DE102022116624B4 - Method for controlling an electromechanical brake and braking system - Google Patents

Abstract

The invention relates to a method for controlling an electromechanical brake and a braking system with an electromechanical brake. According to the invention, a current signal (8), which is applied to an electric motor of the electromechanical brake, is regulated by means of a controller (1). The controller (1) has a P element (9), an I element (11) and a D element (13). A target braking request, in particular a target positioning path (19) and/or a target braking path (5), is supplied to the controller (1). According to the invention, different feedback signals or control difference signals (22, 20), which are based on different actual measurement signals (3a, 3b), are processed in a first branch (10) and in a second branch (14).

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a method for controlling an electromechanical brake, in which the brake is actuated and a braking torque is generated by means of an electric motor depending on a current applied to the electric motor. The invention further relates to a brake system with at least one electromechanical brake and an associated controller. The method and the braking system are used for a motor vehicle, in particular a commercial vehicle such as a towing vehicle and/or a trailer.

BACKGROUND OF THE INVENTION

WO 2005/030 549 A2 and the prior art cited therein disclose electromechanical brakes in which the actuation and generation of a braking torque takes place by means of an electric motor as a function of a current acting on the electric motor. Different (for example self-reinforcing and/or self-locking) transmission gears can be arranged between the motor and a braking element such as a brake shoe or brake disc, the design and integration of which depends on WO 2005/030 549 A2 and the prior art cited therein is referred to. A distinction is made here between brakes that are released automatically without generating a brake actuation force, brake systems in which self-reinforcement occurs, so that a releasing brake actuation force must be applied in order to keep the braking torque constant, and brake systems that are actuated automatically depending on the friction conditions are self-reinforcing. In all cases, careful control of the brake actuation force is required to ensure the desired braking torque.

DE 10 2004 040 953 A1 discloses an electric braking system in which an actuation of the brake pedal by the user is detected by means of a pedal actuation sensor. The signal from the pedal operation sensor is supplied to an ECU. The ECU also receives signals from a wheel speed sensor and a yaw rate sensor. The ECU determines a target braking force. The ECU controls an electric brake, which is designed as a disc brake. If a target deceleration is calculated from the signal from the pedal actuation sensor, it is first checked whether the brake system carries out stability control as a result of slip or yaw rate occurring. If this is not the case, a target braking force is determined specifically for the respective wheel. Furthermore, a target value for a delivery of the electric brake is determined according to the target braking force. The setpoint serves as a target control variable. Subsequently, a feedback gain correction process for a feedback control variable is performed by the ECU, thereby preventing the occurrence of overshoot or deviations in the instruction stream. A PID feedback control can be used here. In this case, the difference between the setpoint and the actual control variables is supplied to all branches of the PID feedback control as an input variable.

OBJECT OF THE INVENTION

The present invention is based on the object of proposing a method for controlling an electromechanical brake and a braking system with an electromechanical brake, which is particularly effective with regard to the control for bringing about the desired braking torque (preferably with regard to the performance of the control, the stability of the control, etc.). Control quality and the control gain that can be achieved) is improved.

SOLUTION

The object of the invention is achieved according to the invention with the features of the independent patent claims. Further preferred embodiments according to the invention can be found in the dependent patent claims.

DESCRIPTION OF THE INVENTION

• - ein mittels der elektromechanischen Bremse erzeugtes Bremsmoment,
• - eine an dem der elektromechanischen Bremse zugeordneten Fahrzeugrad erzeugte Bremskraft,
• - die Betätigungskraft, mit welcher ein Bremselement wie eine Bremsbelag beaufschlagt wird,
• - die Betätigungskraft, mit welcher ein beliebiges dem Bremselement vorgeordnetes Übertragungselement beaufschlagt wird, oder
• - das Moment, welches von dem elektrischen Motor der elektromechanischen Bremse erzeugt wird

(oder eine hiermit korrelierende Größe).If we talk about a (target or actual) brake actuation force in the following, it is a “generalized force” in the sense of mechanics and in particular

• - a braking torque generated by the electromechanical brake,
• - a braking force generated on the vehicle wheel assigned to the electromechanical brake,
• - the actuating force with which a braking element such as a brake pad is applied,
• - the actuating force with which any transmission element arranged upstream of the braking element is acted upon, or
• - the torque generated by the electric motor of the electromechanical brake

(or a variable that correlates with this).

