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- 2015
- Calibration process of OSL detectors
- Iodine-131
- OSL-BeO
- Dosimetry of staff and patients
- Optically Stimulated Luminescence (OSL)
- Akdeniz University
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[IEEE 2020 IEEE/SICE International Symposium on System Integration (SII) - Honolulu, HI, USA (2020.1.12-2020.1.15)] 2020 IEEE/SICE International Symposium on System Integration (SII) - Calibration of Laser Optics for Sensor Guided Remote Cutting
摘要： In the last several years, laser based material processing has established itself in many industrial branches as an economical manufacturing process. Laser remote cutting in particular is widespread in the automotive sector. In order to take full advantage of laser remote cutting, it is necessary to position the laser beam precisely on the workpiece using a handling kinematic system. Therefore, this work focuses on the combination of standard industrial robots with laser scanner optics. To address this configuration, this paper proposes a method for the calibration of the parameters, which describe the precise position of the 3D laser scanner optics in respect to the robot. Moreover, the robot introduces a new source of deviation, which is then compensated by using an external measuring system to guide the scanner optics during processing.
关键词： thermography,remote laser scanner optics,machining,calibration,automation,digital image processing
更新于2025-09-19 17:13:59
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[IEEE 2019 International Conference on Signal Processing and Communication (ICSC) - NOIDA, India (2019.3.7-2019.3.9)] 2019 International Conference on Signal Processing and Communication (ICSC) - Restoration of the Network for Next Generation (5G) Optical Communication Network
摘要： This paper describes the design, development and testing of an AR system that was developed for aerospace and ground vehicles to meet stringent accuracy and robustness requirements. The system uses an optical see-through HMD, and thus requires extremely low latency, high tracking accuracy and precision alignment and calibration of all subsystems in order to avoid mis-registration and “swim”. The paper focuses on the optical/inertial hybrid tracking system and describes novel solutions to the challenges with the optics, algorithms, synchronization, and alignment with the vehicle and HMD systems. Tracker accuracy is presented with simulation results to predict the registration accuracy. A car test is used to create a through-the-eyepiece video demonstrating well-registered augmentations of the road and nearby structures while driving. Finally, a detailed covariance analysis of AR registration error is derived.
关键词： see through HMD,hybrid tracking,augmented reality,image processing,calibration,registration,Inertial,sensor fusion
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Portland, OR, USA (2019.10.14-2019.10.16)] 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Recent Trends in Space Laser Communications for Small Satellites and Constellations
摘要： An online robot self-calibration method based on an inertial measurement unit (IMU) and a position sensor is presented in this paper. In this method, a position marker and an IMU are required to be rigidly attached to the robot tool to obtain the position of the manipulator from the position sensor and the orientation of the manipulator from the IMU in real time. An efficient approach that incorporates a Kalman filter (KF) and a particle filter to estimate the position and orientation of the manipulator is proposed in this paper. The use of these pose (orientation and position) estimation methods improves the reliability and accuracy of pose measurements. Finally, an extended KF is used to estimate the kinematic parameter errors. The primary advantage of this method over existing automated self-calibration methods is that it does not involve complex steps, such as camera calibration, corner detection, and laser alignment, which makes the proposed robot calibration procedure more autonomous in a dynamic manufacturing environment. Moreover, the reduction of complex steps improves the accuracy of calibration. Experimental studies on a GOOGOL GRB3016 robot show that the proposed method has better accuracy, convenience, and effectiveness.
