Active geometry control suspension system for the enhancement of vehicle stability

Abstract

The active control of suspension geometry has historically been a challenging perspective for chassis teams of worldwide automakers. Manufacturers and suppliers have offered different solutions, but few have succeeded in combining a marked improvement in handling performance, low-energy consumption, simplicity, and low cost.

The new and revolutionary approach of an active geometry control suspension (AGCS) reinvents the possibilities of rear-suspension active toe control. This system employs the use of the complexity of a rear multi-link suspension, and a clever design layout to minimize the energy use. Additionally, because of an efficient control logic strategy, the vehicle-handling performance and stability are substantially improved. The system is the most successful in controlling vehicle transient situations initiated mainly by aggressive lane-change manoeuvres at medium to high speeds.

This paper presents the most relevant actions of the development process of the AGCS. The use of different evaluation methods and accurate measurement equipment was crucial for optimization of the system. The methods presented combine subjective evaluations in different road conditions (icy, wet, and dry asphalt), suspension kinematics and elastokinematics characterization, and objective road measurements using dynamic wheel position measurement equipment.

Finally, a comprehensive summary of the handling-test results are explained, which outline the efficiency of the system, and its influence on the active safety level of the vehicle.

Keywords

active toe control handling performance stability road objective evaluation methods kinematics and compliance testing dynamic wheel position measurement

Get full access to this article

View all access options for this article.

References

Lee

U. K.

Vehicle suspension note (1) (in Korean). In Proceedings of the KSAE Conference on Vehicle dynamics, 1997, p. 29 (Korea Society of Automotive Engineers, Seoul).

Gillespie

T. D.

Fundamentals of vehicle dynamics, 1992 (SAE International, Warrendale, Pennsylvania).

Namio

Junsuke

4WS technology and the prospects for improvement of vehicle dynamics. SAE Paper 901167, 1990.

Sano

Furukawa

Shiraishi

Four wheel steering system with rear wheel steer angle controlled as a function of steering wheel angle. SAE Paper 860625, 1986.

Jang

J. H.

Kim

S. H.

Han

C. S.

Development of the dynamic model and control logic for the rear wheel steering in 4WS vehicle (in Korean). Auto J. (J. KSAE), 1995, 4, 39.

Lee

Sung

Lee

The development of active geometry control suspension (AGCS) System. SAE Paper 2005–01–1927, 2005.

Lee

U. K.

Four-wheel steering system for vehicle. US Pat. 5,718,304, 1998.

Lee

U. K.

Suspension system for vehicles US Pat. 6,182,979, 2001.

Lee

U. K.

Lee

S. H.

Català

The development of AGCS (active geometry control system) for the new Hyundai Sonata. In Proceedings of the FISITA World Automotive Congress, Yokohama, Japan, 22–27 October 2006, Paper F2006V223.

10.

10 ISO 4138: 2004. Passenger cars-steady state circular driving behaviour - open loop test methods, 2004 (International Standardization Organization, Geneva).

11.

11 ISO 7401: 1988. Road vehicles - lateral transient response test methods, 1988 (International Standardization Organization, Geneva).

12.

12 ISO/TR 3888:1975. Road vehicles - test procedure for a severe lane-change manoeuver, 1975, p. 458 (International Standardization Organization, Geneva).

13.

13 ISO/TR 8726:1988. Road vehicles - transient open-loop response test method with pseudo-random steering input, 1988 (International Standardization Organization, Geneva).

14.

Inagaki

Kshiro

Yamamoto

Analysis on vehicle stability in critical cornering using phase plane method. In Proceedings of the Second International Symposium on Advanced Vehicle Control (AVEC 94), Tsukuba, Japan, 24–28 October 1994, pp. 287–292.