723 results about "Calibration algorithm" patented technology

A method of calibrating glucose monitor data includes collecting the glucose monitor data over a period of time at predetermined intervals. It also includes obtaining at least two reference glucose values from a reference source that temporally correspond with the glucose monitor data obtained at the predetermined intervals. Also included is calculating the calibration characteristics using the reference glucose values and corresponding glucose monitor data to regress the obtained glucose monitor data. And, calibrating the obtained glucose monitor data using the calibration characteristics is included. In preferred embodiments, the reference source is a blood glucose meter, and the at least two reference glucose values are obtained from blood tests. In additional embodiments, calculation of the calibration characteristics includes linear regression and, in particular embodiments, least squares linear regression. Alternatively, calculation of the calibration characteristics includes non-linear regression. Data integrity may be verified and the data may be filtered.

A method of calibrating glucose monitor data includes collecting the glucose monitor data over a period of time at predetermined intervals, obtaining reference glucose values from a reference source that temporally correspond with the glucose monitor data obtained at the predetermined intervals, calculating the calibration characteristics using the reference glucose values and corresponding glucose monitor data to regress the obtained glucose monitor data, and calibrating the obtained glucose monitor data using the calibration characteristics. In additional embodiments, calculation of the calibration characteristics includes linear regression and, in particular embodiments, least squares linear regression. Alternatively, calculation of the calibration characteristics includes non-linear regression. Data integrity may be verified and the data may be filtered. Further, calibration techniques may be modified during a fast rate of change in the patient's blood glucose level to increase sensor accuracy.

The present invention relates to a method of controlling a modular, tiled, large-screen emissive display application, e.g. an OLED display application. The method of controlling e.g. includes a first control level (214) for controlling the emissive devices, a second control level (212) for controlling the emissive display modules and a third control level for controlling the emissive display tiles (210). The number of control levels can be larger or it can be restricted to two levels. The method of controlling according to the present invention allows for similar control and calibration algorithms to be run at all levels, and allows for distributed processing in order to reduce bandwidth requirements and processing complexity. Furthermore, the control method of the present invention includes a method of operating and a method of monitoring a modular, tiled, large-screen emissive display.

A calibration method for a hand-held surgical instrument is disclosed. The hand-held instrument includes a drive motor, a firing rod controlled by the drive motor and having at least one indicator, and a sensor configured to detect the at least one indicator. A microcontroller includes a pulse modulation algorithm stored therein to control the drive motor. The microcontroller executes a calibration algorithm to adjust at least one program coefficient in the pulse modulation algorithm.

The invention relates to a vector-relation-based method for calibrating single-line laser radar and a CCD camera. Point set information of the laser radar for scanning a V-shaped target is extracted in a laser coordinate system, and direction vectors and intersection coordinates of straight lines in two different planes of the target are obtained by means of straight line fitting; the CCD camera is used for capturing images in a camera coordinate system, target plane equations and an equation of a plane passing through an original point and laser radar scanning lines are obtained by processing image information, a straight-line equation of laser radar scanning is built, and furthermore, the direction vectors and the intersection coordinates of the straight lines are obtained; finally, calibration is finished according to the relations between direction vectors and the intersection coordinates of the straight lines corresponding to the different coordinate systems. According to the method, no object in a calibration scene needs to be moved, collection of all calibration data can be completed at a time, and calibration efficiency is improved greatly. According to the method, the direction vectors of the straight lines of the laser scanning target planes under the coordinate systems of sensors to be calibrated are obtained directly, calibration precision is guaranteed, and meanwhile the calibration algorithm is simplified.

Automated image on media registration and self-calibration using a built-in printing system duplex media path is enabled. The media sheet can be registered in a registration system and a calibration image can be placed on the media sheet after registration of the media. The media sheet can be inverted in the duplex media path and re-fed for detection of calibration image placement accuracy on the media sheet. The registration system can transmit the image registration placement data to a printer controller. Thereafter, the printer controller can adjust system settings to compensate for an image placement registration offset using a calibration algorithm. The invention enables system adjustments without requiring manual measurements or media transfer to an independent scanning device or adding complexity to printing systems.

Apparatus and methods are disclosed for the calibration of a tracked imaging probe for use in image-guided surgical systems. The invention uses actual image data collected from an easily constructed calibration jig to provide data for the calibration algorithm. The calibration algorithm analytically develops a geometric relationship between the probe and the image so objects appearing in the collected image can be accurately described with reference to the probe. The invention can be used with either two or three dimensional image data-sets. The invention also has the ability to automatically determine the image scale factor when two dimensional data-sets are used.

