DE202014007337U1 - Tread detection device - Google Patents

Abstract

Tire profile detecting device, comprising a base unit (1) with a plate-shaped positioning element (2) on which a tire (3) can be erected, wherein the positioning element (2) has a longitudinal recess (4) and wherein the base unit (1) below the longitudinal recess (4) a free space (5), wherein the free space (5) by Lotrechte (6) of boundaries of the longitudinal recess (4) to the positioning element (2) is fixed, and comprising a projection unit, with which an optical pattern (7) on the tire (3) is projectable, the projection unit comprising a pattern generating element (8) for providing the optical pattern (7) and a projection deflecting element (9) for deflecting the optical pattern (7) on the tire (3), and comprising an image capturing unit which an image (10) of the optical pattern (7) is detectable, wherein the image capture unit comprises an image capture element (11) for capturing the image (10) of the optical must 7 and an image deflecting element (12) for deflecting the image (10) of the optical pattern (7) onto the image sensing element (11), and wherein the projection deflecting element (9) and the image deflecting element (11) are located outside the free space (5). are arranged in the base unit (1).

Description

The invention relates to a tire tread detecting device for optically detecting the tread and the tread depth of a tire.

Tire profile detecting devices based on optical detection means are already known from the prior art.

Such devices provide the detection of a tire profile and its tread depth, for example by means of line projection and triangulation. For this purpose, the known devices generally have a receiving plate on which the tire to be detected can be set up or driven up via a ramp. The receiving plate has at a fixed position a stable, transparent disc which is run over by the tire and under which an optical system, usually consisting of a pattern projector and a camera, is arranged. To capture the tire tread, a pattern is first projected onto the tire by the pattern projector. Subsequently, the image of the pattern on the tire is detected by the camera and provided on this basis an image of the profile for further processing. In particular, in conventional devices, the disc serves to protect the underlying optical system from contaminants in the form of dirt or liquids which may become detached from the tire during a sensing operation.

A major disadvantage of such devices is in particular that both the projection, as well as the detection of the pattern must be done through the disc. On the one hand, this leads to the fact that the disk itself, due to its refraction behavior, has to be taken into account in the beam path of the projection or the reflection. On the other hand, this poses the problem that the disc is contaminated or scratched during use of the device or that it can fog up in unfavorable cases from the inside. Such events may result in non-recognition disadvantageous to incorrect results.

Another disadvantage of such tire profile detecting devices is that the optical system due to its design and arrangement within the device requires a relatively large height and so the entire device has a corresponding height. Depending on the type of vehicle, it may thus lead to an unfavorable Einfederstellung the wheel of the tire to be detected or to a placement of attachments of the vehicle on the device during startup on this.

The object of the present invention is thus to provide, while avoiding the disadvantages of the prior art, a tire tread sensing device which allows a permanent correct detection of the tire and in particular the tire profile, which is low maintenance and which at the same time has a low overall height.

The problem is solved by the features listed in the protection claim 1. Preferred developments emerge from the subclaims.

A tire tread detection device according to the invention comprises a base unit, a projection unit and an image capture unit.

In the present case, the base unit has a plate-shaped positioning element on which a tire to be detected, for example a motor vehicle, can be set up. Preferably, the tire is retractable in the assembled state. The base unit may have ramp sections for this purpose. The tire is hereinafter merely a better understanding of the invention and is not understood as part of it. In the erecting element according to the invention a longitudinal recess is arranged, which extends in particular transversely to the tire to be measured and which corresponds in its longitudinal extent at least the width of the tread of the tire to be measured. The longitudinal recess has no protective disk or the like. Furthermore, the positioning element is preferably designed such that it allows opening or closing of the interior of the base unit.

The base unit also has a free space below the longitudinal recess, which is defined by the verticals of the boundaries of the longitudinal recess to the positioning and whose dimensions thus correspond to the dimensions of the longitudinal recess. The free space is thus a geometrically defined portion of the interior of the base unit. The space is the portion of the interior, in which gravitational dirt particles or drops of water, especially from an upright tire, can fall down.

