EP2250460A2

EP2250460A2 - System amd method for measuring gaps and flushnesses

Info

Publication number: EP2250460A2
Application number: EP09720881A
Authority: EP
Inventors: Gilbert Calve
Original assignee: Peugeot Citroen Automobiles SA
Current assignee: PSA Automobiles SA
Priority date: 2008-03-06
Filing date: 2009-02-25
Publication date: 2010-11-17
Also published as: FR2928453B1; WO2009112761A3; FR2928453A1; WO2009112761A2; RU2010140804A; BRPI0905615A2; CN101952684A

Abstract

System (10) for measuring clearances and degree of flushness between bodywork parts (12) exhibiting respective opposite edges, characterized in that it comprises: - projection means (14) separate from and independent of the image sensors (18) able to project onto the surfaces of the parts at least one luminous line (26) cutting said edges of the parts at the location of the trace to be measured - at least two image-taking means (18) able to capture at least two images of a luminous line (26) relating to a trace to be measured at two different viewing angles, - calculating means (16) comprising an image processing module (34) intended to extract information from the images taken by the image sensors (18), in particular the values representative of the clearances and degree of flushness, - calculation means (16) comprising a calculation module (36) which makes it possible to determine by a stereoscopic method the positions and orientations of the image-taking and projection means with respect to each of the traces to be measured defined along the luminous lines (26), and to correct the values of clearances and degree of flushness previously determined by the image processing module (34).

Description

Game and outcrop measurement system and method thereof.

The present invention relates to a system for measuring play and outcropping between bodywork parts having respective edges vis-à-vis.

Controlling the compliance of games and outcrops on motor vehicles is an important objective for manufacturers as it contributes significantly to the assessment of the quality of manufacture by end customers.

Currently, in order to measure the play and outcrop, different techniques exist and have already been the subject of patents. For example, mention may be made of US Pat. No. 5,129,010, which discloses a portable acquisition means integrating into the same housing an image pickup means and a single-line projection means whose positions and relative orientations are determined by construction.

This means needs to be repositioned manually before each trace to be measured. Patent FR 2 756 626 A1 relates to a portable gun incorporating in the same housing an image pickup means and a projection means whose positions and relative orientations are determined by construction. This gun requires to be repositioned manually before each trace to be measured. Finally, patent US-B1-6 542 249 discloses a portable scanning system incorporating on the same medium an image pickup means and a multi-line projection means whose positions and relative orientations are determined by construction. This system needs to be moved manually in front of the area to be scanned.

However, the implementation of manual solutions is long, tedious, expensive and unsuitable for performing unit measurements on the vehicle production line.

The object of the invention is to propose an automatic measurement device, easy to use, adapted to the constraints of a control in the workflow, versatile and more flexible than the solutions currently used. For this purpose, the subject of the invention is a system of the aforementioned type, characterized in that it comprises:

- Dissociated projection means independent of image sensors adapted to project on the surfaces of the parts at least one line light cutting said edges of the pieces at the location of the trace to be measured

at least two image taking means suitable for capturing at least two images of a light line relating to a trace to be measured under two different angles of view,

calculation means comprising an image processing module intended to extract information from the images taken by the image sensors, in particular the values representative of the games and outcrops.

calculating means comprising a calculation module which makes it possible to determine, by a stereoscopic method, the positions and orientations of the image taking and projection means with respect to each of the measured traces defined along the light lines, and of correcting the values of gaps and outcrops previously determined by the image processing module. The system according to the invention can comprise one or more of the following characteristics:

the imaging means are dimensioned and arranged so that the fields of vision overlap as widely as possible.

the at least two image sensors are capable of capturing each an image of several light lines each corresponding to a different trace to be measured.

it comprises, upstream, imaging means and calculation means, a system adapted to transmit a cycle code specific to the model and the silhouette of the vehicle to be tested, to a range management module, the arrival of a new, different vehicle generating the sending by said adapted system of a different cycle code suitable for selecting a different range of measurements.

the range management module is capable of selecting the range of measurements to be applied and of managing the activation of the projection means and the acquisition of the imaging means. the projection means comprise a plurality of laser diodes each adapted to project a laser line and actuated selectively according to the range of measurements to be applied to the vehicle to be controlled. - It comprises downstream image acquisition means and calculation means, a display module for an operator to view the results.

