Automatic brake and steering system and method for a vehicle

• US 20040090117A1
• Filed: 06/19/2003
• Published: 05/13/2004
• Est. Priority Date: 07/26/2000
• Status: Active Grant

• Current Assignee: Tsing-Hua Capital, LLC (Intellectual Ventures LLC)
• Original Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Kurz, Gerhard, Dudeck, Ingo, Schoeb, Reinhold, Troester, Harry, Zimmer, Richard, Yap, Andy, Roehrig-Gericke, Thomas, Freitag, Rainer, Lauer, Wofgang
• Granted Patent: US 6,926,374 B2
• Time in Patent Office: Days
• US Class Current: 303/191
• CPC Class Codes: B60T 2201/08 Lane monitoring; Lane Keeping Systems
• CPC Class Codes: B60T 2201/083 using active brake actuation
• CPC Class Codes: B60T 2201/087 using active steering actuation
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/20 including control of steering systems
• 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 30/09 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: B60W 30/0956 the prediction being responsive to traffic or environmental parameters
• CPC Class Codes: B62D 15/0265 Automatic obstacle avoidance by steering
• CPC Class Codes: G05D 1/0257 using a radar radar systems designed for anti-collision purposes between land vehicles or between land vehicle and fixed obstacles G01S13/931
• CPC Class Codes: G05D 1/0278 using satellite positioning signals, e.g. GPS
• CPC Class Codes: G05D 2201/0213 Road vehicle, e.g. car or truck

Abstract

An automatic brake and steering system for a vehicle containing a sensor unit for sensing vehicle state variables and vehicle characteristic variables and ambient conditions. Furthermore, a control unit and actuator devices are provided for setting the vehicle brake system and/or the vehicle steering system.

In order to be able to carry out automatic avoidance manoeuvres with maximum safety, an avoidance route is determined if there is an obstacle in the path of the vehicle, in which case, if there is a further obstacle on the avoidance route, the strategy for determining the avoidance route is applied once more. If it is not possible to find a collision-free avoidance route, that route on which the difference between the remaining braking distance and the remaining distance from the obstacle is smallest is selected.

Claims

1. Automatic brake and steering system for a vehicle having a sensor unit for sensing vehicle state variables and vehicle characteristic variables as well as for sensing ambient conditions, having a control unit in which actuation signals can be generated as a function of the vehicle state variables and the ambient conditions, it being possible to feed actuation signals to actuation devices in the vehicle in order to set the vehicle brake and/or the vehicle steering system, the distance between the current position of the vehicle and the obstacle as well as the expected braking distance in order to stop the vehicle being determined when there is an obstacle (3) in the path of the vehicle, and an avoidance path (b, d) for driving around the obstacle (3) being automatically driven along in accordance with a stored avoidance strategy, characterized

in that, in the event of a further obstacle (4) lying in the avoidance path (b, d), the avoidance strategy is applied once more in order to calculate an alternative avoidance path (e),

in that, in the event of it being impossible to find a collision-free avoidance path, that avoidance path (d, e) on which the difference (Δ

s₁, Δ

s₂) between the remaining braking distance (s_B) and the remaining distance (s_H1, s_H2) from the obstacle (4, 5) on the respective avoidance path (d, e) is the shortest is selected from a plurality of alternatives.

2. Brake and steering system according to claim 1, characterized in that peripheral conditions which are to be sensed by means of the sensor unit and which describe characteristic features of the surroundings are to be taken into account in the avoidance strategy.

3. Brake and steering system according to claim 2, characterized in that the obstacles are divided into categories, avoidance paths which lead to a collision with a defined category of obstacles being eliminated.

4. Brake and steering system according to claim 2 or 3, characterized in that, in the case of alternative avoidance paths, that avoidance path which does not lead to an oncoming carriageway is selected.

5. Brake and steering system according to one of claims 1 to 4, characterized in that the width of the obstacle which is to be measured in the lateral direction with respect to the direction of the vehicle is determined, and the minimum lateral component (Y_min) of the avoidance path is determined from the addition of half the obstacle width (b_H) and half the vehicle width (b_F).

6. Brake and steering system according to one of claims 1 to 5, characterized in that the lateral component (y) of the avoidance path is determined in accordance with the clothoid

y=∫

(v²(t){dot over (Θ

)}(t)t²)/L dt,

where

v is the speed of the vehicle

t is the time

{dot over (Θ

)} is the steering speed

L is the wheel base.

7. Brake and steering system according to one of claims 1 to 6, characterized in that, in the case of a failure of the steering actuating device, an assembly which influences the longitudinal dynamics of the vehicle is acted on in accordance with a predefined equivalent strategy.

8. Brake and steering system according to claim 7, characterized in that the vehicle is decelerated with maximum deceleration by activating the vehicle brake and/or the engine brake.

9. Brake and steering system according to one of claims 1 to 8, characterized in that a graphic display for representing the actual position of the vehicle and the setpoint position determined in accordance with the avoidance strategy is provided in the vehicle.

10. Brake and steering system according to one of claims 1 to 9, characterized in that a memory unit is assigned to the brake and steering system, and in that at least some of the data which is relevant for the automatic triggering of the brake and/or steering process and/or at least some of the data which is generated by the brake and steering system can be stored in the memory unit.

11. Brake system according to claim 10, characterized in that some of the data is stored in the memory unit only for a limited, predefined period of time before the vehicle last comes to a standstill.

12. Brake system according to claim 10 or 11, characterized in that some of the data is stored in the memory unit without time restriction.

13. Brake and steering system according to one of claims 1 to 12, characterized in that a position-determining system, in particular a satellite-supported position-determining system, is provided for determining the instantaneous position of the vehicle.

14. Brake and steering system according to one of claims 1 to 13, characterized in that an electronic road map is provided which contains information in digitized form relating to the topography of the road being driven along at a particular time, and the surroundings.

15. Brake system according to claims 13 and 14, characterized in that the vehicle position can be entered into the electronic road map, and in that peripheral conditions which are to be taken into account in the avoidance strategy can be generated from the position of the vehicle on the road map.