METHOD FOR SECURING A VEHICLE

Description

[0001] The invention relates to a method for securing a vehicle, preferably a commercial vehicle, in an emergency braking situation, wherein the vehicle has a vehicle bus system and a braking system.

[0002] To protect the occupants of a vehicle, especially a commercial vehicle, automated braking is often desirable. Particularly immediately after an accident, braking can be helpful to prevent the vehicle from shifting in a subsequent impact or to facilitate the rescue of injured persons. Rescue workers often face the challenge of securing the damaged vehicle before they can begin extricating people, thus eliminating any additional risk to their personnel. Depending on the vehicle's load and the accident location, this can require time and a large number of personnel, delaying the rescue of injured individuals. This problem is especially pronounced in multi-vehicle accidents.

[0003] Especially when commercial vehicles, such as trucks, are involved in an accident, the problem often arises that a driver must be rescued from a deformed cab. In many cases, the use of hydraulic rescue cylinders is insufficient, so the cab must be pulled apart, making prior stabilization of the vehicle essential. Another problem can occur when recovering overturned trailers or vehicles if the wheels are released during the righting process and the vehicle starts rolling after being righted. Rescue workers can be particularly endangered if additional equipment, such as a crane or winch, is used to right the trailer or vehicle, as these can be pulled along by the vehicle.

[0004] Furthermore, especially on busy roads, there is a risk that a stationary vehicle will be hit by another vehicle and pushed into a third vehicle, which could trap vehicle occupants.

[0005] Modern vehicles are often equipped with emergency braking systems designed to detect hazardous situations and, if necessary, initiate emergency braking. During this emergency braking, the vehicle is braked to a standstill, and the brakes are released once stationary. To brake a stationary vehicle, methods are known that engage the vehicle's parking brake. For example, EP 2 214 940 B1 discloses a method for operating a motor vehicle, comprising the following steps: detecting whether emergency braking has been performed; if so, detecting whether there is a vehicle ahead in the direction of travel of the motor vehicle; if so, detecting whether the motor vehicle is stationary; and if so, engaging the parking brake. A disadvantage of this method is that the parking brake is only engaged if a vehicle ahead is detected.Furthermore, a detection device for the vehicle in front must be present and functional. However, in many frontal collisions, such a detection device is damaged, meaning that the vehicle in front cannot be detected even when stationary.

[0006] From DE 10 2007 052 ​​439 A1, a driver assistance system for motor vehicles is known, comprising at least one operational data sensor for recording operational data characterizing the current or future movement state of the motor vehicle and an electrical control unit configured to trigger autonomous emergency braking of the motor vehicle when predetermined operational data is present. Furthermore, the electrical control unit is designed to bring the vehicle's parking brake into an activation position immediately before, during, or after emergency braking, in which a power failure passively engages the parking brake. Here, too, the control unit is directly connected to the operational data sensor, meaning that functionality cannot be guaranteed if the driver assistance system is damaged in an accident.Both emergency braking and stationary braking are based on commands from the electrical control system, so a failure of the control system results in a failure of the entire functionality.

[0007] US2019263423A1 discloses a control device comprising a receiver and a controller. The receiver receives a brake control command from a bus used for communication among a plurality of electronic control units in a moving device. The controller executes the control action to cancel or reject the brake control command under certain conditions.

[0008] DE102011114072A1 relates to a driver assistance system for a vehicle with a detection device designed to capture driving data characterizing the vehicle's driving state, and with a control unit designed to process the driving data captured by the detection device and, in the presence of predetermined driving data, to initiate a braking device to perform autonomous braking of the vehicle.

[0009] The object of the present invention is therefore to provide a method for securing a vehicle which, compared to the prior art, offers improved functionality and safety, preferably at lower costs. In particular, a particularly high level of reliability is to be achieved.

[0010] The invention solves the aforementioned problem in a first aspect using a method mentioned at the outset, comprising the steps of: monitoring signals on the vehicle bus system; detecting an emergency braking signal provided by a driver assistance system on the vehicle bus system; determining whether the vehicle is stationary; and moving a braking device of the braking system into a braking position when a stationary state of the vehicle is detected.

[0011] The invention is based on the understanding that signals provided on the vehicle bus system can be detected by several devices or modules of the vehicle connected to the vehicle bus system. Vehicle bus systems are characterized by the fact that data and / or signals are transmitted between several participants via a common transmission path. Several systems can also receive the signal provided by a driver assistance system on the bus system. If the driver assistance system now provides the emergency braking signal on the vehicle bus system, this emergency braking signal can also be detected by one or more systems or elements that monitor the vehicle bus system. This advantageously achieves redundancy.For example, a braking device of the braking system can be brought into a braking position by means of another system and / or module even if the driver assistance system is damaged. Furthermore, the braking device of the braking system can be brought into the braking position when the vehicle is stationary and the driver assistance system is not designed to bring the braking device into the braking position when the vehicle is stationary. The method according to the invention is therefore particularly suitable for implementation using retrofitted systems and / or modules. However, it can also be provided that the method is carried out using an existing system and / or an existing component of the vehicle, in particular the braking system.