• - ein Stellweg eines Bremselementes wie ein Bremsbelag,
• - ein Stellweg eines beliebigen dem Bremselement vorgeordneten Übertragungselements oder
• - ein Stellweg des elektrischen Motors

(oder eine hiermit korrelierende Größe), wobei ein Stellweg ein im Sinne der Mechanik „verallgemeinerter Stellweg“ und insbesondere eine translatorische Verschiebung, eine Bewegung entlang eines beliebigen kurvenförmigen Freiheitsgrades oder einen Drehwinkel bezeichnen kann.If we are talking about a braking request, it can be a brake actuation force or a brake actuation distance. This is a brake actuation path in particular

• - a travel of a braking element such as a brake pad,
• - an adjustment path of any transmission element arranged upstream of the braking element or
• - a travel of the electric motor

(or a variable that correlates therewith), whereby an adjustment path can denote a “generalized adjustment path” in the sense of mechanics and in particular a translational displacement, a movement along any curved degree of freedom or an angle of rotation.

The invention relates to a method for controlling an electromechanical brake, the electromechanical brake corresponding to the usual configurations, cf. WO 2005/030 549 A2 and the prior art cited in this publication. The method is preferably carried out by a control unit, which can be a central control unit connected to a plurality of electromechanical brakes or a control unit that is assigned to a subgroup of the electromechanical brakes, for example the electromechanical brakes of one or more vehicle axles, or a control unit that is one is assigned to an individual electromechanical brake, wherein the control unit in the cases mentioned can be arranged at a central location, can be part of an axle assembly or can be assigned to an electromechanical brake or the assigned vehicle wheel immediately adjacent. It is possible, for example, for the control unit to form a structural unit with the electromechanical brake. It is also possible for several sub-control units networked with one another to form the control unit.

In the electromechanical brake, an actual brake actuation force of the brake is specified via an electric motor depending on a current acting on the electric motor, with the method according to the invention regulating the current. Alternatively or additionally, an actual brake actuation path of the electromechanical brake can be specified via the current, which corresponds to the actual brake actuation force of the brake in accordance with a predetermined dependency (in particular depending on the friction partners and materials, the material stiffness, the friction coefficient, the temperature, the humidity, the kinematics, ...) correlates.

In the method according to the invention, a controller (in particular implemented in the control unit mentioned) is used. The controller has a P-link branch with a P-link, an I-link branch with an I-link and a D-link branch with a D-link. A target braking request, in particular a target positioning path and/or a target braking torque of the electromechanical brake, is supplied to the controller, so that the target braking request forms/forms an input variable of the controller. Here, the target braking request can be specified by the driver, for example, via a brake pedal. Alternatively or additionally, the target braking request can be specified via a control unit or an autonomous driving system, a brake assistance system or an automatic distance system from a vehicle in front. The controller's output signal is the current applied to the electric motor.

Basically, a type of PID controller is used in the method according to the invention. However, the different branches are not supplied with the same control difference signal.

Rather, according to the invention, different feedback signals or control difference signals are processed in a first branch and in a second branch. The different feedback signals or control difference signals are based on different feedback actual measurement signals. According to the invention, two different measurement signals are determined in the electromechanical brake in the chain of action from the motor to the brake elements or brake pads, both of which are then taken into account in the controller. It has been shown that improved control performance, increased control stability and large control gain can be guaranteed in this way.

