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A decoupling approach for time-dependent robust optimization with application to power semiconductor devices

APPLIED MATHEMATICAL MODELLING 2021年 99卷 129-146页

作者： Huang, Zhiliang Guo, Xiaohui Yang, Tongguang Lei, Shuwen Zhao, Zhiguo Hunan City Univ Key Lab Energy Monitoring & Edge Comp Smart City Yiyang 413002 Peoples R China Hunan Haicheng Yuxin Informat Technol Co Ltd Changsha 410141 Hunan Peoples R China

In this paper, a time-dependent robust optimization model is proposed by introducing a concept of expected interval quality loss as the robustness metric. The purpose is to provide a potential analysis tool for power semiconductor devices involving stochastic processes. Unlike conventional robustness indicators, the metric is formulated by calculating the expectation and variation of the maximal instantaneous quality loss and capturing the auto-correlation of the quality loss over the time interval. In terms of model solving, the time-dependent robust optimization involves a nested optimization, namely the outer design optimization requires to call the inner robustness analysis frequently. It will lead to extremely low computational efficiency. For reducing robustness evaluations, a decoupling framework is proposed to convert the nested optimization into a sequential iterative process of design optimization and time-dependent robustness analysis. For further improving the efficiency of each robustness analysis, a semi-second-order approximation of quality characteristics is created based on the information at the previous iteration. Two engineering applications of power semiconductor devices verify the validity and feasibility of the proposed approach. (c) 2021 Elsevier Inc. All rights reserved.

关键词： Time-dependent problem Quality loss function Robust design optimization decoupling algorithm Power semiconductor device

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Time-Variant Reliability Optimization for Stress Balance in Press-Pack Insulated Gate Bipolar Transistors

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IEEE ACCESS 2023年 11卷 98059-98069页

作者： Li, Hangyang Yang, Tongguang Liu, Xinglin Zhong, Jingyi Mo, Jiaxin Zhou, Han Xiao, Zhongkun Hunan City Univ Hunan Prov Key Lab Energy Monitoring & Edge Comp S Yiyang 413000 Peoples R China

Stress imbalance significantly affects the performance of a press-pack insulated gate bipolar transistor (IGBT). Time-variant loads and conditions lead to the stress fluctuations, exacerbating the impacts. The conventional reliability optimization faces efficiency barriers due to the nested time-variant reliability analysis and design optimization. In this paper, a time-variant reliability optimization approach for press-pack IGBTs is proposed to address the efficiency issue of the IGBT reliability optimization. The performance functions of the maximum and typical stresses are formulated as the optimization objective and constraint. A time-variant reliability optimization model is formulated considering the stress balance reliability degradation within the service cycle. A decoupling algorithm is proposed to transform the nested optimization into a sequential iteration of static reliability optimization and time-variant reliability analysis. The reliability analysis utilizes the performance function continuity in the time domain to reduce the evaluations for the most likelihood points, thereby enhancing efficiency. Numerical and experimental results on an actual IGBT demonstrate the accuracy of the stress balance performance analysis. The time-variant reliability optimization based on the performance functions improves the stress balance performance by 16.3% and meets the reliability requirements within the service cycle. Compared with the conventional double-loop approach, the difference between the solution of the proposed approach with the reference solution is 0.4%, and the efficiency is 334 times that of the double-loop approach. The performance advantages in accuracy and efficiency exhibit the application potential of this approach.

关键词： Insulated gate bipolar transistors Reliability Stress Optimization Power system reliability Uncertainty Stochastic processes decoupling algorithm insulated gate bipolar transistor stress balance time-variant reliability optimization

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A FINITE-ELEMENT SOLUTION OF THE SHALLOW-WATER WAVE-EQUATIONS

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APPLIED MATHEMATICAL MODELLING 1990年第1期14卷 20-29页

作者： UTNES, T Norwegian Hydrotechnical Laboratory Trondheim Norway

A finite element method is presented for the solution of the shallow-water wave equations. The method is characterized by a semi-implicit decoupling algorithm; the grid is composed of isoparametric, biquadratic elements; and the interpolation is mixed, with biquadratic velocity and bilinear elevation. Several test cases are presented to demonstrate the ability of the method, including a simulation of internal waves in Lake Mjøsa.