[0012] Monitoring signals from the vehicle bus system preferably includes receiving a signal provided on the vehicle bus system. Furthermore, monitoring preferably includes identifying the signals provided on the vehicle bus system. For example, it can be determined whether the signal provided on the vehicle bus system is an emergency braking signal or another signal, such as an airbag signal. Particularly preferably, monitoring signals on the vehicle bus system includes determining a checksum and / or a counter that identifies the signal provided on the vehicle bus system.Preferably, the detection of an emergency braking signal provided by a driver assistance system on the vehicle bus system comprises comparing the determined checksum and / or counter with a predefined security checksum and / or a predefined security counter, wherein the emergency braking signal is detected if the determined checksum of the signal matches the predefined security checksum and / or if the determined counter of the signal matches the security counter. Preferably, the monitoring of signals on the vehicle bus system and the detection of an emergency braking signal are performed by a brake control unit of the braking system.However, it can also be provided that the monitoring of signals on the vehicle bus system and the detection of an emergency braking signal are carried out alternatively or redundantly by a handbrake control unit, particularly preferably a handbrake control unit of an electro-pneumatic handbrake. Preferably, the handbrake control unit and the brake control unit can also cooperate for monitoring and / or detection. A potentially negative interaction with an emergency braking of the vehicle can be avoided by only moving the braking device of the brake system into the braking position when a standstill of the vehicle is detected.

[0013] In a first preferred embodiment, the method comprises, in the event that a vehicle standstill is not detected: determining whether a manual user input is being provided; and moving the braking device of the braking system to the braking position if the provision of the manual user input is not detected. The event that a vehicle standstill is not detected can have several possible causes. For example, an emergency braking situation that triggers the emergency brake signal may not require the vehicle to brake completely. This is the case, for instance, if a vehicle ahead only decelerates briefly and then continues driving, so that the following vehicle does not need to brake completely either.If the journey continues after an emergency brake signal has been generated, a user command is provided on the vehicle bus system. This command could, for example, be a driving signal generated by pressing the vehicle's accelerator pedal. If a driving signal is not received, this indicates an emergency situation, making it advisable to engage the brakes even if the vehicle is not stationary. Preferably, the brakes are engaged if the manual user command is not received for a predefined period. This period is preferably measured from the time the emergency brake signal is generated.

[0014] InIn a preferred embodiment, the step of determining whether the vehicle is stationary comprises: acquiring a wheel speed signal provided by a wheel speed sensor and / or a central module on the vehicle bus system; evaluating the wheel speed signal; and determining whether the vehicle is stationary when a certain amount of the rotational speed falls below a predefined speed threshold, preferably for a predefined period. Preferably, the step of determining whether the vehicle is stationary may also include: acquiring an acceleration signal provided by an acceleration sensor on the vehicle bus system; evaluating the acceleration signal; and determining whether the vehicle is stationary when an acceleration value represents a standstill, preferably for a predetermined period.For example, the absence of a positive and / or negative acceleration value can represent a standstill of the vehicle.

[0015] Preferably, the wheel speed signal is evaluated using a module that also monitors the vehicle bus system. However, it can also be provided that the wheel speed sensor evaluates the wheel speed signal and determines whether the vehicle is stationary. If necessary, the wheel speed sensor is then configured to provide a standstill signal on the vehicle bus system. Preferably, the method includes, in the event that a wheel speed signal is not provided, moving the braking device of the braking system into the braking position if the time since the last provision of a wheel speed signal exceeds a predefined speed-time limit.Preferably, the vehicle's standstill can be determined when the rotational speed falls below a predefined speed limit, preferably for a predefined period, and an acceleration value determined within a predefined period before the wheel speed signal is acquired exceeds a predefined acceleration limit. For example, it is typical in vehicle accidents for the wheels to come to a standstill after a strong deceleration of the vehicle. Alternatively or additionally, the vehicle's standstill can preferably be determined by acquiring a speedometer signal, evaluating the speedometer signal, and determining that the vehicle is stationary when the speedometer signal falls below a predefined speedometer limit.

[0016] According to the invention, the method further comprises: determining whether the emergency brake signal is absent, and determining whether the absence of the emergency brake signal occurs in response to an emergency brake termination signal provided by the driver assistance system to terminate an emergency braking maneuver of the vehicle.

