73results about How to "Increase the measurement distance" patented technology

An optoelectronic distance measuring device is disclosed. The device has a transmitting unit with a driver stage for emitting optical pulses, a receiving unit for receiving a portion of the optical pulses, said portion being reflected from a target object, and converting it into an electrical reception signal, via a photosensitive electrical component. It also has an analog-digital converter for digitizing the reception signal, and an electronic evaluation unit to ascertain a distance from the target object on the basis of a signal propagation time using the digitized reception signal. The driver stage can be designed so that at least two pulse durations of different length for the optical pulses can be set.

The invention discloses a distributed optical fiber vibration sensor based on the relay amplifying and sensing technology and a method thereof, belonging to the technical field of optical fiber vibration sensing. The system comprises a light source, an electro-optical modulator, a pulse driver, a light amplifier, a circulator, a polarizing beam splitter, a collector and a signal analysis processing system. The sensor is characterized in that the system also comprises a pumping laser light source and an optical remote sensing relay amplifying and sensing optical module. The pumping laser light source is arranged in the distributed optical fiber vibration sensing demodulation device and the optical remote sensing relay amplifying and sensing optical module is embedded between multistage sensing fibers. The passive optical modules of the pumping laser light source and optical remote sensing relay amplifying and sensing optical module perform long-distance connection through transmission fiber to form the light amplifier, the gain of the optical remote sensing relay amplifying and sensing optical module is utilized to overcome fibre loss, increase the intensity of the spontaneous Rayleigh scattering light of the optical fibre, enhance the signal-to-noise ratio of the distributed optical fiber vibration sensing system, enlarge the transmission distance of the system and increase the measurement accuracy of vibration events in the target area. The system is mainly used in the fields requiring long-distance measurement vibration signals such as perimeter safety precaution, border precaution, seismic detection and tsunami early warning.

The invention relates to a radio frequency cable fault positioning detection device and method. The device comprises an excitation source for generating a sweep frequency signal, a power divider for enabling a signal to be transmitted to a directional coupler and a frequency mixer, the directional coupler which is used for receiving the signal, enabling the signal to be transmitted to a measurement port, receiving a reflection signal transmitted by the measurement port, and transmitting the signal to the frequency mixer, the measurement port which is used for enabling the received signal to be outputted to a measured radio frequency cable, receiving the reflection signal, and transmitting the reflection signal to the directional coupler, the frequency mixer which is used for enabling the sweep frequency signal and the reflection signal to be mixed to obtain a difference frequency signal, and transmitting the difference signal to a filter amplification module, the filter amplification module, an A/D conversion module, an FPGA processor, and a CPU which is used for carrying out Fourier transform so as to obtain a difference frequency signal frequency value and a power value. The method does not need correction, is high in testing efficiency, can achieve real-time monitoring, is large in measurement distance, and is low in installation and maintenance cost.

The invention is mainly used for the optical fiber sensing temperature measurement field, and especially relates to a long-distance high-spatial-resolution Raman temperature measurement sensor and a realization method thereof. The long-distance high-spatial-resolution Raman temperature measurement sensor is characterized in that the long-distance high-spatial-resolution Raman temperature measurement sensor comprises an ultra-narrow-linewidth laser, a circulator, an acoustic-optic modulator, a reflector, a radio frequency generator, a 1*2 optical splitter (1:1), two wavelength division multiplexers, a Raman amplifier, an EDFA, two 2*1 couplers, a photoelectric detector, a signal processing and collection unit and a microprocessor unit. The beneficial effects are that the invention discloses the realization method of the long-distance high-spatial-resolution Raman temperature measurement sensor; the monitoring distance of the Raman temperature measurement sensor based on OTDR is generally smaller than 10 km, and spatial resolution is generally larger than 1 m; and the invention provides the realization method of the Raman temperature measurement sensor based on OFDR location technique, wherein the method can greatly improve measuring distance and spatial resolution index of the system, and the method can enable the monitoring distance of the Raman temperature sensor to reach 20 km, and spatial resolution index to reach the centimeter scale.

A laser receiver for detecting the position of incidence of a beam of laser light thereon includes a first photodetector and a second photodetector aligned in series with each other and spaced apart from each other by a gap. If the laser is evenly distributed between the two photodetectors, then the laser position will be set as the correct position and a corresponding signal will be displayed. However, if the first photodetector detects more light than the second photodetector, then a signal will also be displayed to inform the user that more laser is being projected onto the first photodetector. On the other hand, if the second photodetector detects more light than the first photodetector, then a signal will be displayed to inform the user that more laser being projected onto the second photodetector. These signals will assist users to adjust the laser receiver to accurately position the laser.

