Method and control unit for detecting a rollover of a vehicle and assistance system

Abstract

Method (200) for detecting a rollover of a vehicle (100), wherein the vehicle (100) has an offset-stable, first acceleration sensor (120) and a second acceleration sensor (122) with zero-point feedback, wherein the method (200) comprises at least the following steps: Reading in (210) a first sensor signal (124), a second sensor signal (126) and a third sensor signal (128), wherein the first sensor signal (124) represents acceleration values detected by the first acceleration sensor (120) with respect to a first extension axis of the vehicle (100), wherein the second sensor signal (126) represents acceleration values detected by the second acceleration sensor (122) with respect to the first extension axis of the vehicle (100), and wherein the third sensor signal (128) represents acceleration values detected by the second acceleration sensor (122) with respect to a second extension axis of the vehicle (100) orthogonal to the first extension axis; characterized in that the method comprises the following steps: Setting (220) a signal threshold value (406) depending on a difference amount (402) between the first sensor signal (124) and the second sensor signal (126); Performing (230) a comparison of the third sensor signal (128) with the set signal threshold value (406); and Providing (240) a rollover signal (140) depending on a result of the comparison to indicate the presence of a rollover.

Description

State of the art

[0001] The invention is based on a device or a method according to the class of the independent claims. The present invention also relates to a computer program.

[0002] A vehicle rollover can be detected, and an emergency call can be automatically triggered, for example. Such a rollover can occur in a variety of ways.

[0003] DE 197 44 083 A1 discloses an arrangement for generating a trigger signal for a safety device during a rollover. A rotation rate measured around the vehicle's longitudinal axis and / or acceleration values along the transverse and vertical axes are used to determine whether to trigger the safety device.

[0004] From the document DE 100 19 416 A1 a method for checking the plausibility of a rollover decision is known, in which a rollover situation is detected if either an acceleration measured in the direction of the vertical axis exceeds an upper or a lower threshold value or, if this acceleration lies between the threshold values, an acceleration value in the transverse direction exceeds another threshold value.

[0005] DE 10 2005 011 103 B4 discloses a method for detecting a rollover of a motor vehicle, in which at least two acceleration signals are recorded in the vertical direction and perpendicular to it. Two acceleration signals of different directions are linked and compared with at least one threshold value.

[0006] DE 10 2010 008 406 A1 describes a method for detecting an impending rollover of a vehicle. A vehicle acceleration-dependent lateral velocity is determined based on the vehicle's longitudinal speed and a driving dynamics condition. The vehicle acceleration-dependent lateral velocity can then be used for rollover detection.

[0007] Another method for detecting a rollover condition of a vehicle is known from DE 60 2004 006 609 T2. Disclosure of the invention

[0008] Against this background, the approach presented here presents a method, a control unit that uses this method, and finally a corresponding computer program according to the main claims. The measures listed in the dependent claims enable advantageous further developments and improvements of the device specified in the independent claim.

[0009] According to embodiments, a rollover of a vehicle can be detected by comparing an acceleration signal from an offset-stable acceleration sensor with an acceleration signal from a zero-point feedback acceleration sensor. For example, a first acceleration signal from a control unit for an electronic stability package can be compared with a second acceleration signal from an airbag control unit in order to set at least one threshold value for detecting a rollover, in particular a slow rotation, of the vehicle for an acceleration sensor of the airbag control unit.

[0010] Advantageously, according to embodiments, robust and reliable detection of a rollover, in particular a slow rollover, of a vehicle can be realized. For example, using existing systems or architectures, for example with offset-stable sensors and offset-regulated sensors, it can be possible to reliably detect rollovers and, in particular, slow rotations that can last for several minutes. This can, for example, avoid the need to use offset-stable sensors for airbag sensors in order to detect a load case that is classified as rare. Thus, with regard to controllable assistance systems, for example, the probability of false positive activations of an emergency call can be reduced, thus increasing the robustness of the detection.

