Snap-on Incorporated
VEHICLE WHEEL ALIGNMENT SYSTEMS AND METHODS USING DRIVE DIRECTION

Abstract:

A vehicle wheel alignment system includes a pair of wheel mounted targets, a pair of reference targets mounted to a stationary reference, a pair of gravity sensors, and a pair of vehicle-mounted active heads mounted on first and second sides of the vehicle. The active heads each have an image sensor for producing image data of one of the reference targets and one of the wheel mounted targets. The gravity sensors are disposed on each side of the vehicle in a known relationship to either the respective reference targets or the image sensors. A data processor calculates, using the image data, a plurality of poses of the wheel mounted targets as the vehicle wheels rotate; calculates a vehicle drive direction using the target poses and a measured orientation relative to gravity from the gravity sensors; and calculates a wheel alignment measurement using the vehicle drive direction.