[0017] It should be understood that the emergency brake termination signal need not be a separate signal. It can also be part of the emergency brake signal. Preferably, the emergency brake signal includes an emergency brake termination signal, which identifies a correct end to the emergency brake signal. Preferably, the emergency brake termination signal is a predefined termination bit and / or a predefined termination bit sequence of the emergency brake signal. For example, the emergency brake termination signal can be a termination bit sequence of seven consecutive recessive bits. The emergency brake termination signal indicates that the emergency brake signal should be terminated. This can be the case, for example, when emergency braking is no longer necessary or when the vehicle is stationary. If emergency braking is no longer required and the emergency brake termination signal is absent, this indicates damage to the driver assistance system.For example, the driver assistance system may be damaged or destroyed, in which case it will no longer provide an emergency braking signal on the vehicle bus system. Since driver assistance systems are often located at the front of the vehicle, they are frequently destroyed when the vehicle collides with an obstacle. Even after the driver assistance system has been destroyed, however, braking may still be necessary. In this case, it is preferable to determine whether the absence of the emergency braking signal occurs in response to an emergency braking termination signal.

[0018] Preferably, the method further comprises: determining the time interval between the detection of the emergency brake signal and the detection of its absence, in the event that the absence of the emergency brake signal does not occur in response to an emergency brake termination signal; comparing this time interval with a predefined time limit; and performing at least one subsequent operation if the time interval exceeds the predefined time limit. If a vehicle is involved in an accident, a certain minimum time interval, represented by the time limit, elapses between the initial detection of the emergency brake signal and its absence caused by the actual collision.If the time interval between the detection of the emergency braking signal and its absence is shorter than this time threshold, the absence of the emergency braking signal is highly unlikely to be due to a vehicle accident. Therefore, premature or unnecessary execution of the follow-up operation can be avoided by comparing the time interval with the time threshold. For example, another driver assistance system may be designed to brake the vehicle to a standstill during an accident, even if the emergency braking system is damaged. A follow-up operation should preferably only be performed once this so-called "in-crash" braking is complete, for which a pre-defined minimum time interval is generally required, which then defines the time threshold. It may also be possible to define the time threshold using additional parameters.

[0019] In a preferred embodiment, the subsequent operation comprises: moving the braking device of the braking system into the braking position to brake the vehicle to a standstill if a standstill is not detected, and holding the braking device in the braking position after the vehicle has been braked to a standstill. If the driver assistance system is damaged or destroyed in an accident, no emergency braking signal is provided on the vehicle bus system. The vehicle may still be in motion, so braking may still be desirable to prevent further collisions. The subsequent operation therefore preferably includes braking the vehicle to a standstill. This preferably achieves redundancy in the driver assistance system. Thus, braking the vehicle is possible even if the driver assistance system is destroyed and no longer provides an emergency braking signal.Furthermore, after braking to a standstill, the vehicle continues to be braked, thus facilitating the securing of the vehicle and / or the rescue of injured persons.

[0020] Preferably, the subsequent operation includes: moving the braking device of the braking system into the braking position when it is impossible to determine that the vehicle is stationary. For example, determining that the vehicle is stationary may be impossible if the wheel speed sensor(s) are damaged and / or if the vehicle bus system is interrupted. Even in such cases, braking the vehicle should preferably be possible.

[0021] According to a preferred embodiment, the method further comprises: detecting a driving signal following the braking device of the braking system being moved into the braking position; and moving the braking device of the braking system into a driving position in response to the detection of the driving signal. In many cases, it may be necessary to move crashed vehicles during the rescue of injured persons. For example, if a driver of a commercial vehicle is trapped in a cab, it may be necessary to separate two wedged vehicles to allow the driver to be rescued. To release the braking device of the braking system, which has been moved into the braking position, and to allow the vehicle to be moved, moving the braking device of the braking system into a driving position is preferably provided.According to the invention, this is achieved by detecting the driving signal, which is preferably provided by the vehicle's accelerator pedal. Furthermore, the braking device of the braking system may also have been moved into the braking position without the vehicle being involved in an accident. For example, an accident may have been prevented by the vehicle's emergency braking. If the vehicle is to continue its journey, the driver can provide the driving signal, thereby moving the braking device into the driving position and enabling the vehicle to move again. Preferably, the driving signal can also be provided by means of a release device mounted externally on the vehicle and / or by a central control unit of the vehicle.

[0022] Preferably, the vehicle bus system is a CAN bus system. CAN bus systems are widely used in all common vehicle types, so the method can preferably be applied to a particularly large number of vehicles. Furthermore, preferably, the vehicle bus system can also be a CAN FD bus system, a LIN bus system, an SAE J1939 bus system, a FlexRay bus system, a MOST bus system, or a K-Line bus system.

[0023] In a preferred embodiment of the method, the driver assistance system is an autonomous emergency braking system of the vehicle. Such autonomous emergency braking systems preferably have at least one radar unit designed to detect the path of travel ahead of the vehicle in the direction of travel. In a vehicle accident, such a radar unit is often damaged, so the method provides particularly good redundancy when the driver assistance system is an autonomous emergency braking system of the vehicle.

