Sliding mode observer-based multi-fault reconstruction of nonlinear system

For a class of nonlinear system with multi-dimensional actuator faults and multi-dimensional unknown input disturbances, the twice-linear coordinate transformation is made and the sliding mode observer is designed to obtain two dynamic deviation equations. One equation only deals with the faults and the other deals with both the faults and the disturbances. By means of the principle of equivalence of sliding mode observer and sliding mode variable structure, both the actuator faults and the unknown input disturbances can be reconstructed. The effectiveness of such method can be verified by the simulation example.