47results about How to "Avoid the effects of electromagnetic interference" patented technology

The invention discloses a roadway surrounding rock stress monitoring device based on fiber bragg grating sensing. Grooves are symmetrically carved in a metal rod along the axial center, an FBG set is fixedly installed inside each groove, FBGs serve as sensitive elements, when roadway surrounding rock is deformed, the stress of the surrounding rock will be changed, therefore, force is generated through the metal rod, surface micro-deformation is generated, the grating distances of the FBGs attached to the metal rod are changed along with the metal rod, the center reflection wavelength of the FBGs can be caused to generate drifting, wavelength signals are demodulated into electrical signals through an FBG interrogator, and the stress situations of different sites can be obtained. The roadway surrounding rock stress monitoring device has the advantages that installation is easily achieved, and the roadway surrounding rock stress monitoring device is suitable for wide popularization; power is not required to be supplied to the working face end, and site safety is guaranteed; all-optical measurement and fiber transmission are adopted, and influences of electromagnetic interference are effectively avoided; the temperature error is compensated, and the accuracy is improved; the surrounding rock stress monitoring results can be timely and accurately provided, and guidance on site production and scientific research is facilitated.

The invention discloses a three-dimensional induced polarization method advanced forecast system carried by an earth pressure balance shield, and a detection method. The system penetrates a needle-like electrode into soil for power supply and acquisition by use of a push electrode system carried by a cutter head and overcomes the difficulty of zero detection space in a conventional earth pressure balance shield. Detection currents are enabled to be distributed forwards by use of a shielding electrode, and a guniting device on the cutter head injects a high-resistance grouting material towards soil around the cutter head and the shield, and the difficulties of electromagnetic interference and conduction of currents by taking the shield as a good conductor are overcome. By use of automatic control in a whole process, multipath parallel acquisition and a rapid inversion means, the difficulty of small detection time is overcome. The method provided by the invention realizes detection of spherical weathering bodies, soft and hard layered strata, front full-section hard rocks, pebble layers and muddy layers by use of resistivity differences among geologic bodies; and detection of water containing condition of a water-rich layer by use of excitation polarization half failure is realized.

The invention relates to a surrounding rock stress on-line monitoring system and method based on a fiber bragg grating borehole stress meter. A plurality of measurement points are arranged on a surrounding rock, the fiber bragg grating borehole stress meter is installed in a surrounding rock wall drill hole, an optical fiber connector is connected with an optical fiber, and the optical fiber is connected to a mining optical cable, is then directly connected to the ground, and is connected with a fiber bragg grating modulator; an optical signal is modulated to a digital signal by the fiber bragg grating modulator, the digital signal is transmitted to a computer, is monitored in real time and is analyzed and processed, and a surrounding rock axial stress and transverse stress analyzing and processing method is provided under the temperature compensation condition according to grating stress characteristics. The surrounding rock stress on-line monitoring system and method have the advantages that equipment is easy to install, long in service life and suitable for popularization and use; power supply is not needed underground, electrical signals and electronic devices do not exist, and therefore the field is safe; because all-optical measurement and optical fiber transmission are adopted, monitoring precision is greatly improved, and effect of electromagnetic interference can be effectively avoided under complex and poor environment; surrounding rock stress monitoring results can be provided in time and guiding of field production and scientific research work is facilitated.

A gob-side entry retaining pasty filler on-line detection method comprises the steps that before each monitored space is ready to be filled, supporting rods are fixed to a base plate of a space to be filled through ground anchors, the upper ends of the supporting rods support a top plate of the space to be filled, measuring optical fibers are arranged between the supporting rods, an optical fiber connector is introduced out of the tail portion of the last supporting rod in each set of supporting rods and is connected in a mining optical cable through optical fibers so that optical fiber monitoring signals can be transmitted to a distributed optical fiber demodulator, demodulated signals are transmitted to a computer system, and pasty filler is monitored in real time on line and is analyzed and processed after the space is filled. The gob-side entry retaining pasty filler on-line detection method has the advantages that equipment installation is easy, the method is suitable for being universally popularized, no power supply is needed under a well, a site is safe, all-optical measurement and optical fiber transmission are adopted, influences caused by electromagnetic interference are effectively avoided, a monitoring result can be provided in time, and the method is favorable for directing on-site filling mining production work.

