WO2014048831A1

WO2014048831A1 - Method and system for inspection, maintenance or repair of a vehicle or of a part of a vehicle

Info

Publication number: WO2014048831A1
Application number: PCT/EP2013/069490
Authority: WO
Inventors: Thomas KASSOUF; Pietro AZZARI; Steven Rogers; Robert D'agostino; Paolo Sotgiu; Francesco Braghiroli
Original assignee: Snap On Equipment SRL
Current assignee: Snap On Equipment SRL
Priority date: 2012-09-27
Filing date: 2013-09-19
Publication date: 2014-04-03
Anticipated expiration: 2015-03-27

Abstract

A method and system for inspection, maintenance or repair of a vehicle, especially a motor vehicle or of at least one part of the vehicle, wherein for determining position or geometrical data of the vehicle or of the at least one part of a vehicle, a light field image of the vehicle or of the part of the vehicle or of a target attached to the vehicle or to the at least one part of the vehicle is produced to localize the vehicle or the at least one part of the vehicle in three dimensions by determining distinct incident angles of light coming from the vehicle or form the at least one part of the vehicle or from the target attached to the vehicle or to the at least one part of the vehicle by light-sensitive elements which are positioned in predetermined locations.

Description

Method and system for inspection, maintenance or repair of a vehicle or of a

part of a vehicle.

This invention concerns a method and system for inspection, maintenance or repair of a vehicle, especially a motor vehicle or at least one part of a vehicle, wherein geometrical data of the vehicle or of at least one part of a vehicle are determined.

An increasing variety of applications involve machine vision measurements taken by processing image data from cameras. For example, wheels of motor vehicles may be aligned on an alignment rack using a computer-aided, three-dimensional (3D) machine vision alignment apparatus. In such a technique, one or more cameras of the alignment apparatus view targets attached to the wheels of the vehicle. The cameras form images of the targets, and a computer in the alignment apparatus analyzes the images of the targets to determine wheel position. The computer guides an operator in properly adjusting the wheels to accomplish precise alignment, based on calculations obtained from processing of the image data.

Examples of methods and apparatus useful in 3D alignment of motor vehicles are described in US patent 5,943,783 entitled "Method and apparatus for determining the alignment of motor vehicle wheels"; US patent 5,809,658 entitled "Method and apparatus for calibrating cameras used in the alignment of motor vehicle wheels"; US patent 5,724,743 entitled "Method and apparatus for determining the alignment of motor vehicle wheels"; and US patent 5,535,522 entitled "Method and apparatus for determining the alignment of motor vehicle wheels". Imaging systems using cameras are described in US patent 7,355,687 and US patent 8, 1 13,049 for wheel balancers and in US patent 7,495,755 for tire changers. The image data are digitally processed to determine geometrical data of vehicle wheels for the calculation of wheel balancing weights or for controlling the operations of tire changer tools. US patent 8, 141 ,414 describes an imaging system for determining the condition of tire treads.

Cameras used in the known imaging systems have typically been limited to CCD type cameras capable of capturing a static image of either a target or tire/wheel assembly. Multiple images are taken at different rotations and inclinations of the wheel assembly to provide sufficient data to allow determination of needed alignment data calculated from the image data. In other systems, multiple cameras located at different known locations with respect to each other capture simultaneous images of the target or wheel assembly and using stereoscopic algorithms, to determine the three-dimensional location of the captured object. Single camera systems do not directly enable the estimation of 3D position except for restricted special cases. For example, if the geometry of the object being imaged is known ahead of time or if the camera is moved a known amount with respect to the object, a single image can enable 3D position estimation.

Stereoscopic camera systems suffer the increased cost of multiple cameras and the cost of creating a stable housing for fixing the location of one camera to the next. Further, any dislocation of one camera with respect to another will necessitate recalibration or replacement of the camera set.

Stereo camera systems do not have perfectly overlapping fields of view. Objects that are visible in one camera may not be visible in other cameras that comprise the stereo sys- tern, and if so their depth cannot be estimated. This problem is more significant for objects at closer ranges.

