Method for filling a brake system of a vehicle and control device for a brake system of a vehicle

Abstract

The present invention relates to a method for filling a brake system (100) of a vehicle (104), wherein a filling facility (106) is connected to the brake system (100), a control device (102) of the brake system (100) is actuated, and the control device (102) monitors a pressure signal (136) of a pressure sensor (134) of the brake system (100) in order to identify a filling process (200) carried out by the filling facility (106). In response to the identification of the start (212) of the filling process (200), a valve (128) of the brake system (100) is actuated by the control device (102), and in response to the identification of the end (218) of the filling process (200), the valve (128) is deactivated by the control device (102).

Description

Technical Field

[0001] Field of the Invention The present invention relates to a method for filling a vehicle brake system, a control device for a vehicle brake system, and a corresponding computer program product.

Background Art

[0002] A vehicle brake system can be filled for the first time during vehicle manufacture. For this purpose, for example, a filling head of a filling facility can be placed over a reservoir of a master brake cylinder. To avoid air ingress, air can be sucked from the brake system via the filling head and the brake system emptied of air can then be filled with brake fluid. The brake fluid can be filled into the brake system by positive pressure.

[0003] If the brake system includes, for example, ABS or ESP, the brake system has a secondary circuit that is disconnected from the brake circuit of the brake system by a valve that is closed when no current is flowing. The closed valve makes it impossible to suck air from the secondary circuit and impossible for brake fluid to reach the secondary circuit during filling. Therefore, the secondary circuit can be pre-filled with brake fluid at a separate filling station before assembly into the vehicle. The closed valve makes it impossible for the brake fluid to flow out.

[0004] Alternatively, to connect the secondary circuit to the brake circuit, the valve can be driven to actively open during filling by the filling facility. For this purpose, the filling facility can be connected to the vehicle's data bus via an adapter, whereby a control command for opening the valve can be sent to the brake system.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Disclosure of the Invention Based on such a background, according to the approach presented in this specification, a method for filling a brake system of a vehicle, a control device for a brake system of a vehicle, and a corresponding computer program product as described in the independent claims are presented. Advantageous developments and improvements of the approach presented in this specification will become apparent from the specification and are described in the dependent claims.

Means for Solving the Problem

[0006] Advantages of the Invention For example, by generating a strong negative pressure or vacuum in the brake system, then increasing the pressure to fill the brake fluid, and finally decreasing the pressure to ambient pressure, the filling process will have a characteristic pressure transition. The pressure transition may vary for each type of brake system, but is known for each type of brake system.

[0007] In the approach presented in this specification, at least one control device of the brake system is actuated during the filling process. At least one pressure sensor of the brake system is connected to the control device and can communicate with the control device. The pressure sensor is used to detect the pressure transition of the filling process. The control device stores at least the sample points of the pressure transition expected for this brake system. The control device evaluates the pressure information provided by the pressure sensor and compares this pressure information with the stored information to identify the filling process. The control device is also connected to the valve drive device of the brake system. When the filling process is identified, the control device drives the valve drive device required to connect the secondary circuit to the brake circuit, thereby connecting the secondary circuit to the brake circuit.

[0008] According to the approach presented in this specification, the data connection between the filling equipment and the braking system becomes unnecessary and can be omitted. This omission can save costs and time. In particular, an adapter for connecting the filling equipment to the vehicle's data bus becomes unnecessary. The insertion and removal of the adapter are also omitted. As a result, the time required to reach the data bus interface twice, which would otherwise be necessary, is also omitted.

[0009] The omission of the data line also eliminates the need for protocol compatibility between the filling equipment and the vehicle. Therefore, the development costs related to the software of the filling equipment and the control device can be reduced.

[0010] A method for filling a vehicle's braking system, in which a filling equipment is connected to the braking system, the control device of the braking system is activated, and the control device monitors the pressure signal of the pressure sensor of the braking system to identify the filling process implemented by the filling equipment. In response to the identification of the start of the filling process, the valve of the braking system is activated by the control device, and in response to the identification of the end of the filling process, the valve is deactivated by the control device, is proposed.

[0011] The inspiration for the embodiments of the present invention can be considered to be based in particular on the ideas and knowledge described below.

