Observability recovering by additional sensor implementation in structured bilinear systems

Sensor placement on the basis of a graphical study for the observability of structured bilinear systems is dealt with. The proposed method is based on a graph-theoretic approach and assumes only the knowledge of the system structure. If a system is not generically observable, solutions of minimal (in sense of quantity) sensor placement are given in order to recover the system observability. This sensor placement is easy to determinate because it consists of finding paths on a digraph and of decomposing the bipartite graph associated to the system.