A procedure for the postoptimal analysis of dynamic positioning control system of floating vessels is proposed. The control system design is based on the optimal constrained covariance control (OC 3 ). Using the OC 3 ...
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A procedure for the postoptimal analysis of dynamic positioning control system of floating vessels is proposed. The control system design is based on the optimal constrained covariance control (OC 3 ). Using the OC 3 technique, the disadvantages of the classical LQG optimal control technique are avoided. The presented numerical example illustrates the properties of the new approach.
作者：
Branco, PJC[?]Paulo Jose da Costa Branco (1965) received the B.Sc. and M.Sc. degrees in Electrical Engineering from the Universidade Federal do Rio de Janeiro (UFRJ)
Rio de Janeiro/Bnsil in 1988 and 1991 respectively. Since 1992 he has been an Assistant at the Department of Electrical and Computing Engineering Section of Electrical Machines and Power Electronics in the Instituto Superior Tecnico (I.S.T.). He is currently working toward the Ph.D. degree in Electrical Engineering in an application of fuzzy learning theory in the design of “intelligent” electromechanica1 systems. His majorfieldsof interest are Control of Electrical Drives mainly their rncdellization and control using fuzzy logic and neural networks energy conservation and non-linear dynamic systems. In April I992 he joined at Centro de Automictica of Universidade Tecnica de Lisboa (CAUTL) as a researchassistant and in 1993 joined to the Mechatronics Laboratory in the same university. (Instituto Superior TCcnico (I.S.T.) Department of Electrical and Computing Engineering. Section of Electrical Machines and Power Electronics Lisboflortugal Phone: +35 I 1/8417432 Fax: +3511/848 29 87 E-mail: pbranco@alfa.ist.utl.pt)
A self-adaptive scheme is described for automatically tracking the temperature and saturation-dependent rotor time constant T-r in indirect vector control. This method is based on a monitoring signal injected into the...
A self-adaptive scheme is described for automatically tracking the temperature and saturation-dependent rotor time constant T-r in indirect vector control. This method is based on a monitoring signal injected into the process. A cross-correlation function between the monitoring signal and the speed error indicates the T-r changes in direction (increase or decrease) and magnitude. The proposed identification algorithm presents unique characteristics: it does not use current or voltage sensors;it is not motor-parameter dependent;the amplitude of the monitoring signal can be reduced but with an increase on the speed-error sensibility to control interference in drive's performance and it works either on steady-and dynamic transient-state. it will need some load to operate but this condition is satisfied in all practical cases. Tests were conducted with a 1.2 kW four-quadrant AC drive. The adaptive indirect vector-control was implemented in a microcomputer with the motor supplied by a voltage-source inverter with current control using IGBT Experimental and simulated results using this adaptive digital scheme for different loads and values of model T-r(representing a detuned operation) are presented showing good performances.
The novel idea of an orthogonal fuzzy rule-based system is introduced in this paper. It is shown that in a fuzzy rule-based system where rules are orthogonal, each rule induces its maximum effect on the final decision...
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The novel idea of an orthogonal fuzzy rule-based system is introduced in this paper. It is shown that in a fuzzy rule-based system where rules are orthogonal, each rule induces its maximum effect on the final decision. Using 18 orthogonal fuzzy rules, a model for the solder paste printing stage of SMT is created. The predicted percentage of deposit volume from the orthogonal and non-orthogonal models are compared with actual values. The orthogonal model shows less error in 85% of the data points.
This paper presents results for a tomographic system using an array of electrodynamic sensors. Sensitivity maps are derived for the individual sensors and then used by a back projection algorithm to calculate concentr...
This paper presents results for a tomographic system using an array of electrodynamic sensors. Sensitivity maps are derived for the individual sensors and then used by a back projection algorithm to calculate concentration profiles from measured sensor values. Limitations in linearity over the sensing area are reduced by applying a filter to the images. The filtered back projection algorithm is tested on both uniformly and artificially produced non-uniformly distributed solids flows.
