12092

11078

كارشناسي ارشد

كنترل

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1395

يازده،67ص.: مصور، جدول، نمودار

ص. ع. به فارسي و انگليسي

محسن مجيري

جواد عسگري

ايمان ايزدي، مرضيه كمالي

1395/11/16

كتابنامه

برق و كامپيوتر

مهندسي برق و كامپيوتر

ID11078

Introducing an adaptive compensator of periodic disturbances with unkown frequency Shima Bikineh s bikineh@ec iut ac ir January 14 2017 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Dr Mohsen Mojiri mohsen mojiri@cc iut ac ir Abstract One of the basic requirements in control systems is that they had the ability to regulate the controlled variables toreference commands without a steady state error against unknown and unmeasurable disturbance inputs Control systemswith this property are called servo systems In servo systems design the internal model principle plays an important role Based on the internal model principle for perfect tracking or rejecting an input signal a model of signal should be insertedin stable closed loop system In practice we often encounter the situations where the refrence commands to be trackedand or disturbance input to be rejected are periodic signals Examples are industrial robots disc drives numerical controlmachines servo scanners and every system that rotates or repeats the same task on a periodic basis Repetitive control isa potential solution to this kind of precision systems When the periodic disturbance is not purely sinusoidal and containsinfinite harmonics in its Fourier series expantion according to the internal model principle a finite dimentional compensatorcan not achieve disturbance rejection perfectly even though the frequency is known In this thesis we address this controlproblem in the case of unknown frequency For this purpose the thesis proceeds with introducing a chain of n filterswhich is capable of estimating the fundamental frequency of a signal composed of harmonically related sinusoids and ofdecomposing it into its constituent components It shown that by tending n to infinity we reach to a linear time delay systemwhich when furnished with a frequency estimator block is capable of estimating the fundamental frequency of any periodicsignal Another ability of proposed estimator is reproducing the periodic signal In contrary it could not decomposed theperiodic signal to its components In compersion with the previous methods the proposed fundamental frequency estimatorhas a simple structure high convergence rate and accurate estimated value The proposed estimator is employed in thestructure of a repetitive control system to track or reject periodic signals with unknown frequency The proposed structurehas robust properties with respect to uncertainties in plant and frequency of periodic input and also is adaptive with respectto frequency of periodic input Stability analysis of proposed stractures is carried out based on the concepts of integralmanifold of slow adaptation and averaging theory Various simulations confirm the desirable performance of proposedstructures Key Words Repetitive Control Disturbance Rejection Periodic Signals Fundamental FrequencyEstimation

محسن مجيري

جواد عسگري

ايمان ايزدي، مرضيه كمالي