“…Potentially, the SSIE can be applied to a wide range of problems such as fault diagnosis (see, e.g. Gao & Ding, 2007;Patton, Clark, & Frank, 1989), fault-tolerant control (Jiang & Fahmida, 2005), disturbance rejection control (Profeta, Joseph, William, & Marin, 1990). In the field of fault detection and fault-tolerant control, for example, actuator, sensor and/or structure faults are usually modelled as inputs to the system with unknown dynamics.…”