631 results about "Fitting algorithm" patented technology

A method for geometric calibration of a CT scanner, including, for each row of at least one row of detector cells, establishing a complete geometric description of the CT scanner, including at least one unknown geometric parameter, establishing a description of a forward projection function using the complete geometric description, acquiring actual projection coordinates of a calibration phantom placed in a scanning field of view (SFOV) on a current row of detector cells and corresponding to a plurality of angles, acquiring calculated projection coordinates of the calibration phantom on the current row of detector cells and corresponding to the plurality of angles using the description of the forward projection function, and acquiring a calibrated value for the at least one unknown geometric parameter by evaluating the at least one unknown geometric parameter based on the acquired actual projection coordinates and calculated projection coordinates via a nonlinear least square fitting algorithm.

Disclosed is an improved algorithm for estimating the 3D shape of a 3-dimensional object, such as a human face, based on information retrieved from a single photograph by recovering parameters of a 3-dimensional model and methods and systems using the same. Beside the pixel intensity, the invention uses various image features in a multi-features fitting algorithm (MFF) that has a wider radius of convergence and a higher level of precision and provides thereby better results.

The invention discloses a method for calculating oil saturation of a reservoir. The method comprises the following steps of: establishing a reservoir oil saturation model including a free fluid porosity phi f, a bound fluid porosity phi b, as well as corresponding macropore bond index mf, micropore bond index mb and micropore bond index characteristic value parameters; measuring a core porosity phi of a selected core sample; carrying out a nuclear magnetic resonance T2 spectrum experiment and an electric petrophysical experiment on the selected core sample to determine the core porosity phi and bound water saturation Swir of the selected core sample, the free fluid porosity phi f and bound fluid porosity phi b, stratum water resistivity Rw of a saturated rock sample, saturated water rock resistivity Ro of each rock sample, and resistivity Rt of each rock under different conditions of water saturation Sw; determining parameters of a reservoir oil saturation model by adopting an optimization data fitting method; establishing a relationship between the core micropore bond index mb and the bound water saturation Swir; classifying reservoir cores according to the bound water saturation; and determining a saturation index n of each type of cores by using the optimization fitting algorithm.

A detecting and error-correcting method capable of rapidly and accurately obtaining an element center and a deflection angle is disclosed. Interested edge area can be rapidly and accurately found out through an automatic edge area extraction method based on combination of binary morphology and image reduction, and subsequent edge extraction image scope is minimized as possible. Pixel level edge is roughly positioned at first, and accordingly a sub-pixel edge is rapidly extracted by one-dimensional curve fitting method. The method overcomes the defect of complex algorithm of a conventional sub-pixel edge extraction algorithm based on two-dimensional images, and the time of extracting accurate sub-pixel edge can be shortened. Weighted least square rectangular edge fitting algorithm based on linear hazen paradigm can detect straight lines on any positions of an image, and effectively minimizes influence of outlier on fitting precision due to uneven edges. The central positions of a plurality of elements and deflect angles can be rapidly and accurately detected at once, and the efficiency of visual detection is improved.

An optical analysis unit especially suitable for performing grating coupled surface plasmon resonance (SPR) imaging features a pivoting light source capable of scanning through a range of angles of incident light projected onto a stationary target sensor, such as an SPR sensor. The reflected image from the illuminated sensor is detected, e.g., by a CCD camera and the image and angular scan data are processed, for example by a fitting algorithm, to provide real time analysis of reactions taking place on the surface of the sensor.

Disclosed is an improved algorithm for estimating the 3D shape of a 3-dimensional object, such as a human face, based on information retrieved from a single photograph by recovering parameters of a 3-dimensional model and methods and systems using the same. Beside the pixel intensity, the invention uses various image features in a multi-features fitting algorithm (MFF) that has a wider radius of convergence and a higher level of precision and provides thereby better results.

A computational methodology that improves the accuracy of model parameters in a compact model uses methods and algorithms to self-consistently match independently developed base and stress models by re-fitting the stress model to the data set that generates the base model. The re-fitting algorithm removes any discrepancy between the base model and the stress model as the stress model is applied to the data set obtained from a dimension-scaling macro. Stress offsets for dimension-scaling macro devices are calculated to fit the measured values of the model parameters for the same devices. The process of fitting the model parameters to the data set from the dimension-scaling macro calculates constant, linear, and quadratic coefficients for the model parameters, which are employed to increase the accuracy of the model parameters and of the compact model used in circuit simulations and optimization.

