Slip angle estimation for vehicles on automated highways

Lateral control of vehicles on automated highways often requires estimates of tire side-slip angle and lateral velocity, which are difficult to measure directly. Observers, which are designed to estimate lateral velocity, utilize the dynamic model of the vehicle with nominal values for tire cornering stiffness, vehicle mass and moment of inertia, and distances between center of mass and tires. Naturally, these observers depend on an accurate knowledge of these parameters, and are affected by variations in them. This paper uses appropriate approximations and proper sensor placement to estimate tire side-slip angles without reference to a dynamic model of the vehicle. The estimation technique is completely independent of all vehicle parameters. Experimental results are presented to verify the technique.