Study On Functional Safety Technology Of Vehicle Control Unit System For Pure Electric Vehicle

Faced with enormous pressure of energy shortage and environmental pollution,pure electric vehicles have become one of the important directions for the automobile industry development.In a power train of pure electric vehicle,it usually includes some high-voltage components such as a power battery,a driving motor,etc.In order to achieve power,economy and safety properties of vehicle,a vehicle control unit(VCU)is needed to make each control unit in coordination.The VCU is the highest-level control unit and the ultimate operational carrier of the vehicle control strategy and a key component to actualize the coordination of a power system,which is equivalent to the “brain” of a pure electric vehicle.Therefore,it is necessary to ensure the functional safety of VCU to the greatest extent.The ISO26262,an international standard for functional safety of automotive electronic and electrical systems,has been released by International Standards Organization in November 2011.It provides guidance on the development and management of functional safety-related processes throughout the life cycle.The paper started from the key point of functional safety technology,and mainly focused on the following researches on the VCU system of pure electric vehicle:1.The basic composition and working principle of the vehicle control system were analyzed,and the key technologies of VCU were introduced.The research boundary and specific functions of VCU were defined,which laid the foundation for the researches about the technical development of functional safety of VCU.2.According to the functional safety standard ISO26262,the functional safety development of VCU system was studied and a layered architecture scheme of the VCU system was designed.Based on the technical safety requirements of the VCU system,corresponding safety mechanisms and safety monitoring functions were designed and evaluated.Then the hardware architecture platform of the dual MCU mechanism and the modular and structured software platform that conforms to the AUTOSAR architecture were designed for the VCU system,which improved the safety of the vehicle control system.3.From the perspective of function and control strategy,the VCU was studied.A fuzzy controller for regenerative braking force distribution was designed and utilizing ADVISOR simulation software,the braking energy feedback control strategy was simulated and verified under a certain cycle condition.And genetic algorithm has been used to optimize the fuzzy control membership function.4.According to the d SPACE,a VCU system functional safety hardware-in-the-loop test platform has been built.The functional safety goals and safety mechanisms of the VCU system were tested and verified.Nowadays,with the rapid development of new energy vehicles,it is necessary to study the functional safety technology of its core control unit-VCU.It is one of the future directions for the development of safer,more reliable and more environmentally friendly driving.