Method of controlling brake system and associated brake system

Abstract

A method of controlling a brake system (1) of a vehicle for activating a parking brake force actuated by the brake system (1), the method comprising the steps of: actuating a first actuator (2) to bring the first actuator (2) into proximity against a first pad to exert a first force (Fa), and actuating the second actuator (3) such that the second actuator (3) approaches the second pad to apply a second force (Fb); detecting values of the first force (Fa) and the second force (Fb); synchronously applying a first force (Fa) and a second force (Fb) on the brake disc; continuing to actuate the first actuator (2) and the second actuator (3) until the first force (Fa) reaches the first predetermined force value (F1) and the second force (Fb) reaches the second predetermined force value (F2); the first actuator (2) and the second actuator (3) are stopped by means of an electronic processing unit.

Description

Technical Field

[0001] The invention relates to a method for controlling a brake system, in particular a brake system of a vehicle, and to a brake system of a vehicle. Background Art

[0002] Automobiles and generally vehicles with more than two wheels used to transport passengers on roads are provided with a manual parking brake, the function of which is to lock the wheels when the vehicle is parked, thereby preventing the vehicle from moving.

[0003] In modern brake systems, for example those provided with electronic brake-by-wire (BBW) technology, the manual parking brake is replaced by an electronic parking brake (EPB).

[0004] For all purposes, the EPB electronic parking brake can be considered as a subsystem for service braking of an electronic braking system with BBW technology.

[0005] In more detail, using the EPB subsystem, the driver can enable the wheel locking mechanism with the help of an actuating device, such as a suitable button, or other automatic functions managed by an electronic processing unit, such as signal logic related to the ignition key, gear engagement and accelerator pedal, which, when enabled, sends a request for parking brake activation to the vehicle's electronic control unit, which electronic control unit actuates the brake disc in an electrically manner to lock the brake disc, thereby locking the movement of the vehicle.

[0006] Vice versa, when restarting, the driver can deactivate the wheel locking mechanism by means of an actuator which, when activated, sends a parking brake deactivation request to the vehicle's electronic control unit, which electrically actuates the brake discs to unlock them and thus prevent the vehicle from moving.

[0007] In addition, in addition to replacing the parking brake function performed by a conventional manual parking brake, the EPB subsystem is also configured to provide the driver with automatic assistance functions, including a so-called "AutoHold" function, that is, providing the driver with: when the vehicle is stationary, such as going uphill, the wheels are automatically locked without the driver's request, and the wheels will be released as soon as the driver steps on the vehicle's accelerator pedal.

[0008] In known disc brakes with fixed brake calipers, the two pads opposite the brake disc are actuated by respective pistons which can be actuatable independently by at least two actuators, at least one of which is located on each side of the brake disc.

[0009] The at least two opposing actuators are independently controlled by the electronic control unit, so that the at least two actuators can be actuated and controlled simultaneously and independently of each other.

[0010] For each of the two actuators, the activation of the parking brake according to a known control logic can be divided into three consecutive steps:

[0011] - an inrush step, from the moment the electronic control unit commands the actuator, located at a given starting position, to start moving, to the moment the actuator starts moving but does not apply any braking force to the corresponding pad;

[0012] - an approach step, from the moment the actuator starts moving without applying any braking force to the corresponding pad to the moment the actuator comes into contact with the pad and starts applying a braking force to the pad;

[0013] - an applying step, from the moment the actuator starts applying the braking force and increasing the braking force acting on the pad to the moment the braking force applied by the actuator to the pad reaches a given predetermined reference value.

[0014] In the known control logic, at least two actuators in opposition are arranged to initiate the surge step of the parking brake application process simultaneously in order to act as symmetrically as possible on the two opposite faces of the brake disc with respect to the axial thrust.

[0015] This symmetry is required to minimize stresses on the brake rotor that might otherwise cause cracks, damage or breakage of the brake rotor.

[0016] In known disc brakes with at least two independently controllable opposing actuators, wear and tear of mechanical components and uncertainties regarding the starting positions of the two opposing actuators may result in differences in the braking forces actuated by the two actuators, in particular with respect to the time required for the two actuators to approach the respective pads and apply the respective braking forces, resulting in approach steps of different durations.