[0011] A method for detecting a rollover of a vehicle is presented, wherein the vehicle has an offset-stable, first acceleration sensor and a second acceleration sensor with zero-point feedback, wherein the method comprises at least the following steps: Reading in a first sensor signal, a second sensor signal, and a third sensor signal, wherein the first sensor signal represents acceleration values detected by the first acceleration sensor with respect to a first extension axis of the vehicle, wherein the second sensor signal represents acceleration values detected by the second acceleration sensor with respect to the first extension axis of the vehicle, wherein the third sensor signal represents acceleration values detected by the second acceleration sensor with respect to a second extension axis of the vehicle orthogonal to the first extension axis; Setting a signal threshold value depending on a difference between the first sensor signal and the second sensor signal; Performing a comparison of the third sensor signal with the set signal threshold; and Providing a rollover signal depending on a result of the comparison, wherein the rollover signal represents the presence of a rollover.

[0012] This method can be implemented, for example, in software or hardware, or in a hybrid form of software and hardware, for example in a control unit. A rollover can include a stable position of the vehicle after a rollover, for example a sideways or roof-on position. The first extension axis can be a transverse axis or longitudinal axis of the vehicle. The second extension axis can be a vertical axis of the vehicle. An acceleration sensor can have at least one sensitive axis. If zero-point feedback is performed, a useful signal from the second acceleration sensor can be corrected by at least one control value. The first acceleration sensor can be designed without zero-point feedback. In other words, the first acceleration sensor can be stable over time or robust against an offset.The reading step, the setting step, and additionally or alternatively the execution step can be performed continuously. The method can also include a step of determining the difference between the first sensor signal and the second sensor signal.

[0013] According to one embodiment, in the setting step, the signal threshold can be set depending on the result of a comparison of the difference amount with an amount threshold. Such an embodiment offers the advantage that the signal threshold can be set quickly and easily to a situation-appropriate value.

[0014] In the setting step, the signal threshold can also be increased or set to a high value if the difference falls below a threshold value. The signal threshold can be lowered or set to a low value if the difference exceeds the threshold value. Such an embodiment offers the advantage that the signal threshold can be reliably set to a value suitable for reliably detecting a rollover, depending on the actual zero point return of the second acceleration sensor.

[0015] Furthermore, in the setting step, the signal threshold can be adjusted in steps or continuously. More specifically, the signal threshold can be adjusted in steps or continuously over time. Such an embodiment offers the advantage that even a slow rollover can be correctly detected and false positive detection can be prevented for fast processes or non-rollover events, such as cornering.

[0016] Furthermore, in the providing step, the rollover signal can be provided depending on the result of a further comparison of the first sensor signal with a further signal threshold value. Such an embodiment offers the advantage that a rollover of the vehicle can be detected even more reliably and accurately.

[0017] According to a further embodiment, in the step of performing the comparison, it can be checked whether the third sensor signal exceeds the signal threshold for a predefined period of time, or whether the first sensor signal exceeds another signal threshold for a predefined period of time and the third sensor signal exceeds the signal threshold for a predefined period of time. Such an embodiment offers the advantage that the probability of a false positive detection of a rollover can be further reduced.

[0018] The approach presented here further provides a control unit configured to perform, control, or implement the steps of a variant of a method presented here in corresponding devices. This embodiment of the invention in the form of a control unit also allows the problem underlying the invention to be solved quickly and efficiently.

[0019] For this purpose, the control unit can have at least one computing unit for processing signals or data, at least one memory unit for storing signals or data, at least one interface to a sensor or an actuator for reading sensor signals from the sensor or for outputting control signals to the actuator, and / or at least one communication interface for reading or outputting data embedded in a communication protocol. The computing unit can be, for example, a signal processor, a microcontroller, or the like, wherein the memory unit can be a flash memory, an EEPROM, or a magnetic storage unit.The communication interface can be designed to read in or output data wirelessly and / or wired, wherein a communication interface that can read in or output wired data can read this data, for example, electrically or optically from a corresponding data transmission line or output it to a corresponding data transmission line.

[0020] In this context, a control unit can be understood as an electrical device that processes sensor signals and outputs control and / or data signals depending on them. The control unit can have an interface that can be implemented in hardware and / or software. In a hardware implementation, the interfaces can, for example, be part of a so-called system ASIC, which contains a wide variety of functions of the control unit. However, it is also possible for the interfaces to be separate integrated circuits or to consist at least partially of discrete components. In a software implementation, the interfaces can be software modules that are present, for example, on a microcontroller alongside other software modules.

