FR3056172A1 - METHOD FOR INSTALLING ZONES ON THE GROUND FOR CALIBRATION OF CAMERAS OF A MOTOR VEHICLE AND ADAPTED EQUIPMENT - Google Patents

Abstract

The invention relates to a method for installing marking zones on a substantially flat horizontal ground for the calibration of the cameras of a motor vehicle (1), comprising: - the positioning of the vehicle (1) on the ground, wheels parallel to a longitudinal axis (X) of the vehicle, - the positioning of a tracking device (10) on the ground around the vehicle, said tracking equipment (10) comprising a set of separate elongated plates forming rulers (11-18) this positioning being performed by placing the rules on the ground according to a predetermined pattern, at a predetermined distance from the vehicle. Each rule (11-18) has a lower planar face resting at least partially on the ground, an upper face having a registration area and is sufficiently rigid not to deform in a plane parallel to the upper and lower faces. The invention also relates to the corresponding equipment.

Description

© Publication number: 3,056,172 (to be used only for reproduction orders)

©) National registration number: 16 58806 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY

COURBEVOIE © Int Cl ⁸ : B 60 R 16/00 (2017.01), B 60 W30 / 00

A1 PATENT APPLICATION

©) Date of filing: 20.09.16. (© Applicant (s): RENAULT S.A.S Joint-stock company (© Priority: simplified - FR. @ Inventor (s): FERREIRA FREDERICO and HOLLART CEDRIC. (43) Date of public availability of the request: 23.03.18 Bulletin 18/12. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents (73) Holder (s): RENAULT S.A.S Société par actions sim- related: folded. ©) Extension request (s): © Agent (s): RENAULT SAS.

METHOD OF INSTALLING TRACKING ZONES ON A FLOOR FOR THE CALIBRATION OF CAMERAS OF A MOTOR VEHICLE AND ADAPTED EQUIPMENT.

FR 3 056 172 - A1 (6 /) The invention relates to a method of installing location zones on substantially flat horizontal ground for calibrating the cameras of a motor vehicle (1), comprising:

- the positioning of the vehicle (1) on the ground, wheels parallel to a longitudinal axis (X) of the vehicle,

- the positioning of tracking equipment (10) on the ground around the vehicle, said tracking equipment (10) comprising a set of separate elongated plates forming rules (11-18), this positioning being carried out by laying down the rules on the ground according to a predetermined pattern, at a predetermined distance from the vehicle.

Each rule (11 -18) has a lower flat face resting at least partially on the ground, an upper face comprising a locating zone and is rigid enough not to deform in a plane parallel to the upper and lower faces.

The invention also relates to the corresponding equipment.

METHOD OF SETTING UP LOCATION AREAS ON

A SOIL FOR THE CALIBRATION OF CAMERAS OF A VEHICLE

AUTOMOTIVE AND ADAPTED EQUIPMENT

The invention relates to a method of installing tracking zones on a ground for calibrating cameras of a motor vehicle and suitable equipment.

Many vehicles are now equipped with cameras to visualize the environment of the vehicle. In particular, a system called AVM (in English “Around View Monitor”) allows you to create an image from above of the vehicle by recomposing video images from at least 4 cameras, notably a front camera, a rear camera, left side camera, right side camera. The reconstitution of the top view of the vehicle requires an electronic adjustment of the 4 cameras, this adjustment being learned in a computer dedicated to the AVM system with an electronic diagnostic tool. This adjustment can consist of an adjustment by superimposing lines on a multimedia screen with a marking on the ground.

This adjustment (or calibration) is carried out in the factory, before putting the vehicle into service, but must also be able to be carried out in after-sales, for example when replacing one of the 4 cameras or of parts supporting one of the cameras or when replacement of the dedicated AVM calculator. Thus, the calibration of the cameras must be carried out as soon as the bodywork or support parts of the cameras have been touched or damaged due to shocks or accidents.

Camera calibration requires positioning of contrasting landmarks on the ground and precise positioning of the vehicle relative to these landmarks. In the factory, the adjustment is usually made on a dedicated bench presenting a controlled light environment, the marks being permanently present on the ground.

In an after-sales workshop, setting up benchmarks can be problematic. One solution is to use adhesive tapes applied directly to the floor. However, this solution is hardly compatible with the condition of the floors in a workshop and the positioning accuracy of these strips on the ground proves to be insufficient for correctly performing the calibration. In addition, the floor space required is relatively large and not always available, and the installation time relatively long. It is also known to have only parallel white lines on either side of the vehicle. This solution also requires a relatively large shop floor area and these parallel lines do not always correspond to the benchmarks used in the factory, it is then necessary to adapt the AVM computer. There are also solutions using one or more mats on which the markers are drawn. However, this solution is generally used for a single vehicle size and it can be difficult to precisely position the vehicle on the mat or in relation to the mats. In addition, here again, it may be necessary to adapt the AVM computer.

