Patent Description:
Accordingly, systems, components and methodologies are provided for adaptively controlling traffic light signals using bidirectional communications with one or more approaching vehicles. By communicating with the approaching vehicle, the status of that vehicle relative to the intersection may be continuously updated via recall messages and cancellation messages, thereby allowing the traffic light controller to integrate this information into its control scheme to more effectively regulate traffic at the intersection.

According to the invention, the system comprises the features of appended claim <NUM>. The system comprises a virtual induction loop system including a transportation vehicle, a traffic light control system in communication with the vehicle that communicates a map message to the vehicle including lane geometry at an intersection, and, means for analyzing the map and the position of the vehicle and issuing a recall message from the vehicle to the traffic light control system so that the traffic light control system can account for the vehicle in the control of a traffic light at the intersection.

In some embodiments, the means may comprise a processor in the vehicle, the processor configured to include a transceiver to communicate directly with a road side unit that controls the traffic signal. In some embodiments, the means may comprise a processor in the vehicle, the processor configured to include a transceiver to communicate with a traffic management center via an existing vehicle manufacturer communication network.

According to the invention, the map message includes a virtual loop position of a virtual loop positioned in a predetermined location relative to the intersection and the means determines that the vehicle has crossed the virtual loop and issues a recall message in response to that determination. In some embodiments, the means determines an estimated time of arrival ("ETA") to the intersection and the recall message includes the ETA.

The vehicle continuously monitors the vehicle position and the information in the map message and may send updated recall messages, including cancellation messages, when the vehicle deviates from approaching the intersection.

Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.

Traffic control devices, such as traffic signals, provide important guidance and communication for roadway vehicle operations. However, even properly implemented traffic control devices can create inefficiencies. For example, a typical - phase (red, amber, green) traffic light can generate vehicle and/or traffic inefficiencies duc to failure to properly account for real-time traffic situations in the traffic signal's controller program. Induction loops and "video loops' are fixed installations at actuated signalized intersections that can detect vehicles and let the controller know a vehicle is approaching. However, these fixed detection installations must be installed in close proximity to the intersection, often providing too little time for the controller to integrate the approaching vehicle information into its traffic light control program. By providing a virtual induction loop, the virtual induction loop may be placed or even repositioned without the expense of modification of the roadway and irrespective of whether the stoplight or stoplight camera is within view of the location of the virtual induction loop. In this manner, an approaching vehicle can issue a recall (also referred to as a call) message requesting to be served well in advance of arriving at the traffic signal.

As shown in <FIG>, a traffic light <NUM> is oriented to govern the flow of traffic through a roadway intersection. The traffic light <NUM> may be a portion of a traffic system of the surrounding area. The traffic system may include numerous traffic lights, indicators, signs, and/or other traffic control devices. The traffic system may be in communication with a network <NUM> to communicate traffic information, as represented by communication link <NUM> between the traffic light <NUM> and the network <NUM>, although traffic information may be communicated through devices of the traffic system other than the traffic light <NUM> itself, for example, through a communication hub. Traffic information may include light phases (i.e., red, yellow, green), phase timing, triggering of detectors (e.g., pedestrian crosswalk request buttons), intersection topology information, and/or other intersection and/or traffic related information.

The network <NUM> may be formed as a data collection and/or processing center. The network <NUM> may include various processors <NUM>, databases <NUM>, terminals <NUM>, and/or other hardware and/or or software for data collection and/or processing. The processors <NUM> may execute instructions for triggering a virtual loop and may communicate with the various databases <NUM>, terminals <NUM>, and/or other components to achieve their functions. The network <NUM> may be programmed to control and adjust operation of the traffic signal <NUM> based on information received from the traffic system, including information about an approaching vehicle <NUM>. For example, the operation of the traffic signal may be adjusted to extend the green light signal for an approaching vehicle <NUM> in motion while maintaining a red light for another stopped vehicle <NUM>.

Referring now to <FIG>, a flow is illustrated for developing and implementing virtual loop control of the operation of the traffic light <NUM> using a bidirectional datapath. The traffic system <NUM> may communicate intersection topology map information including a signal identifier and the position of a virtual loop for the signal. The map topology according to the invention further includes map lines to define each lane which may extend from the last traffic signal traversed to the stop line at the approaching intersection as discussed further in <FIG> The virtual loop control system <NUM> may be provided by a single content provider <NUM> or may be provided in collaboration with an optional additional content providers <NUM>, and may include the vehicle <NUM>. The content provider <NUM>, <NUM> may communicate map information, including the location of a virtual loop in the map corresponding to traffic light <NUM> to the vehicle <NUM>. The vehicle is configured to process the received information by continuously comparing the map information received with the real-time vehicle position and provide a recall message based on the received map information to the content provider <NUM>, <NUM> and back to the traffic system <NUM> to control the traffic signal.

