3. Conclusions

After a few theoretical reminders of the fundamental principles of modal control, we have shown in this dossier, through a complete and detailed application to a problem involving the piloting of an approaching civil aircraft, that these techniques can very quickly produce a relevant initial solution. The real strength of modal control techniques lies in the relatively natural possibilities they offer for taking into account the "physics" of the control problem (via the choice of poles and their assignment to outputs). These techniques also have the advantage of generating simple correctors that are easy to interpolate when necessary.

On the other hand, taking parametric robustness constraints into account can prove tricky. Classical extensions to modal control in this domain (based on a better choice of eigenvectors) are rather limited, as they often only take...