected by the first reflector and the beam reflected by the second reflector are combined to generate interference fringes; a signal processing system, for obtaining interference fringes, and analyzing the operating condition of the tested piston of the tested piston pressure gauge based on the displacement of the interference fringes.

[0005] In the second aspect, an embodiment of the present invention proposes a piston detection method for a piston pressure gauge, which is applied to the piston detection system of the piston pressure gauge described in any embodiment of the first aspect, the method comprising: setting a first reflector on the load-bearing plate of the standard piston pressure gauge, and setting a second reflector on the load-bearing plate of the piston pressure gauge to be tested; connecting the standard piston pressure gauge and the piston pressure gauge to be tested and placing them in a working position, adjusting the initial counterweight of the standard piston of the standard piston pressure gauge and the tested piston of the tested piston pressure gauge to compensate for the additional mass of the first reflector and the second reflector, respectively; when the standard piston pressure gauge and the piston pressure gauge to be tested reach pressure equilibrium, obtaining the position or number of interference fringes; analyzing the change of the interference fringes based on the position or number of fringes, and recording the number of fringes moving within a preset time period; calculating the displacement difference between the standard piston and the tested piston based on the number of fringes moving; and analyzing the operating condition of the tested piston of the tested piston pressure gauge based on the displacement difference.

[0006] The piston detection method and system for a piston pressure gauge provided in embodiments of the present invention utilize the principle of optical interference for measurement, eliminating the need for direct contact with the object being measured and avoiding the potential errors and damage associated with contact measurement. Furthermore, the system can monitor piston displacement changes in real time with high resolution, achieving high measurement accuracy and providing intuitive equilibrium status indication. The system is more sensitive to minute displacement changes and can quickly determine the pressure relationship between a standard piston pressure gauge and the one being tested, significantly reducing measurement time.

[0007] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0009] Figure 1 A schematic structural diagram of a piston detection system for a piston pressure gauge provided in an embodiment of the present invention;

[0010] Figure 2 A schematic structural diagram of another piston detection system of a piston pressure gauge provided by an embodiment of the present invention;

[0011] Figure 3 This is a flow chart of a piston detection method for a piston pressure gauge provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0012] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0013] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components; wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0014] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0015] Please refer to Figure 1 , Figure 1 The present invention provides a schematic structural diagram of a piston detection system for a piston pressure gauge according to an embodiment of the present invention. The piston detection system mainly includes: a laser light source 1, a first reflector 2, a second reflector 3, an optical system 4, and a signal processing system 5. Among them, the laser light source 1 is used to emit a laser beam. In practical applications, a helium-neon laser or a semiconductor laser can be used, which has a stable wavelength and good monochromaticity. In this embodiment, the piston detection system is mainly used to detect the operating condition of the inspected piston of the inspected piston pressure gauge. In order to detect the operating condition, the detection is achieved by comparing a standard piston pressure gauge with the inspected piston pressure gauge.

[0016] To implement the detection process of this embodiment, a first reflector 2 is disposed on the bearing plate of the standard piston pressure gauge to reflect the light impinging thereon; a second reflector 3 is disposed on the bearing plate of the piston pressure gauge under test to reflect the light impinging thereon. In actual applications, the surface of the bearing plate of the piston pressure gauge is not necessarily perfectly flat, and its reflection of the impinging light may be relatively scattered. Therefore, in order to obtain more consistent reflected light, in this embodiment, reflectors are disposed on the bearing plates of the piston pressure gauge under test and the standard pressure gauge, respectively, to form more complete and consistent reflected light.

