Patent Description:
Road signs vary in size, shape, images, and words to communicate to a driver. For example, many signs have similar perimeter shapes yet convey different messages or images. Images on a sign, like an arrow, can convey different meanings depending on the other features on the sign. For example, a sign with an arrow might indicate a "one way" road, while another similar-sized and colored sign with an arrow might indicate the direction to a destination. Critical road signs, whose function is to provide important information for safe vehicle operation, can be difficult to identify and differentiate from the broader range of signs with similar shapes.

The electronic and communication capabilities available could aid in identification and communication between the road sign and a vehicle. Camera-based vision systems in particular are becoming common in new vehicles. However, current vision systems typically have difficulty accurately reading the broad range of highway road signs. For example, as discussed, a reader might identify the arrow, but not accurately distinguish the context of identifying whether the arrow might indicate a "one way" sign or a direction to a destination. There is a need for an improved identification system to more accurately detect or recognize, or both detect and recognize critical road signs, roadway information, and adjacent roadway information. <CIT> discloses a traffic sign having reflectors installed thereon and a non-visible light source installed on a vehicle. The reflectors can reflect polarized non-visible light back towards the vehicle which can be detected by a sensor module mounted on the vehicle to provide traffic information to a display in the vehicle. <CIT> discloses detecting, interpreting and displaying traffic signs and signals to the driving motorist in real time by means of Radio Frequency Identification (RFID) technology coupled with a processor and a display unit mounted in the vehicle. <CIT> discloses a traffic information acquisition system for vehicles having a first opto-electrical transceiver on the vehicle side and a second opto-electrical transceiver provided at predetermined locations in traffic lanes. The first transceiver emits a first signal and receives and decodes a second signal from the second transceiver and the second transceiver receives the first signal from the first transceiver and sends back a coded, second signal to the first transceiver. <CIT> discloses a system for delivering road sign content information to a mobile computing device for display to the driver of a vehicle. The system consists of a wireless communication network in communication with a mobile computing device operationally coupled to a dashboard display device or a vehicle head up display device. <CIT> discloses a communication system to transmit information pertaining to a measured operational characteristic of a vehicle to an external device via a wireless transmitter. The external device may be mounted as a receiver in an adjacent vehicle which is provided with a display to display a parameter of the information transmitted. In <CIT>, a vehicle detects a symbolic code associated with a traffic sign. Information associated with the symbolic code (URL) is accessed at a corresponding website and displayed to the driver in the vehicle.

Disclosed is an identification system to improve safety on roads and allow for the driver or for the vehicle itself (if it is autonomous or semi-autonomous) to have readable and useful information about road signs, roadways, and adjacent roadway information. The disclosed identification system comprises a marker with marker communication information that can be read by a vehicle information system to provide information to the vehicle. Information that the marker communication information may convey would allow the vehicle information system to detect or recognize, or both detect and recognize critical road sign, roadway information, and adjacent roadway information. Then, the vehicle information system could respond to the information received from the marker communication information.

The present invention is defined by the features of claim <NUM>. Preferred embodiments are defined by the features of the dependent claims.

In general, sign communication information may be any text or graphic or combination thereof intended to provide information to a road user. Optical communication comprises communication based on patterns (for example, machine-readable text, graphics, indicia, patterns, shape, or a code, such as a bar code or QR code) read using visible or non-visible wavelengths as well as communication based on variations or patterns in properties such as frequency, wavelength, polarization or amplitude including pulsed amplitude.

In any one of the described embodiments, the identification system further comprises any one of:.

<FIG> is a top view of one embodiment of an identification system.

While the above-identified drawings and figures set forth embodiments of the invention, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art. The figures may not be drawn to scale.

The identification system <NUM> comprises a marker <NUM> that includes marker communication information that can be read by a vehicle information system. <FIG> is a top view of a roadway <NUM> with a vehicle <NUM> driving in the direction of the arrow. Adjacent to the roadway is a marker <NUM> that includes marker communication information. Also, shown in <FIG> is a sign <NUM> which contains sign communication information, such as "STOP" or an arrow to turn right. In one embodiment, the marker communication information may communicate information about the sign communication information. In one embodiment, the marker communication information may communicate information about critical road signs, roadway information, and adjacent roadway information. On the vehicle <NUM> is a vehicle information system <NUM> for reading and processing the marker communications information.

