WO2017008825A1

WO2017008825A1 - Reflective marker network

Info

Publication number: WO2017008825A1
Application number: PCT/EP2015/025047
Authority: WO
Inventors: Pepijn Rombout KOLE
Original assignee: Kole Pepijn Rombout
Priority date: 2015-07-10
Filing date: 2015-07-10
Publication date: 2017-01-19

Abstract

Road-side reflector network (Reflective Marker Network), established through optically coupling of individual roadside markers / reflectors. Each individual roadside marker acts as a light collector and reflector; partly reflecting the light and partly transmitting the light through optical coupling (e.g. optical fibres) to other roadside markers. The proportion of transmitted light can be anything from 0 to 100% of the incident light, the proportion of reflected light being the remainder of the total incident light. Any coupling distribution is possible, thereby theoretically extending the distance over which the roadside markers are lit-up to infinity, and far beyond the reach of conventional, non- coupled road side markers, where the distance is limited to the range of a car's head light.

Description

Description of invention for patent application Invention: Reflective Marker Network

Background

At night or in bad weather conditions, such as rain or fog, road-outlines (road side, dividers, median, etc) can be poorly visible, creating a dangerous environment. Devices such as Cat's eyes [1] and Road studs [2] have been invented and installed in many countries to improve the visibility of the road, by reflecting the light from a car's headlight back to the driver, thereby outlining the side of the road. These systems, however, only reach as far as the headlights from the car. A driver can increase the range by turning on the high beam, however this can blind oncoming traffic, and will only increase the range to a certain extend (normal beam typically 50-100 m, high beam typically 100-150 m, longer ranges possible but never exceeds about two hundred metres).

The invention described in this document can theoretically increase the range of the road side reflectors to infinity, and practically to at least several hundred metres, far beyond a driver's required anticipation plus reaction distance. The invention thereby highlights twists, turns, lane changes, and other potentially dangerous changes in the road configuration, far ahead of when the driver reaches these changes, giving plenty of time to anticipate.

The invention achieves the increased range of lit-up markers by optically connecting single reflective markers into a long stretching network of light markers, which reflect only part of the incident light from a car, and transmit the rest to other markers in the network. These other markers in turn emit this light again towards the driver. These emitting markers can be far outside the headlight's reach, thereby increasing the distance at which the outline of the road is visible.

Brief description with figures

The system consists of several components, where we use the following nomenclature:

The network as a whole, referred to as Reflective Marker Network. Workings are illustrated in Figure 1.

The network is made up of individual markers. An individual marker example is given in Figure 2.

Individual markers have components that reflect incident light and components collect light and transfer this light to be emitted from other markers in the network. These collecting and reflecting components are referred to as collector / reflectors (note that these do not have to be single components, but can be separate components). A schematic example of the workings of a collector / reflector is given in Figure 3.

The markers are connected via a coupling system. An example of a coupling distribution is given in Figure 4. Figure 1: Two schematics, showing a light source (e.g. car) in red along a road which is marked by reflective markers, both along the outline of the road as well as the lane divider. In a), the road is marked by conventional single reflective markers, that currently already exist (such as car's eyes, or road studs). The markers are represented by the sun symbols. In the conventional case, only those markers that fall inside the range of the car's headlight are lit up (light suns), those outside the headlight range do not receive any light, therefore also do not reflect any light (black squares). In b), the road is marked using a Reflective Marker Network, whereby the individual markers inside the network are linked (e.g. optically through fibre optics). Light incident from the headlight onto some of these markers, is not only reflected back to the light source by these markers, but partly transmitted to other markers in the network, that could be well outside the headlight's range. These markers that receive the light through other markers, can now emit this light back to the original light source, thereby appearing as being lit up as well, and extending the marked outline of the road to as far as the links of the network are made. In the schematic here, all the markers are linked (to those that fall inside the car's headlights), hence all markers are lit up (all are yellow, none are black).

Figure 2: An individual marker; a collection of these, coupled together, makes up a Reflective Marker Network. The housing (A) and optical coupling (B) are shown in a schematic fashion, and can have any shape, orientation, material choice, and number of components; the invention described here is not limited to any details here. The marker is similar to those currently used on many roads around the world, like cat's eyes [1] and road studs [2], but differs in that the reflectors in these common cat's eyes and road studs are replaced by optical collectors / reflectors (C). Besides reflecting the light directly, these collectors / reflectors (C) also transmit (part of) the light incident on one marker to other markers in the network, who emit this light again.

Figure 3: Schematic of an individual collector / reflector, which sits inside a marker housing. Shape, proportions, orientations and configurations are schematic; the invention described here is not limited to any of the details here. Part of the component reflects the incident light (like a

conventional road side reflector), the remainder collects the light and transmits this through the optical coupling to a collector / reflector inside a different marker, a certain distance away (e.g. further down a road).

Figure 4: Illustration of the coupling system between several markers along a line or road. Optical connections are established between any number of markers. In the example given here, there is connection between nearest neighbours through the solid connections, to the next-nearest neighbours through the dashed connections, and to the next-next-nearest neighbours through the dotted connections. Note that much further, theoretically infinite, connections can be made between an infinite number of markers. The connection profile determines how the light from a head light is distributed along the road, e.g. the range over which light is emitted back to the light source is extended by establishing connections between markers that are far apart.

