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This research focuses on an integration of two optimal tracking controllers, the active suspension controller and the rear-wheel steering controller, with the objective of improving vehicle performances in terms of maneuverability and safety by enhancing road holding capability and lateral stability. The active suspension controller adjusts the vehicle roll angle and utilizes the vertical force at each active suspension to boost road holding capability. On the other hand, the rear-wheel steering controller adjusts rear steering angles to use lateral force at each ground-tire contact point and amplify the vehicle’s ability to follow the desired yaw rate and sideslip angle during cornering maneuvers. Though the active attitude motion and mass shifting of car body may seem to hold relationship with lateral stability, its ability to evenly distribute vertical tire forces benefits the rear-wheel steering controller by enhancing the road holding capability.

As one of the key technologies for EVs and HEVs, the design of their motors has been researched extensively, and some novel rotors of permanent magnet motor were proposed in order to improve torque capability, including average torque and torque ripple. Rotor structure selection of drive motor for various electric vehicles has been one of the key issues in matching of electric vehicle power system. Three motors are analyzed for providing visible insights to the contribution of different rotor structures to the torque characteristics, efficiency and extended speed range. First, an iterative comparative analysis of torque-speed characteristics with different flux linkage, d-axis inductance and rotor saliency ratio is performed for demonstrating the design principle. Then, the three motors are optimized by a genetic algorithm (GA) for further improving the torque characteristics.