It would be costly and time consuming to completely redesign existing road signs to include information that would be more easily read by a reader on a vehicle. Therefore, the identification system <NUM> disclosed includes a marker <NUM>, which discretely contains marker communication information. In one embodiment, the marker <NUM> may be attached to a sign <NUM> or to the post holding the sign. For example, the marker <NUM> could be attached during the original construction of the sign <NUM>, or may be separately attached to a finished, already existing sign <NUM>. If attached during the original construction of the sign <NUM>, the marker <NUM> could be embedded within the sign <NUM>. If attached to a finished sign <NUM>, the marker <NUM> could be adhesively secured to the sign <NUM>. If the identification system <NUM> relies on optical identification of the marker communication information of the marker <NUM>, then the marker <NUM> is attached to the viewable surface or viewable portion of the sign <NUM>.

In one embodiment, the marker <NUM> is not attached or connected to any portion of the sign <NUM>. Instead, the marker <NUM> is located near the road <NUM>. If the identification system <NUM> relies on optical identification of the marker communication information of the marker <NUM>, then the marker <NUM> is placed near the road <NUM> in a viewable location. The marker <NUM> itself may appear like a sign. The marker <NUM> may be secured on its own post, to other road way fixtures, adjacent fixtures, or buried underground.

To provide additional data to the vehicle information system <NUM>, in one embodiment, the marker <NUM> is at a predetermined location relative to a sign <NUM>. In one embodiment, the marker <NUM> is located on the sign. Typically, when the marker <NUM> is separate from the sign <NUM>, the marker <NUM> will preceding the sign <NUM>, relative to the direction of a moving vehicle, such as shown in <FIG>. The marker <NUM> may also be displaced from the sign <NUM> but located on the sign post or other supporting structure. When the marker <NUM> is at a predetermined location relative to a sign <NUM>, such as a stop sign, the vehicle information system <NUM> can use the location information of the marker <NUM> relative to the sign <NUM> along with any other inputs to calculate such things as the time to stop before the sign, or the direction the car must turn after the sign.

The marker <NUM> comprises marker communication information. Marker communication information is information that the marker <NUM> communicates to the vehicle information system <NUM> which reads and processes the marker communication information (the details of the vehicle information system <NUM> are described below).

In one embodiment, the marker <NUM> further comprises a passive communication device. A passive communication device is a device that contains marker communication information that can be read, and the marker communication information does not change. Therefore, in such an embodiment, the marker communication information comprises static information, which is information that does not change. In one embodiment, the static information comprises an optical communication such as, for example, machine-readable text, graphics, indicia, patterns, shape, or a code, such as a bar code or QR code.

Depending on the marker functionality, the marker <NUM> may require a power source, which may be provided from such elements as a battery, solar panel, or electrical connection. To limit power consumption or the need required to monitor and change batteries, a preferred marker <NUM> functions without an external power source.

In embodiments where the marker communication information comprises an optical communication, the optical communication may be reflected light from a source which illuminates the marker. To reflect light, the marker <NUM> may comprise reflective and/or retroreflective materials. The term "reflective" as used herein refers to the attribute of reflecting an obliquely incident light ray at an equal angle measured with respect to the surface normal of the marker wherein the incident and reflected rays and the surface normal are coplanar (also called specular reflection). The term "retroreflective" as used herein refers to the attribute of reflecting an obliquely incident light ray in a direction antiparallel to its incident direction, or nearly so, such that it returns to the light source or the immediate vicinity thereof. The incident direction is typically angularly displaced from the surface normal of the sign or marker by the entrance angle. Preferably the return light is angularly displaced from its incident direction by the observation angle so that it can be read by a detector which is displaced from the source (e. g the human eye which is displaced relative to the vehicle head light). Both entrance and observation angle vary as a function of vehicle position relative to a sign or marker. Two known types of retroreflective sheeting are microsphere-based sheeting and cube corner sheeting (often referred to as prismatic sheeting). Microsphere-based sheeting, often referred to as "beaded" sheeting, employs a multitude of microspheres typically at least partially embedded in a binder layer and having associated specular or diffuse reflecting materials (e.g., pigment particles, metal flakes, vapor coats) to retroreflect incident light. Illustrative examples are described in, for example, <CIT>), <CIT>), and <CIT>). Cube corner retroreflective sheeting, often referred to as "prismatic" sheeting, comprises a body portion typically having a substantially planar front surface and a structured rear surface comprising a plurality of cube corner elements. Each cube comer element comprises three approximately mutually perpendicular optical faces. Illustrative examples are described in, for example, <CIT>), <CIT>), <CIT>), <CIT>), and <CIT>). A seal layer may be applied to the structured surface to keep contaminants away from individual cube comers. Flexible cube corner sheetings, such as those described, can be found for example, in <CIT>). Retroreflective sheeting for use in connection with the present application can be, for example, either matte or glossy.

