中文摘要：

介绍了一种基于三线扭摆法测试动力总成质心和惯性参数的测量方法和实验台的开发。该方法和实验台的特点是：（1）采用悬吊法悬吊被测试物体，因而容易保证被测物体的质心落在三线摆的扭摆轴线上；（2）计算质心与惯性参数的方法基于坐标变换，坐标变换中的数据由测量的坐标点计算得到。坐标点由三坐标测量仪测量得到，测试精度高。对一个长方形组合件的质心和惯性参数进行了测试，并和理论值进行了对比，表明了实验台具有测试简单、高效和文中的数据处理方法有效、精度高的特点。给出了一个动力总成质心与惯性参数的测试结果，分析表明基于该测试方法和数据处理方法建立的实验台和数据处理系统，具有较好的测试重复性和测试精度。

英文摘要：

An equipment and the measurement method based on Trifilar Torsional Pendulum （TTP） for obtaining these parameters are presented in this paper. The key improvements to the conventional TTP are： （1） a body with irregular shape is suspended under the TTP, so the c.g. of the body is in line with the torsional axial of the TTP naturely; （2） the methods are based on matrix transformation. The data in the matrix are calculated with the coordinates that are measured with tri-coordihate measurement system. The measured coordinates are with high precisions, so the calculation methods are also with high precisions; （3） the data obtained in each measurement that the body are suspended for different directions can be used both for calculating the c.g. and the inertia properties of an irregular body, such as a powertrain. The method for identification the length and the empty mass of the TTP are described in detail. The c.g. and inertia properties for a regular body that merged with two different regular rectangular bodies are measured. The results are compared with the theoretical solution obtained from the CAD model. The comparisons show that the test rig based on the proposed method and the data processing technologies in the paper is effective. Finally, the c.g. and the inertia properties for an automotive powertrain from the two approaches are given. One approach is to measurement the parameters from the powertrain. And the second is to calculate the parameters based on the c.g. and the inertia properties for the engine and the transmission, which are identificated from the measurement on the engine and the transmission, respectively. The parameters from the two approaches agree reasonably well. It is demonstrated that the test rig has good characteristics for repeat measurement and with high precision. The test methods and experimental data processing technologies proposed in this paper can be also used for getting the c.g. and the inertia properties for other irregular bodies.