Method and control device for monitoring brake components

Abstract

The present invention relates to a method for monitoring brake components (3) of a vehicle (1a), and to a control device (11) which is designed to carry out the method according to the invention, the method comprising the following steps: - detecting cumulative first wheel information (11) of a first brakable wheel (5) and detecting cumulative second wheel information (12) of a second brakable wheel (7), - determining a wheel information deviation (D) between the cumulative first wheel information (11) and the cumulative second wheel information (12), - outputting a signal (S) if the wheel information deviation (D) exceeds a predetermined limit value (G).

Description

[0001] Method and control unit for monitoring brake components

[0002] The present invention relates to a method for monitoring brake components of a vehicle and to a control unit which is configured to carry out the method according to the invention.

[0003] Vehicles, especially commercial vehicles, sometimes have complex braking systems with a multitude of different braking components, such as valves, actuators, and pneumatic and / or hydraulic components. These braking components are assigned to individual braked wheels of the vehicle, so that individual wheel brakes are usually present.

[0004] Faulty brake components can lead to critical driving situations, especially during braking. A complete or partial failure of individual brake components in a vehicle can, for example, reduce the vehicle's braking performance or lead to unwanted lateral forces due to different braking torques on the left and right sides of the vehicle.

[0005] One result of the unintended lateral forces acting on the vehicle due to a complete or partial failure of individual brake components is the vehicle pulling to the left or right. This is because, for example, defective brake components inadvertently decelerate the brakeable wheels to different degrees, for example, more on the left side of the vehicle than on the right. Thus, a complete or partial failure of individual brake components of a vehicle can lead to uncontrollable and therefore dangerous driving conditions.

[0006] Various methods for monitoring a vehicle's brake components are known from the prior art. For example, US Pat. Nos. 8532897 B2 and 9283937 B2 disclose methods in which brake components are monitored by comparing the specified steering angle with the actual steering angle of the vehicle or by means of pressure sensors on the respective brake actuators of the wheels.

[0007] From EP 3 753 794 A1 a method is known in which the braking performance of a vehicle is monitored by monitoring and comparing the respective braking performance of individual wheels.

[0008] From US 2012 / 0010779 A1 a method is known in which predetermined parameters must be achieved during a defined braking test.

[0009] Some of the methods described in the prior art have the disadvantage that a significant defect must already be present in at least one of the vehicle's brake components in order for the monitored reaction or effect of the defect to indicate or suggest a complete or partial failure of an individual brake component of the vehicle.

[0010] In addition, some of the processes require additional and sometimes expensive components, such as sensors.

[0011] It is therefore the object of the present invention to provide a sensitive and effective method for monitoring brake components of a vehicle.

[0012] This object is achieved according to the invention by a method for monitoring brake components of a vehicle, wherein the vehicle has at least one first brakeable wheel and at least one second brakeable wheel, wherein the method comprises the following steps:

[0013] - detecting a cumulative first wheel information of the first brakeable wheel and detecting a cumulative second wheel information of the second brakeable wheel,

[0014] - determining a wheel information deviation between the cumulative first wheel information and the cumulative second wheel information,

[0015] - Outputting a signal if the wheel information deviation exceeds a predetermined limit. Brakable vehicle wheels have various braking components, such as valves, actuators, and / or pneumatic and / or hydraulic components, as well as hoses and lines. Some of these braking components are designed for each wheel, meaning they are uniquely assigned to a particular brakeable wheel.

[0016] In this case, cumulative wheel information is understood to mean information about a quantity or a measured value relating to a property of a wheel, whereby the quantity or the measured value is summed up, i.e. cumulated or added together.

[0017] In the simplest case, this could involve measuring a quantity or measured value over a period of time and summing them together. Furthermore, it could involve continuously recording a quantity or measured value, and the temporally integrated value of the quantity or measured value would represent the cumulative wheel information.

[0018] According to one embodiment of the method, for example, the cumulative first wheel information and the cumulative second wheel information correspond to the number of revolutions of the first brakeable wheel or the number of revolutions of the second brakeable wheel or a variable derivable therefrom, for example the respective wheel speeds or wheel distances.

