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arXiv 2018年

作者： Kungurtsev, Vyacheslav Mitchell, Tim Vyhlídal, Tomáš Department of Computer Science Faculty of Electrical Engineering Czech Technical University in Prague Max Planck Institute for Dynamics of Complex Technical Systems Magdeburg Germany Department of Instrumentation and Control Engineering Faculty of Mechanical Engineering Czech Institute of Informatics Robotics and Cybernetics Czech Technical University in Prague

We present a detailed set of performance comparisons of two state-of-the-art solvers for the application of designing time-delay compensators, an important problem in the field of robust control. Formulating such robust control mechanics as constrained optimization problems often involves objective and constraint functions that are both nonconvex and nonsmooth, both of which present significant challenges to many solvers and their end-users hoping to obtain good solutions to these problems. In our particular engineering task, the main difficulty in the optimization arises in a nonsmooth and nonconvex stability constraint, which states that the infinite spectrum of zeros of the so-called shaper should remain in the open left half-plane. To perform our evaluation, we make use β-relative minimization profiles, recently introduced visualization tools that are particularly suited for benchmarking solvers on nonsmooth, nonconvex, constrained optimization problems. Furthermore, we also introduce new visualization tools, called Global-Local Profiles, which for a given problem and a fixed computational budget, assess the tradeoffs of distributing the budget over few or many starting points, with the former getting more budget per point and latter less. Copyright © 2018, The Authors. All rights reserved.

关键词： Robust control

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Dominant four-pole placement in filtered PID control loop with delay

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IFAC-PapersOnLine 2017年第1期50卷 6501-6506页

作者： Fišer J. Zítek P. Vyhlídal T. Department of Instrumentation and Control Engineering Faculty of Mechanical Engineering Czech Technical University in Prague Technická. 4 166 07 Praha 6 Czech Republic Czech Inst. of Informatics Robotics and Control Czech Technical University in Prague Czech Republic

The paper proposes a novel approach to the filter design in the delayed PID control loop. The novel approach is based on the dominant four-pole placement providing all five controller parameters including the filter time constant and damping factor. Moreover, the dominant four-pole placement is carried out iteratively as long as an optimum dominant four-pole placement is achieved by means of the constrained IAE optimization. The constraints considered for the optimization are the dominance of the placed poles and the fixed value of the filter damping factor. The achieved optimum dominant four-pole placement then corresponds to the least IAE obtained under these constraints. Then the filtered PID controller results very close to the ideal PID controller up to the filter cut-off frequency. Finally, the constrained IAE optimization of the disturbance rejection is preferred in the paper. © 2017

关键词： dominant pole placement filtering optimization PID control Time delay systems

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Numerical modelling of non-equilibrium condensation of carbon dioxide (CO2) in a converging-diverging nozzle

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AIP Conference Proceedings 2020年第1期2293卷

作者： Chuang Wen Xiaowei Zhu Yan Yang Hongbing Ding Yuying Yan 1Faculty of Engineering University of Nottingham University Park Nottingham NG7 2RD UK 2Department of Mechanical Engineering Technical University of Denmark Nils Koppels Allé 2800 Kgs. Lyngby Denmark 3Tianjin Key Laboratory of Process Measurement and Control School of Electrical and Information Engineering Tianjin University Tianjin 300072 China 4Center for Fluids & Thermal Engineering University of Nottingham Ningbo China

The condensing flow model is developed to predict the non-equilibrium condensation of CO2 in a converging-diverging nozzle using computational fluid dynamics modelling, which is expected to contribute to the carbon capture and storage. The numerical result shows that the nucleation process of CO2 occurs in the downstream of the nozzle throat where the extremely non-equilibrium state is reached, which generates the maximum value of the nucleation rate of approximately 2.5 x 1018 m−3 s−1. The excessive nucleation induces the growth of the condensed droplet and the liquid fraction increase in the diverging part of the supersonic nozzle with achieving 8% of the total mass at the nozzle exit.

