RU2471161C1 - Method for remote control and diagnosis of state of structures and engineering structures and device for realising said method - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: device which realises the disclosed method has a structural component 1, units for measuring: deformation 2, mechanical stress 3, vibration 4, pressure 5, flow 6, temperature 7 of the transported product, temperature 8 of the soil, electric current 9, electric potential 10 with a comparison electrode, transducers 11-19, a controller 20, a modem 21, a communication line 22 and a control station 23. The controller 20 has a reader and a microprocessor 30 with memory. The measuring units and transducers are in form of delay lines operating on surface acoustic waves. Each delay line has a piezoelectric crystal.

EFFECT: high efficiency of the method and device for remote control and diagnosis of the state of structures and engineering structures by reducing power consumption and increasing reliability of measuring units and transducers.

2 cl, 3 dwg

Description

The proposed technical solutions relate to test equipment and can be used for continuous non-destructive testing, assessment and prediction of the technical condition of structures and engineering structures, for example, potentially dangerous sections of pipelines, during the entire period of their operation.

Known methods and devices for remote monitoring and diagnostics of the state of structures and engineering structures (Autosvid. USSR No. 934.269, 1.458.647, 1.695.161, 1.733.837, 1.781.564, 1.781.577, 1.812.386; RF patents No. No. 2.037.797, 2.046.311, 2.079.829, 2.135.887, 2.146.810, 2.190.152, 2.194.919, 2.206.817, 2.229.703, 2.230.978, 2.247.958, 2.276.304; patents USA No. 3.170.152, 3.851.521, 4.206.402, 5.894.092; French patent No. 2.294.389; BM Lapshin et al. Automated system for continuous monitoring of the integrity of underwater pipelines. - Oil industry, 1989, No. 10 , p. 63, fig. 1; Karmazinov F.V., Zarenkov D.V., Dikarev V.I., Koinash B.V. Water, oil, gas and pipes in our life. St. Petersburg, 2005, “Technical Book”, pp. 179-214 and others).

Of the known methods and devices closest to the proposed are the "Method of remote monitoring and diagnostics of the state of structures and engineering structures and a device for its implementation" (RF patent No. 2.247.958, G01M 5/00, 2003), which are selected as prototypes.

The known method consists in the fact that at the control point register signals from the measurement units installed in the places of diagnosis of structures, and compare them with pre-fixed values. In this case, the measurement units are mounted on a structural element made of the same material as the entire structure. Metrological certification of the structural element is carried out by establishing dependencies between the signals from the measurement units and the calibrated external influences, register them at the control point and use them as pre-recorded signals. An element with measuring units mounted on it is cut into the places of diagnosis of the structure, and the state of the structure is judged by the deviation of the received signals from the measurement units from pre-registered signals. The device contains a control point, measurement units located in the places of diagnosis of the structure, converters, communication line, controller. Moreover, the measurement units are placed on a metrologically certified structural element, made of the same material as the entire structure, and embedded in the diagnostic places of the structure. The structural element is connected to the corresponding converters connected by their outputs to the input of the controller connected to the modem, which is connected via the output line to the control point via a communication line.

In the known technical solutions, one of the main elements is the measurement units and transducers, which are used as deformation, linear shear, pressure, vibration, temperature, humidity, flow sensors, etc. In this case, the converters are based on various physical principles. Inductive, potentiometric, and strain gauge converters are widely known.

The advantage of inductive sensors and converters are:

- accuracy (0.1%) of measurements in a wide range of displacements (± 20 mm) in a wide temperature range from -55 to + 85 ° C;

- resolution (10 ^-3 mm);

- high linearity (0.1%);

- reliability (10 ^-6 );

- manufacturability;

- practically independent of atmospheric conditions;

- suitable for use in extremely aggressive environments.

The main disadvantages are:

- high power consumption from 100 to 500 W;

- difficulty in processing the recorded signals;

- require a stable sinusoidal voltage supply.

The advantage of potentiometric sensors and transducers are:

- measurement accuracy (0.5%) in a wide range of movements, in a wide temperature range from -40 to + 65 ° C;

- resolution (10 ^-2 mm);

- reliability (10 ^-6 );

- high linearity (0.5%);

- low power consumption from 2 to 10 mW.

The main disadvantages are:

- low efficiency in the range of movements less than ± 1 mm;

- wear of the potentiometric element;

- high price.

The advantage of strain gauges and transducers are:

- measurement accuracy (1%) in the range of movement (± 0.2; ± 2.0; ± 5.0 mm) in a wide temperature range from -40 to + 65 ° C;

- resolution (10 ^-3 mm);

- low power consumption from 1 to 5 mW, which is very important for wireless monitoring systems.

