Sliding modes for switched uncertain linear time invariant systems: An output integral sliding mode approach

A robustifying methodology for switched uncertain linear time invariant systems with matched uncertainties/perturbations and state-dependent location transitions using only output information is presented. An output integral sliding mode control technique, based on an algebraic hierarchical observer is proposed. his approach allows the theoretically exact compensation of the matched uncertainties/perturbations right after the initial time; but it requires the use of filters to reconstruct the state vector and produces a high level of chattering. To eliminate the necessity of filtering and to diminish the chattering, a continuous output integral sliding mode controller is designed. This controller is based on the super-twisting algorithm and it compensates the matched uncertainties/perturbations after a finite transient. For this case, sufficient conditions to ensure the convergence of the controller and the observer before every switching are given. The proposed approach is illustrated via numerical simulations.