Optical fiber distributed perturbation sensor and method for implementing perturbation positioning

The invention discloses an optical fiber distributed disturbance sensor, and a method, by which the disturbance sensor can achieve disturbance positioning. The method is characterized in that light path output signals from an interferometer are divided into three equal paths of light, pass through analyzers with polarization angle differences of 0 DEG, 60 DEG and minus 60 DEG respectively, enter a photo detector and are converted to electrical signals therein, are subjected to the square summing calculation after being conditioned by filtered signals and amplified signals, get rid of the DC amount by filtration, and are taken as the final interference output signals for related computation so that disturbance positioning can be carried out. The method can ensure the final interference signals always remain in a certain amplitude range and available, and the possibility of the signals being zero is zero. The invention solves the problem in the prior dual interferometer type distributeddisturbance ...

Method and apparatus for implementing optical fiber perimeter alarm

The present invention provides a method for realizing optical fiber perimeter warning and a device thereof. Concretely, a signal modulating module is used for modulating the phase of a light path signal and feeds back and controls the polarization state of the light path signal after the phase modulation, so as to eliminate the influence caused by system parameter change and improve the reliability of a system. At the same time, the present invention solves positioning error caused by external environmental change and system internal component parameter drift and improves the positioning precision of the system.

Pulse width regulating method and device independent from voltage

In the pulse with regulating method, one voltage linearity related current source is first used to charge a capacitor and the voltage across the capacitor is coupled to voltage linearity related fundamental frequency reference comparator. When the output voltage of the capacitor reaches the reference voltage, the comparator output signal to make the capacitor charge to output one series of fundamental frequency sawtooth waves, and in different power supply the generated sawtooth waves has the same period. The fundamental frequency sawtooth waves are then transmitted to the speed controlling comparator to regulate the output pulse width in the pulse width regulating mode and to control the rotation speed of the motor.

Destabilization sensing localization method

The invention discloses a disturbance sensing and positioning method, which comprises the following steps: emitting a light wave by a wide-spectrum light source; splitting the light wave by an optical fiber coupler to form two light waves; forming two light waves in reverse transmission directions when the two light waves pass through a sensing arm consisting of a single-mode optical fiber, a multi-mode optical fiber and a single-mode optical fiber connected with each other from reverse directions; and modulating the light waves of different modes by a disturbance when an external disturbance is present on the multi-mode optical fiber to generate coupling among the modes, wherein the mode coupling in the multi-mode optical fiber is transformed to the intensity change of an output light wave due to the spatial filtering when the modulated light beams enter the single-mode optical fiber from the multi-mode optical fiber; receiving the two disturbance signals by a detector; and obtaining the ...

Optical fiber distributed perturbation sensor of Sagnac interferometer and its perturbation positioning method

The invention discloses a distributed fiber disturbance sensor of a Sagnac interferometer and a disturbance positioning method thereof, comprising the following steps, using a Sagnac interferometer to couple an arm, synchronously adding a delayed fiber ring, namely superposing a delayed fiber ring in a single Sagnac interferometer to form two Sagnac interferometers with different length; realizing the time division multiplexing of the two Sagnac interferometers with different length by the propagation of optical pulses in the interferometer; and calculating the positions of disturbing points to realize the distributed sensing of the disturbance according to the amplitude of output signals of two Sagnac interferometers. The sensor has the advantages of low cost, simple structure and good stability.

Perimeter alarming method and system for implementing orientation of composite type complete optical fiber

The embodiment of the invention provides a method and a system for realizing composite entire optical fiber localizable perimeter alarm. An auxiliary optical fiber micro vibration sensor is arranged on a monitor optical cable provided with a precise positioning sensor; whether a disturbance signal exists is judged by the precise positioning sensor and the auxiliary optical fiber micro vibration sensor together, namely, whether people invade is judged; if the judgment is confirmed, an alarming signal is sent out, thus effectively improving the anti-interference capacity of the system, loweringeffect caused by outside environmental factors like temperature and stress, and the like, reducing false alert rate and missing report rate, and improving the alarming precision of the monitoring system.

