报告人：苏卫东（Faculty of Engineering and Information Technology
University of Technology, Sydney (UTS), Australia）

时间：2015年9月23日(周三) 下午 2:00pm

地点：七号楼412

报告主题：Fall Detection and Prevention by Using Wearable Devices

报告摘要：One of the major public health problems among elderly people is falling injury.  A fall detection system, as an assistive device for alleviation of this problem, is urgently needed. Smartphone-based fall detectors are attractive because of the widespread use of mobile phones, even among the older population. This presentation will cover several aspects of fall detection and prevention techniques developed in our research team, which includes sensor in-field calibration, mapping from feature to class, particle swarm clustering, gait analysis, and issues with mobile phone based fall detector.

 

报告人：苏卫东（Faculty of Engineering and Information Technology
University of Technology, Sydney (UTS), Australia）

时间：2015年9月25日(周五) 下午 2:00pm

地点：七号楼412

报告主题：Decentralized Integral Controllability and Its Extension

报告摘要：Decentralized integral control is one of the most popular control strategies used in practice. This study investigates decentralized integral control with a special focus on the DIC analysis of processes whose steady state gain matrices are critically D-stable. Firstly, this study proposes a new unconditional stability criterion. Then, by using the proposed criterion, it is proved that for up to four-channel processes, their DIC can be totally determined by their steady state gain matrices. We also present a multi-loop PI control design method, which provides an explicit lower bound of the proportional coefficient to achieve decentralized unconditional stability for low dimensional processes. Recently, the concept of DIC for a single model has been extended to SDIC for multiple models, and an easy-to-use sufficient SDIC condition for a set of systems is provided.

 

报告人：李永东（清华大学电机系，电力电子与电机控制研究室）

时间：2015年9月 28日(周一) 下午 1:20pm

地点：研究生教学楼307

报告主题：大容量电力电子技术在海陆空潜电气化系统中的应用研究

报告摘要：多电平变换器在高压大容量电力电子领域应用广泛，而近年来在高速铁路、船舰/潜艇驱动、航空航天等领域，对全电化和多电化以及设备体积和重量的要求日渐苛刻。随着新材料和新器件的发展，采用中高频变压器替代变换器拓扑中的原有工频变压器，可以大大减小变换器系统的体积和重量，提高系统可靠性和灵活性。清华大学电机系李永东教授主持研究了大容量电力电子技术在下一代高铁牵引系统、全电化船舰和潜艇、多电/全电飞机以及下一代电网中的应用，提出了几种实用的中高频变压器隔离变换器新拓扑结构，推导了中高频变压器隔离变换器DAB电流应力表达式并提出了最优电流应力移相（OCPS）控制方法。李永东教授主持的研究中还提出了两种进行多绕组功率解耦的方法，并提出了基于直流电压PI调节的电压平衡控制方法和 MAB隔离单元的软开关移相（SSPS）控制方法。在新拓扑基础上，李永东教授还提出了中高频隔离变换器系统中CHBR基于改进PD-SPWM的电压平衡控制辅助方法；并提出了系统的故障运行策略、变压器抗饱和的软件控制算法以及采用LLC谐振变换器提高效率的方法。