Tire thread measurement assembly

Abstract

The disclosure describes a drive-over tyre tread depth gauging system (100), the system (100) comprising an elongated chassis unit (110) and a plurality of sensor units (150), where each sensor unit (150) comprises a housing (160) comprising an I / O interface (170), where the I / O interface (170) comprises an internal connector (171) and an external connector (172), an optical scanner (180) arranged in the housing (160) and connected to the internal connector (171) of the I / O interface (170), where each sensor unit (150) is releasably fastened to the elongated chassis unit (110) in a chassis unit interior (111), and configured to measure the tread depth of the tyre (140) as the tyre (140) rolls across the elongated chassis unit (110), and where the sensor units (150) are spaced apart from one another in the chassis unit interior (111) in the longitudinal direction of the elongated chassis unit (110).

Description

Tire thread measurement assemblyField of disclosureThe disclosure relates to the field of optical systems.Background

[0001] Tyre treads are generally employed for improving the traction of tyres with the ground, for example against wet surfaces by preventing hydroplaning. Treaded tyres are particularly important in cold climates that are prone to snowfall and frost, as treads are commonly employed in order to give traction with snow and ice. Tyre treads are unfortunately prone to wear, hence causing a reduction of traction over time, and eventually resulting in a need to replace the tyre.

[0002] In order to maintain road safety, most jurisdictions have introduced requirements on tyre tread depth. However, as it is generally the responsibility of the owner of the vehicle to ensure that the tread depths are within the legal limits, many vehicles may be found on the road equipped with tyres that are not road legal. Increasing international travel, and varying requirements for tread depths across international border further contribute to a high number of vehicles on the road without road legal tyres. The latter being a particular problem when freight is transported by road into a country with icy conditions from a country with a warm and generally frost free climate.

[0003] In order to improve road safety, various national authorities have recently started showing interest in installing automatic drive-over tyre tread dept gauging sensors in the road that are configured to measure the tyre tread depth of cars as these drive across the sensor. Several drive-over tyre tread depth gauging sensors are already know in the art, but these have until now largely been employed inside, for example in garages and workshops.

[0004] A problem with existing drive-over tyre tread dept gauging sensors is namely that the optics of the sensors over time get polluted by environmental debris like dust, gravel, dirt etc., hence causing a need for frequent maintenance. Various solutions have been implemented in order to reduce the need for maintenance, including the employment of built in cleaning systems, for example based on the provision of a cleaning fluid or the employment of air blasts for cleaning optical surfaces.

[0005] US9046446 describes an example of a drive-over optical tyre tread depth sensor with a build in self-cleaning system. The drive-over optical tyre tread depth sensor of US9046446 comprises an optical component placed beneath a vehicle support surface through which the optical component is configured to measure atyre as the latter rolls over the vehicle support surface. An air nozzle is provided in order to periodically blast-clean the vehicle support surface as debris accumulate on said surface over time. A problem with the solution in US9046446, however, is that debris is in fact freely allowed to gather on the vehicle support surface. The vehicle support surface is therefore prone to wear over time, especially if the drive-over optical tyre tread depth sensor is employed in the road for a prolonged duration of time, or is employed in ice conditions where there is extensive debris pollution from pollutants such as road salt, dust, sand and gravel.

[0006] The present disclosure describes a drive-over tyre tread depth gauging system for being integrated / embedded in a road that may be easily maintained on site.Summary of the disclosure

[0007] A first aspect of the present invention provides a drive-over tyre tread depth where the system comprises an elongated chassis unit comprising a chassis unit interior and an elongated optical opening, where the elongated chassis unit is configured to be embedded in a road such that a tyre of a vehicle can roll across the elongated optical opening of the elongated chassis unit, and where the longitudinal direction of the elongated optical opening is substantially parallel to the longitudinal direction of the elongated chassis unit, and a plurality of sensor units, where each sensor unit comprises a housing comprising an I / O interface, where the I / O interface comprises an internal connector and an external connector, an optical scanner arranged in the housing and connected to the internal connector of the I / O interface, where each sensor unit is releasably fastened to the elongated chassis unit in the chassis unit interior, and configured to measure, through the elongated optical opening of the elongated chassis unit, the tread depth of the tyre as the tyre rolls across the elongated optical opening of the elongated chassis unit, and where the sensor units are spaced apart from one another in the chassis unit interior in the longitudinal direction of the elongated chassis unit.