Vehicle embodiments for implementing this bidirectional datapath are illustrated in <FIG>. As seen in <FIG>, a vehicle <NUM> may be provided with a positioning or navigation system <NUM> in communication with a processor <NUM> that may be configured to receive and process information from the positioning system <NUM> and a traffic light controller <NUM>. The vehicle <NUM> may be communicatively connected to the traffic light controller <NUM> via dedicated short-range communications (DSRC) with a road side unit <NUM>, such as the SAE J2735 Standard. Alternatively, vehicle <NUM> may be connected through <NUM>/<NUM>/<NUM> LTE communications <NUM> via a vehicle content provider or manufacturer network <NUM> o a traffic management center <NUM>. Traffic management center <NUM> may be in further wired or wireless communication with one or more traffic light controllers <NUM>. This alternative bidirectional connectivity can be done, for example, via the Audi Connect Traffic Light Information System as disclosed in <CIT>, which is incorporated in its entirety by reference. In another edge computing embodiment (not shown), the content provider network may be local, such as a computer placed at the traffic management center or near a <NUM>/<NUM> cellular tower to minimize latency.

As discussed above, the traffic light controller is configured to transmit a map or topology message to a vehicle. The map or topology message may include information regarding the lane geometry at the intersection, a corresponding signal group and movement, and location of a virtual loop for a traffic signal. Examples of various virtual loop scenarios are provided in <FIG>, of which <FIG> illustrates an embodiment of the invention. As seen in <FIG>, there are no turn lanes at the intersection <NUM>. In this example not encompassed by the wording of the claims, virtual loop <NUM> may be a line across all lanes approaching the intersection as all lanes may be governed by the same traffic signal <NUM>. <FIG> illustrates an example not encompassed by the wording of the claims in which a virtual loop <NUM> is positioned within an entry into a turn lane <NUM> to control a corresponding turn lane traffic signal <NUM> of a traffic signal group at an intersection. As seen in <FIG>, the virtual induction loop may be formed as a combination of identification of a turn signal <NUM> being activated in the approaching vehicle and a corresponding turn lane <NUM> to control a corresponding turn lane traffic signal <NUM>. As seen in the embodiment of <FIG>, the topology map of the intersection includes lane geometries defined by a center line <NUM> for each lane present at the intersection. In this manner, each lane may be mapped to a particular traffic light in a signal group. Each lane geometry may be defined to extend from the previously encountered intersection to a stop, or limit line, at an approaching intersection. The virtual loop for a turn lane may be triggered when it is determined that the vehicle is in the turn lane, or positioned on the turn lane center line <NUM>, to control the corresponding turn lane traffic signal <NUM>. <FIG> shows an example not encompassed by the wording of the claims in which the recall signal may be updated. In this example, virtual loop may be a combination of the turn signal indicator <NUM> may be activated in vicinity of an oncoming turn lane <NUM> similar to <FIG>. A recall message may be sent by the vehicle to control the traffic signal when the turn signal is activated as discussed above with respect to <FIG>. However, an additional turn path, <NUM>, such as an entry to a retail center, gas station, or other roadway may be positioned before the traffic signal <NUM>. In this scenario, the vehicle may turn onto this additional turn path <NUM> prior to the intersection, in which case another recall message, or cancellation message, may be sent to the traffic signal control to update the traffic situation. Although depicted as distinct virtual loop scenarios for the purposes of discussion, any of these examples not encompassed by the wording of the claims and embodiments may be present in combination at an intersection.

A method of controlling a traffic light system using virtual loops is provided in <FIG>. A vehicle receives a map message <NUM>, which includes topology information about lanes in an upcoming intersection as well as a virtual loop position. The map may be sent by the road side unit or content provider to be transmitted to the vehicle as discussed above with respect to <FIG>, <FIG>. The vehicle continuously determines whether the virtual loop has been crossed <NUM>. This may be performed by comparing <NUM> the position of the vehicle with the position of the virtual loop in the map message. If the loop has not been crossed, the vehicle may continue to compare the position of the vehicle with the virtual loop message until the loop is crossed. In response to a determination that the virtual loop is crossed, a recall message may be issued <NUM>. The recall message may be issued through the network as disclosed in <FIG> for example and routed back to the traffic light controller. The recall message may include identifiers that allow the message to be routed back to the correct traffic light controller. For example, identifiers may include a traffic light identifier, a direction of travel of the vehicle, and a lane identifier of the vehicle. The vehicle may continue to monitor the position of the vehicle in the received map message. If the vehicle deviates from the information indicated in the map message <NUM>, an additional recall message, or cancellation message <NUM>, may be sent to cancel the request to be served at the intersection. This may occur when the vehicle turns or in some other way deviates its travel path to avoid the approaching intersection. If the vehicle does not deviate from the information indicated in the recall message, then the traffic light controller receives the recall message and uses the message for controlling the traffic light <NUM>.

