White Paper: Stability of Discrete Systems Controlled in the Presence of Intermittent Sensor Faults
This paper presents sufficient conditions for stability of unstable discrete time invariant models, stabilized by state feedback, when interrupted observations due to intermittent sensor faults occur. It is shown that the closed-loop system with feedback through a reconstructed signal, when, at least, one of the sensors is unavailable, remains stable, provided that the intervals of unavailability satisfy a certain time bound, even in the presence of state vanishing perturbations. The result is first proved for linear systems and then extended to a class of Hammerstein systems.
In recent years, the mass advent of digital communication networks and systems has boosted the integration of teleoperationin feedback control systems. Applications like unmanned vehicles  or internet-based real time control provide significant examples raising, in turn, new problems.This paper deals with one of such problems, if the communication channel through which feedback information passes is not completely reliable, sensors’ measurements may not be available to the controller during some intervals of time. In such a situation, one has to couple the controller with a block, hereafter called supervisor, which is able to discriminate between intervals of signal availability(availability time Tai ) and unavailability (unavailability time Tui+1 ), and to generate an estimate of the plant’s state during this Tui+1 intervals. Methods for detection and estimation for abruptly changing systems  can be applied in the problem considered here. For that purpose an algorithm based on Bayesian decision could be implemented, for example.
Annual Salary Survey
After almost a decade of uncertainty, the confidence of plant floor managers is soaring. Even with a number of challenges and while implementing new technologies, there is a renewed sense of optimism among plant managers about their business and their future.
The respondents to the 2014 Plant Engineering Salary Survey come from throughout the U.S. and serve a variety of industries, but they are uniform in their optimism about manufacturing. This year’s survey found 79% consider manufacturing a secure career. That’s up from 75% in 2013 and significantly higher than the 63% figure when Plant Engineering first started asking that question a decade ago.