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IEEE International Symposium on Circuits and Systems (ISCAS)

作者： Yang, Yihao Lyu, Yanjin Hu, Yuanqi Beihang Univ Sch Integrated Circuit Sci & Engn Beijing Peoples R China

ISBN: (纸本)9781665484855

The inevitable capacitor mismatch due to the process variation is one of the major bottlenecks in high-resolution ADC (Analogue to Digital Converter) design. In this work we propose a new compensation strategy which adopts the DEM (Dynamic Element Matching) technique to conventional cyclic ADCs with minimum hardware cost. Theoretical analysis has been done first, and to the best of authors' knowledge, it is the first time that the relation of the capacitor mismatch, output deviation and THD (Total Harmonic Distortion) has been mathematically established. Consequently, the statistical distribution of expected THD under certain mismatch can be derived. Based on that we further analyse the effect of DEM in frequency domain, which effectively performs a harmonic shaping function to the original output spectrum. Simulation results show that the DEM compensation strategy can effectively boost the worst SINAD (Signal to Noise and Distortion Ratio) figure from 68.8 dB to 89.5 dB (99.7% yield) under 0.1% capacitor mismatch and 32x oversampling ratio scenario.

关键词： ADC calibration DEM mismatch compensation calibration algorithm

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Compact chromatic confocal sensor for displacement and thickness measurements

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MEASUREMENT SCIENCE AND TECHNOLOGY 2023年第5期34卷 055104-055104页

作者： Liu, Chunmin Lu, Guoyi Liu, Chunyang Li, Dong Shenzhen Univ Key Lab Optoelect Devices & Syst Minist Educ & Guangdong Prov Shenzhen 518060 Peoples R China Shenzhen Univ Coll Phys & Optoelect Engn Shenzhen 518060 Peoples R China Shenzhen Tensun Precis Equipment Co Ltd Shenzhen 518109 Peoples R China

Chromatic confocal sensors are widely used in various precision measurement fields because of their high measurement accuracy, fast response speed, and good stability. Unlike traditional fiber-coupled structures, we propose an integrated compact chromatic confocal sensing system that can overcome the device-integrating constraints met in industrial environments. Aiming at the distortion of the peak waveform caused by the inconsistent spectral response of the system and to accurately extract the peak wavelength, a spectral characteristic compensation algorithm and a peak wavelength extraction method based on Gaussian curve fitting are proposed. Based on these methods, a segmented curve calibration algorithm is applied to achieve accurate mapping between peak wavelength and position. For the thickness measurement of transparent objects, a simple thickness measurement model and its calibration procedure are proposed, which do not need to obtain previous parameters, such as incident angle or refractive index. Finally, the performance of the proposed sensing system is tested by displacement measurement and thickness measurement experiments. The experimental results show that the root mean square error (RMSE) of displacement measurement is less than 0.1 mu m, and the RMSE of thickness measurement is less than 1 mu m, which verifies the effectiveness and feasibility of the proposed sensing system.

关键词： chromatic confocal signal processing calibration algorithm displacement measurement thickness measurement

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Dither-based calibration of bit weights in pipelined-SAR ADCs with fast convergence speed using partially split structure

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ELECTRONICS LETTERS 2020年第18期56卷 916-+页

作者： Sun, Jie Li, Xin Yan, Chenggang Liu, Weiqiang Nanjing Univ Aeronaut & Astronaut Nanjing Peoples R China Southeast Univ Natl ASIC Syst Engn Res Ctr Nanjing Peoples R China

A background calibration technique is proposed to correct bit weights in pipelined-successive-approximation-register (SAR) analogue-to-digital converters (ADCs). By splitting the second stage, the input signal interference is mostly removed, thereby greatly enhancing the convergence speed of the algorithm. Besides, the dither signal assists to eliminate mismatch issues between the partially split ADCs, thus relaxing the analogue overheads. According to the simulation, after calibration, the spurious-free-dynamic-range and signal-to-noise-and-distortion-ratio are improved from 53.2 to 88.2 dB and 49.5 to 75.2 dB, respectively. The calibration algorithm converges with about only 600 K samples.

