Optimal modified tracking performance for networked control systems with QoS constraint

This paper investigates the optimal modified tracking performance of networked control systems with a constraint on quality of service (QoS). The QoS is characterized by two parameters of the system, viz. data dropout and the additive white Gaussian noise. The proposed modified tracking performance index prevents the probability of invalid data arising from the variations in the tracking error in the absence of an integrator in the plant. The derived optimal filter eliminates the influence of channel noise in the feedback channel. The optimal modified tracking performance expression is obtained by using the co-prime factorization. Results indicate that the optimal modified tracking performance is influenced by the non-minimum phase zeros, modification factor, packet dropout probability, and the characteristics of the reference signals. The obtained results will give some guidance for the design of networked control systems. The efficiency of the model is verified using some typical examples.