چكيده انگليسي :
H2 Controller Design for Non uniform Sampled data Systems Maryam Khosroshahi m khosroshahi@ec iut ac ir January 4 2016 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Assist Prof Iman Izadi iman izadi@cc iut ac ir Abstract The use of sampled data systems is abundant in industry due to many developments in digital technology In sampled data systems the process under control is continuous time but the controller is implemented in discrete time In manypractical and industrial applications sampled data systems operate non uniformly In these systems the output sampling andcontrol signal updating occur in the unequally distributed time instants Communication network limitations human factors unpredictable delays in sensors and measurement devices as well as delays in providing data in chemical and industrialprocesses are some of the reasons that make systems operate non uniformly One of the most important issues about sampled data systems is controller design There are some difficulties in controller design for non uniform systems In these systems when the data is delivered to the controller as well as the time the control signals are updated are not predictable Therefore the controller does not know when the data will be provided Thus these systems are inherently time varying and thecontrollers should also be time varying Implementing such controller is difficult On the other hand methods used to designcontrollers cannot be explicitly utilized for non uniform systems Since these systems are time varying concepts such asZ transform and H2 norm do not apply and controller design cannot be done in frequency domain Therefore controllerdesign must be done in time domain Because of the difficulties mentioned controller design problem for non uniformsampled data systems has not been resolved completely In this thesis H2 controller is designed for non uniform sampled data systems In uniform sampled data systems this controller minimizes the 2 norm of the system impulse response Non uniform systems are time varying and H2 norm has not been defined for time varying systems So first the H2 norm definition is extended for non uniform sampled data systems and then the controller is designed for these systems The controller is designed using three methods first indirect method second indirect method and direct method Finally through a case study the H2 controller is designed for a linearized ball and beam system with all methods and the resultsare compared Key Words Sampled data Systems Non uniform sampling H2 Cantroller Linear Matrix Inequali ties
