Red light warning system based on predictive traffic signal state data

• US 10,192,436 B2
• Filed: 02/19/2018
• Issued: 01/29/2019
• Est. Priority Date: 04/12/2013
• Status: Active Grant

• Current Assignee: Traffic Technology Services, Inc.
• Original Assignee: Traffic Technology Services, Inc.
• Inventors: Bauer, Thomas, Ma, Jingtao, Hatcher, Kyle Zachary, Pellekoorne, Paul-Gerard Joseph Albert, Offermann, Frank
• Primary Examiner(s): Bendidi, Rachid
• Application Number:
  US15/899,189
• Publication Number:
  US 20180190116A1
• Time in Patent Office: 344 Days
• CPC Class Codes: G08G 1/0116 from roadside infrastructure, e.g. beacons
• CPC Class Codes: G08G 1/0129 for creating historical data or processing based on historical data
• CPC Class Codes: G08G 1/0141 for traffic information dissemination
• CPC Class Codes: G08G 1/095 Traffic lights
• CPC Class Codes: G08G 1/096 provided with indicators in which a mark progresses showing the time elapsed, e.g. of green phase
• CPC Class Codes: G08G 1/0962 having an indicator mounted inside the vehicle, e.g. giving voice messages
• CPC Class Codes: G08G 1/096716 where the received information does not generate an automatic action on the vehicle control
• CPC Class Codes: G08G 1/096725 where the received information generates an automatic action on the vehicle control
• CPC Class Codes: G08G 1/096758 where no selection takes place on the transmitted or the received information
• CPC Class Codes: G08G 1/096775 where the origin of the information is a central station

Abstract

Methods and systems are disclosed for generating a timely and reliable warning message before a traffic control signal changes to a red light state. A preferred process leverages traffic signal state data, state change predictions, and signal timing plans. The warning message may be distributed for various uses by downstream users and applications.

Claims

1. A computer-implemented method comprising steps of:

identifying a traffic signal;

accessing a signal timing plan of the identified traffic signal;

in a processor, pre-processing the signal timing plan to derive a set of rules from the signal timing plan and storing the derived rules in a derived rules database, the derived rules including (a) identification of state changes that are certain to occur;

(b) identification of state changes that begin a fixed-time control event; and

(c) identification of state changes that necessarily end with a change to red signal state;

receiving a set of predicted traffic signal state data for the identified traffic signal located at an intersection;

wherein the predicted traffic signal state data indicates, for a phase of the identified traffic signal, a current signal state, an expected signal state change to a next signal state, and a predicted time interval remaining until the expected signal state change;

applying a timestamp to the received predicted traffic signal state data;

querying the derived rules database, based on the predicted traffic signal state data, to obtain results;

determining, based on the query results, that the expected signal state change will change to a fixed-time control event;

determining, based on the query results, that at a conclusion of the fixed-time control event, the identified traffic signal will change state to a red signal state;

based on the determination that the fixed-time control event will conclude with the selected traffic signal changing state to the red signal state;

generating a red-light warning message associated with the identified traffic signal;

applying the timestamp to the red-light warning message; and

transmitting the time-stamped red-light warning message to a downstream application for input into operational logic of an autonomous vehicle system;

wherein the downstream application is configurable, for a non-autonomous vehicle, to cause display of a message in the vehicle based on the time-stamped, generated red-light warning message; and

for an autonomous or semi-autonomous vehicle, to provide the red-light warning message to the operational logic to affect controlling the vehicle ahead of the intersection.

2. The method of claim 1 wherein transmitting the time-stamped, red-light warning message includes transmitting the time-stamped, red-light warning message to a server for communication to at least one vehicle in a vicinity of the traffic control signal.

3. The method of claim 1 including periodically updating the predicted traffic signal state data and after each update of the predicted traffic signal state data, repeating the steps of:

querying the derived rules database, based on the updated predicted traffic signal state data, to obtain second query results;

determining, based on the second query results, that the updated expected signal state change will change to a fixed-time control event;

determining, based on the second query results, that at a conclusion of the fixed-time control event, the identified traffic signal will change state to a red signal state;

based on the determination that the fixed-time control event will conclude with the identified traffic signal changing state to the red signal state, generating a red-light warning message associated with the identified traffic signal.

4. The method of claim 3 including updating the predicted traffic signal state data approximately once per second.

5. The method of claim 1 including providing in the time stamped red light warning message an estimated time interval remaining until the identified traffic signal state is expected to change state to the red signal state.

6. The method of claim 1 wherein the fixed-time control events comprise a fixed yellow time for a given phase of a Field Signal Controller (“

FSC”

) that controls the identified traffic signal.

7. The method of claim 1 wherein the fixed-time control events include an “

all-red”

period during which the signal heads of all phases of the identified traffic control signal remain red for a predetermined period to allow traffic to clear the intersection.

8. The method of claim 1 wherein the fixed-time control events include a fixed timer wherein the phase sequence and splits comprising green signal state duration, plus yellow signal state duration, plus all-red signal state duration remain the same.

