# US 7,746,456 B2 · Apparatus for contactless 3D wheel alignment, system and method therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,746,456 B2 - Document ID: US7746456B2 - Status: Granted - Kind: B2 - Application number: 11/733,629 - Filed: 2007-04-10 - Published: 2008-02-14 - Granted: 2010-06-29 - Earliest claimed: 2006-04-10 - Assignees: Snap-On Equipment Srl A Unico Socio - Inventors: Francesco Braghiroli - Web page: https://patentgrep.com/patent/US7746456B2 ## CPC - G01B 11/2755: {using photoelectric detection means} - G01B 2210/28: Beam projector and related sensors, camera, inclinometer or other active sensing or projecting device - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract An alignment measuring apparatus for 3D contactless measuring alignment of a wheel of an automotive vehicle, a system formed by several apparatuses for a total wheel alignment of all wheels of an automotive vehicle, and a respective method for carrying out 3D contactless wheel alignment in real time. The several embodiments provide a comprehensive diagnosis tool for the alignment operation of vehicle wheels by contactless scanning, in particular a real time measuring for total wheel alignment, and enable a respective hassle-free adjustment operation. ## Claims ### Claim 1 An alignment measurement apparatus for contactless measuring alignment of a vehicle wheel, the apparatus comprising: a support at which a carrier is rotatable mounted about a rotation point; at least one measuring unit mounted to the carrier such that the measuring unit has a defined geometrical position and configured to measure distance data of a measurement point on the wheel from the respective measurement unit in a contactless manner, wherein the measuring unit being pivotable about an axis, parallel to a reference plane corresponding to a rotation plane of the carrier device about the mounting point and orthogonal to an radius from the rotation point to the measuring unit; control means configured to control rotation of the carrier device and pivoting of the at least one measuring unit such that a measurement point is on the wheel in the area of the bead of the rim; and processing means configured to calculate wheel alignment data from the provided measured distance data of at least three measurement points together with the respective geometrical position and a respective pivoting angle of the respective at least one measurement unit, and a respective rotation angle of the carrier. ### Claim 2 (depends on 1) Apparatus according to claim 1, wherein the apparatus comprises a controllable carrier pivoting means at the support to which the carrier is operable mounted, the pivoting means being arranged such that the respective pivoting angle can directly be determined from a controlled pivoting of the carrier. ### Claim 3 (depends on 2) Apparatus according to claim 2, wherein the carrier pivoting means is a step motor having at least one predetermined pivoting position as a reference position for the respective pivoting angle. ### Claim 4 (depends on 2) Apparatus according to claim 2, wherein the carrier pivoting means is a motor provided with a pivoting sensor means configured to measure an actual pivoting angle of the carrier. ### Claim 5 (depends on 1) Apparatus according to claim 1, wherein the measuring unit comprises an optical triangulation measuring device. ### Claim 6 (depends on 1) Apparatus according to claim 1, wherein the measuring unit comprises pivoting means arranged for determining the respective pivoting angle. ### Claim 7 (depends on 1) Apparatus according to claim 1, wherein the apparatus comprises three measuring units, which are arranged to each other with respect to a reference point in the reference plane such that respective two adjacent measuring units are spaced by an angle of 120 degree. ### Claim 8 (depends on 1) Apparatus according to claim 1, wherein the control means are configured to control pivoting of the at least one measuring unit such that measurement data produced by the measuring unit during pivoting is evaluated by the processing means for detecting measuring points on the surface of rim of the wheel corresponding to the bead of the rim. ### Claim 9 (depends on 1) Apparatus according to claim 1, wherein the support is a stand and the carrier is mounted to the stand such that the reference plane is substantial orthogonal to a footprint of the stand. ### Claim 10 (depends on 1) Apparatus according to claim 1, wherein the control means are configured to continuously adjust the pivoting of a measuring unit such that the respective measuring point on the surface of rim of the wheel at the bead of the rim is maintained. ### Claim 11 (depends on 1) Apparatus according to claim 1, wherein the apparatus further comprises at least two additional optical angle-measuring units configured to track a relative orientation of the apparatus with respect to at least one another adjacent apparatus. ### Claim 12 An apparatus for contactless measuring alignment of a vehicle wheel, the apparatus comprising: at least three measuring units arranged on a carrier such that their geometrical positions define a reference plane, each measuring unit being configured to measure distance data of a respective measurement point on the wheel from the respective measurement unit in a contactless manner; a support at which the carrier is mounted at a mounting point, wherein each measuring unit is pivotable about an respective axis, being parallel to the reference plane and orthogonal to an radius from a geometrical center of the geometrical positions of the at least three measuring units; and control means configured to control pivoting of each measuring unit such that a respective measurement point on the wheel is in the area of the bead of the rim; and processing means configured to calculate wheel alignment data from the provided measured distance data of the at least three measurement points together with the respective geometrical position