Prescribed-Time Fuzzy Adaptive Control for Robotic Manipulators With Dead Zone Input
Shenquan Wang, Huadi Shan, Mohammed Chadli, Yanzheng Zhu, Yulian Jiang
Abstract
To remove the influence of system initial values and controller parameters on the settling-time function of finite/fixed-time control, a prescribed-time fuzzy adaptive control is designed for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\boldsymbol{n}$</tex-math></inline-formula>-link robotic manipulators in this work. The proposed setting-time function only relies on the parameters of the prescribed-time function and is no longer determined by the initial system value and controller parameters. By setting the convergence range of tracking error, the chattering of tracking error is reduced. Moreover, the dead zone input issue is addressed by using the dead-zone slope and boundary value theory. Based on the above methods, the designed prescribed-time fuzzy adaptive controller can ensure that all system signals are bounded, and the tracking error can converge to a preset interval within a prescribed time. Finally, experiments of a two-link robotic manipulator are conducted to verify the superiority of the developed control approach.