The main disadvantages are:

- aging of strain-sensitive elements;

- the presence of hysteresis.

Therefore, the main disadvantages of the known sensors and converters are high power consumption and low reliability.

High energy consumption is associated with the presence of power sources (batteries and accumulators) and the operation of sensors and converters in continuous mode. Since the process, for example, pipeline deformation is very slow and only in emergency situations requires a continuous flow of information, the algorithm of the known method and device allows you to set the polling intervals of the measurement units from 5 seconds to 1 month. In most cases, 1-2 measurements per day are enough to monitor pipelines.

The low reliability of known measurement units and transducers is associated with the reliability of power supplies and the need for their regular replacement. As a rule, the duration of any power source does not exceed several days.

High energy consumption and low reliability of measurement units and converters reduce the effectiveness of the method and device for remote monitoring and diagnostics of the state of structures and engineering structures.

An object of the invention is to increase the efficiency of the method and device for remote monitoring and diagnostics of the state of structures and engineering structures by reducing energy consumption and improving the reliability of measurement units and converters.

The problem is solved in that the method of remote monitoring and diagnostics of the state of the structure and engineering structures, consisting, in accordance with the closest analogue, in that the control point records signals from the measurement units installed in the places of diagnosis of the structure, compares them with pre-fixed values and judging by the deviation of the received signals from pre-recorded signals about the presence of changes in the controlled parameters, the structural element is made of the same material and, as the whole structure, place measurement units on it, carry out metrological certification of the element with the measurement units placed on it by establishing the dependencies between the signals from the measurement units and calibrated external influences, register these dependencies at the control point and use them as pre-recorded signals , insert the element with the measurement units mounted on it to the places of diagnosis of the structure and the deviation of the received signals from the measurement units from pre-registered of the measured signals is judged on the state of the structure, differs from the closest analogue in that the measurement units and transducers are performed as delay lines on surface acoustic waves, m harmonic oscillations are generated sequentially on the controller at different carrier frequencies, they are irradiated with delay lines tuned to m carrier frequencies , on each delay line, electromagnetic harmonic vibration is converted into an acoustic wave, ensure its propagation over the surface of the piezocrystal and back reflection, pr form a reflected acoustic wave into an electromagnetic signal with phase shift keying, the internal structure of which corresponds to the structure of interdigital transducers of surface acoustic waves, which reflects the serial number of the delay line and the magnitude of the parameter being monitored, a complex signal with phase shift keying is radiated into the air, received on the controller, synchronized detection, emit a low-frequency voltage corresponding to the serial number of the delay line and the phase shift, respectively Enikeev external impact, and is sent to the microprocessor with a memory in which calculate and transform the information received.

The problem is solved in that the device for remote monitoring and diagnostics of the state of structures and engineering structures, containing, in accordance with the closest analogue, a control point, measurement units located in the places of diagnosis of the structure, converters, communication line, controller, while the measurement units are located on metrologically certified structural element, made of the same material as the whole structure, and embedded in the diagnostic places of the structure, structural element, with the measuring units on it, connected to the corresponding transducers, connected by their outputs to the input of the controller connected to the modem, which is connected via the output line to the control point, differs from the closest analogue in that the controller is equipped with a reader, and each measurement unit and converter made in the form of a delay line on surface acoustic waves, and the reader contains sequentially connected synchronizer, carrier frequency synthesizer, duplexer, the input-output of which is connected an antenna with a transceiver antenna, a high-frequency amplifier and a phase detector, the second input of which is connected to the output of the carrier frequency synthesizer, and the output is connected to the input of the microprocessor with a storage device, the output of which is connected to the modem input, each delay line contains a piezocrystal, on whose surface an input and output interdigital transducers, input and output absorbers, wherein the input interdigital transducer is connected to a microstrip transceiver antenna, and the output the interdigital transducer connected to a matched load, the impedance of which depends on external influences.

The structural diagram of a device that implements the proposed method for remote monitoring and diagnostics of the state of structures and engineering structures is presented in figure 1. The block diagram of the controller 20 is shown in figure 2. Functional diagrams of measurement units and converters based on delay lines are shown in FIG.

The device consists of a structural element 1 made of the same material as the controlled section of the structure on which the measurement units are located:

- deformation 2, mechanical stress 3, vibration 4, pressure 5, flow 6, temperature 7 of the transported product, temperature 8 of the soil, electric current 9, electric potential 10 with a reference electrode.

The outputs of measurement units 2–9 and 10 are connected to the inputs of the corresponding transducers 11–19, the outputs of which, in turn, are connected to the input of the controller 20. The output of the controller 20 is connected to a modem 21, which is connected via a communication line 22 to the input of a remote point 23 controls.

