建立并求解座椅系统非线性动力学微分方程,以不同车速下座椅加速度均方根值仿真与试验结果的误差平方和最小为优化目标,基于约束随机优化算法反求并优化座椅悬架系统的非线性刚度和阻尼值。参数识别结果表明,原系统刚度和阻尼值不匹配是悬架减振效果差的主要原因,参数优化结果使座椅加速度均方根值降低了50%,改善了座椅的减振性能。根据最佳刚度特性曲线,借助有限元法设计出新型非线性座椅减振弹簧。
The nonlinear dynamic differential equation of seat suspension system was built and solved with Runge-Kutta method. Taking the minimum sum of square errors of root-mean-square values of seat acceleration between simulation and test results as the objective function, the nonlinear stiffness and damping parameters of the system were identified and optimized with constraint random direct method. The identified results showed the original stiffness and damping parameters of the seat suspension were mismatched and weakened the attenuating vibration ability of the system. Using the optimized stiffness and damping parameters, the root-mean- square values of seat acceleration were brought down by 50%. To coincide with the optimized parameters, the new nonlinear rubber spring was developed with finite element method according to the ideal stiffness curve of seat suspension. So the analytical methods above have important reference value to identify and optimize the dynamic parameters of other vehicle suspension systems.