A method for filling a vehicle's brake system, and a control device for a vehicle's brake system.

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, to a control device for a vehicle brake system, and to a corresponding computer program product.

Background Art

[0002] A vehicle brake system can be filled for the first time during vehicle manufacturing. For this purpose, for example, a filling head of filling equipment can be fitted over the reservoir of a master brake cylinder. In order to avoid air entrainment, air can be sucked out of the brake system via the filling head, and brake fluid can then be filled into the deaerated brake system. 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 de-energized. The closed valve makes it impossible to suck air out of the secondary circuit and prevents brake fluid from reaching 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 prevents the brake fluid from flowing out.

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

Summary of the Invention

Problem to be Solved by the Invention

[0005] Disclosure of the Invention Given this background, the approach presented herein provides a method for filling a vehicle's brake system, a control device for the vehicle's brake system, and a corresponding computer program product, as described in the independent claims. Advantageous developments and improvements of the approach presented herein are evident from the specification and 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 within the brake system, then increasing the pressure to fill with brake fluid, and finally decreasing the pressure to ambient pressure, the filling process will have a characteristic pressure transition. The pressure transition may differ depending on the type of brake system, but it is known for each type of brake system.

[0007] In the approach presented herein, at least one control device of the brake system is activated 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 pressure transitions during the filling process. The control device stores sample points of expected pressure transitions, at least with respect to 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 a valve drive of the brake system. Once the filling process is identified, the control device drives the valve drive required to connect the secondary circuit to the brake circuit, thereby connecting the secondary circuit to the brake circuit.

[0008] The approach presented herein eliminates and can even omit data connections between the filling equipment and the braking system. This omission saves costs and time. In particular, it eliminates the need for an adapter to connect the filling equipment to the vehicle's data bus. The plugging and unplugging of the adapter is also eliminated. This also eliminates the time that would otherwise be required to access the data bus interface twice.

[0009] By eliminating data lines, the need for communication protocol matching between the filling equipment and the vehicle is also eliminated. Consequently, development costs for the software of the filling equipment and control devices can be reduced.

[0010] A method for filling a vehicle's brake system is proposed, wherein a filling device is connected to the brake system, a control device for the brake system is activated, the control device monitors the pressure signal of a pressure sensor in the brake system to identify the filling process performed by the filling device, the control device activates a valve in the brake system in response to the identification of the start of the filling process, and the control device deactivates the valve in response to the identification of the end of the filling process.

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

[0012] The brake system should be installed in the vehicle in a dry state. Initial filling of brake fluid is required to bring the brake system into a functional state. Filling should be carried out without air bubbles. The filling process can be performed from outside the vehicle by a filling device. The filling process may have a vacuum phase and a pressurization phase. In the vacuum phase, air can be removed from the brake system, or the brake system can be degassed. In the pressurization phase, brake fluid can be filled into the brake system. The filling process can be incorporated into the vehicle's manufacturing 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 device can be fitted over the master brake cylinder or the reservoir of the master brake cylinder and connected under pressure. The filling head can be connected to the filling device via a tubular conduit. The filling device may have, for example, a vacuum pump and a pressurization pump.

[0013] A brake system may have two separate brake circuits and multiple secondary circuits. At least one secondary circuit can be used to adjust the brake pressure within the brake circuits. Multiple valves may be placed between each brake circuit and a secondary circuit. These valves can be driven by one or more control devices of the brake system. These valves can be placed in a valve block of the brake system. The secondary circuits may extend between the multiple valves within the valve block. The valves may be closed in a no-current state, for example, by a return spring. 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 valve 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 during vehicle operation, for example, for the vehicle's ABS and / or ESP.

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

[0015] The control device can be operated by energizing it. For this purpose, for example, battery voltage can be connected to the terminals of the control device. Battery voltage can be provided via the vehicle's cable harness. Alternatively, power can be supplied to the control device separately, for example, via an adapter or terminals. Battery voltage may be supplied from the vehicle's battery or from an external energy source such as a power supply. Similarly, battery voltage may be supplied from the traction voltage of the vehicle's traction battery via a voltage converter. Alternatively, power can be supplied to the control device via the filling head. Additional signals may also be required for operation. These signals may be referred to as, for example, a wake-up signal or ignition signal.

