Bidirectional vibration sensor based on Fabry-Perot interference principle

Abstract

According to the bidirectional vibration sensor based on the Fabry-Perot interference principle provided by the invention, the mass block can be fixed in the shell through the first acceleration measurement assembly, the second acceleration measurement assembly, the third spring and the fourth spring, and the mass block is in a suspended state; the balance of the mass block in the first direction and the second direction can be kept. According to the technical scheme provided by the invention, the use of an adhesive is avoided, the influence of temperature is avoided, and the precision of the bidirectional vibration sensor can be greatly improved. The bidirectional vibration sensor provided by the invention is based on the Fabry-Perot interference principle, belongs to a non-contact type, and has the advantages of high linearity, long service life, electromagnetic interference resistance, zero drift and the like.

Description

Technical Field

[0001] This application relates to the technical field of sensors, and specifically to a bidirectional vibration sensor and a power device based on the Fabry - Perot interference principle. Background Art

[0002] Vibration sensors based on electrical principles such as piezoelectric ceramics and diffused silicon are widely used in industrial production and engineering monitoring. However, vibration sensors based on electrical principles are vulnerable to electromagnetic interference, with limited usage scenarios, and also have drawbacks such as long - term zero drift and temperature drift.

[0003] To reduce electromagnetic interference, vibration sensors based on optical principles are usually adopted. Specifically, a fiber Bragg grating (FBG) or distributed optical fiber can be adhered to a cantilever beam through an adhesive. After vibration occurs, the cantilever beam also vibrates, and tensile strain or compressive strain will be generated on the upper and lower surfaces of the cantilever beam. The magnitude of the tensile strain or compressive strain can be measured through the fiber Bragg grating and the distributed optical fiber, thereby reflecting the vibration acceleration of the object to be measured. However, on the one hand, the adhesive will age and deform, resulting in long - term creep and zero drift problems of the fiber Bragg grating or distributed optical fiber, leading to a reduction in the accuracy of the vibration sensor. On the other hand, vibration sensors based on optical principles are vulnerable to temperature effects. The temperature influence coefficient can be as high as 8 με / °C, that is, the change in the resonant wavelength per degree Celsius is equivalent to 8 microstrains, accounting for three - thousandths of the range of the vibration sensor, which will also lead to a reduction in the accuracy of the vibration sensor. Summary of the Invention

[0004] To solve the problem of low accuracy in the prior art, this application provides a bidirectional vibration sensor and a power device based on the Fabry - Perot interference principle.

[0005] In a first aspect, this application provides a bidirectional vibration sensor based on the Fabry - Perot interference principle, which may include a mass block, a first acceleration measurement component, a second acceleration measurement component, a third spring, a fourth spring, a housing, and a demodulation module.

[0006] The demodulation module is located outside the housing. The first acceleration measurement component, the second acceleration measurement component, the third spring, and the fourth spring are all located inside the housing. The first ends of the first acceleration measurement component and the third spring are fixed to different sides of the mass block in a first direction, and the first ends of the second acceleration measurement component and the fourth spring are fixed to different sides of the mass block in a second direction. The mass block can be in a suspended state.

[0007] The second ends of the first acceleration measurement component, the second acceleration measurement component, the third spring, and the fourth spring are fixed to the housing, and the second ends of the first acceleration measurement component and the second acceleration measurement component are connected to the demodulation module.

[0008] Wherein, the first direction is perpendicular to the second direction.

[0009] Optionally, both the first acceleration measurement component and the third spring are configured to: fix the mass block in the first direction.

[0010] Both the second acceleration measurement component and the fourth spring are configured to: fix the mass block in the second direction.

[0011] The demodulation module is configured to: collect a first spectrum from the first acceleration measurement component and a second spectrum from the second acceleration measurement component, calculate the vibration acceleration of the object to be measured in the first direction according to the first spectrum, and calculate the vibration acceleration of the object to be measured in the second direction according to the second spectrum.

[0012] In some possible implementation manners, the bidirectional vibration sensor further includes a third displacement measurement component and a fourth displacement measurement component.

[0013] The third displacement measurement component is located inside the third spring, and the third displacement measurement component is coaxial with the third spring. The third displacement measurement component and the third spring form a third acceleration measurement component.

[0014] The fourth displacement measurement component is located inside the fourth spring, and the fourth displacement measurement component is coaxial with the fourth spring. The fourth displacement measurement component and the fourth spring form a fourth acceleration measurement component.

[0015] In some other possible implementation manners, the demodulation module is further configured to: collect a third spectrum from the third acceleration measurement component and a fourth spectrum from the fourth acceleration measurement component, and calculate the vibration acceleration of the object to be measured in the first direction according to the first spectrum and the third spectrum, and calculate the vibration acceleration of the object to be measured in the second direction according to the second spectrum and the fourth spectrum.

[0016] Exemplarily, the first acceleration measurement component includes a first spring and a first displacement measurement component. The first displacement measurement component is located inside the first spring, and the first displacement measurement component is coaxial with the first spring.

[0017] The second acceleration measurement component includes a second spring and a second displacement measurement component. The second displacement measurement component is located inside the second spring, and the second displacement measurement component is coaxial with the second spring.

