Device and method for assisting with driving a motor vehicle

1. A self-contained driver-assistance device for assisting with driving a motor vehicle following a road, the driver-assistance device comprising:

a sensor for acquiring a signal representative of the presence of an obstacle in an interior of a detection field of the sensor; and

a control module that is programmed to:

control a driver-assistance function for assisting with driving the motor vehicle, depending on the signal acquired by said sensor,

a) detect, on the basis of a position of the motor vehicle and of characteristics of said road, a section of the road located outside of the detection field of said sensor, and

b) in case of detection of this road the section of the road located outside of the detection field of said sensor, control said driver-assistance function while taking into account the potential presence of the obstacle on said road section,

wherein the self-contained driver assistance device is limited to only the motor vehicle which detects the obstacle.

2. The driver-assistance device according to claim 1 , in addition comprising a navigation system including locating means for determining said position of the motor vehicle, and digital map data comprising said characteristics of the road followed by the motor vehicle.

3. The driver-assistance device according to claim 1 , wherein said characteristics of the road followed by the motor vehicle comprise a piece of information representative of a change in direction and/or in slope of the road followed by the motor vehicle.

4. The driver-assistance device according to claim 1 , wherein the control module is programmed:

in step a), determine, on the basis of said position of the motor vehicle and of said characteristics of the road that it is following, a distance separating the motor vehicle from said road section, and

in step b), control said driver-assistance function while taking into account this distance separating the motor vehicle from said road section.

5. The driver-assistance device according to claim 4 , wherein said driver-assistance function comprises a function for decreasing the speed of the motor vehicle on the approach of an obstacle.

6. The driver-assistance device according to claim 5 , wherein the control module is programmed, in step b), to command a deceleration of the motor vehicle when the distance separating the motor vehicle from said road section is smaller than a given limiting distance.

7. The driver-assistance device according to claim 5 , wherein said signal is representative of a distance separating the sensor and the obstacle present in its detection field.

8. The driver-assistance device according to claim 7 , wherein the control module is programmed:

when the presence of an obstacle in the detection field of said sensor is detected on the basis of the signal acquired by this sensor, then this obstacle exits from the detection field of this sensor and said road section located outside of the detection field of this device as detected in step a),

to then conclude that said obstacle is present on said road section, and to control said driver-assistance function while taking into account the presence of this obstacle on said road section.

9. The driver-assistance device according to claim 8 , wherein the control module is programmed:

when it is concluded that said obstacle is present on said road section,

to then determine a probable distance separating this obstacle and the motor vehicle, depending on a distance, between said obstacle and said sensor, determined on the basis of the signal having permitted beforehand the presence of this obstacle in the detection field of said sensor to be detected, and

to control said driver-assistance function depending on said probable distance.

10. The driver-assistance device according to claim 9 , wherein the control module is furthermore programmed to determine said probable distance separating the motor vehicle and said obstacle depending on a speed of movement of this obstacle, determined depending on said signal having permitted beforehand the presence of this obstacle in the detection field of said sensor to be detected.

11. The driver-assistance device according to claim 9 , wherein the control module is programmed to command a deceleration of the motor vehicle when said probable distance is smaller than a given safety distance.

12. The driver-assistance device according to claim 9 , wherein, said obstacle is another motor vehicle followed by the motor vehicle equipped with the driver-assistance device, and said driver-assistance function comprises a function for automatically following a vehicle, wherein the control module is programmed to control the speed of the motor vehicle that is equipped therewith so that, when it is concluded that said followed vehicle is present on said road section, said probable distance is about equal to a given set point distance.

13. The driver-assistance device according to claim 1 , wherein said sensor comprises an image sensor.

14. The driver-assistance device according to claim 1 , wherein said characteristics of the road followed by the motor vehicle comprise characteristics which are representative of the geometry of a portion of said road.

15. A driver-assistance method for assisting with driving a motor vehicle following a road, in which a control module controls a driver-assistance function for assisting with driving the motor vehicle depending on a signal, acquired by a sensor, representative of the presence of an obstacle in an interior of a detection field of this sensor, the method comprising:

a) detecting, on the basis of a position of the motor vehicle and of characteristics of said road, a section of this road located outside of the detection field of said sensor; and

b) in case of detection of this road section located outside of the detection field of said sensor, controlling said driver-assistance function while taking into account the potential presence of an obstacle on said road section,

wherein the self-contained driver assistance device is limited to only the motor vehicle which detects the obstacle.