Method for controlling a vacuum pump of a brake booster of a vehicle, in particular a commercial vehicle, computer program and / or computer-readable medium, brake system, vehicle

Abstract

Method (100) for controlling a vacuum pump (270) of a brake booster (260) with a vacuum chamber (265) for a brake system (250) of a vehicle (200a), in particular a commercial vehicle (200b); wherein the method (100) comprises: detecting (110) a pressure (p) present in the vacuum chamber (265); detecting (115) a current atmospheric pressure (p1); determining (120) a control pressure (pC) based on the pressure (p), the current atmospheric pressure (p1) and an atmospheric pressure (p2) present under normal conditions; determining (130) a switching signal (280) for activating (281) and / or deactivating (282) the vacuum pump (270) depending on a threshold condition (285, 286) relating to the control pressure (pC); and output (140) of the switching signal (280).

Description

[0001] The present disclosure relates to a method for controlling a vacuum pump of a brake booster with a vacuum chamber for a braking system of a vehicle, in particular a commercial vehicle. The disclosure also relates to a computer program and / or computer-readable medium, a data processing device, a braking system for a vehicle, in particular a commercial vehicle; wherein the braking system comprises a brake booster with a vacuum chamber, a vacuum pump and the data processing device, and a vehicle, in particular a commercial vehicle.

[0002] Vacuum pumps are used for brake force amplification, particularly in pneumatic or hydraulic braking systems. Brake force amplification reduces the effort required by the driver of a vehicle, especially a commercial vehicle, to apply sufficient brake pressure via an actuating device, such as a brake pedal, to achieve the desired braking effect.

[0003] It is known to create a vacuum for brake force amplification using a pump coupled to an internal combustion engine and / or a mechanical pump, each drawing power from a primary drive. However, due to their dependence on the primary drive, such pumps exhibit an overall efficiency that could be improved.

[0004] Furthermore, electric vacuum pumps (EVP) are known from the prior art, for example to avoid power consumption by the primary drive caused by the aforementioned mechanisms and thus to decouple the brake force amplification from the primary drive.

[0005] In electrically powered vehicles, a drive for the vacuum pump by the vehicle's primary drive is typically not provided.

[0006] While mechanical pumps, for example, are kinematically connected to the internal combustion engine via a shaft to drive the pump and thus always run with the drive, a constant running of an electric vacuum pump can be avoided in order to reduce and / or prevent unnecessary wear of the vacuum pumps.

[0007] It is known how to switch the electric vacuum pump on and off. This switching can be triggered, for example, by the vacuum pressure range. In this scenario, a switch-on pressure and a switch-off pressure are programmed into a control unit, and the switching is carried out by a relay controlled by the control unit.

[0008] However, ambient pressure can change. Ambient pressure depends particularly on altitude and temperature. Therefore, the switching on and off times must be adjusted to prevent, for example, continuous operation of the vacuum pump when the ambient pressure has already fallen below a cut-off pressure.

[0009] EP 2 726 351 A1 discloses a method for deactivating an electric vacuum pump of a vacuum brake booster of a vehicle, the method comprising: detecting the vacuum level in the brake booster; detecting the ambient air pressure; determining a pump deactivation threshold as a percentage of the maximum available vacuum with reference to the detected atmospheric pressure; and deactivating the pump when the level reaches the deactivation threshold.

[0010] Against the background of this prior art, one objective of the present disclosure is to provide a device and a method, each of which is suitable for enriching the prior art and improving at least the aforementioned aspects of the prior art. In particular, the disclosure aims to provide an alternative and enhanced method for dealing with different atmospheric pressures.

[0011] The problem is solved by the features of the independent claims. The dependent claims contain further developments of the disclosure.

[0012] The problem is then solved according to one aspect of the disclosure by a method for controlling a vacuum pump of a brake booster with a vacuum chamber for a braking system of a vehicle, in particular a commercial vehicle; wherein the method comprises: detecting a pressure present in the vacuum chamber; detecting a current atmospheric pressure; determining a control pressure based on the pressure, the current atmospheric pressure and an atmospheric pressure present under normal conditions; determining a switching signal for activating and / or deactivating the vacuum pump depending on threshold conditions relating to the control pressure; and outputting the switching signal.

