The body freedom flutter phenomenon is one of the aeroelastic instabilities that occurs due to the coupling of the aeroelastic bending mode of the wing with the short-period mode in the flight dynamics of the aircraft. By using the aeroservoelastic model and applying closed loop control, this phenomenon can be suppressed in the operating conditions of the aircraft and the velocity of this event can be increased. The simplest model aircraft capable of displaying this instability includes the flexible wing and the planar flight dynamics model. For this purpose, the wing structure is modeled using the Euler-Bernoulli beam and, the theory of minimum variable state is used to model unstable aerodynamics to make the conditions suitable for modeling the system in state space. In the control section, the elevator is used as the control surface and LQR theory with Kalman filter is used to body freedom flutter suppression. Finally, the effect of adding a closed loop control to increase the body freedom flutter velocity and the limitations of this work are studied.

One of the issues of reliable performance in the power grid is the existence of electromechanical oscillations between interconnected generators. The number of generators participating in each electromechanical oscillation mode and the frequency oscillation depends on the structure and function of the power grid. In this paper, to improve the transient nature of the network and damping electromechanical fluctuations, a decentralized robust adaptive control method based on dynamic programming has been used to design a stabilizing power system and a complementary static var compensator (SVC) controller. By applying a single line to ground fault in the network, the robustness of the designed control systems is demonstrated. Also, the simulation results of the method used in this paper are compared with controllers whose parameters are adjusted using the PSO algorithm. The simulation results show the superiority of the decentralized robust adaptive control method based on dynamic programming for the stabilizing design of the power system and the complementary SVC controller. The performance of the control method is tested using the IEEE 16-machine, 68-bus, 5-area is verified with time domain simulation.

Electro-mechanical oscillations are produced in the machines of an interconnected power network, followed by a disturbance or due to high power transfer through weak tie lines. These oscillations should be damped as quickly as possible to ensure the reliable and stable operation of the network. To damp these oscillations different controllers, based on local or wide area signals, have been the subject of many papers. This paper presents the analysis of the PID of Conventional Power System Stabilizer (PSS) and Fuzzy Logic controller.

In this paper, a new comparative approach was proposed for reliable controller design. Scientists and engineers are often confronted with the analysis, design, and synthesis of real-life problems. The first step in such studies is the development of a 'mathematical model' which can be considered as a substitute for the real problem. The mathematical model is used here as a plant. Fractional integrals and derivatives have found wide application in the control of dynamical systems when the controlled system and the controller are described by a set of fractional order differential equations. Here the stability and robustness of fractional order system is checked at the different level and it is found that the stability region is large in the complex plane. This large stability region provides the more flexibility for system implementation in the control engineering. Generally, an analytically or experimentally approaches are used for designing the controller. If a fractional order controller design approach used for a given plant then the controlled parameter gives the better result.

In this study, a robust H_2/H_∞ multi-objective state-feedback controller and tracking design are presented for a mobile two-wheeled inverted pendulum (MTWIP). The proposed control has to track the desired angular velocity while keeping the mobile two-wheeled inverted pendulum balanced. First, error of output states are added to the dynamic of system for better tracking control. And uncertainties of parameters are defined by affine parameters. Next, Takagi-Sugeno (T-S) fuzzy model is used for estimating the uncertainty of nonlinear model parameters. Robust H_2/H_∞ controller is designed and analyzed for each local linear subsystem of mobile two-wheeled inverted pendulum by using a linear matrix inequalities method. To sum up, in order to calculate the whole dynamic of system from each local linear subsystem, weight average defuzzifer method is used and the total controller is designed and analyzed according to parallel distribute compensation. The simulation indicate that the proposed scheme has high accuracy, robustness, good tracking, fast transient responses and lower control effort for a mobile two-wheeled inverted pendulum despite the uncertainties and external disturbance.

Research subject: Energy is an integral part of human life and from the beginning of history, mankind is looking for a way to control it to provide the basic needs. One of the available energy sources is fossil energy that has been considered due to the huge amount of energy. Microbial fuel cell is a bioreactor which converts the chemical energy stored in chemical bonds of the organic compounds to electrical energy through the catalytic reactions. Research approach: In this paper, two types of classical PI and MPC controller are used to investigate the voltage control of a two chamber microbial fuel cell using the model which has been presented by Esfandyari et al. [1, 2]. Considering the features of the proposed model, it can be used to optimize and control the MFC in continuous and batch modes. For this purpose, a classical PI controller based on internal model and MPC controller was designed and implemented. Based on the designed controllers, the adjustment of substrate input flow rate was implemented considering the distribution such as substrate input concentration or the uncertainty of the process model parameter such as Ks and rmax. Main results: For to control the output voltage, step change of 5 units was made in setpoint (inlet flowrate to anode chamber). The values of absolute integral error, rise time and overshoot for the classical PI controller were 3. 75, 13. 159, and 0. 091, respectively, while these values were 0. 035, 11. 908, and 0. 142, respectively for the MPC controller. Considering the achieved data, it can be concluded MPC controller performed better than the classic PI controller.

In this paper, Teaching-Learning-Based Optimization (TLBO) algorithm is employed for controlling the speed of induction motors using fuzzy sliding mode controller. The proposed control scheme formulates the design of the controller as an optimization problem. First, a sliding mode speed controller with an integral switching surface is designed, in which the acceleration information for speed control is not required. In this case, the upper bound of the lumped uncertainties including the parameter uncertainties and the load disturbance must be available. The importance of this parameter on the system performance is illustrated. Then, the fuzzy sliding mode speed controller is designed to estimate the upper bound of the lumped uncertainties. Finally, TLBO algorithm is adopted to determine the optimal upper bound of the uncertainty. Simulation results are given to demonstrate the superiority of the proposed controller in comparison with the proportional-integrator, traditional sliding mode controller, fuzzy sliding mode controller and adaptive fuzzy sliding mode controller.

In this paper, a non-linear carrier controller with an exponential carrier generator is designed and simulated for power factor correction (pfc). then, this controller is applied to single phase and three phase rectifier using a boost regulator for PFC. the power factor and its variations are measured by computer simulation against the changes in various loads and switching frequencies and the results are discussed. In order to produce voltages lower than the input voltage, a PFC using a buck regulator is used in rectifiers. However, the buck type PFC produces lower power factor then the boost type. For this reson, a flyback regulator is used as a PFC to produce lower voltage then input voltage. Power factor obtained by computer simulation of Fly back pfc are acceptable and are above 95%.