In disturbance-observer-based control, the closed loop system consists of a main feedback control loop and an inner disturbance observer loop. This paper presents a design method for a disturbance observer to satisfy closed loop performance specifications, provided that the main feedback controller is known. Taking advantage of certain fixedstructure disturbance observers, the disturbance obser...

The connection of wind generators with electric power system influences the system stability and nodal voltages. This paper performs uncertainty analysis to investigate the impact of wind generation variation on the small disturbance voltage stability. The probabilistic collocation method (PCM) is presented as a computationally efficient method to conduct the uncertainty analysis. It has been i...

In this work a motion control scheme, which belongs to the class of the control schemes known as a sliding mode control with disturbance estimation is proposed. Adaptive fuzzy disturbance estimator works as an identifier of variable part of a system dynamics. Adaptation algorithm is derived by using the Lyapunov stability theory and provides global asymptotic stability of the state errors. For ...

This note investigates the trade-off arising in disturbance attenuation for nonlinear feedback systems in the framework of integral input-to-state stability. Similarly to the linear case, we show that if a gain tuning on one subsystem is used to drastically reduce the effect of its exogenous disturbances, then the other subsystem’s disturbance attenuation is qualitatively the same as in open loop.

Robot hybrid control has been noted for its difficulty due to the so-called dynamic stability problem, and consequently demands robust control algorithms that can overcome this difficulty, yet with accuracy. In this paper, • control law based on time-delay controlhas been derived for hybrid control with • condition for closed-loop stability. In addition, its relationship with the disturbance ob...

In this paper we investigate the e®ects of microphone and speaker locations on the performance of active noise control in ducts. We study a so-called \symmetric" con ̄guration in which the collocated performance microphone/control speaker and the collocated measurement microphone/disturbance source pairs are located equidistance from the duct center. By applying an \alignment angle" analysis to ...

A novel control scheme for the active steering of railway vehicles is presented in the paper using disturbance observer based control (DOBC) techniques. In contrast to existing DOBC schemes which are mainly for singleinput-single-output (SISO) systems and designed by trial and error, a new DOBC technique for multi-input-multi-output (MIMO) systems is developed. This is achieved by reforming the...

Topics covered: 1. Landscape dynamics concepts – stability, persistence, resistance, resilience and recovery 2. Landscape equilibrium concepts – absolute constancy, shifting mosaic-steady state, stationary processes, bounded equilibrium 3. Nonequilibrium landscapes – role of legacies, landscape uniqueness, importance of scale 4. Disturbance and landscape equilibrium – scaling of disturbance reg...

In this paper, control of uncertain fractional-order financial chaotic system with input saturation and external disturbance is investigated. The unknown part of the input saturation as well as the system's unknown nonlinear function is approximated by a fuzzy logic system. To handle the fuzzy approximation error and the estimation error of the unknown upper bound of the external disturbance, f...

This paper relates generally to sliding mode control (SMC) system based on uncertainty and disturbance estimation (UDE) and more particularly to a system, with the presence of high frequency measurement noise and unmodeled dynamics. Higher order dynamics are difficult to identify and remain excluded from theoretical model of the system, generally the main cause of instability. The presence of u...