experiment start time, and a second Step block to step from 1 to 0 at the end time. Feed
the sum of the two signals into the start/stop port of the PID autotuner block.You can configure any other logic appropriate for your application to control the start and
stop times of the experiment. For more information about when to start and stop the
experiment, see “Step 5. Run Model and Initiate Tuning Experiment” on page 8-13.Step 3. Specify Controller Parameters and Tuning Goals
In the PID autotuner block, specify the configuration of the PID controller you are tuning,
using the following block parameters:- Type
- Form
- Time Domain
- Controller sample time (sec)
- Integrator method
- Filter method
Then, specify the target bandwidth and phase margin for tuning with the Target
bandwidth (rad/sec) and Target phase margin (degrees) parameters, respectively.The target bandwidth is the target value for the 0-dB gain crossover frequency of the
tuned open-loop response CP, where P is the plant response, and C is the controller
response. This crossover frequency roughly sets the control bandwidth. For a desired rise-
time τ, a good guess for the target bandwidth is 2/τ.The target phase margin reflects your desired robustness of the tuned system. Typically,
choose a value in the range of about 45°– 60°. In general, higher phase margin improves
overshoot, but can limit response speed. The default value, 60°, tends to balance
performance and robustness, yielding about 5-10% overshoot, depending on the
characteristics of your plant.For more information about setting these parameters, see the Closed-Loop PID Autotuner
or Open-Loop PID Autotuner block reference pages.8 PID Autotuning