8180 results about "Accuracy and precision" patented technology

Methods and system for noninvasive determination of tissue analytes utilize tissue properties as reflected in key features of an analytical signal to improve measurement accuracy and precision. Physiological conditions such as changes in water distribution among tissue compartments lead to complex alterations in the measured analytical signal of skin, leading to a biased noninvasive analyte measurement. Changes in the tissue properties are detected by identifying key features in the analytical signal responsive to physiological variations. Conditions not conducive to the noninvasive measurement are detected. Noninvasive measurements that are biased by physiological changes in tissue are compensated. In an alternate embodiment, the analyte is measured indirectly based on natural physiological response of tissue to changes in analyte concentration. A system capable of such measurements is provided.

Apparatus and method for determining at least one parameter, e. g., concentration, of at least one analyte, e. g., urea, of a biological sample, e. g., urine. A biological sample particularly suitable for the apparatus and method of this invention is urine. In general, spectroscopic measurements can be used to quantify the concentrations of one or more analytes in a biological sample. In order to obtain concentration values of certain analytes, such as hemoglobin and bilirubin, visible light absorption spectroscopy can be used. In order to obtain concentration values of other analytes, such as urea, creatinine, glucose, ketones, and protein, infrared light absorption spectroscopy can be used. The apparatus and method of this invention utilize one or more mathematical techniques to improve the accuracy of measurement of parameters of analytes in a biological sample. The invention also provides an apparatus and method for measuring the refractive index of a sample of biological fluid while making spectroscopic measurements substantially simultaneously.

A method and an arrangement for producing a workpiece using additive manufacturing techniques involve in-process measurement in order to determine individual characteristics of one or more workpiece layers. In particular, dimensional and/or geometrical characteristics of a workpiece layer are measured before the next workpiece layer is produced. Advantageously, the measurement results are fed back into the production process in order to increase accuracy and precision of the production process.

Design driven inspection/metrology methods and apparatus are provided. A recipe is a set of instructions including wafer processing parameters, inspection parameters, or control parameters for telling an inspection/metrology system how to inspect/measure a wafer. Design data is imported into a recipe extraction system that recognizes instances of target structures and configures recipe parameters accordingly, thereby reducing manual instrument setup time, improving inspection/measurement accuracy, and improving fabrication efficiency.

New optical coherence tomography (OCT) techniques are disclosed which are designed to improve OCT glucose concentration measure accuracy and are capable of being performed on a continuous basis. New multi-wavelength optical coherence tomography (OCT) techniques are also disclosed and designed to reduce artifacts do to water. New optical coherence tomography (OCT) techniques are also disclosed for determining local profusion rates, local analyte transport rates and tissue analyte transport rates as a measure of tissue health, disease progression and state and tissue transplantation effectiveness.

The invention discloses a parking position detecting device of an intelligent parking system. The parking position detecting device comprises a sensor unit, a signal processing unit, and a man-machine interface unit. The sensor unit comprises four wide-angle cameras and an ultrasonic ranging sensor. The signal processing unit comprises an annular view generation module and a parking position detecting module. The man-machine interface unit comprises an output module used for displaying an annular view and detected garage positions, and an input module used for receiving various commands inputted by a driver. The parking position detecting module comprises a garage position line detection submodule, an obstacle vehicle detection submodule and a parking position output submodule. The invention further discloses a parking position detecting method of the intelligent parking system. A low-cost sensor scheme is adopted, accuracy and precision of parking position detection are improved by mixing distance value obtained by the ultrasonic ranging sensor with image information collected by the cameras, and parking positions can be effectively detected under multiple conditions that garage lines and obstacle vehicles exist on a ground.

The invention relates to a non-contact measuring method for a leaf apex radial clearance of an engine rotor, and the method comprises the following steps: 1) assembling a measuring system, calibrating a sensor and determining the relation between the radial clearance and voltage of a leaf apex; 2) preparing before measuring; and 3) measuring the leaf apex radial clearance of the engine rotor. In the measuring method provided by the invention, a measurement technique based on a capacitance method is adopted; the measuring course and the assembling are synchronously carried out; the once cartridge disassembly and assembly is reduced; the measuring time is shortened; the production efficiency is improved; and the measuring accuracy is improved, thereby improving the assembly quality of an engine and reducing the failure rate of the engine. The non-contact measuring method provided by the invention is mainly used for measuring the leaf apex radial clearance of the rotors of parts such as an engine, a high-pressure compressor, a low-pressure compressor, a high-pressure turbine, a low-pressure turbine and the like.

