Model development for hybrid electric vehicle stability assist systems

The focus of current research towards electric, hybrid electric, and fuel cell{09} vehicles has been on increasing energy efficiency and reducing emissions. Future vehicles will include electric drive-train components that must be capable of performing conventional anti-lock braking, traction control, and active yaw control safety functions. A vehicle dynamic modeling tool is needed to help develop control algorithms, vehicle specifications, and components for these future electric based vehicle safety systems. This study expands a comprehensive dynamic vehicle model (HVOSM) to include realistic electric component models and the ability to simulate various configurations of electric, hybrid electric, and fuel cell vehicles along with their control algorithms. The new model, Hybrid Electric Vehicle Dynamic Environment, Virtual (HEVDEV) was used to simulate an electric based stability system implemented in a range extending series hybrid electric vehicle. A hybrid Vehicle Stability Assist (VSA) algorithm was developed to blend conventional hydraulic brakes with front wheel motor drive and regenerative braking functions. Skid pad testing was performed to validate steady state simulations of standard J-turn maneuvers. The validated vehicle model was used to develop Hybrid VSA control parameters. Further simulations predicted successful vehicle safety system performance during dynamic step steer and braking in a turn test procedures. Conclusions were drawn about the Hybrid VSA stability system and vehicle components specifications. Researchers and designers may use the new model to develop control algorithms and vehicle components for future hybrid electric and fuel cell vehicles while considering both fuel economy and stability systems requirements.