Research

Main research subjects

High gain observer design for uniformly observable systems (observable for any input) and non uniformly observable systems. The proposed observers include adaptive observers and unknown inputs observers. The observers are first designed by assuming that the outputs are available under a continuous form. Then, a systematic redesign is carried out in order to account for the other possible forms under which the outputs may be available.
- non uniformly sampled outputs with a single sampling partition and a single short output (time-varying) delay.
- non uniformly sampled outputs with multirate sampling and a multiple short output (time-varying) delays.
- non uniformly sampled outputs with multirate sampling and multiple arbitrarily long (time-varying) output delays. To account for the arbitrarily long (time-varying) delays, the proposed observers have a cascade structure constituted by chained subsystems each one of which has the same dimension as the original system.

Improvement of high gain observer design to cope with the peaking phenomenon occurring during the transient periods as well as the sensitivity to high frequency measurement noise.

Nonlinear control design: a unified design based on a reference model characterizing the adopted design: high gain, linearizing feedback and backstepping.