The projection unit according to the invention is able to project an optical pattern on the tire for profile detection. For this purpose, the projection unit has a pattern generation element, in particular a pattern projector, through which an optical pattern can be provided. The optical pattern can be designed differently depending on the application, preferably However, a line pattern is used for the profile measurement.

The projection unit also has a projection deflection element, for example in the form of a mirror or a plurality of mirrors, by means of which the pattern which can be provided by the pattern generation element can be deflected onto the tire.

The projection unit is not necessarily to be understood as a space-forming structure. Rather, the projection unit is a functional unit of pattern-generating element and projection-deflection element, which is preferably designed such that the pattern-generating element and the projection-deflection element are arranged spatially separated from one another. Depending on the application, however, it is alternatively also possible to arrange the pattern-generating element and the projection-deflecting element within a spatial structure, for example a common housing.

The image capture unit according to the invention is capable of capturing an image of the optical pattern, the image in the present case being the remission and reflection of the optical pattern projected onto the tire. For this purpose, the image capture unit has an image capture element, in particular designed as an image camera, with which the image of the optical pattern can be received. The image-sensing element is preferably arranged in the region of the pattern-generating element in the base unit. In addition, the image sensing element and the pattern generating element may also be combined in a pattern generation and detection system. The image capture unit further has an image deflection element, for example in the form of a mirror, with which the image of the optical pattern can be deflected onto the image capture element. Analogously to the projection unit, the image capture unit is likewise not necessarily a space-forming structure but rather a functional unit in which the image capture element and the image deflection element are spatially separated from one another within the base unit. Alternatively, it is also possible here according to the invention to arrange the image-sensing element and the image-deflecting element in a spatial structure, for example a common housing.

The captured image of the optical pattern is provided transferably by the image capture unit, preferably in the form of image data for further processing. In this context, the image acquisition unit can be connected, for example, to an external evaluation unit, by means of which an evaluation of the image data and thus an evaluation of the detected tire profile can be performed.

In a possible further development of the invention, such an evaluation unit can also be assigned directly to the image acquisition unit or integrated into it, so that tire profile data can be provided in a dispensable manner directly by the tire profile acquisition device.

During a detection process that can be carried out with the tire tread detection device according to the invention, in a first step, the optical pattern is provided by the pattern generation element, which is subsequently deflected onto the tire by the projection deflection element. The image of the optical pattern on the tire is deflected in a next step by the image deflection on the image sensing element and received by this. In this case, the tire tread detection device according to the invention is characterized in particular in that the projection deflection element and the image deflection element are arranged outside the free space in the base unit. The projection deflection element is arranged in this context within the base unit such that the optical path of the optical pattern is directed through the longitudinal recess of the positioning element onto the tire. Furthermore, the beam path of the image of the optical pattern is also directed through the longitudinal recess and deviates from the angle of the beam path to the projection of the optical pattern to allow triangulation for profile depth determination. In this case, the image deflection element is arranged according to the invention within the base unit in such a way that the beam path of the image of the optical pattern is directed to the image detection element after passing through the longitudinal recess.

With the arrangement of the projection deflecting element and the image deflecting element according to the invention, the optical path of the optical pattern on the tire and the optical path of the image of the optical pattern are directed to the image sensing element without the projection deflecting element and the image deflecting element being located directly below the longitudinal recess and thus in the space of the base unit Need to become.

Thus, contaminants, in the form of dirt or liquids, that may dissolve away from the tire during a detection process can fall through the longitudinal recess into the free space of the base unit without the risk of contamination or damage to the projection unit or the image acquisition unit. In addition to the projection deflection element and the Image deflection element are preferably also the pattern-generating element and the image-sensing element outside the free space in the base unit arranged.

Due to the inventive design of the tire tread detection device, in which no optical elements in the free space of the base unit and thus located immediately below the longitudinal recess, over conventional tire tread measuring devices with a disc for protecting the optical system, several particular advantages.