[0024] Preferably, the braking device is a parking brake or a service brake of the braking system. A particular advantage is that a parking brake is generally designed to continuously brake the vehicle, for example, even when no brake signal is provided. Commercial vehicles often have so-called spring-applied brakes, where a pre-tensioned spring brakes the vehicle even when no hydraulic or pneumatic brake pressure and / or no brake signal is provided.

[0025] However, it is also possible for the braking device to be an electronic handbrake and / or a magnetic brake.

[0026] According to a second aspect, the invention solves the aforementioned problem with a control unit for a vehicle, which includes means suitable for carrying out the steps of a method according to the first aspect of the invention. Preferably, the control unit is a main control unit of a braking system of the vehicle. However, it can also be provided that the control unit is a separate control unit intended solely for carrying out the method according to the first aspect of the invention. This is particularly desirable when a particularly high level of redundancy is required.

[0027] According to a third aspect, the invention solves the aforementioned problem with a computer program comprising instructions that cause the control unit according to the second aspect of the invention to execute the method according to the first aspect of the invention when the computer program is executed on a computing unit. The computing unit is preferably a computing unit of the control unit according to the second aspect of the invention.

[0028] In In a fourth aspect, the invention solves the aforementioned problem with a braking system for a vehicle, in particular a commercial vehicle, comprising a control unit according to the second aspect of the invention. Preferably, the braking system has a trailer brake circuit for a trailer of the vehicle, wherein the braking device particularly preferably comprises a braking device of the trailer brake circuit.

[0029] InIn a fifth aspect, the aforementioned problem is solved with a vehicle, preferably a commercial vehicle, having a braking system according to the fourth aspect of the invention.

[0030] It should be understood that the method according to the first aspect of the invention, the control unit according to the second aspect of the invention, the computer program according to the third aspect of the invention, the braking system according to the fourth aspect of the invention, and the vehicle according to the fifth aspect of the invention have the same and similar sub-aspects, as set forth in particular in the dependent claims. In this respect, for further embodiments of the control unit, the computer program, the braking system, and the vehicle, and their advantages, reference is made in full to the above description of the first aspect of the invention. Embodiments of the invention are now described below with reference to the drawings. These are not necessarily intended to represent the embodiments to scale; rather, the drawings are presented in a schematic and / or slightly distorted form where this is useful for clarification.With regard to additions to the teachings immediately apparent from the drawings, reference is made to the relevant prior art. It should be taken into account that numerous modifications and changes concerning the form and detail of an embodiment can be made without deviating from the general idea of ​​the invention.

[0031] The general idea of ​​the invention is not limited to the exact form or detail of the preferred embodiments shown and described below, nor is it limited to an object that would be restricted compared to the object claimed in the claims. For specified dimensioning ranges, values ​​lying within the stated limits are also disclosed as limit values ​​and may be used and claimed as desired. For the sake of simplicity, the same reference numerals are used below for identical or similar parts or parts with identical or similar functions. Further advantages, features, and details of the invention will become apparent from the following description of the preferred embodiments and from the drawings. These show: Figure 1 shows a vehicle according to a first embodiment with a braking system and a driver assistance system; Figure 2 shows a schematic representation representing the steps of a first embodiment of the method according to the invention; Figure 3 shows a schematic representation further illustrating a determination of whether a vehicle is stationary; and Figure 4 shows a schematic representation representing the steps of a second embodiment of the method according to the invention.

[0032] Figure 1Figure 200 shows a vehicle 200, which in this case is a commercial vehicle 202. The vehicle 200 has a braking system 220, which includes a front axle brake circuit 232 for a front axle (VA) and a rear axle brake circuit 234 for a rear axle (HA) of the vehicle 200. A parking brake circuit 236 is also provided for the rear axle (HA). The front axle brake circuit 232 is supplied from a first compressed air reservoir 238, the rear axle brake circuit 234 from a second compressed air reservoir 240, and the parking brake circuit 236 from a third compressed air reservoir 242. The first compressed air reservoir 238, the second compressed air reservoir 240, and the third compressed air reservoir 242 all provide a reservoir pressure pV. Alternatively, the parking brake circuit 236 may also be supplied by the first compressed air reservoir 238 and / or the second compressed air reservoir 240. The brake system 220 has several brake devices 222.The braking system comprises two front axle brake actuators 222: one first and one second front axle brake actuator 244a, 244b on the front axle (VA) and two rear axle brake actuators 246c, 246d on the rear axle (HA). The rear axle brake actuators 246c, 246d are designed as so-called Tristop brake cylinders and can function as both service brakes 226 and parking brakes 224 by incorporating a spring-applied brake cylinder.