[0013] It was recognized that the operation of the vacuum pump, particularly its activation and deactivation, can be influenced by the current atmospheric pressure. Instead of adjusting a threshold, for example, it is proposed that the vacuum pump be operated using a control pressure. This control pressure is then used, rather than the current atmospheric pressure, to check the threshold conditions. Using the control pressure eliminates the need to adjust multiple threshold conditions, such as those for activating and deactivating the vacuum pump, which is numerically efficient and thus saves hardware resources.

[0014] Optionally, the control pressure is proportional to a quotient of the atmospheric pressure under standard conditions and the current atmospheric pressure. This quotient can be interpreted as a correction factor for the current atmospheric pressure, allowing the control pressure to be calculated based on the current atmospheric pressure.

[0015] Optionally, the control pressure is proportional to the pressure present in the vacuum chamber. This allows the pressure present in the vacuum chamber to be directly and efficiently converted into the control pressure using a correction factor.

[0016] Optionally, the threshold conditions define a first pressure threshold; and the switching signal is determined to activate the vacuum pump when the control pressure exceeds this first pressure threshold. It was found that this method can be used to activate the vacuum pump. If the first pressure threshold is exceeded, and the vacuum in the vacuum chamber is therefore comparatively weak, the vacuum pump must be activated to generate a stronger vacuum.

[0017] Optionally, the threshold conditions define a second pressure threshold; and the switching signal is determined to deactivate the vacuum pump when the control pressure falls below this second pressure threshold. It was found that this method can be used to deactivate the vacuum pump. If the second pressure threshold is undershot, meaning the vacuum in the vacuum chamber is comparatively strong, the vacuum pump must be deactivated because a sufficient vacuum has been created and / or a stronger vacuum cannot be generated.

[0018] Optionally, the second pressure threshold is lower than the maximum vacuum level corresponding to the vacuum pump. It was recognized that by correcting the pressure, it is possible to take the maximum vacuum level into account. The second pressure threshold can therefore define a lower vacuum level than the maximum vacuum level.

[0019] According to one aspect of the disclosure, a computer program and / or a computer-readable medium is provided. The computer program and / or the computer-readable medium includes instructions that, when executed by a data processing device, cause the device to perform the method according to the disclosure and / or steps thereof. Optionally, the computer program and / or the computer-readable medium includes instructions that, when executed by a data processing device, cause the device to perform the process steps described as advantageous or optional in order to achieve an associated technical effect.

[0020] According to one aspect of the disclosure, a data processing device for the braking system of a vehicle, in particular a commercial vehicle, is provided. The data processing device is configured to carry out the method according to the disclosure. Optionally, the data processing device is configured to carry out a method step described as advantageous or optional and / or to implement a method feature in order to achieve an associated technical effect.

[0021] According to one aspect of the disclosure, a braking system for a vehicle, in particular a commercial vehicle, is provided; wherein the braking system comprises a brake booster with a vacuum chamber, a vacuum pump, and the data processing device according to the disclosure. Optionally, the data processing device is configured to perform a process step described as advantageous or optional and / or to implement a process feature in order to achieve an associated technical effect.

[0022] According to one aspect of the disclosure, a vehicle, in particular a commercial vehicle, is provided; wherein the vehicle, in particular a commercial vehicle, comprises the braking system according to the disclosure. Optionally, the braking system and / or the vehicle, in particular a commercial vehicle, is configured to perform a process step described as advantageous or optional and / or to implement a process feature in order to achieve an associated technical effect.

[0023] One embodiment of each is described below with reference to the figures. Fig. Figure 1 schematically shows a vehicle, in particular a commercial vehicle, according to one aspect of the disclosure; Fig. 2 schematically shows a flowchart of a procedure according to an aspect of the revelation; Fig. Figure 3 shows a schematic representation of a computer program and / or computer-readable medium according to one aspect of the revelation; Fig. Figure 4 schematically shows components of a braking system according to one aspect of the disclosure; and Fig. Figure 5 schematically shows an alternative representation of a flowchart of a procedure according to one aspect of the disclosure.

[0024] Fig. Figure 1 schematically shows a vehicle 200a, in particular a commercial vehicle 200b, according to one aspect of the disclosure. The vehicle 200a, in particular the commercial vehicle 200b, is hereinafter referred to as vehicle 200a, 200b. The vehicle 200a, 200b is a land vehicle. The vehicle 200a, 200b is, for example, a towing vehicle of a multi-unit towing vehicle-trailer combination, a single-unit vehicle, and / or a passenger car.

