1993-11-01

Vehicle Stability Considerations with Automatic and Four Wheel Steering Systems 931979

Automatic and four wheel steering control laws are often developed from the performance point of view to optimize rapid response. Under linear tire operating conditions (i.e., maneuvering at less than .5g's) both performance and safety conditions can be simultaneously met. Under severe operating conditions, such as might be encountered during crash avoidance maneuvering, tire characteristics can change dramatically and induce directional dynamic instability and spinout. The challenge in automatic and four wheel steering system design is to achieve a compromise between performance and safety.
This paper will describe analyses carried out with a validated vehicle dynamics computer simulation that shed some light on the vehicle and control characteristics that influence tradeoffs between performance and safety. The computer simulation has been validated against field test data from twelve vehicles including passenger cars, vans, pickup trucks and utility vehicles. The simulation includes a very complete tire model for representing the effects of skidding under hard maneuvering conditions, and has been shown to properly represent spinout conditions that occurred during the validation field testing.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Improvement of Vehicle Dynamics by Vehicle-Speed-Sensing Four-Wheel Steering System

860624

View Details

TECHNICAL PAPER

The Development of an Experimental Four-Wheel-Steering Vehicle

860623

View Details

TECHNICAL PAPER

Online Estimation of Vehicle Stability Factor for Electronic Stability Control

2013-01-0690

View Details

X