Road surface recognition and adaptive steering wheel torque compensation method based on rack force

Abstract

The invention discloses a road surface recognition and adaptive steering wheel torque compensation method based on rack force. The method comprises the steps of calibrating a reference curve, specifically, calibrating a reference rack force curve, calibrating a change factor of the rack force along with the vehicle speed, and calibrating a change factor of the rack force along with the steering speed of a steering wheel; then confirming that a triggering condition of rack force calculation is met and calculating the rack force; and achieving recognition of the low-adhesion-coefficient road surface for calculation of the vehicle speed, the steering wheel rotating angle, the rack force and the steering wheel rotating angle speed through input signals; and finally compensating the torque of the steering wheel in the mode of compensating the output torque of the motor when the judgment condition of the low-adhesion-coefficient road surface is met. According to the road surface recognitionand adaptive steering wheel torque compensation method based on the rack force, the problem that the hand force of the steering wheel is sharply reduced when a vehicle steers on a low-adhesion road surface can be solved, the operation that a driver turns too much or needs to repeatedly correct the steering wheel during steering is avoided, and the risk of traffic accidents is avoided.

Description

technical field [0001] The invention relates to the field of automobile driving safety, in particular to a rack force-based road surface recognition and adaptive steering wheel torque compensation method applied to an automobile steering system. Background technique [0002] At present, when it comes to car driving safety, it is usually divided into driver active factors and environmental road surface factors, and the environmental road surface factors usually refer to road conditions, weather conditions, etc., and these are usually fed back to the vehicle and the driver themselves through the road surface adhesion coefficient . [0003] The so-called road surface adhesion coefficient refers to the ratio of the adhesion force to the pressure in the normal direction of the wheel (that is, the direction perpendicular to the road surface). It can be regarded as the static friction coefficient between the tire and the road surface. The road surface adhesion coefficient is usuall...

AI Technical Summary

Problems solved by technology

[0013] In order to solve the problem that the torque of the steering wheel decreases sharply when the vehicle in the prior art turns on a road with a low adhesion coefficient, the driver will feel that the hand force is too light, and the feedback feel and road feel are poor. The present invention provides a rack-based The road surface recognition and adaptive steering wheel torque compensation method, the present invention does not require manual switching by the driver, the steering system adopting the present invention can automatically identify the low-adhesion road surface and automatically switch to the steering assist mode of the low-adhesion road surface

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