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Modulation technique for Four-Leg Voltage Source Inverter without a Look-Up Table

IET POWER ELECTRONICS 2016年第4期9卷 648-656页

作者： Ebrahimzadeh, Esmaeil Farhangi, Shahrokh Iman-Eini, Hossein Blaabjerg, Frede Univ Tehran Coll Engn Sch Elect & Comp Engn Tehran Iran Aalborg Univ Energy Technol Aalborg Denmark

Three-dimensional space-vector modulation (3D SVM) has more popularity among the other modulation techniques of the four-leg inverter due to higher DC-link voltage utilisation. Sequencing schemes of the switching vectors in the 3D SVM are divided into Class I and II categories. Each of these classes itself has four kinds: (a) rising-edge aligned, (b) falling-edge aligned, (c) symmetrically aligned and (d) alternative sequence. In this study, implementation of the conventional 3D SVM technique in abc-coordinate for four-leg voltage source inverters is simplified, while it can be so easily adopted in all kinds of sequencing schemes. Unlike conventional techniques, the proposed technique needs no switching vector determination and duty ratio calculation as well as reduces the computational burden. In this technique, turn-on interval of the upper switches, in every switching period, is calculated without need of a look-up table and complex equations. Applying the dead time by software is very straightforward in the proposed technique. In addition, by simplification of the proposed modulation technique, it can be applied to the three-leg inverters. Simulation results in PSCAD/EMTDC environment confirm the validity and effectiveness of the proposed technique. Experimental results are also provided to confirm the validity of the new approach.

关键词： invertors voltage control power engineering computing control engineering computing four-leg voltage source inverter 3D space-vector modulation 3D SVM DC-link voltage utilisation sequencing schemes class I category class II category rising-edge aligned falling-edge aligned symmetrically aligned alternative sequence switching period PSCAD environment EMTDC environment

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Intelligent ship control with online learning ability

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computing & control engineering JOURNAL 1997年第5期8卷 196-200页

作者： Polkinghorne, MN Roberts, GN Burns, BS Univ Plymouth Plymouth PL4 8AA Devon England Univ Wales Newport Gwent Wales

As recently demonstrated on the BBC1 science programme 'Tomorrow's World', it is now feasible to employ a technique called fuzzy logic to develop an intelligent autopilot for small ships which has the ability to learn about its performance and make relevant tuning adjustments online to maintain levels of operation.

关键词： Artificial intelligence small ships self-organising controller fuzzy control performance intelligent ship control naval engineering computing intelligent autopilot Self-adjusting control systems performance index online learning ships Fuzzy control tuning adjustments self-adjusting systems intelligent control learning (artificial intelligence) control engineering computing Marine system control fuzzy logic fuzzy logic controller

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Robust controller for an autonomous small refrigeration unit

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IEE PROCEEDINGS-SCIENCE MEASUREMENT AND TECHNOLOGY 1999年第3期146卷 159-163页

作者： Kattakayam, TA Srinivasan, K KACST Energy Res Inst Riyadh 11442 Saudi Arabia Indian Inst Sci Dept Engn Mech Bangalore 560012 Karnataka India Curtin Univ Technol Sch Mech Engn Perth WA 6845 Australia

The authors describe the constructional features of a controller for operating an autonomous refrigeration unit powered by a field of photovoltaic panels and backed up by a generator set. The controller enables three voltage levels of operation of an inverter to meet the start, run and off cycle conditions of the refrigerator compressor. The algorithm considers several input and output parameters and status signals from each subsystem of the unit to deduce a control strategy. Such units find application for storage of vaccines and life-saving medicines requiring uninterrupted refrigeration, in medical shops, rural health centres, veterinary laboratories etc.

关键词： start conditions control of heat systems output parameters controllers compressors control engineering computing Power convertors and power supplies to apparatus off cycle conditions photovoltaic power systems autonomous small refrigeration unit constructional features watchdog circuit Refrigeration and cold storage generator set backup microprocessor based controller PWM section controllers computerised control three voltage levels of operation storage of vaccines robust controller supervisory monitoring and control PWM invertors control strategy status signals uninterrupted refrigeration input parameters run conditions voltage regulators refrigerator compressor Voltage control refrigeration inverter robust control voltage control field of photovoltaic panels Stability in control theory Solar power stations and photovoltaic power systems

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TIME-OPTIMAL control ALGORITHM FOR MICROPROCESSOR WITH ASYMMETRICAL BOUNDS

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IEE PROCEEDINGS-D control THEORY AND APPLICATIONS 1984年第6期131卷 238-242页

作者： SERRA, I MORENO, L LUQUE, E Departamento de Electricidad y Electrónica Universidad Autónoma de Barcelona Barcelona Spain

A microprocessor-based time optimal control algorithm is presented. The method is based on the bang-bang approach which incorporates an asymmetrical control strategy to allow load disturbance. The implementation is carried out in such a way as to minimise the number of real-time computations. A relationship involving the sampling period, the asymmetrical value and the amplitude disturbance has been developed. The time-response deterioration as a consequence of the asymmetrical control signal is also evaluated. The method has been applied to a second-order process, and experimental results are presented.

