Sleeve motor steer-by-wire device and control method

Abstract

The invention discloses a sleeve motor steer-by-wire device and a control method. The steer-by-wire device comprises a steering wheel, a steering pipe column connected with the steering wheel, a leftside wheel steering transmission mechanism connected with a left side wheel, a right side wheel steering transmission mechanism connected with a right side wheel and a mechanical steering transmissionmechanism connected with the steering pipe column through an electromagnetic clutch. The steering pipe column is connected with a road sensing / assistant power motor through a reducer, the steeringdevice further comprises a steer-by-wire execution mechanism, the steer-by-wire execution mechanism comprises a first sleeve motor, a second sleeve motor and a planetary roller screw mechanism drivenby the first sleeve motor and / or the second sleeve motor. The sleeve motor steer-by-wire device adopts the double sleeve motors and the planetary roller screw mechanism, and sufficiently utilizes the axial spaces of a rack and a tie rod protective sleeve to reduce the radial sizes of the motors, is high in transmission efficiency, and liable to improve the driving consistency of the double sleeve motors when working with a heavy load.

Description

technical field [0001] The invention relates to the technical field of automobile parts, in particular to the automobile steering by wire technology. Background technique [0002] The intelligentization of automobiles is developing rapidly. Steering by wire is a key link in the development of intelligent automobiles, especially one of the necessary technologies for unmanned driving. The steer-by-wire technology has gradually matured and has been applied to a small number of models. The steer-by-wire system requires redundancy and fault-tolerant functions. Not only does it need to implement diagnostic and fault-tolerant control algorithms on the software, but it also requires redundant design of the hardware, which leads to complex hardware layout, high cost, and low hardware utilization of the steer-by-wire system. [0003] At present, there have been many researches on steering-by-wire technology. Among them, the dual-motor redundant steering-by-wire system designed by Inf...

AI Technical Summary

Problems solved by technology

Becker et al. proposed an electronically controlled hydraulic steer-by-wire system (patent number US20160068182A1). This device controls the pressure of the steering wheel cylinder through two motor pumps to drive the tie rods on both sides to move left and right, but the response speed of the motor to establish hydraulic pressure is slow. Unreliable factors such as increased oil leakage and air bubbles in the high-pressure oil pipeline, and the direct mechanical connection after the steering-by-wire failure cannot be realized

A hybrid steer-by-wire system (Patent No. 201610989594.2) invented by Yang Lin et al. In this system, the road sense motor and the power assist motor are separated, and only one set of steering executive motor is used to drive the double-row planetary gear reducer, which is then driven by the worm rack. The tie rod moves left and right, and the steering wheel and the steering wheel have real-time controllable force transmission characteristics and angle transmission characteristics. When the system fails, the clutch returns to the mechanical steering state, but the system has a complex structure and low transmission efficiency.

Yu Leiyan designed a steer-by-wire system and control method for electric vehicles (Patent No. 201310649410.4). The system designed a steering wheel force feedback motor and a worm reducer to simulate the road feel, and the steering motor and planetary gear reducer drive the steering gear. The gear realizes the steering, and the motor and the planetary gear reducer are installed near the steering gear, which needs to occupy more layout space, and the working efficiency of the motor is reduced through the transmission of the rack and pinion steering gear, and the steering mode in which the motor fails cannot be realized.

[0004] To sum up, the existing steering-by-wire system has contradictions between low transmission efficiency, complex structure, difficult space layout, and redundant and failure working mode requirements.

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