663results about How to "Expand the measurement range" patented technology

A thermocouple vacuum sensor is provided, the thermocouple being surrounded by a gas or mixture of gases the pressure of which is to be measured. Cyclically the thermocouple is heated until its temperature reaches an upper temperature threshold. The thermocouple is subsequently cooled until its temperature reaches a lower temperature threshold. The heating time required to heat the thermocouple from the lower to the upper temperature threshold is measured. The cooling time required to cool the thermocouple from the upper temperature threshold to the lower temperature threshold may also be measured. The pressure surrounding the thermocouple may then be determined as a function of either the heating time, or the cooling time, or both.

A method for detecting and representing one or more objects, such as teeth, their preparations and their immediate environment, using a camera. A first recording is made wherein a still image is produced. The still image is blended into a current, mobile search image in at least one sub-area in the second step, so that both images are recognizable. In the third step, the camera is positioned in such a way that the search image overlaps the blended-in still image in at least one sub-area. The second recording process is initiated in a fourth step.

The mass flow rate sensor includes a waveguide disposed in a flow passage having a bluff body facing in an upstream direction. Waves are pulsed along the waveguide for interaction with the fluid. A receiver is coupled to the waveguide to detect a propagated wave and provides a first output signal proportional to the transit time of the propagated wave for determining fluid density. The receiver also provides a second output signal proportional to the shedding frequency of vortices from the waveguide to determine velocity. An electronics module calculates mass flow rate from the velocity times density times area of the flow passage and a constant. In other forms, the velocity is ascertained by transmitting an ultrasonic beam through the shedding vortices to determine vortex frequency which is proportional to velocity.

A radar level gauge system, for determining a filling level of a product contained in a tank, the radar level gauge system comprising: a transceiver for generating, transmitting and receiving electromagnetic signals; a probe electrically connected to the transceiver at a probe-transceiver connection and arranged to extend towards and into the product contained in the tank, for guiding a transmitted signal from the transceiver towards a surface of the product, and for returning a surface echo signal resulting from reflection of the transmitted signal at the surface back towards the transceiver; an impedance matching device arranged to extend along a portion of the probe inside the tank, an extension of the impedance matching device, in a direction perpendicular to the probe, decreasing along the portion of the probe with increasing distance from the probe-transceiver connection, to thereby provide impedance matching between an impedance of the probe-transceiver connection and an impedance of the probe; and processing circuitry connected to the transceiver for determining the filling level based on the surface echo signal.

The invention discloses an optical fiber Fabry-Perot sound pressure sensor manufacturing method based on a graphene membrane and a measuring method and device thereof. A sensor is manufactured based on the graphene membrane and the optical fiber Fabry-Perot interference optical principle. Firstly, a single mode fiber is rinsed and processed, the graphene membrane is transferred, and the graphene membrane is adsorbed to a zirconium oxide single mode inserting core; then, the zirconium oxide single mode inserting core is inserted into the processed single mode fiber from the other end. Therefore, two reflecting surfaces of Fabry-Perot interference are formed by the end face of the single mode fiber and the graphene membrane, an optical fiber-air-graphene membrane interference cavity is formed, an interference cavity length detecting device is set up, interference spectrum signals are demodulated by using a two-peak method, and the high sensitivity detection of weak sound pressure signals is achieved. The sensor has the advantages of being simple in manufacturing, high in sensitivity, small in size, resistant to electromagnetic interference and the like, the problem that a sensor is low in sensitivity due to the limitation of the reduction of the thickness of a membrane in the prior art is solved, the sensitivity of the membrane type sound pressure sensor is improved, and the sensor can be expected to be applied to the underwater sound field, the electroacoustic field, medical field, biomedical engineering filed and the like.

Disclosed is a current sensor including magnetic sensors disposed on a conductor having at least two separated current-carrying areas with different current magnitudes and detecting a magnetic field generated according to currents flowing through the conductor and a controller controlling outputs of the magnetic sensors, wherein the magnetic sensors are disposed in at least two respective areas having different current magnitudes and the controller switches outputs of the magnetic sensors.