[0017] If the duration of the approach step of one actuator is different from the duration of the approach step of the opposing actuator, both actuators may start to apply braking force, but not simultaneously, so that undesirable and harmful asymmetric axial thrust may act on the brake disc. Summary of the invention

[0018] An object of the present invention is to provide a method of controlling a brake system and a brake system so as to obviate at least some of the disadvantages of the related art.

[0019] A particular object of the invention is to provide a method of controlling a braking system and a braking system in order to minimize the asymmetric axial thrust acting on the brake disc during application of the parking brake.

[0020] Another specific object of the present invention is to provide a control method of a brake system and a brake system configured to perform the control method, which is simplified so as to have fewer energy and structural limitations.

[0021] These and other objects are achieved by a method of controlling a brake system and a brake system according to the independent claims.

[0022] The dependent claims relate to preferred and advantageous embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to better understand the present invention and appreciate its advantages, some non-limiting exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which:

[0024] - Figure 1 A braking system according to an embodiment of the present invention is shown diagrammatically;

[0025] - Figure 2 In a diagrammatic manner are shown the supply current of an actuator of a braking system according to an embodiment of the invention, and the corresponding force actuating the pads of the same braking system;

[0026] - Figure 3 The diagram shows the supply current and the corresponding force actuated by two independently controllable actuators of a brake caliper of a brake system according to the related art;

[0027] - Figure 4 The supply current and the corresponding force actuated by two independently controllable actuators of a brake caliper of a brake system according to an embodiment of the invention are shown in a diagram. DETAILED DESCRIPTION

[0028] A method for controlling a brake system 1 of a vehicle for activating a parking brake force actuated by the brake system 1 is described below with reference to the accompanying drawings.

[0029] The brake system 1 is a brake system of the type comprising at least:

[0030] - brake discs;

[0031] - a first pad and a second pad, the first pad and the second pad being spaced apart from each other and positioned opposite to the brake disc;

[0032] a first actuator 2 configured to apply and release a first force Fa on the first pad to move the first pad from an open position, in which the first pad is separated from the brake disc and does not actuate the parking brake force, to a closed position, in which the first pad is biased against the brake disc and actuates the parking brake force;

[0033] a second actuator 3 configured to exert a second force Fb on the second pad to move the second pad from an open position, in which the second pad is separated from the brake disc and does not actuate the braking force, to a closed position, in which the second pad is biased against the brake disc and actuates the parking brake force;

[0034] an electronic processing unit 4 configured to control the actuation of the first actuator 2 and the actuation of the second actuator 3;

[0035] - a detection device operatively connected to the electronic processing unit 4, configured to detect directly or indirectly the value of a first force Fa actuated by the first actuator 2 on the first pad, and to detect directly or indirectly the value of a second force Fb actuated by the second actuator 3 on the second pad.

[0036] The method comprises the following steps:

[0037] - actuating the first actuator 2 by means of the electronic processing unit 4 so that the first actuator 2 approaches against the first pad so as to apply a first force Fa and increase the value of the first force Fa, and actuating the second actuator 3 by means of the electronic processing unit 4 so that the second actuator approaches against the second pad so as to apply a second force Fb and increase the value of the second force Fb;

[0038] - during the actuation of the first actuator 2 and the second actuator 3, detecting by means of the detection means the value of the first force Fa and the value of the second force Fb;

[0039] - synchronously exerting a first force Fa and a second force Fb on the brake disc by means of the electronic processing unit 4;

[0040] - continuing to actuate the first actuator 2 and the second actuator 3 until the first force Fa reaches a first predetermined force value F1 and the second force Fb reaches a second predetermined force value F2;

[0041] The first actuator 2 and the second actuator 3 are stopped by means of the electronic processing unit 4 .

[0042] Furthermore, the step of synchronously applying the first force Fa and the second force Fb on the brake disc comprises the following steps:

[0043] - at a first moment t1 when the detection device detects that the first force Fa has increased to a value significantly greater than the third predetermined force value F3, the first actuator 2 is stopped and the second actuator 3 is continued to be actuated;

[0044] - At a second instant t2, when it is detected by the detection means that the second actuator 3 applies a second force Fb which is significantly greater than the fourth predetermined force value F4, the first actuator 2 is actuated.

