On the relative degree of multivariable linear systems in geometric terms

The purpose of the paper is to present two simple algorithms for computing the relative degree of multivariable linear systems. Both algorithms are based on standard numerical routines of the geometric approach, i.e. that for the computation of the maximum controlled invariant contained in a given subspace and the minimum conditioned invariant containing a given subspace. Their usefulness is related to some techniques for achieving almost perfect tracking in multivariable systems through noncausal inversion, which, in turn, can also be expressed in geometric terms