Integrated Calibration Method Research Articles

Towards the assessment of exposure to bisphenols in everyday items with increased accuracy by the use of integrated calibration method (ICM)-based methodology

The most crucial purpose of the measurement is to obtain a reliable result that reflects the actual qualitative and/or quantitative features of the tested material. The overriding goal of analytical chemistry is to obtain accurate results after compensating of various interference effects as well as non-linear calibration dependence. A new approach based on an integrated calibration method (ICM) supported by H-point standard addition method (HPSAM) has been used to improve the quality of analytical results. The proposed methodological approach was extended using the step-by-step dilution procedure, and five measurement conditions were used to eliminate multiplicative, additive, and non-linear interferences. On this basis, a set of estimations is obtained to improve the quality of the analytical results. The analytical usefulness of the proposed approach was tested on the example of the determination of three compounds from the group of bisphenols (BPs) using the chromatographic technique - HPLC-DAD (high-performance liquid chromatography with diode array detection). Compared to the reference method - fluorescence spectroscopy - the obtained results were characterized by excellent accuracy (RE=3 % in most cases). The developed methodology allowed to carry out a risk assessment on BPA, BPF, and BPS present in samples of shop receipts and canned food. Store clerks have been shown to be particularly vulnerable to PBF and BPS in receipts due to skin permeation (exposure factors were equal to 308.97 µg/g for BPF and 181.89 µg/g for BPS). Consumers should also pay close attention to the BPA found in canned food samples (the average concentration was equal to 20.61 µg/mL, and the tolerable daily intake was exceeded over 165.000 times). The analytical method and the methodological approach were evaluated using the RGB model and the AGREE approach - it was shown that the method can be successfully used for other analytical purposes (the method is White) and is environmentally friendly (Significance=0.63).

An Integrated Kinematic Calibration and Dynamic Identification Method With Only Static Measurements for Serial Robot

In this article, we propose an integrated calibration and identification method that can identify kinematic and dynamic parameters at the same time. Only a series of static experiments are required in this method, which can significantly simplify the experimental operation and improve the accuracy of identification. A novel calibration model based on axis configuration space and adjoint error model considering joint compliance with only position measurements is developed and both joint compliance and joint zero-offset errors are included in the proposed model. Identifiability analysis shows which joint compliance can be identified and the relationships between the identifiability of joint compliance and the number of measurement points. A recursive algorithm considering physical consistency is newly derived to obtain the derivatives of estimated inertial matrix and gravity vector with respect to joint twists. In this way, the coupling between kinematic and dynamic model is solved and the optimal kinematic and dynamic parameters can be derived using gradient-based optimizer. Comparative study with experiments are reported to show the effectiveness of our algorithm.

An integrated calibration method for the cross-shaped magnetic gradiometer

An integrated calibration method for the cross-shaped magnetic gradiometer

Investigation of the origin and concentration of polycyclic aromatic hydrocarbon with improved accuracy by the use of a multi-component integrated calibration method in the Katowice region, Poland

The basic variant of the integrated calibration method (ICM), based on a combination of external calibration (EC) and standard addition method (SAM), was applied to multi-component (MC) analysis to obtain a new methodological approach to improve the quality of analytical results. The analytical performance of the proposed method was evaluated on indicated by EPA polycyclic aromatic hydrocarbons (PAHs) determination in various environmental samples (air, house dust, tap water, river water, river sediment, and snow) from the Katowice region (Poland). HPLC-FLD was used during all analyses. The main aim was to show the origin of PAHs in different places in the urban and industrialized region of Poland. MC-ICM allowed for the elimination of interference from the coelution of other substances. Several diagnostic coefficients were calculated for the results free from systematic errors and interferences. The obtained results were consistent with the chemometric analysis (PCA). The method was assessed regarding analytical usefulness using the RGB model (the color method is White) and environmental friendliness using the AGREE approach.

