Page 14 - Distributed model predictive control for plant-wide systems

xii Preface

MPC 4
Information network MPC m

MPC 1
MPC m-1
MPC 2 MPC*
MPC 3

S 4
S m

S 1
S m-1
S *
S 2
S 3
Field plant
Figure 1 The schematic of distributed model predictive control

subsystem is controlled by a subsystem-based MPC and these controllers are interconnected
by the network.
As mentioned before, how to improve the global performance under distributed control
framework is a valuable problem. It is exactly true for the DMPC. There are many DMPC
strategies and design methods in the literature, all to different ends. We have done extensive
research in this topic for more than 10 years, and have proposed some strategies, e.g., the
Nash optimization-based DMPC and the impacted region optimization based DMPC, etc. We
found that the DMPC is definitely a useful method for large-scale plant-wide systems. Thus,
we decided to write this book.
This book systematically introduces different distributed predictive control methods for
plant-wide systems, including system decomposition, classification of distributed predictive
control, unconstrained distributed predictive control, and the stabilized distributed predictive
control with different coordinating strategies for different purposes, as well as the implemen-
tation examples of distributed predictive control. The major new contribution of this book is
to show how the distributed MPCs can be coordinated efficiently for different control require-
ments, namely network connectivity, error tolerance, performance of entire closed-loop sys-
tem, calculation speed, etc., and how to design distributed MPC. The remaining contents of
this book are structured into four parts.
In the first part, we recall the main concepts and some fundamental results of the predictive
control for discrete-time linear systems. The system structure model and some decomposition
methods to present how to divide the entire system into interacting subsystems according to
the specific control requirements is also introduced. Our intent is to provide the necessary
background knowledge to understand the rest of the book.
The second part introduces the unconstrained distributed MPCs with different coordination
strategies. The simplest and most practical local cost optimization based distributed MPC,
Nash optimization based distributed MPC, the cooperative distributed MPC that can obtain
very good performance of the entire system but each subsystem-based MPC of which requires