Description

Passive, reflective road side markers such as cat's eyes [1] or road studs [2] have been around for many decades. These devises reflect light from oncoming vehicles, thereby marking the side of the road, road dividers, and other bearings that drivers should be aware of. The Reflective Marker Networks described here, extend the range of these road side markers significantly by coupling individual markers into an array or network, by for example using fibre optics or electronic communication, or other communication between markers.

The optical coupling between the markers works as follows. Each marker is connected to its nearest neighbour markers along the line (e.g. road) via, for example, fibre optics or other signal transfer system. Light from a vehicle incident on a marker is not only reflected from this one marker, but is also partly transmitted to the next markers down the road, where the light is emitted again. The emission of light from these additional markers increases the range from where light is emitted along the road side significantly, and making the outline of a road or bearing much clearer.

It is now not only the markers that are directly lit by the head lights, but also the markers outside the headlight range, which are optically coupled to the ones inside the headlight range. The distance along which the markers are lit up can be hundreds of metres ahead of the car, and, because of the coupling, the markers that are lit up can also follow ahead throughout bends and corners (away from the direction of the headlight), aiding a driver's ability to anticipate on the road ahead.

The coupling of the individual markers can be done using various density distributions, tailored to the situation. For example, an exponential distribution can be used, where the number of optical fibres to markers further away decays in an exponential fashion, having the most light transmitted from one receiver to its nearest neighbours, and less to markers further away. The result will be that the network will emit most light close to the driver, and will die out further away, at a distance deemed far enough to not be necessary to be lit (such a distance will depend on the type of road, average speeds, etc). Other distributions are also possible; every distribution can have advantages in practicality of the installation of a Reflective Marker Network, and/or optimised illumination profile for the application where the network is installed.

Installation of the network to actual roads, airports, etc, depends on the type of coupling chosen and the coupling distribution present. For long-tail distributions, connections with markers far away have to be established, making a large total of connections necessary. This can be difficult to practically achieve. Modular installation of a Reflective Marker Network is possible, whereby pre-coupled, smaller networks can be installed and in turn coupled to their next-nearest network upon field installation.

The networks can be either mounted on top of the (road) surface, fixing it by adhesives. A more secure (but also more involved) installation would be by milling out holes for each individual marker (same procedure to installation of some existing road side markers), and a slot in between for the coupling to be placed inside. The milled out part of surface can be filled up with normal resin, commonly used for installing car detection and traffic measurement loops etc. References

[1] Improvements relating to blocks for road surface marking, Applicant: Percy Shaw, Application number: GB19340009943 19340403, 3 October 1935 (link:

http://worIdwide.espacenet.com/pubIicationDetaiIs/bibIio?CC=GB&N

&FT=E)

[2] Road studs, Inventor: Medynski Mieczyslaw Tadeusz Wl, Publication number: US3693511 A, Publication date: 26 September 1972 (link:

https://www.google.nl/patents/US3693511?dq=catseye+road+side&hl=en&sa=X&ei=lqJIVf6JFs3taLS Og M gC & ved = 0C C M Q6A E w A A )

Claims

This patent describes a device and claims the following:

1) Optically coupled system of two or more markers, where light illuminating the collector is not only reflected by the marker itself, but also (partly) transferred to other markers that emit the transferred light, thereby extending the reach over which light is reflected back to the light source (e.g. car).

2) A marker according to claim 1) is a device that collects and partly reflects light (similar to the workings of a cat's eye or road stud), but differentiates from existing devices in that a collection of markers (a collection existing of two or more markers) are coupled to one another. Through the coupling, part of the collected light on one of the markers is partly reflected, and partly transferred to other markers in the collection, where the light is emitted again, back in the direction of the original light source (e.g. car).

3) The proportion of light transmitted by one marker to other markers in a system as described in claim 1) can range from zero to one hundred percent of the total incident light; directly reflected and light absorbed in the device make up the remainder of the portion of incident light.

4) The optical coupling in the system in claim 1) can be established in any means, being

passively through, but is not limited to, optical fibres, or actively through, but is not limited to, system using electronic signal transfer.

5) Coupling distribution of the system in claim 1) linking individual markers to their neighbours can be in any profile, be it Gaussian, blocked, linear, etc.

6) Optical coupling system as in claim 1) to be used, but not limited to, enhancing the effective reflective distance for highlighting road sides, road medians, curbs, lane dividers, soft/hard road shoulders, airport runways, racetrack outlines, or any other markings.

7) The individual markers as detailed in claim 2) can have any shape. Any of the housing

components can be made of any material.

8) The housing of one individual marker as described in claim 2) can contain any number of individual collector / reflectors. These collector / reflectors can be placed in any orientation or pattern inside the housing. Any of the collector / reflector components can be made of any material.

9) A collector / reflector as in claim 8) is a component inside a marker that either reflects the light directly or collects it for transferring the light or signal to a collector / reflector inside a different marker in the network. A collector / reflector does not have to be one single component; it can also be split up in several components, where one or more of these components take on the function of reflecting the light, and one or more other of these components take on the function of collecting and transmitting the light. 10) The direction in which the optical coupling of the system in claim 1) is established does not necessarily have to be along the direction of travel (in case of a road, along the line that is marked); markers in the network can also be placed off-line, e.g. in tunnels some of the markers can be on the ground, collecting light, whereas other markers can be placed on the ceiling, from where they emit the light again towards the original light source. Markers can also be connected on the other side of the road, outside the lateral reach of the headlights. It is therefore possible to make a ID, 2D and even 3D network.