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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： Xavier Domont Martin Heckmann Frank Joublin Christian Goerick Honda Research Institute Europe GmbH Offenbach am Main Germany Control Theory and Robotics Laboratory Technische Universität Darmstadt Germany

Previously we presented an auditory-inspired feed-forward architecture which achieves good performance in noisy conditions on a segmented word recognition task. In this paper we propose to use a modified version of this hierarchical model to generate features for standard hidden Markov models. To obtain these features we firstly compute the spectrograms using a Gammatone filterbank. A filtering over the channels permits to enhance the formant frequencies which are afterwards detected using Gabor-like receptive fields. Then the responses of the receptive fields are combined to complex features which span the whole frequency range and extend over three different time windows. The features have been evaluated on a single digit recognition task. The results show that their combination with MFCCs or RASTA features yields improved recognition scores in noise.

关键词： Robustness Speech recognition Hidden Markov models Frequency Feedforward systems Computer architecture Spectrogram Filter bank Gabor filters Filtering

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A Probabilistic Method for Motion Pattern Segmentation

A Probabilistic Method for Motion Pattern Segmentation

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International Joint Conference on Neural Networks (IJCNN)

作者： Daniel Weiler Volker Willert Julian Eggert Edgar Korner Institute of Automatic Control Control Theory and Robotics Lab Darmstadt University of Technology Darmstadt Germany Honda Research Institute Europe GmbH Offenbach Germany

In this paper we present an approach for probabilistic motion pattern segmentation. We combine level-set methods for image segmentation with motion estimations based on probability distribution functions (pdf's) calculated at each image position. To this end, we extend a region based level-set framework to exploit the motion pdf's. We then compare segmentation results of the pdf-based with those of optical-flow-based motion segmentation approaches. We found that the straightforward way of characterizing the segmented region by spatially averaging the motion measurement pdf's does not yield satisfactory results. However, describing the spatial characteristics of the motion pdf's with nonparametric density estimates enables to solve complex motion segmentation problems. In particular for situations with demanding motion patterns like partly overlapping objects and transparent motion, we show that the probabilistic approach yields better results. This confirms the idea that for motion processing it is beneficial to consistently retain the uncertainty and ambiguity of the measurement process right up to the final integration stage, instead of directly processing optical flow vectors.

关键词： Image segmentation Pixel Motion estimation Motion measurement Motion segmentation Computer vision Image motion analysis Neural networks Probability distribution Fluid flow measurement

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TRACKING DOMAINS FOR UNSTABLE PLANTS WITH SATURATING-LIKE ACTUATORS

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Asian Journal of control 2008年第4期1卷

作者： V.A. Yakubovich S. Nakaura K. Furuta Vladimir A. Yakubovich is a corresponding member of Russian Academy of Science. Vladimir A. Yakubovich was born in Novosibirsk Russia in 1926. he entered Moscow University in 1946 and graduated in 1949. he received the Candidate of Science degree (Ph.D.) in 1953 and the Doctor of Science degree in 1959 from Leningrad University. In 1959 he joined the Leningrad University and he has remained since then. He is the author of more than 270 papers and a coauthor of seven books in different areas of applied mathematics and control theory. he has worked in parametric resonance theory in the theory of stability of nonlinear systems and in optimization theory. Dr. Yakubovich has served on many scientific committees and editorial boards. he is a member of several scientific socienties in Russia. He was awarded the Norbert Wiener Prize (1991) a prize from the international editorial company “Nauka” for best publication in its journals (1995) and the IEEE Control Systems Award (1996). Since 1991 he has been a corresponding member of the Russian Academy of Sciences. Dept. of Control Engineering Tokyo Institute of Technology Japan. Shigeki Nakaura received his B.S. and M.S. degrees in Control Engineering from the Tokyo Institute of Technology in 1995 and 1997 respectively. He is currently a PhD student of the Tokyo Institute of Technology. His research interests include robotics and intelligent machining. He is a member of SICE JSPE and IEEE. Katsuhisa Furuta was born in Tokyo Japan in 1940. He received his B.S. M.S. and Ph.D. degrees in Engineering from the Tokyo Institute of Technology in 1962 1964 and 1967 respectively. he was a post doctoral fellow at Laval University (Quebec Canada) from July 1967 to August 1969. Since then he has been a member of the teaching staff of the Tokyo Institute of Technology Department of Control Engineering where he is currently a Professor Graduate School of Information Science and Engineering. He was a Russell Severance Springer Professor University of California at

