397results about How to "With anti-electromagnetic interference" patented technology

The present invention provides one kind of system to perform distributive multi-point detection for corrosion, crack, leakage, wax precipitation, scaling and other status in long oil and gas conveying pipeline by means of fiber grating sensing technology. The system includes near-infrared wide-band semiconductor laser source array, wavelength division multiplexer, bi-directional fiber coupler, fiber grating sensor array, spectral analyzer and signal transmission optical cable. The continuous near-infrared light signal the laser source array emits is transmitted to fiber grating sensor array embedded inside the long oil and gas conveying pipeline through the wavelength division multiplexer and the bi-directional fiber coupler, the sensor array detects the varying temperature and pressure of fluid inside the pipeline and reflects to the bi-directional fiber coupler while being coupled to the analyzer and the computer to obtain the conveying status inside the pipeline.

The invention relates to a vibration monitoring structure based on optical fiber polarized light time domain reflection sense, comprising a laser (1), a first coupler (2), a second coupler (7), a third coupler (8), a fourth coupler (11), a fifth coupler (13), an acoustic optical modulator (3), a polarizer (4), a circulator (5), a sensing optical fiber (6), a first analyzer (9), a second analyzer (10), a first detector (12), a second detector (14), a first low-pass filter (15), a second low-pass filter (16), a first analog-to-digital converter (17), a second analog-to-digital converter (18), anFPGA (19) and a microprocessor MCU (20); the method comprises the following steps: measuring the changes of the polarization state of each optical fiber section with time according to a plurality ofmeasurements, combining Fourier transformation technology to obtain frequency spectrum information, and analyzing the frequency spectrum information to obtain vibration information. Compared with theprevious method which is adopted by a POTDR system and carries out iteration operation on polarization state, the method has the advantages of simple algorithm and small data operation and greatly reduces monitoring time and cost of the system.

The invention discloses a distributed optical fiber test platform for monitoring an earth rock dam seepage condition. The distributed optical fiber test platform comprises a heating system, a seepage system and a DTS system; the distributed optical fiber test platform is a practical platform having strong operability, aimed at dam seepage monitoring and based on construction of a dam seepage monitoring two-field coupling simplified model; with combination of the DTS system, the distributed optical fiber test platform provides a possibility for a practical application of seepage monitoring engineering of a porous medium structural body, such as an earth rock dam and a dyke-dam, and builds a reliable test platform for various related test researches; and the distributed optical fiber test platform has the advantages of wide test range, high precision, simple layout, low monitoring cost, high working efficiency, strong engineering applicability and the like.

The invention discloses a wind generating set blade load measurement device. The wind generating set blade load measurement device comprises at least three fiber bragg grating sensor arrays, a demodulation module and a load data processing module, wherein each fiber bragg grating sensor array is formed by connecting at least four fiber bragg grating sensor groups in series sequentially; each fiber bragg grating sensor group consists of a strain sensor and a temperature sensor; the strain sensor is used for measuring the strain amount of a blade when the blade is loaded; the temperature sensor is used for compensating the temperature drift of the strain sensor caused by the ambient temperature change; the demodulation module is used for converting the signals of each strain sensor and each temperature sensor into corresponding strain amount values and temperature values respectively; the load data processing module is integrated with a load algorithm to process the strain amount value and the temperature value of each measurement point, convert the strain amount value and the temperature value of each temperature point into a waving bending moment and a shimmy bending moment, and output the waving bending moment and the shimmy bending moment to a pitch-variable control system or a master control system of a wind generating set.

The invention discloses a multi-dimensional multiplexing soliton optical fiber laser device which comprises a laser pump source and an annular laser resonant cavity consisting of a gain medium, a dispersive medium, a wavelength division multiplexer, an optical coupler, an optical circulator, a polarization controller and a polarizer. The laser pump source and the gain medium work together so as toprovide a gain amplification mechanism for laser device operation. The dispersive medium can be used for chromatic dispersion compensation of pulse laser so as to achieve chromatic dispersion management of an internal optical path of the laser device, and the optical circulator is a non-reciprocal optical transmission device for coupling the chromatic dispersion medium to construct a bidirectional transmission optical path structure. Via use of the polarization controller, a local polarization state of the internal optical path of the laser device can be changed, and mode-locking operation ofthe pulse laser and adjustment and switching of a mode-locking state can be realized. The multi-dimensional multiplexing soliton optical fiber laser device of the invention can be used for bidirectional transmission, and mode-locking laser pulses can be respectively obtained, generation of polymorphic soliton pulses can be supported, and a wideband wavelengths tuning function and a multiple wavelength switching function can be fulfilled via output laser pulses.

