394results about How to "Reduced measurement accuracy" patented technology

A 3-D camera and a method for recording surface structures on an object of interest by triangulation, in particular for dental purposes. The camera provides for producing a group of light beams in order to illuminate the object of interest via a projection optical path, an image sensor for receiving light back-scattered by the object of interest via an observation optical path, and provides, in the projection optical path, for producing a pattern projected onto the object of interest. To avoid ambiguities in the event of large height differences, the camera provides for the projection optical path and / or the observation optical path for altering the triangulation angle, which is defined by the angle between the centroid beam of the projection optical path and the centroid beam of the observation optical path. The proposed process involves the taking of at least two 3-D measurements of the same object of interest with different triangulation angles.

The invention discloses a fiber grating sensing layer-divided sinking apparatus for observing unconsolidated strata sedimentation, a data monitoring processing system, a grating sensor and an implantation method. The fiber grating sensing layer-divided sinking apparatus comprises a grating sensor and a grating sensor array, wherein the grating sensor array is used for applying a light source to the grating sensor through a broadband light source of a fiber grating demodulator and a coupler; a light signal returned by the grating sensor is input to the fiber grating demodulator through the coupler; the fiber grating demodulator is used for converting the light signal into an electric signal and calculating a center wavelength value of each grating sensor; the monitoring processing system is connected with a wavelength data acquiring module, a data analysis module, a time display wavelength module, a real-time monitoring curve module, an information prompt module, a forecasting alarm system module and the like respectively; and another path of data analysis is connected with a memory and a data processing module respectively. The device is simple in structure, not influenced by a severe environment, resistant to corrosion and electromagnetic interference, safe and reliable, convenient to use and widely applied to strata sedimentation; and sensing and transmission are integrated.

The invention relates to a measuring array with an earth connection point (5) for determining the insulation resistance (Riso) of an energized electrical apparatus or of an installation with a supply voltage UB with a positive pole (6) and a negative pole (7), two switches (S1, S2) or a corresponding two-way switch being provided for creating a current path between one of the two poles and said earth connection point (5) in order to determine the insulation resistance (Riso) generally obtained when one or a plurality of insulation faults occur at any potential reference, two measurements being performed one after the other for determining the insulation resistance, the first switch (S1) being closed and the second switch (S2) open during the first of these two measurements and the first switch (S1) being open and the second switch (S2) closed during the second of these measurements.

A measurement device capable of sensing presence of an obstacle within a vessel from outside the vessel in operating a linear body inserted in the vessel is provided. According to this measurement device, an easy-to-use measurement device capable of measuring compressive force in a direction of longitudinal axis applied to the linear body that has a sheath thicker than the linear body, such as a wire having a coil for embolizing an aneurysm attached at a tip end, without lowering measurement accuracy, can be provided. In addition, a length of a restraint portion is minimized, to achieve a smaller size of the measurement device. Moreover, the measurement device capable of measuring compressive force in the direction of longitudinal axis applied to the linear body regardless of magnitude of buckling load of the linear body can be provided, and the same measurement device is applicable to linear bodies of various materials, which leads to cost efficiency.

The invention relates to a time measurement system, which comprises a start signal fine time measurement unit, a timing signal fine time measurement unit, a rough time measurement unit and a time calculation unit, wherein the start signal fine time measurement unit comprises a delay chain, a plurality of registers and a data converter; one end of the delay chain receives a start signal; outputs of delay units receiving the start signal are sequentially changed into second levels; each register reads and stores an output value of the corresponding delay unit at the rising edge of a first clock when the start signal is input; the data converter converts the stored data into time data to acquire start signal fine time; the timing signal fine time measurement unit is used for acquiring timing signal fine time; the working theory of the timing signal fine time measurement unit is similar to that of the start signal fine time measurement unit; the rough time measurement unit is used for measuring rough time under the driving of a field programmable gate array (FPGA) clock signal; and the time calculation unit is used for subtracting the timing signal fine time from a sum of the rough time and the start signal fine time to acquire time to be measured. According to the system, the precision and the instantaneity of time measurement are improved.