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

[0017] The start and / or end of the filling process can be characterized by a distinctive pressure change. 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. When the valve is to be activated, the valve can be continuously switched on and off by the valve's valve drive. When the valve is to be deactivated, the valve drive can be switched off and the valve can be switched to the shut-off state by the valve's return spring.

[0018] The control device can use pressure signals to identify the vacuum phase and the pressurizing phase. To degass the secondary circuit, a valve can be activated during the vacuum phase or switched to the open state. The valve can be deactivated or switched to the shut-off state at the end of the pressurizing phase. To identify the vacuum phase, for example, negative pressure in the brake system, which is mapped in the pressure signal, can be identified. In this case, the vacuum phase can be started before the pressure sensor is able to map negative pressure in the pressure signal. The presence of negative pressure in the brake circuit allows for particularly rapid degassing of the secondary circuit. The vacuum phase can follow a preceding preparation phase. The preparation phase may have characteristic pressure transitions. 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 is identified, the valve can be activated with a time delay. By activating the valve, it is possible to wait until a strong negative pressure is formed in the brake circuit with a high probability. In that case, the secondary circuit can be degassed particularly rapidly.

[0020] The control device may operate the brake system's pump to empty at least one low-pressure accumulator in the brake system after the filling process is complete. The brake system may have at least one low-pressure accumulator. In particular, the brake system may have one low-pressure accumulator per brake circuit. During the adjustment operation of the brake system, brake fluid can be interimly stored in the low-pressure accumulator to adjust the brake pressure in the brake circuit by opening at least one valve. Subsequently, the brake system's pump can pump the brake fluid back from the low-pressure accumulator to the brake circuit. The brake system may have one pump per low-pressure accumulator. The low-pressure accumulators and pumps may be located in a valve block.

[0021] The filling equipment can suction excess brake fluid from the brake system reservoir to set a predetermined level in the reservoir after the filling process is complete. This process can be called brake system leveling. After pressure filling, excess brake fluid is present in at least one low-pressure accumulator. A pump can pump the brake fluid from the low-pressure accumulator to the reservoir. The pump can be operated for a predetermined period of time. In particular, the control device can drive the pump's drive motor. The drive motor can be coupled to multiple pumps. After the pump is deactivated, the filling of the brake system can be completed.

[0022] The filling equipment can perform a seal test on the brake system and place it under pressure before the filling process. The control unit can use the pressure signal to identify the seal test. For the seal test, air can be pumped into the brake system to increase the pressure. The pressure can be maintained and monitored by the filling equipment over the test period. If the pressure during the test period does not drop below the pressure tolerance, the brake system is identified as sealed. After the test period, air can be discharged from the brake system again. After the seal test, ambient pressure can occupy the brake system. The seal test may be part of the preparation phase. The control unit can identify the start of the filling process at the end of the seal test. Valves may remain deactivated during the seal test.

[0023] The filling process can be recorded in the control device's non-volatile memory. 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 may be called a filling byte. The memory area can store various values. During the filling process, the progress of the filling process can be recorded in memory via various values. Preceding and / or succeeding steps can also be recorded in the same way. After the completion 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, error entries related to brake fluid shortage can be cleared from the control device's error memory. At the end of the filling process, the control device's manufacturing mode 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 valves may be provided for pulsed actuation. Continuous operation cannot be assumed. By repeating opening and closing of the valves, overloading of the valve driving device can be avoided. The generation of pressure waves can expel air bubbles that may potentially remain in some cases.

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

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

[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 in dependence on the sensor signals, a so-called system ASIC or 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 a sensor and / or as an actuator interface for outputting data signals and / or control signals to an actuator. The communication interface may be configured to read or output data wirelessly and / or by wire. The interface may be, for example, a software module provided on a microcontroller adjacent to other software modules.

[0028] It is also advantageous to provide a computer program product or a computer program stored on a machine-readable carrier or a machine-readable memory medium such as a semiconductor memory, a hard disk or an optical memory, which comprises program code used for implementing, executing and / or driving each step of the method according to one of the above-described embodiments, particularly when the program product or the program is executed on a computer or a device.

[0029] It should be noted that in the present specification, some of the achievable features and advantages of the present invention have been described with reference to various different embodiments. A person skilled in the art will recognize that the features of the control device and the method can be combined, adjusted, or replaced by appropriate means to arrive at further embodiments of the present invention.