[0021] In an advantageous embodiment, the control unit detects a rollover of a vehicle or controls a detection method for detecting a rollover of a vehicle. For this purpose, the control unit can access, for example, sensor signals such as acceleration signals and yaw rate signals. The control unit is configured to provide a rollover signal using the sensor signals when a rollover is detected. At least one assistance function, such as making an emergency call or the like, can also be initiated, activated, or controlled.

[0022] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out, implement and / or control the steps of the method according to one of the embodiments described above, in particular when the program product or program is executed on a computer or a device.

[0023] An assistance system for a vehicle is also presented, whereby the assistance system has at least the following features: an embodiment of the above-mentioned control device; and the offset-stable, first acceleration sensor; and the second acceleration sensor with zero point feedback, wherein the first acceleration sensor, the second acceleration sensor and the control unit are connectable or connected to one another in a signal-transmitting manner.

[0024] Thus, an embodiment of the above-mentioned control unit can be advantageously employed or used in the assistance system to detect a rollover of a vehicle.

[0025] Examples of the approach presented here are shown in the drawings and explained in more detail in the following description. It shows: Fig. 1 a schematic representation of an assistance system according to an embodiment in a vehicle; Fig. 2 is a flowchart of a method for detection according to an embodiment; Fig. 3 shows a schematic acceleration-time diagram according to an embodiment; Fig. 4 shows a schematic difference amount signal threshold diagram according to an embodiment; Fig. 5 shows a schematic acceleration-time diagram according to an embodiment; Fig. 6 shows a schematic acceleration-time diagram according to an embodiment; Fig. 7 shows a schematic acceleration-time diagram according to an embodiment; Fig. 8 shows a schematic acceleration-time diagram according to an embodiment; and Fig. 9 is a flowchart of a process for detecting according to an embodiment.

[0026] In the following description of advantageous embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, whereby a repeated description of these elements is omitted.

[0027] Fig. 1 shows a schematic representation of an assistance system 110 according to an embodiment in a vehicle 100. The vehicle 100 is, for example, a motor vehicle, in particular a passenger car, a truck, or another commercial vehicle. According to the Fig. In the exemplary embodiment shown in Figure 1, an assistance function 105 and the assistance system 110 are shown. The assistance function 105 and the assistance system 110 are connected to each other in a signal-transmitting manner. The assistance function 105 is, for example, an emergency call function.

[0028] The assistance system 110 has, according to the Fig. The exemplary embodiment shown in Figure 1 includes a first acceleration sensor 120, which is designed to be offset-stable, a second acceleration sensor 122 with zero-point feedback, and a control unit 130. The first acceleration sensor 120, the second acceleration sensor 122, and the control unit 130 are connected to one another for signal transmission. The control unit 130 is designed to detect a rollover of the vehicle 100 or to control the detection of the rollover.

[0029] The first acceleration sensor 120 and the second acceleration sensor 122 are configured to detect acceleration values relative to at least one sensitive axis. A sensitive axis extends along a longitudinal axis, a transverse axis, or a vertical axis of the vehicle 100. For example, the first acceleration sensor 120 can be part of another vehicle function, in particular an electronic stability control (ESC), and the second acceleration sensor 122 can also be part of another vehicle function, such as an airbag control unit.

[0030] The first acceleration sensor 120 is configured to provide a first sensor signal 124. The first sensor signal 124 represents acceleration values relative to a first extension axis of the vehicle 100. The second acceleration sensor 122 is configured to provide a second sensor signal 126 and a third sensor signal 128. The second sensor signal 126 represents acceleration values relative to the first extension axis of the vehicle 100. The third sensor signal 128 represents acceleration values relative to a second extension axis of the vehicle 100, which is orthogonal to the first extension axis. The first extension axis of the vehicle 100 is, for example, the transverse axis of the vehicle 100. The second extension axis of the vehicle 100 is, for example, the vertical axis of the vehicle 100.

[0031] The control unit 130 is configured to generate a rollover signal 140 using the first sensor signal 124, the second sensor signal 126, and the third sensor signal 128, which signal represents the presence of a rollover or an ongoing or completed rollover of the vehicle 100. For this purpose, the control unit 130 has a read-in device 132, a setting device 134, an implementation device 136, and a provision device 138.