[0018] The first ends of the first spring and the second spring are each fixed to the mass block, and the second ends of the first spring and the second spring are each fixed to the housing.

[0019] Optionally, the first spring, the second spring, the third spring, and the fourth spring have the same length and the same stiffness.

[0020] Further, the first displacement measurement component, the second displacement measurement component, the third displacement measurement component, and the fourth displacement measurement component each include an optical fiber and a protective tube.

[0021] The optical fiber is located inside the protective tube and coaxial with the protective tube. The first end face of the optical fiber is fixed to the protective tube, the second end face of the optical fiber passes through the housing and is connected to the demodulation module, and the second end of the protective tube is fixed to the housing.

[0022] Optionally, there is a gap between the first end face of the optical fiber and the mass block, and the width of the gap is in the millimeter range.

[0023] Exemplarily, the first end face of the optical fiber and the end face of the mass block form a Fabry - Perot interference cavity.

[0024] The end face of the mass block is provided with a mirror, or the end face of the mass block is polished.

[0025] In some possible implementation manners, the demodulation module is specifically configured to:

[0026] Calculate the cavity length of the first Fabry - Perot interference cavity formed between the first displacement measurement component and the mass block according to the wavelengths corresponding to adjacent wave peaks or wave valleys in the first spectrum, and calculate the vibration acceleration of the object to be measured in the first direction according to the cavity length of the first Fabry - Perot interference cavity.

[0027] Calculate the cavity length of the second Fabry - Perot interference cavity formed between the second displacement measurement component and the mass block according to the wavelengths corresponding to adjacent wave peaks / valleys in the second spectrum, and calculate the vibration acceleration of the object to be measured in the second direction according to the cavity length of the second Fabry - Perot interference cavity.

[0028] Specifically, the cavity lengths of the first Fabry - Perot interference cavity and the second Fabry - Perot interference cavity respectively satisfy:

[0029]

[0030] Wherein, d1 represents the cavity length of the first Fabry - Perot interference cavity, λ 11 represents the wavelength corresponding to the h - th wave peak / valley in the first spectrum, λ 12 represents the wavelength corresponding to the (h + 1) - th wave peak / valley in the first spectrum. d2 represents the cavity length of the second Fabry - Perot interference cavity, λ 21 represents the wavelength corresponding to the h - th wave peak / valley in the second spectrum, λ 22 represents the wavelength corresponding to the (h + 1) - th wave peak / valley in the second spectrum.

[0031] The vibration acceleration of the object to be measured in the first direction and the vibration acceleration of the object to be measured in the second direction respectively satisfy:

[0032]

[0033] Among them, a1 represents the vibration acceleration of the object to be measured in the first direction, and a2 represents the vibration acceleration of the object to be measured in the second direction. k represents the elastic coefficient of the first spring and the second spring. m represents the mass of the mass block. Δd1 represents the change in the cavity length of the first Fabry-Perot interferometer cavity, satisfying Δd1 = d1 - d 10 , d 10 represents the initial cavity length of the first Fabry-Perot interferometer cavity. Δd2 represents the change in the cavity length of the second Fabry-Perot interferometer cavity, satisfying Δd2 = d2 - d 20 , d 20 represents the initial cavity length of the second Fabry-Perot interferometer cavity.

[0034] In some other possible implementation manners, the demodulation module is specifically configured to:

[0035] Calculate the cavity length of the first Fabry-Perot interferometer cavity formed between the first displacement measurement component and the mass block according to the wavelengths corresponding to adjacent wave peaks or wave valleys in the first spectrum, calculate the cavity length of the third Fabry-Perot interferometer cavity formed between the third displacement measurement component and the mass block according to the wavelengths corresponding to adjacent wave peaks or wave valleys in the third spectrum, and calculate the vibration acceleration of the object to be measured in the first direction according to the cavity lengths of the first Fabry-Perot interferometer cavity and the third Fabry-Perot interferometer cavity respectively.

[0036] Calculate the cavity length of the second Fabry-Perot interferometer cavity formed between the second displacement measurement component and the mass block according to the wavelengths corresponding to adjacent wave peaks / valleys in the second spectrum, calculate the cavity length of the fourth Fabry-Perot interferometer cavity formed between the fourth displacement measurement component and the mass block according to the wavelengths corresponding to adjacent wave peaks or wave valleys in the fourth spectrum, and calculate the vibration acceleration of the object to be measured in the second direction according to the cavity lengths of the second Fabry-Perot interferometer cavity and the fourth Fabry-Perot interferometer cavity respectively.

