Self-driving automobile EPS system based on function safety design and design method thereof

The invention relates to an automatic driving automobile EPS system based on functional safety design and a design method thereof.The system comprises a steering wheel, the steering wheel is connected to a universal joint through a tubular column, the universal joint is connected to an automobile chassis, a steering gear and a power-assisted motor are installed on the automobile chassis, and the power-assisted motor is connected with an EPS controller and automobile wheels; and the EPS controller is connected with an angle/torque sensor and a vehicle state acquisition unit and is used for controlling the power-assisted motor to output corresponding torque and driving wheels to complete steering action. The design method comprises the steps of adopting an HAZOP method, referring to a function failure guide word in SAE J2980, determining a function failure condition and correspondingly caused vehicle-level harm, completing harm analysis and risk assessment, determining an ASIL level, further determining a funct