EP3631359A1

EP3631359A1 - Device and method for vehicle measurement

Info

Publication number: EP3631359A1
Application number: EP18727729.8A
Authority: EP
Inventors: Stefan Schommer; Stefanie PETERS; Stefan Strasser; Trendafil ILCHEV; Dominik MATTHEIS; Stefan Markus Kaefer; Christian Wagmann; Vikranth KAMBHALURU; Davide IACOVELLI; Rita RINKL; Christopher HANDSCHUH
Original assignee: Beissbarth GmbH
Current assignee: Beissbarth GmbH
Priority date: 2017-05-22
Filing date: 2018-05-17
Publication date: 2020-04-08
Also published as: WO2018215294A1; DE102017208608A1

Abstract

The invention relates to a device for determining the wheel or axle geometry of a vehicle (1), comprising a measuring site (10) where the vehicle (1) to be measured can travel and which has at least one known reference pattern (7; 7a, 7b) which is arranged above or below the wheel (4; 4a, 4b) of the vehicle (1) to be measured; and a measuring sensor (2) having an image capturing device (3) and an evaluation device (9). The measuring sensor (2) can be attached to a vehicle wheel (4; 4a, 4b) to be measured such that the position and alignment of the image capturing device (3) relative to the vehicle wheel (4; 4a, 4b) is known, and such that the image capturing device (3) can capture at least one image of at least one sub-region of the at least one known reference pattern (7; 7a, 7b). The evaluation device (9) is designed to evaluate an image captured by the image capturing device (3) when the vehicle wheel (4; 4a, 4b) is stationary, in order to determine the local track of the vehicle wheel (4; 4a, 4b).

Description

description

title

The invention relates to a device and a method for vehicle measurement

PRIOR ART In previously known optical methods for vehicle measurement, during a movement of the vehicle, images of measuring targets ("targets") attached to the vehicle and in the surroundings of the vehicle are recorded and evaluated in order to determine the wheel, axle and / or vehicle geometry determine.

Disclosure of the invention:

It is an object of the invention to simplify vehicle surveying. According to one embodiment of the invention, a method for

Vehicle measurement, in particular for determining the wheel and / or axle geometry of a vehicle, to position a wheel of the vehicle to be measured next to or below a known reference pattern ("target pattern") which is arranged vertically above or below the vehicle wheel. to mount an image pickup device on the vehicle wheel to be measured such that the image pickup device is capable of taking an image of at least a portion of the reference pattern; if the vehicle wheel is stationary, picking up at least one image of the reference pattern, the position of the image pickup device being known with respect to the vehicle wheel and evaluate the at least one captured image of the reference pattern to determine the local orientation of the vehicle wheel. According to one exemplary embodiment, a device (measuring sensor) for measuring a vehicle, in particular for determining the wheel or axle geometry of a vehicle, comprises a measuring station accessible by a vehicle with at least one known reference pattern and a measured value sensor comprising an image recording device and an evaluation device. The transducer is mountable to a wheel of a vehicle to be measured such that the imaging device is capable of receiving at least one image of at least a portion of the at least one known reference pattern disposed vertically above or below the vehicle wheel and orientation of the image pickup device with respect to the vehicle wheel are known. The

Evaluation device is designed to evaluate an image taken by the image pickup device when the vehicle wheel is stationary in order to determine the local orientation of the vehicle wheel.

An inventive device has a small footprint than conventional transducers. In particular, the invention enables lightweight, compact and robust transducers that can be easily and quickly mounted on the vehicle wheel. The risk of damage and / or change in the measurement accuracy due to a change in the position and / or orientation of the image pickup device is reduced.

It is not necessary to attach additional reference patterns to the vehicle and / or to move the vehicle during the measurement. The fact that the reference pattern is arranged above or below the vehicle wheel, the space required in the horizontal direction is reduced. There is no need to keep any space next to, in front of, or behind the vehicle to position the datum pattern and to allow a clear view of the datum pattern on the image pickup direction.