A High-Precision Integrated Calibration Method for Position and Attitude of Visual-Inertial System

A High-Precision Integrated Calibration Method for Position and Attitude of Visual-Inertial System

Integrated Calibration of Strap-Down Geomagnetic Vector Measurement System

Strap-down geomagnetic vector measurement system usually consists of three-axis magnetometer and inertial units, which is an effective device for measuring geomagnetic vector. However, its measurement accuracy is limited by disturbance of ferromagnetic material, measurement error of magnetometer and error caused by misalignment. Therefore, an integrated calibration method for strap-down geomagnetic vector measurement system is proposed. Firstly, the integrated error model is established, and a system with linear equations constraint is constructed by the measurements of inertial units, three-axis magnetometer and proton magnetometer; secondly, calibration parameters can be estimated by two-step least squares estimation (LSE); finally, geomagnetic vector measurement can be calibrated with these parameters in real time. Simulation results show that the relative errors between estimation and true parameters are less than 3%. Experimental results demonstrate that the errors of strap-down geomagnetic vector measurement system are suppressed effectively after integrated calibration, where North, Vertical and East component measurement errors are reduced from 809.2 nT, 300.0 nT, 776.8 nT to 14.8 nT (1.83% of uncalibrated value), 11.9 nT (3.97%), 32.5 nT (4.18%) respectively, and measurement accuracy of declination and inclination are achieved to 0.1°. Furthermore, the calibration error and time are least compared with traditional methods.

Monitoring of PAHs in simulated natural and artificial fires by HPLC-DAD-FLD with the application of Multi-Component Integrated calibration method to improve quality of analytical results

Modifications of integrated calibration method (ICM) in its basic variant and complementary dilution method version (CDM) were adapted to multi-component (MC) analysis to obtain novel calibration approaches improving the accuracy of analytical results. Methods were developed conceptually and their performance was assessed on the basis of polycyclic aromatic hydrocarbons (PAHs) determination in air samples. The natural (thuja needles) and synthetic (polymer) materials were combusted simulating fires or home users’ combustion. Analytical method for determination EPA PAHs was developed using HPLC-DAD-FLD. It has been confirmed that the improved analytical results accuracy obtained in MC-ICM and MC-ICM/CDM was described by relative error < 1.5%. Multiplicative effects due to the coelution of other substances were detected by comparing the individual estimations of the analytical results. The results free from this effect were determined. According to RGB Additive Color Model, the proposed approach is White – method is a good candidate of choice for all applications.

Internal Parameters Calibration of Vision Sensor and Application of High Precision Integrated Detection in Intelligent Welding Based on Plane Fitting.

Vision sensing is a key technology to realize on-line detection of welding groove sizes and welding torch relative position and posture parameters during the arc welding process of intelligent production. For the specially designed vision sensor based on combined laser structured lights, an integrated calibration method for its internal parameters is proposed firstly, which improves the efficiency, accuracy and comprehensiveness of internal parameter calibration for a line structured light vision sensor and provides a good foundation for industrial application of the vision sensor. Then, the high precision integrated detection algorithms are derived for the V-groove size parameters and the spatial position and posture (SPP) parameters of the welding torch relative to the welding groove based on a single modulated laser lines image. The algorithms make full use of the data in a single modulated laser lines image, adopting data segmentation and plane fitting to realize the 3D reconstruction of V-groove surfaces and its adjacent workpiece surfaces of planar workpiece, so solving the parameters with high precision. In the verification tests, the relative detection error of V-groove size parameters of planar workpiece is less than 1%, and the relative detection error of SPP parameters of welding torch relative to the welding groove is less than 5%, which separately shows the effectiveness and accuracy of the calibration method and the detection algorithms. This research work provides a good technical support for the practical application of the specially designed vision sensor in the intelligent welding production.

Improvement of analytical results quality in neuroscience – Good Methodology Practice in the acetylcholine determination

A new point of view on ensuring the best quality of analytical results has been presented. We proposed the strategy called Good Methodology Practice leading to the improvement of the quality of analytical results and assessment of interference effects. Four calibration methods: External Calibration, Standard Addition Method, Integrated Calibration Method in the version of Complementary Dilution Method and basic variant of Integrated Calibration Method were tested in terms of acetylcholine determination. Acetylcholine is an important neurotransmitter that plays a crucial role i.e. in memory and movement. The determination of acetylcholine in mice brain was carried out with the use of microdialysis in freely moving animals followed by high-performance liquid chromatograph with electrochemical detection. The comparison of obtained results calculated in various ways allowed an effective assessment and compensation of systematic errors as well as the improvement of the accuracy of analytical results. The most suitable method was chosen.

