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Identification of Gaussian Process State-Space Models with Particle Stochastic Approximation EM

IFAC Proceedings Volumes 2014年第3期47卷 4097-4102页

作者： Roger Frigola Fredrik Lindsten Thomas B. Schön Carl E. Rasmussen Dept. of Engineering University of Cambridge United Kingdom Div. of Automatic Control Linköping University Sweden Dept. of Information Technology Uppsala University Sweden

Gaussian process state-space models (GP-SSMs) are a very flexible family of models of nonlinear dynamical systems. They comprise a Bayesian nonparametric representation of the dynamics of the system and additional (hyper-)parameters governing the properties of this nonparametric representation. The Bayesian formalism enables systematic reasoning about the uncertainty in the system dynamics. We present an approach to maximum likelihood identification of the parameters in GP-SSMs, while retaining the full nonparametric description of the dynamics. The method is based on a stochastic approximation version of the EM algorithm that employs recent developments in particle Markov chain Monte Carlo for efficient identification.

关键词： system identification Bayesian Non-parametric identification Gaussian processes

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A ΓZ-source based hybrid power converter for battery-fuel cell hybrid electric vehicle

A ΓZ-source based hybrid power converter for battery-fuel c...

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UKACC International Conference on control (control)

作者： Jun Cai Qing-Chang Zhong David Stone Dept. Automatic Control and Systems Engineering University of Sheffield Sheffield UK Dept. Electronics and Electrical Engineering University of Sheffield Sheffield UK

Low cost and high reliability are the main issues considered in power converter design for hybrid electric vehicle. In this paper, a hybrid power converter is proposed for the power flow control of the battery-fuel cell hybrid electric vehicle. The converter consists of a unidirectional Γ Z-source converter and a bidirectional DC-DC converter. By controlling the voltage of the Z source capacitor and the modulation index of the inverter, the power flow between the fuel cell, battery and the load can be controlled flexibly. The different operation modes of the system and the power flow control strategies are analysed. To verify the validity of the proposed power converter topology and the control methods, system simulation model is developed in Matlab/Simulink environment. In addition, the simulation model is also implemented in the RT-LAB real-time simulator. The simulation results demonstrated the feasibility of the proposed methods.

关键词： Inverters Batteries Fuel cells Hybrid power systems Load modeling control systems Real-time systems

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Parameter optimization of hydro turbine governor PID controller by chaotic improved PSO algorithm

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Energy Education Science and Technology Part A: Energy Science and Research 2014年第5期32卷 3949-3962页

作者： Chen, Gonggui Du, Yangwei Song, Peizhu Chongqing University of Posts and Telecommunications Key Laboratory of Industrial Wireless Network and Networked Control of Ministry of Education Chongqing China Chongqing University of Posts and Telecommunications Research Center on Complex Power System Analysis and Control Chongqing China Hubei Minzu University Dept. of Electrical Engineering Enshi China Hubei Energy Group Qiyueshan Wind Power Co Ltd Lichuan China

For overcoming the disadvantages of easily falling into local extremum and easily losing species diversity in traditional particle swarm optimization (PSO) algorithm, a cross improved PSO (IPSO) algorithm is proposed. In addition, in order to enhance the exploitation capacity of IPSO algorithm, it also makes use of chaotic sequence features which is called chaotic IPSO (CIPSO) algorithm. In present paper, mathematical structure model of hydro turbine governor is established, and the integral of absolute value of error as the minimum objective function is adopted to select particles. In order to obtain satisfactory transient dynamic characteristics in process of tuning of PID parameters, the square of output signal after PID tuning and the rise time are proposed to integrate into the augmented objective function, and in order to minimize overshoot to the greatest extent, the penalty mechanism is concerned. These algorithms are performed for optimized designs of governor PID parameters on hydro turbine. Several specific working conditions are modeled and CIPSO algorithm results are compared with those in PSO and IPSO algorithms. It comes out that the CIPSO algorithm has made some improvements whether in convergent speed or convergent accuracy in comparing with other two algorithms. © Sila Science. All rights reserved.

关键词： Governors

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Indirect position estimation method for switched reluctance motor using searching windings

Indirect position estimation method for switched reluctance ...

