Summary of the invention
The purpose of this invention is to provide a kind of embedded fiber grating monitoring system based on remote transmission, it can overcome the defective of prior art, be implemented in real-time automatic collecting data and remote transmission under the unattended duty situation, thereby make remote Monitoring and Controlling become possibility.
For achieving the above object, the present invention takes following design proposal:
A kind of embedded fiber grating monitoring system based on remote transmission includes ASE wideband light source, optical circulator, optical fibre optical grating sensing array, Wavelength demodulation module and the energy supply control module of required power supply is provided for each unit; The input port of the broadband light incident light circulator that described ASE wideband light source produces through its output port output, inserts the grating sensor array, and the light signal of grating array reflection is sent into the Wavelength demodulation module by the optical circulator reflector port; Be provided with centralized control unit and data transmission module in this system, described centralized control unit is a core devices with the embedded microprocessor, and the fiber grating data handling utility software that can realize automatic data collection, remote transmission is installed; This monitoring system adopts the modular construction design, described ASE wideband light source, optical circulator, Wavelength demodulation module, centralized control unit, data transmission module and energy supply control module concentrate in the system chassis, described fiber-optic grating sensor array is installed in the monitoring point, by the light input interface on this monitoring system cabinet panel, the light signal of grating array reflection is imported this monitoring system, and the Wavelength demodulation module is demodulated into electric signal with the light signal that receives; Centralized control unit is gathered in real time and is handled the electric signal of Wavelength demodulation module demodulation by computer program, finally calculates the measured physical quantity of monitoring point by analyzing, handling, and the measurand information of preserving original signal automatically and resolving; Data transmission module transfers to numer centre by wireless public network with the original wavelength signal of monitoring point and the physical quantity information that calculates.
Described wireless public network is selected the GPRS wireless public network for use.
Control Software in the computer programming module of described centralized control unit adopts the Labview platform to write.
Described Wavelength demodulation module is selected the FBGA-S-1525-1565-FA demodulation module of U.S. Bayspec company for use, adopts usb mode.
The mode of operation of setting acquiescence in the described fiber grating data process application is automatic measurement pattern, clicks " manual measurement " and can enter the manual measurement pattern.
Monitoring system also disposes and conversion of solar energy can be become the solar panels of power storage in accumulator, for system provides power supply.
Described energy supply control module passes through the closure of Single-chip Controlling relay, and then controls the break-make of above-mentioned each modular power source, reduces system power dissipation.
Described optical circulator has the broadband light input, exports and reflects three ports at least.
Advantage of the present invention is:
1) the embedded fiber grating monitoring system that the present invention is based on remote transmission is provided with acquisition time, acquisition interval by the fiber grating data processing software that is installed on centralized control unit, enter automatic monitoring pattern, realize data automatic collecting, processing, preservation, transmission, the realization engineering is monitored in real time under unattended situation, it is reliable, the data of gathering are accurate, are suitable for promoting the use of;
2) by data transmission module Monitoring Data is transferred to numer centre by the GPRS wireless public network from the monitoring point, the real-time online function of data transmission module is beneficial to the remote transmission of data, is the fiber grating monitoring demodulated equipment that a kind of suitable engineering is used;
3) according to the relation between drift of fiber grating centre wavelength and the measurand, grating wavelength data to the monitoring collection in worksite directly calculate measurand by fiber grating monitoring demodulation software, and can show in real time, preserve, transmit, its visual result, easy and simple to handle;
4) by energy supply control module, the break-make of Control and Monitor System each several part power supply reduces power consumption, is suitable for open-air engineering and uses.