The invention discloses a method for measuring a geometric error parameter value of a rotary oscillation axis of a five-axis linkage numerical control machine tool. The method comprises the following steps of: measuring displacement errors of X, Y and Z directions on at least three positions under different rotating angles of the rotary oscillation axis respectively by using a ballbar, wherein translation axis linkage coordinates provided by a revolving tool central point (RTCP) cutter central point movement control function of a five-axis machine tool serve as measurement datum; and performing data processing according to the displacement errors to identify and calculate the geometric error of each rotating angle of the rotary oscillation axis. The rotary oscillation axis is measured independently by the method, so the geometric error value of the five-axis linkage numerical control machine tools of various structures at each rotary oscillation angles can be obtained. The method is not limited by the structures of the machine tools, is convenient to arrange and has high measuring precision.

The invention discloses a circle center locating method of a circular target, mainly relating to a great deal of target identification and target location. Firstly, rough circle center location is carried out to an image by using a simple contour centroid method, a key square region is extracted as a region of interest according to the information of a rough location circle center and a rough location radius, and pixel-level edge location is carried out to the circular target in the region of interest by a canny operator; then sub-pixel location is carried out to the circular target according to the geometric features and the gray information of the circle, therefore, a precise coordinate of sub-pixel edge points is obtained; after that, a curvature filtering method and an average filtering method are respectively used for filtering 'isolated points' and noise occurring in the sub-pixel edge points; finally, a least squares method is utilized to fit a circle to the filtered sub-pixel edge points so as to obtain the final circular center and radius. The method not only effectively improves the precision of circle center location, but also improves the robustness thereof, thus further improving the measurement precision of a measurement system and perfecting the stability of the measurement system.

An object three-dimensional outline measurement device and a measurement method are disclosed, the device is composed of a laser diode, a lens, an aperture diaphragm, a two-dimensional Dammam grating, a cylindrical mirror and an area array CCD camera, a transmission line and a computer, the connection relationship therebetween is as below: a beam emitted by the laser diode passes through the lens, the aperture diaphragm, the two-dimensional Dammam grating, and the cylindrical mirror sequentially to form one-dimensional projection array stripes, which illuminates the surface of an objective to be measured, the area array CCD camera collects the grating projection strips modulated by three-dimensional digital shape on the surface of the measured objective and outputs the strips to the computer via the transmission line, the computer includes an image collecting interface, image collecting software and three-dimensional measurement information reconstruction algorithm software. The invention has, by utilizing the Fourier transform three-dimensional outline measurement structure, the advantages of high energy utilization rate, simple measurement structure, high measurement precision, convenient computer reconstruction information processing and great easiness for operation.

Methods and systems for optimizing measurement system parameter settings of an x-ray based metrology system are presented. X-ray based metrology systems employing an optimized set of measurement system parameters are used to measure structural, material, and process characteristics associated with different semiconductor fabrication processes with greater precision and accuracy. In one aspect, a set of values of one or more machine parameters that specify a measurement scenario is refined based at least in part on a sensitivity of measurement data to a previous set of values of the one or more machine parameters. The refinement of the values of the machine parameters is performed to maximize precision, maximize accuracy, minimize correlation between parameters of interest, or any combination thereof. Refinement of the machine parameter values that specify a measurement scenario can be used to optimize the measurement recipe to reduce measurement time and increase measurement precision and accuracy.

A method and system for maintaining operator alertness comprises a detector for detecting a physical status of an operator. The physical status indicates a first level of operator alertness. A user interface requests a second level of operator alertness from a self-evaluation of the operator at a request time. An evaluator measures at least one of an accuracy of the operator response to the requested input and a response time of the operator from the request time. An alert module generates alarm data or an alarm signal to alert the operator based on the first level of operator alertness indicating an inattentive state and at least one of the measured accuracy and operator response time indicating the inattentive state.

The present invention relates to robot technology, and is weld seam tracking sight sensor based on laser structure light. The welding seam tracking sight sensor has laser as the light source of structure light, and consists of laser, video camera, monitor, treating unit, etc. By means of forming laser plane with laser beam in a cylindrical mirror, projecting the laser plane to a workpiece to generate laser fringes, acquiring the laser image of weld seam with a visual sensor, calculating weld seam positions through image processing and converting into analog signal or radio signal, the present invention controls welding robot for automatic weld seam tracking. Different weld seam processing modules for different kinds of weld seam are developed. The present invention has high weld seam position measuring precision, raised anti-jamming capacity and high versatility and flexibility.