[0037] Specifically, the cavity lengths of the first Fabry-Perot interferometer cavity, the second Fabry-Perot interferometer cavity, the third Fabry-Perot interferometer cavity, and the fourth Fabry-Perot interferometer cavity respectively satisfy:

[0038]

[0039] Among them, d1 represents the cavity length of the first Fabry-Perot interferometer cavity, λ 11 represents the wavelength corresponding to the h-th wave peak / valley in the first spectrum, λ 12 represents the wavelength corresponding to the (h + 1)-th wave peak / valley in the first spectrum. d2 represents the cavity length of the second Fabry-Perot interferometer cavity, λ 21 represents the wavelength corresponding to the h-th wave peak / valley in the second spectrum, λ 22represents the wavelength corresponding to the (h + 1)-th peak / trough in the second spectrum. d3 represents the cavity length of the third Fabry-Perot interferometer cavity, λ 31 represents the wavelength corresponding to the h-th peak / trough in the third spectrum, λ 32 represents the wavelength corresponding to the (h + 1)-th peak / trough in the third spectrum. d4 represents the cavity length of the fourth Fabry-Perot interferometer cavity, λ 41 represents the wavelength corresponding to the h-th peak / trough in the fourth spectrum, λ 42 represents the wavelength corresponding to the (h + 1)-th peak / trough in the fourth spectrum.

[0040] The vibration acceleration of the object to be measured in the first direction and the vibration acceleration of the object to be measured in the second direction respectively satisfy:

[0041]

[0042] wherein, a1 represents the vibration acceleration of the object to be measured in the first direction, a2 represents the vibration acceleration of the object to be measured in the second direction. k represents the elastic coefficient of the first spring, the second spring, the third spring or the fourth spring. m represents the mass of the mass block. Δd1 represents the change in the cavity length of the first Fabry-Perot interferometer cavity, satisfying Δd1 = d1 - d 10 d 10 represents the initial cavity length of the first Fabry-Perot interferometer cavity. Δd2 represents the change in the cavity length of the second Fabry-Perot interferometer cavity, satisfying Δd2 = d2 - d 20 d 20 represents the initial cavity length of the second Fabry-Perot interferometer cavity. Δd3 represents the change in the cavity length of the third Fabry-Perot interferometer cavity, satisfying Δd3 = d3 - d 30 d 30 represents the initial cavity length of the third Fabry-Perot interferometer cavity. Δd4 represents the change in the cavity length of the fourth Fabry-Perot interferometer cavity, satisfying Δd4 = d4 - d 40 d 40 represents the initial cavity length of the fourth Fabry-Perot interferometer cavity.

[0043] In a second aspect, the present application also provides a power device, which may include the above-mentioned bidirectional vibration sensor.

[0044] Optionally, the power device may be a power transmission and transformation device, a power generation device, etc., and the present application does not make any limitations.

[0045] Compared with the prior art, the beneficial effects of the present application are:

[0046] The two-way vibration sensor based on the Fabry-Perot interference principle provided by this application can fix a mass block inside a housing through a first acceleration measurement component, a second acceleration measurement component, a third spring, and a fourth spring, and keep the mass block in a suspended state, capable of maintaining the balance of the mass block in the first direction and the second direction. Since the aging deformation of the adhesive is greatly affected by temperature, this application avoids using adhesives in the two-way vibration sensor. In addition, the two-way vibration sensor provided by this application is based on the Fabry-Perot interference principle, while the vibration sensors provided by related technologies are based on the optical principle. Compared with related technologies, the two-way vibration sensor provided by this application is not easily affected by temperature and can greatly improve the accuracy of the two-way vibration sensor.

[0047] The demodulation module in this application can collect the spectrum from the acceleration measurement component and calculate the vibration acceleration of the object to be measured in the first direction and the vibration acceleration of the object to be measured in the second direction according to the change in the cavity length of the Fabry-Perot interference cavity based on the wavelength of the spectrum. It can be seen that the sensor provided by this application is a two-way vibration sensor based on the Fabry-Perot interference principle, belonging to non-contact type, and has advantages such as high linearity, long lifespan, anti-electromagnetic interference, and no zero drift.

[0048] This application can obtain the vibration acceleration of the object to be measured in the first direction through the change in the cavity length of the first Fabry-Perot interference cavity and the change in the cavity length of the third Fabry-Perot interference cavity, and can obtain the vibration acceleration of the object to be measured in the second direction through the change in the cavity length of the second Fabry-Perot interference cavity and the change in the cavity length of the fourth Fabry-Perot interference cavity, capable of suppressing the influence of the thermal expansion coefficients of the housing, acceleration measurement component, mass block, etc. on the change in the cavity length of the Fabry-Perot interference cavity, realizing automatic temperature compensation, and further improving the measurement accuracy of the two-way vibration sensor. Description of the Drawings

[0049] In order to more clearly illustrate the technical solutions in this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0050] Figure 1 It is a schematic structural diagram of the two-way vibration sensor in an embodiment of this application;

[0051] Figure 2 It is another schematic structural diagram of the two-way vibration sensor in an embodiment of this application;

[0052] Figure 3It is a schematic principle diagram of the bidirectional vibration sensor in the embodiment of the present application;

[0053] Figure 4 It is a schematic diagram of the wavelength relationship between energy and spectrum in the embodiment of the present application;

[0054] Figure 5 It is a schematic diagram of the relationship between the change in the cavity length of the Fabry - Perot interferometric cavity and time in the embodiment of the present application. Detailed implementation manners

[0055] Next, the technical solutions in the present application will be described with reference to the accompanying drawings.