[0033] The brake system 220 includes a brake pressure sensor 248, which is connected to both the first compressed air reservoir 238 and the second compressed air reservoir 240. The brake pressure sensor 248 is designed as a so-called 1P2E brake pressure sensor and has two electrical outputs in addition to a pneumatic output. When actuated, the brake pressure sensor 248 provides a first front axle brake control pressure pVBS1 at the pneumatic output and a first rear axle brake request signal SHBA1 at a first electrical output. The first front axle brake control pressure pVBS1 is then provided to a front axle modulator 250, which then amplifies the first front axle brake control pressure pVBS1 and, based on this, controls a front axle brake pressure pBVA for the first and second front axle brake actuators 244a and 244b. To achieve wheel-appropriate braking, a gap must be created between the front axle modulator 250 and the first or second wheels.The system includes a second front axle brake actuator 244a, 244b and a first and second front axle ABS valve 252a, 252b, which are electrically connected to a central module 208 so that they can be switched by it. The central module 208 is also connected in a known manner to wheel speed sensors 230a, 230b, 230c, 230d.

[0034] The rear axle brake circuit 234 is electrically controlled by the central module 208, which receives the rear axle brake request signal SHBA1 provided by the brake force sensor 248 and provides a corresponding rear axle brake signal SBH to a rear axle modulator 254. Based on the rear axle brake signal SBH, the rear axle modulator 254 then controls a corresponding rear axle brake pressure pBHA at the respective service brakes 226 of the rear axle brake actuators 246c and 246d. Furthermore, the central module 208 can also provide a front axle brake signal SBV to the front axle modulator 250, which is configured to control a front axle brake pressure pBVA corresponding to the front axle brake signal SBV.

[0035] A parking brake module 256 of the parking brake circuit 236 is connected to both the brake pressure sensor 248 and a parking brake pressure sensor 258. Furthermore, the parking brake module 256 is also connected to the central module 208. When one of the elements connected to the parking brake module 256, such as the parking brake pressure sensor 258, provides a corresponding parking brake signal SBF, the parking brake module 256 applies a parking brake pressure pBFB. In addition, the parking brake module 256 is designed to vent the spring accumulators of the parking brakes 224 and thus place the parking brakes 224 into a braking position BS. For venting, the parking brake module 256 connects the spring accumulators of the parking brakes 224 to a pressure sink, preferably the environment, and thereby provides a venting pressure p0.

[0036] Furthermore, the vehicle 200 is equipped with a driver assistance system 206. The driver assistance system 206 is, in this case, an emergency braking system 207 arranged at the front 218 of the vehicle. To detect the area of ​​travel of the vehicle 200 located in front of the front 218, the emergency braking system 207 has a radar system (not shown). The emergency braking system 207 is designed to determine whether an emergency braking situation NB exists in which the vehicle 200 must be decelerated, and, if necessary, to provide an emergency braking signal SNB. For example, if the emergency braking system 207 detects an obstacle (not shown) appearing in front of the vehicle 200 and evasive action by the vehicle 200 is no longer possible, this is determined by the emergency braking system 207, which then provides the emergency braking signal SNB.

[0037] The driver assistance system 206 is connected to the central module 208 and the parking brake module 256 via a vehicle bus system 204, which in this case is a CAN bus system 205. The vehicle bus system 204 is a system for transmitting data and / or signals between several units connected to the vehicle bus system 204, using a common transmission path. The emergency brake signal SNB provided by the emergency brake system 207 can therefore be received by the central module 208 and the parking brake module 256. Furthermore, there is also a connection between the parking brake module 256 and the central module 208 via the vehicle bus system 204. It should be understood that other units of the vehicle 200, and in particular of the brake system 220, can also be connected to the vehicle bus system 204. For example, a steering angle sensor (not shown) or an electronic steering system could be connected to the vehicle bus system 204.In this embodiment, a wheel speed signal SR is also provided on the vehicle bus system 204 by means of the central module 208.

[0038] If the driver assistance system 206 provides an emergency braking signal SNB on the vehicle bus system 204, this is detected by the central module 208. The central module 208 then provides the front axle brake signal SBV to the front axle modulator 250 and the rear axle brake signal SBH to the rear axle modulator 254. In response, the brake pressures pBVA and pBHA are controlled by the modulators 250 and 254, and the vehicle 200 is braked. If emergency braking of the vehicle 200 is no longer required, for example, if the vehicle 200 is stationary H or there is no longer an obstacle, the driver assistance system 206 provides an emergency braking termination signal SNA on the vehicle bus system 204. Braking of the vehicle 200 is then terminated. Driver assistance systems 206, which are designed to perform such emergency braking operations BN, are well known.However, a critical issue here is that the vehicle 200 only brakes until it comes to a complete stop H, at which point the braking devices 222 are released. Furthermore, the driver assistance system 206 is located at the exposed front of the vehicle 218, meaning it can be damaged and / or destroyed in accidents involving the vehicle 200. If the emergency braking system 207 is destroyed in an accident, the emergency braking signal SNB will also no longer be available, and emergency braking BN of the vehicle 200 will no longer be possible.

