Identification of rigid body inertia properties from experimental frequency response

The estimate of mass properties from the massline characteristic of experimental FRFs has attracted the attention of several authors during the last decade. The problem is tipically non-linear and, in the technical literature, iterative as well as direct methods are proposed for its solution. In this paper a new direct procedure is developed. The non-linear problem is divided into a series of simpler linear problems and solved in subsequent steps. A careful analysis is performed on the conditioning of the systems in order to assess the minimum number of required measurements, necessary to solve the problem even in noisy environments. The proposed approach produces accurate results as it is shown for two real experimentally tested systems: a two and three-dimensional structure, respectively. Of course an accurate measurement of the masslines characteristics is required. An extended discussion on this point is presented.