[0032] The reading device 132 is configured to read the first sensor signal 124, the second sensor signal 126, and the third sensor signal 128 from at least one interface to the first acceleration sensor 120 and the second acceleration sensor 122. The reading device 132 is also configured to forward the first sensor signal 124 and the second sensor signal 126 to the setting device 134 and the third sensor signal 128 to the implementation device 136.

[0033] The setting device 134 is designed to set a signal threshold value depending on a difference between the first sensor signal 124 and the second sensor signal 126. Furthermore, the setting device 134 is designed to forward the set signal threshold value to the implementation device 136. The implementation device 136 is designed to compare the third sensor signal 128 with the set signal threshold value. Furthermore, the implementation device 136 is designed to forward a result of the comparison performed in signal form to the provision device 138. The provision device 138 is designed to provide the rollover signal 140 depending on the result of the comparison.

[0034] In particular, the provisioning device 138 is in accordance with the Fig. 1, the rollover signal 140 is configured to provide the rollover signal 140 for output to the assistance function 105. The rollover signal 140 is suitable, when used by the assistance function 105, for triggering an emergency call due to the rollover of the vehicle 100.

[0035] Fig. 2 shows a flowchart of a method 200 for detecting according to an exemplary embodiment. The method 200 can be executed to detect a rollover of a vehicle. In this case, the method 200 for detecting is implemented by means of or using the control unit of Fig. 1 or a similar control unit. The method 200 for detecting in conjunction with an assistance system such as the assistance system from Fig. 1. Thus, the method 200 for detecting can be carried out in connection with a vehicle having a first acceleration sensor 120 which is designed to be offset-stable and a second acceleration sensor 122 with zero-point feedback, such as the vehicle from Fig. 1.

[0036] In a reading step 210, in the detection method 200, a first sensor signal, a second sensor signal, and a third sensor signal are read in. The first sensor signal represents acceleration values detected by the first acceleration sensor with respect to a first extension axis of the vehicle. The second sensor signal represents acceleration values detected by the second acceleration sensor with respect to the first extension axis of the vehicle. The third sensor signal represents acceleration values detected by the second acceleration sensor with respect to a second extension axis of the vehicle orthogonal to the first extension axis.

[0037] Subsequently, in a setting step 220, a signal threshold is set depending on a difference between the first sensor signal and the second sensor signal. Subsequently, in a performing step 230, a comparison of the third sensor signal with the signal threshold set in the setting step 220 is performed. Subsequently, in a providing step 240, a rollover signal is provided depending on the result of the comparison performed in the performing step 230. The rollover signal represents the presence of a rollover.

[0038] According to one embodiment, in step 220 of setting, the signal threshold is set depending on the result of a comparison of the difference amount with an amount threshold. Additionally or alternatively, in step 220 of setting, the signal threshold is increased or set to a high value if the difference amount falls below an amount threshold, and the signal threshold is decreased or set to a low value if the difference amount exceeds the amount threshold. In particular, the signal threshold is set in a stepped or continuous manner in step 220 of setting.

[0039] According to a further embodiment, in step 240 of providing, the rollover signal is provided depending on the result of a further comparison of the first sensor signal with a further signal threshold. For example, in step 230 of performing the comparison, it is checked whether the third sensor signal exceeds the signal threshold for a predefined period of time. Alternatively, in step 230 of performing the comparison, it is checked whether the first sensor signal exceeds a further signal threshold for a predefined period of time and the third sensor signal exceeds the signal threshold for a predefined period of time.

[0040] Fig. 3 shows a schematic acceleration-time diagram 300 according to an exemplary embodiment. In the diagram 300, a time t is plotted on the abscissa axis, and an acceleration detectable by acceleration sensors is plotted on the ordinate axis. The diagram 300 is used in conjunction with the assistance system of Fig. 1 or a similar assistance system or in connection with the procedure from Fig. 2 or a similar method. The first acceleration signal 124 and the second acceleration signal 126 are plotted in the form of two graphs in diagram 300. The first acceleration signal 124 represents a real signal and corresponds, for example, to a vehicle tilt angle of 40 degrees. The second acceleration signal 126 represents a sensor signal due to the zero-point feedback and would correspond, for example, to a vehicle tilt angle of 20 degrees. Furthermore, a loss 350 due to the zero-point feedback is symbolically indicated in diagram 300 in the form of an arrow.

