Prediction of traffic signal state changes

• US 9,396,657 B1
• Filed: 04/14/2014
• Issued: 07/19/2016
• Est. Priority Date: 04/12/2013
• Status: Active Grant

• Current Assignee: Traffic Technology Services, Inc.
• Original Assignee: Traffic Technology Solutions, LLC
• Inventors: Bauer, Thomas, Ma, Jingtao, Hatcher, Kyle Zachary
• Primary Examiner(s): Holloway, Jason
• Assistant Examiner(s): Bendidi, Rachid
• Application Number:
  US14/252,491
• Time in Patent Office: 827 Days
• Field of Search: 701/1, 701/2, 701/70, 701/22, 701/93, 340/929, 340/901, 340/905, 340/907, 340/917
• US Class Current: 1/1
• 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 1/042 using inductive or magnetic detectors
• 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 1/09626 where the origin of the information is within the own vehicle, e.g. a local storage device, digital map
• 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 1/096741 where the source of the transmitted information selects which information to transmit to each vehicle
• CPC Class Codes: G08G 1/096775 where the origin of the information is a central station

Abstract

Methods and systems are disclosed for predicting the state and/or upcoming state changes of a traffic control signal. The traffic control signal may be an upcoming traffic control signal along a route of a motor vehicle. The prediction information may communicated to a prediction display made available to a driver or passenger in such a motor vehicle.

Claims

1. A computer-implemented traffic signal control emulation method comprising:

provisioning a digital processor for executing a computer software emulator process;

loading and executing a computer software emulator process in the processor to emulate operation of a field traffic signal controller (FSC) at a physical location and its associated timing parameters;

acquiring call data and signal status data provided by the FSC responsive to detector inputs to the FSC during a selected collection period, and storing the acquired call data in a database accessible to the processor;

identifying a signal status at a last sync point of the FSC in the database;

in the processor, initializing the emulator process to an initial state;

in the processor, advancing the emulator process from the initial state to a second state, the second state corresponding to the last sync point of the FSC;

in the processor, further advancing the emulator process from the second state, based on the acquired call data for a time period from the last sync point to a current time, so that at the current time the FSC and the emulator process are synchronized to a current time state;

predicting future detection data for the FSC based on a statistical analysis of a stored collection of long-term past field detection data acquired solely from the FSC;

providing for the emulator process to access the predicted future detection data;

in the processor, fast forwarding the emulator process from the current time state, based on the predicted future detection data;

terminating the emulator process at a future time state;

predicting a signal status based on the future time state of the emulator; and

communicating a result based on the predicted signal status to a vehicle or a vehicle operator.

2. The method of claim 1 including advancing the emulator process responsive to a clock signal.

3. The method of claim 1 and further comprising repeating the foregoing steps within a selected time frame.

4. The method of claim 2 wherein each state of the emulator is substantially aligned to the clock signal.

5. The method of claim 2 wherein the clock signal has a period of one second.

6. The method of claim 1 and further comprising repeating the foregoing steps at a rate of once per second, to enable updating the predicted signal status once per second.

7. The method of claim 1 wherein the field detection data is received as signal phase call data for input to the emulator process.

8. The method of claim 1 wherein a state of the emulator process includes traffic signal phase displays, and current values of at least one active timer.

9. The method of claim 1 wherein the physical location is a signalized intersection.

10. The method of claim 1 wherein the digital processor for executing the computer software emulator process is provisioned in a cloud computing environment.

11. The method of claim 1 wherein the call data is provided by a local traffic control agency in the form of signal phase call data.

12. The method of claim 1 including storing received signal phase call data in a database and analyzing the stored data for each one of a plurality of time periods over multiple days to determine an expected pattern of phase detection.

13. The method of claim 12 wherein the time periods are substantially equal in length.

14. The method of claim 13 wherein the time period is selected to exceed a cycle time of the signaled physical location.

15. The method of claim 1 and further comprising re-synchronizing the emulator to a subsequent sync point of the FSC preparatory to a new emulation operation.

16. The method of claim 1 wherein the emulator process comprises an instance of a control program implemented in the FSC, and its associated timing parameters.

17. The method of claim 1 including using a local traffic control agency'"'"'s communication infrastructure to poll the FSC directly.

18. The method of claim 1 including receiving the short-term past field detection data in a feed from the actual signal controller.

19. The method of claim 1 including receiving the short-term past field detection data from a database that a local traffic control agency maintains at their control center.

20. A traffic control emulation system comprising:

a digital processor for executing a computer software emulator process;

the digital processor coupled to a communication system to acquire signal status data and call data provided by a field traffic signal controller (FSC) responsive to detector inputs to the FSC during a selected collection period;

a database system accessible to the digital processor and configured to store the acquired signal status data and call data over time so as to form past detection data;

a memory coupled to the processor and storing a set of machine-readable instructions configured to implement a computer software emulator process;

a source of predicted future call data accessible to the processor, the predicted future call data based on statistical analysis of the past detection data;

wherein the stored instructions are arranged to cause the processor, when executed, to—

identify a signal status at a last sync point of the FSC;

initialize the computer software emulator process to an initial state;

advance the computer software emulator software process from the initial state to a second state, the second state corresponding to the last sync point of the FSC;

further advance the computer software emulator process from the second state, based on the acquired call data for a time period from the last sync point to a current time, so that at the current time the FSC and the emulator process are synchronized to a current time state;

predict future detection data for the FSC based on a statistical analysis of a stored collection of long-term past field detection data acquired solely from the FSC, and store the predicted future detection data in the memory;

fast forward the emulator process from the current time state, based on the predicted future detection data;

terminate the emulator process at a future time state;

predict a signal status based on the future time state of the emulator process; and

communicate the predicted signal status to a vehicle or vehicle operator.

21. A computer-implemented traffic signal control emulation method comprising:

provisioning a digital processor for executing a computer software emulator process;

loading and executing a computer software emulator process in the processor to emulate operation of a field traffic signal controller (FSC) at a physical location and its associated timing parameters;

acquiring call data and signal status data provided by the FSC responsive to detector inputs to the FSC during a selected collection period, and storing the acquired call data in a database accessible to the processor;

predicting and storing future detection data for the FSC, wherein the future detection data is based on a statistical analysis of past detection data of the FSC;

provisioning and starting n instances of the computer software emulator process;

synchronizing each of the n emulator process instances to the FSC at a current time;

advancing each of the n instances in real time so they remain synchronized with the field signal controller;

selecting one of the n emulator instances;

fast-forwarding only the selected emulator instance using the predicted future detection data as input data to generate a corresponding emulator instance prediction of a state of the field signal controller at a time in the future;

saving the selected emulator instance prediction results;

terminating the selected emulator process;

communicating the emulator instance prediction to a vehicle or a vehicle operator; and

in the case that all n instances have not terminated, repeating the above selecting, fast-forwarding, saving, terminating and communicating steps for a next one of the n emulator instances.

22. The method of 21 and further comprising repeating the foregoing steps until all of the n instances of an emulator process are terminated.

23. The method of 22 and then re-synchronizing all n instances of the emulator to the field signal controller.

24. The method of 21 wherein the number n is equal to the number of seconds per cycle of the signal controller.

25. The method of 21 and further comprising communicating selected emulator instance prediction results to a mobile device.

26. The method of 21 and further comprising communicating selected emulator instance prediction results to a motor vehicle on-board system.

27. The method of 21 and further comprising communicating selected emulator instance prediction results to a motor vehicle for display on a dashboard.

28. The method of 21 and further comprising communicating selected emulator instance prediction results to a motor vehicle head unit.