System and Method for Asymmetric Traffic Control

• US 20200135015A1
• Filed: 10/31/2018
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Kalabic, Uros, Nilsson, Nils Gustav, Grover, Piyush
• Granted Patent: US 10,922,966 B2
• Time in Patent Office: Days
• CPC Class Codes: G08G 1/0116 from roadside infrastructure, e.g. beacons
• CPC Class Codes: G08G 1/0133 for classifying traffic situation
• CPC Class Codes: G08G 1/0145 for active traffic flow control
• CPC Class Codes: G08G 1/091 Traffic information broadcasting broadcasting communication H04H
• CPC Class Codes: H04W 4/024 Guidance services
• CPC Class Codes: H04W 4/44 for communication between vehicles and infrastructures, e.g. vehicle-to-cloud [V2C] or vehicle-to-home [V2H]

Abstract

A traffic control system for controlling a traffic of cooperative and uncooperative vehicles determines delays on each segment of the roads of the network based on the current state of the flow of the traffic and determines flows of the cooperative and uncooperative vehicles that satisfy a Nash equilibrium for the cooperative vehicles having a common objective and the uncooperative vehicles having individual objectives. The system determines, for the cooperative vehicles, costs of segments of the roads that correspond to the Nash equilibrium and determines routes for the cooperative vehicles based on the current locations and target locations of the cooperative vehicles, and the costs of the segments of the roads in the network determined for the cooperative vehicles. The routes are transmitted to corresponding cooperative vehicles.

Claims

1. A traffic control system for controlling a traffic of cooperative and uncooperative vehicles in a network of roads, the traffic control system comprising:

a receiver configured to receive information indicative of a current state of a flow of the traffic in the network of roads, an inflow rate of the traffic into the network of roads, an outflow rate of the traffic out of the network of roads, and current locations and target locations of the cooperative vehicles;

a processor coupled with stored instructions implementing components of the traffic control system, including;

a traffic observer configured to determine delays on each segment of the roads of the network based on the current state of the flow of the traffic;

a traffic allocator configured to

determine flows of the cooperative and uncooperative vehicles that satisfy a Nash equilibrium using the inflow rate of the traffic, the outflow rate of the traffic, and the delays on the roads, the cooperative vehicles having a common objective and the uncooperative vehicles having individual objectives, and

determine, for the cooperative vehicles, costs of segments of the roads that correspond to the Nash equilibrium;

a traffic router configured to determine routes for the cooperative vehicles based on the current locations and target locations of the cooperative vehicles, and the costs of the segments of the roads in the network determined for the cooperative vehicles; and

a transmitter configured to transmit the routes to corresponding cooperative vehicles.

2. The traffic control system of claim 1, wherein the traffic observer updates the delays on the roads in response to a change in the current state of a flow of the traffic, wherein the traffic allocator updates the costs of the segments of the roads in the network determined for the cooperative vehicles in response to the updates of the delays on the roads, wherein the traffic router updates the routes in response to the updates of the costs, and wherein the transmitter transmits the updated routs to the corresponding vehicles.

3. The traffic control system of claim 1, wherein the cooperative vehicles belong to different groups having different common objectives, and wherein the traffic allocator finds the Nash equilibrium using different common objectives of the cooperative vehicles of different groups.

4. The traffic control system of claim 1, further comprising:

a set of sensors configured to sense vehicles passing junctions of the segments of the roads, wherein the processor is configured to determine the current state of the flow of the traffic, the inflow rate of the traffic, the outflow rate of the traffic using data sensed by the sensors and received by the receiver.

5. The traffic control system of claim 1, wherein the receiver is operatively connected to navigators of the cooperative vehicles to receive the current locations and the target locations of the cooperative vehicles.

6. The traffic control system of claim 1, wherein the delay on the road is defined by a nonlinear function.

7. The traffic control system of claim 1, wherein the traffic observer, to determine the delay on a segment of a road is configured to

determine using a fundamental diagram two values of the delay corresponding to a flow of the vehicles on the segment of the road;

compare an average velocity of the vehicles on the segment of the road with a boundary average velocity to produce a comparison result;

select a value of the delay from the two values of the delay based on the comparison result.

8. The traffic control system of claim 1, wherein the traffic allocator determines the flows of the cooperative and uncooperative vehicles that satisfy the Nash equilibrium iteratively until a termination condition is reached, wherein for a current iteration the traffic allocator is configured to

update the flow of the cooperative vehicles for fixed latest value of the flow of the uncooperative vehicles;

and

update the flow of the uncooperative vehicles for fixed latest value of the flow of the cooperative vehicles.

9. The traffic control system of claim 8, wherein the processor, in response to reaching the termination condition, determine the cost by differentiating a term under a summand of the common objective for the determined flows of cooperative and uncooperative vehicles.

10. The traffic control system of claim 1, wherein the traffic router, to determine the routes for the cooperative vehicles is configured to solve an optimization problem corresponding to the minimum cost path in the network of roads.

11. The traffic control system of claim 10, wherein the optimization problem is solved using a variation of Dijkstra'"'"'s algorithm.

12. A traffic control method for controlling a traffic of cooperative and uncooperative vehicles in a network of roads, wherein the method uses a processor coupled with stored instructions implementing the method, wherein the instructions, when executed by the processor carry out steps of the method, comprising:

receiving information indicative of a current state of a flow of the traffic in the network of roads, an inflow rate of the traffic into the network of roads, an outflow rate of the traffic out of the network of roads, and current locations and target locations of the cooperative vehicles;

determining delays on each segment of the roads of the network based on the current state of the flow of the traffic;

determining flows of the cooperative and uncooperative vehicles that satisfy a Nash equilibrium using the inflow rate of the traffic, the outflow rate of the traffic, and the delays on the roads, the cooperative vehicles having a common objective and the uncooperative vehicles having individual objectives;

determining, for the cooperative vehicles, costs of segments of the roads that correspond to the Nash equilibrium;

determining routes for the cooperative vehicles based on the current locations and target locations of the cooperative vehicles, and the costs of the segments of the roads in the network determined for the cooperative vehicles; and

transmitting the routes to corresponding cooperative vehicles.

13. The traffic control method of claim 12, further comprising:

updating the delays on the roads in response to a change in the current state of a flow of the traffic;

updating the costs of the segments of the roads in the network determined for the cooperative vehicles in response to the updates of the delays on the roads;

updating the routes in response to the updates of the costs;

transmitting the updated routs to the corresponding vehicles.

14. The traffic control system of claim 12, wherein the cooperative vehicles belong to different groups having different common objectives, and wherein the method finds the Nash equilibrium using different common objectives of the cooperative vehicles of different groups.

15. A non-transitory computer readable storage medium embodied thereon a program executable by a processor for performing a method, the method comprising:

receiving information indicative of a current state of a flow of the traffic in the network of roads, an inflow rate of the traffic into the network of roads, an outflow rate of the traffic out of the network of roads, and current locations and target locations of the cooperative vehicles;

determining delays on each segment of the roads of the network based on the current state of the flow of the traffic;

determining flows of the cooperative and uncooperative vehicles that satisfy a Nash equilibrium using the inflow rate of the traffic, the outflow rate of the traffic, and the delays on the roads, the cooperative vehicles having a common objective and the uncooperative vehicles having individual objectives;

determining, for the cooperative vehicles, costs of segments of the roads that correspond to the Nash equilibrium;

determining routes for the cooperative vehicles based on the current locations and target locations of the cooperative vehicles, and the costs of the segments of the roads in the network determined for the cooperative vehicles; and

transmitting the routes to corresponding cooperative vehicles.