The invention discloses a digital processing method of an altimeter of a linear frequency modulation continuous wave radar, which belongs to the field of the radio altimeters. The digital processing method comprises the following steps: step 1, obtaining beating signals from an orthogonal mixer arranged at the front end of the altimeter of the radar, and carrying out A / D (analog-to-digital) sampling to obtain a digital signal sequence; step 2, performing Fourier transform on the digital signal sequence, and calculating the amplitude of a spectral line; step 3, judging according to the amplitude of the spectral line of an amplitude spectrum, and measuring the beating frequency of the digital signal sequence; step 4, refining the frequency spectrum, calculating the slope correction of saw-tooth wave, and correcting the slope of the voltage signals of the saw-tooth wave; and step 5, calculating the high value of the current altimeter according to the slope of the voltage signals of the saw-tooth wave. The FFT-CZT method adopted by the invention is insensitive to noises and can perfectly work at lower signal-to-noise ratio, but the measurement precision is reduced. Because of having no limit on the properties of the targets, the digital processing method can be applied to the measurement and the analysis of point targets or surface targets.

The invention discloses a contact measurement error compensation method oriented to a freeform surface and a compensation system. After small-size workpieces are detected, if the workpieces are not qualified, the workpieces need to be remounted in a machining center for secondary finishing and machining, and a secondary chuck-mounting error is accordingly caused; for large-size workpieces, the problems such as secondary chuck-mounting error also can be caused. The contact measurement error compensation method oriented to the freeform surface consists of a ruby measuring head (1), wherein the ruby measuring head is connected with a ceramic measuring rod (2), the ceramic measuring rod is connected with a pressure sensor (3), the pressure sensor is connected with a signal transmitter (4), the pressure sensor is connected with a cutter handle (5), the cutter handle is connected with a three-axis machine tool (6), the signal transmitter is connected with a signal receiver (7) through wireless signals, the signal receiver is mounted on the three-axis machine tool, the signal receiver is electrically connected with the JA40 interface of the three-axis machine tool, and the three-axis machine tool is electrically connected with a computer host (8). The contact measurement error compensation method oriented to the freeform surface and the compensation system are applicable to the error measurement of common planes and freeform surfaces.

The invention relates to an apparatus comprising a measurement chamber and a resonator, which can be integrated in the measurement chamber via a quick-action closure, for the liquid sensor system and for verification and measurement of the concentration of materials, substances, particles and / or microorganisms in liquids. The invention is characterized in that the resonator is held only on its outer circumference by a thin elastomer ring, and in that at the radial distance of the external diameter of the resonator, the elastomer ring on the one hand rests on an upper sealing ring of the measurement chamber, forming a seal, and on the other hand rests on a holding ring.

An objective of the present invention is to provide a technique for reducing measurement errors when measuring specimen using light. An aspect of an optical measurement method according to the present invention: acquires relationship data that describes a relationship between an intensity of reflection light when irradiating light onto a specimen and a size of the specimen; and acquires the size of the specimen using the relationship data and the intensity of the reflection light. Another aspect of an optical measurement method according to the present invention subtracts a component due to an inclination of a vessel of a specimen from a detection signal representing an intensity of reflection light when irradiating light onto the specimen, thereby correcting the inclination of the vessel.

The invention aims to provide a new method for on-line monitoring of an insulation damping defect of a transformer bushing. Transient voltage waves u(t) and current waves i(t) that occur on the bushing are utilized, and through inversion of a changing characteristic of bushing oil paper insulation dielectric constant [epsilon]r with frequency, the purpose of diagnosing whether the bushing is affected with damp is achieved.

The present invention is an electronic height gauge utilizing new technology and includes a first column (Column 1) and a second column (Column 2), a display unit with a cover, a measuring scriber, a fixed capacitance sensor and a linear moving capacitance sensor. The fixed capacitance sensor is located on a flat surface on Column 1, flat surface having a length equivalent to the length of Column 1. The linear moving capacitance sensor is located inside the display unit cover positioned to face the fixed capacitance sensor. The fixed capacitive sensor and linear moving capacitive sensors are facing toward each other only, and do not make direct physical contact with the fixed capacitor sensor when the height gauge is operating in upward and downward movements. The fixed and moving capacitive sensors are instead making only electrical contact with each other when the height gauge is making upward and downward movements. This linear direct data non-contact sensor transfer system results in high accuracy of measurements, which also ensures the repeatability of accurate measurements. Also, since the fixed capacitance sensor and the linear moving capacitance sensor have no physical contact with each other, there is no wear and tear damage on either component part, thereby leading to a longer life of use with stability in accurate measurements and repeatability. Because the measuring system is comparatively simple, and easy to assemble and service and maintain compared to the existing rotary capacitive sensor electronic height gauges that exist on the market, the overall cost of production and maintenance is minimized. On the second column (Column 2), a simple rack and gear system is added. These gears of column 2 are connected to a hand wheel located on the rear of the display unit. The handwheel is used for making upward and downward vertical movements. This rack and gear system of column 2 of the present invention is only used to aid the same in making upward and downward movements, and does not affect the measuring accuracy of the height gauge, as it did in the height gauges that have existed on the market.

