A Method for Balancing Hybrid Torque-Vectoring Differential (H-TD) System with Optimized Counterweight

Abstract

Hybrid torque-vectoring differential (referred as H-TD hereafter) is a differential system which integrates both torque-vectoring and electric hybrid functionality. The system is basically based on a conventional open differential and utilizes an electric motor to differentiate torque between two output shafts or to provide additional driving torque. However, the mechanism of the system inevitably gives rise to different equivalent rotational inertia of two output shafts, which might cause asymmetric traction force condition on two output wheels. So, this paper aims to give a solution to minimize the above-mentioned situation. Firstly, the constitution of H-TD mechanism, and operation modes of the system are introduced. After that, the cause of the unbalanced situation is discussed and a solution combining a counterweight and optimization design is proposed. Regarding the optimization design, the dynamic model is established to formulate the optimization problem, and the design constraints are defined. Lastly, Genetic Algorithm method is used to solve the optimization problem and the effect of the proposed solution is verified by using numerical simulation.