Diagnostic method and braking system having units for performing the diagnostic method

Abstract

The present invention relates to a diagnostic method (2) for self-diagnosis of an electronically controlled pneumatic braking system (1) for a commercial vehicle (4), comprising the following steps: - receiving a learning signal (SL) at the braking system (1); - in response to receiving the signal, switching the braking system to a learning mode (102) and performing the following steps: - performing a predetermined first activity (104) of the braking system (1) while the commercial vehicle (4) is stationary or in motion; - detecting a first learning system response (106) of the braking system (1) in response to performing the first activity (104) via a sensor device (108); and - storing (114) the detected first learning system response (106) as a first target system response (107, 210) in a storage unit (82). The present invention also relates to a braking system (1) and a computer program.

Description

Technical Field

[0001] This invention relates to a self-diagnostic method for an electronically controlled pneumatic braking system used in commercial vehicles. The invention also relates to an electronically controlled pneumatic braking system and a computer program for commercial vehicles. Background Technology

[0002] The diagnostic methods described above are preferably used for electronically controlled pneumatic braking systems in partially or fully autonomous commercial vehicles. This method of self-diagnostic testing is particularly meaningful and preferred for automation levels according to SAE Levels 2 to 5, especially 4 and 5. Modern braking systems rely on the driver's diagnostic skills and fault response in cases of faults that occur very infrequently in their respective frequencies. Especially with mechanical or pneumatic faults, it may not be necessary to use another direct sensor for fault identification to assess the impact of these faults on the system. However, if there is no driver present in a partially or fully autonomous vehicle, additional devices are required to identify such faults.

[0003] A method is known from DE 10 2018 222 677 A1, which can be used for so-called platooning of commercial vehicles. The method involves the operation of vehicles designed for at least temporary autonomous driving, wherein, while the vehicles are operating in a first autonomous driving mode, it is determined whether one or more switching conditions are met. If such switching conditions are met, the vehicles are switched to a second driving mode, which involves leading other vehicles. Switching conditions may in particular be difficult route trajectories, construction sites, or other situations that are only difficult to autonomously manage. In this case, the second driving mode is activated, in which the vehicles are, for example, led through other vehicles traveling ahead.

[0004] DE 10 2017 130 549 A1 describes a method for self-diagnosis. This document assumes that diagnostic methods for identifying fault conditions are known, but that the vehicle must be driven under specific boundary conditions to collect diagnostic data. This is considered disadvantageous because it requires intervention in standard operating procedures and imposes limitations on the driver. DE 10 2017 130 549 A1 attempts to address this by setting its own diagnostic operating procedure in which self-diagnosis is performed. Therefore, for example, the specific operation expected by the driver will not be disturbed by interruptions caused by diagnostics.

[0005] Furthermore, DE 10 2013 007 857 A1 discloses a method for operating a braking system in a motor vehicle having a driver assistance system configured for fully automated, independent vehicle guidance. The concept described here is to achieve a fail-safe state. An action plan is known here, which should be used if a fail occurs. The action plan is known based on operating parameters, including at least one self-parameter describing the current operating state of the motor vehicle and / or at least one environmental parameter describing the environment of the motor vehicle, and is continuously updated. Therefore, the basic concept of DE 10 2013 007 857 A1 is to define a safe state, such as the motor vehicle being stationary in its current lane or an adjacent lane, such as an emergency lane. Thus, an action plan including braking measures can be known based on the current operating state of the motor vehicle described by the operating parameters, which generates this safe state. Therefore, during fail-safe operation, braking changes (Bremsprofil) are generated as an action plan and always kept up-to-date, wherein the action plan is applied in fail-safe conditions. Therefore, the teachings of DE 10 2013 007 857 A1 do not arise during fault identification, but rather after a fault has occurred and the vehicle should be moved to a safe condition. The active identification and elimination of faults will not be discussed further here.