[0041] For example, detection of a vehicle rollover is based on a measurement of a gravity vector when the vehicle has reached a stationary position on its side or roof. For this purpose, a projection of the gravity vector onto an aY-axis and an aZ-axis of the vehicle can be measured. In this context, an effect of zero-point return in Fig. 3, in particular for the second sensor signal 126 in comparison to the offset-stable first sensor signal 124 during a slow rotation about an x-axis or longitudinal axis of the vehicle. The difference or the difference amount between the first sensor signal 124 and the second sensor signal 126 is used to adapt the detection threshold for the third sensor signal 128. Here, the second sensor signal 126 and the third sensor signal 128 originate from at least one offset-controlled acceleration sensor or from at least one acceleration sensor with zero-point feedback. The zero-point feedback or offset control can be implemented in the acceleration sensor itself or in a control unit. The offset control speed of the acceleration sensors does not need to be the same.

[0042] Fig. 4 shows a schematic difference-signal threshold diagram 400 according to an embodiment. In the diagram 400, a difference 402 between the first sensor signal and the second sensor signal is shown on the abscissa axis. Fig. 3 and the signal threshold value 404 is plotted on the ordinate axis. The diagram 400 is related to the assistance system from Fig. 1 or a similar assistance system or in connection with the procedure from Fig. 2 or a similar method and in connection with the diagram from Fig. 3. In the form of a graph, Fig. 4 a set signal threshold 406 is shown. The set signal threshold 406 has, according to the Fig. 4, the exemplary embodiment has a stepped course and decreases with increasing difference amount 402.

[0043] If the first sensor signal and the second sensor signal differ slightly from one another, the set signal threshold 406 is maintained or not lowered. However, if the differences between the first sensor signal and the second sensor signal become large, the set signal threshold 406 is lowered. This ensures that rapid processes, such as cornering, do not lead to a false positive detection of a rollover or activation of assistance functions because the set signal threshold 406 is high. This is because cornering can typically only last a few seconds and not several minutes, like a slow turn. As a result, the difference 402 is small, whereby the threshold or signal threshold 406 is high. This threshold then applies to the third sensor signal, which falls below this threshold when cornering.This makes false positive detection unlikely.

[0044] Fig. 5 shows a schematic acceleration-time diagram 500 according to an embodiment. Fig. 5 shown diagram 500 the diagram from Fig. 3, except that an additional signal threshold value 505 is shown for the first sensor signal 124 and / or the second sensor signal 126. According to the Fig. In the embodiment shown in Figure 5, only the first sensor signal 124 exceeds the further signal threshold value 505.

[0045] Fig. 6 shows a schematic acceleration-time diagram 600 according to an exemplary embodiment. In the diagram 600, a time t is plotted on the abscissa axis, and an acceleration detectable by acceleration sensors is plotted on the ordinate axis. The diagram 600 is used in connection with the assistance system of Fig. 1 or a similar assistance system or in connection with the procedure from Fig. 2 or a similar method and in connection with the diagram from Fig. 5. The third acceleration signal 128 and a real third acceleration signal 628 are plotted in the diagram 600 in the form of two graphs. Furthermore, the set signal threshold value 406 is similar to that of Fig. 4. The set signal threshold 406 represents, for example, an adaptive aZ threshold. The third acceleration signal 128 and the real third acceleration signal 628 exceed the set signal threshold 406 at different points or at different set levels.