A method of controlling a traffic light system using virtual loops is provided in <FIG>. A vehicle receives a map message <NUM>, which includes topology information about lanes in an upcoming intersection as well as a virtual loop position. The map may be sent by the road side unit or content provider as discussed above with respect to <FIG>, <FIG>. The vehicle processes the map message to determine one or more of an estimated time of arrival at the intersection, a distance to the intersection and a speed the vehicle is traveling at <NUM>. The vehicle sends a recall message to the controller with the determined information <NUM> indicating when the vehicle will arrive at the intersection. The vehicle continuously monitors distance and speed <NUM> to determine if the estimated time of arrival has changed <NUM>. If it has, the vehicle sends this change in an updated recall message to the controller <NUM>. If the estimated time of arrival has not changed, then the traffic light controller triggers a virtual loop detector operation at a time that is optimal for the approaching vehicle based on the latest received recall message <NUM>. This may then permit the information about the time of the approaching vehicle to be integrated into the program to control the traffic light <NUM>. Concurrently with determining whether the estimated time of arrival has changed <NUM>, the vehicle may determine whether the vehicle has diverted from a path to the intersection <NUM>. If the vehicle deviates from the map information, such as lane information leading to the intersection, an additional recall message, or cancellation message <NUM>, may be sent to cancel the request to be served at the intersection. This may occur when the vehicle turns or in some other way deviates its travel path to avoid the approaching intersection. If the vehicle does not deviate from the information indicated in the recall message, then the traffic light controller reacts to the recall message to control the traffic light <NUM>, <NUM>.

As described in the systems and methods above, controlling the traffic light may include changing the timing of phases (red/green time) by extending the green-light time for an approaching vehicle or, providing a green indicated if there is no traffic in conflicting directions. In some embodiments, the controlling may include not altering the timing phases in view of the approaching vehicle due to other pre-programmed traffic considerations. For the purposes of this disclosure, recall is not used to mean pre-emption, which is a mode that gives priority to emergency vehicles. Rather, the recall message is integrated in the pre-existing controller program of a traffic light.

In some embodiments, the vehicle recall message may include vehicle weight and/or type and the controller program of the traffic light may be configured to give priority (longer and earlier green light time) to heavy vehicles, tractor trailers, or public transportation vehicles. In some embodiments, a plurality of vehicles may be organized into a platoon by V2V communication. A vehicle in the platoon may convey a platoon identification, the number of vehicles, and vehicle types in the recall message. The traffic light controller may be programmed to integrate platoon information into its traffic light control program to more efficiently manage traffic, for example, by extending the length of green light time so that the entire platoon may traverse the intersection.

Previously existing detector installations for vehicle induction loops are fixed and often installed in close proximity to the intersection. Systems including cameras must be installed within the direct view of the intersection. Maintenance associated with these detector systems is expensive and can involve going to the intersection and cutting slots in the road. Various control systems for public transportation, such as trains, rely on predetermined routes and time schedules to prioritize the public transport based on these known predetermined variables.

The virtual loop system uses a software-defined detector, which can be defined and changed easily in software and at little or no cost. Therefore, if a defined detector, or "virtual loop" is providing inadequate response time or information to a traffic light control system, it can be redefined in the software to either change distance within lanes or to be limited to one or more particular lanes. Additionally, this software-defined detector may be installed further away from an intersection giving the traffic light control a more advanced warning of approaching vehicles. Furthermore, call, recall, updated recall or cancellation messages may be transmitted from a vehicle with a randomly assigned temporary ID so that the content provider and the traffic light controller can associate the messages to the vehicle and associates which recall messages correspond to a cancellation message. Still further, the system communication infrastructure that allows constant bidirectional communication including updates in speed, direction, and time of arrival in real time so that the system can account for and react to general traffic and changes in traffic in real time. This results in a smoother flow of traffic by ensuring the system has sufficient time to respond to the approaching vehicle.

It should be understood that some or all of the methodology explained above may be performed on, utilizing or with access to one or more servers, processors and associated memory. Unless specifically stated otherwise, and as may be apparent from the above description, it should be appreciated that throughout the specification descriptions utilizing terms such as "processing," "computing," "calculating," "determining," or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulate and/or transform data represented as physical, such as electronic, quantities within the computing system's registers and/or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices.

Claim 1:
A virtual induction loop system comprising:
a vehicle (<NUM>, <NUM>),
a traffic light control system (<NUM>) in communication with the vehicle that communicates a map message to the vehicle, the map message including a virtual loop position in the upcoming intersection; and
a traffic light module in the vehicle configured to continuously comparing a current position of the vehicle to the position of the virtual loop in the map message and to generate a recall message in response to the vehicle position aligning with or crossing over a virtual loop, characterised in that
the map message includes topology information about lanes, including topographical lane lines;
the traffic light module is further configured to compare the position of the vehicle with the topographical lane lines in the map message and in that the recall message indicates the lane the vehicle will be in at the intersection, and in that the traffic light module is further configured to transmit the recall message to the traffic light control system so that the traffic light control system can account for the vehicle in the control of a traffic light at the intersection.