Abstract: A tire changing machine including enhanced control features for automated operator of tire change procedures with operator oversight and ability to manually adjust machine operation when desired. Dead man control input, user interfaces and programs for implementing the interfaces, methods for completing tire bead seating, informational displays of wheel rim and tire information, coordinated tool positioning, and automated lubrication features are described.

Abstract: A method and apparatus for carrying out auto-calibration of one or more piezoelectric elements in a force transducer assembly of a vehicle wheel balancing system. Output electrical signals from the piezoelectric transducers in response to application of a known imbalance force are measured and recorded. Subsequently, during an auto-calibration procedure, a known input signal is selectively applied to at least one piezoelectric element in the force transducer assembly, and at least one output electrical signal is received from the force transducer assembly. The obtained auto-calibration output signals are evaluated with respect to the output signals obtained from a previous auto-calibration, and compensation values are derived there from for application to subsequent output signals obtained during imbalance measurements.

Abstract: An optical target for temporary application in non-determined placement on a surface of an object such as a vehicle wheel assembly within the field of view of an imaging sensor of a machine vision vehicle service system. The optical target consists of a flexible body which is relatively thin and generally flat, capable of conforming to the contours of a surface onto which it is secured in releasable manner by a means of adhesion. A set of visible optical elements are disposed on a front face of the target body for observation and imaging by the imaging sensors.

Abstract: A method and apparatus for comparing reference planes during a vehicle wheel alignment procedure using a machine vision vehicle wheel alignment system. The machine vision vehicle wheel alignment system is configured to acquire position and orientation data associated with at least one optical target disposed in a field of view, to establish a first reference plane associated with a surface on which a vehicle undergoing an alignment procedure is disposed. Positional information associated with each wheel of the vehicle is then acquired by the machine vision vehicle wheel alignment system, and utilized to establish a second reference plane associated with each wheel of the vehicle. Differences between an orientation of the first reference plane and an orientation of the second reference plane are determined and identified to an operator or utilized to characterize components of the vehicle or vehicle support surface.

Abstract: A machine vision vehicle wheel alignment system optical target assembly incorporating an adaptor for attachment of an optical target to a vehicle wheel assembly. The adaptor includes at least three contact points for abutment against surfaces of a vehicle wheel assembly, and an attachment mechanism configured to grip surfaces of a tire mounted to the wheel rim to hold the optical target assembly in contact with the wheel assembly surface. The optical target is secured to the adaptor, and maintained in a fixed relationship to the wheel assembly thereby during a vehicle wheel alignment measurement procedure.

Abstract: A method of matching a tire to a wheel rim of a wheel to compensate for wheel rim run-out and tire force variations includes the steps of mounting a bare wheel on a spindle of a balancer and measuring the rim run-out, said wheel rim having a bead seat, mounting a tire on the wheel to form a wheel/tire assembly, mounting the wheel/tire assembly on the spindle and measuring tire force variation, determining a desired change in wheel rim run-out to reduce the tire force variation, removing the tire from the wheel, adding a shim to the bead seat of the wheel rim, the shim being selected to correspond to the desired change in wheel rim run-out, and remounting the tire on the wheel. The wheel shim is preferably elongate and has a width sized to fit in the bead seat of the wheel rim, the thickness of the wheel shim being substantially less than the width of the wheel shim, and the length of the wheel shim being substantially greater than the width of the wheel shim.

Abstract: A vehicle alignment sensor system includes a first sensor assembly for measuring at least a first angle with respect to a fixed reference, that angle being related in a predetermined manner to an alignment angle of a vehicle whose alignment is to be measured, and a second sensor assembly for mounting in a known geometrical relationship to a wheel of a vehicle whose alignment is to be measured. The first sensor assembly has at least one detector, and the second sensor assembly has at least a pair of emitters in fixed geometrical relationship with respect to each other. The detector is capable of measuring the apparent geometrical relationship of the pair of emitters to determine a relative alignment angle of the vehicle, so that a true alignment angle of the vehicle is determinable from the first angle and the relative alignment angle. A calibration method using the present system is also disclosed.

Abstract: Apparatus and method for determining the alignment of a wheel of a vehicle includes mounting a known optical target to a wheel on the vehicle, the known optical target having a plurality of optical elements, each optical element having at least one straight edge disposed on a background, obtaining at least one video image of the optical target, estimating from the video image of the optical target the characteristics in said video image of a plurality of lines corresponding to projections onto the video image of the straight edges of the optical elements, and determining from the estimates of the characteristics the alignment of the wheel. A similar target for determining the position of a runway on which the vehicle is positioned is also disclosed.

Abstract: A system for measuring vehicle alignment angles has a plurality of sensor elements for mounting to wheels of a vehicle to be aligned. The system uses the sensor elements to measure various angles such as steer ahead angle and toe, and the system also has a display for displaying information to a user and a memory for storing operating instructions for the system. Operating instructions are stored in the memory for determining from compensation measurements taken at a minimum of first and second longitudinally displaced positions whether the toe parameter of two wheels falls outside a predetermined toe range, and whether the steer ahead angle of the vehicle falls within a predetermined range. The operating instructions stored in the memory further include instructions responsive to the toe parameter falling outside the toe range to control the system to display to the user information indicative of the need to adjust the toe parameter before taking additional compensation measurements.