The invention relates to an optical fiber current sensor and a manufacturing method thereof. The optical fiber current sensor comprises a first quarter wave plate, a second quarter wave plate, a sensing optical fiber and a coil frame, wherein the first quarter wave plate and the second quarter wave plate are communicated through the sensing optical fiber; the sensing optical fiber is coupled with a half-wave plate; and double wires of the sensing optical fiber double wire are wound on the coil frame in the same direction. The invention provides an optical fiber current sensor which has the advantages of high precision, small volume, light weight and no sensitivity to vibration or rotation due to no Sagnac effect and a manufacturing method thereof.

The invention belongs to mine pressure on-line monitoring systems, and discloses a working face mine pressure on-line monitoring system based on fiber grating sensing. According to the monitoring system, a plurality of measurement points are selected on a working face in a pit, one monitoring system is installed inside each measurement point, a hydraulic control valve of each monitoring system is installed in a hydraulic support and is connected with a pressure guide hole of an intrinsic safety type fiber grating pressure meter through an oil pipe, an optical signal of the intrinsic safety type fiber grating pressure meter is transmitted to a fiber grating demodulator on the ground through an optical fiber and a mining optical cable, the fiber grating demodulator is demodulated into a digital signal to be transmitted to a computer system, and the computer system carries out real-time monitoring and analysis processing. The working face mine pressure on-line monitoring system based on the fiber grating sensing has the advantages of being simple in installation, adopting full-optical measurement and optical fiber transmission, being capable of effectively avoiding influence of electromagnetic interference, greatly improving monitoring accuracy due to adoption of a temperature compensation grating for compensating a temperature error, and being capable of timely providing a working face mine pressure monitoring and predicting result so as to bring convenience to production and scientific researches of a guidance site.

The invention discloses a method for preventing the override trip of a mine power supply system, which is characterized by comprising the following steps that: 1) each protection device in a transformer substation outputs a differential signal to a mine protection transceiver, the mine protection transceiver converts an electric signal into an optical signal and sends the optical signal to a mine protection transceiver on the opposite side, and the mine protection transceiver of a transformer substation on the opposite side converts the optical signal into an electric differential signal and inputs the electric differential signal into each protection device in the transformer substation; and 2) when a fault occurs at a certain position, the protection device closest to a fault point sends a protection blocking signal to the corresponding protection devices of superior switches in turn, and a reverse blocking quick overcurrent protection device of the superior protection device cannot act after the superior protection device receives the blocking signal, and quickly removes the fault because the protection device closest to the fault point does not receive the corresponding blocking signal. By the method, the problem that an optical fiber communication signal cannot be directly connected to the protection device is solved.

The invention discloses a coal mine goaf top plate strain monitoring system and method based on fiber bragg grating sensing, and belongs to a coal mine top plate strain monitoring system and method. The system comprises a fiber bragg grating demodulation instrument, a monitoring computer, a mining transmission optical cable, a communication optical fiber and tail optical fibers, wherein a plurality of monitoring points are arranged in a goaf top plate; each monitoring point is provided with one fiber bragg grating strain sensor; the sensors in the monitoring points are connected in parallel through the tail optical fibers which access the mining transmission optical cable through optical fibers; the mining transmission optical cable is connected to an input end of the fiber bragg grating demodulation instrument on the ground; an output end of the fiber bragg grating demodulation instrument is connected with the monitoring computer; and the monitoring computer constitutes a fiber bragg grating strain monitoring system of coal mine goaf top plate all-fiber communication. The coal mine goaf top plate strain monitoring system and method based on the fiber bragg grating sensing have the advantages that all-optical measurement and optical fiber transmission are adopted, so that the influence of electromagnetic interference is avoided; equipment does not require power supply, so that essential safety of working face production is ensured; and real-time monitoring and analysis of coal mine goaf top plate strain are realized.

