Page 33 - Distributed model predictive control for plant-wide systems

Introduction 7

Coordinator

sp sp sp sp sp
y 1 y 2 y 3 y m−1 y m
Hierarchical
coordinated
decentralized
control
Cont 1 Cont 2 Cont 3 Cont m-1 Cont m

* y
u 1 * y 1 u 2 * y 2 * u 3 y 3 u m–1 m–1 * u m y m
S *
Distributed
S Na system
S 1 S 2
S *
S 3 S Na-1

Figure 1.7 Hierarchical coordinated decentralized control

sp sp sp sp sp
y 1 y 2 y 3 y m−1 y m

Network

Distributed
Cont 1 Cont 2 Cont 3 Cont m-1 Cont m control

y
u * y 1 u * y 2 u * y 3 u * m–1 m–1 u m
* y m
2
1
3
S *
Distributed
S Na system
S 1 S 2
S *
S 3 S Na-1
Figure 1.8 Distributed control

with each other through a network for achieving good global performance or a specifically
common goal. This kind of control structure has the advantage of a decentralized control struc-
ture, e.g., high flexibility and good error tolerance, and the advantage of a centralized control
structure, e.g., good global performance. In a distributed control structure, the most important
problem is how to design coordinating strategies for different purposes.