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International Conference on Electrical Machines and systems (ICEMS)

作者： Cheng Wang Zhiquan Deng Jun Cai Rongguang Hu College of Automation Engineering Nanjing University of Aeronautics and Astronautics Nanjing China School of Information and Control Nanjing University of Information Science and Technology Nanjing China Dept. Automatic Control and System Engineering University of Sheffield UK

This paper presents a new method to estimate rotor position indirectly for 12/8 switched reluctance motor (SRM). In this method, searching windings and main windings are wound on stator together. The structure of searching windings is designed to reduce induced voltages caused by main windings. High frequency voltage is applied to searching windings and the position signal is derived from induced high frequency signals. High frequency voltage can be injected from standstill to high speed in this method, thus it can operate in a wide speed range. The proposed method is implemented on a 12/8 SRM and the experimental results demonstrate the validity of this method.

关键词： Windings Reluctance motors Rotors Inductance Estimation Coils

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Design of robust observers for positive delayed interval systems

Design of robust observers for positive delayed interval sys...

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IEEE SSD International Multi-Conference on systems, Signals and Devices

作者： Ines Zaidi Mohamed Chaabane Fernando Tadeo Dept. of Systems Engineering and Automatic University of Valladolid Valladolid Spain Dept. of Control of Industrial Processes University of Sfax Sfax Tunisia

This paper is concerned with the design of positive observers for positive interval systems with time delay. For that, a solution based on LMI programming is provided to the problem of designing observers that ensure guaranteed bounds on the estimated states that are nonnegative whenever the initial conditions are nonnegative. Furthermore, it is revealed that an unstable positive system cannot be positively stabilized without taking into account the positivity of the dynamic errors. Then, the problem of positive stabilization by dynamic feedback controllers based observer is investigated, taking into account that the positivity of the error signals is necessary to stabilize a positive system and keep it positive at the same time. We derive then necessary and sufficient conditions for the existence of positive observers and show that the solvability can be decided via LMI (Linear Matrix Inequalities) programming techniques.

关键词： Indexes control systems Delays Artificial intelligence

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QoS aware platform for dependable sensory environments

QoS aware platform for dependable sensory environments

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IEEE International Conference on Multimedia and Expo Workshops (ICMEW)

作者： Aitor Agirre Jorge Parra Elisabet Estévez Marga Marcos IK4-Ikerlan Arrasate Spain Dept. of Electronics and Automatic Engineering Universidad de Jaén Jaén Spain Dept. of Automatic Control and Systems Engineering UPV/EHU Bilbao Spain

ISBN: (纸本)9781479947164

Sensory environments for healthcare are commonplace nowadays. A patient monitoring system in such an environment deals with sensor data capture, transmission and processing in order to provide on-the-spot support for monitoring the vulnerable and critical patient. A fault in such a system can be hazardous on the health of the patient. Therefore, such a system must be dependable and ensure reliability, fault-tolerance, safety and other critical aspects, in order to deploy it in real scenario. This paper encounters some of these issues and proposes a component platform to develop a flexible framework with specific support for fault tolerance and safe inter-component communication related QoS aspects. The platform adopts the Service Component Architecture (SCA) model and defines a Data Distribution Service (DDS) binding, which provides the fault tolerance and the required safety-ensuring techniques and measures, as defined in the IEC 61784-3-3 standard.

关键词： Safety Quality of service Fault tolerance Fault tolerant systems Middleware Standards Medical services

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A Study of Circulating Current in MMC based HVDC system under an Unbalanced Grid Condition

A Study of Circulating Current in MMC based HVDC System unde...

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Annual Conference of the IEEE Industrial Electronics Society

作者： Won-Seok Do Si-Hwan Kim Tae-Jin Kim Rae-Young Kim Dept. of Electrical and Biomedical Engineering Hanyang University Energy Electronics Control System Laboratory

ISBN: (纸本)9781479940318

This paper shows a study about circulating current of modular multilevel converter (MMC) based a high voltage direct current (HVDC) system under some unbalanced grid conditions. A basic structure of the MMC HVDC system is introduced and its system dynamics is analyzed. Based on the analysis, the modeling of circulating current and its control method under balanced or unbalanced grid condition are described. From the point of view in circulating current control, two kinds of power control methods are analyzed and their performances compared. In addition, in order to apply the power control methods, some practical considerations are proposed and described. Several simulation results performed in the PSIM software verify the proposed analysis and consideration of the power control methods under various grid conditions.

