Output Feedback Variable Structure Control of Uncertain Linear Systems

The output feedback variable structure control problem is considered for a class of single input single output uncertain linear plants with arbitrary relative degree and with parameter perturbations, unmodeled dynamics and bounded disturbance simultaneously. A novel passivity-based control scheme composed of linear feedback and variable structure control is proposed. If exact differentiations of system output provided, this scheme results in asymptotic stability; if a class of singular perturbation based linear differentiators adopted, it leads to an arbitrarily small regulation/tracking error.