Dynamic Coordinated Control During Mode Transition Process for a Plug-In Hybrid Electric Vehicle

Abstract

The fuel-saving advantages of plug-in hybrid electric vehicles can be improved using optimized configurations and appropriate energy management strategies. However, the noticeable jerks and vibrations of the powertrain can be generated by torque fluctuations in the mode transition (MT), especially, the transition from electric mode to hybrid driving mode that involves engine starting. To address this problem, this paper proposes a dynamic coordinated control strategy that synergizes real-time discrete motor torque change rate limitation (TCRL) and active damping feedback compensation (ADFC) control. First, a detailed vehicle powertrain simulation model is established and validated. The relevant problems in the MT are analyzed by the experimental data. Second, the algorithms relevant to the torque distribution of the power source and the real-time discrete motor TCRL are designed from the kinematic and dynamic relationships of the powertrain at each stage. Considering model inaccuracies, system parameter uncertainties, and load changes, an ADFC is designed based on real-time robust drive shaft torque observer. Moreover, the optimal observer gain is obtained by genetic algorithm under the linear matrix inequalities (LMIs) restriction to improve the robustness of the observer. Finally, the simulation and experimental results indicate that the proposed TCRL-ADFC method can effectively reduce the powertrain shocks and improve the ride comfort.