A new approach to causal output tracking for non-minimum phase nonlinear systems via combined first/second order sliding mode control

This paper deals with the output-tracking control problem for a class of non minimum phase nonlinear systems. In order to provide the desired output tracking features while, at the same time, stabilizing the internal dynamics in finite time, a novel cascade-like control structure is devised, which mixes together first and second order sliding mode methodologies. The scheme provides asymptotic convergence, under full state feedback, bringing the main benefit, as compared with previous literature, that the sliding mode dynamics of the output tracking error variable is of lower dimension, which simplifies the tuning of the scheme and gives rise to improved transient features of the error variables. Theoretical analysis and simulation results support the effectiveness of the proposed solution.