The retroreflective film can be designed in a way to retroreflect light that sends a different optical communication as a function of, for example, entrance or observation angle. For example, a vehicle <NUM> that is <NUM> meters away from a retroreflective marker <NUM> might retroreflect light that provides a first optical signal to the vehicle information system <NUM>, while the vehicle <NUM> that is <NUM> meters away from the retroreflective marker <NUM> might retroreflect light that provides a second optical signal to the vehicle information system <NUM>. For example, for retroreflective film used as the marker <NUM>, if the reader <NUM> is <NUM> meters from the light source <NUM> of the vehicle information system <NUM> then the observation angle is <NUM> degree at <NUM> meters and <NUM> degree at <NUM> meters.

In some embodiment, the reflected light of the marker communication information may be light at a specific wavelength. For example, the marker communication information may comprise IR or near-IR light. An IR or near-IR optical communication would not be significantly visible in the visible light spectrum, and therefore would not cause a visual distraction to the driver of the vehicle <NUM>.

In embodiments where the marker communication information comprises optical communication that is light at a specific wavelength, the marker <NUM> may comprise a layer to control the reflected light. In one embodiment, the marker <NUM> comprises multi-layer optical film to control the reflected light. In one embodiment, the marker <NUM> comprises wavelength specific inks.

For example, the marker <NUM> may include permanent or temporary attachment of one or more visibly-transparent, near-infrared-reflecting multi-layer optical films to the retroreflective sheeting. Such attachment may occur by, for example, use of an adhesive. The use of areas of visibly-transparent, near-infrared-reflecting multi-layer optical films on the marker <NUM> causes specific wavelengths of light, such as near-infrared light, incident on the marker <NUM> to be reflected from the otherwise retroreflective light path and thus creates regions of high contrast compared to adjacent areas on the marker <NUM> without multi-layer optical films when viewed. The specific wavelengths are reflected away from the vehicle information system <NUM> that would read the marker communication information. Multi-layer optical films are effectively wavelength-specific reflecting mirrors with high transmission in the different wavelength regions such as the visible portion of the wavelength spectrum. Meanwhile, the image/graphics/indicialpattern on the marker <NUM> remains largely unaffected by the presence of the multi-layer optical film(s) when viewed with visible light. Because the visibly-transparent, wavelength-specific reflecting multi-layer optical film(s) are not significantly visible in the visible portion of the wavelength spectrum, the image/graphics/indicialpattern created using the multi-layer optical film(s) is not visible to the human eye in the visible portion of the wavelength spectrum and does not cause a visual distraction to the driver.

The multi-layer optical film chosen for any specific implementation will depend on the desired optical, structural, and durability characteristics. As such, desirable multi-layer optical films will vary based on the intended application. Some exemplary multi-layer optical films are described in, for example, <CIT> and <CIT>. Exemplary commercially available multi-layer optical films include, for example, Vikuiti Clear Card Filter, Solar Reflective Film, and SM <NUM>, all manufactured by <NUM> Company of St. The reflectance and transmission spectrum of a particular multi-layer optical film depends, in part, on the optical thickness of the individual layers along the various axes, and is substantially determined by the Fresnel coefficient. Films can be designed to reflect infrared, visible, or ultraviolet light by choice of the appropriate optical thicknesses. The desired relationship between refractive indices of polymeric layers can be achieved by selection of appropriate materials and appropriate processing conditions.

Alternatively or in combination, the wavelength-specific dye may be used to provide the marker communication information (for example, infra-red reflecting or absorbing dye). Exemplary descriptions of such dyes may be found in, for example, <CIT>. Commercially-available infra-red reflecting dyes include, for example, those manufactured by H. Sands Corporation of Juniper, Florida and Epolin Corporation of Newark, NJ. One exemplary advantage of multi-layer optical film usage, especially multi-layer optical films with high visible light transmission, is that unlike near-infrared absorbing dyes, tinting or color change can be largely avoided or minimized.

In one embodiment, the marker <NUM> further comprises an active communication device. An active communication device is a device that is able to read information and contains information that can be read. In active communication devices the information can be altered under certain circumstances. In active communication devices the marker communication comprises dynamic information. In one embodiment, the marker communication information is dynamic information that comprises one or more of an optical signal, audio signal, electronic signal, radio signal. In one embodiment, the electronic signal is a pulsed light emitting diode signal. In an active communication device, in one embodiment, the marker communication is position or location service information which might augment, for example, vehicle-based GPS position information. Typically, an active communication device will have an energy source, such as a battery.

