Method and device for the prediction and adaptation of movement trajectories of motor vehicles

• US 9,081,387 B2
• Filed: 03/01/2012
• Issued: 07/14/2015
• Est. Priority Date: 03/01/2011
• Status: Active Grant

• Current Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Original Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Inventors: Bretzigheimer, Kai, Foerster, Daniel, Hartmann, Andreas, Hartmann, Bernd, Staab, Thorsten, Staehlin, Ulrich
• Primary Examiner(s): ARTHUR JEANGLAUD, GERTRUDE
• Application Number:
  US14/002,441
• Publication Number:
  US 20140074388A1
• Time in Patent Office: 1,230 Days
• Field of Search: 701/41, 701/48, 701/58, 701/117, 701/301
• US Class Current: 1/1
• CPC Class Codes: B60T 1/10 by utilising wheel movement for accumulating energy, e.g. driving air compressors
• CPC Class Codes: B60T 2210/32 Vehicle surroundings
• CPC Class Codes: B60T 8/17558 specially adapted for collision avoidance or collision mitigation road vehicle drive control systems for collision avoidance otherwise than by controlling a particular sub-unit B60W30/09
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 2552/40 Coefficient of friction
• CPC Class Codes: B60W 2555/20 Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 2556/65 Data transmitted between vehicles
• CPC Class Codes: B60W 30/09 Taking automatic action to avoid collision, e.g. braking and steering
• CPC Class Codes: B60W 30/0953 the prediction being responsive to vehicle dynamic parameters
• CPC Class Codes: B62D 15/0265 Automatic obstacle avoidance by steering
• CPC Class Codes: B62D 15/0275 by overlaying a vehicle path based on present steering angle over an image without processing that image
• CPC Class Codes: B62D 15/028 Guided parking by providing commands to the driver, e.g. acoustically or optically
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence
• CPC Class Codes: B62D 6/006 using a measured or estimated road friction coefficient
• CPC Class Codes: G05D 1/0289 with means for avoiding collisions between vehicles vehicle fittings for automatically controlling speed including means for detecting potential obstacles B60K31/0008; avoiding obstacles by action on the steering system B62D; radar, sonar, lidar systems designed for anti-collision purposes G01S13/93, G01S15/93, G01S17/93
• CPC Class Codes: G08G 1/165 for passive traffic, e.g. including static obstacles, trees
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes
• CPC Class Codes: G08G 1/167 Driving aids for lane monitoring, lane changing, e.g. blind spot detection

Abstract

A method and a device are for prediction and adaptation of movement trajectories of a vehicle for assisting the driver and/or for preventing or reducing the severity of a collision. Situatively required movement trajectories for assisting the driver or collision avoidance are determined using an environment sensor system. Physically possible movement trajectories are determined from characteristic properties of the driving dynamics of the vehicle and from the coefficient of friction between the tires and the road up to a maximum coefficient of friction. An intersection between the above two sets of trajectories is determined, and only trajectories that are included in this intersection are taken into account for the prediction and adaptation of movement trajectories for the driving assistance or collision avoidance function.

Claims

1. A method for prediction and adaptation of movement trajectories T of a motor vehicle driving on a road for assisting an driver in his or her task of driving and/or for preventing a collision or reducing consequences of an accident, characterized in that for the prediction and adaptation of movement trajectories (T) of the motor vehicle (1), an intersection (U) of situatively required movement trajectories (SNT), which are determined using environment sensors (2), and physically possible movement trajectories (PMT), which result from properties that are characteristic of driving dynamics of the motor vehicle (1) and from a coefficient of friction (μ

) obtained between tires and the road up to a maximum possible threshold coefficient of friction (μ

_max), is formed, and only those movement trajectories (T) are taken into account that lie within the intersection (U).

2. The method according to claim 1, characterized in that only one movement trajectory (T) from the intersection (U) is taken into account depending on a criticality of a driving situation.

3. The method according to claim 1, characterized in that the situatively required movement trajectories (SNT) are determined based on an avoidance space available and the physically possible movement trajectories (PMT) are limited by a driving physics.

4. The method according to claim 1, characterized in that the environment sensors (2) are used to determine a target corridor with a situatively required and physically possible tolerance margin.