the imaging means are wide-field-of-view sensors, all identical and interchangeable, whose width and height of field, at a nominal working distance substantially equal to 1 m, are between 0.8 m and 2 m, preferably substantially equal to 1 m.

it is suitable for measuring games and outcrops on at least one side opening of a motor vehicle, the image taking means being arranged along an arch, the calculation means comprising an image processing module intended to extract information from the at least two images, in particular to determine distances other than the clearances and outcrops and perform a check presence / absence of elements of the body. - It is suitable for measuring the play and outcrop, when the vehicle is stationary or in scrolling phase

The subject of the invention is also a method for measuring gaps and outcrops between bodywork parts having respective edges facing each other, characterized in that it uses a system as described above and in that it includes the following steps:

projecting on the surfaces of the pieces at least one light line intersecting said edges of the pieces;

- acquisition of at least two images of the light line from two different angles of view;

- Extraction and determination of representative values of games and outcrops from at least two images; and

- Correction of values representative of games and outcrops previously determined according to the position and orientation of the image pickup means and the projection means relative to the trace to be measured. The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the appended drawings, in which:

- Figure 1 is a top view of a system according to the invention used to measure the play and outcrop on several openings and surfaces of a motor vehicle;

Figure 2 is a front view of the system of Figure 1;

Figure 3 is a side view of the system of Figure 1 with the vehicle in a first position; - Figure 4 is a view similar to that of Figure 3, the vehicle being in a second position;

Figure 5 is a view of the image sensor of the system of Figure 1; and

FIG. 6 is a diagram showing the operating principle of the system of FIG. 1. FIGS. 1 and 2 show, in a simplified manner, a system adapted to measure games and outcrops on several openings and surfaces of a motor vehicle 12.

In particular, the system 10 is adapted to measure games and outcrops on the lateral opening of the vehicle 12. In all that follows, the terms of position and orientation indicated, such as "front", "rear", "right" "And" left ", agree with the usual orientations of a vehicle.

The system 10 is stationary and comprises projection means 14, image pickup means 18, calculation means 16 and vehicle drive means 12 with respect to the projection means 14 and the pickup means. pictures 18.

The imaging means 18 are arranged along an arch under which the vehicle 12 scrolls, and are all identical and interchangeable, nine in the example. The image sensors 18 are digital cameras with a wide field of view.

As illustrated in FIG. 5, each image sensor 18 is a sensor with a wide field of view whose field width L and the height of field H, to a nominal working distance D substantially equal to 1 m, are between 0.8 m and 2 m, preferably between 0.7 m and 1.3 m and preferably substantially equal to 1 m.

The nominal working distance D of each image sensor 18 is between 0.6 m and 1.4 m, preferably between 0.8 m and 1.2 m and preferably substantially equal to 1 m.

The resolution of each image sensor 18 is greater than 4 Mpx and their intrinsic reliability is less than 75 microns.

The arrangement and the wide field of view of each image sensor 18 make it possible to obtain at least one zone in which the fields of view of at least two image sensors 18 overlap at least partially, thus covering the same area of the opening in which at least one measurement must be performed.

Referring to Figure 3, the vehicle 12 is in a first position that allows the system 10 to measure the clearances and outcrops on the front portion of the front doors 20.

Since the system 10 is substantially symmetrical with respect to the longitudinal axis of the vehicle 12, only the measurements made on the left side of the vehicle 12 will be described later. The gaps and outcrops are calculated between the front part of the left front door 20 and, for example, the left front wing 22 and the left bay pillar 24.

Each of these parts 20, 22, 24 has a surface substantially in the extension of one another and having an edge vis-à-vis with that of another of the parts 20, 22, 24, the respective edges being spaced from each other by a small gap.

The projection means are adapted to project on the surfaces considered at least one light line cutting substantially transversely the edges of these surfaces. In the example represented here, the projection means 14 comprise a plurality of laser diodes each adapted to project a laser line 26 each corresponding to a trace to be measured. Each light line 26 is captured in at least two images acquired by at least two imaging means 18, each light line 26 thus being taken under at least two different angles of view.

Unlike the solutions already described, the projection means 14 and the imaging means 18 are separate and independent.

The fields of view of the four image sensors 18 disposed on the left side of the arch (Figure 1) are represented by frames in Figure 3.

Only two image sensors 18 would have been sufficient to measure the four traces 26, their field of vision 28, 30 respectively encompassing the four laser lines 26.