The invention aims to at least partially overcome these drawbacks by proposing a method of installing tracking zones on a substantially flat horizontal ground for calibrating the cameras of a motor vehicle, said installation method comprising:

positioning the vehicle on the ground, wheels parallel to a longitudinal axis of the vehicle, positioning tracking equipment on the ground around the vehicle, said tracking equipment comprising a set of separate elongated plates forming rules, each rule having a lower flat face resting at least partially on the ground and an upper face comprising a contrasted locating zone detectable by the cameras and each rule being rigid enough not to deform in a plane parallel to the upper and lower faces, the positioning being carried out by laying down the rules for tracking equipment on the ground according to a predetermined scheme, at a predetermined distance from the vehicle.

The use of this type of rule makes it possible to get rid of the state of the ground, in particular when the latter is not perfectly flat, and to ensure the linearity of the location. In addition, the rules not being fixed on the ground, they can be used anywhere, especially after-sales or even in the factory, if you do not want to bring the vehicle to the dedicated test bench .

The installation of such tracking equipment is particularly well suited to the calibration of the cameras of a vehicle comprising in particular at least one front camera, one rear camera, one left side camera and one right side camera.

The rules being distinct from each other, they can also be arranged according to various diagrams which can correspond to different diagrams used by different AVM computers: it is therefore not necessary to modify a given computer for after-sales adjustments .

In general, the marks used are parallel or perpendicular to the longitudinal direction of the vehicle. Also, advantageously, the rules of the tracking equipment can be positioned perpendicular or parallel to a longitudinal axis of the vehicle.

In this particular arrangement, but also for any other arrangement of the rules relative to one another, the rules can be distributed symmetrically with respect to a predetermined axis, for example with respect to a central longitudinal axis of the vehicle or with respect to any other axis according to the AVM computer.

In order to facilitate the relative positioning of the rules relative to the vehicle, it may be preferable to position at least two rules in abutment against a wheel of the vehicle. Advantageously, a rule can be arranged in abutment on one wheel and another rule arranged in abutment on the other wheel of the same axle, preferably the front axle. Other rules may also be placed in abutment on the other wheels of the vehicle. Preferably, it is the end of the rule which abuts against the wheel, the rule extending parallel to the axis of the wheel, in other words parallel to the transverse axis of the vehicle.

Alternatively or in combination, when positioning the tracking equipment, the relative positioning of the rules can be facilitated by the positioning of at least one shim of predetermined dimensions between a wheel and a rule. In particular, the dimensions of the wedge can be chosen as a function of the predetermined distance between the tracking zones and the vehicle. Preferably, the ruler extends parallel to the longitudinal axis of the vehicle and the wedge extends perpendicular to the ruler.

The positioning of the tracking equipment may include: the positioning of two rules parallel to the longitudinal axis of the vehicle on each side thereof, the positioning of two rules perpendicular to the longitudinal axis of the vehicle in front and behind the vehicle , the positioning of a rule on each side of the vehicle, perpendicular to the longitudinal axis, preferably in the axis of each of the front wheels, the positioning of two rules extending in the central longitudinal axis of the vehicle, in front and behind it.

There are thus obtained identification zones on each side of the vehicle. Of course, other rules can be put in place according to the predetermined scheme to be carried out.

The positioning of the rules can be obtained in a simple way using a plumb line and a square of suitable dimensions.

In particular, the positioning of a rule in the central longitudinal axis of the vehicle can be achieved by means of a plumb bob positioned on a central marker present on the vehicle (for example brand logo at the front and at the rear or trunk opening button at the rear The positioning of a ruler in the axis of a wheel can also be achieved using a plumb bob.

Right angles between the rulers can be obtained by using a sufficiently large square for this purpose, in particular when the perpendicular rulers are not in abutment.

The different rules can be put in position in any order, it can nevertheless be advantageous to position first the rules in abutment against the wheels and the lateral rules perpendicular to these rules in abutment against the wheels, possibly with the help of shims arranged between these lateral rules and the other wheel.

In order to facilitate their adaptation to different vehicle sizes, the rules of the tracking equipment can be adjustable in length. It is then possible to choose the length of the rules so that at least some of the rules are in abutment against other rules, regardless of the dimensions of the vehicles concerned, which can facilitate their positioning.

