R-S-T conventional controller design for slow processes

Discrete time control laws can be synthesized based on the shape of the system´s response in a specified number of samples, as well as by digitizing continuous time controllers (e.g. PI, PD, PID). For SISO linear systems, solving the Diophantine equation from the poles placement method leads to discrete controllers with R-S-T canonical structure. The paper shows the design procedure of discrete time R-S-T controllers for slow processes, particularly for level control processes. From the discrete time controller the equivalent continuous controller is rebuilt and the behavior of the system to parameter variations is studied. The results and simulations are made using the Matlab environment.