[0019] According to this embodiment, the number of revolutions of the respective wheel is cumulated, i.e. summed up.

[0020] A quantity that can be derived from the number of revolutions does not necessarily mean a derivative in the strict mathematical sense, but rather the possibility of converting different quantities into one another.

[0021] For example, the distance traveled by the wheel, called the wheel distance, can be calculated from the number of wheel revolutions given a known wheel circumference, and vice versa. A wheel speed can also be converted into both the number of revolutions of the wheel in question and the distance traveled within a given period of time, and vice versa. Wheel speed can be viewed as the angular velocity or the relative speed of the vehicle relative to the road surface. The distance traveled per period of time, or the wheel distance differentiated by time, provides a measure of the wheel speed, whereby the wheel circumference (angular velocity) may also need to be taken into account.

[0022] Conversely, the cycling distance results from the temporal integration of a cycling speed.

[0023] The number of revolutions of the respective wheels represents an easy-to-determine input variable, which can be recorded, for example, via wheel speed sensors that are already installed.

[0024] In its simplest form, a wheel information deviation can be determined, for example, by calculating the difference between the cumulative first wheel information and the cumulative second wheel information. If the first brakeable wheel and the second brakeable wheel have different properties, for example, different wheel circumferences, these different properties can be taken into account by appropriate standardization.

[0025] In the simplest case, a check to see whether the wheel information deviation exceeds a predetermined limit can also be carried out by calculating the difference value.

[0026] The procedure is based on the principle that, given identical wheel characteristics, such as wheel circumference, installed brake components, and brake control, and consistent, functioning brake components, the limit value should not be exceeded. Exceeding the limit value indicates a significant difference between the cumulative first wheel information and the cumulative second wheel information. This difference, in turn, is due to different characteristics of the first brakeable wheel compared to the second brakeable wheel.

[0027] However, if the known properties of the first and second brakeable wheels are identical and the limit value is nevertheless exceeded, this can be concluded to indicate a fault in the first or second brakeable wheel.

[0028] If the known properties of the first and second brakeable wheels are different, the different known properties of the respective wheels can be taken into account by appropriately normalizing the respective cumulative wheel information or by appropriately selecting the limit value, so that only errors in the brake components can be the cause of a limit value being exceeded.

[0029] For example, if the cumulative wheel information is the number of revolutions of the respective brakeable wheels, and a wheel information deviation is determined from this, an exceedance of the limit value indicates that one of the brakeable wheels has completed significantly more or fewer revolutions than the other.

[0030] Depending on the direction from which the limit value is exceeded, it can be concluded whether there is a fault in the brake components on the first or second flammable wheel.

[0031] Furthermore, the error in the brake components can be further narrowed down by cross-correlation with other brakeable wheels on which the procedure is carried out.

[0032] If the wheel information deviation exceeds the limit, a signal is issued to indicate the presence of a fault or defect in one of the brake components of the first or second brakeable wheel. By accumulating the wheel information over a period of time, even very small influences from defective brake components can be reliably detected, as these small influences also accumulate.

[0033] In principle, there are no restrictions regarding the position of the first and second brakeable wheels on the vehicle. The method is suitable for wheels on one side of the vehicle or on opposite sides of the vehicle.

[0034] The method according to the invention thus provides a sensitive and effective method for monitoring brake components of a vehicle in a simple manner.

[0035] Furthermore, this object is achieved according to the invention by a control unit for a vehicle, wherein the control unit is configured to carry out the method according to the invention.

[0036] The advantages of the procedure listed above apply analogously.

[0037] According to one embodiment of the method, the first brakeable wheel and the second brakeable wheel are each arranged on opposite sides of the vehicle, preferably on opposite sides of an axle of the vehicle.

[0038] As described at the beginning, different braking torques on the left and right sides of the vehicle can lead to lateral forces, which can cause an unstable driving situation.

[0039] By arranging them on opposite sides of the vehicle, preferably on opposite sides of each axle of the vehicle, the brake components of these wheels are monitored accordingly and any defect is detected early and reliably.

