Method for checking whether parking brake regulator is correctly connected to control device, and control device

Abstract

The invention relates to a method for checking whether a controllably adjustable parking brake regulator (1) for braking or locking wheels (2) of a motor vehicle is correctly connected, in particular laterally correctly, to a control device (10) for controlling the parking brake regulator. In detail, the method comprises at least three enforced measures a), b) and c). According to a first measure a), a hydraulic medium (HM) is generated in a hydraulic line (3) for hydraulically adjusting the parking brake regulator (1). In a second measure b) carried out after the measure a), at least one control signal (SSIG) for adjusting the parking brake regulator (1) is output by the control device (10) to an electrical signal output connection (11) of the control device (10) associated with the wheel (2). In a measure c) carried out after the measure b), it is determined whether the hydraulic pressure (pl) of the hydraulic medium (HM) in the hydraulic line (3) varies with the output of the at least one control signal (SSIG) in the measure b).

Description

Technical Field

[0001] This invention relates to a method for checking whether a controllable and adjustable parking brake adjuster for braking or locking the wheels of a motor vehicle is correctly connected to a control device for controlling such a parking brake adjuster. Furthermore, this invention relates to a control device configured or programmed to implement this method. Background Technology

[0002] Motor vehicles equipped with automated parking brakes often include the function that braking force or braking force support is generated in dynamic driving conditions by an electromechanical parking brake modulator. In this operation, wheel movement is monitored, and once a wheel locks up, the braking force generated by the parking brake modulator is reduced. For braking force to be reduced on the correct wheel, it is important that the relevant parking brake modulator is correctly, especially "side-correctly," connected to the control device that operates the parking brake modulator. Therefore, in conjunction with the present invention, "side-correctly" and "side-reversibly" means that the parking brake modulator, in order to generate braking force acting on a specific wheel, is also connected to the electrical signal output terminal of the control device for that wheel and not to the electrical signal output terminal for the other wheels of the motor vehicle. This ensures that the control signal generated by the control device for a specific parking brake modulator is executed by that specific parking brake modulator and not by parking brake modulators distributed to other wheels. Summary of the Invention

[0003] Therefore, the object of the present invention is to provide an improved method for checking whether a particular parking brake adjuster of a parking brake is also correctly connected to a corresponding control device for controlling two or more parking brake adjusters of that parking brake. In particular, a method should be provided that can be implemented particularly easily in terms of technology and without requiring special inspection equipment.

[0004] This task is addressed by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims.

[0005] Therefore, the basic concept of this invention is to utilize the following situation in the error detection mentioned at the beginning: a parking brake regulator, arranged in a hydraulic line and hydraulically coupled to and further electromechanically adjustable in the hydraulic medium within the hydraulic line, causes a pressure change in the hydraulic pressure of the hydraulic medium within the hydraulic line when it is electromechanically adjusted. This pressure change is caused by the electromechanical adjustment of the parking brake regulator or the piston that is part of it, depending on whether the parking brake regulator or its piston is adjusted towards the brake disc of the fitted wheel, i.e., towards the closed position, or in the opposite direction away from the brake disc, i.e., towards the released position, resulting in either an increase or a decrease in the volume formed together by the parking brake regulator and the hydraulic line. By means of a suitable pressure sensor for determining the hydraulic pressure of the hydraulic medium in the hydraulic line or the parking brake regulator, such a pressure change in the hydraulic pressure can be identified, and thereby indirectly determined whether the parking brake regulator has moved or is moving. This effect of hydraulic pressure change during the movement of the parking brake adjuster is utilized in the method according to the invention. For this purpose, a control device that operates the parking brake or its adjuster generates a control signal at a signal output connector assigned to a specific wheel, including the parking brake adjuster. This control signal causes adjustment of the parking brake adjuster connected to this signal output connector. Thus, by means of the hydraulic pressure monitoring explained above, it can be determined whether the desired adjustment of the parking brake adjuster is actually occurring in response to the aforementioned control signal. Because this necessitates that the relevant parking brake adjuster is also connected to the correct signal output connector of the control device, it is thus possible to determine whether such a correct connection exists, particularly the "side-correct" connection of the relevant parking brake adjuster on the control device as explained at the beginning.

[0006] Of particular advantage of the method explained above is that no additional hardware is required for the parking brake to implement this method; this is because not only the parking brake adjuster but also the aforementioned hydraulic pressure sensor are typically available in conventional parking brakes. It goes without saying that the processing described above can also be implemented for all parking brake adjusters located within the parking brake and assigned to the different wheels of the vehicle without significant additional overhead.