[0006] A method for monitoring friction brakes is known from DE 10 2017 207 476 A1. For this purpose, if the vehicle is in a known driving state, the braking system is briefly activated by a test brake. The state of the friction brake can be inferred by evaluating the acceleration value. For this purpose, the known acceleration value is compared with a known value of the braked vehicle. However, it is not disclosed how these values ​​should be obtained, how they are provided, stored, or used, nor is it disclosed how the comparison is performed in detail.

[0007] Similar methods for performing test braking are known from EP 0 733 531 B1 and EP 0 733 532 B1. First, a test braking method for determining and adjusting the distribution of braking energy to the brake based on a description of the response energy is disclosed. Second, a simplified method for determining the response pressure of a vehicle brake is disclosed. In the first design, a test brake with a low braking pressure is provided, wherein the braking pressure is continuously varied until it just indicates a change in vehicle deceleration. In the second design, after the braking operation, the varying braking pressure is used to maintain the braking pressure of the brake under test until the brake causes a change in vehicle deceleration.

[0008] In addition to the aforementioned systems capable of fault-safe operation, guided operation, or obtaining the status of the braking system, such as the status of friction brakes, there is a need to provide methods, braking systems, and computer programs of the types described above that can achieve fault identification in a simple and safe manner. In particular, this method should also be able to account for manufacturing, installation, or life-related variations in the braking system. For example, it has been proven that fixed boundary values ​​preset by the developer are not suitable as boundary values ​​for braking system faults under all circumstances. The braking system's response may vary slightly depending on installation, manufacturing tolerances, or wear, even when they are still within permissible tolerances. Furthermore, faults that cannot be directly detected by sensors or cannot be obtained through functional testing should also be identified. Summary of the Invention

[0009] The present invention addresses this task in a diagnostic method of the type described above, specifically comprising the following steps: receiving a learning signal at the braking system; in response to receiving the learning signal: switching the braking system to a learning mode and performing the following steps: performing a predetermined first activity of the braking system when the commercial vehicle is stationary or in motion; detecting a first learning system response of the braking system by a sensor device and responding to the implementation of the first activity; and storing the detected first learning system response as a first target system response in a storage unit.

[0010] This invention utilizes the understanding that system responses to defined reactions in defined states can be detected and stored for use as a reference for subsequent testing. Therefore, the diagnostic method is not limited to directly providing sensors to the module, function, or subsystem under test, but can be tested based on system responses. The inherent characteristics of the system are also fully considered when detecting and storing system responses in response to the implementation of a predetermined first activity. For example, every pneumatic braking system has a certain amount of leakage, which does not negatively affect functionality but can affect the system response to a certain extent. This leakage, which cannot be completely avoided in the installation of the braking system, is inherently fully considered in the diagnostic method according to the invention.

[0011] Preferably, the learning mode is activated only when the commercial vehicle is in a defined, preferably fault-free, state. For example, the learning signal can be provided after factory acceptance, repair, or maintenance of the commercial vehicle. It can be configured that the learning signal can be provided by the driver of the commercial vehicle, for example, by operating a switch, or wirelessly received via a remote transmitter. It can also be configured that the learning signal can be provided solely by the commercial vehicle manufacturer. In another variation, the learning signal can be configured to be periodically triggered and / or provided within the scope of start-up control or due to routines in a higher-level control unit, such as a control unit for autonomous driving of the commercial vehicle.

[0012] The sensor device used to detect the braking system's response to the first learning system's reaction to the first activity is preferably a sensor device already present in the braking system, such as, in particular, sensors installed in the braking system and existing sensors, especially pressure sensors, wheel speed sensors, wear sensors, etc.

[0013] The first activity can be performed when the commercial vehicle is stationary or when it is in motion. Activities performed while the vehicle is in motion include those performed at very low or low speeds. Often, activities performed when the vehicle is stationary are sufficient to identify most faults. For example, such activities can be used to identify leaks in hoses. Activities that must be performed while the vehicle is in motion are especially those that require detecting vehicle deceleration to identify the fault. As long as wheel speed is not important for fault identification, activities that can and should be performed when the vehicle is stationary are generally sufficient, thereby improving safety.