The embodiment of the invention provides a lidar, a measuring method thereof and a storage medium. The lidar comprises a laser transmitting module with adjustable transmitting power, a receiving module and a control module. According to the control module, the laser transmitting module is controlled to use safe transmitting power to transmit laser signals, and the receiving module is controlled todetect the test echo signals for the laser signals transmitted by using the safe transmitting power; after the test echo signals are determined not to be detected or the signal intensity of the testecho signals is smaller than a first signal intensity threshold, the laser transmitting module is controlled to improve the transmitting power for transmitting the laser signals for at least one time,the receiving module is controlled to detect target echo signals, and the target echo signals are the echo signals for the laser signals transmitted with the improved transmitting power; and a measurement result is acquired by using the target echo signals. The embodiment of the invention can perform long-distance measurement on the premise of ensuring eye safety.

A semiconductor electrostatic discharge (ESD) protection apparatus comprises at least one elementary transistor with a first conductivity type, a well region with a second conductivity type, a guard ring with the second conductivity type and a semiconductor interval region. The elementary transistor is formed in the well region. The guard ring surrounds the at least one elementary transistor. The semiconductor interval region is disposed between the elementary transistor and the guard ring in order to surrounds the elementary transistor, wherein the semiconductor interval region is an undoped region, a doped region with the first conductivity type or a doped region with the second conductivity type that has a doping concentration substantially less than that of the well region.

A laser measuring instrument comprises a light emitter, a driver, a scanning unit, a light receiving signal processing module for detecting a reciprocating time per pulsed light of a distance measuring light and performing a distance measurement, and a timing generating circuit for issuing a timing signal, wherein the timing generating circuit is configured to issue a timing signal for making the light emitter pulse-emit in a short cycle and a timing signal for pausing a light emission, the driver is configured to make the light emitter pulse-emit according to the timing signals, a light emission time interval in the short cycle is set such that a measuring point is multiply irradiated with the pulsed light by two or more times within a time when the pulsed light passes the measuring point, and the light receiving signal processing module is configured to integrate acquired light receiving signals and to carry out the distance measurement.

The invention discloses an implanted passive wireless acoustic surface wave sensor detection device. In the device, the power supply output end of an in-vitro processing module is connected with an in-vitro transmitting antenna, while the signal input end is connected with an in-vitro receiving antenna; an in-vivo receiving antenna is connected with a wireless power supply module which is connected with an acoustic surface wave sensor detection module that is connected with an in-vivo transmitting antenna; the in-vivo receiving antenna device is arranged in the radiation area of the in-vitro transmitting antenna; the in-vitro receiving antenna is arranged in the radiation area of the in-vivo transmitting antenna; the acoustic surface wave sensor detection module has the same central frequency as the in-vivo transmitting antenna; the in-vivo receiving antenna has the same central frequency as the in-vitro transmitting antenna; the in-vitro receiving antenna has the same central frequency as the in-vivo transmitting antenna; and the central frequency of the in-vivo receiving antenna and the in-vitro transmitting antenna is smaller the central frequency of the in-vitro receiving antenna and the in-vivo transmitting antenna. The device can detect the physiological parameters of organisms with high accuracy and has a long measurement distance.

The invention discloses an image collecting device and collecting method capable of collecting incident light, scattered light and transmission light information about dust concentration. The image collecting device comprises a light emitter, a light splitter and a light collector, wherein the light splitter splits probe light emitted from the light emitter into transmission light and reflected light, the light collector collects the reflected light and the transmission light penetrating through dust and comprises an optical fiber branch circuit, an optical fiber main circuit, an optical fiber coupler, a collection lens and a CCD camera, the optical fiber branch circuit is arranged at an exit port of the reflected light, the optical fiber main circuit is arranged at an exit port of the transmission light, light outlets of the optical fiber branch circuit and the optical fiber main circuit are connected to an inlet of the optical fiber coupler, and the collecting lens and the CCD camera are connected to an outlet of the optical fiber coupler sequentially. According to the device, the design complexity of the incident light, scattered light and transmission light collecting device is simplified, besides, the measurement accuracy of the incident light, scattered light and transmission light information is improved, and measurement signals can be collected in real time on line.

A crop chopping arrangement for a forage harvester includes a shearbar mounted adjacent a path swept by chopping knives of a chopper drum and being selectively adjustable toward and away from said path so as to adjust the distance between the shearbar and knives as they pass by the shearbar. An arrangement for measuring and/or checking the distance between the shearbar and the knives includes a vibration sensor located to measure the mechanical vibrations in the shearbar produced by the moving knives, and an electronic evaluation circuit. The evaluation circuit is operable for performing a frequency analysis of the signal provided by the vibration sensor so as to derive information indicative of the distance between the shearbar and knives.

