Control device and method for operating a motorised brake pressure build-up device of a brake system of a vehicle

Abstract

The present invention relates to a control device (10) for a motorised brake pressure build-up device (12) of a brake system of a vehicle and to a method for operating a motorised brake pressure build-up device (12) of a brake system of a vehicle by actuating a motor (12a) of the motorised brake pressure build-up device (12) taking into account at least one defined actuation variable, wherein at least in a first actuation mode, the at least one actuation variable is defined taking into account at least one target variable with respect to a pressure increase to be effected in at least one partial volume of the brake system and additionally taking into account at least one actual variable, measured by means of at least one sensor of the motorised brake pressure build-up device (12) and / or of the brake system, with respect to an actual pressure present in at least the one partial volume, and wherein, taking into account at least one actual operating variable with respect to a current operation of the motorised brake pressure build-up device (12), there is a switch, at least sometimes, from the first actuation mode to a second actuation mode, and the at least one actuation variable is defined in the second actuation mode taking into account the at least one target variable and not taking into account the at least one actual variable.

Description

[0001] Description

[0002] The present invention relates to a control device for a motorized brake pressure build-up device of a vehicle's braking system. The invention also relates to a motorized brake pressure build-up device for a vehicle's braking system and to a vehicle's braking system. Furthermore, the invention relates to a method for operating a motorized brake pressure build-up device of a vehicle's braking system.

[0003] State of the art

[0004] From the prior art, such as DE 10 2013 227 066 A1, it is known to equip a vehicle's hydraulic brake system with a motorized brake pressure build-up device, which has at least one piston that can be linearly adjusted by means of the operation of its motor. As disclosed in DE 10 2013 227 066 A1, the motor can be controlled taking into account at least one target value with respect to a pressure increase to be effected in at least one partial volume of the brake system and taking into account a pre-pressure measured by means of at least one sensor.

[0005] Disclosure of the invention

[0006] The present invention provides a control device for a motorized brake pressure build-up device of a braking system of a vehicle with the features of claim 1, a motorized brake pressure build-up device for a braking system of a vehicle with the features of claim 7, a braking system for a vehicle with the features of claim 10 and a method for operating a motorized brake pressure build-up device of a braking system of a vehicle with the features of claim 12.

[0007] Advantages of the invention

[0008] The present invention provides advantageous means for operating a motorized brake pressure build-up device of a (hydraulic) braking system of a vehicle in such a way that, in the event of a fault / fault condition in the respective braking system, such as in particular a leak in one of its brake circuits, the conventional risk of overbraking or an unintended emergency braking of the vehicle is effectively avoided. In particular, the present invention addresses the problem of the prior art that, often, in the event of a fault / fault condition in the braking system, a brake pressure increase already effected by the motorized brake pressure build-up device cannot be detected by the system's sensors.However, the present invention prevents the sensors from interfering with the operation of the motorized brake pressure build-up device in such a way that a braking request currently made by a driver or the vehicle's automatic system can be fulfilled relatively reliably and without overbraking the vehicle, despite a fault / fault condition affecting the sensors. Thus, the present invention significantly increases driving comfort for the vehicle's driver.

[0009] As will become clear from the following description, the realization / implementation of the present invention does not require complex detection of the fault / fault condition affecting the sensors of the braking system, such as the detection of leaks or circuit failures. Therefore, the use of the present invention is comparatively cost-effective. Furthermore, conventional control electronics for a motorized brake pressure build-up device can be further developed by means of a simple reprogramming procedure so that they can implement the present invention. The components of the present invention can react relatively sensitively to situations with a conventionally high risk of vehicle overbraking, but are also comparatively robust.The present invention can also be used very advantageously for a by-wire braking system in which the driver of the vehicle equipped with it has no mechanical or hydraulic connection from their brake actuation element / brake pedal to the hydraulics of their braking system, even in the event of a malfunction. In addition to the motorized brake pressure build-up device, the respective by-wire braking system can also have an independent and redundant actuator, such as, in particular, at least one pump. By using the present invention, it can be ensured that a deceleration of the vehicle requested by the driver or the vehicle's automatic system can generally be achieved by means of at least the motorized brake pressure build-up device without the risk of the vehicle overbraking.However, it should be noted that the feasibility / usability of the present invention is not limited to by-wire braking systems.