The invention discloses a three-dimensional induced polarization method advanced forecast system carried by an earth pressure balance shield, and a detection method. The system penetrates a needle-like electrode into soil for power supply and acquisition by use of a push electrode system carried by a cutter head and overcomes the difficulty of zero detection space in a conventional earth pressure balance shield. Detection currents are enabled to be distributed forwards by use of a shielding electrode, and a guniting device on the cutter head injects a high-resistance grouting material towards soil around the cutter head and the shield, and the difficulties of electromagnetic interference and conduction of currents by taking the shield as a good conductor are overcome. By use of automatic control in a whole process, multipath parallel acquisition and a rapid inversion means, the difficulty of small detection time is overcome. The method provided by the invention realizes detection of spherical weathering bodies, soft and hard layered strata, front full-section hard rocks, pebble layers and muddy layers by use of resistivity differences among geologic bodies; and detection of water containing condition of a water-rich layer by use of excitation polarization half failure is realized.

A PON-CAN bus architecture and a robot system, the PON-CAN bus architecture comprising an optical fiber bus and a total information device connected to the optical fiber bus, the optical fiber bus being formed by interconnecting a plurality of asymmetric couplers; the symmetric couplers are configured to branch the next level network; the total information device is configured to perform communication interaction with the next level network through the optical fiber bus. The robotic system includes the PON-CAN bus architecture, and various terminal control systems and terminal sensing devicesof robots connected to the PON-CAN bus architecture.

A power transmission iron tower stress online monitoring system is characterized in that eight paths of vibrating wire sensor acquisition systems which are connected in parallel, an exciting circuit, a filter circuit, a shaping circuit, an STM32 processor and a wireless transmission module are connected in sequence to form the power transmission iron tower stress online monitoring system, and the whole monitoring system is powered by a solar power supply module. The power transmission iron tower stress online monitoring system is simple, low in cost, reliable and capable of accurately measuring the stress of a power transmission iron tower; in addition, the cost is low, and batch usage of the systems in a power transmission iron tower line is facilitated. A remote wireless transmission technology overcomes the influences of electromagnetic interference of the power transmission iron tower, so that the system is convenient, rapid and reliable.

The invention, which belongs to the technical field of the aviation integrated core processing, relates to an interconnection method of flexible optical fiber networks and an integrated core processorapplying the same. The integrated core processor is based on the architecture with an integrated design, a modularization idea, and unified high-speed internet interconnection. On the basis of the flexible optical fiber network interconnection method, high-speed fiber communication between all modules and between modules and other external devices is realized. The interconnection method and the integrated core processor are realized simply; the reliability and manufacturability are high; assembling becomes simple; and problems of the traditional electric signal transmission mode structure iscomplicated, the cost is high, the reliability is low, and the technical weight of the light back panel does not conform to the weight reduction requirement of the aviation product can be solved.

The invention discloses robot mounting ropes and a wire live working robot. The wire live working robot is hung on a wire through robot mounting rope bodies, and the robot mounting rope bodies comprise insulating rope sections, metal rope sections and connecting sections; part of insulating rope sections close to the wire is covered with the metal rope sections, and the insulating rope sections are sewn with the metal rope sections through the connecting sections; the wire live working robot comprises a robot body, an ascending structure and the robot mounting rope bodies, the robot body is hung on the wire through the robot mounting rope bodies; the robot body is provided with power connection rods; the ascending mechanism comprises two take-up winches symmetrically arranged on the robotbody, and robot mounting rope bodies are tied to the take-up winches so as to drive the take-up winches to rotate to enable the whole robot body to ascend, and when the metal rope sections in the robot mounting rope bodies make contact with the power connection rods, the electrified access action is completed. According to the robot mounting ropes and the wire live working robot, the robot is prevented from being influenced by electromagnetic interference when getting close to the power transmission wire.

