Hydraulic integrated interconnected regenerative suspension (HIIRS) is a novel suspension system that can simultaneously harvest the vibration energy in the suspension and enhance the vehicle dynamics. The parameter sensitivity of the HIIRS system is analyzed and the significant parameters are optimized in this paper. Specifically, a half-vehicle model with the HIIRS is established. Based on the model, the parameter sensitivity of the hydraulic system is analyzed with three objectives, ride comfort, road holding, and average energy harvesting power. The parameters considered in this study are more abundant than those in previous related studies, including hydraulic cylinder inner diameter, hydraulic motor displacement, resistance, initial system pressure, and accumulator parameters. It turns out that the most sensitive parameters are the inner diameter of the hydraulic cylinder, the resistance, and the displacement of the hydraulic motor. To further study the performances that the HIIRS could present, both the single-objective optimization and the multi-objective optimization problems are solved and compared with the optimized traditional suspensions. The optimized HIIRS performs better in ride comfort and road holding than the optimized traditional suspension and anti-roll bar suspension. Different from the previous suspension optimization design, multi-objective optimization not only considers the traditional performance of the suspension but also incorporates the energy harvesting characteristics into the optimization objective. In the multi-objective optimization, a Pareto front is obtained, which shows that the ride comfort conflicts with the road holding and the energy harvesting power, while road holding and energy harvesting power did not conflict. The Pareto front shows that the optimized HIIRS is superior to the traditional suspension in ride comfort and road holding, and also harvests considerable energy.

Railway transportation has been increasingly significant for modern society in recent decades. To enable smart technology, such as health monitoring and electromagnetic braking for railway vehicles, a mechanical motion rectifier (MMR) based energy harvesting shock absorber (EHSA) has been proposed and proved to be capable of scavenging energy from the train suspension vibration. When installed on the train, MMR-EHSA works as a tunable damper in parallel with an inerter. This new suspension form brings great potential for further optimization of suspension dynamics but is rarely researched before. In this paper, the influence of the energy harvesting shock absorber (EHSA) on the railway vehicle dynamics performance is studied. A ten-degree of freedom vehicle model is established, with MMR shock absorber’s nonlinearity taken into account, with the purpose to analyze the influence of the EHSA on the ride comfort and wheel-rail vertical forces. Simulations are conducted by replacing the traditional shock absorber from train secondary suspension with the EHSA. Results show that EHSA could respectively harvest 180 W and 40 W average power at AAR 6^th and 5^th rail irregularity. In addition, compared with the traditional shock absorber, the MMR-EHSA can provide a higher ride comfort for passengers and slightly reduce the wheel-rail contact force.