576 results about "Calibration Error" patented technology

Safety features are applied to an integrated insulin delivery system to enhance safety while accounting for glucose sensor bias and calibration errors. One safety feature includes comparisons of calibrations of the sensor to nominal sensitivity and taking action, such as limiting insulin delivery or taking a further calibration of the sensor. In another feature, an automatic resumption of a basal delivery rate is programmed into the delivery device to avoid the possibility of complete loss of delivery of insulin in the event that communication with the delivery device is disrupted. Other features include steps taken to avoid hypoglycemia in the event that the sensor is negatively biased.

A closed-loop system for insulin infusion overnight uses a model predictive control algorithm (“MPC”). Used with the MPC is a glucose measurement error model which was derived from actual glucose sensor error data. That sensor error data included both a sensor artifacts component, including dropouts, and a persistent error component, including calibration error, all of which was obtained experimentally from living subjects. The MPC algorithm advised on insulin infusion every fifteen minutes. Sensor glucose input to the MPC was obtained by combining model-calculated, noise-free interstitial glucose with experimentally-derived transient and persistent sensor artifacts associated with the FreeStyle Navigator® Continuous Glucose Monitor System (“FSN”). The incidence of severe and significant hypoglycemia reduced 2300- and 200-fold, respectively, during simulated overnight closed-loop control with the MPC algorithm using the glucose measurement error model suggesting that the continuous glucose monitoring technologies facilitate safe closed-loop insulin delivery.

The invention discloses a gaze estimation method. The gaze estimation method comprises the following steps: finding out calibration error by aligning; then estimating the distance between a face plane and a screen and establishing a three-dimensional model to obtain optical axis information of eyeballs by offset correction of the head and rotary correction of the head; and finally, obtaining the position of a fixation point. According to the gaze estimation method, only a camera is used and no auxiliary equipment is needed; the aim of furthering increasing the estimation precision is achieved by using a correction link by a user; in addition, due to the utilization of estimation of the distance between the face plane and the screen and the offset and rotation correction of the head, limiting conditions are reduced as much as possible, a comfortable use environment for a user is provided and the gaze estimation method has better precision and adaptability of the head motion; and on the basis of an eyeball of a human eye, the gaze estimation method based on a three-dimensional model is established so as to achieve the aim of increasing the estimation precision. According to the gaze estimation method, extra auxiliary equipment is reduced, the adaptability to the head motion is improved, and the better precision for sight light estimation is obtained.

Safety features are applied to an integrated insulin delivery system to enhance safety while accounting for glucose sensor bias and calibration errors. One safety feature includes comparisons of calibrations of the sensor to nominal sensitivity and taking action, such as limiting insulin delivery or taking a further calibration of the sensor. In another feature, an automatic resumption of a basal delivery rate is programmed into the delivery device to avoid the possibility of complete loss of delivery of insulin in the event that communication with the delivery device is disrupted. Other features include steps taken to avoid hypoglycemia in the event that the sensor is negatively biased.

A closed-loop system for insulin infusion overnight uses a model predictive control algorithm (“MPC”). Used with the MPC is a glucose measurement error model which was derived from actual glucose sensor error data. That sensor error data included both a sensor artifacts component, including dropouts, and a persistent error component, including calibration error, all of which was obtained experimentally from living subjects. The MPC algorithm advised on insulin infusion every fifteen minutes. Sensor glucose input to the MPC was obtained by combining model-calculated, noise-free interstitial glucose with experimentally-derived transient and persistent sensor artifacts associated with the FreeStyle Navigator® Continuous Glucose Monitor System (“FSN”). The incidence of severe and significant hypoglycemia reduced 2300- and 200-fold, respectively, during simulated overnight closed-loop control with the MPC algorithm using the glucose measurement error model suggesting that the continuous glucose monitoring technologies facilitate safe closed-loop insulin delivery.

The invention discloses a calibration target device and a calibration method for a three-dimensional ice-shaped digital image system. The calibration target device comprises a rotary cloud deck, a lampstand, a movable calibration assembly and a calibration plate, wherein the rotary cloud deck is arranged on the lampstand; the rotary cloud deck is provided with the movable calibration assembly; and the movable calibration assembly is provided with the calibration plate. By adopting the calibration device, the on-site rapid calibration of a three-dimensional ice-shaped detector can be realized, and the calibration on the internal parameter and the relative positional relation of a camera can be finished through acquiring several images at a time, thereby, the experiment efficiency is greatly improved. By adopting the mechanical device disclosed by the invention, a traditional calibration mode of holding a free target is changed, the calibration error brought by the jitter of hands is avoided, and the calibration precision is improved. Moreover, the device not only is capable of realizing the calibration of a three-dimensional ice-shaped detector but also can be used as a fixed platform for an object to be measured, thereby, the integrated design of the calibration and the measurement is realized, and the manufacturing material and the processing cost of the device are saved.