关键词： calibration analogue-digital conversion signal-to-noise-and-distortion-ratio calibration algorithm pipelined-SAR ADC fast convergence speed partially split structure background calibration technique pipelined-successive-approximation-register analogue-to-digital converters input signal interference dither signal analogue overheads spurious-free-dynamic-range partially split ADC dither-based calibration bit weight correction mismatch elimination

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Effective mutual coupling estimation and calibration for conformal arrays based on pattern perturbation

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IET MICROWAVES ANTENNAS & PROPAGATION 2020年第15期14卷 1998-2006页

作者： Zhang, Xiaowen Liao, Guisheng Yang, Zhiwei Zou, Xintong Chen, Ying Xidian Univ Natl Lab Radar Signal Proc Xian 710071 Peoples R China Xidian Univ Collaborat Innovat Ctr Informat Sensing & Underst Xian 710071 Peoples R China Xidian Univ Key Lab Antennas & Microwave Technol Xian 710071 Peoples R China

Processing conformal array signal is sensitive to antenna patterns on horizontal (H) and vertical (V ) planes while mutual coupling (MC) impacts distinctly on them. Many existing MC calibration algorithms ignore that and thus lose their efficacy. In this study, MC is modelled as distortions of H and V patterns. The direction-dependent and slowly varied properties indicate that MC can be estimated via sampling in the interested spatial range and calibrated. A novel MC estimation and calibration algorithm for all kinds of conformal arrays is proposed based on it. The process requires the use of three signals with diverse sets of polarisation emitted by a known calibrated source in each sampling direction. The selection of diverse polarisations is analysed in terms of optimisation and practical application. Simulations exhibit the potentialities of the proposed algorithm regarding the precision of MC estimation and the efficiency of calibration. It shows that significant superiority influences greatly in the analysis of conformal arrays.

关键词： conformal antennas array signal processing calibration antenna radiation patterns antenna arrays antenna patterns mutual coupling estimation direction-dependent properties slowly varied properties spatial range MC estimation calibration algorithm conformal arrays known calibrated source sampling direction pattern perturbation MC calibration algorithms conformal array signal processing

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How does the calibration method impact the performance of the air2water model for the forecasting of lake surface water temperatures?

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JOURNAL OF HYDROLOGY 2021年 597卷 126219-126219页

作者： Zhu, Senlin Piotrowski, Adam P. Ptak, Mariusz Napiorkowski, Jaroslaw J. Dai, Jiangyu Ji, Qingfeng Yangzhou Univ Coll Hydraul Sci & Engn Yangzhou 225127 Jiangsu Peoples R China Polish Acad Sci Inst Geophys Ks Janusza 64 PL-01452 Warsaw Poland Adam Mickiewicz Univ Dept Hydrol & Water Management Krygowskiego 10 PL-61680 Poznan Poland Nanjing Hydraul Res Inst Nanjing 210029 Peoples R China

The air2water model is a widely used tool for the forecasting of lake water temperatures and projection of climate change. It has been applied in thousands of lakes worldwide. However, it employed the Particle Swarm Optimization (PSO) as the calibration method, which was proposed more than 20 years ago. In this study, 12 advanced optimization algorithms proposed during the recent few years were implemented to calibrate and validate the air2water model. Daily observed water temperature in temperate lakes (22 lowland lakes in Poland) were used to evaluate the model performance. Each optimizer was run 30 times with 3 different settings of the maximum number of function calls, 5000, 20,000, and 100,000. We have found that the PSO method used in the original air2water model performs relatively poor compared with most of the recent algorithms, and the majority of recently proposed algorithms reach the similar best solutions on many lakes when the highest number of function calls is allowed. However, only the HARD-DE (hierarchical archive-based mutation strategy with depth information of differential evolution) algorithm is never outperformed by any competitor, irrespective which lake and maximum number of function calls is considered. As a result, we highly recommend using HARD-DE as the calibration method for the air2water model in the future studies.

