Abstract: Electro-mechanical transmission(EMT) integrates electric drives with transmission systems, yet they face rapid performance degradation under specific conditions, which can be addressed with active torsional vibration suppression. Traditional damping strategies, often based on simplified models, poorly match real-world scenarios and result in sluggish dynamic responses. To improve this, a 27-DOF torsional vibration model of EMT is developed, and a reduction method using modal contribution and stiffness sensitivity analysis is applied, effectively reducing the model to 5 DOFs while preserving 99.89% similarity in the 0-100 Hz range. Addressing the trade-off between strong vibration suppression and low response delay, the mechanism by which the driving torque excites torsional vibrations in the EMT is investigated. The dominant frequency and energy distribution of the driving torque in the frequency domain are optimized. The ideal transfer characteristics from disturbance to half-shaft torque are designed. Finally, based on the reduced-order model, an internal model control-based torsional vibration suppression(IMC-TVS) strategy for EMT was proposed. Simulation and experimental validations show that the IMC-TVS strategy has better advanced performance and real-time capability in torsional vibration suppression compared to PID and linear quadratic regulator(LQR) controllers.

Key words: tracked vehicle, electro-mechanical transmission, torsional vibration, model order reduction, internal model control