A metrology instrument is calibrated using two reference locations with different optical properties designed to produce different measurement results, e.g., different thicknesses. The metrology instrument, for example, may be an ellipsometer with a variable phase retarder. By comparing initial measurements of the two reference locations with later measurements of the two reference locations, the amount of calibration error can be easily determined. In addition, an ellipsometer having a spatially or temporally variable phase retarder may also be calibrated with a single reference location.

The invention discloses a TCP online quick calibration method and device applied to an industrial robot. The device comprises a control cabinet, a TCP calibration device, the industrial robot, a terminal tool and control buses; the control cabinet is separately connected with the TCP calibration device and the industrial robot through the control buses; the terminal tool is mounted on the industrial robot; the TCP calibration device includes a TCP detecting device, a calibration controller and a mounting base; the TCP detecting device is fixedly mounted on one side of the industrial robot through the mounting base; and a measuring plane is parallel to a XOY plane of an industrial robot base coordinate system. According to on-off signals of a correlation photoelectric sensor, the pose data of a flange is recorded, and the pose deviations of the terminal tool in X / Y axis and Z axis directions are calculated and compensated; and through multiple times of repeated operations, the TCP calibration errors are reduced, the operation precision of the industrial robot is effectively improved, the stop maintenance time of the industrial robot is reduced, and the automation degree of an industrial production line is improved.

A moving ground penetrating radar is comprised of multiple transmitters and receivers with multiple, e.g., Horizontal and Vertical, polarizations to detect buried targets with standoff capability. Novel signal and imaging techniques are used to form high quality radar imagery with low artifacts that are due to various sources of self-induced resonances, e.g., transmitter-receiver coupling, calibration errors, and motion errors in the multi transmitter / receiver channels of the radar system. The irradiated target area image is formed via exploiting both the spatial diversity of the physical multi-transmitter and multi-receiver array and synthetic aperture / array that is generated by the motion of the platform that carries the radar system. The images that are formed from the multiple polarizations are combined to remove surface targets / clutter and, thus, enhance signatures of buried targets.

The invention provides a visual measuring system based on self-adapting targets and a calibration method thereof, wherein the system and method provided by the invention are applicable to the technical field of computer vision. In the embodiment of the invention, the targets are constructed based on the samples of the to-be-detected workpieces by sticking a code mark on the surface of the workpiece, so that the manufacturing is simple without mechanical processing. Digital cameras and scales are used for regulating the target and can be recycled for regulating a plurality of targets, so that the cost is low. The cameras in the system ensure that the targets can be seen during a measuring process, so the cameras in the system can be calibrated simultaneously; and the calibration error is not delivered and accumulated, so that the calibration precision is high. The targets can be directly moved and placed by a mechanical device in a production line; and the method is especially applicable to online calibration.

The invention belongs to the technical field of distribution-type optical fiber sensing measurement, in particular to an optical fiber strain and temperature simultaneous calibration device and a method based on Brillouin scattering. The optical fiber strain and temperature simultaneous calibration device comprises optical fiber Brillouin sensing measurement equipment, a shockproof support frame, a metal pipe and constant-temperature equipment. According to the method, the metal pipe with large and stable linear expansion coefficient is adopted to manufacture the strain calibration device, and the position of an optical fiber is accurately controlled by curving a thread on the outer wall of the metal pipe. Due to the characteristic that the optical fiber on the metal pipe bears strain and temperature at the same time, and the loose optical fiber only bears temperature, the temperature and the strain are calibrated simultaneously. The constant-temperature equipment is used for applying accurate and controllable strain and temperature on the optical fiber and the loose optical fiber on the metal pipe, and calibration of the strain of the optical fiber and temperature coefficient is carried out by means of detailed calibration steps. By means of the strain and temperature high-accuracy simultaneous calibration device and the method of the optical fiber Brillouin sensor, the problems of high strain calibration error and low efficiency of strain and temperature calibration are resolved.