[0025] The vehicle 200a, 200b has a braking system 250. The braking system 250 is designed to generate a braking torque. The braking system 250 can exert a braking torque on a wheel and / or an axle. For this purpose, a driver of the vehicle 200a, 200b can initiate a braking request via an actuating device 263, for example, a foot pedal.

[0026] The brake system 250 comprises a brake booster 260 with a vacuum chamber 265, a vacuum pump 270, and a data processing device 251. The brake system 250, or rather the data processing device 251, is configured to process the information related to Fig. 2 and Fig. 5 described procedures to be carried out 100 times.

[0027] The data processing device 251 according to Fig. 1 is designed to detect a pressure p present in the low-pressure chamber 265 and a current atmospheric pressure p1.

[0028] The data processing device 251 is configured to determine a control pressure pC. The control pressure pC is determined based on the pressure p, the current atmospheric pressure p1, and an atmospheric pressure p2 present under normal conditions. The control pressure pC is proportional to a quotient of the atmospheric pressure p2 present under normal conditions and the current atmospheric pressure p1. The control pressure pC is proportional to the pressure p present in the vacuum chamber 265.

[0029] The data processing device 251 is configured to determine a switching signal 280 to activate 281 and / or deactivate 282 the vacuum pump 270 depending on the threshold conditions 285, 286 relating to the control pressure pC.

[0030] The data processing device 251 is configured to output the switching signal 280.

[0031] Further features of the 250 braking system are related to Fig. 4 described.

[0032] Fig. Figure 2 schematically shows a flowchart of a procedure 100 according to one aspect of the disclosure. The procedure 100 according to Fig. 2 is a method 100 for controlling a vacuum pump 270 of a brake booster 260 with a vacuum chamber 265 for a brake system 250 of a vehicle 200a, in particular a commercial vehicle 200b. Such a vehicle 200a, 200b and such a brake system 250 are related to Fig. 1 described. Fig. 2 is referred to Fig. 1 described.

[0033] The procedure 100 according to Fig. 2 indicates: Detecting 110 a pressure p present in the vacuum chamber 265. For this purpose, the data processing device 251 is connected to a pressure sensor 252 via communication technology, and the pressure sensor 252 is configured to sensing the pressure p present in the vacuum chamber 265.

[0034] Method 100 comprises: Detecting 115 a current atmospheric pressure p1. For this purpose, the data processing device 251 is connected to an ambient pressure sensor 240 via communication technology, and the ambient pressure sensor 240 is configured to sensing the current atmospheric pressure p1.

[0035] Procedure 100 is described as follows: Determine 120 a control pressure pC based on the pressure p, the current atmospheric pressure p1, and the atmospheric pressure p2 present under normal conditions. The control pressure pC is proportional to the quotient of the atmospheric pressure p2 present under normal conditions and the current atmospheric pressure p1. The control pressure pC is proportional to the pressure p present in the vacuum chamber 265. The control pressure pC can be determined as the product of the aforementioned quantities, i.e., pC = px p2 / p1.

[0036] Method 100 comprises: Determining 130 a switching signal 280 to activate 281 and / or deactivate 282 the vacuum pump 270 as a function of the threshold conditions 285, 286 relating to the control pressure pC. The control pressure pC is compared with the pressure thresholds 285a, 286a defining the threshold conditions 285, 286 (see Fig. 5) Threshold conditions 285 and 286 define a first pressure threshold 285a. The switching signal 280 is determined to activate 281 the vacuum pump 270 when the first pressure threshold 285a is exceeded by the control pressure pC. Threshold conditions 285 and 286 define a second pressure threshold 286a. The second pressure threshold 286a is lower than a maximum vacuum level 287 corresponding to the vacuum pump 270. The switching signal 280 is determined to deactivate 282 the vacuum pump 270 when the second pressure threshold 286 is not reached by the control pressure pC.

[0037] Method 100 includes: Outputting the switching signal 280 (140). The switching signal 280 is output to activate or deactivate the vacuum pump 270.

[0038] The expert recognizes that the procedure 100 according to Fig. 2. The procedure can also be carried out in a different order than shown. In particular, it is possible to swap, shift, repeat and / or perform steps of procedure 100 simultaneously.

[0039] Fig. Figure 3 shows a schematic representation of a computer program and / or computer-readable medium 200 according to one aspect of the disclosure. The computer program and / or computer-readable medium 200 comprises instructions 201 which, when the program or instructions 201 are executed by a data processing device 251, cause it to execute the method 100 and / or the steps of the method 100 according to Fig. 2 to be carried out.