[0010] In an advantageous embodiment of the control device, the electronic device is additionally designed and / or programmed such that it can be determined by means of the electronic device whether a respective difference between the at least one target value and the at least one assigned actual value lies within a respective predefined normal value range, and whether a respective operating value difference between the at least one actual operating value and a respective assigned target operating value with respect to a currently requested target operation of the motorized brake pressure building device lies within a respective predefined normal value range for operating values, and, if it is determined by means of the electronic device that the at least one difference lies outside its respective normal value range, although the at least one operating value difference lies within its respective normal value range for operating values,The electronic device has transitioned from its first control mode to its second control mode. If at least one difference lies outside its respective normal range, even though at least one operating parameter difference lies within its respective operating parameter normal range, it can be assumed with a high degree of probability that the comparatively large deviation of at least one actual parameter from the respective assigned target parameter is due to an error / fault case influencing the measurement of at least one actual parameter. Therefore, it may be advantageous toThen, using the embodiment of the control device described here, the motorized brake pressure build-up device can be controlled without taking into account at least one actual value. This allows for a particularly advantageous response in the event of a hydraulic leak in one of the brake circuits of the brake system or in the presence of air in the brake system.

[0011] Preferably, the electronic device is additionally designed and / or programmed such that, if the electronic device determines that the at least one difference lies within its respective normal range and / or the at least one operating parameter difference lies outside its respective normal range, the electronic device is in its first control mode. If the at least one difference lies within its respective normal range and / or the at least one operating parameter difference lies outside its respective normal range, it is likely that there is no fault / fault condition in the brake system that would affect a measurement of the actual pressure, the actual rotor position, the actual rotor adjustment angle, the actual piston position, and / or the actual piston travel.Therefore, if necessary, a control of the motorized brake pressure building device executable by means of the embodiment of the control device described here is also very reliable when taking into account at least one actual value.

[0012] For example, the at least one actual operating parameter can represent the position of at least one component of the motorized brake pressure building device, and / or the at least one target operating parameter can represent the target position of at least one component. Thus, the at least one actual operating parameter and / or the at least one target operating parameter can be parameters that are conventionally often measured or determined during operation of the motorized brake pressure building device.

[0013] Preferably, the at least one actual operating parameter is an actual rotor position or an actual rotor adjustment angle of a rotor of the motor and / or an actual piston position or an actual piston travel of at least one piston of the motorized brake pressure building device that is linearly adjustable by means of the motor, and / or the at least one target operating parameter is a target rotor position or a target rotor adjustment angle of the rotor of the motor and / or a target piston position or a target piston travel of the at least one piston of the motorized brake pressure building device that is linearly adjustable by means of the motor. Due to a gear ratio of the motorized brake pressure building device, the actual piston position or the actual piston travel, or the target piston position or the target piston travel, are fixed with the actual rotor position or the actual rotor adjustment angle, respectively.coupled to the target rotor position or the target rotor adjustment angle, so that these values ​​can be used alternatively or additionally.

[0014] In particular, the electronic device can be designed and / or programmed such that a target motor torque of the motor of the motorized brake pressure building device and / or a target current of an operating current supplied to the motor can be defined as at least one control variable. The defined target motor torque and / or the defined target current are then advantageously suitable for controlling the motor of the motorized brake pressure building device.

[0015] The advantages described above are also guaranteed with a motorized brake pressure build-up device for a vehicle's braking system equipped with such a control device. The motorized brake pressure build-up device can, for example, be an actuator for a braking system decoupled from the vehicle's brake pedal. This allows the motorized brake pressure build-up device to be used for an actuator type subject to comparatively high demands. Alternatively, the motorized brake pressure build-up device can also be an electromechanical brake booster that can be positioned upstream of, or is positioned upstream of, a master brake cylinder of the braking system, or a motorized piston-cylinder device that can be integrated into, or is integrated into, the hydraulics of the braking system.