The branches in which different control difference signals are processed can be any combination or all branches (P-member branch and/or I-member branch and/or D-member branch), in which case also Feedback signals or control difference signals based on any measurement signals can be processed.

For a proposal of the invention, a feedback signal or control difference signal is processed in a first branch of the P-member branch, the I-member branch, the I-member branch and the D-member branch, in which the first measured actual -Measuring signal of the actual brake actuation path, in particular the actual actuation path, is returned, an actual actuating speed is returned or an actual braking request or an actual braking torque returned. On the other hand, in the second branch, which deviates from the first branch, a feedback signal or control difference signal is processed by the P-member branch, the I-member branch and the D-member branch, in which the second measured signal deviates from the first measurement signal Measuring signal of the actual brake actuation path or actual actuation path is returned, an actual actuating speed is returned or the actual brake actuation force is returned. This selection of the branches used for the different control difference signals and the returned measurement signals has proven to be particularly advantageous with regard to the control quality of the current output by the controller.

A concrete, non-restrictive embodiment of this method is shown schematically in 1 shown, whereby only the actual braking torque and the actual actuating speed are returned (without the return of a third measurement signal).

It is possible for this embodiment that no third measured measurement signal is fed back in the third branch, in which case the first measured measurement signal and/or the second measured measurement signal is then preferably used in the third branch, possibly with conversion thereof. Alternatively, it is also possible that in this case a third measured measurement signal is fed back and processed in the third branch.

For one embodiment of the invention, a control difference signal of the target braking request and the measured actual braking request is fed back in the P-link branch and/or I-link branch, while in the D-link branch a feedback signal with the target actuating speed or is returned to a signal that correlates with it.

It is also possible for the D-element branch to be supplied with a control difference signal of the setpoint positioning speed and the measured actual positioning speed or signals that correlate therewith.

Within the scope of the invention, a control difference signal with regard to the brake actuation force can also be converted via a suitable conversion into a control difference signal representing the brake actuation path, which can then optionally be additionally limited via a limiting element with regard to a minimum limit value and/or a maximum limit value.

It is also possible that in the P-element branch and the I-element branch the control difference signal is processed with different amplification factors or other different conversion functions.

For an alternative embodiment of the method according to the invention, in the P-member branch a control difference signal of the target brake actuation path and the measured actual brake actuation path is supplied to the P member, while in the I-member branch the I member is supplied with a control difference signal of the target Brake actuation force and the measured actual brake actuation force is supplied. In this case, too, it is possible for the control difference signal with regard to the brake actuation force to be converted into a control difference signal for the brake actuation path, for the control difference signal to be limited by a limiting element and/or for a first amplification factor or another conversion function to be used in the I-element branch, while any gain factor that deviates from the aforementioned gain factor or another conversion function can also be used in the D-member branch.

It is possible for this embodiment of the method that in the D-member branch there is no control difference signal based on a third feedback measurement signal, in which case a control difference signal can then be processed in the D-member branch, which is based on one of the feedback measurement signals in the P -member branch or the I-member branch. For one proposal of the invention, the D-element branch is supplied with a control difference signal which is dependent on the target actuating speed and a measured actual actuating speed, i.e. a third measurement signal. Such an embodiment, which does not limit the described method according to the invention, is shown schematically in 2 shown.

For one proposal of the invention, the control difference signal of the D element branch is generated from the output signal of the D element and the measured actual actuating speed. In this case, the target positioning path can be supplied to the D element.

For a further proposal of the invention, there is no direct specification of the target brake actuation force or the target braking torque. Rather, a target brake actuation path or target actuation path is specified (by the driver and/or a control unit or an autonomous driving system), from which a target brake actuation force is then determined in the method according to the invention, which is then used in the method and in particular in at least one of the branches mentioned is further processed.

