Apparatus and method for the geometric measurement of a vehicle

Claim 2

Apparatus for the geometric inspection of a vehicle, comprising an interactive display panel adapted to guide an operator according to instructions emitted by a first electronic card for processing signals from measurement means and computing values from said signals, said measurement means including: first means for measuring the orientation of a vehicle wheel in the horizontal plane, second means for measuring the rotational angle of the wheel about its axis, third means for measuring inclinations in a first vertical plane perpendicular to, and in a second vertical plane parallel to, the wheel; said third means being connected to a second electronic card; said measurement means emitting electrical signals representative of indications correlated with the physical parameters to be detected for the geometrical inspection of the vehicle; said measurement means being contained in a casing with an axle protruding from the casing, said axle being mounted for rotation in the casing and engaging with its protruding end and being fixed to a support element secured to the wheel of the vehicle to be inspected; wherein said first means is in the form of a camera block comprising one linear optical detector and means for defining an image from an external source upon said linear optical detector; said second means is a rotational potentiometer having a rotational axis disposed substantially coaxial and substantially coincident with said axle for following the wheel in its rotational movement about its axis; and said third means is a biaxial inclinometer for measuring the inclinations in the first and second vertical planes and being mounted on said second electronic card.

Claim 3

Apparatus according to claim 1, wherein the axle has two conformations that are parallel and spaced apart, of which the first comes to bear against an emplacement on the support element and of which the second comes to bear on an emplacement on the casing, so as to supply a reproducible and invariable mounting of the casing on the support element by means of the axle after relative blocking between the casing, the axle and the support element.

Claim 4

Apparatus according to claim 1, wherein said camera block comprises at least one slot transparent to light rays for defining an image transmitted from an external source and at least one linear optical detector disposed downstream of said at least one slot in the direction of incidence of a beam of the light rays to detect the image of the source formed by said at least one slot, and wherein said at least one detector is inclined at an acute angle to a plane passing through a longitudinal axis of said at least one slot and a longitudinal axis of the image of the source on said at least one detector.

Claim 5

Apparatus according to claim 3, wherein said acute angle is comprised between 30 and 60 degrees of arc.

Claim 6

Apparatus according to claim 3, wherein said at least one detector is disposed in a plane parallel to the plane of said at least one slot and forms with the direction perpendicular to a longitudinal axis of said at least one slot an acute angle.

Claim 7

Apparatus according to claim 3, wherein said at least one detector is located in a plane which makes an acute angle with the optical axis of the incident beam.

Claim 8

Apparatus according to claim 3, which further comprises at least one mirror to return the incident beam, so as to minimize the volume and dimensions of the casing.

Claim 9

Apparatus according to claim 3, which further comprises at least one additional casing which has several slots for image definition.

Claim 10

Apparatus according to claim 8, wherein said additional casing comprises at least one prism to deflect the light beam, so as to minimize the spacing between slots.

Claim 11

Apparatus according to claim 3 wherein said at least one slot is in the shape of a cross comprising two perpendicular slits.

Claim 12

Apparatus according to claim 10, wherein the cross supports adjacent the optical axis a pattern adapted to be projected on a linear optical detector bar.

Claim 13

Apparatus according to claim 3, further comprising a filament or an opaque comb to define an inverted image on the linear optical detector.

Claim 14

Apparatus according to claim 3, wherein the width of a given slot is different from the width of another slot.

Claim 15

Apparatus according to claim 3, wherein one slot is a dynamic slot.

Claim 16

Apparatus according to claim 1, wherein the casing carries a light source which is a gas tube lamp producing illumination between two electrodes, which illumination is of a predetermined duration at predetermined intervals of time.

Claim 17

Apparatus according to claim 1, wherein the second means for measuring the rotational angle of the wheel is mounted directly coaxially on said axle.

Claim 18

Apparatus according to claim 16, wherein the second means for measuring the rotational angle of the wheel is a potentiometric receiver.

Claim 19

Apparatus according to claim 1, wherein the second means for measuring the rotational angle of the wheel comprises an angular dead zone.