关键词： Water temperature Lake air2water calibration algorithm PSO HARD-DE

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Air2water model with nine parameters for lake surface temperature assessment

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LIMNOLOGICA 2022年 94卷

作者： Piotrowski, Adam P. Zhu, Senlin Napiorkowski, Jaroslaw J. Polish Acad Sci Inst Geophys Ks Janusza 64 PL-01452 Warsaw Poland Yangzhou Univ Coll Hydraul Sci & Engn Yangzhou 225127 Peoples R China

The air2water model is a physically-based model in which major physical processes are parameterized. It allows to predict the surface lake temperature based solely on the time series of the air temperature. Due to its simplicity and very limited data requirements, it has found numerous applications around the globe. The air2water model defines the normalized depth of the well-mixed surface layer using a fixed parameter. This parameter is a threshold value that is set to 4 degrees C - the temperature of water with maximum density - for dimictic lakes, and to the minimum or to the maximum water temperature for warm or cold monomictic lakes, respectively. In this paper we propose to calibrate the threshold value as the ninth parameter of the model, instead of setting it fixed. We test the proposed approach on a set of 30-years long daily data from 22 lakes located in the lowland part of Poland and 25-years long daily data from the two Great Lakes - Huron and Eire. The proposed modification is very simple and improves the performance of the model, especially for winter-spring season, for the vast majority of lakes not only for the calibration, but also for the independent 8-10 years long validation data.

关键词： Water temperature Lake air2water calibration algorithm Surface layer

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High-Precision calibration Scheme for RIMU

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IEEE ACCESS 2019年 7卷 72376-72386页

作者： Cheng, Jianhua Liu, Ping Gao, Peng Zou, Mingfeng Fu, Wenhuan Harbin Engn Univ Coll Automat Harbin 150001 Heilongjiang Peoples R China

Due to the diversity of redundant configuration schemes, the existing calibration algorithm for the redundant inertial measurement unit (RIMU) cannot be applied generally. In addition, the linearized calibration model utilized in the traditional calibration algorithms also leads to low calibration accuracy. In this paper, a high-precision calibration scheme is proposed for the RIMU, which can be applied generally. At first, a general calibration model for the RIMU is established. Then, a zero-space amplification algorithm is applied to improve the observability of the system. At last, the extended Kalman filter (EKF) based on the second-order Taylor series expansion is proposed, which can estimate the biases, scale factor errors, and installation errors simultaneously. The simulation and experimental results demonstrate that the proposed calibration algorithm calibrates the system accurately and improves the performance of the RIMU effectively. Furthermore, the proposed algorithm can be applied generally in all kinds of RIMU.

关键词： calibration algorithm extended Kalman filter (EKF) calibration model redundant inertial measurement unit (RIMU) Taylor series expansion

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Non-contacted optical measurement system with 16-channel synchronous laser sensor applied for three-axis machine tool 7

Non-contacted optical measurement system with 16-channel syn...

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7th IEEE International Conference on Consumer Electronics - Taiwan (ICCE-Taiwan)

作者： Pham Hoang The Dang Quang Vu Hoang Sun, Chi-Chia Lu, Pin-Wei Natl Formosa Univ Dept Elect Engn Huwei Taiwan Natl Formosa Univ Smart Machine & Intelligent Mfg Res Ctr Huwei Taiwan

ISBN: (数字)9781728173993

ISBN: (纸本)9781728173993

The quality and accuracy are the two main factors of the performance of the cutting tool which are the particularly industrial standard in every almost factories. In this paper, an optical based non-contact machine tool calibration system is presented. It presents a non-contacted optical measurement system with two 8-channels sensor applied for three-axis machine tool with high-speed data accuracy, establishes system connection, and integrates computer interface with a 32-bit MCU to realize optical measurement system of three-axis machine tool. The communication is based on Ethernet network. Hardware architecture contains four sets of laser light source, photoelectric sensors and spherical lens. With the inexpensive price and uncomplicated steps, it can perform the calibration three-axis motor and static error with above average accuracy.

