Adaptive control of uncertain fractional order nonlinear systems subject to unknown input quantization and external disturbance
Volume Title: 1
1Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran, Iran
2Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran, Iran
In this paper an adaptive backstepping controller has been designed for uncertain fractional-order nonlinear systems in the strict-feedback form subject to unknown input quantization and time-varying external disturbance. The controller has been designed using the backstepping technique based on the frequency distributed model which can be applied to both commensurate and non-commensurate fractional order systems. To avoid chattering, the hysteretic quantizer has been employed. Using the Lyapunov stability theorem, it has been shown that all closed-loop signals remain bounded and the output tracking error converges to the origin asymptotically. Finally, a practical simulation example is provided to illustrate the effectiveness of the controller scheme.