An Integrated Calibration Method of the Inertial Group on the Missile without Opening Box

An Integrated Calibration Method of the Inertial Group on the Missile without Opening Box

PSD Integrated Calibration Method Based on Annunciator in Vacuum Environment

In this paper, an integrated calibration method for position sensitive detector (PSD) of moving support mechanism in vacuum plasma environment is proposed. That is, the PSD is used to track the laser spot to restore the coordinate information of the signal. Firstly, a PSD integrated calibration principle is proposed to reduce the position error of the signaler by tracking laser points with PSD. Then on this basis, due to the spatial declination angle in the PSD imaging model, a spatial declination correction model was established to compensate the spatial declination error. Finally, there are errors occurred in the measurement because of the nonlinearity of PSD, and the improved backpropagation (BP) neural network calibration algorithm is adopted to further correct the errors through the Fletcher–Reeves linear search method to obtain the accurate coordinate information of the annunciator. MATLAB is used to verify the convergence of the calibration algorithm error. Simulation results show that 951 epochs need to be trained by using the traditional BP algorithm to make the position error converge to 0.001 mm. But when using the improved BP algorithm, only 44 epochs are needed.

Bioanalytical methodology for determination of glutamate and aspartate for use in pharmacological sciences with application of Integrated Calibration Method

A new calibration approach based on the adaptation of Integrated Calibration Method (ICM) to consecutive two components analysis in separation science is presented. Consecutive ICM method (C-ICM) was conceptually developed and applied to determination of two excitatory amino acids – glutamate and aspartate in cerebrospinal fluids collected by the use of brain microdialysis from freely-moving animals. Both analytes as a neurotransmitters play an important role in formation of the memory trace, and thus the processes of learning and memory. Due to their low concentration and presence of interferences, considered analytical system – animal brain – was a big challenge. High-performance liquid chromatography (HPLC) with electrochemical detection (ECD) was used in all experimental work. The most important feature of proposed method is integration of interpolative and extrapolative ways to calculate analyte concentration in single calibration procedure, which consequently leads to obtain series of six estimations of analytical result. Comparison of individual estimations with each other allows for a more in-depth analysis of systematic errors. It was proved that C-ICM approach enables diagnosis and compensation of systematic errors induced by occurrence of interference effects and improvement of accuracy of analytical results. Most of all, it was demonstrated that application of this method is efficient and useful analytical tool in analysis of complicated biological samples in pharmacology and neuroscience.

Calibration of Imaging Sensor and Fiber Optic Taper-Caused Distortion in an X-Ray Intensified CMOS Camera

An integrated calibration method of the imaging sensor and the fiber optic taper-caused distortion in an intensified Complementary Metal-Oxide-Semiconductor (CMOS) camera for the X-ray capture application is proposed. Generally, four kinds of distortions need to be corrected in this system: the column noise, the inconsistent pixel intensity response of whole frame, the nonlinear intensity response of each pixel, and the geometry distortion of whole frame. To conquer these problems, first, the column noise is estimated and subtracted from the captured image. The multiple measurement data processing method and the strip noise estimation technique are used. Second, a kind of two-step correction technique of the pixel intensity response is proposed to solve middle two distortion problems. The first step builds the ideal intensity response line for all pixels in image; and the second step estimates and compensates the correction error for each pixel by a polynomial function. Third a polynomial fitting method is also utilized to correct the geometry distortion. The RANdom SAmple Consensus (RANSC) computation mechanism is used to improve the calibration precision further. The optic indices of fiber optic taper and camera are considered to assist the selection of key parameters of these calibration method above. Many experiment results have proved the correctness and effectiveness of proposed method.

Integrated spectral phase delay calibration technique for a liquid crystal variable retarder used in wide-bandwidth working channel

Laser sources with limited wavelengths are commonly used to calibrate the phase delays of liquid crystal variable retarders (LCVRs). However, the parameters describing the phase delays obtained in this manner in certain bands do not match the parameters in the wide-bandwidth working channel employed in polarized imaging detection systems based on LCVRs, which results in deviations in the detection precision. In this paper, we propose an integrated calibration method based on both a multi-band light source and a laser source. The method uses the calibration data obtained by the laser source to correct the calibration data obtained by the light source. The parameters of the phase delays in various spectral channels can be used to precisely measure the LCVR phase delays in the bands of the light source. We conducted experiments to obtain and compare the measured and fitted results for a light source in the 568 nm band. Then, the parameters were used in the instrument matrix calibration of our LCVR based polarized imaging system. The results show that the detection precision of the polarization degree improved more than 0.3% for linear polarized incident light, and more than 0.6% for elliptically polarized light, when our calibration method was applied. These improvements will prove useful in polarizer research, and to improve polarized imaging systems based on LCVRs.

