2016 (vol. 26) - Number 4
Practical and asymptotic stability of fractional discrete-time scalar systems described by a new model
D. Krokavec, A. Filasova, P. Liscinsky:
On fault tolerant control structures incorporating fault estimation
Hyperchaos, adaptive control and synchronization of a novel 4-D hyperchaotic system with two quadratic nonlinearities
H. Górecki, M. Zaczyk:
Analytic solutions of transcendental equations with application to automatics
Predictor-based stabilization for chained form systems with input time delay
S. Daniar, R. Aazami, M. Shiroei:
Multivariable predictive control considering time delay for load-frequency control in multi-area power systems
Analysis and comparison of the stability of discrete-time and continuous-time linear systems
M. Rachik, M. Lhous:
An observer-based control of linear systems with uncertain parameters
Identification of stable elementary bilinear time-series model
New observer-based control design for mismatched uncertain systems with time-delay
Parametric optimization of a neutral system with two delays and PD-controller
(AGH University of Science and Technology, Krakow, Poland)
In this paper a parametric optimization problem for a linear neutral system with two delays with an integral quadratic performance index is formulated and solved. The method of computing of a performance index value bases on determining of a Lyapunov functional defined on a state space such that its value for an initial state is equal to a performance index value. In the paper a form of a Lyapunov functional is assumed and a method of computing its coefficients is given. An example illustrating the application of discussed theory is presented. It concerns the system with a PD-controller designed to control a plant with two delays both retarded and neutral type. For such system a value of considered performance index is determined.
keywords: parametric optimization, Lyapunov functional, time delay system, neutral system
Optimizing the operation of a photovoltaic generator by a genetically tuned fuzzy controller
|N. Drir, L. Barazane|
(USTHB, Algiers, Algeria)
(Ecole Nationale Superieure d'Informatique, Algiers, Algeria)
This paper presents design and application of advanced control scheme which integrates fuzzy logic concepts and genetic algorithms to track the maximum power point in photovoltaic system. The parameters of adopted fuzzy logic controller are optimized using genetic algorithm with innovative tuning procedures. The synthesized genetic algorithm which optimizes fuzzy logic controller is implemented and tested to achieve a precise control of the maximum power point response of the photovoltaic generator. The performance of the adopted control strategy is examined through a series of simulation experiments which prove good tracking properties and fast response to changes of different meteorological conditions such as isolation or temperature.
keywords: maximum power point tracking, P&O, styling, fuzzy control, genetic algorithms
Observer-based fault estimation for linear systems with distributed time delay
|A. Filasova, D. Gontkovic, D. Krokavec|
(Technical University of Kosice, Slovakia)
The paper is engaged with the framework of designing adaptive fault estimation for linear continuous-time systems with distributed time delay. The Lyapunov-Krasovskii functional principle is enforced by imposing the integral partitioning method and a new equivalent delay-dependent design condition for observer-based assessment of faults are established in terms of linear matrix inequalities.
Asymptotic stability conditions are derived and regarded with respect to the incidence of structured matrix variables in the linear matrix inequality formulation. Simulation results illustrate the design approach, and demonstrates power and performance of the actuator fault assessment.
keywords: adaptive fault estimation, distributed time delay systems, Lyapunov-Krasovskii functional, integral partitioning technique, time delay segmentation, linear matrix inequalities
Effects of sliding surface on the performances of adaptive sliding mode slip ratio controller for a HEV
(Indus College of Engineering, Odisha, India)
(National Institute of Technology, Odisha, India)
Slip ratio control of a ground vehicle is an important concern for the development of antilock braking system (ABS) to avoid skidding when there is a transition of road surfaces. In the past, the slip ratio models of such vehicles were derived to implement ABS. It is found that the dynamics of the hybrid electric vehicle (HEV) is nonlinear, time varying and uncertain as the tire-road dynamics is a nonlinear function of road adhesion coefficient and wheel slip. Sliding mode control (SMC) is a robust control paradigm which has been extensively used successfully in the development of ABS of a HEV. But the SMC performance is influenced by the choice of sliding surface. This is due to the discontinuous switching of control force arising in the vicinity of the sliding surface that produces chattering. This paper presents a detailed study on the effects of different sliding surfaces on the performances of sliding mode based adaptive slip ratio control applied to a HEV.
keywords: sliding mode control, slip ratio control, hybrid electric vehicle, sliding surface, ABS
Minimum energy control of positive discrete-time linear systems with bounded inputs
(Bialystok University of Technology, Bialystok, Poland)
The minimum energy control problem for the positive discrete-time linear systems with bounded inputs is formulated and solved. Sufficient conditions for the existence of solution to the problem are established. A procedure for solving of the problem is proposed and illustrated by a numerical example.
keywords: positive, discrete-time, minimum energy control, bounded inputs, procedure
Loopshaping of motor torque controller
(AGH University of Science and Technology, Krakow, Poland)
The controller synthesis problem of the motor torque is presented. The tuning of the II^2 controller parameters of the electromagnetic motor torque is introduced. The results are obtained by applying the weighted sensitivity method (nominal performance) which is the optimization in H_infinity space. The waterbed effect for some weighting functions is presented. The results, which are obtained by a parametric optimization (nonlinear programming), are analysed by the calculations of the stability margins.
keywords: electric drive, II^2 controller, robust control, stability region, parametric optimization, nonlinear programming, waterbed effect, weighted sensitivity, modulus criterion
Anti-synchronization in different new chaotic systems via active nonlinear control
|Ayub Khan, R.P. Prasad|
(University of Delhi, New Delhi, India)
In this paper, we discuss anti-synchronization between two identical new chaotic systems and anti-synchronization between another two identical new chaotic systems by active nonlinear control. The sufficient conditions for achieving the anti-synchronization of two new chaotic systems are derived based on Lyapunov stability theory. Numerical simulations are provided for illustration and verification of the proposed method.
keywords: anti-synchronization, new chaotic system, active nonlinear control
Comparison of four state observer design algorithms for MIMO system
|Vinodh Kumar. E., J. Jerome, S. Ayyappan|
(PSG College of Technology, Coimbatore, Tamilnadu, India)
A state observer is a system that models a real system in order to provide an estimate of the internal state of the system. The design techniques and comparison of four different types of state observers are presented in this paper. The considered observers include Luenberger observer, Kalman observer, unknown input observer and sliding mode observer. The application of these observers to a Multiple Input Multiple Output (MIMO) DC servo motor model and the performance of observers is assessed. In order to evaluate the effectiveness of these schemes, the simulated results on the position of DC servo motor in terms of residuals including white noise disturbance and additive faults are compared.
keywords: Luenberger observer, Kalman observer, unknown input observer, sliding mode observer