RU179547U1 - FIBER OPTICAL VIBRATION REGISTRATION DEVICE - Google Patents

Abstract

The utility model relates to the field of measurement technology. The fiber-optic device for recording vibrations contains a housing mounted for attachment to a controlled surface, an electromagnetic radiation source connected in series with a fiber optic fiber, a sensing element made in the form of a portion of a fiber optical fiber housed in the device body, and a photodetector included in the information processing unit . The sensitive element is made in the form of a fiber loop fixed on the base of the device. A load is fixed in the upper part of the loop of the fiber, and along the lower part of the loop there are bumpers for damping horizontal vibrations. The electromagnetic radiation source is configured to switch the working wavelength. EFFECT: continuous recording of vibration of a controlled object in the absence of the need to adjust the operating point before operating the device. 7il.

Description

The utility model relates to measuring equipment, namely to vibration sensors, and can be used to record vibrations.

Known fiber-optic accelerometer containing a housing, a pendulum with an inertial mass of cylindrical shape, two elastic cylindrical substrates, one of which is in contact with one end of the inertial mass, two fiber coils wound tightly on the side surfaces of the elastic cylindrical substrates, forming a double-beam interferometer, coherent two-wave light source, processing unit, consisting of two photodetectors, optical spectral-dividing device, two amplifiers, two integrators, two co comparators, two electronic switches, two reference voltages blocks, two controllable scaling device, two analog-digital converters and divider (RF Patent No. 2115933, 1998.07.20).

The disadvantages of the known device are the relative complexity of the optical circuit of the device, the need to configure the operating point before operating the device; low stability of the output signal to uncontrolled temperature changes in the environment; the need to process the interference signal to obtain measurement information.

The closest device of the same purpose to the claimed utility model in terms of features is a fiber optic accelerometer, consisting of a housing, a pendulum rigidly fixed on it, a sensing element in the form of a single-mode fiber waveguide containing a section with a reduced core diameter, and the housing is sealed and filled with a medium damping the natural oscillations of the pendulum, the pendulum is a flat spring, one end of which is fixed to the housing, and the other to the wave horse fiber portion is of reduced diameter of the core so as to ensure its initial displacement in the longitudinal direction (RF Patent №132564 from 09.20.2013 g). This device is taken as a prototype.

The known device allows for continuous registration of vibrations of a controlled object in the absence of the need to configure the operating point before operating the device and a simplified design.

Signs of the prototype, coinciding with the essential features of the claimed utility model, - the housing is installed with the possibility of attachment to a controlled surface; a source of electromagnetic radiation connected in series with a fiber optic waveguide, a sensing element made in the form of a portion of a fiber light guide located in the device body, and a photodetector included in the information processing unit.

The task to which the claimed technical solution is directed is to expand the arsenal of technical means for recording vibrations, allowing continuous recording of vibrations of a controlled object in the absence of the need to configure the operating point before operating the device.

The problem was solved due to the fact that in the known fiber-optic device for detecting vibrations, comprising a housing mounted with the possibility of attachment to a controlled surface, an electromagnetic radiation source, a sensing element made in the form of a portion of a fiber, placed in series as a fiber in the device case, and the photodetector included in the information processing unit, according to the utility model, the sensitive element is made in the form of a loop whether the fiber is fixed on the base of the device body, the load is fixed in the upper part of the fiber loop, and along the lower part of the loop there are boards for damping horizontal vibrations, while the electromagnetic radiation source is capable of switching the working wavelength.

Signs of the proposed technical solution, distinctive from the prototype - the sensitive element is made in the form of a fiber loop fixed to the base of the device; a load is fixed in the upper part of the fiber optic loop; along the lower part of the loop there are bumpers for damping horizontal vibrations; the electromagnetic radiation source is configured to switch the working wavelength.

Distinctive features in combination with the known ones will allow continuous recording of vibrations of the controlled object in the absence of the need to configure the operating point before operating the device. The arsenal of technical means of recording vibration is expanding.

The proposed device is illustrated by the drawings shown in FIG. 1-7.

In FIG. 1 is a diagram of a fiber optic vibration recording device.

In FIG. 2 shows the design of the sensing element.

In FIG. Figure 3 shows the deformation of a fiber during vibrations of a weight mounted on a fiber waveguide.

