Performance Investigation of Torque Vectoring Topologies for Electric Vehicles' Motorway Tire Fault Conditions

This work investigates the effectiveness of a torque vectoring (TV) system related to an electric vehicle with different tire pressure loss fault conditions in motorway environments. Two different TV topologies are implemented based on a car vehicle dynamics mathematical model with only 7 Degrees of Freedom (DoF) and they are verified with - a 24 DoF car dynamics model developed in MSC ADAMS. Both models have control inputs from MATLAB/Simulink environment. The study reveals a different car behavior between the front and rear axles when identical tire pressure loss is present. Also, the validity of the simple 7 DoF model described within this study at specific tire fault conditions can be used for control algorithms that require a real-time (computationally efficient) car vehicle dynamics model. The topologies are represented as the vehicle model variants, where the first contains two electric motors (one per axle). The second variant has three electric motors, where the rear axle is equipped with two independent motors. A Proportional-Integral-Derivative (PID) control algorithm methodology is used, so, the effectiveness of the torque vectoring topologies can be evaluated for both the 7 DoF and MSC ADAMS car vehicle dynamics model. The results show that both topologies managed by the PID control algorithm methodology significantly reduce the vehicle trajectory deviation under arisen tire pressure fault conditions. Nevertheless, the variant with three motors ensured better response to yaw rate and slip angle errors and the trajectory deviation was smaller in all failure modes. The 7 DoF has similar results with MSC ADAMS model related to yaw rate correction, and comparable results for lateral deviation in both motor topologies, but is not as effective related to sideslip angle.