The invention discloses a device for calibrating geometric quantity of a static calibration table of a wind tunnel balance, belongs to the field of geometric quantity, and is suitable for calibrating geometric parameters of a return mechanism of the static calibration table of the wind tunnel balance, a measurement system and a loading mechanism. According to the device, a loading coordinate system is reproduced by cooperation of a micro-alignment telescope and a reference cubic mirror mounted on a loading head; the micro-alignment telescope is rotated at an angle of 180 degrees by a precise rotary table; a linear guide rail equipped with a double-grating scale is driven to drive the micro-alignment telescope to move and be aligned to a reference line of the loading mechanism, and the geometric parameters of the loading mechanism are measured by data of the double-grating scale, so that the problems of low precision and low efficiency of an existing mounting measurement method are solved; in addition, a lifting mechanism is driven through a spiral lifting machine to adjust the height of the device, so that the calibration needs of geometric parameters of static calibration stables of wind tunnel balances different in type can be met.

A gas sensor (100) includes an oxygen pump cell (135) and an oxygen-concentration detection cell (150) laminated together with a spacer (145) interposed therebetween. The spacer (145) has a gas detection chamber (145c) which faces electrodes (137, 152) of the cells (135, 150). The oxygen-concentration detection cell (150) produces an output voltage corresponding to the concentration of oxygen in the gas detection chamber (145c). The oxygen pump cell (135) pumps oxygen into and out of the measurement chamber (145c) such that the output voltage of the oxygen-concentration detection cell (150) becomes equal to a predetermined target voltage. A leakage portion mainly formed of zirconia is disposed between which electrically connects the oxygen-concentration detection cell (150) and the oxygen pump cell (135).

The invention discloses a measurement and control method for bridge construction. The measurement and control method comprises the measurement on the following parameters: plane control and measurement, elevation control and measurement, perpendicularity control and measurement, beam part construction measurement, template offset correction control, high pier sedimentation and beam body creep monitoring. By using the measurement and control method disclosed by the invention, all corresponding control measures and methods are proposed by analyzing all factors influencing the construction measurement accuracy, so that the influence of human factors on the construction accuracy is scientifically and effectively reduced, and the setting-out accuracy is effectively guaranteed; and the construction method is simple and reliable and the adaptability is wide.

A mechanical decoupling heavy load parallel six-dimension force measuring platform comprises a loading plate, a force measuring plate, an upper cover plate, a bottom frame and more than 12 decoupling force measuring supporting chains. The upper end of the bottom frame is covered with the upper cover plate, a box body is formed, a lower plate of the loading plate is fixed at the plane center of the force measuring plate, an upper plate of the loading plate extends out of an opening in the upper cover plate, the force measuring plate, the upper cover plate and the bottom frame are connected through the decoupling force measuring supporting chains which are distributed on the six faces of the force measuring plate and are fixed on the upper face, the lower face and the four side faces of the force measuring plate respectively, one end of a pressing head A in each decoupling force measuring supporting chain is fixed on the force measuring plate, one end of a pulling pressing force sensor is fixed on the bottom frame and the upper cover plate respectively, the other end of the pulling pressing force sensor and one end of a pressing head B are fixed, the other end of the pressing head A and the other end of the pressing head B are both concave faces, and a steel ball is embedded between the two concave faces. The mechanical decoupling heavy load parallel six-dimension force measuring platform is simple in structure, mechanical decoupling is achieved through the steel ball, dimension-between coupling is small, measuring accuracy is high, and the mechanical decoupling heavy load parallel six-dimension force measuring platform is very suitable for heavy load large-tonnage measuring.