[0046] With reference to Fig. 5 and Fig. 6 shows a purely exemplary scenario in which the vehicle is driving slowly along an embankment. The zero point feedback becomes noticeable in the second sensor signal 126 and the third sensor signal 128 and slowly leads the signals to zero. The deviation between the first sensor signal 124 and the second sensor signal 126 increases over time. As a result, the set signal threshold value 406 for the third sensor signal 128 is reduced, so that if the vehicle falls to the side and comes to a stop, despite the zero point feedback or offset control, the lateral position can be reliably detected with a sensitively set signal threshold value 406 and a robust additional threshold value 505 for the first sensor signal 124. Without such an adaptation orthe set signal threshold value 406, the lateral position would not be detected in the event of a slow rollover because the aZ criterion would not have been met or the threshold for the aZ criterion would have had to be selected so low that a false-positive activation of the emergency call would also be possible below the rollover limit of the vehicle, in particular in the case of dynamic events that have a high lateral acceleration, exceed the threshold 505 and have a low aZ acceleration that could be above the low threshold.

[0047] Fig. 7 shows a schematic acceleration-time diagram 700 according to an embodiment. Fig. 7 diagram 700 shown in the diagram Fig. 5 except that a deviation between the first sensor signal 124 and the second sensor signal 126 is smaller, wherein the second sensor signal 126 is closer to the first sensor signal 124 and also exceeds the further signal threshold value 505.

[0048] Fig. Figure 8 shows a schematic acceleration-time diagram 800 according to an embodiment. Fig. 8 shown diagram 800 the diagram from Fig. 6 except that the set signal threshold 406 is set constant over the time course shown.

[0049] With reference to Fig. 7 and Fig. Figure 8 illustrates a purely exemplary scenario in which the vehicle rolls over about its longitudinal axis or x-axis and comes to a stop or rest on its side. Rollovers typically last only a few seconds, so the zero-point feedback or offset control, which typically only regulates a few mg / s, may not have a significant effect. As a result, the deviation between the first sensor signal 124 and the second sensor signal 126 is small. The signal threshold value 406 is not adapted, or is not adapted in multiple stages. However, since the vehicle is lying on its side, the lateral position is reliably detected based on the first sensor signal 124 and the third sensor signal 128.

[0050] Fig. 9 shows a flowchart of a process 900 for recognition according to an embodiment. The process 900 represents a subprocess of the method of Fig. 2 or a similar method. Process 900 is executable to detect a rollover of a vehicle.

[0051] In a first block 902, the difference is calculated or determined. The process 900 then proceeds to a second block 904, in which the signal threshold is calculated or determined. Subsequently, the process 900 proceeds to a third block 906, in which the third sensor signal is compared with the signal threshold.

[0052] The flowchart of Fig.In other words, Figure 9 shows steps related to setting the signal threshold or the aZ threshold. Depending on the design of the algorithm or process 900, one embodiment may require that the third sensor signal be above the signal threshold for a certain period of time, or alternatively, that the first sensor signal and the third sensor signal be above their respective thresholds for a certain period of time in order to detect a stationary end position of the vehicle in the event of a suspected rollover.

[0053] With reference to the figures mentioned above, exemplary embodiments as well as fundamental principles and possible applications are explained again in summary and / or briefly presented below.

[0054] Rollover detection according to exemplary embodiments for a vehicle 100 can be divided into two categories. For example, yaw-rate-based approaches represent the state of the art for controlling occupant protection systems, such as airbags. Acceleration-based approaches are used to cost-effectively represent non-time-critical secondary functions, such as making an emergency call or unlocking the doors of the vehicle 100.

[0055] Acceleration-based approaches can primarily aim to detect a stable lateral or roof position of a vehicle 100 after a rollover. To provide cost-effective solutions, offset-controlled sensors in the aY and aZ directions are typically used for such functions, which, according to exemplary embodiments, can be combined in the second acceleration sensor 122. The offset control serves to slowly adjust the signal—here, the second sensor signal 126 and the third sensor signal 128—to zero at a slow speed. This concept is particularly well-suited for an event that occurs on a timescale that is much smaller than the control speed of the offset control or zero-point feedback.

[0056] However, if the rotation of the vehicle 100 to the stable side or roof position takes a very long time, the offset control becomes noticeable. There is an overlap of the timescales between the event and the offset control. This can result in a real useful signal being lost, although according to exemplary embodiments, detection of a rollover is still possible without setting detection thresholds so low that an increased probability of false-positive detection is obtained during normal travel of the vehicle 100 or a similar situation. This can, for example, prevent frequent false-positive emergency call activations.