[0039] Figure 2Figure 1 now illustrates the steps of a first embodiment of a method 100 according to the invention for securing a vehicle 200. In a first step S1, signals S on the vehicle bus system 204 are monitored. This monitoring of signals S is performed here by the central module 208, which is or includes a control unit 210 according to the invention. However, it can also be provided that the monitoring of signals S is performed by a separate control unit 210 and / or one of the modulators 250, 256. The central module has a processing unit 214, which is configured to execute instructions CO of a computer program C. When the computer program C is executed on the processing unit 214, means 212 of the control unit 210 preferably perform the steps of the method 100 according to the invention.

[0040] If an emergency braking situation NB occurs, the driver assistance system 206 provides the emergency braking signal SNB on the vehicle bus system 204. The emergency braking signal SNB can then be detected on the vehicle bus system 204 in a second step S2. In response to the detection of the emergency braking signal SNB, the control unit 210 determines in a third step S3 whether the vehicle 200 is at a standstill H. The determination E of a standstill H of the vehicle 200 will be explained in detail later. If it is determined that the vehicle 200 is at a standstill H, then in a subsequent fourth step S4 a braking device 222 of the braking system 200 is moved into a braking position BS. In this embodiment, a venting signal S0 is provided by the central module 208 to the rear axle modulator 256 for this purpose.This then vents the spring brakes to ambient pressure p0, thereby moving the parking brake 224 into the braking position BS. Since spring brakes are engaged in the braking position BS in a depressurized state, a particularly high level of reliability can be achieved.

[0041] If the determination E shows that the vehicle is not stationary H, a fifth step S5 determines whether a manual user input NM is provided. Such a manual user input NM can be provided, for example, by an accelerator pedal 260 on the vehicle bus system 204 or via another line (not shown). Furthermore, the manual user input NM could also be provided by the brake force sensor 248. If a manual user input NM is provided by the driver of the vehicle 200, it can be concluded that the driver is unharmed and the emergency braking situation NB has been resolved. Moving the brake device 222 of the brake system 200 to the brake position BS is then unnecessary, and the vehicle 200 can continue driving.

[0042] If, however, after the detection of an emergency brake signal E SNB and the vehicle 200 is not stationary H, and no manual user input NM is determined, then this is a strong indication that an emergency brake situation NB exists. Therefore, in a sixth step S6, the brake device 222 can also be moved to the brake position BS if the vehicle 200 is not stationary H.

[0043] Figure 3The process of determining whether vehicle 200 is stationary (H) is further illustrated. After monitoring signals S on the vehicle bus system 204 (step S1) and detecting the emergency brake signal SNB (step S2), the wheel speed signal SR is acquired in a first sub-step S3.1. Here, the wheel speed sensors 230 provide signal values ​​to the central module 208, which then in turn provides the wheel speed signal SR. However, the wheel speed signal SR could also be provided by a separate control unit 210 and / or by the wheel speed sensors 230.

[0044] In a second step, S3.2, of determining E, the wheel speed signal SR is evaluated. During evaluation, a value B of the rotational speed D is determined. This value B can also be considered over a period of time. Subsequently, in a third step, S3.3, the determined value B of the rotational speed D is compared with a predefined rotational speed limit GWD. It is particularly useful to consider the value B of the rotational speed D because the vehicle 200 can also be traveling in reverse with a negative value of the rotational speed D. Preferably, the vehicle 200's speed is determined from the wheel speed signal SR during evaluation. However, the wheel speed signal SR can also already contain corresponding speed information.

[0045] If the magnitude B of the rotational speed D falls below the predefined rotational speed limit GWD, then a standstill H of the vehicle 200 is determined. Preferably, the rotational speed limit GWD has a value of zero. However, it is also possible for the rotational speed limit to be greater than zero. For example, a braking device 222 of the braking system 220 can also be moved into the braking position BS even if the vehicle 200 is moving at only a moderate speed (e.g., <= 3 km / h) and thus there is no or only a slight risk of the vehicle 200 skidding due to braking.

[0046] Preferably, the standstill H is only determined if the speed limit GWD is undershot for a predetermined period Z. This prevents a brief locking of one or more wheels of vehicle 200 from being incorrectly interpreted as a standstill H of vehicle 200.

[0047] Depending on the result of determining E, steps S5 or S6 are then carried out (in Fig. 3 (Only the case of a positive determination of standstill H is shown). It should be understood that the determination E can preferably also be carried out continuously and / or in parallel with other steps of procedure 100.

