This example shows how to design two feedback loops in a cascaded control system to track reference signals. The design uses the body rate (q) as an inner feedback loop and the acceleration (az) as an outer feedback signal. This example is based on the Simulink® Control Design™ example "Cascaded Multi-Loop/Multi-Compensator Feedback Design".
After loading the model and pre-configured Simulink Control Design Task, you can design a new controller using Response Optimization.
Requires Simulink® Control Design™.
Opening the Model
Open the model using the command below, and double click on the orange block to launch the Control and Estimation Tools Manager.
The goal of the design is to have an overall rise time of under 0.5 seconds for the outer feedback loop. A preliminary design is done using Simulink Control Design (see "Cascaded Multi-Loop/Multi-Compensator Feedback Design".) and is used as a starting point for optimization. The controller must satisfy the following requirements:
A Gain Margin >= 10db and Phase Margin >= 50 degrees for the inner feedback loop.
A Gain Margin >= 10db and Phase Margin >= 60 degrees for the outer feedback loop.
An overshoot of at most 1%, a 80% rise time of 0.5 seconds, and a 99% rise time of 0.6 seconds for the step response of the outer loop.
These design requirements have been added to the SISO Design Tool and the LTI Viewer. To complete the design, using response optimization, click the Start Optimization button within the Response Optimization node in the Control and Estimation Tools Manager.