[0045] Alternatively, the step of synchronously applying the first force Fa and the second force Fb on the brake disc comprises the following steps:

[0046] - at a first moment t1 when the detection device detects that the second force Fa has increased to a value significantly greater than the fourth predetermined force value F4, the second actuator 3 is stopped and the first actuator 2 is continued to be actuated;

[0047] At a second instant t2 when it is detected by the detection means that the first actuator 2 applies a first force Fb which is significantly greater than a third predetermined force value F3, the second actuator 3 is actuated.

[0048] Advantageously, the control method according to the invention minimizes the asymmetric axial thrust actuated on the brake disc during application of the parking brake.

[0049] This is achieved by synchronously applying a first force Fa and a second force Fb on two opposite faces of the brake disc, this synchronization being obtained by sharing the detection between the two actuators by means of an electronic processing unit when one of the two actuators is in contact with the corresponding pad, which causes the actuators to be temporarily stopped until the other of the two actuators is subsequently detected to be in contact with the corresponding pad.

[0050] By comparing FIG. 6 and FIG. 7 showing a control method according to the present invention with FIG. Figure 4 As can be seen from FIG. 5 , the method according to the invention significantly reduces the asymmetric axial thrust acting on the brake disc, ie, reduces the difference between the opposing forces applied by the corresponding actuators when completing the activation of the parking brake.

[0051] Advantageously, the control method according to the invention can be applied to a brake system comprising at least one fixed brake caliper.

[0052] According to an embodiment of the present invention, the third predetermined force value F3 is substantially equal to the fourth predetermined force value F4.

[0053] According to an embodiment of the present invention, the third predetermined force value F3 is equal to zero.

[0054] According to an embodiment, the fourth predetermined force value F4 is equal to zero.

[0055] According to an embodiment, both the third predetermined force value F3 and the fourth predetermined force value F4 are equal to zero.

[0056] According to an embodiment of the present invention, both the first predetermined force value F1 and the second predetermined force value F2 are greater than the third predetermined force value F3 and the fourth predetermined force value F4.

[0057] Furthermore, the first predetermined force value F1 and the second predetermined force value F2 are equal to force values ​​sufficient to complete activation of the parking brake force.

[0058] According to an embodiment of the present invention, the first predetermined force value F1 is substantially equal to the second predetermined force value F2.

[0059] According to an embodiment of the present invention, the step of detecting the value of the first force Fa by the detection device includes:

[0060] - detecting the angular position of the first actuator 2 by means of detection means; and

[0061] - calculating the value of the first force Fa by means of the electronic processing unit 4 based on the angular position of the first actuator 2; or

[0062] - detecting the value of the first supply current ia supplied to the first actuator 2; and

[0063] - On the basis of the value of the first supply current ia supplied to the first actuator 2 , the value of the first force Fa is calculated by means of the electronic processing unit 4 .

[0064] According to an embodiment, the step of detecting the value of the second force Fb by means of a detection device comprises:

[0065] - detecting the angular position of the second actuator 3 by means of detection means; and

[0066] - calculating the value of the second force Fb by means of the electronic processing unit 4 on the basis of the angular position of the second actuator 3; or

[0067] - detecting the value of the second supply current ib supplied to the second actuator 3; and

[0068] - On the basis of the value of the second supply current ib supplied to the second actuator 3 , the value of the second force Fb is calculated by means of the electronic processing unit 4 .

[0069] According to an embodiment of the present invention, when a parking brake force activation request signal is received by the electronic processing unit 4, the following steps are activated: the first actuator 2 is actuated by means of the electronic processing unit 4 so that the first actuator 2 approaches to abut against the first pad, thereby applying a first force Fa and increasing the value of the first force Fa, and the second actuator 3 is actuated by means of the electronic processing unit 4 so that the second actuator 3 approaches to abut against the second pad, thereby applying a second force Fb and increasing the value of the second force Fb.

[0070] When said actuating device operatively connected to the electronic processing unit 4 is actuated, a parking brake force activation request signal is sent by the actuating device.

[0071] The actuation means can be actuated by a user.

[0072] According to an embodiment of the present invention, after the step of continuing to actuate the first actuator 2 and the second actuator 3 until the first force Fa reaches the first predetermined force value F1 and the second force Fb reaches the second predetermined force value F2, the method comprises the following steps:

[0073] - sending a parking brake force activation completion signal from the electronic processing unit 4 to a signal sending device operatively connected to the electronic processing unit 4 .

[0074] Optionally, the parking brake force completion activation signal can be viewed by a user by means of a signaling device.