[0017] In some optional implementations of the embodiments of the present invention, when calibrating the piston pressure gauge, a reflector needs to be temporarily installed on the piston rod to form an interference light path. However, the mass of the reflector will change the mass ratio of the piston system (including the piston rod, the bearing plate, and the weights), resulting in pressure calculation errors (pressure P=F / A, where the force F=mg, and the mass change directly affects the pressure value. F is the vertical force applied to the piston or the object being measured, usually generated by the gravity of the weight (F=mg, m is the mass of the weight, g is the acceleration of gravity; A is the effective action area of ​​the piston or the object being measured, that is, the contact area for pressure transmission)). After the calibration is completed, the reflector needs to be removed, but it must be ensured that the mass of the system returns to its original state after removal to avoid recalibration. Therefore, it is necessary to use the starting balance method to compensate for the additional mass of the reflector by pre-adjusting the initial counterweight (weight) of the piston so that:

[0018] When installing the reflector: Total mass (original mass M + reflector mass m) = original calibration mass M. That is, by reducing the weight mass m, make M 新 =M−m, and the total mass returns to M after the reflector is installed.

[0019] After removing the reflector: the total mass returns to M 新 = M − m, but since the reflector has been removed, the actual mass M 实际 =M 新 +m=M, consistent with the original calibration state.

[0020] In this embodiment, the initial balancing process achieved through the above-described initial balancing method eliminates the need for specific restrictions on the mass of the reflector in practical applications. This method is applicable regardless of the relative mass of the weight and the reflector. Furthermore, even if the reflector mass is less than 20% of the piston gauge's range, it still meets the testing requirements, thus providing a wide range of applications.

[0021] Optical system 4 is used to split the laser light source into a first transmitted beam and a first reflected beam, directing the first transmitted beam to first reflector 2 and the first reflected beam to second reflector 3. The beams reflected by first reflector 2 and second reflector 3 are then combined to generate interference fringes. In practical applications, during piston-type pressure measurement, the difference in descent speed between the tested piston pressure gauge and the standard piston pressure gauge means there is a slight error in their pressure values. This difference indicates that the pistons are descending asynchronously, which can cause a change in the optical path and, consequently, a shift in the interference fringes.

[0022] Signal processing system 5 is used to obtain interference fringes and analyze the operating condition of the piston of the piston pressure gauge under test based on the displacement of the interference fringes. By accurately measuring the displacement of the interference fringes, the difference in piston descent speed between the piston pressure gauges can be calculated. The high resolution of the interferometer can be used to accurately transmit piston measurement values. Based on this difference in descent speed, the difference between the piston movement of the tested piston pressure gauge and the standard piston movement can be determined, thereby determining whether the tested piston has a problem.

[0023] Piston pressure gauges of different accuracy levels have different requirements for the descent rate. For example:

[0024] Level 0.005: The descent rate is not greater than 0.15 mm / min (the upper limit of the measuring range is 0.6 MPa).

[0025] Level 0.01: The descent rate is not greater than 0.2 mm / min (the upper limit of the measuring range is 6 MPa).

[0026] Level 0.02: The descent rate is not greater than 0.3 mm / min (the upper limit of the measuring range is 25 MPa).

[0027] The minimum piston descending speed that can be measured at present is 0.01mm / min, which is difficult to meet the needs of higher-level piston pressure measurement sensors. Through the detection system of this embodiment, it is possible to detect displacement changes with higher precision and meet the detection requirements of different levels.

[0028] The piston detection system for a piston pressure gauge provided by embodiments of the present invention utilizes the principle of optical interference through the aforementioned process, eliminating the need for direct contact with the object being measured and avoiding the potential errors and damage associated with contact measurement. Furthermore, it can monitor changes in piston displacement in real time, making it suitable for dynamic measurement and significantly shortening measurement time, eliminating the need for traditional methods that take hours to measure even tiny downward piston displacements.

[0029] In some optional implementations of the embodiments of the present invention, the optical system 4 mainly includes: a beam splitter prism 41 , a reflective mirror 42 and a compensating mirror 43 .

