A comparison of stability and performance robustness of multivariable PID tuning methods

Despite the wide popularity of SISO tuning methods, the number of manual tuning methods for MIMO systems is limited. The MIMO control loops are usually tuned sequentially using scalar techniques. Often this is not effective since tuning one loop may detune other loops in the system. Sequential tuning methods are partially open loop, and this is not easily accepted by the plant operators. The objective of this paper is to review and compare the robustness of MIMO PID tuning methods. The study is based on a widely used model of a distillation column and simulation results are presented to demonstrate the performance of the tuning methods. Copyright (C) 2000 IFAC.