Optical fiber distributed perturbation sensor and method for implementing perturbation positioning

The invention discloses an optical fiber distributed disturbance sensor, and a method, by which the disturbance sensor can achieve disturbance positioning. The method is characterized in that light path output signals from an interferometer are divided into three equal paths of light, pass through analyzers with polarization angle differences of 0 DEG, 60 DEG and minus 60 DEG respectively, enter a photo detector and are converted to electrical signals therein, are subjected to the square summing calculation after being conditioned by filtered signals and amplified signals, get rid of the DC amount by filtration, and are taken as the final interference output signals for related computation so that disturbance positioning can be carried out. The method can ensure the final interference signals always remain in a certain amplitude range and available, and the possibility of the signals being zero is zero. The invention solves the problem in the prior dual interferometer type distributed disturbance ...

Destabilization sensing localization method

The invention discloses a disturbance sensing and positioning method, which comprises the following steps: emitting a light wave by a wide-spectrum light source; splitting the light wave by an optical fiber coupler to form two light waves; forming two light waves in reverse transmission directions when the two light waves pass through a sensing arm consisting of a single-mode optical fiber, a multi-mode optical fiber and a single-mode optical fiber connected with each other from reverse directions; and modulating the light waves of different modes by a disturbance when an external disturbanceis present on the multi-mode optical fiber to generate coupling among the modes, wherein the mode coupling in the multi-mode optical fiber is transformed to the intensity change of an output light wave due to the spatial filtering when the modulated light beams enter the single-mode optical fiber from the multi-mode optical fiber; receiving the two disturbance signals by a detector; and obtainingthe ...

Perimeter alarming method and system for implementing orientation of composite type complete optical fiber

The embodiment of the invention provides a method and a system for realizing composite entire optical fiber localizable perimeter alarm. An auxiliary optical fiber micro vibration sensor is arranged on a monitor optical cable provided with a precise positioning sensor; whether a disturbance signal exists is judged by the precise positioning sensor and the auxiliary optical fiber micro vibration sensor together, namely, whether people invade is judged; if the judgment is confirmed, an alarming signal is sent out, thus effectively improving the anti-interference capacity of the system, lowering effect caused by outside environmental factors like temperature and stress, and the like, reducing false alert rate and missing report rate, and improving the alarming precision of the monitoring system.

Optical fiber distributed perturbation sensor of Sagnac interferometer and its perturbation positioning method

The invention discloses a distributed fiber disturbance sensor of a Sagnac interferometer and a disturbance positioning method thereof, comprising the following steps, using a Sagnac interferometer to couple an arm, synchronously adding a delayed fiber ring, namely superposing a delayed fiber ring in a single Sagnac interferometer to form two Sagnac interferometers with different length; realizing the time division multiplexing of the two Sagnac interferometers with different length by the propagation of optical pulses in the interferometer; and calculating the positions of disturbing points to realize the distributed sensing of the disturbance according to the amplitude of output signals of two Sagnac interferometers. The sensor has the advantages of low cost, simple structure and good stability.

Dual-SIM card and dual-standby mobile phone

The invention discloses a dual-SIM card and dual-standby mobile phone, which comprises a master machine and a slave machine. The master machine is provided with a master machine card slot, and a master machine antenna, a master machine radio frequency (RF) module and a master machine baseband processing module which are sequentially connected; the slave machine is provided with a slave machine card slot, and a slave machine antenna, a slave machine RF module and a slave machine baseband processing module which are sequentially connected; the master machine baseband processing module are communicated with the slave machine baseband processing module through a communication module; and if one of the master machine and the slave machine is in a calling state, a signal of the other one of themaster machine and the slave machine is subjected to concurrent processing. By setting two sets of antennae, RF modules and baseband processing modules, two SIM cards can be in a standby state and both ...

Dual-SIM card and dual-standby mobile phone

The invention discloses a dual-SIM card and dual-standby mobile phone, which comprises a master machine and a slave machine. The master machine is provided with a master machine card slot, and a master machine antenna, a master machine radio frequency (RF) module and a master machine baseband processing module which are sequentially connected; the slave machine is provided with a slave machine card slot, and a slave machine antenna, a slave machine RF module and a slave machine baseband processing module which are sequentially connected; the master machine baseband processing module are communicated with the slave machine baseband processing module through a communication module; and if one of the master machine and the slave machine is in a calling state, a signal of the other one of the master machine and the slave machine is subjected to concurrent processing. By setting two sets of antennae, RF modules and baseband processing modules, two SIM cards can be in a standby state and both ...