[0016] A braking system for a vehicle with a corresponding motorized brake pressure build-up device also realizes the advantages described above. Preferably, the braking system is a by-wire braking system. However, the design of the braking system is not limited to this type of braking system. Furthermore, implementing a corresponding method for operating a motorized brake pressure build-up device of a vehicle's braking system also provides the advantages described above. It is expressly pointed out that the method can be further developed according to the embodiments of the control device, the motorized brake pressure build-up device, and / or the braking system described above.

[0017] Brief description of the drawings

[0018] Further features and advantages of the present invention are explained below with reference to the figures. They show:

[0019] Fig. 1 is a flowchart to explain one embodiment of the method for operating a motorized brake pressure build-up device of a vehicle's braking system; and

[0020] Figs. 2a to 2c show schematic overall and partial representations of an embodiment of the control device, or of the motorized brake pressure building device interacting with it.

[0021] Embodiments of the invention

[0022] Fig. 1 shows a flowchart to explain an embodiment of the method for operating a motorized brake pressure build-up device of a vehicle's braking system.

[0023] The motorized brake pressure build-up device operated by the method described below can (essentially) be understood to be any device that has at least one piston that can be linearly adjusted by means of the operation of its motor. Likewise, the feasibility of the method described below is not limited to any specific type of brake system of the (hydraulic) brake system equipped with the motorized brake pressure build-up device, nor to any specific type of vehicle. The method comprises a process step S1 in which the motor of the motorized brake pressure build-up device is controlled taking into account at least one defined control variable Mo.Controlling the motor can be understood, in particular, as supplying an operating current with a defined target current to the motor and / or applying an actual voltage to the motor that causes the operating current to be supplied with the defined target current. For example, when executing process step S1, the at least one control variable Mo can be a target motor torque Mo of the motor of the motorized brake pressure build-up device and / or the target current of the operating current supplied to the motor.

[0024] To determine the at least one control variable Mo, such as in particular the target motor torque Mo and / or the target current, either a process step S2 or a process step S3 is executed before process step S1 in the method described here. Process step S2 implements a first control mode of the motor of the motorized brake pressure build-up device. When executing process step S2 / in the first control mode, the at least one control variable Mo is determined taking into account at least one target variable and additionally at least one actual variable. The at least one target variable is understood to be a variable relating to a pressure increase to be effected in at least one partial volume of the brake system. For example,A target pressure po to be achieved in at least the partial volume of the braking system can be taken into account as at least one target value when determining at least one control value Mo.

[0025] The pressure increase, to be achieved at least by means of the motorized brake pressure build-up device in at least the partial volume of the brake system, serves to fulfill a vehicle deceleration requested by a driver or the vehicle's automatic system. For example, the driver can indicate the requested vehicle deceleration by actuating a brake actuator / brake pedal. The automatic system can, in particular, be an automatic system designed / programmed to execute a highly automated driving function. The at least one target value can, in particular, be a value that is / is determined taking into account the vehicle deceleration requested by the driver or the automatic system. Specifically, the at least one target value can be determined according to a predefined relationship depending on the requested vehicle deceleration.The actuation force of the brake actuator / brake pedal must be specified. Since methods for defining the above-mentioned examples for at least one target value corresponding to the requested vehicle deceleration or the actuation force of the brake actuator / brake pedal are known, they will not be discussed in detail here.

[0026] The at least one actual value is a quantity measured by at least one sensor of the motorized brake pressure build-up device and / or the brake system with respect to an actual pressure present in at least one partial volume. In particular, the actual pressure in at least the partial volume of the brake system can be measured by at least one suitable sensor. Examples of suitable sensors include at least one pre-pressure sensor, at least one pressure sensor, and / or at least one brake pressure sensor. However, the examples of suitable sensor types listed here are not exhaustive.

[0027] Preferably, when executing process step S2, the at least one control variable Mo is determined taking into account a respective difference between the at least one setpoint and the at least one associated actual value. This can also be described as a control of the motor of the motorized brake pressure building device, in which the motor is preferably controlled such that the at least one difference is minimized. An example of the at least one difference that can be considered when executing process step S2 to determine the at least one control variable Mo is a pressure difference between the setpoint pressure po and the actual pressure. Process step S3 implements a second control mode for the motor of the motorized brake pressure building device.If, when executing the procedure described here, process step S3 is performed instead of process step S2, the at least one control variable Mo, such as the target motor torque Mo and / or the target current, is determined taking into account the at least one target variable, but disregarding the at least one actual variable. In comparison to process step S2, process step S3 thus differs by the "deliberate omission" of using the at least one actual variable measured by the at least one sensor when determining the at least one control variable Mo.