[0057] For example, in vehicles 100, the ESP function uses sensors that are offset-stable, particularly in the aY direction. This means that the offset of the sensor, here the first acceleration sensor 120, should not leave a defined range over its lifetime and temperature. Such offset-stable acceleration sensors are suitable in conjunction with the detection of slow rotations or rollovers because they do not have offset control. Typically, however, the ESP function only requires offset-stable sensors in the aX direction and aY direction, but not in the aZ direction, i.e., along the vertical axis of the vehicle 100. However, the aZ direction is important for detecting the slow rotation. As an alternative to the ESP, another control unit or another assistance function with an offset-stable acceleration sensor, in particular an aY sensor, can also be used.

[0058] In connection with legislation regarding automatic emergency call activation after a vehicle rollover, a certification test may be provided that requires a slow rotation of the vehicle around the longitudinal axis of the vehicle 100. Thus, with regard to potential legislation, a potentially required certification test can be implemented with a standard airbag sensor system without compromising robustness. According to exemplary embodiments, it may be possible to reduce the probability of false-positive activations of the emergency call function 105 and thus increase the robustness of rollover detection.

[0059] If an embodiment comprises an “and / or” link between a first feature and a second feature, this is to be read as meaning that the embodiment according to one embodiment has both the first feature and the second feature and according to another embodiment has either only the first feature or only the second feature.

Claims

[1] Method (200) for detecting a rollover of a vehicle (100), wherein the vehicle (100) has an offset-stable, first acceleration sensor (120) and a second acceleration sensor (122) with zero-point feedback, wherein the method (200) comprises at least the following steps: Reading in (210) a first sensor signal (124), a second sensor signal (126) and a third sensor signal (128), wherein the first sensor signal (124) represents acceleration values detected by the first acceleration sensor (120) with respect to a first extension axis of the vehicle (100), wherein the second sensor signal (126) represents acceleration values detected by the second acceleration sensor (122) with respect to the first extension axis of the vehicle (100), and wherein the third sensor signal (128) represents acceleration values detected by the second acceleration sensor (122) with respect to a second extension axis of the vehicle (100) orthogonal to the first extension axis; characterized by that the procedure comprises the following steps: Setting (220) a signal threshold value (406) depending on a difference amount (402) between the first sensor signal (124) and the second sensor signal (126); Performing (230) a comparison of the third sensor signal (128) with the set signal threshold value (406); and Providing (240) a rollover signal (140) depending on a result of the comparison to indicate the presence of a rollover. [2] Method (200) according to claim 1, wherein in the step (220) of setting the signal threshold value (406) is set depending on a result of a comparison of the difference amount (402) with an amount threshold value. [3] Method (200) according to one of the preceding claims, wherein in the step (220) of setting the signal threshold value (406) is increased or set to a high value if the difference amount (402) falls below an amount threshold value, wherein the signal threshold value (406) is decreased or set to a low value if the difference amount (402) exceeds the amount threshold value. [4] Method (200) according to one of the preceding claims, wherein in the step (220) of setting the signal threshold value (406) is set in a step-like or continuous manner. [5] Method (200) according to one of the preceding claims, wherein in the step (240) of providing, the rollover signal (140) is provided depending on a result of a further comparison of the first sensor signal (124) with a further signal threshold value (505). [6] Method (200) according to one of the preceding claims, wherein in the step (230) of performing the comparison it is checked whether the third sensor signal (128) exceeds the signal threshold value (406) for a predefined period of time or whether the first sensor signal (124) exceeds a further signal threshold value (505) for a predefined period of time and the third sensor signal (128) exceeds the signal threshold value (406) for a predefined period of time. [7] Control device (130) configured to carry out steps of the method (200) according to any one of the preceding claims in corresponding units (132, 134, 136, 138). [8] Assistance system (110) for a vehicle (100), wherein the assistance system (110) has at least the following features: the control device (130) according to claim 7; and the offset-stable first acceleration sensor (120); and the second acceleration sensor (122) with zero-point feedback, wherein the first acceleration sensor (120), the second acceleration sensor (122) and the control unit (130) are or can be connected to one another in a signal-transmitting manner. [9] Computer program adapted to carry out the method (200) according to any one of claims 1 to 6. [10] A machine-readable storage medium on which the computer program according to claim 9 is stored.

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