Patent Application
20250164351
The disclosure relates to the field of optical systems.
Tire treads are generally employed for improving the traction of tires with the ground, for example against wet surfaces by preventing hydroplaning. Treaded tires are particularly important in cold climates that are prone to snowfall and frost, as wide treads are commonly employed in order to give traction with snow and ice. Tire treads are unfortunately prone to wear, hence causing a reduction of traction over time, and eventually resulting in a need to replace the tire.
In order to maintain road safety, most jurisdictions have introduced requirements on tire 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 tires 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 tires. 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.
In order to improve road safety, various national authorities have recently started showing interest in installing automatic drive-over tire thread dept gauging sensors in the road that are configured to measure the tire thread depth of cars as these drive across the sensor. Several drive-over tire thread depth gauging sensors are already know in the art, but these have until now largely been employed inside, for example in garages and workshops.
A problem with existing drive-over tire thread 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 reduction of the accuracy of the sensors. Various solutions have been implemented in order to deal with the latter issue, 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.
U.S. Pat. No. 9,046,446 describes an example of a drive-over optical tire tread depth sensor with a build in self-cleaning system. The drive-over optical tire tread depth sensor of U.S. Pat. No. 9,046,446 comprises an optical component placed beneath a vehicle support surface through which the optical component is configured to measure a tire 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 U.S. Pat. No. 9,046,446, 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 tire 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.
The present disclosure describes a drive-over tire tread depth gauging system suitable for long time employment in a road. The drive-over tire tread depth gauging system of the present disclosure is equipped with a pollution rejection mechanism based on a special arrangement of one or more air nozzles.
A first aspect of the present disclosure provides a drive-over tire tread depth gauging system, the system comprising a housing comprising an optical opening, where the housing is configured to be embedded in a road such that a tire of a vehicle can roll across the optical opening of the housing, an optical scanner arranged inside the housing, where the optical scanner is configured to measure, through the optical opening of the housing, the tread depth of the tire as the tire rolls across the optical opening of the housing, a housing lid movable between a closed position in which the optical opening is covered by the housing lid, and an open position in which the optical opening is uncovered or partly covered by the housing lid, and at least one air nozzle configured to continuously provide an air flow barrier between the optical scanner and the optical opening of the housing whenever the housing lid is in the open position.
In an embodiment of the disclosure the at least one air nozzle is configured to provide an air flow from within the housing, out through the optical opening of the housing.
In another embodiment of the disclosure the drive-over tire tread depth gauging further comprises lower suction means for extracting any one or more of air, liquid, dust, sand, salt and gravel at least from below the air flow barrier.
In yet another embodiment of the disclosure the drive-over tire tread depth gauging further comprises upper suction means for extracting any one or more of air, liquid, dust, sand, salt and gravel at least from between the air flow barrier and the optical opening of the housing.
In yet another embodiment of the disclosure the upper suction means is arranged at least partly in a direct air flow path from the air nozzle.
In yet another embodiment of the disclosure the drive-over tire tread depth gauging further comprises a transparent wall provided between the optical scanner and the optical opening of the housing, where the at least one air nozzle is configured to continuously provide the air flow barrier between the transparent wall and the optical opening of the housing whenever the housing lid is in the open position.
In yet another embodiment of the disclosure the upper suction means is configured to extract any one or more of air, liquid, dust, sand, salt and gravel at least from between the transparent wall and the optical opening of the housing.
In yet another embodiment of the disclosure the drive-over tire tread depth gauging further comprises a liquid inlet for providing a cleaning liquid to the surface of the transparent wall facing the optical opening of the housing.
In yet another embodiment of the disclosure the drive-over tire tread depth gauging further comprises a heat source configured to heat at least a part of the drive-over tire tread depth gauging system.
In yet another embodiment of the disclosure the at least one air nozzle comprises at least one air knife.
In yet another embodiment of the disclosure the at least one air knife is a linear air knife arranged in or along at least one wall of the housing.
In yet another embodiment of the disclosure the drive-over tire tread depth gauging further comprises at least one air guide for guiding the air flow from the at least one air nozzle.
In yet another embodiment of the disclosure the optical scanner comprises a laser triangulation scanner.
A second aspect of the present disclosure provides use of a drive-over tire tread depth gauging system for measuring the tread depth of a tire of a moving vehicle, optionally inside a tunnel.
A third aspect of the present disclosure provides a method for gauging the tire tread depth of a moving vehicle, the method comprising the steps of providing a drive-over tire tread depth gauging system, embedding the drive-over tire tread depth gauging system in a road or road segment such that the top opening of the housing of the drive-over tire tread depth gauging system aligns with the surface of the road or road segment, moving the housing lid of the drive-over tire tread depth gauging system from a closed position to an open position, providing a continuous air flow barrier between the optical scanner and the optical opening of the housing as long as the housing lid is in the open position, and measuring, by the optical scanner of the drive-over tire tread depth gauging system, the tire tread depth of the tire of the moving vehicle as the vehicle drives across the drive-over tire tread depth gauging system.