A device and a method for wavefront measurement of an optical system (7), in particular by an interferometric measurement technique. A dynamic range correction element (12, 12a) is arranged in the beam path upstream of the detector arrangement (11) and is designed such that the variation in the spatially dependent characteristic of a phase of the wavefront forming the interference pattern is kept below a prescribed limit value throughout a detection area. In addition or as an alternative, a set of several diffraction structures of different period length can be used with a shearing interferometry technique and / or a set of several pairs of a reference pinhole and a signal passage opening with different hole spacings can be used with a point diffraction interferometry technique for different sub-areas of the detection area. A remaining distortion error can be taken into account by determining a corresponding distortion transformation and applying the inverse distortion transformation.

A two-dimensional imaging surface plasmon resonance (SPR) apparatus for optical surface analysis of a sample area on a sensor surface is disclosed. The apparatus comprises a sensor surface layer of a conductive material that can support a surface plasmon, such as a free electron metal, e.g. gold, silver or aluminum, a source of electromagnetic beams of two or more wavelengths that illuminate a two-dimensional surface area from either the front or the backside of the sensor surface layer, and a detector for simultaneous, or pseudo simultaneous, detection of two or more wavelengths of reflected intensities from the two-dimensional surface area, providing two or more two-dimensional images of the surface area, the two-dimensional images being a function of the effective refractive index at each point on the surface area. The two-dimensional images put together result in a color image. The apparatus is suitable for use in biological, biochemical, chemical and physical testing.

The invention discloses a turbidity transducer relating to the technical field of transducer measurement. The turbidity transducer comprises an optimal measurement module, a temperature measurement module, a TEDS (Transducer Electronic Data Sheet) storage and a microprocessor, wherein the optimal measurement module is used for acquiring turbidity signals of water bodies; the temperature measurement module is used for acquiring temperature signals of the water bodies; the TEDS storage is used for storing TEDS parameters, and the TEDS parameters include calibrated compensating parameters of the relationship of reflecting temperature and turbidity; and the microprocessor is connected with the optimal measurement module, the temperature measurement module and the TEDS storage and used for carrying out analog-to-digital conversion treatment on turbidity voltage signals and temperature voltage signals and calculating a turbidity value generated by the analog-to-digital conversion treatment according to the calibrated compensating parameters. The turbidity transducer can realize the temperature compensation of measured turbidity, thereby enhancing the turbidity measuring accuracy; and in addition, the invention has self-cleaning function and can be used for carrying out on-line measurement on water turbidity.

The invention discloses an intelligent sensor for the electrical conductivity of water quality. The sensor comprises a temperature-conductivity probe used for sensing the temperature and the electrical conductivity of the water; a signal conditioning module which is connected with the temperature-conductivity probe, forms a sensing circuit with the temperature-conductivity probe and carries out filtering and amplification to an output signal; a microprocessor which is connected with the signal conditioning module, is used for digitizing the signal input by the signal conditioning module and adopts IEEE1451 standards to carry out the calibration and alignment of channels; a bus interface module which is connected with the microprocessor and is used for the functions of networking and plugging and playing; and a power module which supplies power to the circuits of all parts of the sensor under the control of the microprocessor and realizes the characteristic of low power consumption. The invention can eliminate the polarization effect of the probe, has pollution resistance, large measuring range and low price, and is characterized by the functions of self alignment and compensation, self diagnosis and plugging and playing and high integrity.

The invention discloses a three-dimensional gesture key point detection method based on a neural network, which comprises the following steps: acquiring a gesture data set including gesture area information and gesture two-dimensional and three-dimensional key point position information; obtaining a gesture data set containing gesture area information and gesture two-dimensional and three-dimensional key point position information. Training a gesture segmentation network which can detect a gesture region in an RGB image by taking an RGB image containing a gesture as an input; the gesture region detected by the gesture segmentation network is truncated, up-sampled or down-sampled. Training a two-dimensional gesture key point detection network, which can detect a plurality of two-dimensionalgesture key points in a gesture region image; the absolute coordinates of the key points of the three-dimensional gesture are converted into relative coordinates; a 2D to 3D gesture key point mappingnetwork is trained. The network can map multiple 2D gesture key points into 3D space to form 3D gesture key points. The invention can quickly and effectively detect three-dimensional gesture key points from RGB images containing gestures.

