Evaluation device, and method for determining actuation information for a motorised brake booster of a vehicle brake system

Abstract

The invention relates to a method, and to an evaluation device (14) for carrying out the method, for determining actuation information for a motorised brake booster (10) whilst the motor (16) thereof is in an inactive mode, wherein: it is determined whether a first value (l1) of a first displacement sensor (18a) of a driver brake force transmission element (18) is within a first comparison value range (W1); it is determined whether a second value (l2) of a second displacement sensor (20a), which is associated with an adjustable motor force transmission element (20), is within a second comparison value range (W2); and, if the first value and the second value are within their relevant comparison value ranges, it is established, as actuation information for the brake booster, that a brake actuation element (22) connected to the driver brake force transmission element is in an unactuated state, the driver brake force transmission element (18) is in its first starting position, and / or the motor force transmission element (20) is in its second starting position.

Description

[0001] Description

[0002] title and method for determining a for a motorized brake booster of a

[0003] The invention relates to an evaluation device for a motorized brake booster of a vehicle brake system and a motorized brake booster which can be or is arranged upstream of a master brake cylinder of a vehicle brake system. Furthermore, the invention relates to a method for determining actuation information for a motorized brake booster of a vehicle brake system.

[0004] State of the art

[0005] Motorized brake boosters are known from the prior art, such as DE 10 2020 209 754 A1, which can be / are mounted upstream of a master brake cylinder of a vehicle braking system. Such a motorized brake booster has a driver brake force transmission element, via which a driver braking force exerted on a brake actuating element can be transmitted to at least one adjustable piston of the master brake cylinder. Furthermore, such a motorized brake booster comprises a motor and a motor force transmission element, which is adjustable both by operation of the motor and by means of the driver brake force transmission element adjusted by at least a predetermined threshold travel such that the driver braking force transmitted to the at least one adjustable piston of the master brake cylinder can be amplified by a motor force of the motor.

[0006] Disclosure of the invention

[0007] The present invention provides an evaluation device for a motorized brake booster of a vehicle brake system having the features of claim 1, a motorized brake booster which can be or is arranged upstream of a master brake cylinder of a vehicle brake system, having the features of claim 7, and a method for determining actuation information for a motorized brake booster of a vehicle brake system having the features of claim 12.

[0008] Advantages of the invention

[0009] The present invention provides advantageous possibilities for reliably determining actuation information for / about a motorized brake booster of a vehicle braking system, the driver brake force transmission element and the motor force transmission element of which are each assigned a displacement sensor with a displacement sensor signal that repeats periodically as a function of an adjustment movement of the respective force transmission element. Although cost-effective sensor types are thus used in the respective brake booster, by using the present invention, an actuation state of a brake actuation element connected to the driver brake force transmission element, a possible presence of the driver brake force transmission element in its first starting position and / or a possibleThe presence of the motor power transmission element in its second initial position can be reliably determined or verified. The present invention also provides possibilities for position sensor initialization for the respective motorized brake booster.

[0010] In an advantageous embodiment of the evaluation device, the electronic device is additionally designed and / or programmed to detect, on the basis of at least one engine sensor signal from at least one engine sensor of the engine and / or on the basis of at least one information signal provided to the electronic device by a control system of the engine, whether the engine is in its inactive mode, wherein the electronic device is designed and / or programmed to specify as actuation information for the brake booster that the brake actuation element is unactuated, the driver brake force transmission element is in its first starting position and / or that the engine force transmission element is in its second starting position only when the engine is in its inactive mode and the first value is in the first comparison value range and the second value is in the second comparison value range.The embodiment of the evaluation device / its electronic device described here can thus reliably detect an actuation state of the brake actuation element, a possible presence of the driver brake force transmission element in its first starting position and / or a possible presence of the engine force transmission element in its second starting position before activation / starting of the engine.

[0011] Preferably, if the first value lies outside the first comparison value range and / or the second value lies outside the second comparison value range, the electronic device is designed and / or programmed to determine a differential travel As between the first adjustment travel of the driver brake force transmission element from its first initial position and the second adjustment travel of the engine force transmission element from its second initial position, taking into account the first value of the first travel sensor signal and the second value of the second travel sensor signal. The use of a relatively expensive and comparatively difficult-to-install differential travel sensor can thus be dispensed with.

[0012] For example, the differential travel As can be determined by means of the electronic device in that the electronic device is designed and / or programmed to determine first adjustment travels Xi of the driver brake force transmission element and second adjustment travels X2 of the engine force transmission element, for which the following applies:

[0013] Xi = fi(h) + ni * in, with m = {0, 1, 2, 3, ...} and X2 = f2 (h) + n2 * 712, with n2 = {0, 1, 2, 3, ...}, wherein the functions fi, f2, the first period width 711, with which the first displacement sensor signal (18s) varies periodically, and the second period width 712, with which the second displacement sensor signal (20s) varies periodically, are stored in a memory of the electronic device (14a). Subsequently, the electronic device can be designed and / or programmed to generate a value pair from the determined first displacement paths Xi and the determined second displacement paths X2 and j such that x^ - x^ < Asmax , and to define the differential travel As according to: As = - %2- This enables the definition / determination of a reliable differential travel As by means of comparatively cost-effective electronics of the electronic device.

