This study aims at providing a solution to the problem of designing a
continuous and finite-time control for a class of nonlinear systems in the
presence of matched uncertainty with an unknown apriori bound. First, we
propose a Full-Order Integral-Terminal Sliding Manifold (FOITSM) with a
conventional (discontinuous) sliding mode to show that it provides the combined
attributes of the nonsingular terminal and integral sliding mode algorithms.
Secondly, an Adaptive Disturbance Observer (ADO) has been designed to alleviate
the effect of the uncertainty acting on the system. On application of the
ADO-based Full-Order Integral-Terminal Sliding Mode Control (FOITSMC), the
chattering phenomenon in control input has been reduced substantially in the
presence of conditionally known matched disturbances. Moreover, the adaptive
gains of ADO are updated non-monotonically without over-bounding the acting
disturbance, yet sustain the global boundedness of state trajectories within a
specific bound. %Finally, an application of the proposed algorithm for attitude
stabilization of a rigid spacecraft has been successively shown.Comment: 14 pages, 9 figure