[0014] According to a preferred first embodiment of the diagnostic method, the diagnostic method includes the following steps: performing a first system diagnosis, which includes the following steps: implementing a predetermined first activity of the braking system when the vehicle is stationary or in motion; detecting a first diagnostic system response of the braking system to the implementation of the first activity via a sensor device; comparing the first diagnostic system response with a pre-stored first target system response in a comparison unit; and outputting a first fault signal when there is a deviation between the first target system response and the first diagnostic system response. Therefore, the same first activity performed for diagnosing the braking system is also performed when detecting the learning system response. In this way, the deviation between the learning system response and the actual system response can be known. Preferably, boundary values ​​are preset for the learning system response corresponding to the target system response. These boundary values ​​can be automatically preset and applied by the braking system, comparison unit, etc. The boundary values ​​can be applied depending on one or more parameters.

[0015] In this way, it is possible to compare the system characteristics to be learned with the actual system characteristics, and to identify whether there is a fault in the braking system based on the comparison.

[0016] In a preferred embodiment, outputting a first fault signal includes at least partially preventing the automated operation of the commercial vehicle. According to this embodiment, it can be configured such that, in order to authorize at least partial, preferably full, automated operation of the commercial vehicle, it is necessary to first perform a diagnostic method or at least some of its steps. For example, a comparison between the target system response and the diagnostic system response can be performed before activating the automated operation of the commercial vehicle. If no fault signal is output, then the automated operation of the commercial vehicle can be performed; however, if a fault signal is output, then at least partially or completely, the implementation of automated operation is prevented, i.e., partial or full automated operation. In this state, it can be configured such that the commercial vehicle can only be controlled by the driver, and if necessary, certain systems or subsystems can still be used in the case of limited automated operation. This means that even in the event of a fault, it is not necessarily necessary to immediately stop the vehicle or move it to a safe state. Instead, it can be configured such that the commercial vehicle can still operate, but no longer fully automated. In this case, the fault signal is preferably output via the vehicle bus, and particularly to a unit for autonomous driving, preferably above the braking system.

[0017] In another design of the diagnostic method, the predetermined first activity can be configured to relate only to a first subsystem of the braking system. In this case, it is possible to test the first subsystem based on the first activity and diagnose faults within it. For other subsystems, it is preferable to perform separate activities. This also allows for selective or limited testing with respect to that subsystem or the subsystem that should be diagnosed. This is particularly advantageous if only one or more of a plurality of subsystems are maintained, or if only that subsystem is necessary for automated operation and therefore should be diagnosed.

[0018] Preferably, the diagnostic method in the learning mode includes the following steps: implementing a predetermined second activity of the braking system while the commercial vehicle is stationary or in motion; detecting a second learning system response of the braking system to the implementation of the second activity via an additional sensor device or the sensor device thereof; and storing the detected second learning system response as a second target system response in an additional storage unit or the storage unit thereof. The predetermined second activity may involve another subsystem of the braking system, or other aspects of the braking system. However, it may also involve the same subsystem as the first activity, but with different functions. It should be understood that third, fourth, fifth activities, etc., may also be performed to diagnose the braking system as completely as possible. Correspondingly, the third, fourth, fifth learning system responses, etc., are also stored as third, fourth, fifth, fifth target system responses, etc. Preferably, all target system responses are stored in the same storage unit.

[0019] The sensor devices can vary depending on the activity. For example, the first activity could be regulating the braking pressure on the front axle, while the second activity could be regulating the braking pressure on the rear axle. In this regard, the sensor devices used to learn the first learning system response include sensors on the front axle, while the sensor devices used to learn the second learning system response must include sensors on the rear axle. Alternatively, all responses can be recorded by the braking system sensors regardless of the type of activity. In this way, a complete picture of the entire braking system can be obtained. However, to reduce storage and computational requirements, it is preferable to activate only those sensors that are typically relevant to the system response and fall within the detection range of the learning system response.

[0020] When the second activity is implemented in the learning mode, the method preferably further includes: performing a second system diagnosis, which has the following steps: implementing a predetermined second activity of the braking system when the vehicle is stationary or in motion; detecting a second diagnostic system response of the braking system in response to the implementation of the second activity via the sensor device or another sensor device; comparing the second diagnostic system response with a pre-stored second target system response in another comparison unit or the comparison unit; and outputting a second fault signal if there is a deviation between the second target system response and the detected second diagnostic system response.