In one embodiment, the marker <NUM> comprises one or more materials or devices for providing marker communication information. In one embodiment, the marker <NUM> comprises both a passive communication device and an active communication device. In one embodiment, both static information and dynamic information are provided as marker communication information from the marker <NUM> to the vehicle information system <NUM>.

The vehicle information system <NUM> comprises a reader <NUM> and a processor <NUM>. The reader is any kind of device able to detect the marker communication information. The processor is any kind of device that is able to convert the marker communication information into output information. The specific aspects of the reader <NUM> will be determined based on the format of the marker communication information. In one embodiment, the reader <NUM> is able to receive one or more of an optical signal, electronic signal, auditory signal, radio frequency signal, or internet-based signal from the marker <NUM>.

For the vehicle information system <NUM> to read the marker communication information, the vehicle information system <NUM> first needs to identify the marker <NUM>. In one embodiment, the marker <NUM> comprises a predetermined shape, predetermined color, or predetermined retroreflective property comprising a specific retroreflective divergence profile or change in polarization of the retroreflected light that the reader <NUM> and processor <NUM> are designed to recognize. Predetermined color may include non-visible light wavelengths. In one embodiment, the vehicle information system <NUM> identifies the marker <NUM> from the information it receives by reading and processing the marker communication information. In one embodiment, the vehicle information system <NUM> identifies the marker <NUM> by matching with image or character recognitions software the predetermined property, such as shape, color, or retroreflective properties, of the marker <NUM>.

In one embodiment, the reader <NUM> of the vehicle information system <NUM> comprises a camera to receive the marker communication information. In one embodiment, the reader <NUM> of the vehicle information system <NUM> comprises a camera with a lens to receive the marker communication information. In one embodiment, the reader <NUM> of the vehicle information system <NUM> comprises a camera with a lens and a wavelength-sensitive filter to receive the marker communication information. In one embodiment, reader <NUM> receives the marker communication information in a specific range of wavelengths that may be outside of the range of wavelengths visible by the human eye. In one embodiment, the specific range of wavelengths of the marker communication information received by the reader <NUM> is infrared (IR) or near-infrared (IR).

The reader <NUM> will match the functionality of the marker communication information of the marker <NUM>. For example: if the marker communication information is optical communication, the reader <NUM> will comprise a camera and lens; if the marker communication information is optical communication within a specific wavelength range, the reader <NUM> will comprise a wavelength-specific camera and lens; if the marker communication information is a radio signal, the reader <NUM> will comprise a radio reader; if the marker communication information is an RFID signal, the reader <NUM> will comprise an RFID reader. It is understood that the marker communication information can comprise one or more types of information and therefore the reader <NUM> might have one or more capabilities for reading the marker communication information.

For marker communication information that is optical communication, ambient light may be used as the light source to provide the reflected light to the reader <NUM>. However, typically the vehicle information system <NUM> includes a light source <NUM> for directing light to the marker <NUM> to take particular advantage of retroreflective properties of the marker. In one embodiment, the light source <NUM> emits light to the marker <NUM>. In one embodiment, the light source <NUM> emits light to the marker <NUM> in a specific range of wavelengths. In one embodiment, the specific range of wavelengths of light emitted from the light source <NUM> is outside the range of wavelengths visible by the human eye. In one embodiment, the specific range of wavelengths of light emitted from the light source is near-infrared (IR).

The vehicle information system <NUM> includes a processor <NUM> for interpreting the marker communication information received by the reader <NUM> and converting it to output information. The processor <NUM> comprises common computer processor components such as a memory. In one embodiment, the processor <NUM> comprises software code for interpreting the marker communication information. In one embodiment, the processor <NUM> comprises pattern recognition or optical character recognition software. The processor <NUM> may control a transmitter and receiver and be able to send and receive information, such as the output information, from the vehicle information system <NUM> to external devices. For example, the processor <NUM> may send the output information to an internet-based information storage system, which in turn sends comprehensive information back to the processor <NUM> regarding the output information.

The vehicle information system <NUM> receives the marker communication information from the marker <NUM> to the vehicle <NUM>. In one embodiment, the vehicle <NUM> comprises the vehicle information system <NUM> that reads the marker communication information and processes the marker communication into output information. The processed output information may provide visual or audio information to the driver or may control a function of the vehicle <NUM>.