It is possible that the signals in the different branches are processed unchanged according to the functional dependencies and the P-member, I-member and D-member used, whereby any further dependencies can be taken into account. An embodiment of the method in which a limiting song is present has proven to be advantageous. By means of the limiting element, the signal processed or output in the controller is limited to a minimum limiting value and/or a maximum limiting value. Any choice of limit values can be made. However, the limiting values preferably model the physical conditions of the electromechanical brake. For example, a limiting value can be selected such that a maximum and/or minimum actual brake actuation path of the electromechanical brake is modeled using this value. This maximum and/or minimum actual brake actuation path can correspond to the mechanically possible adjustment path of a drive element of the electromechanical brake or of the motor. Alternatively or cumulatively, it is possible for the maximum and/or minimum actual actuating speed, the maximum and/or minimum actual brake actuation force and/or the minimum and/or maximum output current to be modeled via the limitation song and the limitation value.

In this context, it is also possible for a control difference signal to be supplied to the limiting song. To name just a few examples that do not limit the invention, the limiting element can be supplied with a control difference signal, which is supplied to the difference between the target brake actuation force (if necessary converted from a predetermined target brake actuation path) and the actual brake actuation force, and this can be done immediately or by converting the control difference signal with regard to the brake actuation force into a control difference signal with regard to the brake actuation path, this limiting element then preferably being in the I-element branch (cf. 2 ) is arranged or is arranged upstream of the P-member branch and the I-member branch (cf. 1 ). It is possible for another exemplary embodiment that the limiting element is arranged in the P-element branch and the limiting element is supplied with a control difference signal from the target positioning path and the measured actual positioning path (cf. 2 ).

If it is to be avoided that in the method according to the invention a current that is too large and/or too small is controlled for acting on the motor, a further embodiment of the method according to the invention proposes that a limiting element of the merging of the P-member branch, the I- Link branch and the D link branch is subordinate.

What can be problematic with the method according to the invention is that instability occurs (particularly when using a limiting member after merging the P-member branch, the I-member branch and the D-member branch). For this purpose, an embodiment of the method according to the invention suggests that an anti-windup signal is fed back to the I-member branch.

For one proposal of the invention, the anti-windup signal is determined from a control difference signal of the current before a limiting element and after this limiting element, in which case the limiting element (and the removal of the current before the limiting element) is preferably the merging of the P-element. branch, which is subordinate to the I-member branch and the D-member branch (cf. 2 ).

A further solution to the problem on which the invention is based is a brake system. The brake system has an electromechanical brake, which in turn has an electric motor. In the electromechanical brake, the actual brake actuation path and/or the actual brake actuation force of the brake are/are specified via the electric motor as a function of a current acting on the electric motor. The controller has a P-link branch with a P-link, an I-link branch with an I-link and a D-link branch with a D-link. This controller is supplied with a target brake actuation path and/or a target brake actuation force of the electromechanical brake. The controller's output signal is the current applied to the electric motor. The controller is designed to carry out a method as explained previously. Here, the controller is preferably implemented by means of an electronic control unit, whereby what has been said above can apply to the arrangement of the electronic control unit. The method can be implemented in the form of control logic or software in the control unit.

Advantageous developments of the invention result from the patent claims, the description and the drawings.

The advantages of features and combinations of several features mentioned in the description are merely examples and can have an alternative or cumulative effect without the advantages necessarily having to be achieved by embodiments according to the invention.

With regard to the disclosure content - not the scope of protection - of the original application documents and the patent, the following applies: Further features can be found in the drawings - in particular the geometries shown and the relative dimensions of several components to one another as well as their relative arrangement and operative connection. The combination of features of different embodiments of the invention or of features of different patent claims is also possible, deviating from the selected relationships of the patent claims, and is hereby encouraged. This also applies to features that are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different patent claims. Likewise, features listed in the patent claims may be omitted for further embodiments of the invention, but this does not apply to the independent patent claims of the granted patent.

