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arXiv 2019年

作者： Talaeizadeh, Amin Antunes, Duarte Pishkenari, Hossein Nejat Alasty, Aria Mechanical Engineering Department Sharif University of Technology Tehran Iran Control Systems Technology Group Department of Mechanical Engineering Eindhoven University of Technology Eindhoven5600MB Netherlands

It is well-known that helicopters descending fast may enter the so-called Vortex Ring State (VRS), a region in the velocity space where the blades lift differs significantly from regular regions. This may lead to instability and therefore this region is avoided, typically by increasing the horizontal speed. This paper researches this phenomenon in the context of small-scale quadcopters. The region corresponding to the VRS is identified by combining first-principles modeling and wind-tunnel experiments. Moreover, we propose that the so called Windmill-Brake State (WBS) or autorotation region should also be avoided for quadcopters, which is not necessarily the case for helicopters. A model is proposed for the velocity constraints that the quadcopter must meet to avoid these regions. Then, the problem of designing optimal time descend trajectories that avoid the VRS and WBS regions is tackled. Finally, the optimal trajectories are implemented on a quadcopter. The flight tests show that by following the designed trajectories, the quadcopter is able to descend considerably faster than purely vertical trajectories that also avoid the VRS and WBS. Copyright © 2019, The Authors. All rights reserved.

关键词： Vortex flow

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Opportunities and challenges for monitoring terrestrial biodiversity in the robotics age

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Nature Ecology and Evolution 2025年第6期9卷 1031-1042页

作者： Pringle, Stephen Dallimer, Martin Goddard, Mark A. Le Goff, Léni K. Hart, Emma Langdale, Simon J. Fisher, Jessica C. Abad, Sara-Adela Ancrenaz, Marc Angeoletto, Fabio Auat Cheein, Fernando Austen, Gail E. Bailey, Joseph J. Baldock, Katherine C. R. Banin, Lindsay F. Banks-Leite, Cristina Barau, Aliyu S. Bashyal, Reshu Bates, Adam J. Bicknell, Jake E. Bielby, Jon Bosilj, Petra Bush, Emma R. Butler, Simon J. Carpenter, Dan Clements, Christopher F. Cully, Antoine Davies, Kendi F. Deere, Nicolas J. Dodd, Michael Drinkwater, Rosie Driscoll, Don A. Dutilleux, Guillaume Dyrmann, Mads Edwards, David P. Farhadinia, Mohammad S. Faruk, Aisyah Field, Richard Fletcher, Robert J. Foster, Chris W. Fox, Richard Francksen, Richard M. Franco, Aldina M. A. Gainsbury, Alison M. Gardner, Charlie J. Giorgi, Ioanna Griffiths, Richard A. Hamaza, Salua Hanheide, Marc Hayward, Matt W. Hedblom, Marcus Helgason, Thorunn Heon, Sui P. Hughes, Kevin A. Hunt, Edmund R. Ingram, Daniel J. Jackson-Mills, George Jowett, Kelly Keitt, Timothy H. Kloepper, Laura N. Kramer-Schadt, Stephanie Labisko, Jim Labrosse, Frédéric Lawson, Jenna Lecomte, Nicolas de Lima, Ricardo F. Littlewood, Nick A. Marshall, Harry H. Masala, Giovanni L. Maskell, Lindsay C. Matechou, Eleni Mazzolai, Barbara McConnell, Alistair Melbourne, Brett A. Miriyev, Aslan Nana, Eric Djomo Ossola, Alessandro Papworth, Sarah Parr, Catherine L. Payo-Payo, Ana Perry, Gad Pettorelli, Nathalie Pillay, Rajeev Potts, Simon G. Prendergast-Miller, Miranda T. Qie, Lan Rolley-Parnell, Persie Rossiter, Stephen J. Rowcliffe, Marcus Rumble, Heather Sadler, Jon P. Sandom, Christopher J. Sanyal, Asiem Schrodt, Franziska Sethi, Sarab S. Shabrani, Adi Siddall, Robert Smith, Simón C. Snep, Robbert P. H. Soulsbury, Carl D. Stanley, Margaret C. Stephens, Philip A. Stephenson, P.J. Struebig, Matthew J. Studley, Matthew Svátek, Martin Tang, Gilbert Taylor, Nicholas K. Umbers, Kate D. L. Ward, Robert J. White, Patrick J. C. Whittingham, Mark J. Wich, Serge Williams, Christopher D. Yakubu, Ibrahim B. Yoh, Natalie Durrell Institute of Conservation and Ecology (DICE) School of Natural Sciences University of Kent Canterbury United Kingdom Centre for Environmental Policy Imperial College London London United Kingdom Department of Geography and Environmental Sciences Northumbria University Newcastle upon Tyne United Kingdom School of Computing Engineering and the Built Environment Edinburgh Napier University Edinburgh United Kingdom Synthotech Ltd Milner Court Hornbeam Square Harrogate United Kingdom Mechanical Engineering Department University College London London United Kingdom HUTAN SWD Kota Kinabalu Malaysia Programa de Pós-Graduação em Gestão e Tecnologia Ambiental da Universidade Federal de Rondonópolis Rondonópolis Brazil Department of Engineering Harper Adams University Newport United Kingdom Applied Ecology Research Group School of Life Sciences Anglia Ruskin University Cambridge United Kingdom Centre for Ecology and Hydrology Penicuik United Kingdom Department of Life Sciences Imperial College London Silwood Park Campus Ascot United Kingdom Department of Urban and Regional Planning Faculty of Earth and Environmental Sciences Bayero University Kano Nigeria Greenhood Nepal Kathmandu Nepal Animal Rural & Environmental Sciences Nottingham Trent University Nottinghamshire United Kingdom School of Biological and Environmental Sciences Liverpool John Moores University Liverpool United Kingdom Lincoln Centre for Autonomous Systems University of Lincoln Lincoln United Kingdom Royal Botanic Garden Edinburgh Edinburgh United Kingdom School of Biological Sciences University of East Anglia Norwich Research Park Norwich United Kingdom Digital Ecology Limited Bristol United Kingdom School of Biological Sciences University of Bristol Bristol United Kingdom Department of Computing Imperial College London London United Kingdom Department of Ecology and Evolutionary Biology University of Colorado Boulder CO United States Faculty of Science Technology Engineering

