329 results about "Measurement uncertainty" patented technology

A system vitally determines a position of a train. The system includes a plurality of diverse sensors, such as tachometers and accelerometers, structured to repetitively sense at least change in position and acceleration of the train, a global positioning system sensor, which is diverse from each of the diverse sensors, structured to repetitively sense position of the train, and a track map including a plurality of track segments which may be occupied by the train. A processor cooperates with the diverse sensors, the global positioning system sensor and the track map. The processor includes a routine structured to provide measurement uncertainty for each of the diverse sensors and the global positioning system sensor. The routine cross-checks measurements for the diverse sensors, and cross-checks the global positioning system sensor against the track map. The routine provides the vitally determined position of the train and the uncertainty of the vitally determined position.

The invention belongs to the precise instrument manufacturing and detecting technology, especially relates to the bidimensional photoelectric self-alignment equipment and method based on dynamic differentiation compensation method. The equipment comprises the light source, the calibrated board, the CCD image sensor, the beam splitter prism, the aligning object lens, the measuring reflecting lens and the beam splitter between the aligning object lens and the reflecting lens. The two faces of the beam splitter are separately plated with the splitting film and the reflection reducing coating; the surface coarseness of the photic base plate is more than 0.08 um, and paralleling degree of the two faces is smaller than 10'; the light splitting ratio is 52/48 is less than or equal to T/R is less than or equal to 72/28 and the reflection reducing coefficient alpha is greater than or equal to 99%. The invention improves the stability and the repetition of the measuring.

A method is implemented by computer for the management of a convoy comprising at least two vehicles, each of the at least two vehicles comprising satellite positioning means and vehicle-to-vehicle communication means, the method comprising the determination of the relative positioning of the vehicles, the determination comprising the measurement of the propagation time of a signal between vehicles by the communication means, the clocks associated with the communication means being synchronized via satellite positioning means at a reference clock time. Developments comprise the communication between the vehicles of various data (e.g. measurement uncertainties, signal-to-noise ratios, residual values), the determination of absolute locations, the use of an SBAS-type system, the use of differential GPS, the use of Doppler measurements for the turns or even the exclusion of a failing satellite. A computer program product and associated systems are described.

The invention belongs to the technical field of reliability engineering, and relates to an equipment residual service life prediction method under the condition of uncertain degradation measured data. The method includes the following steps: creating an equipment performance degradation model under the condition of the uncertain degradation measured data, estimating model parameters, estimating an equipment potential performance degradation state and predicating residual service life. The equipment residual service life prediction method under the condition of the uncertain degradation measured data is provided, degradation state uncertainty and measurement uncertainty are considered, characteristic quantity of individual service life and overall reliability service life of equipment are predicated and analyzed, and the method can serve as an effective analysis tool for predicating the residual service life of the equipment so as to provide powerful theoretical basis and technical support to state-based maintenance of the equipment, so that expenditure is reduced, unnecessary economic loss is avoided, and good engineering application value is realized.

The invention discloses a method for determining the uncertainty of the S parameter measurement conducted through a vector network analyzer, and relates to the technical field of calibration methods for the vector network analyzer. The method is achieved through MCM simulation, and therefore the problem that the relevance between S parameters needs to be considered when the uncertainty is evaluated through a GUM method and the problem that the uncertainty obtained through an experience algorithm is incomplete are solved. The method starts from the definition of a calibration piece, self-calibration is conducted on the vector network analyzer based on an SOLT calibration method, the uncertainty introduced through the calibration piece is transmitted to a measured piece through the vector network analyzer, and finally the measurement uncertainty of the S parameters of the measured piece measured by the vector network analyzer and the relevance between the S parameters are obtained through the MCM simulation method so that it can be ensured that performance of obtaining the accurate S parameters of the measured piece can be achieved for the vector network analyzer and measurement accuracy can be improved.