[0008] In an embodiment of the invention the chassis interior is subdivided into a plurality of chassis unit compartments, and where each sensor unit is arranged in separate chassis unit compartments.

[0009] In another embodiment of the invention any two directly adjacent chassis unit compartments are subdivided by a wall.

[0010] In yet another embodiment of the invention each sensor unit is electrically connected to the elongated chassis unit via its I / O interface.

[0011] In yet another embodiment of the invention the I / O interface comprises an external power connector and an external data connector, optionally where the external power connector and the external data connector is combined as an external combined connector.

[0012] In yet another embodiment of the invention each external connector of the I / O interface of the housing of each sensor unit is waterproof.

[0013] In yet another embodiment of the invention each sensor unit is configured to operate independently of other sensor units of the drive-over tyre tread depth gauging system.

[0014] In yet another embodiment of the invention the elongated chassis unit comprises a plurality of connection bolts arranged in the chassis unit interior, and where each sensor unit is releasably fastened to at least one of the plurality of connection bolts.

[0015] In yet another embodiment of the invention the optical scanner of each sensor unit comprises an optical lens, where each sensor unit further comprises a pressurized air connector and an air nozzle, and where the air nozzle is arranged to provide an air flow across the lens of the optical scanner.

[0016] In yet another embodiment of the invention the drive-over tyre tread depth gauging system comprises a data processing unit connected to the external connector of the I / O interface of each of the plurality of sensor units.

[0017] In yet another embodiment of the invention each sensor unit comprises a lifting handle.

[0018] In yet another embodiment of the invention the elongated chassis unit comprises a lid configured to removably close an opening between the interior and exterior of the elongated chassis unit.

[0019] In yet another embodiment of the invention each sensor unit further comprises a detection sensor configured to detect the presence of the tyre over the elongated optical opening of the elongated chassis unit.

[0020] In yet another embodiment of the invention the drive-over tyre tread depth gauging system further comprises one or more additional chassis units connected to the elongated chassis unit.

[0021] A second aspect of the present invention provides use of the drive-over tyre tread depth gauging system for measuring the tread depth of the tyre.Brief description of the drawings

[0022] Figure 1 is a schematic illustration of a drive-over tyre tread depth gauging system embedded in a road,

[0023] Figure 2a is a schematic illustration of a sensor unit,

[0024] Figure 2b is a schematic illustration of a sensor unit, illustrated with a transparent housing, where the sensor unit comprises an optical scanner, a control unit and an I / O interface,

[0025] Figure 3 is a schematic illustration of a chassis unit comprising a sensor unit, where a tyre rolls over the chassis unit,

[0026] Figure 4 is a schematic illustration of a sensor unit comprising an air nozzle and a pressurized air connection,

[0027] Figure 5 is a schematic illustration of sensor unit connected to a data processing unit,

[0028] Figure 6 is a schematic illustration of a chassis unit comprising a lid,

[0029] Figure 7 is a schematic illustration of a drive-over tyre tread depth gauging system comprising a plurality of interconnected chassis units,

[0030] Figure 8 is a schematic illustration of a sensor unit illustrated with a transparent housing, where the sensor unit comprises an I / O interface having a plurality of external connectors.Detailed description of the disclosure

[0031] In the following, general embodiments as well as particular exemplary embodiments of the disclosure will be described. References will be made to the accompanying drawings. It shall be noted, however, that the drawings are exemplary embodiments only, and that other features and embodiments may well be within the scope of the disclosure as claimed. Further, the mentioning of references such as "a" or "an" etc. should not be construed as excluding a plurality.

[0032] Unless otherwise defined, all terms of art, notations and other scientific terms or terminology used herein are intended to have the meanings commonly understood by those of skill in the art to which this disclosure pertains. Certain terms of art, notations, and other scientific terms or terminology may, however, be defined specifically as indicated below.

[0033] The present disclosure provides a drive-over tyre tread depth gauging system 100 configured to being embedded in a road 130 such that the tread depth of a tyre may be measured as a vehicle equipped with said tyre drives along the road 130 and across the drive-over tyre tread depth gauging system 100. It will be appreciated that a drive-over tyre tread depth gauging system 100 may generally be known in the art under different terminologies, e.g. a drive-over optical tread depth sensor, a tyre tread scanner drive-over device, a tyre tread scanner drive-over system or similar. The term gauge may in the context of thepresent disclosure be understood as synonymous with terms such as measure or determine.