[0021] Regarding the comparison and fault signals, as well as the sensor devices, the content already described above regarding the first system diagnostics applies. However, it is also possible to configure a second fault signal to have a different result than the first fault signal. This can be particularly related to which subsystem or system of the braking system is functioning with the aid of the first or second activity. For example, if a system critical to function or safety-related is involved, then the fault signal output should also prevent the commercial vehicle from continuing to operate. If a system that only restricts autonomous operation is involved, then the fault signal should prevent autonomous operation. In other cases, such as if the comfort system is not working or is not working correctly, it can be configured that the commercial vehicle can still operate or can operate with certain restrictions.

[0022] According to another preferred embodiment, the comparison unit is configured to perform a comparison step while considering at least one parameter selected from the following: ambient temperature, reserve pressure, especially static reserve pressure before the start of the diagnostic method or dynamic reserve pressure curve during the diagnostic method, supply voltage level in the braking system or one or more parts thereof, and power consumption in the braking system or one or more parts thereof.

[0023] These parameters can affect the specific response of the system. For example, a lower reserve pressure is also expected, because the braking pressure is related to the reserve pressure. Therefore, a lower braking pressure does not necessarily indicate a leak in the wiring between the axle modulator and the brake actuator, but could also be due to a slightly lower reserve pressure. By considering one or more of the parameters mentioned above, the reliability and robustness of fault identification can be improved. Preferably, the parameters are also detected and stored when the target system response is known. Preferably, the parameters are known and stored when the diagnostic system response is known. The comparison unit may have an algorithm that considers one or more parameters during comparison. Alternatively, the diagnostic system response is available in the form of normalization and / or parameter compensation and is preferably stored, preferably at least in the comparison unit. Here, one or more of the parameters mentioned above can be used. It can also be determined that one or more of the parameters are not within a range that is meaningful for performing the method. For example, if one or more of the parameters are outside the range of about 20% below or above the normal value, performing the diagnostic method may be meaningless. In this case, it can be canceled, repeated, or performed according to the plan at a later time.

[0024] Preferably, the predetermined first activity is a signal transition at the brake force modulator. This activity is a well-defined process. For example, for this purpose, it is short, preferably within a time period of less than one second, and more preferably within a few milliseconds, regulating the brake signal that requires maximum braking force during that time period. This may apply to the wheels, axles, or the entire braking system. Other predetermined first activities may also include driving specific, if necessary, individual solenoid valves, such as ABS valves, activating the parking brake, activating the air suspension, compressor, trailer control valve, electric steering, etc. Activities that can be performed while the vehicle is in motion include, in particular, manipulating the friction brakes to detect the condition of the brakes. In this case, the diagnostic system responds with vehicle deceleration. Thus, for example, worn or tattered brake pads can be identified.

[0025] Preferably, the sensor device includes at least one pressure sensor. The pressure sensor is preferably a pressure sensor disposed in the modulator of the braking system. In this respect, diagnostic methods can utilize systems and subsystems already existing in conventional braking systems.

[0026] Additionally or alternatively, the sensor device may include a measuring unit for detecting volumetric flow rate or mass flow rate and / or a noise sensor. A measuring unit for detecting volumetric flow rate or mass flow rate is preferred to determine the mass flow rate or volumetric flow rate of compressed air at a specific location in the system. For example, there are situations where, although the pressure remains constant, a leak exists, and the escaped compressed air is resupplyed by a reservoir and / or by a compressor. In this case, although there is a volumetric flow rate of compressed air, the pressure sensor will not detect a pressure drop. Such a leak can also be identified by a measuring unit configured to detect volumetric flow rate or mass flow rate. An additional noise sensor can only improve the measurement results. If a leak is present, it is usually also associated with acoustic noise. Typically, such leaks are identified by the driver of a commercial vehicle within the scope of start-up control. The driver walks around the commercial vehicle and identifies when a leak is present based on their experience. In fully autonomous vehicles, it is preferable to perform such checks automatically. A noise sensor is used for this purpose. Multiple noise sensors may also be placed at different locations in the braking system.

