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The Society of Instrument and control Engineers Annual Conference 2015

作者： Chi Weijie Qiao Jianzhong Zhu Yukai Guo Lei School of Instrument Science and Opto-electronics Engineering Beihang University National Key Laboratory of Aerospace Intelligent Control Technology Beijing Aerospace Automatic Control Institute School of Automation Science and Electrical Engineering Beihang University

ISBN: (纸本)9784907764487

Gravity gradient measurement satellite is a kind of drag-free satellite and suffers from multiple disturbances in the low earth orbit. So the disturbances estimation and compensation for the drag-free satellite is very important to improve measurement precision. In this paper, the characteristics of multiple disturbances are analyzed. Then, the frequency domain disturbance observer is designed for disturbance estimation and compensation. Next, a composite controller combining the frequency domain disturbance observer with PID controller is presented to reject and attenuate the multiple disturbances. At last, the simulation verification is carried out to verify the effectiveness of the proposed method.

关键词： drag-free satellite,multiple disturbances,frequency domain disturbance observer

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A Fast Growing Cascade Neural Network for BOD Estimation

A Fast Growing Cascade Neural Network for BOD Estimation

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第三十四届中国控制会议

作者： LI Fanjun QIAO Junfei ZHANG Wei College of Electronic Information and Control Engineering Beijing University of Technology School of Mathematical Science University of Jinan Beijing Key Laboratory of Computational Intelligence and Intelligent System

ISBN: (纸本)9781467374439

In this paper, a fast growing cascade neural network(FGCNN) is proposed, as a software sensor, to rapidly estimate the biochemical oxygen demand(BOD) in wastewater treatment plants(WWTPs). Firstly, a novel method, based on the orthogonal least squares(OLS), is put forward to add input and hidden units to the existing network one by one. Every unit added to the network affords the maximal reduction of the sum of squared errors(SSE). Then, the FGCNN incrementally updates its output weights by iterations without gradients and generalized inverses, while the other weights remain unchanged during the growth of the network. The simple and effective training method make the FGCNN learn extremely fast. Finally, the proposed FGCNN is applied to estimate the BOD in WWTPs using other easy-to-measure or secondary variables. The experiment results show that the FGCNN has better performance on real-time estimation of BOD than other similar methods.

关键词： Artificial neural network,biochemical oxygen demand,wastewater treatment plant,software sensor

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An algorithm and observability research of autonomous navigation and joint attitude determination in asteroid explorationdescent stage

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science China(Information sciences) 2014年第10期57卷 128-144页

作者： MA HongLiang CHEN Tong HE YingZi Schoolof Astronautics Beijing University of Aeronautics and Astronatics Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control Engineering

In this paper, an autonomous relative navigation and joint attitude determination algorithm in asteroid exploration descent stage is researched based on feature point information of perpendicular asteroid surface image observed by optical navigation camera, distance vectors from spacecraft to asteroid measured by three angled installed lidars and relative velocity increment measured by accelerometer when the relative distance vector to the centroid of asteroid can not be obtained. The inertial attitude of spacecraft is determined by sun vector, star vectors and inertial angular velocity respectively measured by sun sensor, star trackers and inertial reference unit. Also, in order to obtain measurement error model transferred from sensor noise, a covariance matrix solver considering error correlation is presented via the error model of normalized vector to first *** simulation and improved observability evaluation of filtering are undertaken to discuss the results of complete sensor observation and weak observation of lidars, and verify the effectiveness of the presented relative navigation and attitude determination algorithm.

关键词： asteroid exploration relative navigation attitude determination feature points normal vector covariance matrix solver

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Disturbance estimation and compensation for drag-free satellite based on frequency domain disturbance observer 54

Disturbance estimation and compensation for drag-free satell...

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54th Annual Conference of the Society of Instrument and control Engineers of Japan, SICE 2015

作者： Weijie, Chi Jianzhong, Qiao Yukai, Zhu Lei, Guo School of Instrument Science and Opto-electronics Engineering Beihang University Beijing China School of Automation Science and Electrical Engineering Beihang University Beijing China National Key Laboratory of Aerospace Intelligent Control Technology Beijing Aerospace Automatic Control Institute Beijing China

ISBN: (纸本)9784907764487

关键词： Satellites

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Robust Guidance Law for Drag Tracking in Mars Atmospheric Entry Flight 33

Robust Guidance Law for Drag Tracking in Mars Atmospheric En...

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第三十三届中国控制会议

作者： WANG Da-yi GUO Min-wen Beijing Institute of Control Engineering Science and Technology on Space Intelligent Control Laboratory

ISBN: (纸本)9789881563842

A robust entry guidance law is designed for drag tracking in Mars entry atmospheric flight for low-lifting lander with maximum lift-to-drag ratio of only *** the flight process the bank angle is the only control variable to be modulated to eliminate the tracking error when considering the initial derivation and parameter *** the tough problem of the guidance law design is analyzed which the input coefficient of the drag dynamics equations is uncertain due to kinds of parameter *** this study,we divided input coefficient on both sides of the drag *** the robust control applied to robot manipulators can be adopted for drag tracking in the entire Mars entry atmospheric *** we can guarantee uniform ultimate bounded stability of uncertain ***,Monte-Carlo simulation result demonstrates robust method leads to the landing precision within 15km of a specified parachute deployment piont while subject to significant parameters uncertainties.

关键词： Low-lifting vehicle,Mars atmospheric entry fight,robust guidance law,parameter uncertainties

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Robust Gain & Phase Margin of Minimum Phase MIMO Interval Systems 33

Robust Gain & Phase Margin of Minimum Phase MIMO Interval Sy...