关键词： finite elements decoupling algorithm shallow-water equations

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A Novel Two-Axis Load Sensor Designed for in Situ Scratch Testing inside Scanning Electron Microscopes

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SENSORS 2013年第2期13卷 2552-2565页

作者： Huang, Hu Zhao, Hongwei Wu, Boda Wan, Shunguang Shi, Chengli Jilin Univ Coll Mech Sci & Engn Changchun 130025 Peoples R China

Because of a lack of available miniaturized multiaxial load sensors to measure the normal load and the lateral load simultaneously, quantitative in situ scratch devices inside scanning electron microscopes and the transmission electron microscopes have barely been developed up to now. A novel two-axis load sensor was designed in this paper. With an I-shaped structure, the sensor has the function of measuring the lateral load and the normal load simultaneously, and at the same time it has compact dimensions. Finite element simulations were carried out to evaluate stiffness and modal characteristics. A decoupling algorithm was proposed to resolve the cross-coupling between the two-axis loads. Natural frequency of the sensor was tested. Linearity and decoupling parameters were obtained from the calibration experiments, which indicate that the sensor has good linearity and the cross-coupling between the two axes is not strong. Via the decoupling algorithm and the corresponding decoupling parameters, simultaneous measurement of the lateral load and the normal load can be realized via the developed two-axis load sensor. Preliminary applications of the load sensor for scratch testing indicate that the load sensor can work well during the scratch testing. Taking advantage of the compact structure, it has the potential ability for applications in quantitative in situ scratch testing inside SEMs.

关键词： load sensor in situ scratch testing decoupling algorithm frequency response calibration experiment

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DSM-based Complex Aerospace Projects Development Process Design and Optimization 9

DSM-based Complex Aerospace Projects Development Process Des...

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9th Annual IEEE International Systems Conference (SysCon)

作者： Xiong, Weitao Liu, Can Zhao, Qingsong Yang, Kewei Natl Univ Def Technol Coll Informat Syst & Management Changsha 410073 Hunan Peoples R China

ISBN: (纸本)9781479959273

With the scale and complexity of aerospace projects raising, how to shorten the development time of aero-components has become an emergent problem. In this paper, we focus on the technical needs in Complex Product Development Process Planning (CPDPP) for aerospace projects. The difficulties of designing a complex aero-component result not only from masses of tasks, but also from iterations between coupled tasks. Iteration is a somewhat negative word since it implies re-doing work and often takes a long time to converge during a whole development process. Under the support of researches in the past, this paper specifies the steps of constructing Design structure matrix (DSM) and proposes a method of handling overlapping iteration and sequential iteration, which makes designers integrate all DSMs established from different views and understand products design structure on the whole. Furthermore it proposes a new decoupling method of DSM based on relevant analyses which is evaluated by an index system consisted of sensitivity and changeability.

关键词： CPDPP DSM Overlapping Iteration Changeability Sensibility decoupling algorithm Simulation

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decoupling and Sensorless Vector Control Scheme for Single-Phase Induction Motor Drives

Decoupling and Sensorless Vector Control Scheme for Single-P...

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38th Annual Conference on IEEE-Industrial-Electronics-Society (IECON )

作者： Azzolin, R. Z. Bernardes, T. A. Vieira, R. P. Gastaldini, C. C. Gruendling, H. A. Fundacao Univ Fed Rio Grande Rio Grande Brazil

ISBN: (纸本)9781467324212

Vector control has improved the performance and energy efficiency in SPIM drives. However, high current and torque pulsations are produced by winding asymmetry of SPIM. This paper proposes a decoupling scheme to reduce the current and torque pulsations and improve the performance of vector control. A stator current observer is used to estimate the coupling signals, which are compensated by control law. This method is an alternative to improve the performance of single-phase induction motor used in hermetic refrigeration systems. The thermal efficiency of refrigeration system can be improved by the variable speed operation and the advantages of robustness and low-cost of single-phase induction motor can be maintained.

关键词： decoupling algorithm single-phase induction motor stator current observer vector control

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BP and RBF Neural Network in decoupling Research on Flexible Tactile Sensors

BP and RBF Neural Network in Decoupling Research on Flexible...

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IEEE International Conference on Information and Automation 2015

作者： Ding, Junxiang Gao, Fang Wei, Xuan Wang, Yongping Pan, Hongqing Wang, Yubing Ge, Yujian Chinese Acad Sci Inst Intelligent Machines Hefei 230031 Peoples R China New Star Res Inst Appl Technol Hefei City Hefei 230031 Peoples R China

ISBN: (纸本)9781467391047

This paper proposes two decoupling methods for a flexible tactile sensor, improved back propagation neural network (BPNN) and radical basis function neural network (RBFNN). In the numerical experiments, the number of hidden layer nodes of the BPNN is optimized and k-fold-cross-validation (k-CV) method is also applied to construct the dataset. Information of the tactile sensor array at different scales is also used to construct the BPNN. RBFNN is applied to approach the nonlinear relationship between the deformation and the three-dimensional force of the tactile sensor numerical model built through finite element analysis. The decoupling results show that the RBFNN with high nonlinear approximation ability has good performance in decoupling three-dimensional force and satisfies both the decoupling accuracy and real-time requirements of the tactile sensor. Different white Gaussian noises (WGN) are added into the ideal model of the flexible tactile sensors. Then the modified RBFNN is applied to approximate and decouple the mapping relationship between row-column resistance with WGNs and the three-dimensional deformation. Numerical experiments demonstrate that the improved RBFNN doesn't rely on the mathematical model of the system and has good anti-noise ability and robustness.

