DE102022211135A1 - Evaluation device and method for determining actuation information for a motorized brake booster of a vehicle braking system - Google Patents

Abstract

The invention relates to an evaluation device (14) and a method for determining actuation information for a motorized brake booster (10) of a vehicle brake system while its motor (16) is in its inactive mode, by determining whether a first value (I1) of a first travel sensor (18a) of its driver brake force transmission element (18) as a signal that varies periodically depending on a first adjustment path (x1) of the driver brake force transmission element (18) from its first starting position lies within a first comparison value range (W1), and determining whether a second value (I2) of a second travel sensor (20a) of its motor force transmission element (20) that can be adjusted by means of operation of the motor (16) as well as by means of the driver brake force transmission element (18) adjusted from its first starting position by at least a predetermined threshold path Δsmax lies within a first comparison value range (W1). second starting position periodically varying signal lies within a second comparison value range (W2), wherein, if appropriate, it is determined that a connected brake actuating element (22) is not actuated, the driver brake force transmission element (18) is in its first starting position and/or the engine force transmission element (20) is in its second starting position.

Description

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

State of the art

From the state of the art, such as the EN 10 2020 209 754 A1 , motorized brake boosters are known which can be/are mounted upstream of a master brake cylinder of a vehicle brake system. Such a motorized brake booster has a driver brake force transmission element, via which a driver brake force exerted on a brake actuation element can be transmitted to at least one adjustable piston of the master brake cylinder. In addition, such a motorized brake booster comprises a motor and a motor force transmission element which can be adjusted both by operating the motor and by means of the driver brake force transmission element adjusted by at least one predetermined threshold travel in such a way that the driver brake force transmitted to the at least one adjustable piston of the master brake cylinder can be amplified by a motor force of the motor.

Disclosure of the invention

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

Advantages of the invention

The present invention provides advantageous possibilities for reliably determining actuation information for/about a motorized brake booster of a vehicle brake 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 depending on an adjustment movement of the respective force transmission element. Although inexpensive sensor types are used in the respective brake booster, the use of the present invention can nevertheless reliably determine or check 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 possible presence of the motor force transmission element in its second starting position while a motor of the brake booster is in its inactive mode. The present invention also provides possibilities for displacement sensor initialization for the respective motorized brake booster.

In an advantageous embodiment of the evaluation device, the electronic device is additionally designed and/or programmed to detect, based on at least one engine sensor signal from at least one engine sensor of the engine and/or based on at least one information signal provided to the electronic device by a control 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 not actuated, 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 therefore already 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.

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

$${\text{x}}_2={\text{f}}_2\left({\text{I}}_2\right)+{\text{n}}_2*{\mathrm{\pi }}_2,{\text{ mit n}}_2=\left\{\mathrm{0,1,2,3,}\dots \right\},$$

wobei die Funktionen f₁, f₂, die erste Periodenbreite π₁, mit welcher das erste Wegsensorsignal (18s) periodisch variiert, und die zweite Periodenbreite π₂, mit welcher das zweite Wegsensorsignal (20s) periodisch variiert, auf einem Speicher der Elektronikeinrichtung (14a) hinterlegt sind. Anschließend kann die Elektronikeinrichtung dazu ausgelegt und/oder programmiert sein, aus den ermittelten ersten Verstellwegen x₁ und den ermittelten zweiten Verstellwegen x₂ ein Wertepaar $\widetilde{x_1}$

und $\widetilde{x_2}$

auszuwählen, für welches gilt: $\widetilde{x_1}-\widetilde{x_2}\le \mathrm{\Delta }{\text{s}}_{\text{max}},$

und den Differenzweg Δs festzulegen gemäß: $\mathrm{\Delta }s=\widetilde{x_1}-\widetilde{x_2}.$

