RU150177U1 - DEVICE FOR MEASURING THE VALUE OF WEAR AND PRODUCT TEMPERATURE DURING FRICTION - Google Patents

Abstract

1. A device for measuring the amount of wear and temperature of the product during friction, containing a series-connected laser source, a beam splitter, and at least one measuring optical fiber, the second end of which is designed to be placed in the product at a depth equal to or less than the distance to friction surface, as well as sequentially connected at least one transmitting fiber optic fiber, a detector and a controller for determining the amount of wear and temperature of the product during friction, when The first end of the transmitting fiber-optic fiber is connected to the second output of the beam splitter, characterized in that on the segment of the measuring fiber-optic fiber in the region of its second end, an intra-fiber optical sensor for wear and temperature of the product during friction is formed, the laser radiation source is made as a continuous laser source radiation, and the beam splitter as an optical circulator. 2. The device according to claim 1, characterized in that the source of continuous laser radiation is made broadband and has a spectral range of radiation, the width of which overlaps the width of the spectral reflectometric response of an intra-fiber optical sensor lying in this spectral range over the entire range of measured temperatures. The device according to claim 1, characterized in that the intra-fiber optical sensor is designed as an intra-fiber Bragg grating. The device according to claim 1, characterized in that the intra-fiber optical sensor is designed as an intra-fiber long-period grating.

Description

The technical solution relates to the technique of optical measurements of several product parameters simultaneously, in particular, to devices for measuring the amount of wear and temperature of products during friction, and can be used both in the process of their operation and in the study of these characteristics during development. Products under consideration are, as a rule, elements of various engines, turbines, and electric machines that are in contact motion with another product. The most obvious example of such products is the brush-collector assembly of an electric machine, the product being controlled is its brush, and the measured parameters are the amount of wear and temperature of the brush.

Devices for measuring the amount of wear and temperature of products during friction are, as a rule, built into the controlled product, and, for example, contain two control electrical conductors located in the product, isolated from the body of the product, at a certain depth and recording equipment (see A.с 1809481 USSR, IPC5 H01R 39/58. Device for controlling brush wear / NN Pavlutsky; publ. 15.04.1993, Bull. No. 14). At the same time, the threshold value of the wear of the product is determined, which is determined by the depth of the control electrical conductors, at which the rubbing products break the insulation of the conductors, the conductors are closed by the elements of the second rubbing product, and an electrical signal is received to the registration system to reach the wear threshold.

The disadvantage of this device is the lack of temperature control, which is of great importance for assessing the process and friction conditions. To measure the temperature, an additional sensor is required. Only a threshold indication of the amount of wear is provided. In addition, in a number of applications, for example, in electric machines, the control electric conductors can receive a high voltage supply of the motors, which can lead to failure of the measuring part of the device or require special additional measures to decouple the measuring part from the voltage.

A fiber-optic device is known for monitoring the amount of wear of products (see US Pat. No. 4884434, 73/7, G01M 11/08. Wear Sensor / T. Satake, E. Imada; publ. 05.12.1989), which contains control conductors several loops of segments of fiber optic optical fibers located at different depths of the product. Each segment is connected to a laser source and a detector. When the amount of wear of the depth of the first loop is reached, the length of the fiber optic fiber is torn, which leads to the formation of a corresponding value of wear at the detector output, etc.

This device allows you to get rid of the disadvantages of devices that use electrical control conductors and the possibility of high-voltage voltages on the measuring circuit. The disadvantage of this device is the lack of temperature control, which is of great importance for assessing the process and friction conditions. To measure the temperature, an additional sensor is required. In addition, only a threshold indication of the amount of wear is provided, although several measurement thresholds are generated.

The prototype of the technical solution is a device (see US Pat. 8571813 USA, 702/34, G01 / N 3/56. Fiber-optic sensor system for determining surface wear / Johnston RT; publ. 10.29.2013), which contains sequentially connected by a laser source, a beam splitter, and at least one measuring optical fiber, the second end of which is placed in the product at a depth equal to or less than the distance to the rubbing surface, as well as connected at least one transmitting optical fiber tovod detector and controller determine the wear quantity and temperature of the product by friction, wherein the first end of the transmitting fiber optic light guide is connected to the second output of the beamsplitter and the second end of the measuring fiber optic light guide portion is further formed from reemitted material.

