Tuning of decentralised PI (PID) controllers for TITO processes

Centralized multivariable control by simplified decoupling

“…Some decoupling schemes are static [8], and others are dynamic [9][10][11][12][13][14]. Static decoupling guarantees complete decoupling only for low frequencies, which may not be sufficient for a good performance.…”

An extended approach of inverted decoupling

“…Some decoupling schemes are static [19], and others are dynamic [6], [13], [14], [20]. Most of these methodologies focus on systems with two inputs and two outputs (TITO systems).…”

“…There are two approaches of centralized control: a pure centralized strategy [4][5][6][7][8][9] or a decoupling network combined with a diagonal decentralized controller [10][11][12][13][14]. A decentralized control system with a decoupling matrix can be designed by combining a diagonal controller C(s) with a block compensator D(s) in such a way that the controller sees the apparent process G(s)·D(s) as a set of n completely independent processes.…”

Practical advantages of inverted decoupling

“…There are two approaches of centralized control: a pure centralized strategy [2][3][4][5][6] or a decoupling network combined with a diagonal decentralized controller [7][8][9][10]. In the last case, a decoupler is used to minimize interaction or to make the system diagonal dominant; then, the controllers are designed using some decentralized method.…”

“…Some approaches are static [15], and others are dynamic [9][10], [14], [16]. Static decoupling guarantees complete decoupling only for low frequencies.…”