[0027] Additionally or alternatively, the sensor device may include a unit for olfactory sensing (odor sensor) and / or a gas sensor for detecting fragrances, neurotransmitters, and / or gases. In this way, leaks in the braking system can also be identified. For this purpose, specific odors or neurotransmitter substances or specific gases, preferably not present in nature and / or in the vehicle, may be added to the compressed air. This may only occur for the purposes of the diagnostic method or continuously. The odor sensor or gas sensor then provides a corresponding signal, which can be further evaluated and / or processed within the scope of the diagnostic method.

[0028] In cases where the first activity involves operating one or more friction brakes, within the sensor unit, a deceleration sensor is preferably also used to detect the deceleration of the commercial vehicle. Such a deceleration sensor can be configured, for example, as a control sensor or a gyroscope, and is used to detect the resulting vehicle deceleration. Other parameters, such as, in particular, the vehicle's load, tire type, and street conditions, are preferably considered here.

[0029] Alternatively or additionally, a gas sensor 207 may be provided. This unit 209 can detect fragrance 301, neurotransmitter 302, or gas 303, and provide a corresponding olfactory signal SO at a unit for monitoring health status 200, which is preferably configured to evaluate the olfactory signal. In this way, when the corresponding fragrance 301 or neurotransmitter 302 is added to the compressed air, a leak at the braking system 4 can be detected.

[0030] Figure 4 and Figure 5An example is shown of how to construct a comparison 128 of the target system response and the diagnostic system response. The two graphs are pressure-time plots, which use pressure on the vertical axis and time on the horizontal axis. Figure 4 and Figure 5 The two graphs are typical for those recorded by the third pressure sensor 69. The target system response 210 is here formed by a target pressure curve 212, which is surrounded by an upper boundary value 213 and a lower boundary value 214. In response to a first activity 104, for example in the form of a jump signal SR, such as in learning mode 102, the target pressure curve 212, recorded by the third pressure sensor 69, has its upper boundary value 213 and lower boundary value 214 preset or calculated, for example, by the comparison unit 84. Furthermore, in Figure 4 The diagnostic system response 124 is plotted, and it is shown here as a diagnostic pressure curve 215. (As from...) Figure 4 As can be seen, the pressure of the diagnostic pressure curve 215 increases significantly slower than that of the target pressure curve 212, with the target pressure curve 212 only actually being achieved at time point t1. A first deviation A1 occurs at this specific time point, and this deviation changes over time. This indicates a reduction in the nominal width of the reserve path or a fault in the main valve, such as the relay valve of the front axle brake pressure valve 26. The excessively slow rise of the diagnostic pressure curve 215 suggests that insufficient volume was provided to achieve the strong rise of the target pressure curve 212.

[0031] exist Figure 5 In the second chart, the target system reaction 210 is again plotted using the target pressure curve 212 and the upper boundary value 213 and lower boundary value 214. Figure 5 The graph shows two diagnostic system responses 124a and 124b. For example, diagnostic system response 124a can be detected at a different time point than diagnostic system response 124b, such as in two consecutive cycles. Diagnostic system response 124a, with diagnostic pressure curve 215a, shows excessively low air consumption, resulting in a second deviation A2. Here, a possible fault could be located, for example, in the brake cylinder's operating path. The measured pressure is detected, for example, by a first or second pressure sensor 67, 68, which should detect a pressure drop if compressed air is consumed, i.e., especially during braking.

[0032] The diagnostic system response 124b, with diagnostic pressure curve 215b, initially shows a curve very close to the target pressure curve 212, but then drops more sharply and is not constant. The curve decreases further over time. Here, the third deviation A3 is also variable over time. This indicates an unexpected leak, as the pressure drops further even when the target pressure curve 212 is at rest.