[0007] The method described herein, according to the invention, is therefore used to check whether a controllably adjustable parking brake adjuster for braking or locking the wheels of a motor vehicle is correctly, particularly correctly, connected to a control device for controlling the parking brake adjuster. Specifically, the method includes at least three mandatory steps a), b), and c). According to step a), a specific hydraulic pressure is generated in the hydraulic medium in the hydraulic line, wherein the parking brake adjuster is hydraulically coupled to the hydraulic medium. In step b), implemented after step a), at least one control signal for electromechanically adjusting the parking brake adjuster is output by the control device to the electrical signal output connector of the control device for that wheel. In step c), implemented after step b), it is checked whether the hydraulic pressure of the hydraulic medium in the hydraulic line changes with the output of at least one control signal in step b). This determination can be made by means of a hydraulic pressure sensor located in the hydraulic line, which is connected to the control device in a signal-transmitting manner and thus also in a data-transmitting manner, and transmits the corresponding hydraulic pressure sensor data to the control device, so that the corresponding hydraulic pressure information for implementing measure c) is available to the control device.

[0008] In a preferred embodiment of the method according to the invention, if the difference between the hydraulic pressure before and after the output of at least one control signal for adjusting the parking brake adjuster according to step b) exceeds a predetermined threshold, then in step c) the change in hydraulic pressure is determined to have occurred. Because such a threshold is exceeded along with the adjustment of the parking brake adjuster, it is possible to reliably determine whether the parking brake adjuster has moved without the risk of misjudgment when the threshold is appropriately determined. Alternatively, in this embodiment, if a anticipated increase or decrease in hydraulic pressure up to this point is identified during the adjustment of the parking brake adjuster according to step b), then the change in hydraulic pressure can be determined to have occurred in step c).

[0009] According to a third alternative of this implementation, if a change in hydraulic pressure, particularly an increase or decrease, has been identified after a predetermined duration has elapsed since at least one control signal was output according to measure b), then the change in hydraulic pressure can be determined as having occurred in measure c).

[0010] Preferably, prior to implementing measures b) and c), the other parking brake adjuster used to brake or lock the other wheel of the vehicle is hydraulically decoupled from the hydraulic lines. This prevents adjustments to the other parking brake adjuster from causing changes in the hydraulic pressure in the hydraulic lines, which could lead to an incorrect determination in measure c) that the other parking brake adjuster, rather than the one mentioned, has been activated, even though it is not.

[0011] According to an advantageous improvement of the method of the invention, if a change in hydraulic pressure is identified in measure c), the parking brake adjuster is classified as correctly connected, particularly as being connected to the correct signal output connector of the control device, in the subsequent supplementary measure d1). Conversely, if no change in hydraulic pressure is identified in measure c), the parking brake adjuster is classified as incorrectly connected to the control device, particularly as not connected to the correct signal input connector of the control device, in the subsequent supplementary measure d2).

[0012] According to an advantageous improvement, if it is determined in supplementary measure d2) that the parking brake adjuster is incorrectly connected to the control device, a fault signal can be generated by the control device or / and output in particular. It is determined that the inspected parking brake adjuster is obviously or perhaps laterally reversed, but in any case not correctly connected to the parking brake control device, and thus presents a fault condition that sometimes even jeopardizes safety; such determination allows for further processing.

[0013] If a motor vehicle equipped with a parking brake (which includes a parking brake adjuster, control equipment, and the wheel to be braked) is not in motion, the compliant function of the parking brake can be specifically checked, and the method according to the invention can be implemented during the fault diagnosis of the parking brake. However, the method described herein is also advantageously suited for implementation while the motor vehicle is in motion.

[0014] According to another advantageous improvement, measures a'), b'), and c') can be implemented as measures a'), b'), and c') during the process of the method according to the invention to another parking brake adjuster for braking or locking another wheel of the motor vehicle. Thus, error checking of two or more parking brake adjusters can be performed at least partially simultaneously, i.e., overlapping in time, by means of the method according to the invention.

[0015] In another preferred embodiment, measures a'), b'), and c') are implemented at least partially simultaneously with respect to measures a), b), and c), i.e., overlapping in time. This allows for minimizing the required inspection duration for the method, especially if two or more parking brake adjusters need to be checked for proper electrical connection with the control equipment.

[0016] However, in an alternative variation, it is conceivable that the inspection of the first parking brake adjuster can only begin after the inspection of the first parking brake adjuster has been completed under measures a), b), and c), and then under measures a'), b'), and c'), respectively. This eliminates the possibility of mutual interference between the two inspection processes in each case, which could occur if performed simultaneously.