The features mentioned in the patent claims and the description are to be understood in terms of their number in such a way that exactly this number or a larger number than the number mentioned is present, without the need for an explicit use of the adverb “at least”. For example, when we talk about an element, this should be understood to mean that there is exactly one element, two elements or more elements. The features listed in the patent claims can be supplemented by further features or can be the only features that the subject of the respective patent claim has.

The reference symbols contained in the patent claims do not represent a limitation on the scope of the subject matter protected by the patent claims. They merely serve the purpose of making the patent claims easier to understand.

BRIEF DESCRIPTION OF THE FIGURES

• 1 und 2 zeigen schematisch jeweils ein Blockschaltbild eines in einem Bremssystem und einem Verfahren zur Regelung einer elektromechanischen Bremse eingesetzten Reglers.

The invention is further explained and described below using preferred exemplary embodiments shown in the figures.

• 1 and 2 each show a schematic block diagram of a controller used in a brake system and a method for controlling an electromechanical brake.

FIGURE DESCRIPTION

In the following description of the figures, elements that correspond, are similar or have a common character are marked with the same reference numbers, whereby these can then be distinguished from one another by the additional letters a, b, .... These elements are then referred to with or without the additional letter, which can then refer to one of the elements, several of these elements or all of the elements.

1 shows a controller 1. The controller 1 is supplied with at least one input signal 2, which is a target signal. Furthermore, the controller 1 is supplied with at least one measurement signal 3 from the electromechanical brake. Controller 1 generates an output signal 4.

According to 1 The input signal 2 is a target braking torque 5. Alternatively, it is possible for the input signal 2 to be a target motor torque with which the electric motor is to be controlled in order to bring about a desired target braking torque or a desired target braking force , so that the (target) motor torque can always be used as an alternative at the points where reference is made to the (target) braking torque. A measurement signal 3a is the actual braking torque 6 and a further measurement signal 3b is the actual actuating speed 7. For the alternative embodiment, in which the input signal 2 is the target engine torque, the actual engine torque can be used instead of the actual braking torque, which can be determined taking into account the kinematic dependencies using an actuation force sensor or clamping force sensor. The output signal 4 is the current 8 with which the electric motor of the electromechanical brake is applied.

The controller 1 has a P element 9, which is part of a P element branch 10, an I element 11, which is part of an I element branch 12, and a D element or filter element 13, which Part of a D-member branch or filter branch 14.

The D-member branch 14 is supplied with the input signal 2, here the target braking torque 5, via a branch 15. In the D-element branch 14, a conversion element 16a, the D-element 13 or the filter 13, a feedback combination 17 and an amplification element or a D-element 18 are connected in series in this order. The conversion element 16a preferably converts the target braking torque 5 into a target positioning path 19. The target positioning path 19 generated in this way is processed by means of the D-member 13. The output signal of the D element 13, which is the target actuating speed 40, is processed by the feedback combination 17, to which the actual actuating speed 7 is supplied with the opposite sign Control difference signal 20, which in turn is fed to the amplification element 18.

From the branch 15, the input signal 2, here the target braking torque 5, also reaches a feedback combination 21, which generates a control difference signal 22 from the target braking torque 5 and the actual braking torque 6, which is returned with a negative sign. The control difference signal 22 is converted via a conversion element 16b, the conversion taking place in such a way that a control difference adjustment path 23 is generated from the control difference braking torque, which is represented by the control difference signal 22. The control difference adjustment path 23 is limited by means of a limiting element 24 with respect to a minimum and/or maximum limitation value, the limitation value preferably being correlated with the minimum and/or maximum adjustment path of the electric motor or another drive element of the electromechanical brake. The output signal of the limiting element 24, i.e. the limited control difference adjustment path 23, reaches the P element 9 via a branch 25, in which it is multiplied by an amplification factor or proportionality factor. In this case, the P-member branch 10 has exclusively the P-member 9 (whereby, in an alternative perspective, the series connection of the conversion member 16b, the limiting member 24 and the P-member 9 can also be viewed as a P-member branch 10 ).