The controller 20 comprises serially connected synchronizer 24, a carrier frequency synthesizer 25, a duplexer 26, the input-output of which is connected to the transceiver antenna 27, a high-frequency amplifier 28, a phase detector 29, the second input of which is connected to the output of the carrier frequency synthesizer 25, and a microprocessor 30 s a storage device, the output of which is connected to the input of the modem 21. All blocks, except for the microprocessor 30 with a storage device, form a reader.

Each measurement unit and transducer is made in the form of a surface acoustic wave (SAW) delay line and contains a piezocrystal 31.j, on the surface of which are input 33.j and output 34.j interdigital transducers (IDT), input 35.j and output 36.j absorbers. At the same time, the input IDT 33.j is connected to the microstrip transceiver antenna 32.j, and the output IDT 34.j is connected to the matched load 37.j, the impedance of which depends on the external influence (deformation, mechanical stress, vibration, pressure, flow, temperature, electric current) (j = 1, 2, ..., m).

The proposed method is carried out by the described device as follows (for example, a pipeline).

During operation of the pipeline, its technological parameters change due to aging and structural defects. Since the process of pipeline deformation is very slow and only in emergency situations a continuous flow of information is required, the algorithm of the device allows you to set the polling intervals of measurement units from tens of seconds to 1 month. In most cases, 1-2 measurements per day are enough to monitor the pipeline. At the same time, delay lines for surfactants are used as measurement units and converters, the main feature of which are small dimensions and the absence of power sources (batteries, accumulators). Each delay line is tuned to a specific frequency, which depends on the number of IDT electrodes and the distance between them.

An encoded command signal with a code corresponding to a given measuring pipe, is supplied from a remote control point 23 via a communication line 22 through a modem 21 to the controller 20 and switches it from standby to measurement mode. In this case, the synchronizer 24 includes a synthesizer 25 carrier frequencies, which sequentially generates harmonic oscillations:

u ₁ (t) = U ₁ Cos (w ₁ t + φ ₁ ),

u ₂ (t) = U ₂ Cos (w ₂ t + φ ₂ ),

……………………………………………………

u _j (t) = U _j Cos (w _j t + φ _j ),

……………………………………………………

u _m (t) = U _m Cos (w _m t + φ _m ), 0≤t≤T,

which through the duplexer 26 sequentially in time enter the transceiver antenna 23 and are radiated by it, providing irradiation of the corresponding delay lines to the SAW.

The energy of the high-frequency electromagnetic oscillation received by the microstrip transceiver antenna 32.j is supplied to the electrodes of the input IDT 33.j, causing mechanical harmonic oscillation in the piezoelectric delay line substrate due to the inverse piezoelectric effect. Mechanical vibrations generate a surface acoustic wave (SAW), which propagates both in the direction of the output IDT 34.j and in the direction of the input absorber 35.j. Mechanical vibrations lead to a change in the potential difference between the IDT 34.j electrodes (the phenomenon of direct piezoelectric effect), which causes the appearance of a high-frequency current flowing through the load circuit 37.j. Reflected from the IDT 34.j towards the output absorber 36.j and the IDT 33.j, the SAW, weakened in amplitude due to the loss delay line introduced by the sound pipe, leads to a change in the potential difference between the IDT electrodes 33.j, causing a load (microstrip transceiver antenna 32.j) high-frequency current (j = 1, 2, ..., m). Antenna 32.j emits complex PSK signals:

u _c1 (t) = U _c1 · Cos [w ₁ t + φ _к1 (t) + φ ₁ + Δφ ₁ ],

u _c2 (t) = U _c2 · Cos [w ₂ t + φ _к2 (t) + φ ₂ + Δφ ₂ ],

……………………………………………………………………………………

u _cj (t) = U _cj · Cos [w _j t + φ _кj (t) + φ _j + Δφ _j ],

……………………………………………………………………………………

u _cm (t) = U _cm · Cos [w _m t + φ _кm (t) + φ _m + Δφ _m ], 0≤t≤T,

where φ _кj (t) = {0, π} is the manipulated component of the phase, which displays the law of phase manipulation in accordance with the internal structure of the IDT, which reflects the serial number j of the delay line;

Δφ _j is the phase shift corresponding to external influences (deformations, mechanical stress, vibrations, pressure, etc.), under the influence of which the load impedance 37.j and the reflection coefficient change.

Absorbers 35.j and 36.j provide a regime of traveling acoustic waves.

