Simultaneous estimation of mechanical impedance parameters based on Linear Fractional Transformation

This paper proposes a new parameter identification method based on Linear Fractional Transformation (LFT). It is assumed that the target linear system includes unknown parameters. The parameter deviations are separated from a nominal system via LFT, and identified by organizing I/O signals around the separated deviations of the real system. The purpose of this paper is to apply LFT to simultaneously identify the parameter deviations in systems with fewer outputs than unknown parameters. As a fundamental example, this method is applied to one degree of freedom vibratory system. Via LFT, all physical parameters were simultaneously identified in this system. The procedure for identifying is simple and takes shorter duration in comparison with other conventional methods. Numerical simulations have been conducted for this system to verify the results. This study shows that all the physical parameters of a system with fewer outputs than unknown parameters can be effectively identified simultaneously using LFT.