关键词： High Voltage Direct Current (HVDC) Modular Multilevel Converter (MMC) Circulating current

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Recursive estimation of selective catalyst reduction system parameters using modified Gauss-Newton method

Recursive estimation of selective catalyst reduction system ...

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2014 American control Conference, ACC 2014

作者： He, Fei Guan, Xiaohong Grimble, Mike Sun, Min Clegg, Andy Industrial Control Centre Dept. of Electronic and Electrical Engineering University of Strathclyde Glasgow G1 1XQ United Kingdom Industrial Systems and Control Ltd Culzean House 36 Renfield Street Glasgow G2 1LU United Kingdom Powertrain Advanced Controls General Motors United States Dept. of Automatic Control and Systems Engineering University of Sheffield Mappin Street Sheffield S1 3JD United Kingdom

ISBN: (纸本)9781479932726

Selective catalytic reduction (SCR) system is a complex chemical process which is used to treat exhaust gas in many applications, e.g. diesel engines in automobiles. An SCR model was constructed by General Motors (GM) and the problem considered was to estimate the unknown kinetic parameters on-line taking into account aging effects. There are a number of application constraints that must be taken into consideration, including inaccessible model structure, parametric identifiability difficulties and limited measurement data. In this work, the complexity and identifiability of this estimation problem is investigated through global sensitivity analysis and cost-function based analysis methods. One of the problems is to determine the parameters where the model is most sensitive and should thus be estimated onboard. A modified Gauss-Newton method was proposed and evaluated for this estimation problem. Simulation studies have confirmed that sensitive kinetic parameters of the SCR model can be estimated and tracked recursively using the proposed method. © 2014 American automatic control Council.

关键词： Selective catalytic reduction

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An assembly problem with mobile robots

An assembly problem with mobile robots

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International Conference on Emerging Technologies and Factory Automation (ETFA)

作者： Marius Kloetzer Cristian Mahulea Dept. of Automatic Control and Applied Informatics Technical University “Gheorghe Asachi” of Iasi Romania Dept. of Computer Science and Systems Engineering University of Zaragoza Spain

This paper proposes a solution for solving a specific problem that requires a team of identical robots to collect in a specific order different types of resources scattered throughout an environment. A Petri net with outputs models the environment, the team possible movements and the regions with resources. An iterative solution plans the team such that each robot collects and assembles resources in the required order. Each iteration step is based on a linear programming problem that is guaranteed to return a feasible firing vector for the Petri net system. A pseudocode description of the procedure is given and a simulation example is included.

关键词： Silicon Vectors Assembly Mobile robots Planning Modeling

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ANFIS based Jacobian for a parallel manipulator mobility assistive device 10

ANFIS based Jacobian for a parallel manipulator mobility ass...

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10th UKACC International Conference on control, control 2014

作者： Asker, Ahmed Salah, Omar Fath El-Bab, Ahmed M. R. Ramadan, Ahmed A. Assal, Samy M. F. Sessa, Salvatore Abo-Ismail, Ahmed School of Innovative Design Engineering Egypt-Japan University for Science and Technology E-JUST New-Borg-El-Arab-City-Alexandria Egypt Mechanical Engineering Dept Faculty of Engineering Assiut University Assiut Egypt Dept. of Production Engineering and Mechanical Design Faculty of Engineering Tanta University Tanta Egypt Computer and Automatic Control Dept Faculty of Engineering Tanta University Tanta Egypt Graduate School of Creative Science and Engineering Waseda University Tokyo Japan

ISBN: (纸本)9781479950119

Nowadays parallel manipulators are used widely in bioengineering applications;this leads to many exciting expectations as well as challenges. The kinematic analysis of parallel manipulators with their differential kinematics yielding the Jacobian in a closed form is not a trivial task. In this paper a parallel manipulator based mobility assistive device called EJADII is analyzed to determine forward kinematics, inverse kinematics and closed-form Jacobian. An Adaptive Neuro-Fuzzy Inference system (ANFIS) is trained to estimate the Jacobian. This system would be useful when determination of the Jacobian in a closed-form is difficult to determine. The human motion during sit to stand captured by VICON experiment is used with two assisting scenarios to train and verify this system. Computer simulations show relatively good results of the proposed system. © 2014 IEEE.

关键词： Inverse kinematics

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