Reduced-order switching functions in variable-structure control systems

A variable-structure control system (VSS) for single-input systems is investigated. It is shown that the design of VSS control is similar to that of modal synthesis and can be treated as such if the feedback gains are not switched. The case of reduced-order switching VSS control is investigated where not all states are available for switching function synthesis or control. A second-order example and a third-order example are given with time responses and state trajectories.