With biodiversity loss escalating globally, a step change is needed in our capacity to accurately monitor species populations across ecosystems. Robotic and autonomous systems (RAS) offer technological solutions that may substantially advance terrestrial biodiversity monitoring, but this potential is yet to be considered systematically. We used a modified Delphi technique to synthesize knowledge from 98 biodiversity experts and 31 RAS experts, who identified the major methodological barriers that currently hinder monitoring, and explored the opportunities and challenges that RAS offer in overcoming these barriers. Biodiversity experts identified four barrier categories: site access, species and individual identification, data handling and storage, and power and network availability. Robotics experts highlighted technologies that could overcome these barriers and identified the developments needed to facilitate RAS-based autonomous biodiversity monitoring. Some existing RAS could be optimized relatively easily to survey species but would require development to be suitable for monitoring of more ‘difficult’ taxa and robust enough to work under uncontrolled conditions within ecosystems. Other nascent technologies (for instance, new sensors and biodegradable robots) need accelerated research. Overall, it was felt that RAS could lead to major progress in monitoring of terrestrial biodiversity by supplementing rather than supplanting existing methods. Transdisciplinarity needs to be fostered between biodiversity and RAS experts so that future ideas and technologies can be codeveloped effectively. © The Author(s) 2025.

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An in vitro validation method for inertial-sensor-to-bone alignment

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Gait & Posture 2020年 81卷 385-387页

作者： Weygers, I. Kok, M. Seel, T. Olsson, F. De Vroey, H. Shah, D. Taylan, O. Hallez, H. Scheys, L. Claeys, K. KU Leuven campus Bruges Department of Movement and Rehabilitation Sciences Bruges Belgium TU Delft Department of Mechanical- Maritime and Materials Engineering Delft Netherlands Technische Universität Berlin Control Systems Group Berlin Germany Uppsala University Department of Information Technology- Systems and Control Uppsala Sweden KU Leuven Institute for Orthopaedic Research and Training Leuven Belgium KU Leuven campus Bruges Department of Computer Sciences Bruges Belgium University Hospitals Leuven Division of Orthopaedics Leuven Belgium

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Visual-based Kinematics and Pose Estimation for Skid-Steering Robots

arXiv

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arXiv 2020年

作者： Zuo, Xingxing Zhang, Mingming Wang, Mengmeng Chen, Yiming Huang, Guoquan Liu, Yong Li, Mingyang Department of Informatics Technical University of Munich Munich80333 Germany Mingming Zhang Yiming Chen Mingyang Li are with Alibaba Group Hangzhou311121 China Institute of Cyber-Systems and Control Zhejiang University Hangzhou310027 China Department of Mechanical Engineering University of Delaware NewarkDE19716 United States