Dies ermöglicht die Festlegung/Bestimmung eines verlässlichen Differenzwegs Δs mittels einer vergleichsweise kostengünstigen Elektronik der Elektronikeinrichtung.For example, the differential travel Δs can be determined by means of the electronic device in that the electronic device is designed and/or programmed to determine first adjustment travels x ₁ of the driver brake force transmission element and second adjustment travels x ₂ of the engine force transmission element, for which the following applies: $${\text{x}}_1={\text{e}}_1\left({\text{I}}_1\right)+{\text{<figure-callout id="1" label="n" filenames="DE102022211135A1\_0025.png" state="{{state}}">n</figure-callout>}}_1*{\mathrm{<figure-callout\; id="1"\; label="\pi "\; filenames="DE102022211135A1\_0025.png"\; state="\{\{state\}\}">\pi </figure-callout>}}_1,{\text{with <figure-callout id="1" label="n" filenames="DE102022211135A1\_0025.png" state="{{state}}">n</figure-callout>}}_1=\left\{\mathrm{0,1,2,3,}\dots \right\}\text{and}$$

$${\text{x}}_2={\text{e}}_2\left({\text{I}}_2\right)+{\text{n}}_2*{\mathrm{\pi }}_2,{\text{with n}}_2=\left\{\mathrm{0,1,2,3,}\dots \right\},$$

wherein the functions f ₁ , f ₂ , the first period width π ₁ , with which the first displacement sensor signal (18s) varies periodically, and the second period width π ₂ , with which the second displacement sensor signal (20s) varies periodically, are stored in a memory of the electronic device (14a). The electronic device can then be designed and/or programmed to determine a pair of values from the determined first adjustment paths x ₁ and the determined second adjustment paths x ₂ $\widetilde{x_1}$

and $\widetilde{x_2}$

to select which applies: $\widetilde{x_1}-\widetilde{x_2}\le \mathrm{\Delta }{\text{s}}_{\text{Max}},$

and to determine the differential travel Δs according to: $\mathrm{\Delta }s=\widetilde{x_1}-\widetilde{x_2}.$

This enables the specification/determination of a reliable differential travel Δs by means of a comparatively cost-effective electronics of the electronic device.

In a further advantageous embodiment of the evaluation device, the electronic device is additionally designed and/or programmed to determine whether the difference path Δs is smaller than the threshold path and, if the difference path Δs is smaller than the threshold path, 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 path from its first starting position and/or that the motor force transmission element is in its second starting position and/or, if the difference path Δs is equal to the threshold path, 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 more than the threshold path from its first starting position and/or that the motor force transmission element is advanced from its second starting position. Using the embodiment of the evaluation device/its electronic device described here, a large number of pieces of information can thus be specified as actuation information for/about the brake booster.

As an advantageous further development, if the differential travel Δs is smaller than the threshold travel, the electronic device can be designed and/or programmed to determine as actuation information for the brake booster 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 adjusted from its first starting position lying below the threshold travel, taking the differential travel Δs into account. The embodiment of the evaluation device described here can therefore carry out a travel sensor initialization if necessary.

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 can be adjusted from its first starting position by means of a driver brake force, the motor force transmission element which can be adjusted from its second starting position both by operating 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 travel of the driver brake force transmission element from its first starting position, and the second travel sensor which is assigned to the motor force transmission element and whose second travel sensor signal varies periodically with a second period width as a function of the second adjustment travel of the motor force transmission element from its second starting position.

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.

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 a particularly precise and reliable displacement sensor initialization by means of its evaluation device.

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 every 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 every integer multiple of the threshold travel. It is therefore not necessary to equip the brake booster with travel sensors that have 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.

The above-mentioned advantages are also created by carrying out a corresponding method for determining actuation information for a motorized brake booster of a vehicle brake system. It is expressly pointed out that the method can be further developed according to the embodiments of the evaluation device and/or the motorized brake booster explained above.

Short description of the drawings

• 1a bis 1c eine schematische Darstellung eines motorisierten Bremskraftverstärkers und zwei Koordinatensysteme zum Erläutern einer Funktionsweise einer Ausführungsform der Auswertevorrichtung; und
• 2 ein Flussdiagramm zum Erläutern einer Ausführungsform des Verfahrens zum Ermitteln einer Betätigungsinformation für einen motorisierten Bremskraftverstärker eines Fahrzeugbremssystems.

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

• 1a to 1c a schematic representation of a motorized brake booster and two coordinate systems for explaining the functionality of an embodiment of the evaluation device; and
• 2 a flow chart for explaining an embodiment of the method for determining actuation information for a motorized brake booster of a vehicle braking system.

Embodiments of the invention

1a to 1c show a schematic representation of a motorized brake booster and two coordinate systems for explaining a functioning of an embodiment of the evaluation device.

The 1a The schematically shown motorized brake booster 10 can be mounted/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 that can be operated externally from the brake booster 10.