[0056] In the description of the embodiments of the present application, the terms "first", "second", etc. in the specification, claims and drawings of the present application are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non - exclusive inclusions. For example, a process, method, product or device that comprises a series of steps or units does not necessarily limit to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0057] It should be understood that in the present application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" may mean: only A exists, only B exists, and both A and B exist simultaneously. Here, A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (one) of the following" or similar expressions refer to any combination of these items, including any combination of single item (one) or plural items (ones). For example, at least one (one) of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0058] The present application provides a bidirectional vibration sensor based on the Fabry - Perot interference principle, as Figure 1 shown. The bidirectional vibration sensor 10 includes a mass block 1, a first acceleration measurement component 4, a second acceleration measurement component 5, a third spring 61, a fourth spring 71, a housing 2 and a demodulation module 3. In the embodiment of the present application, the demodulation module 3 can be a spectral demodulator, etc.

[0059] The demodulation module 3 is located outside the housing 2, and the first acceleration measurement component 4, the second acceleration measurement component 5, the third spring 61, and the fourth spring 71 are all located inside the housing 2. The first ends of the first acceleration measurement component 4 and the third spring 61 are fixed to different sides of the mass block 1 in the first direction (which can be the Y direction), and the first ends of the second acceleration measurement component 5 and the fourth spring 71 are fixed to different sides of the mass block 1 in the second direction (which can be the X direction). The mass block 1 can be in a suspended state.

[0060] The second ends of the first acceleration measurement component 4, the second acceleration measurement component 5, the third spring 61, and the fourth spring 71 are fixed to the housing 2, and the second ends of the first acceleration measurement component 4 and the second acceleration measurement component 5 are connected to the demodulation module 3. Among them, the first direction is perpendicular to the second direction.

[0061] Optionally, both the first acceleration measurement component 4 and the third spring 61 are used to: fix the mass block 1 in the first direction.

[0062] Both the second acceleration measurement component 5 and the fourth spring 71 are used to: fix the mass block 1 in the second direction.

[0063] It can be seen that through the first acceleration measurement component 4, the second acceleration measurement component 5, the third spring 61, and the fourth spring 71, the mass block 1 can be stably fixed in the first direction and the second direction and is in a suspended state.

[0064] The demodulation module 3 is used to: collect the first spectrum from the first acceleration measurement component 4 and the second spectrum from the second acceleration measurement component 5, calculate the vibration acceleration of the measured object in the first direction according to the first spectrum, and calculate the vibration acceleration of the measured object in the second direction according to the second spectrum.

[0065] In some possible implementation manners, the bidirectional vibration sensor 10 further includes a third displacement measurement component 62 and a fourth displacement measurement component 72, as Figure 2 shown.

[0066] The third displacement measurement component 62 is located inside the third spring 61, and the third displacement measurement component 62 is coaxial with the third spring 61. The third displacement measurement component 62 and the third spring 61 form the third acceleration measurement component 6.

[0067] The fourth displacement measurement component 72 is located inside the fourth spring 71, and the fourth displacement measurement component 72 is coaxial with the fourth spring 71. The fourth displacement measurement component 72 and the fourth spring 71 form the fourth acceleration measurement component 7.

[0068] Exemplarily, the first acceleration measurement component 4 includes a first spring 41 and a first displacement measurement component 42. The first displacement measurement component 42 is located inside the first spring 41 and is coaxial with the first spring 41.

[0069] The second acceleration measurement component 5 includes a second spring 51 and a second displacement measurement component 52. The second displacement measurement component 52 is located inside the second spring 51 and is coaxial with the second spring 51.

[0070] The first ends of the first spring 41 and the second spring 51 are each fixed to the mass block 1, and the second ends of the first spring 41 and the second spring 51 are each fixed to the housing 2.

[0071] In some other possible implementation manners, the demodulation module 3 is further configured to: collect a third spectrum from the third acceleration measurement component 62 and a fourth spectrum from the fourth acceleration measurement component 72, and calculate the vibration acceleration of the object to be measured in the first direction according to the first spectrum and the third spectrum, and calculate the vibration acceleration of the object to be measured in the second direction according to the second spectrum and the fourth spectrum.

[0072] Optionally, the first spring 41, the second spring 51, the third spring 61, and the fourth spring 71 have the same length and the same stiffness.

[0073] Further, the first displacement measurement component 42, the second displacement measurement component 52, the third displacement measurement component 62, and the fourth displacement measurement component 72 each include an optical fiber A and a protective tube B.

[0074] The optical fiber A is located inside the protective tube B and is coaxial with the protective tube B. The first end face of the optical fiber A is fixed to the protective tube B, the second end face of the optical fiber A passes through the housing 2 and is connected to the demodulation module 3, and the second end of the protective tube B is fixed to the housing 2.

[0075] Optionally, there is a gap between the first end face of the optical fiber A and the mass block 1, and the width of the gap is at the millimeter level, usually between 0.1 mm and 1 mm.

[0076] Exemplarily, the first end face of the optical fiber A and the end face of the mass block 1 form a Fabry - Perot interferometric cavity. Thus, in Figure 1 a first Fabry - Perot interferometric cavity can be formed between the first displacement measurement component 42 and the mass block 1, and a second Fabry - Perot interferometric cavity can be formed between the second displacement measurement component 52 and the mass block 1. In Figure 2In this case, a first Fabry - Perot interferometric cavity can be formed between the first displacement measurement component 42 and the mass block 1, a second Fabry - Perot interferometric cavity can be formed between the second displacement measurement component 52 and the mass block 1, a third Fabry - Perot interferometric cavity can be formed between the third displacement measurement component 43 and the mass block 1, and a fourth Fabry - Perot interferometric cavity can be formed between the fourth displacement measurement component 54 and the mass block 1.

