BRAKING SYSTEM FOR AN AUTONOMOUS VEHICLE

Abstract

A braking system in an at least partially autonomous vehicle, having one vehicle wheel brake per vehicle wheel, which is assigned to both the primary brake regulation system and a redundant secondary brake regulation system, wherein the primary brake regulation system has a primary control unit and one electromechanical primary actuator per vehicle wheel for actuating the vehicle wheel brake, and wherein the primary control unit generates primary positioning signals for activating the respective electromechanical primary actuator on the basis of a setpoint deceleration specification generated in a pilot system and/or a setpoint deceleration specification generated on the part of the driver by a brake pedal. The secondary brake regulation system has a secondary control unit independent of the primary control unit and one electromechanical secondary actuator, independent of the primary actuator, per vehicle wheel.

Claims

1. A braking system in an at least partially autonomous vehicle, comprising: one vehicle wheel brake per vehicle wheel, which is assigned to both the primary brake regulation system and a redundant secondary brake regulation system, wherein the primary brake regulation system has a primary control unit and one electromechanical primary actuator per vehicle wheel for actuating the vehicle wheel brake, and wherein the primary control unit generates primary positioning signals for activating the respective electromechanical primary actuator on the basis of a setpoint deceleration specification generated in a pilot system and/or a setpoint deceleration specification generated on the part of the driver by a brake pedal, wherein the secondary brake regulation system has a secondary control unit independent of the primary control unit and one electromechanical secondary actuator, independent of the primary actuator, per vehicle wheel, and the secondary control unit generates secondary positioning signals for activating the respective electromechanical secondary actuator on the basis of the setpoint deceleration specification generated in the pilot system.

2. The braking system as claimed in claim 1, wherein the brake pedal is a component of a foot pedal simulator unit having at least one pedal sensor, and the foot pedal simulator unit converts the mechanical pedal movement into an electrical foot pedal signal, which is the setpoint deceleration specification generated on the part of the driver.

3. The braking system as claimed in claim 1, further comprising a primary vehicle electrical system and a redundant secondary vehicle electrical system, which each supply the primary control unit and the secondary control unit with electrical energy independently of one another.

4. The braking system as claimed in claim 1, wherein each vehicle wheel is assigned a primary speed sensor and a secondary speed sensor, which each have a signal connection to the primary control unit and to the secondary control unit.

5. The braking system as claimed in claim 1, wherein the pilot system has a signal connection to the primary control unit via a primary signal line, and the pilot system has a signal connection to the secondary control unit via a secondary signal line independent thereof.

6. The braking system as claimed in claim 1, wherein a connecting signal line is laid between the primary control unit and the secondary control unit, via which items of status information are exchangeable between the control units, and in case of error in the primary brake regulation system, the primary control unit generates an error signal, using which the secondary control unit is activatable via the connecting signal line, so that in place of the primary brake regulation system, the secondary brake regulation system takes over the implementation of the setpoint deceleration specification.

7. The braking system as claimed in claim 1, wherein in normal driving operation, both the primary brake regulation system and the secondary brake regulation system are in use, so that both brake regulation systems operate in parallel operation.

8. The braking system as claimed in claim 1, wherein at least one of the electromechanical actuators has a blocking function, by which in a parking situation the actuator blocks the assigned vehicle wheel by brake actuation.

9. The braking system as claimed in claim 1, wherein the primary control unit and the secondary control unit are structurally equivalent, and/or the primary actuator and the secondary actuator are structurally equivalent.

10. The braking system as claimed in claim 2, further comprising a primary vehicle electrical system and a redundant secondary vehicle electrical system, which each supply the primary control unit and the secondary control unit with electrical energy independently of one another.

11. The braking system as claimed in claim 2, wherein each vehicle wheel is assigned a primary speed sensor and a secondary speed sensor, which each have a signal connection to the primary control unit and to the secondary control unit.

12. The braking system as claimed in claim 3, wherein each vehicle wheel is assigned a primary speed sensor and a secondary speed sensor, which each have a signal connection to the primary control unit and to the secondary control unit.

13. The braking system as claimed in claim 2, wherein the pilot system has a signal connection to the primary control unit via a primary signal line, and the pilot system has a signal connection to the secondary control unit via a secondary signal line independent thereof.

14. The braking system as claimed in claim 3, wherein the pilot system has a signal connection to the primary control unit via a primary signal line, and the pilot system has a signal connection to the secondary control unit via a secondary signal line independent thereof.

15. The braking system as claimed in claim 4, wherein the pilot system has a signal connection to the primary control unit via a primary signal line, and the pilot system has a signal connection to the secondary control unit via a secondary signal line independent thereof.

16. The braking system as claimed in claim 2, wherein a connecting signal line is laid between the primary control unit and the secondary control unit, via which items of status information are exchangeable between the control units, and in case of error in the primary brake regulation system, the primary control unit generates an error signal, using which the secondary control unit is activatable via the connecting signal line, so that in place of the primary brake regulation system, the secondary brake regulation system takes over the implementation of the setpoint deceleration specification.

17. The braking system as claimed in claim 3, wherein a connecting signal line is laid between the primary control unit and the secondary control unit, via which items of status information are exchangeable between the control units, and in case of error in the primary brake regulation system, the primary control unit generates an error signal, using which the secondary control unit is activatable via the connecting signal line, so that in place of the primary brake regulation system, the secondary brake regulation system takes over the implementation of the setpoint deceleration specification.

18. The braking system as claimed in claim 4, wherein a connecting signal line is laid between the primary control unit and the secondary control unit, via which items of status information are exchangeable between the control units, and in case of error in the primary brake regulation system, the primary control unit generates an error signal, using which the secondary control unit is activatable via the connecting signal line, so that in place of the primary brake regulation system, the secondary brake regulation system takes over the implementation of the setpoint deceleration specification.

