Current Issue : October - December Volume : 2017 Issue Number : 4 Articles : 5 Articles
With penetration growing of renewable energy sources which integrated into\npower system have caused problems on grid stability. Electric Vehicles (EV)\nare one of the renewable energy sources that can bring significant impacts to\npower system during their charging and discharging operations. This article\nestablished a model of single machine infinite bus (SMIB) power system considering\nEV as a case study of load disturbance for power system oscillation.\nThe objective of this research is to enhance stability and overcome the drawbacks\nof traditional control algorithms such as power system stabilizer (PSS),\nPID controller and fuzzy logic controller (FLC). The implementationââ?¬â?¢s effect\nof FLC parallel with PID controller (Fuzzy-PID) has been shown in this paper.\nThe speed deviation (Ã?â?Ãâ?°) and electrical power (Pe) are the important factors\nto be taken into consideration without EV (only change in mechanical torque),\nEV with change in the mechanical torque and sudden plug-in EV. The\nobtained result by nonlinear simulation using Matlab/Simulink of a SMIB\npower system with EV has shown the effectiveness of using (Fuzzy-PID)\nagainst all disturbances....
Aiming at the control problem of servo system with friction nonlinearity, we\nintroduced the improved LuGre friction model of system. We used adaptive fuzzy system to\napproximate the nonlinear part and unknown parameters in system online. The purpose is to\navoid the complex calculation in deducing the adaptive law of each unknown parameter. By\nusing backstepping approach and recursively selecting the Lyapunov function, introducing the\nvirtual control quantity, we designed an adaptive fuzzy controller with state feedback. Then we\nanalyzed the stability of adaptive fuzzy controller. We carried out the system response analysis\nand system robustness analysis. We used sinusoidal signal as simulation input signal. Two\ncases were considered in simulation test comparing backstepping control with conventional\nPID control. Simulation results show that the proposed backstepping control has better position\ntracking performance and robustness than conventional PID control....
With the advance of science and technology, people have a desire for convenient and\ncomfortable living. Creating comfortable and healthy indoor environments is a major consideration\nfor designing smart homes. As handheld devices become increasingly powerful and ubiquitous,\nthis paper proposes an innovative use of smart handheld devices (SHD), using MIT App Inventor\nand fuzzy control, to perform the real-time monitoring and smart control of the designed intelligent\nwindowsill system (IWS) in a smart home. A compact weather station that consists of environment\nsensors was constructed in the IWS for measuring of indoor illuminance, temperature-humidity,\ncarbon dioxide (CO2) concentration and outdoor rain and wind direction. According to the measured\nenvironment information, the proposed system can automatically send a command to a fuzzy\nmicrocontroller performed by Arduino UNO to fully or partly open the electric curtain and electric\nwindow for adapting to climate changes in the indoor and outdoor environment. Moreover, the IWS\ncan automatically close windows for rain splashing on the window. The presented novel control\nmethod for the windowsill not only expands the SHD applications, but greatly enhances convenience\nto users. To validate the feasibility and effectiveness of the IWS, a laboratory prototype was built and\nconfirmed experimentally....
The low stiffness has limited the applications of robot to machining process. In this paper, a fuzzy-sliding mode control scheme is\nproposed to manage the oscillation and chatter appearing in machining operation by adjusting the feed rate.Therobotic machining\ndynamics is first analyzed to identify the parameters with focus on the system stiffness and the behavior during machining process.\nA controller consisting of a fuzzy estimation enginery which can determine the control gain coefficients according to system status\nand a sliding mode controller which is used to guarantee convergence and global stability of the system is then proposed. Simulations\nand experiments results show that, in comparison with open loop and fuzzy-PID control scheme, the fuzzy-sliding mode control\nscheme can reduce the amplitude and period of oscillation....
This paper is concerned with the adaptive fuzzy control problem for a class of twin-roll strip casting systems. By using fuzzy logic\nsystems (FLSs) to approximate the compounded nonlinear functions, a novel robust output tracking controller with adaptation\nlaws is designed based on the high gain observer. First, the nonlinear dynamic equations for the roll gap and the molten steel\nlevel are constructed, respectively. Then, the mean value theorem is employed to transform the nonaffine nonlinear systems to\nthe corresponding affine nonlinear systems. Moreover, it is also proved that all the closed-loop signals are bounded and the\nsystems output tracking errors can converge to the desired neighborhoods of the origin via the Lyapunov stability analysis. Finally,\nsimulation results, based on semiexperimental system dynamic model and parameters, are worked out to show the effectiveness of\nthe proposed adaptive fuzzy design method....
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