On the one hand, there are advantages due to the omission of the protective screen. The detection process is not influenced by such a protective screen, so that a high optical quality of the detection process can be provided. Associated with this, the device according to the invention has a lower maintenance effort, as can be dispensed with a review, cleaning and possibly a change of such a protective screen. Furthermore, the costs for a protective screen are eliminated. It is possible, for the purpose of precautionary protection of the free space on one or both sides with a substantially vertical orientation, to provide a protective screen for protecting the projection unit and the image acquisition unit, in particular the projection deflection element and the image deflection element. However, even in such a variant, the advantages over the prior art remain, since such vertical protective windows are subject under normal operating conditions neither a fouling attack or scratching, nor the mechanical stress of an upright vehicle. The precautionary protection is intended above all to prevent damage due to misuse, for example due to an obliquely falling tool.

A further advantage of the inventive solution consists in the arrangement of the projection unit and the image acquisition unit in the base unit, wherein the pattern generation element and the image acquisition element can be arranged in the base unit such that the optical path of the optical pattern in front of the projection deflection element and the optical path of the image of the optical pattern extend after the image deflection element substantially plane-parallel to a longitudinal plane of the base unit. As a result of this arrangement of the projection unit and of the image capture unit, in particular a horizontal installation position of the pattern generation element and image capture element and thus a comparatively low overall height of the tire profile acquisition device are made possible. Further, there is an advantage that the pattern generating element and the image sensing element as an active optical module and the projection deflecting element and the image deflecting element as a passive optical module can be structurally grouped.

In addition, another advantage of the Tire Profilierfassungsvorrichtung is that during a detection process, the tire tread is relieved in the region of the longitudinal recess. Compared with conventional solutions in which the tire profile rises and deforms during a detection process on the corresponding disc, the tire profile detecting device according to the invention can provide more exact detection results due to the unloaded tire profile.

An alternative variant of the tire tread detection device provides that the projection unit and the image capture unit need not have any deflection elements. Depending on whether the projection unit or the image detection unit or both have no deflection means, the respective pattern generation element or the image detection element are arranged outside the free space so that they are directed directly at the tire to be detected.

Such a variant brings with it in particular the advantage that, by dispensing with the respective deflection elements, a simpler and cost-effective implementation of the tire profile detection device can be provided.

Both in the variant of the inventive technical solution according to claim 1, as well as in the variant according to claim 2, the tire tread detection device according to the invention is determined by the fact that the optically effective surfaces of the projection unit and the image acquisition unit, with which the immediate generation of the optical pattern on the tire and the immediate detection of the image of the optical pattern can be provided, outside of the free space and thus in particular outside the influence of contaminants in the base unit are arranged.

The solution according to the invention does not exclude special applications in which, for example, a particularly compact design of the base unit is desired, so that for contaminations not relevant portions of the pattern generating element or the image sensing element, such as a housing, partially or completely in the space can be arranged. In such a case, the respective unit associated with the element arranged in the free space has the corresponding deflection means, which however itself is arranged outside the free space. The respective, completely or partially arranged in the free space Pattern-generating or image-sensing element is further protected in such a case, preferably by a corresponding cover from dirt.

Decisive for the invention is that the optically effective surfaces of components of the projection unit or of the image acquisition unit, insofar as they are directed directly onto the tire, are arranged outside the free space.

In an advantageous development of the invention, the pattern-generating element is designed as a laser projector, in particular as a line laser projector.

The design of the pattern generating element as a laser projector in the present case has the particular advantages that on the one hand by the laser depending on the application, any optical pattern can be provided with a very high contrast and on the other no additional elements are required for focusing.

Furthermore, in a preferred variant of the tire tread detection device, the projection deflecting element is capable of dividing the optical pattern into a plurality of partial optical patterns.