In particular, with two image sensors 18, it is possible to measure at least three traces, such as for example five traces or more than five traces.

Referring to Figure 4, the vehicle 12 is in a second position which allows the system 10 to measure the clearances and outcrops on the rear portion of the left front door 20.

These gaps and outcrops are calculated between the rear part of the left front door 20 and, for example, the front part of the left rear door 32.

As shown in FIG. 6, the calculation means 16 comprise an image processing module 34 intended to extract information from the images taken by the image sensors 18, in particular the values representing games and outcrops.

On the basis of this information, a calculation module 36 makes it possible to determine, by a stereoscopic method, the positions and orientations of the image taking and projection means with respect to each of the measured traces defined along the light lines 26, and of correcting the clearance and outcrop values previously determined by the image processing module 34.

The image processing module 34 also makes it possible to determine distances other than the gaps and outcrops, to obtain information on the characteristic points of the surfaces under consideration, such as, for example, the location of the center of gravity of the image of an image. punching, and also to perform a check by checking for example the presence or absence of visible parts of the vehicle such as nuts or studs. Upstream of the imaging means 18 and the calculation means 16, the system 10 comprises a system adapted to transmit a cycle code specific to the model and the silhouette of the vehicle 12 to be controlled, to a range management module 38 The range management module 38 is able to select the range of measurements to be applied and to start the acquisition of images.

The choice of the measurement range according to the vehicle to be controlled actuates the projection means selectively by activating some of the laser diodes, the image sensors 18 with a wide field of view are not modified. The arrival of a different new vehicle generates sending by said adapted system a different cycle code to select a different range of measurements.

Downstream of the imaging means 18 and the calculation means 16, the system 10 comprises a display module 40 allowing an operator to view the results obtained.

The drive means of the vehicle 12 are adapted to move the vehicle 12 under the arch formed by all the laser diodes and image sensors 18, and are formed for example by a roller table. Moreover, these drive means are equipped with a line coder making it possible to know the relative position between the vehicle and the arch, so as to be able to trigger the activation of projection means 14 and the acquisition of the image means. 18 depending on the progress of the vehicle.

The operation of the system 10 will now be explained.

At the beginning of the cycle, the vehicle 12, placed on a support, is in the waiting position or arrives in front of the system 10.

Said adapted system sends a cycle code, corresponding to the model and the silhouette of the vehicle 12 waiting, to the range management module 38 which selects the range of measurements to be applied and to manage the activation of the projection means 14 and the acquisition of the imaging means 18. The vehicle 12 then advances under the arch, driven by the drive means, and passes to the first position shown in Figure 3. The laser diodes project on the surfaces a plurality of light lines 26 corresponding to the traces to be measured and cutting substantially transversely said edges of the surfaces.

The image sensors 18 capture at least two images of each light line 26 from two different angles of view.

The images are then transmitted to the calculation means 16 where two different processing operations are performed.

In a first step and from the transmitted images, the image processing module 34 extracts information in two dimensions on the profile of the surfaces.

In a second step and on the basis of this information, the calculation module 36 establishes the profile of the surfaces, in two dimensions and in three dimensions, along the light lines 26 and determines gambling and outcrop values at the same time. using an algorithm of the type used in the field of stereoscopy.

The results obtained are visualized by an operator on the display module 40.

The advancement of the vehicle 12 under the arch is continuous, the running speed being relatively low and adjusted according to the characteristic time constants of the laser diodes and the image sensors 18.

Vehicle 12 then moves to the second position shown in Figure 4.

The previous steps are repeated then.

The invention thus proposes a measurement solution by sensors with a wide field of vision and stereoscopic process which makes it possible to measure the games and outcrops on a motor vehicle in a simple, inexpensive, flexible, efficient and versatile manner.

Indeed, the wide field of vision of the image sensors makes it possible to have a range of control, ie a set of traces to be measured, large and flexible and the redundancy in the taking of images makes it possible to have reliable measurements. In addition, the image sensors are all substantially identical, their interchangeability and the supply and management of replacement sensors are facilitated.

The flexibility of the system makes it possible to measure the gaps and outcrops in the vehicle manufacturing flow at three different stages: at the workshop exit where, for example, the openings are manually referenced, at the exit of the paint shop and at the exit of the workshop. workshop assembly.

In all that has been described above, the laser lines 26 corresponding to the traces to be measured are projected onto the surfaces substantially transversely to the edges of the surfaces.

