XMQ6838Y客车动力总成悬置系统参数的优化设计

针对XMQ6838Y客车怠速时方向盘抖动和座椅振动剧烈的问题,以其动力总成悬置系统各阶模态的解耦率最大为目标和固有频率的分配为约束,构建一种以悬置元件离散刚度与连续位置为设计变量的优化设计模型.通过建立系统自由振动模型,获取其固有频率和六阶模态;利用能量解耦法,求解系统六自由度的解耦率.在MATLAB和iSIGHT集成条件下,采用刚度离散化的方法和自适应模拟退火算法,优化悬置系统设计参数.实验结果表明:优化后,该车型在启、闭空调时方向盘和各排座椅的三向振动均明显降低,尤其在开启空调时,方向盘Y向振动加速度由3.43 m·s^-2下降至0.35 m·s^-2,提升了乘坐舒适性.

Optimal Design of Parameters of Power Assembly Mounting System for XMQ6838Y

To eliminate serious steering wheel wobbling and seat vibration of XMQ6838Y bus when idling, an optimization model with the discrete stiffness and continuous position as the design variables was constructed. The maximum decoupling rate of each order mode of powertrain mounting system was determined as the target with the natural frequency distribution as the constraint condition. By establishing system free vibration model,the natural frequency and the sixth-order mode were obtained. Through using energy decoupling method, the system’s six degrees of freedom decoupling rate was solved. Under the integrated conditions of MATLAB and iSIGHT, the discretizing stiffness method and adaptive simulated annealing algorithm were used to optimize the mounting system design parameters. The experimental results showed that the three-direction vibra-tion of the steering wheel and each row of seats was significantly reduced when the air conditioner was turned on or off, especially when the air conditioner was turned on, the Y-direction vibration acceleration of the steering wheel was reduced from 3.43 m·s^-2 to 0.35 m·s^-2, which improves the ride comfort.