关键词： tactile sensor BP neural network radical basis function decoupling algorithm

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Modeling and control of the driving system of slant mount telescopes 8

Modeling and control of the driving system of slant mount te...

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8th International Symposium on Advanced Optical Manufacturing and Testing Technologies - Large Mirrors and Telescopes

作者： Zhou, Wangping Wang, Ya Cai, Ziyuan Tian, Yan Nanjing Univ Informat Sci & Technol Sch Informat & Control CICAEET Nanjing 210044 Jiangsu Peoples R China

ISBN: (纸本)9781628419177

The angle between slant and azimuth axes is 45 degrees in slant-mount telescopes, which use the slant rotation to replace altitude movement in traditional mounts. The circular motion can achieve more smooth driving in altitude direction, and can effectively overcome problems in traditional mounts such as vibrations around the zenith. It is a hot topic in researches of current astronomical instruments. While the vertical displacement of the structure is composed by circle rotation of the slant axis, which causes displacements of the two direction coupled. Moreover, the slant rotation can also leads to the revolving movement of CCD images of the tracking system. These two problems bring great challenges to the slant mount driving. In this paper, based on a slant mount, we establish accurate mathematical model of the drive system to effectively compensate for the revolving movement of the image field, decompose in real time the deviation of vertical and horizontal directions by the decoupling algorithm, and design the control system using FPGA to carry out testing experiments. We strive to solve the displacement coupling and the image revolving movement problem, and thus provide a feasible technical support for driving control of slant mounts.

关键词： Telescope slant axis revolving movement decoupling algorithm

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Experiment of double deformable mirrors adaptive optics system for phase compensation

Experiment of double deformable mirrors adaptive optics syst...

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Conference on MEMS Adaptive Optics

作者： Hu, Shijie Chen, Shanqiu Xu, Bing Yang, Ping Cai, Dongmei Wu, Jian Jiang, Wenhan Chinese Acad Sci Inst Opt & Elect Chengdu 610209 Peoples R China Univ Elect Sci & Technol China Chengdu 610054 Peoples R China

ISBN: (纸本)9780819465801

For some adaptive optics (AO) systems, one deformable mirror (DM) can not meet the need of large stroke and high spatial frequency. In this paper, a double DMs way is present. In this system, a large stroke DM (LSDM) with low spatial frequency corrects low order aberrations and a high spatial frequency DM (HSFDM) with small stroke corrects high order aberrations. The decoupling algorithm of two DMs is essential for working properly. In this paper, a decoupling algorithm and experimental results for a double DM AO system are presented. The result indicates that the compensation result of double DMs AO system is almost the same as that of the conventional AO system using single DM with ideal stroke and equivalent spatial frequency.

关键词： adaptive optics double DMs decoupling algorithm gradient response furiction

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Design and Calibration of a Six-axis Force/torque Sensor with Large Measurement Range Used for the Space Manipulator

Design and Calibration of a Six-axis Force/torque Sensor wit...

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Asia-Pacific International Symposium on Aerospace Technology (APISAT)

作者： Chen, Danfeng Song, Aiguo Li, Ang Southeast Univ Sch Instrument Sci & Engn Nanjing 210096 Jiangsu Peoples R China

Multi-axis force/torque sensor is a key component for space robot force control and teleoperation. The special environment of space, however, brings huge challenges to the design of multi-axis force/torque sensor. In this paper, a six-axis force/torque sensor, which could be used as a component for the large manipulator in the space station, is developed. In order to obtain the large measurement range of force/torques, an elastic body based on cross-beam with anti-overloading capability is designed, and the size is optimized by using FEA to guarantee both high stiffness and sensitivity of the six-axis force/torque sensor. Different from the conventional method, the signal acquisition module which includes a high signal-to-noise ratio amplifier circuit is integrated in the sensor so as to be more reliable. Then, a novel calibration system is designed to provide large and accurate force/torque source. According to the particularity of the sensor's coupling errors, two decoupling algorithms are proposed in this paper to achieve high precision and flexible usage. The online decoupling algorithm is based on calculating decoupling matrices in partitioned space, while the offline algorithm is based on an optimized BP Neural Network using GA. Experimental results show that the designed six-axis force/torque sensor works well with high precision and reliability. (C) 2015 The Authors. Published by Elsevier Ltd.

关键词： six-axis force/torque sensor large measurement range calibration system decoupling algorithm

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