[0075] According to an embodiment, the step of synchronously applying the first force Fa and the second force Fb on the brake disc is performed in an iterative manner. Preferably, the iteration time is between 5 ms and 10 ms.

[0076] According to an embodiment, during the step of synchronously applying the first force Fa and the second force Fb on the brake disc, the value of the first force Fa and / or the value of the second force Fb is detected every 5 to 10 ms.

[0077] According to another aspect of the invention, a braking system 1 of a vehicle configured to activate a parking brake force comprises at least the following:

[0078] - brake discs;

[0079] - a first pad and a second pad, the first pad and the second pad being spaced apart from each other and positioned opposite to the brake disc;

[0080] a first actuator 2 configured to apply and release a first force Fa on the first pad to move the first pad from an open position, in which the first pad is separated from the brake disc and does not actuate the parking brake force, to a closed position, in which the first pad is biased against the brake disc and actuates the parking brake force;

[0081] a second actuator 3 configured to exert a second force Fb on the second pad to move the second pad from an open position, in which the second pad is separated from the brake disc and does not actuate the braking force, to a closed position, in which the second pad is biased against the brake disc and actuates the parking brake force;

[0082] an electronic processing unit 4 configured to control the actuation of the first actuator 2 and the actuation of the second actuator 3;

[0083] - a detection device operatively connected to the electronic processing unit 4, the detection device being configured to detect directly or indirectly the value of a first force Fa actuated by the first actuator 2 on the first pad, and to detect directly or indirectly the value of a second force Fb actuated by the second actuator 3 on the second pad.

[0084] The brake system 1 is configured to activate the parking brake force by executing the method as described above.

[0085] Advantageously, the braking system 1 thus configured allows minimizing the asymmetric axial thrust acting on the brake disc when the parking brake is applied.

[0086] By way of additional advantage, the braking system 1 thus configured has reduced energy and structural constraints.

[0087] Advantageously, the brake system comprises at least one fixed brake caliper.

[0088] According to an embodiment of the invention, the braking system 1 comprises an actuation device operatively connected to an electronic processing unit 4 .

[0089] The electronic processing unit 4 is configured such that, upon receiving a parking brake force activation request signal, the electronic processing unit 4 actuates the first actuator 2 so that the first actuator 2 approaches against the first pad, thereby applying a first force Fa and increasing the value of the first force Fa, and actuates the second actuator 3 so that the second actuator 3 approaches against the second pad, thereby applying a second force Fb and increasing the value of the second force Fb.

[0090] The parking brake force activation request signal is sent by the actuation device when the button is actuated.

[0091] The actuation device is actuatable by a user.

[0092] Advantageously, the actuation device can be positioned in the passenger compartment of the vehicle close to a position occupied by a user.

[0093] The actuating device may be, for example, a suitable button, an ignition key, a gearshift actuator, an accelerator pedal or other pedal, or a device connected to an automatic function managed by the electronic processing unit 4 or a suitable electronic processing unit.

[0094] According to an embodiment, the brake 1 comprises signal sending means operatively connected to the electronic processing unit 4 .

[0095] The electronic processing unit 4 is configured to send a parking brake force activation completion signal to the signal sending device.

[0096] The user can view the parking brake force activation signal by means of the signaling device.

[0097] The signaling device may be, for example, a warning light, or a digital screen positioned within the passenger compartment of the vehicle close to the position occupied by the user.

[0098] According to an embodiment, the detection means comprises an angular position detector, preferably an encoder, configured to detect the angular position of the first actuator 2 and / or the second actuator 3 .

[0099] Alternatively or additionally, the detection means comprises a current detector, preferably an ammeter, configured to detect the value of a supply current supplied to the first actuator 2 or the second actuator 3 .

[0100] The electronic processing unit 4 comprises a calculator configured to calculate the value of the first force Fa and / or the second force Fb based on the angular position of the first actuator 2 or the second actuator 3, respectively.

[0101] Alternatively or additionally, the calculator is configured to calculate the value of the first force Fa and / or the second force Fb based on the value of the supply current supplied to the first actuator 2 or the second actuator 3, respectively.

[0102] It is obvious that those skilled in the art will be able to make changes or modifications to the present invention without departing from the scope of the appended claims.