[0012] The braking system may be assembled to the vehicle in a dry state. To transition the braking system to a functional state, an initial filling of brake fluid is necessary. The filling should be carried out without air bubbles. The filling process can be performed by filling equipment from outside the vehicle. The filling process may have a vacuum phase and a pressurization phase. In the vacuum phase, air can be removed from the braking system, or the braking system can be degassed. In the pressurization phase, the braking system can be filled with brake fluid. The filling process can be incorporated into the vehicle's production line as an assembly step. The filling process can be carried out during the manufacture of the vehicle. For filling, the filling head of the filling equipment can be placed over and pressure-tightly connected to the master brake cylinder or the reservoir of the master brake cylinder. The filling head can be connected to the filling equipment via a tube line. The filling equipment may have, for example, a vacuum pump and a pressurization pump.

[0013] The braking system may have two separate brake circuits and a plurality of secondary circuits. At least one secondary circuit can be used to adjust the brake pressure within the brake circuit. A plurality of valves can be arranged between each brake circuit and the secondary circuit. These valves can be driven by one or more control devices of the braking system. These valves can be arranged in a valve block of the braking system. The secondary circuit can extend between a plurality of valves inside the valve block. The valves may be closed by a return spring, for example, in a de-energized state. One or more control devices can be connected to the valve block. To open the valves, a control signal to the valve drive device of the valves may be required. These control signals can be generated by at least one control device. The control device may be referred to as a brake adjustment control device and can drive the valves, for example, for the vehicle's ABS and / or ESP during the operation of the vehicle.

[0014] To fill the braking system, the control device can be operated in the manufacturing mode. After filling, the manufacturing mode can be deactivated. Alternatively, at the end of the production line, the manufacturing mode may be deactivated.

[0015] The control device can be activated by energization. For this purpose, for example, the battery voltage can be connected to the terminals of the control device. The battery voltage can be provided via the vehicle's cable harness. Alternatively, the energization of the control device can also be carried out separately, for example, via an adapter or a terminal. The battery voltage may be provided from the vehicle's battery or may be provided by an external energy source such as a power supply. Similarly, the battery voltage may be provided by a voltage converter from the traction voltage of the vehicle's traction battery. Alternatively, the energization of the control device may be carried out via the filling head. An additional signal may be required for activation. This signal can be referred to as, for example, a wake-up signal or ignition.

[0016] By operating the control device, the pressure sensor of the braking system can be energized. When the pressure sensor is energized, the pressure sensor can detect the pressure in the braking system and map it in a pressure signal. When the control device is operating, a pressure reference value for mapping the ambient pressure can be stored. The pressure sensor may be configured in particular to detect positive pressure. The pressure sensor may have an operating range, for example, from 1 bar to several hundred bar. Negative pressure may be outside this operating region, but negative pressure can also be mapped in the pressure signal. Due to the wide operating range, negative pressure may be mapped with low accuracy in the pressure signal.

[0017] The start and / or end of the filling process can be characterized by characteristic pressure changes. For example, the start and / or end can be identified by monitoring the progression of the pressure signal and / or by reaching a stored threshold value. When actuating the valve, the valve can be continuously switched by the valve drive of the valve. When deactivating, the valve drive can be switched off and the valve can be switched to the blocked state by the return spring of the valve.

[0018] The control device can identify the vacuum phase and the pressurization phase using the pressure signal. In order to degas the secondary circuit, the valve can be actuated or switched to the open state during the vacuum phase. The valve can be deactivated or switched to the blocked state at the end of the pressurization phase. In order to identify the vacuum phase, for example, the negative pressure in the brake system mapped in the pressure signal can be identified. In this case, the vacuum phase can already be started before the pressure sensor is able to map the negative pressure in the pressure signal. Due to the already existing negative pressure in the brake circuit, the secondary circuit can be degassed particularly quickly. The vacuum phase can follow a preceding preparation phase. The preparation phase can have characteristic pressure progression. The control device can identify the end of the preparation phase and, after the end of the preparation phase, identify the start of the vacuum phase.

[0019] After the vacuum phase has been identified, the valve can be actuated with a time shift. By actuating the valve, it is possible to wait until a strong negative pressure is highly likely to be formed in the brake circuit. In that case, the secondary circuit can be degassed particularly rapidly.

