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Frequency determination in control applications: excitation-based approach

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING 2012年第I8期226卷 1142-1148页

作者： Stotsky, Alexander Chalmers Univ Technol Dept Signals & Syst SE-41296 Gothenburg Sweden

New algorithms for estimation of the frequencies of oscillating waveform signals are described. A model of the signals is presented in the form of a linear difference equation with unknown coefficients, which define the frequencies and amplitudes. Coefficients are estimated utilizing the property of the persistence of excitation of oscillating signals. Exponentially damped and oscillating signals are described in a unified framework. A property of excitation is proved for an exponentially damped signal that contains a single frequency via diagonal dominance of an information matrix. Two applications of this frequency estimation technique are considered. The first one is filtering of the wind speed signal in wind turbine control applications, and the second one is the frequency estimation of exponentially damped signals motivated by the engine knock detection applications.

关键词： Frequency estimation persistence of excitation strictly diagonally dominant matrix exponentially damped signal projection algorithm wind speed model engine knock frequency

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Adaptive type-2 fuzzy system for synchronisation and stabilisation of chaotic non-linear fractional order systems

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IET CONTROL THEORY AND APPLICATIONS 2018年第2期12卷 183-193页

作者： Jafari, Pouria Teshnehlab, Mohammad Tavakoli-Kakhki, Mahsan KN Toosi Univ Technol Fac Elect Engn Intelligent Syst Lab ISLab Tehran Iran KN Toosi Univ Technol Fac Elect Engn Ind Control Ctr Excellence Tehran Iran

This study proposes an adaptive interval type-2 Takagi-Sugeno-Kang (IT2 TSK) fuzzy system with a supervisory mode to control and stabilise a certain class of non-linear fractional order systems. In this study, a fractional order adaptation law is derived which adjusts the free parameters and bounds them by utilising a projection algorithm. The global Mittag-Leffler stability of the closed-loop system is proved in the sense that all the involved signals are uniformly bounded. Moreover, if the non-linear system tends to be unstable, a supervisory controller starts cooperating with the adaptive IT2 TSK fuzzy controller to guarantee the stability of the closed-loop system. In addition, a new inference mechanism for the adaptive IT2 TSK fuzzy system is introduced for which the antecedent part is chosen as a type-2 fuzzy set and the consequent parameters are represented as interval sets. According to the practical nature of the proposed inference equation, it would be applicable in online and real-time applications. Numerical simulations show the validity and effectiveness of the introduced control strategy for stabilisation and control of a general class of non-linear fractional order systems perturbed by disturbance and uncertainty.

关键词： fuzzy control adaptive control nonlinear control systems stability inference mechanisms numerical analysis adaptive type-2 fuzzy system chaotic nonlinear fractional order systems synchronisation stabilisation adaptive interval type-2 Takagi-Sugeno-Kang fuzzy system IT2 TSK fuzzy system consequent parameters inference mechanism global Mittag-Leffler stability closed-loop system projection algorithm fractional order adaptation law supervisory mode

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Adaptive MNN control for a class of non-affine NARMAX systems with disturbances

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SYSTEMS & CONTROL LETTERS 2004年第1期53卷 1-12页

作者： Ge, SS Zhang, J Lee, TH Natl Univ Singapore Dept Elect & Comp Engn Singapore 117576 Singapore

In this paper, adaptive multi-layer neural network (MNN) control is developed for a class of discrete-time non-affine nonlinear systems in nonlinear auto regressive moving average with eXogenous inputs (NARMAX) model. By using implicit function theorem, the existence of the implicit desired feedback control (IDFC) is proved. MNNs are used as the emulator of the desired feedback control. projection algorithms are used to guarantee the boundedness of the neural network (NN) weights, which removes the need of persistent exciting (PE) condition for parameter convergence. Simulation results show the effectiveness of the proposed control scheme. (C) 2004 Elsevier B.V. All rights reserved.