The invention provides a wireless temperature and humidity sensor and system and a measuring method. The wireless temperature and humidity sensor comprises a substrate, a feed network, an antenna and an acoustic surface wave oscillator, wherein the acoustic surface wave oscillator carries out feed through the feed network by using the antenna; the acoustic surface wave oscillator comprises a reference oscillator and a measuring oscillator; and the resonant frequency difference value between the reference oscillator and the measuring oscillator is used for encoding temperature and / or humidity to be measured. The system can simultaneously monitor temperature and humidity, or selectively monitor humidity or temperature. In addition, the resonant frequency drift of the sensor in the process of differential encoding because of the aging of materials and connectors is effectively suppressed, thereby improving the long-term stability of measuring and avoiding the calibration in the process of application.

The invention relates to a method and system for measuring the frequency of a single coil vibrating instrument, wherein the method comprises the following steps: firstly, exerting alternating swept-frequency exciting signals on the two ends of a frequency measurement coil in the single coil vibrating instrument so as to drive a steel string to perform mechanical vibration; then, canceling the swept-frequency exciting signals, and forming induced voltage signals at the two ends of the frequency measurement coil, wherein the frequency of each induced voltage signal is consistent with that of the mechanical vibration of the steel ring; carrying out data acquisition on the induced voltage signals by virtue of an AD (analog-digital) converter, and carrying out FFT (fast fourier transform algorithm) spectrum analysis on the signals (acquired by the AD converter) by virtue of a digital signal processor; and finally, extracting the basic frequency signals in the spectrum according to a maximum value method, and then obtaining the frequency measurement value. The method provided by the invention has the advantages of increasing the anti-interference capacity, and improving the accuracy and reliability of frequency measurement of the single coil vibrating instrument.

The invention discloses an outdoor cluster matching and positioning method and device. The method includes the feature library manufacturing stage, wherein cluster segmentation is conducted on a grid according to the grid environment, and a feature library is divided into a plurality of sub feature libraries according to the category; and includes the positioning stage, wherein when a terminal side initiates a positioning request to a network side, the network side conducts position estimation according to the radio frequency signal feature quantity reported by a terminal; after cluster analysis is conducted on the radio frequency signal feature quantity according to a position estimation value, matching is conducted in the corresponding sub feature library according to the category, and then a positioning result is acquired; the positioning result is returned to the terminal side, and then the current positioning process is finished. The outdoor cluster matching and positioning method and device have the advantages that the defects that in the prior art, measurement accuracy is low, the misjudgment rate is high, and the application range is narrow can be overcome, and high measurement accuracy, the low misjudgment rate and the wide application range are achieved.

The disclosed cable adjustment method for giant cable parallel robot cable based on cable length / force comprises: scaling the station coordinate and peak coordinate by measuring apparatus, determining the theoretical attitude angle of feeding cabin; taking cable space shape as the catenary, and solving the theoretical length of cable at every discrete point; detecting the cable tension by sensor, calculating current real length, comparing the real and theoretical lengths to obtain the adjust quantity; finally, sending the adjust quantity into actuator for dragging the feeding cabin. With 2cm / s space scanning speed, this invention introduces position precision less than 3cm, and special fit to giant cable-system parallel robot.

A data fusion architecture with a plurality of sensors, optionally position measuring equipment (PMEs), is described. Each sensor supplies measurement data x1, x2 . . . xM and is associated with accuracy data H1, H2 . . . HM indicative of the accuracy of the supplied measurement data. Sub-processing units derives first estimates sf1, sf2 . . . sfM and second estimates Hn1, Hn2 . . . HnM of the variability of the measurement data supplied by the respective sensor. The first estimates are derived by processing the measurement data x1, x2 . . . xM and the second estimates are derived by processing the accuracy data H1, H2 . . . HM. The first and second estimates are combined in a multiplier to derive overall estimates σ1, σ2 . . . σM of the variability of the measurement data supplied by the respective sensor. Data fusion means such as a Kalman filter combines the measurement data supplied by each sensor and the overall estimates σ1, σ2 . . . σM for each sensor.