The invention provides a device for measuring a thermal diffusivity. The device comprises an excitation light source, an optical control device, a vacuum heating furnace, a temperature controlling device, a temperature measuring device and a data acquiring and processing device, wherein the excitation light source generates excitation light beams; the optical control device is provided with an optical component group, a light beam mass spectrometer and an energy meter and regulates the energy of the excitation light beams through a replaceable optical element in the optical component group; a heating element for heating a sample is arranged in the vacuum heating furnace; the temperature controlling device is used for controlling the heating temperature of the vacuum heating furnace; the temperature measuring device amplifies a temperature rise signal of the sample measured by a detector through a pre-amplifier and transmits the amplified signal to the data acquiring and processing device; the data acquiring and processing device comprises a data acquiring system and a data processing system; the data acquiring system transmits all acquired data signals to the data processing system; and the data processing system analyzes and repeatedly and theoretically corrects the data signals. The device for measuring the thermal diffusivity designed by the invention has the advantages of reducing the measuring repeatability of the thermal diffusivity of a material to be less than 1 percent, lowering uncertainty of measurement, improving the level of thermal diffusivity measurement and laying foundations for the establishment of a standard thermal diffusivity device in China, the preparation of a standard thermal diffusivity substance and the establishment of a standard thermal diffusivity database.

A method for calibrating a projective camera is provided. The method includes acquiring information by detecting at least one object on a substantially flat ground plane within a field of view. A projective camera calibration is performed. A measurement uncertainty is considered to yield a plurality of camera parameters from the projective camera calibration.

The invention discloses an optical fiber length measuring system and a measuring method for measuring optical fiber length by using the optical fiber length measuring system. The measuring system judges the overlay state of two ways of optical signal pulses by adopting a method of combining frequency counting and graphical analyzing, the measuring error brought by the fact that delay inequality is read by an oscilloscope directly can be avoided, and the measuring accuracy of the optical fiber length can be improved. According to the optical fiber length measuring system and the measuring method, an internal modulation mode is adopted by a light source, the elimination of the dependency on the polarization state of optical signals by the optical fiber length measuring system can be facilitated, and the influences on uncertainty of measurement when polarization and reflection components and the like are used for measuring the optical fiber length can be eliminated. Due to the fact that the optical fiber length measuring system and the measuring method are free of the influences of the polarization state of the light source, the length of single mode fibers can be measured, the length of the multimode fibers can also be measured, and the problems of the accurate calibration of the length of the multimode fibers and the length value traceability of a multimode optical time-domain reflectometer are solved.

The invention discloses a water cooling balance which comprises a rod-type balance and a water-cooled jacket. Two water flow pipelines are arranged in the rod-type balance. The two ends of each water flow pipeline are arranged on the two end faces of the rod-type balance respectively. A switching joint is arranged between the water-cooled jacket and the rod-type balance and fixed to one end face of the rod-type balance through a screw. A water inlet switching pipeline and a water outlet switching pipeline are arranged on the switching joint. One end of the water inlet switching pipeline and one end of the water outlet switching pipeline correspond to openings of the two water flow pipelines on the end faces of the rod-type balance in position and the other end of the water inlet switching pipeline and the other end of the water outlet switching pipeline correspond to a water inlet and a water outlet of the water-cooled jacket in position. The defects that a corrugated pipe type water cooling balance is large in drag measurement error and inconvenient to install and use and a corrugated pipe is prone to being damaged and leaking water are overcome. In addition, due to the fact that corrugated pipe related devices are omitted, the length of the balance is reduced, the diameter of the balance is increased, the rigidity and the cooling effect of the balance are greatly improved, the temperature effect is reduced, and measurement uncertainty is obviously reduced.

The invention discloses a sinusoidal phase modulation type laser self-mixing interferometer and a measuring method thereof. The interferometer comprises a helium-neon laser, a variable neutral density filter, an electro-optical crystal modulator, a target to be measured, a photoelectric detector and a signal generator. The signal generator is used for generating sinusoidal signals with frequency of omega<m>, wherein one loop of signals is used for driving the electro-optical crystal modulator, one loop of signals is used as base-frequency signal output and the other loop of signals passes through a frequency doubler and a phase shifter and then outputs doubled-frequency signals with frequency of 2 omega<m>. The output of the photoelectric detector is amplified by an operational amplifier and then is respectively mixed with the base-frequency signals and the doubled-frequency signals to obtain two loops of signals. The signals are subject to low-pass filtering and then a computer unit controls an analog-to-digital conversion unit to acquire and demodulate a phase, so as to obtain and display the real-time displacement of the target to be measured. After the interferometer is calibrated, relative measurement accuracy of 10<-6>*L can be obtained, the measurement uncertainties within the measurement ranges of 100mum and 300mum are respectively 10nm and 0.15mum, and the measurable speed range is 0-60mm/s.

