Method and system for forward collision avoidance in an automotive vehicle

• US 7,647,178 B2
• Filed: 04/28/2006
• Issued: 01/12/2010
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: Volvo Car Corporation (AB Volvo)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Jansson, Jonas, Ekmark, Jonas
• Primary Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US11/380,748
• Publication Number:
  US 20070112514A1
• Time in Patent Office: 1,355 Days
• Field of Search: 701/29, 701/30, 701/33, 701/36, 701/901, 340/435, 340/436, 340/438, 340/903
• US Class Current: 701/301
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 2554/4041 Position
• CPC Class Codes: B60W 30/08 Active safety systems predicting or avoiding probable or impending collision or attempting to minimise its consequences
• CPC Class Codes: B60W 30/12 Lane keeping
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B60W 50/14 Means for informing the driver, warning the driver or prompting a driver intervention
• CPC Class Codes: G08G 1/161 Decentralised systems, e.g. inter-vehicle communication

Abstract

A method and system for autonomous collision avoidance in multiple obstacle scenarios. A forward collision avoidance system detects obstacles in front of a vehicle hosting the system and estimates a position, a velocity and an acceleration of each of the obstacles. The maneuvers which the vehicle is capable of performing that will lead to a collision with each respective obstacle are evaluated separately. The union of maneuvers which will lead to collision with any one of the obstacles is formed. The set of maneuvers which the vehicle is capable of performing through which collision with any of the obstacles may be avoided is established, and the set used for deciding how to avoid or mitigate collision with any one of the obstacles. Finally, a collision avoidance maneuver based on the decision is executed autonomously.

Claims

1. A method for autonomous collision avoidance in multiple obstacle scenarios comprising the steps of:

operating at least one sensor to detect a plurality of obstacles in front of a vehicle hosting the system;

operating a forward collision avoidance system to estimate a position, a velocity and an acceleration of each of the obstacles;

evaluating for each respective one of the obstacles separately a set of collision maneuvers which the vehicle is capable of performing that will lead to a collision with the respective obstacle;

forming a union of the sets of collision maneuvers which will lead to collision with any one of the obstacles;

establishing a set of avoidance maneuvers which the vehicle is capable of performing through which collision with any of the obstacles may be avoided;

deciding how to avoid or mitigate collision with any one of the obstacles based at least in part on the set of avoidance maneuvers; and

autonomously executing a collision avoidance maneuver based on the decision.

2. A method according to claim 1, further comprising the steps of:

defining a set E of all possible maneuvers that the vehicle can perform;

defining, for each obstacle i={1, . . . , N}, a new set f_i, where f_i defines the set of collision maneuvers for obstacle i;

forming a combined set of all collision maneuvers, which is given by F=f₁∪

. . . ∪

f_N; and

where all avoidance maneuvers are given by the set G=E\F, and a collision may be considered to be unavoidable if G=Ø

; and

establishing a maneuver that avoids collision using min(G), which denotes the maneuver with a smallest effort that avoids collision.

3. A method according to claim 1, wherein the step of deciding how to avoid or mitigate collision comprises:

calculating a lateral acceleration required to avoid collision with each of the plurality of obstacles.

4. A method according to claim 3, wherein in the step of calculating a lateral acceleration required to avoid collision with a each of the plurality of obstacles it is assumed that both the vehicle and the respective obstacle move with constant acceleration laterally, and the lateral acceleration required to avoid collision with an obstacle is calculated as:

5. A safety system for an automotive vehicle comprising:

at least one sensor operable to detect a plurality of obstacles in front of the vehicle; and

a forward collision avoidance system operative to;

receive signals from the at least one sensor and, based at least in part upon the signals, estimate a position, a velocity and an acceleration of each of the obstacles;

evaluate for each respective one of the obstacles separately a set of collision maneuvers which the vehicle is capable of performing that will lead to a collision with the respective obstacle;

form a union of the sets of collision maneuvers which will lead to collision with any one of the obstacles;

establish a set of avoidance maneuvers which the vehicle is capable of performing through which collision with any of the obstacles may be avoided;

decide how to avoid or mitigate collision with any one of the obstacles using the set of avoidance maneuvers; and

direct a collision avoidance maneuver based on the decision.

6. A system according to claim 5, wherein the at least one sensor comprises at least one of a RADAR system, a LIDAR system or a camera based system monitoring a region in front of the vehicle.

7. A system according to claim 5, wherein the forward collision avoidance system is further operative to:

define a set E of all possible maneuvers that the vehicle can perform;

define, for each obstacle i={1, . . . , N}, a new set f_i, where f_i defines the set of collision maneuvers that lead to a collision with obstacle i;

form a combined set of all maneuvers leading to a collision, which is given by F=f₁∪

. . . ∪

f_N, and where the set of avoidance maneuvers is given by a set G=E\F, and a collision may be considered to be unavoidable if G=Ø

; and

establish a maneuver that avoids collision using min(G), which denotes a maneuver with a smallest effort that avoids collision.

8. A system according to claim 7, wherein the forward collision avoidance system is further operative to:

calculate a lateral acceleration required to avoid collision with each of the plurality of obstacles under the assumption that both the vehicle and the respective obstacle move with constant acceleration laterally, the lateral acceleration required to avoid collision with the obstacle calculated as;

9. A method for autonomous collision avoidance in multiple obstacle scenarios comprising the steps of:

operating at least one sensor to detect a plurality of obstacles in front of a vehicle hosting the system;

operating a forward collision avoidance system to estimate a position, a velocity and an acceleration of each of the obstacles;

evaluating for each respective one of the obstacles separately a set of collision maneuvers which the vehicle is capable of performing that will lead to a collision with the respective obstacle;

forming a union of the sets of collision maneuvers which will lead to collision with any one of the obstacles;

establishing a set of avoidance maneuvers which the vehicle is capable of performing through which collision with any of the obstacles may be avoided;

selecting from the set of avoidance maneuvers a collision avoidance maneuver requiring a minimum level of acceleration experienced by the vehicle; and

autonomously executing the collision avoidance maneuver.