The present invention discloses an industrial robot performance measurement method based on a laser tracker. The method comprises the laser tracker, a computer and a demonstrator arranged on a robot, and the computer is connected with the laser tracker and the demonstrator separately and electrically. The method comprises the following steps of establishing a robot tool coordinate system; collimating coordinates; determining a robot measurement plane and a test pose; selecting the distance accuracy as a measurement item; using the laser tracker to measure the spatial position data of two laser target spheres; using the computer to calculate a measurement distance and an instruction distance; using the computer to output a distance accuracy index, and generating a test report. The industrial robot performance measurement method based on the laser tracker of the present invention has the characteristics of being able to realize the robot performance measurement accurately, being high in measurement accuracy, simple in operation and short in measurement time.

The invention discloses a method and a device for measuring tiny two-dimensional displacement by a computer camera, providing a method and a device for measuring displacement in a non-contact mode by taking a computer camera as a displacement sensor. The device is formed by connecting the computer camera with a common computer. The computer is also provided with a camera shooting and digital image processing program, so that the computer can obtain the tiny two-dimensional displacement vector and velocity vector of a measured object on a plane which is vertical to the optical axis of the camera under the situation that the lighting condition is good and relatively constant; and the measurement precision is less than one pixel unit. The method for measuring displacement of the invention comprises: by means of autocorrelation calculation carried out on a reference frame, selecting an optimal matching comparison window; by means of cross correlation matching calculation, obtaining the instant relative displacement vector and the total displacement vector of the object; according to the measuring result, determining whether to update the reference frame and the optimal matching comparison window thereof; and automatically regulating to search the magnitude of the matched cross correlation operator array.

The invention discloses a workpiece platform system of a photoetching machine. The workpiece platform system comprises a rack, a base platform, two silicon-chip platforms, a measuring grating, a dual-frequency laser, three-freedom-degree heterodyne grating interferometers and a signal receiving and processing part, wherein the two silicon-chip platforms operate at an exposure station and a preprocessing station; the four corners of each silicon-chip platform are provided with one three-freedom-degree heterodyne grating interferometer respectively, and the measuring grating is arranged on the rack above the silicon-chip platform. Dual-frequency orthogonal-polarization laser emitted by the dual-frequency laser is transmitted to the three-freedom-degree heterodyne grating interferometers and the measuring grating by optical fiber, four beams of diffraction light of the measuring grating irradiate back to the three-freedom-degree heterodyne grating interferometers, and finally the four beams of measuring light signals are emitted to the signal receiving and processing part. When the silicon-chip platforms move relatively to the measuring grating, the reading in the signal receiving and processing part is utilized for acquiring six-freedom displacement of the silicon-chip platforms by calculation. The workpiece platform system disclosed by the invention has the advantages that the indexes such as measuring accuracy and dynamic performance of the silicon-chip platforms can be improved, and further the whole performance of the workpiece platform system is further improved.

The invention discloses a measurement method for the rotation angle of an automobile steering wheel. A main rotation body in the automobile steering wheel drives an auxiliary rotation body to rotate under the rotation driving of a transmission shaft; the transmission ratio of the main rotation body and the auxiliary rotation body is m:n; the main rotation body gains the relative rotation angle Theta1 of the main rotation body by a first rotation angle sensor; the auxiliary rotation body gains the relative rotation angle Thelta2 of the auxiliary rotation body by a second rotation angle sensor, thus gaining practical intercept K; theoretical intercept L is gained by the practical intercept K; the rotation ring number P of the main rotation body is then gained by the theoretical intercept L; the relative rotation angle Thelta1 of the main rotation body and the relative rotation angle Theta2 of the auxiliary rotation body are input into a micro-processor; after processing, the micro-processor outputs an absolute rotation angle Theta in m ring of the main rotation body, namely, the absolute rotation angle Theta in m ring of the main rotation body is gained by the rotation ring number P of the main rotation body and the relative rotation angle Theta1 of the main rotation body. The measurement method of the automobile steering wheel can eliminate the system error which is caused by idle course and realize precisely measuring the absolute rotation angle Theta in m ring in small volume and simple structure.

The invention relates to a method for improving the sensitivity of linearity test, and a relative device, wherein it is a laser testing system formed by fixed unit, movable unit and computer; it comprises laser emitter, deviation splitter, lambada / 4 wave plate, reflector, photoelectric receiver and signal processor. The optical element sets the testing light to pass the movable target mirror several times, to magnify its testing sensitivity several times; and it sets lens group before the detector, to magnify the sensitivity more. The invention can test two-dimension linearity of straight track real time.