The invention also relates to tracking equipment for calibrating external cameras of a motor vehicle comprising a set of separate elongated plates forming rules each having a lower planar face and an upper face comprising a tracking area, in particular a tracking area. contrast detection detectable by a camera, each rule being rigid enough not to deform in a plane parallel to the upper and lower faces.

Such equipment can in particular be used for the implementation of the installation method of the present invention.

The location area is advantageously able to be detected by an optical camera. It can for example consist of one or more parts absorbing or reflecting light radiation. It is thus possible to produce a part of a color different from the rest of the rule, for example of black color on a gray metal ruler, or else to produce several contrasting parts (black and white).

The marking area may consist of one or more rectilinear lines drawn on the upper face and extending over the entire length of the rule, parallel to the edges of the rule. The line or lines can be arranged symmetrically with respect to a longitudinal central axis of the rule.

In order to facilitate the positioning of the rules in relation to each other and in relation to the vehicle, at least part of the rules may have at least one marking chosen from a reference point and a graduation. The graduation can be a graduation extending along the length of the ruler. The reference point or points may be provided for different vehicle sizes or different predetermined diagrams.

To facilitate the use of the rules, in particular for vehicles of different dimensions, the length of at least part of the rules can be adjustable. For this purpose, the rules can be telescopic or even be formed of segments connected two by two by any appropriate means (snap-fastening, interlocking, magnetization, ...).

The tracking equipment can comprise pairs of rules which are not parallel to each other, optionally perpendicular, mounted to slide with respect to one another. This can make it easier to position the rulers around a vehicle.

The invention is now described with reference to the accompanying non-limiting drawings, in which:

- Figure 1 shows a top view of a motor vehicle equipped with cameras;

- Figure 2 schematically shows a top view of a vehicle and a location area;

- Figure 3 schematically shows a perspective view of a vehicle around which tracking equipment is partially installed according to one embodiment of the statement;

- Figures 4 and 5 each show a perspective view of a rule of tracking equipment according to different embodiments of the invention;

- Figure 6 shows a side view of a rule of tracking equipment according to another embodiment.

- Figure 7 shows a perspective view of two rules of tracking equipment according to another embodiment of the invention;

- Figure 8 shows a front view of a vehicle.

In the present description, the terms front, rear, upper, lower, refer to the front and rear directions of the vehicle. The X, Y, Z axes correspond respectively to the longitudinal (front to back), transverse and vertical axis of the vehicle.

FIG. 1 represents a top view of a motor vehicle 1 equipped with four cameras 2, 3, 4, 5, respectively arranged in front, behind, on the left lateral side and on the right lateral side. The areas delimited by dotted lines represent the shooting fields of each camera. Such a set of cameras 2-5 makes it possible to create an image from above of the vehicle by recomposing the images coming from the 4 cameras. Of course, it is also possible to display the images taken by each of the cameras.

Recomposing the images requires calibrating the cameras. To this end, a predetermined reference frame is generally used, defined by identification zones on the ground. This frame of reference is predefined in a computer of an AVM system.

FIG. 2 represents an example of a reference system usable by a computer. In this figure, the vehicle 1 is shown schematically, as well as the front wheels 6 and 7. It is noted that the reference system has 4 crosses A, B, C, D: two crosses (A, B) arranged respectively at the front and rear of the vehicle and two crosses (C, D) arranged on each lateral side of the vehicle, at the height of a front wheel 6, 7. These crosses are each composed of a segment extending parallel to the longitudinal axis X of the vehicle and of a segment extending parallel to the transverse axis Y of the vehicle.

This type of benchmark can be drawn directly on a flat horizontal floor in a dedicated area of a factory (test bench). The floor of an after-sales workshop is however much less regular in general, it can be difficult to achieve benchmarks, especially permanent, especially when space is limited.

In order to allow easy calibration of the cameras, the present invention provides tracking equipment 10 which can be easily used anywhere, and in particular on the floor of a workshop or any other place.

FIG. 3 represents a tracking equipment 10 according to an embodiment of the invention, arranged around a vehicle 1. This tracking equipment 10 has a set of separate elongated plates forming rules referenced from 11 to 18.

It will be noted that these rules present here rectilinear edges and perpendicular to each other. In other words, each rule has a rectangular shape whose length is much greater than the width.

The rules are substantially identical and differ essentially in their length.

Each rule 11-18 is also rigid enough not to deform in a plane parallel to the upper and lower faces. These rules may be metallic, for example aluminum, steel or other metal alloy, or else be made of a polymer material, or of metallic material coated with polymer material, provided that they have the desired rigidity.

Various embodiments of rules are described with reference to FIGS. 4 to 7.

As shown in FIG. 4, one or more rules 11-18 can be graduated along their length, or even include reference marks.