[0014] In a further advantageous embodiment of the evaluation device, the electronic device is additionally designed and / or programmed to determine whether the differential travel As is smaller than the threshold travel, and, if the differential travel As is smaller than the threshold travel, to specify as actuation information for the brake booster that the brake actuation element is actuated, the driver brake force transmission element is adjusted by less than the threshold travel from its first initial position and / or that the engine force transmission element is in its second initial position, and / or, if the differential travel As is equal to the threshold travel, to specify as actuation information for the brake booster that the brake actuation element is actuated,The driver brake force transmission element is displaced from its first initial position by more than the threshold travel and / or the engine force transmission element is advanced from its second initial position. Using the embodiment of the evaluation device / its electronic device described here, a variety of information can thus be defined as actuation information for / about the brake booster.

[0015] As an advantageous further development, if the differential travel As is smaller than the threshold travel, the electronic device can be designed and / or programmed to define, as actuation information for the brake booster, a current first position of the driver brake force transmission element lying between the first initial position and the threshold travel and / or the first adjustment travel of the driver brake force transmission element adjusted from its first initial position, lying below the threshold travel, taking into account the differential travel As. The embodiment of the evaluation device described here can thus, if necessary, carry out a travel sensor initialization.

[0016] The advantages described above are also ensured in a motorized brake booster which can be or is mounted upstream of a master brake cylinder of a vehicle brake system, if it is equipped with such an evaluation device, the driver brake force transmission element which is adjustable from its first starting position by means of a driver brake force, the motor force transmission element which is adjustable from its second starting position both by means of an operation of the motor of the brake booster and by means of the driver brake force transmission element adjusted from its first starting position by at least the predetermined threshold travel, the first travel sensor,which is assigned to the driver brake force transmission element and whose first travel sensor signal varies periodically with a first period width as a function of the first adjustment path of the driver brake force transmission element from its first initial position, and the second travel sensor, which is assigned to the engine force transmission element and whose second travel sensor signal varies periodically with a second period width as a function of the second adjustment path of the engine force transmission element from its second initial position.

[0017] Preferably, the first displacement sensor signal of the first displacement sensor is a first sawtooth signal with the first period width, and / or the second displacement sensor signal of the second displacement sensor is a second sawtooth signal with the second period width. The signal types mentioned here enable particularly precise and reliable displacement sensor initialization by means of the evaluation device of the respective brake booster.

[0018] Preferably, the first period width of the first travel sensor and / or the second period width of the second travel sensor are greater than the threshold travel. As will become clear from the following description, the details of the brake booster described here enable particularly precise and reliable travel sensor initialization by means of its evaluation device.

[0019] In particular, the first period width of the first travel sensor can be equal to the second period width of the second travel sensor, wherein the first period width deviates from the threshold travel and any integer multiple of the threshold travel. Alternatively, the first period width of the first travel sensor can deviate from the second period width of the second travel sensor, wherein an amount of a difference between the first period width and the second period width deviates from the threshold travel and any integer multiple of the threshold travel. It is therefore not necessary to equip the brake booster with travel sensors having the same period width. The first period width of the first travel sensor and the second period width of the second travel sensor can thus be selected such that they are optimal for the travel sensing of the respectively assigned force transmission element.

[0020] The above-mentioned advantages are also achieved by implementing a corresponding method for determining actuation information for a motorized brake booster of a vehicle braking system. It is expressly noted that the method can be further developed according to the above-explained embodiments of the evaluation device and / or the motorized brake booster.

[0021] Short description of the drawings

[0022] Further features and advantages of the present invention are explained below with reference to the figures. They show:

[0023] Fig. 1 a to 1 c show a schematic representation of a motorized brake booster and two coordinate systems for explaining the operation of an embodiment of the evaluation device; and

[0024] Fig. 2 is a flow chart for explaining an embodiment of the

[0025] Method for determining actuation information for a motorized brake booster of a vehicle braking system.

[0026] Embodiments of the invention

[0027] Fig. 1 a to 1 c show a schematic representation of a motorized brake booster and two coordinate systems for explaining a mode of operation of an embodiment of the evaluation device.

[0028] The motorized brake booster 10 shown schematically in Fig. 1 a can be / is mounted upstream of a master brake cylinder 12 of a vehicle brake system (not shown in detail).The usability of the evaluation device 14 interacting with the brake booster 10 is limited neither to a particular brake booster type of the brake booster 10 nor to a special brake system type of the vehicle brake system or to a specific vehicle type / motor vehicle type of the vehicle / motor vehicle equipped with the vehicle brake system. Instead, the evaluation device 14 can interact with (almost) any brake booster type which comprises at least one motor 16, a driver brake force transmission element 18 with at least one associated first travel sensor 18a and a motor force transmission element 20 with at least one associated second travel sensor 20a. The brake booster 10 can in particular be an electromechanical brake booster 10. The evaluation device 14 can optionally be a component of the brake booster 10 or a device which can be operated externally by the brake booster 10.