Embodiment
Consult embodiment shown in Figure 1, the embedded fiber grating monitoring system that the present invention is based on remote transmission includes: wideband light source 1, optical circulator 2, optical fibre optical grating sensing array 3, Wavelength demodulation module 4, centralized control unit 5, data transmission module 6, energy supply control module 7, solar panels 8 and accumulator 9.The input port of the output termination optical circulator 2 of wideband light source 1, the photoscanning incident optical grating sensing array 3 of optical circulator 2 delivery outlets output, the reflected light of optical fiber optical grating array 3 enters Wavelength demodulation module 4 by the reflex port of optical circulator 2, Wavelength demodulation module 4 is demodulated into the wavelength electric signal with light signal, centralized control unit is gathered these wavelength electric signal during by the fiber grating data processing software, calculate the drift of fiber grating centre wavelength, float the variable quantity that skew and the relation of measurand calculate measurand according to wavelength, centre wavelength and measurand are preserved, show, Monitoring Data is transferred to numer centre by the GPRS wireless public network.Energy supply control module passes through the closure of Single-chip Controlling relay, and then controls the break-make of each modular power source, reduces system power dissipation.Solar panels become power storage in accumulator conversion of solar energy, to the embedded fiber grating monitoring system power supply based on remote transmission.
Described wideband light source 1 is selected ASE(amplified spontaneous emission for use) wideband light source, have big, the degree of stability advantages of higher of output power.According to the centre wavelength of sensor, in wideband light source output spectrum scope, each sensor takies certain spectral range, according to the initial wavelength and the test wavelength of sensor, calculates the wave length shift of sensor in this spectral range.Power supply+the 5V of ASE light source, power supply ripple are less than 100mV, and wavelength output area 1525~1565nm, light output end joint style are FC/APC.
Described optical circulator 2 is nonreciprocal devices of a kind of multiport input and output, has the forward sequence conducting and characteristic that reverse transfer stops, can finish main story and lose with catoptrical and separate.The present invention selects three port photocirculators for use, and the light joint style is FC/APC.
Described optical fibre optical grating sensing array 3 is composed in series by the fiber-optic grating sensor of one group of different centre wavelength, is not subjected to wavelength that external physical quantity influences as initial wavelength sensor.After sensor was installed, each wavelength of measuring was as measuring wavelength, and the difference of measuring wavelength and initial wavelength is the wavelength shift of sensor.In the grating sensing array, different grating sensor initial center wavelength differences, the spectral range that takies during wave length shift are also different, thus, can realize the accurate location to survey sensor.
Described Wavelength demodulation module 4 can be selected the FBGA-S-1525-1565-FA demodulation module of U.S. Bayspec company for use, and the advantage of this module is: response speed is fast, and thermal stability is good, can realize the fast detecting to the grating sensor wavelength.Power supply+the 5V of Wavelength demodulation module, power supply ripple are less than 100mV, and the light input end joint style is FC/APC.Wavelength demodulation module and centralized control unit can carry out communication by parallel port, serial ports and USB mode, consider that the USB mode has interface flexible, communication characteristics efficiently, adopt the USB mode in based on the embedded fiber grating monitoring system of remote transmission.Connection mode is seen Fig. 2.
Setting, the collection of fiber grating sensor wavelength, the measurand that described centralized control unit 5 is main realizes acquisition parameters calculates, shows in real time, output and preserve and to the control of total system.Centralized control unit of the present invention is core with the embedded microprocessor, employing WindowsXP is an operating system, the fiber grating data process application is installed on it, is had the visual interface of hommization, carry out the real-time demonstration of parameter setting and test result easily.
Behind the described fiber grating data handling system application program launching, the mode of operation of acquiescence is automatic measurement pattern, and the workflow diagram of software as shown in Figure 3.Click " manual measurement " and can enter the manual measurement pattern.
Described automatic mode operation flow process is: at first open the information log file, detect the duty of demodulation module.When demodulation module is working properly, read acquisition time and sensor parameters, judge whether to arrive acquisition time according to the current time.When arriving acquisition time, carry out data acquisition, calculate measurand, metrical information is preserved with file mode, simultaneously data are transferred to numer centre by data transmission module, calculate next acquisition time according to acquisition interval then, next acquisition time, acquisition interval are write the acquisition time file, and instruction is finished in next acquisition time, acquisition interval and this collection sent to energy supply control module, energy supply control module is received instruction, disconnect the each several part power supply, system enters park mode.When arriving acquisition time, system can wake up automatically, connects each modular power source, enters duty.In automatic drainage pattern,, work state information is deposited in the information specific file for conveniently checking each surveying work state.When the demodulation module working state abnormal, with current time, demodulation module error message writing information file, and to energy supply control module transmission shutdown-instruction of restarting, closing center's control module simultaneously.Energy supply control module is received this instruction, disconnects the demodulation module power supply, delays time after 1 minute, recloses demodulation module and centralized control unit power supply, starts fiber grating data handling utility software, detects the demodulation module state, and state is normal, then gathers automatically.If undesired, then send shutdown-instruction of restarting once more, 3 times repeatedly, the demodulation module state is all undesired, then sends error message to numer centre, and the monitoring personnel receive information, handle accordingly according to miscue.