The prototype works as follows. The re-emitting material is excited by pulsed radiation from a laser source through a beam splitter, and at least one measuring fiber optic fiber re-emits light energy at a different wavelength as a result of, for example, luminescence. Such material may be phosphorus. To measure the amount of wear and temperature of the product during friction, the characteristics of the re-emitting material are used. A detector characterized by the possibility of performing both amplitude and spectral measurements with determining the wavelengths of the radiation arriving at it, detects radiation from the re-emitting material through a beam splitter and a fiber-optic optical fiber and determines the amount of wear based on the amplitude characteristics of re-radiation, which changes when the re-emitting material is erased, and temperature - according to the spectral characteristics of re-radiation, namely, the temperature-dependent wavelength of re-radiation.

The prototype, in contrast to the analogs described above, allows you to simultaneously measure both the amount of wear and the temperature of the product, which is of great importance for assessing the process and friction conditions, and accordingly to assessing the quality of the product as a whole.

The disadvantage of the prototype is the design complexity, determined, inter alia, by the need to use chemically active re-emitting material, install it in the product and ensure reliable contact with the fiber optic fiber. The use of re-emitting material allows you to constantly monitor the amount of wear, however, a relatively small thickness of the re-emitting material is used, which leads to the need to use several fibers located in the product at different depths to ensure a given measurement range of the amount of wear. The method of measuring wear is cumbersome and difficult to implement. It should be noted the relatively low accuracy and temperature measurements using the luminescence method.

The technical problem to be solved is to increase the range of continuous measurement of the amount of wear per fiber, increase the accuracy of measurements of the amount of wear and temperature, and simplify the design of the device.

The technical problem to be solved is a device for measuring the amount of wear and temperature of a product during friction, which contains a laser radiation source, a beam splitter, and at least one measuring optical fiber, the second end of which is designed to be placed in the product at a depth equal to or less than the distance to the rubbing surface, as well as connected in series to at least one transmitting fiber-optic optical fiber, a detector and a controller for determining the amount of wear and temperature rounds of the product during friction, the first end of the transmitting fiber optic fiber connected to the second output of the beam splitter, is achieved by the fact that on the segment of the measuring fiber optic fiber in the region of its second end, an intra-fiber optical sensor for wear and temperature of the product during friction is formed, a laser radiation source made as a source of continuous laser radiation, and the beam splitter as an optical circulator.

A source of continuous laser radiation can be made broadband and has a spectral range of radiation, the width of which overlaps the width of the spectral reflectometric response of an intra-fiber optical sensor, also lying in this spectral range, in the entire range of measured temperatures.

The device can be performed using an intra-fiber optical sensor based on an intra-fiber Bragg grating.

The device can be performed using an intra-fiber optical sensor based on an intra-fiber long-period grating.

In FIG. 1 shows a block diagram of a device with an article.

In FIG. 2 shows the algorithm of the controller for determining the amount of wear and temperature of the product during friction.

A device for measuring the amount of wear and temperature of the product during friction (Fig. 1) contains a laser radiation source 1 connected in series, an optical circulator 2, and at least one measuring optical fiber 3, as well as at least one transmitter fiber optic fiber 4, detector 5 and controller for determining the amount of wear and temperature of the product during friction 6, and the first end of the transmitting optical fiber 4 is connected to the second output of the optical circuit ora 2. In addition, on a length L of the measuring optical fiber 3 in the region of its second end, an intra-fiber optical sensor 7 of the amount of wear and temperature of the product 8 during friction is formed, which is placed in the product 8 at a depth H equal to or less than the distance R from the rubbing surface, the source of laser radiation 1 is made as a source of continuous laser radiation.

The device can be made using a broadband source 1 of continuous laser radiation and has a spectral range of radiation, the width of which overlaps the width of the spectral reflectometric response of an intra-fiber optical sensor 7, also lying in this spectral range, over the entire range of measured temperatures.