In many mechanical systems, the tracking control is one of the most important issues. Therefore for the unstable system subject to actuator saturation, the domain of the initial states corresponding to an arbitrary reference signal, within which tracking condition can be achieved, is interesting to be considered. In this paper, an approximate tracking domain is derived analytically. First in Theorem 1, for simple case, it is constructed by using the partial Lyapunov function and the absolute stability theory. In the following Theorems 2 and 3, a new idea is used to obtain larger domains. Finally in the last section, a simple numerical example is given.

关键词： Actuator constraint tracking control nonlinear analysis absolute stability

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LANDING AN UNMANNED AIR VEHICLE: VISION BASED MOTION ESTIMATION AND NONLINEAR control

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Asian Journal of control 2008年第3期1卷

作者： Omid Shakernia Yi Ma T. John Koo Shankar Sastry Dept. of Electrical Engineering & Computer Science University of California at Berkeley Berkeley CA94720-1774 U.S.A. Tak-Kuen John Koo received the B.Eng. degree in 1992 in Electronic Engineering and the M.Phil. in 1994 in Information Engineering both from the Chinese University of Hong Kong. From 1994 to 1995 he was a graduate student in Signal and Image Processing Institute at the University of Southern California. He is currently a Ph.D. Candidate in Electrical Engineering and Computer Sciences at the University of California at Berkeley. His research interests include nonlinear control theory hybrid systems inertial navigation systems with applications to unmanned aerial vehicles. He received the Distinguished M.Phil. Thesis Award of the Faculty of Engineering The Chinese University of Hong Kong in 1994. He was a consultant of SRI International in 1998. Currently he is the team leader of the Berkeley AeRobot Team and a delegate of The Graduate Assembly University of California at Berkeley. He is a student member of IEEE and SIAM. S. Shankar Sastry received his Ph.D. degree in 1981 from the University of California Berkeley. He was on the faculty of MIT from 1980-82 and Harvard University as a Gordon McKay professor in 1994. He is currently a Professor of Electrical Engineering and Computer Sciences and Bioengineering and Director of the Electronics Research Laboratory at Berkeley. He has held visiting appointments at the Australian National University Canberra the University of Rome Scuola Normale and University of Pisa the CNRS laboratory LAAS in Toulouse (poste rouge) and as a Vinton Hayes Visiting fellow at the Center for Intelligent Control Systems at MIT. His areas of research are nonlinear and adaptive control robotic telesurgery control of hybrid systems and biological motor control. He is a coauthor (with M. Bodson) of “Adaptive Control: Stability Convergence and Robustness Prentice Hall 1989.” and (with R. Murray and Z. Li) of “A Mathematical Introduction to Robotic Manipulati