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

The first displacement sensor 18a associated with the driver brake force transmission element 18 is understood to be a displacement sensor type whose first displacement sensor signal 18s varies periodically with a first period width π ₁ as a function of a first adjustment path x ₁ of the driver brake force transmission element 18 from its first starting position. Such a displacement sensor type is referred to below as a “periodic displacement sensor”. In the coordinate system of the 1b an abscissa indicates the first adjustment path x ₁ of the driver brake force transmission element 18 from its first starting position, while by means of an ordinate shows a corresponding first value I ₁ of the first displacement sensor signal 18s.

The motor power 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 power transmission element 20 is adjustable from its (powerless) second starting position by means of an operation of the motor 16 due to a motor force F _motor of the motor 16 transmitted to the motor power transmission element 20. The motor power transmission element 20 can be, for example, a valve body (boost body) 20. As a rule, the motor power transmission element 20 is connected to the motor 16 via a gear (not sketched).

However, even when the driver brake force transmission element 18 (by means of the driver brake force F _driver ) is adjusted from its first starting position by at least a predetermined threshold travel Δs _max , the motor force transmission element 20 can also 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 F _driver and by means of the motor force F _motor . The motor force transmission element 20 is generally only in its second starting position when the motor force F _motor is zero and the first adjustment travel x ₁ of the driver brake force transmission element 18 from its first starting position is smaller than the threshold travel Δs _max . In order to effect 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 path Δs _max , 1a Stops 24a and 24b, which are only shown schematically, may be formed on the driver brake force transmission element 18 and/or on the engine force transmission element 20.

The second displacement sensor 20a associated with the motor power transmission element 20 is also a “periodic displacement sensor”. This means that a second displacement sensor signal 20s of the second displacement sensor 20a also varies depending on a second adjustment path x ₂ of the motor power transmission element 20 from its second starting position with a second period width π ₂ . In the coordinate system of the 1c an abscissa corresponds to the second adjustment path x ₂ of the motor power transmission element 20 from its second starting position.

An ordinate of the coordinate system of the 2c indicates a corresponding second value I ₂ of the second displacement sensor signal 20s.

Optionally, the brake booster 10 can 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 motor force transmission element 20 such that the further force transmission element 26 can be adjusted in the direction of the master brake cylinder 12 based on the driver brake force F _driver and/or motor force F _motor transmitted to it. An addition element 28, such as specifically a reaction disk 28, can possibly 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 F _driver and the motor force F _motor can be “added” to the further force transmission element 26.

Optionally, a third displacement sensor 26a can also be arranged on the brake booster 10 for the further force transmission element 26, by means of which at least one third displacement sensor signal 26s can be output, which varies depending on a third adjustment path of the further force transmission element 26 from its third starting 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 with the third displacement sensor 26a.

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 the at least one motor sensor 16a.

The evaluation device 14 has an electronic device 14a which is designed and/or programmed, at least while the motor 16 is in its inactive mode and before the motor 16 is activated/started, to determine whether the first value I ₁ of the first displacement sensor signal 18s of the first displacement sensor 18a lies within a first comparison value range W ₁ and whether the second value I ₂ of the second displacement sensor signal 20s of the second displacement sensor 20a, which is preferably read at the same time as the evaluated first value I ₁ , lies within a second comparison value range W _2. The first comparison value range W ₁ is to be understood as a predetermined value range or a value range determined by the electronic device 14a, within which values of the first displacement sensor signal 18s during a probable chen presence of the driver brake force transmission element 18 in its first starting position. Accordingly, the second comparison value range W ₂ should also be understood as a predetermined value range or a value range determined by the electronic device 14a, which includes values of the second travel sensor signal 20s when the engine force transmission element 20 is likely to be in its second starting position. The first comparison value range W ₁ and/or the second comparison value range W ₂ can be stored in a memory (not shown) of the electronic device 14a. Optionally, the first comparison value range W ₁ and the second comparison value range W ₂ can be determined 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 W ₁ and/or the second comparison value range W ₂ can correspond to an error deviation of the respective displacement sensor 18a or 20a.