The projection deflection element is in this case preferably designed as a diffractive optical element, hereinafter also abbreviated to DOE, by means of which the optical pattern, which can be provided by the pattern generation element, can be disassembled into the optical subpatterns and projected onto the tire. In this way, a plurality of images of the partial optical patterns are provided on the tire, which are then detectable by the image acquisition unit.

The division of the optical pattern into optical partial patterns offers the advantage in particular that several sections of the tire profile can be detected by the optical partial patterns at the same time and thus several images of the optical partial patterns can be provided for the later evaluation of the tire profile data. In this way, the risk of misjudgements, such as may occur in the area of wear markers of a tire, can be reduced.

In a further advantageous embodiment, the tire profile detection device has a further projection unit with a further pattern generation element and a further projection deflection means. In the present case, a further optical pattern can be provided by means of the further projection unit and can be projected onto the tire so that an additional image of the further optical pattern can be provided on the tire. This image of the further optical pattern can be detected by the image acquisition unit according to the invention, so that there are several images of optical patterns for a subsequent evaluation of the tire profile data.

Also in this case, the danger of misjudgment of the tire tread can be reduced by the multiple optical patterns and the multiple images of the optical patterns that can be provided thereby.

The images of the optical patterns are preferably detectable by image acquisition unit provided according to the invention, wherein the deflection of the images of the optical pattern can be provided either by one and the same image deflection element or by a separate image deflection element for each image of an optical pattern.

A particularly advantageous development of the tire profile sensing device provides that a removable dirt collecting element is arranged in the free space of the base unit. The dirt collecting element is preferably in the region of the free space on the bottom of the base unit and is advantageously designed in its dimensions so that this at least partially protrudes in its length and width from the free space. In addition, centering elements can be provided on the base of the base unit, which allow a correct placement of the dirt collecting element.

The dirt collecting element is particularly advantageously trough-shaped and is able, during positioning of the tire over the longitudinal recess and during a detection process, to catch dirt falling from the tire and falling through the longitudinal recess into the free space or liquids dripping off the tire. Due to the removability a particularly simple cleaning of the tire tread recognition device is made possible in this way.

At the same time, the dirt collecting element in the bottom region of a splash guard, for example in the form of a fleece, felt or grid element, by which a splashing of dirt from the dirt collecting element is prevented.

In a further advantageous variant of the tire profile sensing device, the positioning element has dirt discharge openings, in particular in the edge regions of the longitudinal recess. The dirt discharge openings in this case allow an effective discharge of dirt or dripping liquids, below collectively referred to as impurities which detach during positioning over the longitudinal recess or during the detection process of the tire and applied to the set-up.

Furthermore, the variant of the tire profile sensing device described here provides that profile elements, for example formed as V-profile elements, are arranged below the soil discharge openings. By means of these profile elements are the particular, derived by the dirt discharge openings from the top of the set-up, impurities, in particular waste water, receivable and discharged from the base unit. In this case, the removal of the impurities can take place either parallel to the detection process or in a subsequent cleaning process of the tire profile detection device.

As a further advantage, a structural reinforcement of the positioning element can be provided by the profile elements. For this purpose, the profile elements are in particular firmly connected to the positioning element on the underside thereof, so that bending of the positioning element can be reduced by the weight of the erected tire or of the partially deployed vehicle.

As a particular advantage, the profiles have a dual function in that they form a channel-like catch for the first and a structural reinforcement of the positioning element for the second.

The invention will be described as an embodiment with reference to

1 schematic side view with a projection unit

2 schematic side view with two projection units

3 schematic side view with dirt collecting element

4 schematic side view with dirt discharge openings

5 schematic side view with direct arrangement of the pattern generating element
explained in more detail.

The 1 shows a tire tread detection device according to the invention in a first embodiment. The tire tread detection device here has a base unit 1 with a positioning element 2 on which a tire to be detected 3 is set up. The positioning element 2 has a longitudinal recess 4 in whose area a detection process for detecting the profile of the tire 3 is feasible. In addition, the base element 1 a free space 5 on which by the perpendiculars 6 the longitudinal recess is fixed.