In the embodiment shown in FIG. 4, the rule 11 comprises a lower planar face 11a and an upper face 11b comprising a locating zone 11, here a rectilinear black band (symbolically represented by hatching). This upper face 11b is preferably planar, but non-planar faces are possible, provided that an optical camera can distinguish the location area.

The location area formed in the example illustrated with a single black band is centered with respect to the width direction of the ruler. The ratio of the width of the black band to the width of the ruler is typically from 1/3 to 1/2.

The contrasting identification zone is here constituted by the black color and the dark appearance of the strip which is framed by adjacent longitudinal edges of the ruler, here typically of aluminum appearance (unpainted).

FIG. 5 represents an embodiment in which a rule 111 is formed of several sections 121, 122 which slide one inside the other in their longitudinal direction. This allows you to adjust the length of the rule. Each section 121, 122 carries a marking area 121c, 122c, here in the form of a rectilinear black line. The lower wall 123 of the section 122 can then be relatively thin (for example 1 cm or less) so that the difference in level between the lower face 121a and the lower face 122a is relatively small when the two sections rest on the ground.

FIG. 6 shows another embodiment in which a rule 211 is formed of several sections 221, 222 nested one inside the other. The invention also extends to any other embodiment allowing adjustment of the total length by relative sliding between the sections.

In the embodiments shown in FIGS. 5 and 6, each section has a rectangular shape in a horizontal plane. Of course, the invention is not limited to a particular number of sections. It will be noted that the connecting means of the different sections are preferably arranged so that the locating zones coincide from one section to another and that the rule is rectilinear over its entire length.

FIG. 7 shows an embodiment in which two rules 311 and 312 are slidably mounted relative to one another, being perpendicular to each other. To this end, a strip 313 sliding on the first rule 311 can be provided, the second rule 312 being slidably mounted on the strip 313. Of course, any other type of slide connection can be provided. It can also be provided that only one of the rules can slide relative to the other and or that the rules do not cross at a right angle but at another predetermined angle.

The different embodiments of the rules described above can be combined with one another. In addition, equipment according to the invention may include rules for different embodiments.

The installation of the tracking zones by means of the equipment 10 according to the invention is now described with reference to FIGS. 3 and

8. Rules 11 to 18 are as shown in Figure 4.

In the example illustrated, rules 18 or 14 according to the visual reference system have a minimum length of 1250 mm.

Rules 17 or 13 according to the visual reference system have a minimum length corresponding to the width of the vehicle increased by 600 mm, or for a Renault Clio ® type vehicle approximately 2,600 mm in total.

The width of the rulers is typically of the order of 100 mm.

In these figures, the vehicle 1 rests on a substantially flat horizontal ground.

By substantially flat is meant a surface having asperities of at most 5 cm in height, preferably at most 4 cm in height.

The front drive wheels 6, 7 of the vehicle 1 are positioned parallel to the longitudinal axis X of the vehicle.

By wheel parallel to an axis, it is meant that the plane of the wheel is parallel to an axis or that the wheel rotation tax is perpendicular to this axis. Wheels are parallel to a longitudinal axis of a vehicle when they are "straight" and a plane containing the wheel does not form an angle with a longitudinal vertical plane of the vehicle.

Once the vehicle is positioned, the tracking equipment 10 can be placed on the ground around the vehicle, here according to a diagram corresponding substantially to the diagram in FIG. 2.

The different rules can be arranged as follows:

a first rule 11 is positioned along the length of the vehicle, parallel to the longitudinal axis X. For this purpose, the end of a chock 19 is placed in abutment against the rear wheel 8 perpendicular to the rule 11 and the end of a second rule 12 is positioned in abutment against the front wheel 6 also perpendicular to the first rule 11.

A third rule 13 is then positioned in front of the vehicle parallel to the transverse axis Y. To this end, it is placed at right angles to the first rule 11.

A fourth rule 14 is positioned perpendicular to the third rule 13, in the central longitudinal axis X of the vehicle. To do this, a plumb line 20 can be stretched from a central mark 21 on the vehicle, as shown in FIG. 8.

A fifth rule 15 is then placed along the length of the vehicle, on the other side of the vehicle relative to the first rule 11, perpendicular to the third rule 13. Possibly a wedge in abutment (not visible in the figure) against the wheel rear can be used to facilitate the installation of the rule.

A sixth rule 16 is positioned perpendicular to rule 15, in the axis of the other front wheel.

A seventh rule 17 perpendicular to the first and fifth rules 11 and 15 is then positioned at the rear of the vehicle.

Finally, an eighth rule 18 is positioned perpendicular to the seventh rule 17, also in the central longitudinal axis of the vehicle, like rule 14.