关键词： non-affine nonlinear system implicit function theorem multi-layer neural networks projection algorithm

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DAPS3D: Domain Adaptive Projective Segmentation of 3D LiDAR Point Clouds

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IEEE ACCESS 2023年 11卷 79341-79356页

作者： Klokov, Alexey A. Pak, Di Un Khorin, Aleksandr Yudin, Dmitry A. Kochiev, Leon Luchinskiy, Vladimir D. Bezuglyj, Vitaly D. Russian Acad Sci Fed Res Ctr Comp Sci & Control Moscow 119333 Russia Auton Tech CY-3032 Limassol Cyprus Moscow Inst Phys & Technol Moscow 141701 Russia Artificial Intelligence Res Inst AIRI Moscow 121170 Russia

LiDARs are one of the key sources of reliable environmental ranging information for autonomous vehicles. However, segmentation of 3D scene elements (roads, buildings, people, cars, etc.) based on LiDAR point clouds has limitations. On the one hand, point- and voxel-based segmentation neural networks do not offer sufficiently high speed. On the other hand, modern labeled datasets primarily consist of street scenes recorded for driverless cars and contain little data for mobile delivery robots or cleaners that must work in parks and yards with heavy pedestrian traffic. This article aims to overcome these limitations. We have proposed a novel approach called DAPS3D to train deep neural networks for 3D semantic segmentation. This approach is based on a spherical projection of a point cloud and LiDARspecific masks, enabling the model to adapt to different types of LiDAR. First of all, we have introduced various high-speed multi-scale spherical projection segmentation models, including convolutional, recurrent, and transformer architectures. Among them, the SalsaNextRecLSTM architecture with recurrent blocks showed the best results. In particular, this model achieved the 83.5% mIoU metric for the SemanticKitti dataset with joint categories. Secondly, we have proposed several original augmentations for spherical projections of LiDAR data, including FoV, flip, and rotation augmentation, as well as a special T-Zone cutout. These augmentations increase the model's invariance when dealing with changes in the data domain. Finally, we introduce a new method to generate synthetic datasets for domain adaptation problems. We have developed two new datasets for validating 3D scene outdoor segmentation algorithms: the DAPS-1 dataset, which is based on the augmentation of the reconstructed 3D semantic map, and the DAPS-2 LiDAR dataset, collected by the on-board sensors of a cleaning robot in a park area. Particular attention is given to the performance of the developed models, demonst

关键词： ~Autonomous vehicles computer vision artificial neural networks projection algorithm image segmentation

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On the computation and efficiency of a HBP-GM estimator some simulation results

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COMPUTATIONAL STATISTICS & DATA ANALYSIS 1997年第1期25卷 1-15页

作者： Hinloopen, J Wagenvoort, R EUROPEAN UNIV INST DEPT ECON I-50016 FIESOLE FI ITALY

We propose and test a specific correction factor which improves both the resampling and projection algorithm for approximating the minimum volume ellipsoid (MVE) estimator. Simulations show that a high-breakdown-point GM estimator, based among other things on these improved MVE-estimates of location and scatter (i) is little less efficient than OLS if data are free from outlying observations, but in most cases is much more efficient if outliers corrupt the data, (ii) is always more efficient than Rousseeuw's least median of squares (LMS) estimator, and (iii) is always superior to both LMS and OLS if both precision and efficiency are considered. (C) 1997 Elsevier Science B.V.

关键词： LMS MVE resampling algorithm projection algorithm efficiency

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A variational model for multiscale texture extraction

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OPTIK 2016年第1期127卷 299-309页

作者： Tang, Liming He, Chuanjiang Hubei Univ Nationalities Sch Sci Enshi 445000 Peoples R China Chongqing Univ Coll Math & Stat Chongqing 401331 Peoples R China

We propose a hierarchical (BV, G) variational decomposition model for multiscale texture extraction in this paper, which can offers a hierarchical, separated representation of image texture in different scales. The proposed hierarchical decomposition is obtained by replacing the fixed scale parameter of the A(2)BC model with a varying sequence. Some properties of this hierarchical decomposition are presented and its convergence is proved. We adopt Euclidean projection algorithm to solve this hierarchical decomposition model numerically. In addition, we use this hierarchical decomposition to achieve the multiscale texture extraction. The performance of the proposed model is demonstrated with both synthetic and real images. (C) 2015 Elsevier GmbH. All rights reserved.

关键词： Variational image decomposition Texture extraction Multiscale projection algorithm

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Nonlinear speed and yaw control for wind turbine powered vessels

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING 2016年第3期230卷 255-265页

作者： Stotsky, Alexander Chalmers Ind Tekn Chalmers TeknikpkSven Hultins Gata 9 SE-41288 Gothenburg Sweden

The application of conventional wind turbines on board a vessel creates a number of new challenges for turbine control systems. Thrust force is used in marine applications as an additional control variable for propulsion of the vessel. Variability of the wind speed and wind direction, together with the yaw rate and range constraints, impose strong requirements on the turbine control system. A new projection algorithm that projects the turbine thrust force on the heading direction of vessel is proposed in this paper for controlling propulsion. Variations in the wind direction and wind speed are counteracted via turbine yaw angle, making the turbine thrust force always aligned with the heading direction of the vessel. The conventional speed controller is modified for varying yaw offset and a combined algorithm for simultaneous control of the turbine speed and thrust force is proposed. Stability of the speed controller for varying yaw offset is proved via the Lyapunov method. The controller also takes into account the constraints on the yaw rate and minimizes the turbine gyroscopic effects via a proper choice of the virtual upper bound of the input voltage of the yaw motor. All of the results are illustrated by simulations using measurement data acquired from the Hono turbine.

