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Ali Saghafinia   Dr.  University Educator/Researcher 
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Ali Saghafinia published an article in January 2015.
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Atefeh Amindoust

11 shared publications

University of Malaya

5
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16
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Publication Record
Distribution of Articles published per year 
(2011 - 2015)
Total number of journals
published in
 
4
 
Publications
Article 0 Reads 8 Citations Adaptive Fuzzy Sliding-Mode Control Into Chattering-Free IM Drive Ali Saghafinia, Hew Wooi Ping, Mohammad Nasir Uddin, Khalaf ... Published: 01 January 2015
IEEE Transactions on Industry Applications, doi: 10.1109/TIA.2014.2328711
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This paper presents an adaptive fuzzy sliding-mode controller (AFSMC) based on the boundary layer approach for speed control of an indirect field-oriented control (IFOC) of an induction motor (IM) drive. In general, the boundary layer approach leads to a tradeoff between control performances and chattering elimination. To improve the control performances, a fuzzy system is assigned as reaching control part of the fuzzy sliding-mode so that it eliminates the chattering completely in spite of the large uncertainties in the system. The applied fuzzy controller acts like a saturation function with a nonlinear slope inside thin boundary layer near the sliding surface to guarantee the stability of the system. Moreover, an adaptive law is implemented to estimate the unknown bound of uncertainty, which is obtained in the sense of Lyapunov stability theorem to minimize the control effort. The proposed AFSMC-based IM drive is implemented in real-time using DSP board TI TMS320F28335. The experimental and simulation results show the effectiveness of the proposed AFSMC-based IM drive at different operating conditions.
BOOK-CHAPTER 0 Reads 2 Citations Supplier Evaluation Using Fuzzy Inference Systems Atefeh Amindoust, Ali Saghafinia Published: 01 January 2014
Recent Developments and the New Direction in Soft-Computing Foundations and Applications, doi: 10.1007/978-3-642-53939-8_1
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Supplier selection is an important area of decision making in manufacturing and service industries, mainly for large and medium companies—either multinational (MNCs) or local. As sustainability in terms of economic, environmental, and social aspects has gained world-wide focus in supply chain management, this dimension deserves due attention in supplier selection decision. In real life applications, the importance of supplier selection criteria is different and depends on the circumstances and situations and each organization may consider its individual relative importance of the criteria. The relative importance of the criteria and also the suppliers’ performance with respect to these criteria would be verified with the relevant decision makers. So, the supplier selection decision involves a high degree of vagueness and ambiguity in practice. This chapter takes the aforesaid issues into account and proposes a modular FIS method for supplier selection problem. To handle the subjectivity of decision makers’ preferences, fuzzy set theory is applied. The applicability and feasibility of the proposed method are tested through a real-life supplier selection problem.
BOOK-CHAPTER 1 Read 2 Citations Supplier Evaluation and Selection Using a FDEA Model Atefeh Amindoust, Ali Saghafinia Published: 29 November 2013
Recent Developments and the New Direction in Soft-Computing Foundations and Applications, doi: 10.1007/978-3-642-41372-8_13
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Due to the growth of global outsourcing, supplier evaluation and selection is one of the strategic decisions for purchasing management in the supply chain. In this chapter, we address the important attributes through the literature that constituent suppliers should possess in order to achieve the successful supply chain. These attributes (criteria) are obtained using an Affinity Diagram. Then, a committee of decision makers is formed to provide linguistic ratings to the candidate suppliers for the selected criteria. The linguistic ratings are then transformed into fuzzy numbers and fed into a fuzzy DEA (FDEA) model based on the α- cut approach assessment of candidate suppliers. A hypothetical application is provided to demonstrate the applicability and feasibility of the method.
Article 0 Reads 7 Citations Fuzzy sliding mode control based on boundary layer theory for chattering-free and robust induction motor drive Ali Saghafinia, Hew Wooi Ping, M. Nasir Uddin Published: 19 November 2013
The International Journal of Advanced Manufacturing Technology, doi: 10.1007/s00170-013-5398-7
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The boundary layer approach is the most popular method to reduce the chattering phenomenon in sliding mode control (SMC) for uncertain nonlinear systems. This paper applies the fuzzy sliding mode structure based on the boundary layer theory which is used as speed controller of an indirect field-oriented control (IFOC) of an induction motor (IM) drive. A fuzzy inference system is assigned for reaching the controller part of the fuzzy sliding mode controller (FSMC) to eliminate the chattering phenomenon in spite of the small and large uncertainties in the system. The applied fuzzy system acts like a saturation function technique in a thin boundary layer near the sliding surface so that the stability of the system is guaranteed. Also, the equivalent control part is estimated to avoid the computational burden by an averaging filter. On the other hand, the averaging filter assists to improve the tracking performance despite the possibility of large uncertainties in the system so that the stability of the system is guaranteed. The main advantages of the proposed chattering-free speed controller are robustness to parameter variations and external load disturbance. The simulation results are shown to verify the effectiveness of the proposed speed controller, and its advantages are shown in comparison with the FSMC system and the conventional SMC.
PROCEEDINGS-ARTICLE 0 Reads 0 Citations Induction motor fault tolerant control with wavelet indicator Khalaf Salloum Gaeid, Hew Wooi Ping, Mustafa Khalid Masood, ... Published: 01 December 2011
Proceedings 2011 International Conference on Transportation, Mechanical, and Electrical Engineering (TMEE), doi: 10.1109/tmee.2011.6199360
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Fault tolerant control of induction motors is proposed using both vector control as the dominant controller and a Voltage-to-Frequency (V/F) controller as the complimentary controller. The system falls back on the V/ F controller when either stator short winding or stator open winding faults occur. The wavelet index is used as fault indicator. To estimate the speed, a novel Boosted Model Reference Adaptive System (BMRAS) is used. To develop a new fault tolerant control algorithm, a protection unit is added to the main circuit to stop the induction motor operation in the case of high severity faults.