[0029] The driver brake force transmission element 18 is understood to be a component of the brake booster 10 which is adjustable from a (forceless) first starting position of the driver brake force transmission element 18 by means of a driver brake force Fdriver. For this purpose, the driver brake force transmission element 18 can be connected (directly or indirectly) to a brake actuation element 22 in such a way that the driver brake force Fdriver exerted by a driver of the vehicle / motor vehicle on the brake actuation element 22 can be transmitted to the driver brake force transmission element 18, while the driver brake force transmission element 18 is in its first starting position when the driver does not actuate the brake actuation element 22. The driver brake force transmission element 18 can, in particular, be an input rod 18. The brake actuation element 22 can, for example, be a brake pedal 22.

[0030] The first displacement sensor 18a assigned to the driver brake force transmission element 18 is understood below to be a displacement sensor type whose first displacement sensor signal 18s varies periodically with a first period width m as a function of a first adjustment displacement Xi of the driver brake force transmission element 18 from its first initial position. Such a displacement sensor type is referred to below as a "periodic displacement sensor." In the coordinate system of Fig. 1b, an abscissa indicates the first adjustment displacement Xi of the driver brake force transmission element 18 from its first initial position, while an ordinate indicates a corresponding first value h of the first displacement sensor signal 18s.The motor force transmission element 20 is a component of the brake booster 10, which is connected (directly or indirectly) to the motor 16 in such a way that the motor force transmission element 20 can be / is adjusted from its (powerless) second starting position by means of an operation of the motor 16 due to a motor force Fmotor of the motor 16 transmitted to the motor force transmission element 20. The motor force transmission element 20 can be, for example, a valve body (boost body) 20. As a rule, the motor force transmission element 20 is connected to the motor 16 via a gear (not shown).

[0031] However, even when the driver brake force transmission element 18 (by means of the driver brake force Fdriver) is adjusted from its first initial position by at least a predetermined threshold travel ASmax, the engine force transmission element 20 can be adjusted together with the driver brake force transmission element 18 which is still adjusted in the direction of the master brake cylinder 12. Thus, at least one (not shown) adjustable piston of the master brake cylinder 12 can be adjusted both by means of the driver brake force Fdriver and by means of the engine force F mo The motor force transmission element 20 is generally only in its second initial position when the motor force Fmotor is zero and the first adjustment path Xi of the driver brake force transmission element 18 from its first initial position is smaller than the threshold path As max is. In order to compensate for the adjustment movement of the engine force transmission element 20 from an adjustment of the driver brake force transmission element 18 from its first starting position by the threshold travel As ma x, stops 24a and 24b, shown only schematically in Fig. 1 a, can be formed on the driver brake force transmission element 18 and / or on the engine force transmission element 20.

[0032] The second displacement sensor 20a assigned to the motor power transmission element 20 is also a "periodic displacement sensor." Thus, a second displacement sensor signal 20s of the second displacement sensor 20a also varies depending on a second displacement X2 of the motor power transmission element 20 from its second starting position with a second period width 712. In the coordinate system of Fig. 1c, an abscissa corresponds to the second displacement X2 of the motor power transmission element 20 from its second starting position. An ordinate of the coordinate system of Fig. 2c indicates a corresponding second value h of the second displacement sensor signal 20s.Optionally, the brake booster 10 can also have at least one further force transmission element 26, such as an output rod 26, which is arranged downstream of the driver brake force transmission element 18 and the engine force transmission element 20 such that the further force transmission element 26 is actuated by the driver brake force Fdriver and / or engine force F transmitted thereto. mo gate is / is adjustable in the direction of the master brake cylinder 12. Possibly, an addition element 28, such as specifically a reaction disc 28, can be arranged between the driver brake force transmission element 18, the motor force transmission element 20, and the further force transmission element 26 such that the driver brake force Fdriver and the motor force Fmotor can be "added" to the further force transmission element 26.

[0033] Optionally, a third displacement sensor 26a can also be arranged on the brake booster 10 for the additional force transmission element 26, by means of which at least one third displacement sensor signal 26s can be output, varying as a function of a third adjustment path of the additional force transmission element 26 from its third initial position. However, it is expressly pointed out that, due to the advantageous design of the evaluation device 14, the brake booster 10 can also be dispensed with the third displacement sensor 26a.

[0034] Optionally, the motor 16 can also be equipped with at least one motor sensor 16a, such as a rotor position sensor, a rotation rate sensor, and / or a motor current sensor. However, it should be noted that the use of the evaluation device 14 described below does not require the motor 16 to be equipped with at least one motor sensor 16a.

