US Patent 7313869 Vehicle wheel alignment system and methodology

A hybrid wheel alignment system and methodology use passive targets for a first pair of wheels (e.g. front wheels) and active sensing heads for another pair of wheels (e.g. rear wheels). The active sensing heads combine image sensors for capturing images of the targets with at least one spatial relationship sensor for sensing a relationship between the active sensing heads. One or both of the active sensing heads may include inclinometers or the like, for sensing one or more tilt angles of the respective sensing head. Data from the active sensing heads may be sent to a host computer for processing to derive one or more vehicle measurements, for example, for measurement of parameters useful in wheel alignment applications.