In some embodiment, information may be received to the vehicle information system <NUM>, such a GPS or other positional information, that will make certain received marker communication information irrelevant. For example, information about the lane that a car is traveling in can make some road signs more or less relevant. For example, if a car is traveling in a center lane, then an "Exit Only" sign is not relevant and the vehicle information system may be programed to disregard that marker communication information.

In one embodiment, the vehicle information system <NUM> includes a transmitting source, such as a light source <NUM>, that first sends a signal, such as light, audio, electrical, or radio, to the marker <NUM>. Then, the vehicle information system <NUM> reads the returned marker communication information and processes the marker communication into output information.

The marker <NUM> functions to send marker communication information from the marker <NUM> to the vehicle <NUM>. In one embodiment, the marker <NUM> sends one or more of optical communications, an audio signal, an electrical signal, a radio signal, an internet-based signal that is capable of being read by the reader <NUM> of the vehicle information system <NUM> and processed into output information that provides visual or audio information to the driver or may control a function of the vehicle <NUM>. In one embodiment, the marker <NUM> receives a signal, such as light, audio, electrical, radio, internet-based, from the vehicle information system <NUM>. Then the marker <NUM> returns marker communication information to the vehicle information system <NUM>.

The marker communication information may provide information to the vehicle information system <NUM> about sign communication information, other adjacent critical road signs, roadway information, or adjacent roadway information.

In one embodiment, the output information is matched from stored information in the vehicle information system <NUM> such that a function is applied by the processor <NUM>. For example, marker communication information may provide information that there is a "stop" sign <NUM> meters ahead. The processor <NUM> could match to any number of functions, such as an audio message to the driver that says "Stop Ahead" or the processor <NUM> could control braking of the vehicle <NUM>.

In one embodiment, the output information is sent to an internet-based information storage system. Based on the information sent, the internet-based information storage system may send back to the processor <NUM> in the vehicle information system <NUM> comprehensive information that may include the local weather, local traffic conditions, adjacently-located fixtures (such as vehicles, houses, restaurants or businesses), and upcoming road signs. For example, the marker communication information may be a code that is deciphered and which includes a fixed IP address or URL to the internet-based storage system. The processor <NUM> may communicate this comprehensive information to the driver of the vehicle <NUM>. The processor <NUM> may use this comprehensive information to control aspects of the vehicle <NUM>.

For example, if the marker communication information is an optical communication that is read by a camera in the vehicle information system <NUM>, the processor may process that optical communication into output information that is location information and send that output information to an internet-based information storage system. Based on the location information the internet based information storage system may send back to the processor <NUM> in the vehicle information system <NUM> comprehensive information that may include the local weather, local traffic conditions, adjacently located fixtures (such as vehicles, houses, restaurants or businesses), and upcoming road signs. The processor <NUM> may communicate this comprehensive information to the driver of the vehicle <NUM>. The processor <NUM> may use this comprehensive information to control aspects of the vehicle <NUM>. For example, if the comprehensive information received to the processor <NUM> from the internet based information storage system indicated there is a stop sign in <NUM> meters, then the processor <NUM> could control braking of the vehicle <NUM>.

The processor <NUM> may also receive positional information to identify a particular marker such that the marker communication information received from a particular marker can be connected to certain information from the internet based information storage system. For example, if marker communication information is received at a known location that is information related to a nearby hotel, that marker communication information could be updated to include vacancy information about the hotel. For example, if marker communication information is received about a constructions zone, new changes, cautionary messages, or detours can be communicated for that location.

Claim 1:
An identification system (<NUM>) between a sign (<NUM>) and a vehicle (<NUM>) comprising:
a sign (<NUM>) with sign communication information;
a marker (<NUM>) at a predetermined location relative to the sign (<NUM>), wherein the marker (<NUM>) comprises marker communication information comprising optical communication;
a vehicle information system (<NUM>) comprising a light source (<NUM>) to send light to the marker (<NUM>), a reader (<NUM>) to read the optical communication, and a processor (<NUM>) to convert the optical communication into output information;
wherein the optical communication of the marker (<NUM>) is retroreflected light from the light source (<NUM>);
wherein the output information is at least one of a detection of the presence of the sign (<NUM>) and a recognition of the sign communication information;
characterized in that
the processor (<NUM>) is configured to send, to an internet-based information storage system, the output information, receive additional information relating to the output information from the internet-based information storage system, and, in response to determining that the additional information is relevant to the vehicle (<NUM>), perform at least one operation that corresponds to a function of the vehicle (<NUM>).