9. The method of claim 1 wherein the fixed-time control events include a predetermined signal switch time.

10. The method of claim 1 wherein transmitting the time-stamped red light warning message utilizes a web service that enables wireless communication with in-vehicle computers that have wireless network access.

11. The method of claim 1 wherein the time-stamped red light warning message is packaged as a separate add-on to a dedicated short range communication (DSRC) broadcast radio in a roadside unit (RSU).

12. A process for a vehicle comprising steps of:

receiving a set of predicted traffic signal state data for a selected traffic signal located at an intersection;

wherein the predicted traffic signal state data indicates, for a phase of the selected traffic signal, a current signal state, an expected signal state change to a next signal state, and a predicted time interval remaining until the expected signal state change;

applying a timestamp to the predicted traffic signal state data;

accessing a signal timing plan of the selected traffic signal;

in a processor, pre-processing the signal timing plan to derive a set of rules from the signal timing plan and storing the derived rules in a derived rules database, the derived rules including (a) identification of state changes that are certain to occur;

(b) identification of state changes that begin a fixed-time interval signal control event; and

(c) identification of state changes that necessarily end with a change to red signal state;

based on the derived rules, determining that the expected signal state change is certain to occur and will trigger a start of a fixed-time control event;

determining, based on the derived rules, that at a conclusion of the fixed-time control event, the selected traffic signal will change state to a red signal state;

based on the determination that the fixed-time control event will conclude with the selected traffic signal changing state to the red signal state;

generating a red-light warning message associated with the traffic control signal;

applying the timestamp to the red-light warning message; and

transmitting the time-stamped red-light warning message to a downstream application for input into operational logic of an autonomous vehicle system;

wherein the downstream application is configurable, for a non-autonomous vehicle, to cause display of a message in the vehicle based on the time-stamped, generated red-light warning message; and

for an autonomous or semi-autonomous vehicle, to provide the red-light warning message to the operational logic to affect controlling the vehicle ahead of the intersection.

13. The process of claim 12 wherein transmitting the time-stamped, red-light warning message includes transmitting the time-stamped, red-light warning message to a server for communication to at least one vehicle in a vicinity of the selected traffic signal.

14. The process of claim 12 including periodically updating the predicted traffic signal state data and after each update of the predicted traffic signal state data, repeating the steps of:

determining, based on the signal timing plan, that the updated expected signal state change will change to a fixed-time control event;

determining, based on the signal timing plan, that at a conclusion of the fixed-time control event, the selected traffic signal will change state to a red signal state; and

based on the determination that the fixed-time control event will conclude with the selected traffic signal changing state to the red signal state, generating a red-light warning message associated with the selected traffic control signal.

15. The method of claim 14 including updating the predicted traffic signal state data approximately once per second.

16. The method of claim 12 including providing in the time-stamped red-light warning message an estimated time interval remaining until the selected traffic signal state is expected to change state to the red state.

17. A memory machine or manufacture storing a non-transitory machine-readable instructions executable in a digital processor to cause the processor to carry out the steps of:

receiving a set of predicted traffic signal state data for a selected traffic signal located at an intersection;

wherein the predicted traffic signal state data indicates, for a phase of the selected traffic signal, a current signal state, an expected signal state change to a next signal state, and a predicted time interval remaining until the expected signal state change;

applying a timestamp to the predicted traffic signal state data;

accessing a signal timing plan of the identified traffic signal;

in a processor, pre-processing the signal timing plan to derive a set of rules from the signal timing plan and storing the derived rules in a derived rules database, the derived rules including (a) identification of state changes that are certain to occur;

(b) identification of state changes that begin a fixed-time control event; and

(c) identification of state changes that necessarily end with a change to red signal state;

”

based on the derived rules, determining that the expected state change is certain to occur and will trigger a start of a fixed-time control event;

determining, based on the derived rules, that at a conclusion of the fixed-time control event, the selected traffic signal will change state to a red signal state;

based on the determination that the fixed-time control event will conclude with the selected traffic signal changing state to the red signal state;

generating a red-light warning message associated with the traffic signal;

applying the timestamp to the red-light warning message; and

transmitting the time-stamped red-light warning message to a downstream application for input into operational logic of an autonomous vehicle system;

wherein the downstream application is configurable, for a non-autonomous vehicle, to cause display of a message in the vehicle based on the time-stamped, generated red-light warning message; and

for an autonomous or semi-autonomous vehicle, to provide the red-light warning message to the operational logic to affect controlling the vehicle ahead of the intersection.

18. The memory of claim 17 wherein transmitting the time-stamped, red-light warning message includes transmitting the time-stamped, red-light warning message to a server for communication to at least one vehicle in a vicinity of the selected traffic signal.

19. The memory of claim 17 including periodically updating the predicted traffic signal state data and after each update of the predicted traffic signal state data, repeating steps of:

based on the updated received set of predicted traffic signal state data and the signal timing plan of the selected traffic signal, determining that the expected state change is certain to occur, determining that the expected state change that is certain to occur is one that will trigger a start of a fixed-time control event, and determining whether at a conclusion of the fixed-time control event, the selected traffic signal will change state to a red signal state.

20. The memory of claim 17 including updating the predicted traffic signal state data approximately once per second.