Setpoint dynamic compensation via output feedback control with network induced time delays

In operational control of most industrial systems, two layers, the control layer and the operational layer, exist, and are communicated via networks. Network induced time delays have negative impact on operational control performance. For a class of industrial processes, this paper proposes a method of setpoint dynamic compensation based on output feedback control with network induced stochastic delays. Firstly, given a process, a multi-input multi-output PID controller with an adjustable response speed is designed to stabilize the plant without any steady-state error for setpoint tracking. Secondly, a network stochastic time-delay model is established by analyzing the characteristics of data transmission in the Ethernet, and is used in designing an operational layer controller based on output feedback. In particular, a condition to guarantee asymptotic stability of the whole closed-loop system is given. Finally, a simulation experiment in an industrial flotation process is employed to demonstrate the effectiveness of the proposed method.