and a respective pivoting angle of the respective measurement unit. ### Claim 13 (depends on 12) Apparatus according to claim 12, wherein the pivoting means is a step motor having at least one predetermined pivoting position as a reference position for the respective pivoting angle. ### Claim 14 (depends on 12) Apparatus according to claim 12, wherein the measuring unit comprises an optical triangulation measuring device. ### Claim 15 (depends on 12) Apparatus according to claim 12, wherein the measuring unit comprises pivoting means arranged for determining the respective pivoting angle. ### Claim 16 (depends on 12) Apparatus according to claim 12, wherein the apparatus comprises three measuring units, which are arranged to each other with respect to a reference point in the reference plane such that respective two adjacent measuring units are spaced by an angle of 120 degree. ### Claim 17 (depends on 12) Apparatus according to claim 12, wherein the control means are configured to control pivoting of the at least one measuring unit such that measurement data produced by the measuring unit during pivoting is evaluated by the processing means for detecting measuring points on the surface of rim of the wheel corresponding to the bead of the rim. ### Claim 18 (depends on 12) Apparatus according to claim 12, wherein the support is a stand and the carrier is mounted to the stand such that the reference plane is substantial orthogonal to a footprint of the stand. ### Claim 19 (depends on 12) Apparatus according to claim 12, wherein the control means are configured to continuously adjust the pivoting of a measuring unit such that the respective measuring point on the surface of rim of the wheel at the bead of the rim is maintained. ### Claim 20 (depends on 12) Apparatus according to claim 12, wherein the apparatus further comprises at least two additional optical angle-measuring units configured to track a relative orientation of the apparatus with respect to at least one another adjacent apparatus. ### Claim 21 (depends on 1) An alignment measurement system for contactless alignment of wheel of an automotive vehicle, the system comprising at least four alignment apparatuses according to claim 1. ### Claim 22 (depends on 21) System according to claim 21, wherein the alignment apparatuses are movable mounted to a lift for lifting a automotive vehicle the wheels the alignment of which to be adjusted, wherein the alignment apparatuses are movable mounted on the sides of the lift such that the position is adjustable to the position of the wheels of a vehicle on the lift. ### Claim 23 (depends on 21) System according to claim 21, wherein the alignment apparatuses of the system are connected to a central processing device configured to calculate respective optical angle angles of each wheel required for a total wheel alignment with respect to predetermined reference angles. ### Claim 24 (depends on 21) System according to claim 21, wherein each alignment measurement apparatus further comprises at least two additional angle measuring units configured to track a relative orientation of the respective apparatus with respect to another apparatus of the system. ### Claim 25 (depends on 12) An alignment measurement system for contactless alignment of wheel of an automotive vehicle, the system comprising at least four alignment apparatuses according to claim 12. ### Claim 26 (depends on 25) System according to claim 25, wherein the alignment apparatuses are movable mounted to a lift for lifting a automotive vehicle the wheels the alignment of which to be adjusted, wherein the alignment apparatuses are movable mounted on the sides of the lift such that the position is adjustable to the position of the wheels of a vehicle on the lift. ### Claim 27 (depends on 25) System according to claim 25, wherein the alignment apparatuses of the system are connected to a central processing device configured to calculate respective optical angle angles of each wheel required for a total wheel alignment with respect to predetermined reference angles. ### Claim 28 (depends on 25) System according to claim 25, wherein each alignment measurement apparatus further comprises at least two additional angle measuring units configured to track a relative orientation of the respective apparatus with respect to another apparatus of the system. ### Claim 29 An alignment measurement method of determining alignment of a motor vehicle wheel, the method comprising the steps of: controlling a contactless measuring device to detect at least three different measurement points on the bead of the rim of the wheel and to measure respectively a distance and an angle from the measuring device to the respective measurement point; and calculating alignment of the vehicle wheel using the distances and angles of the at least three different measurement points. ### Claim 30 (depends on 29) Method according to claim 29, wherein the controlling of the contactless measuring device comprises continuous measuring of a distance of a measurement point on the rim of the wheel to provide real time alignment data during the alignment operation. ### Claim 31 (depends on 29) Method according to claim 29, wherein the controlling of the contactless measuring device further comprises a step of periodically performing quick rim scans in-between continuous measuring of the distance of the measurement point such that the location of the measurement point on the bead of the rim of the wheel is maintained. ### Claim 32 (depends on 29) Method according to claim 29, wherein the calculating step comprises calculation of respective inclination angles of each wheel required for a total wheel alignment with respect to predetermined reference angles. ### Claim 33 (depends on 29) Method according to claim 29, comprising contactless tracking of a relative orientation of alignment of all wheels of the vehicle with respect to each other; and calculating a total wheel alignment of all wheels of the vehicle.