The reference pattern can be formed in particular on the bottom of the measuring station. Alternatively, the reference pattern may be formed or suspended from the ceiling above the measuring station. A device according to the invention may, but not necessarily on the

Rim of the vehicle wheel are attached. It can also be attached to the tire, if a stable connection that is maintained over the entire time of the measurement can be realized. In one embodiment, the method includes movably attaching the image pickup device to the vehicle wheel, aligning it with the reference pattern, and fixing it in that position. By aligning the image pickup device with the reference pattern, it is ensured that the reference pattern is always at least partially in the field of view of the image pickup device.

In one embodiment, the image pickup device is movably attached to the vehicle wheel and has a weight distribution which automatically aligns the image pickup device with the reference pattern under the influence of gravity.

The image pickup device need not be exactly aligned with the reference pattern. Rather, it is sufficient if the imaging device is aligned so that at least a portion of the

Reference pattern is located in the field of view of the image pickup device.

In one embodiment, the method includes using the local orientations of the vehicle wheels of an axle or a vehicle using a known spatial reference of two reference patterns for a track determination in terms of wheel alignment.

In one embodiment, the method additionally includes hitting the vehicle wheel and determining the steering angle of the vehicle wheel from images of the reference pattern taken before and after hitting the vehicle wheel. In this way, the local steering angle can be determined and used for the calculation of further vehicle-specific parameters. It is important to ensure that at least a portion of the reference pattern remains in the field of view of the image pickup device when the vehicle is turned in a steering movement.

In one embodiment, the method additionally includes determining the camber and / or the rim of the vehicle wheel. For this purpose, the device can have at least one sensor, for example a pendulum and / or a MEMS inertial sensor, which makes it possible to control the alignment of the

To determine the transducer in the room. In this way, it is not necessary to perform another method and / or another To use measuring device to determine the fall and / or the rim of the vehicle wheel.

In one embodiment, the method includes positioning the image pickup device within the rim edge, particularly near the center of the vehicle wheel. Centering the image pickup device reduces the risk of damage to the image pickup device upon movement of the vehicle or steering lock. In addition, regardless of the size of the wheel, the image pickup devices are approximately in a stable plane with respect to the vehicle at each time of the measurement. The determination of the vehicle geometry is thereby facilitated.

The type of attachment (on the rim, on the wheel, on the wheel bolts, etc.) does not play a decisive role. The method of attachment only has to ensure that the position of the image acquisition device does not change during the measurement in a manner relevant to wheel alignment.

In one embodiment, the reference pattern has a plurality of measurement points, which are arranged in particular along one or more lines. Several

Measuring points make it possible to unambiguously determine the position of the image recording device with respect to the reference pattern. A reference pattern, which consists of measurement points arranged along a line, has a small space requirement and can therefore be arranged, for example, next to a rotary plate which is designed to accommodate a vehicle wheel. The reference pattern is substantially aligned in or parallel to the roadway plane.

In one embodiment, the measurement points of the reference pattern are arranged in a two- or three-dimensional pattern.

As long as the pattern or features of the pattern are known, i. in particular, as long as the orientation of the pattern in the track direction can be determined, the geometry, in particular the arrangement of the measuring points, of the pattern can be chosen as desired. The features can be determined, for example, from the measuring points. Instead of measuring points can also

Textures of any kind, eg other measurement point geometries or stochastic textures, can be used. In one embodiment, each of the two front wheels of the vehicle is assigned its own reference pattern. In a further embodiment, each wheel of the vehicle is assigned its own reference pattern. In this way, the reference patterns can be arranged in the vicinity of the respective wheel, so that they are clearly visible by the respective image pickup device and the risk of a blockage of the field of view between the reference pattern and the respective image pickup device is reduced.

In one embodiment, the device has at least one illumination device which is designed to illuminate the reference pattern. With the aid of a lighting device, the reference pattern can be detected well by the image pickup device regardless of the ambient light.

In one embodiment, the reference pattern includes fluorescent, phosphorescent, or reflective elements that facilitate determination of the measurement points.