To build commercial robots, skid-steering mechanical design is of increased popularity due to its manufacturing simplicity and unique mechanism. However, these also cause significant challenges on software and algorithm design, especially for the pose estimation (i.e., determining the robot’s rotation and position) of skid-steering robots, since they change their orientation with an inevitable skid. To tackle this problem, we propose a probabilistic sliding-window estimator dedicated to skid-steering robots, using measurements from a monocular camera, the wheel encoders, and optionally an inertial measurement unit (IMU). Specifically, we explicitly model the kinematics of skid-steering robots by both track instantaneous centers of rotation (ICRs) and correction factors, which are capable of compensating for the complexity of track-to-terrain interaction, the imperfectness of mechanical design, terrain conditions and smoothness, etc. To prevent performance reduction in robots’ long-term missions, the time- and location- varying kinematic parameters are estimated online along with pose estimation states in a tightly-coupled manner. More importantly, we conduct in-depth observability analysis for different sensors and design configurations in this paper, which provides us with theoretical tools in making the correct choice when building real commercial robots. In our experiments, we validate the proposed method by both simulation tests and real-world experiments, which demonstrate that our method outperforms competing methods by wide margins. Note to Practitioners— This paper was motivated by the problem of long-term pose estimation of the commonly commercial-used skid-steering robots with only low-cost sensors. Skid-steering robots change their orientation with a skid, which poses a significant challenge for pose estimation when using the wheel encoders. We propose to online estimate the robot’s kinematics, which succeeds in compensating for the complexity of track-to

关键词： Kinematics

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An Analysis of Dynamic Lighting control in Landscape Offices

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IFAC-PapersOnLine 2018年第4期51卷 232-237页

作者： Juchem, Jasper Lefebvre, Stijn Mac, Thi Thoa Ionescu, Clara M. Ghent University Dynamical Systems and Control research group Technologiepark 914 Ghent9052 Belgium School of Mechanical Engineering Hanoi University of Science and Technology No. 1 Dai Co Viet Viet Nam

This paper makes a discussion on the control of light in landscape offices. This is a feature of modern office buildings, with increasing incidence as the number of employees increase while individual space allocation decreases. This can have already an impact on the efficiency and versatility of coping with stress situations of the employees. Apart from the stress induced by the lack of space and privacy, the light level is yet another important factor. Poor light or extreme illumination, or even more relevant: periodic shadow disturbance (i.e. windmills) are all increasing factors of stress levels. control of illumination in a closed environment seem to be a feasible solution, but perhaps not very useful for the overall mood of the employee. Windows and possibility to see green patches, sunlight, have significant positive influence on the overall working conditions. Although easy to implement and broadly available in industrial lighting components, PID control has some limitations which we discuss here. © 2018

关键词： Multi agent systems Convergence of numerical methods Lighting Machinery Office buildings Personnel Robustness (control systems) Three term control systems Wind power Closed environment Dynamic lighting Extreme illuminations Feasible solution Light control systems Space allocation Stress levels Stress induced

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Towards an Ontology for Scenario Definition for the Assessment of Automated Vehicles: An Object-Oriented Framework

arXiv

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arXiv 2020年

作者： de Gelder, Erwin Paardekooper, Jan-Pieter Saberi, Arash Khabbaz Elrofai, Hala den Camp, Olaf Op Kraines, Steven Ploeg, Jeroen De Schutter, Bart TNO Dept. of Integrated Vehicle Safety Helmond Netherlands Delft University of Technology Delft Center for Systems and Control Delft Netherlands Radboud University Donders Institute for Brain Cognition and Behaviour Nijmegen Netherlands Symphony Co. Tokyo Japan 2getthere Utrecht Netherlands Eindhoven University of Technology Dept. of Mechanical Engineering Dynamics and Control group Eindhoven Netherlands

The development of new assessment methods for the performance of automated vehicles is essential to enable the deployment of automated driving technologies, due to the complex operational domain of automated vehicles. One contributing method is scenario-based assessment in which test cases are derived from real-world road traffic scenarios obtained from driving data. Given the complexity of the reality that is being modeled in these scenarios, it is a challenge to define a structure for capturing these scenarios. An intensional definition that provides a set of characteristics that are deemed to be both necessary and sufficient to qualify as a scenario assures that the scenarios constructed are both complete and intercomparable. In this article, we develop a comprehensive and operable definition of the notion of scenario while considering existing definitions in the literature. This is achieved by proposing an object-oriented framework in which scenarios and their building blocks are defined as classes of objects having attributes, methods, and relationships with other objects. The object-oriented approach promotes clarity, modularity, reusability, and encapsulation of the objects. We provide definitions and justifications of each of the terms. Furthermore, the framework is used to translate the terms in a coding language that is publicly available. Copyright © 2020, The Authors. All rights reserved.

关键词： Reusability

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Feedforward Motion control: From Batch-to-Batch Learning to Online Parameter Estimation

Feedforward Motion Control: From Batch-to-Batch Learning to ...