[0020] After the filling process is completed, the control device can operate the pump of the braking system to empty at least one low-pressure accumulator of the braking system. The braking system can have at least one low-pressure accumulator. In particular, the braking system can have one low-pressure accumulator per braking circuit. During the adjustment operation of the braking system, the brake fluid in the low-pressure accumulator can be stored intermediate to adjust the brake pressure in the braking circuit by opening at least one valve. Subsequently, the pump of the braking system can pump the brake fluid back from the low-pressure accumulator to the braking circuit. The braking system can have one pump per low-pressure accumulator. The low-pressure accumulator and the pump can be arranged in a valve block.

[0021] After the filling process is completed, the filling equipment can suck excess brake fluid from the reservoir of the braking system to set a predetermined level in the reservoir. This process can be referred to as leveling of the braking system. After the pressure filling, there is excess brake fluid in at least one low-pressure accumulator. The pump can pump the brake fluid from the low-pressure accumulator to the reservoir. The pump can be operated for a predetermined period. In particular, the control device can drive the drive motor of the pump. The drive motor can be coupled to a plurality of pumps. After the pump is deactivated, the filling of the braking system can be completed.

[0022] Before the filling process, the braking system can be subjected to a tightness check and placed under pressure. The control device can use the pressure signal to identify the tightness check. For the tightness check, air can be pumped into the braking system for the purpose of increasing the pressure. The pressure can be held over the inspection period and monitored by the filling equipment. If the pressure during the inspection period does not drop below the pressure tolerance, the braking system is identified as being tight. After the inspection period, air can be discharged from the braking system again. After the tightness check, the ambient pressure can occupy the braking system. The tightness check may be part of the preparation phase. The control device can identify the start of the filling process at the end of the tightness check. The valve may remain inactive during the tightness check.

[0023] The filling process can be recorded in the non-volatile memory of the control device. The non-volatile memory may be, for example, an EEPROM. The non-volatile memory may have a separate memory area for recording the filling process. This memory area can be referred to as a filling byte. The memory area can store various different values. During the filling process, the progress of the filling process can be recorded in the memory via various different values. The preceding and / or subsequent steps can be recorded in the same way. After the end of a predetermined phase of the filling process, the value of the filling byte can be set to a predetermined value. The filling byte value can be increased step by step or in synchronization with the phases of the filling process. Furthermore, at the end of the filling process, an error entry regarding the lack of brake fluid can be deleted from the error memory of the control device. At the end of the filling process, the production mode of the control device can also be deactivated.

[0024] The control device can alternately open and close the valve of the first brake circuit of the brake system and the valve of the second brake circuit of the brake system. The valve may be provided for pulsed drive. Continuous operation cannot be assumed. By repeating the opening and closing, an overload of the valve drive device can be avoided. By generating a pressure wave, air bubbles that may possibly remain in some cases can be expelled.

[0025] This method is preferably computer-implemented and may be implemented, for example, by software or hardware, or in a mixed form of software and hardware, for example, in a control device.

[0026] The approach presented in this specification further provides a control device for a brake system of a vehicle, the control device being configured to implement, drive, and / or execute each step of one variant of the method presented in this specification in corresponding means.

[0027] The control device may be an electrical device comprising at least one computing unit for processing signals or data, at least one memory unit for storing signals or data, and at least one interface and / or communication interface for reading or outputting data embedded in a communication protocol. The computing unit may be, for example, a signal processor for processing sensor signals and outputting data signals depending on the sensor signals, a so-called system ASIC or a microcontroller. The memory unit may be, for example, a flash memory, an EPROM, or a magnetic memory unit. The interface may be configured as a sensor interface for reading sensor signals from sensors, and / or may be configured as an actuator interface for outputting data signals and / or control signals to actuators. The communication interface may be configured to read or output data wirelessly and / or wired. The interface may be, for example, a software module provided on a microcontroller adjacent to other software modules.

[0028] A computer program product or computer program storable on a machine-readable carrier or machine-readable memory medium such as a semiconductor memory, a hard disk, or an optical memory, and in particular, when the program product or program is executed on a computer or a device, used to implement, execute, and / or drive each step of the method according to one of the above-described embodiments, a computer program product or computer program comprising program code is also advantageous.

[0029] It should be noted that in this specification, some of the implementable features and advantages of the present invention are described in relation to various different embodiments. A person skilled in the art will recognize that it is possible to combine, adjust, or replace the features of the control device and the method in a suitable manner in order to conceive of further embodiments of the present invention.

