An Acrobat robot is a two-link surface robot that emulates the behavior of an acrobat man. This paper designed a Dynamic output feedback control strategy to overcome system challenges such as its balancing and swing. This method is employed for the optimal control of the nonlinear model of the acrobat robot. It is important to note that Dynamic feedback controllers are preferable to static ones due to their more effective control performances alongside with more degrees of freedom in achieving control objectives. In addition, the presented approach is incorporated with fuzzy control to optimize and update the parameters of the proposed controller. Simulations are performed in several cases consisting of the nominal system and considering the noise and disturbances. Simulation results demonstrate that the proposed controller in the form of fuzzy Dynamic output feedback has a good performance compared to the static and Dynamic output feedback in various situations.

High gain Balun-low-noise-amplifier (LNA) is proposed for tuner of digital televisions (DTVs). The proposed Balun-LNA is based on CS-CG (common-source-common-gate) structure. To improve the isolasion and frequency response, Balun-LNA has cascode transistors before load resistors. Balun-LNA uses current-bleeding circuit to increasie transconductance of CS transistor, so that current-bleeding transistor has transconductance of N-1 times larger than transconductance of cascode transistor. Thereby, transconductance and current of CS transistor are increased N times, as N-1 times of current pass to current-bleeding transistor. Therefore current of CG and CS stages stay identical. Also, Balun-LNA employs a positive feedback to satisfy input impedance matching and CG transistor has higher transconductance. By increasing transconductance of CS and CG transistors, the proposed Balun-LNA achieves to high voltage gain. Accordingly, CG and CS tansistors have symmetrical currents and loads at the differential output of the proposed Balun-LNA. Symmetrical loads cause the balanced differential outputs. This proposed Balun-LNA is designed in 90-nm CMOS technology and covers the frequency range of 40 MHz to 1GHz. This Balun-LNA achieves the voltage gain of 22.6 dB, S11 of less than -10 dB and the Minimum NF of 5 dB. This Balun-LNA operates at the nominal supply voltage of 2.2v.

In this paper, we study the containment control problem of heterogeneous linear multi-agent systems under directed topology based on output regulation framework and using output feedback control. Motivated by leader-follower output regulation problems, the leaders are assumed to be exosystems with identical Dynamics. In controller design approach for each follower, we utilize a distributed Dynamic output feedback control scheme. To achieve the objective of this work we utilize the containment error, which enables us to consider more than one leader in output regulation framework and to use output regulation techniques with some modifications to solve the containment problem. Finally, the validity of theoretical results are demonstrated through an example.

this paper studies output feedback control of pure-feedback systems with immeasurable states and completely non-affine property. Since availability of all the states is usually impossible in the actual process, we assume that just the system output is measurable and the system states are not available. First, to estimate the immeasurable states a state observer is designed. Relatively fewer results have been proposed for pure feedback systems because the cascade and non-affine properties of pure-feedback systems make it difficult to find the explicit virtual controls and actual control. Therefore, by employing the singular perturbation theory in back-stepping control procedure, the virtual/actual control inputs are derived from the solutions of a series of fast Dynamical equations which can avoid the “explosion of complexity’’ inherently existing in the conventional back-stepping design. The stability of the resulting closed-loop system is proved by Tikhonov’s theorem in the singular perturbation theory. Finally, the detailed simulation results are provided to demonstrate the effectiveness of the proposed controller, which can overcome the non-affine property of pure-feedback systems with lower complexity and fewer design parameters.

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.

A common method for controlling a group of parallel converters in decentralized control strategy structure in an island microgrid, the use is the droop-down characteristics of frequency ω-P and voltage E-Q. However, the problem with using this method is that the reactive power is not properly distributed (in proportion to the capacity of the micronutrients) between the micronutrients, which may lead to overload in the converters. Microgrids may also suffer from Dynamic stability problems such as power fluctuations, which can be increased by switching between active and reactive power control. To avoid this problem, the X / R ratio of transmission lines is an important parameter that should be carefully considered in the design of micronutrient controllers. By linearizing and simplifying conditions, the control system conversion function model becomes a single input-single output system, which is efficient enough to show the relationship between control parameters such as slope of droop characteristics and derivative sentences, virtual impedance, and voltage controllers. Using this model, stability conditions for different parameters are analyzed. Also, to improve power distribution stability, common droop strategies are modified by adjusting the slope as well as adding nonlinear sentence sections. This approach reduces the coupling between active and reactive power control and reduces the dependence of power distribution on grid parameters such as the X / R ratio. To evaluate the reliability of the proposed model, the simulation results in a sample island microgrid in MATLAB software are presented.

This article deals with the design of an adaptive controller for switched non-strict feedback nonlinear systems. In the studied system, the switching signal is arbitrary, the states are not measurable, and the signs of the control gain functions that describe the control directions are completely unknown. First, the unknown nonlinear functions in the switched system are approximated using the universal approximation theorem. Then, the unmeasured states are estimated using the linear state observer, and the controller is designed through an adaptive back-stepping design procedure. Due to the appropriate change of coordinates, 1) neither fuzzy nor radial basis function is used in the design of the controller, 2) only one adaptation law is designed to estimate the unknown parameters in the switched non-strict feedback nonlinear system, and 3) there is no Nussbaum function in the proposed adaptive controller so, the large control signal in the initial stages and the consequent damage to the actuators can be prevented. These features can lead to the simplicity of controller design and the reduction of computational burden. Therefore, the proposed method can be used for practical systems. The stability of the closed-loop system is proved using Lyapunov stability theory. It is shown that, in addition to the semi-globally uniformly ultimately boundedness of all closed loop signals, the tracking error converges to a small neighborhood around zero. In the end, the efficiency of the proposed control method is confirmed through the simulation results of an example.

The Dynamic voltage restorer (DVR) is the most advanced mitigation device that has been proposed to protect sensitive loads from the effects of voltage sags. The performance of DVR depends on the ability of PWM scheme to produce the required voltage and the control method. To improve transient and steady state response of DVR, in this paper a new closed 100p control based on the state feedback is proposed. Since the inverter switching using space vector modulation gives some advantages and the control algorithm based on DC signals are much more feasible than those based on sinusoidal signals, we presents a new state space description of DVR in terms of dq quantities that is used to derive a new control scheme, including state feedback and feed-forward path, to eliminate the source disturbance effects and the steady state error. Furthermore, the proposed state space feedback control is completed by integral control to eliminate the steady state error under variable load conditions. To compare the performance of this new control approach with that of some other control methods, some balanced and unbalanced voltage sags have been simulated on a test system in the PSCAD/EMTDC.

Due to the growth of renewable energies and the need for sustainable electrical energy, AC microgrids (MGs) have been the subject of intense research. Medium voltage MGs will soon have a special place in the power industry. This paper uses a new and effective control scheme for islanded inverter-based medium voltage MGs using the master-slave (MS) technique. The controllers only need local measurements. The designed controls are based on adaptive input-output feedback linearization control (AIOFLC). These controls have a high-performance response; and are robust against some uncertainties and disturbances. The use of the designed control scheme makes the output voltage of distributed generation (DG) sources have negligible harmonics. Besides, the generated voltage and active/reactive powers track their references effectively. The model of the inverter-based DGs is considered in a stationary reference frame, and there is no need for any coordinate frame transformation. The control method presented in this paper can be used for MGs with any number of inverter-based DGs and parallel inverters. The effectiveness of the proposed control scheme is evaluated by simulation in SIMULINK/MATLAB environment and compared with that of feedback linearization control (FLC) and conventional sliding mode control (CSMC).