Extended sliding-mode control for the tracking problem of a rotational inverted pendulum

The tracking problem of a rotational invert pendulum with modeling uncertainties and external disturbances is considered. The tracking problem is solved by using a proposed extended sliding-mode control scheme, where a global invariance is achieved and the resulting control signal is chattering free. In the conventional sliding mode control, a discontinuous switching control signal is applied and it causes chattering. Some modified approaches with continuous switching control were used to eliminate chattering at the cost of the invariance property or accuracy. This paper proposes an extended sliding surface across the initial state such that the sliding mode motion will occur with global invariance.