[0103] Reference numerals list

[0104] 1. Braking system

[0105] 2. First actuator

[0106] 3. Second actuator

[0107] 4. Electronic processing unit

[0108] Fa.The first force

[0109] Fb. Second Force

[0110] F1. First predetermined force value

[0111] F2. Second preset force value

[0112] F3. The third predetermined force value

[0113] F4. Fourth predetermined force value

[0114] ia. First supply current

[0115] ib. Second supply current

[0116] t1. First moment

[0117] t2. The second moment.

Claims

1. A method for controlling a braking system (1) of a vehicle for activating a parking brake force actuated by the braking system (1), the braking system (1) being a braking system of the type comprising at least: - brake discs; - a first pad and a second pad, the first pad and the second pad being spaced apart and positioned opposite the brake disc; a first actuator (2) configured to apply and release a first force (Fa) on the first pad to move the first pad from an open position, in which at least one of the first pads is separated from the first brake disc and does not actuate a parking brake force, to a closed position, in which the first pad is biased against the brake disc and actuates a parking brake force; a second actuator (3) configured to apply a second braking force (Fb) on the second pad to move the second pad from an open position, in which the second pad is separated from the brake disc and does not actuate a braking force, to a closed position, in which the second pad is biased against the brake disc and actuates a parking brake force; - an electronic processing unit (4) configured to control the actuation of the first actuator (2) and the actuation of the second actuator (3); - detection means, operatively connected to the electronic processing unit (4), configured to detect directly or indirectly the value of a first braking force (Fa) actuated by the first actuator (2) on the first pad, and to detect directly or indirectly the value of a second braking force (Fb) actuated by the second actuator (3) on the second pad, the method comprising the following steps: - operating the first actuator (2) by means of the electronic processing unit (4) so ​​as to bring the first actuator close to the first pad so as to apply the first force (Fa) and to increase the value of the first force (Fa), and operating the second actuator (3) by means of the electronic processing unit (4) so ​​as to bring the second actuator close to the second pad so as to apply the second force (Fb) and to increase the value of the second force (Fb); - detecting the value of the first force (Fa) and the value of the second force (Fb) by means of the detection means during actuation of the first actuator (2) and the second actuator (3); - synchronously applying the first force (Fa) and the second force (Fb) on the brake disc by means of the electronic processing unit (4); - continuing to actuate the first actuator (2) and the second actuator (3) until the first force (Fa) reaches a first predetermined force value (F1) and the second force (Fb) reaches a second predetermined force value (F2); - stopping said first actuator (2) and said second actuator (3) by means of said electronic processing unit, The step of synchronously applying the first force (Fa) and the second force (Fb) on the brake disc comprises the following steps: - at a first moment (t1) when the detection device detects that the first force (Fa) has increased to a value significantly greater than a third predetermined force value (F3), stopping the first actuator (2) and continuing to actuate the second actuator (3); - at a second moment (t2) when the detection device detects that the second actuator (3) applies a second force (Fb) which is significantly greater than a fourth predetermined force value (F4), actuating the first actuator (2); Alternatively, the step of synchronously applying the first force (Fa) and the second force (Fb) on the brake disc comprises the following steps: - at a first moment (t1) when the detection device detects that the second force (Fa) has increased to a value significantly greater than a fourth predetermined force value (F4), stopping the second actuator (3) and continuing to actuate the first actuator (2); - At a second moment (t2) when the detection device detects that the first actuator (2) applies a first force (Fb) which is significantly greater than a third predetermined force value (F3), the second actuator (3) is actuated.

2. The method according to claim 1, wherein: The third predetermined force value (F3) is substantially equal to the fourth predetermined force value (F4).

3. The method according to claim 1 or 2, wherein: The third predetermined force value (F3) is zero, and / or wherein the fourth predetermined force value (F4) is zero.

4. A method according to any one of the preceding claims, wherein: The first predetermined force value (F1) and the second predetermined force value (F2) are both greater than the third predetermined force value (F3) and the fourth predetermined force value (F4), And wherein the first predetermined force value (F1) and the second predetermined force value (F2) are equal to force values ​​sufficient to complete activation of the parking brake force.

5. The method according to claim 4, wherein: The first predetermined force value (F1) is substantially equal to the second predetermined force value (F2).