[0030] The beam splitter 41 is used to split the laser light source into a first transmitted beam and a first reflected beam. The first transmitted beam passes through the compensating mirror 43 and is irradiated by the reflective mirror 42, while the first reflected beam passes through the first reflective mirror 2. The first reflective mirror 2 reflects the first reflected beam, causing the reflected second reflected beam to pass through the beam splitter 41. The reflective mirror 42 reflects the first transmitted beam and the third reflected beam reflected by the second reflective mirror 3, causing the third reflected beam to pass through the compensating mirror 43 and pass through the beam splitter 41. The beam splitter 41 is further used to combine the second and third reflected beams into interference fringes. The compensating mirror 43 is primarily used to offset the optical path and dispersion differences introduced by the beam splitter 41, thereby offsetting half-wave loss.

[0031] In some optional implementations of the embodiments of the present invention, such as Figure 2 As shown, the piston detection system of the piston pressure gauge may further include a beam expander 6 , which is used to expand the laser beam emitted by the laser light source 1 .

[0032] In some optional implementations of the present invention, the signal processing system 5 includes a photodetector for acquiring interference fringes and a data processing unit for calculating the displacement of the interference fringes and analyzing the operating condition of the piston of the piston pressure gauge under test based on the displacement.

[0033] In some optional implementations of the embodiments of the present invention, such as Figure 2 As shown, the signal processing system 5 includes an observation screen 51, a CCD camera 52, and a computer terminal 53. The observation screen 51 is used to display interference fringes; the CCD camera 52 is used to detect the amount of movement of the interference fringes; and the computer terminal 53 is used to calculate the displacement of the interference fringes based on the amount of movement and analyze the operating condition of the piston under test of the piston pressure gauge based on the displacement.

[0034] Furthermore, the piston detection system of the piston pressure gauge may also include: an adjustment module for adjusting the counterweight of the piston under test so that the descending speed of the standard piston and the piston under test are consistent; correspondingly, the above-mentioned signal processing system 5 is further used to calculate the speed average based on the accumulated displacement. The speed average is calculated by obtaining the displacement difference data obtained by repeated measurement, which can be used to characterize the stability of the piston pressure gauge under test. For example, the number of interference fringes N moved by the standard piston and the piston under test at different time points can be recorded, and the formula , the displacement difference between different pistons can be calculated. Among them, Represents the wavelength of the laser light source. Combined with the displacement differences obtained from multiple measurements, the average displacement difference is calculated. Then, the formula Calculate the average value of the piston's speed, where t is the time interval.

[0035] Further references Figure 3 As an implementation of the systems shown in the above figures, the present invention provides an embodiment of a piston detection method for a piston pressure gauge. Figure 1 Corresponding to the system embodiment shown, the method can be specifically applied to the piston detection system of the piston pressure gauge described in any of the above embodiments.

[0036] like Figure 3 As shown, the piston detection method 300 of the piston pressure gauge of this embodiment includes:

[0037] Step 301: Place the first reflector on the weight plate of the standard piston gauge and the second reflector on the weight plate of the piston gauge under test. Before this step, perform some basic initialization operations, such as ensuring the stability of the optical path and mechanical structure. Adjust the optical path to ensure clear interference fringes and calibrate the interferometer to ensure proper operation.

[0038] Step 302: Pre-adjust the initial counterweights of the standard piston of the standard piston pressure gauge and the test piston of the test piston pressure gauge to compensate for the added mass of the first and second reflectors, respectively. When calibrating a piston pressure gauge, a reflector must be temporarily installed on the piston rod to create an interference optical path. However, the mass of the reflector changes the total mass of the piston system (including the piston rod, bearing plate, and weights), leading to errors in pressure calculation (pressure P = F / A, where force F = mg. Mass changes directly affect the pressure value. F is the vertical force applied to the piston or measured object, typically generated by the weight of the weight (F = mg, m is the weight mass, g is the acceleration due to gravity; A is the effective area of ​​the piston or measured object, i.e., the contact area for pressure transmission). After calibration, the reflector must be removed, but it is important to ensure that the system mass returns to its original state after removal to avoid recalibration. Therefore, a starting balance method is required to pre-adjust the initial counterweight (weights) of the piston to compensate for the added mass of the reflector.