The invention provides an optical measurement system and method for a three-dimensional shape of a large-scale complex curved surface member. The method is based on binocular optical grating projection measurement technologies, point cloud poses of all station positions during multiple station position measurement are obtained via a laser tracker and a corresponding target ball, point cloud obtained via the multiple station position measurement is converted to be under a unified laser tracker coordinate system according to corresponding pose data, and overall merging of point cloud data of a large-scale complex surface-shaped member can be realized; in the system, a six degree-of-freedom robot is used as a carrier for a point cloud space pose tracking unit and a binocular structured light measurement device, single station position measurement precision is ensured via calibration of the binocular structured light measurement device before measurement work starts, and data integrity and measurement efficiency are ensured via measurement route planning. Via the optical measurement system and method, all kinds of large-scale complex surface-shaped members can be accurately measured in non-contact conditions; practical, reliable and complete original three dimensional shape data can be provided for evaluation of all kinds of processing quality.

The invention relates to the technical field of gait analysis in biomedical engineering and provides a human gait analyzing method and system based on multi-sensor fusion. The method comprises the steps of filtering sensor signals to eliminate the signal noise error according to human motion features, and eliminating the integral error by means of the improved zero velocity updating algorithm, so that the method and system can be adapted to different walking scenes; fusing multiple sensor data with the Denavit-Hartenberg method, and reducing the leg position calculation error; calculating the step speed, step length, step frequency, walking period and walking track of a tested person accurately during walking after error correction is conducted; establishing a gait database, and conducting statistic analysis on gait data of different tested persons with the quantile regression analysis method. By the adoption of the method and system, gait parameter measurement precision can be improved, and gait parameters of different tested persons are comparable through standardization.

Methods and apparatus are described for providing a time-based warning indicating that the energy capacity of a primary energy source of a battery-powered computer has discharged to a low level, and using residual energy of the primary energy source to perform at least one pre-cutoff function. The time-based warning ensures that the warning is provided in a timely manner by overcoming problems caused by analog to digital converter voltage measurement accuracy limitations and flat battery operating voltage versus discharge curves. The primary energy source can be a rechargeable battery, which can also be the sole energy source for the computer. The battery provides power to operate the computer until the battery voltage discharges to the cutoff voltage. The methods and apparatus provide advantages because they reserve the residual energy in the battery to perform at least one pre-cutoff function within a first duration before the battery discharges to the cutoff voltage. For example, the residual energy can be used to retain data stored in the computer between opportunities to charge the battery. Some embodiments of the invention include hardware resources coupled with the processor to lock out power and application activation when the rechargeable battery has discharged to a predetermined hardware lockout voltage. The value of the hardware lockout voltage can be based on the battery retaining a residual energy sufficient for performing the corresponding pre-cutoff function within an amount of time that is expected to enable the user to perform the function.

A method for improving the measurement accuracy of a portable coordinate measurement machine which comprises an articulated arm having jointed arm segments is presented. This method includes sensing deformation of a portion of the articulated arm when the arm is placed under a load, this deformation causing an error in the measurement made by the CMM, and correcting such error in response to the sensed deformation.

Methods are provided for deriving a partially continuous dependency of metrology metric(s) on recipe parameter(s), analyzing the derived dependency, determining a metrology recipe according to the analysis, and conducting metrology measurement(s) according to the determined recipe. The dependency may be analyzed in form of a landscape such as a sensitivity landscape in which regions of low sensitivity and/or points or contours of low or zero inaccuracy are detected, analytically, numerically or experimentally, and used to configure parameters of measurement, hardware and targets to achieve high measurement accuracy. Process variation is analyzed in terms of its effects on the sensitivity landscape, and these effects are used to characterize the process variation further, to optimize the measurements and make the metrology both more robust to inaccuracy sources and more flexible with respect to different targets on the wafer and available measurement conditions.

Electrodynamic on funnels confine, guide, or focus ions in gases using the Dehmelt potential of oscillatory electric field. New funnel designs operating at or close to atmospheric gas pressure are described. Effective on focusing at such pressures is enabled by fields of extreme amplitude and frequency, allowed in microscopic gaps that have much higher electrical breakdown thresholds in any gas than the macroscopic gaps of present funnels. The new microscopic-gap funnels are useful for interfacing atmospheric-pressure ionization sources to mass spectrometry (MS) and on mobility separation (IMS) stages including differential IMS or FAIMS, as well as IMS and MS stages in various configurations. In particular, “wedge” funnels comprising two planar surfaces positioned at an angle and wedge funnel traps derived therefrom can compress on beams in one dimension, producing narrow belt-shaped beams and laterally elongated cuboid packets. This beam profile reduces the ion density and thus space-charge effects, mitigating the adverse impact thereof on the resolving power, measurement accuracy, and dynamic range of MS and IMS analyzers, while a greater overlap with coplanar light or particle beams can benefit spectroscopic methods.

