275results about How to "Eliminate systematic errors" patented technology

The present invention provides applicators for performing thermokeratoplasty. One embodiment of such applicators includes two generally tubular electrical conducting elements coaxially disposed relative to one another and separated by an electrically insulating element having a selected thickness. At least a portion of each conducting tube is coated with an electrically insulating and thermally conductive material, e.g., anodized aluminum, so as to electrically insulate the conducting tubes from corneal tissue upon placement of the applicator on a subject's cornea while facilitating extraction of heat from the cornea.

The present invention provides applicators for performing thermokeratoplasty. One embodiment of such applicators includes two generally tubular electrical conducting elements coaxially disposed relative to one another and separated by an electrically insulating element having a selected thickness. At least a portion of each conducting tube is coated with an electrically insulating and thermally conductive material, e.g., anodized aluminum, so as to electrically insulate the conducting tubes from corneal tissue upon placement of the applicator on a subject's cornea while facilitating extraction of heat from the cornea.

A microwave thermokeratoplasty system uses an applicator having embedded sensors that provide feedback signals to a controller. The controller interprets these feedback signals to dynamically adjust or cease a keratoplasty operation. The system uses a microwave applicator that is specially adapted for direct application of energy to an eye in the course of treatment. The applicator is formed of discrete zones or sectors that are selectively controlled in an individual manner.

The invention discloses a method for testing the grouting compactness degree of a prestressed pore of a bridge based on an elastic-wave energy dissipation rate, belonging to the technical field of quality detection on bridge / culvert engineering. In the grouting construction on a prestressed anchor (cable) of a bridge, the prestressed anchor (cable) can be corroded caused by undesirably-packaged cement mortars and anchor rods, thereby causing the failure of the prestressed anchor (cable) and then endangering the safety of structures. In the prior art, the anchoring quality of an anchor rod can not be evaluated completely. The method provided by the invention is implemented through analyzing the fluctuation characteristics (speed, frequency, elastic-wave energy dissipation, and the like) of pickup signals of sensors at the two ends of the prestressed anchor by adopting impact elastic waves generated by vibrations at the two ends of the prestressed anchor of the bridge so as to detect the grouting compactness degree of the prestressed anchor (cable) of the bridge. The method provided by the invention has the advantages of maximizing the elimination of system errors caused in the process of test, accurately testing the elastic-wave energy dissipation rate of the prestressed anchor (cable), and effectively completing the test on the grouting compactness quality of the prestressed anchor (cable) of the bridge. The method provided by the invention is also applicable for the test on the grouting compactness qualities of all prestressed structures the two ends of which are provided with exposed anchor heads.

The invention belongs to the field of an inert measuring technique or geophysical experiment and instrument, in particular to a dynamically rotary modulated north-seeking method for a gyroscope. The dynamically rotary modulated north-seeking method for the gyroscope provided by the invention aims to realize fast and precise north-seeking measurement under the condition that a carrier has a large attitude angle without leveling or knowing the latitude of a measuring point, so that the speed of geodesic operation is improved. A rotary table which rotates uniformly at an angular speed Omega is used. The rotary table is provided with the gyroscope and two accelerometers. The method comprises the steps of: first, solving an angle of pitch and a roll angle by the two accelerometers; then, solving the geographic latitude L and a course angle by the gyroscope; and after calculating an initial value, improving the precision by using a real time recursive least square method. The dynamically rotary modulated north-seeking method for the gyroscope provided by the invention has the advantages that fast and precise north-seeking measurement can be realized under the condition without leveling or knowing the latitude of the measuring point, so that the speed of geodesic operation is improved.

The invention provides a method for processing formation data based on the lithologic parameter of a reservoir rock, which belongs to the field of geophysical exploration and well logging evaluation and development of lithologic parameters of reservoir rocks and the formation data. The method comprises the following steps of: acquiring formation lithology and fluid information by using geological exploration and development equipment; analyzing the acquired formation lithology and fluid information by using analytical equipment to acquire a basic parameter required by the calculation of pore fluid volume of the reservoir rock; and establishing a petroleum volume and petroleum geological reserve calculation equation by selecting reservoir parameters such as corresponding porosity, oil saturation and the like. The method is suitable for evaluating reservoir rock petroleum resources with proved reserves, controlled reserves and predicted reserves, which belongs to the field of reserve calculation by a volume method. By a volume method reserve calculation equation established in the method, system errors caused by the original volume method reserve calculation formula are eliminated, so that the calculation accuracy of petroleum geological reserves is improved by 6 to 21 percent.