In this paper, we use computer vision as a feedback sensor in a control loop for landing an unmanned air vehicle (UAV) on a landing pad. The vision problem we address here is then a special case of the classic ego-motion estimation problem since all feature points lie on a planar surface (the landing pad). We study together the discrete and differential versions of the ego-motion estimation, in order to obtain both position and velocity of the UAV relative to the landing pad. After briefly reviewing existing algorithm for the discrete case, we present, in a unified geometric framework, a new estimation scheme for solving the differential case. We further show how the obtained algorithms enable the vision sensor to be placed in the feedback loop as a state observer for landing control. These algorithms are linear, numerically robust, and computationally inexpensive hence suitable for real-time implementation. We present a thorough performance evaluation of the motion estimation algorithms under varying levels of image measurement noise, altitudes of the camera above the landing pad, and different camera motions relative to the landing pad. A landing controller is then designed for a full dynamic model of the UAV. Using geometric nonlinear control theory, the dynamics of the UAV are decoupled into an inner system and outer system. The proposed control scheme is then based on the differential flatness of the outer system. For the overall closed-loop system, conditions are provided under which exponential stability can be guaranteed. In the closed-loop system, the controller is tightly coupled with the vision based state estimation and the only auxiliary sensor are accelerometers for measuring acceleration of the UAV. Finally, we show through simulation results that the designed vision-in-the-loop controller generates stable landing maneuvers even for large levels of image measurement noise. Experiments on a real UAV will be presented in future work.

关键词： Motion estimation computer vision based control unmanned air vehicle differential flatness

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Structuring Time Domain Blind Source Separation Algorithms for CASA Integration

Structuring Time Domain Blind Source Separation Algorithms f...

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2006 ISCA Tutorial and Research Workshop on Statistical and Perceptual Audio Processing, SAPA 2006

作者： Schölling, Björn Heckmann, Martin Joublin, Frank Goerick, Christian Honda Research Institute Europe GmbH Offenbach am MainD-63073 Germany Control Theory and Robotics Lab Darmstadt University of Technology DarmstadtD-64283 Germany

Most algorithms based on Computational Auditory Scene Analysis (CASA) for binaural speech separation do not have the ability to inhibit already localized and for a long time present sources in the auditory scene. This has the major drawback that the auditory cues of weaker and new sources are subject to interference from already localized and perceived signals and the separation performance is worse if the signals overlap in their processing domain. In this paper we outline how one can build intuitively a separation system that has this inhibition feature. The main block and starting point of our derivation is a simple cross correlation based localization system with two microphones. The inhibition is achieved by feeding back localization results to a filter and sum structure that cancels localized sounds. Interestingly, our intuitive approach leads to a special case of a well known time domain blind source separation algorithm which was derived from a statistical signal processing viewpoint and exhibits good convergence even in reverberant environments. Finally, we discuss how the insights gained from building a blind source separation this way can be used to integrate CASA techniques. © SAPA 2006. All rights reserved.

关键词： Blind source separation

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Modeling the precedence effect for binaural sound source localization in noisy and echoic environments

Modeling the precedence effect for binaural sound source loc...

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INTERSPEECH 2006 and 9th International Conference on Spoken Language Processing, INTERSPEECH 2006 - ICSLP

作者： Heckmann, Martin Rodemann, Tobias Schölling, Björn Joublin, Frank Goerick, Christian Honda Research Institute Europe GmbH Carl-Legien-Strasse 30 D-63073 Offenbach/Main Germany Darmstadt University of Technology Institute for Automatic Control Control Theory and Robotics Lab. Landgraf-Georg-Str. 4 D-64283 Darmstadt Germany

ISBN: (纸本)9781604234497

We present a new way of modelling the Precedence Effect to enable the robust measurement of localization cues (ITD and IID) in echoic environments. Based on this we developed a localization system which is inspired by the auditory system of mammals. It uses a Gammatone filter bank for preprocessing and extracts the ITD cue via zero crossings (IID calculation is straight forward). The mapping between the cue values and the different angles is learned offline which facilitates the adaptation to different head geometries. The performance of the system is demonstrated by localization results for two simultaneous speakers and the mixture of a speaker, music, and fan noise in a normal meeting room. A real-time demonstrator of the system is presented in [1].

关键词： Acoustic generators

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A passivity based Cartesian impedance controller for flexible joint robots - part I: torque feedback and gravity compensation

A passivity based Cartesian impedance controller for flexibl...