An equipment fault diagnosis method successively comprises fault diagnosis training steps and fault diagnosis operation steps. The method focuses on a data form characteristic essence and combines a multi-dimensional segmentation fitting algorithm and an optimized dynamic time warping algorithm based on equipment fault data to carry out pattern expression of modeling and distance threshold extraction, and extract form characteristics from the found equipment abnormity data to carry out mode matching, so that an equipment data fault type can be identified and a reason diagnosis function is realized. In this way, the difficulties in current fault diagnosis technologies that similarity degrees among the fault data can hardly be described efficiently and accurately can be solved.

The invention relates to a system calibration method based on depth information. The method includes: firstly utilizing a circular plane target, extracting a feature point sub pixel outline by adopting self-adaptive threshold value edge detection and a multinomial fitting algorithm, and obtaining a central coordinate by using ellipse fitting; working out the optimal solution of a camera parameter by using a least square method according to a nonlinear imaging geometric model with distortion to obtain the pose of the target; at least providing depth information between the surface of an object to be detected and the target plane as the correction item of the camera model for correcting the pose of the measurement plane, and determining parts dimension by using an imaging principle and a point of intersection of a straight line with the parts surface; according to the system calibration method based on depth information, the problem that the dimension measuring system for the large-dimension plane parts is not high in calibration precision, thus being worthy of popularization and application.

The invention discloses a drivable region detection method based on a laser radar. The method includes the steps that the laser radar is used for scanning an actual traffic scene, and flat and rugged conditions of a current scene are obtained; scanning data returned by the laser radar are divided into a plurality of fragments through the height variation condition, an iterative linear fitting algorithm is used for extracting appropriate linear features from all the segments, flat regions are found out from the fragments which meet constraint conditions, and drivable regions are determined from the flat regions according to the requirements of the vehicle width; if a multi-line laser exists, corresponding drivable regions can be determined from the flat regions reflected by the line data on the basis of a drivable region of former line data from the near to the distant. According to the method, detection of the drivable regions in the actual traffic scene can be effectively completed, safe passage regions of an automobile are described accurately, and the method has good real-time performance, usability and robustness.

The invention provides an indoor location and navigation method based on LED lighting. Each LED has a programmable ID code, each LED lamp has a different and unique emitting power change mode, a visible data light signal which can be identified by a receiving end is formed, and the programmable ID codes are emitted in the form of time division multiplexing; the receiving end parses the received data light signal, and calculates the received power from different LED lamps; and the initial 3D coordinates of the receiving end are calculated according to a location algorithm, and the initial 3D coordinates are modified through a nonlinear fitting algorithm. The invention correspondingly provides an indoor location and navigation device applied to the method. The brightness change of the LEDs cannot be identified with the naked eye, and thus, an LED lighting system is built. The method can still provide precise location service for users when an individual LED is abnormal. By correcting the coordinates through the nonlinear fitting algorithm, centimeter-level location accuracy is guaranteed.

The invention discloses an equipment fault diagnosis method based on multidimensional segmentation fitting. The method successively comprises a fault diagnosis training step and a fault diagnosis operation step. The method realizes mode expression and distance threshold extraction functions of modeling through combining a multidimensional segmentation fitting algorithm and an optimized dynamic time bending algorithm by focusing on the essence of data form characteristics on the basis of equipment fault data, and realizes equipment data fault type identification and cause diagnosis functions by performing mode coupling through extracting form characteristics of discovered equipment abnormal data, thereby solving the problem of incapability of efficiently and accurately describing the similarity degree between fault data by use of a conventional fault diagnosis technology.

The invention relates to an optical fiber wavelength demodulating light spectrum peak value positioning method, belonging to the technical field of optical fiber sensing. The method comprises the following steps: firstly, carrying out maximum value detection on obtained diffraction light spectrum energy data; determining a suitable threshold value according to a maximum value and utilizing the threshold value to carry out peak searching treatment; constructing a fitting array by the processed data; and utilizing an LM peak value positioning algorithm to carry out accurate peak value positioning on the spectrum. Compared with the existing power weighted algorithm and Gaussian-polynomial fitting algorithm, the algorithm has the advantages of high-precision positioned light spectrum peak value; and the method is easy to realize on a digital television through a simplified data processing process.