The control difference adjustment path 23 limited by the limiting element 24 is also fed to the I-element 11 via the branch 25. In the I-element branch 12, an amplification element 26, an anti-windup combination 27 and the I-element 11 are connected in series in a series connection. In an alternative perspective, the conversion member 16b, the limiting member 24, the amplification member 26, the anti-windup combination 27 and the I-member 11 can be viewed as part of the I-member branch 12.

The output signals of the P-link branch 10, the I-link branch 12 and the D-link branch 14 are combined by a merge 28 and superimposed to form a merge output signal 29. The merge output signal 29 is fed to a limiter 30 , which generates the output signal 4 of the controller 1, namely the current 8. If an anti-windup signal 31 is to be returned, the signals at the input of the limiting element 30 and at the output of the limiting element 30 are fed to an anti-windup combination 32 with different signs. The difference signal 39 of the anti-windup combination 32 is fed to the anti-windup combination 27 via an amplifier 33 as an anti-windup signal 31.

It is possible that the output signal of the I-member branch 10 and the output signal of the I-member branch 12 are supplied not only to the combination 28, but also to an output and/or processing unit 34.

For those in 2 In the embodiment shown schematically, this basically applies 1 Said. However, according to 2 by the driver or a control unit or an autonomous driving system, the specification of a target positioning path 30. The target positioning path 19 is then supplied to the controller 1 as an input signal 2a and in the D-member branch 14 accordingly 1 processed.

In addition to the measurement signals 3a, 3b in the form of the actual braking torque 6 and the actual actuating speed 7, the controller 1 is also supplied with a measurement signal 3c in the form of an actual actuating path 35. In the P-element branch 10, a control difference signal 37 is generated by means of a positioning path combination 36 from the target positioning path 19 and the actual positioning path 35, which is then further processed via the limiting element 24 and the P-member 9.

Using a conversion element 38, a target braking torque 5 is calculated from the target travel 19 as an input signal 2b. The processing of the target braking torque 5 generated in this way in the I-member branch 12 then corresponds to the processing in the I-member branch 12 in the following 1 .

Also the merging of the P-member branch 10, the I-member branch 12 and the D-member branch 14 by the merging 28, the limitation of the current 8 by a limiting member 30 and the feedback of an anti-windup signal 31 corresponds to the exemplary embodiment according to 2 according to the embodiment 1 .

In this case, the output signals of the P-member branch 10, the I-member branch 12 and the D-member branch 14 can be fed to an output and/or processing unit 34.

It is possible that the conversion element 38 is integrated into the controller 1, so that the controller 1 differs 2 not two input signals 2a, 2b are supplied, but only one input signal 2 in the form of the target travel 19.

For another embodiment, several input variables can also be specified by the driver, a control unit or an autonomous driving system, preferably one Both the target travel 19 and the target braking torque 5 are given.

If in the context of the present description and the patent claims there is talk of a target positioning path, this preferably refers to the target positioning path of a braking element such as a brake pad. As an alternative to such a target positioning path, a signal that correlates with the target positioning path can also be used. For example, the travel of the motor or a transmission element, which is arranged between the motor and the brake element, correlates with the target travel. The dependence of the target positioning path can be mapped via a model or a dependence and a corresponding conversion can be carried out in the method according to the invention. For example, the dependency between the signal correlating with the target positioning path and the target positioning path is predetermined by the kinematics of the gear ratio involved.

The same applies to the target braking torque. For example, the target braking torque depends on the radius with which a friction element of the brake acts on a target braking force, which can therefore represent a signal that correlates with the target braking torque. It is also possible that a force or a torque that is generated by the motor or is transmitted by a transmission element between the braking element and the motor is used as the signal correlating with the target braking torque.

The same applies to the output signal of the controller in the form of the current 8. It is possible that the controller 1 directly outputs the current 8, which then acts on the windings of the electric motor. However, it is also possible for the current 8 to be converted via a power amplifier and other electronic components in accordance with a predetermined dependency into the current which is then applied directly to the electric motor.

