AN ALGEBRAIC METHOD FOR NONLINEAR SYSTEM DECOMPOSITION

This paper is about model decomposition with a robustness and a fault sensitivity criteria. The model to decompose is nonlinear. The objective is to obtain the part of the model which is robust to the perturbations and to only one fault, while being sensitive to all other faults. This is especially useful for system monitoring, where the fault isolation and robustness to unknown signals is a major concern. To achieve the decomposition, an algebraic method is used, based on algebra of functions. However, this method, in its original form, will not always reach a solution even if this solution exists. In this paper, a solution is proposed to fix that issue. The initial model is rewritten into an adequate form using variable elimination techniques. Both the algebraic decomposition and the proposed improvement are presented and illustrated through an example.