METHOD FOR PERFORMING BRAKE DISC CLEANING OF A VEHICLE

Abstract

A method for performing brake disc cleaning of an at least partially electrically driven vehicle including a brake system with at least one friction brake, the surface of which can be brought into contact with a corresponding brake disc, the method includes: determining an upcoming brake event by using at least vehicle-ahead information, predicting a needed deceleration level of an ego-vehicle by using the vehicle-ahead information, and carrying out a brake disc cleaning of the friction brake only in case the needed deceleration level of the ego-vehicle in the upcoming brake event is predicted as being above a predefined value.

Claims

1. A method for performing brake disc cleaning of an at least partially electrically driven vehicle comprising a brake system with at least one friction brake, a surface of the friction brake brought into contact with a corresponding brake disc, the method comprising: determining an upcoming brake event of the at least partially electrically driven vehicle by using at least vehicle-ahead information of a vehicle ahead, predicting a needed deceleration level of the at least partially electrically driven vehicle by using the vehicle-ahead information, and carrying out the brake disc cleaning of the friction brake of the at least partially electrically driven vehicle only in case the needed deceleration level of the at least partially electrically driven vehicle in the upcoming brake event is predicted as being above a predefined value.

2. The method according to claim 1, the vehicle-ahead information comprising at least one of a time gap to the vehicle ahead, a predicted deceleration needed and a brake energy anticipated.

3. The method according to claim 1, further information comprising at least one of an adaptive regenerative braking force and a driver behavior information being combined with the vehicle-ahead information.

4. The method according to claim 1, the prediction of the needed deceleration level of the at least partially electrically driven vehicle being carried out by: determining a safety distance to the vehicle ahead, calculating an adaptive regeneration brake force, determining a required braking force based on the mass of the at least partially electrically driven vehicle and an estimated road load, and determining a required brake energy and brake power.

5. The method according to claim 1, the brake event being triggered when at least one of the following conditions is fulfilled: the adaptive regeneration brake force exceeds a predetermined level and/or rate, a determined speed difference between the at least partially electrically driven vehicle and the vehicle ahead exceeds a predetermined speed, an accelerator pedal release rate exceeds a predetermined value, and a driver requested brake torque exceeds a predetermined value.

6. The method according to claim 1, in case a one-pedal-drive is applicable, at least one of the following conditions needs to be fulfilled: the adaptive regeneration brake force exceeds a predetermined level and/or rate, a determined speed difference between the at least partially electrically driven vehicle and the vehicle ahead exceeds a predetermined speed, an accelerator pedal position is below a predetermined value, and a driver requested brake torque rate exceeds a predetermined value.

7. A non-transitory computer-readable medium comprising instructions stored in a memory and executed by a processor to carry out steps comprising: for performing brake disc cleaning of an at least partially electrically driven vehicle comprising a brake system with at least one friction brake, a surface of the friction brake brought into contact with a corresponding brake disc, determining an upcoming brake event of the at least partially electrically driven vehicle by using at least vehicle-ahead information of a vehicle ahead, predicting a needed deceleration level of the at least partially electrically driven vehicle by using the vehicle-ahead information, and carrying out the brake disc cleaning of the friction brake of the at least partially electrically driven vehicle only in case the needed deceleration level of the at least partially electrically driven vehicle in the upcoming brake event is predicted as being above a predefined value.

8. An at least partially electrically driven electric vehicle, comprising: a brake system with at least one friction brake, a surface of the friction brake brought into contact with a corresponding brake disc, one or more units configured to acquire vehicle-ahead information, one or more units configured to acquire vehicle information of the at least partially electrically driven vehicle, and at least one control unit configured to: for performing brake disc cleaning, determining an upcoming brake event of the at least partially electrically driven vehicle by using at least vehicle-ahead information of a vehicle ahead, predicting a needed deceleration level of the at least partially electrically driven vehicle by using the vehicle-ahead information, and carrying out the brake disc cleaning of the friction brake of the at least partially electrically driven vehicle only in case the needed deceleration level of the at least partially electrically driven vehicle in the upcoming brake event is predicted as being above a predefined value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Exemplary examples of the disclosure will be described in the following with reference to the following drawings.

