adaptive control of uncertain fractional order nonlinear systems subject to unknown input quantization and external disturbance

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#