Adaptive chattering alleviation of variable structure systems control

A new adaptive chattering alleviation algorithm for variable structure systems (VSS) control is proposed. The adaptive control algorithm consists of two phases. In phase one, the authors try to minimise the time required to reach the switching surface. In phase two, they alleviate the chattering about the switching surfaces in the sliding mode. The automatic switching between these two phases is based on a recursive prediction procedure performed at each step. The automatic adjustment of the controllers is called an adaptive VSS control algorithm. The algorithm can be applied to uncertain linear and nonlinear systems. The resulting trajectories of a nonlinear robotic experiment indicate almost no chattering at all. Moreover, this clear-cut benefit is not obtained at the expense of any added time required to reach the steady state.<>