Design of a data-oriented cascade control system

In process industries, PID control has been applied to controlled objects such as chemical plants. A cascade control system is applied in order to improve control performance by using several feedback loops. However, it is complicated to design a cascade control system because this control system includes plural controllers. In this paper, a design scheme of data-oriented cascade control system without system identification is proposed. According to the proposed scheme, PID gains included in plural controllers can be determined by using only closed-loop data. The effectiveness of the proposed scheme is verified by using a simulation example and an experiment of the water level control system.