Stereo camera systems tend to be much bulkier and more obtrusive than an equivalent number of cameras arranged in a non-stereo manner. This is significant for areas where space is at a premium (on a lift, for example). To get depth information, stereo camera systems require that the same 3D scene points be matched in each of the images that comprise the stereo system. This image matching task is known as the "correspondence problem" and is often a significant obstacle despite advances in algorithms.

The problem to be solved by the invention is to provide a method and a system for inspection, maintenance or repair of vehicles, especially motor vehicles or at least one part of the vehicle in which the determination of the spatial position of a vehicle, especially of a motor vehicle or of one or more parts of the vehicle is enabled by using a simplified imaging system.

This problem is solved by the method having the features of claim 1 and by the system having the features of claim 1 1. Advantageous embodiments are covered by the sub- claims.

The simplified imaging system enables the capture of multiple images of the vehicle, especially of a motor vehicle or of one or more parts of the vehicle simultaneously from a light field imaging system and enables determination of distance and angle measurements needed to support the parameter calculation for determining the spatial position of the vehicle and of one or more parts of it. The used light field imaging system is designed to procedure a light field image of the vehicle or of at least one part of the vehicle or of a target attached to the vehicle or to the at least one part of the vehicle. Light sensitive elements are positioned in predetermined locations and designated to determine distinct incident angles of light coming from the vehicle or from the target attached to the vehicle or to the at least one part of the vehicle. Processing means, especially digital processing means are operatively connected to the light sensitive elements to determine from the output data of the light sensitive elements the spatial location of the vehicle or of the at least one part of the vehicle.

A preferred embodiment of the invention comprises a light field (i.e. plenoptic) camera which comprises a microlens array located between the camera image sensor (light sensitive sensor) and the camera main lens. The microlens array facilitates the capture of light ray direction in addition to the basic image information available form a single lens camera. By recording this additional light direction parameter in one single image capture, plenoptic cameras can store information of a 3D scene comparable to taking many shots at the same time from different points of view. Depth to different points of interest within the plenoptic camera field of view can be estimated using a combination of the light ray direction and image information collected. An imaging system including a plenoptic camera is described in US patent 7,936,392, in REN NG ET AL: "Light Field Photography with Hand-held Plenoptic Camera, in "Standford Tech Report CTSR" 2005-02, and in Edward H. Adelson and John Y.A. Wand, Single Lens Stereo with a Plenoptic Camera", Feb. 1992, IEEE, vol. 14, No. 2, pp. 99- 106*.

The known imaging systems concern the improvement of the imaging quality of the plenoptic camera, whereas the invention uses the plenoptic camera to achieve information about the geometrical properties and characteristics of the vehicle or of at least one part of the vehicle and its spatial position. The plenoptic camera used for the invention is preferably designed such that light passing via each microlens to the light sensitive sensor does not overlay light passed via adjacent microlens. Thus, the function of the plenoptic camera significantly reduces the difficulty of the "correspondence problem", the task of matching landmark points across multiple cameras in a stereoscopic imaging system. Useable plenoptic cameras are designed as described in the before mentioned state of art or as described in EP 2 244 484 B1.

Another usable embodiment of the light field imaging system includes an angle-sensitive pixel device provided with light-sensitive detectors disposed at predetermined positions and sensitive to both the intensity and the incident angle of incident light from the vehicle or from at least one part of the vehicle. Processing means are adapted to determine from the output data of the detectors the spatial location of the vehicle or of the at least one part of the vehicle and are operatively connected to the light-sensitive detectors.

Such a light field image device is known from WO 2010/044943 A2 and comprises a pixel-scale sensor that uses the Talbot effect to detect the local intensity and incident angle of light. The sensor comprises two local diffraction gratings stacked above a photo- diode. When illuminated by a plane wave, the upper grating generates a self-image at the half Talbot depth. The second grating, placed at this depth, blocks or passes light depending upon incident angle. Several such structures, tuned to different incident angles, are sufficient to extract local incident angle and intensity. Furthermore, arrays of such structures are sufficient to localize light sources in three dimensions.

