Sensor validation for structural systems with additive sensor faults

Structures with a large number of sensors and actuators are becoming more common, and their applications vary from active control to damage location. This large amount of spatial information should be used to advantage to continuously monitor the correct functioning of the sensors during normal operation. Errors introduced by faulty sensors can cause a loss of performance and erroneous conclusions, and this paper analyses additive sensor faults. Two residual generation schemes are proposed to monitor sensor faults, namely the modal filtering approach and the so-called Parity Space approach. These residuals are then tested using a probabilistic approach using a chi(2) test to determine if there is a faulty sensor. These approaches are demonstrated on a simulated cantilevered beam excited at its tip and also on an experimental subframe structure.