Detection and Isolation of Incipient Sensor Faults in a Flight Control Actuator

Abstract

This paper presents a scheme for the detection and isolation of incipient sensor faults in an electromechanical flight control actuation system. The system considered h ere is a practical system, which is an electromechanical flight actuator, based on a DC torque motor. The scheme utilizes the analytical redundancy that exists in the system between the linear actuator position, motor shaft velocity and motor current for detection and isolation of the incipient sensor faults. The fault detection scheme is based on a single Luenberger observer, which is driven b y the position sensor of t he actuator. Residuals that can indicate various types of sensor faults are generated from the estimate of the sensor output provided by the Luenberger observer. The capability of the residuals, to detect and isolate incipient faults in the sensors, such as bias errors, scale factor err ors and d ead zone err ors is demonstrated through simulations. The robustness of the detection scheme in presence of plant parameter variations is also examined.