[0030] Embodiments of the present invention will be described below with reference to the attached drawings. Neither the drawings nor the specification should be construed as limiting the present invention. [Brief explanation of the drawing]

[0031] [Figure 1] This is a diagram of a brake system equipped with a control device according to one embodiment. [Figure 2] This diagram shows the progress of the filling process according to one embodiment.

[0032] The drawings are only schematic and not to scale. The same reference numeral indicates the same feature or a feature having an equivalent function. [Modes for carrying out the invention]

[0033] Embodiments of the Invention Figure 1 shows a diagram of a brake system 100 with a control device 102 according to one embodiment in a filling process according to the approach presented herein. The brake system 100 is installed on the vehicle 104 in an unfilled or empty state as it passes through the vehicle 104's production line. On the production line, the vehicle 104 arrives at a filling facility 106 for initial filling of brake fluid. The filling facility 106 has a filling head 108, which is connected to the brake system 10. A vacuum line and a pressurized line run from the filling head 108 to the filling facility 106. The vacuum line is connected to the vacuum pump of the filling facility 106. The pressurized line is connected to the pressurized pump of the filling facility 106.

[0034] For the filling process, power is supplied to the control device 102, thereby activating the control device 102. Here, the vehicle 104's cable harness 110 is connected to the vehicle 104's battery 112 and the control device 102 for power supply. Additionally, the vehicle 104's ignition 114 is activated.

[0035] The brake system 100 has a master brake cylinder 116 with a reservoir 118. Two separate brake circuits 120 run from the master brake cylinder 116 to two 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 valve 128 is closed, the secondary circuits 126 cannot be filled during the filling process.

[0036] A pressure sensor 134 is located in at least one of the brake circuits 120. 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 pressure-tightly connected to the reservoir 118 of the brake system 100. During the filling process, a strong negative pressure is generated within the brake system 100 to remove as much air as possible from it. In particular, at least one partial vacuum is drawn within the brake system 100 by a vacuum pump. Subsequently, positive pressure forces brake fluid into the air-free brake system 100.

[0038] A strong negative pressure is characteristic of the filling process. Under normal operation, such negative pressure would not occur within 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, it activates 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 progress of the brake system filling process 200, based on characteristic pressure transitions 202 within the brake system and various signal transitions. The pressure transitions 202 are generated by the filling equipment 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 changes characteristically.

[0041] Prior to the filling process 200, the control device of the brake system to be filled is activated. For this purpose, a battery voltage 204 is applied to the control device. Upon activation of the control device, the control device can read the pressure signal 136 from the brake system's pressure sensor. The pressure sensor detects the pressure transition 202 and maps the pressure transition 202 to the pressure signal 136.

[0042] The pressure transition 202 or the transition of the pressure signal 136 is shown in a graph where time t is plotted in seconds on the horizontal axis and absolute pressure p is plotted in bars 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, the control device compares the pressure signal 136 with the stored expected values ​​p1, p2, p3, p4 and / or the expected transition of the pressure signal 136.

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

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

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

[0046] In one embodiment, the control device drives the valve after a time delay of 210 units following the identification of the start of the filling process 200 212.

[0047] The filling process 200 has a vacuum phase 214 with negative pressure in the brake system and a pressurizing phase 216 with positive pressure in the brake system. In this case, both negative and positive pressure are maintained for a holding period to achieve a stable state in the brake system. In one embodiment, although the pressure sensor is configured to detect brake pressure during the braking process, negative pressure is mapped in the pressure signal 136. However, since negative pressure can be at most 1 bar below ambient pressure, negative pressure is several orders of magnitude smaller than brake pressure, which can be several hundred bar. By the time the pressure sensor maps negative pressure in the pressure signal 136, the start 212 is in the past, and the vacuum phase 214 has already started. Therefore, 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 begins. The valve is no longer driven only when the end of the pressurization phase 216 218 is identified. The pressurization phase 216 is identified when the positive pressure becomes greater than threshold p3. The end of the pressurization phase 216 218 is identified when the positive pressure falls below a further threshold p4. The further threshold p4 is less than threshold p3 and within the range of ambient pressure.