To capture the profile of the tire 3 In the present case, the device has a projection unit consisting of a pattern-generating element 8th and a projection deflecting element 9 wherein, by means of the pattern generating element 8th an optical pattern 7 is providable and where the optical pattern 7 by means of the projection deflection element 9 on the tires 3 is distractible. The present is the pattern-generating element 8th as a laser projector and the projection deflecting element 9 designed as a mirror.

Furthermore, the device in the present case has an image capture unit, consisting of an image capture element 11 and an image deflection element 12 on, by means of the image sensing element 11 a picture 10 of the optical pattern 7 is receivable and wherein by means of the image deflection element 12 the picture 10 of the optical pattern 7 on the image capture element 11 is distractible. The image capture element 11 is present as an image camera and the image deflection element 12 designed as a mirror.

As in 1 can be seen, the reflection concept allows a particularly advantageous arrangement of all elements of the projection unit and the image acquisition unit outside the free space 5 , In this way it is made possible that on a disc in the area of the longitudinal recess 4 , as it must be provided mandatory in conventional devices for protecting the optical elements, can be dispensed with.

2 shows another embodiment of the tire tread detection device. In the exemplary embodiment illustrated here, the tire tread detection device has, in addition to a first projection unit with a first pattern generation element 8.1 and a first projection deflecting element 9.1 additionally a second projection unit with a second pattern generation element 8.2 and a second projection deflecting element 9.2 on. By means of the first projection unit, in this case a first optical pattern 7.1 available and on the tire 3 deflected while using the second projection unit, a second optical pattern 7.2 available and on the tire 3 is distractible. The two optical patterns 7.1 and 7.2 produce present on the tire 3 a first picture 10.1 of the first optical pattern 7.1 as well as a second picture 10.2 of the second optical pattern 7.2 , The pictures 10.1 and 10.2 are in the further course by means of the image deflection element 12 on the image capture element 11 deflectable, wherein the image deflection element 12 in the present case is designed so that all available beam paths of the images 10.1 and 10.2 on the image capture element 12 are distractible.

3 shows an embodiment of the tire tread measuring device, in which in the region of the free space 5 additionally a dirt collecting element 13 in the base unit 1 is arranged. The dirt collecting element 13 In the present case, it is possible to collect contaminants that are present during positioning of the tire 3 over the longitudinal recess 4 or during a detection process of the tire 3 solve and into the free space 5 fall. The dirt collecting element 13 is present trough-shaped and in particular from the base unit 1 designed removable, so in the present case a correspondingly uncomplicated cleaning of the dirt collecting element 13 is possible. In addition, the dirt collecting element 13 in particular so formed and within the base unit 1 arranged that the optical paths of the optical pattern 7 and the picture 10 of the optical pattern 7 through the dirt collecting element 13 not be disturbed or disabled.

Another embodiment of the tire tread detection device is shown in FIG 4 shown. The embodiment shown here provides that the positioning 2 , in particular in the opposite edge regions of the longitudinal recess 4 , a plurality of dirt discharge openings 14 having. These dirt discharge openings 14 serve in the present case, impurities which occur during the positioning of the tire 3 over the longitudinal recess 4 or during a detection process of the tire 3 solve and on the positioning element 2 fall or drip, from the top of the positioning element 2 derive.

The derived impurities are then in profile elements 15 , which in the area of dirt discharge openings 14 at the bottom of the positioning element 2 are arranged, picked up and removed from the base unit 1 dissipated. The profile elements 15 are also, for example by welding, fixed to the positioning 2 connected so that through this a structural reinforcement of the positioning element 2 and a lower deflection thereof during a load by the tire 3 be enabled.

In 5 a particular embodiment of the tire tread detection device is shown, in which the projection unit has no projection deflection element, but in which the pattern generating element 8th so in the base unit 1 is arranged that through this the optical pattern 7 directly and without distraction on the tire 3 is projected. According to the idea of the invention, the pattern-generating element is 8th also in the variant shown here outside the open space 5 and thus protected from entering contaminants within the base unit 1 arranged.