The device can be performed using an intra-fiber optical sensor 7 based on an intra-fiber Bragg grating.

The device can be performed using an intra-fiber optical sensor 7 based on an intra-fiber long-period grating.

Consider the operation of the device for measuring the amount of wear and temperature of the product during friction.

The components of the circuit according to FIG. 1, a laser radiation source 1, a detector 5 and a controller for determining the amount of wear and temperature of the product during friction 6 are connected to power sources, a signal processing program is recorded according to the algorithm shown in FIG. 2 to the controller for determining the amount of wear and temperature of the product during friction 6. The product 8 has a part of the measuring optical fiber 3, the second end of which is placed in the product 8 at a depth H equal to or less than the distance R from the rubbing surface of the product 8 and some other products (not shown in FIG. 1). At the same time, on the length L of the measuring optical fiber 3 in the region of its second end (the distance from the edge of the optical sensor to the edge of the measuring optical fiber must be not less than the required resolution for measuring the amount of wear of the product during friction), an intra-fiber optical sensor 7 of the amount of wear is formed and product temperature during friction. The intra-fiber optical sensor 7 can be constructed on the basis of the Bragg intra-fiber lattice, as well as on the basis of the long-period intra-fiber lattice. The distance H-L = P is a constant value and determines the difference between the depth of installation of the intra-fiber optical sensor and its length. The value of P can be equal to 0, and R = H, which will be taken to simplify the explanation of the operation of the device.

Then the amount of wear of the product during friction will be determined as:

those. to measure the amount of wear of the product during friction, the length of the fiber optic sensor 7 is measured.

To measure the temperature of the product during friction, the central resonance wavelength λ _{i of the} reflectometric response of the intra-fiber optical sensor 7 is measured, which, when calibrated by the temperature T _C after installation in the product, is equal to the Bragg grating:

and for a long-period grating:

where n is the effective refractive index of the main mode of the core of the Bragg grating; Δn is the difference between the effective refractive indices of the core and shell of the long-period grating; Λ _BG and Λ _LPG , respectively, the period of the Bragg lattice and the long-period lattice (See Vasiliev, S.A. Fiber gratings of the refractive index and their applications / S.A. Vasiliev, O.I. Medvedkov, I.G. Korolev, A. S. Bozhkov, A.S. Kurkov, E.M. Dianov // Quantum Electronics. - 2005.- V. 35, No. 12. - S. 1085-1103).

As the temperature changes, the central resonance wavelength of the reflectometric response changes, which is a function of the temperature of the product, and its change is described by the following expression for the Bragg intra-fiber lattice integrated in the product:

where ΔT is the temperature change; α is the coefficient of thermal expansion of quartz glass.

Relation (3) gives a typical shift of λ _BG depending on the temperature of ~ 0.01 nm / ° C. (See ibid.)

For an intrafiber long-period grating, the shift Δλ _{LPG is} determined

Relation (4) gives a typical shift Δλ _LPG depending on the temperature of ~ 0.1 nm / ° C. (See ibid.)

Thus, the temperature measurement will be determined by the dependence:

or, expressed in terms of temperature from equations (2) - (5) and from the conditions:

- измеренная центральная резонансная длина волны рефлектометрического отклика внутриволоконного оптического датчика 7; T_M - измеряемая температура изделия, i - BG или LPG, в зависимости от типа решетки на которой выполнен внутриволоконный оптический датчик 7.Where

- the measured central resonant wavelength of the reflectometric response of the intrafiber optical sensor 7; T _M is the measured temperature of the product, i - BG or LPG, depending on the type of grating on which the intra-fiber optical sensor 7 is made.

To measure the temperature, the laser source 1 generates continuous radiation. This radiation through the optical circulator 2, enters the measuring fiber-optic optical fiber 3 and through it into the intra-fiber optical sensor 7.

