Simplicial algorithms on V-triangulation of uncertainty space

The application of simplicial algorithms to crossover computation in robust stability problems is developed. The authors briefly review a commonly used simplicial algorithm which consists of integer-labelling rule on Q-triangulation of uncertainty space. Next, the authors introduce a vector-labelling rule on V-triangulation. Finally, the authors expand on the case where the crossover intersects the singularity set of the Nyquist map, in which case the crossover is structurally unstable relative to "certain" parameters. Because of extreme sensitivity the algorithm makes some detours, but eventually goes to the correct solution, the latter being not continuous relative to certain parameters.