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International Journal of Automotive Technology

, Volume 20, Issue 4, pp 827–834

# Analysis of Steering Returnability and Compensation Logic Developmet in Limit Cornering Condition

• Han Seung Lee
• Dae Suk Jung
• Jae Kil Lee
Article
• 3 Downloads

## Abstract

This paper describes steering returnability by analyzing forces applied to kingpin axis in limit cornering conditions. The steering returnability is related to forces applied to kingpin axis. These forces are classified by its source: Tire force and steering force. Tire force is generated from tire such as longitudinal, lateral, vertical force, and residual self-aligning torque. Steering force consists of friction force and assist force. These forces are vectorized by suspension geometry and calculated with respect to kingpin axis. The simulation results are compared with measurement data and verifies that steering returnability can be formulated by tire forces and steering forces. Using these relations, this paper proposes new steering control logics at limit driving conditions. This logic is verified by simulation model to check performance and confirmed in various test conditions for robustness.

## Key Words

Steering system Suspension system Kinematics mechanism Geometry Returnability Kingpin axis

## Nomenclature

M

vehicle mass on front axle, kg

CGH

height of center of gravity, m

Rtire

radius of tire, m

Tengine

engine torque, Nm

ngear

gear ratio, −

η

drive-train efficiency, %

TBR

differential torque bias ratio, −

Slip

tire slip ratio, −

c, cw

caster trail, wheel center caster trail, m

t

pneumatic trail, m

d, dw

kingpin, wheel center kingpin offset, m

ay

lateral acceleration, m/s2

ξ

caster angle, deg

ζ

kingpin angle, deg

θ

tire steer angle, deg

Fx, Fy, Fz

element of tire force, N

Mcomp

aligning torque by components, Nm

μ

friction coeffient of road surface, −

## Subscripts

P

Fz position vector

L

Fy position vector

W

Fz position vector

u

kingpin axis unit vector

A

kingpin axis vector

Br, Dr

stiffness, peak factor in magic formula

Kxk, Kya

longitudinal, lateral slip stiffness in magic formula

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## References

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© KSAE 2019

## Authors and Affiliations

1. 1.High Performance Vehicle Chassis Engineering Design TeamHyundai Motors CompanyGyeonggiKorea