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

[0050] In one embodiment, the entire process includes a seal test 222 prior to the filling process 200. For this purpose, compressed air is introduced into the brake system, thereby applying positive pressure to the empty brake system via the filling head. In this case, the test pressure is set and held over the test period before the positive pressure is released and ambient pressure again occupies the brake system. If the test pressure is not maintained nearly constant during the test period, the brake system is identified as not sealed, and the filling process 200 is not initiated.

[0051] The sealing test 222 is mapped in the pressure transition 202 and, consequently, in the pressure signal 136. Here, the control device identifies the sealing test 222 based on the fact that the pressure in the brake system rises above threshold p1 and, after the test period, falls below the next threshold p2. In this case, threshold p2 is smaller than the first threshold p1. In particular, threshold p2 is within the range of ambient pressure.

[0052] When the threshold p2 is exceeded, the control device identifies the end of the sealing test 222 and, consequently, the start of the filling process 200 212, 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, if different phases of the filling process 200 are identified, the value of the so-called filling byte 226 in the memory 224 is changed step by step.

[0054] In one embodiment, the start of the vacuum phase 214 is recorded, and if it exceeds the threshold p3, the start of the pressurization phase 216 is recorded, and if it falls below the threshold p4, the end of the pressurization phase 216 is recorded.

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

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

[0057] In one embodiment, after the pump motor is deactivated, the error entry 230 in memory 224, which states "The brake is not filled," is cleared.

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

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

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

[0061] For vacuum filling of a dry vehicle brake mechanism, it is desirable that all areas of the brake mechanism be dry, sealed, and vacuum-compatible. However, since secondary circuits within brake control systems (e.g., ABS, ESP®, etc.) are usually isolated from the rest of the brake circuit by hydraulic actuators, these areas can be pre-filled, or the actuators can be structurally made openable under vacuum, or the corresponding actuators can be driven during vacuum filling.

[0062] The actuator is conventionally driven by series diagnostic communication with the brake adjustment system during vacuum filling. In this case, power is supplied to the brake adjustment system. Driving the brake adjustment system actuator using series diagnostic communication during vacuum filling is common in most OEMs (original equipment manufacturers). Some OEMs use brake adjustment systems that fill the secondary circuit for various reasons.

[0063] The omission of series communication in testerless vacuum filling, as presented herein, can save additional costs for brake adjustment systems that perform secondary circuit filling, or for structurally modifying actuators. Furthermore, it can eliminate the need for communication systems (testers) that were previously required, including the development of communication software for brake filling equipment. In addition, it can save handling time on the OEM assembly line for contacting the tester at the in-vehicle communication interface, for example, via the OBD2 connector. Moreover, it can eliminate structural adjustments to the brake adjustment system, such as special pump elements or seal rings. By eliminating separate filling of secondary circuits, the filling equipment and correspondingly laborious filling process required for that purpose can be eliminated.

[0064] In the approach presented herein, the brake adjustment system software enables the automatic identification of vacuum filling at the OEM assembly plant.

[0065] Since vacuum filling is characterized by a specific pressure transition, the approach presented herein utilizes this to enable automatic identification by the software and hardware of the brake adjustment system. Based on pressure sensors in the brake adjustment system, the start of vacuum filling is automatically identified, and the necessary actuators are driven. Furthermore, corresponding progress information is written to the brake adjustment system's control unit in a so-called "filling byte" in non-volatile memory (EEPROM). The initial value of the "filling byte" is "testerless vacuum filling is not being performed." This value may be a number between 0 and 6, each representing the corresponding progress information. The function is limited to use in OEM manufacturing plants and is only possible when the "manufacturing mode" is activated in the brake adjustment system. For safety reasons, the "testerless vacuum filling" function is only possible in a stationary state (V <= 2 km / h).

[0066] In the vacuum filling area of ​​the OEM assembly line, power is supplied to the vehicle, and consequently to the brake adjustment system. In this case, for example, a cable harness may be plugged into the brake adjustment system, a low-voltage battery may be installed, or a DC / DC converter may be activated. Additionally, the ignition may be switched on, or the brake adjustment system may be activated by a corresponding wake-up function in the control unit, such as by identifying active vehicle bus communication. The wake-up function in the brake adjustment system's control unit requires, for example, only a standard voltage power supply from the battery voltage via terminal 30. This eliminates the step of switching on the ignition for line workers, providing the OEM with further time and labor advantages.

