Method and device for performing braking in an ego vehicle

Abstract

The present invention relates to a method for performing braking in an ego vehicle (1). First data is acquired by sensors on board the ego vehicle (1), which detect an environment of the ego vehicle (1). Second data is acquired via vehicle-to-vehicle communication, V2X, via an opponent vehicle (2). The second data comprise a position, a direction, and a speed of the opponent vehicle (2). Third data, comprising a position, a direction, and a speed of the ego vehicle (1), are acquired. A collision probability between the ego vehicle (1) and the opponent vehicle (2) is determined as a function of the first data, second data, and third data. A first braking application is performed with a first braking force if a first set of conditions is met. A second braking application is performed with a second braking force if a second set of conditions is met.

Description

Prior ArtThe present invention relates to a method for carrying out braking in an ego vehicle and to a corresponding device.A long term goal currently exists to reduce the number of traffic deaths and severe trauma in traffic accidents to zero. An average human driver may cause errors that may result in critical situations. Furthermore, human abilities to avoid accidents due to physical limitations are limited. In order to reduce the number of dead spots and injured spots, modern cars support the human driver through various assist functions. One of the most important functions for avoiding and / or mitigating accidents is automatic braking. In the most critical form, this is referred to as an automatic emergency brake (AEB). This function activates full braking if an accident threatens that the driver can no longer avoid.Triggering of the AEB is based on data provided by a vehicle sensor system, which typically includes cameras, radar, and possibly lidar. However, these in-vehicle sensors require a direct visual connection between the sensor and the collision encounterr. However, this restriction also applies to the human driver. The visual link may be affected, for example, by weather influence, dense traffic, or other physical obstacles, e.g., at hidden intersections or non-visible curves.Vehicle-to-Everything (V2X) communication allows the ego vehicle to exchange information with, for example, other road users, an infrastructure, and / or network services, such as a cloud or a server. This form of communication requires the transmitting and receiving capabilities of the vehicles and the establishment of a secure and reliable wireless connection between the communication partners. A visual connection between the communication partners is, however, not absolutely necessary for this purpose. Therefore, V2X may be used as an additional sensor that supplements the sensors on board the ego vehicle in limited vision scenarios. Thus, automatic braking or performing collision avoidance action may be enabled even though the opponent is not visible to the driver and vision-based sensors onboard the ego vehicle.Patent application FR 3 123 616 A1 describes a method for determining a risk of collision between an ego vehicle and an opposing vehicle. By means of V2V ("vehicle-to-vehicle communication"), the ego vehicle receives position and dynamic parameters of the opponent and predicts both the own trajectory and the trajectory of the opponent. Based on the predictions, a collision risk is calculated. If this risk exceeds a certain threshold value, automatic braking is triggered.Patent application US 2023 / 070 314 A1 describes a similar approach in which the ego vehicle receives information about the speed and / or acceleration of an opponent via a V2V channel. Based on this information, collision probabilities are calculated and an appropriate reaction scheme is chosen to avoid unnecessarily strong braking behavior.The method of patent application US 2020 / 257 308A1 uses additional information for calculating the collision probability: steering angle and steering angle change of the opposing vehicle are transmitted via V2V in addition to information about dynamic parameters. Moreover, relevant information transmitted from an infrastructure (Vehicle-to-Infrastructure Communication, V2I) or a remote server (Vehicle-to-Network Communication, V2N) is also taken into account. When a limit value of the collision risk is exceeded, a collision warning and an action request are output to the driver of the ego vehicle.One possible disadvantage of V2X communication is that received V2X data may not be sufficiently reliable and / or trusted for use in safety critical driving functions. Functions such as AEB, however, must meet high safety requirements, which are defined in particular by a corresponding automotive safety integrity level (ASIL) according to the standard ISO 26262. The required level of security required to trigger an AEB may not be achieved by V2X communication alone. However, in many situations where the visibility connection