Specifications

Schedule Controllers at Multiple Operating Points
5-17
In the above, mass M2 is uncontrollable. It responds solely to the spring pulling it to the
left.
If the two masses collide, however, they stick together until a change in the applied force
separates them.
The control objective is to make M1 track a reference signal. The blue triangle in the
above indicates the desired location, which varies with time. At the instant shown, the
desired numeric location is -5.
For an animated version of the plant, see Scheduling Controllers for a Plant with
Multiple Operating Points.
Animation of the Multi-Model Example
In order to achieve its objective, the controller can adjust the applied force magnitude
(the length of the red arrow). It receives continuous measurements of the M1 location.
There is also a contact sensor to signal collisions. The M2 location is unmeasured.
If M1 were isolated, this would be a routine control problem. The challenge is that the
relationship between the applied force and M1’s movement changes dramatically when M2
attaches to M1.
Define the model.