Degradation dynamics modeling and phase transition analysis for complex electromechanical systems using S-parameter network

Complex electromechanical systems (CEMS) integrate mechanics and electronics, but current models (complex network/bond graph) suffer from high computational costs and poor intuitive physical representation. Inspired by scattering parameter (S-parameter) models from radio frequency engineering, this paper innovatively proposes an S-parameter-based modeling framework for CEMS. First, a unified lumped-parameter modeling methodology is established for individual subsystems within CEMS. Next, the S-parameter characteristics of transmission channels between subsystems are analyzed. Based on this, load distribution and subsystem degradation equations are formulated. Furthermore, phase transition analysis during degradation is conducted by the degradation correlation length. By integrating system performance characterization equations, this study reveals underlying laws governing phase transitions of degradation structures and abrupt performance shifts during system degradation. Finally, the applicability of the proposed methodology is demonstrated through a numerical case involving an early warning radar system.