14950

13455

كارشناسي ارشد

كنترل

اصفهان : دانشگاه صنعتي اصفهان

1398

هشت، 81ص. : مصور، جدول، نمودار

مرضيه كمالي

فريد شيخ‌الاسلام

جواد عسكري، ايمان ايزدي

1398/05/28

كتابنامه

برق

مهندسي برق و كامپيوتر

1398/06/02

2553306

Adaptive backstepping fault tolerant control for nonlinear systems in the presence of actuator saturation Mohammad Javanmardi mohammad13881370@gmail com June 26 2019 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors Prof Marzieh Kamali m kamali@cc iut ac ir Abstract Actuator failure compensation is an important topic in designing control systems because it can potentially affect thesystem operation Also control input saturation which means that due to hardware limitations the actuator can only supplya limited range of signals is common in practical control systems This work presents suitable controller structures forsystems with actuator faults input saturation and unknown control direction for this purpose first a class of uncertainsingle input and single output SISO strict feedback nonlinear systems with unknown control direction and disturbancesis considered To overcome the difficulty of nondifferentiable input saturation a smooth hyperbolic tangent function isemployed to approximate the symmetric saturation function in this system Moreover Nussbaum function is employed tohandle the problem of the unknown control coefficient and saturation approximation Dynamic surface control is utilizedto overcome the problem of explosion of complexity occurred in the conventional backstepping design method Forthis purpose a first order filter is used to generate the command signals and their derivatives In the next step a noveladaptive fault tolerant control FTC scheme is suggested for a class of control input constrained multi input multi output MIMO nonlinear systems with multiplicative actuator faults An auxiliary system is designed to analyze the effect of theinput constraints in this system The command filters and auxiliary systems are integrated with the control law to avoidthe complicated calculation of the derivatives of the virtual controls in backstepping method In addition the bounds ofuncertainties and disturbances are estimated and compensated with an adaptive algorithm Stability analysis shows that theproposed controllers can guarantee the stability of the closed loop systems under actuator fault and saturation Illustrativeexamples are presented to demonstrate the effectiveness of the proposed schemes Key Words Adaptive control Backstepping control Input saturation Nussbaum functions Actua tor fault

مرضيه كمالي

فريد شيخ‌الاسلام

جواد عسكري، ايمان ايزدي