Loop-Shaping Synthesis
In loop-shaping controller synthesis, you specify the shape of the open-loop response you want, and use a loop-shaping function to compute a controller that approximates that shape.
Use ncfsyn for a first cut
design that provides some stability margin. For more control of the
shapes of system responses, you can instead perform mixed-sensitivity
loop shaping with mixsyn.
Mixed-sensitivity loop shaping combines performance and stability
robustness specifications into one cost function that penalizes both
sensitivity and complementary sensitivity.
Functions
ncfsyn | Loop shaping design using Glover-McFarlane method |
mixsyn | Mixed-sensitivity H∞ synthesis method for robust control loop-shaping design |
loopsyn | H∞ optimal controller synthesis for LTI plant |
makeweight | Weighting function with monotonic gain profile |
mkfilter | Generate Bessel, Butterworth, Chebyshev, or RC filter |
augw | Plant augmentation for weighted mixed-sensitivity H∞ and H2 loop-shaping design |
Topics
Tradeoff Between Performance and Robustness
Plant model uncertainty can be a fundamental limiting factor in determining what can be achieved with feedback.
Typical Loop Shapes, S and T Design
To quantify the multivariable stability margins and performance of a system, use the singular values of the closed-loop transfer functions of the system.
Loop-Shaping Controller Design
In loop-shaping controller synthesis, you specify the shape of the open-loop
response you want, and use loopsyn to compute a controller
that approximates that shape.
Loop-Shaping Control Design of Aircraft Model
This example shows how to use loopsyn to address robustness and
performance tradeoffs.
Fine-Tuning the Target Loop Shape to Meet Design Goals
When the initial results from loopsyn are not satisfactory, refine
the target loop shape.
Mixed-Sensitivity Loop Shaping
Mixed-sensitivity loop shaping combines robustness specifications for both performance and stability into one cost function that penalizes both sensitivity and complementary sensitivity.