A structure finite element model correcting method based on multi-element uncertainty comprises the following steps: (1) building an initialized parameterization equivalent finite element model in finite element software; (2) screening out significance parameters; (3) obtaining sample points, and constructing an incomplete variable high-order response surface model; (4) judging validity of the response surface model, if the validity of the response surface model meets the requirement, executing the next step, and if the validity of the response surface model does not meet the requirement, executing the step (3) again; (5) building a rapid random sampling analysis model with the combination of a high-order response surface and the Monte Carlo method, and conducting statistics on a mean value and a covariance matrix of simulation output responses; (6) conducting statistics on a mean value and a covariance matrix of test output results; (7) constructing a weighting objective function of the mean values and covariances of tests and simulation; (8) reversely estimating a mean value and a covariance matrix of input parameters; (9) judging whether the mean value and the covariance matrix of the input parameters meet correction accuracy or not, if yes, stopping iteration, and if not, executing the step (8) again. According to the structure finite element model correcting method, the calculated amount of the iteration is reduced, the application range is wide, and optimization of a large-scale parameter range is achieved.

Methods and related program product for assessing and optimizing metrology instruments by determining a total measurement uncertainty (TMU) based on precision and accuracy. The TMU is calculated based on a linear regression analysis and removing a reference measuring system uncertainty (U_RMS) from a net residual error. The TMU provides an objective and more accurate representation of whether a measurement system under test has an ability to sense true product variation. The invention also includes a method for determining an uncertainty of the TMU.

The invention discloses a GNSS high precision positioning method for an intelligent terminal. Original pseudorange observation values are smoothed by measuring a Doppler observation value with low noise and no cycle slip, and the measurement noise of the original pseudorange observed quantity of an intelligent terminal GNSS can be significantly reduced; a real-time precise satellite orbit and theclock difference correction information are utilized to precisely modify a satellite orbit and the clock difference calculated through the broadcast ephemeris and clock difference parameters, and calculation accuracy of the satellite orbit and the satellite clock difference can be significantly improved; the ionospheric delay information is accurately calculated through utilizing the real-time precise ionospheric information, and high precision correction of the ionospheric delay error can be realized; the pseudorange and carrier phase measurement uncertainty information is utilized to performpseudorange and carrier phase observed quantity variance, contribution of measurement accuracy of different satellite observed quantities to positioning solution can be more effectively distinguished, and the intelligent terminal can be finally substantially improved, especially for positioning performance of an intelligent handset.

The invention relates to a general calibration system and method of phase shift sensitivity based on an optical phase demodulator. The calibration system is established based on an OPD4000 optical phase demodulator for the calibration of phase shift sensitivity of an interference type optical fiber hydrophone. The calibration system is consisted of four sub-systems, namely a control and management system, an underwater sound signal emitting system, an optical phase demodulating system and an electrical signal receiving system. The optical phase demodulating sub-system is formed based on the principle of outer modulation demodulating technology of phase generation carrier, and can demodulate the interference optical phase in real time and output the result using a simulation signal. The system has the following beneficial effects that the frequency response for phase shift sensitivity of phase interference type optical fiber hydrophone is acquired accurately in real time, and the output in two data forms of simulation and digit is provided. The system is suitable for the calibration of phase shift sensitivity of phase interference type optical fiber hydrophone of each type with different arm length differences, and has the characteristics of wide calibration frequency band, wide dynamic range, low measurement uncertainty and the like, and is simple in operation.

The invention discloses a DDAG-based SVM multi-class classification active learning algorithm. The active learning through is adopted in the multi-class SVM learning process, the defects that according to the traditional 'one-to-many' or 'one to one' multi-class classification method, large amount of indivisible points or decision blind areas are provided during sample testing are utilized, the active learning algorithm based on the 'o-v-o' classification decision blind areas is provided, samples with the 'highest uncertainty' of the indivisible points or decision blind areas corresponding to a current learning device are selected actively, according to the limitation caused by the single active learning strategy during active learning, a multi-strategy integration active learning method on the basis of posterior probability and similarity measurement uncertainty is provided in the multi-class SVM learning process, the two active learning methods are combined effectively, the sample labeling load is reduced in the multi-class SVM learning process, the learning sample labeling cost is reduced, and an SVM classification device with the best performance can be obtained through the least labeled sample training.

A method of evaluating uncertainty associated with the value of a measurand derived from measurements of a device under test comprising providing a mathematical model wherein the measurand is expressed as a function of (i) at least one physically observable quantity, and (ii) the reference value of said physically observable quantity in a reference device; measuring the reference value of the reference device and the value of the measurand of the device under test; measuring the value of said at least one physically observable quantity; and determining at least one uncertainty value as a function of said physically observable quantity from said mathematical model, wherein the mathematical model takes into account the at least one source of uncertainty and the reference value of the reference device.