[0033] Once the diagnostic pressure curve 215 is no longer located between the upper boundary value 213 and the lower boundary value 214, a fault signal can be output, which may, for example, cause the automatic operation to be restricted and thus restrict the autonomous mode 116.

[0034] List of reference numerals in attached figures (part of the instruction manual)

[0035] 1. Electronically controlled pneumatic braking system

[0036] 2. Diagnostic methods

[0037] 3 First Subsystem

[0038] 4. Commercial vehicles

[0039] 5 Second Subsystem

[0040] 6 First Braking Circuit

[0041] 7 First compressed air reservoir

[0042] 8 Second Braking Circuit

[0043] 9 Second compressed air reservoir

[0044] 10 Air preparation units

[0045] 12 Compressors

[0046] 14 Central Control Unit

[0047] 15-unit central module

[0048] 16 Vehicle Bus

[0049] 17 First Voltage Source

[0050] 18 Units for autonomous driving

[0051] 19 Second Voltage Source

[0052] 20 Active Steering System

[0053] 22 Rear axle brake pressure valve

[0054] 24a-24d Rear Axle Brake Actuator

[0055] 26 Front axle brake pressure valve

[0056] 28 First Braking Signal Circuit

[0057] 30a and 30b ABS valves

[0058] 32a, 32b Front axle brake actuators

[0059] 34 Braking value transmitter

[0060] 35 Pneumatic connector for brake value transmitter

[0061] 36 First braking value transmitter line

[0062] 40 secondary central control units

[0063] 42 Rear Axle Redundant Pressure Output Terminal

[0064] 44. Front axle redundant pressure output terminal

[0065] 46 First shuttle valve

[0066] 48. Redundant pressure connectors for the central control unit

[0067] 49. Reserve connector for the central control unit

[0068] 50 Second shuttle valve

[0069] 52a-52f Wheel Speed ​​Sensor

[0070] 54 Second Bus

[0071] 60 Parking Brake System

[0072] 62 Parking Brake Unit

[0073] 64a-64d Parking brake actuator

[0074] 66 Parking brake switch

[0075] 67 First pressure sensor

[0076] 68 Second pressure sensor

[0077] 69 Third pressure sensor

[0078] 70 Fourth pressure sensor

[0079] 71 Fifth pressure sensor

[0080] 72 Sixth Pressure Sensor

[0081] 73 Seventh Pressure Sensor

[0082] 74 Eighth pressure sensor

[0083] 75 Ninth Pressure Sensor

[0084] 80 Trailer Control Valve

[0085] 81 Diagnostic Control Unit

[0086] 82 storage units

[0087] 84 Comparison Units

[0088] 100 Commercial vehicle / braking system spare

[0089] 102 Learning Mode

[0090] 103 First System Diagnosis

[0091] 104 The first scheduled event

[0092] 105 Second System Diagnosis

[0093] 106 First Learning System Response

[0094] 108 Sensor Devices

[0095] 109 Deceleration Sensor

[0096] 110 The second scheduled event

[0097] 112 Second Learning System Response

[0098] 114 Storage

[0099] 116 Autonomous Mode

[0100] 118 Diagnostic Mode

[0101] 120 Start-up Control

[0102] 122 Health Check

[0103] 124 First Diagnostic System Response

[0104] 126 Second Diagnostic System Response

[0105] 128 Comparison

[0106] 130 Decision Steps

[0107] 132 Diagnostic Steps (cyclically)

