Electric drive power assisted steering system capable of performing drive ratio variation control by motor and control method thereof

Abstract

The invention discloses an electric drive power assisted steering system capable of performing drive ratio variation control by a motor and a control method thereof. The invention relates to an electric drive power assisted steering system. The steering system comprises a steering wheel, a rack connected with the steering wheel by a steering column, a torque sensor positioned below the steering wheel, a power assisted motor connected with the rack by a reducing mechanism, a steering arm connected with the rack, and an electronic control unit (ECU). The steering system is characterized in that: the steering servo motor is arranged on the steering column between the torque sensor and the rack; and a stator and a rotor of the steering servo motor are respectively connected with the torque sensor and the steering column arranged above the gear rack. The invention is capable of realizing the functions of power assisted steering and active steering, and realizing the perfect integration of vehicle safety and mobility.

Description

technical field [0001] The invention relates to an electric power steering system, in particular to a new electric power steering system that relies on a motor for variable transmission ratio control, which can realize variable transmission ratio control and active steering intervention functions, and ensure that the road feel of electric power steering is not affected. Background technique [0002] The electric power steering system is a new and promising power steering system. It completely cancels the hydraulic components. The whole system is composed of a steering wheel torque sensor, a vehicle speed sensor, a controller, a power assist motor and its deceleration mechanism. The basic principle is that the controller receives the steering wheel torque signal and the vehicle speed signal, and after judgment and processing, outputs a control signal according to the pre-determined power boost characteristics, and controls the motor to output power boost torque. [0003] At p...

AI Technical Summary

Problems solved by technology

[0004] At present, there are also some documents and patents discussing the electric power steering system with variable transmission ratio. The utility model patent applied by Beijing Institute of Technology-electric power steering mechanism with coupling control of force and displacement (CN200820180655.1) proposes to add a set of planetary The gear mechanism and the active steering motor realize variable transmission ratio control and active steering intervention functions (patent application number 201010018342), but adding a planetary gear mechanism will make the steering system very cumbersome, and the installation on the steering column is also difficult

Images