between the ego vehicle and the opponent vehicle is impaired, triggering the AEB solely based on the ego vehicle's onboard sensors may not prevent the collision.Disclosure of the InventionWith the present invention, an ego vehicle can be safely decelerated to avoid collision with an opponent vehicle even if the opponent vehicle cannot be detected by sensors on board the ego vehicle.According to the invention, therefore, a method for carrying out braking in an ego vehicle according to patent claim 1 and a device for carrying out braking in an ego vehicle having the features of patent claim 10 are specified. Braking is understood here to mean an automated braking process for avoiding a collision with another road user, in which the driver of the ego vehicle does not initiate the braking process itself.Advantageous embodiments and refinements emerge from the further dependent claims and from the description with reference to the figures.The present invention proposes using a two-stage braking scheme so that collisions can be avoided even in situations where a visual obstacle does not allow the timely detection of a potential collision by on-board sensors. The first stage comprises a moderate braking scheme that requires only a low ASIL level, for example the level referred to as QM ("quality management"), and can therefore be triggered solely on the basis of V2X data if no visual connection can be established. In this moderate braking pattern, the braking force is limited, for example, to a maximum deceleration of 4 m / s 2.In a second stage, emergency braking with a higher braking force (e.g., maximum braking force) may be triggered at a later time using on-board sensors if a visual connection between ego vehicle and opposing vehicle may be established and the collision may not be avoided solely by the first braking stage. The second stage requires a higher ASIL level due to the necessarily higher braking force, e.g., ASIL B, which can only be fulfilled by using the data of the on-board sensors according to the current prior art. This allows a maximum delay of, for example, 9 m / s 2.In addition to the improved ability to avoid accidents and increased riding comfort due to the moderate first-stage braking, the two-stage braking scheme gains robustness against inaccuracies of all types, in particular measurement errors and tolerances in calculating position, speed and direction of the ego vehicle and / or the opponent vehicle and the like. This is achieved by the independent second brake stage, which, due to the later triggering, can correct inaccuracies which can be accepted at the time of the triggering of the first stage. If the second stage is triggered at a later time, inaccuracies due to better data quality, longer observation time, and shorter prediction time may be reduced.In the present case, the ego vehicle is the vehicle from whose perspective the method according to the invention is carried out or which has the device according to the invention. The ego vehicle may be a passenger car, commercial vehicle, motorcycle, or an autonomously driving vehicle steered by a human.The opponent vehicle denotes that vehicle or generally road user with which the ego vehicle has calculated a collision at a certain probability. In the simplest case, there is only one possible collision encounter. However, there may also be two or more likely collision partners, which may increase the computing effort. The collision sign relevant to the present consideration is the one with the highest collision probability. This is then considered an opposing vehicle. The opposing vehicle can be any vehicle or generally road user via which information is available and a correspondingly high collision probability has been calculated. Accordingly, a pedestrian or cyclist, for example, can also be considered an "opposing vehicle".For example, data can be transmitted from a mobile telephone or a smart watch of a pedestrian or cyclist to the ego vehicle by means of V2X communication. In the future, two-wheel vehicles with their own power source (e.g. Pedelecs or E-bikes) can additionally be equipped with their own V2X communication units. In addition, it may be possible to transmit sensor data about a road user to the ego vehicle by means of V2V or V2I without its own V2X communication unit. For example, sensors of a third-party vehicle or a road infrastructure can capture data about a pedestrian, cyclist or vehicle without a V2X output and transmit this data to the ego vehicle by means of V2V or V2I, respectively.In a step of the method, first data are acquired by one or more sensors on board the ego vehicle that detect an environment of the ego vehicle. A sensor may include, for example, a camera, a radar, a lidar, an ultrasonic sensor, or the like. The first data relate to the environment of the ego vehicle. Other road users, traffic signs, road boundaries, road markings, buildings on the side of the road, obstacles and the like can be detected on the basis of the first