The invention discloses an automatic recognition method for lightning arrester gauge reading, which is characterized in that recognition for a lightning arrester gauge is divided into region segmentation and reading recognition; firstly, a gauge dial is segmented into multiple regions by using a connected region detection algorithm and a rectangle fitting algorithm; then the regions are detected by using prior knowledge, and connected regions representing a pointer region and a digital region is reserved; then minimum area rectangle fitting is performed on the two connected regions to acquire two rectangles with a deflection angle; rotation correction is performed on an image according to the angle, then the pointer region and the digital region are segmented from the corrected image; and finally, reading recognition is performed on the pointer region and the digital region by respectively using an angle method and a convolutional neural network method. According to the automatic recognition method, pointer reading recognition and digital reading recognition can be accomplished simultaneously, effective correction can be performed on the image, and the reading accuracy is improved.

An analytical model simulates the propagation of radiation through a coated continuous web where layer thickness and refractive index, as variables, determine the speed and direction of transmitted radiation. The model predicts characteristics of transmitted radiation based on characteristics of incident radiation and initially assigned values for layer thicknesses. Coating thickness(s) are ascertained in a process whereby incident radiation of known characteristics is directed onto a coated web and thereafter, actual measurements of transmitted radiation are compared to predicted characteristics. Using a fitting algorithm, the assigned thickness(es) of the layer(s) of the model are adjusted and the process repeated until the actual and predicted values are within desired limits at which time, the assigned thickness(es) represent the measured calipers. Radiation measurements are obtained using terahertz time-domain spectroscopy apparatus that creates a continuous reference whereby a sample pulses' phase and amplitude can be tracked and corrected.

An image processing apparatus is provided. A silhouette extractor may extract a silhouette image of a target object from an input depth image. A first calculator may determine a location of at least one limb of the target object and a location of at least one joint connecting the at least one limb by applying a rectangle fitting algorithm with respect to the silhouette image.

A method for visualizing structure form of space flexible boardsail includes implanting discrete Brag fiber grating sensor network in distribution mode on surface of boardsail structure, detecting structure strain information at each measurement point, carrying out data treatment on detected information in computer and utilizing pattern treatment technique of computer to carry out accurate 3-D real time restructuring and display of deformation state at simulated space flexible boardsail structure on computer. The device used for realizing said method is also disclosed.

The invention relates to an obstacle detection and garage position distinguishing method of an intelligent parking system. The method comprises the following six steps: completing data acquisition depending on radar and a positioning system; realizing global localization of obstacle data points depending on transformation of coordinates; realizing the classification of the data points by analyzing the geometrical relationship among the data points; realizing the fitting of the data points depending on an optimal exterior rectangle fitting algorithm; realizing garage position distinguishing by analyzing the geometrical relationship among rectangular fitting results; realizing data transmission depending on a garage position information protocol. The invention further discloses an obstacle detection and garage position distinguishing system of the intelligent parking system for implementing the method. The obstacle detection and garage position distinguishing system comprises a sensor unit and a signal processing unit. The garage position detection of a vehicle along any route in a certain range can be realized for a garage position with front and rear fixed obstacles, a used garage position detection algorithm accords with the rule that the geometrical information of the garage position is distinguished by human better, and the system has higher detection precision, reliability and practical value.

Metrology for ultrathin dielectric layers of the order of less than 10 nanometers in thickness is achieved by specular ellipsometry in a totally controlled ambient between the light source and the detector, in which, a precise 2.75 through 9.0 eV photon energy range continuum of light is employed. In the signal analysis there is the taking into consideration the effect of noise in the development of the ellipsometric parameter values and in the resulting data. In the invention the precise photon energy range operates to sharpen the identifiability of the change parameters imparted into the reflected light in the ellipsometry while minimizing absorption and signal definiteness masking; and the taking into consideration of noise in the signal analysis involves providing a simulated noise spectrum for comparison with the least squares fitting algorithm-derived parameters to determine the quality of the minimum and the reliability of the inferred parameters.

The invention discloses a method of moving-target relocation and velocity ambiguity resolution based on a velocity synthetic aperture radar (VSAR) system, which mainly solves the problems that the velocity estimation accuracy of a moving target is low and the velocity of a fast moving target is ambiguous in the radar detection system. According to the method of moving-target relocation and velocity ambiguity resolution based on the VSAR system, the process includes perform range-doppler algorithm imaging to received data of each of array elements of the VSAR system; detecting the moving target and recording the corresponding position of the moving target after image registration, clutter suppression and cell average constant false alarm detection processing; using subspace fitting algorithm to estimate normalized velocity frequency after phase compensation so that the velocity estimation accuracy is effectively improved; extracting speed channel of the target, using multi-look differential frequency method to estimate doppler ambiguity number; calculating radial velocity of non-ambiguity according to the ambiguity numbers and estimate value of the velocity frequency and achieving an accurate location of the target. According to the method of moving-target relocation and velocity ambiguity resolution based on the velocity synthetic aperture radar (VSAR) system, the estimation accuracy and the detection performance are improved. Due to the fact that the ambiguity resolution processing is merely required for 2-3 iterations, the calculation is reduced, the accurate probability of understanding doppler ambiguity is improved and the effectiveness of the method is proved in a simulation experiment.