The invention discloses a device and method for measuring swelling representation parameters of swelling soil. The device for measuring the swelling representation parameters of the swelling soil comprises a sample container, a soil body permeation coefficient measurement part, a jacking cylinder applying a vertical load, a dial indicator for testing a swelling soil sample to generate vertical deformation, and a deformation pipe used for testing water seepage coefficients of the swelling soil. The method comprises the steps of: immersing the swelling soil sample into water for swelling stably, measuring the water seepage coefficients; and then electrically heating the swelling soil sample to ensure that the swelling soil sample is dehydrated and contracted stably, and measuring the permeation coefficients of the swelling soil. Therefore, the invention can be used for measuring water seepage and permeation coefficients of the swelling soil in a repeatedly-swelling deformation process by controlling temperature and water content changes of the swelling soil sample in the sample container so as to reflect the change of a fracture and a soil body structure inside the soil body of the swelling soil in the repeatedly-swelling deformation process. In addition, the sample container of the device is connected with an external pipeline through each joint arranged on the sample container, therefore, data measurement in an experiment process is facilitated, and measurement precision of data is increased.

The invention discloses a physical coordinate positioning method based on binocular vision. The physical coordinate positioning method comprises the following steps: S1) setting a left camera and a right camera, establishing a coordinate system of a camera model, and obtaining a conversion relationship between the coordinate system of the camera model and a world coordinate system; S2) extracting a feature point, and obtaining a pixel coordinate of the feature point in a left image and a right image; and S3) calculating a space coordinate of the feature point in the world coordinate system. The left camera and the right camera are used for simulating two eyes, the coordinate system conversion model is established, then, each image shot by the two cameras is subjected to feature point extraction and pixel coordinate calculation, the pixel coordinate is converted into a theoretical coordinate of the camera model, and finally, the space coordinate of a target point is calculated. Measurement accuracy and efficiency is improved, and binocular coordinate positioning can have a better application prospect in the fields including an eye-in-hand system of an industrial robot, industrial cutting, logistics transportation business, packaging business, optical detection and processing and the like.

The invention discloses a method for measuring positioning points based on a laser tracker in a docking process of airplane parts. The method provided by the invention comprises the following steps of 1, establishing a model of transformation between an airplane global coordinate system and a laser tracker measure coordinate system according to common observation points, 2, acquiring current calculating positions of positioning measure points of airplane parts according to a process joint sphere centre position, and 3, controlling and driving a laser tracker to search current accurate positions of the positioning measure points of the airplane parts from the current calculating positions according to a cross helical search method and to carry out automatic measure. The method provided by the invention has the advantages that 1, an advanced laser measure technology is adopted so that the airplane assembling measure precision is improved; and 2, a measure process does not need artificial light introduction and full automatic search measure of a docking assembling process is realized according to an algorithm so that working efficiency and measure precision are greatly improved and working strength of workers is reduced.

The invention discloses a double rood beam high-sensitivity six-dimensional moment sensor in the technical field of robots. The double rood beam high-sensitivity six-dimensional moment sensor comprises two rood beams, two dead rings, one outer ring, and a plurality of resistance strain gages; a first rood beam and a second rood beam are arranged outside the outer ring respectively and are used as elastic bodies of the sensor for sensing stress; two dead rings are arranged outside the first rood beam and the second rood beam respectively; the resistance strain gages are adhered to the rood beams; each of the rood beams consists of four identical double-hole parallel sub beams; each double-hole parallel sub beam is provided with an I-shaped through hole; and a center hole is formed in the geometric center of each rood beam. In the double rood beam high-sensitivity six-dimensional moment sensor, floating beams used by the conventional six-dimensional moment sensor and crosstalk caused by the floating beams are removed, multi-component coupling is reduced conveniently and the measurement accuracy is improved.

The invention relates to the technical field of computer vision, and discloses a volume measurement method and system based on a depth camera. The method includes the steps: acquiring depth images with objects to be measured from the depth camera; extracting the objects to be measured from the depth images according to depth information to obtain target areas of the objects to be measured; converting two-dimensional image coordinates of pixels in the target areas of the objects to be measured to three-dimensional coordinates under a three-dimensional camera coordinate system by the aid of pre-calibrated parameters of the depth camera; calculating heights and lengths and widths of the objects to be measured according to the three-dimensional coordinates of the objects to be measured under the three-dimensional camera coordinate system, and calculating volumes of the objects to be measured. The depth images comprise depth information of the objects to be measured. The method is high in measuring accuracy and simple and convenient to use and can not be affected by shooting angles and heights, and mounting heights and angles of the camera cannot be calibrated.