[0040] Furthermore, this approach has the advantage that at least wheels on opposite sides of a vehicle's axle generally have identical properties, such as the type of brake control and wheel circumference. This eliminates the need for the above-described standardization of the wheel information or adjustment of the limit value.

[0041] According to a further embodiment of the method, the cumulative first wheel information and the cumulative second wheel information are recorded exclusively during a braking operation, in particular on a straight stretch of road.

[0042] This means that wheel information is only accumulated when the vehicle is actually braking. Furthermore, the potentially minor influences of defective brake components are also only accumulated during a pre-braking event. Since these influences typically only occur during a braking event, their relationship is improved compared to the accumulated wheel information without the influence of defective brake components.

[0043] Furthermore, during braking on a straight stretch, the brakes of the wheels on the left and right sides of the vehicle are usually controlled identically, at least on an axle-by-axle basis, which simplifies the procedure described above with regard to standardizing the wheel information or adjusting the limit value.

[0044] According to a further embodiment of the method, when detecting the cumulative wheel information, a distinction is made between detected cumulative wheel information during automatic braking and detected cumulative wheel information during manual braking, and when determining the wheel information deviation, an additional distinction is made between the cumulative wheel information detected during automatic braking and the cumulative wheel information detected during manual braking.

[0045] By determining a wheel information deviation, in particular by comparing the cumulative wheel information recorded during automatic braking and the cumulative wheel information recorded during manual braking, further defects in a vehicle's brake components can be detected. For example, during automatic braking by an EBS or ACC, different brake components are involved in a wheel-specific braking process than during manual braking by a driver. For example, during automatic braking, the brake components of the brake pedal are not part of the braking precursor.

[0046] If the cumulative wheel information recorded during automatic braking differs from the cumulative wheel information recorded during manual braking, it can be concluded that there is a defect in the exclusively used brake components.

[0047] According to a further embodiment of the method, the cumulative wheel information is recorded over a minimum period of time and / or a minimum number of cumulative wheel information items.

[0048] By providing a minimum period and / or a minimum number of wheel information items, the sensitivity at which a defective brake component is detected can be further increased. For example, the effect of a defective brake component on, for example, the number of wheel revolutions can only be reliably detected after a certain time or a certain number of revolutions.

[0049] According to a further embodiment of the method, the output of the signal causes one or more of the following measures:

[0050] - Outputting an acoustic, haptic or optical signal to a driver of the vehicle,

[0051] - Output of an error message to a control unit of the vehicle and / or

[0052] - Braking the vehicle.

[0053] All of the above-mentioned measures are designed to reliably prevent critical driving situations caused by a defective brake component. For example, after detecting the acoustic, haptic, or visual signal, a driver can bring the vehicle to a stop and drive more carefully. The same applies to a corresponding control unit, depending on the error message received.

[0054] According to a further embodiment of the method, the cumulative first wheel information and the cumulative second wheel information are each cumulated over the entire service life of the vehicle or at least one brake inspection interval of the vehicle and provided as historical information to a new vehicle or to the same vehicle after a brake inspection, so that when determining the wheel information deviation, a distinction is additionally made between current cumulative wheel information of the new vehicle or the same vehicle after a brake inspection and the historical information, in particular the historical information is compared with current cumulative wheel information.

[0055] By accumulating the data over the entire service life of the vehicle or at least one brake inspection interval of the vehicle, a particularly long interval is selected so that even the smallest deviations due to faults in individual wheel-specific brake components can be reliably detected.

[0056] By providing this cumulative historical information and comparing current cumulative wheel information with this historical information, there is another possibility to detect even minor defects in the vehicle's brake components.

[0057] Especially if the historical data comes from a vehicle that demonstrably has no defective brake components, the historical data can be used as reference data. Thus, if the current cumulative wheel information deviates from this historical reference data, a brake component defect is present.

[0058] According to a further embodiment of the method, the method is carried out continuously, in particular the steps

[0059] - Determining the wheel information deviation and - Outputting a signal if the wheel information deviation exceeds a predetermined limit value, are carried out in parallel or simultaneously with the step

[0060] - Collecting cumulative wheel information.