A spray dispenser is configured to generate a swirled output spray pattern 152 with improved rotating or angular velocity ω and smaller sprayed droplet size. Cup-shaped nozzle member 60 has a cylindrical side wall 62 surrounding a central longitudinal axis 64 and has a circular closed end wall 68 with at least one exit aperture 74 passing through the end wall. At least one enhanced swirl inducing mist generating structure is formed in an inner surface 70 of the end wall, and including a pair of opposed inwardly tapered offset power nozzle channels 80, 82 terminating in an interaction chamber 84 surrounding the exit aperture 74. The power nozzle channels generate opposing offset flows which are aimed to very efficiently generate a vortex of fluid which projects distally from the exit aperture as a swirled spray of small droplets 152 having a rapid angular velocity.

The invention discloses a distributed optical fiber vibration sensor for enhancing long-distance detection, and a method of the distributed optical fiber vibration sensor, and belongs to the technical field of optical fiber vibration sensing. The system comprises a light source, an electro-optic modulator, a pulse driver, an active optical amplifier, a circulator, a polarizing beam splitter, a collector, and a signal analysis and processing system. The system characterized by further comprising a far-end optical relay. The far-end optical relay is embedded between multistage sensing optical fibers, optical fiber losses are avoided by using gains of the far-end optical relay, the strength of spontaneous Rayleigh scattered light in the optical fibers is enhanced, a signal to noise ratio of the distributed optical fiber vibration sensor system is increased, the transmission distance of the distributed optical fiber vibration sensor system is increased, and measuring accuracy of the vibration in a target area is improve; and meanwhile, safety hazards caused by highlight power pump light are avoided.

The invention provides a track breaking monitoring system of a high-speed railway. The system comprises a MCU for generating a testing signal according to received instruction information and sending to an ultrasonic sending probe, the ultrasonic sending probe for receiving the testing signal and sending an ultrasonic signal to a high-speed railway track according to the testing signal, an ultrasonic receiving probe for receiving the ultrasonic signal from the high-speed railway track and sending the ultrasonic signal to an FPGA processing circuit, and the FPGA processing circuit for performing digital filter and FFT analysis for the ultrasonic signal as well as carrying out frequency spectrum comparison and signal correlation comparing and analyzing for the FFT analysis result so as to determine the track breaking condition of the high-speed railway. According to the track breaking monitoring system of the high-speed railway, the measures of shielding and isolating loops are carried out to increase the signal conversion quality, and the influence of an electromagnetic environment on the detection result is reduced; in addition, the wavelet analysis algorithm is carried out for the FPGA processing circuit, and therefore, the signal receiving sensitivity is high, and the measurement distance is effectively increased.

The invention provides a precise synchronization-unrequired coal mine underground spread spectrum accurate ranging method and a device. According to the precise synchronization-unrequired coal mine underground spread spectrum accurate ranging method, a parallel and tracking loop-free pseudo-noise code synchronization accurate measurement algorithm is adopted, such that higher time resolution can be obtained based on rough synchronization without precise synchronization process required, and therefore, ranging pseudo code speed can be decreased, and bandwidth occupied by ranging pseudo codes is limited below 100MHZ, and thus, meter-level positioning accuracy can be achieved. The device for realizing the method comprises a communication control module and a wireless response module; the communication control module, adopting a high-performance FPGA as a core processor, mainly comprises a transmitter and a receiver; and the wireless response module de-spreads received signals through adopting a search-track-free synchronization mode without a separate processor required. The precise synchronization-unrequired coal mine underground spread spectrum accurate ranging method and the device of the invention can inhibit serious electromagnetic interference under a coal mine, and are advantageous in robust hardware designs, redundant algorithms, high-accurate ranging and strong real-time property, are suitable for a coal mine underground personnel precise positioning system.

The invention relates to a distributed optical fiber temperature measuring system which comprises a wavelength division multiplexing (WDM) optical device and an APD multistage amplifying module. A measured optical cable is connected with the WDM optical device, the output end of a pulse light source is connected with the WDM device, and the APD multistage amplifying module is used for receiving optical signals transmitted by the WDM optical device and outputting simulation signals to a multi-channel collection board card in a segmentation mode. The multi-channel collection board card is connected with a software platform, and the software platform is used for receiving the simulation signals transmitted by the multi-channel collection board card, conducting segmentation processing on the signals and combining the signals into a whole channel. The distributed optical fiber temperature measuring system with the structure effectively extends optical fiber measuring distance of a single channel, the device number is reduced, problems of signal transmission, device power supply, device maintenance and the like caused by device cascade connection required by long-distance transmission measurement are solved, product measuring distance is increased, temperature measuring cost is reduced, temperature measuring accuracy is improved, the signal to noise ratio of measuring signals of each segment is kept at a high level, and the temperature measuring accuracy is improved.