By means of the points P ₁ in the coordinate systems of the 1b and 1c a first value pair P ₁ is marked, which comprises a first value I ₁ of the first displacement sensor signal 18s read at a first time and a second value I ₂ of the second displacement sensor signal 20s read at the same first time. The values I ₁ and I ₂ of the first value pair P ₁ are each in the assigned comparison value range W ₁ or W ₂ . In contrast, by means of the coordinate systems of the 1b and 1c A second value pair P ₂ is shown at the marked points P ₂ , which comprises a first value I ₁ of the first displacement sensor signal 18s read at a second point in time and a second value x ₂ of the second displacement sensor signal 20s read at the same second point in time. In contrast to the first value pair P _{1 ,} at least one of the values I ₁ and I ₂ of the second value pair P ₂ lies outside its associated comparison value range W ₁ or W ₂ .

Based on the presence of both values I ₁ and I ₂ of the first value pair P ₁ in the associated comparison value range W ₁ or W ₂ , it can therefore be reliably recognized that the brake actuation 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 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 time. In contrast, the presence of at least one of the values I ₁ and I ₂ of the second value pair P ₂ outside its associated comparison value range W ₁ or W ₂ indicates that the brake actuation element 22 is/is actuated by the driver at the second time and thus at least the driver brake force transmission element 18 is moved from its first starting position and possibly also the engine power transmission element 20 from its second starting position.

In summary, it is therefore advantageous that, if the first value I ₁ is in the first comparison value range W ₁ and the second value I ₂ is in the second comparison value range W ₂ , 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 W ₁ or W ₂ even if the brake actuating element 22 is actuated and therefore at least the driver brake force transmission element 18 is moved from its first starting position and possibly also the engine force transmission element 20 from its second starting position. In contrast, both travel sensor signals 18s and 20s are never present in their associated comparison value ranges W ₁ or W ₂ if the driver actuates the brake actuating element 22 while the engine 16 is in its inactive mode.

By comparing both the first value I ₁ of the first travel sensor signal 18s with its first comparison value range W ₁ and the second value I ₂ of the second travel sensor signal 20s with its second comparison value range W ₂ , 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 not actuated, the driver brake force transmission element 18 is in its first starting position and/or that the motor force transmission element 20 is in its second starting 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 together in their starting positions.

Optionally, the electronic device 14a can also be designed and/or programmed to determine or verify whether/that the motor 16 is actually still in its inactive mode before, after or simultaneously with a comparison of the values I ₁ and I ₂ of the position sensor signals 18s and 20s with the comparison value ranges W ₁ or W ₂ assigned to them. The inactive mode can be understood to mean a non-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 non-energized rotor starting position in relation to a stator of the motor 16, ie in a position in which the rotor (as a rule) remains before an activation/starting of the motor 16. For example, the electronic device 14a can be designed and/or programmed to detect whether the motor is in its inactive mode based on at least one motor sensor signal 16s of the at least one motor sensor 16a. Specifically, the electronic device 14a can be used to examine whether the rotor is in its non-energized rotor starting position in relation to the stator 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. Alternatively or additionally, the electronic device 14a can also be designed and/or programmed to detect whether the motor 16 is in its inactive mode based on at least one information signal 30s provided to the electronic device 14a by a controller 30 of the motor 16. Optionally, the evaluation device 14 can also be part of the controller 30 of the motor 16.

$${\text{x}}_2={\text{f}}_2\left({\text{I}}_2\right)+{\text{n}}_2*{\mathrm{\pi }}_2,{\text{ mit n}}_2=\left\{\mathrm{0,1,2,3,}\dots \right\}$$

If the first value I ₁ is outside the first comparison value range W ₁ and/or the second value I ₂ is outside the second comparison value range W ₂ , 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 further development, if the first value I ₁ lies outside the first comparison value range W ₁ and/or the second value I ₂ lies outside the second comparison value range W ₂ , a differential path Δs between the first adjustment path x ₁ of the driver brake force transmission element 18 from its first starting position and the second adjustment path x ₂ 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 I ₁ of the first travel sensor signal 18s and the second value I ₂ of the second travel sensor signal 20s, which is preferably read at the same time as the evaluated first value I _1. To do this, the electronic device 14a determines first adjustment paths x ₁ of the driver brake force transmission element 18 and second adjustment paths x ₂ of the engine force transmission element 20, for which equations (Eq. 1) and (Eq. 2) apply: $${\text{x}}_1={\text{e}}_1\left({\text{I}}_1\right)+{\text{<figure-callout id="1" label="n" filenames="DE102022211135A1\_0025.png" state="{{state}}">n</figure-callout>}}_1*{\mathrm{<figure-callout\; id="1"\; label="\pi "\; filenames="DE102022211135A1\_0025.png"\; state="\{\{state\}\}">\pi </figure-callout>}}_1,{\text{with <figure-callout id="1" label="n" filenames="DE102022211135A1\_0025.png" state="{{state}}">n</figure-callout>}}_1=\left\{\mathrm{0,1,2,3,}\dots \right\}$$

