15-06-2010, 05:20 PM
Abstract :
Four wheel steering is a system that allows the rear wheels to turn for maneuvering, rather than just following the front wheels. It is a relatively new technology that improves maneuverability in cars, trucks and trailers. At higher speeds, the rest wheels steer in the same direction as the front wheels. The result is more stability and less body lean during fast lane changes and turns because the front wheels donâ„¢t have to drag non-steering rear wheels onto the path.
For parking and low-speed maneuvers, the rear wheel steer in the opposite direction of the front wheels, allowing much sharper turns. It should not be confused with four-wheel drive in which all four wheels of a vehicle are powered. In standard two wheel steering vehicles, the rear set of wheels are always directed forward and therefore do not play an active role in controlling the steering. In four-wheel steering systems, the rear wheels can turn left and right. To keep the driving controls as simple as possible, a computer is used to control the rear wheels.