Motor protection method and device for electric power steering system

Abstract

The embodiment of the invention provides a motor protection method and device for an electric power steering system, and the method comprises: multiplying a target auxiliary steering torque by a torque gain coefficient, and obtaining a corrected target auxiliary steering torque, wherein the calculation process of the torque gain coefficient comprises the following steps: detecting that the hand torque of a driver for operating a steering wheel is greater than a preset first torque value; and after a period of time, gradually reducing the corrected target auxiliary steering torque by graduallyreducing the torque gain coefficient, so that the current of the motor is not kept at a relatively large value for a long time no matter whether the current is blocked by a hard object or the steeringwheel reaches a tail end area, and the burnout risk of the motor is reduced. Furthermore, a protection method based on a steering wheel angle signal is combined with a protection method based on manual torque, multiple protection of the motor is achieved, and the risk that the motor is burnt out when the steering wheel reaches the tail end area is reduced.

Description

technical field [0001] The present invention relates to the technical field of electric power steering systems of vehicles, and more specifically, relates to a motor protection method and device of electric power steering systems. Background technique [0002] Electric Power Steering (EPS) detects information such as the driver's hand torque, vehicle speed, and steering wheel angle, and uses a certain control algorithm to drive the motor to provide auxiliary steering torque, so as to realize the convenience and stability of the steering wheel. Sexual control system. Generally, in the steering system, as the steering wheel is gradually turned to the left and right end positions, the resistance of the entire steering system will increase accordingly, or when the tires encounter obstacles, the resistance of the steering system will also increase. Therefore, when the steering wheel is close to the end, or encounters an obstacle, if no measures are taken, the motor will provide ...

AI Technical Summary

Problems solved by technology

Although this method can realize the protection of the motor and the terminal mechanical parts, it also has certain disadvantages. For example, when the wheel stops on the road shoulder or is blocked by a hard object, when the driver keeps turning the steering wheel in the direction of the obstacle, the steering wheel will It has not entered the end, but there is a large resistance in the steering system, the motor will continue to run with a large current, and it is easy to burn the motor

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