2021, 48(12):10-18.
Abstract:In order to investigate the influence of the parameters of the swing-cylinder hydro-pneumatic suspension （HPS） on the “load wheel - suspension - sprung mass” system, a parameter sensitivity analysis on the dynamic response characteristics of the system was conducted under typical working conditions. The mechanical-hydraulic coupled dynamic model was built according to the structural characteristics of the HPS, and then it was verified with the comparison of the results obtained by simulation and experiments from the test rig. The key parameters of the HPS were selected to study their influence on the variation trend of the stiffness and damping characteristics of the suspension, after that their impacts on the dynamic response behavior of the HPS system were investigated under bump excitation. The results show that the stiffness of HPS system is greatly influenced by the initial gas volume of the accumulator when suspension deflection is small，while the position angle of the hydraulic suspension affects most when suspension deflection becomes large at compression travel； the vertical acceleration at the center-of-gravity of the sprung mass and the wheel load are most affected by the initial gas volume of the accumulator at low frequencies and it is most affected by the cross-section area of the damping valve at high frequencies; the suspension deflection is affected by these parameters in a reverse trend.
2020, 47(10):1-9.
Abstract:The parameter matching of the hydraulically interconnected suspension（HIS） system has a critical effect on its dynamic performance. To improve the overall dynamic performance of the system，the global sensitivity analysis and multi-objective optimization are proposed for an anti-pitch and anti-roll HIS system. Firstly，a seven degree-of-freedom vehicle dynamic model is established in the frequency domain. Then，the riding comfort，stability，and anti-pitch and anti-roll performance of the vehicle are evaluated by stochastic road input. In addition，the global parameter sensitivity analysis of the HIS system is presented using the Sobol method to evaluate the influence of each parameter and find out the critical parameters of the HIS system. Furthermore，a multi-objective optimization procedure is proposed to optimize vehicle performance by the NSGA-II algorithm. The result illustrates that the linear loss coefficients of the damping valves on cylinders and accumulators have a significant influence on each performance index，and the interaction effect of some parameters has a great influence on vehicle anti-roll performance. After multi-objective optimization，the optimization result obtained by the weighted coefficient method shows that：the root mean square（RMS） value of sprung mass′s weighted acceleration is decreased by 20.94%；the RMS value of pitch acceleration is decreased by 12.95%；the RMS value of roll acceleration is decreased by 8.05%；the mean value of tire dynamic force RMS value is decreased by 11.17%. Through the global sensitivity analysis and multi-objective optimization，the overall vehicle performance can be improved significantly.
2017, 44(10):1-8.
Abstract:To improve suspension regenerative power with reasonable vehicle ride comfort,sensitivity analysis and optimization of hydraulic parameters to a hydraulic-electrical regenerative suspension were carried out. The regenerative suspension consists of a spring and a hydra-electrical regenerative unit. Based on the suspension structure and principle,a simulation model of the hydra-electrical regenerative unit was established by AMESim software. And the model was verified by a prototype testing of the hydraulic-electrical regenerative unit. Taking ISIGHT software as a platform,sensitivities of hydraulic system parameters affecting car-body vertical acceleration and suspension regenerative power were analyzed by a quarter car vehicle mode in AMESim. The results show that,compared with recharging pressures and volumes of two accumulators,hydraulic motor displacement has a significant effect on both the vehicle vertical acceleration and suspension regenerative power. Moreover,taking the vehicle vertical acceleration RMS value of a traditional suspension as a constraint,the hydraulic system parameters were optimized to maximize the suspension average regenerative power. The results show that the average regenerative power is improved by 12.7% after optimization when the vehicle ride comfort is acceptable.
