your specified target bandwidth for tuning. For nonintegrating plants, the block can
also inject a step signal to estimate the plant DC gain. All test signals are injected on
top of the nominal plant input, which is the value of the signal at u when the
experiment begins.- If you use the Closed-Loop PID Autotuner block, the plant remains under control of the
PID controller with its current gains during the experiment. Closed-loop tuning uses
sinusoidal test signals at the frequencies [1/10,1/3, 1, 3, 10]ωc.
When the experiment ends, the block uses the estimated frequency response to compute
PID gains. The tuning algorithm aims to balance performance and robustness while
achieving the control bandwidth and phase margin that you specify. You can configure
logic to transfer the tuned gains from the block to your PID controller, allowing you to
validate closed-loop performance in real time.
Workflow for PID Autotuning
The following steps provide a general overview of the workflow for PID autotuning.
(^1) Incorporate a PID autotuner block into your system, as shown in the schematic
diagram.
(^2) Configure the start/stop signal that controls when the tuning experiment begins and
ends. You can use this signal to initiate the PID autotuning process at any time. When
you stop the experiment, the block returns tuned PID gains.
(^3) Specify controller parameters such as controller type and the target bandwidth for
tuning.
4 Configure experiment parameters such as the amplitudes of the perturbations
injected during the frequency-response experiment.
(^5) Start the autotuning process using the start/stop signal, and allow it to run long
enough to complete the frequency-response estimation experiment.
(^6) Stop the autotuning process. When the experiment stops, the autotuner computes
and returns tuned PID gains.
(^7) Transfer the tuned gains from the block to your PID controller. You can then validate
the performance of the tuned controller in Simulink or in real time.
For detailed information on performing each of these steps, see:
- “PID Autotuning for a Plant Modeled in Simulink” on page 8-9
How PID Autotuning Works