关键词： particle filter (PF),Extended Kalman filter (EKF),kinematic identification,online robot calibration,Kalman filter (KF)
更新于2025-09-19 17:13:59
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Plasma Diagnostic by Optical Emission Spectroscopy on Dolomite and Cross-Validation Using Scanning Electron Microscopy Coupled with Energy Dispersive X-ray Spectroscopy and Electron Probe Micro-Analysis
摘要： Dolomite [CaMg(CO3)2] is an important carbonate mineral mainly composed of calcium magnesium carbonate. The correct determination of magnesium content in carbonate rocks is important for accessing its suitability for different applications; however, presence of different phases with varying magnesium contents makes their analysis difficult. In the present work, a natural carbonate mineral dolomite is analyzed qualitatively and quantitatively using laser-induced breakdown spectroscopy along with X-ray diffraction, scanning electron microscopy coupled with energy dispersive spectroscopy and electron-probe microanalysis. The optical emission spectra recorded in 200–720 nm wavelength region revealed presence of emission lines for Ca, Mg, Al, Sr, and Na with varying intensities. We used two different techniques, that is, Boltzmann plot and Saha–Boltzmann plot methods to calculate the plasma temperature, and an average value of 4500 ± 450 K was deduced.The Stark broadening line profile method was exploited to calculate the electron number density using calcium and magnesium lines which resulted in 2.39 × 1017 cm–3. The quantitative compositional analysis was carried out using calibration-free laser-induced breakdown spectroscopy method for which the local thermodynamic equilibrium and optically thin plasma conditions were satisfied.The composition for dolomite major constituents calcium and magnesium were estimated as 68.58 and 31.41%, respectively.The results demonstrated the LIBS, EDS, and EPMA ability as an effective, powerful and complementary analytical techniques for the elemental composition analysis of carbonate minerals.
关键词： magnesium,calibration-free laser-induced breakdown spectroscopy,EPMA,plasma diagnostic techniques,dolomite,EDS
更新于2025-09-19 17:13:59
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AIP Conference Proceedings [AIP Publishing 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Fes, Morocco (25–27 March 2019)] 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - GD-OES depth profiling and calibration of B doped dielectric layers
摘要： Doped Si-based glasses such as boron silicate glass have a variety of applications in photovoltaics. A well suited, fast method for analysing the elemental composition of these layers is glow discharge optical emission spectroscopy. In addition to qualitative depth profiling, quantitative analysis is of special interest. This requires a calibration in the relevant concentration range, which cannot be achieved by certified commercial standards and therefore requires laboratory standards. In context of calibration, the influence of the substrate surface on the depth profile is investigated. It is found that calibration is not unambiguously possible with a rough surface. Optical effects can be identified and a layer system consisting of a SiNx:H interface layer is used, which was optimized by simulating reflection on interfaces using the transfer matrix method so that calibration is possible using such laboratory standards.
关键词： depth profiling,GD-OES,photovoltaics,B doped dielectric layers,calibration
更新于2025-09-19 17:13:59
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A calibration method of dual two-dimensional laser range finders for mobile manipulator
摘要： In this article, a method for calibrating the relative position between dual two-dimensional laser range finders is proposed. This relative position is affected by the manufacture or assembling error of mobile platform, and this error could reduce the accuracy of localization. This article focuses on three-degree-of-freedom calibration, that is, one rotational and two translational degrees of freedom. The entire calibration process can be summed up into three steps. The first step is to allow the dual finders to scan one corner at the same time and then extract the parameters of the corner. The second step is to establish a cost function which is established according to the direction vector of the line and the repeatability of the corners. With this function, the genetic algorithm is used to obtain the final calibration result. Moreover, the finder systematic error and the statistical error are also considered into this article. Simulations and experiments are carried out to verify the proposed method.
关键词： 2-D laser range finder,genetic algorithm,Calibration,mobile manipulator
更新于2025-09-19 17:13:59
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[IEEE 2019 FISE-IEEE/CIGRE Conference - Living the energy Transition (FISE/CIGRE) - Medellin, Colombia (2019.12.4-2019.12.6)] 2019 FISE-IEEE/CIGRE Conference - Living the energy Transition (FISE/CIGRE) - Analysis of a photovoltaic solar installation in accordance to performance parameters of IEC61724
摘要： An online robot self-calibration method based on an inertial measurement unit (IMU) and a position sensor is presented in this paper. In this method, a position marker and an IMU are required to be rigidly attached to the robot tool to obtain the position of the manipulator from the position sensor and the orientation of the manipulator from the IMU in real time. An efficient approach that incorporates a Kalman filter (KF) and a particle filter to estimate the position and orientation of the manipulator is proposed in this paper. The use of these pose (orientation and position) estimation methods improves the reliability and accuracy of pose measurements. Finally, an extended KF is used to estimate the kinematic parameter errors. The primary advantage of this method over existing automated self-calibration methods is that it does not involve complex steps, such as camera calibration, corner detection, and laser alignment, which makes the proposed robot calibration procedure more autonomous in a dynamic manufacturing environment. Moreover, the reduction of complex steps improves the accuracy of calibration. Experimental studies on a GOOGOL GRB3016 robot show that the proposed method has better accuracy, convenience, and effectiveness.
