684 results about "Field calibration" patented technology

The invention discloses a camera on-field calibration method in a measuring system, belonging to the field of computer vision detection, in particular to an on-field calibration method for solving inside and outside parameters of cameras in a large forgeable piece size measuring system. Two cameras and one projector are provided in the measuring system. The calibration method comprises the following steps of: manufacturing inside and outside parameter calibration targets of the cameras; projecting inside parameter targets and shooting images; extracting image characteristic points of the images through an image processing algorithm in Matlab; writing out an equation to solve the inside parameters of the cameras; processing the images shot simultaneously by the left camera and the right camera; and measuring the actual distance of the circle center of the target by using a left theodolite and a right theodolite, solving a scale factor and further solving the actual outside parameters. The invention has stronger on-field adaptability, overcomes the influence of impermeable and illegible images caused by the condition that a filter plate filters infrared light in a large forgeable piece binocular vision measuring system by adopting the projector to project the targets, and is suitable for occasions with large scene and complex background.

The automatic calibration of a sensor panel is disclosed by varying the amplitude of an input stimulus Vstim to simulate a full-touch condition and calibrating each pixel of the sensor panel in accordance with the difference between the simulated full-touch condition and a baseline full-touch condition. To accomplish this, a baseline full scale output FS_targ_cal can be measured at during pre-delivery calibration for each pixel using a test fixture capable of applying a no-touch to full-touch condition given a nominal Vstim. A full-touch condition can then be emulated for each pixel by lowering Vstim until the current full scale output FS_targ_current equals FS_targ_cal, and determining the Vstim value Vstim_cal at that point. During field calibration, Vstim_cal can be applied to each pixel to simulate a full-touch condition, and FS_targ_current can be obtained and compared against FS_targ_cal. Each analog channel can then be tuned so that in subsequent full-touch conditions, FS_targ_current will approximately equal FS_targ_cal.

This invention is device and method for electronic measurements of the force and torque applied to a work piece. The measured values are visually displayed, audibly indicated, and / or transferred in electronic formats to other controlling devices. The values could be displayed in different physical measuring units, and as an average or peak. The device produces different output signals when the torque applied equals or exceeds predetermined values. This device and method provide an automatic, accurate, and easy calibration, which could be self-calibration or in-the-field calibration. It has protection from accidental activation of the switches, and provides a permanent record of the incidents in which the device was operated at conditions beyond its specifications. It provides a manual and / or automatic scale selection to improve the accuracy.

An encoder calculates position error values and applies compensation values to encoder position measurements in-situ. The encoder includes a scale and a multi-section detector for detecting a spatially periodic pattern, such as an optical interference pattern, produced by the scale. The detector includes spatially separated first and second sections. A signal processor estimates respective phase values from detector sections and calculates a phase difference reflecting a spatial position error in the scale. A compensation value is calculated from the phase difference and included in the estimate of the scale position to compensate for this spatial position error. The compensation values may be calculated and used on the fly, or calculated and saved during an in-situ calibration operation and then utilized during normal operation to compensate uncorrected measurements.

The present invention is in-situ visual measurement system calibrating equipment and process. The calibrating equipment is 3D coordinate measuring system and stereo target, and the stereo target set inside the work range of the 3D coordinate measuring system consists of base plate as well as sensor calibrating target and system measured target, which are standard balls, set on two sides of the base plate. The 3D coordinate measuring system may be an industrial theodolite measurement system or a laser tracking instrument. The calibrating process includes calibrating the stereo target in the coordinate measuring system, acquiring the image of the sensor calibrating target, obtaining the conversion relation between the system measured target and the sensor calibrating target via coordination conversion, and other steps. The present invention can realize the in-situ measurement element calibration and overall system calibration.

The invention relates to a method for the determination of the concentration of a non-volatile analyte in an aqueous sample medium, with the use of an optical sensor which contains a luminescent dye and is calibrated at the user site by means of a single-point-calibration. To enable the user to completely dispense with all calibration media a luminescence measurement value is obtained at the user site with the sensor in contact with the aqueous or bloodlike sample medium, which value is referenced to the relative characteristic obtained at the factory site and to a measured dry calibration value obtained at the user site, the concentration of the non-volatile analyte being deduced from these data.