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American control Conference

作者： Noud Mooren Gert Witvoet Tom Oomen Faculty of Mechanical Engineering Control Systems Technology Group Eindhoven University of Technology Eindhoven MB 5600 The Netherlands TNO Technical Sciences Delft CK 2628 The Netherlands

ISBN: (纸本)9781538679012;9781538679265

Feedforward control is essential in high-performance motion control. The aim of this paper is to develop a unified framework for automatic feedforward optimization from both batch-wise data sets as well as real-time data. A statistical analysis is employed to analyze the effect of noise, i.e., an iteration varying disturbance, on feedforward controller performance. This provides new insights, both potential advantages as well as possible hazards of real-time estimation are considered. Finally, a case study confirms and illustrates the results.

关键词： FEEDFORWARD Time Estimation FEEDFORWARD control Noise effects Case studies Parameter estimation WELLS

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controlling Heterogeneous Stochastic Growth Processes on Lattices with Limited Resources

Controlling Heterogeneous Stochastic Growth Processes on Lat...

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IEEE Annual Conference on Decision and control

作者： Ravi N. Haksar Friedrich Solowjow Sebastian Trimpe Mac Schwager Department of Mechanical Engineering Stanford University Stanford USA Intelligent Control Systems Group Max Planck Institute for Intelligent Systems Stuttgart Germany Department of Aeronautics & Astronautics Stanford University Stanford USA

ISBN: (数字)9781728113982

ISBN: (纸本)9781728113999

We consider controlling a heterogeneous stochastic growth process defined on a lattice with a control resource constraint. We address heterogeneous effects in three respects: (i) the process grows at different rates for different directions on the lattice, (ii) the nodes of the lattice may have different dynamics, and (iii) nodes may have different priorities for control. We use a forest wildfire driven by a west-to-east wind near an urban region to illustrate our approach, where preserving the urban region is prioritized over the forest. We leverage the Galton-Watson branching process as an approximation to predict the process growth rate and stopping time and to construct effective control policies. Our approach is also applicable to processes with an underlying graph structure, such as robot swarms, disease epidemics, computer viruses, and social networks. In contrast to prior work, we directly address heterogeneous models and our framework allows for a broader class of control policy descriptions. Lastly, we characterize the conditions under which a control policy will stabilize a supercritical heterogeneous growth process.

关键词： Lattices Urban areas Forestry Vegetation Process control Markov processes

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Experimental Validation of Vehicle Velocity, Attitude and IMU Bias Estimation

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IFAC-PapersOnLine 2019年第8期52卷 118-123页

作者： Wouter J. Scholte Vicent Rodrigo Marco Henk Nijmeijer Mechanical Engineering Department Eindhoven University of Technology Eindhoven Netherlands Research and Development Daimler AG 71059 Sindelfingen Germany Control Systems Group Department of Electrical Engineering and Computer Science Technische Universität Berlin D-10587 Berlin Germany

This paper proposes an estimation method for the three dimensional velocity, and the roll and pitch angles of a land vehicle. The usage of low-cost sensors is required for applications in production vehicles. The proposed estimation method uses a low-cost inertial measurement unit (IMU) of which the biases are estimated. A nonlinear system is used to create an observer for simultaneous state and parameter estimation. Experimental results show the potential of this approach in a real world environment.

关键词： Autonomous vehicles State estimation Parameter estimation Sensor fusion Inertial measurement units Motion estimation

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Event-triggered Learning for Linear Quadratic control

arXiv

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arXiv 2019年

作者： Schlüter, Henning Solowjow, Friedrich Trimpe, Sebastian Intelligent Control Systems Group Max Planck Inst. for Intelligent Systems Stuttgart70569 Germany Institute for Systems Theory and Automatic Control University of Stuttgart Stuttgart70550 Germany Institute for Data Science in Mechanical Engineering RWTH Aachen University Aachen52068 Germany

When models are inaccurate, the performance of model-based control will degrade. For linear quadratic control, an event-triggered learning framework is proposed that automatically detects inaccurate models and triggers the learning of a new process model when needed. This is achieved by analyzing the probability distribution of the linear quadratic cost and designing a learning trigger that leverages Chernoff bounds. In particular, whenever empirically observed cost signals are located outside the derived confidence intervals, we can provably guarantee that this is with high probability due to a model mismatch. With the aid of numerical and hardware experiments, we demonstrate that the proposed bounds are tight and that the event-triggered learning algorithm effectively distinguishes between inaccurate models and probabilistic effects such as process noise. Thus, a structured approach is obtained that decides when model learning is beneficial. Copyright © 2019, The Authors. All rights reserved.

关键词： Stochastic systems

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