data.In one step of the method, second data are acquired by means of vehicle communication, V2X ("vehicle-to-everything"), via an opposing vehicle. The second data includes a position, a direction, and a speed of the opposing vehicle. This information can alternatively be described as a two- or three-dimensional planned trajectory that describes the future position profile of the opposing vehicle over time. The planned trajectory can be described, for example, as a point list or with piecewise polynomial functions (spline functions). By acquiring the second data, a direct visual connection of the sensors on board the ego vehicle to the opponent vehicle is not necessary to obtain information about the opponent vehicle. Consequently, the safety of road users can be increased. This may be particularly useful at poorly visible intersections in urban traffic, where e.g. buildings, trees, other vehicles and the like may obstruct vision.In a step of the method, third data, which include a position, a direction and a speed of the ego vehicle, are acquired. These third data can be read out by control units of the vehicle, for example, by means of a CAN bus. Position, speed and direction of the ego vehicle can also be determined, for example, via a GNSS sensor or the like. Further, information on a steering angle, a position of the accelerator pedal, a braking force, a rotational speed of the wheels, etc. may be obtained. On the basis of the third data, for example, a two- or three-dimensional trajectory can be generated which comprises a starting point as position and further points which are predicted on the basis of the current speed and direction of the ego vehicle.determining a collision probability between the ego vehicle and the opponent vehicle as a function of the first data, second data and third data. The calculation of the collision probability can be carried out, for example, by processors on board the ego vehicle or on an edge server. In this case, for example, artificial intelligence or algorithms that use machine learning can also be used in order to increase the accuracy and / or to shorten the computing time.According to the method, in a first stage, a first braking operation is carried out with a first braking force if a first set of conditions is fulfilled. In a second stage, a second braking operation is carried out with a second braking force if a second set of conditions is fulfilled. Here, the second braking force is larger than the first braking force. A two-stage braking scheme is thus realized, in which moderate braking (first stage) is initially carried out, after which emergency braking (second stage) can optionally be carried out in order to avoid a collision with the opposing vehicle.The first set of conditions includes the first data not including information about the opponent vehicle. In other words, the on-board sensors cannot acquire data about the opposite vehicle, for example, because a direct visual link is blocked by an obstacle. Accordingly, it is necessary that the second data acquired via V 2X include information on the opposing vehicle so that a collision probability can be determined. Another condition for performing the first brake stage is that the calculated collision probability is equal to or greater than a first threshold value.The threshold value for the collision probability can be selected depending on a plurality of factors, for example a driver preference. Thus, the limit value (this applies to both the first and second limit values) can be selected to be lower, for example, in the case of a detensive driving mode, which can increase false-positive function triggerings and reduce false-negatives. In the case of aggressive driving, this can be correspondingly reversed. Furthermore, predicted speeds of the ego vehicle and the opponent vehicle (the limit values may be selected lower at higher speeds because the potential accident severity is higher, and vice versa) and the vehicle types of the ego vehicle and the opponent vehicle (the limit value is selected lower at weak road users because the potential accident severity is higher) may be taken into account in determining the limit values.The calculated collision probability here preferably relates to the case in which no braking is carried out. In other words, it is calculated depending on the acquired first, second and / or third data whether a collision is likely if the ego vehicle continues to travel without braking.The second set of conditions includes the first data including a position, a direction, and a speed of the opposing vehicle. In other words, the second braking is initiated only when the on-board sensors of the ego vehicle acquire information about the opponent vehicle. A further condition is that the collision probability now also calculated on the basis of the present first data is equal to or greater than a second limit value.A preferred embodiment of the method comprises a step for generating an environment model of the ego