Effects of torque distribution on gear shift strategy for the planetary gearbox on multi-axles independent driving HEVs

On a multi-axles independent driving HEV, the engine distributes its torque via two routes. One route transfers the torque through a planetary gearbox, while the other through generator-motor system. In this paper, a model for multi-axles independent driving system was built. Under different torque distribution ratio, changes of joint working characteristics of the engine and the torque converter were investigated, and the impact on power shifting was studied. The results indicated that the impact of torque distribution ratio on power shifting points were complicated. Gear shift strategies considered the torque distribution ratio could effectively improve the power performance.