A metrology target design may be optimized using inputs including metrology target design information, substrate information, process information, and metrology system information. Acquisition of a metrology signal with a metrology system may be modeled using the inputs to generate one or more optical characteristics of the metrology target. A metrology algorithm may be applied to the characteristics to determine a predicted accuracy and precision of measurements of the metrology target made by the metrology system. Part of the information relating to the metrology target design may be modified and the signal modeling and metrology algorithm may be repeated to optimize the accuracy and precision of the one or more measurements. The metrology target design may be displayed or stored after the accuracy and precision are optimized.

The invention relates to a geometric parameter visual measurement method for a large composite board, and belongs to the field of visual measurement. By means of the method, on-site quick three-dimensional reconstruction and geometric parameter measurement of the large composite board can be achieved. According to the method, a binocular vision measurement system, a laser tracker system and an indoor Bluetooth locating system are used for measurement, feature points are distributed on the measured composite board, and reflection targets are pasted to the feature points; the binocular vision measurement system is set up and is composed of a left camera, a right camera, a continuous line laser and an automatic position control platform; the laser tracker system is arranged, and the indoor Bluetooth locating system is mounted, so that measurement is completed. By means of the method, visual calibration of the large composite board can be quickly and precisely achieved, splicing precision of adjacent images is improved, data measurement precision is improved on the whole, and the defects that a traditional measurement method is low in efficiency, precision and stability are overcome.

A simulation device displays a three-dimensional model of a robot system on a display device and simulates a robot system including a robot and an image pickup camera. The simulation device includes a display device for displaying a three-dimensional virtual space on a screen, a camera position determination unit for determining an installation position of the image pickup camera based on an image pickup range designated by the operator, optical characteristic information of the used image pickup camera, and required measurement precision, and a virtual image generator unit for generating a virtual image to be obtained by the image pickup camera based on the position of the image pickup camera in the three-dimensional virtual space and the optical characteristic information, thereby facilitating the determination of the suitable position of the image pickup camera and adjustment of the detection parameters.

This invention belongs to measuring technique field and relates to improvement for space round geometry parameters non-contact measuring method. This invention can calculate eh real three dimensional coordinates of round fringe by use of polar line restriction and calculate space round geometry parameters based on space round optimal fit. This invention reduces the measuring error caused by shape distortion of space round perspective projecting and increases the measuring accuracy of round geometry parameters based on the optical method. When the surface of space round to be measured is angle more than fifty degrees, the repeatability accuracy 3sigma of space round geometry center is superior to minus or plus 0.01 mm.

The invention discloses a metro tunnel fracture surface deformation detection system, belonging to the tunnel engineering monitoring technical field. The system comprises a fracture surface scanning device, a mileage positioning device, an electrical equipment control device, a power source, a track detection vehicle and a station data processing system, wherein, the fracture surface scanning device, the mileage positioning device and the electrical equipment control device are arranged on the track detection vehicle; the power source is respectively connected with the fracture surface scanning device, the mileage positioning device and the electrical equipment control device through a power source convertor to supply power for the fracture surface scanning device, the mileage positioning device and the electrical equipment control device; a PLC controller is arranged in the electrical equipment control device; a rotary coder in the mileage positioning device, a sensor in the fracture surface scanning device and a rotary table stepped driver are respectively connected with the PLC controller; the PLC controller is connected with a wireless communicator through a wireless communicator in the station data processing system. The whole detection system of the invention has high portable integration degree, automatic operation process, convenient operation, low specialty technical requirements, rapid operation speed, extremely-time section surface measuring and high measuring precision, and the system precision is less than 3mm.

The invention discloses a distance measurement method of a binocular stereoscopic gazing monitoring system. The distance measurement method comprises the following steps that firstly, the coordinates of a principal point of an image, the focal length of a left camera and the focal length of a right camera are determined; secondly, the postures of the binocular cameras are adjusted so as to enable the binocular cameras to gaze at a target point; thirdly, a target distance measurement model based on a rotation angle is established; fourthly, the adjusted binocular convergence cameras are calibrated stereoscopically; fifthly, a transformational relation between the rotation angle and relative external parameters is established; sixthly, target distance measurement and coordinate reestablishment are carried out on the basis of the relative external parameters. On the basis of the distance measurement model, after corresponding parameters are introduced, the distances between the target point and the binocular cameras and the space three-dimensional coordinates of the target point can be worked out. According to the distance measurement method of the binocular stereoscopic gazing monitoring system, the measurement accuracy is high, the detectable distance is long, the result is worked out rapidly and accurately, and the requirement for target positioning of video monitoring can be met.