Design And Research Of EPB Controller Based On ISO26262 Standard

With the popularization of automotive electronic technology,the vehicle dynamics and handling stability have been greatly improved.At the same time,it brings more potential security risks.More and more vehicles have been recalled due to design defects and functional safety,which damages the brand image of automobiles and wastes great amounts of resources.For these reasons,the international automotive industry has launched ISO26262 standard.As a popular automotive electronic product,EPB provides convenience for drivers and improves the security of automobiles.Therefore,it is necessary to develop an EPB controller based on ISO26262 standard to improve the reliability and safety.This paper introduces ISO26262 standard “Road Vehicles-Functional Safety” and applies it to the design of EPB system.The risk analysis and assessment will also be conducted.Automotive Safety Integration Level(ASIL)and safety objectives were determined.These provide a theoretical basis for the design of functional safety of EPB controller.In this paper,a dual MCU scheme is proposed for the EPB system,which contained the core MCU and the monitoring MCU.The reliability of the system is enhanced.The working principle of EPB system was described.The minimum system,monitoring module,signal arbitration module,solenoid valve drive module were designed,which provide hardware support for the proposed security objectives.Then three-layer software of EPB system is described,which includes basic function layer,fault detection layer and monitoring layer.The basic function layer is then divided into components,and the software development was carried out using Matlab/Simulink.The fault detection layer is used for fault diagnosis strategy and processing mechanism,which mainly includes solenoid valve fault,CAN bus fault and angle sensor fault.The monitoring layer is used for monitor the operation of the core MCU.When the core MCU fails,the monitoring module detect the fault and replace the main MCU to achieve function failure safety.Finally,EPB function verification experiment and EPB safety test was carried out.The experimental result shows that the designed EPB controller not only meets the design requirements of the EPB system,the proposed control strategy can also detect faults accurately and respond in time.The EPB controller satisfies the proposed security objectives and improves the reliability of the EPB system greatly.