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Structural controllability on graphs for drifted bilinear systems over Lie groups

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arXiv 2021年

作者： Wang, Xing Li, Bo Li, Jr-Shin Petersen, Ian R. Shi, Guodong Key Laboratory of Mathematics Mechanization Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China School of Mathematical Sciences University of Chinese Academy of Sciences Beijing100049 China Key Laboratory of Mathematics Mechanization Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China Department of Electrical and Systems Engineering Washington University St. LouisMO63130 United States Research School of Engineering Australian National University CanberraACT0200 Australia Australian Center for Field Robotics School of Aerospace Mechanical and Mechatronic Engineering The University of Sydney NSW2006 Australia

In this paper, we study graphical conditions for structural controllability and accessibility of drifted bilinear systems over Lie groups. We consider a bilinear control system with drift and controlled terms that evolves over the special orthogonal group, the general linear group, and the special unitary group. Zero patterns are prescribed for the drift and controlled dynamics with respect to a set of base elements in the corresponding Lie algebra. The drift dynamics must respect a rigid zero-pattern in the sense that the drift takes values as a linear combination of base elements with strictly non-zero coefficients;the controlled dynamics are allowed to follow a free zero pattern with potentially zero coefficients in the configuration of the controlled term by linear combination of the controlled base elements. First of all, for such bilinear systems over the special orthogonal group or the special unitary group, the zero patterns are shown to be associated with two undirected or directed graphs whose connectivity and connected components ensure structural controllability/accessibility. Next, for bilinear systems over the special unitary group, we introduce two edge-colored graphs associated with the drift and controlled zero patterns, and prove structural controllability conditions related to connectivity and the number of edges of a particular color. © 2021, CC BY.

关键词： Lie groups

Robust Localization with Architectural Floor Plans and Depth Camera

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Robust Localization with Architectural Floor Plans and Depth...

IEEE/SICE International Symposium on System Integration

作者： Yoshiaki Watanabe Karinne Ramirez Amaro Bahriye Ilhan Taku Kinoshita Thomas Bock Gordon Cheng Robotics Group Research and Development Institute Takenaka Corporation Japan Department of Electrical Engineering Chalmers University of Technology Sweden Division of Project and Construction Management Faculty of Architecture Istanbul Technical University Turkey Division of Human Mechanical Systems and Design Graduate School of Engineering Hokkaido University Japan Chair of Building Realization and Robotics Technical University of Munich Germany Institute for Cognitive Systems Technical University of Munich Germany

ISBN: (数字)9781728166674

ISBN: (纸本)9781728166681

Autonomous navigation is of great importance for service robots. Such robots need various technologies, especially localization, and mapping. In this paper, we focus on the localization problem. Commonly, to solve the localization problem, the creation of a map is needed. However, creating the map takes considerable time and costs. Therefore, one solution for indoor environment is to use architectural floor plans since buildings have own floor plans. If a robot can use them for localization, it enables users to cut the time and costs for creating the map from scratch. However, the floor plans sometimes do not match with a real building. Besides, sensor measurement sometimes contains objects such as a pedestrian, which are not contained in the floor plans. In this paper, we propose a localization algorithm with architectural floor plans that is robust to such inconsistencies. The algorithm estimates a robot coordinate by matching the floor plan with the point clouds obtained from depth images. Outliers derived from the inconsistencies in the point clouds are filtered with plane information from the depth images with the Generalized ICP framework. We tested our algorithm with floor plans in a real building and in a simulator as a case study. The results show that our algorithm can localize a robot with average more than twice accuracy compared to AMCL and be used for real-time applications.

关键词： Robot kinematics Three-dimensional displays Robot sensing systems Buildings Two dimensional displays Cloud computing

Globally exponentially stable attitude observer with Earth velocity estimation

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Globally exponentially stable attitude observer with Earth v...

作者： Batista, Pedro Silvestre, Carlos Oliveira, Paulo Institute for Systems and Robotics Instituto Superior Técnico Universidade de Lisboa Lisboa Portugal Department of Electrical and Computer Engineering Faculty of Science and Technology of the University of Macau China Department of Mechanical Engineering Instituto Superior Técnico Universidade de Lisboa Lisboa Portugal

This paper presents a novel observer for attitude estimation based on a triad of high-grade rate gyros aided by a body-fixed vector measurement of a constant inertial vector, departing from the majority of solutions that consider at least two of these vectors. A cascade approach is proposed, where the first block estimates a vector that is related to the angular velocity of the Earth and a second block estimates the attitude. While the topological characteristics are relaxed in the attitude observer so that global exponential stability is achieved, an additional stage is also devised that yields estimates directly on the special orthogonal group, preserving global convergence of the estimation error. Simulation results with realistic sensor noise were performed, including extensive Monte Carlo runs. These results illustrate the convergence of the proposed solution, as well as the achievable performance and robustness to sensor noise. © 2019 Chinese Automatic Control Society and John Wiley & Sons Australia, Ltd

