Search results for "Feedback"
showing 10 items of 538 documents
Finite-Timel1-Gain Control for Positive Switched Systems with Time-Varying Delay via Delta Operator Approach
2014
This paper is concerned with the problem of finite-timel1-gain control for positive switched systems with time-varying delay via delta operator approach. Firstly, sufficient conditions which can guarantee thel1-gain finite-time boundedness of the underlying system are given by using the average dwell time approach and constructing an appropriate copositive type Lyapunov-Krasovskii functional in delta domain. Moreover, the obtained conditions can unify some previously suggested relevant results seen in literature of both continuous and discrete systems into the delta operator framework. Then, based on the results obtained, a state feedback controller is designed to ensure that the resulting …
Robust H∞ reliable control for delta operator switched systems with time-varying delays under asynchronous switching
2014
The problem of robust H∞ reliable control for a class of delta operator switched systems with time-varying delays and actuator faults under asynchronous switching is considered in this paper. Asynchronous switching means that the switches between the candidate controllers and system modes are asynchronous. Based on the average dwell time approach and delta operator theory, a state feedback controller is designed such that the closed-loop system is exponentially stable with H∞ performance in the presence of actuator faults. The obtained results are formulated in the form of linear matrix inequalities (LMIs). Finally, a numerical example is provided to demonstrate explicitly the feasibility …
Stability and -Gain Control of Positive Switched Systems with Time-Varying Delays via Delta Operator Approach
2013
This paper investigates the problems of stability and -gain controller design for positive switched systems with time-varying delays via delta operator approach. The purpose is to design a switching signal and a state feedback controller such that the resulting closed-loop system is exponentially stable with -gain performance. Based on the average dwell time approach, a sufficient condition for the existence of an -gain controller for the considered system is established by constructing an appropriate copositive type Lyapunov-Krasovskii functional in delta domain. Moreover, the obtained conditions can unify some previously suggested relevant methods in the literature of both continuous- and…
Input-Output Feedback Linearization Control of a Linear Induction Motor Taking Into Consideration Its Dynamic End-Effects and Iron Losses
2020
This article proposes a new input-output feedback linearization control (FLC) technique of linear induction motors (LIMs), taking into consideration both the dynamic end-effects and the iron losses. Starting from a previously conceived dynamic model, including the dynamic end-effects and the iron losses, all the theoretical framework of the FLC has been developed. The proposed FLC improves a previous version of FLC in accounting also the iron losses, which in LIMs with fixed-secondary sheet play a pivotal role more than in rotating induction motors (RIMs). The proposed FLC has been experimentally tested on a suitably developed test setup, and experimental comparisons between the proposed FL…
Teaching process control in food engineering: dynamic simulation of a fermentation control process
2017
Abstract Students usually have difficulties to understand abstract concepts of process control. Implementing in teaching process the inquiry-based learning helps students to follow methods and practices similar to those of professional scientists in order to construct knowledge. The paper describes the steps reached in simulation-based learning: from experimental data obtained by the students in their practical method (study and measurement of variables to some fermentation processes) to the simulated the behaviour of the process under a feedback control system. By providing opportunities for students to check their understanding and reflect on their learning process performance is enhanced…
The Euro's Effect on Trade Balance Dynamics
2015
During the pre-EMU period changes in real effective exchange rate or faster-than-trading-partners growth rates Granger caused changes in trade balance in most of the EMU-12 countries. However, our data driven article provides evidence that after the adoption of euro, these Granger causalities disappeared. We decompose trade balances into intra balances (trade balance vis-a-vis the euro area) and extra balances (trade balance vis-a-vis the rest of the world), and find that the disappearance of dynamic feedback effect typically occurred in the intra balances rather than in the extra balances. Our results imply that debtor countries cannot reduce their trade deficits in the short-run by enhanc…
Integration of Peripheral Adiposity Signals and Psychological Controls of Appetite
2007
Publisher Summary This chapter presents an overview of the major anatomical and neurochemical participants in brain reward circuitry. It also elaborates the evidence available to date that supports the hypothesis that energy regulatory signals can modulate food reward. Psychological modulation of feeding involves taste hedonics and preferences, and the rewarding aspects of food. The brain circuitries implicated in stimulus reward, and in the regulation of energy balance, have traditionally been considered as separate. However, more recently, accumulated evidence suggests that there is both anatomical and functional crosstalk between these sets of central nervous system (CNS) circuitry. Addi…
Biofeedback and functional perineal electro-stimulation in male urinary incontinence
1997
– The aim of the study is to evaluate the efficacy of biofeedback (BF) and of electrostimulation (SEF) of the perineal floor in male patients suffering from urinary incontinence. Eleven patients entered the study, five of them suffering from mixed urinary incontinence and six from pure stress incontinence. They were treated with six sittings of BF, SEF and domiciliary exercises. The results are promising. Additional monthly sittings and domiciliary SEF maintenance are advised.
Spark ignition feedback control by means of combustion phase indicators on steady and transient operation
2014
In order to reduce fuel cost and CO2 emissions, modern spark ignition (SI) engines need to lower as much as possible fuel consumption. A crucial factor for efficiency improvement is represented by the combustion phase, which in an SI engine is controlled acting on the spark advance. This fundamental engine parameter is currently controlled in an open-loop by means of maps stored in the electronic control unit (ECU) memory: such kind of control, however, does not allow running the engine always at its best performance, since optimal combustion phase depends on many variables, like ambient conditions, fuel quality, engine aging, and wear, etc. A better choice would be represented by a closed-…
Robust Active Disturbance Rejection Control of Induction Motor Systems Based on Additional Sliding-Mode Component
2017
This paper deals with motion control systems with induction motor, subject to severe requirements on both dynamics and steady-state behavior. The proposed control methodology could be viewed as an advancement of the standard field oriented control. It consists of two control loops, i.e., the rotor flux and the speed control loops, designed using the active disturbance rejection control method, with the aim to cope with both exogenous and endogenous disturbances, which are estimated by means of two linear extended state observers and then compensated. Moreover, with the aim of achieving total robustness, a sliding-mode based component is designed, in order to take into account disturbance es…