$${\text{x}}_2={\text{e}}_2\left({\text{I}}_2\right)+{\text{n}}_2*{\mathrm{\pi }}_2,{\text{with n}}_2=\left\{\mathrm{0,1,2,3,}\dots \right\}$$

und $\widetilde{x_2}$

auszuwählen, für welche Gleichung (Gl. 3) gilt mit: $$\widetilde{x_1}-\widetilde{x_2}\le \mathrm{\Delta }{\text{s}}_{\text{max}}$$

The functions f ₁ , f ₂ , the first period width π ₁ , with which the first displacement sensor signal 18s varies periodically, and the second period width π ₂ , with which the second displacement sensor signal 20s varies periodically, can be stored in the memory of the electronic device 14a. The electronic device 14a is then designed/programmed to calculate a pair of values from the first adjustment paths x ₁ determined by means of the equation (Eq. 1) and the second adjustment paths x ₂ determined by means of the equation (Eq. 2). $\widetilde{x_1}$

and $\widetilde{x_2}$

to select for which equation (Eq. 3) applies with: $$\widetilde{x_1}-\widetilde{x_2}\le \mathrm{\Delta }{\text{s}}_{\text{Max}}$$

und $\widetilde{x_2}$

zur Festlegung des Differenzweg Δs geeignet ist.As already explained above, the differential travel Δs increases when the driver brake force transmission element 18 is initially adjusted from its first initial position from zero to the threshold travel Δs _max while the engine power transmission element 20 is in its second initial position, whereby from a differential travel Δs equal to the threshold travel Δs _max , the engine power transmission element 20 is also adjusted together with the driver brake force transmission element 18. As a rule, the differential travel Δs is therefore less than or equal to the threshold travel Δs _max . It can therefore be reliably assumed that each pair of values that satisfy equation (Eq. 3) $\widetilde{x_1}$

and $\widetilde{x_2}$

is suitable for determining the differential travel Δs.

und $\widetilde{x_2}$

gemäß Gleichung (Gl. 4) fest mit: $$\mathrm{\Delta }\text{s}=\widetilde{x_1}-\widetilde{x_2}$$

The electronic device 14a then determines the differential path Δs using the selected value pair $\widetilde{x_1}$

and $\widetilde{x_2}$

according to equation (Eq. 4) with: $$\mathrm{\Delta }\text{s}=\widetilde{x_1}-\widetilde{x_2}$$

The situation described in the previous paragraph can be used for an advantageous functional extension of the evaluation device 14 by its electronic device 14a being designed and/or programmed to determine whether the determined differential path Δs is smaller than the threshold travel Δs _max . If the difference travel Δs is smaller than the threshold travel Δs _max , the electronic device 14a can additionally 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 adjusted by less than the threshold travel Δs _max from its first starting position and/or that the motor force transmission element 20 is in its second starting position. Otherwise, i.e. if the difference travel Δs is equal to the threshold travel Δs _max , 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 is adjusted by more than the threshold travel Δs _max from its first starting position and/or that the motor force transmission element 20 is advanced from its second starting position.

Furthermore, if the differential travel Δs is smaller than the threshold travel Δs _max , the electronic device 14a can be designed and/or programmed to determine as actuation information for the brake booster 10 a current first position of the driver brake force transmission element 18 lying between the first starting position and the threshold travel Δs _max and/or the first adjustment travel x ₁ of the driver brake force transmission element 18 lying below the threshold travel Δs _max from its first starting position taking into account the determined differential travel Δs. In particular, equation (Eq. 4) applies to the first adjustment travel x ₁ of the driver brake force transmission element 18 lying below the threshold travel Δs _max from its first starting position: $${\text{x}}_1=\mathrm{\Delta }\text{s}$$

If necessary, ie if the differential travel Δs is smaller than the threshold travel Δs _max , the second starting position can additionally be set as the current second position of the motor power transmission element 20 and/or the second adjustment travel x ₂ of the motor power transmission element 20 from its second starting position can be set equal to zero.