In FIG. 4 - dependences ΔР on the relative amplitude of oscillations at a frequency of 40 Hz and different bending diameters: 1 - d = 16 mm, 2 - 18 mm, 3 - 20 mm.

In FIG. 5 - dependences ΔР on the relative amplitude for different masses m: 1-m = 50 mg, 2-70, 3-100, 4-130, 5-160. Frequency 80 Hz, loop diameter 18 mm.

In FIG. 6 - dynamics of power changes at different relative amplitudes of oscillations, bending diameter 18 mm, frequency 40 Hz. 1 - S / S ₀ = 10%, 2-15%, 3-20%.

In FIG. 7 - dependences ΔР on the relative amplitude of oscillations, the bending diameter of 18 mm, for different frequencies. 1-40 Hz, 2-80 Hz.

The fiber-optic device for recording vibrations (Fig. 1) contains an electromagnetic radiation source - a laser 1, a sensitive element 2, a photodetector 3, which is included in the information processing unit 4 (personal computer PC).

The sensing element 2 is connected on one side to the photodetector 3, while on the other hand it is connected to the electromagnetic radiation source 1 by means of a fiber optical fiber 5. The electromagnetic radiation source 1 is configured to switch the operating wavelength.

Fiber-optic device for recording vibrations (Fig. 2) contains a housing 6 mounted with the possibility of attachment to a controlled surface. The sensitive element 2 is made in the form of a section of a fiber waveguide and is placed in the housing 6 of the device. The sensitive element is made in the form of a loop 7 of the optical fiber, mounted on the base of the housing 6 of the device. A load 8 is fixed in the upper part of the loop 7 of the optical fiber, and along the lower part of the loop 7 there are mounted bumpers 9 for damping horizontal vibrations. As a fiber waveguide, a single-mode or multimode fiber waveguide can be used. The sensitive element 2 during operation is installed on the controlled object.

In the claimed design, the amplitude registration of the signal, it is possible to use an incoherent radiation source.

The device operates as follows.

The radiation from the source 1 is directed to the sensing element 2 through the fiber 5, resistant to bending (Fig. 1, 2). The presence of vibration causes vertical oscillations of the load 8, which in turn leads to a change in the diameter of the curved fiber (Fig. 3). Part of the radiation passing through the curved fiber 7 leaves the fiber due to the violation of the total internal reflection, therefore, the power loss increases. The light transmitted through the sensing element 2 propagates further along the optical fiber 5 and enters the photodetector 3. The signal from the photodetector 3 is processed using specialized programs on PC 4.

In FIG. Figures 4-5 show the results of measuring the power loss P on the sensitive element at various loop diameters, as well as the dependence of the power loss on the mass of the load in the sensitive element.

Based on the data of FIG. 4-5, you can select the required sensitivity at the assembly stage, varying the mass of the load and the diameter of the loop.

To measure vibration, an experimental setup was implemented, the circuit of which is shown in FIG. 1. As a radiation source 1, a Thorlabs SFL1550S laser with a working wavelength of 1550 nm was used. Sensing element 2 is made of Corning SMF-28 Ultra optical fiber in the form of a loop with a diameter of 18 mm and a weight of 70 mg. The change in power loss due to vibration was produced by a 3 Thorlabs PM-200 photodetector.

The power loss measurement results are shown in FIG. 6-7.

According to the results obtained, it is seen that the magnitude of the power loss in the sensitive element depends on the frequency and amplitude of the vibration.

Thus, the proposed device allows for continuous registration of vibrations of the controlled object in the absence of the need to configure the operating point before operating the device. The arsenal of technical means of recording vibration is expanding.

Claims (1)

The fiber-optic device for recording vibrations comprises a housing mounted for attachment to a controlled surface, an electromagnetic radiation source connected in series with a fiber optic fiber, a sensing element made in the form of a portion of a fiber optical fiber housed in the device body, and a photodetector included in the information processing unit characterized in that the sensitive element is made in the form of a fiber optic loop, fixed on the base of the device body, in the upper th fiber loop part is secured goods, while along the bottom hinge part mounted bumpers for damping horizontal vibrations, the electromagnetic radiation source is adapted to switch the operating wavelength.

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