An energy-balance approach for oscillator parameter identification

An energy-based approach for parametric nonlinear identification was investigated. The presented method uses an energy balance on the oscillator governing equations for identification purposes, thus requiring the availability of the position and velocity signals. Since it is rarely practical to measure every state variable in an experimental setting, we describe an alternative procedure for estimating velocity from the measured displacement. The presented approach uses cubic smoothing splines to avoid the noise amplification effect that occurs for numerical signal derivatives. Finally, we investigate the identification of parameters from both numerical and experimental data for three nonlinear oscillators. These studies demonstrate the effectiveness of the presented energy-balance approach for transient, periodic, and chaotic response behavior.