Robust nonlinear observer design for actuatorfault detection in diesel engines

Boulaïd Boulkroune (1) , Issam Djemili (1) , Abdel Aitouche (2) , Vincent Cocquempot (2)

1 LAGIS - Laboratoire d'Automatique, Génie Informatique et Signal
2 STF - Systèmes Tolérants aux Fautes

This paper is concerned with actuator fault detection in nonlinear systems in presence of disturbances. A nonlinear unknown input observer is designed and the output estimation error is used as a residual for fault detection. To deal with the problem of high Lipschitz constants, the modi ed mean value theorem is used to express the nonlinear error dynamics as a convex combination of known matrices with time-varying coe cients. Moreover, the disturbance attenuation is performed using the modi ed H¥ criterion. A su cient condition for the existence of the unknown input observer is obtained using linear matrix inequality formula and the observer gains are obtained by solving this set of inequalities. The advantages of the proposed method are that no a priori assumption on the unknown input is required and that it can be applied to a large class of nonlinear systems. Performances of the proposed approach are shown through the application to a diesel engine model.

Mots clés: nonlinear observer; diesel engine; mean value theorem; unknown input observer; H infinity

Domaines: Automatique / Robotique

Boulaïd Boulkroune, Issam Djemili, Abdel Aitouche, Vincent Cocquempot. Robust nonlinear observer design for actuatorfault detection in diesel engines. International Journal of Applied Mathematics and Computer Science, 2013, pp.1-7. ⟨hal-00819485⟩