The present invention provides a method of calibrating a spectroscopic device for providing a non-invasive measurement of an analyte level in a sample. The method comprises the steps of: (a) providing a plurality of calibration algorithms; (b) taking a set of non-invasive measurements on said sample with said spectroscopic device; (c) calculating a predicted set of analyte levels for each of the calibration algorithms in response to the set of non-invasive measurements, each of the predicted sets of analyte levels being characterized by a variability range, a slope, an R_{<?img id="CUSTOM-CHARACTER-00001" he="2.46mm" wi="1.78mm" file="US06919566-20050719-P00900.TIF" alt="custom character" img-content="character" img-format="tif" ?>}2_{<?img id="CUSTOM-CHARACTER-00002" he="2.46mm" wi="1.78mm" file="US06919566-20050719-P00900.TIF" alt="custom character" img-content="character" img-format="tif" ?>} (a square of the correlation between said set of non-invasive measurements and said predicted set of analyte levels), and a standard error of prediction; and (d) selecting an appropriate calibration algorithm by using a suitability score based on the variability range, the slope, the R² an the standard error of prediction for each of the predicted sets of analyte levels. A method of generating suitable calibration algorithms in step (a) is also provided.

The invention discloses a light stream based vehicle motion state estimating method which is applicable to estimating motion of vehicles running of flat bituminous pavement at low speed in the road traffic environment. The light stream based vehicle motion state estimating method includes mounting a high-precision overlook monocular video camera at the center of a rear axle of a vehicle, and acquiring video camera parameters by means of calibration algorithm; preprocessing acquired image sequence by histogram equalization so as to highlight angular point characteristics of the bituminous pavement, and reducing adverse affection caused by pavement conditions and light variation; detecting the angular point characteristics of the pavement in real time by adopting efficient Harris angular point detection algorithm; performing angular point matching tracking of a front frame and a rear frame according to the Lucas-Kanade light stream algorithm, further optimizing matched angular points by RANSAC (random sample consensus) algorithm and acquiring more accurate light stream information; and finally, restructuring real-time motion parameters of the vehicle such as longitudinal velocity, transverse velocity and side slip angle under a vehicle carrier coordinate system, and accordingly, realizing high-precision vehicle ground motion state estimation.

An asynchronous, distributed, and calibrated apparatus provides a composite display from a plurality of plug-and-play projectors. The apparatus comprises a plurality of self-sufficient modules. Each module comprises at least one plug-and-play projector of the plurality of plug-and-play projectors. A camera is coupled to the projector. A software or firmware controlled, computation and communication circuit is coupled to the projector and executes a single-program-multiple-data (SPMD) calibration algorithm that simultaneously runs on each self-sufficient module to generate a scalable and reconfigurable composite display without any need for user input or a central server.

The invention relates to a mixed measurement analysis method for a satellite antenna. The method effectively solves the problems that various measurement devices are used for co-measurement to reduce detection difficulty and improve detection efficiency during a measurement process of the satellite antenna. The method comprises the steps: cubic mirror collimating measurement is carried out by electronic theodolites during antenna installation and detection processes, scanning measurement of an antenna shaped surface is carried out by a laser radar, a space point position is measured by a laser tracker, and thus the measurement of the satellite antenna is jointly completed by the various measurement devices; union calibration algorithm of 'six freedom degree measurement station three-dimensional network' is employed, a conversion relationship between measurement station coordinates and measurement coordinates is utilized, various observed value error equations are directly listed, so as to overcome shortcomings of a traditional algorithm and improve adaptability of the algorithm. The method provided by the invention is simple, is easy to operate, enables an initial value to be fast acquired, has low requirements for precise degree of the initial value, has a few iteration times, is quick in convergence speed, theoretically is an optimal solution, and has strong algorithm adaptability, high measuring efficiency, fast speed and high precision.

A system and method for calibrating a vehicle heading sensor, such as a yaw-rate sensor, when GPS signals are not available using a bias update model that employs a bias gain factor. In order for the bias update model to be accurate, the vehicle should be traveling relatively straight. One embodiment of the present invention uses three thresholds to determine if the vehicle is traveling straight. These thresholds include a yaw-rate threshold, a steering wheel angle threshold and a wheel speed threshold. If all three of the thresholds indicate that the vehicle is traveling straight, then the update bias model can be used to calibrate the yaw-rate sensor.

Systems and methods may include a signal component separator that receives a non-constant envelope input signal and at least one phase offset value, and generates first digital phase data and second digital phase data; at least one digital phase modulator that receives the first phase data and the second phase data and operates with a frequency synthesizer to generate a first component signal having a first constant envelope and a second component signal having a second constant envelope; at least one power amplifier that amplifies the first component signal and the second component signal; a non-isolated power combiner that combines the first amplified component signal and the second amplified component signal to generate an output signal having a non-constant envelope; and a mismatch compensator that monitors the output signal to determine the at least one phase offset value, where the at least one phase offset value is utilized by the signal component separator for phase adjustment.