The evaluation device 14 can, for example, output the actuation information determined by its electronic device 14a to the control 30 of the motor 16 by means of an output signal 14s. In this case, the control 30 can control the motor 16 taking the actuation information into account, but this is not possible in 1a is not reproduced pictorially.

The brake booster 10, which cooperates with/is equipped with the evaluation device 14 explained above, also ensures the advantages described. The first displacement sensor signal 18s of the first displacement sensor 18a can be a first sawtooth signal with the first period width π ₁ , while the second displacement sensor signal 20s of the second displacement sensor 20a is a second sawtooth signal with the second period width π ₂ . Preferably, the first period width π ₁ of the first displacement sensor 18a is greater than the threshold displacement Δs _max , so that for each differential displacement Δs smaller than the threshold displacement Δs _{max ,} only a first adjustment displacement x ₁ is assigned to a read first value I ₁ . The second period width π ₂ of the second displacement sensor 20a is also preferably greater than the threshold displacement Δs _max , so that only a second displacement x ₂ can be assigned to a first displacement x ₁ for a read value I ₁ according to equation (Eq. 3).

The first period width π ₁ can optionally be equal to the second period width π ₂ . If the first period width π ₁ is equal to the second period width π ₂ , it is advantageous if the first period width π ₁ (or the second period width π ₂ ) deviates from the threshold path Δs _max and any integer multiple of the threshold path Δs _max (see 1c ).

Alternatively, the first period width π ₁ of the first displacement sensor 18a can also deviate from the second period width π ₂ of the second displacement sensor 20a. The first period width π ₁ of the first displacement sensor 18a and the second period width π ₂ of the second displacement sensor 20 can thus be selected such that they are optimal for the displacement sensing of the respective associated force transmission element 18 or 20. However, if the first period width π ₁ deviates from the second period width π ₂ , an amount of a difference between the first period width π ₁ and the second period width π ₂ should also deviate from the threshold displacement Δs _max and every integer multiple of the threshold displacement Δs _max .

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.

The method described below can be carried out, for example, by means of the brake booster explained above. 1a 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 installed upstream of a master brake cylinder and is equipped with a motor, a brake pedal that can be adjusted from its first starting position by means of a driver's braking force. Driver brake force transmission element, an engine force transmission element that can be adjusted from its second starting position, a first travel sensor assigned to the driver brake force transmission element and a second travel sensor assigned to the engine force transmission element. Furthermore, the executability of the method is neither limited to a specific brake system type of the vehicle brake system nor to a specific vehicle type/motor vehicle type of the vehicle/motor vehicle equipped with the vehicle brake system.

The motor power transmission element is understood to be a power transmission element which is adjustable both by operating the motor and by means of the driver brake force transmission element adjusted from its first starting position by at least a predetermined threshold distance. A first travel sensor signal is output by means of the first travel sensor as a signal which varies periodically depending on a first adjustment path of the driver brake force transmission element from its first starting position. Accordingly, a second travel sensor signal is output by the second travel sensor as a signal which varies periodically depending on a second adjustment path of the motor power transmission element from its second starting position.

The method described here is carried out while the engine is in its inactive mode and before the engine is activated/started. Optionally, the method can therefore have a method step S0 in which the presence of the engine in its inactive mode is queried or verified. Options for determining or verifying the presence of the engine in its inactive mode have already been described above.

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

As already explained above, if both values of the travel sensor signals of the first and second travel sensors are in the associated comparison value range W ₁ or W ₂ , it can be reliably recognized that a brake actuating element connected to the driver brake force transmission element, such as a brake pedal, is not yet actuated and therefore the driver brake force transmission element and the engine force transmission element are both in their respective starting positions. On the other hand, the presence of at least one of the values of the travel sensor signals of 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 adjusted at least the driver brake force transmission element from its first starting position and possibly also the engine force transmission element from its second starting position.

The method described here therefore also has a method step S3, which is carried out if it is determined in method steps S1 and S2 that the first value x ₁ is in the first comparison value range and the second value x ₂ is in the second comparison value range. In method step S3, the actuation information is determined as being that the brake actuation element is not actuated, 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.

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.

Optionally, the method can also have an (optional) method step S4, which is carried out if the first value is outside the first comparison value range and/or the second value is 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 adjusted from its first starting position.

As an alternative or as a supplement to method step S4, if the first value is outside the first comparison value range and/or the second value is outside the second comparison value range, an (optional) method step S5 can also be carried out. As method step S5, a differential travel between the first adjustment travel of the driver brake force transmission element from its first starting position and the second adjustment travel of the engine force transmission element from its second starting 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.