A two beam laser interference measuring method to measure thermal material expansion coefficient relates to two beam laser interference measuring for thermal material expansion coefficient. A tested sample is positioned into a fastener of a highly vacuum heating furnace and the heating furnace is vacuumized below 10-4Pa. A laser emitting box of a SIOS-SP120D laser interference instrument emits two beams of laser onto a surface of the tested sample, thus making the lasers reflected to respectively return to a laser emitting port along an original path through the sample surface and forming interference with incident laser. Laser path displacement of the laser beam a and b respectively achieves Delta a and Delta b according to measuring. Expansion of the tested sample in section L is Delta L according to a difference between Delta a and Delta b. A K type thermocouple measures temperature of the tested sampled in the highly vacuum heating furnace. Temperature data will be collected through a data collection data. The thermal expansion of the tested sample of the present invention is a difference of laser path displacement between two laser beams totally offset system errors of single-beam laser resulting from thermal expansion of sampling table and clamp, etc. Therefore, the method completely eliminates system errors while measuring the thermal expansion, improves measuring precision and accurately reflects process of material phase variation.

The invention discloses a measuring method and a measuring device for coefficients of thermal expansion. The measuring method comprises the following steps of: plating a layer of membrane which transmits light partially and reflects the light partially on upper and lower surfaces of a light transmission material to be measured respectively; heating the light transmission material; allowing a beamof monochromatic light to be incident to the light transmission material to be measured in the heating process, and reflecting the monochromatic light on the upper and lower surfaces of the light transmission material respectively, so that two beams of reflected light are interfered with each other; detecting the power of the interfered reflected light, finding a temperature value corresponding to the maximum value of the power of the reflected light, and determining the change period of the power of the reflected light in preset temperature intervals of the light transmission material; and calculating according to the change period to obtain the coefficients of thermal expansion of the light transmission material to be measured in the temperature intervals. By the measured method, the coefficients of thermal expansion of the light transmission material can be measured accurately, the test accuracy is relatively high, and system error caused by thermal expansion of sample frames and the like can be eliminated effectively; and due to the adoption of a single light source, a light path is simple, the cost is low, and the thermal expansion condition of each temperature interval can be reflected visually.

The invention discloses an error compensating method for a positioning system based on a dual-rotation laser plane transmitter network. The method provides a compensating algorithm model and designs a parameter estimation algorithm, and the main implementation steps include: (1) marking the parameter; (2) collecting compensating data; (3) collecting angle data of the point to be measured; and (4) compensating measuring equation error. The step (4) includes: a) determining a compensation factor; b) compensating the measuring equation; and c) iterating until suspension condition is satisfied, so as to solve the final result. The invention relates to large scale space coordinate measuring error compensation, solves the difficulty in systemic error marking in the dual rotation laser plane space measuring positioning system, can compensate the error item of the laser plane measuring equation and improves the systemic measuring precision.

The invention discloses a water quality heavy metal multi-parameter online monitoring instrument which comprises an online sample digestion system, an online sample detection system and a measurement and control system. The water quality heavy metal multi-parameter online monitoring instrument disclosed by the invention can realize automatic online monitoring of content of heavy metals such as mercury, lead, cadmium, chromium and arsenic in water, can be widely applied to the fields of surface water quality pollution monitoring, seawater pollution monitoring, up-to-standard release monitoring of industrial wastewater treatment and municipal sewage treatment and the like and has the advantages of high functional expansibility, wide measurement range and low cost.

The invention relates to a double frequency laser interferometer for absolute distance measurement and a measurement method thereof. The double frequency laser interferometer comprises a light source, an optical fiber coupler, an isolator, a collimator, a photoelectric detector, a piezoelectric ceramic, a data acquisition card and a computer, wherein the light source adopts two semiconductor lasers in different wavelengths having light source controllers; the photoelectric detector is used for converting a received interference signal into an electric signal and inputting to the data acquisition card; and the computer is used for performing data treatment, thereby acquiring a to-be-measured distance. The linear frequency modulation technique is combined with the sine phase modulation interference measurement technique in the interferometer provided by the invention, thereby widening the measurement scope. The phase of an interference signal is calculated by solving a linear equation by utilizing the related parameters, thereby eliminating the system error caused by light intensity modulation of the light source in principle and increasing the measurement precision.

