Brake system and method for controlling a brake system

Abstract

The invention relates to a brake system for a vehicle, comprising at least one brake (1a-1f), at least one sensor (3a-3l) for measuring a temperature of the at least one brake (1a-1f), and a control unit (4). The control unit (4) is configured for receiving an actuating signal demanding a brake actuation, and for receiving temperature data from the at least one sensor (3a-3l), indicating the temperature measured by the at least one sensor (3a-3l). The control unit (4) is further configured for effecting a brake torque of the at least one brake (1a-1f) based on the actuating signal. The control unit (4) is furthermore configured for controlling the brake torque of the at least one brake (1a-1f) based on the temperature data. The invention also relates to a method for controlling a brake system of a vehicle.

Claims

1. A brake system for a vehicle, comprising at least one brake, at least one sensor for measuring a temperature of the at least one brake, and a control unit, wherein the control unit is configured for receiving an actuating signal demanding a brake actuation, and for receiving temperature data from the at least one sensor, indicating the temperature measured by the at least one sensor, wherein the control unit is configured for effecting a brake torque of the at least one brake based on the actuating signal, and wherein the control unit is configured for controlling the brake torque of the at least one brake based on the temperature data.

2. The brake system according to claim 1, wherein, for a given actuating signal, the brake torque of the at least one brake is controlled in a closed loop control.

3. The brake system according to claim 1, wherein the at least one brake includes a first brake for braking a first wheel of the vehicle and a second brake for braking a second wheel of the vehicle, wherein the at least one sensor includes one or more first sensors for measuring at least one first temperature of the first brake and one or more second sensors) for measuring at least one second temperature of the second brake, wherein the control unit is configured for controlling the brake torque of the first brake and/or for the second brake based on the temperature data, the temperature data including the first and second temperatures.

4. The brake system according to claim 3, wherein the first wheel is a front wheel of the vehicle and the second wheel is a rear wheel of the vehicle, and the control unit is configured for adapting a front/rear brake-torque distribution based on the temperature data and/or wherein the first wheel is a left wheel of the vehicle and the second wheel is a right wheel of the vehicle and the control unit is configured for adapting a left/right brake-torque distribution based on the temperature data.

5. The brake system according to claim 1, wherein the at least one sensor has a temporal resolution of less than one second, preferably less than 0.1 seconds, particularly preferably less than 0.01 seconds and wherein the control unit is configured for adapting the brake torque for the at least one brake within less than one second, preferably less than 0.1 seconds, particularly preferably less than 0.01 seconds after a change in the temperature is detected by the at least one sensor.

6. The brake system according to claim 1, wherein the at least one sensor is configured for measuring the temperature at a friction part of the at least one brake, in particular at a brake disk.

7. The brake system according to claim 6, wherein the at least one sensor comprises two sensors for measuring the temperature on two opposing sides of the friction part, in particular on opposing sides of a brake disk.

8. The brake system according to claim1, wherein the at least one sensor is a contact sensor, in particular a sliding sensor, or an integrated sensor.

9. The brake system according to claim 1, wherein the at least one sensor is a contactless sensor, in particular a pyrometer.

10. The brake system according to claim 1, wherein an ABS and/or ESC system is controlled based on the temperature data, in particular based on the first and second temperature data.

11. The brake system according to claim 1, wherein the control unit has a memory containing a temperature model for the at least one brake, wherein the control unit is configured for comparing changes of the measured temperature with the temperature model, and wherein the control unit is configured for adjusting control of the brake torque(s) based on a deviation of the temperature changes from the temperature model.

12. The brake system according to claim 11, wherein the temperature model is provided for a brake disk of the at least one brake, the at least one sensor being configured for measuring the temperature of the at least one brake at the brake disk

13. The brake system according to claim 1, wherein the control unit is configured for receiving outside temperature data and is configured for adjusting control of the brake torque(s) based on the outside temperature data, in particular by calibrating a/the temperature model for the at least one brake based on the outside temperature.

14. The brake system according to claim 1, wherein the control unit is configured for receiving motion data, in particular indicating a vehicle speed, and wherein the control unit is configured for adjusting control of the brake torque(s) based on the motion data.

15. A method for controlling a brake system of a vehicle, in particular a brake system according to any of the preceding claims, comprising the steps: receiving an actuating signal demanding a brake actuation, receiving temperature data indicating a temperature of at least one brake of the brake system, effecting a brake torque of the at least one brake based on the actuating signal and controlling the brake torque based on the temperature data.

Description

[0030] The brake system and method are illustrated in an exemplary fashion in the appended figures. Therein,

[0031] FIG. 1 shows a brake system for a vehicle, and

[0032] FIG. 2(a) & FIG. 2(b) show brakes for the brake system, comprising different types of sensors.

[0033] FIG. 1 schematically depicts a brake system for a vehicle. The vehicle has four wheels 5a, 5b, 5c, 5d, each of which is equipped with a brake 1a, 1b, 1c, 1d, pertaining to the brake system. The brakes 1a, 1b, 1c, 1d are carried out as disk brakes, each having a brake disk 6a, 6b, 6c, 6d and a caliper 7a, 7b, 7c, 7d holding brake pads which can be pressed against the respective brake disk 6a, 6b, 6c, 6d for braking. The brakes 1a, 1b, 1c, 1d are in communication with a control unit 4, which, in turn, is connected to an actuating device 2 comprising a brake pedal. If the brake pedal of the actuating device 2 is actuated, the control unit 4 receives a corresponding actuating signal demanding a brake actuation, which actuating signal indicates an actuating force that is applied to the brake pedal of the actuating device. Depending on the amount of actuating force applied to the pedal, the brake system aims at stronger or gentler deceleration. The control unit 4 is also connected to an automatic vehicle control 12 which, when turned on, is able to send the actuating signal to the electronic control unit 4, demanding a brake actuation. If an actuating signal is received by the control unit 4, the control unit 4 effects a brake torque for each of the brakes 1a, 1b, 1c, 1d based on the actuating signal.

