The invention discloses a multi-
mode switching control method and
system of an
electric power steering system. The method comprises the following steps that (S1), a vehicle
steering wheel torque and rotary angle and vehicle speed information are obtained, and a
control mode is selected; (S2), a fuzzy switching controller is designed, and the output current is worked out according to the target current and the
weight coefficient; (S3), the differential and the second-order differential of the output current are calculated, an
extension set relevant to the feature state is built, and regional division is conducted; and (S4), the fuzzy switching controller is subjected to functional improvement on the basis of an
extension theory, different control methods are set in different regions of the
extension set, the
correlation function is built, the condition that the output current locates in which region of the
extension set is judged, and the optimized
electricity quantity is input into a motor. According to the multi-
mode switching control method and
system of the
electric power steering system, the target current is optimized according to different adopted control strategies at different current set states, so that the better control property is obtained, and EPS multi-mode smooth switching is achieved.