[0035] The evaluation device 14 has an electronic device 14a which, at least while the engine 16 is in its inactive mode and before the engine 16 is activated / started, is designed and / or programmed to determine whether the first value h of the first travel sensor signal 18s of the first travel sensor 18a lies within a first comparison value range W1 and whether the second value h of the second travel sensor signal 20s of the second travel sensor 20a, which is preferably read simultaneously with the evaluated first value h, lies within a second comparison value range W2. The first comparison value range W1 is to be understood as a predefined value range or a value range determined by the electronic device 14a, within which values ​​of the first travel sensor signal 18s lie during a probable presence of the driver brake force transmission element 18 in its first starting position.Accordingly, the second comparison value range W2 is also to be understood as a predefined value range or a value range determined by the electronic device 14a, which comprises values ​​of the second displacement sensor signal 20s when the engine power transmission element 20 is likely to be in its second initial position. The first comparison value range W1 and / or the second comparison value range W2 can be stored in a memory (not shown) of the electronic device 14a. Optionally, the first comparison value range W1 and the second comparison value range W2 can be defined and stored either during production of the electronic device 14a and / or at any time during use of the evaluation device 14 / its electronic device 14a on the respective vehicle / motor vehicle.A respective width of the first comparison value range W1 and / or the second comparison value range W2 can correspond to an error deviation of the respective displacement sensor 18a or 20a.

[0036] By means of the points Pi in the coordinate systems of Fig. 1 b and 1 c, a first value pair Pi is marked, which comprises a first value h of the first displacement sensor signal 18s read at a first point in time and a second value h of the second displacement sensor signal 20s read at the same first point in time. The values ​​h and h of the first value pair Pi each lie within the associated comparison value range W1 or W2. In contrast, by means of the points P2 marked in the coordinate systems of Fig. 1 b and 1 c, a second value pair P2 is shown, which comprises a first value h of the first displacement sensor signal 18s read at a second point in time and a second value X2 of the second displacement sensor signal 20s read at the same second point in time. In contrast to the first value pair Pi, at least one of the values ​​h and h of the second value pair P2 lies outside its associated comparison value range W1 or W2.

[0037] Based on the presence of both values ​​h and h of the first value pair Pi in the assigned comparison value range W1 or W2, it can therefore be reliably determined that the brake actuating element 22 connected to the driver brake force transmission element 18 is not actuated by the driver of the vehicle / motor vehicle at the first point in time and therefore the driver brake force transmission element 18 and the engine power transmission element 20 are both in their respective starting positions at the first point in time. In contrast, the presence of at least one of the values ​​h and h of the second value pair P2 outside its assigned comparison value range W1 or W2 indicates that the brake actuating element 22 is / is being actuated by the driver at the second point in time and thus at least the driver brake force transmission element 18 is displaced from its first starting position and possibly also the engine power transmission element 20 from its second starting position.

[0038] In summary, it is therefore advantageous that, if the first value h lies in the first comparison value range W1 and the second value h lies in the second comparison value range W2, the electronic device 14a is designed and / or programmed to specify as actuation information for the brake booster 10 that the brake actuation element 22 is not actuated, the driver brake force transmission element 18 is in its first starting position and / or that the engine force transmission element 20 is in its second starting position.The design / programming of the electronic device 14a described here takes into account that, due to the design of the travel sensors 18a and 20a for outputting periodically varying travel sensor signals 18s and 20s, only one of the travel sensor signals 18s and 20s can be present in its associated comparison value range W1 or W2 even when the brake actuating element 22 is actuated and therefore at least the driver brake force transmission element 18 is moved from its first initial position and possibly also the engine force transmission element 20 is moved from its second initial position. In contrast, both travel sensor signals 18s and 20s are never present in their associated comparison value ranges W1 or W2 if the driver actuates the brake actuating element 22 while the engine 16 is in its inactive mode.

[0039] By comparing both the first value h of the first travel sensor signal 18s with its first comparison value range W1 and the second value h of the second travel sensor signal 20s with its second comparison value range W2, the electronic device 14a ensures that only when the motor 16 is in its inactive mode is it determined as actuation information that the brake actuation element 22 is unactuated, the driver brake force transmission element 18 is in its first initial position and / or that the motor force transmission element 20 is in its second initial position, when there is actually no actuation of the brake actuation element 22 by the driver and it can therefore be reliably concluded that the driver brake force transmission element 18 and the motor force transmission element 20 are jointly in their initial positions.

[0040] Optionally, the electronic device 14a can also be designed and / or programmed, before, after, or simultaneously with a comparison of the values ​​h and h of the displacement sensor signals 18s and 20s with the comparison value ranges Wi or W2 assigned to them, to determine or verify whether / that the motor 16 is actually still in its inactive mode. The inactive mode can be understood as a de-energized mode and / or switched-off mode of the motor 16, in which the motor 16 is present before an activation / starting of the motor 16. In particular, while the motor 16 is in its inactive mode, a (not sketched) rotor of the motor 16 can be in its de-energized rotor starting position relative to a stator of the motor 16, i.e., in a position in which the rotor (usually) remains before an activation / starting of the motor 16.For example, the electronic device 14a can be designed and / or programmed to detect, based on at least one motor sensor signal 16s of the at least one motor sensor 16a, whether the motor is in its inactive mode. Specifically, the electronic device 14a can be used to examine, based on the at least one motor sensor signal 16s of the at least one motor sensor 16a, such as in particular the rotor position sensor, whether the rotor is in its de-energized initial position relative to the stator. Alternatively or additionally, the electronic device 14a can also be designed and / or programmed to detect, based on at least one information signal 30s provided to the electronic device 14a by a controller 30 of the motor 16, whether the motor 16 is in its inactive mode. Optionally, the evaluation device 14 can also be part of the controller 30 of the motor 16.If the first value h lies outside the first comparison value range Wi and / or the second value h lies outside the second comparison value range W2, the electronic device 14a can additionally be designed and / or programmed to specify as actuation information for the brake booster 10 that the brake actuation element 22 is actuated and / or at least the driver brake force transmission element 18 is adjusted from its first starting position.As an advantageous development, if the first value h lies outside the first comparison value range W1 and / or the second value h lies outside the second comparison value range W2, a differential travel As between the first adjustment travel Xi of the driver brake force transmission element 18 from its first starting position and the second adjustment travel X2 of the engine force transmission element 20 from its second starting position can also be determined by means of the electronic device 14a, taking into account the first value h of the first travel sensor signal 18s and the second value h of the second travel sensor signal 20s, which is preferably read simultaneously with the evaluated first value h. For this purpose, the electronic device 14a determines first adjustment travels Xi of the driver brake force transmission element 18 and second adjustment travels X2 of the engine force transmission element 20, for which equations (Eq. 1) and (Eq. 2) apply:.

