FLY RUN-OUT CORRECTION FOR VEHICLE WHEEL ALIGNMENT

摘要

Abstract of the DisclosureIn a wheel alignment system, the error causedby run-out of the axis of a fixture that is clamped tothe wheel and mounts gravity stabilized inclinationsensors is corrected by continuously providing fixtureaxis inclination signals during rotation of the wheelthrough at least 360° from any random starting position.Maximum and minimum comparator devices continuouslyreceive these signals, and the signals are also pre-sented to associated maximum and minimum storage latchdevices connected to their respective comparators. Themaximum signal comparator provides a load signal to itsstorage device whenever the signal received by thecomparator from a sensor is greater than that previouslyreceived by the maximum storage device whereby themaximum signal storage device stores the maximum fixtureaxis inclination signal. The minimum comparator deviceprovides a load signal whenever the signal receivedfrom a sensor is less than that previously received bythe associated minimum signal storage device wherebythe minimum storage device stores the minimum inclina-tion signal, A first adder adds the maximum and minimumsignals and divides them by 2 to provide a preliminaryalignment signal proportional to the actual angularinclination of the wheel axis in a selected alignmentplane, and the perliminary alignment signal is sub-tracted from an intermediate inclination signal from thesensor that represents the inclination of the fixtureaxis at the wheel stopped position to provide a run-outerror signal proportional to that portion of the total-1a-angular run-out of the fixture axis that is present ina selected alignment plane at the wheel stopped position.When the wheel is set down, a final inclination signalis received from the sensor means and the run-out errorsignal is subtracted therefrom to provide an inclinationsignal that represents the true wheel axis inclinationin a selected aligmnent plane corrected for run-out error,and this signal is displayed for wheel alignment pur-poses. The sensors measure run-out errors in both thecamber and toe planes and provide separate displays forthe alignment in both planes. The maximum and minimuminclination signals are provided by maximum and minimumdigital comparator and signal storage devices as wellas by digital adding and other devices with suitableconverters for supplying the digital devices with 8 bitsof binary digital information.-1b-