Contribution à la commande adaptative tolérante aux défauts actionneurs des systèmes non linéaires incertains

Abstract

In this chapter, the problem of adaptive actuator failure compensation control for a class of redundant single-output systems with unknown control direction and subject to generalized (non-affine) actuator failures is investigated. Based on structural assumptions, and using the implicit function theorem the existence of an ideal implicit controller to the problem is proved, then, two adaptive approximation control designs were proposed to construct the ideal implicit controller online. The first design uses the Nussbaum-type function technique while the second design uses another new technique that estimates a sign-like term online. The simulation for both designs is carried out on the dynamic model of the angle of attack in a hypersonic aircraft with failures in elevator segments. Fuzzy logic systems were used as approximators for both designs. The simulation results confirm the theoretical claims for both designs. Notice also that the proposed design can be easily extended to general control affine systems with stable zero dynamics studied in chapter 2. This chapter terminates the thesis, in what follows a general conclusion and perspectives for this doctoral research will be provided.