vehicle, which describes a position, direction and speed of the ego vehicle and of the opposing vehicle and their respective uncertainties. In this case, trajectories for the ego vehicle and the opponent vehicle can be generated in a vehicle or world coordinate system. Furthermore, spatial existence probabilities for ego vehicle and opponent vehicle can be calculated. The collision probability can then be determined as a function of the environment model. For example, it can be calculated whether the respective trajectories intersect or the spaces described by the probability of existence of the vehicles overlap.According to a preferred embodiment, the environment model can further comprise information about a lane of the ego vehicle and / or of the opponent vehicle and / or map information which describes a topography of an environment of the ego vehicle and / or of the opponent vehicle and / or information about a right of priority of the ego vehicle and / or of the opponent vehicle. Based on these data, the collision probability can be calculated more accurately.According to a preferred embodiment, the first data can further comprise an acceleration of the opponent vehicle and / or a yaw rate of the opponent vehicle and / or a vehicle type of the opponent vehicle and / or dimensions of the opponent vehicle and / or a past trajectory of the opponent vehicle, and / or a planned trajectory of the opponent vehicle. By means of these additional data, the accuracy of the collision probability can be increased. The risk of a collision and its location and a time of the collision can thus be determined more accurately, so that a false positive detection of a collision risk can be avoided and the safety of the road users can be improved.According to a preferred embodiment, the second data can further comprise an acceleration of the opponent vehicle and / or a braking force of the opponent vehicle and / or a steering angle of the opponent vehicle and / or a yaw rate of the opponent vehicle and / or a vehicle type of the opponent vehicle and / or dimensions of the opponent vehicle and / or a past trajectory of the opponent vehicle and / or, in particular in the case of a self-driving vehicle, a planned trajectory of the opponent vehicle. By means of these additional data, the accuracy of the collision probability can be increased. The risk of a collision and its location and a time of the collision can thus be determined more accurately, so that a false positive detection of a collision risk can be avoided and the safety of the road users can be improved.According to a preferred embodiment, third data can furthermore comprise an acceleration of the ego vehicle and / or a braking force of the ego vehicle and / or a steering angle of the ego vehicle and / or a yaw rate of the ego vehicle and / or a vehicle type of the ego vehicle and / or dimensions of the ego vehicle and / or a past trajectory of the ego vehicle and / or, in particular in the case of a self-driving vehicle, a planned trajectory of the ego vehicle. The risk of a collision and its location and a time of the collision can thus be determined more accurately, so that a false positive detection of a collision risk can be avoided and the safety of the road users can be improved.The first braking force preferably brings about a deceleration of the ego vehicle of at most 4 ms -2. This value corresponds to a usual delay in urban traffic, which is also expected by other road users. Thus, in particular rear-end collisions with another vehicle behind the ego vehicle can be avoided. Particularly preferably, the first braking force can cause a deceleration of the ego vehicle of approximately 3 to 4 ms -2.The second braking force preferably brings about a maximum deceleration of the ego vehicle, of approximately 9 ms -2. for example. The maximum deceleration is preferably triggered at the latest possible time in order to avoid unnecessary braking maneuvers and a risk to other road users. By using the maximum braking force, the stopping distance can be shortened and collision can be prevented as late as possible.According to a preferred embodiment, the first braking is initiated at a point in time at which a calculated time period until the collision falls below a maximum value. In other words, the first braking is to be initiated at a latest possible point in time in order to achieve the highest possible accuracy in calculating the collision probability, so that false-positive first braking operations can be avoided.According to a preferred embodiment, the first set of conditions can further comprise detecting an obstacle which prevents the opposing vehicle from being detected by means of the first data. In other words, it is determined, e.g., by means of the on-board sensors and / or on the basis of data about the environment of the ego vehicle (e.g., map data), that a visual contact with an opposing vehicle is blocked, so that the on-board sensors cannot acquire data about the opposing vehicle. The existence