Abstract: A vehicle wheel service system including a plurality of sensors positioned in proximity to a heavy-duty multi-axle vehicle, to measure angles associated with three or more axles of the vehicle without repositioning the mounting of the sensors after initiating a measurement procedure. Additional sensors, associated with a vehicle reference, such as the vehicle frame axis, are disposed to provide vehicle reference measurement data which is communicated to a processing system. The processing system is configured with software instructions to evaluate the measurement data and to determine various vehicle wheel alignment angle measurements and/or necessary vehicle adjustments for each axle relative to the vehicle reference or to a fixed axle having a determined relationship to the vehicle reference.

Abstract: A process for calibrating and evaluating a machine-vision vehicle wheel alignment system having front and rear imaging components associated with each of the left and right sides of a vehicle support structure. Each pair of imaging components defines a front and rear field of view, with a common overlapping region associated with each respective side of the vehicle support structure. Optical targets disposed within each of the overlapping field of view regions are observed by the imaging components to establish performance ratings for the system as a whole, for groups of components within the system, and for individual components within the system.

Abstract: A procedure for measuring and adjusting an alignment of each axle of a trailer or semi-trailer while the trailer or semi-trailer is coupled to a tow vehicle by a hitch, tow bar, kingpin, or fifth wheel hitch. Measurements of the alignment of each axle of the trailer or semi-trailer are acquired from wheel-mounted sensor means utilizing either directly or indirectly a reference line of the trailer and an established reference point on the tow vehicle. A thrust angle of a first trailer or semi-trailer axle is referenced directly to the established reference line, while scrub angles associated with additional trailer or semi-trailer axles are referenced either directly or indirectly to the first trailer or semi-trailer axle, and indirectly to the established reference point. Any necessary adjustments are made to the first trailer or semi-trailer axle to bring the axle thrust angle to within a specification tolerance, and then to the scrub angle of each additional axle.

Abstract: A procedure for measuring and adjusting an alignment of each axle of a trailer or semi-trailer while the trailer or semi-trailer is coupled to a tow vehicle by a hitch, tow bar, kingpin, or fifth wheel hitch. Measurements of the alignment of each axle of the trailer or semi-trailer are acquired from wheel-mounted sensor means utilizing either directly or indirectly a reference line of the trailer and an established reference point on the tow vehicle. A thrust angle of a first trailer or semi-trailer axle is referenced directly to the established reference line, while scrub angles associated with additional trailer or semi-trailer axles are referenced either directly or indirectly to the first trailer or semi-trailer axle, and indirectly to the established reference point. Any necessary adjustments are made to the first trailer or semi-trailer axle to bring the axle thrust angle to within a specification tolerance, and then to the scrub angle of each additional axle.

Abstract: A method for characterizing the surface over which a vehicle is to be rolled during a rolling compensation procedure. A set of wheel alignment angle sensors are mounted to the rearmost fixed axle of a vehicle which is then backed onto the floor surface to be characterized, and rolled in reverse over the region of the floor surface generally traversed during a rolling compensation procedure. As the vehicle is rolled in reverse, a pair of wheel alignment angle sensors temporarily positioned at selected points on the floor surface measure a distance to the wheel-mounted alignment angle sensors, which in turn, are acquiring camber angle measurements. The resulting set of measurements is stored in an accessible data storage device, characterizing the camber altering contours of a path across the floor surface.

Abstract: A vehicle wheel service system including a plurality of sensors positioned in proximity to a heavy-duty multi-axle vehicle, to measure angles associated with three or more axles of the vehicle without repositioning the mounting of the sensors after initiating a measurement procedure. Additional sensors, associated with a vehicle reference, such as the vehicle frame axis, are disposed to provide vehicle reference measurement data which is communicated to a processing system. The processing system is configured with software instructions to evaluate the measurement data and to determine various vehicle wheel alignment angle measurements and/or necessary vehicle adjustments for each axle relative to the vehicle reference or to a fixed axle having a determined relationship to the vehicle reference.

