Dynamic Simulation and Model-based Control System Design for Comminution Circuits - Advanced Control and Supervision of Mineral Processing Plants - page 242

of the strategy for different changes in the filling level set-point. Between 100 and
160 minutes, the set-point is smaller than the constraint and the controller is able
to take the process at its value. However, at 160 minutes the set-point is larger than
the constraint and the controller stabilizes the processes at the constraint. At 230
minutes, the constraint on the filling level is lifted and the controller is able to take
the process to the reference point. The density is controlled at its set-point and is
only perturbed when the controller activates the constraints, as seen in Figure 5.20.
Finally, all supervised variables (pebble flowrate and sump level) are maintained in
their normal operational ranges, as seen in Figure 5.19.

40

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20

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1400

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1000

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10.5

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9.5

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8.5

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Samples (k)

Figure 5.18 Stabilizing controller: filling level, fresh flowrate, mill speed

400

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80

60

40

20

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800

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Samples (k)

Figure 5.19 Stabilizing controller: pebbles flowrate, sump level, pulp flowrate