The invention provides a film single-shaft bidirectional tensing mechanism and a measuring method for the deformation in the film, and pertains to the field of precision machinery. The mechanism uses two piezoelectric ceramics 8 to push from two directions respectively a slider 4 and an adjustable slider 3 that can move along a slideway 2, between the slider 4 / the adjustable slider 3 and a support 1, limit springs 9 are used for limiting; on the slider 4 and the adjustable slider 3, a force sensing arm 6 is fixedly connected respectively; the top of the force sensing arm 6 is connected with a stage. At measuring, first a film specimen to be measured is clamped on the stage; then the piezoelectric ceramics 8 are applied with voltage continuously, so that the two force sensing arms 6 will have mini displacement opposite to each other; meanwhile, the images and mechanic parameters of the film deformation are recorded by a real-time acquisition system and stress pieces 5 attached on the force sensing arms 6. By the invention, the measuring area can be observed continuously, and measurement of wider range can be carried out by force sensing arms of different measuring ranges.

The invention relates to a co-phasing control device and control method for a spliced telescope.The device comprises a spliced telescope body, a first beam splitter, a wavefront detector, a second beam splitter, a translation error detector and a wavefront controller, wherein the first beam splitter receives emergent rays and generates first divided beams and second divided beams; the wavefront detector detects the first divided beams and obtains system aberration data and wavefront distortion aberration data of transmission paths of all spliced sub mirrors; the second beam splitter receives the second divided beams and generates third divided beams and fourth divided beams; the translation error detector detects the third divided beams and collects dispersion interference fringes between each pair of spliced sub mirrors; the wavefront controller is connected with the wavefront detector, the translation error detector and a driver of a secondary separating deformable mirror.By means of the co-phasing control device and control method for the spliced telescope, real-time detection and compensation and correction of translation, inclination and higher order aberration can be effectively achieved, and compared with the technology in a current similar system, better accuracy and instantaneity are achieved.

A non-contact three-dimensional surface measurement method is provided in which a grating pattern projected onto an object being measured, while the phase of the pattern is being shifted, is observed in a different direction from a projection direction to analyze the contrast of a grating image deformed in accordance with the shape of the object and thereby obtain the shape thereof. The method enables measurement of a three-dimensional shape over a large measurement range in a short time in a non-contact manner by successively shifting the focus on the projection and the imaging sides to enlarge the measurement range in the direction of depth.

The invention belongs to the technical field of integrated circuits, and particularly relates to a high-performance gating vernier type time digital converter. The high-performance gating vernier type time digital converter comprises a phase-frequency detector used for detecting rising edges of two input signals and comparing frequencies, a mode judgment device used for automatically selecting a quantization mode according to the amplitude of the input signals, a quantization unit used for achieving first-step quantization through a single-bit DSSA structure and conducting second-step quantization on the input signals through Vernier GRO, a multiphase counter used for reading a quantization result of the Vernier GRO, a loop locking accelerating unit used for recording the number and the classification of the rising edges of the input signals in a TDC dead zone and correcting TDC output and an assessment logical circuit used for conducting summing operation on multiphase counter output and conversion of original complements is conducted on the TDC output according to a PFD output frequency comparison result. According to the high-performance gating vernier type time digital converter, the obtained resolution ratio of the time digital converter is high, the measurement range is large, and the sample rate is high.

The invention discloses an estimation method of an atmosphere angle of attack and an angle of sideslip in a high-angle-of-attack flight status. Under the premise that the structure of an aircraft is not changed and additional measuring devices and hardware devices are not added, the parameters output by the existing onboard strapdown inertial navigation system, a GPS (Global Position System) system, a flight control system and a fuel measuring system are fully used for resolving the angular acceleration, the rotational inertia, the product of inertia, the coefficient of a moment equation set and the total mass of the aircraft; based on a flight dynamics model, by establishing an extended Kalman filter, and integrating the processes of resolving the flight dynamics model and the status estimation together, accurate estimation of the current angle of attack, the angle of sideslip and the true airspeed is realized, and then the current air speed and the change rate of the air speed are resolved and input into the extended Kalman filter as the feedback information so as to finish the real-time accurate estimation of the angle of attack and the angle of sideslip of next time; the real-time accurate estimation of the angle of attack and the angle of sideslip is realized by a recursive resolving mode, measurement range and measurement precision of an atmosphere data system are improved, and adaptability to complex flight environment is also improved.