The invention discloses a light beam stokes parameter measuring device and a measuring method thereof. The polarization measuring device is composed of a beam splitter prism group, a phase retarder array, a polarization analyzer, a photoelectric detector array and a signal processing system, wherein all units of the photoelectric detector array correspond to all units of the phase retarder array one by one. The measuring method is realized through the following steps: adopting the phase retarder array to replace the rotational phase retarder; according to the polarization direction of a to-be-measured light beam, adjusting the direction of a light-transmitting shaft of the polarization analyzer to be parallel to or vertical to the polarization direction of the to-be-measured light; measuring the polarization parameters of the to-be-measured light beam; processing data as per light intensity signals detected by the photoelectric detector array so as to realize the real-time high accuracy measurement of the light beam stokes parameters. Though adopting the method, the stokes parameters of the light beam can be measured in real time, and furthermore, the influences on the measurement accuracy of the light beam polarization state caused by the phase delay error of phase delaying devices, the fast-shaft direction error, the direction error of the light-transmitting shaft of the polarization analyzer and the extinction ratio error are reduced.

An ultrasonic flow meter is disclosed, the ultrasonic flow meter including a flow tube with a flow channel for a fluid to be measured, and two ultrasound reflectors fixated inside the flow tube, a first ultrasound transducer, a second ultrasound transducer, and an electronic control arrangement for operating the ultrasonic flow meter. The ultrasound transducers and reflectors have relative positions and orientations forming an ultrasound path from the first ultrasound transducer to the at least two ultrasound reflectors, to the second ultrasound transducer, and vice versa. The ultrasonic flow meter measures absolute transit times of the ultrasound signal from the first ultrasound transducer to the second ultrasound transducer, and / or vice versa, and the ultrasound reflectors include at least 50% by weight of copper, and the ultrasound signal includes at least 8 pulses.

A determination method quantifies a specific protein or peptide contained in a trace amount with high accuracy and in a simple manner without the need of using any expensive reagent. A protein or peptide of interest can be quantified by LC / MS / MS by using, as an internal standard, a protein or peptide including an amino acid sequence having the reshuffling the binding order of amino acid residues in the amino acid sequence for the protein or peptide of interest.

The invention discloses a device and a method for splicing interferometry of cylindricity errors. The device for the splicing interferometry comprises a computer (1), a flat interferometer (2), a computing holographic lens (3), a measured six-dimensional cylinder adjusting mechanism (5) and a six-dimensional computing holographic lens adjusting mechanism (6). The computer (1) is provided with measurement data processing software, and is connected with the flat interferometer (2). The device and the method for the splicing interferometry of the cylindricity errors is characterized in that the computer (1) provided with the measurement data processing software is used for receiving measured data from the flat interferometer (2), splicing the measured data of the aperture of each measured cylinder (4) input by the measurement data processing software according to data analysis and data comparison, and splicing the acquired cylindricity errors of the measured cylinder. With the device for the splicing interferometry, sampled data are high in density and rapid in sampling speed, and speed and measurement accuracy of the splicing interferometry of the cylindricity errors can be improved.

The invention discloses a fluid flow rate and flow measurement device and method. The fluid flow rate measurement device comprises an alternating current excitation source, a three-electrode noncontact type conductivity sensor, a two-end grounding structure, a signal processing module, a data acquiring module and a microcomputer. The invention realizes that a noncontact conductivity measurement technology is used in fluid flow rate and flow measurement. Two groups of independent conductivity signals are obtained by using the three-electrode noncontact type conductivity sensor, and processed by adopting relevant technologies to obtain fluid flow rate and flow. According to the adopted series resonance method, the adverse influences on the measurement range and the sensitivity of a coupling capacitor are effectively eliminated. By adopting the two-end grounding structure, the adverse influences to the measurement precision by floating voltages at two ends of a pipeline are eliminated, and an insulation measurement pipeline is facilitated to be connected with an industrial site metal pipeline. The fluid flow rate and flow measurement device has the advantages of simple structure, low cost, non contact, no pressure loss, wide application range and the like, and provides an effective path for measuring the flow rate and the flow in the pipeline.