CONTROL OF A BRAKING PROCESS

Abstract

A method for controlling a braking process of a motor vehicle having an intelligent cruise control and a navigation unit is provided, wherein the braking process is divided into multiple phases in which different deceleration rates are present. Furthermore, a motor vehicle for executing the method is provided.

Claims

1-9. (canceled)

10. A method for controlling braking of a motor vehicle having an intelligent cruise control and a navigation unit, the method comprising: detecting an upcoming situation requiring a speed reduction; calculating a final speed; programming a braking process; and executing the programmed braking process; wherein the programmed braking process includes at least one phase having a first deceleration value of the speed and at least one phase having a second deceleration value of the speed.

11. The method of claim 10, wherein the braking process is divided into three phases, each having different deceleration values.

12. The method of claim 10, wherein, in a first phase, a lesser deceleration of the speed is exerted in relation to a constant braking process.

13. The method of claim 10, wherein, in a second phase, a stronger deceleration is exerted in relation to a constant braking process.

14. The method of claim 10, wherein, in a third phase, a lesser deceleration is exerted in relation to the second phase.

15. The method of claim 10, wherein the situation requiring a speed reduction is ascertained based on data of the navigation unit.

16. The method of claim 10, wherein the situation requiring a speed reduction is recognized by data from sensors of the motor vehicle.

17. The method of claim 10, wherein a curve is ascertained as the situation requiring a speed reduction.

18. A system for a motor vehicle, comprising: a navigation unit; and a control unit communicatively connected to the navigation unit and configured to: detect an upcoming situation requiring a speed reduction; calculate a final speed; program a braking process; and execute the programmed braking process; wherein the programmed braking process includes at least one phase having a first deceleration value of the speed and at least one phase having a second deceleration value of the speed

19. The system of claim 18, wherein the braking process is divided into three phases, each having different deceleration values.

20. The system of claim 18, wherein, in a first phase, a lesser deceleration of the speed is exerted in relation to a constant braking process.

21. The system of claim 18, wherein, in a second phase, a stronger deceleration is exerted in relation to a constant braking process.

22. The system of claim 18, wherein, in a third phase, a lesser deceleration is exerted in relation to the second phase.

23. The system of claim 18, wherein the situation requiring a speed reduction is ascertained based on data of the navigation unit.

24. The system of claim 18, wherein the situation requiring a speed reduction is recognized by data from sensors of the motor vehicle.

25. The system of claim 18, wherein a curve is ascertained as the situation requiring a speed reduction.

Description

BRIEF SUMMARY OF THE DRAWINGS

[0019] The present disclosure is explained in greater detail on the basis of the figures. In the figures:

[0020] FIG. 1 shows a schematic illustration of an embodiment of an example motor vehicle.

[0021] FIG. 2 shows a flow chart of an example method.

[0022] FIG. 3 shows a graphic representation of a curve of a roadway.

[0023] FIG. 4 shows a diagram to compare different braking process profiles.

DESCRIPTION

[0024] An embodiment of an example motor vehicle 1 is shown in FIG. 1. The motor vehicle 1 includes a control unit 2. An intelligent adaptive cruise control (IACC) 3 is implemented in the control unit 2. The control unit 2 is designed to control the brakes 4 of the motor vehicle 1, to thus actuate them as needed at various strengths. Furthermore, an engine controller is implemented in the control unit 2, using which, for example the rotational speed of an engine of the motor vehicle 1 is controlled, in order to control the speed of the motor vehicle 1 via this. The control unit 2 is connected to a navigation unit 5.

[0025] The motor vehicle 1 furthermore includes a camera 6 as an optical imaging unit. The camera 6 is capable of detecting obstacles which make a braking process necessary. Alternatively or additionally, the motor vehicle 1 can include further sensors, for example environmental sensors based on ultrasound, RADAR, or LIDAR. Furthermore, the motor vehicle 1 can be designed for vehicle-to-vehicle communication and/or vehicle-to-infrastructure communication.

[0026] In one example as illustrated in FIG. 2, a braking process is carried out in three phases. A motor vehicle 1 moves on a roadway 7 (FIG. 3). The arrow indicates the travel direction of the motor vehicle 1. According to the flow chart of FIG. 2, in a first step S1, an upcoming situation requiring a speed reduction is detected. For this purpose, the control unit 2 evaluates items of map information and position data of the navigation unit, which indicate an imminent curve 8 of the roadway 7. Alternatively or in combination with the navigation unit 5, for example, data of the camera 6 and/or a vehicle-to-vehicle communication can also be used.

[0027] The curve 8 is too steep to be able to be passed without braking (FIG. 3). The control unit 2 calculates a final speed v.sub.e in a second step S2. The final speed v.sub.e is the speed at which the motor vehicle 1 is supposed to move at the end of the braking process. The final speed v.sub.e is situation-dependent. To drive through the curve, a speed v.sub.e is advantageous which enables driving through the curve and rapid acceleration on the vertex of the curve. The final speed v.sub.e can also be zero if a full stop is required before an obstacle. In a third step S3, a corresponding braking process is programmed, which is to have three phases.

[0028] In a fourth step S4, the programmed braking process is executed (see FIG. 4, dotted line). In a first phase S4a, the motor vehicle 1 is only lightly braked. Light is to be understood here in relation to a constant braking process having uniform deceleration (see FIG. 4, graph having solid line), thus that the deceleration is less. During this first phase S4a, the occupant of the motor vehicle 1 is made aware that a braking process is initiated.

[0029] In a second phase S4b, the motor vehicle 1 is strongly decelerated. Strong is to be understood here in relation to a constant braking process having uniform deceleration (FIG. 4), thus that the deceleration is stronger. The deceleration is similarly strong here as in two-phase braking processes also shown in FIG. 4, which have a deceleration of −2.5 ms.sup.−2 (graph having dot-dash line) or −2 ms.sup.−2 (dashed line graph).

[0030] In a third phase S4c, the motor vehicle 1 is braked more lightly, wherein the deceleration is still stronger than in the case of a constant braking process (FIG. 4). The deceleration corresponds here to the second phase of the two-phase braking process at −2 ms.sup.−2 (FIG. 4, dashed line graph). At the end of the third phase S4c, the motor vehicle 1 has reached the final speed v.sub.e. After the braking process before the curve 8, the motor vehicle 1 can accelerate again at the vertex of the curve 8 (FIG. 3).

LIST OF REFERENCE NUMERALS

[0031] 1 Motor vehicle [0032] 2 Control unit [0033] 3 Intelligent cruise control [0034] 4 Brakes [0035] 5 Navigation unit [0036] 6 Camera [0037] 7 Roadway [0038] 8 Curve