[0030] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Neither the drawings nor the specification should be construed as limiting the present invention.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

[0032] The drawings are only schematic and not to scale. The same reference numerals indicate the same features or features having equivalent functions.

Modes for Carrying Out the Invention

[0033] Embodiments of the Invention FIG. 1 shows a diagram of a braking system 100 equipped with a control device 102 according to an embodiment in a filling process according to the approach presented herein. The braking system 100 is attached to the vehicle 104 in an unfilled or empty state when passing through the manufacturing line of the vehicle 104. The vehicle 104 has arrived at a filling facility 106 for the initial filling of brake fluid on the manufacturing line. The filling facility 106 has a filling head 108 and is connected to the braking system 10 via the filling head 108. A negative pressure pipeline and a pressure pipeline communicate from the filling head 108 to the filling facility 106. The negative pressure pipeline is connected to the vacuum pump of the filling facility 106. The pressure pipeline is connected to the pressure pump of the filling facility 106.

[0034] For the filling process, the control device 102 is energized, whereby the control device 102 is activated. Here, the cable harness 110 of the vehicle 104 is connected to the battery 112 of the vehicle 104 and the control device 102 for energization. Additionally, here, the ignition 114 of the vehicle 104 is activated.

[0035] The brake system 100 has a master brake cylinder 116 with a reservoir 118. Two separate brake circuits 120 lead from the master brake cylinder 116 to two of each of the wheel brakes 122 of the vehicle 104. Inside the valve block 124 of the brake system 100, the brake system 100 has four secondary circuits 126. The secondary circuits 126 are disconnected from the brake circuits 120 by valves 128. The secondary circuits 126 are connected to two pumps 130 and two low-pressure accumulators 132 of the brake system 100. When the valve 128 is closed, it is not possible to fill the secondary circuits 126 during the filling process.

[0036] At least one of the brake circuits 120 has a pressure sensor 134 arranged therein. The pressure sensor 134 is connected to the control device 102. During the filling process, the control device 102 energizes the pressure sensor 134. The pressure sensor 134 maps the pressure in the brake circuit 120 in a pressure signal 136. The activated control device 102 monitors the pressure signal 136 to identify the filling process.

[0037] For the filling process, the filling head 108 is connected in a pressure-tight manner to the reservoir 118 of the brake system 100. During the filling process, a strong negative pressure is generated in the brake system 100 to remove as much air as possible from the brake system 100. In particular, at least one partial vacuum is drawn in the brake system 100 by a vacuum pump. Subsequently, brake fluid is pushed into the airless brake system 100 by a positive pressure.

[0038] The strong negative pressure is characteristic of the filling process. During normal operation, such a negative pressure cannot occur in the brake system 100. The negative pressure is detected by the pressure sensor 134 and mapped in the pressure signal 136. In one embodiment, the control device 102 identifies the filling process based on this characteristic negative pressure.

[0039] When the control device 102 identifies the filling process, the control device 102 actuates the valve 128 to connect the secondary circuit 126 to the brake circuit 120. After the filling process, the control device 102 deactivates the valve 128 again.

[0040] Figure 2 shows the course of the filling process 200 of the brake system based on the characteristic pressure transition 202 within the brake system and various different signal transitions. The pressure transition 202 is generated by a filling facility connected to the brake system as shown in Figure 1. Before the filling process 200, the brake system is empty or filled with air at ambient pressure, and after the filling process 200, it is filled with brake fluid at ambient pressure. During the filling process 200, the pressure within the brake system characteristically changes.

[0041] Before the filling process 200, the control device of the brake system to be filled is actuated. For this purpose, a battery voltage 204 is applied to the control device. By actuating the control device, the control device can read the pressure signal 136 of the pressure sensor of the brake system. The pressure sensor detects the pressure transition 202 and maps the pressure transition 202 in the pressure signal 136.

[0042] The pressure transition 202 or the transition of the pressure signal 136 is shown in a diagram with time t in seconds plotted on the horizontal axis and absolute pressure p in bar plotted on the vertical axis. The control device evaluates the pressure signal 136 to identify the filling process 200. In this case, to identify the filling process 200, in the control device, the pressure signal 136 is compared with the stored expected values p1, p2, p3, p4 of the pressure signal 136 and / or the expected transition of the pressure signal 136.

[0043] When the control device identifies the filling process 200, the control device drives a predetermined valve of the brake system via a control signal 206 so that the secondary circuit of the brake system is also filled with brake fluid during the filling process 200.

