Driving Safety System

Abstract

A controller of a motor vehicle comprises a drive motor, wheels, braking devices for the wheels, said braking devices being separately controllable by the controller, an ambient sensor, a driving status sensor and a steering system. For increasing the driving stability, a steering angle is determinable by the controller from signals of the ambient sensor and of the driving status sensor, said steering angle providing a stable driving status in addition to a targeted braking of the wheels, and the steering angle is adjustable at the steering system in order to keep the motor vehicle on the paved road, in particular when driving along a curve, so that the motor vehicle remains on an intersecting plane of the possible dynamic vehicle area ahead with an actual road without skidding or colliding with other obstacles.

Claims

1.-7. (canceled)

8. A driving system for a motor vehicle including a drive motor, a steering system, wheels, and braking devices for the individual wheels, the driving system comprising: an ambient sensor; a driving status sensor; and a controller adapted to (a) receive signals from the ambient sensor and the driving status sensor, (b) determine from the signals a steering angle (?) providing a stable driving status and (c) adjusting, at the steering system, the steering angle (?) and, at the braking devices, targeted braking of the wheels in order to maintain the motor vehicle on a paved road without skidding or colliding with other obstacles.

9. The driving system of claim 8, wherein the controller is adapted to determine the steering angle (?) irrespective of the targeted braking of the wheels.

10. The driving system of claim 9, wherein the controller is adapted to control the drive motor so that one or more wheels are accelerated in a targeted manner.

11. The driving system of claim 8, wherein the controller is adapted to determine the steering angle (?) depending on the targeted braking of the wheels.

12. The driving system of claim 11, wherein the controller is adapted to control the drive motor so that one or more wheels are accelerated in a targeted manner.

13. The driving system of claim 8, wherein the controller is adapted to jointly determine the steering angle (?) and the targeted braking of the wheels.

14. The driving system of claim 13, wherein the controller is adapted to control the drive motor so that one or more wheels are accelerated in a targeted manner.

15. A method of controlling a motor vehicle including a drive motor, a steering system, wheels, braking devices for the individual wheels, an ambient sensor and a driving status sensor, comprising: receiving, by a controller, signals from the ambient sensor and the driving status sensor; determining, by the controller, from the signals a steering angle (?) providing a stable driving status; and adjusting, by the controller, (a) the steering angle (?) at the steering system and (b) targeted braking of the wheels at the braking devices in order to maintain the motor vehicle on a paved road without skidding or colliding with other obstacles.

16. The method of claim 15, including determining, by the controller, the steering angle (?) irrespective of the targeted braking of the wheels.

17. The method of claim 16, including controlling, by the controller, the drive motor so that one or more wheels are accelerated in a targeted manner.

18. The method of claim 15, including determining, by the controller, the steering angle (?) depending on the targeted braking of the wheels.

19. The method of claim 18, including controlling, by the controller, the drive motor so that one or more wheels are accelerated in a targeted manner.

20. The method of claim 15, including jointly determining, by the controller, the steering angle (?) and the targeted braking of the wheels.

21. The method of claim 20, including controlling, by the controller, the drive motor so that one or more wheels are accelerated in a targeted manner.

22. A motor vehicle, comprising: a drive motor; a steering system; wheels; braking devices for the individual wheels; an ambient sensor; a driving status sensor; and a controller adapted to (a) receive signals from the ambient sensor and the driving status sensor, (b) determine from the signals a steering angle (?) providing a stable driving status and (c) adjusting, at the steering system, the steering angle (?) and, at the braking devices, targeted braking of the wheels in order to maintain the motor vehicle on a paved road without skidding or colliding with other obstacles.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0030] The invention is explained in more detail below with reference to the associated drawing.

[0031] FIG. 1 shows a schematic view of a motor vehicle,

[0032] FIG. 2 shows a top view of the motor vehicle when driving along a curve,

[0033] FIG. 3 shows another top view of the motor vehicle with oncoming traffic, and

[0034] FIG. 4 shows a another top view of the motor vehicle with a projection into the future.

[0035] In the purely schematic FIGS. 1 to 3, the same reference symbols refer to the same components in each case. The same applies to the individual parts of the respective figure descriptions.

DETAILED DESCRIPTION

[0036] FIG. 1 shows a motor vehicle in purely schematic form. It usually comprises at least one drive motor (not shown) and a steering system 8 with steering wheel 7 in order to obtain an intended steering angle ? of two front wheels 2a, 2b, here to the left, so that motor vehicle 1 moves to the left in moving direction F.

[0037] Braking devices 4a, 4b, 4c, 4d are arranged on all four wheels 2a, 2b, 2c, 2d, such as a disc brake in each case, in order to be able to brake wheel 2a, 2b, 2c, 2d in question in a targeted manner. Brakes 4a, 4b, 4c, 4d are actuated for this purpose via control and/or signal lines 6 from a central controller 3 of the motor vehicle corresponding to a known ESP system.

[0038] Furthermore, steering system 8, in particular an associated servomotor, can also be controlled by controller 3 via a control line 6 in order to automatically turn front wheels 2a, 2b at steering angle ?. An ambient sensor 5, which is also connected to controller 3 via a control line 6, is used to detect an environment. Ambient sensor 5 is, for example, a RADAR and/or LIDAR and/or a video sensor. A wet road condition or precipitation can also be detected. Furthermore, a driving status sensor 9 is provided which records, for example, the acceleration values of motor vehicle 1 in all three spatial directions, the acceleration tensor, and/or the current vehicle speed in all three spatial directions, the speed vector, and/or a static friction coefficient between wheels 2a, 2b, 2c, 2d and a road as well as their respective current number of revolutions and/or the current position of the motor vehicle on a road as well as its further course of the road via a GPS system. Driving status sensor 9 is also connected to controller 3 via a data or control line 6.