[0034] As schematically illustrated in figures 1 and 3, the drive-over tyre tread depth gauging system 100 comprises a chassis unit 110 and a plurality of sensor units 150 arranged in the chassis unit 110. The chassis unit 110 comprises an interior 111 and an optical opening 120, where the optical opening 120 provides for optical communication between the interior 111 and exterior of the chassis unit 110 ( / .e., optical transmission from the interior to the exterior or vice versa). The optical opening 120 may be arranged in the top side of the chassis unit and the plurality of sensor units 150 may be arranged inside the interior 111 of the chassis unit 110 in line of sight of the optical opening 120. As a tyre 140 rolls over the chassis unit 110, and thus the optical opening 120 of the chassis unit, a sensor unit 150 in optical communication with the tyre 140 through the optical opening 120 of the chassis unit 110 may gather optical data that may directly or indirectly be used in order to determine the tread depth of said tyre 140. Each sensor unit 150 may more generally be configured to measure, through the optical opening 120 of the chassis unit 110, the tread depth of a tyre 140 as the tyre 140 rolls across the optical opening 120 of the chassis unit 110.

[0035] The chassis unit may generally be configured to being embedded in a road or segment of a road such that a road vehicle may pass across the chassis unit without causing irreversible damage to the chassis unit. The chassis unit may for example be a casing of stainless steel, a concrete enclosure or a housing made of any material or combination of materials chosen in order to enable the chassis unit to bear the weight of any type of standard road vehicles. Preferably, the chassis unit may be made in part of fully from steel.

[0036] The chassis unit 110, and thus the drive-over tyre tread depth gauging system 100 may, as schematically illustrated in figures 1 and 3, be embedded in a road 130 or road segment such that a vehicle may drive across the chassis unit 110 with at least one of its wheels passing over the optical opening 120 of the chassis unit 110. Being embedded in a road 130 or road segment may here be understood as being built in as a part of the road 130 or road segment such that vehicles driving along the road 130 may drive across the chassis unit 110 with one or more of their wheels passing directly over the chassis unit 110. The drive- over tyre tread depth gauging system 100 may ideally be embedded in a road 130 or road segment such that the top of the chassis unit 110, and consequently the optical opening 120 of the chassis unit, aligns with the surface of the road 130 or road segment. The top surface of the chassis unit 110 may thus be flat, and the optical opening 120 may be provided in the flat top surface. Saidalignment will result in a plane road surface, without the drive-over tyre tread depth gauging system 100 creating any protruding bump in the road 130. As will be appreciated by a person skilled in the art with knowledge of the present disclosure, the exact manner in which the chassis unit 110 may be embedded in a road 130 or road segment may vary. The embedment may for example be performed though employment of expansion compensating mechanical joints that compensates for any thermal expansion mismatch between the road 130 and the chassis unit 110. Alternatively, the embedment may be performed by simply placing and securing the chassis unit 110 in a predesigned slot in the road 130 or road segment.

[0037] As schematically illustrated in figures 1 and 3, the chassis unit 110 may be configured such that it comprises a chassis interior 111 with a shape and size suitable for accommodating a plurality of sensor units 150. The chassis unit 110 may optionally be shaped and dimensioned such that the chassis unit interior 111 may accommodate additional equipment, for example any one or more of a heater, a connection element (e.g. a connector cord or connector bus) for each sensor unit, and a control unit. The chassis unit may further have an elongated shape ( / .e., be an elongated chassis unit 110), and the optical opening 120 of the chassis unit may optionally or additionally have an elongated shape ( / .e., be an elongated optical opening 120). An elongated chassis unit 110 comprising an elongated optical opening 120 may, as schematically illustrated in figure 1 be shaped such that the elongated optical opening 120 is substantially aligned with the longitudinal direction of the elongated chassis unit 110. An elongated chassis unit 110 comprising an elongated optical opening 120 is preferable as an elongated chassis unit 110 may be employed to cover a large portion of the width of a road or road segment.