A phase analog coherent demodulation system includes a difference frequency and pulse generator configured to generate a pulsed light and a continuous light with different frequency from the pulsed light, a controller, and an I/Q demodulation module. The controller locks the frequency difference signal of the pulse light, and the pulsed light generates the backward scattered light of constant frequency in the measured medium, and the backward scattered light returns along the original path and mixing beat with the continuous light in the I/Q demodulation module, the difference frequency electrical signals of the two optical signals are obtained. The I/Q demodulation module orthogonally demodulates the difference frequency electrical signal by using the frequency difference signal of the pulsed light and the continuous light as the fundamental frequency signal of the orthogonal demodulation, to detect phase information of the vibration signal. The invention reduces the operating frequency required for quadrature demodulation in system phase detection.

The invention belongs to the technical field of the mobile communication, and discloses an LTE uplink energy measurement method. The method comprises the following steps: detection equipment acquirespublic network information of a public network resided by user equipment through frequency sweeping; the detection equipment and the public network perform air interface synchronization; the detectionequipment acquires public network downlink data to decode PCFICH so as to acquire a CFI value, blindly detects the PDCCH to acquire uplink scheduling information; the detection equipment acquires theuplink data of the uplink scheduling information according to a HARQ mechanism; and the detection equipment measures the uplink energy of the user equipment according to the uplink data. The problemsthat the energy measurement can be started as long as the target user equipment is accessed to a pseudo base station in the existing positioning measurement method, the measurement distance is short,the measurement can be easily sensed by the target user, the volume and the power consumption of the detection equipment are large, and other user equipment can be easily interfered in the process oftracking and positioning the target user equipment are solved.

A device is provided for use with a reference tool during the construction of metal structures. The device comprises a body having a groove formed therein for receiving a portion of a straight side of the reference tool. The body further comprises a base surface for co-operating with the surface of a metal workpiece. The base surface is configured whereby, when a portion of the straight side is received within the groove, the base surface is parallel to the straight side of the reference tool. A retention assembly is mounted on the body for retaining the portion of the straight side of the reference tool, when provided, within the groove. At least one magnet is mounted on the base surface for temporarily holding the device to the metal workpiece, thereby holding the reference tool in position.

This invention relates to a method for detecting a tear in a fibrous web in a drying section of a machine for producing the fibrous web, whereby the fibrous web is passed through the drying section by way of at least one dryer fabric, whereby the tear is detected by at least one optical web tear detection device, which includes at least one luminous source and one detector, and whereby a cut-off apparatus for the fibrous web is directly or indirectly activated by the web tear detection device. The optical web tear detection device is operated over an extended wave length range in order to detect a tear in the fibrous web reliably. In addition, the invention relates to an apparatus for performing the inventive method.

The invention discloses a method for improving the reliability of a radio-frequency identification tag of a low-voltage mutual inductor based on experience modal decomposition, and the method comprises the steps: measuring the performance data of the radio-frequency identification tag of the low-voltage mutual inductor under the factors of different temperature, humidity, mutual inductor coil electric quantities and electromagnetic interference intensities, and building a basic expert database of the radio-frequency identification tag of the mutual inductor; measuring the data of the radio-frequency identification tag of the low-voltage mutual inductor in a normal environment, and building a normal database of the radio-frequency identification tag of the low-voltage mutual inductor in the normal environment; measuring the data of the radio-frequency identification tag of the low-voltage mutual inductor in an on-site environment, and building an on-site database of the RFID(radio-frequency identification) tag of the low-voltage mutual inductor in the on-site environment; and carrying out the analysis of the built basic expert database, normal database and onsite database based on an error analysis method based on the EMD (Empirical Mode Decomposition).

The invention relates to the technical field of laser radars, and provides a three-dimensional laser radar based on a liquid crystal on silicon and a scanning method. A transmitting light source and areceiving detector are arranged on one side of a polarization device in a common optical axis mode. A transmitting optical assembly is located on a transmitting optical path between the transmittinglight source and the polarization device. A receiving optical assembly is positioned on a receiving optical path between the receiving detector and the polarization device. A liquid crystal on siliconis arranged on the other side of the polarization device and used for reflecting the emitted light polarized by the polarization device to a to-be-measured target object at a first specified angle and reflecting the received light reflected back from the to-be-measured target object at a second specified angle. According to the invention, different phase distributions are downloaded by using theliquid crystal on silicon to realize two-dimensional measurement of the length and width dimensions of the to-be-measured target, the height dimension of the to-be-measured target is measured throughlaser beams of two polarization states, so that the three-dimensional measurement of the to-be-measured target is realized.