The invention discloses a method for assessing measurement uncertainty of a coordinate measuring machine. The method of avoiding the complex relation among error sources of the coronate measuring machine and unknown transmission rules between the error sources is adopted, the method of analyzing characteristic indexes of a measurement system of the coordinate measuring machine is adopted, the method and approach of verifying or obtaining corresponding system characteristic index values of the measurement system, an integral calibration method and a detail experiment scheme for obtaining a stability index and a reproducibility index of the coordinate measuring machine are designed, the influence degree of actual temperature in temperature compensation, a standard grating rule and a linear expansion coefficient of a tested workpiece on a measurement result is considered, and the relatively integral measurement uncertainty of the coordinate measuring machine is obtained through synthesis in the root of square sum.

The invention relates to a device and a method for calibrating a flow-dividing vacuum leaking hole, in particular to the device and the method for calibrating the vacuum leaking hole, the leakage value of which is less than 1*10-8 Pa.m3/s by adopting flow-dividing technology, and belongs to the field of measuring technology. The device consists of the calibrated leaking hole, a valve, an ionization gauge, a small hole, a flow-dividing chamber, a non-evaporable getter pump, an ultrahigh vacuum calibrating chamber, a metering hole, a very high vacuum pumping chamber, an oil-free bi-turbo molecular pump air exhauster set, a quadrupole mass spectrometer, a flow meter, a super-high vacuum calibrating chamber, the metering hole, a super-high vacuum pumping chamber and a common molecular pump air exhauster set. The method adopts a fixed flow method gas micro-flow meter to provide a known gas flow rate, so the measuring range of the flow rate is wide and uncertainty of the measurement is low; and by adopting a flow-dividing method to calibrate the vacuum leaking hole, the method of the invention completely avoids a nonlinear error of the quadrupole mass spectrometer and can precisely calibrate the vacuum leaking hole the leakage value of which is less than 1*10-8 Pa.m3/s.

The invention discloses a piece type hinge moment balance. The balance is of an all-steel overall piece type integrated structure, and comprises a fixed connection end, four groups of balance components and two floating connection ends, wherein two ends at the same horizontal plane of the fixed connection end are provided with rigid transition sections respectively; the four groups of balance components are distributed at two sides of the rigid transition sections of the fixed connection end; and the inner side of each floating connection end is provided with a rigid transition section, and the two floating connection ends are connected with the balance components. According to the structure of the piece type hinge moment balance, the additional moment of the balance can be reduced, the matching performance of loads is improved, and aerodynamic force measurement with an axial force can be realized. Meanwhile, interference imposed on measurement by wing deformation can be reduced, thereby enabling the uncertainty of measurement to be significantly reduced, and acquiring an aerodynamic force measurement result with high precision and accuracy.

The invention discloses a prediction method and system for the remaining service life of nonlinear degradation equipment. The method comprises the steps that according to time uncertainty parameters,individual difference parameters and measurement uncertainty parameters of the nonlinear degradation equipment, a nonlinear degradation equipment potential degradation model is established; sampling data of all the nonlinear degradation equipment at different moments is acquired; according to the sampling data of all the nonlinear degradation equipment at different moments, parameters of the nonlinear degradation equipment potential degradation model are determined; according to the nonlinear degradation equipment potential degradation model with the determined parameters, a remaining servicelife prediction model is determined; according to the remaining service life prediction model, a remaining service life value of the nonlinear degradation equipment is determined. According to the prediction method and system, the time uncertainty, individual difference and measurement uncertainty of the nonlinear degradation equipment are comprehensively considered, then the nonlinear degradationequipment potential degradation model is established, the remaining service life of the nonlinear degradation equipment is predicted, and then the accuracy of service life prediction is improved.

The invention discloses a laser interferometer measurement system for eliminating Abbe error. The system comprises three independent laser interference length measuring systems and a high-precision long guide rail. With the use of the three independent laser interference length measuring systems which are placed in an arbitrary triangle, equivalent measuring optical paths with a starting point at any position of an the initial plane are constructed. Meanwhile, with the three independent laser interference length measuring systems having the same optical path with a device under test, measurement uncertainty caused by the fact that an Abbe principle is not met. The laser interferometer measurement system for eliminating Abbe error has the advantages of being simple in technical principles, low in costs, strong in operability and capable of improving accuracy of the large-length laser interferometer measurement system.