The invention relates to the multi-sensor time calibration algorithm field, especially relates to a visual inertial range measurement method and equipment using online time calibration and aims at increasing camera pose calculation precision. The visual inertial range measurement method comprises the following steps of roughly aligning the timestamp of a camera image with the time system of an IMUand taking the data of a camera and the IMU as input; taking the time delay closest to a camera pose calculated by the camera data and the IMU data as the preliminary estimation value of camera timedelay; and using an IMU error item expression method with a time delay parameter to add a correction term related to the time delay into the pre-integration result of the IMU, taking as the parameterof nonlinear optimization and realizing the accurate calibration of the time delay. Compared with an existing method, by using the method of the invention, time delay calibration is accurate, and forequipment which does not carry out hardware synchronization, better performance can be achieved when the equipment rapidly makes a turn and suddenly stops.

A method and apparatus for correcting the offset and linearity error of a data acquisition system. A charge redistribution digital to analog convertor (CDAC) is connected to one of the differential inputs of a comparator whose second input comes from a function CDAC. The calibration algorithm is built into a digital control unit. The digital control unit detects the offset and capacitor mismatch errors sequentially, stores the calibration codes for each error in calibration mode and provides the input-dependent error correction signals synchronized with the binary search timing to adjust the differential input of the comparator and compensate the input-dependent errors present at the output of the non-ideal function CDAC during normal conversions.

A calibration algorithm is provided for calibrating a machine vision system including a color camera, a framegrabber and an illumination source wherein subsequently acquired images are processed on a pixel-by-pixel basis. After framegrabber offsets are measured to obtain initial or offset calibration data, the camera is pointed at a target monotone patch of known reflectance such as pure white and the camera outputs for red, green and blue are determined while observing the monotone patch to obtain spatial calibration data. The gain for each of the output channels of the color camera is automatically determined from the initial calibration data. Applying the three gain factors to a subsequent image on the pixel-by-pixel basis allows one to end up with a color-corrected image without incurring any time performance penalty. At any time during an inspection process, a small area of white reflectance can be observed. The resulting dynamic white calibration data is used to correct for any medium to long term temporal variation in imaging conditions.

The invention provides a camera array calibration algorithm capable of calibrating a 3D camera and obtaining relatively precise extrinsic parameters between the 3D camera and a visible light camera. The algorithm comprises the following steps: firstly, internally calibrating the visible light camera and the 3D camera to obtain intrinsic parameters of the cameras; secondly, adopting the intrinsic parameters of and a depth map provided by the 3D camera to restore the spatial locations of corner points of calibration boards, adopting minimum corner point projection error to obtain the optimum extrinsic parameters from the 3D camera to the required visible light camera, thereby completing the calibration of the whole camera array.

The invention discloses an automatic test platform of a high-speed ADC chip and a software framework design method thereof. The design method comprises the steps of step 1, FPGA underlying logic drive design: the FPGA underlying logic part completes construction of the hardware foundation, including realizing underlying logic control, foundation computation and soft core hardware configuration of the hardware module; and synchronous drive algorithm design including the tested high-speed ADC, calibration algorithm design, hardware drive design of the onboard high-precision ADC/DAC and register array and hardware FFT operation; step 2, test parameter acquisition: the FPGA soft core receives an upper computer command to control the test process and transmits the command to the FPGA hardware program to drive an external circuit to acquire data so as to obtain the test parameter value by applying the processing algorithm, wherein the test parameters are mainly divided into static parameters and dynamic parameters; and step 3, upper computer program design. The high-precision level characteristic and the high-speed data characteristic of the chip can be simultaneously measured, and "one-key acquisition" can be realized through programming control.

In order to increase the accuracy and speed of catheter reconstruction in surgical procedures such as an HDR prostate implant procedure, an automatic tracking system is provided preferably using an electromagnetic tracking device. The system uses a transmitter with a sensor used for catheter position. Due to substantial interference in the electromagnetic field from the surgical table, implant stepper/stabilizer etc, a calibration algorithm using a scattered data interpolation scheme is implemented to correct tracking location errors. The invention includes methods and systems used to carry out the methods.

A motion control device for controlling a motor is presented. The motion control device is operable to scale or adjust an input relative to an input range that is based on calibration values and to use that scaled input to produce a drive signal to drive the motor. The motion control device performs a self-calibration to produce the calibration values. The self-calibration involves measuring home position and full travel position values for the motor.

A system and method for calibrating the bias and scale factors of a heading rate sensor, such as a yaw-rate sensor, using GPS signals. The system receives wheel speed or rotation signals, a vehicle odometer reading, GPS signals and yaw-rate signals. The system includes a wheel-slip detection processor that determines whether there is wheel-slip based on the wheel speed signals and the GPS signals. The system also includes a wheel-based acceleration processor that estimates vehicle acceleration. The system also includes a differential odometry processor that determines vehicle heading based on wheel speed. The system also includes a GPS reference data validation processor that determines whether the GPS signals are valid using the estimated vehicle acceleration and wheel speeds. The valid GPS signals are then used to calibrate the yaw-rate sensor signals, which can be used for vehicle heading purposes.