[0048] Figure 4 illustrates the steps of the inventive method according to a second embodiment. First, signals S on the vehicle bus system 204 are monitored, also according to the second embodiment (step S1). If, analogous to the first embodiment ( Fig. 2If an emergency braking situation NB exists and an emergency braking signal SNB is provided on the vehicle bus system 204, then this emergency braking signal SNB is detected in the second step S2. Based on the present emergency braking signal SNB, the vehicle 200 executes an emergency braking maneuver BN. In a seventh step S7, the absence A of the emergency braking signal SNB is determined. Such an absence A can have several possible causes. For example, the emergency braking situation NB may have been resolved, so that the driver assistance system 206 no longer provides an emergency braking signal SNB. However, it is also possible that providing the emergency braking signal SNB on the vehicle bus system 204 is no longer possible. This is the case, for example, if the vehicle 200 has been involved in a head-on collision in which the driver assistance system 206, located at the front 218 of the vehicle, has been damaged.

[0049] In an eighth step, S8, it is therefore determined whether the absence of the emergency brake signal SNB is in response to an emergency brake termination signal SNA provided by the driver assistance system 206 to end the emergency braking BN of the vehicle 200. If the emergency braking BN is to be ended normally, the driver assistance system 206 provides the emergency brake termination signal SNA, and the vehicle 200 can then continue driving, if necessary. The emergency brake termination signal SNA can also be a component of the emergency brake signal SNB.

[0050] In the second embodiment of method 100, the determination E of whether the vehicle 200 is at rest H is also carried out. Preferably, this is done as described in Figure 4 As shown, the procedure is carried out following the absence of the emergency brake signal (SNB). However, it may also be possible to perform the determination of E continuously or at regular time intervals.

[0051] If step S8 reveals that the absence of the emergency brake signal A (SNB) does not occur in response to an emergency brake termination signal SNA, a time interval Δt between the detection of the emergency brake signal SNB and the determination of the absence of the emergency brake signal A (SNB) is calculated in a ninth step S9. Preferably, this time interval Δt is determined by the central module 208. In a subsequent tenth step S10, the time interval Δt is compared with a predefined time limit GWZ. If the time interval Δt is less than the time limit GWZ, then, according to this embodiment, no further steps are performed.

[0052] If the time interval Δt exceeds the time limit GWZ, a subsequent operation F is performed. By comparing the time interval Δt with the time limit GWZ, it is possible to prevent the subsequent operation F from being performed if the emergency braking signal SNB was unintentionally provided or if the emergency braking situation NB was resolved very quickly. An unintentional provision of the emergency braking signal SNB can be caused, for example, by a loose connection in the driver assistance system 206 or by interference signals on the vehicle bus system 204. Furthermore, the time limit GWZ can also be chosen so that another system of the vehicle 200 can perform an operation first. Figure 4Two possible variants of a subsequent operation F are shown. The first variant is preferably carried out if a standstill H of the vehicle 200 is detected. In this first variant, the subsequent operation F then consists of moving the braking device 222 into the braking position BS (step S11.1).

[0053] If the determination E does not result in vehicle 200 being stationary H, the subsequent operation F has an eleventh step S11.2 and a twelfth step S12. In the eleventh step S11.2, the braking device 222 is moved to the braking position BS, even though vehicle 200 is not stationary H. During this process, vehicle 200 is braked, and the magnitude B of its rotational speed D is simultaneously monitored. The braking of vehicle 200 continues until it is stationary H. Subsequently, in the twelfth step S12, the braking device 222 is held in the braking position BS. Furthermore, the subsequent operation F may also include additional steps. For example, a thirteenth step S13 can determine whether a driving signal SF is provided after the braking device 222 has been moved to the braking position BS.Such a driving signal SF can be provided, for example, by a rescuer or a driver of vehicle 200 using the accelerator pedal 260. In response to the detection of a driving signal SF, the braking device 222 can then preferably be moved to a driving position FS (step S14). Reference symbol list (part of the description)

[0054] 100 Procedure 200 Vehicle 202 Commercial vehicle 204 Vehicle bus system 205 CAN bus system 206 Driver assistance system 207 Emergency braking system 208 Central module 210 Control unit 212 Means of carrying out the procedure 214 Computing unit 220 Braking system 222 Braking device 224 Parking brake 226 Service brake 230, 230a, 230b, 230c, 230d Wheel speed sensor 232 Front axle brake circuit 234 Rear axle brake circuit 236 Parking brake circuit 238 First compressed air reservoir 240 Second compressed air reservoir 242 Third compressed air reservoir 244a, 244b Front axle brake actuators 246c, 246d Rear axle brake actuators 248 Brake force sensor 250 Front axle modulator 252a,252b Front axle ABS valves 254 Rear axle modulator 256 Parking brake module 258 Parking brake pressure sensor 260 Accelerator pedal A Absence H A Rear axle Va Front axle B Amount BN Emergency braking BS Brake position C Computer program CO Commands D Speed ​​E Determine F Follow-up operation FS Driving position GWD Speed ​​limit GWZ Time limit H Standstill NB Emergency brake situation NM User setting pBFB Parking brake pressure pBHA Rear axle brake pressure pBVA Front axle brake pressure pV Supply pressure pVBS1 Front axle brake control pressure p0 Venting pressure S Signal SBF Parking brake signal SBH Rear axle brake signal SBV Front axle brake signal SF Driving signal SHBA1 Rear axle brake request signal SNA Emergency brake termination signal SNB Emergency brake signal SRI Wheel speed signal S0 Venting signal S1, S2, S3, S3.1, S3.2, S3.3, S4, S5, S6, S7, S8, S9, S10, S11.1, steps S11.2, S12, S13, S14 Δttime period Zperiod,