- измеренная центральная резонансная длина волны рефлектометрического отклика внутриволоконного оптического датчика 7. Полученная информация поступает в контроллер определения величины износа и температуры изделия при трении 6, в котором по полученным значениям

, заложенным калибровочным значениям λ_i, T_C, Δλ_i/ΔT и в соответствии с (7) определяется температуры изделия при трении. Полученное значение поступает на устройство отображения информации (на фиг. 1 устройство отображения информации не показано).The reflectometric response of the intra-fiber optical sensor 7 through the measuring optical fiber 3, the first and second output of the optical circulator 2 transmitting the optical fiber 4 is fed to the detector 5, in which

- the measured central resonance wavelength of the reflectometric response of the intra-fiber optical sensor 7. The received information is sent to the controller for determining the amount of wear and temperature of the product during friction 6, in which according to the obtained values

embedded in the calibration values λ _i , T _C , Δλ _i / ΔT and in accordance with (7) the temperature of the product during friction is determined. The obtained value is supplied to the information display device (in Fig. 1, the information display device is not shown).

To measure the amount of wear of the product during friction, the same procedure is used as for measuring the temperature until the information about the reflectometry response of the intra-fiber optical sensor 7 in the detector 5 is processed.

, которая является функцией от его длины L.The intra-fiber optical sensor 7 generates a reflectometric response with amplitude A _i at the central resonant wavelength

, which is a function of its length L.

For an intra-fiber optical sensor 7, based on the Bragg intra-fiber lattice, this function can be described by the following expression:

where k _BG is the coupling coefficient of the Bragg intra-fiber lattice, which is constant for homogeneous Bragg intra-fiber lattices (See ibid.).

For an intra-fiber optical sensor 7 made on the basis of a long-period intra-fiber grating, this function can be described by the following expression:

where k _LPG is the coupling coefficient of the long-period interfiber lattice, which is constant for homogeneous long-wavelength interfiber lattices (see ibid.).

It can be seen from the above expressions that with a change in L, which in our case will be caused by wear of the product and a corresponding decrease in the length of the intrafiber optical sensor 7, there will be a change in the amplitude of its reflectometric response: in the case of the use of the Bragg grating in accordance with expression (8), in the case of using an intrafiber long-period grating in accordance with expression (9).

Let us determine the dependences L _i (A _i ) for the intra-fiber optical sensor 7:

- when using the Bragg intra-fiber grating

- when using a long-period grating

Thus, the reflectometric response of the intra-fiber optical sensor 7 through the measuring optical fiber 3, the first and second output of the optical circulator 2, the transmitting optical fiber 4 is fed to the detector 5, in which A _i is recorded - the measured central resonant wavelength of the reflectometric response of the intra-fiber optical sensor 7. The received information goes to the controller for determining the amount of wear and temperature of the product during friction 6, in which, according to the received values m A _i, laid values for _i, R, in accordance with (10) in the case of using Bragg grating (i = BG) and in accordance with (11) in the case of using long-period grating (i = LPG) (1) is determined by the value wear ΔR of the product during friction, the obtained value is transmitted to the information display device (in Fig. 1, the information display device is not shown).

The advantages of using the intra-fiber optical sensor 7 based on the Bragg intra-fiber lattice and the long-fiber intra-fiber lattice are the unique transformation of the measured temperature into a shift in the wavelengths of the radiation reflected from them and the possibility of simple manufacturing. In this case, the intra-fiber optical sensor 7 itself is an integral part of the measuring optical fiber 3, which further simplifies the design of the device compared to the prototype. In addition, as shown above, gratings are capable of simultaneously measuring the amount of wear. For typical Bragg gratings of 5-30 mm and fiber gratings of 20-60 mm, only one fiber is required to measure the wear of the product during friction by the specified value.

A device for measuring the amount of wear and temperature of a product during friction can be implemented using various types of measuring fiber optic optical fibers 3 and transmitting optical fiber 4, the specific form of which is determined depending on the tasks being solved: the range of measured temperatures, the physicochemical properties of the wear material, etc. It can be quartz, germanium, polymer, sapphire and other fiber optic fibers. In all of these optical fibers, intra-fiber optical sensors 7 may be formed based on Bragg gratings or long-period gratings.

