S.M. Ayob

Publications (18)0 Total impact

• Conference Proceeding: Implementation of Single Input Fuzzy Logic Controller for Boost DC to DC power converter

  F. Taeed, Z. Salam, S.M. Ayob
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  ABSTRACT: This paper describes the application of the Single Input Fuzzy Logic Controllers (SIFLC) to regulate the output voltage of a Boost (step-up) DC to DC power converter. The SIFLC is derived from the Signed Distance Method which reduces the multi-input Fuzzy Logic Controller (FLC) with Toeplitz rule table structure to a single input FLC. Effectively, it allows for the rule table to be approximated to a one dimensional piecewise liner control surface. To validate the effectiveness of the SIFLC compared to the Conventional FLC, MATLAB is simulation carried out. Controller is implemented in digital using FPGA and experimental results are exhibited.
  Power and Energy (PECon), 2010 IEEE International Conference on; 01/2011
• Conference Proceeding: Inverter control using a simpilied Fuzzy PI controller

  S. M. Ayob, Z. Salam, N. A. Azli
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  ABSTRACT: This paper describes the inverter regulation using a simplified Fuzzy PI controller (SFPIC). The proposed controller is a single input Fuzzy with its fuzzification, inferences and defuzzification processes are represented by a piecewise linear control surface. This allows the computation to be faster since the surface can be easily constructed using a look-up table without compromising the performance. For verification purposes, a single-phase inverter prototype is constructed and the proposed control algorithm is implemented. From the results, it was shown that the proposed controller produced a comparable performance as its conventional Fuzzy PI controller, but with a much reduced computation time.
  Power Electronics, Machines and Drives (PEMD 2010), 5th IET International Conference on; 05/2010
• Article: Single Input Fuzzy Logic Controller for Unmanned Underwater Vehicle.

  Kashif Ishaque, S. S. Abdullah, S. M. Ayob, Zainal Salam
  Journal of Intelligent and Robotic Systems. 01/2010; 59:87-100.
• Article: A Simple and Fast pi-Fuzzy Controller for PWM DC/AC converters.

  S. M. Ayob, N. A. Azli, Zainal Salam
  Control and Intelligent Systems. 01/2010; 38.
• Conference Proceeding: Control of a Single Phase Inverter Using Fuzzy Logic

  S.M. Ayob, Z. Salam, N.A. Azli, M.E. Elbuluk
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  ABSTRACT: This paper describes the inverter regulation using single input fuzzy PI controller (SIFPIC). The controller is a simplification of the conventional fuzzy PI controller that results in a one-dimensional rule table and piecewise linear control surface. The employment of a look-up table to construct the control surface provides faster computation time without compromising the performance. For verification purposes, a single-phase inverter prototype is constructed and the proposed control algorithm is implemented using dSPACE DS1104. The experimental results show that the SIFPIC performance is comparable to the conventional fuzzy PI controller, but with a much reduced computation time.
  Industry Applications Society Annual Meeting, 2009. IAS 2009. IEEE; 11/2009
• Conference Proceeding: DSP-based single input PI-Fuzzy controller for inverter system

  S.M. Ayob, N.A. Azli, Z. Salam
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  ABSTRACT: This paper presents a single input PI-fuzzy controller (SIPI-FLC) for inverter system. The SIPI-FLC is based on the 'signed-distance' method which is capable of reducing multi-input fuzzy into a single input fuzzy system without degradation in performance. The SIPI-FLC exhibits a simpler structure, requires less tuning and has much fewer number of rules. It inherits the performance and stability of a linear PI controller for small-signal disturbances but has an improved performance when subjected to large-signal disturbances. To verify the viability of the proposed technique, a prototype inverter is constructed and the control algorithm is implemented. The results are then compared with the conventional PI-FLC (CPI-FLC).
  Power Electronics Specialists Conference, 2008. PESC 2008. IEEE; 07/2008
• Conference Proceeding: An Improved `DC-DC Type' High Frequency Transformer-Link Inverter by Employing Regenerative Snubber Circuit

  Z. Salam, S.M. Ayob, M.Z. Ramli, N.A. Azli
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  ABSTRACT: This work proposes a bidirectional high frequency (HF) link inverter using center-tapped high frequency transformer. The main advantage of this topology is the reduced size of the converter. However the utilization of the high frequency transformer results in the occurrence of high voltage spike at its secondary. To solve this problem, we incorporate a regenerative snubber to clamp the spike and subsequently feed the energy back to the power circuit. The inverter also utilizes less number of switches, which results in lower conduction and switching losses. This paper describes some of the important aspects of the snubber design. It is verified with a 1 kW inverter prototype.
  Power Electronics and Drive Systems, 2007. PEDS '07. 7th International Conference on; 12/2007
• Conference Proceeding: Analysis of Double Loops Discrete Single Input PI Fuzzy for Single phase Inverter