Claim 20

Apparatus according to claim 1, wherein the axle carries an indexing means of the side of the protruding end engaging with the support element, so as to mount the axle and the casing in horizontal position at a preadjusted angular position.

Claim 21

Method of geometrically inspecting a vehicle using a geometric inspection apparatus having an interactive display panel including a display screen for guiding an operator according to instructions emitted by an electronic card processing signals from a measurement device and computing values from said signals, said measurement device including first means for measuring the orientation of a vehicle wheel in the horizontal plane, second means for measuring the rotational angle of the wheel about its axis, third means for measuring inclinations in a first vertical plane perpendicular to, and in a second vertical plane parallel to, the wheel; said measurement device emitting electrical signals representative of indications correlated with the physical parameters to be detected for the geometrical inspection of the vehicle; said measurement device being contained in a casing with an axle protruding from the casing, said axle being mounted for rotation in the casing and engaging with its protruding end and being fixed to a support element secured to the wheel of the vehicle to be inspected, said second means having a rotational axis disposed substantially coaxial and substantially coincident with said axle for following the wheel in its rotational movement about its axis; said display panel including interactive means which together with the electronic card give indications in real time of the inclination of the casing in a plane parallel to the wheel; said method comprising the following steps: displaying on the screen an indication to the operator to place the wheel support element in the vertical position, to fix rigidly the casing maintained horizontally on the axle, to begin a first set of measurements by the first, second and third means of the measurement device, and to store this first set of measurements in memories provided on the electronic card; emitting on the screen an instruction to the operator to loosen a knob to permit relative rotation between the axle and the casing, to turn the wheel through a first angle in a predetermined direction, to take a second set of measurements by the first, second and third means of the measurement device, and to store this second set of measurements in the memories of the electronic card; and displaying on the screen an instruction to the operator to turn the wheel in another predetermined direction, by a second angle different from said first angle, to begin a third set of measurements, and to store this third set of measurements in the electronic card.

Claim 22

Method of geometrically inspecting a vehicle using a geometric inspection apparatus having an interactive display panel including a display screen for guiding an operator according to instructions emitted by an electronic card processing signals from a measurement device and computing values from said signals, said measurement device including first means for measuring the orientation of a vehicle wheel in the horizontal plane, second means for measuring the rotational angle of the wheel about its axis, third means for measuring inclinations in a first vertical plane perpendicular to, and in a second vertical plane parallel to, the wheel; said measurement device emitting electrical signals representative of indications correlated with the physical parameters to be detected for the geometrical inspection of the vehicle; said measurement device being contained in a casing with an axle protruding from the casing, said axle being mounted for rotation in the casing and engaging with its protruding end and being fixed to a support element secured to the wheel of the vehicle to be inspected, said second means having a rotational axis disposed substantially coaxial and substantially coincident with said axle for following the wheel in its rotational movement about its axis; said display panel including interactive means which together with the electronic card give indications in real time of the inclination of the casing in a plane parallel to the wheel; said method comprising the following steps: displaying on the screen an indication to the operator to place the wheel support element in the vertical position, to fix rigidly the casing maintained horizontally on the axle, to begin a first set of measurements by the first, second and third means of the measurement device, and to store this first set of measurements in memories provided on the electronic card; emitting on the screen an instruction to the operator to loosen a knob to permit relative rotation between the axle and the casing, to turn the wheel through a first angle in a predetermined direction, to take a second set of measurements by the first, second and third means of the measurement device, and to store this second set of measurements in the memories of the electronic card; and displaying on the screen an instruction to the operator to turn the wheel in another predetermined direction, by a second angle different from said first angle, to begin a third set of measurements, and to store this third set of measurements in the electronic card.

Claim 23

Method according to claim 20, wherein the operator turns the wheel from one step to the following step with an angular precision of the order of 30 degrees of arc.

Claim 24

Method according to claim 20, wherein the vehicle wheel is driven in rotation by motorized means.

Claim 25

Method according to claim 20, wherein the wheel of the vehicle is steered through a predetermined angle before beginning measurements.

Claim 26

Method according to claim 20, wherein information corresponding to the inclination in a vertical plane parallel to the wheel is utilized to compensate the measurements as a function of the deviation of the position of the casing from the horizontal.