A device for measuring the amount of wear and temperature of a product during friction can be implemented on the following elements, designed to operate at a wavelength of 1550 nm:

- source 1 of laser radiation to produce continuous broadband radiation SLD-1550-3 - laser diode company "Super-lum";

- optical circulator 2 - 3PIOC-1550 circulator of the Flyin company;

- measuring optical fiber 3 and transmitting optical fiber 4 - optical fiber SMF-28 company "Corning";

- an intra-fiber optical sensor 7 based on a Bragg intra-fiber lattice or a long-period lattice recorded on an SMF-28 fiber at the Scientific Center for Higher Education “Photonika” (Moscow), Research Institute of Prefs and Knitu-Kai (Kazan), Inversion-Fiber (Novosibirsk), Inversion-Sensor (Perm ), etc., or purchased sensors of these firms and FiberSense;

- detector 5 - LSIPD-175-FA fiber-optic InGaAs PIN photodetectors (receiving modules) from IFP;

- a controller for determining the amount of wear and temperature of the product during friction; 6 - a microprocessor controller based on chips from Atmel, Microchip, etc.

When implementing a device for measuring the amount of wear and temperature of a product during friction, all of the indicated blocks for generating, receiving and processing signals can be performed on a single chip or in an integral design.

Compared with the prototype device, for measuring the amount of wear and temperature of the product during friction using optical sensors, including sensors with re-emitting material, including those made on a single chip or in an integrated version, in which there is a dependence of the reflectometric response in amplitude on the amount of wear and according to the wavelength of their spectral characteristics of temperature, the proposed device intrafiber optical sensor does not require:

firstly, a significant number of measuring fiber optic fibers to cover the entire range of measured wear values and allows you to continuously measure wear within 5-30 mm for Bragg gratings and 20-60 mm for long-period gratings, while simultaneously taking temperature measurements;

secondly, the use of chemically active re-emitting materials, for example, phosphorus, which avoids the difficulties of joining the specified material with the optical part of the device and its operation, and also allows the manufacture of an integral measuring fiber-optic fiber with a fiber-optic sensor integrated in it without mechanical connections .

The above, allows us to judge a significant simplification of the design of the device as a whole.

Tests of an experimental device for measuring the amount of wear and temperature of a product during friction performed on Bragg intra-fiber gratings manufactured at the Scientific Research Institute of Advanced Research and Development of Optics and Optics KNITU-KAI (Kazan), calibrated on EXFO optical spectrum analyzers in the same place, showed that the device was used on one measuring optical fiber optical fiber to measure the amount of wear, it was possible to measure wear in the range up to 25 mm with a resolution of 100 μm and the product temperature during friction in the range up to 180 ° C with a temperature measurement error s 0,1 ° C. Moreover, the error in measuring the amount of wear and temperature was determined mainly by the error of the ADC of the controller for determining the amount of wear and temperature and significantly exceeds the measurement error of the prototype.

All this allows us to talk about achieving a solution to the technical problem - increasing the range of continuous measurement of the amount of wear per fiber, improving the accuracy of measuring the amount of wear and temperature, simplifying the design of the device.

Claims (4)

1. A device for measuring the amount of wear and temperature of the product during friction, containing a series-connected laser source, a beam splitter, and at least one measuring optical fiber, the second end of which is designed to be placed in the product at a depth equal to or less than the distance to friction surface, as well as sequentially connected at least one transmitting fiber optic fiber, a detector and a controller for determining the amount of wear and temperature of the product during friction, when The first end of the transmitting fiber-optic fiber is connected to the second output of the beam splitter, characterized in that on the segment of the measuring fiber-optic fiber in the region of its second end, an intra-fiber optical sensor for wear and temperature of the product during friction is formed, the laser radiation source is made as a continuous laser source radiation, and a beam splitter as an optical circulator. 2. The device according to claim 1, characterized in that the source of continuous laser radiation is made broadband and has a spectral range of radiation, the width of which overlaps the width of the spectral reflectometric response of an intra-fiber optical sensor lying in this spectral range over the entire range of measured temperatures. 3. The device according to p. 1, characterized in that the intra-fiber optical sensor is designed as an intra-fiber Bragg grating. 4. The device according to p. 1, characterized in that the intra-fiber optical sensor is designed as an intra-fiber long-period grating.

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