关键词： Extended Kalman filter (EKF),particle filter (PF),online robot calibration,Kalman filter (KF),kinematic identification
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Epitaxial GaP grown on Silicon by MEE and MBE Techniques as a Pathway for Dilute Nitride-Si Tandem Solar Cells
摘要： For long-wavelength space-based radars, such as the P-band radar on the recently selected European Space Agency BIOMASS mission, system distortions (crosstalk and channel imbalance), Faraday rotation, and system noise all combine to degrade the measurements. A first-order analysis of these effects on the measurements of the polarimetric scattering matrix is used to derive differentiable expressions for the errors in the polarimetric backscattering coefficients in the presence of Faraday rotation. Both the amplitudes and phases of the distortion terms are shown to be important in determining the errors and their maximum values. Exact simulations confirm the accuracy and predictions of the first-order analysis. Under an assumed power-law relation between σhv and the biomass, the system distortions and noise are converted into biomass estimation errors, and it is shown that the magnitude of the deviation of the channel imbalance from unity must be 4–5 dB less than the crosstalk, or it will dominate the error in the biomass. For uncalibrated data and midrange values of biomass, the crosstalk must be less than ?24 dB if the maximum possible error in the biomass is to be within 20% of its true value. A less stringent condition applies if the amplitudes and phases of the distortion terms are considered random since errors near the maximum possible are very unlikely. For lower values of the biomass, the noise becomes increasingly important because the σhv signal-to-noise ratio is smaller.
关键词： Biomass,Faraday rotation,polarimetric measurements,system distortion,calibration,long-wavelength radar
更新于2025-09-19 17:13:59
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Mixed Centroid Method for Spaceborne Laser Altimeter Calibration
摘要： The on-orbit calibration of spaceborne laser altimeters is based on traditional geometric calibration in which the laser pointing angle error is the primary evaluation index. This study proposes a mixed centroid method for calculating the laser footprint center by using the geometric center of each energy level eliminating the abnormal energy level points, inverting the laser energy level distribution, and correcting the true footprint. Then, the mixed centroid method is compared with the traditional geometric center method and the centroid method. Simulation comparisons demonstrate that the proposed method offers high precision and low calibration cost, thereby improving the calibration accuracy of the target. The proposed method provides a reference algorithm for the ground field calibration of the next generation of high-resolution mapping satellites in China.
关键词： Mixed centroid method,Calibration,Centroid method,Pointing angle error,Geometric center method
更新于2025-09-16 10:30:52
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Flexible method for accurate calibration of large-scale vision metrology system based on virtual 3-D targets and laser tracker
摘要： For the purpose of obtaining high-precision in stereo vision calibration, a large-size precise calibration target, which can cover more than half of the field of view is vital. However, large-scale calibration targets are very difficult to fabricate. Based on the idea of error tracing, a high-precision calibration method for vision system with large field of view by constructing a virtual 3-D calibration target with a laser tracker was proposed in this article. A virtual 3-D calibration target that covers the whole measurement space can be established flexibly and the measurement precision of the vision system can be traceable to the laser tracker. First, virtual 3-D targets by calculating rigid body transformation with unit quaternion method were constructed. Then, the high-order distortion camera model was taken into consideration. Besides, the calibration parameters were solved with Levenberg–Marquardt optimization algorithm. In the experiment, a binocular stereo vision system with the field of view of 4 (cid:2) 3 (cid:2) 2 m3 was built for verifying the validity and precision of the proposed calibration method. It is measured that the accuracy with the proposed method can be greatly improved comparing with traditional plane calibration method. The method can be widely used in industrial applications, such as in the field of calibrating large-scale vision-based coordinate metrology, and six-degrees of freedom pose tracking system for dimensional measurement of workpiece, as well as robotics geometrical accuracy detection and compensation.
关键词： error tracing,virtual 3-D target,Large-scale vision metrology system,laser tracker,calibration
更新于2025-09-16 10:30:52