# US 5,345,675 A · Method of mounting wheel to vehicle

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- Number: US 5,345,675 A
- Document ID: US5345675A
- Status: Granted
- Kind: A
- Application number: 08/016,260
- Filed: 1993-02-11
- Granted: 1994-09-13
- Earliest claimed: 1992-02-13
- Assignees: Honda Giken Kogyo Kabushiki Kaisha
- Inventors: Yasurou Yamanaka; Junichi Yamanaga; Akira Morizono; Akira Miyazaki; Noriyuki Unose
- Web page: https://patentgrep.com/patent/US5345675A

## CPC

- G05B 19/4182: {manipulators and conveyor only}
- B25J 9/1697: {Vision controlled systems}
- B62D 65/12: the sub-units or components being suspensions, brakes or wheel units
- G05B 2219/37553: Two cameras one for coarse scanning, other for fine scanning
- G05B 2219/45021: Wheel mounting
- G05B 2219/49113: Align elements like hole and drill, centering tool, probe, workpiece
- Y02P 90/02: Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
- Y10T 29/49492: Land wheel
- Y10T 29/49902: by manipulating aligning means
- G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G)
- B25J: MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES ({manipulators specially adapted for use in surgery A61B34/70; manipulators used in cleaning hollow articles B08B9/04}; manipulators associated with rolling mills B21B39/20; manipulators associated with forging machines B21J13/10; {manipulators associated with picking-up and placing mechanisms B23P19/007}; means for holding wheels or parts thereof B60B30/00; {vehicles with ground-engaging propulsion means, e.g. walking members B62D57/02, B62D57/032; devices for picking-up and depositing articles or materials between conveyors B65G47/90, B65G47/91; manipulators with gripping or holding means for transferring packages B65H67/065}; cranes B66C; {manipulators used in the protection or supervision of pipe-line installations F17D5/00; walking equipment adapted for nuclear steam-generators F22B37/006}; manipulators specially adapted for, or associated with, nuclear reactors G21C; {apparatus used for handling wafers during manufacture or treatment of semiconductor H10P72/50})
- B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M)
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A pair of second cameras mounted on a robot are located in front of, and symmetrically with respect to the center of a wheel hub of a vehicle, according to approximate coordinates of the center of the wheel hub calculated from an image of the wheel hub taken by a first camera. Revised coordinates of the center of the wheel hub, a rotational displacement from a standard rotational position of the wheel hub, and a turning angle of the wheel hub toward the right or left with respect to a progressive direction of the vehicle are calculated from the images obtained by the second cameras. A wheel is then automatically mounted to the wheel hub by the robot, according to the results of calculation.

## Claims

### Claim 1

A method of mounting a wheel, by a wheel mounting robot, to a vehicle conveyed along an assembly line, comprising the steps of:
obtaining an image of a wheel hub by first imaging means disposed on one side of said conveyed vehicle;
calculating approximate coordinates of the center of said wheel hub based on the image obtained by said first imaging means;
locating second imaging means mounted on said wheel mounting robot so that respective said second imaging means are located in front of said wheel hub and symmetrically with respect to the center of said wheel hub, according to said approximate coordinates of the center of said wheel hub;
calculating revised coordinates of the center of the wheel hub and a rotational displacement from a standard rotational position of the wheel hub, based on said images obtained by said second imaging means; and
mounting the wheel to said wheel hub by said wheel mounting robot based on the revised coordinates of the center and rotational position of said wheel hub.

### Claim 2 (depends on 1)

The method according to claim 1, wherein said step of calculating the revised coordinates of the center of said wheel hub and the rotational displacement of said wheel hub comprises the steps of:
projecting said points recognized as the heads of the hub bolts on each of said ellipses onto circles each having a diameter of the length of the major axis of each of said ellipses;
averaging said circles into one circle and determining the coordinates of the center of said wheel hub which is the center of said one circle;
determining angular distances each defined by neighboring radii passing respective said points in said one circle;
comparing each of said determined angular distances with a predetermined angle to verify whether or not the points on both sides of each of said determined angular distances are false images of the hub bolts; and
determining the rotational displacement of said wheel hub by finding an angle between a vertical line passing through the center of said wheel hub and a radius passing through one of said verified points which is the nearest to said vertical line.

### Claim 3 (depends on 1)

The method according to claim 1, further comprising a step of outputting a wheel-mounting disable signal when said turning angle exceeds a predetermined angle.

### Claim 4

A method of mounting a wheel, by a wheel mounting robot, to a vehicle conveyed along an assembly line, comprising the steps of:
obtaining an image of a wheel hub by first imaging means disposed on one side of said conveyed vehicle;
calculating approximate coordinates of the center of said wheel hub based on the image obtained by said first imaging means;
locating second imaging means mounted on said wheel mounting robot so that respective said second imaging means are located in front of said wheel hub and symmetrically with respect to the center of said wheel hub, according to said approximate coordinates of the center of said wheel hub;
calculating revised coordinates of the center of the wheel hub and a rotational displacement from a standard rotational position of the wheel hub, based on said images obtained by said second imaging means;
extracting points recognized as the heads of hub bolts studded on said wheel hub based on each of said images obtained by said second imaging means;
connecting said recognized points in each of said images with a curve to find a best fitted ellipse;
finding a ratio of the lengths of the minor and major axes of said ellipse in each of said images to determine the direction of the normal of a hub bolt circle with respect to an optical axis of each of said second imaging means;
determining a turning angle of the wheel hub toward the right or left with respect to a progressive direction of the vehicle based on said direction of the normal of the hub bolt circle determined for each of said second imaging means; and
mounting the wheel to said wheel hub by said wheel mounting robot based on the revised coordinates of the center, rotational displacement, and turning angle of said wheel hub.