Single-phase currents at two frequencies f alpha and f beta (f alpha <nxfs<f beta ) of non-integral multiples of a system fundamental wave frequency fs sandwiching an targeted harmonic (frequency nxfs) are injected between two phases of a three-phase power system as interharmonic currents. A frequency analysis of measurement current and measurement voltage of each phase in the system is carried out and a positive-phase-sequence current I1, a positive-phase-sequence voltage V1, a negative-phase-sequence current I2, and a negative-phase-sequence voltage V2 are detected for each of the two frequencies f alpha and f beta in the system based on injecting of the interharmonic currents. Positive-phase-sequence and negative-phase-sequence admittances Y1 and Y2 or positive-phase-sequence and negative-phase-sequence impedances Z1 and Z2 are found for each of the frequencies f alpha and f beta in the system as Y1=I1 / V1 and Y2=I2 / V2 or Z1=V1 / I1 and Z2=V2 / I2. Interpolation operation is performed for finding positive-phase-sequence and negative-phase-sequence admittances or positive-phase-sequence and negative-phase-sequence impedances for the targeted harmonic in the system from the admittances Y1 and Y2 or the impedances Z1 and Z2 for the frequencies f alpha and f beta .

A turbidity measuring system is provided with a chamber and a sensor having a watertight housing, a light source, a first light focusing device for focusing a light emitted from the light source and passing therethough into a sample liquid, a second light focusing device for collecting at least one scattered light resulted form the focused light when passing the sample liquid, a photodiode for receiving the collected light thereby generating electronic signals, and an electronic board for processing the electronic signals. In particular, the watertight housing has a tilted bottom, the light detector includes at least two photodiodes for detecting separated turbidity measuring ranges, or an insert is placed at the bottom of the chamber having first and second insert channels each of whose axis pointing toward an axis of one of the cylindrically-shaped channels in the watertight housing in order to trap light.

A method for distance measuring using at least two contact-less distance sensors, e.g., ultrasound sensors, is provided, which distance sensors each have one emitter for emitting measuring pulses (MI) and one receptor for receiving measuring pulse echos (ME). The distance from an obstacle that reflects the measuring pulse (MI) is determined from the time difference between the measuring pulse (MI) and the received measuring pulse echo (ME). A first measurement is performed, which involves alternatingly emitting by the at least two distance sensors the measuring pulses (MI) offset in time by a first offset, and subsequently receiving the measuring pulse echos (ME) by the distance sensors. In addition, a verification measurement is performed, which involves alternatingly emitting by the at least two distance sensors the measuring pulses (MI) offset in time by a second offset, which is different from the first offset in time used in the first measurement.

The invention discloses a BP (Back Propagation) neural network-based method for measuring air data in a flight state with a high angle of attack. According to the method, on the premise of not changing the configuration of an aircraft and not adding extra measurement devices and hardware equipment, the traditional airborne inertial navigation system, a global positioning system (GPS) and a flight control system are sufficiently utilized to output parameters, and the precise estimation of air data in a flight state with a high angle of attack is realized on the basis of a BP neural network. The method is beneficial to aircraft stealth, and meanwhile, the measurement range and the measurement precision of an air data system and the adaptability to a flight environment with a high angle of attract are improved, so that the method has the advantages of relative economy and easy engineering realization and has important practical significance to enlarging the measurement range of a new generation of aircrafts in the flight state with a high angle of attract and improving the flight performance of the aircrafts.

Provided are a positioning system using ultrasonic waves and a method for controlling the positioning system. The method for controlling a positioning system installs a plurality of ultrasonic satellites generating ultrasonic signals to position a mobile. The method sequentially gives satellite identification numbers to the plurality of ultrasonic satellites, generates a synchronization signal and providing it to the plurality of ultrasonic satellites, and allows the mobile to receive ultrasonic signals, which are generated by the plurality of ultrasonic satellites in the order of the satellite identification numbers when the ultrasonic satellites receive the synchronization signal, to measure distances between the mobile and the ultrasonic satellites. The positioning system using ultrasonic waves includes ultrasonic satellites generating ultrasonic signals, a mobile that receives the ultrasonic signals from the ultrasonic satellites to recognize its current position, a reference time broadcasting device for providing a synchronization signal to ultrasonic satellites currently operating among the ultrasonic satellites and the mobile, and a server for providing the coordinates of the ultrasonic satellites to the mobile.

