Embedded systems are computer-based systems which must respond to external stimuli within time scales determined by the external environment. Such systems are required to achieve ever more demanding behavioural. perfo...
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Embedded systems are computer-based systems which must respond to external stimuli within time scales determined by the external environment. Such systems are required to achieve ever more demanding behavioural. performance and safety requirements. Embedded systems are found in applications such as primary flight control, gas-turbine engine control and railway traffic management Often complex embedded systems are distributed, typically to achieve demanding performance or dependability requirements, and must operate within hard real-time constraints. Considerable effort is required to select optimal design solutions and ensure adherence to specified requirements. In embedded systems safety, reliability and response-times are considered as strict constraints on the system design. Achievement of these constraints requires meticulous analysis, typically through the use of specialist modelling and simulation techniques. Integration of knowledge and understanding obtained from disparate detailed models remains a considerable challenge. Ideally, a system which has both continuous dynamics and event-driven parts. would be modelled in one environment, using the most appropriate techniques for each part, and allowing the analysis of the whole system to be carried out simultaneously. The paper presents an integrated approach in order to translate automatically the information manipulated during the different phases of the design: specification. analysis, design and implementation.
Neural networks and genetic algorithms have been in the past successfully applied, separately, to controller tuning problems. In this paper we purpose to combine its joint use, by exploiting the nonlinear mapping capa...
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Neural networks and genetic algorithms have been in the past successfully applied, separately, to controller tuning problems. In this paper we purpose to combine its joint use, by exploiting the nonlinear mapping capabilities of neural networks to model objective functions, and to use them to supply their values to a genetic algorithm which performs on-line minimization. Simulation results show that this is a valid approach, offering desired properties for on-line use such as a dramatic reduction in computation time and avoiding the need of perturbing the closed-loop operation
A MATLAB-based rapid controller prototyping and development system for on-line tuning is presented. This is capable of automatically generating executable code for a digital signal processor from a Simulink specificat...
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A MATLAB-based rapid controller prototyping and development system for on-line tuning is presented. This is capable of automatically generating executable code for a digital signal processor from a Simulink specification of a controller and also has a real-time parameter adjustment and data logging facility. An optimisation problem can therefore be formulated in MATLAB with the controller parameters as decision variables and direct measures of the controller's performance as optimisation objectives. A multiobjective genetic algorithm is used as an optimisation engine to perform on-line tuning for the controller of an active magnetic bearing system. The optimisation objective function is based on on-line H ∞ and H 2 , measures of controller performance.
In this paper we consider the problem of stabilizing the seeker scan loop mounted in a missile head. The system consist of a spin-stabilizing gyro-optics assembly and its driving signal processor. The model contains t...
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In computer vision, texture plays an important role. In this work we propose five human perceptual texture features heuristically extracted. Since a modeling can not be obtained from these features, we use a discrimin...
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The underactuated free floating robot in space is nonlinear systems where velocity and acceleration constraints are both nonintegrable, therefore it is a second-order nonholonomic system. Some of the existing non-holo...
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The underactuated free floating robot in space is nonlinear systems where velocity and acceleration constraints are both nonintegrable, therefore it is a second-order nonholonomic system. Some of the existing non-holonomic control methods will not be directly applicable to such systems as it is extremely difficult, if not impossible, to find the control Lie brackets. In this paper, by investigating the system dynamics in dept., we propose a simple velocity-based method to control the unactuated joints and a multi-step composite strategy to implement orientation tracking tasks. The proposed algorithm is of significance in controlling of space robots when some joints fail to function, or they are intentionally set to be passive for energy efficiency and safety purposes.
Proposes a simple and effective method for building a fuzzy model from data. A three-layered RBF network is introduced to implement the fuzzy model. Differing from existing clustering-based methods, in this approach t...
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A fast and computationally efficient fuzzy clustering approach is presented. In this approach, fuzzy clustering is implemented in two hierarchical phases: subclusters generation by a self-organising network and fuzzy ...
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This study deals with a new thermal imaging system using the principle of two-color thermometry to determine the temperature of objects without assigning their emissivity. This is an advanced system of conventional th...
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Using wavelet transforms, a system that assesses dept. of anaesthesia is proposed that utilises auditory evoked potential, heart rate, and blood pressure measurements. The recorded auditory evoked potential signal is ...
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Using wavelet transforms, a system that assesses dept. of anaesthesia is proposed that utilises auditory evoked potential, heart rate, and blood pressure measurements. The recorded auditory evoked potential signal is analysed, its features are extracted, and fed to a neurofuzzy system, which in turn decides on the dept. of the anaesthetic state. In addition, the heart rate and the blood pressure are used as a second measure using rule-based fuzzy logic system. The two measures are combined to give a final level of dept. of anaesthesia using rule-based fuzzy logic. The dept. of anaesthesia level is fed back to a Target controlled Infusion system (TCI) for controlling the infusion of the drug propofol for maintaining a constant level of dept. of anaesthesia. The fuzzy logic rule-base is based on pharmacological knowledge provided by the anaesthetist.
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