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Heart work analysis by means of recurrence-based methods

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Diagnostyka 2017年第4期18卷 89-96页

作者： Iwaniec, Joanna Iwaniec, Marek AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics Department of Robotics and Mechatronics Mickiewicz Alley 30 Krakow30-059 Poland AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics Department of Process Control Mickiewicz Alley 30 Krakow30-059 Poland

Currently, for the purposes of recorded ECG signals (electrocardiograms) interpretation, the classical methods involving analysis of geometrical properties of the recorded waveforms in time domain are used. Such an analysis consists in determining the values of parameters describing the heart rate and rhythm. However, these indicators can not be treated as an infallible criterion for diagnosis and, moreover, the limits of increasing the accuracy of ECG analysis by increasing the accuracy of determining its characteristic points have already been reached. Therefore, in the paper, for the purposes of analysis of registered ECG signals and acoustical recordings of heart work, it is proposed to use the recurrence plots and RQA analysis methods that consist in searching for the recurrence properties of the registered signals. Application of the recurrence-based methods is natural due to the cyclic character of the heart work while providing patterns characteristic for different cardiac dysfunctions supported by objective, quantitative measures will contribute to early, credible and reliable classification of cardiovascular dysfunction.

关键词： Electrocardiograms

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Introduction

Advances in Industrial Control

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Advances in Industrial control 2018年第9783319610207期 1-18页

作者： Orsag, Matko Korpela, Christopher Oh, Paul Bogdan, Stjepan Laboratory for Robotics and Intelligent Control Systems Faculty of Electrical Engineering and Computing University of Zagreb Zagreb Croatia Department of Electrical Engineering and Computer Science United States Military Academy West PointNY United States Department of Mechanical Engineering University of Nevada Las Vegas Las VegasNV United States

Aerial robotics has reached significant maturity in the last few years. Thus, the number of new unmanned aerial vehicles (UAV) and unmanned aerial systems (UAS), applications, and companies producing them has increased in a very important way. The number of publications and presentations in conferences has also experienced a large increase. Moreover, almost every day we can find articles, videos, and news in the general media related to drones. © Springer International Publishing AG 2018.

关键词： Antennas

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Prognostics estimations with dynamic states

arXiv

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arXiv 2018年

作者： Bao, Rong-Jing Rong, Hai-Jun Yang, Zhi-Xin Chen, Badong State Key Laboratory for Strength and Vibration of Mechanical Structures Shaanxi Key Laboratory of Environment and Control for Flight Vehicle School of Aerospace Xi'an Jiaotong University Xi'an710049 China Department of Electromechanical Engineering Faculty of Science and Technology University of Macau 999078 China Institute of Artificial Intelligence and Robotics School of Electronic and Information Engineering Xi'an Jiaotong University Xi'an710049 China

The health state assessment and remaining useful life (RUL) estimation play very important roles in prognostics and health management (PHM), owing to their abilities to reduce the maintenance and improve the safety of machines or equipment. However, they generally suffer from this problem of lacking prior knowledge to pre-define the exact failure thresholds for a machinery operating in a dynamic environment with a high level of uncertainty. In this case, dynamic thresholds depicted by the discrete states is a very attractive way to estimate the RUL of a dynamic machinery. Currently, there are only very few works considering the dynamic thresholds, and these studies adopted different algorithms to determine the discrete states and predict the continuous states separately, which largely increases the complexity of the learning process. In this paper, we propose a novel prognostics approach for RUL estimation of aero-engines with self-joint prediction of continuous and discrete states, wherein the prediction of continuous and discrete states are conducted simultaneously and dynamically within one learning framework. Copyright © 2018, The Authors. All rights reserved.