The present invention discloses a human body sleep multiple physical sign non-invasive distributed optical fiber monitoring system and method. The system comprises a mattress, a plurality of physicalsign optical fiber optical grating sensors, a demodulator and an upper computer; the physical sign optical fiber optical grating sensors comprise a plurality of distributed temperature optical fiber optical grating sensors, distributed pressure optical fiber optical grating sensors and distributed heartbeat/respiration optical fiber optical grating sensors; the physical sign optical fiber opticalgrating sensors are all fixedly arranged in fillers embedded between a mattress inner bed net and a fabric inner filling material, and also keep depth on the same horizontal plane; the physical sign optical fiber optical grating sensors are connected with the demodulator, and output signals of the demodulator are transmitted to the upper computer through serial ports, so as to monitor health stateof a user during sleeping, such as physical sign parameters of heart rate, respiration, body temperature, etc.; and sleeping postures and bed leaving conditions are analyzed according to pressure field monitoring conditions of a user in a sleeping state. The distributed multi-parameter optical fiber optical grating sensor networking realizes monitoring of information of multiple physical signs and sleep movement state.

The invention brings forward a distributed fiber monitoring method and system for strains and stresses of a ship lock structure. The system comprises distributed sensitive optical cables, a data acquisition device, and a data processing and analyzing module; and the distributed sensitive optical cables are laid into tops and bottoms or inner surfaces and outer surfaces of reinforced concrete surface layers of a lock head base plate, a water delivery gallery, a lock chamber base plate, and a lock chamber wall by a way of binding with main ribs so as to form a U-shaped loop. After concrete pouring is completed for laying of the distributed sensitive optical cables into the tops and bottoms or inner surfaces and outer surfaces of the reinforced concrete surface layers of the lock head base plate, the water delivery gallery, the lock chamber base plate, and the lock chamber wall by a way of binding with main ribs, the distance between the sensitive optical cables and the surfaces of the concretes is 5 to 10cm; and the sensitive optical cables are deformed synchronously with the reinforced concrete structures and optical fiber sensors generate corresponding stresses. And a data acquisition station is established at the top of the lock head; and the laid sensitive optical cables lines are connected to the data acquisition station by optical cables.

The invention relates to a measuring device for monitoring space relative deformation caused by space relative movement of an upper disc and a lower disc of an in-situ rock joint plane in the wild. The measuring device consists of an upper fixing rod, an upper fixing screw bolt, an upper telescopic rod, an upper fixed regulating screw bolt, an upper regulating rod, an upper connecting seat, an upper locking screw bolt, a lower fixing rod, a lower fixing screw bolt, a lower telescopic rod, a lower fixed regulating screw bolt, a lower regulating rod, a lower connecting seat, a lower locking screw bolt, a normal displacement measuring rod, a telescopic spring, an outer sleeve, rolling balls, a sealing cap, a dial and a support rod through assembling connection. The device is respectively fixed with the upper disc rock and the lower disc rock of the joint plane through the upper fixing rod and the lower fixing rod, in addition, the normal displacement measurement is realized through the telescopic effect of the normal displacement measuring rod, and the plane deformation measurement is realized through the movement of the lower end part of a normal deformation measuring rod on the dial, so the measurement on the space relative deformation between the upper disc and the lower disc of the joint plane can be realized, and the measuring device has the advantage that the space relative deformation value of the upper disc and the lower disc of the rock joint plane is directly obtained.

The invention relates to an array solid probe for radiation detection, comprising a plurality of sensors for detecting rays radiated along a preset direction. Each sensor is provided with a ray incidence end surface and a plurality of first plates almost arranged in parallel to form at least one row space; the sensors are aligned in the space, and the first plates are made of metal. The structural mode can be used for constructing various columns of array solid probes, thereby improving the radiation detection speed of large objects under the condition that the special resolution and the contrast sensitivity of scanned images are not considered.