关键词： Wind turbine on vessel thrust force as propulsion Lyapunov stability of K-2 speed controller with varying yaw offset projection algorithm nonlinear yaw control with bounded input minimization of turbine gyroscopic effects

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3D diffeomorphic image registration with Cauchy-Riemann constraint and lower bounded deformation divergence

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ESAIM-MATHEMATICAL MODELLING AND NUMERICAL ANALYSIS 2023年第1期57卷 299-328页

作者： Han, Huan Wang, Zhengping Wuhan Univ Technol Dept Math Wuhan 430070 Peoples R China Wuhan Univ Technol Ctr Math Sci Dept Math Wuhan 430070 Peoples R China

In order to eliminate mesh folding in 3D image registration problem, we propose a 3D diffeomorphic image registration model with Cauchy-Riemann constraint and lower bounded deformation divergence. This model preserves the local shape and ensures no mesh folding. The existence of solution for the proposed model is proved. Furthermore, an alternating directional projection 3D image registration algorithm is presented to solve the proposed model. Moreover, numerical tests show that the proposed algorithm is competitive compared with the other four algorithms.

关键词： 3D diffeomorphic image registration mesh folding Cauchy-Riemann constraint lower bounded divergence alternating direction projection algorithm

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Classical pole placement adaptive control revisited: linear-like convolution bounds and exponential stability

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MATHEMATICS OF CONTROL SIGNALS AND SYSTEMS 2018年第4期30卷 1-51页

作者： Miller, Daniel E. Shahab, Mohamad T. Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

While the original classical parameter adaptive controllers do not handle noise or unmodelled dynamics well, redesigned versions have been proven to have some tolerance;however, exponential stabilization and a bounded gain on the noise are rarely proven. Here we consider a classical pole placement adaptive controller using the original projection algorithm rather than the commonly modified version;we impose the assumption that the plant parameters lie in a convex, compact set, although some progress has been made at weakening the convexity requirement. We demonstrate that the closed-loop system exhibits a very desirable property: there are linear-like convolution bounds on the closed-loop behaviour, which confers exponential stability and a bounded noise gain, and which can be leveraged to prove tolerance to unmodelled dynamics and plant parameter variation. We emphasize that there is no persistent excitation requirement of any sort;the improved performance arises from the vigilant nature of the parameter estimator.

关键词： Adaptive control projection algorithm Exponential stability Bounded gain

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Distributed Resource Allocation Over Directed Graphs via Continuous-Time algorithms

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IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS 2021年第2期51卷 1097-1106页

作者： Zhu, Yanan Ren, Wei Yu, Wenwu Wen, Guanghui Southeast Univ Sch Math Jiangsu Prov Key Lab Networked Collect Intelligen Nanjing 210096 Peoples R China Univ Calif Riverside Dept Elect & Comp Engn Riverside CA 95251 USA RMIT Univ Sch Engn Melbourne Vic 3000 Australia

This paper investigates the resource allocation problem for a group of agents communicating over a strongly connected directed graph, where the total objective function of the problem is composted of the sum of the local objective functions incurred by the agents. With local convex sets, we first design a continuous-time projection algorithm over a strongly connected and weight-balanced directed graph. Our convergence analysis indicates that when the local objective functions are strongly convex, the output state of the projection algorithm could asymptotically converge to the optimal solution of the resource allocation problem. In particular, when the projection operation is not involved, we show the exponential convergence at the equilibrium point of the algorithm. Second, we propose an adaptive continuous-time gradient algorithm over a strongly connected and weight-unbalanced directed graph for the reduced case without local convex sets. In this case, we prove that the adaptive algorithm converges exponentially to the optimal solution of the considered problem, where the local objective functions and their gradients satisfy strong convexity and Lipachitz conditions, respectively. Numerical simulations illustrate the performance of our algorithms.

关键词： Adaptive algorithm directed graphs projection algorithm resource allocation

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