[0041] (Eq. 1 ) Xi = fi(h) + ni * in, with m = {0, 1, 2, 3, ...}

[0042] (Eq. 2) X2 = f2 (I2) + n2 * 712, with 112 = {0, 1, 2, 3, . . .}

[0043] The functions f1, f2, the first period width 711, with which the first displacement sensor signal 18s periodically varies, and the second period width 712, with which the second displacement sensor signal 20s periodically varies, can be stored in the memory of the electronic device 14a. The electronic device 14a is then designed / programmed to generate a pair of values ​​from the first displacement paths Xi determined by means of equation (Eq. 1) and the second displacement paths X2 determined by means of equation (Eq. 2), and to select for which equation (Eq. 3) applies with:

[0044] (Eq. 3) %1 ^2 — ASmax As already explained above, the differential travel As increases during an initial adjustment of the driver brake force transmission element 18 from its first initial position from zero to the threshold travel ASmax, while the engine force transmission element 20 is in its second initial position, where from a differential travel As equal to the threshold travel As max the engine force transmission element 20 is adjusted together with the driver brake force transmission element 18. As a rule, the differential travel As is therefore less than or equal to the threshold travel As max . Therefore, it can be reliably assumed that any pair of values ​​and j satisfying equation (GL 3) is suitable for determining the differential path As.

[0045] The electronic device 14a then determines the differential travel As using the selected value pair x^ and j according to equation (Eq. 4):

[0046] (Eq. 4) As = x^ - x^

[0047] The situation described in the previous paragraph can be used for an advantageous functional extension of the evaluation device 14, in that its electronic device 14a is designed and / or programmed to determine whether the determined differential travel As is smaller than the threshold travel As max If the differential travel As is smaller than the threshold travel As max is, the electronic device 14a can additionally determine as actuation information for the brake booster 10 that the brake actuation element 22 is actuated, the driver brake force transmission element 18 by less than the threshold travel As max from its first initial position and / or that the motor force transmission element 20 is in its second initial position. Otherwise, ie if the differential travel As is equal to the threshold travel As maxis, the electronic device 14a is preferably designed / programmed to specify as actuation information for the brake booster 10 that the brake actuation element 22 is actuated, the driver brake force transmission element 10 by more than the threshold travel As max is adjusted from its first starting position and / or that the motor power transmission element 20 is advanced from its second starting position.

[0048] Furthermore, if the differential travel As is smaller than the threshold travel As max is, the electronic device 14a is designed and / or programmed to use as actuation information for the brake booster 10 a value between the first initial position and the threshold travel As maxcurrent first position of the driver brake force transmission element 18 and / or the first adjustment path Xi of the driver brake force transmission element 18 lying below the threshold path ASmax from its first initial position, taking into account the determined differential path As. In particular, for the path below the threshold path As max lying first adjustment path Xi of the driver brake force transmission element 18 from its first initial position equation (GL 4) with:

[0049] (Eq. 4) Xi = As

[0050] If necessary, ie if the differential travel As is smaller than the threshold travel As max In addition, the second starting position can be set as the current second position of the motor force transmission element 20 and / or the second adjustment path X2 of the motor force transmission element 20 from its second starting position can be set equal to zero.

[0051] The evaluation device 14 can, for example, output the actuation information determined by its electronic device 14a to the controller 30 of the motor 16 by means of an output signal 14s. In this case, the controller 30 can control the motor 16 taking the actuation information into account, although this is not illustrated in Fig. 1a.

[0052] The brake booster 10, which cooperates with / is equipped with the above-described evaluation device 14, also ensures the described advantages. The first displacement sensor signal 18s of the first displacement sensor 18a can be a first sawtooth signal with the first period width TU, while the second displacement sensor signal 20s of the second displacement sensor 20a is a second sawtooth signal with the second period width 712. Preferably, the first period width 711 of the first displacement sensor 18a is greater than the threshold displacement As. max , so that for each differential path As smaller than the threshold path As maxonly a first adjustment path Xi is assigned to a read first value h. The second period width 712 of the second displacement sensor 20a is also preferably greater than the threshold path Asmax, so that only a second adjustment path X2 can be assigned to a first adjustment path Xi for a read value h according to equation (Eq. 3). The first period width 711 can optionally be equal to the second period width 712. If the first period width 711 is equal to the second period width 712, however, it is advantageous if the first period width 711 (or the second period width 712) is dependent on the threshold path As max and any integer multiple of the threshold path As max deviates (see Fig. 1 c).

