4.2. A SIMPLE FLEXIBLE STRUCTURE EXAMPLE 171
Wenow examine the robustness properties of the new closed loop system. Wealready
know that the robust performancetest will be less than the γvalue from the H∞
synthesis above (in this case 0.2930). The results are again displayed graphically.
Gmug = freq(Gmu,omega)
npbnds = norm(svd(Gmug(4:6,3:4)),inf)
[rsbnds,Drs,Drsinv,Deltars,sensrs] = mu(Gmug(1:3,1:2),[1,2; 1,1])
[rpbnds,D,Dinv,Delta,sens] = mu(Gmug,blk)
gph6 = ctrlplot(npbnds,{log,line style=4});
gph6 = ctrlplot(rsbnds,gph6,{log,linestyle=[3,5]});
gph6 = ctrlplot(rpbnds,gph6,{log,linestyle=[1,2]});
gph6 = plot(gph6,{!grid,legend=["Nom perf";"Rob stab (up bnd)";...
"Rob stab (lw bnd)"; "Rob perf (up bnd)";...
"Rob perf (lw bnd)"],title="mu analysis of Gmu"})?