In an alternative embodiment, the reference pattern may include

be self-luminous reference pattern. The measuring points can be designed in particular as LEDs or as ends of optical fibers.

In one embodiment, the apparatus has two reference patterns arranged such that two vehicle wheels mounted on a common axle of a vehicle are positionable such that each of the vehicle wheels is disposed adjacent each of the two reference patterns. In this case, the relative positions of the reference patterns to each other are known. This allows a reference between the two on one axis of a

Produce vehicle mounted wheels and thus to determine the track of these wheels.

In one embodiment, the device has at least one additional reference pattern arranged such that vehicle wheels mounted on different axles of a vehicle are positionable such that each of the vehicle wheels is disposed adjacent to a respective tensile pattern. In this case, the relative positions of the reference patterns to each other are known. This makes it possible to establish a relationship between wheels mounted on different axles of a vehicle. Brief description of the figures:

Embodiments of the invention will be described below with reference to the accompanying drawings. Showing:

Figure 1 is a perspective view of a vehicle wheel with a

Transducer according to an embodiment of the invention;

Figure 2 is a schematic side view of a wheel of a vehicle with a transducer and a reference pattern according to a

Embodiment of the invention; and

3 shows a measuring station for Fahreugvermessung with the four wheels of a motor vehicle.

Brief Description:

Figure 1 shows a perspective view of a vehicle wheel 4 with a transducer according to an embodiment of the invention; and FIG. 2 shows a schematic side view of a wheel 4 of a vehicle 1 (vehicle wheel 4) with a measuring transducer 2 in accordance with FIG

Embodiment of the invention.

The vehicle wheel 4 shown in FIG. 1 is arranged on a rotary plate 8, which makes it possible for the vehicle wheel 4 to engage in a steering movement in a low-friction manner (rotation about a vertical axis). In addition to the rotary plate 8, a reference pattern 7 is formed with a series of measuring points 6.

In the embodiment shown in Figure 2, the reference pattern 7 is formed with a plurality of measuring points 6 on the bottom 15 of the measuring station 10 below the vehicle 1.

In an alternative embodiment, not shown in the figures, the reference pattern 7 may be formed or suspended on the ceiling of the room or the workshop above the measuring station 10.

The reference pattern 7 comprises at least two measurement points 6. By using a reference pattern 7 with more than two measurement points 6, the accuracy be improved. The measuring points 6 can be arranged on a common line, as shown in FIG. 1; Alternatively, the measuring points 6 may be arranged in a two- or three-dimensional pattern, as shown in FIG.

On the vehicle wheel 4, in particular on the rim 14 of the vehicle wheel 4, a transducer 2 is attached. The sensor 2 is

preferably mounted symmetrically to the axis of the vehicle wheel 4.

The sensor 2 has at least one image pickup device 3, which is aligned in such a way that it is capable of taking pictures of the reference pattern 7. The image pickup device 3 is movable in the

Sensor 2 can be arranged so that the image pickup device 3 can be aligned in the direction of the reference pattern 7 ("downwards") independently of the orientation of the pickup 2. Alternatively, the pickup 2 can be movably attached to the vehicle wheel 4 such that the image pickup device 3 can be aligned by moving, in particular turning the transducer 2, the reference pattern.

A method according to the invention is used in standing, i. non-rotating, vehicle wheel 4 performed. Since the vehicle wheel 4 does not rotate during the measurement, the image recording device 3 does not have to be tracked during the measurement; rather, it is fixed immovably to the vehicle wheel 4 during the measurement.

The sensor 2 may additionally comprise at least one lighting device 5, which makes it possible to illuminate the reference pattern 7.

Alternatively, the reference pattern 7 may be formed as an actively shining reference pattern 7 with self-luminous measuring points 6.

In a self-luminous reference pattern 7, the measuring points 6 may be formed, for example, as LEDs or contain LEDs. It is also possible to use light exit openings of suitably laid optical fibers, into which light is coupled, as measuring points 6.

