An improved event-triggered communication mechanism and L∞ control co-design for network control systems

This paper studies an improved event-triggered mechanism (ETM) and L∞ control co-design for network control systems with communication delay and external disturbances. Most existing ETMs only use the state or state-independent information. The drawback of such schemes is that the low transmission rate of sampled data cannot be obtained when the system is running close to or far away from the origin. To solve the issue, an improved ETM that can effectively improve the transmission efficiency during the whole operation time is firstly proposed. This is achieved by using both the state-dependent and the state-independent information. A general system model with communication delay and external disturbances is then presented, and sufficient conditions for both ultimately bounded stability and asymptotic stability are derived. The relationship between the stability criteria and parameters of the improved ETM, controller gain matrices, maximum communication delay, and upper bound of L∞-gain is established. Moreover, a co-design scheme is provided to design the desired ETM and controller that render the network load and control performance reach an expected level, which is more convenient than the two-step design method. Finally, numerical examples confirm the effectiveness of the proposed method.