The present invention provides a vehicle-mounted panoramic around view calibration system and method. The method comprises: extracting an image containing a feature object from images acquired by a panoramic around view system, and marking the image as a feature object image; extracting feature object useful information from the feature object image; according to the feature object useful information, optimizing a calibration parameter; and verifying accuracy of a calibration result, wherein the calibration result refers to a calibration parameter obtained by optimization. According to the system and method provide by the present invention, optimization of the calibration parameter is taken as an optimization problem, and an error function based on a multi-camera feature projection error, so as to indicate a calibration error under a current optimization result, so that calibration is more accurate and rapider, and calibration precision of the panoramic around view system is improved; and calibration can be optimized and corrected by using an artificial marker or a non-artificial marker, so that calibration efficiency and applicability of the panoramic around view system are improved.

The invention provides a closed-loop calibration method of a micro-mechanic gyro inertia measuring component, which comprises the following steps: data output by a gyro and an accelerometer is collected; a scale factor of the Y axis is roughly measured; a matrix CKg-b is constructed by using the roughly determined scale factor and an installation error; the alignment of a micro-mechanic strapdown inertial navigation system is implemented according to a compass loop method, and a course angle that is output by system navigation parameters and control angular velocities on each axis of a geographical coordinate system are read after the compass alignment is finished, thus measuring constant drift of the gyro; when the system enters a navigation phase, the scale factor and the installation error angle of the gyro are precisely calibrated; the updated matrix CKg-b and the course angle are written into a navigation computer, and a next round of calibration is implemented, when the difference between the course angles that are obtained from two calibrations is less than a given constant 0.0001 degree, the calibration is finished. By using the calibration method provided by the invention, the system lies in a closed-loop feedback state and can implement the feedback calibration of the calibration error, thus improving calibration precision.

This invention provides a system and method for runtime determination (self- diagnosis) of camera miscalibration (accuracy), typically related to camera extrinsics, based on historical statistics of runtime alignment scores for objects acquired in the scene, which are defined based on matching of observed and expected image data of trained object models. This arrangement avoids a need to cease runtime operation of the vision system and / or stop the production line that is served by the vision system to diagnose if the system's camera(s) remain calibrated. Under the assumption that objects or features inspected by the vision system over time are substantially the same, the vision system accumulates statistics of part alignment results and stores intermediate results to be used as indicator of current system accuracy. For multi-camera vision systems, cross validation is illustratively employed to identify individual problematic cameras. The system and method allows for faster, less- expensive and more-straightforward diagnosis of vision system failures related to deteriorating camera calibration.

Methods and systems for evaluating the capability of a measurement system to track measurement parameters through a given process window are presented herein. Performance evaluations include random perturbations, systematic perturbations, or both to effectively characterize the impact of model errors, metrology system imperfections, and calibration errors, among others. In some examples, metrology target parameters are predetermined as part of a Design of Experiments (DOE). Estimated values of the metrology target parameters are compared to the known DOE parameter values to determine the tracking capability of the particular measurement. In some examples, the measurement model is parameterized by principal components to reduce the number of degrees of freedom of the measurement model. In addition, exemplary methods and systems for optimizing the measurement capability of semiconductor metrology systems for metrology applications subject to process variations are presented.

The invention discloses a steering vector and covariance matrix joint iteration robust beam forming method, and solves the problem of the expected signal steering vector and interference-plus-noise covariance matrix estimation in the adaptive beam forming technology. The implementation process is that the sample covariance matrix is estimated by using the radar echo data acquired by the array; theexpected signal steering vector and interference-plus-noise covariance matrix is initialized; the convex optimization equation is established to estimate the expected signal steering vector error; the steering vector and the covariance matrix are updated, and alternating iteration is performed until the optimal estimation of the steering vector and the covariance matrix is obtained; and the weight value is calculated and robust beam forming is realized. The expected signal steering vector constraint capacity is enhanced when the direction of arrival and array calibration errors coexist, the expected signal estimation interference-plus-noise covariance matrix is accurately eliminated from the sample covariance matrix and the 'self-elimination ' phenomenon of the expected signal can be avoided and thus the method can be used for realizing adaptive beam forming under the condition of existence of the direction of arrival and array calibration errors.

A system and method for characterizing noise in a quantum system includes determining pulse sequences for unitary twirling operations. Twirling processes are applied to a quantum system to calibrate errors and to determine channel parameters. Noise characteristics are determined from calibration data collected to calibrate the errors and to determine the channel parameters. The noise characteristics are characterized to determine if the noise is independent relaxation of qubits or collective relaxation of qubits.