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.
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.
The present disclosure provides a drive-over tire tread depth gauging system 100. The drive-over tire tread depth gauging system 100 is configured to being embedded in a road 130 such that the tread depth of a tire may be measured as the vehicle equipped with said tire drives along the road 130 and across the drive-over tire tread depth gauging system 100. The drive-over tire tread depth gauging system 100 comprises a housing 110 with an optical opening 120, a housing lid for covering the optical opening 120, an optical scanner provided in the housing, and an air nozzle.
The drive-over tire tread depth gauging system 100 may, as schematically illustrated in
The housing may according to the present disclosure be any housing that is adapted to being embedded in a road or segment of a road such that a road vehicle may pass across the housing without causing any irreversible damage to the housing. The housing may for example be a casing of stainless steel, a concrete enclosure or a housing made of any other similar rigid material or combination of materials chosen in order to enable the housing to bear the weight of any type of standard road vehicle.
As will be appreciated by a person skilled in the art with knowledge of the present disclosure, the housing may generally take on a wide variety of shapes and sizes. The housing may generally be shaped such that it comprises a housing interior with a shape and size suitable for accommodating the optical scanner and optionally the air nozzle. The housing may additionally be shaped and dimensioned such that the housing interior may accommodate additional equipment, such as for example communication equipment, and/or other auxiliary equipment. Communication equipment may for example comprise a transmitter and/or a sender configured to communicate data to and/or from the optical scanner from some remote source. Examples of auxiliary equipment may for example comprise one or more of a power source, control unit, a data processing device.
As schematically illustrated in
As schematically illustrated in
a and 2b schematically illustrate an example of a 110 housing provided with an optical opening 120. The optical opening 120 is here illustrated with a length, L, and width, W, being perpendicular to one another, where the length of the optical opening 120 being illustrated as being parallel with the driving direction, X, of a road 130 or road segment in which the housing 110 is embedded. A length 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 150 while enabling most standard road tires to pass without causing an unacceptable obstacle to the vehicle carrying the tire. The housing 110 may, as schematically illustrated in
As will be appreciated by a person skilled in the art with knowledge of the present disclosure, the housing lid may generally be moved between the closed and open position by employment of suitable moving means. The housing lid may for example be moved between the closed and open position by employment of an actuator such as an electrical motor or an electromagnet. The moving means, such as an actuator, may further be controlled using a suitable control unit. The latter may for example be an on-site or remote computer. In a particular embodiment of the disclosure, the housing lid may be moved between the closed and open position as a response to the detection of an approaching vehicle. An approaching vehicle may for example be detected using a camera next to the road, which may communicate a signal to the moving means, asking for the housing lid to be opened. In another embodiment of the disclosure, the lid may be kept open between measurements. For example on a highway, a opening and closing cycle of the lid may depend on not only approaching cars, but also weather conditions and the speed/sequence approaching cars. It will be appreciated by a person skilled in the art with knowledge of the present disclosure that the duration of the opening of the lid may vary significantly beyond the passing of a single car.
The drive-over tire tread depth gauging system 100 comprises according to the present disclosure an optical scanner 150 arranged inside the housing 110. The optical scanner 150 is configured to measure, through the optical opening 120 of the housing 110, the tread depth of the tire 140 as the tire 140 rolls across the optical opening 120 of the housing 110. The optical scanner 150 may thus be arranged inside the housing 110 with a line of sight to the optical opening 120 of the housing 110. When a tire 140 is located by the optical opening 120, the optical scanner 150 may then capture an image of the tire 140 that further may be analysed in order to determine the tread depth of the tire 140. The
The optical scanner may generally be considered to include all the means needed in order to measure the tread depth of the tire as the tire roles across the optical opening. The optical scanner may therefore comprise the optical equipment required in order to capture an image of a tire, including at least a camera, and optionally one or more of a lens or lenses, light source, reflectors, etc. The optical scanner may optionally comprise image processing means configured to analyse said image in order to determine the tread depth from the image. Image processing means may for example be a computer, located locally or remotely. The capture of an image of a tire that may subsequently be used in order to determine the tread depth of the tire may in the context of the present disclosure be considered as a measurement of the tread depth of the tire. As will be appreciated by a person skilled in the art, optical scanners suitable for measuring the tread depth of the tire are well known in the art.
In a particular embodiment of the present disclosure the optical scanner comprises a laser triangulation scanner. The laser triangulation scanner comprises 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 housing, i.e. that the laser has a normal incidence with the optical opening of the housing, 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 tires are more reflective than normal. A specular geometry may be preferred if the surface of the tire is very dark, e.g. when a measurement is performed during night or winter.