[0028] When executing process step S3, the target motor torque Mo can be determined, for example, according to equation (Eq. 1) depending on the target pressure po with:

[0029] (Eq. 1) M o= - * i * p0, where A is a hydraulically effective area of ​​the at least one linearly adjustable piston of the motorized brake pressure building device and i is a gear ratio of the motorized brake pressure building device. Consideration of further losses or dependencies, such as the efficiency of seals, friction in the gearbox, and / or at least one environmental parameter, such as temperature, is generally possible, but usually not necessary.

[0030] To determine whether process step S2 or process step S3 is to be executed to define at least one control variable Mo, such as in particular the target motor torque Mo and / or the target current, a process step S4 is executed beforehand in the method described here. In process step S4, taking into account at least one actual operating variable relating to the current operation of the motorized brake pressure build-up device, it is determined whether the first control mode or the second control mode is to be executed, whereby at least sometimes a switch is made from the first control mode to a second control mode.

[0031] The at least one actual operating parameter can, for example, represent the position of at least one component of the motorized brake pressure building device. In particular, the at least one actual operating parameter can be the actual rotor position or the actual rotor adjustment angle of a rotor of the motor of the motorized brake pressure building device and / or the actual piston position or the actual piston travel of at least one linearly adjustable piston of the motorized brake pressure building device. Therefore, a rotor position sensor and / or at least one rod travel sensor can be (co-)used to measure the at least one actual operating parameter.

[0032] In the embodiment described here, process step S4 first determines whether the respective difference between the at least one target value and the at least one associated actual value lies within a predefined normal range, and whether a respective operating value difference between the at least one actual operating value and a predefined target operating value with respect to a currently requested target operation of the motorized brake pressure building device lies within a predefined normal range. The at least one target operating value can be understood, in particular, as a target position of at least one component of the motorized brake pressure building device.Examples of at least one target operating parameter are a target rotor position or a target rotor adjustment angle of the rotor of the motor of the motorized brake pressure building device and / or a target piston position or a target piston travel of the at least one linearly adjustable piston of the motorized brake pressure building device. The at least one operating parameter difference can therefore be, for example, a rotor position difference between the target rotor position and the actual rotor position, a rotor adjustment angle difference between the target rotor adjustment angle and the actual rotor adjustment angle, a piston position difference between the target piston position and the actual piston position, and / or a piston travel difference between the target piston travel and the actual piston travel.If, in process step S4, it is determined that at least one difference lies outside its respective normal range, even though at least one operating variable difference lies within its respective normal range, the system switches from the first control mode to the second control mode, or process step S3 is executed instead of process step S2. The at least one control variable Mo, such as, in particular, the target motor torque Mo and / or the target current, is determined, if necessary, by executing process step S3. This is advantageous because it can be assumed that deliberately omitting consideration of the at least one actual variable when determining the at least one control variable Mo is beneficial.

[0033] The presence of at least one difference within its specified normal range, while simultaneously exhibiting at least one difference in an operating parameter outside its specified normal range, often indicates the fault condition "air in the brake system" or the fault condition "leakage in a brake circuit / circuit failure". Particularly in the case of a leakage in a brake circuit of the brake system, a pressure sensor integrated into the respective brake circuit will measure at most a back pressure across the leakage throttling point, but often only a pressure of (almost) 0 bar. Accordingly, the pressure difference between the target pressure p0 and the actual pressure is usually outside its specified normal range.If, in this case, the measured actual pressure were taken into account when determining the at least one control variable Mo by executing process step S2, the motor would be driven far too hard, thus risking overbraking of the vehicle, and often also an unwanted full deceleration. However, since the procedure described here ensures that process step S3 is executed instead of process step S2 if necessary, the conventional risk of overbraking or an unintended full deceleration of the vehicle is avoided.Even if, due to a leak, the vehicle deceleration desired by the driver or the automatic transmission is not immediately achieved by the motorized brake pressure build-up device, the driver or the automatic transmission, acting as a "deceleration controller," can quickly and reliably compensate for the reduced braking effect of the motorized brake pressure build-up device by requesting increased vehicle deceleration. The procedure described here therefore offers the driver a high level of driving comfort.

