Collision avoidance in traffic crossings using radar sensors

• US 9,558,666 B2
• Filed: 12/02/2014
• Issued: 01/31/2017
• Est. Priority Date: 12/02/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Robert Bosch LLC (Robert Bosch GmbH)
• Original Assignee: Robert Bosch GmbH
• Inventors: Jansson, Christer, Fawaz, Ali, Bhattacharjee, Shuvo, Chanda, Hirak, Shah, Ankit, McCormick, Troy, Farrell, Anthony
• Primary Examiner(s): Bugg, George
• Assistant Examiner(s): AKKI, MUNEAR T
• Application Number:
  US14/558,348
• Publication Number:
  US 20160155334A1
• Time in Patent Office: 791 Days
• Field of Search: 340/906, 340/923, 340/925, 340/917, 340/933, 701/117, 701/301
• US Class Current: 1/1
• CPC Class Codes: G08G 1/07 Controlling traffic signals
• CPC Class Codes: G08G 1/08 according to detected number or speed of vehicles
• CPC Class Codes: G08G 1/083 Controlling the allocation of time between phases of a cycle
• CPC Class Codes: G08G 1/164 Centralised systems, e.g. external to vehicles

Abstract

A system and method for avoiding collisions in a traffic intersection using radar sensors is disclosed. The system detects the location, speed, size, and direction of travel of objects, including vehicles and vulnerable road users, in and approaching a traffic intersection. Using this information, trajectories for all objects are determined, and, if a likelihood of a collision is determined, one or more traffic signal transitions are delayed in an attempt to avoid the collision.

Claims

1. A system for avoiding collisions in a traffic intersection, the traffic intersection having a plurality of sides, the system comprising:

one or more radar sensors, the one or more radar sensors positioned to detect objects approaching the traffic intersection from all of the sides;

a traffic-lights-and-turn-signals controller;

an ambient conditions sensor capable of sensing at least an ambient temperature value and a relative humidity value for the air proximate the traffic intersection; and

a central controller, which is electrically connected to the one or more radar sensors, the traffic-lights-and-turn-signals controller, and the ambient conditions sensor, and is configured to

receive data from the one or more radar sensors;

detect, based on the data from the one or more radar sensors, at least two objects in or approaching the traffic intersection, where each of the at least two objects is a vehicle or a vulnerable road user;

receive, for each of the at least two objects, a speed and a size;

determine, based on the speed and the size, whether each of the at least two objects is the vehicle or the vulnerable road user;

receive data from the ambient conditions sensor, and the traffic-lights-and-turn-signals controller;

determine, based on the data from the ambient conditions sensor and the speed and size of each of the at least two objects, a likelihood of a collision during a traffic signal transition; and

issue a command to the traffic-lights-and-turn-signals controller to cause a delay in the traffic signal transition, while maintaining at least one predetermined traffic signal timing sequence.

2. The system of claim 1, wherein the traffic signal transition comprises the traffic signal for incoming traffic changing from green to amber to red, and the traffic signal for stopped traffic changing from red to green, and delaying the traffic signal transition includes delaying the changing of the traffic signal for stopped traffic from red to green.

3. The system of claim 1, wherein the traffic signal transition comprises a turn arrow for incoming traffic changing from green to amber to red, and the traffic signal for stopped traffic changing from red to green, and delaying the traffic signal transition includes delaying the changing of the traffic signal for stopped traffic from red to green.

7. The system of claim 1 or 4, wherein the central controller is further configured to communicate the likelihood of the collision to an intelligent traffic system.

8. The system of claim 1 or 4, further comprising:

a watchdog mechanism, wherein the watchdog mechanism monitors the operation of the one or more radar sensors, and

when a first radar sensor of the one or more radar sensors detects an object, and

a second radar sensor of the one or more radar sensors does not detect the object,

determines the existence of a malfunction, and

a source of the malfunction; and

a failsafe mechanism for instructing the central controller to avoid relying on the source of the malfunction,

wherein the first radar sensor and the second radar sensor are positioned such that both should detect the object simultaneously, and

the watchdog mechanism activates the failsafe mechanism when the existence of the malfunction is determined.

4. A system for avoiding collisions in a traffic intersection, the traffic intersection having a plurality of sides and at least one pedestrian crosswalk, the system comprising:

one or more radar sensors, the one or more radar sensors positioned to detect objects approaching the traffic intersection from all of the sides, and to detect objects in the at least one pedestrian crosswalk;

a traffic-lights-and-turn-signals controller;

a pedestrian-signals controller;

an ambient conditions sensor capable of sensing at least an ambient temperature value and a relative humidity value for the air proximate the traffic intersection; and

a central controller, which is electrically connected to the one or more radar sensors, the traffic-lights-and-turn-signals controller, the pedestrian-signals controller, and the ambient conditions sensor, and is configured to

receive data from the one or more radar sensors;

detect, based on the data from the one or more radar sensors, at least two objects in or approaching the traffic intersection, where each of the at least two objects is a vehicle or a vulnerable road user;

receive, for each of the at least two objects, a speed and a size;

determine, based on the speed and the size, whether each of the at least two objects is the vehicle or the vulnerable road user;

receive data from the ambient conditions sensor, the traffic-lights-and-turn-signals controller, and the pedestrian-signals controller;

determine, based on the data from the ambient conditions sensor and the speed and size of each of the at least two objects, a likelihood of a collision during a traffic signal transition; and

issue commands to the traffic-lights-and-turn-signals controller and the pedestrian-signals controller to cause a delay in the traffic signal transition, while maintaining at least one predetermined traffic signal timing sequence.

5. The system of claim 4, wherein the traffic signal transition comprises the traffic signal for incoming traffic changing from green to amber to red, and the traffic signal for stopped traffic changing from red to green;

and delaying the traffic signal transition includes delaying the changing of the traffic signal for stopped traffic from red to green, and delaying a crosswalk signal changing from Don'"'"'t Walk to Walk.

6. The system of claim 4, wherein the traffic signal transition comprises a turn arrow for incoming traffic changing from green to amber to red, and the traffic signal for stopped traffic changing from red to green;

and delaying the traffic signal transition includes delaying the changing of the traffic signal for stopped traffic from red to green, and delaying a crosswalk signal changing from Don'"'"'t Walk to Walk.

9. A method for operating traffic signals for collision avoidance, the method comprising:

detecting at least two objects in or approaching a traffic intersection, where each of the at least two objects is a vehicle or a vulnerable road user;

receiving, for each object of the at least two objects,

a location of the object,

a direction of travel of the object,

a speed of the object, and

a size of the object;

receiving a temperature value and a relative humidity value for the air proximate the traffic intersection;

estimating a coefficient of friction of the traffic intersection;

determining whether each of the at least two objects is the vehicle or the vulnerable road user, based on the speed and the size of each object;

determining, for each of the at least two objects, a trajectory;

receiving a remaining time for a traffic signal transition;

determining a likelihood of a collision using the trajectories for each of the at least two objects, the coefficient of friction of the intersection, the temperature value, the relative humidity value, the speed and size of each of the at least two objects, and the remaining time for the traffic signal transition;

delaying the traffic signal transition to avoid the collision, while maintaining at least one predetermined traffic signal timing sequence.