19. The braking system as claimed in claim 5, wherein a connecting signal line is laid between the primary control unit and the secondary control unit, via which items of status information are exchangeable between the control units, and in case of error in the primary brake regulation system, the primary control unit generates an error signal, using which the secondary control unit is activatable via the connecting signal line, so that in place of the primary brake regulation system, the secondary brake regulation system takes over the implementation of the setpoint deceleration specification.

20. The braking system as claimed in claim 2, wherein in normal driving operation, both the primary brake regulation system and the secondary brake regulation system are in use, so that both brake regulation systems operate in parallel operation.

Description

BRIEF DESCRIPTION OF THE FIGURE

[0029] An exemplary embodiment of the invention is described hereinafter on the basis of the appended FIGURE.

DETAILED DESCRIPTION

[0030] A schematic block circuit diagram of the braking system of a two-track autonomous vehicle having a front axle and a rear axle is shown in the FIGURE. Accordingly one vehicle wheel brake 1 is assigned to each of the two front wheels VL, VR and each of the two rear wheels HR, HL. The vehicle wheel brake 1 has a brake caliper 2, to which pressure can be applied via an electromechanical primary actuator 3 and via an electromechanical secondary actuator 5, whereby the brake caliper 2 comes into pressure contact using its brake linings (not shown) with the brake disk 7 of the vehicle wheel brake 1. The electromechanical primary actuator 3 is a component of a primary brake regulation system BRS1, while the electromechanical secondary actuator 5 is a component of a secondary brake regulation system BRS2. All actuators 3, 5 operate free of hydraulics.

[0031] The primary brake regulation system BRS1 is constructed in the FIGURE from a primary control unit 9 and the total of four electromechanical primary actuators 3, which are each assigned to one vehicle wheel brake 1. Moreover, the primary control unit 9 has one signal connection to a primary speed sensor 11 per vehicle wheel VL, VR, HR, HL.

[0032] The redundant secondary brake regulation system BRS2 has structurally equivalent components to the primary brake regulation system BRS1. Accordingly, the secondary brake regulation system BRS2 is constructed from one secondary control unit 13 and one electromechanical secondary actuator 5 per vehicle wheel. The secondary control unit 13 moreover has a signal connection to secondary speed sensors 15, which are provided on each vehicle wheel.

[0033] In normal driving operation, primary positioning signals y.sub.1 are generated in the primary control unit 9 on the basis of a setpoint deceleration specification V.sub.P generated in a pilot system 17 (for example a driver assistance system having ABS and EPS functions) and/or a setpoint deceleration specification V.sub.B generated on the part of the driver by means of a brake pedal 19. With the aid of the primary positioning signals y.sub.1, the respective electromechanical primary actuators 3 are activated to perform diverse braking or steering tasks.

[0034] The primary control unit 9 and the secondary control unit 13 are each supplied with electrical energy independently of one another by a primary vehicle electrical system 31 and a redundant secondary vehicle electrical system 33.

[0035] In the FIGURE, the brake pedal 19 is a foot pedal simulator unit having a pressure sensor 21 and a distance sensor 23. The foot pedal simulator unit converts the pedal movement detected by the two sensors 21, 23 into an electrical foot pedal signal which corresponds to the setpoint deceleration specification V.sub.B generated on the part of the driver.

[0036] In the FIGURE, the pilot system 17 moreover has a signal connection to the primary control unit 9 using a primary signal line 25, while the pilot system 17 has a signal connection to the secondary control unit 13 via a secondary signal line 27 independently thereof. In addition, the two control units 9, 13 are connected to one another by means of a connecting signal line 29. Items of status information can be exchanged between the two control units 9, 13 via the connecting signal line 29.

[0037] In normal driving operation, only the primary brake regulation system BRS1 is used in the illustrated embodiment variant, while the redundant secondary brake regulation system BRS2 is deactivated. If a diagnostic module in the primary control unit 9 detects a case of error in the primary brake regulation system BRS1, an error signal S.sub.F is generated, which is read out by the primary control unit 9 via the connecting signal line 29 in the secondary control unit 13. The secondary brake regulation system BRS2 thereupon takes over the implementation of the setpoint deceleration specifications V.sub.P, V.sub.B.

[0038] Alternatively thereto, both the primary brake regulation system BRS1 and also the secondary brake regulation system BRS2 can already be in use in normal driving operation, so that both brake regulation systems operate in parallel operation.

[0039] In addition, the electromechanical primary and secondary actuators 9, 13 each have a blocking function, by means of which the respective actuator 3, 5 blocks the assigned vehicle wheel by brake actuation in a parking situation.

LIST OF REFERENCE SIGNS

[0040] 1 vehicle wheel brake [0041] 2 brake caliper [0042] 3, 5 primary and secondary actuators [0043] 7 brake disk [0044] 9 primary control unit [0045] 11 primary speed sensor [0046] 12 hydraulic circuit [0047] 13 secondary control unit [0048] 15 secondary speed sensors [0049] 17 pilot system [0050] 19 brake pedal [0051] 21 pressure sensor [0052] 23 distance sensor [0053] 25 primary signal line [0054] 27 secondary signal line [0055] 29 connecting signal line [0056] 31 primary vehicle electrical system [0057] 33 secondary vehicle electrical system [0058] S.sub.F error signal [0059] V.sub.P, V.sub.B setpoint deceleration specifications [0060] y.sub.1, y.sub.2 positioning signals [0061] BRS1 primary brake regulation system [0062] BRS2 secondary brake regulation system