Investigating the positive effects of packet dropouts on network-based<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si0006.gif" overflow="scroll"><mml:msub><mml:mrow><mml:mi>H</mml:mi></mml:mrow><mml:mrow><mml:mo>∞</mml:mo></mml:mrow></mml:msub></mml:math>control for a class of linear systems

This paper investigates the positive effects of packet dropouts on network-based H ∞ control for a linear system that cannot be stabilized by a non-delayed static output feedback controller, but can be stabilized by a delayed static output feedback controller. By intentionally inserting a lossy network between the system and the controller, and embedding a logical packet-selecting algorithm that produces some packet dropouts in the actuator module, the networked control system is modeled as a system with an interval time-delay, which is stable with some nonzero time-varying delay, but is unstable without a time-delay. By constructing a complete Lyapunov–Krasovskii functional and discretizing both the lower bound and the upper bound of the interval delay, some new delay-dependent criteria for H ∞ performance and controller design are derived in terms of linear matrix inequalities. It is shown through an example that (i) proper packet dropouts can produce a stable control effect; (ii) utilizing the discretization of the lower delay bound can reduce the conservatism of the H ∞ performance criterion; and (iii) the proposed design result is effective in achieving satisfactory H ∞ control performance.