Systems and methods for determining traffic conditions

Patent metadata

Field	Value
Publication number	US-2020043325-A1
Application number	US-201816220275-A
Country	US
Kind code	A1
Filing date	Dec 14, 2018
Priority date	Aug 6, 2018
Publication date	Feb 6, 2020
Grant date	—

Abstract

The present disclosure relates to a system and method for determining a traffic condition. The systems may perform the methods to: obtain a length of a road segment, where an upstream intersection and a downstream intersection is linked by the road segment; determine a first queue length of a queue on the road segment at a first time point and a second queue length of the queue at a second time point; determine a duration of the second queue length, based on a cycle length of the first traffic light corresponding to the downstream intersection, a cycle length of the second traffic light corresponding to the upstream intersection, a free-flow speed corresponding to the road segment, a back-propagation wave speed corresponding to the road segment, and the first queue length; and determine whether the second queue length exceeds the length of the road segment.

First claim

1 . A method implemented on a computing device for determining a traffic condition, the computing device including a memory and processing circuits, the method comprising:
obtaining, by processing circuits, signals including a length of a road segment, an upstream intersection and a downstream intersection being linked by the road segment; obtaining, by the processing circuits, signals including a cycle length of a first traffic light and a cycle length of a second traffic light, the first traffic light being located at the downstream intersection, the second traffic light being located at the upstream intersection; determining, by the processing circuits, a free-flow speed corresponding to the road segment and a back-propagation wave speed corresponding to the road segment; determining, by the processing circuits, a first queue length of a queue on the road segment at a first time point and a second queue length of the queue at a second time point; determining, by the processing circuits, a duration of the second queue length, based on the cycle length of the first traffic light, the cycle length of the second traffic light, the free-flow speed, the back-propagation wave speed, and the first queue length; determining, by the processing circuits, whether the second queue length exceeds the length of the road segment; and displaying, by a display, a visual representation of a traffic condition relating to the duration of the second queue length based on a result of the determination that second queue length exceeds the length of the road segment.

2 . The method of claim 1 , wherein
a cycle length of a traffic light includes a green-light cycle length and a red-light cycle length; and determining the second queue length of the queue at a second time point includes:
determining, by the processing circuits, a first growth parameter of the queue related to the green-light cycle length based on the free-flow speed and the back-propagation wave speed;
determining, by the processing circuits, a second growth parameter of the queue related to the red-light cycle length based on the free-flow speed and the back-propagation wave speed; and determining, by the processing circuits, the second queue length of the queue based on the first growth parameter and the second growth parameter.

3 . The method of claim 1 , wherein
the duration of the second queue length includes a green-light spillover duration; determining the duration of the second queue length includes:
determining, by the processing circuits, a reference queue length of the queue based on the cycle length of the first traffic light, the cycle length of the second traffic light, the free-flow speed, and the back-propagation wave speed;
determining, by the processing circuits, a first length difference between the second queue length of the queue and the length of the road segment;
determining, by the processing circuits, a second length difference between the second queue length of the queue and the reference queue length; and
determining, by the processing circuits, the green-light spillover duration based on a ratio of the first length difference and the second length difference; and
the method further includes displaying, by the display, a visual representation of a second indicator related to the green-light spillover duration.

4 . The method of claim 3 , wherein
the duration of the second queue length includes a red-light spillover duration; and determining the duration of the second queue length includes:
determining, by the processing circuits, the red-light spillover duration based on a ratio of a difference between the reference queue length and the length of the road segment to a difference between the second queue length of the queue and the reference queue length; and
the method further includes displaying a third indicator related to the red-light spillover duration.

5 . The method of claim 4 , wherein determining the duration of the second queue length includes:
determine, by the processing circuits, a sum of the green-light spillover duration and the red-light spillover duration as the duration of the second queue length.

6 . The method of claim 3 , wherein the method further comprises:
determining, by the processing circuits, whether the reference queue length exceeds the length of the road segment; determining, by the processing circuits, the green-light spillover duration as the duration of the second queue length based on a result of the determination that the reference queue length exceeds the length of the road segment; and displaying, by the display, a visual representation of a fourth indicator related to the green-light spillover duration.

7 . The method of claim 1 , wherein determining the free-flow speed corresponding to the road segment comprises:
obtaining, by the processing circuits the one or more processors, signals including traffic data related to the road segment, the traffic data related to the road segment including a vehicle flow rate of the road segment and a vehicle density of the road segment corresponding to the vehicle flow rate; determining, by the processing circuits, a first vector corresponding to a first status of the road segment based on the traffic data related to the road segment, wherein the first status is that the vehicle flow rate of the road segment is positively correlated to the vehicle density of the road segment corresponding to the vehicle flow rate; and determining, by the processing circuits, the free-flow speed based on the first vector.

8 . The method of claim 1 , wherein determining the back-propagation wave speed corresponding to the road segment comprises:
obtaining, by the processing circuits, signals including traffic data related to the road segment, the traffic data related to the road segment including a vehicle flow rate of the road segment and a vehicle density of the road segment corresponding to the vehicle flow rate; determining, by the processing circuits, a second vector corresponding to a second status of the road segment based on the traffic data related to the road segment, wherein the second status is that the vehicle flow rate of the road segment is negatively correlated to the vehicle density of the road segment corresponding to the vehicle flow rate; and determining, by the processing circuits, the back-propagation wave speed based on the second vector.

9 . A system configured for determining a traffic condition, comprising:
at least one non-transitory storage medium including a set of instructions; and processing circuits in communication with the at least one non-transitory storage medium, wherein when executing the set of instructions, the processing circuits are directed to:
obtain signals including a length of a road segment, an upstream intersection and a downstream intersection being linked by the road segment;
obtain signals including a cycle length of a first traffic light and a cycle length of a second traffic light, the first traffic light being located at the downstream intersection, the second traffic light being located at the upstream intersection;
determine a free-flow speed corresponding to the road segment and a back-propagation wave speed corresponding to the road segment;
determine a first queue length of a queue on the road segment at a first time point and a second queue length of the queue at a second time point;
determine a duration of the second queue length, based on the cycle length of the first traffic light, the cycle length of the second traffic light, the free-flow speed, the back-propagation wave speed, and the first queue length;
determine whether the second queue length exceeds the length of the road segment; and

Assignees

• Beijing Didi Infinity Technology & Dev Co Ltd

Inventors

• Sun Weili
• Liu Xianghong
• Liu Bingbing
• Ye Jianfeng

Classifications

• G08G1/081 Primary

  Plural intersections under common control · CPC title

• G08G1/065

  by counting the vehicles in a section of the road or in a parking area, i.e. comparing incoming count with outgoing count · CPC title

• G08G1/0133 Primary

  for classifying traffic situation · CPC title

• G08G1/0967

  Systems involving transmission of highway information, e.g. weather, speed limits (transmission of navigation instructions to the vehicle G08G1/0968) · CPC title

• G08G1/052

  with provision for determining speed or overspeed {(speed measuring in general G01P)} · CPC title