Sensitivity Analysis of Drivetrain Oscillations in Electric Vehicles

The increase of electric mobility is leading to new drivetrain designs in vehicle development. A common problem in electric drivetrains are torsional oscillations caused by elastic components. These components are wheel shafts, tires and bushings. A common problem, its sensitivity to parameter variation has not yet been fully investigated. The objective of this study is to quantify the sensitivity of oscillation frequency, damping and coupling between components with respect to key drivetrain parameters. A parameter space is investigated using Monte-Carlo sampling. A linear state space model is parameterized for each sample. Modal analysis permits the analysis of oscillation frequency, damping and coupling between components using the state variables. Subsequently, a Gaussian mixture model clusters the resulting data to form mode groups. Finally, linear regressions quantify the sensitivities. The results show oscillation damping can be increased by stiff wheel shafts. Decoupling of components in oscillation modes is mainly achieved by separating the oscillation frequencies of the different modes.