[0044] In one embodiment, in order to activate the control device before the start of the filling process 200, an activation signal 208, such as an ignition or wake-up command, for example, is additionally transmitted.

[0045] In one embodiment, the control device alternately drives the valve of the first braking system and the valve of the second braking system of the braking system during the filling process 200. Thus, either the valve of the first braking system is open and the valve of the second braking system is closed, or the valve of the first braking system is closed and the valve of the second braking system is open.

[0046] In one embodiment, after the start 212 of the filling process 200 is identified, the control device drives the valve with a time delay of the delay period 210.

[0047] The filling process 200 has a vacuum phase 214 with a negative pressure in the braking system and a pressurization phase 216 with a positive pressure in the braking system. In this case, both the negative pressure and the positive pressure are held over a holding period to achieve a stable state in the braking system. In one embodiment, although the pressure sensor is configured to detect the braking pressure during the braking process, a negative pressure is mapped in the pressure signal 136. However, since the negative pressure can be at most 1 bar below the ambient pressure, the negative pressure is several orders of magnitude smaller than the braking pressure which can be in the hundreds of bars. By the time the pressure sensor maps the negative pressure in the pressure signal 136, the start 212 is in the past and the vacuum phase 214 has already started. Thus, the control device starts driving the valve immediately after identifying the vacuum phase 214.

[0048] The control device drives the valve without interruption while the vacuum phase 214 ends and the pressurization phase 216 starts. The valve stops being driven only when the end 218 of the pressurization phase 216 is identified. The pressurization phase 216 is identified when the positive pressure becomes greater than the threshold value p3. The end 218 of the pressurization phase 216 is identified when the positive pressure becomes smaller than a further threshold value p4 again. The further threshold value p4 is smaller than the threshold value p3 and is within the range of the ambient pressure.

[0049] In one embodiment, when the end 218 of the filling process 200 is identified, the control device drives the pump motor of at least one pump of the brake system via a further control signal 206. By means of the pump, surplus brake fluid can be pumped from at least one low-pressure accumulator of the brake system and sucked from the filling equipment. This process can be referred to as leveling 220 of the brake system.

[0050] In one embodiment, the entire process includes a tightness check 222 before the filling process 200. For this purpose, compressed air is introduced into the brake system, so that a positive pressure is applied via the filling head to the empty brake system. In this case, an inspection pressure is set and held over the inspection period before the positive pressure is discharged and the ambient pressure occupies the brake system again. If the inspection pressure is not maintained substantially constant during the inspection period, the brake system is identified as non-tight and the filling process 200 is not started.

[0051] The tightness check 222 is also mapped in the pressure profile 202 and thus also in the pressure signal 136. Here, the control device identifies the tightness check 222 based on the fact that the pressure in the brake system has risen above the threshold value p1 and has become smaller than the next threshold value p2 again after the inspection period. In this case, the threshold value p2 is smaller than the first threshold value p1. In particular, the threshold value p2 is within the range of the ambient pressure.

[0052] When the control device falls below the threshold value p2, it identifies the end of the airtightness inspection 222 and thus the start 212 of the filling process 200, and subsequently drives the valve.

[0053] In one embodiment, the progress of the filling process 200 is recorded in the non-volatile memory 224 of the control device. For this purpose, when various different phases of the filling process 200 are identified, the value of the so-called filling byte 226 of the memory 224 is changed step by step.

[0054] In one embodiment, the identification of the start 212 of the vacuum phase 214 is recorded, and when it exceeds the threshold value p3, the start 228 of the pressurization phase 216 is recorded, and when it falls below the threshold value p4, the end 218 of the pressurization phase 216 is recorded.

[0055] In one embodiment, the airtightness inspection 222 is also recorded in the memory 224. When it exceeds the threshold value p1, the start of the airtightness inspection 222 is recorded, and when it falls below the threshold value p2, the end of the airtightness inspection 222 and the start 212 of the vacuum phase 214 are recorded.

[0056] In one embodiment, with the threshold value p4 being exceeded, that is, with the end 218 of the filling process 200, the start of the leveling 220 is recorded by the operation of the pump motor. After the pump motor is deactivated, the end of the entire process is recorded in the memory 224.

[0057] In one embodiment, after the pump motor is deactivated, the error entry 230 in the memory 224 stating that "the brake is unfilled" is erased.

