Detection of decoupled input/output pairs in multivariable systems

A Loop Pairing Method for Multivariable Control Systems Under a Multi-Objective Optimization Approach

“…To show the proposed multi-objective approach to select input-output pairings in MIMO systems, the example proposed in [11] is analyzed. For the process described in (18), RGA ( ) suggests a diagonal pairing, and DRGA ( D ) suggests an off-diagonal pairing according to equation (19). To control the system, 1-DOF PIs controllers were designed and tuned by optimizing a single specific index or control objective.…”

“…To analyze the interactions of the control loops of multivariable systems in permanent and transitory regimes, the relative normalized gain array (RNGA) was proposed [15]. Other works that propose methodologies to face the complex problem of finding optimal input-output pairings for the control of MIMO systems are shown in [16]- [19].…”

Contribution to improve the dynamic control of a binary distillation column

“…Due to their slow dynamics and the huge amount of energy consumed inside the distillation columns-approximately 40 % of consumed energy in a chemical plant is allocated to distillation, considerable efforts are devoted to control distillation columns more effectively (Shinskey 1996;Porru et al 2015). Similar to other industrial processes, distillation columns uses the multi-loop approach to deal with multivariable problems, this approach is based on dividing the multivariable system to a set of single input single output loops and tuning each loop alone (Huang et al 1994;Skogestad and Postlethwaite 2007;Nandong and Zang 2014;Potts et al 2015). This type of control suffers from the problem of interactions that usually exists between the loops.…”

“…Several solutions are presented in literature to overcome this problem. Choosing the best configuration that presents the small level of interaction is one of possible ways that designers and engineers take into consideration, however this method presents some limitations according to the tools used to assess the interactions and the difficulties faced in the implementation of some control schemes, since there are some configurations that can be deduced theoretically and might give good results but it cannot be implemented due to some other practical limitations (Kurt and Kurt 1990;Xiong et al 2005;Deeptanshu et al 2011;Khelassi et al 2012;Sujatha and Panda 2013;Potts et al 2015). Another possible way is the use of de-couplers, this method and similar to the first presents very good results in the theoretical part but in the realisation part still face many difficulties (Garrido et al 2012).…”