The invention belongs to the technical field of machine vision, and particularly relates to a vision-based method of detecting defects on the end surface of a bearing finished product, aiming at solving the problem of on-line detection of defects such as rust, scratches, pressed marks and bumps which probably exist on the end surface of the bearing finished product. The method comprises the following steps of: acquiring an original acquired image; acquiring a first workpiece image of the end surface of the bearing to be detected; performing edge extraction, obtaining the precise positioning ofthe bearing workpiece by using the fitting algorithm of a circle, and obtaining a second workpiece image; and based on the second workpiece image, expanding an annular workpiece drawing into a rectangular workpiece drawing; dividing the rectangular workpiece drawing into a plurality of end surface region drawings by adopting a unidirectional projection segmentation method; carrying out binarization segmentation through an adaptive gray threshold to obtain a defect candidate region; and as to the defect candidate region, obtaining a detect region by using a connected domain analysis method according to the defect position and shape information. The method realizes the on-line detection of the bearing end surface, improves the detection efficiency and the detection stability.

The invention provides a method for realizing sampling value synchronization in an intelligent substation system, which comprises the following steps of: a, monitoring the receiving time of each datum by a protecting device in real time; b, deducing the sampling time of each merging unit with a phase locked loop algorithm; and c, obtaining the information of the sampling time corresponding to the protecting device clock by a linear interpolation algorithm, and realizing the synchronization of the protective device with each sampling value of the merging unit. The invention tracks the receiving time of each datum by using an FPGA (Field Programmable Gate Array) chip, and then deduces the sampling time of each sampling device with the PLL (Phase Locked Loop) algorithm, and further obtains the information of the sampling time corresponding to a receiving device clock by an interpolation or fitting algorithm, thereby realizing the synchronization of the data. The method is performed by hardware, has high precision and strong real-time property, saves the software workload of a secondary device and increases the work efficiency of the secondary device; moreover, the configuration is flexible, the output of data of different sampling rates can be realized, and the reliability of the system is improved.

The invention discloses a method and system for speech quality perception evaluation based on the speech semantic recognition technology. According to a text of a sender after user speech conversion and a text of a receiver after user speech conversion, text similarity evaluation is carried out based on a text similarity fitting algorithm; network parameters and event information of communicationunit connection networks of the sender and the receiver are displayed in real time and are stored; a user speech perception evaluation model is established by using speech information according to a telecom psychology algorithm and speech perception evaluation is carried out on a user; and then user perception evaluation is formed by means of text similarity evaluation , network information and voice perception evaluation. With the method disclosed by the invention, problems of poor repeatability of the subjective evaluation method and the human brain thinking paradigm can not be restored by the objective issues can be solved; the method is close to the human brain thinking mode and the perception of the network conversation speech quality of the user; and on the basis of the time-positionmapping, a network issue can be located precisely by combining the network parameter information and events.

The invention discloses a fluctuation quantity method-based user side harmonic emission level practicality estimation method, belongs to the field of power quality harmonic treatment, is used for dividing rights and liabilities of harmonic pollution on a power supply side and an electricity side and belongs to a theoretical method practicality technology. The invention provides a complete processfor estimating the user side harmonic emission level by employing a fluctuation quantity method, provides a method for quantizing deviation between a power supply side harmonic impedance amplitude estimated value and an actual value, provides power supply side harmonic impedance amplitude estimated value accuracy for engineering, and easily and quantitatively judges whether the estimated value meets the requirement on engineering accuracy. In the method, various problems which possibly exist in actual engineering are considered theoretically. The conception of the time-varying dynamic phasor-based fluctuation quantity method is stated, the conventional harmonic impedance estimated value algorithm is improved, the least squares fitting algorithm which is wider in applicability and higher in accuracy is provided to estimate power supply side harmonic impedance; therefore, a practical flow more accords with actual operating conditions of a power system.