[0077] Optionally, a mirror can be provided on the end face of the mass block 1, or the end face of the mass block 1 can be polished so that the end face of the mass block 1 can serve as the first reflection point. The first end face of the optical fiber A can serve as the second reflection point.

[0078] The light from the modulation module 3 passes through the optical fiber A to reach the first reflection point and the second reflection point. The light reflected from the first reflection point and the light reflected from the second reflection point will interfere to form a first energy W1 and a second energy W2, as Figure 3 shown. The relationship between the energy after interference and the wavelength of the spectrum (which can be the first spectrum, etc.) is as Figure 4 shown.

[0079] In some possible implementation manners, in combination with Figure 1 , the demodulation module 3 is specifically configured to:

[0080] Calculate the cavity length of the first Fabry - Perot interferometric cavity according to the wavelengths corresponding to adjacent peaks or valleys in the first spectrum, and calculate the vibration acceleration of the object to be measured in the first direction according to the cavity length of the first Fabry - Perot interferometric cavity.

[0081] Calculate the cavity length of the second Fabry - Perot interferometric cavity according to the wavelengths corresponding to adjacent peaks / valleys in the second spectrum, and calculate the vibration acceleration of the object to be measured in the second direction according to the cavity length of the second Fabry - Perot interferometric cavity.

[0082] Specifically, the cavity lengths of the first Fabry - Perot interferometric cavity and the second Fabry - Perot interferometric cavity respectively satisfy:

[0083]

[0084] where d1 represents the cavity length of the first Fabry - Perot interferometric cavity, λ 11 represents the wavelength corresponding to the h - th peak / valley in the first spectrum, λ 12 represents the wavelength corresponding to the (h + 1)-th peak / valley in the first spectrum. d2 represents the cavity length of the second Fabry - Perot interferometric cavity, λ 21 represents the wavelength corresponding to the h - th peak / valley in the second spectrum, λ 22 represents the wavelength corresponding to the (h + 1)-th peak / valley in the second spectrum.

[0085] The vibration acceleration of the object to be measured in the first direction and the vibration acceleration of the object to be measured in the second direction respectively satisfy:

[0086]

[0087] wherein, a1 represents the vibration acceleration of the object to be measured in the first direction, and a2 represents the vibration acceleration of the object to be measured in the second direction. k represents the elastic coefficient of the first spring and the second spring. m represents the mass of the mass block. Δd1 represents the change in the cavity length of the first Fabry-Perot interferometer cavity, and satisfies Δd1 = d1 - d 10 , d 10 represents the initial cavity length of the first Fabry-Perot interferometer cavity. Δd2 represents the change in the cavity length of the second Fabry-Perot interferometer cavity, and satisfies Δd2 = d2 - d 20 , d 20 represents the initial cavity length of the second Fabry-Perot interferometer cavity. The unit of the change in the cavity length of the above Fabry-Perot interferometer cavity is mm.

[0088] It can be seen that the change in the cavity length Δd1 of the first Fabry-Perot interferometer cavity can be calculated based on the cavity length of the first Fabry-Perot interferometer cavity, and the change in the cavity length Δd2 of the second Fabry-Perot interferometer cavity can be calculated based on the cavity length of the second Fabry-Perot interferometer cavity. The relationship between the change in the cavity length of the Fabry-Perot interferometer cavity (which can be the change in the cavity length Δd1 of the first Fabry-Perot interferometer cavity or the change in the cavity length Δd2 of the second Fabry-Perot interferometer cavity) and time is as Figure 5 shown.

[0089] In some other possible implementation manners, in combination with Figure 2 , the demodulation module 3 is specifically configured to:

[0090] calculate the cavity length of the first Fabry-Perot interferometer cavity formed between the first displacement measurement component 42 and the mass block 1 according to the wavelengths corresponding to adjacent wave peaks or wave valleys in the first spectrum, calculate the cavity length of the third Fabry-Perot interferometer cavity formed between the third displacement measurement component 62 and the mass block 1 according to the wavelengths corresponding to adjacent wave peaks or wave valleys in the third spectrum, and calculate the vibration acceleration of the object to be measured in the first direction according to the cavity lengths of the first Fabry-Perot interferometer cavity and the third Fabry-Perot interferometer cavity respectively.

[0091] calculate the cavity length of the second Fabry-Perot interferometer cavity formed between the second displacement measurement component 52 and the mass block 1 according to the wavelengths corresponding to adjacent wave peaks / valleys in the second spectrum, calculate the cavity length of the fourth Fabry-Perot interferometer cavity formed between the fourth displacement measurement component 72 and the mass block 1 according to the wavelengths corresponding to adjacent wave peaks or wave valleys in the fourth spectrum, and calculate the vibration acceleration of the object to be measured in the second direction according to the cavity lengths of the second Fabry-Perot interferometer cavity and the fourth Fabry-Perot interferometer cavity respectively.