[0038] The drive-over tyre tread depth gauging system 100 comprises according to the present disclosure a chassis unit 110 and a plurality of sensor units 150 arranged in the chassis unit interior 111. Each sensor unit 150 may, as schematically illustrated in figures 2a and 2b, comprise a housing 160 and an optical scanner 180 arranged in the housing 160. The housing 160 may thus comprise a housing wall and a housing interior. The optical scanner 150 may be configured to measure, through the optical opening 120 of the chassis unit 110, the tread depth of a tyre 140 as the tyre 140 rolls across the optical opening 120 of the chassis unit 110. Each sensor unit 150 may thus be arranged inside the chassis unit 110 such that the optical scanner 180 of the sensor unit 150 is arranged within line of sight of the optical opening 120 of the chassis unit 110. Since the optical scanner 180 of each sensor unit 150 herein is defined as being arrangedinside the housing 160 of said sensor unit 150, it will be appreciated that the housing 160 may further comprise one or more separate optical openings 161, for example in order for the optical scanner 180 to obtain visual communication with the exterior of the housing 160. The optical scanner 180 may alternatively be integrated at least in part with the housing 160, where for example a lens or transparent lens cover of the optical scanner 180 form a part of the housing wall, and where any electronic components of the optical scanner is arranged in the housing 160.

[0039] The optical scanner may generally include all the means needed to measure the tread depth of a tyre as the tyre roles across the optical opening of the chassis unit. The optical scanner may therefore comprise a detector (e.g., a camera), and optionally comprise one or more of a lens or lenses, light source, reflectors, etc. The optical scanner may optionally comprise image processing means configured to analyse optical data acquired by the detector, e.g., an image of the tyre, to determine the tread depth of the tyre. Image processing means may for example be a local computer. The capture of optical data of a tyre, such as an image, that may subsequently be used in order to determine the tread depth of the tyre, may in the context of the present disclosure be considered as a measurement of the tread depth of the tyre. As will be appreciated by a person skilled in the art, optical scanners suitable for measuring the tread depth of a tyre are well known in the art, and each sensor unit may thus comprise any such suitable optical scanner.

[0040] The optical scanner may, as schematically illustrated in figures 2a and 2b comprise a light source 181 and a detector 182. Said with other words, figures 2a and 2b schematically illustrate the optical scanner 180 as a combination of two units, for example a light source 181 and a detector 182. It will be appreciated, however, that the optical scanner 180 may be provided as a single physical unit. The two units illustrated in figures 2a and 2b may for example constitute a laser triangulation scanner, with one unit illustrating a laser and the other unit illustrating a detector or camera. When a tyre 140 is located above the optical opening 120 of the chassis unit 110, the optical scanner 180 may for example capture an image of the tyre 140 that further may be analysed in order to determine the tread depth of the tyre 140.

[0041] In general, all the components, or at least all the optical components of an optical scanner of a sensor unit may be arranged inside the housing of the same sensor unit. The latter is preferable for enabling a modularity of the drive-over tyre tread gauging system. The optical components may include at least adetector and a light source, but may further include one or more lenses, and optionally or alternatively one or more reflectors.

[0042] In a particular embodiment of the present disclosure the optical scanner comprises a laser triangulation scanner. The laser triangulation scanner may comprise at least a detector (e.g., a camera) and a laser, preferably a line laser. The laser triangulation scanner may generally have a standard geometry with relationship to the optical opening of the chassis unit, i.e., that the laser has a normal incidence with the optical opening of the chassis unit, and that the laser has an inclined incidence. The laser triangulation scanner may alternatively have a reverse alignment, i.e., where the laser and the detector have swapped position relative to the standard geometry. The laser triangulation scanner may alternatively have a specular geometry, or a look-away geometry. A reverse geometry may be preferred in order to achieve a high hight resolution image, while a look away geometry may be preferred in order to obtain high resolution with reflective surfaces, e.g., during wet or icy conditions when the tyres are more reflective than normal. A specular geometry may be preferred if the surface of the tyre is very dark, e.g., when a measurement is performed during night or winter.

[0043] Figure 1 schematically illustrates an example of a chassis unit 110 provided with an optical opening 120. The optical opening 120 is here illustrated with a length, L, and width, W, where the length of the optical opening 120 is illustrated as being parallel with the driving direction, X, of a road 130 or road segment in which the chassis unit 110 is embedded. A width in the range from 5 cm to 10 cm has generally been found to be preferred, as such a width has been found to enable adequate line of sight between the optical scanner 180 of each sensor unit 150 while enabling most standard road tyres to pass without causing an unacceptable obstacle to the vehicle carrying the tyre.

