فهرست مطالب

Science Research (Modeling, Identification, Simulation & Control) - Volume:48 Issue: 1, Spring 2016
  • Volume:48 Issue: 1, Spring 2016
  • تاریخ انتشار: 1395/04/14
  • تعداد عناوین: 6
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  • Mehdi Hosseinzadeh, Farzad Rajaei Salmasi* Pages 1-12
    In this paper, a supervisory controller is proposed to manage the power flow in a hybrid AC/DC micro-grid for both grid-connected and disconnected modes. When the hybrid AC/DC micro-grid is connected to the utility grid, power surplus or shortage leads to power trade between the micro-grid and the utility grid. In the grid-disconnected mode, the renewable power sources (wind and solar generation subsystems) are responsible of supplying the power demanded by the loads by themselves. In this case, the loads are classified as critical and non-critical loads, where critical loads are those that should be supplied in any condition. When the maximum available power is smaller than the power demanded by the critical loads, the battery banks are set in the discharging mode to satisfy the demand. Otherwise, the non-critical loads are supplied according to the proposed load shedding scheme, which is developed based on the bankruptcy problem. In summary, this paper proposes a new supervisory controller for a hybrid AC/DC micro-grid, as well as a new load shedding scheme to supply the non-critical load in grid-disconnected mode. The effectiveness of the proposed supervisor controller is evaluated through simulation.
    Keywords: Hybrid AC, DC Micro, Grid, Power Management, Load Shedding, Bankruptcy Problem
  • Mahdi Sabet Rasekh, Seyed Kamaleddin Yadavar Nikravesh*, Nematollah Ghahramani Pages 11-27
    In this paper, an efficient method is presented to control the attitude of a satellite with ON-OFF actuator. The main objective of this novel method is to control the amplitude of the limit cycle which commonly appears in the steady state of such systems; and at the same time by consideration of real actuator constraints, reduce the fuel consumption of system. The Proposed method is a combination of a command modifier (which based on the set point and the required accuracy of pointing, by means of optimization, calculate the desired limit cycle), a phase plane controller (PPC) and a compensator (to compensate for the real constraints of the actuator). The effectiveness and outperformance of the proposed method is approved in comparison with the previous methods of attitude control problem through the closed loop simulation and the stability and robustness of the closed loop system is fully analyzed and illustrated by simulations.
    Keywords: limit cycle, on, off actuator, phase plane controller, attitude control, robustness
  • Amir Hooshang Mazinan* Pages 27-37
    Contemporary research is improving techniques to maneuvers control in the area of spacecraft. In the aspect of further development of investigations, a high-performance strategy of maneuvers control is proposed in the present research to be applicable to deal with a class of the aforementioned spacecrafts. In a word, the main subject behind the research is to realize a high-performance three-dimensional orbital maneuvers to transfer the system under control from the initial orbit to the corresponding final ones, in finite burn, while the referenced trajectories are provided through an optimization approach. It is shown that two sets of actuators such as the reaction thrusters should be handled through the proposed control strategy, as long as the x in connection with the y, z axes are dealt with through low and high-thrust control channels, respectively. It aims the strategy to manage the orbital parameters to be accurately varied with respect to time, in order to complete the procedure of transferring, in finite burn. A series of experiments in association with a number of benchmarks are considered to verify the performance of control strategy, tangibly. The contribution of the research is to organize an integration of the trajectory optimization and the new structure of the control scheme to deal with the orbital maneuvers, in finite burn, where the low and the high-thrust controls are synchronously compounded to present high-performance of the investigated outcomes.
    Keywords: High, performance three, dimensional maneuvers control, trajectory optimization, spacecraft, orbital parameters, finite burn
  • Mohammad Dosaranian Moghadam*, Nasfise Haji Karimi Pages 37-45
    Today, given the extensive use of convertors in industry, reducing the power consumed by these convertors is of great importance. This study presents a new method to reduce consumption power in Flash ADC in 65nm CMOS technology. The simulation results indicate a considerable decrease in power consumption, using the proposed method. The simulations used a frequency of 1 GHZ, resulting in decreased power consumption by approximately 90% for different processing corners. In addition, in this paper the proposed method was designed using Interpolation technique for purpose of promoting the performance as well as decreasing the class of Chip. The simulation results indicate that the power consumption for Interpolation technique was decreased by approximately 5% compared to the proposed method. On the other hand, we compare the results of the proposed convector with those of convertors frequently referred in other studies. The results show that the power consumption is considerably decreased, using the proposed method.
    Keywords: Flash ADC, Interpolation, Power Consumption, 65nm CMOS Technology
  • Reza Ghasemi*, Mohammd Bagher Menhaj Pages 45-56
    This paper fully discusses how to design an observer based decentralized fuzzy adaptive controller for a class of large scale multivariable non-canonical nonlinear systems with unknown functions of subsystems’ states. On-line tuning mechanisms to adjust both the parameters of the direct adaptive controller and observer that guarantee the ultimately boundedness of both the tracking error and that of the observer error are derived through Lyapunov stability analysis. The most important merits of the proposed controller as well as the observer are their robustness against external disturbances. The observer proposed in the paper is designed based on a reconfiguration of the system in which the dynamics of the model reference is taken into account. It should be emphasized that compared to the other methods recently cited in the literature, this paper designs proper controllers for a class of nonlinear large scale MIMO systems in which merely the structure of the systems is known. The simulation results easily approve the remarkable capability of the proposed method.
    Keywords: Adaptive Control, Large Scale System, nonlinear Observer, Stability, Fuzzy System
  • Mehdi Tale Masouleh*, Alaleh Arian, Ahmad Kalhor Pages 55-65
    Blinking and eye movement are one of the most important abilities that most people have, even people with spinal cord problem. By using this ability these people could handle some of their activities such as moving their wheelchair without the help of others. One of the most important fields in Human-Robot Interaction is the development of artificial limbs working with brain signals. The purpose of this project consists in detecting blinking and left and right eye movements via electroencephalogram signals which is also useful in determining sleepiness. Moving Window, Fast Fourier Transform and Wavelet Transform are the methods which are used in this project. Obtained results reveals that the most reliable method to recognize blinking and eye movements is Fast Fourier Transform since it is almost insensitive and invariant to the defined variables. After recognition of blinking and eye movement, these actions are transferred to a robot which is called the spherical 2-DOF parallel robot, first built at Laval University.
    Keywords: Human, Robot Interaction, Electroencephalogram, Moving Window, Fast Fourier Transform, Wavelet Transform