The invention discloses a vehicle type accurate classification system and method based on real-time double-line video stream. The system comprises a vehicle body scanning camera, a high-definition capturing camera and a video vehicle detector. The method comprises the steps that the vehicle body scanning camera and the high-definition capturing camera carry out double-line video collecting on vehicles; after vision field calibration, one-to-one-corresponding logic relation of virtual pixel spaces and real physical spaces is established; the vehicles in a vision field are subjected to target separating; and accurate vehicle physical data are given, model rebuilding and three-dimensional measuring are carried out, and vehicle types are finally judged. The system and method have the advantages that two-line high-definition video stream of the vehicle body scanning camera and the high-definition capturing camera, the embedded double-channel video vehicle type detector and a three-dimensional vision vehicle body model rebuilding and fitting mode are used, various parameters of the vehicles can be provided at the same time, and the vehicles are accurately classified.

An apparatus and method for calibrating machine vision measuring systems that have more than one camera are disclosed. A first calibration target is mounted in a fixed relationship to a first camera of the machine vision measuring system. A third camera mounted in a fixed relationship to a second camera of the machine vision measuring system. Second and third calibration targets are mounted in a fixed relationship to one another and viewable by the first camera and by the third camera. A data processor is programmed to compute calibration of the first camera and the second camera, based on a position of the second calibration target relative to the third calibration target and based on a position of the first camera with respect to the third camera. The apparatus and method provide a way to continuously measure the positions of two or more cameras used in the measuring system, and to use such measurements to calibrate the system. If the cameras move with respect to each other, their respective positions are calculated and used in subsequent measurements. The apparatus and method enable a machine vision measuring system to be used without field calibration at the time of installation.

The invention discloses a large-scale MIMO (Multiple Input Multiple Output) antenna array far field calibration system. The calibration accuracy of a wave beam direction error caused by an array element position error and an amplitude phase error in an antenna array under test can be effectively increased by the calibration system. The calibration system is implemented by the following technical scheme: a server control device controls the relative position between the antenna array under test and a beacon antenna, and changes a wave beam incident angle from a transmitting beacon antenna to areceiving antenna array under test or a wave beam departure angle from a transmitting antenna array under test to a receiving beacon antenna; a phased array wave control device controls all phase shifters, attenuators, switches and digital weighting of a feed network of the antenna array under test; a data transmitting and acquiring device controls digital signals transmitted by the transmitting antenna array under test and the transmitting beacon antenna, and acquires digital signals received by the receiving antenna array under test and the receiving beacon antenna; and the array element positioning error and the amplitude phase error of the antenna array under test are calculated on the basis of a digital domain signal processing algorithm, and a calibration result of the antenna arrayunder test is output.

This invention provides an easy-to-manufacture, easy-to-analyze calibration object which combines measurable and repeatable, but not necessarily accurate, 3D features—such as a two-sided calibration object / target in (e.g.) the form of a frustum, with a pair of accurate and measurable features, more particularly parallel faces separated by a precise specified thickness, so as to provide for simple field calibration of opposite-facing DS sensors. Illustratively, a composite calibration object can be constructed, which includes the two-sided frustum that has been sandblasted and anodized (to provide measurable, repeatable features), with a flange whose above / below parallel surfaces have been ground to a precise specified thickness. The 3D corner positions of the two-sided frustum are used to calibrate the two sensors in X and Y, but cannot establish absolute Z without accurate information about the thickness of the two-sided frustum; the flange provides the absolute Z information.

The invention provides a simple and flexible field calibration and precision measurement method for a spot laser measuring system by analyzing the camera imaging principle, establishing a camera imaging model and introducing the concepts of two structural parameters, namely a basic line distance and a reference angle aiming at the defects of extreme calibration conditions and complicated calibration steps of the traditional spot laser-camera measuring system. In the method, only two standard planar heights H1 and H2 are needed to precisely complete the calibration task of the system structure, and the spot laser-camera measuring system of the algorithm has higher measuring precision so as to meet the requirement of precision measurement. The algorithm makes the spot laser-camera structure adjustable and field calibration of system structural parameters possible; and the flexibility of a laser ranging system is greatly improved and the method has important significance for actual vision measurement.

A system and software for controlling output devices used in association with machinery is disclosed. The system includes a control module which may be connected to a personal digital assistant (PDA), personal pocket PC, personal computer, organizer, cell phone, or other data storage device. The data storage device has programmed within it particularized manufacturer information for various input devices and output devices available on the market. The system allows an operator to select a particular manufacturer, as well as product information, including product model number and operating parameters. The machine can then be calibrated such that the input device being used, as well as the output device manufacturer information, is used to dynamically adjust, monitor or perform diagnostics on the machine. The system allows for on-site calibration of the machine controllers. The invention contemplates the use of any output device used with the operation of the machine or any input device used to input information or operation instructions to the machine. The software may be programmed into any personal electronic device or may be connected to a driver or controller associated with the machine to be regulated.