关键词： Angular velocity

Passive Quadrupedal Gait Synchronization for Extra Robotic Legs Using a Dynamically Coupled Double Rimless Wheel Model

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arXiv 2020年

作者： Gonzalez, Daniel J. Harry Asada, H. Robotics Research Center Department of Electrical Engineering and Computer Science United States Military Academy West PointNY10996 United States d’Arbeloff Laboratory for Information Systems and Technology Department of Mechanical Engineering Massachusetts Institute of Technology CambridgeMA02139 United States

The Extra Robotic Legs (XRL) system is a robotic augmentation worn by a human operator consisting of two articulated robot legs that walk with the operator and help bear a heavy backpack payload. It is desirable for the Human-XRL quadruped system to walk with the rear legs lead the front by 25% of the gait period, minimizing the energy lost from foot impacts while maximizing balance stability. Unlike quadrupedal robots, the XRL cannot command the human’s limbs to coordinate quadrupedal locomotion. Using a pair of Rimless Wheel models, it is shown that the systems coupled with a spring and damper converge to the desired 25% phase difference. A Poincaré return map was generated using numerical simulation to examine the convergence properties to different coupler design parameters, and initial conditions. The Dynamically Coupled Double Rimless Wheel system was physically realized with a spring and dashpot chosen from the theoretical results, and initial experiments indicate that the desired synchronization properties may be achieved within several steps using this set of passive components alone. Copyright © 2020, The Authors. All rights reserved.

关键词： Exoskeleton (robotics)

A Survey on Deep Learning for Skin Lesion Segmentation

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arXiv 2022年

作者： Mirikharaji, Zahra Abhishek, Kumar Bissoto, Alceu Barata, Catarina Avila, Sandra Valle, Eduardo Celebi, M. Emre Hamarneh, Ghassan Medical Image Analysis Lab School of Computing Science Simon Fraser University BurnabyV5A 1S6 Canada Institute for Systems and Robotics Instituto Superior Técnico Avenida Rovisco Pais Lisbon1049-001 Portugal RECOD.ai Lab Institute of Computing University of Campinas Av. Albert Einstein 1251 Campinas13083-852 Brazil RECOD.ai Lab School of Electrical and Computing Engineering University of Campinas Av. Albert Einstein 400 Campinas13083-952 Brazil Department of Computer Science and Engineering University of Central Arkansas 201 Donaghey Ave. ConwayAR72035 United States

Skin cancer is a major public health problem that could benefit from computer-aided diagnosis to reduce the burden of this common disease. Skin lesion segmentation from images is an important step toward achieving this goal. However, the presence of natural and artificial artifacts (e.g., hair and air bubbles), intrinsic factors (e.g., lesion shape and contrast), and variations in image acquisition conditions make skin lesion segmentation a challenging task. Recently, various researchers have explored the applicability of deep learning models to skin lesion segmentation. In this survey, we cross-examine 177 research papers that deal with deep learning-based segmentation of skin lesions. We analyze these works along several dimensions, including input data (datasets, preprocessing, and synthetic data generation), model design (architecture, modules, and losses), and evaluation aspects (data annotation requirements and segmentation performance). We discuss these dimensions both from the viewpoint of select seminal works, and from a systematic viewpoint, examining how those choices have influenced current trends, and how their limitations should be addressed. To facilitate comparisons, we summarize all examined works in a comprehensive table as well as an interactive table available online. Copyright © 2022, The Authors. All rights reserved.

关键词： Computer aided diagnosis

LSTM and GPT-2 Synthetic Speech Transfer Learning for Speaker Recognition to Overcome Data Scarcity

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arXiv 2020年

作者： Bird, Jordan J. Faria, Diego R. Ekárt, Anikó Premebida, Cristiano Ayrosa, Pedro P.S. ARVIS Lab Aston University Birmingham United Kingdom School of Engineering and Applied Science Aston University United Kingdom Institute of Systems and Robotics Department of Electrical and Computer Engineering University of Coimbra Coimbra Portugal Department of Computer Science & LABTED State University of Londrina Londrina Brazil

In speech recognition problems, data scarcity often poses an issue due to the willingness of humans to provide large amounts of data for learning and classification. In this work, we take a set of 5 spoken Harvard sentences from 7 subjects and consider their MFCC attributes. Using character level LSTMs (supervised learning) and OpenAI’s attention-based GPT-2 models, synthetic MFCCs are generated by learning from the data provided on a per-subject basis. A neural network is trained to classify the data against a large dataset of Flickr8k speakers and is then compared to a transfer learning network performing the same task but with an initial weight distribution dictated by learning from the synthetic data generated by the two models. The best result for all of the 7 subjects were networks that had been exposed to synthetic data, the model pre-trained with LSTM-produced data achieved the best result 3 times and the GPT-2 equivalent 5 times (since one subject had their best result from both models at a draw). Through these results, we argue that speaker classification can be improved by utilising a small amount of user data but with exposure to synthetically-generated MFCCs which then allow the networks to achieve near maximum classification scores. Copyright © 2020, The Authors. All rights reserved.

