in this article, the sliding mode control of frequency load control of power systems is studied. the study areaconsists of a system of water and heat. first, a mathematical model of the proposed system disturbances ismade and then sliding control mode for frequency load control is provided. by the system simulation andsliding mode control, it can be shown that the damping of oscillations is wel...

in this paper, a new t-s fuzzy hyperbolic delay model for a class of nonlinear systems with time-varying delay, is presented to address the problems of stability analysis and feedback control. fuzzy controller is designed based on the parallel distributed compensation (pdc), and with a new lyapunov function, delay dependent asymptotic stability conditions of the closed-loop system are derived v...

This work presents a general theory for the construction of a polyhedral outer approximation of the reachable set (“polyhedral bounds”) of a dynamic system subject to time-varying inputs and uncertain initial conditions. This theory is inspired by the efficient methods for the construction of interval bounds based on comparison theorems. A numerically implementable instance of this theory leads...

We study the problem of secondary frequency regulation where ancillary services are provided via load-side participation. In particular, we consider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing secondary frequency control mechanisms. We show that system stability is not compromised despite the switching nature of the loads. However, such...

Usually, expert systems use numbers to describe the experts’ degrees of belief in their statements. In practice, however, it is difficult to assign an exact numerical value to the expert’s degree of belief. At best, we can get an interval of possible values. This fact leads to the use of interval-valued degrees of belief. When intervals are used to describe degrees of belief, then computations ...

The stabilization of periodic control systems using time scales is studied. Time scale is a model of time. The language of time scales seems to be an ideal tool to unify the continuous-time and the discrete-time theories. In this work we suggest an alternative way to solve stabilization problems. This method is based on a combination of the Lyapunov functions method with local controllability c...

Nonlinear dynamical and control systems are an important source of applications for theories of computation over the the real numbers, since these systems are usually to complicated to study analytically, but may be extremely sensitive to numerical error. Further, computerassisted proofs and verification problems require a rigorous treatment of numerical errors. In this paper we will describe h...

This paper presents an application of a design method of robust H∞ optimal control to a structural control system. A dynamic model for a building structure under earthquake and wind excitations is considered. Structured uncertainties are introduced to reflect errors between the model and the reality. To obtain the best possible performance in the face of uncertainties, robust H∞ optimal control...

Robust stabilization of an uncertain system subject to input constraints is addressed without making open-loop stability assumptions. A local approach is taken to nd a robust control law and a set of initial conditions that can be stabilized. A piecewise-linear control law is described. It is generated by a parametrized algebraic Riccati equation of the H 1 control theory. Once system trajector...