[0017] Particularly preferred is that measures a'), b'), and c') are implemented at times staggered relative to measures a), b), and c). This avoids or at least suppresses electrical overload of the control equipment caused by undesirable current peaks resulting from simultaneous adjustments to two or more parking brake regulators. Accelerated inspection is achieved due to the simultaneous implementation of at least part of the two inspection processes. Therefore, in this variant, measure a') begins after the implementation of measure a).

[0018] This invention also relates to a control device for a motor vehicle, which is configured / programmed to implement the method described above according to the invention. The advantages of the method described above can therefore be applied to the control device according to the invention.

[0019] Other important features and advantages of the invention are apparent from the dependent claims, the drawings, and the accompanying description of the drawings.

[0020] It goes without saying that the features mentioned above and explained below can be used not only in the combinations described, but also in other combinations or alone, without departing from the scope of the invention. Attached Figure Description

[0021] Preferred embodiments of the present invention are shown in the accompanying drawings and explained in detail in the following description.

[0022] The attached figures are shown schematically as follows: Figure 1 An exemplary structure of a parking brake, including a control device for the parking brake, is shown, by means of which the method according to the invention can be implemented.

[0023] Figure 2 An exemplary flowchart of the method according to the present invention is shown. Detailed Implementation

[0024] Figure 1 The structure of a parking brake 4 is schematically and exemplaryly illustrated in a greatly simplified diagram, the parking brake having two hydraulically actuated and electromechanically adjustable parking brake adjusters 1, 1* and a control device 10 in which the method according to the invention can be executed. Each parking brake adjuster 1, 1* includes a movable piston 5, 5*, which can be hydraulically adjusted by means of a hydraulic medium HM. For this purpose, the adjustable volume of the parking brake adjusters 1, 1* with pistons 5, 5* is connected to a hydraulic line 3 containing the hydraulic medium HM. The hydraulic line 3 is in fluid connection to a hydraulic medium container 6, in which the hydraulic medium HM is stored, and thus the hydraulic medium HM can be introduced from the hydraulic medium container into the hydraulic line 3 and through the hydraulic line into the parking brake adjusters 1, 1*. Braking force can be applied to brake discs 7 or 7* arranged on the associated wheels 2, 2* by means of the adjustable piston 5 or 5*. The corresponding parking brake adjusters 1, 1* or pistons 5, 5* can thus be adjusted between a released position and a closed position by means of hydraulic medium HM, but also electromechanically, wherein no braking force is generated in the released position, and such braking force acts on the brake disc 7 in the closed position. Because the volume of the parking brake adjusters 1, 1* or their pistons 5, 5* in fluid communication with the hydraulic line 3 is increased when the parking brake adjusters 1, 1* are electromechanically adjusted toward the closed position, the hydraulic pressure p of the hydraulic medium HM decreases during such electromechanical adjustment toward the closed position. Because the volume of the parking brake adjusters 1, 1* in fluid communication with the hydraulic line 3 is decreased when the parking brake adjusters 1, 1* or their pistons 5, 5* are electromechanically adjusted toward the released position, the hydraulic pressure p of the hydraulic medium HM increases during such adjustment toward the released position.

[0025] In order to adjust the parking brake adjusters 1, 1* or their pistons 5, 5*, the control device 10 controls the parking brake adjusters or their pistons accordingly by transmitting corresponding control signals SSIG generated by the control device 10. These control signals SSIG are transmitted by the control device 10 to the corresponding parking brake adjusters 1, 1* via corresponding signal lines 13, 13*.

[0026] For the signal to be correctly transmitted to the parking brake adjuster 1, it is mandatory that the signal line 13, which is electrically connected to the parking brake adjuster 1, is also connected to the signal output connector 11 assigned to this parking brake adjuster 1, because only at this signal output connector is the control signal SSIG necessary for adjusting the parking brake adjuster 1 provided. A connection of the signal line 13 to the signal output connector 11* (on which the control signal for controlling the parking brake adjuster 1* is generated by the control device 10) will cause the parking brake adjuster 1* to be incorrectly adjusted and the parking brake adjuster 1 will not be adjusted as intended. Whether the signal line 13 is correctly connected to the assigned signal output connector 11 can be determined by means of the following... Figure 2 The flowchart exemplarily explains the method according to the invention for inspection. Figure 2 In the example, the method includes three mandatory measures a), b), and c).

