Recall that RHP zeros severely limit the performance of SISO processes. For example, a model inverse can not be implemented as the controller, because this would cause the controller to be unstable. A similar problem exists for multivariable processes; RHP transmission zeros limit MIMO performance.
For a SISO process transfer function with the form
the zeros are the roots of the numerator polynomial, N(s). The inverse of the process transfer function is
That is, the ...