US 5,519,489 A · Vehicle alignment system

Abstract

An improved vehicle alignment system includes automatic angle and distance range calibration whereby various vehicle distances such as track width and wheelbase may be measured electro-optically during the alignment process. The system also includes an improved process which results in shorter measurement cycles for the sensors by utilizing an electronic shutter control. The sensors work in pairs, and a novel synchronization scheme is used to ensure that the emitters of one sensor are not radiating at the same time the emitters of the other sensor of that pair are radiating and to determine which emitter of the pair corresponding to a sensor is radiating. Reflections of the emitters from nearby surfaces are discriminated from direct transmissions so that the angle of incidence is accurately determined. Moreover, determination of the angle of incidence is simplified by use of a lens whose image position varies in a specific manner as the imaged object moves radially away from the axis of the lens. The present system is particularly suited for measuring difficult alignment measurements such as toe-out on turns electro-optically with a minimal number of sensors.

Claims15

Dependent claims

In a method of electronically determining distances in connection with servicing of a vehicle, the method of calibrating a sensor comprising:

fixing a sensor at a first known distance from a pair of radiation sources, said pair of radiation sources being separated by a second known distance from each other, said sensor having an image detector mounted a fixed distance behind an image forming element;
causing images from the pair of radiation sources to fall upon the image detector;
measuring the spatial separation on the image detector of the images created by the pair of radiation sources;
determining from said spatial separation and the known first and second distances a calibration factor for the sensor.

1 more element

A vehicle wheel aligner comprising:

a first unit for attachment to a first wheel of a vehicle, said first unit including a first pair of radiation emitters and a first modulation detector;
a second unit for attachment to a second wheel of a vehicle, said second unit including a second pair of radiation emitters and a second modulation detector;
said first modulation detector detecting modulation in the radiation from the second pair of radiation emitters, and the second modulation detector detecting modulation in the radiation from the first pair of radiation emitters;
a first image detector mounted on the first unit for receiving an image from the radiation emitters of the second unit;
a second image detector mounted on the second unit for receiving an image from the radiation emitters of the first unit;
a first synchronizing controller operatively connected to the first modulation detector for synchronizing the output of the first pair of radiation emitters so that said first pair of radiation emitters emit radiation only during periods of time when the second pair of radiation emitters are not emitting radiation;
means responsive to the image received by at least one of the image detectors to determine vehicle alignment information for the vehicle.

4 more elements

Dependencies are inferred from the claim text.

Vehicle alignment system

Life of this patent

Vehicle alignment system

Life of this patent

Abstract

Claims15