关键词： Aircraft engines

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Mixed-sensitivity design of a dynamic controller for systems pre-compensated by input shapers

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IFAC-PapersOnLine 2017年第1期50卷 1304-1309页

作者： Pilbauer D. Michiels W. Vyhlídal T. Hromčík M. Department of Computer Science Katholieke Universiteit Leuven Celestijnenlaan 200A Heverlee B-3001 Belgium CIIRC - Czech Institute of Informatics Robotics and Cybernetics Dept. of Instrumentation and Control Eng. Faculty of Mechanical Engineering Czech Technical University in Prague Technická 4 166 07 Praha 6 Czech Republic M. Hromčík is with Deptartment of Control Engineering Faculty of Electrical Engineering Czech Technical University in Prague Technická 4 166 07 Praha 6 Czech Republic

We employ recent control design algorithms for delay systems to address the mixed sensitivity design of a dynamic controller for multiple degree of freedom systems interconnected with an inverse signal shaper. A delay based inverse shaper is included within a feedback loop in order to eliminate oscillatory modes due to an attached flexible substructure, which has been shown to be advantageous to inducing directly the filtering property by an appropriate controller design. Due to the presence of the inverse shaper, the closed loop dynamics become infinite dimensional. Furthermore we design fixed-order controllers, aiming at an easy implementation. As a consequence of these two features standard techniques from H-infinity control can no longer be used. We present a two-stage method, which firstly makes the closed-loop system asymptotically stable and, secondly, computes a low-order controller that minimizes the H-infinity norm of the weighted closed-loop transfer functions. The approach is grounded in recent methods for fixed-order H-infinity control of delay systems, and the delay-differential algebraic equations (DDAE) modelling and control framework. © 2017

关键词： H-infinity control inverse shapers spectral optimization time-delay

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Discrete PID algorithm with non-uniform sampling – Practical implementation in control system

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AIP Conference Proceedings 2018年第1期2029卷

作者： Miroslaw Kondratiuk Leszek Ambroziak Ewa Pawluszewicz Justyna Janczak Bialystok University of Technology Faculty of Mechanical Engineering Department of Automatic Control and Robotics Wiejska St. 45C 15-351 Bialystok Poland

In the paper the practical implementation of a discrete PID algorithm (DPID) with non-uniform sampling is presented. Studies starts with the discretized well known continuous PID equation with trapezoidal integration method. As a result, difference equation associated with the respect continuous-time model is obtained. Then, MATLAB/Simulink block model is developed in such way that a change sampling time during simulation is enabled. Algorithm is tested numerically in modeled DC motor speed control system. In order to compare results with conventional fixed-step controller, functions of control quality and number of samples are used. In the next step, developed DPID with non-uniform sampling is implemented to microprocessor of Arduino board and put into a series of experimental tests. Obtained results are compared to simulation. In the last part of the paper advantages and disadvantages of the proposed system are described, conclusions are drawn and directions of future work are pointed out.

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Cooperation of two heterogeneous mobile robots

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AIP Conference Proceedings 2018年第1期2029卷

作者： Arkadiusz Nikonowicz Leszek Ambroziak Mirosław Kondratiuk Arkadiusz Bożko Maciej Sulewski Bialystok University of Technology Faculty of Mechanical Engineering Automatic Control and Robotics Department Wiejska St. 45C 15-351 Bialystok Poland

The paper presents cooperation of two heterogeneous mobile robots which are two-wheeled robot and an unmanned aerial vehicle. Those platforms are fully autonomous and are equipped with indoor positioning system to acquire position of each. This paper introduces simple algorithms of path planning in static environment which is known for rover robots and path handling for both platforms. Accurate environment map is given a priori. The main aim of this work are the simulation tests of the simple cooperation algorithm. Tests were conducted in Simulink and its results are presented in both mobile platforms trajectories and path errors in x and y directions. The presented results show the effectiveness of proposed method.

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Identification of electric propulsion system for unmanned aerial vehicles

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AIP Conference Proceedings 2018年第1期2029卷

作者： Maciej Sulewski Leszek Ambroziak Mirosław Kondratiuk Adam Stulgis 1Bialystok University of Technology Faculty of Mechanical Engineering Automatic Control and Robotics Department Wiejska St. 45C 15-351 Bialystok Poland

This paper presents the identification process of the electric propulsion system for Unmanned Aerial Vehicles. Prepared identification test rig was described in details. It allows to control the electric motor with a propeller and to measure the parameters like thrust force, torque, current and supply voltage, that were used during identification. The worked out and presented identification test helps to check and verify the electric propulsion properties and to develop more accurate simulation models of UAVs.

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