[0092] Specifically, the cavity lengths of the first Fabry - Perot interferometric cavity, the second Fabry - Perot interferometric cavity, the third Fabry - Perot interferometric cavity, and the fourth Fabry - Perot interferometric cavity can satisfy:

[0093]

[0094] where d1 represents the cavity length of the first Fabry - Perot interferometric cavity, λ 11 represents the wavelength corresponding to the h - th peak / trough in the first spectrum, and λ 12 represents the wavelength corresponding to the (h + 1)-th peak / trough in the first spectrum. d2 represents the cavity length of the second Fabry - Perot interferometric cavity, λ 21 represents the wavelength corresponding to the h - th peak / trough in the second spectrum, and λ 22 represents the wavelength corresponding to the (h + 1)-th peak / trough in the second spectrum. d3 represents the cavity length of the third Fabry - Perot interferometric cavity, λ 31 represents the wavelength corresponding to the h - th peak / trough in the third spectrum, and λ 32 represents the wavelength corresponding to the (h + 1)-th peak / trough in the third spectrum. d4 represents the cavity length of the fourth Fabry - Perot interferometric cavity, λ 41 represents the wavelength corresponding to the h - th peak / trough in the fourth spectrum, and λ 42 represents the wavelength corresponding to the (h + 1)-th peak / trough in the fourth spectrum.

[0095] The vibration acceleration of the object to be measured in the first direction and the vibration acceleration of the object to be measured in the second direction respectively satisfy:

[0096]

[0097] where a1 represents the vibration acceleration of the object to be measured in the first direction, and a2 represents the vibration acceleration of the object to be measured in the second direction. k represents the elastic coefficient of the first spring, the second spring, the third spring, or the fourth spring, with the unit of N / m. m represents the mass of the mass block, with the unit of g. Δd1 represents the change in the cavity length of the first Fabry - Perot interferometric cavity, satisfying Δd1 = d1 - d 10 , and d 10 represents the initial value of the cavity length of the first Fabry - Perot interferometric cavity. Δd2 represents the change in the cavity length of the second Fabry - Perot interferometric cavity, satisfying Δd2 = d2 - d 20 , and d 20 represents the initial value of the cavity length of the second Fabry - Perot interferometric cavity. Δd3 represents the change in the cavity length of the third Fabry - Perot interferometric cavity, satisfying Δd3 = d3 - d 30 , and d 30It represents the initial cavity length of the third Fabry - Perot interferometric cavity. Δd4 represents the change in the cavity length of the fourth Fabry - Perot interferometric cavity, and it satisfies Δd4 = d4 - d 40 where d 40 represents the initial cavity length of the fourth Fabry - Perot interferometric cavity. The unit of the change in the cavity length of the above - mentioned Fabry - Perot interferometric cavity is mm.

[0098] It can be seen that the vibration accelerations of the object to be measured in the first direction and the second direction are both positively correlated with the change in the cavity length of the Fabry - Perot interferometric cavity. Through the above process, the influence of the thermal expansion coefficients of the housing, the acceleration measurement component, the mass block, etc. on the change in the cavity length of the Fabry - Perot interferometric cavity can be suppressed, realizing automatic temperature compensation and further improving the measurement accuracy of the two - way vibration sensor.

[0099] It can also be seen that according to the cavity length of the first Fabry - Perot interferometric cavity, the change in the cavity length Δd1 of the first Fabry - Perot interferometric cavity can be calculated. According to the cavity length of the second Fabry - Perot interferometric cavity, the change in the cavity length Δd2 of the second Fabry - Perot interferometric cavity can be calculated. According to the cavity length of the third Fabry - Perot interferometric cavity, the change in the cavity length Δd3 of the third Fabry - Perot interferometric cavity can be calculated. According to the cavity length of the fourth Fabry - Perot interferometric cavity, the change in the cavity length Δd4 of the fourth Fabry - Perot interferometric cavity can be calculated. The relationship between the change in the cavity length of the Fabry - Perot interferometric cavity (which can be the change in the cavity length Δd1 of the first Fabry - Perot interferometric cavity, the change in the cavity length Δd2 of the second Fabry - Perot interferometric cavity, the change in the cavity length Δd3 of the third Fabry - Perot interferometric cavity, and the change in the cavity length Δd4 of the fourth Fabry - Perot interferometric cavity) and time is as Figure 5 shown.

[0100] Furthermore, according to the vibration acceleration of the object to be measured in the first direction, the vibration frequency and vibration intensity of the object to be measured in the first direction can be obtained. According to the vibration acceleration of the object to be measured in the second direction, the vibration frequency and vibration intensity of the object to be measured in the second direction can be obtained. This application embodiment will not be introduced in detail.

[0101] The two - way vibration sensor provided by this application can be used for vibration measurement in transmission towers, pipe galleries, buildings, water conservancy projects, and geological projects. The two - way vibration sensor based on the Fabry - Perot interference principle is non - contact, so it has the advantages of high linearity, high precision, long service life, anti - electromagnetic interference, and no zero drift.

[0102] This application embodiment also provides a power device, which can include the above - mentioned two - way vibration sensor.