The invention discloses a calibration method of a line-structured light vision measuring sensor based on the space plane restriction, comprising the following calibrating steps: placing a two-dimensional planar target in a camera field range; collecting a group of images of multiple characteristic circles at the different positions on a two-dimensional target panel; determining the target topological relation; and synchronously completing the internal parameter calibration and the light planar calibration of a camera. In the process of the light planar calibration, substantial quantity of line-structured light planar three-dimensional points can be easily extracted by utilizing a camera imaging model and the restraining provided by the space plane formed by each position target; and planar fitting is carried out on the three-dimensional point set based on a principal element analytical method, so as to obtain an equation of the light plane in the coordinate system. The calibration method of the invention has simple operation and reliable result, is suitable for field calibration, and can satisfy the requirements of the line-structured light vision high-precision detecting tasks.

Disclosed is a calibration method for parameters of a double monocular white light three-dimensional measurement system, which belongs to the field of optical measurement and mechanical engineering. The method adopts a plane calibration board as a known calibration object positioned in the measuring range of the system, and obtains the corresponding projection pixel point of a calibration spot in a left camera and the absolute phase value through processing a structured light fringe image on the calibration board projected by a left slide projector and taken by the left camera, and the corresponding projection pixel point of a calibration spot in a right camera and the absolute phase value through processing the structured light fringe image on the calibration board projected by a right slide projector and taken by the right camera. The method goes on linear calibration to a left and a right single measuring head according to the basic data calibrated by the system to obtain as much initial value of parameters of the measurement system as possible and overall nonlinear optimized calibration to the measurement system based on the linear calibration to obtain the optimized value of all the parameters of the measurement system, thereby realizing the precise calibration of parameters of the double monocular white light three-dimensional measurement system.

The invention relates to a phased array amplitude-phase error near-field calibration method based on one-dimensional rotation, and the method comprises the steps: S1, building a phased array amplitude-phase error testing system, enabling a phased array antenna to be fixed at an initial rotating angle, and measuring the initial position of a calibration source and the initial position of a reference array element; S2, measuring the receiving channel amplitude information and phase measurement information of the phased array antenna; S3, measuring the transmitting channel amplitude information and phase measurement information of the phased array antenna; S4, judging whether the measurement of all preset rotating angles is carried out or not: executing step S5 if the measurement of all preset rotating angles is carried out, or else enabling the phased array antenna to be rotated to another preset rotating angle, and executing step S2 and step 3; S5, calculating the calibration value of a phased array amplitude-phase error; S6, calculating the initial position of the calibration resource and the initial position of the reference array element through an optimization principle; S7, calculating the calibration value of the phased array amplitude-phase error. The method just needs to meet the far-field condition of a single antenna unit in the phased array antenna, is simple in calibration, is high in operability, is higher in measurement precision, and is easy in engineering realization.

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.

A LAN tester has display and remote units each having a connector jack attached to an adapter board for connection to the plug of a patch cord. Both the display and remote units have circuits which are capable of measuring the phase between a drive signal voltage and the corresponding coupled or reflected signal due to the drive signal. Scattering parameters for the mated connector pairs and the patch cord itself are measured during a field calibration. A computer in one or both of the tester units stores the measured scattering parameters and uses the scattering parameters to move the reference plane to any desired location along the patch cord. Channel link or permanent link tests can be conducted using the same equipment.

The invention belongs to the technical field of measurement, and relates to an improvement to a calibration method of structured light parameters in 3D vision measurement of structured light. The invention provides a calibration method of the structured light parameters based on a one-dimensional target. After a sensor is arranged, a camera of the sensor takes a plurality of images of the one-dimensional target in free non-parallel motion; a vanishing point of a characteristic line on the target is obtained by one-dimensional projective transformation, and a direction vector of the characteristic line under a camera coordinate system is determined by the one-dimensional projective transformation and a camera projection center; camera ordinates of a reference point on the characteristic line is computed according to the length constraint among characteristic points and the direction constraint of the characteristic line to obtain an equation of the characteristic line under the camera coordinate system; the camera ordinates of a control point on a plurality of non-colinear optical strips are obtained by the projective transformation and the equation of the characteristic line, and then the control point is fitted to obtain parameters of the structured light. In the method, high-cost auxiliary adjustment equipment is unnecessary; the method has high calibration precision and simple process, and can meet the field calibration need for the 3D vision measurement of the large-sized structured light.