[0040] The commands 201 can be in the form of program code in any code or language, in particular code suitable for controlling and / or monitoring vehicles 200a, 200b and / or braking systems 250. The computer program and / or computer-readable medium 200 can be or comprise any digital data storage device, such as a USB flash drive, hard drive, CD-ROM, SD card, or SSD card. The computer program need not necessarily be stored on such a computer-readable storage medium, but can also be accessed via the Internet or otherwise.

[0041] Fig. Figure 4 schematically shows components of a brake system 250 according to one aspect of the disclosure. The brake system 250 is the one relating to Fig. 1 described brake system 250. Fig. 4 is referred to Fig. 1, Fig. 2 to Fig. 3 described.

[0042] The braking system 250 comprises an actuating device 253. The actuating device 253 is, for example, a pedal, in particular a brake pedal.

[0043] The braking system 250 includes the brake booster 260. The brake booster 260 is operatively connected to the actuating device 253 in order to amplify a braking force applied by the actuating device 253.

[0044] The brake booster 260 includes a vacuum chamber 265. The vacuum chamber 265 is a section of the brake booster 260 which is designed to create a pressure p as a vacuum relative to a current atmospheric pressure p1 by means of suction.

[0045] The brake system 250 has a pressure sensor 252. The pressure sensor 252 is designed to sensing the pressure p in the vacuum chamber 265.

[0046] The brake system 250 includes an ambient pressure sensor 240. The ambient pressure sensor 240 is configured to sensing the current atmospheric pressure p1 in the environment of the vehicle 200a, 200b.

[0047] The brake system 250 includes the data processing device 251 (electronic control unit, ECU). The data processing device 251 is communicatively connected to the pressure sensor 252 in order to detect the pressure p sensed by the pressure sensor 252. The data processing device 251 is communicatively connected to the ambient pressure sensor 240 in order to detect the current atmospheric pressure p1 sensed by the ambient pressure sensor 240.

[0048] As an alternative to or in addition to the ambient pressure sensor 240, the braking system 250 can include an altitude sensor 241 and a temperature sensor 242 and / or be communicatively connected to the altitude sensor 241 and the temperature sensor 242. This allows the current altitude and temperature to be sensed. This information can be processed by the data processing device 251 to determine the current atmospheric pressure p1.

[0049] The brake system 250 comprises an electric or electrically driven vacuum pump 270. The vacuum pump 270 is designed to extract air from the vacuum chamber 265 and thus achieve the pressure p present in the vacuum chamber 265. For this purpose, the vacuum pump 270 has a pump drive 271 and / or is operatively connected to it. The pump drive 271 can be supplied with electrical energy to operate the vacuum pump 270.

[0050] The brake system 250 includes an electrical fuse 276 and a switching device 275, for example, a relay. The electrical fuse 276 is configured to electrically protect the switching device 275 and / or the pump drive 271. The switching device 275 is configured to switch, i.e., to activate and deactivate, the pump drive 271. For this purpose, the data processing device 251 and the switching device 275 are connected by communication technology, and the data processing device 251 is configured to transmit a switching signal 280 to the switching device 275. The switching device 275 is configured to switch the pump drive 271 according to the switching signal 280, thereby activating or deactivating the vacuum pump 270.

[0051] Fig. Figure 5 schematically shows an alternative representation of a flowchart of a process 100 according to one aspect of the disclosure. The process 100 is the one relating to Fig. 2 described procedures 100. Fig. 5 is referred to Fig. 1, Fig. 2, Fig. 3 to Fig. 4 described.

[0052] Procedure 100 begins with a start 101. Initially, the first pressure threshold 285a, the second pressure threshold 286a, and a maximum vacuum level 287 are defined. The first pressure threshold 285a is lower than the second pressure threshold 286a. The maximum vacuum level 287 is higher than both the first pressure threshold 285a and the second pressure threshold 286a.

[0053] The maximum vacuum level 287 indicates the maximum vacuum level that can be generated by the vacuum pump 270. The first pressure threshold 285a, the second pressure threshold 286a, and the maximum vacuum level 287, for example, characterize a difference from a standard pressure p2 or an atmospheric pressure p2 present under normal conditions.

[0054] This is followed by the measurement of the pressure p prevailing in the low-pressure chamber 265 and the measurement of the current atmospheric pressure p1.