The invention provides a multi-polarization SAR compact polarimetry calibration method which comprises a calibration field compact polarimetry SAR data preprocessing process and a polarization distortion parameter calibration process. In the calibration field compact polarimetry SAR data preprocessing process, compact polarimetry SAR data radiation correction and Faraday rotation correction are mainly completed. In the polarization distortion parameter calibration process, four different types of common corner reflectors are used as reference calibrators, and a compact polarimetry calibration method (namely, a compact polarimetry polarization distortion parameter calibration method) is deduced based on a calibration model. Through the method, a polarization distortion parameter can be calibrated precisely. The calibration algorithm does not depend on the absolute RCS values of the corner reflectors, and calibration error caused by RCS inconsistency of different corner reflectors can be avoided effectively. The algorithm is of high robustness and practicability.

The invention belongs to the technical field of relative position calibration between a camera and a robot, and discloses an automatic hand-eye calibration method and device for optimal calibration point selection and error automatic measurement. The method comprises the following steps that a calibration plate guiding six-axis mechanical arm is used for aligning a calibration plate with the camera, and an initial sampling position of the mechanical arm is obtained; the mechanical arm clamps the camera or the calibration plate to complete a series of rotary movements, photographing and sampling are carried out on the calibration plate by the camera in the movement process, a calibration plate recognition algorithm is used for estimating the pose of the calibration plate, and meanwhile, unreasonable points are filtered out; and a calibration equation is solved, error measurement is conducted on a solution result by using sampled points in the calibration process so as to realize a fully-automatic quantifiable calibration solution scheme and device. According to the method, an obtained calibration error can be quantified in various dimensions such as rotation and translation, the whole calibration process can be guaranteed to be automatic, accurate and efficient, and the problems of eye in hand calibration and eye to hand calibration in practical application are solved.

The invention relates to a method for calibrating zero offset of a quartz flexible accelerometer component, which is a system grade calibrating method using a velocity error as observed quantity. In the method, the conventional calibration equipment is still used, the six-position calibration scheme has simple operation and high calibration accuracy; and compared with conventional multi-position division calibration test, the calibrating time of the method of the invention is greatly shortened, calibration errors caused by rotary table errors when multiple positions are calibrated are reduced, and the navigation performance of a strapdown inertial navigation system can be improved. The invention provides a practical system grade calibration method for the accelerometer component.

The invention provides a machine vision based workpiece defect detection method. According to the method, the image of a flange type workpiece is acquired; a camera is calibrated, and calibration error is obtained; sub-pixel edge information extraction is performed on a workpiece contour; a distance from a fitting edge to the workpiece contour is calculated; whether the distance is larger than a given threshold value is judged through comparison, so that the damage condition of the workpiece contour is determined; and with the problem that the complex surface texture of the workpiece affects the segmentation of the surface scratches and corrosions of the workpiece considered, pixel stratified sampling-based PixelNet convolutional neural network is adopted to segment the surface defects. Results show that the method of the invention can accurately detect the shape defects and surface defects of the workpiece and has improved robustness.

The invention discloses a TOF camera calibration and correction system and a device and method thereof, wherein the TOF calibration method comprises the steps: (A), setting the integration time of a TOF camera; (B), measuring the related parameters; (C), obtaining the proper integration time according to the related parameters; (D), obtaining a measurement value in the proper integration time, comparing the measurement value with an actual value, and obtaining a calibration error value. The TOF camera correction system comprises a calibration unit and a correction unit. The calibration unit obtains the proper integration time of the TOF camera, so as to obtain the stable calibration error. The correction unit corrects the calibration error of the calibration unit.

The invention relates to a hand-eye calibration method for a mechanical arm, a calibration plate, a device, equipment and a storage medium. The method comprises the steps that the calibration plate issequentially put at different positions in the view of a scanner, and the tool center point position of a mechanical arm tail tool coincides with the geometric figure center of the calibration platein a world coordinate; and the tool center point positions in a mechanical arm-based coordinate system and the geometric figure center positions in a scanner camera coordinate system are collected simultaneously, a hand-eye relational matrix of the mechanical arm and a calibration error corresponding to the hand-eye relational matrix are calculated and output according to all the collected tool center point positions and all the collected geometric figure center positions, and the calibration error can be used for judging whether the hand-eye relational matrix is accurate or not. By adopting the method, the mechanical arm hand-eye calibration convenience, efficiency and accuracy can be improved, and the mechanical arm hand-eye calibration cost is reduced.