The invention provides a soil settlement observation and measurement system based on a Bragg grating, and relates to a soil settlement observation system. The soil settlement observation and measurement system based on the Bragg grating comprises a deformation plate, a fixed plate, a settlement rod and another deformation plate, wherein the settlement rod is arranged on the deformation plate; one end of the deformation plate is fixed at the other end of the fixed plate and is connected with the settlement rod; a deformation testing Bragg bare grating is arranged in the middle of the deformation plate and is connected with a temperature compensation Bragg bare grating through a single-mode single-core optical fiber; and the deformation testing Bragg bare grating and the temperature compensation Bragg bare grating are connected to a Bragg grating demodulator. Compared with the prior art, the measurement system is provided with an optical fiber sensor, so that influence of electromagnetic interference is avoided. Meanwhile, the soil settlement observation and measurement system has a temperature compensation function. The measurement system is stable in operation and high in measurement precision, can be regulated and changed according to measurement requirements, and can adapt to measurement of most of settlement surfaces.

The invention discloses a force magnification driving device based on shape memory alloy, and relates to the technical field of deformable aircrafts. In order to solve the problems that a force driving device of an existing aircraft is complicated in structure, excessively large in resistance and excessively limited in application range, the force magnification driving device comprises a force magnification mechanism and a shape memory alloy driving mechanism. The force magnification mechanism comprises a top support, a screw rod, a threaded hole pin shaft, a pedestal, an unthreaded hole pin shaft, a spline shaft, two upper supporting arms and two lower supporting arms. The shape memory alloy driving mechanism comprises a flat belt, an outer belt wheel and two driving units. Each driving unit comprises an outer shell, a shape memory alloy belt and an inner belt wheel. The force magnification driving device based on the shape memory alloy can be used in the deformable aircrafts.

The invention discloses a silk thread tension measuring device. The silk thread tension measuring device comprises a hollow shell, wherein a front baffle is arranged at one end of the hollow shell by virtue of a screw, and a rear baffle is arranged at the other end of the hollow shell by virtue of a screw; two guide rods are erected at a middle position of the upper part between the front baffle and the rear baffle; a rack device sheathes the two guide rods; a measurement guide wheel device is arranged on the rack device; one fixed guide wheel device is symmetrically arranged on the top surface at each of the two sides of the rack and guide rod mounting holes, of the hollow shell; a potentiometer is arranged in a potentiometer mounting hole, and a gear is arranged on a spindle of the potentiometer; and the gear is connected with the rack devices in a meshing manner. The silk thread tension measuring device disclosed by the invention is simple in structure, easy and reliable to use and beneficial to batch application on a production line; secondly, electromagnetic interference influence is avoided, measurement accuracy is high, and connection with an automatic system is easy; besides, key parts are easy to dismount, maintain and replace, so that production efficiency can be beneficially improved.

The invention discloses a distributed optical fiber coal mine roof safety monitoring system and method, and belongs to the technical field of coal mine roof safety monitoring. The invention aims to provide an improvement of a distributed optical fiber coal mine roof safety monitoring system hardware structure. According to the technical scheme adopted by the invention, the system comprises a narrow linewidth laser, a distributed optical fiber multi-parameter fusion sensing system, a signal acquisition and processing module and a GFPR optical cable; light waves generated by the narrow linewidth laser enter the distributed optical fiber multi-parameter fusion sensing system; a Brillouin scattering light signal and a Rayleigh scattering light signal generated by the GFPR optical cable enter the distributed optical fiber multi-parameter fusion sensing system; the distributed optical fiber multi-parameter fusion sensing system outputs the Brillouin scattering light signal and the Rayleigh scattering light signal to the signal acquisition and processing module; and the signal acquisition and processing module acquires Brillouin frequency shift and Rayleigh scattering light phase and intensity at the same time through demodulation to obtain strain, temperature and micro-seismic information along the GFPR optical cable. The system and method are applied to coal mines.

The invention relates to an inductance coil charging and discharging power supply with low harmonic output. The inductance coil comprises: a diode rectifying circuit, an H-bridge inverter and an inductance coil which are electrically connected in sequence, wherein a current-limiting inductor is connected in series on the input side line of the diode rectifying circuit, and a support capacitor C is bridged between a positive bus and a negative bus on the output side; a low-voltage output circuit connected to the input end of the diode rectifying circuit through a switch S1, and a high-voltage output circuit connected to the input end of the diode rectifying circuit through a switch S2, wherein the voltage of the low-voltage output circuit is small enough so as to make the amplitude of high-frequency harmonic current of the inductance coil be smaller than 1A when the current slowly rises, and the voltage of the high-voltage output line is large enough so as to make the direct-current voltage of the direct-current side of the H-bridge inverter be larger than the electromotive force generated by the inductance coil when the current drops sharply; and a current sensor used for collecting the current of the output side of the H-bridge inverter, and a controller used for receiving the electrical parameters of the current sensor and controlling the turn-off of the H-bridge inverter.