  S.M. Ayob, Z. Salam, N.A. Azli
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  ABSTRACT: This paper presents an analysis of double loop Pi-Fuzzy controller for a single phase inverter. The scheme comprises two feedback control loops arranged in a cascaded manner. The current in the filter inductor and voltage across the filter capacitor are sensed and fed back to the system to form the inner loop and the outer loop, respectively. Both loops are controlled by a discrete single input Pi-Fuzzy controller. It is derived using the "sign- distance" method, which simplifies fuzzy set into a single input single output system. The work analyses the effect of fuzzy control surface for both loops in improving large- signal performance of the controller. Based on the analysis, the replacement of single input PI Fuzzy for voltage loop with a simple discrete linear PI controller will be justified.
  Power Electronics and Drive Systems, 2007. PEDS '07. 7th International Conference on; 12/2007
• Conference Proceeding: Piecewise Linear Control Surface for Single Input Nonlinear PI-Fuzzy Controller

  S.M. Ayob, Z. Salam, N.A. Azli
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  ABSTRACT: This paper presents an analysis on piecewise linear control surface for a single-input nonlinear PI Fuzzy controller. The analysis is carried out to determine the conditions that should be met in order for the piecewise linear control surface approximation to be validated. An equivalent two-input Pi-Fuzzy with conventional fuzzification, inference and deffuzification process is built for verification purpose and both controllers are then applied to a single phase inverter system. The dynamic response of both controllers are examined and compared. From the simulation results, it is shown that the approximation is valid.
  Power Electronics and Drive Systems, 2007. PEDS '07. 7th International Conference on; 12/2007
• Conference Proceeding: A Discrete Single Input PI Fuzzy Controller for Inverter Applications

  S.M. Ayob, Z. Salam, N.A. Azli
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  ABSTRACT: In this paper, a discrete single input PI Fuzzy controller for inverter applications is presented. In contrary to the typical PI Fuzzy which requires minimum of two inputs variables, the proposed controller requires only one input. However the performance of the controller is not degraded. The reduction in the number of inputs minimized the number of fuzzy rules, tuning parameters and thus simplifies the overall fuzzy controller design. Furthermore, with single input, the input-output mapping can be presented as a simple control surface. In this case, it is mapped as a piecewise linear and can be realized by using a simple look-up table. As a result, a faster fuzzy calculation can be achieved using an inexpensive digital processor. A design example of the proposed controller for a single phase inverter is outlined. Using Matlab simulations, it can be shown that the proposed controller exhibits equivalent performance with the typical PI fuzzy controller.
  Industrial Electronics Society, 2007. IECON 2007. 33rd Annual Conference of the IEEE; 12/2007
• Conference Proceeding: Operation And Modelling Of The Unloaded Bi-Directional DC/DC Converter Performing As An Active Damping Function In A Simple DC System

  A. Jusoh, Z. Salam, S.M. Ayob
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  ABSTRACT: The sub-system interaction and instability phenomena is a common problem in the distributed power system (DPS). The instability phenomena that occur in the DC bus bar of a DPS are mainly due to a negative incremental input impedance characteristic of a connected constant power load (CPL). The CPL has such a characteristic due to its internal control function such as to regulate the converter output voltage, which results in the converter tends to draw a constant power. This paper briefly presents the instability phenomena due the CPLs and the modelling of a DC-DC converter to behave as an damping network, purposely to eliminate the instability in a simple system comprising L-C filters and a CPL. The modelling of the DC-DC converter using the state averaging and linearizing technique is discussed. A small-signal converter model was derived and the factors that may affect its performance were obtained. The obtained model of the DC-DC converter can be used to design of the controller.
  Power and Energy Conference, 2006. PECon '06. IEEE International; 12/2006
• Conference Proceeding: Trapezoidal PWM Scheme for Cascaded Multilevel Inverter

  S.M. Ayob, Z. Salam, A. Jusoh
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  ABSTRACT: This paper proposes a new PWM switching strategy for the cascaded multilevel inverter (CMI). This scheme employs multiple trapezoidal modulation waveforms with a single triangular carrier. The main advantage of this technique is the ability to generate PWM waveform generation in real time using very simple algorithm. Furthermore it also results in higher fundamental component magnitude. Although it is known that trapezoidal modulation suffers from the presence of low-order harmonics, it can be minimized by appropriately selecting the slope angle of the trapezoidal, alpha. This paper carried out the simulation on a five level CMI to justify the merits of the proposed scheme. A low cost FPGA based single phase five-level CMI test-rig is also constructed to verify the simulation results.
  Power and Energy Conference, 2006. PECon '06. IEEE International; 12/2006
• Conference Proceeding: Simple PI Fuzzy Logic Controller Applied in DC-AC Converter