Described artificial mode workflow diagram is: sensor parameters and the time of gathering automatically and interval at first are set, then demodulation module are carried out initialization, detect the duty of demodulation module, read the acquisition parameter of demodulation module.When the duty of demodulation module is normal, image data, and dynamically show the wavelength of each grating sensor is in real time calculated measurand according to the relation between sensor wavelength and the measurand, and is shown in real time in the mode of chart.For the handled easily personnel use, fiber grating monitoring demodulation application software has operations prompting, practicality simple to operate.
At the function that can directly calculate the measurand data based on the embedded fiber grating monitoring system of remote transmission, described application software is dissimilar according to fiber-optic grating sensor, the calculating sensor test result.For strain transducer, according to
B=1000-2.3×K (2)
In the formula, Δ ε is strain, unit is μ ε, and K is the strain transducer strain coefficient, and λ ε 1 is strain transducer test wavelength, λ ε 0 is sensor reference wavelength (testing wavelength for the first time), λ T1 temperature sensor test wavelength, λ T0 temperature sensor reference wavelength, B is the temperature correction coefficient, α is the testee thermal expansivity, and Δ T is a temperature variation.According to 1,2,3 formulas calculate the strain value of sensor.
For displacement transducer, according to
In the formula, Δ L is displacement, and unit is mm, and K is a sensor coefficient, and λ l1 is a sensor displacement grating test wavelength, and λ l0 is a displacement grating reference wavelength; λ T1 temperature compensation grating test wavelength, λ T0 temperature compensation grating reference wavelength, λ y0 temperature compensation grating original wavelength, Ty0 temperature compensation grating initial temperature.Shift value according to 4,5 displacement calculating sensors.
For temperature sensor, according to
In the formula, T is a temperature, and unit is ℃, and A, B, C are the sensor temperature coefficient, and λ is a temperature sensor test wavelength, and λ 0 is the sensor original wavelength.Temperature value according to (6) accounting temperature sensor.
In one embodiment of the invention, it is the wireless transport module of GF-2008WW that described data transmission module 6 can be selected model for use.Digital transmission module is connected with centralized control unit by standard RS232 interface, centralized control unit sends to digital transmission module with monitoring information (grating wavelength data and the corresponding measurand that calculates) by RS232, digital transmission module utilizes the GPRS wireless public network, sensor information is transferred to numer centre, be convenient to the unified management and the Treatment Analysis of data.
The advantage that described public network has utilized GPRS to have because the GPRS technology makes full use of China Mobile's public network resource, is greatly saved construction cost, shortens the construction period, total system ratio of performance to price height; Message transmission rate is compared the fastest with other mechanics of communication, the communication propagation delay time is less; The monitoring coverage is wide, and the system scale expansion fast; After system built up, post and telecommunication tariff was according to the actual data communication flow rate calculation, and expense is cheap.Based on above-mentioned advantage, the present invention utilizes the GPRS wireless public network to carry out remote data transmission.
Described energy supply control module 7 carries out filtering with the voltage of power supply input, reduce ripple, according to of the requirement of each module to power supply, convert each module required voltage to, by the Single-chip Controlling relay closes, and then control the break-make of each modular power source, when not working in system, in time cut off each modular power source, realize the low-power consumption of system.The power supply control flow as shown in Figure 4.