The invention belongs to the field of control, in particular to a current harmonic suppression control algorithm of a four-quadrant converter, and particularly relates to a current low-order harmonicsuppression method for a four-quadrant converter of an electric locomotive. The method is a harmonic suppression method fused in a four-quadrant control algorithm, solves the problems of influence ofcurrent low-order harmonics of the four-quadrant converter on the control of the converter and pollution to the electric energy quality of a power grid, and solves the problem of influence caused by filtering the low-order harmonics by adopting a software filter method. According to the method, a harmonic extraction and suppression function is added to the four-quadrant converter control algorithm, no extra hardware control circuit or device is added, so the method has high adaptability and flexibility, the purpose of harmonic suppression can be achieved, and meanwhile the design cost is reduced.

Disclosed is a coal mine top plate aquiclude stability monitoring system based on a fiber Bragg grating. A measurement station is arranged on a work surface mining roadway, a vertical top plate drilling hole is drilled in a top plate of the work surface mining roadway to an aquiclude, a fiber Bragg grating pressure sensor is arranged at the top end of the drilling hole, a fiber Bragg grating top plate bed separation instrument is installed at the height position of the drilling hole between the aquiclude and a rock stratum below, and an optical fiber connector is led out of the drilling hole and connected with an optical fiber tail fiber, thereby being connected with an optical fiber splitter. The optical fiber connector is connected with an optical fiber terminal box through a communication optical fiber and connected to an optical fiber interrogator of a ground control chamber through a mining optical cable, signals are transmitted to a monitoring server after demodulation and are processed through the monitoring server, and the data processing result is shared with a client side through a mine local area network. The stability conditions of the aquiclude are monitored in real time through a computer display, and an alarm is given timely when the stress is near the bearing upper limit of the aquiclude and separation occurs between the aquiclude and the overlying strata blow.

The invention discloses a roadway surrounding rock stress monitoring device based on fiber bragg grating sensing. Grooves are symmetrically carved in a metal rod along the axial center, an FBG set is fixedly installed inside each groove, FBGs serve as sensitive elements, when roadway surrounding rock is deformed, the stress of the surrounding rock will be changed, therefore, force is generated through the metal rod, surface micro-deformation is generated, the grating distances of the FBGs attached to the metal rod are changed along with the metal rod, the center reflection wavelength of the FBGs can be caused to generate drifting, wavelength signals are demodulated into electrical signals through an FBG interrogator, and the stress situations of different sites can be obtained. The roadway surrounding rock stress monitoring device has the advantages that installation is easily achieved, and the roadway surrounding rock stress monitoring device is suitable for wide popularization; power is not required to be supplied to the working face end, and site safety is guaranteed; all-optical measurement and fiber transmission are adopted, and influences of electromagnetic interference are effectively avoided; the temperature error is compensated, and the accuracy is improved; the surrounding rock stress monitoring results can be timely and accurately provided, and guidance on site production and scientific research is facilitated.

The invention discloses a self-learning grating interference spectrum analysis technology for motor fault early warning in the technical field of motor fault detection, and the technology comprises the steps: determining a wavelet basis function according to the parameters of a motor and an environment, training a judgment model through the data of the motor during normal operation, deducing fault features based on the model, and carrying out the early warning of the motor fault; a signal frequency band with abnormal energy can be more accurately determined as a frequency band where a fault feature is located, so that a fault feature frequency is further identified by utilizing wavelet packet node reconstruction, and a fault type is judged by utilizing machine learning; only two signals of the vibration sensor and the temperature sensor are fused, and the two signals are optical fiber sensors, so that the influence of electromagnetic interference can be completely avoided.