Size and position of the reference pattern 7 are on the field of view of the image pickup device 3 and the maximum possible distance of Image pickup device 3 from the bottom 15 of the measuring station 10 tuned. The image pickup device 3 need not be exactly aligned with the reference pattern 7. Rather, it is sufficient if the image pickup device 3 is oriented so that at least a portion of the reference pattern 7 is in the field of view of the image pickup device 3.

If the measurement is to be carried out even when a vehicle wheel 4 has been turned, care must be taken to ensure that at least a portion of the

Reference pattern 7 remains in the field of view of the image pickup device 3 when the vehicle wheel 4 is taken in a steering movement.

The transducer 2 also comprises an evaluation device 9, which is designed to evaluate the at least one image of the reference pattern 7 recorded by the image recording device 3 in order to determine the position and orientation of the transducer 2 with respect to the reference pattern 7.

Since the position of the reference pattern 7 in space, for example by calibration, is known; and also the position and orientation of the

Measuring transducer 2 with respect to the vehicle wheel 4 due to the mounting of the transducer 2 on the vehicle wheel 4 are known, the

Evaluation device 9 determine the position and orientation, in particular the local track, of the vehicle wheel 4 in space when the position and the

Alignment of the transducer 2 with respect to the reference pattern 7 and the rim of the vehicle wheel 4 are known.

The rim impact of the vehicle wheel 4 may be determined by measurements that are not part of the claimed invention.

The transducer 2 may also include additional sensors 11, such as pendulum sensors and / or MEMS inertial sensors, which allow the rim to be determined.

In this way, the rim of the vehicle wheel 4 can be determined without having to replace the measuring sensor 2 by another measuring device or supplement. FIG. 3 shows a measuring station 10 for vehicle measurement with four wheels 4a, 4b of a motor vehicle 1. The motor vehicle 1 itself is not shown in FIG. 3 in order to allow a free view of the measuring station 10.

The measuring station 10 comprises two rotary plates 8, as shown in FIG. The rotary plates 8 are mirror-symmetrical to a longitudinal axis L of the

Measuring station 10 arranged. The front wheels 4a of the vehicle 1 are positioned on the rotary plates 8.

The two rotary plates 8 are referenced with respect to each other, e.g. by purposefully installing the reference patterns 7a formed on each of the rotary plates 8 so that the reference patterns 7a are arranged in a predetermined spatial relationship with each other; by means of a post-installation calibration in which the relative position of the two reference patterns 7a is determined and made known to the transducers 2; or by means of reference systems 12 mounted on the turning plates 8, which make it possible to reference the two turning plates 8 with respect to each other.

By referencing the rotary plates 8 and / or the reference pattern 7a, a relationship can be established between the front wheels 4a mounted on the left and right sides of the vehicle 1.

In order to be able to make a reference to the rear wheels 4b of the vehicle 1 mounted on a rear axle (not shown) of the vehicle 1, additional reference patterns 7b may be provided at the rear of the measuring station 10 at / below the rear wheels 4b, their positions and with respect to to the reference patterns 7a formed on the front wheels 4a / turning plates 8 are referenced.

Claims

claims

1. A method for determining the wheel and / or axle geometry of a

Vehicle (1), the method comprising: positioning a wheel (4; 4a, 4b) of the vehicle (1) to be measured next to or below a known reference pattern (7; 7a, 7b) above or below the wheel (4; 4a, 4b) is arranged; to mount an image pickup device (3) on the wheel (4; 4a, 4b) to be measured in such a way that the position and orientation of the image pickup device (3) with respect to the wheel (4; 4a, 4b) are known, and that the image pickup device (4) 3) is capable of taking an image of at least a portion of the reference pattern (7; 7a, 7b); at least one image of the reference pattern (7; 7a, 7b) and the at least one recorded image of the reference pattern (7; 7a, 7b) to evaluate the local orientation of the wheel to be measured (4 4a, 4b).

