Torque vectoring and rear wheel steering conrol to improve handling dynamics of an electric vehicle

This thesis investigated the potential for improving the handling and stability of electric vehicles through the combined use of rear-wheel steering (RWS) and torque vectoring control (TVC) systems. A non-linear vehicle model with combined tyre slip effects was used in this study. RWS and TVC systems were designed and optimized for different drive modes using proposed optimization methodologies. An Integrated Chassis Lateral Controller (ICLC) system was developed to coordinate the control of RWS and TVC systems. The proposed systems were evaluated regarding vehicle handling and stability through open and closed-loop test scenarios. Practical implications for offline optimization of advanced vehicle control systems were highlighted, paving the way for enhanced handling performance and improved driving experience in electric vehicles. Firstly, considering their characteristics and limitations, RWS and TVC systems were designed and optimized for different drive modes. Proposed optimization methodologies were applied to determine the optimal parameters for these systems, aiming to enhance the handling performance of electric vehicles. An ICLC system was then developed to coordinate the control of optimum RWS and TVC systems, enabling seamless integration and coordinated control of these systems for improved lateral dynamics and handling performance. The proposed systems were evaluated through open and closed-loop test scenarios to assess their effectiveness in enhancing vehicle handling and stability. The results showed that using RWS and TVC systems in an electric vehicle can significantly improve its lateral dynamics, enhancing handling performance and stability. The findings of this thesis have practical implications for the offline optimization of advanced vehicle control systems. The optimized RWS and TVC systems, along with the integrated ICLC system, provide insights into how these systems can be effectively optimized to enhance the handling performance of electric vehicles. Further research is suggested to explore more intelligent control methods in a more centralized approach, evaluate energy-efficient modes for both RWS and TVC systems, and conduct actual vehicle tests to verify critical safety points. Additionally, the potential conflicts and challenges of decentralized control of RWS and TVC systems should be addressed in future research. In conclusion, the findings of this thesis provide insights into the potential combined usage of RWS and TVC systems for improving lateral dynamics in electric vehicles, contributing to the advancement of electric vehicle technology, and providing a foundation for future research in vehicle dynamics and control.