关键词： Classification (of information)

Chattering-free fixed-time sliding mode control for bilateral teleoperation under unknown time-varying delay via disturbance and state observers

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Advanced Control for Applications: Engineering and Industria...

Advanced Control for Applications: engineering and Industrial systems 2020年第4期2卷

作者： Abadi, Ali Soltani Sharif Hosseinabadi, Pooyan Alinaghi Mekhilef, Saad Ordys, Andrzej Department of Electrical Engineering Faculty of Engineering Yazd University Yazd Iran Faculty of Engineering University of Malaya Kuala Lumpur Malaysia School of Software and Electrical Engineering Faculty of Science Engineering and Technology Swinburne University of Technology Melbourne Australia Center of Research Excellence in Renewable Energy and Power Systems King Abdulaziz University Jeddah Saudi Arabia The Institute of Automatic Control and Robotics Faculty of Mechatronics Warsaw University of Technology Warsaw Poland

This paper proposes a new chattering-free Fixed-time Observer-Based Sliding Mode Control (FOBSMC) scheme for synchronization of two bilateral teleoperations under unknown time-varying delay. The system is subjected to unknown disturbances which are estimated in a fixed time by utilizing the Disturbance Observer-based SMC scheme. The fixed-time State Observer-based SMC is designed to estimate the unmeasured velocity state, while the position state is assumed to be available. Fixed-time stability method is used to provide the system convergence time independently of initial states. A FOBSMC scheme is first designed for master system of bilateral teleoperation under unknown time-varying delay to track the environmental torque by the human operating torque in the presence of time delay in the communication channel, as well as estimating the unknown disturbances and unmeasured states. A FOBSMC scheme is designed to synchronize slave system to master system in the presence of time delay in the communication channel, as well as estimating disturbances and states. The stability analysis is performed for closed-loop system of combined controller-observer by using Lyapunov theory. The efficacy of the proposed method to fulfill a good transparency and stability under time-varying communication delays is tested by performing numerical simulation in Simulink/MATLAB. © 2020 John Wiley & Sons Ltd.

关键词： Time delay

Lecture Notes in Networks and Systems

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Preface

Lecture Notes in Networks and systems 2024年 1076 LNNS卷 v-vii页

作者： Biele, Cezary Kacprzyk, Janusz Kopeć, Wieslaw Możaryn, Jakub Owsiński, Jan W. Romanowski, Andrzej Sikorski, Marcin National Information Processing Institute Warszaw Poland Polish Academy of Sciences Systems Research Institute Warsaw Poland Polish-Japanese Academy of Information Technology Warsaw Poland Institute of Automatic Control and Robotics Faculty of Mechatronics Warsaw University of Technology Warsaw Poland Institute of Applied Computer Science Faculty of Electrical Electronic Computer and Control Engineering Lódż University of Technology LODZ Poland Department of Applied Informatics in Management Faculty of Management and Economics Gdańsk University of Technology Gdańsk Poland

Accelerating surgical robotics research: A review of 10 years with the da Vinci research kit

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arXiv 2021年

作者： D’Ettorre, Claudia Mariani, Andrea Stilli, Agostino Rodriguez y Baena, Ferdinando Valdastri, Pietro Deguet, Anton Kazanzides, Peter Taylor, Russell H. Fischer, Gregory S. DiMaio, Simon P. Menciassi, Arianna Stoyanov, Danail University College London LondonW1W 7EJ United Kingdom Pisa Italy Mechanical Engineering Department Imperial College London United Kingdom STORM Lab Institute of Robotics Autonomous Systems and Sensing School of Electronic and Electrical Engineering University of Leeds Leeds United Kingdom Johns Hopkins University Baltimore United States Automation and Interventional Medicine Laboratory Worcester Polytechnic Institute WorcesterMA United States Intuitive Surgical Inc SunnyvaleCA United States

Robotic-assisted surgery is now well-established in clinical practice and has become the gold standard clinical treatment option for several clinical indications. The field of robotic-assisted surgery is expected to grow substantially in the next decade with a range of new robotic devices emerging to address unmet clinical needs across different specialties. A vibrant surgical robotics research community is pivotal for conceptualizing such new systems as well as for developing and training the engineers and scientists to translate them into practice. The da Vinci Research Kit (dVRK), an academic and industry collaborative effort to re-purpose decommissioned da Vinci surgical systems (Intuitive Surgical Inc, CA, USA) as a research platform for surgical robotics research, has been a key initiative for addressing a barrier to entry for new research groups in surgical robotics. In this paper, we present an extensive review of the publications that have been facilitated by the dVRK over the past decade. We classify research efforts into different categories and outline some of the major challenges and needs for the robotics community to maintain this initiative and build upon it. © 2021, CC BY.

关键词： Robotic surgery