[0034] The piston travel differential can be considered to be within its specified normal range as long as it is less than or equal to the first product of a specified first factor and the target piston travel, specifically 20% of the target piston travel. A pressure differential outside its specified normal range can be identified as soon as it exceeds the second product of a specified second factor and the target pressure po, e.g., 80% of the target pressure po. In such a situation, because no significant pressure build-up is detected despite at least one piston being (almost) in its target position, there is a justified suspicion of a leak or air ingress.Therefore, executing procedure step S3 instead of procedure step S2 is advantageous in this situation, ensuring that the conventional risk of vehicle overbraking is reliably avoided for both fault conditions: "air in the brake system" and "leakage in a brake circuit / circuit failure." Additionally, executing procedures S3 and S1, if necessary, ensures that any air present in the brake system (regardless of the affected brake circuit) is compensated for, or that the vehicle is braked using the other brake circuit despite a leakage-related circuit failure in the brake system (regardless of the affected brake circuit). While the motorized brake pressure build-up device has a reduced braking effect in both fault conditions, this is usually quickly compensated for by the driver or the automatic transmission acting as a "deceleration controller" by means of a readjustment, i.e., by requesting increased vehicle deceleration.Since the driver quickly notices the fault condition "air in the brake system" due to the changed behavior of their brake actuation element / brake pedal, they will also adjust their braking habits accordingly at an early stage. However, if in process step S4 it is determined that at least one difference lies within its respective normal value range and / or at least one operating variable difference lies outside its respective operating variable normal value range, the at least one control variable Mo is preferably determined by executing process step S2, taking into account at least one target value and at least one actual value.

[0035] As soon as it is recognized during the execution of procedure step S4 that procedure step S3 should be executed instead of procedure step S2, the procedure described here can be continued / repeated with procedure step S3 instead of procedure step S2 until the driver or the automatic system no longer requests vehicle deceleration, i.e., for the entire duration of the respective braking maneuver. Alternatively, procedure step S3 can also be executed instead of procedure step S2 during each subsequent braking maneuver of the vehicle until the existing fault condition has been checked and, if necessary, rectified.

[0036] The method described here implements an operating strategy for the motorized brake pressure build-up device that is particularly well-suited for the difficult-to-distinguish fault conditions of "air in the brake system" and "leakage in a brake circuit / circuit failure." It is expressly pointed out that the method described here allows for a very advantageous response to the presence of either fault condition without requiring identification of which fault condition is currently present.

[0037] Figs. 2a to 2c show schematic overall and partial representations of an embodiment of the control device, or of the motorized brake pressure building device interacting with it.

[0038] It is expressly pointed out that the usability of the control device 10 schematically depicted in Fig. 2a and the motorized brake pressure building device 12 interacting with or equipped with it is not limited to any specific brake system type of a (hydraulic) brake system using the motorized brake pressure building device 12 and to any specific vehicle type / motor vehicle type of the vehicle / motor vehicle equipped with the brake system.

[0039] The control device 10 has an electronic unit 10a, which is designed and / or programmed such that a motor 12a of the motorized brake pressure build-up device 12 can be controlled / is controlled by the electronic unit 10a. The control of the motor 12a is effected by the electronic unit 10a taking into account at least one defined control variable Mo and Io. The at least one control variable Mo and Io can, for example, be a target motor torque Mo and / or a target current Io of an operating current 14 which is output / is output to the motor 12a.The control of the motor 12a by means of the electronic device 10a can in particular be understood as an output of the operating current 14 with an actual current I corresponding to the specified target current Io or an application of an actual voltage U to the motor 12a that causes the operating current 14 with the specified target current Io.