[0067] In the first process step, the vehicle brakes are inspected for airtightness using compressed air with 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 brake adjustment system's pressure sensor, and initiates a function called "testless vacuum filling." To shorten manufacturing time, it is also possible to apply the desired pressure to the brake mechanism for a short time and then immediately release the pressure again. Even this short pressure pulse is sufficient to activate the "testless vacuum filling" function. The initiation of the "testless vacuum filling" function is recorded in the non-volatile memory (EEPROM) of the brake adjustment system's control unit with the value "testless vacuum filling initiated."

[0068] In the second process step, after the sealing test is completed, the entire brake mechanism is vacuumed. 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 actuators of the brake adjustment system required to vacuum and fill the secondary circuit within the brake adjustment system. The process step called "vacuum phase" is recorded in the non-volatile memory (EEPROM) of the control device of the brake adjustment system as the value "start of vacuum phase," or, after a predetermined delay time has elapsed, as the value "start of actuator (valve) driving."

[0069] In the third process step, after the completion of the vacuum phase and vacuum sealing test, the filling equipment switches to a filling phase using a typical filling pressure of 3 to 6 bar. The software within the brake adjustment system identifies this pressure change, for example, via the relative pressure p3 > 2 bar at the pressure sensor. The already running operation of the brake adjustment system's actuators continues without modification or change. The process step known as the "filling phase" is recorded in the non-volatile memory (EEPROM) of the brake adjustment system's control unit with the value "start of filling phase". From this phase onward, the "testless vacuum filling" function is disabled indefinitely and is no longer possible, regardless of the "manufacturing mode" present within the brake adjustment system.

[0070] In the fourth process step, after the completion of the filling phase, the filling equipment switches to leveling, during which the excess volume in the brake fluid tank is drawn down 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 at the pressure sensor, and terminates the driving of the brake adjustment system's actuators for filling the secondary circuit, and then starts driving the actuators required to empty the low-pressure accumulator in the brake adjustment system. The process step called "leveling" is recorded as the value "leveling" in the non-volatile memory (EEPROM) of the brake adjustment system's control unit. After the completion of driving the actuators to empty the low-pressure accumulator, the value "testless vacuum filling is performed" is recorded, and the error entry "brakes are unfilled" in the brake adjustment system is automatically reset.

[0071] Finally, it should be noted that terms such as "have" or "include" should not exclude other elements or steps, and that terms such as "one" should not exclude multiple elements. Reference numerals in the claims should not be considered limiting.

Claims

1. A method for filling the brake system (100) of a vehicle (104), The filling equipment (106) is connected to the brake system (100), and the control device (102) of the brake system (100) is activated. The control device (102) monitors the pressure signal (136) of the pressure sensor (134) of the brake system (100) in order to identify the filling process (200) carried out by the filling equipment (106). In response to the identification of the start (212) of the filling process (200), the valve (128) of the brake system (100) is activated by the control device (102). In response to the identification of the end (218) of the filling process (200), the valve (128) is deactivated by the control device (102). A method wherein the control device (102) operates a pump (130) of the brake system (100) to empty at least one low-pressure accumulator (132) of the brake system (100) after the completion of the filling process (200).

2. The filling process (200) includes a vacuum phase (214) and a pressurizing phase (216). The filling equipment (106) degass the brake system (100) during the vacuum phase (214) and fills it with brake fluid during the pressurization phase (216). The control device (102) uses the pressure signal (136) to identify the vacuum phase (214) and the pressurization phase (216), The valve (128) is operated during the vacuum phase (214) and deactivated at the end of the pressurization phase (216) (218). 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. The filling equipment (106) performs a sealing inspection (222) of the brake system (100) before the filling process (200), and places the brake system (100) under pressure. The control device (102) uses the pressure signal (136) to identify the airtightness test (222). The method according to claim 1.

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

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

7. A control device (102) for the brake system (100) of a vehicle (104), The control device (102) is configured to implement the method described in any one of claims 1 to 6 in the corresponding means. Control device (102).

8. A computer program, which, when the computer program is executed on a computer, is configured to cause the computer to perform the method described in any one of claims 1 to 6.

9. A machine-readable memory medium in which the computer program described in claim 8 is stored.

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