FIELD OF THE INVENTION

[0001] The present invention relates to the field of urban furniture. More specifically it relates to methods and systems to detect objects in a space.

BACKGROUND OF THE INVENTION

[0002] There is a tendency in cities to place urban furniture. Such urban furniture are usually used to indicate to people passing by various information such as advertisements, maps, news, traffic information, public transportation schedule, ... US2018307453 describes such an urban furniture, more specifically an interactive multimedia kiosk.

[0003] There is a trend to use such urban furniture to count people passing in front of such urban furniture. W02020084213 describes a people counting device. It comprises a sensor to detect people, such as a camera. However, as mentioned in this document, a problem is to guarantee the anonymity of the people counted. This document solves the problem by defining a specific method to count people, including not furnishing information if the number is too low. Such solution therefore leads to a lack of information in some cases. Furthermore, people tend not to accept to be captured by a camera in a public place. A camera on such an urban furniture is usually vandalized.

[0004] There is however a need for an urban furniture able to count people while keeping the anonymity of the people counted.

SUMMARY OF THE INVENTION

[0005] The present invention concerns an urban furniture. Such urban furniture comprises a display and a structure surrounding such display. It further comprises a lidar integrated in the structure. A cover covers the lidar, such cover being transparent in the operating wavelength range of the lidar and opaque in the visible wavelength range. The urban furniture further comprises communication means configured to send data from the lidar to a server, the communication means being hidden in the structure. [0006] The present invention also concerns the use of such an urban furniture for object recognition and tracking.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The invention will now be described further, byway of examples, with reference to the accompanying drawings, wherein like reference numerals refer to like elements in the various figures. These examples are provided by way of illustration and not of limitation. The drawings are a schematic representation and not true to scale. The drawings do not restrict the invention in any way. More advantages will be explained with examples.

[0008] Fig.1a illustrates an urban furniture, exemplified as a digital totem. Fig.lb illustrates the same digital totem in an exploded view. Fig.lc illustrates an alternative embodiment.

[0009] Fig.2 illustrates an urban furniture, exemplified as a bus shelter.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0010] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims.

[0011] While some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0012] The present invention proposes an urban furniture. The term “urban furniture” encompasses digital totem or kiosk, also referred to as advertising panel, as well as bus shelter. It could also consist of a candelabra for public lighting, a public restroom building, ...

[0013] The urban furniture comprises a display. As a variant, instead of a display, one or more posters made of paper or the like could be used. The display could be onesided or two-sided viewable, meaning the display forecasts on one or two faces.

[0014] The urban furniture further comprises a structure configured to surround the display. Such structure is usually made in a plastic or metallic material.

[0015] The urban furniture further comprises a lidar integrated in the structure. Lidar is an acronym for “light detection and ranging”. It is sometimes called “laser scanning” or “3D scanning”. The technology uses eye-safe laser beams to create a 3D- representation of the surveyed environment. Operating wavelength of lidar compatible with the present invention is comprised between 750 and 1650nm (usually referred to as near-infrared range). More specifically, known operating wavelengths of currently produced lidars compatible with the present invention are 850nm, 905nm, 940nm, 1064nm, 1310nm, 1350nm, 1550nm, 1650nm. An acceptable variance of 25nm around the nominal value of the wavelength may be considered, such that, for example, a wavelength range of 1525 to 1575nm may be accepted around the nominal value of 1550nm. Lidar acquires anonymized data (i.e. no acquisition of biometric data like facial information or skin/hair color) which makes it naturally GDPR (General Data Protection Regulation) compliant, contrary to a camera. This key feature allows the installation of the system in a city without extensive authorizations and security protocols.

[0016] The urban furniture further comprises a cover covering the lidar. The cover is transparent in the operating wavelength range of the lidar. The cover is further opaque in the visible wavelength range. It therefore allows the lidar to operate efficiently while being hidden behind the cover, being then less exposed to vandalism.

