Self-configuring traffic signal controller

• US 9,978,270 B2
• Filed: 07/28/2015
• Issued: 05/22/2018
• Est. Priority Date: 07/28/2014
• Status: Active Grant

• Current Assignee: Econolite Group Incorporated
• Original Assignee: Econolite Group Incorporated
• Inventors: Raamot, Eric
• Primary Examiner(s): Kingston, Shawna M
• Application Number:
  US14/811,657
• Publication Number:
  US 20160027299A1
• Time in Patent Office: 1,029 Days
• Field of Search: None
• CPC Class Codes: G08G 1/0112 from the vehicle, e.g. floating car data [FCD]
• CPC Class Codes: G08G 1/0116 from roadside infrastructure, e.g. beacons
• CPC Class Codes: G08G 1/012 from other sources than vehicle or roadside beacons, e.g. mobile networks
• CPC Class Codes: G08G 1/0129 for creating historical data or processing based on historical data
• CPC Class Codes: G08G 1/0145 for active traffic flow control
• CPC Class Codes: G08G 1/052 with provision for determining speed or overspeed speed measuring in general G01P
• CPC Class Codes: G08G 1/08 according to detected number or speed of vehicles

Abstract

Embodiments describe new mechanisms for signalized intersection control. Embodiments expand inputs beyond traditional traffic control methods to include awareness of agency policies for signalized control, industry standardized calculations for traffic control parameters, geometric awareness of the roadway and/or intersection, and/or input of vehicle trajectory data relative to this intersection geometry. In certain embodiments, these new inputs facilitate a real-time, future-state trajectory modeling of the phase timing and sequencing options for signalized intersection control. Phase selection and timing can be improved or otherwise optimized based upon modeling the signal'"'"'s future state impact on arriving vehicle trajectories. This improvement or optimization can be performed to reduce or minimize the cost basis of a user definable objective function.

Claims

1. A self-configuring traffic signal controller method, the method comprising:

under control of a traffic controller comprising electronic hardware,

receiving sensor data from a trajectory sensor at an intersection, the trajectory sensor including a radar or video camera;

generating trajectory data from the sensor data based on intersection geometric data about the intersection stored in data storage, the intersection geometric data comprising data regarding intersection features represented in a coordinate system derived from latitude and longitude, wherein said generating the trajectory data comprises computing vehicle positions relative to the coordinate system and vehicle speeds for a plurality of vehicles, wherein said generating the trajectory data further comprises computing the vehicle positions as relative latitude and longitude values offset from an origin defined with respect to the intersection;

automatically adjusting a signal timing configuration of the traffic controller by analyzing the trajectory data according to an objective function specified by user-defined policies; and

outputting control signals to traffic signal lights according to the adjusted signal timing configuration to cause the traffic signal lights to selectively turn on and off the traffic signals according to the adjusted signal timing configuration.

2. The method of claim 1, further comprising using the vehicle speeds in the sensor data to predict future vehicle positions with respect to the intersection.

3. The method of claim 1, wherein automatically adjusting the signal timing configuration of the traffic controller comprises adjusting one or more of green time, yellow time, and red time according to predicted future vehicle trajectory.

4. The method of claim 1, wherein the user-defined policies emphasize some policies over other policies in the objective function.

5. The method of claim 1, further comprising providing at least some of the trajectory data to a second traffic controller at another intersection to enable the second traffic controller to use at least some of the trajectory data to adjust signal timing at the second traffic controller.

6. The method of claim 1, wherein the objective function is user-definable.

7. The method of claim 1, wherein said automatically adjusting the signal timing configuration comprises selecting a traffic phase from a plurality of possible traffic phases and selecting a phase termination time from a plurality of possible phase termination times.

19. The method of claim 1, wherein said generating the trajectory data further comprises specifying a path of a vehicle over time, the path of the vehicle comprising the vehicle positions.

20. The method of claim 1, wherein said automatically adjusting the signal timing comprises attempting to optimize the objective function based on two or more of the following factors:

delay of vehicles, number of stopped vehicles, vehicle emissions, a safety factor, and intersection capacity.

21. The method of claim 20, wherein the factors are weighted.

22. The method of claim 20, further comprising computing the safety factor based on future state trajectory modeling to predict which vehicles will have a safety conflict with one or more of:

another vehicle, a pedestrian, or states of the traffic signal.

23. The method of claim 20, further comprising determining the intersection capacity based on one or more of the following factors:

a capacity of a movement, saturation flow rate, green time for the movement, startup lost time for the movement, and cycle length.