[0039] Step 303: placing the standard piston pressure gauge and the piston pressure gauge to be tested at a rotational equilibrium position, and obtaining the position or number of interference fringes.

[0040] Step 304: Analyze the change of interference fringes based on the position or the number of fringes, and record the number N of fringes moved within a preset time period t.

[0041] Step 305: Calculate the displacement difference between the standard piston and the piston under test based on the number of fringe movements. , the displacement difference between different pistons can be calculated. Among them, Indicates the wavelength of the laser light source.

[0042] Step 306: Analyze the operating condition of the inspected piston of the inspected piston pressure gauge based on the displacement difference. By accurately measuring the movement of the interference fringes, the difference in piston descent speed between the piston pressure gauges can be calculated. The high resolution of the interferometer enables precise transmission of piston measurement values. Based on this difference in descent speed, the difference between the piston movement of the inspected piston pressure gauge and the standard piston movement can be determined, thereby determining whether the inspected piston has a problem.

[0043] Furthermore, in order to calibrate the piston under test, the counterweight of the piston under test can be adjusted, and steps 303 to 306 can be repeated to make the descending speed of the standard piston and the piston under test consistent. In addition, the speed average value can be calculated based on the accumulated displacement. The speed average value can be calculated by obtaining the displacement difference data obtained by repeated measurement of the displacement, which can be used to characterize the stability of the piston pressure gauge under test. For example, the number of interference fringes N moved by the standard piston and the piston under test at different time points can be recorded, and the formula , the displacement difference between different pistons can be calculated. Among them, Represents the wavelength of the laser light source. Combined with the displacement differences obtained from multiple measurements, the average displacement difference is calculated. Then, the formula Calculate the average value of the piston's speed, where t is the time interval.

[0044] This embodiment, a method embodiment corresponding to the aforementioned system embodiment, provides a piston pressure gauge piston detection method that utilizes the principle of optical interference for measurement, eliminating the need for direct contact with the object being measured and avoiding the potential errors and damage associated with contact measurement. Furthermore, it can monitor changes in piston displacement in real time, making it suitable for dynamic measurement and significantly shortening measurement time, eliminating the need for traditional methods that take hours to measure even tiny downward piston displacements.

[0045] In some optional implementations of this embodiment, situations causing the interference fringes to move may include the following:

[0046] (1) Synchronous descent of the piston under test and the standard piston due to leakage.

[0047] In this case, if the two pistons descend synchronously and at the same speed due to leakage, the optical path length changes in both directions are similar, and the optical path difference remains almost unchanged. Correspondingly, the interference fringes remain stationary or slowly drift. A leak can be determined by identifying when the interference fringes remain stationary or move a distance less than a preset value within a preset time period.

[0048] (2) The weight on the piston being tested is too heavy, causing it to drop.

[0049] In this case, the downward movement of the inspected piston lengthens the optical path, while the upward movement of the standard piston shortens the optical path, increasing the total optical path difference. If the initial fringes are oriented vertically, an increase in the optical path difference will cause the interference fringes to shift horizontally; if the initial fringes are oriented horizontally, an increase in the optical path difference will cause the interference fringes to shift vertically.

[0050] (3) The weight of the standard piston is too heavy, causing it to drop.

[0051] In this case, the standard piston moves downward and the inspected piston moves upward, reducing the total optical path difference. If the initial fringes are oriented vertically, a reduced optical path difference will cause the interference fringes to move horizontally; if the initial fringes are oriented horizontally, a reduced optical path difference will cause the interference fringes to move vertically.

[0052] Conventional detection equipment typically uses digital displays, reading the numbers and combining them with the absolute position of the current piston disc to perform position addition and subtraction. This process is cumbersome and inefficient. However, the piston detection method and piston detection system for a piston pressure gauge provided in this embodiment eliminate the need for specific numerical values ​​and can more quickly and effectively identify various conditions that cause interference fringe movement, with higher accuracy.

