Specifications

5 Designing and Testing Controllers in Simulink
5-16
Schedule Controllers at Multiple Operating Points
In this section...
“A Two-Model Plant” on page 5-16
“Animation of the Multi-Model Example” on page 5-17
“Designing the Two Controllers” on page 5-18
“Simulating Controller Performance” on page 5-19
If your plant is nonlinear, a controller designed to operate in a particular target
region may perform poorly in other regions. The common way to compensate is to
design multiple controllers, each intended for a particular combination of operating
conditions. Switch between them in real-time as conditions change. Gain scheduling is a
conventional example of this technique. The following example shows how to coordinate
multiple model predictive controllers for this purpose.
The rest of this section is an illustrative example organized as follows:
• “A Two-Model Plant” on page 5-16 describes the example application involving two
distinct operating conditions.
• “Animation of the Multi-Model Example” on page 5-17 explains how to simulate
the plant.
• “Designing the Two Controllers” on page 5-18 shows how to obtain the controllers
for each operating condition.
• “Simulating Controller Performance” on page 5-19 shows how to use the Multiple
MPC Controllers block in Simulink to coordinate the two controllers.
A Two-Model Plant
The figure below is a stop-action snapshot of the plant. It consists of two masses, M1
(upper) and M2 (lower). A spring connects M1 to a rigid wall and pulls it to the right. An
applied force, shown as a red arrow, opposes the spring pulling M1 to the left.