[0058] In one embodiment, the memory 224 can be changed only when the manufacturing mode 232 of the control device is activated.

[0059] In what follows, the implementable embodiments of the present invention will be summarized again or described using slightly different word choices.

[0060] A method is presented for filling a vehicle brake mechanism without a tester (testerless) using a brake adjustment system.

[0061] For vacuum filling of a dry vehicle brake mechanism, it is desirable that all areas in the brake mechanism are dry, sealed, and capable of being evacuated. However, since secondary circuits within the brake adjustment system (e.g., ABS, ESP (registered trademark), etc.) are usually disconnected from the remaining brake circuit by a hydraulic actuator, it is possible to pre-fill these areas, or the actuator can be structurally made valve-openable under vacuum, or the corresponding actuator can be driven during vacuum filling.

[0062] Actuator drive has conventionally been carried out by serial diagnostic communication with the brake adjustment system during vacuum filling. In this case, power is supplied to the brake adjustment system. Actuator drive of the brake adjustment system using serial diagnostic communication during vacuum filling is used by most OEMs (manufacturers of partner brands). Some OEMs use a brake adjustment system in which filling of the secondary circuit is carried out for various reasons.

[0063] In the approach presented herein, by omitting serial communication in vacuum filling in a testless manner, additional costs for a brake adjustment system in which filling of the secondary circuit is performed or for structurally modifying an actuator can be saved. Further, the hitherto required communication system (tester) can be omitted, including the development of communication software in brake filling equipment. Further, for example, handling time in an OEM assembly line for contacting a tester at a communication interface in a vehicle via an OBD2 connector can be saved. Additionally, structural adjustments in a brake adjustment system, for example, in special pump elements or seal rings, can be omitted. By omitting a separate filling of the secondary circuit, the filling equipment required therefor and the correspondingly time-consuming filling process can be omitted.

[0064] In the approach presented herein, automatic identification of vacuum filling in an OEM assembly plant is carried out by the software of the brake adjustment system.

[0065] Since vacuum filling is characterized by a specific pressure profile, in the approach presented in this document, this is utilized to enable automatic identification by the software and hardware of the brake adjustment system. Based on the pressure sensors provided in the brake adjustment system, the start of vacuum filling is automatically identified and the required actuator drive is carried out. Further, the corresponding progress information is written to the control device of the brake adjustment system in the so-called "filling byte" in the non-volatile memory (EEPROM). The initial content of the "filling byte" is a value indicating that "vacuum filling at the testeress has not been carried out". This value may well be a number between 0 and 6, with each number representing the corresponding progress information. The function is limited to use in the OEM manufacturing plant and is only feasible when the "manufacturing mode" is activated in the brake adjustment system. For safety reasons, the function of "vacuum filling at the testeress" is only feasible in a stationary state (V <= 2 km / h).

[0066] In the area of vacuum filling on the OEM assembly line, the vehicle, and thus also the brake adjustment system, is energized. In this case, for example, a cable harness may be plugged into the brake adjustment system, or a low-voltage battery may be assembled, or a DC / DC converter may be activated. Additionally, the ignition may be switched on, or the brake adjustment system may be activated by the corresponding wake-up function in the control device, such as by the identification of active vehicle bus communication. By the wake-up function in the control device of the brake adjustment system, only the supply of the standard voltage by the battery voltage via terminal 30 is required, for example. This provides further time and labor advantages for the OEM by omitting the step of switching on the ignition for the operator on the line.

[0067] In the first process step, the vehicle brake is inspected for tightness using compressed air having a typical pressure of 3 to 6 bar. The brake adjustment software identifies the pressure change, for example, via the relative pressure value p1 > 2 bar at the pressure sensor of the brake adjustment system, and starts the function of "vacuum filling without a tester". In order to shorten the manufacturing time, it is also possible to apply the desired pressure to the brake mechanism only for a short time and then immediately reduce the pressure again. Even this short pressure pulse is sufficient to activate the function of "vacuum filling without a tester". The start of the function of "vacuum filling without a tester" is recorded with the value "vacuum filling without a tester is started" in the non-volatile memory (EEPROM) of the control device of the brake adjustment system.