[0027] According to the first measure a), pressure is applied to the hydraulic medium HM (to which the parking brake regulator 1 is hydraulically coupled) in the hydraulic line 3, so that the hydraulic medium HM has a hydraulic pressure p1. This can be done by introducing additional hydraulic medium HM from the pressure-loaded hydraulic medium container 6 by means of an actuator 8 controllable by the control device 10. Once the hydraulic medium HM in the hydraulic line 3 has the desired hydraulic pressure p1, the fluid connection between the hydraulic line 3 and the hydraulic medium container 6 can be interrupted by means of the actuator 8. However, it is also conceivable that in this configuration, the fluid connection between the hydraulic line 3 and the hydraulic medium container 6 is first interrupted by adjusting the actuator 8 and then the desired hydraulic pressure p1 is generated by further adjusting the actuator 8. The instantaneous hydraulic pressure p of the hydraulic medium HM in the hydraulic line 3 can be determined by means of a hydraulic pressure sensor 14 arranged in or in fluid communication with the hydraulic line 3. The hydraulic pressure sensor transmits the sensor data corresponding to the measured hydraulic pressure p to the control device 10 through the signal line 21.

[0028] Immediately following measure a), the fluid connection between the parking brake regulator 1* (not to be inspected) and the pressure sensor 14 is interrupted by means of a valve device 9* arranged in the hydraulic line 3 between the pressure sensor 14 and the parking brake regulator 1*. Thus, the parking brake regulator 1* is fluidly isolated from the parking brake regulator 1 and the pressure sensor 14. Accordingly, it must be ensured before implementing measure a) that the fluid connection between the parking brake regulator 1 and the pressure sensor 14 is not interrupted by means of the valve device 9 arranged in the hydraulic line 3 between the pressure sensor 14 and the parking brake regulator 1. The aforementioned measures provide a closed hydraulic system 15 consisting of the parking brake regulator 1 and the pressure sensor 14, which are hydraulically or fluidly connected to each other via a hydraulic medium HM in the hydraulic line 3.

[0029] In the second measure b) implemented after measure a), the control device 10 now outputs the control signal SSIG for adjusting the parking brake regulator 1 to the electrical signal output connector 11 of the control device 10 for distributing electricity to the wheel 2.

[0030] If as in Figure 1 The parking brake adjuster 1 shown is correctly connected to the signal output connector 11 via signal line 13. Then the control signal SSIG is transmitted to the parking brake adjuster 1 via signal line 13 and causes the parking brake adjuster 1 to adjust either to the closed position or to the released position.

[0031] As described above, the adjustment of the parking brake regulator 1 is accompanied by an increase or decrease in the hydraulic pressure p of the hydraulic medium HM relative to the previously set hydraulic pressure p1. Such changes in the hydraulic pressure p to a value that increases or decreases relative to the hydraulic pressure p1 are detected by means of the pressure sensor 14 and transmitted to the control device 10 via the signal line 21.

[0032] Therefore, by means of pressure sensor 14, in measure c) implemented after measure b), it is checked whether the output of control signal SSIG in measure b) has caused a change in the hydraulic pressure p1 of hydraulic medium HM in hydraulic line 3, or whether this is not the case.

[0033] Here, if the difference Δp between the hydraulic pressure p1 before and after the output of at least one control signal SSIG for adjusting the parking brake regulator 1 according to measure b exceeds a predetermined threshold ps, then the change in hydraulic pressure p1 is determined to have occurred in sub-measure c1) of measure c). Alternatively, if a change in hydraulic pressure p1, particularly an increase or decrease, is identified after a predetermined duration T measured since the output of at least one control signal SSIG according to measure b) has elapsed, then the change in hydraulic pressure p1 can be determined to have occurred in sub-measure c2) of measure c).

[0034] If a change in hydraulic pressure p1 is identified in measure c), as explained in the two alternatives above, then in supplementary measure d1) immediately following measure c), the parking brake adjuster 1 is classified as correctly connected, i.e., connected to the correct signal output connector 11 of the control device 2. Conversely, if a change in hydraulic pressure p1 is not identified in measure c), then as an alternative to supplementary measure d1), in supplementary measure d2) immediately following measure c), the parking brake adjuster 1 is classified as incorrectly connected, i.e., not connected to the correct signal output connector 11 of the control device 10. This is the case if the signal line 13 leading to the parking brake adjuster 1 is connected, in reverse, to the signal output connector 11* belonging to another parking brake adjuster 1*.