[0053] Alternatively, the first period width 711 of the first displacement sensor 18a can also deviate from the second period width 712 of the second displacement sensor 20a. Thus, the first period width 711 of the first displacement sensor 18a and the second period width 712 of the second displacement sensor 20a can be selected such that they are optimal for the displacement sensing of the respectively assigned force transmission element 18 or 20. However, if the first period width 711 deviates from the second period width 712, an amount of a difference between the first period width 711 and the second period width 712 should also be taken into account by the threshold displacement As. max and any integer multiple of the threshold path As max differ.

[0054] Fig. 2 shows a flow chart for explaining an embodiment of the method for determining actuation information for a motorized brake booster of a vehicle brake system.

[0055] The method described below can be carried out, for example, using the brake booster of Fig. 1a explained above. However, it should be noted that the method is not limited to this type of brake booster. Instead, the method can be carried out using (almost) any brake booster that is located upstream of a master brake cylinder and is equipped with a motor, a driver brake force transmission element that can be adjusted from its first starting position by means of a driver brake force, a motor force transmission element that can be adjusted from its second starting position, a first travel sensor associated with the driver brake force transmission element, and a second travel sensor associated with the motor force transmission element.Furthermore, the feasibility of the method is limited neither to a specific braking system type of the vehicle braking system nor to a specific vehicle / motor vehicle type equipped with the vehicle braking system. The motor force transmission element is to be understood as a force transmission element that is adjustable both by operation of the motor and by the driver brake force transmission element, which is adjusted from its first starting position by at least a predetermined threshold travel. By means of the first travel sensor, a first travel sensor signal is output as a signal that periodically varies depending on a first adjustment travel of the driver brake force transmission element from its first starting position.Accordingly, a second travel sensor signal is / is output by the second travel sensor as a signal that varies periodically depending on a second adjustment path of the motor power transmission element from its second initial position.

[0056] The method described here is executed while the engine is in its inactive mode and before activating / starting the engine. Therefore, the method can optionally include a method step

[0057] 50, in which the presence of the motor in its inactive mode is queried or verified. Options for determining or verifying the presence of the motor in its inactive mode have already been described above.

[0058] In a method step S1, it is determined whether a first value of the first travel sensor signal of the first travel sensor lies within a first comparison value range that is predetermined or determined for / when the driver brake force transmission element is in its first starting position. Before, after, or simultaneously with the method step S1, a method step S2 is also carried out. In the method step S2, it is determined whether a second value of the second travel sensor signal of the second travel sensor lies within a second comparison value range that is predetermined or determined for / when the engine force transmission element is in its second starting position. Preferably, the values ​​determined in the method step

[0059] 51 with the first comparison value range and the second value compared in method step S2 with the second comparison value range are read at (almost) the same time from the first displacement sensor signal of the first displacement sensor and the second displacement sensor signal of the second displacement sensor. Alternatively, the first value compared in method step S1 with the first comparison value range and the second value compared in method step

[0060] 52 The second value compared with the second comparison value range can also be read at different times from the respective travel sensor signal of the associated travel sensor, provided that (essentially) no movement of the driver brake force transmission element or the engine force transmission element is to be expected between the different times.

[0061] As already explained above, if both values ​​of the travel sensor signals from the first and second travel sensors are within the associated comparison value range Wi or W2, it can be reliably detected that a brake actuating element connected to the driver brake force transmission element, such as a brake pedal, is still unactuated and therefore the driver brake force transmission element and the engine power transmission element are both in their respective initial positions. In contrast, the presence of at least one of the values ​​of the travel sensor signals from the first and second travel sensors outside its associated comparison value range indicates that the driver has already actuated the brake actuating element and, in this way, has moved at least the driver brake force transmission element from its first initial position and possibly also the engine power transmission element from its second initial position.

[0062] The method described here therefore also includes a method step S3, which is executed if it is determined in method steps S1 and S2 that the first value Xi is within the first comparison value range and the second value X2 is within the second comparison value range. In method step S3, the actuation information is determined to be that the brake actuation element is not actuated, the driver brake force transmission element is in its first initial position, and / or that the engine force transmission element is in its second initial position.

[0063] The method described here can also be used to reliably detect or verify a (current) actuation of the brake actuation element while the engine is in its inactive mode.

[0064] Optionally, the method may also include an (optional) method step S4, which is executed if the first value lies outside the first comparison value range and / or the second value lies outside the second comparison value range. In method step S4, the actuation information for the brake booster is determined to be that the brake actuation element is actuated and / or that at least the driver brake force transmission element is displaced from its first initial position.