The invention relates to a miniature optical fiber current sensor probe and a making method thereof. The probe is formed by butt welding a D type fiber bragg grating (9) sputtered with a TbDyFe thin film (10) and an uncoated reference grating (8) with the same central wavelength as the D type fiber bragg grating (9), wherein the D type fiber bragg grating (9) sputtered with the TbDyFe thin film is formed by sputtering a layer of giant magnetostrictive material TbDyFe thin film on a fiber bragg grating with polished sides, and the thickness of the thin film is 2-20 mum. The miniature optical fiber current sensor probe is made by combining a magnetostrictive TbDyFe thin film sensitive to a magnetic field with an anti-electromagnetic interference D type fiber bragg grating. Because a magnetic-control sputtering process, a heat processing process and a temperature compensation technique are adopted, the accuracy and the sensitivity of a sensor are greatly improved, and the volume of the sensor probe is greatly reduced, thereby the sensor probe is beneficial to the miniaturization of an optical fiber current sensor.

The invention provides a fiber bragg grating type pipeline strain real-time detector. The fiber bragg grating type pipeline strain real-time detector comprises a sensitive membrane plate and high-temperature fiber bragg grating sensors, wherein the high-temperature fiber bragg grating sensors comprise the high-temperature fiber bragg grating axial strain sensor, the high-temperature fiber bragg grating transverse strain sensor and the high-temperature fiber bragg grating temperature sensor. The minimum straight-line distance between the high-temperature fiber bragg grating transverse strain sensor and a line formed by the high-temperature fiber bragg grating axial strain sensor and the high-temperature fiber bragg grating temperature sensor is not less than 10 cm. The strain real-time detector can detect two-dimensional strain situations of a pipeline under a high-temperature environment, and temperature compensation is achieved in a sensing system. The fiber bragg grating type pipeline strain real-time detector has the advantages of being resistant to electromagnetic interference, high in precision, rapid in dynamic response, small in size, low in weight and the like, and further has reliability, stability and simplicity. Meanwhile, a plurality of strain real-time detectors are arranged and used so that multipoint distributed networking detection can be conducted on the high-temperature pipeline.

The invention provides a magnetic field and temperature simultaneous measurement method based on photonic crystal micro-cavities filled with magnetic fluid. Air holes in different regions of a photonic crystal waveguide flat plate are filled with two different types of magnetic fluid respectively so that the two cascaded photonic crystal micro-cavities can be formed, and therefore two resonance troughs corresponding to two resonant wavelengths can appear in an output spectrum of a photonic crystal waveguide, wherein the resonance troughs are independent of each other. According to the changes of the external magnetic field or the temperature, the refractive indexes of the two types of filling magnetic fluid can change to different degrees, and therefore the two resonant wavelengths in the output spectrum of the photonic crystal waveguide can move, and the sensitivity of the two resonant wavelengths to the changes of the refractive indexes of the magnetic fluid is inconsistent. Finally, the change amount of the external magnetic field and the change amount of the temperature can be obtained through reverse calculation according to the movement amount of the two resonant wavelengths by means of a double-wavelength matrix method, and the magnetic field and the temperature can be simultaneously measured. Calculation shows that the minimum detectable magnetic field change amount is 1.333Oe, and the minimum detectable temperature change amount is 0.301K.

The invention relates to a leakage monitoring and warning system of a large fiber-grating liquid gas storage tank, which comprises a wideband light source, a Y-shaped optical splitter, a temperature probe string, a wavelength demodulator, a computing unit, and an acousto-optic warning device, wherein the temperature probe string comprises a plurality of bragg fiber gratings; the wideband light source is connected with one splitting port of the Y-shaped optical splitter through an optical fiber; the combining port of the Y-shaped optical splitter is connected with the probe string comprising the bragg fiber gratings through an optical fiber; the other splitting port of the Y-shaped optical splitter is connected with the wavelength demodulator in series though an optical fiber; data is transmitted to the computing unit by the wavelength demodulator through a data wire; and the computing unit is connected with the acousto-optic warning device through a lead. The changing situation of the temperature within the range of -100-100 DEG C on the tank wall of the large liquid gas storage tank is monitored in real time and on line through a fiber-grating sensing network, and when liquid gas leaks and the monitored temperature change of the fiber grating is caused to exceed a temperature-reduction threshold value, acousto-optic warning can be triggered by the system.

The invention discloses a pipeline deformation monitoring and handheld warning system and method based on BOTDR (Brillouin Optical Time Domain Reflection). The system comprises a distributed sensing optical cable, a temperature compensation optical cable, a BOTDR automatic data acquisition device, a solar cell panel, a digital signal processing system, a deformation data display terminal, an alarmgenerator, a data server cloud and a handheld warning APP. A strain sensing optical cable is arranged in the wall of a pipeline, and long-distance monitoring of the tension and compression deformation, deflection deformation, pressure state and temperature of the pipeline is realized through distributed optical fiber strain test. The results are uploaded to a network server finally, and the staffcan directly understand the health information of the sewage pipeline through the handheld warning APP. Thus, pipeline rupture prevention and damage detection are realized. The system and the methodhave the advantages of electromagnetic interference resistance, long transmission distance and easy layout, avoid missing monitoring, and can realize long-distance distributed real-time monitoring ofstress-strain and temperature of a large-diameter pipeline.