6. A method according to any one of the preceding claims, wherein: The step of detecting the value of the first force (Fa) by means of the detection device comprises: - detecting the angular position of the first actuator (2) by means of the detection means; and - calculating the value of said first force (Fa) by means of said electronic processing unit (4) as a function of said angular position of said first actuator (2); or - detecting the value of a first supply current (ia) for powering at least one of said first actuators (2); and - calculating, by means of said electronic processing unit (4), the value of said first force (Fa) based on the value of said first supply current (ia) powering said first actuator (2), and / or The step of detecting the value of the second force (Fb) by means of the detection device comprises: - detecting the angular position of the second actuator (3) by means of the detection means; and - calculating the value of the second force (Fb) by means of the electronic processing unit (4) as a function of the angular position of the second actuator (3); or - detecting the value of a second supply current (ib) for powering at least one of said second actuators (3); and - calculating the value of the second force (Fb) by means of the electronic processing unit (4) on the basis of the value of the second supply current (ib) powering the second actuator (3).

7. A method according to any one of the preceding claims, wherein: When the parking brake force activation signal is received by the electronic processing unit (4), the following steps are activated: actuating the first actuator (2) by means of the electronic processing unit (4) so ​​that the first actuator approaches against the first pad to apply the first force (Fa) and increase the value of the first force (Fa), and actuating the second actuator (3) by means of the electronic processing unit (4) so ​​that the second actuator approaches against the second pad to apply the second force (Fb) and increase the value of the second force (Fb), wherein, when an actuator device operatively connected to the electronic processing unit (4) is actuated, the parking brake force activation request signal is sent by the actuator device, The actuation means can be actuated by a user.

8. The method according to any of the preceding claims, comprising, after the step of continuing to actuate the first actuator (2) and the second actuator (3) until the first force (Fa) reaches a predetermined force value (F1) and the second force (Fb) reaches a second predetermined force value (F2), the step of: - sending a parking brake force activation completion signal from the electronic processing unit (4) to a signal sending device operatively connected to the electronic processing unit (4); Optionally, the parking brake force activation completion signal can be viewed by a user by means of the signal sending device.

9. A method according to any one of the preceding claims, wherein: During the step of synchronously applying the first force (Fa) and the second force (Fb) on the brake disc, the value of the first force (Fa) and / or the value of the second force (Fb) is detected every 5 to 10 milliseconds.

10. A braking system (1) for a vehicle, the braking system (1) being configured to activate a parking brake force, the braking system (1) comprising at least the following: - brake discs; - a first pad and a second pad, the first pad and the second pad being spaced apart and positioned opposite the brake disc; a first actuator (2) configured to apply and release a first force (Fa) on the first pad to move the first pad from an open position, in which at least one of the first pads is separated from the first brake disc and does not actuate a parking brake force, to a closed position, in which the first pad is biased against the brake disc and actuates a parking brake force; a second actuator (3) configured to apply a second braking force (Fb) on the second pad to move the second pad from an open position, in which the second pad is separated from the brake disc and does not actuate a braking force, to a closed position, in which the second pad is biased against the brake disc and actuates a parking brake force; - an electronic processing unit (4) configured to control the actuation of the first actuator (2) and the actuation of the second actuator (3); - a detection device, which is operatively connected to the electronic processing unit (4), and is configured to: directly or indirectly detect the value of a first braking force (Fa) actuated by the first actuator (2) on the first pad, and directly or indirectly detect the value of a second braking force (Fb) actuated by the second actuator (3) on the second pad, wherein the braking system (1) is configured to activate the parking braking force by executing a method according to any of the preceding claims.

11. System (1) according to claim 10, comprising an actuation device operatively connected to the electronic processing unit (4), in, The electronic processing unit (4) is configured to: upon receiving a parking brake force activation signal by the electronic processing unit (4), the electronic processing unit (4) actuates the first actuator (2) so that the first actuator approaches against the first pad, thereby applying the first force (Fa) and increasing the value of the first force (Fa), and actuates the second actuator (3) so that the second actuator approaches against the second pad, thereby applying the second force (Fb) and increasing the value of the second force (Fb), wherein the parking brake force activation request signal is sent by the actuating device when the actuating device is actuated, and wherein the actuation means is actuatable by a user, and / or wherein the braking system (1) comprises a signal sending device operatively connected to the electronic processing unit (4), The electronic processing unit (4) is configured to send a parking brake force activation completion signal to the signal sending device, And wherein the parking brake force activation signal is viewable by a user by means of the signaling device.

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