[0065] As an alternative or in addition to method step S4, if the first value lies outside the first comparison value range and / or the second value lies outside the second comparison value range, an (optional) method step S5 can also be executed. As method step S5, a differential travel between the first adjustment travel of the driver brake force transmission element from its first initial position and the second adjustment travel of the engine force transmission element from its second initial position can be determined, taking into account the first value of the first travel sensor signal and the second value of the second travel sensor signal. Formulas for determining the differential travel have already been given above.

[0066] In a further (optional) method step S6, it can be determined whether the differential travel is smaller than the threshold travel. If the differential travel is smaller than the threshold travel, in an (optional) method step S7, the actuation information for the brake booster can be determined as follows: that the brake actuation element is actuated, the driver brake force transmission element is displaced from its first starting position by less than the threshold travel, and / or that the engine force transmission element is in its second starting position. Alternatively, i.e.If the differential travel is equal to the threshold travel, in an (optional) method step S8 it can be determined as actuation information for the brake booster that the brake actuation element is actuated, the driver brake force transmission element is adjusted by more than the threshold travel from its first starting position and / or that the engine force transmission element is advanced from its second starting position.

[0067] If the differential travel As is smaller than the threshold travel, an (optional) method step S9 can also be carried out as an alternative or in addition to method step S7. In method step S9, a current first position of the driver brake force transmission element lying between the first starting position and the threshold travel and / or the first adjustment travel of the driver brake force transmission element from its first starting position lying below the threshold travel can be defined as actuation information for the brake booster, taking the differential travel into account. Accordingly, in method step S9, the second starting position can also be defined as the current second position of the engine force transmission element and / or the second adjustment travel X2 of the engine force transmission element 20 from its second starting position can be defined as zero.Process step S9 thus provides absolute positions of the driver brake force transmission element and the engine force transmission element when the brake actuation element is actuated.

