US Patent 7908751 Method for optical chassis measurement

For optical chassis measurement of motor vehicles at a testing site that has at least one measuring unit having at least two imaging devices associated with one another in position and location, the measuring units are oriented with respect to the testing site with reference characteristics located fixedly at the testing site, evaluation in an evaluation device is effected on a basis orientation data and associated data obtained, for determining chassis data of a motor vehicle, in addition to the reference characteristics located fixedly at the testing site, at least one reference device is positioned which is usable in mobile fashion at the testing site with reference characteristics, and with a totality of reference characteristics in the evaluation device, the orientation data and the association data of the measuring units are obtained, and thus a common measuring station coordinate system is defined.