Complex QPSK signals u _cj (t) (j = 1, 2, ..., m) are sequentially received by the transceiver antenna 27 of the controller 20 and fed through the duplexer 26 and the high-frequency amplifier 28 to the first input of the phase detector 29, to the second input of which harmonic oscillations u _j (t) from the output of the synthesizer 25 carrier frequencies as reference voltages. As a result of synchronous detection at the output of the phase detector 29, low-frequency voltages are sequentially released

U _нj (t) = U _нj · Cos [φ _кj (t) + Δφ _j ],

;Where

;

proportional to the serial number of the delay line and the controlled parameter (deformation, mechanical stress, vibration, pressure, etc.).

Interrogation and control of delay lines characterizing the flow rate, temperature of the transported product, soil temperature, electric current and electric potential are carried out in a similar way. The low-frequency voltages from the output of the phase detector 29 are sequentially supplied to the microprocessor 30 with a storage device that calculates and converts the phase shifts Δφ _i into a digital form. The calculation result is sequentially fed to the modem 21 and through the communication line 22 to the remote control point 23, where this result is compared with the data obtained during metrological certification, and the technical condition of the pipeline is analyzed.

During metrological certification of the device, the determination of the static characteristics of the delay lines and the entire device as a whole is carried out according to GOST 8.508-84, according to which the static characteristics are determined with the given levels of accuracy and reliability in the form of polynomials from the given external influences.

Metrological certification of the pipe is carried out before its insertion into the pipeline.

A pipe with sensors installed on it, which after certification becomes a multichannel measuring device, is installed on a potentially hazardous section of the pipeline, previously determined by the project, and incoming signals are recorded, which are compared with the initial ones obtained during certification, and they determine the deviation by the static characteristics, evaluate state of the operational characteristics of the pipeline section.

Thus, the proposed method and device in comparison with prototypes and other technical solutions of a similar purpose provide an increase in the effectiveness of remote monitoring and diagnostics of the state of the structure and engineering structures, for example, potentially dangerous sections of pipelines, during the entire period of their operation. This is achieved by reducing energy consumption and improving the reliability of sensors, which are one of the main elements of the device that implements the proposed method.

The main feature of the sensors in the form of delay lines for surfactants is the small size and lack of power sources (batteries, accumulators).

Claims (2)

1. The method of remote monitoring and diagnostics of the state of structures and engineering structures, which consists in the fact that the control point records signals from the measurement units installed in the places of diagnosis of the structure, compares them with pre-recorded values and judges the presence of received signals from pre-recorded ones changes in the controlled parameters, while making a structural element from the same material as the whole structure, place measurement blocks on it, conduct the metro Logical certification of the element with the measurement units placed on it by establishing dependencies between the signals from the measurement units and calibrated external influences, register these dependencies at the control point and use them as pre-recorded signals, insert the element with the measurement units installed on it into the diagnostic places of the structure and the deviation of the received signals from the measurement units from pre-registered signals is judged on the state of the structure, characterized in that the unit measurements and transducers are performed in the form of delay lines on surface acoustic waves, m harmonic oscillations at different carrier frequencies are sequentially generated on the controller, they are irradiated with delay lines tuned to m carrier frequencies, electromagnetic harmonic oscillation is converted into an acoustic wave on each delay line, provide it propagation along the surface of the piezocrystal and back reflection, convert the reflected acoustic wave into an electromagnetic signal with phase shift keying, extra the directional structure of which corresponds to the structure of the interdigital transducers of surface acoustic waves, which reflects the serial number of the delay line and the magnitude of the controlled parameter, the complex signal with phase shift keying is radiated into the air, received on the controller, synchronously detected, the low-frequency voltage corresponding to the serial number of the delay line is isolated and a phase shift corresponding to external influence, and direct it to the microprocessor with a storage device, in which the calculation and conversion of the information received. 2. A device for remote monitoring and diagnostics of the state of structures and engineering structures, containing a control point, measuring units located in the places of structural diagnosis, transducers, a communication line, a controller, while the measuring units are placed on a metrologically certified structural element made of the same material, as the whole structure, and embedded in the places of diagnosis of the structure, the structural element with the measurement units placed on it is connected to the corresponding transducer connected by their outputs to the input of the controller connected to the modem, which is connected through the output line to the control point, characterized in that the controller is equipped with a reader, and each measurement unit and converter are made in the form of a delay line on surface acoustic waves, moreover, the reader contains a synchronizer, a carrier frequency synthesizer, a duplexer, the input-output of which is connected to a transceiver antenna, a high-frequency amplifier and a phase detector, a second input It is connected to the output of the carrier frequency synthesizer, and the output is connected to the input of the microprocessor with a storage device, the output of which is connected to the modem input, each delay line contains a piezocrystal, on the surface of which are input and output interdigital transducers, input and output absorbers, while the input interdigital converter is connected to a microstrip transceiver antenna, and the output interdigital converter is connected to a matched load, the impedance of which depends sieve from external influences.

Images