[0061] This ensures that defects in brake components, which have a major influence on the cumulative wheel information, are reliably detected right at the beginning of the process.

[0062] In addition, the sensitivity to detecting defects in brake components increases over time, as additional information is continuously added to the cumulative wheel information, so that due to the continuous accumulation, defects in brake components with very little influence on the cumulative wheel information can also be detected.

[0063] According to a further embodiment of the method, the brake components are valves, actuators and / or pneumatic and / or hydraulic components of a brake system, in particular a wheel brake.

[0064] By determining the wheel information deviation of more than two wheels, for example by means of cross-correlation, defects in different brake components, some of which are exclusively used for individual wheels or some of which are used jointly or on an axle basis, can be detected.

[0065] According to a further embodiment of the method, the limit value is a relative limit value, in particular with respect to a period of time and / or a number of wheel information items of the cumulative wheel information items.

[0066] For example, the limit value can be set such that a wheel information deviation of more than 5% indicates an exceedance of the limit value. Absolute limits are disadvantageous for continuous wheel information accumulation, as they are regularly exceeded over a sufficiently long period of accumulation.

[0067] With a relative limit, however, an absolute increase in the wheel information deviation due to the accumulation of wheel information over a period of time and / or a number of wheel information items is permissible without the limit being exceeded.

[0068] According to a further embodiment of the method, the predetermined limit value depends on a braking force distribution.

[0069] In particular, a brake force distribution provides that the front axles of a vehicle are controlled with different brake pressures than the rear axles of a vehicle. When implementing the method, with the first brakeable wheel located on a front axle and the second brakeable wheel located on a rear axle, the corresponding brake force distribution must be taken into account when selecting the limit value or when normalizing the cumulative first wheel information and the cumulative second wheel information, so that only defects in the brake components of the two wheels contribute to a wheel information deviation.

[0070] The invention is explained in more detail below with reference to the accompanying drawings. They show:

[0071] Fig. 1 is a schematic representation of a vehicle which is configured to carry out an embodiment of the method;

[0072] Fig. 2 shows a first embodiment of the method;

[0073] Fig. 3 shows a second embodiment of the method;

[0074] Fig. 4 shows a third embodiment of the method; Figure 1 shows a schematic representation of a vehicle 1a which is set up to carry out an embodiment of the method. For this purpose, the vehicle 1a has a first brakeable wheel 5 on the left-hand side of the vehicle 1 and a second brakeable wheel 7 on the right-hand side of the vehicle r. Both brakeable wheels 5, 7 have wheel brakes 6, which are formed by brake components 3 such as valves 3a, actuators 3b and pneumatic and / or hydraulic components 3c, for example lines and hoses. The respective brake components 3 can be exclusively wheel-specific, such as the illustrated actuators 3b and pneumatic and / or hydraulic components 3c, or used jointly, such as the illustrated valves 3a.

[0075] The two wheel brakes 6 in turn form a braking system 6. In the present case, the brakeable wheels 5, 7 are arranged opposite one another on an axle 9, but the brakeable wheels can also be arranged on one side 1, r of the vehicle 1 a.

[0076] A speed sensor 13 is arranged on each of the first brakeable wheel 5 and the second brakeable wheel 7, which transmits the cumulative first wheel information 11 and the cumulative second wheel information I2, in this case the number of revolutions of the first brakeable wheel U1 and the number of revolutions of the second brakeable wheel U2, to a control unit 11.

[0077] The control unit 11 outputs a signal S depending on the method described below.

[0078] The embodiments of the methods shown in Figs. 2, 3 and 4 can be combined with each other.