The determined position or geometrical data can be used to perform, especially to control maintenance services on the captured vehicle or on the at least one part of the vehicle in a vehicle service station, especially in service or maintenance equipments, like tire changers, wheel balancers, wheel alignment systems, vehicle testing stands, for instance break test stands and suspension test stands, vehicle body measuring system, especially in equipments for the repair of damaged vehicles and vehicle body structures. The captured part of the vehicle can be a tire/rim assembly or the vehicle body or at least a part of the vehicle body. The invention can be also used in stand-alone applications, for instance in a wheel diagnosis system of EP 22 1 1 1 61 B1.

Other advantages and embodiments of the present invention shall now be described with reference to the attached drawings. The terms "top", "bottom", "up", "low", "left" and "right" used when describing the embodiment, relate to the drawings orientated in such a way that the reference numerals and the name of the figures can be read normally.

Fig. 1 shows a first embodiment of the invention; and

Fig.2 shows a second embodiment of the invention;

Fi.3 shows a wheel alignment system for which the first or the second embodiment can be used;

Fig.5 shows a tire changer for which the first or the second embodiment can be used, and

Fig. 6 shows a vehicle body measurement and repair station for which the first or the second embodiment can be used, and

Fig. 7 shows an analysis device for analysing a tire.

The Figures 1 and 2 illustrate schematically imaging systems which enable the simultaneous capture of multiple images of an object. The object can be a vehicle 14, especially a motor vehicle or one or more parts of the vehicle, for instance vehicle wheels, or the vehicle body or the like. The light field imaging systems of Figures 1 and 2 enable determination of distances and angles needed to support the parameter calculation for determining the spatial position of the vehicle or of one or more parts of it. The used light field imaging systems are designed to process a light field image of the vehicle or of the at least one part of the vehicle. Light sensitive elements are positioned in predetermined locations and designated to determine distinct incidents angles of light coming from the vehicle. Processing means 1 1 , especially digital processing means are operatively con- nected to the light-sensitive elements to determine from the output data of the light- sensitive elements the spatial location of the vehicle or of the at least one part of the vehicle.

The shown embodiments enable the determination of geometrical data of an object, in particular of a tire/rim assembly 8 (vehicle wheel) or of at least one part of it in a system 1 for maintenance or repair of vehicles or of at least one part of a vehicle. Another captured object can be the vehicle 14 or the vehicle body 20. The vehicle 14, the body 20 or the tire/rim assembly 8 are preferably positioned in a service system 12 or a maintenance equipment, for instance in a wheel balancer, a tire changer, a wheel alignment system, a break test stand, suspension test stand or a vehicle body alignment device.

The light field imaging system 2 of the Figure 1 establishing along an optical axis 13 a plenoptic camera comprises a main lens 6 and a light sensitive sensor 4 which is placed in an imaging plane 5. A microlens array 3 is arranged between the main lens 6 and the light sensitive sensor 4 to capture a light field emitted from the object. A particular microlens 7 of the microlens array 3 is positioned and designed to form a microimage of the main lens aperture which captures the object. The microimages are formed in the imaging plane 5 including the light sensitive sensor 4. Preferably, the imaging plane 5 is the focal plane of the microlenses 7. If a field lens, which places the main lens aperture at optical infinity, is positioned in front of the microlens array 3, the microimages can be focussed directly after the microlens array in the light path. The particular microlens 7 produces at different positions in the imaging plane 5 respective microimages of the main lens aperture and of the captured object. The mircoimages correspond to images of the object captured from different viewpoints. The microimages are detected by sensor elements 9, for instance CCD elements constituting pixels for detecting the microimages. The output signals of the sensor elements 9 include an information about both the horizontal and vertical parallax in the imaging plane 5 combined with an information about the depth which can be derived from the intensity distribution in the micro-image.

Digitally processing means 1 1 are operatively connected to the light sensitive sensor 4 for processing the output data of the sensor elements 9 to determine the spatial position and geometric characteristics of the captured object by performing an displacement analysis of the microimages in the imaging plane. When using the respective focal lengths of the main lens 6 and the respective positions of the microlenses 7, the spatial position with respect to the microlens array and/or to the imaging plane can be determined by back triangulation. The microlens array 3 is located in a predetermined position especially with respect to a reference position.