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IEEE International Conference on robotics and Automation (ICRA)

作者： C. Ott A. Albu-Schaffer A. Kugi S. Stamigioli G. Hirzinger Institute of Robotics and Mechatronics German AerosPace Center (DLR) Germany Chair of System Theory and Automatic Control Saarland University Germany

In this paper a novel approach to the Cartesian impedance control problem for robots with flexible joints is presented. The proposed controller structure is based on simple physical considerations, which are motivating the extension of classical position feedback by an additional feedback of the joint torques. The torque feedback action can be interpreted as a scaling of the apparent motor inertia. Furthermore the problem of gravity compensation is addressed. Finally, it is shown that the closed loop system can be seen as a feedback interconnection of passive systems. Based on this passivity property a proof of asymptotic stability is presented.

关键词： Impedance Torque control Feedback Gravity Robot kinematics Damping robotics and automation control systems Automatic control Robot control

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Optimizing supervision and control for industrial furnaces: Predictive control based design 4

Optimizing supervision and control for industrial furnaces: ...

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4th IFAC Workshop Automatic Systems for Building the Infrastructure in Developing Countries, DECOM-TT 2004

作者： Dimirovski, Georgi M. Dinibütün, A. Talha Vukobratovic, Miomir K. Zhao, J. Faculty of Electrical Engineering MK-1000 Skopje SS Cyril and Methodius University Macedonia Computer Engineering Department Faculty of Engineering Acibadem Dogus University Zeamet Sk. 21 Kadikoy IstanbulTR-34722 Turkey Centre of Robotics and Flexible Automation Institute Mihailo Pupin Belgrade11000 Serbia School of Information Science and Engineering Institute of Control Theory Northeastern University Shenyang Liaoning110004 China

A systems re-engineering technique to integrated control and supervision for applications to industrial multi-zone furnaces has been elaborated by using known theories on generalized predictive control and nonlinear programming. This paper presents the derivation of optimizing equations and inequalities. The design is based on the use of general predictive control to provide optimized set-points under the presumption a well designed regulatory control was implemented at the executive level. Digital implementation of control functions are sought within standard computer process control platform for practical engineering and maintenance reasons. Copyright © 2004 IFAC.

关键词： Integrated control

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Optimizing Supervision and control for Industrial Furnaces: Predictive control Based Design

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IFAC Proceedings Volumes 2004年第19期37卷 17-28页

作者： Georgi M. Dimirovski A. Talha Dinibütün Miomir K. Vukobratovic J. Zhao SS Cyril and Methodius University Faculty of Electrical Engineering MK-1000 Skopje Republic of Macedonia Dogus University Computer Engineering Department Faculty of Engineering Acibadem Zeamet Sk. 21 Kadikoy TR-34722 Istanbul Turkey Institute “Mihailo Pupin” Centre of Robotics and Flexible Automation 11000 Belgrade Serbia and Montenegro Northeastern University School of Information Science and Engineering Institute of Control Theory Shenyang Liaoning 110004 P.R. of China

关键词： Complex time-delay processes generalized predictive control integrated control and supervision optimization set-point control

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Decoupling based Cartesian impedance control of flexible joint robots

Decoupling based Cartesian impedance control of flexible joi...

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IEEE International Conference on robotics and Automation (ICRA)

作者： C. Ott A. Albu-Schaffer A. Kugi G. Hirzinger German Aerospace Center (DLR) Institute of Robotics and Mechatronics Germany German Aerospace Center (DLR) Institute of Robotics and Mechatronics Chair of System Theory and Automatic Control Saarland University USA

This paper addresses the impedance control problem for flexible joint manipulators. An impedance controller structure is proposed, which is based on an exact decoupling of the torque dynamics from the link dynamics. A formal stability analysis of the proposed controller is presented for the general tracking case. Preliminary experimental results are given for a single flexible joint.

关键词： Impedance Robots Torque control Automatic control robotics and automation Stability analysis control systems Manipulator dynamics Aerodynamics Symmetric matrices

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