[0044] Each sensor unit of the drive-over tyre tread depth gauging system may instead of (e.g., by replacing) the optical scanner, comprise any one or more of a weigh in motion sensor a thermic scanner and a profiling scanner. Optionally, each sensor unit of the drive-over tyre tread depth gauging system may in addition to the optical scanner comprise any one or more of a weigh in motion sensor a thermal scanner and a profiling scanner. The drive-over tyre tread depth gauging system may thus be more generally defined as a drive-over vehicle weigh gauging system, a drive-over thermal gauging system or a drive-over chassis profiling system, wherein the chassis unit generally comprises a chassis unit interior and optionally an optical opening. The weigh in motion sensor may be configured to measure the weight of a vehicle as the vehicle drives across thechassis unit. The thermic scanner may be configured to measure the temperature of one or more breaks of a vehicle as the vehicle drives across the chassis unit. The profiling scanner may be configured to measure the profile of the underside of a vehicle chassis of a vehicle as the vehicle drives across the chassis unit.

[0045] Each sensor unit 150 of the drive-over tyre tread depth gauging system 100 may, as schematically illustrated in figures 2a and 2b comprise a housing 160, where the housing 160 comprises an in-out interface 170 (I / O interface). The I / O interface 170 may be a physical connector interface between one or more electronic components located within the housing 160 ( / .e., internal electronic components) and one or more electronic component located outside the housing 160 ( / .e., external electronic components). The I / O interface 170 may more specifically comprise one or more internal connectors 171 and one or more external connectors 172. Each internal connector 171 may be arranged in the interior of the housing 160, or more generally be arranged facing the interior of the housing 160, thereby providing a connection point for an electronic component arranged inside the housing 160. Each external connector 172 may be arranged on the exterior of the housing 160, or more generally be arranged facing away from the exterior of the housing 160, thereby providing a connection point for an electronic component arranged outside the housing 160. One or more electronic components located inside the housing 160 may thus be connected to one or more electronic components outside the housing 160 via the I / O interface 170.

[0046] Referring to figures 2b and 5, the I / O interface 170 may be connected at least to an optical scanner 180 arranged in the housing 160 and may additionally be connected to or be configured to be connected to a data processing unit 250 arranged outside the housing 160 ( / .e., an external data processing unit 250). The external data processing unit 250 may here generally be an electronic unit or system configured to process or communicate data received from or at least originating from the optical scanner of a sensor unit 150. The external data processing unit 250 may form part of the drive-over tire tread depth gauging system 100 (e.g., arranged in the chassis unit), or be a separate external data processing unit 250 that may be connected to the drive-over tire tread depth gauging system 100. As will be appreciated by a person skilled in the art with knowledge of the present invention, the external data processing unit 250 may for example be a computer, a transmission system, a control unit, etc.

[0047] Each sensor unit 150 may, as schematically illustrated in figures 1 and 3, be electrically connected to the chassis unit 110 via its I / O interface 170, and thechassis unit 110 may optionally be connected to an external data processing unit 250. The chassis unit 110 may thus comprise one or more electrical conductors173 that is configured to being connected to the I / O interface 170 of each sensor unit and configured to being connected to an external data processing unit 230. The one or more electrical conductors 173 may comprise a connector bus configured to being connected directly or indirectly to the I / O interface 170 of each sensor unit. An electrical conductor 173 may in this context be any one or more of a signal cord, a power cord and a combined signal and power cord.

[0048] Each sensor unit may be electrically connected to an external data processing unit via one or more separate electrical conductors arranged at least in part in the chassis unit. Said separate electrical conductor or conductors may be arranged through the chassis unit and may or may not form part of the drive- over tire tread depth gauging system. The one or more separate electrical conductor or conductors may for example comprise one electrical conductor for each sensor unit, where each electrical conductor extends out of the chassis unit. The one or more separate electrical conductor or conductors may alternatively comprise one branched conductor connected to each sensor unit and extending out of the chassis unit.

[0049] The I / O interface may optionally comprise one or more of a printed circuit board, a processor and a memory. The I / O interface of a sensor unit may generally be configured to act as a bridge between the optical scanner and any external data processing unit located outside the housing, and the I / O interface may be configured to convert signals from the optical scanner into a signal readable by an electronic component located outside the housing. As will be appreciated by a person skilled in the art with knowledge of the present invention, the I / O interface may generally be defined as the electronic components located between one or more internal connectors of the I / O interface, and one or more external connectors of the I / O interface.