2. The method of claim 1, wherein the local orientations of the vehicle wheels (4; 4a, 4b) of an axle or a vehicle (1) using a known spatial reference of two reference patterns (7; 7a, 7b) to a track determination in the sense of Wheel alignment can be used.

3. Method according to claim 1 or 2, wherein the method additionally comprises striking the wheel (4; 4a, 4b) and images of the reference pattern (7; 7a, 7b) which before and after the wheel (4; 4a , 4b) have been recorded to determine the steering angle of the wheel (4; 4a, 4b).

A method according to any one of the preceding claims, wherein the method comprises, the image pickup device (3) movable on the wheel (4; 4a, 4b) to fix, to the reference pattern (7, 7a, 7b) to align and fix.

Method according to one of the preceding claims, wherein the method comprises, in addition to determine the camber and / or the wheel rim of the wheel (4; 4a, 4b).

Method according to one of the preceding claims, wherein the method comprises positioning the image pickup device (3) within the rim edge, in particular in the vicinity of the center of the wheel (4; 4a, 4b).

Device for determining the wheel or axle geometry of a

Vehicle (1), the device comprising: a measuring station (10), which can be driven by a vehicle (1), having at least one known reference pattern (7; 7a, 7b), the reference pattern (7; 7a, 7b) being above or below a wheel (4; 4a, 4b) of the vehicle to be measured (1) is arranged; a transducer (2) having an image recording device (3) and an evaluation device (9), wherein the transducer (2) can be attached to a wheel (4; 4a, 4b) to be measured so that the position and orientation of the image recording device (3) with respect to the wheel (4; 4a, 4b), and that the image pickup device (3) is capable of receiving at least one image of at least a portion of the at least one known reference pattern (7; 7a, 7b); and wherein the evaluation device (9) is designed to evaluate the image recorded by the image recording device (3) when the wheel (4; 4a, 4b) is stationary in order to determine the local orientation of the wheel (4; 4a, 4b).

Apparatus according to claim 7, wherein the reference pattern (7; 7a, 7b) comprises a plurality of dots (6), the plurality of dots (6) being arranged in particular along a line or in a two- or three-dimensional pattern.

9. Apparatus according to claim 8, wherein the reference pattern (7; 7a, 7b) has separately arranged points or other types of textures which make it possible to determine the features necessary for local tracking by means of the separately arranged points or textures.

10. Device according to one of claims 7 to 9, wherein the image pickup device (3) is movably mounted and has a weight distribution, which automatically aligns the image pickup device (3) on the reference pattern (7; 7a, 7b).

11. Device according to one of claims 7 to 10, wherein in addition to the reference pattern (7; 7a, 7b), a rotary plate (8) for receiving the wheel (4; 4a, 4b) is formed.

Device according to one of claims 7 to 11, wherein the device comprises at least one sensor (11), which makes it possible to determine the Ausrichtun the transducer (2) in space.

13. Device according to one of claims 7 to 12, wherein the device

at least one lighting device (5), which is designed to illuminate the reference pattern (7; 7a, 7b), and / or wherein the reference pattern (7; 7a, 7b) is formed as a self-luminous reference pattern (7; 7a, 7b).

14. Device according to one of claims 7 to 13, wherein the device comprises two reference patterns (7; 7a, 7b) which are arranged such that two vehicle wheels (4; 4a, 4b), which on a common axis of a vehicle (1 ) are positionable such that each of the vehicle wheels (4; 4a, 4b) is arranged next to each one of the two reference patterns (7; 7a, 7b), wherein in particular the relative positions of the reference patterns (7; 7a, 7b) to each other are known.

15. Device according to one of claims 7 to 14, wherein the device

at least one additional reference pattern (7; 7a, 7b), which is arranged such that vehicle wheels (4; 4a, 4b), which at different

Axes of a vehicle (1) are mounted so positionable that each of the vehicle wheels (4; 4a, 4b) each next to a reference pattern (7; 7a, 7b) wherein, in particular, the relative positions of the reference patterns (7; 7a, 7b) are known to each other.