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 provides a target displacement vector measuring device and method based on laser tracker point-by-point calibration, and belongs to the technical field of infinitesimal displacement measurement. The target displacement vector measuring device and method aim to solve the problem that measurement results obtained through a method for detecting target infinitesimal displacement through an existing visual-inspection measuring system are low in accuracy. The device comprises a high-speed CCD video camera, a laser tracker and a diffuse reflection projection screen, wherein a target object moves on the diffuse reflection projection screen. According to the method, first, a corresponding relation look-up table is established based on the principle that imaging points of target object calibration points and target object calibration points acquired through the laser tracker are conjugated; then, the high-speed CCD video camera is used for sequentially imaging screen light spots of the target object, a conjugate point of a target object projection point is acquired, and the coordinate value of the target object projection point on a projection screen coordinate system is obtained through table look-up or a resolving method combining table look-up with bilinear interpolation. The target displacement vector measuring device and method based on laser tracker point-by-point calibration are used for measuring a target displacement vector.

Methods and apparatus for providing self-contained guidance, navigation, and control (GN&C) functions for a vehicle moving through an environment on or near the ground, in the air or in space without externally provided information are disclosed. More particularly, one embodiment of the present invention includes a Heading Sensor (36), an Absolute Location Sensor (38), a timer (40), a Range Doppler Processor (42), a Navigation Reference Sensor (44), an Area Range and a Velocity Sensor (46) which provide enhanced navigation information about a universal reference frame (22) and one or more targets (20).

The present invention relates to a measurement method and a device for the phase delay quantity and the fast axle direction of a birefringent optical device, which can well solve the problem of poor measurement accuracy in a measurement process. The method is that a pair of orthogonal dual-frequency lasers emitted from an optical laser is divided into reflected light and transmitted light; in a reflected light path and a transmitted light path, through the birefringence of a measured sample measuring point after the polarizing angle of at least one path is changed, and then through the measured sample measuring point after returning, the phases of the polarized components of the two frequencies in the light beams are delayed differently, thus leading to the phase change; then after being synthesized by an analyzer, the two light paths are respectively transformed into a reference beat frequency signal and a measurement beat frequency signal with different phase differences; at least two times of phase differences are obtained, and then the phase delay quantity and the fast axle direction of the measured point can be calculated; the method and the device of the present invention make the measurement of two parameters become simple and eliminate the principle error and the system error.

The invention relates to a high-accuracy measurement technical field of current amplitude and phase, in particular to an online mark and check method for the transformation ratio and angle difference of current transformer CT, and a relative system, wherein lg(t) is the sensitive output of the current transformer with linearly mixed lx(t) and lx(t), therefore, Ig(t)=1Ix(t)+a2IS(t), while lx(t) is the object current, ls(t) is the current signal generated on the measurer, a1 and a2 are the sensitive factors of lx(t) and ls(t) on the output signal lg(t) of the current transformer, then the invention uses independent element analysis method to separate signal ls(t) from signal lg(t), to obtainthe evaluated signal ls'(t) of ls(t), and via the mixed factors a1 and a2 to obtain the transformation ratio and angle difference or the like of current transformer in real condition. Via comparing ls'(t) and ls(t), the invention can easily and reliably realize online check of current transformer and check the result of the independent element analysis.

The invention discloses a correction method for multi-point measurement of a steam drum liquid level of a high pressure boiler. The method comprises the following steps of: calculating a range and migration of a differential pressure transmitter according to height between a liquid level measurement device and two connecting ports of a steam drum, height from the liquid level measurement device and the lower connecting port of the steam drum to the differential pressure transmitter, saturated water density and saturated steam density in the steam drum and condensate density in the liquid level measurement device; inputting the range and the migration to the differential pressure transmitter to serve as an original zero point and an original range; actually measuring a thermal-state zero value PA and a thermal-state range value PR of the differential pressure transmitter; calculating effective measuring ranges in PA and PR; establishing polygonal function relation; corresponding an effective thermal-state zero value Pr and an effective thermal-state range value Pr to a zero value La and a range value Lr of liquid level indication respectively; displaying according to linear relation; and performing temperature and pressure compensation calculation on La, Lr, steam drum temperature Tsteam and steam drum pressure Psteam to acquire a corrected value of the steam drum liquid level Ldelta so as to play a role in three-impulse adjustment and interlocking control of the steam drum liquid level.