The invention belongs to the technical field of optical precision detection, and relates to a bilateral misalignment differential confocal detection method and device for the free-form curve topography, which can be used for nano-precision detection of the free-form curve topography. The device comprises an active air floating vibration isolation spring, an air floating vibration isolation base, an X-direction air floating guide rail, a gantry, a bilateral misalignment laser confocal fixed-focus trigger measurement system, a laser interference displacement measuring mirror group, a Y-directionair floating guide rail, a Z-direction air floating guide rail, a free-form surface sample attitude adjustment device, a reference flat-crystal attitude adjustment device and a laser interferometer.By the way of contour measurement of a gantry structure coordinate measuring machine (CMM), in combination with the high-precision planar flat crystal as a reference reflecting mirror, the influence of the straightness of the X-direction and Y-direction air floating guide rails on the high-precision detection of the surface contour of the free-form surface is reduced, so that the 21 errors of theCMM are reduced. A spherical air floating table with a three-point support structure is used to adjust the attitude of a free-form surface part to be tested, and the high-precision detection of the contour of the free-form surface part is realized.

In one embodiment, a TMR field sensor utilizes existing one or more self-test current lines in a configuration to extend magnetic field measurement range without sacrificing measurement sensitivity. The self-test current lines are energized to facilitate magnetic field measurement when the measured magnetic field reaches a threshold. The magnetic field created by self-test coil opposes an external magnetic field being measured to keep the net magnetic field within a desired range where the magnetic field sensor has linear output and desired sensitivity.

The invention provides an active vision non-contact servo mechanism parameter measuring device, consisting of a measuring screen, a servo mechanism mounting platform, an image acquiring and processing system, and a red light laser light source, wherein a servo mechanism to be detected is provided with the red light laser light source which is positioned on the servo mechanism mounting platform and is arranged in front of the measuring screen, a digital camera is arranged behind the measuring screen to image on the screen. Firstly, the device shoots a picture of a gridiron pattern on the measuring screen by the camera which is demarcated; secondly, the servo mechanism controls a main frame to give a command so as to control the rotation of the servo mechanism to be detected, a computer extracts laser point coordinates of the image, the rotational angle at each moment of the servo mechanism to be detected is calculated and recorded in real time, the motion parameters of the servo mechanism to be detected such as the angular velocity, the pointing accuracy, and the overshoot are calculated by the rotational angle; the measuring method is simple, convenient and flexible, and the device and the measuring method realize the measurement in real time and with high accuracy of the movement parameters of a biaxial servo mechanism through the non-contact way.

A field bus interface for connecting a device to a field bus, comprising communication circuitry for providing communication via the field bus, first power supply circuitry arranged to provide said communication circuit with a predefined communication power at a predefined drive voltage, and second power supply circuitry arranged to provide a processing circuitry with processing power at said bus voltage only when a power available from said field bus exceeds said communication power.More specifically, the power provided to the processing circuitry at a given bus current will be decided by the power actually available, instead of a power level decided by the lower limit of the voltage range of the field bus specification. The first circuitry and the communication circuitry will ensure that the field bus requirements are met in a case when the bus voltage falls close to the lower limit of the bus voltage range.

A circuitry for measuring a time interval with ring oscillator has a ring oscillator formed by a plurality of delay switching units, a counter and an encoder. Wherein, the ring oscillator generates a plurality of oscillating signals when receives a pulse signal used to turn on or turn off the ring oscillator. The counter can count the numbers of the oscillating signal during an active period of the pulse signal to generate a counting value. In addition, the encoder encodes the oscillation signals generated by a plurality of delay switching unit with a certain interval of delay time. Therefore, when the pulse signal is disabled to lead to turn off the ring oscillator, one can obtain the time interval of the pulse signal based on the encode data and the counting value.