应用传递路径分析方法对方向盘抖动贡献量的研究

Vehicle Steering Wheel Wobbling Contribution Investigation by Transfer Path Analysis

针对某国产样车存在的怠速时方向盘抖动的问题,采用传递路径分析方法寻找定位方向盘抖动的具体原因,将发动机4个悬置在x、y、z方向的振动作为路径输入端,以方向盘在z方向的振动作为目标点,建立了传递路径的分析模型。通过获取各条传递路径的传递函数来识别各输入端的工作载荷,计算了各条传递路径对方向盘抖动的贡献量,从而找出了发动机激励和悬置系统固有频率之间存在耦合的问题。根据弹性支撑系统的隔振要求,将发动机悬置系统固有频率设计为18Hz,不仅解决了样车存在的怠速时方向盘抖动的问题,而且表明了用于车内振动分析的传递路径方法的正确性和有效性。

For the steering wheel wobbling at idle speed in a vehicle, the theory and modeling process of transfer path analysis （TPA） were first introduced in details. To localize the source of the problem, a 12× 1 TPA model was constructed with x, y and z direction vibration of four engine mounts as the path input, and wheel vibration in z direction as a target. After obtaining the transfer function and working loads, the contribution of every transfer path was computed, and the coupling between the engine excitation and the mounting system was identified as the root of the problem, the stiffness of engine mount was then redesigned following the vibration isolation requirement of elastically supported system. The result verifies the convenience of TPA for vehicle vibration diagnosis.