Pulse width regulating method and device independent from voltage

Drive method of brushless D.C. motor and its driving circuit

The present invention relates to a driving method of brushless A.C. motor and its driving circuit. Its interval energy-forbidden driving method is characterized by that the magnet pole distribution of the motor rotor is sensed and the driving control signal is produced. and when the rotor is reached to the critical zone before or after the critical position, the driving control signal is in energy-forbidding indication state to make motor stator do not produce magnetic field in said interval and make rotor rotate according to its original inertia, and when the rotor is positioned out of the critical zone, the driving control signal is in general driving state to make motor stator produce magnetic field according to preset mode to make motor accelerate rotation. Its driving circuit consists of comparator, pulse-width modulation circuit and logic operator which are connected together.

Drive method of brushless D.C. motor and its driving circuit

Optical fiber perimeter alarm method and device for implementing anti-polarization decay

The present invention provides an optical fiber perimeter warning method for realizing anti-polarization comedown and a device thereof. Concretely, a signal modulating module is used for modulating the phase of a light path signal and feeds back and controls the polarization state of the light path signal after the phase modulation; a polarization controller is arranged at one path sensing optical fiber of a Mach-Zehnder interferometer; the polarization controller is used for feeding back and controlling the input polarization state of a one path Mach-Zehnder interferometer and adjusting the output light path signal of the path, so the visibility of light path output can be stabilized by the technology of feeding back polarization control to provide the stable light path output signal for signal identification; at the same time, the feeding back and controlling process of a system is also simpler, thereby reducing the operating and maintaining cost of the system.

Optical fiber distributed perturbation sensor based on Sagnac interferometer

The invention discloses a distributed fiber disturbance sensor based on a Sagnac interferometer. A Sagnac interferometer is used for coupling an arm, synchronously a delayed fiber ring is added, namely a delayed fiber ring is superposed in a single Sagnac interferometer to form two Sagnac interferometers with different length; the time division multiplexing of the two Sagnac interferometers with different length is realized by the propagation of optical pulses in the interferometer; and the positions of disturbing points are calculated to realize the distributed sensing of the disturbance according to the amplitude of output signals of two Sagnac interferometers. The sensor has the advantages of low cost, simple structure and good stability.

FPGA-based distributed double M-Z optical fiber micro-destabilization sensor and PGC demodulation method thereof

The invention discloses a distributed double-M-Z optical fiber micro-disturbance sensor based on FPGA and a double-channel symmetrical full-digital PGC demodulation method thereof. Firstly, two detectors are used for collecting interference signals in the same position of an optical fiber to be detected and transmitted through different optical paths, and the two interference signals are respectively demodulated by two full-digital symmetrical PGC demodulation units on an FPGA chip to obtain two disturbance signals with higher relativity. The method can effectively solve the problem of phase slow variation and blanking of the double-M-Z optical fiber micro-disturbance sensor to achieve stable detection of optical fiber disturbance signals. Furthermore, a network communication interface is used for achieving network connection of the sensor.

Optical fiber distributed perturbation sensor based on Sagnac interferometer

The invention discloses a distributed fiber disturbance sensor based on a Sagnac interferometer. A Sagnac interferometer is used for coupling an arm, synchronously a delayed fiber ring is added, namely a delayed fiber ring is superposed in a single Sagnac interferometer to form two Sagnac interferometers with different length; the time division multiplexing of the two Sagnac interferometers with different length is realized by the propagation of optical pulses in the interferometer; and the positions of disturbing points are calculated to realize the distributed sensing of the disturbance according to the amplitude of output signals of two Sagnac interferometers. The sensor has the advantages of low cost, simple structure and good stability.

Method and apparatus for implementing optical fiber perimeter alarm

The present invention provides a method for realizing optical fiber perimeter warning and a device thereof. Concretely, a signal modulating module is used for modulating the phase of a light path signal and feeds back and controls the polarization state of the light path signal after the phase modulation, so as to eliminate the influence caused by system parameter change and improve the reliability of a system. At the same time, the present invention solves positioning error caused by external environmental change and system internal component parameter drift and improves the positioning precision of the system.