of the opposing vehicle is known by receiving the second data. On the basis of the active determination that an obstacle is present, it is possible, for example, to exclude a malfunction of the on-board sensors. Thus, safety can be further enhanced.According to a preferred embodiment, the method comprises a step for acquiring information about a right of priority of the ego vehicle and of the opponent vehicle. This can be done, for example, on the basis of map data and / or by recognizing traffic signs and the like. The first set of conditions may correspondingly further comprise the ego vehicle having to pay attention to a right of priority of the opponent vehicle. The first braking operation may be carried out, for example, when the method recognizes that the driver of the ego vehicle is not observing the forward travel of the opponent vehicle. Thus, depending on the situation, a high collision probability can be detected and the collision prevented.An apparatus for carrying out braking in an ego vehicle comprises, for example, one or more control and / or regulating devices which communicate with sensors and communication devices and the CAN bus of the ego vehicle in order to acquire first, second and third data. The apparatus is configured to perform a method according to the invention. For this purpose, the device can also interact, for example, with an ESP and / or ABS system in order to carry out the first and / or second braking. In further developments of the present invention, a steering system for avoiding and avoiding a collision may preferably also be carried out.The present invention is explained in more detail below with reference to the exemplary embodiments indicated in the schematic figures. The following are shown: FIG. 1 is a schematic top view of an intersection where a building blocks vision; FIG. 2 shows a schematic view of an exemplary embodiment of a device for carrying out braking; FIG. 3 shows a time sequence of a method for carrying out braking according to one exemplary embodiment;The accompanying figures are intended to provide a further understanding of the embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the advantages mentioned are evident with reference to the drawings. The elements of the drawings are not necessarily shown to scale with respect to each other.In the figures of the drawing, elements, features and components that are the same, have the same function and act in the same way-unless stated otherwise-are each provided with the same reference numerals.FIG. 1 shows a schematic top view of an intersection at which a building blocks the view. X and y denote orthogonal axes of a (spatially fixed) coordinate system.In FIG. 1, a vehicle 1 coming from below approaches the intersection at speed ve. From the right, an opposing vehicle 2 approaches the intersection at speed vt. A right roadside building 3 adjacent to the lane of the ego vehicle 1 blocks the visual axis between the ego vehicle 1 and the opponent vehicle 2. If both vehicles 1, 2 were to drive further straight ahead, a collision would occur. A typical vision-based brake assist would fail and could not prevent the collision.The situation shown in Fig. 1 frequently occurs in urban traffic. However, the invention is not limited to this situation. It is also effective in other situations of this type, such as in circumcircle traffic, curved intersections, side roads with parked vehicles, wheel path intersections, railroad crossings, road railroad crossings, dense traffic around the ego vehicle, oncoming vehicle in the lane of the ego vehicle, slow vehicle in front of the ego vehicle in a curve, etc.In the situation shown in FIG. 1, a conventional vision-based brake assist would react too late and could only mitigate but not prevent the collision. The present invention includes a first moderate braking force that is initiated early enough by receiving V2X data before the opposing vehicle 2 is visible so that the collision can be avoided. Due to the high safety requirements of an emergency braking function, the V2X data only trigger moderate braking, since emergency braking requires a higher safety level (e.g. ASIL B) due to the strong deceleration of 9 ms -2 for example.FIG. 2 shows a schematic view of an exemplary embodiment of an apparatus or a method for carrying out emergency braking. The first three boxes on the left denote the first data 11, the second data 12 and the third data 13, which data 11, 12, 13 are combined to form an environment model 14 of the ego vehicle. Collision probabilities 15 are calculated on the basis of the environment model 14 and the third data 13. A decision is then made as to whether a first brake stage S 1 and / or a second brake stage S 2 is to be carried out. Based on the decision, brake signals are generated and output to a brake system 4 of the ego vehicle.The first data 11 are acquired by sensors on board the ego vehicle 1. Vision-based sensors on board are required to detect the opposing vehicle 2 with a