LIST OF REFERENCE NUMBERS

1

base unit

2

positioning element

3

tires

4

longitudinal recess

5

free space

6

vertical

7

optical pattern

8th

Pattern generating element

9

Projection deflection element

10

image

11

Image capture element

12

Image deflection element

13

Dirt collecting element

14

Dirt drain holes

15

profile elements

Claims (7)

Tire profile detecting device comprising a base unit ( 1 ) with a plate-shaped positioning element ( 2 ) on which a tire ( 3 ) is erectable, wherein the Aufstellelement ( 2 ) a longitudinal recess ( 4 ) and wherein the base unit ( 1 ) below the longitudinal recess ( 4 ) one Free space ( 5 ), wherein the free space ( 5 ) by verticals ( 6 ) of boundaries of the longitudinal recess ( 4 ) to the positioning element ( 2 ), and comprising a projection unit with which an optical pattern ( 7 ) on the tires ( 3 ), the projection unit being a pattern-generating element ( 8th ) for providing the optical pattern ( 7 ) and a projection deflecting element ( 9 ) for deflecting the optical pattern ( 7 ) on the tires ( 3 ), and comprising an image acquisition unit, with which an image ( 10 ) of the optical pattern ( 7 ), wherein the image capture unit comprises an image capture element ( 11 ) to take the picture ( 10 ) of the optical pattern ( 7 ) and an image deflection element ( 12 ) for the deflection of the image ( 10 ) of the optical pattern ( 7 ) to the image capture element ( 11 ), and wherein the projection deflecting element ( 9 ) and the image deflection element ( 11 ) outside the open space ( 5 ) in the base unit ( 1 ) are arranged. Tire profile detecting device comprising a base unit ( 1 ) with a plate-shaped positioning element ( 2 ) on which a tire ( 3 ) is erectable, wherein the Aufstellelement ( 2 ) a longitudinal recess ( 4 ) and wherein the base unit ( 1 ) below the longitudinal recess ( 4 ) a free space ( 5 ), wherein the free space ( 5 ) by verticals ( 6 ) of boundaries of the longitudinal recess ( 4 ) to the positioning element ( 2 ), and comprising a projection unit with which an optical pattern ( 7 ) on the tires ( 3 ), the projection unit being a pattern-generating element ( 8th ) for providing the optical pattern ( 7 ), and comprising an image acquisition unit, with which an image ( 10 ) of the optical pattern ( 7 ), wherein the image capture unit comprises an image capture element ( 11 ) to take the picture ( 10 ) of the optical pattern ( 7 ), and wherein the pattern generating element ( 8th ) and the image capture element ( 11 ) outside the open space ( 5 ) in the base unit ( 1 ) are arranged. Tire profile detecting device according to claim 1 or 2, wherein the pattern generating element ( 8th ) is designed as a laser projector. Tire profile detecting device according to one of the preceding claims, wherein the projection deflecting element ( 9 ) is capable of producing the optical pattern ( 7 ) into a plurality of partial optical patterns. Tire profile sensing device according to one of the preceding claims 1, 3 or 4, wherein the tire tread detection device comprises a further projection unit with a further pattern generation element ( 8.1 ) and another projection deflection element ( 9.1 ) and wherein by means of the further projection unit a further optical pattern ( 7.1 ) and on the tire ( 3 ) is projectable and wherein by means of the image capture unit an image ( 10.1 ) of the further optical pattern ( 7.1 ) is detectable. Tire profile detecting device according to one of the preceding claims, wherein in the free space ( 5 ) a removable dirt collecting element ( 13 ) is arranged. Tire profile detecting device according to one of the preceding claims, wherein the positioning element ( 2 ) a plurality of dirt discharge openings ( 14 ) for deriving from the tire ( 3 ) and having below the dirt discharge openings ( 14 ) Profile elements ( 15 ) for picking up and removing the dirt to be removed from the base unit ( 1 ) are arranged.

Images