Abstract:
A method for distance calibration of machine vision optical targets and associated observing imaging sensors using separation distances between discrete surface measurement points. First, a spatial position for each surface point is established from a series of observations by the associated observing imaging sensor of the optical targets mounted to a calibration fixture. Second, measures of a linear separation distance between particular pairs of surface points are identified independently from the machine vision observations. All resulting spatial positions and measurements are conveyed to a processing system configured with a set of software instructions for carrying out distance calibration calculations to establish a set of refined distance calibration parameters associated with each combination of optical target and observing imaging sensor. During subsequent use of the machine vision vehicle service system, the parameters are retrieved and utilized to improve vehicle measurement precision.
Abstract:
A vehicle service system and method to determine spatial parameters of a vehicle, employing a display system under processor control, to display or project visible indicia onto surfaces in proximity to a vehicle undergoing a safety system service or inspection identifying one or more locations, relative to the determined vehicle centerline or thrust line, at which a calibration fixture, optical target, or simulated test drive imagery is visible for observation by a sensor onboard the vehicle.
Abstract:
A vehicle service system configured to modify an ongoing vehicle service procedure in response to changes in vehicle wheel alignment angles which alter the vehicle tracking, thrust line, or thrust angle, in a manner which will affect the operation of an onboard vehicle safety system sensor which is aligned or calibrated relative to a selected characteristic of the vehicle.
Abstract:
A procedure for calibrating a vehicle onboard sensor 202 by facilitating the placement of a calibration fixture 110 on a floor relative to a stationary vehicle 100 using a laser emitter 102 secured to a front steerable wheel 104 of the vehicle on the same lateral side as the vehicle onboard sensor. A beam projection axis X of the laser projector is aligned at a known orientation relative to a geometric characteristic of the vehicle 100, such that the beam projection axis X is directed over a placement location P of the calibration fixture on the floor, either inherently or by guided steering of the supporting steerable wheel. A distance between the calibration fixture 110 and a reference point associated with the vehicle 100 is measured, and a current position of the calibration fixture on the floor along the beam projection axis X is adjusted as required to position the calibration fixture for calibration of the vehicle sensor 202 at a selected distance from the reference point along the beam projection axis X,
Abstract:
An on-car brake lathe is provided with a runout compensation system configured to monitor the rotational position of a pair of slant discs within an aligning joint of the on-car brake lathe. The system monitors the amount of runout present between the rotating components of the on-car brake lathe and the wheel hub to which the on-car brake lathe is secured. The system calculates the appropriate rotational position for each slant disc within the aligning joint required to impart a necessary adjustment in the wheel coupling rotational axis in order to align the on-car brake lathe with the rotational axis of the wheel hub. Finally, an adjustment mechanism is activated to rotationally drive each slant disc directly to the calculated rotational position with a minimum amount of rotational movement based on the current rotational position of each slant disc and the required calculated rotational positions.
Abstract:
A vehicle wheel balancer system having a processing system and a spindle shaft upon which a vehicle wheel assembly is mounted for measurement of imbalance characteristics and forces. The processing system is configured with software instructions to evaluate the remaining imbalance present in a vehicle wheel assembly following the application of imbalance correction weights, and to determine if the remaining imbalance is the result of the vehicle wheel assembly having deviated from an expected rotational position during the time between the measurement of the imbalance and the application of the imbalance correction weights. In the event of such a deviation, the processing system is further configured to provide the operator with a suitable warning to evaluate and correct the mounting of the vehicle wheel assembly before proceeding to rebalance or re-measure the vehicle wheel assembly.
Abstract:
A method for contactless measurements of a vehicle wheel assembly by acquiring a sequence of images as the vehicle wheel assembly moves within a projected pattern of light. Images of the vehicle wheel assembly are acquired and processed to identify the portions of the images corresponding to the wheel assembly, such as by recognition of the wheel rim edge. The identified portion of each image is cropped and a resulting point cloud of data rotational aligned by an optimization procedure to remove the effect of wheel translation and rotation between each image, as well as to identify a center of rotation and amount of rotation for each image which yields a best-fit result. Superimposing the resulting point clouds produces a generated image with a high density of data points on the optimally fit surfaces of the wheel assembly, which can be used to further refine the axis of rotation determination.
Abstract:
An imaging sensor observes a field of view through which a vehicle passes, at an orientation and position suitable for acquisition of license plate data from a surface of the vehicle. Responsive to the vehicle position, at least one image of a surface of the vehicle including a license plate is acquired and evaluated to extract license plate data. The position of the vehicle for acquisition of the image is established by a trigger in a fixed relationship with the imaging sensor.
Abstract:
A method for detecting the occurrence of deviations from level, straight-line rolling movement of a wheel assembly across a supporting surface during a rolling compensation procedure associated with a vehicle wheel alignment measurement or inspection system by identifying changes in measurements or calculated parameters associated with the wheel assembly which would be unchanged during an ideal level and straight-line rolling movement. Identified changes in the measurements or calculated parameters are evaluated to either warn an operator of the occurrence of a deviation, or to generate a correction factor to account for at least a portion of an effect which the deviations introduce into compensation calculations or subsequent wheel alignment measurements or service procedures.