[0040] The design / programming of the electronic device 10a also ensures that the at least one control variable Mo and Io can be determined / are determined by means of the electronic device 10a, which is present in at least one control mode, taking into account at least one target variable and at least one actual variable. The at least one target variable is understood to be a variable relating to a pressure increase to be effected in at least one partial volume of the brake system. Similarly, the at least one actual variable is understood to be a variable measured by at least one (not shown) sensor of the motorized brake pressure build-up device 12 and / or the brake system relating to an actual pressure p present in at least one partial volume. Examples of the at least one target variable and the at least one actual variable have already been listed above.An example of determining the at least one control variable Mo and Io, specifically the target motor torque Mo and / or the target current Io, taking into account both the at least one target variable and the at least one actual variable, is shown schematically in Fig. 2b. In the example shown, a target pressure po to be achieved in at least the partial volume of the braking system is used as the target variable. The measured actual pressure p present in at least the partial volume of the braking system is used as the corresponding actual variable. A pressure difference Ap between the target pressure po and the actual pressure p is output to a pressure regulator 16 of the electronic device 10a, which sets a target rotor adjustment angle corresponding to the pressure difference Ap. <po eines (nicht dargestellten) Rotors des Motors 12a bestimmt. Unter Verwendung eines pV-Modells 18 kann außerdem ein Vor- steuerungs-Soll-Rotorverstellwinkel <POFF (FF: Feed-Forward) bestimmt werden.

[0041] At least based on the target rotor adjustment angle. <po, eines gemessenen Ist- Rotorverstellwinkels cp und evtl, auch des Vorsteuerungs-Soll-Rotorverstell- winkels <POFF kann eine Rotorverstellwinkel-Differenz A<p bestimmt werden. Mittels eines Positionsreglers 20 der Elektronikeinrichtung 10a wird dann eine der Rotorverstellwinkel-Differenz A<p entsprechende Soll-Drehge- schwindigkeit wo des Rotors bestimmt. Ebenso kann unter Verwendung eines Differentiators 22 aus dem Vorsteuerungs-Soll-Rotorverstellwinkel <POFF eine Vorsteuerungs-Soll-Drehgeschwindigkeit WOFF des Rotors abgeleitet werden.

[0042] The target rotational speed wo of the rotor, a measured actual rotational speed co of the rotor, and possibly also the feedforward target rotational speed WOFF can be used to determine a rotational speed difference Aw. Using a speed controller 24 of the electronic device 10a, a target current Io corresponding to the rotational speed difference Aw can then be determined. Additionally, using another differentiator 26, a feedforward target rotational acceleration or a feedforward target current IOFF can be derived from the feedforward target rotational speed WOFF. Then, using the target current Io, the measured actual current I, and possibly also the feedforward target current IOFF, a current difference AI, by which the operating current 14 of the motor 12a of the motorized brake pressure building device 12 is to be varied, can be calculated.

[0043] A current controller 28 of the electronic device 10a can then derive a target voltage Uo to be applied to the motor 12a from the current difference AI. Through a correspondingly implemented current control 30, the actual voltage U corresponding to the target voltage Uo is applied to the motor 12a. According to a UI characteristic curve 32, the operating current 14 then flows through the motor 12a with the corresponding actual current I. This results in an actual motor torque M of the motor 12a according to an IM characteristic curve 34 of the motor 12a. The actual rotational speed w of the rotor results from the difference between the actual motor torque M and a motor load Miast, according to an Mw characteristic curve 36 of the motor 12a. According to a further characteristic curve 38 of the motor 12a, the actual rotational speed w of the rotor results in the respective actual rotor pitch angle. <p. Abhängig von einer Druck-Volumen-Kennlinie 40 des Bremssystems resultiert der Ist- Rotorverstellwinkel <p in dem jeweiligen Ist-Druck p.

[0044] In Fig. 2b, the pre-control component is marked by reference numeral 42, by means of which a high response dynamic can be achieved when determining the at least one control variable Mo and Io, in particular the target motor torque Mo and / or the target current Io, taking into account both the at least one target variable and the at least one actual variable.