The invention discloses a hearth workpiece temperature measuring device and a method and mainly aims to realize on-line measurement on an industrial furnace hearth workpiece surface temperature field in the hot working field. The hearth workpiece temperature measuring device comprises an infrared endoscope lens group having a cooling protection sleeve, a high temperature flue gas filter, an infrared heat imaging probe, an automatic lens group rotation driving and reversing mechanism, an infrared heat imaging temperature measurement host, monitoring display equipment and a contact type workpiece surface temperature thermodetector. The hearth workpiece surface temperature field infrared heat imaging temperature measurement system device and the temperature measurement method are realized. According to the device, the infrared heat imaging lens group has the high temperature flue gas filter, so a temperature shielding effect for workpieces in the hearth can be realized through effectively filtering high temperature flue gas. Through a heat pixel temperature system error correction algorithm, a system error can be effectively eliminated, and temperature measurement precision is improved.

The invention discloses a method and a device for measuring a phase delay spectral characteristic of a wave plate, comprising a broadband light source; and continuously emergent light is received after passing through a multi-wavelength photoelectric detector through a collimator, a polarizer, two wave plates to be detected, a polarization analyzer and an optical splitter respectively, wherein the two wave plates to be detected are connected with a motor, data received by the multi-wavelength photoelectric detector are uploaded to a data acquisition card which transmits the data to a computer which is connected with the motor. The method disclosed by the invention can automatically measure the phase delay spectral characteristics of the two wave plates to be detected within a wide spectral range, not only can be used for measuring the phase delay spectral characteristics of two rotary wave plates in a rotating double-compensator type broad-spectrum ellipsometer so as to eliminate system errors caused by inaccurate calibration, but also can be used for directly calibrating the phase delay spectral characteristics of two unknown wave plates in practical production and research work, and besides, the measurement result is not influenced by the light source and the spectral characteristic of a detector.

The invention relates to a satellite image system error correction method based on bias matrix with a time factor. The problem of system error correction comes down to the solution of two bias angles of a camera going around a satellite body, aiming at linear variation rules of the geometric positioning error of an image in a certain in-orbit testing period, a first order polynomial with the time factor is used for expressing the bias angles, the first order polynomial is solved based on the selected sample images and the error compensation of a plurality of automatically extracted control points, and thereby the bias matrix of any satellite images in the period is obtained and is substituted in a co-linearity condition equation to realize the effective compensation and the correction of the geometric positioning system error. According to the in-orbit testing results, the method is simple and feasible, the system errors changing with time can be effectively eliminated and the long-term stability of the precision of the system geometrically corrected product is kept.

The invention relates to a device and a method for measuring the micropore diffraction wavefront quality. According to the invention, measurement is carried out on the micropore diffraction wavefront quality by adopting a Shack-Hartmann wavefront sensor method. High-precision calibration for a Shack-Hartmann wavefront sensor is realized through a high-precision planar reference wavefront, then accurate measurement for the micropore diffraction wavefront shape is carried out according to a calibration result of a high-precision system error, the deviation of the micropore diffraction wavefront can be acquired by comparing the micropore diffraction wavefront shape with an optimal reference sphere, measurement for the micropore diffraction wavefront quality can be realized by only directly adding a focusing objective lens and a micropore on the basis of a calibration device, the operation is simple and convenient, the introduced system error is small, and high-precision calibration for the system error is implemented easily. Spherical aberration introduced by a micropore board can be compensated through the focusing lens, and quick high-precision measurement for the diffraction wavefront quality with different pore sizes can be realized through adjusting the distance between the Shack-Hartmann wavefront sensor and the micropore.

The invention relates to a water hammer pressure sensor field calibrating device comprising a water hammer pressure generating device, a standard sensor, and a data processing system for acquiring and processing data of a calibrated water hammer pressure sensor and the standard sensor. The water hammer pressure generating device comprises a propellant supplying system, a propellant supplying pipeline connected with the outlet of the propellant supplying system, a propellant valve disposed on the propellant supplying pipeline, a pressure regulating device for regulating pressure in the propellant supplying pipeline, and a flow regulating device for regulating propellant flow. The calibrated water hammer pressure sensor and the standard sensor are arranged on the propellant supplying pipeline behind the propellant valve and are used for measuring pressure in the propellant supplying pipeline. By establishing the water hammer pressure generating device, the water hammer pressure sensor field calibrating device really simulates a water hammer sensor operating environment in a test, eliminates system errors, and improves water hammer pressure measurement accuracy.