Pachteret al. (1994) proposed a new method for parameters estimation of second-order dynamical system models of high-order real plants based on knowledge of the theoretical transient time Tu(onset delay, OD) and the s...
Pachteret al. (1994) proposed a new method for parameters estimation of second-order dynamical system models of high-order real plants based on knowledge of the theoretical transient time Tu(onset delay, OD) and the slope of the inflection tangent yn′(ti) (onset rate, OR) of experimental unit step responses (USRs). However, two equations in the paper are shown to be incorrect. Therefore, in this note we present the correct expressions for characteristic quantities of an alternative parametrization of the second-order system with ξ > 1.
The paper presents results of research with the new predictive autopilot structure (PIP+D) with gain scheduling. The autopilot is tested and compared with conventional PID autopilot for a mariner class ship. The autop...
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The paper presents results of research with the new predictive autopilot structure (PIP+D) with gain scheduling. The autopilot is tested and compared with conventional PID autopilot for a mariner class ship. The autopilot parameters are changed with the speed of the ship using the gain scheduling technique. Results obtained during the research show that the proposed autopilot structure is to be recommended if improved performance is of prime interest, when the velocity of the ship is changing. The analysis is based on the simulation of a mariner class ship as a nonlinear system, with the steering servo system taken as a nonlinear model. Results of the simulation are included.
Multichannel time-series result from observations of a given engineering, biomedicai, econometric or environmental variable taken at different locations. Processing this type of signal presents problems associated wit...
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Multichannel time-series result from observations of a given engineering, biomedicai, econometric or environmental variable taken at different locations. Processing this type of signal presents problems associated with its extrapolation in given space ranges and its possible prediction. This paper presents a comparison of seasonal AR modelling of such signals and the application of wavelet networks to the system identification and prediction of a particular signal. The choice of wavelet functions and the optimization of their coefficients is discussed as well. Each method suggested in the paper is verified for simulated signals at first and then used for the analysis of real signals, including the observation of air pollution. All algorithms are written in the MATLAB environment.
Advances in signal processing allow us to model the audio signal in terms of mathematical representation. Compressed audio signal are also important for low-bit-rate media in order to minimize transmission cost. Appli...
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Advances in signal processing allow us to model the audio signal in terms of mathematical representation. Compressed audio signal are also important for low-bit-rate media in order to minimize transmission cost. Applications such as movies on compact disc, audio conferencing, and digital television also require a good model for the audio compression. We present a model for compressed audio signal. By varying different modelling parameters, we obtain the simulation result of the proposed model of the audio coder. Simulation results found that it has a good compression Ssignal-to-noise ratio compared with NICAM, CD, and OCF coders.
The paper present an efficient O(T/sup 2/) algorithm for the general single-item dynamic lot-sizing problem, where the time horizon spans over T periods, inventory levels are limited, and nonzero initial and safety st...
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The paper present an efficient O(T/sup 2/) algorithm for the general single-item dynamic lot-sizing problem, where the time horizon spans over T periods, inventory levels are limited, and nonzero initial and safety stock levels are assumed to exist. The properties of the model were previously found by the author (1992) to transform the problem of finding an optimal, extreme solution into an equivalent shortest-path problem in a multigraph, which is a nontrivial generalization of the Wagner-Whitin (1958) model. Although the resulted multigraph contains O(T/sup 3/) edges, this paper shows how to construct the shortest path solution in O(T/sup 2/) time. For this type of the lot-sizing problems, the resulted algorithm has the lowest complexity over known methods.
In this paper, the architecture of a fuzzy processor intended for high-speed control applications is described. Its main advantage is the inference speed that does not depend on the number of used inputs and rules. Th...
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In this paper, the architecture of a fuzzy processor intended for high-speed control applications is described. Its main advantage is the inference speed that does not depend on the number of used inputs and rules. This is accomplished by the usage of content addressable memory as a rule set storage. The proposed architecture was simulated and the simulation results give the inference speed of about 200 KFLIPS.
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