On the representation of sensor faults in fault detection filters

~ T h i s paper presents an extension of the wellknown Beard-Jones detection filter that permits isolation of sensor faults in a dynamic system to a fixed direction in output space. The method is based on augmenting the system equations by an auxiliary state to represent t h e dynamic behavior of the sensor fault, and in effect converts the sensor fault into the same form as an actuator 'fault. The only condition required is observability of the original system.