[0103] Optionally, the power device can be a power transmission and transformation device, a power generation device, etc., which is not limited in this application embodiment.

[0104] The above are only embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application are included within the scope of the claims of the present application pending for invention.

Claims

1. A bidirectional vibration sensor based on the Fabry-Perot interference principle, characterized in that: It includes a mass block, a first acceleration measurement component, a second acceleration measurement component, a third spring, a fourth spring, a housing and a demodulation module; The demodulation module is located outside the housing, the first acceleration measurement assembly, the second acceleration measurement assembly, the third spring, and the fourth spring are all located inside the housing, the first ends of the first acceleration measurement assembly and the third spring are respectively fixed to different sides of the mass block in the first direction, the first ends of the second acceleration measurement assembly and the fourth spring are respectively fixed to different sides of the mass block in the second direction, and the mass block is in a suspended state; The second ends of the first acceleration measurement assembly, the second acceleration measurement assembly, the third spring and the fourth spring are fixed to the housing, and the second ends of the first acceleration measurement assembly and the second acceleration measurement assembly are connected to the demodulation module; The first direction is perpendicular to the second direction.

2. The bidirectional vibration sensor according to claim 1, characterized in that: The first acceleration measurement assembly and the third spring are both used to: fix the mass block in the first direction; The second acceleration measurement assembly and the fourth spring are both used to: fix the mass block in the second direction; The demodulation module is used to collect a first spectrum from the first acceleration measurement component and a second spectrum from the second acceleration measurement component, calculate the vibration acceleration of the object under test in the first direction according to the first spectrum, and calculate the vibration acceleration of the object under test in the second direction according to the second spectrum.

3. The bidirectional vibration sensor according to claim 2, characterized in that: The bidirectional vibration sensor also includes a third displacement measurement component and a fourth displacement measurement component; The third displacement measuring assembly is located inside the third spring, and the third displacement measuring assembly is coaxial with the third spring, and the third displacement measuring assembly and the third spring constitute a third acceleration measuring assembly; The fourth displacement measuring component is located inside the fourth spring, and the fourth displacement measuring component is coaxial with the fourth spring. The fourth displacement measuring component and the fourth spring constitute a fourth acceleration measuring component.

4. The bidirectional vibration sensor according to claim 3, characterized in that: The demodulation module is also used to collect a third spectrum from the third acceleration measurement component and a fourth spectrum from the fourth acceleration measurement component, and calculate the vibration acceleration of the object under test in the first direction according to the first spectrum and the third spectrum, and calculate the vibration acceleration of the object under test in the second direction according to the second spectrum and the fourth spectrum.

5. The bidirectional vibration sensor according to claim 4, characterized in that: The first acceleration measurement assembly includes a first spring and a first displacement measurement assembly, wherein the first displacement measurement assembly is located inside the first spring, and the first displacement measurement assembly is coaxial with the first spring; The second acceleration measurement assembly includes a second spring and a second displacement measurement assembly, the second displacement measurement assembly is located inside the second spring, and the second displacement measurement assembly is coaxial with the second spring; A first end of each of the first spring and the second spring is fixed to the mass block, and a second end of each of the first spring and the second spring is fixed to the housing.

6. The bidirectional vibration sensor according to claim 5, characterized in that: The first displacement measurement assembly, the second displacement measurement assembly, the third displacement measurement assembly and the fourth displacement measurement assembly all include an optical fiber and a protective tube; The optical fiber is located inside the protective tube and is coaxial with the protective tube. The first end face of the optical fiber is fixed to the protective tube. The second end face of the optical fiber passes through the outer shell and is connected to the demodulation module. The second end of the protective tube is fixed to the outer shell.

7. The bidirectional vibration sensor according to claim 6, characterized in that: There is a gap between the first end face of the optical fiber and the mass block, and the width of the gap is in millimeter order.

8. The bidirectional vibration sensor according to claim 7, characterized in that: The first end face of the optical fiber and the end face of the mass block form a Fabry-Perot interference cavity; The end surface of the mass block is provided with a reflector, or the end surface of the mass block is polished.

9. The bidirectional vibration sensor according to claim 8, characterized in that: The demodulation module is specifically used for: Calculating the cavity length of a first Fabry-Perot interferometer cavity formed between the first displacement measurement component and the mass block according to wavelengths corresponding to adjacent peaks or troughs in the first spectrum, and calculating the vibration acceleration of the measured object in the first direction according to the cavity length of the first Fabry-Perot interferometer cavity; The cavity length of the second Fabry-Perot interference cavity formed between the second displacement measurement component and the mass block is calculated according to the wavelengths corresponding to adjacent peaks / troughs in the second spectrum, and the vibration acceleration of the object under test in the second direction is calculated according to the cavity length of the second Fabry-Perot interference cavity.

10. The bidirectional vibration sensor according to claim 9, characterized in that: The cavity lengths of the first Fabry-Perot interferometer cavity and the second Fabry-Perot interferometer cavity satisfy: Wherein, d1 represents the cavity length of the first Fabry-Perot interferometer cavity, λ 11 represents the wavelength corresponding to the hth peak / trough in the first spectrum, λ 12 represents the wavelength corresponding to the h+1th peak / trough in the first spectrum; d2 represents the cavity length of the second Fabry-Perot interferometer cavity, λ 21 represents the wavelength corresponding to the hth peak / trough in the second spectrum, λ 22 Indicates the wavelength corresponding to the h+1th peak / trough in the second spectrum.