[0108] 200 units for monitoring health status

[0109] 202 Voltage connector for units used to monitor health status

[0110] 203 Bus Connector

[0111] 204 First Flow Sensor

[0112] 206 Second Flow Sensor

[0113] 207 Gas Sensor

[0114] 208 Noise Sensor

[0115] 209 Units for olfactory sensing

[0116] 210 Target System Response

[0117] 212 Target Pressure Curve

[0118] 213 Upper Boundary Value

[0119] 214 Lower Boundary Value

[0120] 215 Diagnostic pressure curve

[0121] 301 Spices

[0122] 302 Neurotransmitters

[0123] 303 gas

[0124] 305 Safe Driver

[0125] 306 External Operators

[0126] 307 Higher-level automation unit

[0127] A1 first deviation

[0128] A2 Second Deviation

[0129] A3 Third Deviation

[0130] EV supply voltage level

[0131] LW turn signal

[0132] HA1 First Rear Axle

[0133] HA2 Second Rear Axle

[0134] P1 First parameter

[0135] pBHA Rear Axle Braking Pressure

[0136] pBP Parking brake pressure

[0137] pBST Braking Value Transmitter Pressure

[0138] pBVA Front axle braking pressure

[0139] pRHA rear axle redundancy pressure

[0140] pRVA front axle redundancy pressure

[0141] pV reserve pressure

[0142] pV1 Static Reserve Pressure

[0143] pVd dynamic reserve pressure

[0144] SA1 First Activity Signal

[0145] SA2 Second Activity Signal

[0146] SABS ABS signal

[0147] SB Braking Signal

[0148] SBF Foot Brake Signal

[0149] SD wheel speed signal

[0150] SE Limit Signal

[0151] SF release signal

[0152] SL learning signal

[0153] SO olfactory signals

[0154] SP parking brake signal

[0155] SR transition signal

[0156] TU ambient temperature

[0157] VA front axle

[0158] VEL power consumption

[0159] ZSoll Braking Requirement Signal

Claims

1. A diagnostic method (2) for self-diagnosing an electronically controlled pneumatic braking system (1) for a commercial vehicle (4), the diagnostic method comprising the following steps: - Receive a learning signal (SL) at the braking system (1); - In response to receiving the signal, the braking system (1) is switched to learning mode (102), and the following steps are performed: - When the commercial vehicle (4) is stationary or moving, the predetermined first activity (104) of the braking system (1) is implemented. - The braking system (1) responds to the first learning system reaction (106) in response to the implementation of the first activity (104) by the sensor device (108); and - The detected first learning system response (106) is stored (114) in the storage unit (82) as the first target system response (107, 210). The diagnostic method is characterized by comprising the following steps: - Perform a first system diagnostic (103), which includes the following steps: - Implement the predetermined first activity (104) of the braking system (1) when the commercial vehicle (4) is stationary or in motion. - The first diagnostic system response (124) of the braking system (1) in response to the implementation of the first activity (104) is detected by the sensor device (108). - In the comparison unit (84), the first diagnostic system response (124) is compared (128) with the pre-stored first target system response (107); and - When there is a deviation (A1, A2, A3) between the first target system response (107) and the first diagnostic system response (124): output the first fault signal (SFE1).

2. The diagnostic method according to claim 1, wherein, Outputting the first fault signal (SFE1) includes: at least partially preventing the automated operation (116) of the commercial vehicle (4).

3. The diagnostic method according to claim 1 or 2, wherein, The predetermined first activity (104) involves only the first subsystem (3) of the braking system (1).

4. The diagnostic method according to claim 1 or 2, wherein the diagnostic method includes the following steps in the learning mode (102): - Implement the predetermined second activity (110) of the braking system (1) when the commercial vehicle (4) is stationary or in motion. - The braking system (1) responds (112) to the second learning system's response to the second activity (110) by an additional sensor device or the sensor device (108); and - The detected second learning system response (112) is stored (114) as the second target system response (213) in another storage unit or the storage unit (82).

5. The diagnostic method according to claim 4, wherein the diagnostic method comprises the following steps: - Perform a second system diagnostic (105), which includes the following steps: - Implement the predetermined second activity (110) of the braking system (1) when the commercial vehicle (4) is stationary or in motion. The braking system (1) is detected by the sensor device (108) or the other sensor device in response to the second diagnostic system response (126) to the implementation of the second activity (110). - In another comparison unit or the comparison unit (84), the second diagnostic system response (126) is compared (128) with a pre-stored second target system response (113); and - In the event of a discrepancy (A1, A2, A3) between the second target system response (113) and the second diagnostic system response (126): output a second fault signal (SFE2).

6. The diagnostic method according to claim 4, wherein, The predetermined second activity (110) involves only the second subsystem (5) of the braking system (1).

