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In this paper, a new model reference adaptive controller (MRAC) for uncertain switched linear systems is developed. A class of uncertain switched linear systems with parametric mismatched and input matched uncertainties, control input effectiveness and unmodeled dynamics is studied in this paper. The difference in input matrix for different switching modes which means the input channel degradation is investigated through this paper. By using common Lyapunov function method and developing new linear matrix inequality based sufficient conditions, uniform ultimate boundedness of the reference tracking error is guaranteed by switched MRAC and by using a novel nonlinear controller term, the size of the uniform ultimate bounded region can be made arbitrarily small which could enhance the performance of the overall control structure. Modified versions of MRAC systems using low-frequency learning adaptation MRAC is also used for better transient performance at switching instants. An illustrative numerical example demonstrates the performance of the proposed approach. Results also show that for the cases without parametric uncertainty in the linear part, asymptotic stability of the reference tracking error is guaranteed.

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In this study, a distributed control problem is addressed for switched affine multi-agent systems. In dynamical systems with an affine control input, the use of error feedback is essential for the realization of consensus protocols, but different from most existing results with affine control multi-agent systems, switched affine multi-agent systems face additional difficulties in the analysis and control; meanwhile, affine diffusive coupling consensus algorithms are not applicable. For this reason, a switching signal is considered as a control mechanism. We study switched networks in which the leader’s state is accessible only for a portion of agents, and the Lyapunov matrix-based min-projection control strategy is proposed to determine the active mode for each agent based on the state information of the neighbors. Using parameter-dependent stability analysis, a range of different reference points can be tracked by distributed min-projection switching without any redesigning. Also, benefiting from the hybrid dynamical system, min-projection switch is modified such that a periodic time-triggered sampled control is introduced to obtain finite switching frequency. Finally, a multi-motor system fed by DC–DC buck–boost converters is simulated for a stepwise changing of leader signal and different dwell-time switching, and the effectiveness of proposed method is assessed.