11. The bidirectional vibration sensor according to claim 10, characterized in that: The vibration acceleration of the measured object in the first direction and the vibration acceleration of the measured object in the second direction respectively satisfy: Wherein, a1 represents the vibration acceleration of the measured object in the first direction, a2 represents the vibration acceleration of the measured object in the second direction; k represents the elastic coefficients of the first spring and the second spring; m represents the mass of the mass block; Δd1 represents the change in the cavity length of the first Fabry-Perot interferometer cavity, satisfying Δd1=d1-d 10 , d 10 represents the initial value of the cavity length of the first Fabry-Perot interferometer cavity; Δd2 represents the change in the cavity length of the second Fabry-Perot interferometer cavity, satisfying Δd2=d2-d 20 , d 20 represents the initial value of the cavity length of the second Fabry-Perot interferometer cavity.

12. The bidirectional vibration sensor according to claim 8, characterized in that: The demodulation module is specifically used for: Calculating the cavity length of a first Fabry-Perot interferometer cavity formed between the first displacement measurement component and the mass block according to wavelengths corresponding to adjacent peaks or troughs in the first spectrum, calculating the cavity length of a third Fabry-Perot interferometer cavity formed between the third displacement measurement component and the mass block according to wavelengths corresponding to adjacent peaks or troughs in the third spectrum, and calculating the vibration acceleration of the measured object in the first direction according to the respective cavity lengths of the first Fabry-Perot interferometer cavity and the third Fabry-Perot interferometer cavity; The cavity length of the second Fabry-Perot interference cavity formed between the second displacement measurement component and the mass block is calculated according to the wavelengths corresponding to adjacent peaks / troughs in the second spectrum, the cavity length of the fourth Fabry-Perot interference cavity formed between the fourth displacement measurement component and the mass block is calculated according to the wavelengths corresponding to adjacent peaks or troughs in the fourth spectrum, and the vibration acceleration of the object under measurement in the second direction is calculated according to the respective cavity lengths of the second Fabry-Perot interference cavity and the fourth Fabry-Perot interference cavity.

13. The bidirectional vibration sensor according to claim 12, characterized in that: The cavity lengths of the first Fabry-Perot interferometer cavity, the second Fabry-Perot interferometer cavity, the third Fabry-Perot interferometer cavity and the fourth Fabry-Perot interferometer cavity respectively satisfy: Wherein, d1 represents the cavity length of the first Fabry-Perot interferometer cavity, λ 11 represents the wavelength corresponding to the hth peak / trough in the first spectrum, λ 12 represents the wavelength corresponding to the h+1th peak / trough in the first spectrum; d2 represents the cavity length of the second Fabry-Perot interferometer cavity, λ 21 represents the wavelength corresponding to the hth peak / trough in the second spectrum, λ 22 represents the wavelength corresponding to the h+1th peak / trough in the second spectrum; d3 represents the cavity length of the third Fabry-Perot interferometer cavity, λ 31 represents the wavelength corresponding to the hth peak / trough in the third spectrum, λ 32 represents the wavelength corresponding to the h+1th peak / trough in the third spectrum; d4 represents the cavity length of the fourth Fabry-Perot interferometer cavity, λ 41 represents the wavelength corresponding to the hth peak / trough in the fourth spectrum, λ 42 Indicates the wavelength corresponding to the h+1th peak / trough in the fourth spectrum.

14. The bidirectional vibration sensor according to claim 13, characterized in that: The vibration acceleration of the measured object in the first direction and the vibration acceleration of the measured object in the second direction respectively satisfy: Wherein, a1 represents the vibration acceleration of the measured object in the first direction, a2 represents the vibration acceleration of the measured object in the second direction; k represents the elastic coefficient of the first spring, the second spring, the third spring or the fourth spring; m represents the mass of the mass block; Δd1 represents the change in the cavity length of the first Fabry-Perot interferometer cavity, satisfying Δd1=d1-d 10 , d 10 represents the initial value of the cavity length of the first Fabry-Perot interferometer cavity; Δd2 represents the change in the cavity length of the second Fabry-Perot interferometer cavity, satisfying Δd2=d2-d 20 , d 20 represents the initial value of the cavity length of the second Fabry-Perot interferometer cavity; Δd3 represents the cavity length change of the third Fabry-Perot interferometer cavity, satisfying Δd3=d3-d 30 , d 30 represents the initial value of the cavity length of the third Fabry-Perot interferometer cavity; Δd4 represents the cavity length change of the fourth Fabry-Perot interferometer cavity, satisfying Δd4=d4-d 40 , d 40 represents the initial value of the cavity length of the fourth Fabry-Perot interferometer cavity.

15. The bidirectional vibration sensor according to claim 5, characterized in that: The first spring, the second spring, the third spring and the fourth spring have the same length and the same stiffness.

16. An electric power device, characterized in that: Comprising a bidirectional vibration sensor as claimed in any one of claims 1 to 15.

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