Analytical Scheme of Centralized PI Controller for Non-square Processes with Time-delays

Based on the direct synthesis approach, a simple and effective design method of centralized proportional integral (PI) controller for non-square processes is investigated in this paper. With the help of desired closed-loop diagonal transfer function to reduce interaction between individual loops, analytical expressions for PI controller, through the steady and dynamic information of the open-loop transfer function, are derived for the first order plus time delays model which often arises in the chemical production process. Compared with the existing direct synthesis approaches, the proposed controller design method requires no approximation of the pseudo-inverses of process. Example is introduced to show the effectiveness and simplicity of the proposed technique.