关键词： microprocessor-based time optimal control Nonlinear control systems optimal control control engineering computing Optimal control bang bang control computerised control time-response deterioration bang-bang control asymmetrical bounds

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Distributed real-time control and data acquisition of free-electron laser beams

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computing & control engineering JOURNAL 2001年第4期12卷 179-187页

作者： Moallem, M Univ Western Ontario Dept Elect & Comp Engn London ON N6G 1H1 Canada

Implementation of a feedback control scheme and its associated user-interface and data acquisition modules in a distributed real-time computing environment are described. The distributed system consists of an ethernet network interconnecting real-time processor modules to host workstations and other embedded controllers. The goal of the feedback control scheme is to maintain positions of the electron beam in the middle of the vacuum chamber in the presence of electromagnetic interference and noise. Technical details of implementing the data acquisition and control scheme and their integration with the existing control system modules are presented, along with experimental results.

关键词： feedback control scheme embedded controllers data acquisition modules host workstations laser beam applications real time processor modules control system modules feedback distributed real time computing environment real-time systems Computer communications Optical engineering computing Data handling techniques data acquisition electromagnetic interference electron beam Local area networks user interface distributed real time control control engineering computing vacuum chamber local area networks free electron lasers computerised control free-electron laser beams optical engineering computing ethernet network control scheme

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Vulnerability assessment of electrical and thermal cyber physical system considering dual coupling characteristics

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IET GENERATION TRANSMISSION & DISTRIBUTION 2022年第20期16卷 4215-4229页

作者： Dong, Shen Zhou, Buxiang Zang, Tianlei Xiao, Xianyong Sichuan Univ Coll Elect Engn Chengdu 610065 Peoples R China

With the continuous improvement of the informatization and intelligence of the Electrical and Thermal Cyber Physical System (ETCPS), the coupling between the various subsystems is getting closer and closer. When the system fails, due to the coupling characteristics, the system security risk is intensified. On this basis, the dual coupling characteristics of ETCPS have been analyzed according to the cyber physical model established first. Secondly, a two-state optimal scheduling model and comprehensive vulnerability (CV) index, which consider various characteristics of ETCPS, are established, and interactions between the subsystems are analyzed quantitatively. Then, the source load loss rate is defined, which quantifies system security risk. Finally, five vulnerability assessment methods as well as the proposed method are compared. The feasibility and rationality of the proposed method are proved by two test systems.

关键词： vulnerability assessment methods cyber physical model power system security dual coupling characteristics power generation scheduling control engineering computing comprehensive vulnerability index CV index electrical and thermal cyber physical system cyber-physical systems system security risk ETCPS power engineering computing two-state optimal scheduling model

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Vision-aided intelligent vehicle sideslip angle estimation based on a dynamic model

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IET INTELLIGENT TRANSPORT SYSTEMS 2020年第10期14卷 1183-1189页

作者： Liu, Wei Xiong, Lu Xia, Xin Lu, Yishi Gao, Letian Song, Shunhui Tongji Univ Clean Energy Automot Engn Ctr Shanghai 201804 Peoples R China Tongji Univ Sch Automot Studies Shanghai 201804 Peoples R China

The vehicle sideslip angle is an important state for vehicle dynamic control, which needs to be estimated as it could not be obtained directly by the vehicle. To improve the estimation accuracy of the sideslip angle based on the intelligent vehicle platform, this study proposes a novel vehicle sideslip angle estimation algorithm with the fusion of dynamic model and vision information. Firstly, to further improve the model accuracy of the vehicle during lateral acceleration conditions, a vehicle dynamic model is established considering the acceleration error compensation with the assistance of attitude information. In addition, based on the lane line information obtained from the equipped camera in intelligent vehicles, a visual geometric model is established. Owing to the measurement delay and low sampling frequency of the camera, a multi-rate sideslip angle observer with delay compensation is designed to coordinate with the inter-frequency signal of the vehicle chassis. Finally, the effectiveness of the algorithm is verified by the slalom test.