[0068] In the second process step, after the tightness inspection is completed, the entire brake mechanism is evacuated. The brake adjustment software identifies this pressure change, for example, via the relative pressure value p2 = 0 ± 1 bar at the pressure sensor of the brake adjustment system, and then, after a predetermined delay time, starts driving the actuator of the brake adjustment system required to evacuate and fill the secondary circuit in the brake adjustment system. The process step of "vacuum phase" is recorded with the value "start of vacuum phase" in the non-volatile memory (EEPROM) of the control device of the brake adjustment system, or, after the elapse of a predetermined delay time, is recorded with the value "start of driving the actuator (valve)".

[0069] In the third process step, after the vacuum phase and the vacuum tightness inspection, the filling equipment switches to the filling phase using a typical filling pressure of 3 to 6 bar. The software in the brake adjustment system identifies this pressure change, for example, via the relative pressure p3 > 2 bar in the pressure sensor. The already ongoing drive of the actuator of the brake adjustment system remains unchanged or continues further without change. The process step "filling phase" is recorded in the non-volatile memory (EEPROM) of the control device of the brake adjustment system with the value "start of filling phase". After this phase, the function "vacuum filling at testerless" is blocked for the future and can no longer be carried out regardless of the "manufacturing mode" existing in the brake adjustment system.

[0070] In the fourth process step, after the end of the filling phase, the filling equipment switches to leveling, in which the excess volume in the brake fluid tank is sucked to the maximum allowable level. In this phase, the filling pressure is reduced. The brake adjustment software identifies this pressure change, for example, via the relative pressure value p4 = 0 ± 1 bar in the pressure sensor, ends the drive of the actuator of the brake adjustment system for filling the secondary circuit, and then starts the drive of the actuator required to empty the low-pressure accumulator in the brake adjustment system. The process step "leveling" is recorded in the non-volatile memory (EEPROM) of the control device of the brake adjustment system with the value "leveling". After the end of the drive of the actuator to empty the low-pressure accumulator, the value "vacuum filling is carried out at testerless" is recorded, and the error entry "brake is unfilled" in the brake adjustment system is automatically reset.

[0071] Finally, it should be noted that terms such as "have" and "include" do not exclude other elements or steps, and terms such as "one" do not exclude a plurality. The reference signs in the claims should not be regarded as limiting.

Claims

1. A method for filling a brake system (100) of a vehicle (104), comprising: connecting a filling facility (106) to the brake system (100) and activating a control device (102) of the brake system (100); the control device (102) monitoring a pressure signal (136) of a pressure sensor (134) of the brake system (100) to identify a filling process (200) performed by the filling facility (106); in response to identifying the start (212) of the filling process (200), a valve (128) of the brake system (100) is activated by the control device (102); in response to identifying the end (218) of the filling process (200), the valve (128) is deactivated by the control device (102).

2. The filling process (200) has a vacuum phase (214) and a pressurization phase (216), the filling facility (106) degassing the brake system (100) during the vacuum phase (214) and filling with brake fluid during the pressurization phase (216), the control device (102) using the pressure signal (136) to identify the vacuum phase (214) and the pressurization phase (216), the valve (128) being activated during the vacuum phase (214) and deactivated at the end (218) of the pressurization phase (128), The method according to claim 1.

3. After the vacuum phase (214) is identified, the valve (128) is activated with a time delay. The method according to claim 2.

4. After the end of the filling process (200), the control device (102) activates a pump (130) of the brake system (100) to empty at least one low-pressure accumulator (132) of the brake system (100). The method according to any one of claims 1 to 3.

5. Before the filling process (200), the filling facility (106) performs a leak test (222) on the brake system (100), places the brake system (100) under pressure, and the control device (102) uses the pressure signal (136) to identify the leak test (222). The method according to any one of claims 1 to 4.

6. The filling process (200) is recorded in a non-volatile memory (224) of the control device (102). The method according to any one of claims 1 to 5.

7. The control device (102) alternately opens and closes a valve (128) of a first brake circuit (120) of the brake system (100) and a valve (128) of a second brake circuit (120) of the brake system (100). The method according to any one of claims 1 to 6.

8. A control device (102) for a brake system (100) of a vehicle (104), The control device (102) is configured to implement, execute, and / or drive the method according to any one of claims 1 to 7 in corresponding means. Control device (102).

9. A computer program product, wherein the computer program product is configured to cause a processor to implement, execute, and / or drive the method according to any one of claims 1 to 7 when the computer program product is executed.

10. A machine-readable memory medium storing the computer program product according to claim 9.

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