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 it can be specified 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 starting position and/or that the motor 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 specified 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 motor force transmission element is advanced from its second starting position.

If the difference path Δs is smaller than the threshold path, 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 path and/or the first adjustment path of the driver brake force transmission element lying below the threshold path from its first starting position can be defined as actuation information for the brake booster, taking the difference path into account. Accordingly, in method step S9, the second starting position can also be defined as the current second position of the motor force transmission element and/or the second adjustment path x ₂ of the motor force transmission element 20 from its second starting position can be defined as zero. Method step S9 thus provides absolute positions of the driver brake force transmission element and the motor force transmission element when the brake actuation element is actuated.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102020209754 A1 [0002]

Claims (12)

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 present in its inactive mode, is designed and/or programmed to determine: - whether a first value (I ₁ ) 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 which varies periodically as a function of a first adjustment path (x ₁ ) of the driver brake force transmission element (18) from its first starting position, lies within a first comparison value range (W ₁ ) predetermined or determined for the presence of the driver brake force transmission element (18) in its first starting position; and - whether a second value (I ₂ ) of a second travel sensor signal (20s) of a second travel sensor (20a), which is assigned to a motor power transmission element (20) of the brake booster (10) that is adjustable both by means of operation of the motor (16) and by means of the driver brake force transmission element (18) adjusted from its first starting position by at least a predetermined threshold path Δs _max and by means of which the second travel sensor signal (20s) is output as a signal that periodically varies as a function of a second adjustment path (x ₂ ) of the motor power transmission element (20) from its second starting position, lies within a second comparison value range (W ₂ ) predetermined or determined for the presence of the motor power transmission element (20) in its second starting position; wherein, if the first value (I ₁ ) is in the first comparison value range (W ₁ ) and the second value (I ₂ ) is in the second comparison value range (W ₂ ), 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 starting position and/or that the engine force transmission element (20) is in its second starting 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 motor sensor signal (16s) of at least one motor sensor (16a) of the motor (16) and/or 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, and wherein the electronic device (14a) is designed and/or programmed to specify as actuation information for the brake booster (10) only when the motor (16) is in its inactive mode and the first value (I ₁ ) is in the first comparison value range (W ₁ ) and the second value (I ₂ ) is in the second comparison value range (W ₂ ), 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 motor force transmission element (20) is in its second starting position. Evaluation device (14) according to Claim 1 or 2 , wherein, if the first value (I ₁ ) is outside the first comparison value range (W ₁ ) and/or the second value (I ₂ ) is outside the second comparison value range (W ₂ ), the electronic device (14a) is additionally designed and/or programmed to determine a differential path Δs between the first adjustment path (x ₁ ) of the driver brake force transmission element (18) from its first starting position and the second adjustment path (x ₂ ) of the engine force transmission element (20) from its second starting position, taking into account the first value (I ₁ ) of the first travel sensor signal (18s) and the second value (I ₂ ) of the second travel sensor signal (20s). Evaluation device (14) according to Claim 3 , wherein the differential travel Δs can be determined by means of the electronic device (14a) in that the electronic device (14a) is designed and/or programmed to: - determine first adjustment travels x ₁ of the driver brake force transmission element (18) and second adjustment travels x ₂ of the engine force transmission element (20), for which the following applies: $${\text{x}}_1={\text{e}}_1\left({\text{I}}_1\right)+{\text{n}}_1*{\mathrm{\pi }}_1,{\text{with n}}_1=\left\{\mathrm{0,1,2,3,}\dots \right\}\text{and}$$

$${\text{x}}_2={\text{e}}_2\left({\text{I}}_2\right)+{\text{n}}_2*{\mathrm{\pi }}_2,{\text{with n}}_2=\left\{\mathrm{0,1,2,3,}\dots \right\},$$

wherein the functions f ₁ , f ₂ , the first period width π ₁ , with which the first displacement sensor signal (18s) varies periodically, and the second period width π ₂ , with which the second displacement sensor signal (20s) varies periodically, are stored in a memory of the electronic device (14a), - a pair of values is determined from the determined first adjustment paths x ₁ and the determined second adjustment paths x ₂ $\widetilde{x_1}$

and $\widetilde{x_2}$

to select which applies: $$\widetilde{x_1}-\widetilde{x_2}\le \mathrm{\Delta }{\text{s}}_{\text{Max}},$$

and to determine the differential travel Δs according to: $\mathrm{\Delta }\text{s}=\widetilde{x_1}-\widetilde{x_2}.$