[0017] The urban furniture further comprises communication means allowing the lidar to send data to a server. These communication means are hidden in the structure. Non-limiting examples of communications means are a central unit connected to the lidar and able to transmit data through a wireless communication protocol to an external server, or such central unit equipped with a communication port in order to retrieve information manually, or any other communication mean known by the skilled in the art.

[0018] According to a preferred embodiment, the cover has a transmission in the visible wavelength range of less than 1 %, preferably less than 0.1 %, more preferably less than 0.01 %. The visible wavelength range is defined as from 380nm to 780nm. In the present description, to quantify the luminous transmittance, one considers the total light transmission with illuminant D65 (LTD) at a solid angle of observation of 2° (according to standard IS09050). The luminous transmittance represents the percentage of light flux emitted between wavelengths 380nm and 780nm which is transmitted through the cover. The cover is understood to have a luminous transmittance of less than 1 %, preferably less than 0.1 %, more preferably less than 0.01 %. It allows the cover to hide the lidar placed behind.

[0019] The cover can be colored in the bulk, meaning that the material of the cover itself is colored in the visible wavelength range (while still being transparent at the operating wavelength range of the lidar). The cover could also be printed (with an ink or an enamel) or coated (for example through plasma vapor deposition process or any other process known by the skilled in the art) in order to render it opaque in the visible wavelength range.

[0020] According to a preferred embodiment, the cover comprises at least one glass sheet. The glass sheet has a composition that is not particularly limited. The glass sheet may be a soda-lime-silicate glass, an alumino-silicate glass, an alkali-free glass, a boro-silicate glass, ... Preferably, the glass sheet of the invention is made of a sodalime glass or an alumino-silicate glass. The glass sheet according to the invention may be a glass sheet obtained by a floating process, a drawing process, a rolling process or any other process known to manufacture a glass sheet starting from a molten glass composition. According to a preferred embodiment according to the invention, the glass sheet is a float glass sheet. The term “float glass sheet” is understood to mean a glass sheet formed by the float glass process, which consists in pouring the molten glass onto a bath of molten tin, under reducing conditions. The glass sheet preferably has a thickness comprised between 0.5mm and 6mm, more preferably between 1 mm and 4mm. Usual thickness for such glass sheet is 1 ,6mm, 2.1 mm, 3.1 mm or 4mm.

[0021] For such embodiment, the at least one glass sheet has an absorption coefficient at the operating wavelength of the lidar of less than 15m ^-1 , preferably less than 10m ^-1 , even more preferably less than 5m’ ¹ .

[0022] To quantify the low absorption of the glass sheet in the near infrared range, in the present description, the absorption coefficient is used in the wavelength range from 750 to 1650nm. The absorption coefficient is defined by the ratio between the absorbance and the optical path length traversed by electromagnetic radiation in a given environment. It is expressed in rrr ¹ . It is therefore independent of the thickness of the material but it is function of the wavelength of the absorbed radiation and the chemical nature of the material.

[0023] In the case of glass, the absorption coefficient (p) at a chosen wavelength X can be calculated from a measurement in transmission (T) as well as the refractive index n of the material (thick = thickness), the values of n, p and T being a function of the chosen wavelength X: with p = (n-1 ) ² /(n+1 ) ² .

[0024] According to the present invention, the glass having an absorption coefficient at the operating wavelength of the at least one lidar of less than 15m’ ¹ , preferably less than 10m’ ¹ , even more preferably less than 5m’ ¹ , may be a soda-lime-silica glass, alumino-silicate, boro-silicate, ...

[0025] Preferably, a glass composition compatible with the present invention comprises a total content expressed in weight percentages of glass:

SiO ₂ 55 - 85%

AI2O3 0 - 30%

B2O3 0 - 20%

Na ₂ O 0 - 25%

CaO 0 - 20%

MgO 0 - 15%

K ₂ O 0 - 20%

BaO 0 - 20%.