high functional safety level and serve as a data source for triggering the second braking operation, as emergency braking operation with maximum braking force. They may consist of a single sensor, a combination of similar sensors or a combination of different sensor technologies (such as radar, video, lidar or ultrasound) in order to meet the requirements for the functional safety level and the sensor range.The second data 12 are acquired by means of V2X and relate to the opponent vehicle 2. the second data 12 comprise at least a position, a direction and a speed of the opponent vehicle 2. the ego vehicle 1 comprises a suitable V2X interface for receiving the second data 12.Optionally, further state information that can improve a prediction of the movement of the opposing vehicle 2 can be contained in the second data 12. For example, the second data 12 comprise an acceleration, a brake pressure, a yaw rate, a vehicle type, dimensions, a past trajectory and / or a planned trajectory, e.g. in the case of a self-driving opposing vehicle.The sender of the V2X communication may be the opponent vehicle 2 itself (V2V), an infrastructure (V2I) equipped with sensors for recognizing the opponent vehicle and a V2X communication unit, or a third traffic participant who can recognize the opponent vehicle and relay the information on the opponent vehicle via V2X.The third data 13 describes the state of the ego vehicle 1, in particular position, speed and direction. Optionally, further state information of the ego vehicle 1 that improves the movement prediction of the ego vehicle 1, such as, for example, an acceleration, a brake pressure, a yaw rate, a vehicle type, dimensions, a past trajectory and / or a planned trajectory in the case of an automatically driving ego vehicle 1, can be acquired.In a computing device of the ego vehicle, the first data 11, the second data 12 and the third data 13 can be merged to generate an environment model 14 of the ego vehicle. Collision probabilities 15 can be calculated on the basis of the environment model 14. The environment model 14 combines, in a uniform representation (e.g. in a world or vehicle coordinate system), all information about states and trajectories and uncertainties or spatial probabilities about the ego vehicle and all potential opponent vehicles. Furthermore, the environment model 14 can comprise additional information about the traffic situation and traffic rules.Collision probabilities 15 between the ego vehicle and each potential opponent vehicle can be calculated, for example, by a device specifically configured for this purpose, which comprises a processor and a storage device and suitable interfaces for inputting and outputting data. For this purpose, a movement prediction is necessary for the ego vehicle and each potential opponent. It takes all object data into account, including the existence probabilities and uncertainties from the environment model 14 and the data components of the ego vehicle.A means for performing the braking makes the decision as to whether the ego vehicle applies the first braking S 1. As described above, this response pattern is a moderate braking intervention that requires only a relatively low ASIL level that can be met by V2X communication, so that this first braking stage S1 can be activated with information that originates exclusively from the V2X communication (second data 12). For example, when an ASIL level "QM" is reached, the first brake engagement S 1 may be limited to a maximum deceleration value of about 4 m / s 2. Such a delay frequently occurs in urban traffic and does not compromise other road users. The first braking S 1 may be performed with a constant deceleration value or with a deceleration value adapted to the need for collision avoidance. Preferably, a high deceleration value close to the QM limit is used, as this reduces the prediction time and thus false positive triggers of braking.A first set of triggering conditions for the first braking S 1 comprises the following criteria, which preferably all have to be fulfilled. A first condition is that without braking, a collision between the ego vehicle and the opponent vehicle is predicted with a certain probability. Furthermore, second data 12 on the position and state of the opposing vehicle received via V2X communication must be present. A third condition for triggering is that a latest possible point in time at which the first braking S 1 can avoid the collision has been reached. In other words, the first braking operation S 1 is initiated as late as possible in order to achieve the highest possible prediction accuracy and to avoid false-positive braking operations.The latest possible time point may be achieved by calculating a stopping distance on the assumption that the first braking S 1 is initiated at the current time point. The condition is fulfilled if the currently remaining distance from the calculated collision position falls below the stopping distance. With this strategy, the ego vehicle