Sensitivity Bound
Specify the maximum sensitivity as a function of frequency.
Enter a SISO numeric LTI model whose magnitude represents the desired sensitivity
bound as a function of frequency. For example, you can specify a smooth transfer function
(tf, zpk, or ss model). Alternatively, you can sketch a piecewise maximum sensitivity
using an frd model. When you do so, the software automatically maps the profile to a
smooth transfer function that approximates the desired sensitivity. For example, to specify
a sensitivity that rolls up at 20 dB per decade and levels off at unity above 1 rad/s, enter
frd([0.01 1 1],[0.001 0.1 100]).
If you are tuning in discrete time, you can specify the maximum sensitivity profile as a
discrete-time model with the same sampling time as you use for tuning. If you specify the
sensitivity profile in continuous time, the tuning software discretizes it. Specifying the
profile in discrete time gives you more control over the profile near the Nyquist
frequency.
Options
Use this section of the dialog box to specify additional characteristics of the sensitivity
goal.
- Enforce goal in frequency range
Limit the enforcement of the tuning goal to a particular frequency band. Specify the
frequency band as a row vector of the form [min,max], expressed in frequency units
of your model. For example, to create a tuning goal that applies only between 1 and
100 rad/s, enter [1,100]. By default, the tuning goal applies at all frequencies for
continuous time, and up to the Nyquist frequency for discrete time.- Equalize cross-channel effects
For multiloop or MIMO sensitivity requirements, the feedback channels are
automatically rescaled to equalize the off-diagonal (loop interaction) terms in the open-
loop transfer function. Select Off to disable such scaling and shape the unscaled
open-loop response.- Apply goal to
Use this option when tuning multiple models at once, such as an array of models
obtained by linearizing a Simulink model at different operating points or block-Sensitivity Goal