Another usable embodiment of the light field imaging system 1 is illustrated in Fig. 2 and includes a pixel device 16 provided with light-sensitive detectors 17 disposed at prede- termined positions and sensitive to both the intensity and the incident angle of incident light from the vehicle 14 or from at least one part of the vehicle. Processing means adapted to determine from the output data of the detectors the spatial location of the vehicle 14 of at least one part of the vehicle is operatively connected to the light-sensitive detectors. The at least one part of the vehicle can be the tire/rim assembly 8, which forms a vehicle wheel, or the vehicle body 20. As explained in conjunction with Figure 1 , the captured vehicle 14 or the at least one part of the vehicle 14 can be arranged in a service system 12 or maintenance system or similar device for vehicles, especially motor vehicles. Such a light field imaging device is known from WO 2010/044943 A2 and comprises the pixel-scale sensor 16 that uses the Talbot-effect to detect the local intensity and incident angle of light. The sensor comprises two local diffraction gratings stacked above a photo-diode. When illuminated by a plane wave, the upper grating generates a self- image at the half Talbot-depth. The second grating, placed at this depth, blocks or passes light depending upon incident angle. Several such structures, tuned to different incident angles, are sufficient to extract local incident angle and intensity. Furthermore, array of such structures are sufficient to localize light sources in three dimensions.

The embodiment uses the angle-sensitive pixel 16 as imaging sensor in combination with a lens system 19, which may be advantageous to image more distant objects. As shown in Fig. 2, the object (vehicle 14, tire/rim assembly 8, vehicle body 20) at the focal plane of the lens system 19 will appear completely in focus on the surface of the light-sensitive detectors 17, and will appear to have an even distribution of angles of incidence. In this case the array acts like normal CMOS imager. Such a light field imaging system is described in detail in WO 2010/044943 or in OPTICS LETTERS, August 201 1 , Vol. 36, No. 15 pages 2949 to 2951. By detecting incident angle an information about an object region that is thicker than the normal depth of focus associated with a given lens can be used. This information may be used, e.g., to reconstruct the three-dimensional structure of the captured object, or to computationally refocus the image to different focal depths after the image has been captured. The data from the imaging system may be used to simultaneously refocus different parts of the image to different depths. And although a single light- emitting object will generate a sensor response that maps to a single incident angle, multiple light sources will result in a linear superposition of responses, each of which depends on the incident angle of each source. Figure 3 shows a wheel balancer 29 which is equipped with a light field imaging device 2 or 16 of the Fig. 1 or 2. The tire/rim assembly 8, especially a vehicle wheel is mounted onto a measuring shaft 31 of the wheel balancer 29. The measuring shaft is operatively connected in a known manner with force measuring elements in a measuring device 30 of the wheel balancer. During a measuring run, the forces resulting from an unbalance of the wheel are measured. A known wheel balancer is described for instance in US 5,488,861. The light field imaging device 2 or 16 can determine the geometrical structure of the vehicle wheel (tire/rim assembly 8) to get an information about the wheel type, for instance by comparison with stored structural features of various wheel types. Additionally, the geometrical sizes of the rim and of the tire can be determined in the processing means 1 1. The respective output data of the processing means 1 1 are delivered to a measuring device 30 of the wheel balancer 29 which calculates from the forces measured during a measuring run and from the determined wheel sizes, especially rim diameter and/or the rim width, at least one balancing mass for the balancing of the tire/rim assembly. Optical selecting means 10, for instance a laser can illuminate one or more specific two-dimensional or linear areas or parts of the tire/wheel assembly 8 for determining the geometric characteristics or spatial position of the selected area of the part.

In another embodiment the service system 12 can be configured as a wheel alignment system, as shown in figure 4. The light field imaging system 2 or 16 is positioned for capturing vehicle wheels 15, especially two vehicle wheels 15 on each side of a motor vehicle 14. However, it is also possible to use for each wheel 15 an imaging system 2 or 16. The imaging system 2 or 16 is connected to the central processing means 1 1 to determine the positional relationship of vehicle wheels on the vehicle 14. In another embodiment, targets are attached to the vehicle wheels 15, as known from US patent 5,724,743 wherein the targets are captured by the light field imaging systems 2 or 16. Furthermore, it is possible to attach a target to the vehicle body, especially for defining a reference location. The target having a predetermined configuration is disposed such that it can be captured by the imaging system 2 or 16.

