Motor position detection circuit of electric power steering system

Abstract

The invention discloses a motor position detection circuit of an electric power steering system. The motor position detection circuit of the electric power steering system comprises a rotary transformer, a phase line relay, a rotary transformer decoder chip, a main MCU (microcontroller unit) and an auxiliary MCU, wherein the rotary transformer is used for obtaining the position of an assist motor; the phase line relay is used for being connected or disconnected so as to respectively control the assist motor to provide or not to provide assisting torque; the rotary transformer decoder chip decodes analog signals output by the rotary transformer into digital signals and meanwhile transmits the digital signals to the main MCU and the auxiliary MCU; the main MCU dependently collects data output by the rotary transformer decoder chip, obtains the position of the assist motor through calculation, also collects MCU-calculated position of the assist motor and also controls the connection and the disconnection of the phase line relay; the auxiliary MCU dependently collects data output by the rotary transformer decoder chip and obtains the position of the assist motor through calculation; the phase line relay is closed by default; once the motor position calculated by the main MCU is not in accordance with that calculated by the auxiliary MCU, the main MCU disconnects the phase line relay. The motor position detection circuit of the electric power steering system can recognize conditions such as parallel port faults and MCU software errors.

Description

technical field [0001] The present application relates to an electric power steering system (Electric Power Steering, EPS system for short) of an automobile, in particular to a motor position detection circuit therein. Background technique [0002] see figure 1 , which is the mechanical steering system on the car. It includes a steering wheel 11 , a steering column 12 , a steering gear 13 , a steering tie rod 14 and steering wheels 15 . The driver applies steering torque to the steering wheel 11, and the steering torque is input to the steering gear 13 through the steering column 12, and the amplified torque and decelerated motion of the steering gear 13 are transmitted to the steering rod 14, thereby driving the steering wheels 15 to move. [0003] see figure 2 , which is the electric power steering system on the car. On the basis of the mechanical steering system, it adds: [0004] ——The torque angle sensor 21 is used to detect the torque and the angle of rotation of...

AI Technical Summary

Problems solved by technology

[0017] The interior of the resolver decoding chip 231 has a certain diagnostic function for the analog signal output by the resolver 241, but if the parallel port between the resolver decoding chip 231 and the MCU 232 breaks down, or the processing of the parallel port inside the MCU232 occurs If the software is wrong, the MCU 232 still cannot obtain the correct motor position

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