The drive-over tire tread depth gauging system 100 comprises, as schematically illustrated in
The drive-over tire tread gauging system 100 may generally comprise one or more air guides 260 for guiding the air flow from the at least one air nozzle 170. The air guides 260 may thus be used in order to shape the air flow barrier 180 as desired, for example by concentrating the air flow into a volume adjacent to the optical opening 120.
a and 2b schematically illustrate a drive-over tire tread depth gauging system 100 that comprises an air knife 240. The drive-over tire tread depth gauging system 100 may generally comprise one or more air knives 240. An air knife 240 may in the context of the present disclosure be considered as an air nozzle 170 configured to provide a laminar air flow. An air knife 240 may for example be an elongated air knife 240 configured to provide an approximately plane laminar air flow. A plane laminar air flow is particularly suitable for providing an air flow barrier 180 between the optical scanner 150 and the optical opening 120 of the housing 110. A plane laminar air flow is preferred as it allows for similar air flow conditions across the air flow barrier 180. An elongated air knife 240 may generally be known as a linear air knife.
The housing lid may generally be used to protect the optical scanner when the drive-over tire tread depth gauging system is turned off or idle. The housing lid may thus generally be employed in order to protect the the optical scanner from environmental pollutants such as water, dust, sand, salt, pollen, snow and gravel. During a measurement, however, the lid needs to be in the open position in order to enable visual communication between the optical scanner and the tire to be measured, thereby no longer offering protection of the optical scanner from pollutants. As a way of maintaining a continuous protection of the optical scanner from pollutants, the at least one air nozzle of the drive-over tire tread depth gauging system is configured to continuously provide an air flow barrier between the optical scanner and the optical opening of the housing whenever the housing lid is in an open position. The air nozzle is thus used both to protect the optical scanner from both environmental pollutants, and also from pollutants introduced by the tire itself. The air nozzle may therefore be activated as a response to the opening of the housing lid. As previously described the housing lid is in an open position when the housing lid is not covering or only partly covering the optical opening of the housing. It will be appreciated by a person skilled in the art that the mechanism controlling the activation of the air nozzle may be realized in a series of ways. The housing lid and the air nozzle may for example both be connected to a control unit that is configured to control the activation and deactivation of the air nozzle based on the position of the housing lid.
In addition to or as an alternative to comprising lower suction means 190, the drive-over tire tread depth gauging system 100 may, as schematically illustrated in
In order to isolate the optical scanner 150 from the exterior of the housing 110 the drive-over tire tread depth gauging system 100 may further comprise a transparent wall 210 arranged between the optical scanner 150 and the optical opening 120 of the housing 110. The employment of a transparent wall 210 may be preferred in order to reduce the need for maintenance of the optical scanner 150, for example because the employment of a transparent wall 210 contributes to keeping moisture and other previously mentioned pollutants away from the optical scanner 150. Moisture in particular may cause corrosion of key elements of the optical scanner 150, hence eventually leading to a need for performing maintenance. When employing a transparent wall 210, the air flow barrier 180 may be provided between the optical opening 120 of the housing 110 and the transparent wall 210. The air flow barrier 180 may then contribute to keeping pollutants away from the transparent wall 210, hence keeping transparent wall 210 clean and thereby transparent to light. Optionally, a transparent wall 210 may be employed in combination with upper suction means 200 as previously described. The upper suction means 200 may then be configured to extract any one or more of air, liquid, dust, sand, salt and gravel at least from between the transparent wall 210 and the optical opening 120 of the housing 110.
The drive-over tire tread depth gauging system may according to the present disclosure comprise additional optional features. As an example the drive-over tire tread depth gauging may further comprise a liquid inlet for providing a cleaning liquid to the surface of the transparent wall facing the optical opening of the housing. The cleaning liquid may for example be a windscreen washer fluid, water, or any alcohol-based cleaning liquid. The cleaning liquid may for example be provided periodically, and optionally be removed from the transparent wall using the lower suction means.
In order to adapt the drive-over tire tread depth gauging system 100 to Nordic climates, the drive-over tire tread depth gauging system 100 may, as schematically illustrated in
A particular aspect of the present disclosure provides a method for gauging the tire tread depth of a moving vehicle. The method comprising the steps of a) providing a drive-over tire tread depth gauging system according to any of the embodiments previously described, b) embedding the drive-over tire tread depth gauging system in a road or road segment such that the top opening of the housing of the drive-over tire tread depth gauging system aligns with the surface of the road or road segment, c) moving the housing lid of the drive-over tire tread depth gauging system from a closed position to an open position, d) providing a continuous air flow barrier between the optical scanner and the optical opening of the housing as long as the housing lid is in the open position, and e) measuring, by the optical scanner of the drive-over tire tread depth gauging system, the tire tread depth of the tire of the moving vehicle as the vehicle drives across the drive-over tire tread depth gauging system.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20220226 | Feb 2022 | NO | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/NO2023/050037 | 2/16/2023 | WO |