Alternatively, the laser lines 26 have an angle with the perpendicular to the edges of the surfaces and the calculation means 16 comprise a correction module adapted to compensate for this inclination.

Still alternatively, the system 10 applies to any suitable portion of the vehicle 12 and the image sensors 18 are correspondingly arranged.

For example, with the image sensors 18 arranged along the arch described above, the system 10 is able to measure games and outcrops on the roof of the vehicle 12, or on its hood. Similarly, the image sensors 18 may be arranged in two arches or substantially in a sphere, depending on the location of the traces to be measured.

In another variant, the number of image sensors 18 of the system 10 is any appropriate, at least equal to two, for example equal to seven or more. Still alternatively, the system 10 can operate with image sensors 18 with a wide field of view of different types.

In another variant, the advancement of the vehicle under the arch is discontinuous, the vehicle being stopped successively in the first and second positions. In yet another variant, the system and method according to the invention apply to any body, for example that of a rail or air vehicle.

Claims

1.- System (10) for measuring play and outcropping between bodywork parts (12) having respective edges facing each other, characterized in that it comprises: - projection means (14) dissociated and independent of the image sensors (18) for projecting on the surfaces of the parts at least one light line (26) intersecting said edges of the parts at the location of the trace to be measured

at least two image-taking means (18) capable of capturing at least two images of a light line (26) relating to a trace to be measured under two different angles of view,

calculation means (16) comprising an image processing module (34) intended to extract information from the images taken by the image sensors (18), in particular the values representative of the games and outcrops. calculation means (16) comprising a calculation module (36) which makes it possible to determine, by a stereoscopic method, the positions and orientations of the image taking and projection means with respect to each of the measured traces defined along the light lines (26), and correcting the clearance and outcrop values previously determined by the image processing module (34).

2. System (10) according to claim 1, characterized in that the imaging means (18) are sized and arranged so that the fields of vision (28, 30) overlap as widely as possible.

3.- System (10) according to claim 2, characterized in that the at least two image sensors (18) are adapted to each capture an image of several light lines (26) each corresponding to a different trace to be measured.

4 - System (10) according to any one of claims 1 to 3, characterized in that it comprises upstream of the imaging means (18) and calculating means (16), a system adapted to transmit a cycle code specific to the model and the silhouette of the vehicle (12) to be tested, to a range management module (38), the arrival of a new, different vehicle generating the consignment by said adapted system of a different cycle code adapted to select a different range of measurements.

5 - System (10) according to claim 4, characterized in that the range management module (38) is adapted to select the range of measurements to be applied and to manage the activation of the projection means (14) and the acquisition of the imaging means (18).

6. System (10) according to any one of claims 1 to 5, characterized in that the projection means (14) comprise a plurality of laser diodes each adapted to project a laser line (26) and selectively actuated depending on the range of measurements to be applied to the vehicle to be tested.

7 - System (10) according to any one of claims 1 to 6, characterized in that it comprises downstream of the imaging means (18) and calculation means, a display module (40). ) allowing an operator to view the results.

8. System (10) according to any one of claims 1 to 7, characterized in that the imaging means (18) are wide field of view sensors, all identical and interchangeable whose width (L ) and the height (H) of field, at a nominal working distance (D) substantially equal to 1 m, are between 0.8 m and 2 m, preferably substantially equal to 1 m.

9. System (10) according to any one of claims 1 to 8, characterized in that it is adapted to measure clearances and outcrops on at least one side opening (20) of a motor vehicle (12), the means imaging means (18) being arranged along an arch, the computing means (16) comprising an image processing module (34) for extracting information from the at least two images, in particular for determine distances other than clearances and outcrops and check for presence / absence of bodywork elements. 10 - System (10) according to claims 1 to 9, characterized in that it is adapted to measure the games and outcrops, when the vehicle is stationary or in scrolling phase

1 1.- Method for measuring clearances and outcrops between body parts (12) having respective edges vis-à-vis, characterized in that it uses a system (10) according to any one of preceding claims and in that it comprises the following steps: - projection on the surfaces of the pieces of at least one light line

(26) cutting said edges of the pieces;

acquiring at least two images of the light line (26) from two different angles of view;

- Correction of values representative of games and outcrops previously determined according to the position and orientation of the image pickup means and the projection means relative to the trace to be measured.