The invention provides an antenna calibration method and a device. The antenna calibration method comprises the following steps. Cooperation base stations or radio remote units (RRUs) are divided into small groups which are not mutually overlapped, the number of the small groups is smaller than that of the cooperation base stations or the RRUs, and calibration is performed on antennas in a multi-point cooperation area after grouping. Calibration results of all the antennas are confirmed so that the problems that when a large amount of cooperation base stations or RRUs in the multi-point cooperation area need to be calibrated, an existing calibration scheme not only possibly does not obtain a good calibration effect due to the fact that any empty calibration has calibration errors, but also causes long-time calibration and high demands in design of orthogonal calibration pilot frequency are solved.

An image acquisition unit acquires an image including an object, and a controller starts a visual servo using the acquired image, on the basis of at least one of an error in calibration, an error in installation of a robot, an error resulting from the rigidity of the robot, an error of a position where the robot has gripped the object, an error regarding imaging, and an error regarding a work environment. Additionally, the controller starts the visual servo when the distance between one point of a working unit of the robot and the object is equal to or greater than 2 mm.

The invention discloses a foreground digital calibration method applicable to a pipeline ADC (analog to digital converter). On the basis of the structure of the traditional pipeline ADC, a level-calibrated adding circuit is added on a level with the error required to be calibrated. During calibration period, four special inputs are supported for the level-calibrated adding circuit with an error level required to be calibrated and a sampling capacitor, and by the aid of the foreground digital calibration computing and calibrating circuit, a calibration level capacitor mismatch error, a operational amplifier mismatch error and a sub-DAC (digital to analog converter) reference voltage error are extracted. During the normal working period, the foreground digital calibration computing and calibrating circuit works. The foreground digital calibration method is simple in structure, few additional elements are added, sequential control is easy, few registers are required, and digital circuit design is low in difficulty and short in period. By the use of the foreground digital calibration method, static characteristics of the pipeline ADC is calibrated excellently, and a certain calibration effect of dynamic characteristics of the pipeline ADC is achieved.

The invention provides a method for calibrating multiple cameras, comprising the following steps: synchronizing the system time of the multiple cameras; establishing a field-of-view overlap area relationship diagram of the multiple cameras; calculating the average depth error estimated value of trajectory points of a tracked object extracted from each field-of-view overlap area, estimating the calibration error magnification factor of one jump of each field-of-view overlap area based on the average depth error estimated value, and giving the corresponding jump a weight based on the estimated calibration error magnification factor so as to convert the field-of-view overlap area relationship diagram into a weighted field-of-view overlap area relationship diagram; and acquiring a reference camera corresponding to the minimum calibration cumulative error by a minimum path algorithm based on the weighted field-of-view overlap area relationship diagram.

Disclosed is a method of analysing tissue from an image comprising providing an electronic image of tissue (100, 400, 450, 600, 800, 1100), determining a reference value from the image (1070, 1170, 1270), establishing an hint representation (500,700) of the image, and using the hint representation in analysis of the tissue to quantify the breast and compute a calibration error. Also disclosed is a system which runs an inner breast edge detection algorithm (1310) on the electronic image to detect the inner breast edge on the image (1315), and refined the inner breast edge location (1340) if a calibration error is not acceptable (1324). Also disclosed is automatic estimation of breast composition and temporal analysis of images.

Measurements made with a multicomponent logging system oriented in a horizontal position above the surface of the earth must satisfy certain relationships. These relationships are used to establish calibration errors in the system.

The invention discloses a time frequency synchronization calibration method of an SCA-based multi-channel high-speed data acquisition system. The SCA-based multi-channel high-speed acquisition system is composed of a waveform acquisition and time measurement module assembly and a comprehensive processor module, a high-speed switch capacitor array in an SCA chip is used for storing an analog signal and reading the analog signal through a slow-speed clock, then the analog signal is subjected to digital quantification through a high-accuracy low-speed AD to be stored into a buffer unit, and online real-time calibration can be achieved while multi-channel waveform acquisition and time measurement are completed. The time frequency synchronization calibration method is simple in calibration process, the calibration result is good in adaptability, the system calibration error is small, the measurement accuracy is superior to 80ps, and the method is particularly suitable for the technical field of whole waveform analysis.