[0055] The determination of the control pressure pC follows. The control pressure pC is equal to the product of the pressure p and the atmospheric pressure p2 prevailing under normal conditions divided by the current atmospheric pressure p1, i.e., pC = px p2 / p1, where p2 is the atmospheric pressure prevailing under normal conditions.

[0056] The control pressure pC is checked to determine the switching signal 280 with regard to threshold conditions 285 and 286. Threshold conditions 285 and 286 define the first pressure threshold 285a and the second pressure threshold 286a, respectively. The switching signal 280 is used to activate the vacuum pump 270 when the control pressure pC exceeds the first pressure threshold 285a. The switching signal 280 is used to deactivate the vacuum pump 270 when the control pressure pC falls below the second pressure threshold 286a. Threshold conditions 285 and 286 can define the operation of the vacuum pump 270 at atmospheric pressure p2. Threshold conditions 285 and 286 are thus independent of the current atmospheric pressure p1. Reference symbol (part of the description) 100 procedures 101 Start 110 Capture 115 Capture 120 Determine 130 Determine Spend 140 200a vehicle 200b commercial vehicle 240 ambient pressure sensor 241 Altitude sensor 242 Temperature sensor 250 braking system 251 Data processing device 252 Pressure sensor 253 Actuating device 260 brake booster 265 Low-pressure chamber 270 vacuum pump 271 Pump drive 275 Switching device 276 fuse 280 switching signal 281 Activate 282 Deactivate 285 Threshold condition 285a first pressure threshold 286 Threshold condition 286a second pressure threshold 287 Maximum vacuum level 300 computer program and / or computer-readable medium 301 commands p pressure, pressure present in a vacuum chamber p1 Atmospheric pressure, current atmospheric pressure p2 atmospheric pressure present under normal conditions, normal pressure pC control pressure QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 2 726 351 A1

[0009]

Claims

Method (100) for controlling a vacuum pump (270) of a brake booster (260) with a vacuum chamber (265) for a brake system (250) of a vehicle (200a), in particular a commercial vehicle (200b); wherein the method (100) comprises: - detecting (110) a pressure (p) present in the vacuum chamber (265); - detecting (115) a current atmospheric pressure (p1); - determining (120) a control pressure (pC) based on the pressure (p), the current atmospheric pressure (p1) and an atmospheric pressure (p2) present under normal conditions; - determining (130) a switching signal (280) for activating (281) and / or deactivating (282) the vacuum pump (270) depending on the threshold conditions (285, 286) relating to the control pressure (pC); and output (140) of the switching signal (280). Method (100) according to claim 1, wherein the control pressure (pC) is proportional to a quotient of the atmospheric pressure (p2) prevailing under normal conditions and the current atmospheric pressure (p1). Method (100) according to claim 1 or 2, wherein the control pressure (pC) is proportional to the pressure (p) present in the vacuum chamber (265). Method (100) according to one of the preceding claims, wherein- the threshold conditions (285, 286) define a first pressure threshold (285a); and- the switching signal (280) for activating (281) the vacuum pump (270) when the first pressure threshold (285a) is exceeded by the control pressure (pC). Method (100) according to one of the preceding claims, wherein- the threshold conditions (285, 286) define a second pressure threshold (286a); and- the switching signal (280) for deactivating (282) the vacuum pump (270) when the second pressure threshold (286a) is undershot by the control pressure (pC). Method (100) according to claim 5, wherein the second pressure threshold (286a) is smaller than a maximum vacuum level (287) corresponding to the vacuum pump (270). Computer program and / or computer-readable medium (300), comprising instructions (301) which, when the program or instructions (301) are executed by a data processing device (251), cause the device to perform the method (100) and / or the steps of the method (100) according to any one of claims 1 to 6. Data processing device (251) for a braking system (250) of a vehicle (200a), in particular a commercial vehicle (200b), wherein the data processing device (251) is configured to perform the method (100) according to any one of claims 1 to 6. Braking system (250) for a vehicle (200a), in particular a commercial vehicle (200b); wherein the braking system (250) comprises a brake booster (260) with a vacuum chamber (265), a vacuum pump (270) and the data processing device (251) according to claim 8. Vehicle (200a), in particular commercial vehicle (200b); wherein the vehicle (200a), in particular commercial vehicle (200b), comprises the braking system (250) according to claim 9.

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