US 5,295,073 AGranted

Device for checking the position of various points of a vehicle

AssigneeCelette S.A.

InventorGermain Celette

Life of this patent

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Abstract

A laser telemeter is driven on two mutually orthogonal axes by stepper motor assemblies to acquire targets mounted at predetermined points on a vehicle. The distances to the targets and the angular orientations are obtained. A computer equipped with a microprocessor controls the movement of the stepper motors by storing in memory the number of steps made during rotation about each axis, and calculates, from the distance between the telemeter and each point, and from the angles of rotation of the beam between the various points measured, the distance between at least two points. These are automatically compared with known standard distances to obtain discrepancies which indicate the deformation of the vehicle. The targets can be disks with back-reflective material thereon as a peripheral ring and a central dot.

Claims14

Dependent claims

Apparatus for checking the relative positions of two or more predetermined points on a vehicle, comprising:

a laser telemeter for measuring distance therefrom to a respective target positioned at each of said predetermined points, including means for producing a beam which is reflected back to the telemeter,
first and second stepper motor assemblies for orienting the telemeter about first and second mutually perpendicular axes by steps,
a computer that includes means for storing in memory the respective number of steps about each said axis from a reference orientation to the orientation of the telemeter at which the beam is centered on the target, means for calculating distance from the telemeter to each said target and based on the respective stored number of steps an angle of rotation about each said axis corresponding to the position of the respective target, means for calculating from the distance from the telemeter to each said target and from the respective angles of rotation about each said axis respective XYZ coordinates for the position of each said target, and means for calculating from said XYZ coordinates relative positions of said targets from one another, comparing said relative positions with predetermined standard values for producing discrepancy values DX, DY, DZ;
and
means for printing or displaying the discrepancy values for each said target position.

2 more elements

A process for checking the relative positions of two or more predetermined points on a vehicle, comprising:

positioning at each of said predetermined points a target that includes means to reflect incident light back towards its source;
positioning adjacent said vehicle a laser telemeter for measuring distance therefrom to any of said targets, including first and second stepper motor assemblies for orienting the telemeter about each of first and second mutually orthogonal axes;
orienting said telemeter to direct its laser beam onto each of said targets in turn by controllably actuating said stepper motor assemblies until said laser beam is incident on a center of the associated target, and storing for each target a distance measurement from the telemeter to the target and angular displacement information for each said axis based on the displacement of each of said stepper motor assemblies;
calculating, for each said target, from the respective distance measurement and angular displacement information the position of the target in XYZ coordinates,
calculating relative positions of the targets from one another,
comparing the calculated relative positions with predetermined standard values appropriate for said vehicle to produce discrepancy values, and
printing or displaying the discrepancy values for each said target position.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/770,451Filed 3 Oct 1991 · continuation in part
Priority: FR 89 0421024 Mar 1989
Granted: 15 Mar 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G01B 11/2755
For testing wheel alignment: using photoelectric detection means
G01B 11/002
Measuring arrangements characterised by the use of optical techniques: for measuring two or more coordinates
G01B 2210/12
Wheel alignment: method or fixture for calibrating the wheel aligner
G01B 2210/16
Wheel alignment: active or passive device attached to the chassis of a vehicle