Analysis of an Electrically Interconnected Half-Car Suspension System With Resistive Loads Under Random Road Excitation

Abstract The primary objective of this paper is to study an electrically interconnected suspension (EIS) system designed to operate under random excitation conditions for energy harvesting purposes. The system comprises of two distinct sections: firstly, a four-degree-of-freedom half-car model suspension system; secondly, a two-port electrical network integrated with the suspension, facilitated by generators positioned on either side of the suspension. In this study, a network from the literature is used, which was shown to effectively decouple the bounce and roll motions of the system, corresponding to vertical force and torque, thus enabling power generation at each branch. The analysis of the system is conducted by utilizing three established methods suitable for systems subject to stochastic excitation: Monte Carlo Simulation (MCS), moment equations, and ∥H∥2 method. Additionally, by employing these methodologies, a comprehensive parameter study is conducted, focusing on how resistive load variations influence both mechanical and electrical behaviors. More specifically, we use the power spectral density (PSD) functions of the mechanical and electrical variables to gain knowledge about the system’s behavior in terms of vibrations and energy harvesting. In this regard, it is found that sprung mass roll and bounce motions are decoupled in the case of identical resistive loads at each branch of the electrical network. Also, we can generate power on each branch related to the roll and bounce motions of the sprung mass at the same time due to the property of the electrical circuit. Finally, we did optimization on the electrical network to find the optimal load resistance values on each branch for maximizing the total power which is six times higher than the internal resistance of the generators of the system.