The different rules intersect at a predetermined distance from the vehicle, chosen according to the computer used.

As a variant, the first rule 11 could be put in place without using the chock 19. It may then be advantageous to position the rules 11 and 15 on each side of the vehicle as well as the rules 12 and 16 in abutment against the wheels before, then ensuring their parallelism to the longitudinal axis by positioning one of the rules 13 or 17 at right angles to each of the rules 11 and 15.

Note that the tracking equipment 10 is positioned in Figure 6 so that part of the rules is in abutment against another rule. Here, rules 11 and 17 are in abutment against rules 11 and 15, rules 11, 13, 15 and 17 forming a kind of frame around the vehicle 1. This can facilitate the control of the angle between these rules, in particular by means of a square 22 shown in Figure 3. However, it is not necessary that the rules are in abutment against the adjacent rule for adjusting the angle, it suffices that the square 22 is long enough to be put pressing against the two rules to be positioned perpendicularly.

Each rule being rigid enough not to deform in a plane parallel to its upper and lower faces, it is understood that even posed on an uneven ground, the lower face then not resting entirely on the ground due to its irregularities , the rule remains rectilinear, which allows the use of the location area for camera calibration. The same is true when the underside of a rule is not strictly planar, for example in the case of crossing rules or rules composed of segments.

The invention has been described for the establishment of rules oriented in longitudinal and transverse directions. The rules of the tracking equipment according to the invention can nevertheless be arranged in relation to each other at non-right angles. Angle measurement tools can then be used, such as protractors or corner tools forming the required angle. It is thus understood that the equipment according to the invention can be used for any type of diagram. It can also be set up easily and quickly anywhere. Finally, it can be implemented for different sizes of vehicles, in particular when at least certain rules are of adjustable length.

Claims (11)

1. Method for installing location zones on substantially flat horizontal ground for calibrating the cameras of a motor vehicle (1), said installation method comprising: positioning of the vehicle (1) on the ground, wheels parallel to a longitudinal axis (X) of the vehicle, positioning of tracking equipment (10) on the ground around the vehicle, said tracking equipment (10) comprising a set of separate elongated plates forming rulers (11-18), each ruler (11-18) having a lower planar face (11a) resting at least partially on the ground and an upper face (11b) comprising a marking area (11c ) contrast detectable by cameras and each rule (11-18) being rigid enough not to deform in a plane parallel to the upper and lower faces, the positioning being carried out by laying down the rules of the tracking equipment on the ground according to a predetermined pattern, at a predetermined distance from the vehicle. 2. Installation method according to claim 1, in which the rules (11-18) of the tracking equipment are positioned perpendicular or parallel to a longitudinal axis (X) of the vehicle, optionally distributed symmetrically with respect to a longitudinal axis. vehicle center. 3. Installation method according to claim 1 or 2, wherein at least two rules (12, 16) are positioned in abutment against a wheel (6) of the vehicle. 4. Installation method according to any one of claims 1 to 3, in which at least one shim (19) of predetermined dimensions is positioned between a wheel (8) and a rule (11) when positioning the equipment. of location. 5. Installation method according to any one of claims 1 to 4, in which the positioning of the tracking equipment comprises: the positioning of two rules (11, 15) parallel to Longitudinal tax of the vehicle on each side of it, the positioning of two rules (13, 17) perpendicular to the longitudinal axis of the vehicle in front and behind the vehicle, the positioning of a rule (12, 16) on each side of the vehicle, perpendicular to the longitudinal axis, preferably in the axis of each of the front wheels, the positioning of two rules (14, 18) in the central longitudinal axis of the vehicle, in front of and behind it. 6. Installation method according to any one of claims 1 to 5, in which the length of the rules (11-18) is adjustable, this length being chosen so that at least part of the rules are in abutment against d 'other rules. 7. Locating equipment (10) for calibrating external cameras of a motor vehicle comprising a set of separate elongated plates forming rules (11-18) each having a lower planar face (11a) and an upper face (11b) comprising a locating zone (lie), each rule being rigid enough not to deform in a plane parallel to the upper and lower faces. 8. Locating equipment (10) according to claim 7, characterized in that at least some of the rules have at least one marking chosen from a benchmark and a graduation. 9. Locating equipment (10) according to claim 7 or 8, characterized in that the length of at least part of the rules is adjustable. 10. Locating equipment (10) according to any one of claims 7 to 9, characterized in that it comprises pairs of non-parallel rules between them, optionally perpendicular, slidably mounted relative to one another. B 2/3 11a Fig. 5 122c 121a 121 3/3 NOT