The invention relates to an optical fiber bending loss principle-based wire strand breakage and damage detection method. The method comprises the following steps of: (1) fixing a sensing optical fiber for detection on a high-voltage power transmission wire at a certain angle; (2) transmitting detection laser to an incident end of the sensing optical fiber for detection by an optical time domain reflectometer; (3) returning a back Rayleigh scattering light signal to the optical time domain reflectometer by the sensing optical fiber for detection; (4) after receiving the back Rayleigh scattering light signal by the optical time domain reflectometer, performing sampling acquisition and analytic processing on the signal to obtain back Rayleigh scattering light power at each different position of the optical fiber transmission line and displaying a detection result curve on a panel of an oscilloscope of the optical time domain reflectometer; and (5) acquiring state information of the sensing optical fiber for detection, and further detecting and positioning strand breakage and damage existing on the high-voltage power transmission wire. Compared with the prior art, the method has the advantages of accuracy in positioning, capabilities of improving the polling efficiency of the power transmission line and the reliability of the power system and the like.

This invention relates to a sensor capable of timely monitoring and measuring the parameters of flow rate and flow capacities of various fluids composed of a sealed extension tube, a fiber grating, a split ring and fibers characterizing that the flow rates of the designed flow rate pressure tube are different at two places, which are used in converting the flow rate to pressure for sensing and monitoring. When a fluid flows through the tube, a pressure difference exists between the inside and outside of the extension tube to drive it to extend and shorten along the axis and further to drive the split ring to compress and extend to result in the shift of the fiber grating central wavelength to be used to sense and monitor parameters of flow rates and flow capacities of high flexibility.

The invention discloses an optical fiber interference water level sensor. The optical fiber interference water level sensor is composed of a semiconductor laser device, a 3dB coupling device, a sensitive element, a Faraday polariscope, a light guide optical fiber, a photoelectric detector and a computer, wherein the sensitive element is a key part of the water level sensor and is used for converting the change of a water level into vertical strain and radial strain of the optical fiber so that the phase difference of two interference arms is changed; finally, the change of the water level is inverted by using the change of the phase difference. By the aid of the optical fiber interference water level sensor, the high-precision water level measurement can be realized, and the optical fiber interference water level sensor has the advantages of reliability, electromagnetic interference resistance, corrosion resistance, high sensitivity, simple and exquisite structure and the like, and is suitable for the environment needing high-precision water level monitoring.

The invention relates to the technical field of a weak grating on-line monitoring system, in particular to an optical fiber grating array intelligent vibration positioning and temperature monitoring system. The system includes a swept source, an optical circulator, an optical fiber, identical weak grating arrays, an elimination optical fiber end face reflection device, an optical fiber transmission optical cable, a signal demodulation unit, a computer and a display screen, wherein the swept source is connected to the first port of the optical circulator, the second port of the optical circulator is connected to the head ends of the weak gratings of the identical weak grating arrays through the optical fiber, the tail end of the weak grating is connected with the elimination optical fiber end face reflection device, and the third port of the optical circulator is connected with the optical fiber transmission optical cable, the optical fiber transmission optical cable is connected to thesignal demodulation unit, the signal demodulation unit is connected to the computer, the computer is connected to the display screen, the optical fiber is fixed on a measured medium through a specially-made optical fiber clamp, and the identical weak grating arrays are uniformly distributed on the measured medium, and the temperature and vibration sensing points are customized by a temperature sensing unit and a vibration sensing unit according to monitoring requirements.

It is a light fiber micro-electron mechanical system pressure sensor and its complex structure. The said sensor end polished fiber end is connected with the boron and silicon underlay and their outer end is connected with the light fixed epoxide resin and there is monocrystalline silicon on the underlay. Its complex structure wide band light source is connected with the tunable filter controller and tunable filter. The output end of the filter is connected with the array wave-guide grating. The output end of the array wave-guide grating is separately connected with photoelectricity detector and sensor through fiber adapter, light single direction isolator and light fiber coupler.