[0045] FIG. 1 shows a schematic diagram of an exemplary example of the method for performing brake disc cleaning.

[0046] FIG. 2 shows an abstract diagram of measurements of an adaptive regeneration force function of an exemplary example of the method for performing brake disc cleaning.

[0047] FIG. 3 shows steps of the method for performing brake disc cleaning of an exemplary example.

[0048] The figures are merely schematic representations and serve only to illustrate examples of the disclosure. Identical or equivalent elements are in principle provided with the same reference signs.

DESCRIPTION OF EMBODIMENTS

[0049] FIG. 1 shows a schematic diagram of an exemplary example of the method for performing brake disc cleaning. Here, information is shown that is needed in order to carry out the prediction of the deceleration level in order to decide, whether a brake disc cleaning is to be done or not.

[0050] As can be seen, information is collected in a central module 10, which can process the information and also instruct the braking system 200, 201. The braking system 200, 201 is indicated as brake control module 200 for friction brakes, of which the brake discs need to be cleaned e.g. from rust, and an electric motor unit 201, which is responsible for regeneration braking. In order for the central module 10 to instruct the braking module 200, 201, information from units 100 for environmental observation such as cameras, radar and other sensors, as well as driver behavior information from unit 101 and needed brake energy from the brake disc model 102 of the vehicle are necessary.

[0051] Driver behavior information is mainly the status of the acceleration and brake pedals or from the single pedal, being adapted for accelerating and braking in case of a one pedal drive.

[0052] When all necessary information is available, the central module 10 calculates the predicted brake force (in N) and converts it into energy (in J). This energy is compared with needed brake energy (in J) for the upcoming brake event. Then, a level for friction brake torque as well as for regeneration brake torque is calculated.

[0053] As soon as the accelerator pedal is released or the brake pedal is pressed (in one pedal configuration only as soon as the pedal is released in a predetermined position), the request for applying the respective torques is sent to the modules 200 and 201 for acting accordingly, thus activating brake disc cleaning.

[0054] In one example, the following conditions need to be fulfilled to send the request: [0055] adaptive regeneration force has an absolute level of 1500N and a rate of >300 N/s, [0056] speed difference between ego-vehicle and vehicle ahead is >10 km/h, [0057] accelerator pedal release rate is >X %/s and accelerator pedal position is <Y % (in one pedal drive), where X and Y are predefined values depending on the vehicle and its configuration, and [0058] driver requested brake torque is >V Nm and driver requested brake torque rate is >W Nm/s (in one pedal drive), where V and W are predefined values depending on the vehicle and its configuration.

[0059] In FIG. 2, an abstract diagram of measurements of an adaptive regeneration force function of an exemplary example of the method for performing brake disc cleaning is shown. Here, the possible need to brake was registered (indicated by the dotted graph) about 1.63 seconds before the driver requested brake force (indicated with the rising flank of the continuous line). As can be seen, the release rate of accelerator pedal or driver brake request rise rate can be used as a hint/trigger of upcoming high deceleration demand, and thus prepare to engage friction brakes primarily in order to clean brake discs.

[0060] With the suggested method, it is possible to minimize the activation of disc cleaning application, by predicting the use of friction brake at upcoming brake events. Only in case a needed deceleration level of the vehicle is predicted as high enough (exceeding a predefined value) and thus high brake energy is expected in an upcoming brake event, the brake disc cleaning is carried out. Hence, the unnecessary use of friction brakes can be minimized.

[0061] Other variations to the disclosed examples can be understood and effected by those skilled in the art in practicing the claimed invention, from the study of the drawings, the disclosure, and the appended claims. In the claims the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items or steps recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/distributed on a suitable non-transitory computer-readable medium such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, including a processor and a memory, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope of the claims.