Journal of Intelligent & Fuzzy Systems - Volume 28, issue 3

Authors: Singh, Sujeet Kumar | Yadav, Shiv Prasad

Article Type: Research Article

Abstract: This paper develops an approach for solving non-linear programming problem in intuitionistic fuzzy environment. Since, fuzziness may occur in some or all parameters of a system, we discuss both situations in this study. We transform the intuitionistic fuzzy model into a fuzzy model using the concept of component wise optimization. We propose a non-linear membership function and utilize it to convert the fuzzy model into a crisp model. For application, we consider some manufacturing systems having some or all intuitionistic fuzzy parameters. After modeling these systems, we apply our methodology for justification.

Keywords: Triangular intuitionistic fuzzy number, intuitionistic fuzzy non-linear programming problem, membership function

DOI: 10.3233/IFS-141427

Citation: Journal of Intelligent & Fuzzy Systems, vol. 28, no. 3, pp. 1421-1433, 2015

Authors: Sun, Shoubin | Xiu, Zhenyu | Li, Ling-Qiang

Article Type: Research Article

Abstract: In this paper, we prove that not all of fuzzifying matroids have dual matroids. Then we give a sufficient and necessary condition such that a fuzzifying matroid has dual matroid. We also present the notion of spanning of fuzzifying matroids and prove that a fuzzifying matroid with dual matroid can be reproduced by its dual matroid and its spanning, respectively.

Keywords: Fuzzifying matroid, dual matroid, spanning

DOI: 10.3233/IFS-141428

Citation: Journal of Intelligent & Fuzzy Systems, vol. 28, no. 3, pp. 1435-1440, 2015

Authors: Farahani, Mohsen | Ganjefar, Soheil | Kasalani, Jafar Najafi

Article Type: Research Article

Abstract: The purpose of this paper is to improve the stability in a power system using a new intelligent controller. In this paper, a new online control strategy of a static synchronous series compensator (SSSC) is proposed to improve the transient stability of power systems. In this strategy, an auxiliary damping controller with an adaptive structure is used to generate an essential signal which can enhance the damping of the SSSC. This auxiliary damping controller consists of a Wiener-type neural network controller (WNNC). The back propagation (BP) algorithm is utilized to online training of the WNNC. The Lyapunov method is used …to guarantee the stability of WNNC. The test power system is a two-area four-machine system power. The simulation results show that the oscillations are satisfactorily damped out by the WNNC. The proposed approach is effective to mitigate power system oscillations and improve the stability. Since the Lyapunov stability theory is used to obtain the adaptive learning rates, the stability of closed-loop system can be guaranteed. In this case, the overall control scheme has capabilities of learning and adaptiveness. Show more

Keywords: Static synchronous series compensator (SSSC), supplementary damping controller, intelligent controller, Winner neural network

DOI: 10.3233/IFS-141429

Citation: Journal of Intelligent & Fuzzy Systems, vol. 28, no. 3, pp. 1441-1450, 2015

Authors: Fateh, Mohammad Mehdi | Souzanchikashani, Mahdi

Article Type: Research Article

Abstract: A robot manipulator including its actuators is a complex system due to the nonlinearity, uncertainty and joint flexibility. To overcome complexity, this paper develops a novel indirect adaptive fuzzy control for electrically driven flexible-joint robot manipulators in which a novel estimation technique is introduced to estimate the uncertainty. The control structure differs from the previous ones due to using the voltage control strategy instead of the torque control strategy. The control design has only one control loop whereas the commonly used control design employs two control loops. Moreover, it is a decentralized control whereas the torque-based control design is a …centralized control. The required feedbacks for each controller are the motor current, joint position, joint velocity and motor velocity. Some advantages are: considering the whole robotic system including robot and its actuators as a fifth-order model, simplicity of control design, computational efficiency, good performance, and guaranteed stability. Simulation results and comparisons show the effectiveness and superiority of the control approach over two control approaches. The first approach is a modified fuzzy proportional-integral control as a torque-based control method and the second one is a robust control as a voltage-based control method. Show more

Keywords: Indirect adaptive fuzzy control, flexible-joint robot, voltage control strategy, actuator dynamics

DOI: 10.3233/IFS-141430

Citation: Journal of Intelligent & Fuzzy Systems, vol. 28, no. 3, pp. 1451-1459, 2015

Authors: Fazlollahtabar, Hamed | Mahdavi-Amiri, Nezam | Muhammadzadeh, Amir

Article Type: Research Article

Abstract: We concern with both time and cost optimization in an automated manufacturing system. In our proposed system, material handling is carried out by automated guided vehicles and robots for the manufacturing functions. In this way, defect rates, breakdown times, waiting time, processing time, and certain other parameters are not expected to be deterministic. Therefore, we apply stochastic programming to optimize the production time and material handling cost. The proposed stochastic program is a nonlinear model, for this reason we apply a successive linear programming (SLP) technique for its optimization. Numerical test results point to the inefficacy of the proposed optimization …method for large sized problems. Hence, a genetic algorithm (GA) is presented to optimize large sized problems. Show more

Keywords: Automated manufacturing system, stochastic programming, nonlinear optimization, genetic algorithm

DOI: 10.3233/IFS-141431

Citation: Journal of Intelligent & Fuzzy Systems, vol. 28, no. 3, pp. 1461-1475, 2015