of closed-loop tunable models corresponding to each design point. For more
information, see “Multiple Design Points in slTuner Interface” on page 11-26.(^4) Model the gain schedules as parametric gain surfaces. A parametric gain surface is a
basis-function expansion with tunable coefficients. For a vector σ of scheduling
variables, such expansion is of the form:
Kσ =K 0 +K 1 F 1 nσ +...+KMFMnσ.
n(σ) is a normalization function. For tuning with systune, you use tunableSurface
to represent the parametric gain surface K(σ). In the slTuner interface you create
for tuning, use setBlockParam to associate the resulting gain surface with the block
that represents the gain schedule. systune tunes the coefficients K 0 ,...,KM over all
the design points.
For more information, see “Parameterize Gain Schedules” on page 11-32.
(^5) Specify your tuning goals using TuningGoal objects. You can specify tuning goals
that apply at all design points or at a subset of design points. You can also specify
tuning goals that vary from design point to design point. For example, you might
define a minimum gain margin that becomes increasingly stringent as a particular
scheduling variable increases in magnitude.
For information about specifying tuning goals that vary with design point, see
“Change Requirements with Operating Condition” on page 11-42.
For information about specifying tuning goals generally, see “Tuning Goals”.
(^6) Use systune to tune the control system. systune tunes the set of parameters,
K 0 ,...,KM, against all plant models in the design grid simultaneously (multimodel
tuning).
(^7) Validate the tuning results. You can examine the tuned gain surfaces and validate the
performance of the linearized system at each design point. However, local linear
performance does not guarantee global performance in nonlinear systems. Therefore,
it is important to perform simulation-based validation using the tuned gain schedules.
For more information, see “Validate Gain-Scheduled Control Systems” on page 11-
46.
11 Gain-Scheduled Controllers