The invention relates to a surrounding rock stress on-line monitoring system and method based on a fiber bragg grating borehole stress meter. A plurality of measurement points are arranged on a surrounding rock, the fiber bragg grating borehole stress meter is installed in a surrounding rock wall drill hole, an optical fiber connector is connected with an optical fiber, and the optical fiber is connected to a mining optical cable, is then directly connected to the ground, and is connected with a fiber bragg grating modulator; an optical signal is modulated to a digital signal by the fiber bragg grating modulator, the digital signal is transmitted to a computer, is monitored in real time and is analyzed and processed, and a surrounding rock axial stress and transverse stress analyzing and processing method is provided under the temperature compensation condition according to grating stress characteristics. The surrounding rock stress on-line monitoring system and method have the advantages that equipment is easy to install, long in service life and suitable for popularization and use; power supply is not needed underground, electrical signals and electronic devices do not exist, and therefore the field is safe; because all-optical measurement and optical fiber transmission are adopted, monitoring precision is greatly improved, and effect of electromagnetic interference can be effectively avoided under complex and poor environment; surrounding rock stress monitoring results can be provided in time and guiding of field production and scientific research work is facilitated.

The invention discloses a filling body transverse deformation online monitoring system based on fiber bragg grating sensing, and relates to the technical field of mine filling body monitoring. The device comprises a bidirectional displacement measuring device based on fiber bragg grating sensing, a fixed disc, a coupler, an optical fiber, a mining optical cable, a fiber bragg grating demodulator and a computer system, the bidirectional displacement measuring device based on fiber bragg grating sensing comprises a measuring main body, an extension line, a steel pipe and two fiber bragg gratingdisplacement sensors, wherein the measuring main body comprises a shell and an upper cover matched with the shell; the shell is of a hollow cuboid structure, the left side and the right side of the shell are each provided with an outlet, the movable pull rods of the two fiber bragg grating displacement sensors penetrate through the outlets in the left side and the right side respectively and facethe outlets in the left side and the right side of the shell, and the axes of the movable pull rods are overlapped with the axes of the corresponding outlets. Real-time and on-line remote monitoring of the left side, the right side and the total transverse deformation of the filling body can be achieved.

The invention discloses a wireless unmanned aerial vehicle charging system with an optical communication function. The system comprises an unmanned aerial vehicle charging airport end and an unmanned aerial vehicle end, wherein the unmanned aerial vehicle charging airport end comprises an airport optical communication transmitting module, a wireless charging transmitting device and an airport optical communication receiving module; the unmanned aerial vehicle end comprises an unmanned aerial vehicle optical communication receiving module, a wireless charging receiving device and an unmanned aerial vehicle optical communication transmitting module; the airport optical communication transmitting module of the unmanned aerial vehicle airport end sends an optical signal to the unmanned aerial vehicle optical communication receiving module of the unmanned aerial vehicle end, and the unmanned aerial vehicle optical communication transmitting module of the unmanned aerial vehicle end sends an optical signal to the airport optical communication receiving device of the unmanned aerial vehicle charging airport end; and a wireless charging transmitting device of the unmanned aerial vehicle charging airport end sends charging energy to the unmanned aerial vehicle, and the unmanned aerial vehicle end receives the charging energy based on a wireless charging receiving device. According to embodiments of the invention, signal transmission is realized through a simple structure, and the influence of electromagnetic interference on the optical signal in a transmission process is avoided.

The invention belongs to the technical field of monitoring, in particular to an anti-theft safety monitoring device used for information technology. Aiming at the problems that an existing safety monitoring device cannot operate when being powered off, the timeliness of monitoring and early warning is poor, and the electric signal transmission accuracy is poor, the following scheme is provided atpresent: the device comprises a display shell, a monitoring screen is fixedly installed at the position of the front wall of the display shell, the lower surface of the display shell is fixedly weldedwith a fixed cabinet, a storage battery is arranged at the middle position of the bottom of the inner wall of the fixed cabinet, a host machine is fixedly installed at the position of the rear wall of the display shell, and the same group of welding blocks are fixedly installed on the outer surface of the host machine. According to the anti-theft safety monitoring device, the power-on operation of a monitoring circuit under the power-off condition can be guaranteed by the safety monitoring device, a dangerous area can be accurately positioned, an early-warning signal can be transmitted to a nearby management and control room so as to improve the timeliness of monitoring and early warning, meanwhile, the wiring is tidy and orderly, and mutual interference is avoided, so that the accuracy of electric signal transmission is improved.