Abstract: A method for compensating axial misalignment between wheel-mounted alignment sensors and an axis of rotation for an associated wheel. The method compensates sensors mounted to each wheel of a vehicle simultaneously, without requiring jacking of the vehicle wheels above a supporting surface, and which only requires wheel rotational movement over an arc of 60 degrees or less. The method utilizes measurements of a change in a wheel toe angle and measurements of a change in a wheel camber angle, during a measured rotational movement of the wheel, to identify sinusoidal variation in the respective toe and camber angles during the wheel's rotational movement, from which a measure of axial misalignment between the wheel-mounted alignment sensor axis of rotation and the wheel axis of rotation is identified.

Abstract: A system for target identification in a vehicle wheel alignment system includes first and second units. A target with at least four collinear reference points is attached to the first unit, and an image sensor is attached to the second unit. The collinear reference points have at least one known cross-ratio, and the image sensor has an imaging element that produces an image data-set to capture an image of the target. The system also includes a processor for identifying image points within the image data-set and for calculating vehicle wheel alignment information using the image data that corresponds to the target. To identify the image data corresponding to the target, the processor computes a series of cross-ratios for sets of four points within the image data-set and rejects noise points by comparing the cross-ratios to the known cross-ratio.

Abstract: A system for target identification in a vehicle wheel alignment system includes first and second units. A target with at least four collinear reference points is attached to the first unit, and an image sensor is attached to the second unit. The collinear reference points have at least one known cross-ratio, and the image sensor has an imaging element that produces an image data-set to capture an image of the target. The system also includes a processor for identifying image points within the image data-set and for calculating vehicle wheel alignment information using the image data that corresponds to the target. To identify the image data corresponding to the target, the processor computes a series of cross-ratios for sets of four points within the image data-set and rejects noise points by comparing the cross-ratios to the known cross-ratio.

Abstract: A method and apparatus for the calibration of vehicle wheel alignment sensors or optical targets and for the detection and correction of wear or damage to no-compensation type wheel adapters to which the vehicle wheel alignment sensors are attached during a vehicle wheel alignment procedure. A first aspect of the present invention is a method for electronically storing separate calibration values associated with a vehicle wheel alignment sensor or optical target for a variety of types of vehicle wheel adapters. A second aspect of the present invention is a method and apparatus for detecting and compensating for wear or damage to no-compensation type wheel adapters by utilizing a known flat surface against which the contact points of the adapter are placed, any misalignment of the sensor mounting shaft axis from the plane is detected and corrected for, either by adjustment of the contact points or by adjustment of the sensor mounting shaft.

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.

Abstract: A system for measuring angular relationships of wheels of a vehicle includes a radiation source mounted with respect to a first wheel for providing a radiation signal, an image detector having an active array of pixels mounted with respect to a second wheel for receiving an image from the radiation source and for producing an output in response to the radiation signal, and a radiation detector disposed in the path of the radiation from the radiation source for detecting the presence of the radiation signal. A controller is responsive to the presence of the radiation signal to activate the image detector to receive the image from the radiation source and determine an alignment angle of a wheel of the vehicle from the output of the image detector. A mask is mounted between the radiation source and the detector for defining an image of the radiation source upon the detector, the mask preferably having at least three slits therein.

Abstract: A system for measuring angular relationships of wheels of a vehicle includes a radiation source mounted with respect to a first wheel for providing a radiation signal, an image detector having an active array of pixels mounted with respect to a second wheel for receiving an image from the radiation source and for producing an output in response to the radiation signal, and a radiation detector disposed in the path of the radiation from the radiation source for detecting the presence of the radiation signal. A controller is responsive to the presence of the radiation signal to activate the image detector to receive the image from the radiation source and determine an alignment angle of a wheel of the vehicle from the output of the image detector.