  S.M. Ayob, Z. Salam, N.A. Azli
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  ABSTRACT: In this paper, a simple proportional integral fuzzy logic controller (PI-FLC) applied to a DC-AC converter is presented. This approach uses signed distance method, where the multiinput single output (MISO) system can be reduced to single input single output (SISO) system without degrading the original performance of MISO PI-FLC system. The input-output relationship of SISO PI-FLC system then can be simply mapped using piecewise linear approximation. A comparison with the original PI-FLC is carried out by MATLAB-Simulink simulation to verify the performance of the proposed approach.
  Power and Energy Conference, 2006. PECon '06. IEEE International; 12/2006
• Conference Proceeding: Simulation and experimental results of the bi-directional DC-DC converter operating as an active damping device in a simple system

  A. Jusoh, Z. Salam, S.M. Ayob, M.R. Sahid
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  ABSTRACT: This paper discusses the simulation and experimental results of the bi-directional DC-DC converter operating as an active damping device in a system, which comprises a DC source, L-C filter and constant power load (CPL). The analysis, control design and system simulation are presented. Frequency response measurements are shown to confirm the current controller design. The overall system performance as the input voltage imposed on the system is presented in both simulation and experimental results
  Power Electronics and Drives Systems, 2005. PEDS 2005. International Conference on; 02/2006
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  Conference Proceeding: A New Hybrid Multilevel Inverter Topology with Harmonics profile improvement

  S.M. Ayob, C.H. Yee, N.D. Muhamad, A. Jusoh
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  ABSTRACT: A new hybrid multilevel inverter topology with harmonics profile improvement is presented in this paper. From the literature, it is agreed that hybrid multilevel inverter with its DC sources configured in trinary fashion presents the largest output levels and the lowest total harmonics distortion (THD) percentage. However the output contains low order harmonics due to the impossibility of modulating all adjacent voltage levels at high frequency. With this proposed topology, all adjacent voltage levels are possible to be modulated at high frequency. As a result, the output voltage waveform presents better harmonics profile. The proposed topology and its modulation scheme are presented and verified with simulation results
  Power Electronics and Drives Systems, 2005. PEDS 2005. International Conference on; 12/2005
• Conference Proceeding: A new PWM scheme for cascaded multilevel inverter using multiple trapezoidal modulation signals

  S.M. Ayob, Z. Salam
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  ABSTRACT: This work proposes a new PWM scheme for the cascaded multilevel inverter (CMI). The proposed scheme uses multiple trapezoid modulating signals with a single triangular carrier. The scheme offers several advantages compared to sinusoidal PWM (SPWM) in terms of easy and fast real-time waveform generation with higher fundamental output voltage. This paper details the technique and the parameters that affect its performance. A low power 5-level CMI prototype is constructed to verify the viability of the modulation scheme.
  Power Electronics, Machines and Drives, 2004. (PEMD 2004). Second International Conference on (Conf. Publ. No. 498);
• Article: Simple PI fuzzy logic controller applied in DC-AC converter

  S.M. Ayob, Zainal Salam, N. A. Azli
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  ABSTRACT: In this paper, a simple proportional integral fuzzy logic controller (PI-FLC) applied to a DC-AC converter is presented. This approach uses signed distance method, where the multiinput single output (MISO) system can be reduced to single input single output (SISO) system without degrading the original performance of MISO PI-FLC system. The input-output relationship of SISO PI-FLC system then can be simply mapped using piecewise linear approximation. A comparison with the original PI-FLC is carried out by MATLAB-Simulink simulation to verify the performance of the proposed approach
• Article: A simplified approach to design fuzzy logic controller for an underwater vehicle

  K. Ishaque, S.S. Abdullah, S.M. Ayob, Z. Salam
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  ABSTRACT: Fuzzy logic controller (FLC) performance is greatly dependent on its inference rules. In most cases, the more rules being applied to an FLC, the accuracy of the control action is enhanced. Nevertheless, a large set of rules requires more computation time. As a result, an FLC implementation requires fast and high performance processors. This paper describes a simplified control scheme to design a fuzzy logic controller (FLC) for an underwater vehicle namely, deep submergence rescue vehicle (DSRV). The proposed method, known as the single input fuzzy logic controller (SIFLC), reduces the conventional two-input FLC (CFLC) to a single input FLC. The SIFLC offers significant reduction in rule inferences and simplifies the tuning process of control parameters. The performance of the proposed controller is validated via simulation by using the marine systems simulator (MSS) on the Matlab/Simulink® platform. During simulation, the DSRV is subjected to ocean wave disturbances. The results indicate that the SIFLC, Mamdani and Sugeno type CFLC give identical response to the same input sets. However, an SIFLC requires very minimum tuning effort and its execution time is in the orders of two magnitudes less than CFLC.
  Ocean Engineering.