| A toolbox is developed of novel design methods for asymptotic, output-tracking, sliding mode control in a class of causal, nonminimum-phase, multi-input-multi-output systems with nonlinear time-varying uncertainties and unmeasurable disturbances. The presented techniques employ the sliding mode control approach, linear algebraic methods and the internal model principle of control theory. The local asymptotic stability of output tracking-error dynamics is provided in sliding modes for a given class of uncertain, nonminimum-phase, nonlinear systems with linearized internal dynamics forced by reference output profiles and external disturbances defined by a known linear exogenous system. Tools and techniques are developed for the design of a series of sliding mode controllers that provide for decoupled tracking-error dynamics under the formulated conditions of the reduced-dimension nonlinear tracking-problem. A case study, the nonminimum-phase flight control of an aircraft, is considered. The design solutions comprise complete constructive algorithms, where the robust properties of a servocompensator and a sliding mode controller are combined. |
