Abstract: Fuzzy adaptive tracking controllers for a class of uncertain nonlinear dynamical systems are proposed and analyzed. The controller consists of adaptive and robustifying components whose role is to nullify the effect of uncertainties and achieve a desired tracking performance. The interactions between the two components have been investigated. We use the Takagi-Sugeno-Kang type of the fuzzy logic system to approximate the controller. It is proved that the closed-loop system using this adaptive fuzzy controller is globally stable in the sense that all signals involved are bounded. Finally, we apply the method of direct adaptive fuzzy controllers to control an inverted pendulum and the simulation results are included.
Keywords: adaptive fuzzy approach, nonlinear plant, T-S-K fuzzy logic
Abstract: For students learning the simplex method of linear programming it is a wellbeloved occasion to solve the so-called transportation problem by the method of distribution. This method is simple to calculate and easy to follow. The simple way of solution suggests that its correctness may be proven by basic means. This paper has two main aims. One of them is to present the problem and to solve it by basic means. The other one is the analysis of the so-called array-bases defined for this reason. In case of a transportation problem m stores and n destinations are given, and the goods have to be taken from the stores to the destinations such that the cost of transporting has to be minimal. The unit costs of the transportation are given by an array. In the solution some routes (elements of the array) are chosen and the number of units to transport there is given. It will be proven that the routes for the optimal transportation compose a basis, and the solution is also achieved by those through the searches. (The basis of an m× n array consists of m+ n −1 elements such that they do not span a loop.) In the proof some characteristics of the bases are needed, for example that the number of them is finite. To prove this it is enough to give an easily calculated upper bound, the exact value is given in the appendix. As an extra result of this calculation some interesting formulas of combinatorics are also proven.
Keywords: transportation problem, linear algebra, bases
Abstract: The paper presents a computer analysis of inductive coupling of the electromagnetic compatibility (EMC) problem. Its focus is on power electronics and electrical drives and tests performed by a numerical computer simulation that can disclose suite surprising findings about EMC.
Keywords: converters, inductance, electromagnetic compatibility, power electronics
Abstract: This paper deals with the finite element based optimal design of a wind energy based heater. The proposed device ensures the conversion of the wind kinetic energy into heat by means of Joule effect of eddy currents induced in the wall of a tubular stator due to the rotating magnetic field produced by rotor permanent magnets. The transient electromagnetic field problem associated to the operation of the device is solved using a 2D finite element approach based on vector potential formulation. A simplified method for the 2D heat transfer analysis of the device is also proposed. The influence of stator wall material and thickness, number of poles, the airgap thickness and the geometrical parameters of the permanent magnets is analyzed in the aim of optimizing the studied heater.
Keywords: Finite element analysis, wind energy based heater, optimal design
Abstract: Authors of the article evaluate the influence of temperature and thickness of coating onto the thermal endurance of magnesium alloy ML-5 with a 0,5 mm thickness NiAl coating METCO 404. Described are both of experiments and also samples preparation.
Keywords: coating, plasma spraying, thermal endurance
Abstract: The paper – similarly to our earlier publications since 1993 – is trying to ‘synchronize’ early quantum physics, the Kalmanian representation theory, Jungian analytic psychology, and certain aesthetical categories. The number ‘137’, the so-called inverse Fine Structure Constant (IFSC), is placed at the centre of this heuristic and epistemological experiment, along with the scientific cooperation of Pauli and Jung. A new possibilistic twin concept of “controlling-observing equations” is proposed for the reinterpretation of the FSC and other Number Archetypes on the basis of the Hermeneutic and symbolic languages found in the W. Pauli and C. G. Jung “Correspondence”. The first part of the paper deals in first line with the introduction of the possibilistic twin concept of FSC together with its interpretation according to the hermeneutical “tradition” of the Pauli-Jung collaboration.
Keywords: system and control theory, fine structure constant (FSC), inverse (reciprocal) fine structure constant (IFSC), number archetype, W. Pauli and C. G. Jung correspondence
Abstract: The paper – similarly to our earlier publications since 1993 – is trying to ‘synchronize’ early quantum physics, the Kalmanian representation theory, Jungian analytic psychology, and certain aesthetical categories. The number ‘137’, the so-called inverse Fine Structure Constant (FSC), is placed at the centre of this heuristic and epistemological experiment, along with the scientific cooperation of Pauli and Jung. A new possibilistic twin concept of “controlling-observing equations” is proposed for the reinterpretation of the FSC and other Number Archetypes on the basis of the Hermeneutic and symbolic languages found in the W. Pauli and C. G. Jung “Correspondence”. The second part of the paper deals with the new ways of cognition and imagination related to the “Background Control Theory” which can be identified mainly in the Pauli-Jung collaboration anticipating the new system and control approach of R. E. Kalman Furthermore, we summarize this unusual attempt and give an extensive bibliography for further reading.
Keywords: Control Theory, fine structure constant, Number archetype, W. Pauli and C. G. Jung correspondence