An electric meter box belongs to the field of electric meter boxes. It includes a box base and a box door, and an electric energy meter room for installing an electric energy meter is formed in the box body base. The electric energy meter has a constant light-emitting lamp group, and a physical isolation type Observation section; also includes a light sensor, a beam splitter is provided on the box door, and the beam splitter is used to divide the display light beam emitted by the constant-on type light-emitting lamp group of the corresponding electric energy meter into at least two beams, and make one of them It can be irradiated on the light sensor to form a detection beam, and another beam can pass through the physically isolated observation part to form an indicating beam. The light sensor is installed at the corresponding position in the box base, and a There is a light-shielding part, so that the light-shielding part can block the light beam incident from the outside of the box base and the box door to stimulate the false response of the light sensor. It does not produce electromagnetic radiation, and it can avoid the influence of electromagnetic interference.

The invention discloses a force magnification driving device based on shape memory alloy, and relates to the technical field of deformable aircrafts. In order to solve the problems that a force driving device of an existing aircraft is complicated in structure, excessively large in resistance and excessively limited in application range, the force magnification driving device comprises a force magnification mechanism and a shape memory alloy driving mechanism. The force magnification mechanism comprises a top support, a screw rod, a threaded hole pin shaft, a pedestal, an unthreaded hole pin shaft, a spline shaft, two upper supporting arms and two lower supporting arms. The shape memory alloy driving mechanism comprises a flat belt, an outer belt wheel and two driving units. Each driving unit comprises an outer shell, a shape memory alloy belt and an inner belt wheel. The force magnification driving device based on the shape memory alloy can be used in the deformable aircrafts.

The invention provides a preparation method of a humidity sensitive grating. The preparation method comprises the following steps: firstly, conducting hydrolysis and impurity removal on plant fibers to obtain a clean solution; conducting desugaring on the clean solution by a certain quantity of ketene or acetic anhydride; then under the action of acid, esterfying a hydroxyl functional group of cellulose to form an acetyl functional group; modifying the surface of the grating by a silane coupling agent so as to change hydroxyl on the surface of the grating into an amido group which is easy to bond with acetyl and comprises silane; cleaning and drying the grating of the amido group comprising silane, placing the grating into the solution of cellulose comprising acetyl to soak so as to form the humidity sensitive grating grafted with cellulose; finally, cleaning and drying the humidity sensitive grating and enabling the plant fibers on the surface of the grating to be connected mutually to form a coating layer. The invention further provides a fiber bragg grating temperature and humidity sensor prepared according to the preparation method of the humidity sensitive grating. The fiber bragg grating temperature and humidity sensor prepared according to the preparation method of the humidity sensitive grating can be simultaneously sensitive to temperature and humidity.

The invention discloses a filling body transverse deformation online monitoring system based on fiber bragg grating sensing, and relates to the technical field of mine filling body monitoring. The device comprises a bidirectional displacement measuring device based on fiber bragg grating sensing, a fixed disc, a coupler, an optical fiber, a mining optical cable, a fiber bragg grating demodulator and a computer system, the bidirectional displacement measuring device based on fiber bragg grating sensing comprises a measuring main body, an extension line, a steel pipe and two fiber bragg gratingdisplacement sensors, wherein the measuring main body comprises a shell and an upper cover matched with the shell; the shell is of a hollow cuboid structure, the left side and the right side of the shell are each provided with an outlet, the movable pull rods of the two fiber bragg grating displacement sensors penetrate through the outlets in the left side and the right side respectively and facethe outlets in the left side and the right side of the shell, and the axes of the movable pull rods are overlapped with the axes of the corresponding outlets. Real-time and on-line remote monitoring of the left side, the right side and the total transverse deformation of the filling body can be achieved.