فهرست مطالب

fuzzy systems - Volume:6 Issue:3, 2009
  • Volume:6 Issue:3, 2009
  • تاریخ انتشار: 1388/06/11
  • تعداد عناوین: 6
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  • P. Melba Mary, N. S. Page 1
    This paper proposes an approach, for the minimum time swing up of a rotary inverted pendulum. Our rotary inverted pendulum is supported by a pivot arm. The pivot arm rotates in a horizontal plane by a servo motor. The opposite end of arm is instrumented with a joint whose axis is along the radial direction of the motor. A pendulum is suspended at the joint. The task is to design a controller that swings up the pendulum and maintains it upright and maintains the arm position. In the general intelligent hybrid controller, a PD controller with a positive feedback is designed for swinging up and a fuzzy balance controller is designed for stabilization. In order to achieve the swing up in a minimal time, a controller named Minimum Time Intelligent Hybrid Controller is proposed in this paper which is nothing but a PD controller plus a pulse step controller for swinging up along with the fuzzy balance controller for stabilization. By trial and error, tuning of the impulsive control action is done to achieve the minimum-time swing-up. To switch over from swing up mode to stabilization mode energy based switching control method is proposed. Compared to the existing general hybrid nonlinear controller, the swing up time is significantly reduced in the proposed minimum-time controller as demonstrated by extensive computer simulation results.
  • N. Javadian, Y. Maali, N. Mahdavi, Amiri Page 17
    We present a new model and a new approach for solving fuzzy linear programming (FLP) problems with various utilities for the satisfaction of the fuzzy constraints. The model, constructed as a multi-objective linear programming problem, has the significance to provide flexibility for the decision maker (DM), allowing for the assignment of distinct weight corresponding to each constraint and the objective function. A DM’s desired solution is produced by solving a crisp problem controlled by a parameter. We establish the validity of the proposed model and show the effect of the control parameter over the solution. We also show the effectiveness of the model and present three algorithms for solving the FLP problem. One algorithm computes a desired solution by solving a single crisp problem. The other two algorithms, interacting with the decision maker, each time compute a solution achieving a new satisfaction level. Finally, we work out an illustrative example showing that the solutions obtained are often more satisfactory than desired.
  • G. Chowdhury Page 37
    In this paper we introduce the notions of fuzzy transposition hypergroup, fuzzy regular relation and study some basic properties of them. We also study fuzzy quotient hypergroup of a fuzzy transposition hypergroup
  • Xueling Ma, Jianming Zhan, Young Bae Jun Page 53
    In this paper, we first introduce the notions of interval-valued fuzzy (p-,q- and a-) ideals of BCI algebras and investigate some of their related properties. Further, we introduce the notions of ()-interval-valued fuzzy (p-,q- and a-) ideals of BCI algebras and investigate some of their related properties. Some characterization theorems of these generalized intervalvalued fuzzy ideals are derived. The relationship among these generalized interval-valued fuzzy ideals of BCI algebras is also considered.
  • Iffat Jahan Page 65
    We show that the lattice of all ideals of a ring R can be embedded into its lattice of all fuzzy ideals in uncountabily many ways. For this purpose we introduce the concept of a generalized characteristic function of a subset A of a ring R for each fixed pair r, s [0, 1] and show that A is an ideal of R if and only if its generalized characteristic function is a fuzzy ideal of R. Also, we show that the set of all generalized characteristic functions of the members of I (R) for a fixed pair r, s [0, 1] is a complete sublattice of the lattice of all fuzzy ideals of R. We establish that the lattice of all fuzzy ideals of R is generated by the union of all its complete sublattices.
  • Sh., Q. Jiangc., H. Yan Page 73
    In this paper, a new definition of fuzzy bounded sets and totally fuzzy bounded sets is introduced and their interesting properties are studied. By the aid of examples, we find our definition differs from the former authors. Then a relation between totally fuzzy bounded set and N-compactness is discussed. Finally, a geometrical characterization for fuzzy totally bounded sets in I-topological vector spaces is proved