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StabilityAnalysis For Uncertain Discrete-Time Control Systems With Actuator Saturation

Posted on:2013-07-21Degree:MasterType:Thesis
Country:ChinaCandidate:Y Q CaoFull Text:PDF
GTID:2248330395986804Subject:Applied Mathematics
Abstract/Summary:PDF Full Text Request
Saturation nonlinearity is unavoidable in practical control system. Actuatorsaturation is one of the most common and most important saturation nonlinearity.When control input is subjected to certain constraints, the system will besaturated, and the dynamic performance of the system, especially the stability ofthe system, will be changed or destroyed. Actuator saturation stability has beenthe mian problem considered by the scholars, and plays an important role tosolve the saturation problem in the control system. In this thesis, stability of theuncertain discrete-time system is analysed when the actuator has saturationconstraints.Firstly, the stability of the uncertain discrete systems with actuatorsaturation is analysed. For robust stability problem of multi-input uncertaindiscrete linear systems with actuator saturation, based on Lyapunov stabilitytheory, saturation dependent Lyapunov function is constructed, combining withthe corresponding matrix inequalities and Finsler’s lemma, the sufficient criteriato ensure that the closed-loop system is asymptotically stable and robust statefeedback control law are derived. The domain of attraction of the system isestimated by the level set to make the domain of attraction as large as possible aconvex optimization problem is designed.Secondly, the stability of the uncertain discrete-time delay systems withactuator saturation is anlaysed. For delay of the system, based on Lyapunov-Krasovskii method, in order to make the system conservative performance assmall as possible to select to saturation dependent Lyapunov function. Thestability method of feedback control system is derived by LMI technique,combining with matrix theory to give determinant theorem of the state delayclosed-loop system is asymptotically stable and the controller design method of robust stability.Finally, the feasibility and effectiveness of the controller design method isverified by numerical examples.
Keywords/Search Tags:discrete-time control system, actuator saturation, norm boundeduncertainty, robust stability
PDF Full Text Request
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