Identification of Vehicle Powertrain Rigid-Body Inertia Properties

It is one of the prerequisites in an engine mounting system design to accurately determine the inertia properties of a powertrain rigid-body. But a powertrain has a complicated shape, its centre of gravity and moments of inertia cannot be easily determined by purely theoretical tools. An experiment-based method, the residual inertia method, is applied for identifying powertrain rigid-body inertia properties in this paper. This method is known to be relatively insensitive to measurement noises. However, the accuracy of the residual inertia method depends heavily on the selection of response measurement points and excitation conditions. This work focuses on how to select response measurement points to minimize the errors of identified powertrain rigid-body inertia properties. To accomplish this, an analysis of errors is performed according to the matrix condition number theory. From the investigations, the best and the worst configurations formed by the selected response points are proposed, as well as a minimal number of response points. The modal test of powertrain rigid-body is performed by taking into account the suggested ideas. Finally, some other methods are given for accurately estimating powertrain rigid-body inertia properties.