Abstract
The parallel hybrid configuration in which a clutch is installed between an engine and a transmission-mounted motor can improve efficiency on low load driving and regenerative braking by disengaging the clutch and realizing electric vehicle mode. In the electric vehicle mode, however, jerk can be induced since there are insufficient damping elements in the driveline. This study suggests the jerk reduction control strategy, composed of active damping and torque profiling method, to suppress the jerk without hardware modification. The former method creates a virtual damper by generating absorbing torque in the opposite direction of the oscillation induced by the jerk. The latter method reduces impulse on the mated gear teeth of the driveline by limiting the gradient of traction torque when the direction of the input torque is reversed. To validate the effectiveness of the suggested strategy, a series of vehicle tests are carried out and it is observed that the amplitude of the oscillation can be reduced by up to 83%.
Keywords: hybrid driveline, backlash, drivability, active damping, torque profiling