Frequency-domain controller design
Robust Control Toolbox™ commands let you apply the powerful methods of
H∞ synthesis to
SISO and MIMO control design problems. You can use
hinfstruct to tune fixed-structure control
systems, which are control systems that have predefined architectures
and controller structures. Commands such as
perform traditional synthesis of full-order, centralized controllers.
For more information about the difference, see Difference Between Fixed-Structure Tuning and Traditional H-Infinity Synthesis.
|Compute H-infinity optimal controller|
|Option set for |
|Compute H2 optimal controller|
|Option set for |
|H∞ tuning of fixed-structure controllers|
|Set options for hinfstruct|
|Full-control H-infinity synthesis|
|Full-information H-infinity synthesis|
|Compute H∞ controller for sampled-data system|
|Mixed H2/H∞ synthesis with regional pole placement constraints|
|H∞ norm of dynamic system|
|Weighting function with monotonic gain profile|
|Generate Bessel, Butterworth, Chebyshev, or RC filter|
|Plant augmentation for weighted mixed-sensitivity H∞ and H2 loop-shaping design|
About Fixed-Structure Controller Tuning
- What Is a Fixed-Structure Control System?
Fixed-structure control systems are have predefined architectures and controller structures.
- Difference Between Fixed-Structure Tuning and Traditional H-Infinity Synthesis
Traditional H∞ synthesis designs a full-order, centralized controller. Fixed-structure tuning lets you specify your control architecture and the structure and parameterization of the tunable elements of your system.
- What Is hinfstruct?
hinfstructlets you use H∞ synthesis to tune control systems that have predefined architectures and controller structures.
- Formulating Design Requirements as H-Infinity Constraints
hinfstruct, you express your design requirements as constraints on the closed-loop gain.
- Structured H-Infinity Synthesis Workflow
Get an overview of the steps required to perform structured H∞ synthesis.
H∞ Tuning of Fixed-Structure Controllers
- Fixed-Structure H-infinity Synthesis with hinfstruct
This example shows the complete workflow for tuning a control system with
- Build Tunable Closed-Loop Model for Tuning with hinfstruct
To tune a control system with
hinstruct, create a generalized LTI model of the system that includes the fixed and tunable elements and weighting functions that represent your design requirements.
- Tune the Controller Parameters
hinfstructto tune the tunable parameters in the
genssmodel of your control system.
- Interpret the Outputs of hinfstruct
hinfstructreturns a tuned version of the control system model a parameter that indicates how well the requirements are met.
- Validate the Controller Design
To validate the
hinfstructcontrol design, examine the performance of the tuned system.
- Speed Up Tuning with Parallel Computing Toolbox Software
If you have the Parallel Computing Toolbox™ software installed, you can speed up the tuning of fixed-structure control systems.
H∞ Synthesis of Centralized Controllers
- Robust Control of Active Suspension
In this example, use H∞ synthesis to design a controller for a nominal plant model. Then, use μ synthesis to design a robust controller that accounts for uncertainty in the model.
- Control of a Two-Tank System
This example shows how to use Robust Control Toolbox™ to design a robust controller (using D-K iteration) and to do robustness analysis on a process control problem.
- Norms and Singular Values
For MIMO systems the transfer functions are matrices, and relevant measures of gain are determined by singular values, H∞, and H2 norms.
- Interpretation of H-Infinity Norm
There are several ways of defining norms of a scalar signal, which have different physical interpretations and provide different measures of performance.
- H-Infinity Performance
Many types of control objectives can be posed as a minimization of norms of closed-loop transfer functions.