[0045] Furthermore, the electronic device 10a is additionally designed and / or programmed in such a way that the electronic device 10a takes into account at least one actual operating parameter. <p bezüglich eines aktuellen Betriebs der motorisierten Bremsdruckaufbauvorrichtung 12 aus dem ersten Ansteuermodus in einen zweiten Ansteuermodus überführbar ist / überführt wird. Zusätzlich ist / wird die mindestens eine Ansteuergröße Mo und Io mittels der in dem zweiten Ansteuermodus vorliegenden Elektronikeinrichtung 10a unter Berücksichtigung der mindestens einen Soll-Größe und unter Nichtberücksichtigung der mindestens einen Ist- Größe festlegbar / festgelegt Damit ermöglicht auch eine Nutzung der Steuervorrichtung 10 die Vorteile des vorausgehend erläuterten Verfahrens. Beispiele für die mindestens eine Ist-Betriebsgröße <p, anhand von welcher insbesondere ein Leckage- oder Luft-Verdacht erkannt / bestätigt werden kann, sind oben bereits aufgezählt.

[0046] As illustrated in Fig. 2c by means of a switch 44 of the electronic device 10a, in the event of a suspected leak or air leak, the system switches from the pressure regulation shown in Fig. 2b to a pressure control system. In this system, the target motor torque Mo and the target current Io can be set, taking into account the target pressure po, but disregarding at least one actual value (such as the actual pressure p). The target motor torque Mo can be set by a first computer unit 46 of the electronic device 10a according to a predefined function, such as equation (GL 1), as a function of the target pressure po. Subsequently, a target current Io, which produces the target motor torque Mo, can be determined by a second computer unit 48 of the electronic device 10a.

[0047] If abrupt changes during the switch from pressure regulation to pressure control are to be avoided, this transition can also be dampened by appropriate filtering or gradient limiting. Similarly, the target motor torque Mo and / or the target current Io can be filtered, gradient-limited, or limited to a predefined value range to dampen unwanted overshoot and prevent exceeding the vehicle deceleration requested by the driver or the automatic system.

[0048] The control device 10 can optionally be a subunit of the motorized brake pressure build-up device 12 or be configured separately from the motorized brake pressure build-up device 12. The motorized brake pressure build-up device 12 can, in particular, be an actuator for a brake system decoupled from a vehicle brake pedal, such as a by-wire actuator (BWA). Alternatively, the motorized brake pressure build-up device 12 can also be an electromechanical brake booster that can be positioned upstream of or is positioned upstream of a master brake cylinder of the brake system, or a piston-cylinder device that can be integrated into or is integrated into a hydraulic system of the brake system, specifically an integrated power brake (IPB).

[0049] Although the operating strategy realized by means of the present invention is particularly advantageous for use in a by-wire braking system, its applicability is not limited to this type of braking system.

Claims

Claims 1. Control device (10) for a motorized Brake pressure build-up device (12) of a vehicle brake system comprising: an electronic device (10a) which is designed and / or programmed such that a motor (12a) of the motorized brake pressure build-up device (12) can be controlled by means of the electronic device (10a) taking into account at least one defined control variable (Mo, Io), wherein the at least one control variable (Mo, Io) can be determined by means of the electronic device (10a) which is available in at least a first control mode, taking into account at least one target value (po) with respect to a pressure increase to be effected in at least one partial volume of the brake system and taking into additional account at least one actual value (p) measured by means of at least one sensor of the motorized brake pressure build-up device (12) and / or the brake system with respect to an actual pressure (p) present in at least one partial volume;characterized in that the electronic device (10a) is additionally designed and / or programmed such that the electronic device (10a) takes into account at least one actual operating parameter ( <p) bezüglich eines aktuellen Betriebs der motorisierten Bremsdruckaufbauvorrichtung (12) aus dem ersten Ansteuermodus in einen zweiten Ansteuermodus überführbar ist; and the at least one control variable (Mo, Io) can be determined by means of the electronic device (10a) present in the second control mode, taking into account the at least one target variable (po) and disregarding the at least one actual variable (p).

2. Control device (10) according to claim 1, wherein the electronic device (10a) is additionally designed and / or programmed such that it is possible to determine by means of the electronic device (10a) whether a respective difference between the at least one target value and the at least one assigned actual value lies within a respective predetermined normal value range and whether a respective operating value difference between the at least one actual operating value ( <p) und einer jeweils zugeordneten Soll-Betriebsgröße (<po) bezüglich eines aktuell angeforderten Soll-Betriebs der motorisierten Bremsdruckaufbauvorrichtung (12) innerhalb eines jeweils vorgegebenen Betriebsgrößen-Normalwertebereichs liegt, und, sofern mittels der Elektronikeinrichtung (10a) bestimmt ist, dass die mindestens eine Differenz außerhalb ihres jeweiligen Normalwertebereichs liegt, obwohl die mindestens eine Betriebsgrößen-Differenz innerhalb ihres jeweiligen Betriebsgrößen-Normalwertebereichs liegt,the electronic device (10a) has been transferred from its first control mode to its second control mode.

