Page 22 - Distributed model predictive control for plant-wide systems

xx List of Figures

Figure 5.5 Shell heavy oil fractionator benchmark control problem 95
Figure 5.6 Closed-loop system output responses and manipulated/control
signals with no communication failure under the disturbance
1 T
pattern d =[0.50.5] 97
Figure 5.7 Closed-loop system output responses and manipulated/control
signals with no communication failure under the disturbance
2
pattern d =[−0.5 − 0.5] T 97
Figure 5.8 Closed-loop system output responses and manipulated/control signals
with mixed communication failure under the disturbance pattern
1
d =[0.50.5] T 98
Figure 5.9 Closed-loop system output responses and manipulated/control signals
with mixed communication failure under the disturbance pattern
2
d =[−0.5 − 0.5] T 98
Figure 6.1 Plant with = 0.1: (a) maximum closed-loop eigenvalues with
LCO-DMPC and C-DMPC; (b) control performance with = 1
for LCO-DMPC (blue line, MSE = 0.2568) and C-DMPC (red line,
MSE = 0.2086) 115
Figure 6.2 Plant with = 1: (a) maximum closed-loop eigenvalues with
LCO-DMPC and C-DMPC; (b) control performance with = 1
for LCO-DMPC (blue line, MSE = 0.2277) and C-DMPC (red line,
MSE = 0.2034) 116
Figure 6.3 Plant with = 10: (a) maximum closed-loop eigenvalues with
LCO-DMPC and C-DMPC; (b) control performance with = 1for
LCO-DMPC (blue line, unstable) and C-DMPC (red line, MSE = 0.1544) 117
Figure 6.4 The outputs and inputs of each subprocess 122
Figure 6.5 The outputs and inputs of the second subprocess 122
Figure 7.1 ACC process for middle and heavy plates 138
Figure 7.2 Control strategy of ACC 140
Figure 7.3 Equilibriums of states of entire system 141
Figure 7.4 Performance of close-loop subsystems using centralized MPC,
N-DMPC, and the LCO-MPC 142
Figure 7.5 Flux of each header unit using centralized MPC, N-DMPC,
and LCO-MPC 143
Figure 7.6 Diagram of a serially connected process 144
Figure 7.7 Diagram of the MPC unit for each subsystem 148
Figure 7.8 Diagram of networked MPC algorithm 149
Figure 7.9 Outputs and control signals under the decentralized MPC 155
Figure 7.10 Outputs and control signals under the LCO-DMPC with Nash
optimization 155
Figure 7.11 Outputs and control signals under the N-DMPC iterative algorithm 156
Figure 7.12 Performance index comparisons for three schemes 156