The same applies to the positioning speed.

The controller 1 is preferably designed using control logic of an electronic control unit.

The controller 1 can be integrated into a control unit, which also serves other purposes. It is possible that several such controllers 1 for the different electromechanical brakes, which are assigned to different vehicle wheels, can be integrated into a common control unit or different control units. Several control units can be combined with the control unit in which the controller 1 is implemented.

The embodiment according to the invention preferably leads to a regulation of the current and thus the actual braking torque in such a way that the relevant regulations ISO 26865 and ECE R13 [3] are met.

The current 8 applied to the motor can correlate with the actual motor torque, which can be represented using a pure proportionality factor or a more complex model. The electric motor has a sensor that measures the angle of rotation, which correlates with the actual travel. Alternatively or cumulatively, a sensor in the motor can detect the speed or angular velocity. It is also possible for the speed or angular velocity to be determined via a derivation from the angle of rotation.

A measured actual brake actuation force, with which the brake elements are pressed against a brake disc, can be converted into the actual motor torque of the electric motor using a conversion element.

Within the scope of the invention, the control difference signal between the actual engine torque and the target braking torque can be processed in the I-element branch 12. It is possible that additional filtering of signals takes place as part of the method according to the invention.

It is possible that an offset of an actual braking torque 6 in the I-element branch 10 is estimated. The offset can be used a priori in controller 1 (not shown here).

REFERENCE SYMBOL LIST

1

Regulator

2

Input signal

3

measurement signal

4

Output signal

5

Target braking torque or target engine torque

6

Actual braking torque or actual engine torque

7

Actual positioning speed

8th

Electricity

9

P-member

10

P-member branch

11

I-member

12

I-member branch

13

D-link

14

D-member branch

15

branch

16

conversion element

17

Return merge

18

reinforcing member

19

Target travel

20

Control difference signal

21

Return merge

22

Control difference signal

23

Control difference travel

24

Limiting member

25

branch

26

reinforcing member

27

Anti-Windup Merge

28

Merge

29

Merge output signal

30

Limiting member

31

Anti-windup signal

32

Anti-Windup Merge

33

reinforcing member

34

Output and/or processing unit

35

Actual travel distance

36

Travel merging

37

Control difference signal

38

conversion element

39

Differential signal

40

Target positioning speed

Claims (17)