The imaging system 2 or 16 generates a light field image of each vehicle wheel 15 and, if present, of each target and the processing means 1 1 correlates each of the images with the true shape of the wheel or of the target for the calculation of the position of each vehicle wheel 15 and of the positioned relationship of the vehicle wheels on the vehicle 14.

The embodiment of Fig. 4 shows two light field imaging devices 2 or 16, wherein each imaging device 2 or 16 images the vehicle wheels or the target on one side of the vehicle 14. The imaging devices 2 or 16 can be mounted in predetermined positions on a carrier 32 so that the imaging elements of imaging devices 2 or 16 are positioned in respective reference positions on the carrier 32. The carrier 3 can be provided with respective markers for defining the reference positions. Instead of two light field imaging devices, only one light field imaging device 2; 16 can be used and positioned in predetermined positions to generate for the vehicle wheels 15 or for the target on each side of the vehicle 14 at least one respective light field image.

The light field imaging devices 2; 16 can be able to generate for one or more parts or points of each vehicle wheel 15 a light field image. For the determination of the spatial location three points or parts around the rotation axis of the vehicle wheel are sufficient. The parts or points on the vehicle wheel can be selected with a selection means, especially a laser, like the selection means 10 of the embodiment shown in Fig. 3.

The invention described before is related to a wheel alignment system for determining the position and for the alignment of vehicle wheels 15 of a vehicle 14. The system includes at least one light field imaging device 2 (Fig. 1 ) or 16 (Fig. 2) which provides a light field image of at least one vehicle wheel or of at least one part or point of the vehicle wheel. The data representing at least one light field image are processed in a processing means 1 1 , especially in computing means to determine the spatial position or alignment of each vehicle wheel or of at least one part or point on the vehicle wheel. The Fig. 5 illustrates an embodiment in which the service system 12 (Fig. 1 and 2) is designed as a tire changer 24. The tire changer 24 comprises a machine frame 23 which has a shaft to which the tire/rim assembly (vehicle wheel) 8 can be fixed. The shaft and the thereto fixed tire/rim assembly 8 can be rotatably driven by a motor drive 21 which is preferably an electric motor. One or more mounting/demounting tools 22 are supported on a vertical pillar 33. The at least one mounting/demounting tool 22 can be moved in horizontal and vertical directions during the mounting or demounting operation. In another embodiment, the shaft and the thereto fixed tire/rim assembly 8 can be moved with respect to the at least on mounting/demounting tool 22 which can be moved at least vertically. The tire changer 24 is equipped with a light field imaging device 2 (Fig. 1 ) or 16 (Fig. 2). The device 2 or 16 can capture at least the area in which the at least one mounting/demounting tool 22 is acting onto the tire. The imaging device 2 or 16 is connected to the processing means 1 1. In dependence of the captured location of the tire, of the at least one tool 22 and of the rim edge, the movement of the tool 22 and/or the horizontal movement and rotation of the rim fixed to the driven shaft is controlled by the processing means 1 1 to achieve a gentle action onto the tire and the respective rim edge behind which the tire is mounted or from which the tire is demounted. The respective locations of the tire, of the rim edge and of the tool within the working area of the tool 22 is deter- mined by the processing means 1 1 which are connected to the light field imaging device 2 or 16 to receive the output data of the captured light field image. Also the operation of bead breakers (not shown) can be controlled in the same manner.

According to the embodiment shown in Fig. 6, the service system 12 (Fig. 1 and 2) is designed as a vehicle body measurement repair station, especially as a device 25 for alignment a vehicle body 20. The alignment device 25 comprises at least two beam members 29 extending longitudinally of the vehicle body 20 and at least two beam members 27 disposed transversely to the beam members 28 to form a frame. The vehicle body 20 is connected by means of connecting members 26 to the frame. By adjusting the position of the crossing points of the beam members the vehicle body can be aligned into the required design.