关键词： vehicle dynamics cameras steering systems traffic engineering computing observers road vehicles control engineering computing computer vision estimation accuracy intelligent vehicle platform novel vehicle sideslip angle estimation algorithm vision information model accuracy vehicle dynamic model intelligent vehicles visual geometric model multirate sideslip angle observer vehicle chassis vision-aided intelligent vehicle sideslip angle estimation vehicle dynamic control

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A SAFE COMMUNICATION-SYSTEM FOR WHEELCHAIR-MOUNTED MEDICAL ROBOTS

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computing & control engineering JOURNAL 1995年第5期6卷 216-221页

作者： DAVIES, B HIBBERD, R Dept. of Mech. Eng. Imperial Coll. of Sci. Technol. & Med. London UK

When a powered medical manipulator is added to a motorised electric wheelchair, the result is a system which can be safety critical for the user. When a number of other systems, such as environmental controllers, displays and navigation systems are incorporated into the overall systems, the complexity of central can further affect safety. The solution to these problems has resulted in the development of a new safe communication system for wheelchair mounted manipulator systems called Multiple-Master, Multiple-Slave (M3S). This work has been carried out as part of a consortium funded by the European TIDE programme.

关键词： manipulators safety-critical software wheelchair mounted manipulator systems Software engineering techniques control complexity environmental controllers medical computing motorised electric wheelchair Multiple-Master Multiple-Slave navigation systems wheelchair mounted medical robots safe communication system Biology and medical computing Manipulators M3S Health and safety aspects wheelchair-mounted medical robots safety critical control engineering computing powered medical manipulator biomedical equipment computerised control Biological and medical control systems

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Mathematical modeling of a two spool flow control servovalve using a pressure control pilot

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JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND control-TRANSACTIONS OF THE ASME 2002年第3期124卷 420-427页

作者： Anderson, RT Li, PY Univ Minnesota Dept Mech Engn Minneapolis MN 55455 USA

A nonlinear dynamic model for an unconventional, commercially available electrohydraulic flow control servovalve is presented. The two stage valve differs from the conventional servovalve design in that: it uses a pressure control pilot stage;the boost stage uses two spools, instead of a single spool, to meter flow into and out of the valve separately;and it does not require a feedback wire and ball. Consequently, the valve is significantly less expensive. The proposed model captures the nonlinear and dynamic effects. The model has been coded in Matlab/Simulink and experimentally validated.

关键词： servomechanisms Valves pressure control nonlinear dynamical systems Dynamics (Mechanics) Design nonlinear control systems Flow (Dynamics) Flow control Pressure control control engineering computing digital simulation Pressure flow control Steady state electrohydraulic control equipment

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SYSTEM FOR AUTOMATIC REALIGNMENT OF THE HEAD IN MAGNETIC-RESONANCE-IMAGING

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IEE PROCEEDINGS-F RADAR AND SIGNAL PROCESSING 1990年第5期137卷 319-330页

作者： MARSHALL, S SAEED, N YOUNG, H DURRANI, TS DALTON, B DUBOULAY, G GEC RES LABS HIRST RES CTRWEMBLEY HA9 7PPMIDDXENGLAND NATL HOSP INST NEUROLLONDON WC1N 3BGENGLAND

The condition of patients with various diseases of the brain, may be monitored over a period of time using magnetic resonance imaging (MRI) techniques. To make an accurate assessment of changes in their condition it is necessary that the patients be repositioned to a very high degree of accuracy. Current techniques rely on the skill of the radiographer to return the head to the same position during each scanning. Various mechanical fixation methods, such as the use of head moulds and indelible markers, have been proposed. This paper describes an approach to automatic patient realignment using a combination of image analysis techniques and symbolic reasoning. A set of key anatomical features are extracted from the images and these are compared using a knowledge-based expert system to measure and then correct the positional inaccuracies. The system is capable of extension for crossmatching images from other modalities.

关键词： Radiation and radioactivity applications in biomedicine biomedical NMR magnetic resonance imaging Microwaves and other electromagnetic waves (medical uses) head realignment symbolic reasoning medical computing Biomagnetism expert systems knowledge-based expert system Patient diagnostic methods and instrumentation image analysis techniques Expert systems and other AI software and techniques automatic patient realignment Biology and medical computing Optical information, image and video signal processing computerised picture processing Computer vision and image processing techniques patient monitoring control engineering computing position control Spatial variables control biomedical equipment computerised control Biological and medical control systems

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