should always come to a standstill in front of the calculated collision position of the opposing vehicle. Alternatively, the latest possible time may be determined such that the ego vehicle may use the space behind the opponent vehicle after passing the path of the ego vehicle.Moreover, the trigger time is preferably limited by a maximum value for the remaining time to collision, in order to limit the prediction time to an upper limit and thus to reduce the false positive brakings. An exemplary value for this maximum allowable time to collision is 2 to 2.5 seconds for urban speeds.The means for performing the braking makes the decision as to whether the vehicle should perform the second braking S 2. This response pattern is emergency braking that requires a high level of ASIL (e.g., ASIL B), which cannot be met by data alone received via V2X communication. Therefore, the second braking operation S 2 is only triggered when there is a visual connection to the opposing vehicle and this can be detected by the on-board sensors, i.e. when first data 11 are present. The deceleration value during the second braking S 2 is preferably close to full braking. A typical value is, for example, 9 m / s 2.A second set of trigger conditions for the second braking S 2 comprises the following criteria, which preferably all have to be fulfilled. According to a first condition, in the case that no braking or only the first braking S 1 is performed, a collision between the ego vehicle and the opposing vehicle must be predicted with a certain probability. Alternatively, the second braking operation S 2 can also be triggered completely independently of the first braking operation S 1.A further obligatory prerequisite for the second braking S 2 is that the position and state of the opposing vehicle are detected by the on-board sensors, that is to say that first data 11 about the opposing vehicle are present. This ensures that the position, speed, direction, and acceleration of the opposing vehicle are detected with high reliability and high certainty.Another condition is that the latest possible point in time is reached at which the execution of the second braking S 2 can avoid the collision. Here, the strategies described above with respect to the first braking may also be applied. The ego vehicle should preferably come to a standstill in an area in front of the opposing vehicle.Reference numeral 4 in FIG. 2 shows a brake device. This may be, for example, a component that transmits the required braking force to the brakes of the ego vehicle. This is usually a control device of an ESC or ESP system ("Electronic Stability Control") with corresponding interfaces.FIG. 3 shows a time sequence of a method for carrying out braking according to one exemplary embodiment. The vertical axis indicates deceleration (negative acceleration) in m / s 2. The horizontal axis is the time axis. The thick line illustrates the time profile of the deceleration of the ego vehicle. The points in time t1 to t6 marked in FIG. 3 are explained below.At the first time t 1, the opposing vehicle is in communication range for V2X communication. From this first time t 1, second data 12 about the opposing vehicle can be periodically received by means of V 2X. The probability of existence of the opponent vehicle can be increased with each received message comprising, for example, the second data 12 and a time stamp. The present method or the corresponding system can then calculate the probability of collision with the opposing vehicle and the corresponding remaining time for collision, as described above.The time t 2 denotes a latest possible triggering point for avoiding a collision by means of first braking S 1. At time t 2, the first braking S 1 should be triggered in order to avoid a collision. However, not all conditions of the first set of conditions are yet met. In particular, the remaining time for collision is still greater than a predefined maximum value for triggering the first braking S 1.At time t 3, the remaining time to collision reaches the highest allowable value for triggering first braking S 1. All first conditions are now fulfilled and the first braking S 1 is triggered. A first braking force B 1 is applied in this case in order to bring about a deceleration of here approximately 4 m / s 2. The trigger signal for the first braking operation S 1 is denoted by TS 1.At the time t 4, there is a visual connection to the opponent vehicle for the first time: the opponent vehicle is now detected by the on-board sensors of the ego vehicle, so that first data 11 about the opponent vehicle are acquired. However, it is not necessary to initiate emergency braking S2.The time t 5 denotes the latest possible time for triggering the second braking S 2 in order to avoid the collision. At this moment, all second conditions are fulfilled and the second braking S 2 is triggered by the second trigger signal TS 2. Here, the second braking force B 2 is applied to cause a maximum deceleration of 9 m / s 2.At