[0026] More preferably, a glass composition compatible with the present invention comprises in a content expressed as total weight of glass percentages:

SiO ₂ 55 - 78%

AI2O3 0 - 18%

B2O3 0 - 18% Na ₂ O 0 - 20%

CaO 0 - 15%

MgO 0 - 10%

K ₂ O 0 - 10%

BaO 0 - 5%

[0027] More preferably, for reasons of lower production costs, the glass compatible with the present invention is made of soda-lime glass. A glass composition compatible with the present invention comprises a content expressed as the total weight of glass percentages:

SiO ₂ 60 - 75%

AI ₂ O ₃ 0 - 6%

B ₂ O ₃ 0 - 4%

CaO 0 - 15%

MgO 0 - 10%

Na ₂ O 5 - 20%

K ₂ O 0 - 10%

BaO 0 - 5%.

[0028] In addition to its basic composition, the glass may include other components, nature and adapted according to quantity of the desired effect. A solution to obtain a very transparent glass in the near infrared, with weak or no impact on its aesthetic or its color, is to combine in the glass composition a low iron quantity and optionally chromium in a range of specific contents. Thus, the glass preferably has a composition which comprises a content expressed as the total weight of glass percentages:

Fe total (expressed asFe ₂ O ₃ ) 0,002 - 0,06%

Cr ₂ O ₃ 0 - 0,06 %.

[0029] Such glass compositions combining low levels of iron and chromium showed particularly good performance in terms of infrared reflection and show a high transparency in the visible and a little marked tint, near a glass called "extra-clear". These compositions are described in international applications W02014128016A1 , WO2014180679A1 , W02015011040A1 , WO2015011041 A1 , W02015011042A1 , WO201 5011043A1 and WO2015011044A1 .

[0030] In a preferred embodiment, the cover further covers the structure. It allows to hide behind the cover other elements of the structure, for example for aesthetical purpose.

[0031] In a preferred embodiment, the cover further covers the display. For such embodiment, the part of the cover covering the display is transparent in the visible wavelength range, allowing to show the display behind it.

[0032] According to a preferred embodiment, the cover further comprises a coating which is antireflective in the operating wavelength range of the lidar. Such coating is usually placed on the face of the cover facing the lidar, allowing to increase the transmission at the operating wavelength range of the lidar.

[0033] The present invention also concerns the use of an urban furniture as described previously for object recognition and tracking.

[0034] In a preferred embodiment, the object is a pedestrian, a cyclist and/or a motor vehicle.

[0035] An urban furniture (1 ), exemplified as a digital totem is shown in Fig.la and in Fig.lb in an exploded view. The digital totem comprises a display (2). This display (2) is surrounded by a structure (3). A lidar (4) is integrated into the structure (3). In this embodiment, the lidar (4) is positioned above the display (2), but it could be placed elsewhere in the structure (3), as long as its field of view is positioned outside of the display (2). In this case, the field of view of the lidar is orientated towards a cover (5). In this embodiment, the cover (5) comprises a first element (51 ) covering the display (2), the structure (3) and the lidar (4). This first element (51 ) is transparent in the visible wavelength range. The cover (5) further comprises a second element (52) covering the structure (3) and the lidar (4). This second element (52) is transparent in the operating wavelength range of the lidar (4) and opaque in the visible wavelength range. This second element (52), in this example, is printed or coated on the first element (51 ). An overlay (6) closes the opposite side of the digital totem.

[0036] In an alternative embodiment shown in Fig.1c, the lidar (4) has a 360° field of view, allowing the lidar (4) to perceive both in front and behind the digital totem. In this case, the overlay (6) is replaced by a cover (5) as defined previously. Depending if the display (2) is one-sided or two-sided viewable, the cover (5) can be made fully opaque in the visible wavelength range or opaque in the visible wavelength range where it covers the structure (3) and the lidar (4) and transparent in the visible wavelength range where it covers the double-sided display (2). [0037] An urban furniture (1 ), exemplified as a bus shelter is shown in Fig.2. In this embodiment, the bus shelter comprises two digital totem as described previously.

[0038] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The foregoing description details certain embodiments of the invention. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the invention may be practiced in many ways. The invention is not limited to the disclosed embodiments.