Claims

Claims 1 . Evaluation device (14) for a motorized brake booster (10) of a vehicle braking system, comprising: an electronic device (14a) which, when a motor (16) of the brake booster (14) upstream of a master brake cylinder (12) is in its inactive mode, is designed and / or programmed to determine: - whether a first value (h) of a first travel sensor signal (18s) of a first travel sensor (18), which is assigned to a driver brake force transmission element (18) of the brake booster (10) and by means of which the first travel sensor signal (18s) is output as a signal that varies periodically as a function of a first adjustment path (xi) of the driver brake force transmission element (18) from its first initial position, lies within a first comparison value range (Wi) predetermined or determined for the presence of the driver brake force transmission element (18) in its first initial position; and - whether a second value (h) of a second travel sensor signal (20s) of a second travel sensor (20a), which is assigned to a position sensor (16) which is moved from its first initial position by at least a predetermined threshold travel As maxadjusted driver brake force transmission element (18) is assigned to an adjustable motor force transmission element (20) of the brake booster (10) and by means of which the second travel sensor signal (20s) is output as a signal which varies periodically as a function of a second adjustment path (X2) of the motor force transmission element (20) from its second starting position, lies within a second comparison value range (W2) predetermined or determined for the presence of the motor force transmission element (20) in its second starting position; Wherein, if the first value (h) lies in the first comparison value range (Wi) and the second value (h) lies in the second comparison value range (W2), the electronic device (14a) is designed and / or programmed to specify, as actuation information for the brake booster (10), that a brake actuation element (22) connected to the driver brake force transmission element (18) is not actuated, the driver brake force transmission element (18) is in its first initial position, and / or that the engine force transmission element (20) is in its second initial position. Evaluation device (14) according to claim 1, wherein the electronic device (14a) is additionally designed and / or programmed to detect, based on at least one engine sensor signal (16s) from at least one engine sensor (16a) of the engine (16) and / or based on at least one information signal (30s) provided to the electronic device (14a) by a controller (30) of the engine (16),whether the motor (16) is in its inactive mode, and wherein the electronic device (14a) is designed and / or programmed to determine, as actuation information for the brake booster (10), only when the motor (16) is in its inactive mode and the first value (h) is in the first comparison value range (W1) and the second value (I2) is in the second comparison value range (W2). Evaluation device (14) according to claim 1 or 2, wherein, if the first value (h) is outside the first comparison value range (W1) and / or the second value (I2) is outside the second comparison value range (W2), the electronic device (14a) is additionally designed and / or programmed toa differential travel As between the first adjustment travel (xi) of the driver brake force transmission element (18) from its first initial position and the second adjustment travel (X2) of the engine force transmission element (20) from its second initial position, taking into account the first value (h) of the first displacement sensor signal (18s) and the second value (h) of the second displacement sensor signal (20s). Evaluation device (14) according to claim 3, wherein the differential displacement As can be determined by means of the electronic device (14a) by the electronic device (14a) being designed and / or programmed to: - to determine first adjustment paths Xi of the driver brake force transmission element (18) and second adjustment paths X2 of the engine force transmission element (20), for which the following applies: Xi = fi(h) + ni * in, with m = {0, 1, 2, 3, ...} and X2 = f2 (I2) + n2 * 712, with 112 = {0, 1, 2, 3, ...}, wherein the functions fi, f2, the first period width 711, with which the first displacement sensor signal (18s) varies periodically, and the second period width 712, with which the second displacement sensor signal (20s) varies periodically, are stored in a memory of the electronic device (14a), - to select a pair of values ​​and xj from the determined first adjustment paths Xi and the determined second adjustment paths X2, for which applies: ASmax, and to determine the difference path As according to: As = - x^. Evaluation device (14) according to claim 3 or 4, wherein the electronic device (14a) is additionally designed and / or programmed to determine whether the differential travel As is smaller than the threshold travel As max and, if the differential travel As is smaller than the threshold travel As maxis to specify as actuation information for the brake booster (10) that the brake actuation element (22) is actuated, the driver brake force transmission element (18) by less than the threshold travel As max is displaced from its first initial position and / or that the motor force transmission element (20) is in its second initial position, and / or, if the differential travel As is equal to the threshold travel As max is to specify as actuation information for the brake booster (10) that the brake actuation element (22) is actuated, the Driver brake force transmission element (18) is displaced from its first starting position by more than the threshold travel ASmax and / or that the engine force transmission element (20) is advanced from its second starting position. Evaluation device (14) according to claim 5, wherein, if the differential travel As is smaller than the threshold travel As maxthe electronic device (14a) is designed and / or programmed to use as actuation information for the brake booster (10) a value between the first initial position and the threshold travel As max current first position of the driver brake force transmission element (18) and / or the threshold travel As maxto determine the first adjustment path (xi) of the driver brake force transmission element (18) adjusted from its first starting position, taking into account the differential path As. Motorized brake booster (10), which is or can be arranged upstream of a master brake cylinder (12) of a vehicle brake system, comprising: an evaluation device (14) according to one of the preceding claims; the driver brake force transmission element (18), which is adjustable from its first starting position by means of a driver brake force (Fdriver); the motor force transmission element (20), which is adjustable from its first starting position by at least the predetermined threshold path As both by means of operation of the motor (16) of the brake booster (10) and by means of the maxadjusted driver brake force transmission element (18) is adjustable from its second starting position; the first travel sensor (18a), which is assigned to the driver brake force transmission element (18) and whose first travel sensor signal (18s) varies periodically with a first period width (m) as a function of the first adjustment path (xi) of the driver brake force transmission element (18) from its first starting position; and the second displacement sensor (20a), which is assigned to the motor power transmission element (20) and whose second displacement sensor signal (20s) varies periodically with a second period width (712) as a function of the second adjustment path (X2) of the motor power transmission element (20) from its second initial position. Motorized brake booster (10) according to claim 7, wherein the first displacement sensor signal (18s) of the first displacement sensor (18a) is a first sawtooth signal with the first period width (711) and / or the second displacement sensor signal (20s) of the second displacement sensor (20a) is a second sawtooth signal with the second period width (TI S ). Motorized brake booster (10) according to claim 7 or 8, wherein the first period width (711) of the first displacement sensor (18a) and / or the second period width (712) of the second displacement sensor (20a) is greater than the threshold displacement As maxMotorized brake booster (10) according to one of claims 7 to 9, wherein the first period width (711) of the first displacement sensor (18a) is equal to the second period width (712) of the second displacement sensor (20a), and wherein the first period width (711) is determined by the threshold displacement As max and any integer multiple of the threshold path As max Motorized brake booster (10) according to one of claims 7 to 9, wherein the first period width (711) of the first displacement sensor (18a) deviates from the second period width (712) of the second displacement sensor (20a), and wherein an amount of a difference between the first period width (711) and the second period width (712) of the threshold displacement As max and any integer multiple of the threshold path As maxdeviates. Method for determining actuation information for a motorized brake booster (10) of a vehicle braking system, wherein, while a motor (16) of the brake booster (10) upstream of a master brake cylinder (12) is in its inactive mode, the following steps are carried out: Determining whether a first value (h) of a first travel sensor signal (18s) of a first travel sensor (18a), which is assigned to a driver brake force transmission element (18) of the brake booster (10) and by means of which the first travel sensor signal (18s) is output as a signal periodically varying as a function of a first adjustment path (xi) of the driver brake force transmission element (18) from its first initial position, lies within a first comparison value range (Wi) predetermined or determined for the presence of the driver brake force transmission element (18) in its first initial position (S1); and Determining whether a second value (h) of a second travel sensor signal (20s) of a second travel sensor (20a), which is assigned to a sensor which is moved from its first initial position by at least a predetermined threshold travel As by means of an operation of the motor (16) as well as by means of the sensor maxadjusted driver brake force transmission element (18) is assigned to an adjustable motor force transmission element (20) of the brake booster (10) and by means of which the second travel sensor signal (20s) is output as a signal which varies periodically as a function of a second adjustment path (X2) of the motor force transmission element (20) from its second starting position, lies within a second comparison value range (W2) predetermined or determined for the presence of the motor force transmission element (20) in its second starting position (S2);wherein, if the first value (h) lies in the first comparison value range (W1) and the second value (h) lies in the second comparison value range (W2), it is determined as actuation information that a brake actuation element (22) connected to the driver brake force transmission element (18) is not actuated, the driver brake force transmission element (18) is in its first starting position and / or that the engine force transmission element (20) is in its second starting position (S3).;

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