Chapter 2 RobustnessAnalysis
© National Instruments Corporation 2-19 MATRIXx Xmath Robust Control Module
Using this relation and any of the previously discussed approximations for
μ(.), you can compute an approximation to wcgain( ). Because the
approximations to μ(.) are upper bounds, the resulting approximations to
wcgain( ) also are upper bounds. For speed purposes, wcgain( ) uses
Perron-Frobenius scaling to calculate the approximation of μ.
wcgain( )gamma = wcgain(H, gammin, gammax, gam0)
The wcgain( ) function estimates the largest possible magnitude from
ag iven input of the system to a given output, when the other inputs are
connected to the other outputs through uncertain transfer functions
bounded by one.
For a discussion of wcgain( ) syntax, refer to the Xmath Help. This is a
low-level function that calculates the worst-case gain at a single frequency,
where the magnitude bounds are normalized to one as follows:
Because it is a lower level function, there is no syntax checking. This
function is called by the wcbode( ) function.
l1…lk1===