In this paper symbolic quantifier elimination methods are used to explore the fragility of feedback compensators, and to design feedback systems with non-fragile compensators. A compensator is said to be fragile if given variations in compensator parameters result in significant deterioration of feedback performance. The issue of fragility is important in understanding the level of acurracy req...

Most of the adaptive feedforward vibration (or noise) compensation systems feature an internal ”positive feedback” coupling between the compensator system and the correlated disturbance measurement which serves as reference. This may lead to the instability of the system. Instead of the standard IIR structure for the adaptive feedforward compensator, the paper proposes a Youla-Kucera parametriz...

Motivated by the objective to further reduce the storage and computation time required by finite-horizon discrete-time optimal reduced-order LQG compensators, this paper introduces the modified reachability canonical form of a minimal finite-horizon discrete-time compensator and an algorithm to compute it. Next recursive algorithms for efficient storage and recovery of the compensator matrices ...

A phase compensation method is presented for measuring the cell gap of reflective LCD. We use the so-called QHQ compensator that is made up of two quarter-wave plates (Q) and one half-wave plate (H). This method is different from other compensation methods in that we can change both the orientation angle and retardation value of the compensator by rotating the quarterwave and halfwave retarders...

The problem of designing an output feedback compensator for any biased sinusoidal disturbance is considered. In this paper, we will develop the approach presented in (Marino et al., 2003). In (Marino et al., 2003) a compensator of order (2n+6) is proposed, which solves the posed problem by using the adaptive observers developed in (Marino and Tomei, 1995; Marino et al., 2001). This problem is s...

This paper presents multiplierless CIC compensator for software-defined radio (SDR) application. The compensator is composed of two simple filters with sinewave form of magnitude responses. The parameters of the design are the sinewave amplitudes expressed as powers-of-two and estimated in a way to fulfill the absolute value of the maximum passband deviation of 0.25 dB and 0.05 dB, for the wide...

This paper presents an adaptive iterative learning control scheme that is applicable to a class of nonlinear systems. The control scheme guarantees system stability and boundedness by using the feedback controller coupled with the fuzzy compensator and achieves precise tracking by using the iterative learning rules. In the feedback plus fuzzy compensator unit, the feedback control part stabiliz...

Background: This study aims to investigate radiation beam geometry of Cyberknife beam and change in dosimetric characteristics of six megavoltage (6MV) flattening filter free (FFF) beam after passing through high density cadmium free compensator alloy.Material and Methods: In this experimental study, changes in FFF beam dosimetric characteristics after passing through compensator alloy wa...

We have evaluated the performance of strain-chirped fiber Bragg grating (FBG) based tunable dispersion compensator in a 40 Gb/s transmission link. In our proposed compensator, the value of dispersion could be changed from -353 ps/nm to -962 ps/nm by adjusting the rotation angle of the metal beam on which the FBG was mounted. In order to evaluate the effect of ripples in reflectivity and variati...

This report concentrates on presenting transient stability and power ow models of Thyristor Controlled Reactor (TCR) and Voltage Sourced Inverter (VSI) based Flexible AC Transmission System (FACTS) Controllers. Appropriate models for voltage and angle stability studies are discussed in detail for the Static Var Compensator (SVC), the Thyristor Controlled Series Compensator (TCSC), the Static Va...