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 Δs is smaller than the threshold travel Δs _max and, if the differential travel Δs is smaller than the threshold travel Δs _max , 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 adjusted by less than the threshold travel Δs _max from its first starting position and/or that the motor force transmission element (20) is in its second starting position and/or, if the differential travel Δs is equal to the threshold travel Δs _max , 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 adjusted by more than the threshold travel Δs _max from its first starting position and/or that the motor force transmission element (20) from its second starting position. Evaluation device (14) according to Claim 5 , wherein, if the differential travel Δs is smaller than the threshold travel Δs _max , the electronic device (14a) is designed and/or programmed to determine, as actuation information for the brake booster (10), a current first position of the driver brake force transmission element (18) lying between the first starting position and the threshold travel Δs _max and/or the first adjustment travel (x ₁ ) of the driver brake force transmission element (18) adjusted from its first starting position lying below the threshold travel Δs _max , taking into account the differential travel Δs. Motorized brake booster (10) which can be or is mounted upstream of a master brake cylinder (12) of a vehicle braking system, with: an evaluation device (14) according to one of the preceding claims; the driver brake force transmission element (18), which can be adjusted from its first starting position by means of a driver braking force (F _driver ); the motor force transmission element (20), which can be adjusted from its second starting position both by means of operation of the motor (16) of the brake booster (10) and by means of the driver brake force transmission element (18) adjusted from its first starting position by at least the predetermined threshold distance Δs _max ; the first displacement sensor (18a), which is assigned to the driver brake force transmission element (18) and whose first displacement sensor signal (18s) varies periodically as a function of the first adjustment distance (x ₁ ) of the driver brake force transmission element (18) from its first starting position with a first period width (π ₁ ); 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 (π ₂ ) depending on the second adjustment path (x ₂ ) of the motor power transmission element (20) from its second starting 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 (π ₁ ) and/or the second displacement sensor signal (20s) of the second displacement sensor (20a) is a second sawtooth signal with the second period width (π _s ). Motorized brake booster (10) according to Claim 7 or 8th , wherein the first period width (π ₁ ) of the first displacement sensor (18a) and/or the second period width (π ₂ ) of the second displacement sensor (20a) are greater than the threshold displacement Δs _max . Motorized brake booster (10) according to one of the Claims 7 until 9 , wherein the first period width (π ₁ ) of the first displacement sensor (18a) is equal to the second period width (π ₂ ) of the second displacement sensor (20a), and wherein the first period width (π ₁ ) deviates from the threshold displacement Δs _max and any integer multiple of the threshold displacement Δs _max . Motorized brake booster (10) according to one of the Claims 7 until 9 , wherein the first period width (π ₁ ) of the first displacement sensor (18a) deviates from the second period width (π ₂ ) of the second displacement sensor (20a), and wherein an amount of a difference between the first period width (π ₁ ) and the second period width (π ₂ ) deviates from the threshold displacement Δs _max and any integer multiple of the threshold displacement Δs _max . Method for determining actuation information for a motorized brake booster (10) of a vehicle brake 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 (I ₁ ) 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 determined as a function of a first adjustment path (x ₁ ) of the driver brake force transmission element (18) from its first output position periodically varying signal is output, lies within a first comparison value range (W ₁ ) predetermined or determined for the presence of the driver brake force transmission element (18) in its first starting position (S1); and determining whether a second value (I ₂ ) of a second displacement sensor signal (20s) of a second displacement sensor (20a), which is assigned to a motor power transmission element (20) of the brake booster (10) that is adjustable both by means of operation of the motor (16) and by means of the driver brake force transmission element (18) adjusted from its first starting position by at least a predetermined threshold distance Δs _max and by means of which the second displacement sensor signal (20s) is output as a signal that periodically varies as a function of a second adjustment path (x ₂ ) of the motor power transmission element (20) from its second starting position, lies within a second comparison value range (W ₂ ) predetermined or determined for the presence of the motor power transmission element (20) in its second starting position (S2); wherein, if the first value (I ₁ ) is in the first comparison value range (W ₁ ) and the second value (I ₂ ) is in the second comparison value range (W ₂ ), 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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