[0034] The brake system furthermore comprises a plurality of sensors 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h for measuring a temperature of the brakes 1a, 1b, 1c, 1d. Specifically, for each of the brakes 1a, 1b, 1c, 1d a pair of sensors is provided, measuring a temperature on opposing sides of the brake. The sensors may for instance be carried out as shown in FIG. 2(a) or FIG. 2(b). Temperature data, which indicates the temperature measured by each sensor 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, is forwarded to the control unit 4. Based on the temperature data which is received by the control unit 4, the control unit 4 controls the brake torque of the brakes 1a, 1b, 1c, 1d.

[0035] The control unit 4 thus carries out a method for controlling the brake system, wherein it receives an actuating signal demanding a brake actuation. Within the method, the control unit 4 furthermore receives the temperature data indicating the temperature of the brakes 1a, 1b, 1c, 1d of the brake system, and the control unit 4 effects a brake torque of the brakes 1a, 1b, 1c, 1d based on the actuating signal and controls the brake torque based on the temperature data.

[0036] For a given actuating signal, in particular while the actuating signal lasts due to, for instance, continued application of force to the brake pedal, the brake torque of the at least one brake is controlled in a closed loop control. As the temperature data is received during brake application, the brake torque is continuously adjusted in order to increase or reduce the temperature in the brakes 1a, 1b, 1c, 1d. As this adjustment of the brake torques results in a change of temperature for each of the brakes 1a, 1b, 1c, 1d, this change of temperature is again detected by the sensors 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h and, if determined necessary by the control unit 4, may prompt a further adjustment of the brake torque, and so on. The process may be terminated when the actuating signal stops. The brakes are then fully released.

[0037] In a possible braking scenario, this may mean that, while the actuating signal remains unchanged, the brake torque of one or more of the brakes 1a, 1b, 1c, 1d is changed in response to the temperature data. If a change in brake torque occurs for one of the brakes 1a, 1b, 1c, 1d, this may be in response to the temperature measured for that same brake, and/or in response to the temperature measured for one or all of the other brakes.

[0038] The control unit 4 is configured for adapting a front/rear brake-torque distribution and a left/right brake-torque distribution based on the temperature data.

[0039] The sensors 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h each have a temporal resolution of less than 0.1 seconds, or of less than 0.01 seconds, and the control unit 4 is configured for adapting the brake torque for the brakes 1a, 1b, 1c, 1d within less than 0.1 seconds, or within less than 0.01 seconds, after a change in the temperature is detected by any one of the sensors 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h.

[0040] The brake system includes an ABS 8 and an ESC 9, each of which is controlled based on the temperature data received by the sensors 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h. Specifically, if a brake actuation includes a control of the brakes by way of the ABS 8 or the ESC 9, the brake torques associated with this brake actuation are altered by the ABS 8 or the ESC 9, respectively. On top of this, a further control of the brake torques based on the temperature data takes place, in particular a closed loop control as described above, which further control aids the ABS 8 or the ESC 9.

[0041] The control unit 4 has a memory 10 containing a temperature model for the brakes 1a, 1b, 1c, 1d, including temperature models for the brake disks 6a, 6b, 6c, 6d of the brakes 1a, 1b, 1c, 1d, at which the temperatures are measured. The control unit 4 is configured for comparing changes of the measured temperature with the temperature model, and the control unit 4 is configured for adjusting control of the brake torque(s) based on a deviation of the temperature changes from the temperature model.

[0042] The brake system comprises a thermometer 11 configured for measuring an outside temperature. The control unit 4 receives outside temperature data form the thermometer 11 and adjusts control of the brake torque(s) based on the outside temperature data. This is done by calibrating the temperature model for the brakes 1a, 1b, 1c, 1d based on the received outside temperature.

[0043] The control unit 4 is also connected to a vehicle control and receives motion data, including data indicating a current vehicle speed, from the vehicle control. The control unit 4 adjusts control of the brake torques further, based on the motion data.

[0044] FIG. 2(a) and FIG. 2(b) show, in each case, a single disk brake 1e, 1f, each comprising a brake disk 6e, 6f and a brake caliper 7e, 7f. The brakes 1e, 1f are each equipped with a pair of sensors, 3i and 3j on the one hand, and 3k and 31, on the other hand. One or all of the brakes 1a, 1b, 1c, 1d shown in FIG. 1 and their respective sensors 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h may be designed as shown in FIG. 2(a) or in FIG. 2(b).

[0045] The brake 1e of FIG. 2(a) comprises two sensors 3i, 3j, configured for measuring the temperature on opposing sides of the brake disk 6e. The sensors 3i, 3j are designed as contact sensors, namely sliding sensors, having a contact member in touching engagement with the brake disk 6e.

[0046] The brake 1f of FIG. 2(b) comprises two sensors 3k, 31, configured for measuring the temperature on opposing sides of the brake disk 6f. The sensors 3i, 3j are each designed as contactless sensors, namely pyrometers, comprising a thermographic camera device.

LIST OF REFERENCE NUMERALS

[0047] 1a-1f brake

[0048] 2 actuating device

[0049] 3a-3l sensor

[0050] 4 control unit

[0051] 5a-5d wheel

[0052] 6a-6f brake disk

[0053] 7a-7f brake caliper

[0054] 8 ABS

[0055] 9 ESC

[0056] 10 memory

[0057] 11 thermometer

[0058] 12 automatic vehicle control