The invention is applicable to the technical field of optical measurement and provides a projector calibration method for multi-directional projection, which comprises: step S1, using a projector to sequentially project calibration patterns preset at N assigned positions preset around a target to a target plane, and collecting a target information map by using a camera at each assigned position; step S2, processing the target information map collected at each assigned position, calculating an accurate phase value of a target feature point, and further obtaining sub-pixel coordinates in a projector image coordinate system corresponding to the target feature point; step S3, calibrating the projector by using the sub-pixel coordinates in the projector image coordinate system and a three-dimensional world coordinate X of the known target feature point to obtain initial calibration parameters; and step S4, using a bundle adjustment method to optimize the initial calibration parameters and the three-dimensional world coordinate X to obtain final calibration parameters. The calibration method provided by the invention makes the final calibration results more accurate.

The invention discloses a rectangular resonant cavity system for testing parameters of a microwave ferrite material, belongs to the field of ferromagnetic resonance line width testing, and relates to rectangular perturbation resonant cavities. A novel method for testing the ferromagnetic resonance line width of the microwave ferrite material is provided to overcome the defects that according to original systems, operation is complicated, the uncertainty of measurement results is high, and testing accuracy is low. The rectangular resonant cavity system comprises a rectangular resonant cavity, a gauss meter, an electromagnet, a vector network analyzer, a program control computer and a direct-current power supply. After connection and calibration are conducted on the system, a test sample is placed in the rectangular resonant cavity, and then the ferromagnetic resonance line width of the test sample can be calculated simply by obtaining a Q value corresponding to a half-power point or an S21 parameter through testing.

The invention discloses an accurate calibration method for an MWD (measurement while drilling) system and the application of the accurate calibration method. The accurate calibration method comprises the step of calibrating a real-time calculation result of an attitude angle of the MWD system by virtue of an error model. According to the method, the attitude angle of the MWD system is calibrated by virtue of the error model under the condition that set values of a hole drift angle and an azimuth angle are unchanged, so that the fluctuation of calculation results of the hole drift angle and the azimuth angle can be effectively reduced, and a system error in an attitude angle calculation process can be eliminated; the hole drift angle and the azimuth angle are measured to guide the drilling of a drilling rig, so that accurate control over a well trajectory and improvement in the drilling accuracy can be effectively helped by the accurate calibration method. In addition, the accurate calibration method can also be popularized and applied to calibration flows of a series of products such as an automatic vertical drilling system and a rotary steering product.

The invention provides a time shift magnetotelluric signal acquisition and inversion method. The method comprises the following steps: arranging a plurality of signal receiving devices along a specified testing line in a testing region to acquire a plurality of groups of magnetotelluric signals in a time-sharing way; performing standard inversion on magnetotelluric original data obtained at an initial moment to obtain an initial moment underground electrical structure; forwarding the electrical structure to obtain a group of forwarding analog data, and subtracting original data from the analog data to obtain a data residual; subtracting the data residual from observed data at each moment to obtain a group of new time shift data sets; performing standard inversion by using a new time shift data set; during inversion, restraining the model updating direction to obtain an inversion result which is closer to a real situation. The method has the advantages that system errors in time shift data and calculation errors in a forwarding process are eliminated, the influences of system errors on the difference among different moment models can be lowered through a differential inversion result, and model change realized through inversion is closer to a real situation.

The invention discloses a method for extracting fetus gene information. In the provided method, maternal cell DNA and acellular DNA are separated from a maternal sample, wherein the acellular DNA is from the fetus. Two DNA samples are strictly processed by same reagents and methods and subjected to parallel sequencing in a same sequencing reaction; and the fetus gene information and fetus gene abnormity can be obtained by comparing the sequencing results of two DNA samples. The provided autologous comparing method can be applied to detection of chromosome aneuploidy, and can also be applied to gene detections such as chimera detection, copy number variation detection, single point mutation detection, and the like.