[0079] Fig. 2 shows a first embodiment of a method for monitoring brake components 3 of a vehicle 1a, wherein the vehicle 1a has at least one first brakeable wheel 5 and at least one second brakeable wheel 7. In a step S1, cumulative first wheel information 11 of the first brakeable wheel 5 and cumulative second wheel information 12 of the second brakeable wheel 7 are recorded. The cumulative first and second wheel information 11 and 12 can, for example, consist of the number of revolutions of the first and second brakeable wheels U1 and U2, respectively, the wheel speed of the first and second brakeable wheels w1 and w2, respectively, and / or the wheel speed of the second and first brakeable wheels s1 and s2, respectively. All of these variables represent variables Z(U) that can be converted into or derived from one another.

[0080] Corresponding cumulative wheel information 11, 12 can be detected, for example, by means of a speed sensor 13.

[0081] The cumulative first and second wheel information 11 and 12 is recorded over a minimum period Tmin and / or a minimum number Cmin of cumulative wheel information 11, 12, which is indicated by the dashed arrow.

[0082] As soon as the minimum period Tmin and / or the minimum number Cmin of cumulative wheel information 11, I2 is exceeded, sufficient cumulative wheel information 11, I2 is available and the system proceeds to step S2.

[0083] In step S2, a wheel information deviation D is determined, which in the simplest form is determined by forming the difference value of the cumulative first wheel information I1 and the cumulative second wheel information I2.

[0084] In step S3, a limit value G is determined depending on a brake force distribution F, a period of time over which the wheel information is accumulated T and the number of wheel information items C, and a check is made to determine whether the wheel information deviation D is above the limit value G. The limit value G can also be a relative limit value Gr, in particular with respect to a period of time T and / or a number of wheel information items C. If the limit value G or the relative limit value Gr is exceeded, a signal S is output. The signal S can also be a haptic or optical signal Sh and / or an error message Sf.The dependence of the limit value G on the brake force distribution F is selected, for example, such that if the first brakeable wheel 5 is arranged on a rear axle of the vehicle 1a, while the second brakeable wheel 7 is arranged on a front axle of the vehicle 1a, the wheel information deviation D, which results exclusively from the different brake force distribution F between the front and rear axles, is taken into account in the limit value G, so that the brake force distribution F has no influence on the exceeding of the limit value G.

[0085] This applies analogously to the period over which wheel information is accumulated T and the number of wheel information C, whereby their influences on the wheel information deviation D do not contribute to the selection of a relative limit value.

[0086] The limit value G is thus selected in such a way that only influences due to defects in brake components 3 of the first or second brakeable wheel 5 or 7 contribute to the limit value G being exceeded.

[0087] Alternatively or additionally, the cumulative first wheel information I1 and / or the cumulative second wheel information I2 can be standardized so that influences due to brake force distribution F, a period over which wheel information is accumulated T and / or the number of wheel information C have no influence on the wheel information deviation D.

[0088] Fig. 3 shows a second embodiment of a method for monitoring brake components 3 of a vehicle 1a, wherein the vehicle 1a has at least one first brakeable wheel 5 and at least one second brakeable wheel 7.

[0089] In a step S1, cumulative first and second wheel information 11 and 12 are calculated.

[0090] I2 are detected, wherein these are additionally differentiated according to whether they are detected during an automatic braking application Ba or whether they are detected during a manual braking application Bm. The cumulative first or second wheel information 11 or I2 can analogously contain the variables mentioned in the first exemplary embodiment. In a step S2, the wheel information deviation D1 between the cumulative first wheel information 11 during an automatic braking application Ba and the cumulative first wheel information 11 of a manual braking application Bm is determined. This makes it possible, for example, to detect defective wheel components 3 which act exclusively on the first brakeable wheel 5 during a manual braking application Bm, but not on the first brakeable wheel 5 during an automatic braking application Ba.

[0091] The same applies to determining the wheel information deviation D2 between the cumulative second wheel information I2 during an automatic braking Ba and the cumulative second wheel information I2 of a manual braking Bm.

[0092] Furthermore, the wheel information deviation D3 between the cumulative first wheel information I1 during automatic braking Ba cumulated with the cumulative first wheel information I1 during manual braking Bm and the cumulative second wheel information I2 during automatic braking Ba cumulated with the cumulative second wheel information I2 during manual braking Bm is determined. This step is largely analogous to step S2 of the first embodiment.