A calibration system for a flow meter includes a flow simulator, the flow simulator including a receiver configured to receive flow meter transducer signals from a flow meter. A simulation subsystem is configured to create simulated transit time signal pulses, and to transmit the simulated transit time signal pulses to the flow meter at preselected time intervals. A calibration subsystem is configured to receive from the flow meter a transit time differential value generated by the flow meter based on the simulated transit time signal pulses and output a calibration factor to the flow meter.

A calibration system for a flow meter includes a flow simulator, the flow simulator including a receiver configured to receive flow meter transducer signals from a flow meter. A simulation subsystem is configured to create simulated transit time signal pulses, and to transmit the simulated transit time signal pulses to the flow meter at preselected time intervals. A calibration subsystem is configured to receive from the flow meter a transit time differential value generated by the flow meter based on the simulated transit time signal pulses and output a calibration factor to the flow meter.

The invention belongs to field of measuring technique and relates to a calibration method and improvement for binocular vision sensor of stereopsis three-dimensional measurement. In the invention, a calibration method of binocular vision sensor based on uncertain moving one-dimensional target is provided. When the sensor is installed completely, two cameras shoot images of moving one-dimensional target, use the image coordinates of characteristic points in the target and the distance between two characteristic points; adopt non-linear optimization technique to estimate the structural parameters of binocular vision sensor. The present method doesn't need expensive ancillary adjusting equipments, high calibration accuracy, simple course, high efficiency, could satisfy requirements for site calibration for binocular vision sensor structural parameters of large dimension.

Calibration systems and methods simultaneously calibrate a magnetic compass and gyroscopes. An exemplary embodiment rotates the field calibration system. Based upon the rotation sensed by the magnetic compass and the gyroscopes, the field calibration system determines compensation for both the magnetic compass and the gyroscopes.

A portable harmonics measurement instrument performs in-situ self-calibration of its current transducers and their associated measurement channels and of its voltage probes and their associated measurement channels. In-situ self-calibration is performed immediately before making a measurement on the alternating current power distribution grid. In-situ self-calibration is performed by means of a built-in voltage reference source and a built-in current reference source, which generate highly-accurate voltage and current calibration waveforms with harmonic components.

This invention disclosed a calibration technique for three-dimensional measure system. It can calibrate all the systematic model parameters in bi-sensor laser vision by using two-dimension plane drone, including the inner parameters of camera, camera coordinate system, etc. The advantages are as follows: no need for costly assistant equipment; high calibration precision; the process is brief and efficiency is high.

The invention discloses a method for judging false wiring of a three-phase three-wire electric energy meter. The method is characterized in that the method comprises the following steps that (1) parameters of a first component and parameters of a second component in the three-phase two-component electric energy meter are obtained; (2) a voltage vector mother board hexagon vector diagram of a three-phase three-wire metering device is drawn; (3) a two-phase current vector diagram of the three-phase three-wire metering device is drawn; (4) a four-wire vector diagram is drawn; (5) the four-wire vector diagram is compared with the voltage vector mother board hexagonal vector diagram and the two-phase current vector diagram in order to obtain correct wiring judgment. According to the method, false wiring of the three-phase three-wire electric energy meter can be quickly judged so that a judgment result can be provided. Meanwhile, field workers can use the method to conduct manual, quick and effective wiring interpretation. The method can be widely applied to algorithms for judging false wiring of field calibration instruments of electric energy metering devices.

The invention provides a near-field calibration method for relative amplitude and phase characteristics of spherical surface array antenna channels, and aims to provide a method with few calibration source and capable of automatically performing self-correction on the relative amplitude and phase characteristics. The near-field calibration method is characterized in that: calibration frames distributed around a spherical surface antenna array plane are set up on the periphery of a phased-array antenna and a calibration frame is set up at the center of the phased-array antenna, thus a conformalspherical surface array distribution model for antenna unit approximate uniform distribution is formed; optical equipment is used for performing high-precision measurement on a coordinate position ofeach calibration antenna relative to a central point of the spherical surface array antenna, and a spatial distance and an axial included angle between each array element on the spherical surface array antenna and each calibration antenna are calculated; and a calibration reference signal generated by calibration test equipment is used for calibrating uplink / downlink channels of the spherical surface array antenna, and amplitude / phase characteristics of element antenna channels are obtained through deducting relative amplitude and phase characteristics of the antenna and amplitude / phase changes introduced by the spatial distances and axial deflection between each calibration antenna and each array element.