Electric power-assisted steering system of electric vehicle and power-assisted steering method thereof

Abstract

The invention provides an electric power-assisted steering system of an electric vehicle. The electric power-assisted steering system comprises an electric power-assisted steering controller, a power-assisted electromotor, an electromagnetic clutch, a speed changer and a torque sensor which is arranged on an input shaft of a steering gear of the electric vehicle, wherein an input end of the speedchanger is connected with a steering wheel of the electric vehicle by an input shaft; an output end of the speed changer is connected with a cardan joint by an output shaft; the cardan joint is also connected with a wheel gear which is meshed with a rack; the rack is connected with wheels of the electric vehicle; the power-assisted electromotor is connected with the electromagnetic clutch which is also connected with the speed changer; an output signal of the torque sensor, an output signal of a vehicle speed sensor of the electric vehicle and an output signal of a revolution speed transducerof a driving motor of the electric vehicle are respectively connected with an input end of the electric power-assisted steering controller; and an output end of the electric power-assisted steering controller is respectively connected with the power-assisted electromotor and the electromagnetic clutch.

Description

technical field [0001] The invention relates to a device in an electric vehicle, in particular to an electric power steering system of an electric vehicle and a steering assist method thereof. Background technique [0002] At present, the power steering system used in automobiles driven by gasoline and diesel is relatively mature, such as a "hydraulic power steering booster" disclosed in Chinese patent document 99247185.0, which mainly includes a slide valve, a piston sleeve and a housing, and five The oil chamber, the oil inlet chamber is located between the propulsion oil chamber and the return oil chamber and communicates with the oil inlet through the oil passage, the propulsion oil chamber communicates with the left oil chamber of the oil cylinder, and the return oil chamber communicates with the right oil chamber of the oil cylinder, respectively set in the propulsion The two oil return chambers on the side of the oil chamber and the return oil chamber communicate with...

AI Technical Summary

Problems solved by technology

[0003] The invention mainly solves the technical problems of the original electric vehicle that the steering is laborious when driving at low speed, and the steering is unstable and has a fluttering feel when driving at high speed; it provides an electric power steering system and a steering assist method for an electric vehicle, which can The torque signal, the vehicle speed signal and the speed signal of the drive motor control the power-assisted motor and the electromagnetic clutch, so that the steering gear of the electric vehicle can turn lightly when the electric vehicle is low-speed, and the steering stability of the electric vehicle is improved when the electric vehicle is high-speed, and the driver does not feel fluttering.

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