Fault diagnosis of nonlinear system based on generalized observer

The fault model of the nonlinear system and the generalized nonlinear observer are presented in this paper. The algorithm compensates the influence of faults on the remnant order by means of adjusting the gain matrix of the observer to track the fault parameters of the system on line. It is proved that the nonlinear observer can realize fault diagnosis. In fact, here the problem of fault diagnosis is converted to the problem of model matching. The fault estimation can be exactly and timely. At last, experiments of three-tank system illustrate the effectiveness of the proposed algorithm.