Development Of A Test Rig For Measuring The Inertial Parameters Of Heavy Commercial Vehicle Powertrain

It is one of the important requisites in the powertrain mounting system design to accurately determine the inertial properties of a powertrain. As to the existing successful inertial parameter test rig, it is mainly aims at the small quality of the powertrain. There are not an effective method for measuring the big quality of the powertrain inertial parameter at present, as a result of the measuring accuracy, the security and the reliable reason. Particularly, it is helpless for heavy commercial vehicle powertrain that the mass surpasses one ton.This paper, firstly, based on the existing inertial parameter test method of the rigid body, a test rig for measuring the inertial parameter of heavy commercial vehicle powertrain is proposed in this paper. The test rig's characteristics are: (1) Adopts the weighing way to guarantee that the center of powertrain falls in line with the torsional axial of the Trifilar Torsional Pendulum (TTP); (2) The test rig can determine all ten inertial parameters of the powertrain at the same time, namely the mass, the coordinates of the center of gravity (C.G.), the moments of inertia and the products of inertia. The biggest load bearing is 3 tons; (3) In order to measure the distance of two spatial points, the author has designed one kind of new space length measuring instrument. The powertrain space position description is completed only through the distance measurement, and the posture of the powertrain is not strictly limit in the test; (4) The inertial parameter's computation method is based on matrix transformation, the data in the matrix are calculated with the coordinates that are measured with space length measuring instrument, the coordinates are obtained by four locations, The measured coordinates are with high precisions; (5) The data obtained in each group of the powertrain posture can be used both for calculating C.G. , the moment of inertia and the products of inertia.Secondly, this paper has precisely gained the system parameters of the TTP through the parameter demarcation's method, and carried on the detailed analysis to the parameter demarcation process's error source, and proposed the solution. As a result, this test rig precision increased greatly; the inertial properties of a regular rectangular body are measured. The results are compared with the theoretical value obtained from the CAD model. The comparisons show that the proposed method and the data processing technologies in the paper are effective.Finally, the inertial properties for the same automotive powertrain from the two approaches are given. One approach is to measure the parameters using the weighting TTP method. And the other is to test the parameters based on the hanging TTP method. The test result had indicated that the proposed method and the data processing technologies in the paper are effective. It is suited for widely spread in the actual project application. The test methods and experimental data processing technologies proposed in this paper can be also used for getting the inertia properties for other irregular bodies.