The invention relates to a method for detecting shape change of a metro tunnel section. The method comprises the following steps: with a center line of a tunnel track as an original point, establishing a rectangular coordinate system of the metro tunnel section; according to an angle meter, a laser ranger and a laser scanner, performing data measurement on the tunnel section to obtain a coordinate offset angle alpha and coordinates of all measuring points of the metro tunnel section in the rectangular coordinate system, wherein the coordinates of an ith measuring point is (xi, yi); by an elliptic fitting algorithm, performing curve fitting on basic measurement data to obtain a shape parameter, meeting an error requirement, of the tunnel section; judging whether the offset between the shape parameter of the tunnel section and a historical shape parameter exceeds an offset threshold, if yes, indicating that the metro tunnel section has obvious shape change, otherwise, indicating that the metro tunnel section does not have obvious shape change. Compared with the prior art, the method has the advantages of high measurement accuracy, comprehensive measurement, convenience in implementation and the like.

The invention relates to the technical field of gold immune test strip quantitative detection, in particular to a gold immune quantitative detection method and a gold immune quantitative detection device on the basis of embedded type charge coupled device (CCD) image acquisition. The method comprises the following steps of: 1) placing a test strip into a CCD image acquisition device and beginningto time by using a timer after detecting that the test strip is placed; 2) when the timing time is up, extracting the CCD image information of the test strip and transmitting the information to a digital signal processing unit; 3) performing denoising pretreatment; 4) extracting characteristic vectors, namely extracting the color characteristic vector 1 of a color histogram and the characteristicvector 2 of a chromaticity space-like model respectively; 5) preliminarily judging whether the detection is effective or not; and 6) fitting a concentration model by using the characteristic parameters as the input end of a machine learning fitting algorithm, and calculating and outputting the related quantitative analysis result. By the method and the device, the detection precision of gold immune test strip concentration quantitative detection is improved. The method and the device are easy to operate and good in using effect.

The invention discloses a ground data processing method for the radiometric correction of a remote sensing image taken by a double-sided mirror rotary multiple parallel-scan infrared camera. The method is based on the imaging principle of the double-sided mirror rotary multiple parallel-scan of an HJ-1B infrared camera, and solves the actual engineering problem of the data processing in a satellite ground system; the position of a damaged line is automatically detected by a DN value mapping-energy level statistical method, and the image recovery is carried out by the linear interpolation; aiming at the unevenness in a scan band caused by the multiple parallel-scan and the unevenness among the bands caused by the double-sided mirror scan, the multipoint piecewise linear interpolation fitting algorithm and the two-point linear algorithm are adopted for correction; aiming at the image dislocation between the adjacent scan bands caused by the double-sided mirror scan, the algorithm for minimizing the difference value of adjacent pixels is adopted for correction; and aiming at a vertical stripe appeared on the B2 waveband of the infrared camera after the satellite is launched, the first derivative gradient value method is adopted for automatic detection and recovery, thereby effectively eliminating the stripe and obviously improving the image quality.

The invention relates to a method for measuring the straightness of a guide rail and particularly relates to a method for measuring the straightness of a super-long guide rail, which aims to solve the problems that the conventional measuring method is low in measurement precision and has large errors, and the data processing and operation are complex. According to the method, a plurality of data points on the super-long guide rail are measured and acquired through a laser tracker, the data points are subjected to spatial straight line fitting, and data information of the acquired N tested sampling points is subjected to straightness calculation by a least square fitting algorithm, thereby obtaining the straightness of the guide rail. The method provided by the invention has the beneficial effects of easiness and convenience in data analysis and experimental operation, short testing time, simplicity data processing, low testing cost and high testing efficiency.

The invention provides a rapid extraction method and system for a target central point. All connecting areas in an obtained binary image are marked; a target connecting area is detected according to the marked connecting areas; an external rectangular area is determined based on the target connecting area; and thus a target central point coordinate in the external rectangular area is obtained. In the prior art, the multiplication and division operation load for the employed edge detection, Hessian matrix, Hough conversion, and fitting algorithms is heavy. However, according to the provided method, the most operation of the image binaryzation, connecting area marking and center of mass method belongs to the logic operation and adding and subtraction operation, so that the execution efficiency is high.

The invention discloses a method for on-line monitoring and positioning of partial discharge of a gas insulation combined electrical apparatus, which belongs to the technical field of insulation monitoring of electrical equipment. The gas insulation combined electrical apparatus mainly comprises a sensor antenna, an intelligent select switch, a high-speed digital collector, a processor, a control module and the like; and in the method, data fitting is performed on partial discharge signals received by the sensor antenna through a wave head fitting algorithm, and a simple approximate function is solved to reflect the overall change trend of a primary function, so a source point of the partial discharge can be accurately determined. The method can effectively detect the partial discharge of a GIS, automatically monitor the partial discharge inside the GIS on line, and improve the anti-jamming capability of a detection system.