Method for controlling an electromechanical brake, which is actuated via an electric motor depending on a current (8) acting on the electric motor, a) with a controller (1), aa) which has a P-element branch (10) with a P -Link (9), an I-member branch (12) with an I-member (11) and a D-member branch (14) with a D-member (13) or a filter branch with a filter , ab) to which a target braking request or a signal correlating therewith is/is supplied and ac) whose output signal (4) is the current (8) with which the electric motor is supplied, or a signal correlating with this current, characterized that b) different feedback signals or control difference signals determined from the feedback signals are processed in a first branch and in a second branch, which are based on different actual measurement signals (3). Procedure according to Claim 1 , characterized in that when controlling the electromechanical brake, an actual brake actuation path and / or an actual brake actuation force of the brake is generated via an electric motor depending on the current (8) acting on the electric motor or a signal correlating therewith. Procedure according to Claim 1 or 2 , characterized in that a) the target brake request is a target brake actuation path (19) or a target brake actuation force of the electromechanical brake or a signal correlating therewith and / or b) the actual brake request is an actual brake actuation path (19) or a Actual brake actuation force of the electromechanical brake or a signal correlating therewith. Method according to one of the preceding claims, characterized in that a) in the first branch of the P-member branch (10), the I-member branch (12) and the D-member branch (14) a feedback signal or Control difference signal (20; 22; 37) is processed, in which the actual brake actuation path or actual actuation path (35) is fed back as the first measured actual measurement signal (3) or ab) an actual actuation speed (7) or a herewith correlating signal is fed back or ac) the actual brake actuation force is fed back, and b) in the second branch, which deviates from the first branch, from the P-member branch (10), the I-member branch (12) and the D -Link branch (14), a feedback signal or control difference signal (20; 22; 37) is processed, in which the actual brake actuation path or actual actuation path (35) is the second measured actual measurement signal ba) which deviates from the first actual measurement signal. is returned or bb) an actual actuating speed (7) or a signal correlating therewith is returned or bc) the actual brake actuation force is returned. Procedure according to Claim 4 , characterized in that a) the P-element branch (10) and / or the I-element branch (12) is supplied with a control difference signal (22) of the target braking request (5) and the measured actual braking request (6). and b) the D-member branch (14) with a feedback signal the target setting speed (40) or a signal correlating therewith is supplied. Procedure according to Claim 4 , characterized in that a) the P-element branch (10) and / or the I-element branch (12) is supplied with a control difference signal (22) of the target braking request (5) and the measured actual braking request (6). and b) the D-element branch (14) is supplied with a control difference signal (20) of the target actuating speed (40) and the measured actual actuating speed (7) or signals correlating therewith. Procedure according to Claim 4 , characterized in that a) the P-element branch (10) and / or the I-element branch (12) is supplied with a control difference signal (22) of the target braking request (5) and the measured actual braking request (6). and b) the D-element branch (14) is supplied with a control difference signal (20) of the target actuating speed (40), which is set to zero, and the measured actual actuating speed (7) or signals correlating therewith. Procedure according to Claim 4 , characterized in that in the P-member branch (10) the P-member (9) receives a control difference signal (37) of the target brake actuation path or target actuation path (19) and the measured actual brake actuation path or actual actuation path ( 35) is supplied and in the I-element branch (12) the I-element (11) is supplied with a control difference signal (22) of the target brake actuation force and the measured actual brake actuation force. Procedure according to Claim 8 , characterized in that the D-element branch (14) is supplied with a control difference signal (20) of the target actuating speed (40) and a measured actual actuating speed (7) or signals correlating therewith. Method according to one of the preceding claims, characterized in that the control difference signal (22) of the D-member branch (14) is generated from the output signal of the D-member (13) and the measured actual actuating speed (7) or a signal correlating therewith becomes. Method according to one of the preceding claims, characterized in that the target brake actuation force is determined from the target brake actuation path or target actuation path (19). Method according to one of the preceding claims, characterized in that a limiting member (24; 30) is present, which a) the maximum and/or minimum actual brake actuation path or actual actuation path (35) and/or b) the maximum and/or minimum actual actuating speed (7) and / or c) the maximum and / or minimum actual brake actuation force (6) and / or d) the minimum and / or maximum current (8) is modeled. Procedure according to Claim 12 , characterized in that the limiting element (24) is supplied with one or the control difference signal (22; 37). Procedure according to Claim 12 or 13 , characterized in that the or a limiting member (30) is arranged downstream of a merger (28) of the P-member branch (10), the I-member branch (12) and the D-member branch (14). Method according to one of the preceding claims, characterized in that an anti-windup signal (31) is fed back to the I-member branch (12). Procedure according to Claim 11 in relation to Claim 10 , characterized in that the anti-windup signal (31) is determined from a control difference signal (39) of the current (8) or a signal correlating therewith before a limiting element (30) and after this limiting element (30). Brake system with an electromechanical brake, which is actuated via an electric motor depending on a current (8) acting on the electric motor, with a controller (1) which has a P-member branch (10) with a P-member (9) , an I-link branch (12) with an I-link (11) and a D-link branch (14) with a D-link (13), which has a target braking request of the electromechanical brake or a corresponding one Signal is supplied and the output signal of which is the current (8) with which the electric motor is applied, or an output signal (4) correlating therewith, characterized in that the controller (1) is designed to carry out a method according to one of the preceding claims .

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