LAUSR

The problem of observer-based fault diagnosis is investigated for a class of nonlinear systems via an improved homogeneous polynomial technique (HPT). In the design of the estimator, some adjustable parameters are introduced that can lead to less conservatism. By developing an improved HPT, the employment of multi-instant and multi-index can achieve desired $$H_{\infty }$$H∞ system performance. A tunnel diode circuit example is shown to demonstrate that (1) less conservative results are expected in comparison with existing ones; and (2) faults can be distinguished in only a few steps after their occurrence.