looptune tunes the feedback loop illustrated below to meet default requirements or requirements that you specify.
C represents the controller and G represents the plant. The sensor outputsy (measurement signals) and actuator outputs u (control signals) define the boundary between plant and controller. The controller is the portion of your control system whose inputs are measurements, and whose outputs are control signals. Conversely, the plant is the remainder—the portion of your control system that receives control signals as inputs, and produces measurements as outputs.
For example, in the control system of the following illustration, the controller C receives the measurement y, and the reference signal r. The controller produces the controls qL and qV as outputs.
The controller C has a fixed internal structure. C includes a gain matrix D , the PI controllers PI_L and PI_V, and a summing junction. The looptune command tunes free parameters of C such as the gains in D and the proportional and integral gains of PI_L and PI_V. You can also use looptune to co-tune free parameters in both C and G.