Engine Speed Regulation During Gear Shift Process of Torque Decoupled HEV Using Triple-Step Nonlinear Method

Abstract

For the torque decoupled hybrid electric vehicles (HEVs) equipped with automated manual transmission (AMT), the motor torque can be used to compensate for traction loss during gear shift. Thus, engine speed regulation can be used to achieve speed synchronization, and the clutch can be removed, which simplifies the overall structure of AMT. A triple-step nonlinear method is proposed in this paper to improve the engine speed tracking accuracy, which utilizes the steady-state, reference trajectory dynamics, and the tracking error information comprehensively. By the expense of the intake manifold pressure tracking performance, the developed controller can guarantee the asymptotic convergence of the engine speed tracking error. After the triple-step controller is deduced, it is verified through co-simulation between AMT HEV plant model in AMESim and controller model in Simulink. The simulation results demonstrate that the proposed controller can exert the advantages of the two control inputs: throttle opening α and spark advance deviation Δθ, and certificate the overall gear shift quality, including shift time and vehicle jerk.