7. The diagnostic method according to claim 1, wherein, In the comparison unit (84), a comparison step is performed with regard to at least one parameter (P1), which is selected from the following: ambient temperature (UT), reserve pressure (pV), supply voltage level (EV) in the braking system (1) or one or more parts (3, 5, 6, 8) of the braking system (1), and power consumption (VEL) in the braking system (1) or one or more parts (3, 5, 6, 8).

8. The diagnostic method according to claim 7, wherein, The reserve pressure (pV) is the static reserve pressure (pV1) before the start of the diagnostic method (2) or the dynamic reserve pressure curve (pVd) during the diagnostic method (2).

9. The diagnostic method according to claim 1 or 2, wherein, The predetermined first activity (104) includes a transition signal (SR) at the braking force modulator (26, 22, 62, 80).

10. The diagnostic method according to claim 1 or 2, wherein, The sensor device (108) includes at least one pressure sensor (67, 68, 69, 70, 71, 72, 73, 74, 75).

11. The diagnostic method according to claim 10, wherein, The sensor device (108) includes a measurement unit (204, 206) for detecting volumetric flow rate or mass flow rate and / or a noise sensor (208).

12. The diagnostic method according to claim 10, wherein, The sensor device (108) includes at least one of the following components: a unit (209) for olfactory sensing, and a gas sensor (207) for detecting fragrance (301), neurotransmitters (302) and / or gases (303).

13. The diagnostic method according to claim 1 or 2, wherein, The predetermined first activity (104) includes operating one or more friction brakes (32a, 32b, 64a-64d) by means of regulating the braking pressure (pBVA, pBHA) at one or more axles (VA, HA1, HA2) of the commercial vehicle (4) with predetermined braking force (F1, F2, F3, F4, F5, F6) while the commercial vehicle (4) is in motion.

14. The diagnostic method according to claim 13, wherein, The sensor device (108) includes a deceleration sensor (109) for detecting the deceleration (SV) of the commercial vehicle (4).

15. The diagnostic method according to claim 1, wherein, The first fault signal (SFE1) is output to the safety driver (305), external operators (306) and / or the superior automation system (307).

16. The diagnostic method according to claim 5, wherein, The second fault signal (SFE2), or The first fault signal (SFE1) and the second fault signal (SFE2) It is output to a safety driver (305), an external operator (306), and / or a superior automation system (307).

17. The diagnostic method according to claim 1, wherein, In response to the first fault signal (SFE1), the driver of the commercial vehicle (4) is required to release the automated operation (116) of the commercial vehicle (4).

18. The diagnostic method according to claim 5, wherein, In response to The second fault signal (SFE2), or The first fault signal (SFE1) and the second fault signal (SFE2) The driver of the commercial vehicle (4) is required to release the automated operation (116) of the commercial vehicle (4).

19. An electronically controllable pneumatic braking system (1) for a commercial vehicle (4), said pneumatic braking system having: - First braking circuit (6), the first braking circuit is supplied by first compressed air reservoir (7), - Second braking circuit (8), which is supplied by second compressed air reservoir (9), - At least one front axle brake pressure valve (26) for regulating the front axle brake pressure (pBVA) on the front axle (VA) of the commercial vehicle (4). - At least one rear axle brake pressure valve (22), the rear axle brake pressure valve being used to regulate the rear axle brake pressure (pBHA) on at least one rear axle (HA1, HA2) of the commercial vehicle (4). - Central control unit (14), which controls the braking system (1); and - A diagnostic control unit (81) adapted to implement the diagnostic method (2) according to any one of claims 1 to 18.

20. The electronically controlled pneumatic braking system (1) according to claim 19, wherein, The diagnostic control unit (81) is part of the central control unit (14) or integrated with the central control unit into a module (15).

21. The electronically controlled pneumatic braking system (1) according to claim 19, wherein, The diagnostic control unit (81) is configured as a separate module (200), which has a voltage connector (202) and a connector (203) for the bus system (16).

22. A computer program product comprising instructions that cause the braking system (1) according to claim 19 to perform the method steps of the diagnostic method (2) according to claim 1.

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