Design of Reliable Control Systems in the Presence of Actuator or Sensor Degradation

Chieh-chuan Feng, Yun-Yeh Lin,Jun-Jie Yang

In this paper we design controller that combines an observer and a control to handle systems subject to actuator or sensor degradation (including complete failure). The observer contains a pre-filter, an adaptive law, and a modified Luenberger observer that achieves estimation of system state and estimation of conditions of actuator or sensor.  We have shown that if a set of differential Riccati inequatities (DRI) is satisfied then the system can be stabilized under actuator degradation. While in sensor degradation case if an Algebraci Riccati inequality (ARI) and a DRI are satisfied then the system is stabilized.