The power supply control flow is: after each monitoring collection is finished, will be next time acquisition time, acquisition interval, and this collection finish instruction and send to energy supply control module, after power module is received instruction, disconnect light source module and conciliate the mode transfer block power supply, delayed time 2 minutes, after waiting for that centralized control unit is closed, disconnect the power supply of centralized control unit, total system enters park mode.Arrive acquisition time, energy supply control module wakes up automatically, connects light source and conciliates the mode transfer block power supply, delayed time 30 seconds, treat that power supply is stable after, connect the centralized control unit power supply, start fiber grating data handling utility software, enter the automatic operation mode state according to default setting.
After energy supply control module is received shutdown-instruction of restarting, disconnect light source and conciliate the mode transfer block power supply, delayed time 2 minutes, disconnect the centralized control unit power supply, delay time after 1 minute, connect light source, demodulation module and centralized control unit power supply more according to this, start the fiber grating data processing software, gather again.
Embedded fiber grating monitoring system based on remote transmission adopts DC power supply, and input voltage range is 10-20V, and energy supply control module carries out filtering to outside power supply, reduces ripple, and converts 12V to other module required voltage.The DC-DC dc conversion modules is selected VI-JOO, the VI-JO1 power module of U.S. VICOR company for use.Fig. 5 a, Fig. 5 b are the power supply filter circuit of pressure-stabilizing.
V1 converts input voltage to 5V among the figure, passes through C3, L2, C4 filtering then, reduces power supply ripple, and the 5V direct supply after the processing uses for ASE light source, demodulation module.Processing mode with same converts input voltage to 12V, uses for centralized control unit.
Because digital transmission module adopts the 9V power supply, therefore convert 12V to 9V with the AOZ1014 chip, provide power supply to digital transmission module.Concrete scheme as shown in Figure 6.
Because the embedded fiber grating monitoring system based on remote transmission is to be used for the engineering long term monitoring, so the Overall Power Consumption of system is a very important index.In order to reduce power consumption, by the closure of Single-chip Controlling relay, and then control the break-make of each modular power source, reduce system power dissipation.Specific implementation such as Fig. 7.
Vlaser is a light source power among the figure, and Vfbga is a Wavelength demodulation power module power supply.When monitoring, PFBG=1(is a high level), the JD1(relay) conducting, Vlaser=5Vout, Vfbga=5Vout; After having monitored, PFBG=0(is a low level), JD1 closes, Vlaser=0V, Vfbga=0V.
The control signal of relay is by the P1 mouth control of single chip computer AT 89C51, and specific implementation as shown in Figure 8.Among the figure, the break-make of P9V control data transmission modular power source, P9V=1, the power supply of connection data transmission module, P9V=0, deenergization; PFBG control light source is conciliate the break-make of mode transfer block power supply, PFBG=1, the power supply of connection light source and demodulation module, PFBG=0, deenergization; The break-make of PCPU control center control module power supply, PCPU=1 connects the centralized control unit power supply, PCPU=0, deenergization.
At function based on the embedded fiber grating monitoring system remote transmission of remote transmission, by data transmission module 6, Monitoring Data is transferred to numer centre by the GPRS wireless public network from the monitoring point, the remote transmission of the data that are beneficial to is fiber grating monitoring demodulated equipments that a kind of suitable engineering is used.
Because engineering monitoring equipment is monitored the restriction of condition in use, some monitoring of environmental does not have alternating current.Therefore for making things convenient for engineering monitoring, there are two kinds, Alternating Current Power Supply and solar powered dual mode based on the power supply mode of the embedded fiber grating monitoring system of remote transmission.When monitoring of environmental can connect alternating current, adopt the 220V/12V AC adapter, adapter output 12V powers to monitoring system.When monitoring of environmental does not have alternating current, adopt solar powered mode, solar panels with conversion of solar energy be power storage in accumulator, accumulator output 12V powers to monitoring system.
Our experiments show that the final embedded fiber grating monitoring system performance based on remote transmission that realizes of the present invention is: demodulation speed 200Hz, demodulation accuracy ± 5pm realizes can gathering automatically under the unmanned situation, the function of remote transmission.
The various embodiments described above can not depart from the scope of the present invention down in addition some variations, thus above explanation comprises and accompanying drawing shown in structure should be considered as exemplary, but not in order to limit the protection domain of the present patent application patent.