A four wheel steering (4WS) control strategy is derived and evaluated
using a nonlinear vehicle model along with a nonlinear tire model. The
vehicle model used is a three degree-of-freedom model. Yaw rate, late
ral velocity and longitudinal velocity are considered with the roll ef
fects included in the calculation of the normal loads for each of the
four wheels. These normal forces are used in the tire model to calcula
te the tire forces and moments for each wheel. The results of simulati
on indicate the potential benefits gained by using 4WS. These benefits
include stability and performance at high speeds and maneuverability
at low speeds.