关键词： Machine Tool calibration algorithm Sensor Non-Contact ADC IoT

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Study of the metrological characteristics of the hydrostatic pressure sensor

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SENSOR REVIEW 2019年第5期39卷 665-669页

作者： Nadezhdin, Igor S. Goryunov, Aleksey G. Svinolupov, Yuri G. Zadorozhnaya, Olga J. Tomsk Polytech Univ Sch Nucl Sci & Engn Tomsk Russia JSC Manotom Tomsk Russia JSC NEVZ Ceram Novosibirsk Russia

Purpose The purpose of this paper is to develop a digital hydrostatic pressure sensor with the required metrological and operational characteristics. The developed sensor is designed to control hydrostatic pressure in wells during various geophysical works and studies. Design/methodology/approach To obtain the required metrological and operational characteristics of the sensor, a method was developed and applied to reduce the measurement error based on the calibration algorithm and the sensor model. Findings By using the developed calibration algorithm and the mathematical model of the sensor, it was possible to compensate for the measurement errors of the hydrostatic pressure sensor. Originality/value In the course of this research, tests of the developed sensor were carried and the maximum/minimum of measurement result errors was determined.

关键词： Temperature Sensor calibration algorithm Error Hydrostatic pressure

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Distributed temperature sensing in OPGW with multiple optical fibres

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IET SCIENCE MEASUREMENT & TECHNOLOGY 2019年第8期13卷 1219-1223页

作者： Carvalho, Renatto, V do Couto Bonfim, Marlio Jose Ussuna, Daniel A. Toledo, Luiz F. R. B. Martins, Rafael Filho, Vitoldo S. Lactec Dept Mat Engn Curitiba Parana Brazil Univ Fed Parana Dept Elect Engn Curitiba Parana Brazil Companhia Paranaense Energia Eletr COPEL Substn Project Div Curitiba Parana Brazil

The ampacity of a material is defined as its maximum electrical current capacity. In an overhead transmission line, it is related to the maximum sag that does not compromise its safe operation. As the sag depends on the conductor's temperature, with this parameter it is possible to estimate its ampacity, increasing the efficiency of the electrical system via real-time energy dispatch management. With the Brillouin backscattering phenomena, the distributed temperature measurement in the fibre inside the optical ground wire (OPGW) or optical phase conductor is possible. However, it is common for overhead power transmission lines to be composed by more than one optical fibre. A calibration algorithm was developed to enable the application of a distributed temperature sensing equipment to monitor the temperature of an OPGW with more than two different fibres. The 230 kV Ibipora-Londrina Transmission Line was used as a case study, being approximately 20 km long and composed of three different fibres spliced in series along with its extension. Through comparison with calibrated sensors, the technique and algorithm were validated. It was possible to characterize the system and perform the temperature monitoring with a spatial resolution of 1 m and amplitude error of less than 6 degrees C.

关键词： optical cables temperature sensors refractive index fibre optic sensors temperature measurement calibration overhead line conductors power overhead lines distributed sensors Brillouin spectra OPGW multiple optical fibres maximum electrical current capacity overhead transmission line maximum sag thermal expansion electrical system real-time energy dispatch management Brillouin backscattering phenomena strain gradients distributed temperature measurement optical phase conductor overhead power transmission lines distributed temperature sensing equipment temperature monitoring refractive index fluctuation Ibipora-Londrina transmission line conductor temperature cables optical ground wire calibration algorithm calibrated sensors voltage 230 0 kV

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