In this paper we discuss a problem of numerical calculation accuracy of the Fractional-order Backward Difference/Sum (FOBD/S) of some discrete functions applied in discrete control strategies, in real-time closed-loop...
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In this paper we discuss a problem of numerical calculation accuracy of the Fractional-order Backward Difference/Sum (FOBD/S) of some discrete functions applied in discrete control strategies, in real-time closed-loop systems. We compare Grünwald-Letnikov formula vs. its Horner's equivalent form, as well as their “simplified” forms, in our opinion, an interesting tool in minimization of the time and memory shortage problems often to meet in such systems.
In the paper a multicontroller-based switchable control system for nonlinear MIMO plants is presented. the control system synthesis is carried out by linearization of the adopted nonlinear plant model at its operating...
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In the paper a multicontroller-based switchable control system for nonlinear MIMO plants is presented. the control system synthesis is carried out by linearization of the adopted nonlinear plant model at its operating “points”. thus the considered structure contains a collection of linear feedback controllers. In the first stage of the adopted method a great number of controllers is synthesized. the paper discuss problems with reduction of such controller set to make it smaller and possible to implement the system in e.g. constrained memory of programmable automation devices. As an example a nonlinear model of a drilling vessel in three degrees of freedom (3DOF) on a sea surface is used as a MIMO plant to be controlled. Here the controller set depends on the preset ship yaw angle and the velocity of the sea current. the methods of reduction and their possible results are compared and discussed.
the problem of state estimation with partially unknown system dynamics is proposed and discussed. the unknown part of nonlinear functions in system dynamics are approximated by neural networks (NN's). System state...
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the problem of state estimation with partially unknown system dynamics is proposed and discussed. the unknown part of nonlinear functions in system dynamics are approximated by neural networks (NN's). System state and the NN unknown parameters are estimated simultaneously in real-time without necessity of any off-line training process of NN. three local estimators were applied to the problem of NN based state estimation. the estimation qualities of the considered estimators are compared within three numerical examples covering a different kind of uncertainty in the model description.
To calculate feedforward control strategies by means of dynamic optimization procedures, the alternatives of direct and indirect methods are compared in this paper. the direct optimization approaches that are consider...
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To calculate feedforward control strategies by means of dynamic optimization procedures, the alternatives of direct and indirect methods are compared in this paper. the direct optimization approaches that are considered in this paper make use of the Hermite-Simpson method and of the Legendre Pseudospectral method as underlying discretization strategies. their description is followed by a short introduction to the maximum principle of Pontryagin, i.e., the indirect method. All procedures are employed to compute feedforward control sequences for the flight control of a four-rotor UAV, which is an unstable, nonlinear multi-input multi-output system. the optimization results are compared with respect to their accuracy and applicability.
the paper deals with solving algebraic Riccati equations with two-sided polynomials, which arise in some applications of optimal control of linear time-invariant spatially distributed systems. the conditions are given...
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the paper deals with solving algebraic Riccati equations with two-sided polynomials, which arise in some applications of optimal control of linear time-invariant spatially distributed systems. the conditions are given for the existence of a solution in the set of finite-order polynomials. If such a solution does not exist, the infinite-order solution is truncated and given in the form of polynomial of an arbitrary high order. the proposed numerical algorithm is based on the discrete Fourier transform theory. An example on optimal control of spatially-distributed systems is also given. the proposed algorithm is used to design of the distributed LQ controller.
the paper deals with a study of model predictive control applied to three-phase Permanent Magnet Synchronous Motors (PMSM). these motors are used in drives of robots and machine tools. the construction of their model ...
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the paper deals with a study of model predictive control applied to three-phase Permanent Magnet Synchronous Motors (PMSM). these motors are used in drives of robots and machine tools. the construction of their model is discussed here with respect to a model-based control design. the model is composed via mathematical-physical analysis. the analysis is outlined in the main theoretical points. the predictive control is explained as a promising alternative to standard solution based on vector cascade control. In predictive control design, the quadratic criterion, equations of predictions and specific square-root optimization procedure are explained. the proposed solution is illustrated by several simulation examples and compared with data records of real experiment of vector control.
this paper considers the design of observers for a class of continuous and discrete-time nonlinear systems presented by Takagi-Sugeno (T-S) model with nonlinear subsystems and unmeasurable premise variables. As a resu...
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this paper considers the design of observers for a class of continuous and discrete-time nonlinear systems presented by Takagi-Sugeno (T-S) model with nonlinear subsystems and unmeasurable premise variables. As a result, the proposed T-S structure reduces the number of rules in the Sugeno model by using local nonlinear rules. Moreover, it can represent larger class of nonlinear systems as compared to the measurable premise variable case. the proposed observer guarantees exponential convergence of state estimation error by Lyapunov stability analysis and linear matrix inequality (LMI) formulation. Numerical examples illustrate effectiveness of the proposed method.
Livelong education in electro-mechanical industry is increasingly important as it allows practicing engineers and technicians to gain the knowledge necessary to cope withthe fast development and consequently with hig...
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Livelong education in electro-mechanical industry is increasingly important as it allows practicing engineers and technicians to gain the knowledge necessary to cope withthe fast development and consequently with higher demands on their workplaces. this paper addresses different aspects of development and execution of such industrial training. Concrete solutions and results are presented including: (1) extensive international knowledge needs analysis in electro-mechanical sector, (2) e-learning solutions for industry including learning management systems and application of remote working stations/experiments for practical part of the training and (3) examples of the training modules from robotics developed for industry. Applied solutions and education methodology is evaluated by feedback obtained from the training participants. Based on a gained experience a long-term perspective and possible further development direction of modern industrial education is also addressed.
the paper proposes a carrier synchronization procedure for high-order QAM modulated signals that uses a decision-directed extended Kalman filtering (EKF) technique. the proposed method combines the Kalman filter with ...
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the paper proposes a carrier synchronization procedure for high-order QAM modulated signals that uses a decision-directed extended Kalman filtering (EKF) technique. the proposed method combines the Kalman filter with a lock detector to establish the status of the synchronization process, modifying adaptively the Kalman filter parameters. As compared withthe complete EKF filter, the proposed synchronization algorithm simplifies the Kalman measurement model to a single scalar equation reducing significantly the computational complexity of the algorithm. Simulations show that the simplified Kalman algorithm has equivalent synchronization performances withthe complete EKF filter.
In this paper, a model reference adaptive system (MRAS) approach is applied for estimating the armature position in electromagnetic actuators. Two different MRAS strategies are carried out. the first applies a Lyapuno...
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In this paper, a model reference adaptive system (MRAS) approach is applied for estimating the armature position in electromagnetic actuators. Two different MRAS strategies are carried out. the first applies a Lyapunov approach in order to derive the adaptation law, the second uses hyperstability theory. the results are compared to a state-of-the-art position estimation method, and the MRAS approach shows better performance, in particular at higher speed. Some problems in regard to the hyperstability approach are analyzed as well, and the next steps towards a robust and practical feasible approach are addressed.
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