Claims

1. Method (100) for securing a vehicle (200), preferably a commercial vehicle (202), in an emergency braking situation (NB), wherein the vehicle (200) has a vehicle bus system (204) and a braking system (220), the method comprising the steps of: - monitoring signals (S) on the vehicle bus system (204); - detecting an emergency braking signal (SNB) provided by a driver assistance system (206) on the vehicle bus system (204); - determining (E) whether the vehicle (200) is at a standstill (H); - moving a braking device (222) of the braking system (220) into a braking position (BS) if a standstill (H) of the vehicle (200) is determined, characterized by - determining a failure (A) of the emergency braking signal (SNB), and - determining whether the failure (A) of the emergency braking signal (SNB) occurs in response to an emergency braking termination signal (SNA) provided by the driver assistance system (206) for ending emergency braking (BN) of the vehicle (200).

2. Method (100) according to claim 1, wherein the method (100) comprises, in the event that a standstill (H) of the vehicle (200) is not determined: - determining whether a manual user specification (NM) is provided; - moving the braking device (222) of the braking system (220) into the braking position (BS) if the provision of the manual user specification (NM) is not determined.

3. Method (100) according to claim 1 or 2, wherein the step of determining (E) whether the vehicle (200) is at a standstill (H) comprises: - detecting a wheel speed signal (SR) provided by a wheel speed sensor (230) or a central module (208) on the vehicle bus system (204); - evaluating the wheel speed signal (SR); and - determining (E) the standstill (H) of the vehicle (200) if an amount (B) of the speed (D) falls below a predefined speed limit value (GWD), preferably for a predefined period of time (Z).

4. Method (100) according to any of claims 1 to 3, further comprising: - determining a time period (Δt) between detecting the emergency braking signal (SNB) and determining the failure (A) of the emergency braking signal (SNB), in the event that the failure (A) of the emergency braking signal (SNB) does not occur in response to an emergency braking termination signal (SNA), - comparing the time period (Δt) with a predefined time limit value (GWZ); and - performing at least one follow-up operation (F) if the time period (Δt) exceeds the predefined time limit value (GWZ).

5. Method (100) according to claim 4, wherein the follow-up operation (F) comprises: - moving the braking device (222) of the braking system (220) into the braking position (BS) for braking (B) the vehicle (200) to a standstill (H) if a standstill (H) of the vehicle (200) is not determined, and - holding (HA) the braking device (222) in the braking position (BS) following braking (B) of the vehicle (200) until the vehicle comes to a standstill (H).

6. Method (100) according to claim 4 or 5, wherein the follow-up operation (F) comprises: - moving the braking device (222) of the braking system (220) into the braking position (BS) if it is impossible to determine (E) that the vehicle (200) has come to a standstill (H).

7. Method (100) according to any of the preceding claims, further comprising: - detecting a driving signal (SF) following moving the braking device (222) of the braking system (220) into the braking position (BS); and - moving the braking device (222) of the braking system (220) into a driving position (FS) in response to detecting the driving signal (SF).

8. Method (100) according to any of the preceding claims, wherein the vehicle bus system (204) is a CAN bus system (205).

9. Method (100) according to any of the preceding claims, wherein the driver assistance system (206) is an autonomous emergency braking system (207) of the vehicle (200).

10. Method (100) according to any of the preceding claims, wherein the braking device (222) is a parking brake (224) or a service brake (226) of the braking system (220).

11. Control unit (210) for a vehicle (200), comprising means (212) for executing the steps of the method (100) according to any of the preceding claims 1 to 10.

12. Computer program (C) comprising instructions (CO) which cause the control unit (210) according to claim 11 to execute the method (100) according to any of claims 1 to 10 when the computer program (C) is executed on a computing unit (214).

13. Braking system (220) for a vehicle (200), in particular a commercial vehicle (202), comprising a control unit (210) according to claim 11.

14. Vehicle (200), preferably a commercial vehicle (202), comprising a braking system (220) according to claim 13.