New Calibration Model: Combining Integrated Calibration Method and H-point Standard Addition Method to Detect and Avoid Interference Effects

ABSTRACTA new calibration methodology based on the combination of integrated calibration method (ICM) and the H-point standard addition method (HPSAM) is presented. It allows the diagnosis and correction of errors caused in an analytical system by different kinds of interference effects. Six calibration solutions consisting of mixtures of sample, diluent, and one standard are prepared in accordance with the ICM principle to integrate the external calibration method with the standard addition method and thereby to detect and eliminate proportional interferences. Absorbance increments chosen according to the HPSAM principle are proposed to correct the errors caused by additive interferences. A set of as many as six apparent estimations of analyte concentration in a single calibration procedure is calculated for validating accuracy. As a consequence, doing calibration by the ICM-HPSAM method, it is possible to obtain the final analytical results with considerably improved accuracy. The determination of calcium in several different water samples (containing amounts between 4.9 and 127 mg L−1) with Arsenazo III has been chosen as an example because it is biased if the errors are not diagnosed and corrected. The results are characterized by small (not higher than 8%) relative error (RE), and good precision (RSD values smaller than 6%).

Integrated calibration of a 3D attitude sensor in large-scale metrology

A novel calibration method is presented for a multi-sensor fusion system in large-scale metrology, which improves the calibration efficiency and reliability. The attitude sensor is composed of a pinhole prism, a converging lens, an area-array camera and a biaxial inclinometer. A mathematical model is established to determine its 3D attitude relative to a cooperative total station by using two vector observations from the imaging system and the inclinometer. There are two areas of unknown parameters in the measurement model that should be calibrated: the intrinsic parameters of the imaging model, and the transformation matrix between the camera and the inclinometer. An integrated calibration method using a three-axis rotary table and a total station is proposed. A single mounting position of the attitude sensor on the rotary table is sufficient to solve for all parameters of the measurement model. A correction technique for the reference laser beam of the total station is also presented to remove the need for accurate positioning of the sensor on the rotary table. Experimental verification has proved the practicality and accuracy of this calibration method. Results show that the mean deviations of attitude angles using the proposed method are less than 0.01°.

An active UHF RFID localization system for fawn saving

Abstract. We present a localization concept for active UHF RFID transponders which enables mowing machine drivers to detect and localize marked fawns. The whole system design and experimental results with transponders located near the ground in random orientations in a meadow area are shown. The communication flow between reader and transponders is realized as a dynamic master-slave concept. Multiple marked fawns will be localized by processing detected transponders sequentially. With an eight-channel-receiver with integrated calibration method one can estimate the direction-of-arrival by measuring the phases of the transponder signals up to a range of 50 m in all directions. For further troubleshooting array manifolds have been measured. An additional hand-held receiver with a two-channel receiver allows a guided approaching search without endangering the fawn by the mowing machine.

Novel multicommuted flow manifold dedicated to the integrated calibration method

Integrated calibration method (ICM) is one of the novel approaches in the field of analytical calibration. ICM enables several (e.g., six) estimates of an analytical result to be obtained in a single calibration procedure.

Integrated Calibration Method for Dithered RLG POS Using a Hybrid Analytic/Kalman Filter Approach

For improving the calibration precision of ring laser gyroscope (RLG) inertial measurement unit (IMU) with antivibration system, a novel integrated calibration method using a hybrid analytic/Kalman filter approach was proposed. An optimization analytic calibration method with four-direction rotations, based on three-axis turn table, was designed to coarsely calculate all the coefficients of RLG IMU mathematical error model. For further amending the remains of analytic calibration caused by an antivibration system disturbance and gyroscope drifts, a fine calibration method based on extended Kalman filter was proposed. It regarded the velocity errors as observation using a lever arm compensation technique. The experimental results show that the proposed integrated calibration method can improve the efficiency and precision of RLG position and orientation system which had been practically applied in airborne survey/mapping system.

Novel integrated system calibration method for impulse ground penetrating radar

Abstract This paper proposes a new method of integrated system calibration that uses the transmitting and receiving signals from the impulse ground penetrating radar itself. In order to eliminate the influence from each subsystem or part including antenna, transmitter, receiver, signal processing circuits and transmission cables, two new calibration parameters that are different from the conventional S-parameters are introduced. The characteristic and influence of all parts in the transmitting and receiving channels are incorporated into the calibration equation through the new parameters. The calibration results of the radar detection data show that the new integrated system calibration can improve the quality of the data greatly in many aspects. It removes direct coupled waves, suppresses wave distortion and tail oscillation, and improves the quality of waveform and signal-clutter-ratios. It also compresses the pulse width and enhances resolution.