[0050] Referring to figures 2a, 2b and 5, each sensor unit 150 of the drive-over tyre tread depth gauging system 100 may further comprise a control unit 174 connected to the I / O interface 170, either directly or indirectly. The control unit174 may be configured to activate the optical scanner 180 of the sensor unit 150 and may for example further be configured to initiate said activation upon receipt of a signal that indicates the approach of a vehicle. Each sensor unit 150 may for example comprises a detection sensor 280 configured to detect the presence of a tyre over the optical opening 120 of the chassis unit 110, and to send a signal that indicates the approach of a vehicle to the control unit 120. The drive-over tyre tread depth gauging system 100 may alternatively comprise anexternal detection sensor arranged outside the sensor units 150 and connected to the sensor units 150 of the drive-over tyre tread depth gauging system 100 via their respective I / O interfaces 170. The presence of a detector sensor 280 as a component of each sensor unit 150 is preferable in that only the optical scanner 180 in line of sight of the tire to be measured needs to be activated. The other sensor units 150 may for example be kept inactivated, thus reducing the need for data processing, and also reducing power consumption. The control unit 174 of an optical scanner 180 of a sensor unit 150 may, as schematically illustrated in figures 2a and 2b, be arranged in the housing 160 of the sensor unit 150. As also schematically illustrated in figures 2a and 2b, a control unit 174 and an optical scanner 180 comprising a light source 181 and detector 182 may be connected to an internal connector 171 of the sensor unit 150. Alternatively, the optical scanner 180 may be connected to the control unit 174, and the control unit 174 may further be connected to the internal connector 171.

[0051] Each sensor unit may generally comprise a variety of electronic components, for example one or more of a data processing means, a communication circuit, a fan, and a heater. The I / O interface of the housing of each sensor unit may thus optionally be connected to or be configured to be connected to any one or more of a data processing means, a communication circuit, a fan, and a heater.

[0052] Referring to figures 2b, 5 and 8, the employment of an I / O interface 170 as a part of the housing 160 of each sensor unit 150 is preferable in that the I / O interface 170 may enable each sensor unit 150 to be connected to an external data processing unit with fewer connections than what would be necessary if every electronic component of each sensor 150 unit were to be directly coupled to an external data processing unit 250. More specifically, instead of coupling electronic components of each sensor unit 150 directly to an external data processing unit 250, the electronic components may be connected indirectly to an external data processing 250 unit via the I / O interface 170. More specifically, electronic components of a sensor unit 150 arranged in the housing 160 of the sensor unit 150 may be connected to the I / O interface 170 of the sensor unit 150, which may further be connected to an external data processing unit 250. The connection from the I / O interface 170 to an external data processing unit 250 may for example include one single connection, or alternatively one power connection and one data communication connection. The I / O interface 170 of each sensor unit 150 may thus comprise one or more external connectors ( / .e., a connector, such as a socket, arranged on the outside of the housing), for example one external power connector 211, and one external data connector 212, or alternatively one external power connector 211, one external local areanetwork connector, and one external signal connector. The power connector 211 and the data connector 212 may be combined as a combined connector 172. The employment of an I / O interface 170 of the housing 160 of each sensor unit 150 is further beneficial in that in that the electronic components arranged inside each sensor unit 150 may be protected from the environment outside the housing 160. The housing 160, and the external connector 172 or connectors of the I / O interface 170 of the housing 160 may be waterproof.

[0053] Each sensor unit of the drive-over tyre tread depth gauging system may generally be configured to operate independently of other sensor units of the drive-over tyre tread depth gauging system. The latter is preferable in that the drive-over tyre tread depth gauging system thus will be able to operate even if one of the sensor units of the drive-over tyre tread depth gauging system malfunctions. Also, instead of having to perform maintenance on the whole drive-over tyre tread depth gauging system in the event of a sensor unit malfunction, it will suffice to perform maintenance on the malfunctioning sensor unit.

[0054] The employment of a housing comprising an I / O interface as described herein is further beneficial in that maintenance of a malfunctioning electronic component within a single sensor unit may be performed by simply exchanging the whole sensor unit comprising the malfunctioning electronic component with a replacement sensor unit. The latter operation may, due to the sensor unit comprising an I / O interface, be performed by 1) unplugging any connections (e.g., cables or similar) to the external connector or connectors of the I / O interface of the housing of the malfunctioning sensor unit, and 2) reinserting the same connections in the external connector or connectors of the I / O interface of the housing of the replacement sensor unit.

