Design and Optimization of a Novel Energy-Regenerative Hydraulically Interconnected ISD Suspension

A novel energy-regenerative hydraulically interconnected ISD (inerter–spring–damper) suspension system (ER-HIISDS) is proposed by incorporating a fluid inerter into the hydraulic interconnection architecture, with the objective of simultaneously enhancing vehicle ride quality and vehicle stability while recovering suspension vibration energy. A coupled vehicle–hydraulic model is developed by integrating the 14-degree-of-freedom (DOF) full-vehicle dynamics with the ER-HIISDS hydraulic subsystem. On this basis, the key system parameters are optimized using the Electromagnetic Wave Propagation Algorithm (EMWPA). The mechanical characteristics and energy-regeneration performance of the optimized ER-HIISDS are subsequently investigated under sinusoidal excitations and stochastic road inputs. Comparative simulations are further conducted under representative transient maneuvers, including single-wheel bump excitation, emergency braking, and double-lane-change conditions, with a conventional passive suspension and an energy-regenerative hydraulically interconnected suspension (ER-HIS) employed as benchmark systems. The results indicate that the proposed ER-HIISDS can attenuate vehicle-body vibrations and improve body attitude stability while maintaining favorable dynamic performance and energy-regeneration capability over a range of stochastic road excitations. Under the representative transient maneuvers, the hydraulic interconnection generates additional coupling forces and corresponding anti-roll and anti-pitch moments, thereby effectively suppressing vehicle-body roll and pitch motions. Overall, the proposed ER-HIISDS achieves a favorable balance among ride comfort, handling stability, attitude control, and vibration-energy regeneration, demonstrating its potential for advanced vehicle suspension applications.