Specifications

Design Controller for Plant with Delays
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Design Controller for Plant with Delays
This example shows how to design an MPC controller for a plant with delays.
The Model Predictive Control Toolbox can handle models that include delays. A typical
example is the distillation column model, which includes a delay in each input/output
channel. The presence of delays influences controller performance, and your controller
specifications should account for them.
Create the distillation column plant model.
g11 = tf( 12.8, [16.7 1], 'IOdelay', 1.0,'TimeUnit','minutes');
g12 = tf(-18.9, [21.0 1], 'IOdelay', 3.0,'TimeUnit','minutes');
g13 = tf( 3.8, [14.9 1], 'IOdelay', 8.1,'TimeUnit','minutes');
g21 = tf( 6.6, [10.9 1], 'IOdelay', 7.0,'TimeUnit','minutes');
g22 = tf(-19.4, [14.4 1], 'IOdelay', 3.0,'TimeUnit','minutes');
g23 = tf( 4.9, [13.2 1], 'IOdelay', 3.4,'TimeUnit','minutes');
DC = [g11 g12 g13
g21 g22 g23];
DC.InputName = {'Reflux Rate', 'Steam Rate', 'Feed Rate'};
DC.OutputName = {'Distillate Purity', 'Bottoms Purity'};
DC = setmpcsignals(DC, 'MD', 3);
The largest ioDelay of the DC model delay is 8.1 minutes.
Open the Model Predictive Control Toolbox design tool.
mpctool
Click Import Plant and import the DC model into the tool.
In the tree, select MPC Design Task > Controllers > MPC1.