【作者】 徐传燕；

【导师】 丁康；

【作者基本信息】 华南理工大学 ， 车辆工程， 2012， 博士

【摘要】 如何对发动机进行减振隔振处理，避免发动机的振动过多地传递到车身影响成员的乘坐舒适性和引起车身零部件的疲劳破坏成为整车开发中的一个重要问题。发动机激励力和惯性参数的识别是进行发动机减振隔振的前提。同时发动机惯性参数还是进行基于振动分析的发动机激励力识别的前提。针对精确获取发动机惯性参数和激励力这一目标，系统研究了发动机惯性参数的精确识别方法、离散频谱校正比值校正法的抗噪性能，并将精确识别的发动机惯性参数和加Hanning窗的比值校正法应用到发动机激励力的识别中。主要的理论研究内容有：提出了忽略悬吊弹性绳刚度和阻尼的发动机惯性参数识别方法，进行了实验验证。提出了已知支撑刚度和阻尼的发动机惯性参数识别方法，进行了仿真和实验验证。提出了发动机惯性参数和系统刚度和阻尼矩阵的全参数识别法，仿真计算和实验结果表明发动机惯性参数和系统刚度和阻尼矩阵的识别结果精度较高。推导了比值校正法幅值和相位加不同的窗函数及加性高斯白噪声时的统计方差公式，并通过不同信噪比下的计算机仿真验证了其正确性，得出避免在归一化频率误差较低的情况下使用加矩形窗的比值校正法来校正相位的结论。将加Hanning窗的离散频谱比值校正法引入到发动机激励力的识别中，精确的提取发动机缸体表面振动响应各谐次的幅值和相位。通过多刚体动力学模型仿真验证了激励力识别方法的正确性，定量分析了各测试参数对激励力识别精度的影响。基于加Hanning窗的离散频谱比值校正法和第四章识别的发动机惯性参数，对发动机激励力的识别进行了初步的实验验证。更多还原

【Abstract】 It has become a vital issue in the process of vehicle development to deal with the enginevibration attenuation and isolation, in order to avoid transmitting excessive engine vibrationwhich influences passengers’ comfort and causes fatigue failure of body’s components to thebody. The identification of engine’s inertia parameters and excitation force is a prerequisitefor vibration attenuation and isolation. At the meantime, the identification of the engineexcitation force requires a previous knowledge of the inertia parameters. Only when theinertia parameters are available, the engine excitation force can be extracted from the cylindersurface vibration.The identification methods of engine inertia parameters and the influence of windowingand additive White Gaussian Noise on the accuracy of amplitude and phase based oninterpolation method are studied, based on the above research, the excitation force isidentified. The main contributions studied in this paper mainly focused on the follows.Firstly, simple direct methods are presented to identify the engine inertia parameters ofthe engine under a free-free condition or with a previous knowledge of elastic mount stiffnessin situ, simulation and experiment results confirm the validity of the presented methods.Secondly, a direct system identification method for engine inertia parameters is presented,which can accurately identify not only the ten inertia parameters but also the system stiffnessand the damp, and the method is validated through both simulating as well as through thetesting of an engine’s inertia properties. At last, the paper investigates the influence ofwindowing and additive White Gaussian Noise on the accuracy of amplitude and phase basedon interpolation method. Analytical expression of the estimator variance for amplitude andphase correction is derived, respectively. Simulation results confirm the validity of thepresented analysis.The interpolation method with a Hanning window is applied to the excitation forceidentification, simulation results vilified the accurate amplitude and phase extracted from thevibration by the interpolation method with a Hanning window. Influences on the excitationforce identification are analyzed quantitatively. Through the multi-rigid-body dynamics modelsimulation experiment, the excitation force identification method is confirmed. Based on theinterpolation method with a Hanning window and the identified inertia parameters, apreliminary engine excitation force experiment is carried out.更多还原