A neuro controller for high precision manoeuvring of underwater vehicles require special attention to a number of factors including thruster and vehicle’s nonlinearities, couplings which exist between various degrees...
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A neuro controller for high precision manoeuvring of underwater vehicles require special attention to a number of factors including thruster and vehicle’s nonlinearities, couplings which exist between various degrees of freedom as well as effects of the sea currents. The neuro control system for underwater vehicle maneouvring described here is based on the conventional controller supported with the so called adaptive neural network.
A characteristic feature of the neural network models is the large number of parameters. A model offering many parameters usually gives rise to problems, and the variance contribution to the modeling error might be ve...
A characteristic feature of the neural network models is the large number of parameters. A model offering many parameters usually gives rise to problems, and the variance contribution to the modeling error might be very high. Therefore, it is crucial to find the model with the optimal number of parameters. In this paper two techniques of selection of the optimal number of model parameters are described and compared: explicit and implicit regularization techniques. Model validation forms the final stage of an identification procedure with the aim of assessing objectively whether the identified model agrees sufficiently well with the observed data. In this paper the reliability of the correlation-based validation tests and the χ2-test is analyzed.
An explicit self-tuning controller based on the Takagi-Sugeno fuzzy model of the process is proposed. The fuzzy model is represented as a linear regression model whose parameters are functions of some of the process v...
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An explicit self-tuning controller based on the Takagi-Sugeno fuzzy model of the process is proposed. The fuzzy model is represented as a linear regression model whose parameters are functions of some of the process variables. Such a model can be considered as a linear time-varying model whose parameter values are known at every moment. The pole placement design procedure modified for time-varying systems is applied to obtain the polynomial controller parameters that provide the desired closed-loop poles. The proposed algorithm is very simple, and thus suitable for on-line controller design in adaptive control systems.
This paper presents a modification to the Kandadai and Tien’s learning algorithm for tuning a fuzzy-neural controller that is able to automatically generate a knowledge base. Tuning is based on reinforcements from a ...
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This paper presents a modification to the Kandadai and Tien’s learning algorithm for tuning a fuzzy-neural controller that is able to automatically generate a knowledge base. Tuning is based on reinforcements from a dynamical system, thus giving a pseudosupervised learning scheme using error backpropagation. Originally, a weak reinforcement in the form of a binary failure signal was assumed which proved to be insufficient in terms of steady-state error. Therefore, a continuous reinforcement signal is applied enabling the system to correct the error as well as decreasing the overall control effort in the learning phase.
The majority of nonlinear models based on neural networks are of the black-box structure. A nonlinear system can be nonlinear in many different ways, thus the nonlinear black-box model structure must be very flexible....
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The majority of nonlinear models based on neural networks are of the black-box structure. A nonlinear system can be nonlinear in many different ways, thus the nonlinear black-box model structure must be very flexible. This means that it must have many parameters. A model offering many parameters usually creates problems, and the variance contribution to the error might be high. For a particular identification problem, only a subset of the parameters may be necessary, and the main topic in nonlinear system identification is how to select a model structure that describes the system dynamics with the minimum number of parameters. This paper discusses nonlinear input-output models that are suitable for implementation of feedforward neural networks. The proposed model structures were tested and compared using the identification procedure of a pH process. The results indicated that a simplest model structure can satisfactorily represent the investigated process.
In this paper, we present the theoretical development to stabilize a class of uncertain time-delay system and its application to model-following systems. The system under consideration is described in state space mode...
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ISBN:
(纸本)078039805X
In this paper, we present the theoretical development to stabilize a class of uncertain time-delay system and its application to model-following systems. The system under consideration is described in state space model containing state delay, uncertain parameters and disturbance. The main idea is to reduce the state of system into an equivalent one, by employing generalized transformation, which is easier to analyze its behavior and stability. Then, the min-max approach is employed to find the stabilizing control law. After that, a class of model-following system is introduced for controlling the error between the model and process. With the extended theorem, the suitable control law that guarantees model tracking is derived. Finally, two numerical simulations are illustrated to show the algorithm for applying the proposed theorems and the effectiveness of the designed control law in stabilizing the controlled systems.