5. The method according to claim 1, characterized in that the predicted movement trajectories (T) are constantly monitored during a driving maneuver and, if required, adjusted to a dynamically changing driving situation or discarded and newly predicted.

6. The method according to claim 1, characterized in that braking and/or steering interventions are performed depending on calculated movement trajectories (T) with a purpose of supporting the driver, correcting a driver input, or automated interventions in the braking and/or steering system.

7. The method according to claim 1, characterized in that wheel forces resulting from combined braking and/or steering interventions based on the movement trajectories (T) are always below the maximum available coefficient of friction (μ

_max).

8. The method according to claim 1, characterized in that the maximum possible coefficient of friction (μ

_max) is determined using additional signals from optical road sensors and/or from vehicle dynamics control systems and/or from other sensors such as rain, temperature, or tire sensors and/or by including information transmitted via car-to-x communication.

9. The method according to claim 8, characterized in that the maximum possible coefficient of friction (μ

_max) is tested for plausibility using the signals from the sensors that were not used for its determination.

10. The method according to claim 8, characterized in that the maximum possible coefficient of friction (μ

_max) is logically limited to predetermined values.

11. The method according to claim 1, characterized in that a finite number (Z) of movement trajectories (T) for supporting the driver in all driving situations is determined in advance and stored.

12. The method according to claim 11, characterized in that the movement trajectory (T) that comes closest to a current driving situation is selected from predefined movement trajectories (T).

13. The method according to claim 11, characterized in that upon detection of a critical driving situation, a suitable movement trajectory (T) is selected and a sequence number of the movement trajectory (T) is transmitted to the executing control unit.

14. The method according to claim 1, characterized in that a movement trajectory (T) is found optimal if it is within the intersection (U) and has a minimum curvature.

15. A device for prediction and adaptation of movement trajectories (T) of a motor vehicle driving on a road (1), characterized in that means for the prediction and adaptation of movement trajectories (T) of the motor vehicle (1) are provided that establish an intersection (U) of situatively required movement trajectories (T), which are determined using environment sensors (2), and physically possible movement trajectories (T), which result from properties that are characteristic of driving dynamics of the motor vehicle (1) and from a coefficient of friction (μ

) obtained between tires and the road up to a maximum possible threshold coefficient of friction (μ

_max), and take into account only those movement trajectories (T) that lie within the intersection (U).

16. The device according to claim 15, characterized in that the environment sensors (2) comprise a radar sensor, a lidar sensor, a camera system, or a combination of these sensors.

17. The device according to claim 15, characterized in that a memory is provided in which a predetermined, finite number (Z) of movement trajectories (T) for supporting the driver in all driving situations is stored.

18. The device according to claim 15, characterized in that the movement trajectory (T) is stored under a sequence number in the executing control unit.

19. A method of assisting a driver in driving a vehicle, preventing a collision of the vehicle, and/or reducing a severity of a collision of the vehicle, comprising steps:

a) using environment sensors of the vehicle, detecting environment data regarding a driving situation of the vehicle in a driving environment of the vehicle;

b) based on the environment data, determining situatively required movement trajectories of the vehicle, which are required for assisting the driver, preventing a collision of the vehicle, and/or reducing a severity of a collision of the vehicle in the driving situation;

c) obtaining vehicle property values that are characteristic of driving dynamics of the vehicle;

d) determining a coefficient of friction between tires of the vehicle and a road on which the vehicle is driving, up to a maximum threshold coefficient of friction;

e) based on the vehicle property values and the coefficient of friction, determining physically possible movement trajectories of the vehicle, which are physically possible for the vehicle to carry out;

f) forming an intersection of the situatively required movement trajectories and the physically possible movement trajectories to determine an intersection set of trajectories that are both situatively required and physically possible;

g) selecting a selected trajectory from the intersection set of trajectories; and

h) executing a driving assistance function to maneuver the vehicle along or toward the selected trajectory, for assisting the driver in driving the vehicle, for preventing a collision of the vehicle, and/or for reducing a severity of a collision of the vehicle.

20. The method according to claim 19, performed continuously during a driving maneuver and not only when an emergency collision-avoidance situation arises.