Search

This paper presents a comparative analysis of a fractional-order proportional–integral–derivative (FO-PID) controller against the standard proportional–integral–derivative (PID) controller, applied to a nonlinear robotic arm manipulator systems. The genetic algorithm (GA) optimization method was implemented to tune the gain parameters of the FO-PID and PID controllers. The performance of the FO-PID and PID controllers were evaluated though different cost functions, including integral of squared error (ISE), integral of absolute error (IAE), integral of time-weighted absolute error (ITAE), and integral of time-weighted squared error (ITSE). The performance of these controllers was examined via extensive simulations by using MATLAB/SIMULINK for different operating scenarios of the robotic arm manipulator system. Based on the obtained results, a comparative performance matrix is proposed, wherein cost functions ISE, IAE, ITAE, and ITSE are represented as columns while characteristic parameters (overshoot, rising time, and settling time) are represented as rows. The proposed performance matrix facilitates the selection between the PID and FO-PID controllers. [ABSTRACT FROM AUTHOR]

Distributed generation (DG) technology arises in several applications of power supply to tackle the issues of increasing energy demands. The concept of microgrids is introduced to integrate the DG technology into utility power networks. This paper introduces a fuzzy control scheme for networked systems utilizing a quantized H∞ estimator over communication networks for DGs subject random constraints. The developed estimation algorithm is worthy for ensuring the network stability and enduring any sort of quantization, time delay, and packet drops. In these senses, adequate conditions have been mainly derived by means of linear matrix inequalities. An illustrative examples are demonstrated to confirm the effectiveness of the meant design procedure. [ABSTRACT FROM AUTHOR]

In this paper, we implement an output-feedback adaptive controller for islanded distributed generation systems (DGs) with communication, load and generation constraints. The adaptive controller is introduced to deal with nonlinearities of dynamical systems and unknown constraints. It primarily consists of a predictor, an adaptive law, and a control law. Herein, the controller can sustain desired performance and the robustness, in which the control law loop contains a low pass filter that sustain a rapid adaptation rate without fluctuations. The critical challenge into a standalone microgrid is to coordinate the necessitate load power with the distributed generations production in the presence of load/generation fluctuations. The coordinated controller is implemented to undertake the conflicts, and to enhance the performance, and to minimise the control cost by coordinate the requirements between decentralised controllers. The proposed controller is worthy for ensuring the network stability of DGs in a microgrid environment in the presence of uncertainties and transmission time delays. A typical simulation example is presented to confirm the effectiveness of the proposed design procedure. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of linear-quadratic Gaussian feedback control over unreliable communication channels with observation noise. We consider the problems of estimation and control under two different protocols. In one protocol, the transfer control protocol-like protocol, the estimation/control unit provides acknowledgments to successfully deliver the packets. In the other protocol, the user datagram protocol (UDP)-like protocol, no acknowledgments are permitted. We address the nonlinearity for the UDP protocol using the suboptimal approach. It is shown that there is a critical value at which the system becomes unstable. These unstable properties do not only depend on the rates of the control packets but also on the eigenvalues for the considered system. Simulation of two numerical examples is carried out in detail to illustrate the theoretical analysis. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of dynamic feedback control over unreliable communication channels with non-stationary packet loss. The rate of control and observation signals are modelled by two mutually independent random variables. In particular, the problem is considered for two control packet rate compensation schemes. In one scheme, called as a zero-input scheme, where the control input packet applied by the actuator sets to zero when the control packet dropped out. In the other scheme, called as a hold-input scheme, the previous control input is applied by the actuator when the control packet dropped out. Classes of observer-based stabilizing controllers for networked control system are designed with the observer and the feedback control gains are being determined by solving linear matrix inequalities. Numerical simulations are performed to confirm the effectiveness of the proposed design procedure. [ABSTRACT FROM PUBLISHER]