24. The method of claim 20, wherein said automatically adjusting the signal timing configuration further comprises temporarily extending a first red light of the traffic signal lights based on predicting, from the trajectory data, that a first vehicle will run a second red light of the traffic signal lights, to reduce a chance that a second vehicle halted by the first red light will collide with the first vehicle.

25. The method of claim 1, wherein said automatically adjusting the signal timing configuration comprises accounting for past safety conflicts measured prior to receiving the sensor data and generating the trajectory data.

8. A self-configuring traffic signal controller apparatus, the apparatus comprising:

a traffic controller comprising electronic hardware that;

receives sensor data from a trajectory sensor at an intersection, the trajectory sensor including a radar or video camera;

generates trajectory data from the sensor data based on intersection geometric data about the intersection stored in data storage, the trajectory data comprising data about vehicle speeds, the intersection geometric data comprising data regarding intersection features represented in a coordinate system derived from latitude and longitude, wherein said generation of the trajectory data comprises computing vehicle positions relative to the coordinate system and vehicle speeds for a plurality of vehicles, wherein the traffic controller generates the trajectory data by at least computing the vehicle positions as relative latitude and longitude values offset from an origin defined with respect to the intersection;

automatically adjusts a signal timing configuration of the traffic controller by analyzing the trajectory data according to user-defined policies; and

outputs control signals to traffic signal lights according to the adjusted signal timing configuration to cause the traffic signal lights to selectively turn on and off the traffic signals according to the adjusted signal timing configuration.

9. The apparatus of claim 8, wherein the traffic controller is further configured to use the vehicle speeds in the sensor data to predict future vehicle positions with respect to the intersection.

10. The apparatus of claim 8, wherein the traffic controller generates the trajectory data by at least using the vehicle speeds in the sensor data to predict future vehicle speeds with respect to the intersection.

11. The apparatus of claim 8, wherein the traffic controller automatically adjusts the signal timing configuration of the traffic controller by at least adjusting one or more of green time, yellow time, and red time according to predicted future vehicle trajectory.

12. The apparatus of claim 8, wherein the user-defined policies weight some policies over other policies.

13. The apparatus of claim 8, wherein the traffic controller also provides at least some of the trajectory data to a second traffic controller at another intersection to enable the second traffic controller to use at least some of the trajectory data to adjust signal timing of at the second traffic controller.

14. The apparatus of claim 8, wherein the traffic controller comprises a co-processor or separate circuit board that overrides a traffic controller.

15. The apparatus of claim 8, wherein the traffic controller automatically reconfigures the signal timing configuration by selecting a traffic phase from a plurality of possible traffic phases and selecting a phase termination time from a plurality of possible phase termination times.

16. The apparatus of claim 8, wherein the traffic controller generates the trajectory data multiple times within a single traffic signal cycle until a calculated time to remain in a current phase has been reached.

17. The apparatus of claim 16, wherein the calculated time is based on an average time difference between initial vehicle trajectory detection, obtained from the trajectory data, and a time at which vehicles are detected from the plurality of inputs as entering a dilemma zone.

18. The apparatus of claim 17, wherein the traffic controller automatically reconfigures the signal timing configuration in response to reaching the calculated time.

26. The apparatus of claim 8, wherein the traffic controller is further configured to automatically adjust the signal timing configuration by at least accounting for past safety conflicts measured prior to receiving the sensor data and generating the trajectory data.

27. A self-configuring traffic signal controller method, the method comprising:

under control of a traffic controller comprising electronic hardware,

receiving sensor data from a trajectory sensor at an intersection, the trajectory sensor including a radar or video camera;

generating trajectory data from the sensor data based on intersection geometric data about the intersection stored in data storage, the intersection geometric data comprising data regarding intersection features represented in a coordinate system derived from latitude and longitude, wherein said generating the trajectory data comprises computing vehicle positions relative to the coordinate system and vehicle speeds for a plurality of vehicles;

automatically adjusting a signal timing configuration of the traffic controller by analyzing the trajectory data according to an objective function specified by user-defined policies, wherein said automatically adjusting the signal timing configuration comprises accounting for past safety conflicts measured prior to receiving the sensor data and generating the trajectory data; and

outputting control signals to traffic signal lights according to the adjusted signal timing configuration to cause the traffic signal lights to selectively turn on and off the traffic signals according to the adjusted signal timing configuration.

28. The method of claim 27, wherein said generating the trajectory data further comprises computing the vehicle positions as relative latitude and longitude values offset from an origin defined with respect to the intersection.