[0035] If it has been determined in measure c) or supplementary measure d2) that the parking brake adjuster 1 is incorrectly connected to the control device 10, especially to the output connector 11* assigned to the other wheels 2*, then alternatively, a fault signal ERR may be generated and output in the control device 10 in another supplementary measure e) immediately following supplementary measure d2).

[0036] In one improved embodiment of the example, measures a), b), and c) can be implemented as measures a'), b'), and c') during the process of the method according to the invention using another parking brake adjuster 1* for braking or locking the other wheel 2* of the motor vehicle.

[0037] Here, measures a'), b'), and c') can be implemented in a time-staggered manner relative to measures a), b), and c), but with temporal overlap. For this purpose, the implementation of measure a') begins after the implementation of measure a).

[0038] However, as an alternative, it is also conceivable that measures a), b), and c) be implemented concurrently with measures a'), b'), and c').

[0039] In the example, the method according to the invention described above is implemented as a diagnostic method, and therefore is not implemented during the operation of the motor vehicle. However, it is also conceivable to implement it during the operation of the motor vehicle.

Claims

1. A method for checking whether an electromechanically adjustable and hydraulically actuated parking brake adjuster (1) for braking or locking the wheels (2) of a motor vehicle is correctly, especially laterally, connected to a control device (10) for controlling such a parking brake adjuster (1), The method includes the following measures: a) A specific hydraulic pressure (p1) is generated in the hydraulic medium (HM) in the hydraulic line (3), and the parking brake regulator (1) is hydraulically coupled to the hydraulic medium. b) The control device (10) outputs at least one control signal (SSIG) for electromechanically adjusting the parking brake regulator (1) to the signal output connector (11) of the control device (10) for the electrical distribution to this wheel (2). c) Check whether the hydraulic pressure (pl) of the hydraulic medium (HM) in the hydraulic line (3) changes with the output of at least one control signal (SSIG) mentioned in measure b).

2. The method according to claim 1, Its features are, - If the difference (Δp) between the hydraulic pressure (p1) before and after the output of at least one control signal (SSIG) for adjusting the parking brake regulator (1) in accordance with measure b) exceeds a predetermined threshold (ps), then in measure c), the change in the hydraulic pressure (p1) is determined to have occurred; or - If an increase or decrease in hydraulic pressure (p1) up to this point is identified during the period when the parking brake adjuster (1) is expected to be adjusted according to measure b), then the change in hydraulic pressure (Δp) is determined to have occurred in measure c); or - If a change (D), particularly an increase or decrease, in the hydraulic pressure (p) is identified after a predetermined duration (T) has elapsed since at least one control signal (SSIG) was output according to measure b), then the change in the hydraulic pressure (p1) is determined to have occurred in measure c).

3. The method according to claim 1 or 2, Its features are, Before implementing measures b) and c), another parking brake regulator (1*) used to brake or lock the other wheel (2) of the motor vehicle will be decoupled from the hydraulic line (3) in terms of hydraulics.

4. The method according to any one of claims 1 to 3, Its features are, In the supplementary measure d1) that follows measure c), - If a change in the hydraulic pressure (p1) has been identified in measure c), the parking brake regulator (1) shall be classified as correctly connected to the control device (10), and in particular to the correct signal output connector (11) of the control device (10); or / and -In the supplementary measure d2) that immediately follows measure c), If the change in the hydraulic pressure (p1) is not identified in measure c) or the change in the hydraulic pressure is too small, the parking brake regulator (1) is classified as being incorrectly connected to the control device (10), and in particular as not being connected to the correct signal input connector (11) of the control device (10).

5. The method according to any one of the preceding claims, Its features are, If it has been determined in measure c) or / and d2) that the parking brake regulator (1) is incorrectly connected to the control device (10), a fault signal (ERR) can be generated by the control device (10) or / and in the control device.

6. The method according to any one of the preceding claims, Its features are, The method is implemented during the operation of a motor vehicle having wheels (2), a parking brake adjuster (1) and control equipment (10).

7. The method according to any one of the preceding claims, Its features are, During the process of the method, measures a'), b') and c') are implemented by another parking brake adjuster (1*) for braking or locking the other wheel (2*) of the motor vehicle.

8. The method according to claim 7, Its features are, Measures a', b', and c' are implemented in time that overlap with or are concurrent with measures a), b), and c).

9. The method according to claim 7 or 9, Its features are, - Implement measures a'), b'), and c') at staggered times relative to measures a), b), and c). -The implementation of measure a') shall begin after the implementation of measure a) in terms of time.

10. A control device for a motor vehicle, Its features are, The control device (10) is configured / programmed to implement the method according to any one of the preceding claims.

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