[0093] In a step S3, an exceeding of the respective limit values ​​G1, G2, G3 by the respective previously mentioned wheel information deviations D1, D2, D3 is checked and a corresponding signal S is output.

[0094] By cross-correlating the various previously mentioned exceedances of the respective limit values ​​G1, G2, G3, defective brake components 3 can be identified more precisely.

[0095] Fig. 4 shows a third embodiment of a method for monitoring brake components 3 of a vehicle 1a, wherein the vehicle 1a has at least one first brakeable wheel 5 and at least one second brakeable wheel 7. In a step S1, cumulative first and second wheel information 11 and 12, respectively, are stored.

[0096] I2 is recorded analogously to the first embodiment of the method over a period of time T. The cumulative first and second wheel information 11 and I2 can analogously contain the variables mentioned in the first embodiment.

[0097] In a step S2, when determining the wheel information deviation D2, D3, additional historical information Ih is used, which has been accumulated over the entire service life T1 of another or new vehicle 1b of the same design or at least over a brake inspection interval T2 of the same vehicle 1a. Preferably, the historical information represents reference data from a vehicle in which no defect in a brake component 3 existed.

[0098] The wheel information deviation D2 is determined between the cumulative first wheel information 11 and corresponding historical information Ih for the first brakeable wheel 5, and for the wheel information deviation D3 between the cumulative second wheel information I2 and corresponding historical information Ih for the second brakeable wheel 7, and for the wheel information deviation D1 analogously to the first embodiment between the cumulative first wheel information 11 and the cumulative second wheel information I2.

[0099] In a step S3, an exceeding of the respective limit values ​​G1, G2, G3 by the respective previously mentioned wheel information deviations D1, D2, D3 is checked and a signal S is output accordingly.

[0100] In particular, by comparing the historical information Ih with the respective cumulative first and second wheel information 11 and I2 and by exceeding a respective limit value G2, G3, small defects in brake components 3 can be reliably detected in their effect on the cumulative wheel information 11, I2.

[0101] By cross-correlating the various previously mentioned exceedances of the respective limit values ​​G1, G2, G3, defective brake components 3 can be more precisely identified. A further advantageous embodiment combines embodiments 2 and

[0102] 3, so that a wheel information deviation D from historical information Ih and current cumulative wheel information 11, I2, in particular broken down by cumulative wheel information 11, I2, is monitored for exceeding the respective limit values ​​G during an automatic braking Ba and a manual braking Bm.

[0103] Reference symbol (part of the description)

[0104] 1a vehicle

[0105] I b additional / new vehicle

[0106] 3 brake components

[0107] 3a Valves

[0108] 3b Actuators

[0109] 3c pneumatic and / or hydraulic components

[0110] 4 Braking system

[0111] 5 first brakeable wheel

[0112] 6 wheel brake

[0113] 7 second brakeable wheel

[0114] 9 Axis

[0115] II Control unit

[0116] 13 Speed ​​sensor

[0117] 11 cumulative first bike information

[0118] 12 cumulative second wheel information

[0119] U1 Number of revolutions of the first brakeable wheel

[0120] U2 Number of revolutions of the second brakeable wheel w1 Wheel speed of the first brakeable wheel w2 Wheel speed of the second brakeable wheel s1 Wheel distance of the first brakeable wheel s2 Wheel distance of the second brakeable wheel

