7. Correction by pole placement

The adjustments described above are simple, and involve eliminating the dominant time constant of the process. They are therefore not applicable to unstable open-loop systems. These adjustments are a special case of a more general technique known as pole placement, which introduces into the corrector a sufficient number of parameters to arbitrarily shift the position of the roots of the characteristic equation in the complex plane. It is known (see the article Analyse temporelle [R 7 150]...