[0039] Based on this information and current steering angle ?, the controller 3, which is set up accordingly in terms of hardware and/or software, can automatically brake individual wheels 2a, 2b, 2c, 2d in accordance with a known ESP system and also influence steering system 8 independently of a position of steering wheel 7 in order to restore or maintain a stable driving state of motor vehicle 1, taking into account the road and its course. Furthermore, a drive motor and corresponding components of a gearbox can also be controlled accordingly in order to accelerate one or more of wheels 2a, 2b, 2c, 2d in order to maintain a stable driving state of the motor vehicle, as well.

[0040] In particular, this is done autonomously without the intervention of a driver of motor vehicle 1. The monitoring of the states of all components of motor vehicle 1 and its surroundings is preferably carried out cyclically at high frequency in order to enable rapid adaptation to changing traffic conditions.

[0041] FIG. 2 shows a driving situation of motor vehicle 1 driving along a right-hand curve. The driver had to avoid an obstacle 10 such as a snow bank or they drove through a snow bank with the left wheels, for example. The snow brakes the left half of the vehicle relatively abruptly as it passes through and the vehicle turns to the left without this being reflected by the position of the wheels and the speed vector, which does not want to follow a curve despite the impact. If the vehicle is accelerated or braked while driving through the curve, so that longitudinal forces act on the tires, the changing friction u, which starts out as static friction and turns into sliding friction once the tires affected become unstable, may cause the vehicle to swerve. If a non-straight steering position is assumed while driving through, so that lateral forces act on the tires, the different u can also take effect. When driving straight ahead, motor vehicle 1 would leave a road 11 on the inside of a curve and could skid on an unpaved road edge. Even with a conventional ESP program, driving stability could then not be guaranteed when braking. In particular, although an ESP system could restore a stable driving state, a moving direction of motor vehicle 1 wouldin all probabilityno longer correspond to the course of road 11 ahead, i.e., motor vehicle 1 would veer off road 11.

[0042] Now, however, controller 3 of motor vehicle 1 is set up in such a way that it can automatically calculate a steering angle ? from the measured values of ambient sensor 5 and driving status sensor 9 and transmit it to a steering system 8 of motor vehicle 1 via control lines 6. Subsequently, the front wheels (here only right front wheel 2b is designated as an example) are then turned in such a way that in a possible dynamic vehicle area 13 (which is indicated here essentially in the shape of a club in front of motor vehicle 1), motor vehicle 1 is held within intended area 14, which essentially represents the intersecting plane with road 11 and is hatched here. This allows motor vehicle 1 to continue driving through the curve in the intended moving direction F, although it may also brake automatically to avoid hitting another motor vehicle 12 ahead that is also driving through the curve. For all obstacles, a trajectory relative to the vehicle trajectory or relative to the stationary world is estimated. In the simplest case, this can be assumed to be linear from calculation step to calculation step and extrapolated into the future if the calculation steps are sufficiently frequent. Using the trajectories of moving and stationary objects, the lengths of time to the first collision can be determined depending on the trajectory, i.e., the selected steering position, and braking interventions, in order to select the steering position and braking interventions in such a way that the length of time before a collision and also before leaving the road is maximized.

[0043] FIG. 3 shows the same situation, with a first other motor vehicle 12a traveling in the same moving direction F as motor vehicle 1 and a second other motor vehicle 12b traveling in the opposite moving direction F. In this case, possible dynamic vehicle area 13 on road 11 must be selected in such a way that a collision with second other motor vehicle 12b and a driving into first other motor vehicle 12a is effectively avoided. For this purpose, the front wheels (indicated here by the right front wheel 2b) can be turned later in order to remain reliably in their own lane.

[0044] In an execution program, the position of the moving objects or obstacles is estimated in the next calculation step(s) or in the calculation step(s) following thereafter using the current trajectory. With sufficiently short calculation cycles, the change is very small, so that even a linear estimate, i.e., a current position+(dt of the velocity vector), contains only very small deviations. For better accuracy, the future location of other vehicles, obstacles and objects can also be estimated using higher order terms from sensor data with computer vision, for example+ (dt?2/2 of the acceleration vector)+ . . . .

[0045] A linear estimate for extremely large dt is exaggerated in FIG. 3. Like other obstacles, the estimated positions of the objects are subtracted from the dynamically possible vehicle area.

[0046] In particular, FIG. 4 shows how two other motor vehicles 12a, 12b continue to move along the road 11 within time period dt, at least mathematically simulated, assuming normal driving. After time period dt, they each assume projected position 15a, 15b and should therefore pose no danger to their own motor vehicle 1.

Reference Signs

[0047] 1. motor vehicle [0048] 2. wheel of 1 [0049] 3. controller of 1 [0050] 4. braking device for 2 [0051] 5. ambient sensor [0052] 6. control line [0053] 7. steering wheel of 1 [0054] 8. steering system of 1 [0055] 9. driving status sensor [0056] 10. obstacle [0057] 11. road [0058] 12. other motor vehicle [0059] 13. possible dynamic vehicle area [0060] 14. intended area [0061] 15. projected position [0062] ? steering angle of 8 [0063] F moving direction of 1