When to Use PID Autotuning
The PID autotuner blocks in Simulink Control Design let you tune a PID controller without
a parametric plant model or an initial controller design. If you have a code-generation
product such as Simulink Coder, you can generate code that implements the tuning
algorithm on hardware. Deploying the algorithm to hardware lets you tune a controller
for a physical plant, with or without using Simulink to manage the tuning process.To achieve model-free tuning, use the Closed-Loop PID Autotuner or Open-Loop PID
Autotuner blocks. These blocks perform a frequency-response estimation experiment that
injects signals into the plant and measures the plant output with the feedback loop closed
or open, respectively. The blocks use the resulting estimated frequency response to tune
PID gains for the plant.PID autotuning works with any asymptotically stable or integrating SISO plant, whether
low-order or high-order, with or without time delay, and with or without direct
feedthrough. It can tune any type of PID controller. You trigger the tuning process via an
input to the block, so you can tune your controller at any time.PID Autotuning for a Physical Plant
Embedded PID autotuning is a useful option when you have a PID-controlled system and a
test bed or control environment to operate in. In this case, you can deploy an autotuner
block to your hardware and automatically tune the gains of the PID controller in your
system.In practice, you can manage the PID autotuning process in several ways, including:- Deploy the autotuning algorithm as a standalone embedded module and manage the
tuning process in your own software and hardware environment. For details, see “PID
Autotuning in Real Time” on page 8-17. - Initiate, monitor, and analyze the autotuning process via Simulink. For details, see
“Control Real-Time PID Autotuning in Simulink” on page 8-27.
PID Autotuning for a Plant Model in Simulink
If you have a plant model in Simulink, you can use PID autotuning to:- Obtain an initial PID design for your plant, which you can refine by tuning against the
physical plant.
8 PID Autotuning