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第三十三届中国控制会议

作者： LI Xindong GOU Xingyu Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control Engineering

ISBN: (纸本)9781479947249

This paper calculates exact stability margins of MIMO linear time-invariant interval systems based on the frequency domain theorem. After regarding each eigenvalue function of the MIMO linear system as a single SISO linear time-invariant system, two methods are studied in this paper. The one is a new analytical method which is proposed to give the worst-case gain margin and phase margin, The other is a graphical method which is also presented to analyze stability margin of the MIMO linear interval systems based on the definition of stability margin from Nyquist theorem. At last the simulation examples are presented to validate the effectiveness and the correctness of the two proposed methods.

关键词： Stability Margin,Interval System,Nyquist Theorem

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An Linear Matrix Inequality Approach to Simultaneous Fault Detection and control Design for LTI Systems 33

An Linear Matrix Inequality Approach to Simultaneous Fault D...

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第三十三届中国控制会议

作者： LIU Weijie CHEN Ying NI Maolin Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control Engineering

ISBN: (纸本)9781479947249

In this paper, the problem of simultaneous fault detection and control（SFDC） for linear Time Invariant（LTI） systems in continuous-time case is considered, and a new design method of SFDC problem is realized based on linear matrix inequality（LMI）. The SFDC problem is formulated as a mixed H2/H∞ optimization problem and a state observer is used to reconstruct the faults. By virtue of the Bounded Real Lemma and Shur Complement, a single unit called detector/controller（D/C） is obtained based on LMIs to stabilize the systems and detect the faults. To optimize the performances of the close-loop systems, a D-stable analysis for the D/C is also presented based on LMIs, therefore we can place the pole of the close-loop systems to an appointed region. The result of simulation indicats that the SFDC can stabilize the linear systems with fault happened and the detection can identify the fault clearly.

关键词： simultaneous fault detection and control linear systems linear matrix inequality（LMI） pole placement

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Attitude control of spacecrafts Based on Small-Gain Theorem 33

Attitude Control of Spacecrafts Based on Small-Gain Theorem

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第三十三届中国控制会议

作者： YAN Han Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control Engineering

ISBN: (纸本)9781479947249

A nonlinear attitude control law for spacecrafts is proposed based on small-gain theorem considering the effects of the control loop *** attitude angular rate commands,which are aimed at driving the attitude angles to the desired ones,are designed according to input-to-state stability(ISS) ***,the small-gain theorem is iteratively used to propose the final torque *** is shown that the attitude angles under the control law can robustly track the desired values,and the tracking errors are ISS with respect to *** results have confirmed the effectiveness of the proposed scheme.

关键词： Attitude control,generalized small-gain theorem,input-to-state stability,robustness.

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第三十三届中国控制会议

作者： WANG Hanlei Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control Engineering

ISBN: (纸本)9781479947249

This paper addresses the oscillatory synchronization problem for multiple uncertain mechanical systems with a virtual leader,and the interaction topology among them is assumed to contain a directed spanning *** on the physically measurable relative information between the neighboring systems,we propose an adaptive control scheme to achieve the synchronization of multiple mechanical systems with a virtual leader that is governed by the standard mass-spring oscillator *** the similarity decomposition approach,we show that the position and velocity synchronization errors between each mechanical system(or follower)and the virtual leader converge to *** performance of the proposed adaptive scheme is shown by numerical simulation results.

关键词： Oscillatory synchronization,Mechanical systems,Virtual leader,Uncertainty,Adaptive control

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Frequency-specific Alterations of Large-scale Functional Brain Networks in Patients with Alzheimer＇s Disease

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Chinese Medical Journal 2015年第5期128卷 602-609页

作者： Yuan-Yuan Qin Ya-Peng Li Shun Zhang Ying Xiong Lin-Ying Guo Shi-Qi Yang Yi-Hao Yao Wei Li Wen-Zhen Zhu Department of Radiology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan Hubei 430030 China Department of Control Science and Engineering Image Processing and Intelligent Control Key Laboratory of Education Ministry of China Huazhong University of Science and Technology Wuhan Hubei 430074 China

Background：Previous studies have indicated that the cognitive deficits in patients with Alzheimer＇s disease （AD） may be due to topological deteriorations of the brain ***,whether the selection of a specific frequency band could impact the topological properties is still not *** hypothesis is that the topological properties of AD patients are also ***：Resting state functional magnetic resonance imaging data from l0 right-handed moderate AD patients （mean age：64.3 years; mean mini mental state examination [MMSE]：18.0） and 10 age and gender-matched healthy controls （mean age：63.6 years; mean MMSE：28.2） were enrolled in this *** global efficiency,the clustering coefficient （CC）,the characteristic path length （CpL）,and ＂small-world＂ property were calculated in a wide range of thresholds and averaged within each group,at three different frequency bands （0.01-0.06 Hz,0.06-0.11 Hz,and 0.11-0.25 Hz）.Results：At lower-frequency bands （0.01-0.06 Hz,0.06-0.11 Hz）,the global efficiency,the CC and the ＂small-world＂ properties of AD patients decreased compared to *** at higher-frequency bands （0.11-0.25 Hz）,the CpL was much longer,and the ＂small-world＂ property was disrupted in AD,particularly at a higher *** topological properties changed with different frequency bands,suggesting the existence of disrupted global and local functional organization associated with ***：This study demonstrates that the topological alterations of large-scale functional brain networks inAD patients are frequency dependent,thus providing fundamental support for optimal frequency selection in future related research.

关键词： Alzheimer＇s Disease Frequency Network

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