During the alignment procedure, the structure of the vehicle body 20 is captured by at least one light field imaging device 2 (Fig.1 ) or 16 (Fig. 2). Especially at least one imaging device forms a light field image of each body side which has to be aligned. The aligning movements of the alignment device 25 is controlled by the processing means 1 1 which receives the output data representing the light field image of the captured vehicle body or of a part of the vehicle body.

In the embodiment of the Fig. 7, the service device 12 of the Fig. 1 and 2 is configured as an analysis device 36 for analysing the performance of a tire tread. When rotating the tire/rim assembly 8 which can be a vehicle wheel on the measuring shaft 31 , successive light field images were produced by the light field imaging device 2 (Figure 1 ) or 16 (Figure 2). The light field imaging device 2 or 16 is disposed to capture the tread pattern 34 of the tire. The successive light field images can be associated to respective rotation angles of the measuring shaft 31 so that an information about the condition of the tire tread on the complete circumference of the tire can be achieved. The data of the successive light field images are transmitted from the imaging device 2 or 16 to the processing device 1 1 which can be disposed in the machine frame 23. The processing device 1 1 can include a storage unit for storing the data of the successive light field images associated to respective rotation angles. A transmitter 18 for the rotation angle is operatively connected to the measuring shaft 31 and the output signals of the transmitter 18 are delivered to the stor- age unit of the processing means 1 1. The embodiment of Figure 7 can be used in con- junction with a tire changer, a wheel balancer or with test stands, like brake or suspension test stands.

The light field images include information about the surface profile of the circumferential tread, especially of the depth or height of the tread pattern 34 and of the tread wear.

The analysis device 36 can be incorporated into a wheel balancer, like that of Figure 3 or into a tire changer, like that of Figure 5. The machine frame 23 can be the machine frame of the wheel balancer or the machine frame of the tire changer.

Thus the invention provides also a service system for the inspection, maintenance and repair of vehicles especially motor vehicles of at least one part of the vehicle, like the vehicle body or the vehicle wheel, wherein at least one light field imaging device or system is used to achieve information about the spatial location of the vehicle or of at least one part of the vehicle with respect to a predetermined spatial reference. From such information, geometrical sizes and structural features can be derived. The operation of the light field imaging device or system is performed preferably with the aid of digital processing means.

List of reference signs

1 System f

2 Light filed imaging system (plenoptic camera)

3 Microlens array

4 Light sensitive sensor

5 Imaging plane

6 Main lens

7 Microlens

8 Tire/wheel assembly

9 Sensor element

10 Selecting means

1 1 Processing means

12 Service system

13 Optical axis

14 Vehicle

15 Vehicle wheels

16 Light filed imaging system (angle sensitive pixel device)

17 Light-sensitive detectors

18 Transmitter of rotation angle

19 Lens system

20 Vehicle body

21 Motor drive

22 Mounting/demounting tool

23 Machine frame

24 Tire changer

25 Vehicle body alignment device

26 Connecting members

27,28 Beam members

29 Wheel balancer

30 Measuring device

31 Measuring shaft

32 Carrier

33 Pillar

34 Tread pattern

35 Analyzing device

Claims

A method for inspection, maintenance or repair of a vehicle, especially a motor vehicle or of at least one part of the vehicle, wherein for determining position or geometrical data of the vehicle or of the at least one part of a vehicle, a light filed image of the vehicle or of the part of the vehicle or of a target attached to the vehicle or to the at least part of the vehicle is produced to localize the vehicle or the at least one part of the vehicle in three dimensions by determining distinct incident angles of light coming from the vehicle or from the at least one part of the vehicle or from the target attached to the vehicle or to the at least one part of the vehicle by light-sensitive elements which are positioned in predetermined locations.

The method according to claim 1 , wherein the intensity of the incident light is detected by the light-sensitive elements.

The method according to claim 1 or 2, wherein a plenoptic camera, which includes a microlens array between a light- sensitive sensor in an imaging plane and a main lens, is capturing the light field emitted or reflected from the vehicle or from the at least one part of the vehicle or from the target, wherein a particular microlens of the microlens array forms a microimage of the main lens aperture as seen from the position in the imaging plane after the respective microlens in the optical path, sensor elements of the light-sensitive sensor produce output data including an information about both a parallax parallel to the imaging plane and the depth vertical to the imaging plane, and said output data are digitally processed to determine the spatial position of the vehicle or of at least one part of the vehicle.