3. Control device (10) according to claim 2, wherein the electronic device (10a) is additionally designed and / or programmed such that, if it is determined by means of the electronic device (10a) that the at least one difference lies within its respective normal value range and / or the at least one operating size difference lies outside its respective operating size normal value range, the electronic device (10a) is in its first control mode.

4. Control device (10) according to one of the preceding claims, wherein the at least one actual operating parameter ( <p) eine Position zumindest einer Komponente der motorisierten Bremsdruckaufbauvorrichtung (12) wiedergibt und / oder die mindestens eine Soll-Betriebsgröße (<po) eine Soll-Position zumindest der einen Komponente wiedergibt 5. Control device (10) according to one of the preceding claims, wherein the at least one actual operating parameter ( <p) eine Ist-Rotorstellung oder ein Ist- Rotorverstellwinkel (<p) eines Rotors des Motors (12a) und / oder eine Ist-Kolbenposition oder ein Ist- Kolbenverstellweg mindestens eines mittels des Motors (12a) linear verstellbaren Kolbens der motorisierten Bremsdruckaufbauvorrichtung (12) sind und / oder die mindestens eine Soll-Betriebsgröße (<po) eine Soll-Rotorstellung oder ein Soll- Rotorverstellwinkel (<po) des Rotors des Motors (12a) und / oder eine Soll-Kolbenposition oder ein Soll- Kolbenverstellweg des mindestens einen mittels des Motors (12a) linear verstellbaren Kolbens der motorisierten Bremsdruckaufbauvorrichtung (12) sind.

6. Control device (10) according to one of the preceding claims, wherein the electronic device (10a) is designed and / or programmed such that a target motor torque (Mo) of the motor (12a) of the motorized brake pressure building device (12) and / or a target current (Io) of an operating current (14) output to the motor (12a) can be determined as the at least one control variable (Mo, Io) by means of the electronic device (10a).

7. Motorized brake pressure build-up device (12) for a braking system of a vehicle comprising: a control device (10) according to one of the preceding claims.

8. Motorized brake pressure build-up device (12) according to claim 7, wherein the motorized brake pressure build-up device (12) is an actuator for a brake system decoupled from a brake pedal of the vehicle.

9. Motorized brake pressure build-up device (12) according to claim 7, wherein the motorized brake pressure build-up device (12) is an electromechanical brake booster that can be positioned upstream of or is positioned upstream of a master brake cylinder of the brake system, or a piston-cylinder device that can be integrated into or is integrated into a hydraulic system of the brake system.

10. Braking system for a vehicle comprising: a motorized brake pressure building device (12) according to one of claims 7 to 9.

11. Braking system according to claim 10, wherein the braking system is a by-wire braking system.

12. Method for operating a motorized brake pressure build-up device (12) of a braking system of a vehicle comprising the step: Controlling a motor (12a) of the motorized brake pressure building device (12) taking into account at least one defined control variable (Mo, lo)(S1); wherein the at least one control variable (Mo, Io) is at least in a first control mode taking into account at least one setpoint (po) with respect to a pressure increase to be effected in at least one partial volume of the brake system and taking into account at least one sensor of the motorized The actual value (p) measured by the brake pressure build-up device (12) and / or the brake system is determined with respect to an actual pressure (p) present in at least one partial volume (S2), characterized in that, taking into account at least one actual operating value ( <p) bezüglich eines aktuellen Betriebs der motorisierten Bremsdruckaufbauvorrichtung (12) zumindest manchmal aus dem ersten Ansteuermodus in einen zweiten The control mode is changed, and at least one control variable (Mo, Io) is used in the second control mode, taking into account at least one setpoint variable (po) and disregarding at least one The actual size (p) is determined.

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