[0055] In order to further ease maintenance of the drive-over tyre tread depth gauging system 100, each sensor unit 150 may, as schematically illustrated in figure 5 and 6, be provided with a lifting handle 260. The housing 160 of each sensor unit 150 may for example comprise the lifting handle 260, and the lifting handle 260 may be positioned facing the optical opening 120 of the chassis unit 110 when the sensor unit 150 is mounted in the chassis unit 110. The chassis unit 110 may additionally or optionally comprise a plurality of connection bolts 220, where each sensor unit 150 may be releasably fastened to at least one of the connection bolts 220. The sensor units 150 may as such be releasably connected in the interior of the chassis unit 110 via one or more of the connection bolts 220. connection bolts 220 may thus enable a secure connection between each sensor unit 150 and the chassis unit 110, and also enable time effectivereplacement of a sensor unit 150 in the event where maintenance of the sensor unit 150 is needed.

[0056] In order to ease replacement of a sensor unit from the chassis unit 110, the chassis unit 110 may comprise a lid 270. The lid 270 may, as schematically illustrated in figure 6, be arranged between the interior 111 and exterior of the chassis unit 110 and may be configured to cover at least in part an opening of the chassis unit and to be removably secured to the chassis unit 110. The lid 270 may in closed position for example be releasably fixed to the rest of the chassis unit 110, and the opening may be shaped to allow for the insertion of a sensor unit 150 into the chassis interior 111, and for the removal of a sensor unit 150 from within the chassis interior 111. It will be appreciated by a person skilled in the art with knowledge of the present invention that the opening coverable by the lid 270 may be directly adjacent to the optical opening 120 or be considered a part of the optical opening 120. The opening and the optical opening 120 may thus in combination form a single opening.

[0057] The plurality of sensor units 150 may generally be arranged inside the chassis unit 110 such that they are spaced apart from one another. As schematically illustrated in figure 1, the chassis unit 110 may have an elongated shape, and the plurality of sensor units 150 may be spaced apart and arranged along the longitudinal direction of the chassis unit 110. The latter enables the chassis unit 110 to be mounted in a road 130 or road segment such that each sensor unit 150 may cover a separate portion of the width of the road 130 ( / .e., be able to measure a tyre tread depth of a tyre passing within a portion of the width of the road 130). Each sensor unit 150 may as a way of example cover a width of 40 cm, meaning that 12 sensor units 150 evenly aligned may cover a standard road lane of 4.4 meter. It will be appreciated by a person skilled in the art with knowledge of the present invention that the chassis unit theoretically may be made wider than its length ( / .e. longer in the driving direction of the road than in the direction perpendicular to the driving direction of the road). The chassis unit 110, and elongated chassis unit 110 as described herein may thus refer to a portion of the drive-over tire tread depth gauging system 100 being elongated in the direction perpendicular to the driving direction of the road when installed in a road.

[0058] As schematically illustrated in figure 7, the chassis unit interior 111 may subdivided into a plurality of chassis unit compartments 190, and each sensor unit 150 may be arranged in separate chassis unit compartments 190. The latter is inter alia preferable for reducing the risk of damage to the system 100 when in operation, as for example flooding of the chassis unit 110 may be contained to asubset of the chassis unit compartments 190, and thus not affect all the sensor units 150 simultaneously. Arrangement of each sensor unit 150 in separate compartments 190 may further be beneficial as single chassis unit compartments 190 may undergo individual maintenance, and that maintenance may be performed on the system 100 without having to engage the whole system 100 each time.

[0059] Any two directly adjacent chassis unit compartments 190 may, as schematically illustrated in figure 7, be subdivided by a wall 200 (e.g. vertical wall). Here, each wall 200 may for extend vertically from the base of the chassis unit 110. Each wall 200 may optionally or additionally support a top surface of the chassis unit 110 ( / .e. a top surface of the chassis unit 110 in which the optical opening 120 is provided). Each wall 200 may thus be configured to distribute load in the chassis unit 110 from a vehicle driving across the cassis unit 110. Providing the chassis unit 110 by one or more walls 200 in between chassis unit compartments 190 may thus be beneficial for providing a more durable chassis unit 110.

[0060] Each of the plurality of sensor units 150 may, as schematically illustrated in figure 4 comprise and air nozzle 240 and a pressurized air connector 230, where the pressurized air connector 230 may be arranged as a part of the I / O interface 170 of the housing 160 of each respective sensor unit 150. The housing 150 of each sensor unit 150 may comprise separate optical openings, optionally being part of the optical scanner of the sensor unit 150 (e.g., forming an optical lens cover or lens), and the air nozzle 240 may be arranged to provide an air flow across the separate optical opening of the sensor unit 150. The pressurized air connector 230 may thus be connected to the air nozzle 240, optionally inside the housing 160 of the sensor unit.