作者:
Jasmin VelagicZoran VukicEdin OmerdicUniversity of Sarajevo
Faculty of Electrical Engineering Skenderija 70 BH-71000 Sarajevo Bosnia and Herzegovina fax : (+387 71) 654 972 University of Zagreb
Faculty of Electrical Engineering and Computing Department of Control and Computer Engineering in Automation Unska 3 HR-10000 Zagreb Croatia fax : (+385 1) 612 98 09 University of Tuzla
Faculty of Electrical and Mechanical Engineering Franjevacka 2 BH-75000 Tuzla Bosnia and Herzegovina
We develop in this paper an adaptive fuzzy gain autopilot for ship track-keeping. This autopilot is composed of Sugeno fuzzy type autopilot in an ordinary feedback loop and adjustable scaling factors mechanism in an a...
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We develop in this paper an adaptive fuzzy gain autopilot for ship track-keeping. This autopilot is composed of Sugeno fuzzy type autopilot in an ordinary feedback loop and adjustable scaling factors mechanism in an additional feedback loop. The adjustment mechanism represents a fuzzy controller that changes scaling factors of the base fuzzy autopilot. The control system for the track-keeping is completely described. For the track-keeping problem, the maneuver of way-point turning and ship guiding through a complex path (trajectory) are presented. The influence of sea current and wave disturbances on track-keeping performance was also considered. We first present simulation results obtained by the Sugeno fuzzy type autopilot. Then, we compare those results with ones obtained by an adaptive fuzzy autopilot.
The application of a nonlinear predictive controller in the cascade control structure of a boost converter is investigated. The neuro-predictive controller is realized as a nonlinear optimizer, using the Levenberg-Mar...
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The application of a nonlinear predictive controller in the cascade control structure of a boost converter is investigated. The neuro-predictive controller is realized as a nonlinear optimizer, using the Levenberg-Marquardt unconstrained optimization procedure. For the prediction of future process responses, two MLP neural networks are used. One network is used for modeling the converter dynamics and the other for online estimation of the converter's input voltage. This structure ensures good system performance in all operating regions and inherent compensation of ripples in the converter's input current caused by variations of the input voltage. The advantages of the proposed control structure are demonstrated through experimental comparison with a linear GPC with manually adjusted feedforward compensator.
作者:
Vukic, Z.Velagic, J.University of Zagreb
Faculty of Electrical Engineering and Computing Department of Control and Computer Engineering in Automation Unska 3 ZagrebHR-10000 Croatia University of Sarajevo
Faculty of Electrical Engineering Skenderija 70 SarajevoBH-71000 Bosnia and Herzegovina
In this paper a comparative analysis of Mamdani and Sugeno type fuzzy autopilots for ships is given. Both autopilots have two inputs: the heading signal and the yaw rate signal, and only one output: command rudder ang...
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Friction appears in the bearings and reduction gear of controlled electrical drives and affects the quality of the position, speed or force control. The servosystem performance can be improved by implementation of acc...
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Friction appears in the bearings and reduction gear of controlled electrical drives and affects the quality of the position, speed or force control. The servosystem performance can be improved by implementation of acceleration feedback. For the reason that acceleration measurement is often either not possible or practical, the implementation of acceleration estimation by an observer or differentiation of speed is proposed. Another approach to friction influence compensation is based on the disturbance observer. Its advantage is that it can be applied generally to the estimation of various disturbances. This paper deals with these friction compensation methods which are not based on friction model, but on the compensation of friction as a disturbance. The efficiency of these methods in a servodrive with Stribeck friction is compared by computer simulation and experimentally on a servosystem laboratory model.
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