[0121] Your historical information

[0122] D, D1, D2, D3 wheel information deviation

[0123] G, G1, G2, G3 limit

[0124] Gr relative limit value

[0125] S Signal

[0126] Sh haptic or optical signal

[0127] Sf error message

[0128] Ba automatic braking

[0129] Bm manual braking

[0130] I left side of the vehicle r right side of the vehicle

[0131] T Period over which wheel information is accumulated

[0132] T1 total lifetime of the vehicle 1

[0133] T2 brake inspection interval

[0134] C Number of wheel information

[0135] Tmin minimum period over which cycling information is accumulated

[0136] Cm in minimum number of wheel information

[0137] F Brake force distribution

[0138] Z(U) quantity derivable from U1 or U2

Claims

Patent claims 1. A method for monitoring brake components (3) of a vehicle (1 a), wherein the vehicle (1 a) has at least one first brakeable wheel (5) and at least one second brakeable wheel (7), the method comprising the following steps: - detecting a cumulative first wheel information (11) of the first brakeable wheel (5) and detecting a cumulative second wheel information (12) of the second brakeable wheel (7) (S1), - determining a wheel information deviation (D) between the cumulative first wheel information (I1) and the cumulative second wheel information (I2) (S2), - outputting a signal (S) if the wheel information deviation (D) exceeds a predetermined limit value (G) (S3).

2. Method according to claim 1, characterized in that the first brakeable wheel (5) and the second brakeable wheel (7) are each arranged on opposite sides (I, r) of the vehicle (1a), preferably on opposite sides (I, r) of an axle (9) of the vehicle (1a).

3. Method according to one of the preceding claims, characterized in that the cumulative first wheel information (11) and the cumulative second wheel information (12) correspond to the number of revolutions (U1) of the first brakeable wheel (5) or the number of revolutions (U2) of the second brakeable wheel (7) or to a variable (Z(U)) derivable therefrom, for example the respective wheel speeds (w1, w2) or wheel distances (s1, s2).

4. Method according to one of the preceding claims, characterized in that the cumulative first wheel information (11) and the cumulative second wheel information (12) are recorded exclusively during a braking operation (Ba, Bm), in particular on a straight stretch of road.

5. Method according to one of the preceding claims, characterized in that when detecting (S1) the cumulative wheel information (11, I2) between detected cumulative wheel information (11, I2) during an automatic braking (Ba) and detected cumulative wheel information (11, I2) during manual braking (Bm) and that when determining the wheel information deviation (D) (S2) a distinction is additionally made (S4) between the cumulative wheel information (11, I2) detected during automatic braking (Ba) and the cumulative wheel information (11, I2) detected during manual braking (Bm).

6. Method according to one of the preceding claims, characterized in that the recording of the cumulative wheel information (11, I2) (S1) takes place over a minimum period of time (Tmin) and / or a minimum number (Cmin) of cumulative wheel information (11, I2).

7. Method according to one of the preceding claims, characterized in that the output of the signal (S) (S3) causes one or more of the following measures: - outputting an acoustic, haptic or optical signal (Sh) to a driver of the vehicle (1a), - Outputting an error message (Sf) to a control unit (11) of the vehicle (1a) and / or - Braking the vehicle (1a).

8. Method according to one of the preceding claims, characterized in that the cumulative first wheel information (11) and the cumulative second wheel information (I2) are each cumulated over the entire service life (T1) of the vehicle (1a) or at least one brake inspection interval (T2) of the vehicle (1a) and are provided as historical information (Ih) to a new vehicle (1b) or to the same vehicle (1a) after a brake inspection, so that when determining the wheel information deviation (D) (S2), a distinction is additionally made between current cumulative wheel information (11, I2) of the new vehicle (1b) or the same vehicle (1a) after a brake inspection and the historical information (Ih).

9. Method according to one of the preceding claims, characterized in that the method is carried out continuously, in particular the steps - Determining the wheel information deviation (D) (S2) and - Outputting a signal (S) if the wheel information deviation (D) exceeds a predetermined limit value (G) (S3), parallel or simultaneously with the step - the cumulative wheel information (12, 12) (S1 ) is recorded.

10. Method according to one of the preceding claims, characterized in that the brake components (3) - valves (3a), - actuators (3b) and / or - pneumatic and / or hydraulic components (3c) of a braking system (4), in particular a wheel brake (6).

11. Method according to one of the preceding claims, characterized in that the limit value (G) is a relative limit value (Gr), in particular with respect to a period of time (T) and / or a number (C) of wheel information of the cumulative wheel information (11, 12).

12. Method according to one of the preceding claims, characterized in that the predetermined limit value (G) depends on a braking force distribution (B).

13. Control unit (11) for a vehicle (1a), configured to carry out a method according to one of the preceding claims.

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