The method of anyone of the claims 1 to 3, wherein the output data of each microimage provides position data of the position of the respective microimage in the sensor plane and characteristic data of the light distribution characteristic in the microimage.

The method of anyone of the claims 1 to 4, wherein the spatial position of the vehicle or of at least one part of the vehicle is determined with respect to a reference location which is stationary in relation to the lens array and the imaging plane.

The method of anyone of the claims 1 to 5, wherein the output data of the micro images which are seen from different positions in the imaging plane are used.

The method according to claim 1 or 2, wherein an angle-sensitive pixel device which is sensitive to both the intensity and the incident angle of incident light from the vehicle or from the at least one part of the vehicle or from the target.

The method of anyone of the claims 1 to 7, wherein the determined position or geometrical data are used to perform, especially to control maintenance services on the captured vehicle or on the at least one part of the vehicle.

The method according to anyone of the claims, wherein the determined position or geometrical data are used to control maintenance services on the captured vehicle or on the at least one part of the vehicle in a tire changer, wheel balancer, wheel alignment system, vehicle testing stand or vehicle body measuring system.

The method of claim 5, wherein the captured part of the vehicle is a tire/wheel assembly or the vehicle body or at least a part of the vehicle body.

A system (1 ) for inspection, maintenance or repair of vehicles, especially motor vehicles or of at least one part of the vehicle, having means for determining positions or geometrical data of a vehicle or at least one part of a vehicle comprising: a light field imaging device (2; 16) designed to produce a light field image of the vehicle (14) or of at least one part of the vehicle or of a target attached to the vehicle or to the at least one part of the vehicle; light-sensitive elements (9; 17) which are positioned in predetermined locations and designated to determine distinct incident angles of light coming from the vehicle or from the at least one part of the vehicle or from the target attached to the vehicle or to the at least one part of the vehicle, and processing means (1 1 ) operatively connected to the light-sensitive elements (9: 17) to determine from the output data of the light-sensitive elements (9; 17) the spatial location of the vehicle or of the at least one part of the vehicle.

A system according to claim 1 1 comprising: a plenoptic camera (2) including a microlens array (3) between a light sensitive sensor (4) in an imaging plane (5) and a main lens (6); said plenoptic camera (2) is designed to be positioned for capturing the light field emitted from the vehicle (14) or from the at least one part of the vehicle (14), a particular microlens (7) of the microlens array (3) is positioned and designed to form a microimage of the main lens aperture as seen from a position in the imaging plane (5) after said microlens (7) in the optical light path, said lightsensitive sensor (4) has sensor elements (9) designed to produce output data of the microimages, wherein the output data include information about both parallax parallel to the imaging plane and the depth vertical to the imaging plane, and digitally processing means (1 1 ) designed to determine from the information provided by said output data the spatial position of the vehicle (14) or of at least one part of the vehicle.

The system of claim 1 1 or 12, wherein selecting means (10) are provided for selecting at least one part of the captured vehicle or of the at least one captured part of the vehicle, means for determining the respective output data of the light sensitive sensor (4) associated to said selected at least one part of the vehicle, and processing means (1 1 ) designed to determine from said associated output data the spatial position of the at least one part of the vehicle.

14. The system of claim 12 or 13, wherein the output data of the light sensitive sensor (4) includes position data of the microimages produced by the micro-lenses (7) in the imaging plane (5) and light characteristic data of the light detected by means of the sensor elements (9).

15. The system according to claim 1 1 , wherein the light field imaging device includes an angle-sensitive pixel device (16) provided with light-sensitive detectors (17) disposed at predetermined positions and sensitive to both the intensity and the incident angle of incident light from the vehicle (14) or from at least one part of the vehicle or from the at least one target, and wherein the processing means is designed to determine from the output data of the detectors (17) the spatial location of the vehicle or of the at least one part of the vehicle.

16. The system of anyone of the claims 1 1 to 15, wherein the system (1 ) is designed to control maintenance operations of the service system (12) in dependence of the determined geometrical data or position data of the vehicle (14) or of the at least one part of the vehicle.