[0061] The drive-over tyre tread depth gauging system 100 may generally be employed for roads 130 with any width, either by adjusting the length of the chassis unit 110 or by interconnecting a plurality of chassis units 110. The drive-over tyre tread depth gauging system 100 may, as schematically illustrated in figure 7, comprise a plurality of interconnected chassis units 110. In other words, the drive-over tyre tread depth gauging system 100 may comprise a chassis unit 110 and one or more additional chassis units 290 interconnected with the chassis unit 110. Each additional chassis unit 290 may generally be configured as and comprise any components of the chassis unit 110 described herein.

Claims

Claims1. A drive-over tyre tread depth gauging system (100), the system (100) comprising: an elongated chassis unit (110) comprising a chassis unit interior (111) and an elongated optical opening (120), where the elongated chassis unit (110) is configured to be embedded in a road (130) such that a tyre (140) of a vehicle can roll across the elongated optical opening (120) of the elongated chassis unit (110), and where the longitudinal direction of the elongated optical opening (120) is substantially parallel to the longitudinal direction of the elongated chassis unit (110), and a plurality of sensor units (150), where each sensor unit (150) comprises a housing (160) comprising an I / O interface (170), where the I / O interface (170) comprises an internal connector (171) and an external connector (172), an optical scanner (180) arranged in the housing (160) and connected to the internal connector (171) of the I / O interface (170), wherein the optical scanner (180) comprises a light source (181) and a detector (182), where each sensor unit (150) is releasably fastened to the elongated chassis unit (110) in the chassis unit interior (111), and configured to measure, through the elongated optical opening (120) of the elongated chassis unit (110), the tread depth of the tyre (140) as the tyre (140) rolls across the elongated optical opening (120) of the elongated chassis unit (110), and where the sensor units (150) are spaced apart from one another in the chassis unit interior (111) in the longitudinal direction of the elongated chassis unit (HO).

2. The drive-over tyre tread depth gauging system (100) according to claim 1, where the chassis interior is subdivided into a plurality of chassis unit compartments (190), and where each sensor unit (150) is arranged in separate chassis unit compartments.

3. The drive-over tyre tread depth gauging system (100) according to claim 2, where any two directly adjacent chassis unit compartments (190) are subdivided by a wall (200).

4. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, where each sensor unit (150) is electrically connected to the elongated chassis unit (110) via its I / O interface (170).

5. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, where the I / O interface (170) comprises an external power connector (211) and an external data connector (212), optionally where the external power connector (211) and the external data connector (212) is combined as an external combined connector (210).

6. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, where each external connector (172) of the I / O interface (170) of the housing (160) of each sensor unit is waterproof.

7. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, where each sensor unit (150) is configured to operate independently of other sensor units (150) of the drive-over tyre tread depth gauging system (100).

8. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, where the elongated chassis unit (110) comprises a plurality of connection bolts (220) arranged in the chassis unit interior (111), and where each sensor unit (150) is releasably fastened to at least one of the plurality of connection bolts (220).

9. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, where the optical scanner (180) of each sensor unit (150) comprises an optical lens, where each sensor unit (150) further comprises a pressurized air connector (230) and an air nozzle (240), and where the air nozzle (240) is arranged to provide an air flow across the lens of the optical scanner (180).

10. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, where the drive-over tyre tread depth gauging system (100) comprises a data processing unit (250) connected to the external connector (172) of the I / O interface (170) of each of the plurality of sensor units (150).

11. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, where each sensor unit (150) comprises a lifting handle (260).

12. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, where the elongated chassis unit (110) comprises a lid (270) configured to removably close an opening between the interior and exterior of the elongated chassis unit (110).

13. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, where each sensor unit (150) further comprises a detection sensor (280) configured to detect the presence of the tyre (140) over the elongated optical opening (120) of the elongated chassis unit (110)14. The drive-over tyre tread depth gauging system (100) according to any one of the preceding claims, further comprising one or more additional chassis units (290) connected to the elongated chassis unit (110).

15. Use of the drive-over tyre tread depth gauging system (100) according to any one of the claims 1 - 14 for measuring the tread depth of the tyre (140).

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