[0053] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0054] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0055] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0056] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0057] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A piston detection system for a piston pressure gauge, characterized in that: include: A laser light source, used for emitting a laser beam; A first reflector is provided on the bearing plate of the standard piston pressure gauge; A second reflector is provided on the bearing plate of the piston pressure gauge to be tested; wherein the additional mass of the first reflector and the second reflector is compensated by pre-adjusting the initial counterweight of the standard piston of the standard piston pressure gauge and the tested piston of the tested piston pressure gauge; an optical system for splitting the laser light source into a first transmitted beam and a first reflected beam, directing the first transmitted beam to the first reflector and the first reflected beam to the second reflector, and combining the beam reflected by the first reflector and the beam reflected by the second reflector to generate interference fringes; A signal processing system is used to obtain the interference fringes and analyze the operating condition of the inspected piston of the inspected piston pressure gauge based on the displacement of the interference fringes.

2. The system according to claim 1, wherein: The optical system includes: a beam splitter prism, a reflector and a compensation mirror, wherein: The beam splitter prism is used to split the laser light source into the first transmitted light beam and the first reflected light beam, wherein the first transmitted light beam is irradiated to the reflective mirror through the compensation mirror, and the first reflected light beam is irradiated to the first reflective mirror; The first reflector is used to reflect the first reflected light beam so that the reflected second reflected light beam is irradiated to the beam splitter prism; The reflective mirror is used to reflect the first transmitted light beam and the third reflected light beam reflected back by the second reflective mirror, so that the third reflected light beam passes through the compensation mirror and is irradiated to the beam splitter prism; The beam splitter prism is further configured to combine the second reflected light beam and the third reflected light beam into the interference fringes.

3. The system according to claim 2, characterized in that The optical system further comprises: The beam expander is used to expand the laser beam emitted by the laser light source.

4. The system according to claim 1, wherein: The signal processing system comprises: A photoelectric detector, used for acquiring the interference fringes; A data processing unit is used to calculate the displacement of the interference fringes and analyze the operating condition of the inspected piston of the inspected piston pressure gauge based on the displacement.

5. The system according to claim 1, wherein: The signal processing system comprises: an observation screen for displaying the interference fringes; A CCD camera is used to detect the movement amount of the interference fringes; The computer terminal is used to calculate the displacement of the interference fringes based on the movement amount, and analyze the operating condition of the inspected piston of the inspected piston pressure gauge based on the displacement.

6. The system according to claim 1, wherein: Also includes: An adjustment module, configured to adjust the counterweight of the inspected piston so that the descending speeds of the standard piston and the inspected piston are consistent; The signal processing system is further configured to calculate a velocity average value based on the accumulated displacement.

7. A piston detection method for a piston pressure gauge, applied to a piston detection system for a piston pressure gauge according to any one of claims 1 to 6, characterized in that: include: The first reflector is arranged on the bearing plate of the standard piston pressure gauge, and the second reflector is arranged on the bearing plate of the piston pressure gauge to be tested; Pre-adjusting the initial counterweights of the standard piston of the standard piston pressure gauge and the tested piston of the tested piston pressure gauge to compensate for the additional mass of the first reflector and the second reflector respectively; placing the standard piston pressure gauge and the piston pressure gauge to be tested at a rotational equilibrium position, and obtaining the position or number of the interference fringes; Analyzing the change of the interference fringes based on the position or the number of fringes, and recording the number of fringes moved within a preset time period; Calculating the displacement difference between the standard piston and the inspected piston based on the amount of fringe movement; The operating condition of the inspected piston of the inspected piston pressure gauge is analyzed based on the displacement difference.

8. The method according to claim 7, characterized in that Also includes: Adjusting the counterweight of the piston to be tested so that the descending speed of the standard piston and the piston to be tested are consistent; The velocity average is calculated based on the accumulated displacement.

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