time t 6, the automatic braking intervention is deactivated. There may be two reasons for this: the ego vehicle has come to a standstill and / or a collision is no longer predicted. For example, the ego vehicle may pass behind the opponent vehicle that has fully passed the path of the ego vehicle.Moderate braking is believed not to cause dangerous situations with other road users. Nevertheless, unnecessary brake triggerings, so-called false positive brakings, should be kept low for reasons of acceptance. The probability of false positive braking is still great with a high remaining time for collision, since uncertainties increase with time. For example, the behavior of the drivers may change. However, the moderate first braking S 1 needs to be triggered earlier than full braking and may therefore have a higher false positive rate. Measures are described below in order to avoid or reduce false positive braking operations.The triggering of the first braking S 1 may be limited to cases where an obstacle that hinders direct recognition of the opposing vehicle is directly recognized by the on-board sensors. Alternatively, by second data 12 about the opposing vehicle acquired via V 2X but no first data 11 being present, it can be concluded that an obstacle blocks a direct detection of the opposing vehicle. This check may also be made dependent on, for example, the opposing vehicle being within range of the on-board sensors.The triggering of the first braking S 1 can also be limited to cases in which the ego vehicle does not have a forward drive. The first braking S 1 is usually triggered at a later point in time than the driver would begin to brake if he recognizes the present driving-in situation. If the driver does not brake for any reason, the method according to the invention can prevent an accident.Preferably, however, the first braking S 1 is not triggered if the opposing vehicle violates the forward travel of the ego vehicle. In this situation, false positive braking is likely when the opponent vehicle has not yet started its braking maneuver. Omitting these situations carries a great potential for reducing the occurrence of false positive braking operations overall. For this purpose, the method requires information about applicable priority rules, which can be obtained, for example, by map information and / or the recognition of traffic signs and traffic lights.Normally, drivers brake 2 in a range up to 3 m / s to handle urban situations. The first braking S 1 can therefore be delayed until the opposing vehicle is unlikely to brake and / or yield. This can be achieved if the first braking S 1 is permitted to be triggered, for example, only when the opposing vehicle would have to brake with an above-average deceleration, for example greater than 3 m / s 2, in order to avoid a collision with the ego vehicle. This constraint may reduce false positive braking. The same condition may also be applied to braking by the driver of the ego vehicle.The absence of the first data 11 about the opposing vehicle may have reasons other than a visual obstacle from an obstacle. For example, the sensor range may be limited by weather influences such as fog, snow or heavy rain or by glare (deep-standing) sun or by dust, dirt or snow on the sensor itself. Furthermore, the sensors may have a low quality or measurement accuracy. Other reasons include malfunction of one or more onboard sensors. In these cases, the first braking S 1 may prevent collisions based on the second data 12 received by V 2X.In the present invention, several features have been designated "first / r" and "second / r". These terms are used only to clearly distinguish the individual features. In particular, no spatial or functional arrangement or prioritization should be derived therefrom.If a list of alternatives is provided with the designation "or" in the present application, this is to be understood to mean that both the listed alternatives, taken alone in each case, but also, if appropriate, a combination of a plurality of or all the listed alternatives are to be understood.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedFR 3 123 616 A1

[0005] US 2023 / 070 314 A1

[0006] US 2020 / 257 308A1

[0007]

Claims

Method for carrying out braking in an ego vehicle (1), having the steps of: acquiring first data (11) from sensors on board the ego vehicle (1) which detect a surrounding area of the ego vehicle (1); acquiring second data (12) by means of vehicle communication, V2X, via an opposing vehicle (2), the second data (12) comprising a position, a direction and a speed of the opposing vehicle (2); acquiring third data (13) which comprises a position, a direction and a speed of the ego vehicle (1); determining a collision probability (15) between the ego vehicle (1) and the opponent vehicle (2) as a function of the first data (11), second data (12) and third data (13); performing a first braking (S1) with a first braking force (B1) if a first set of conditions is fulfilled; and performing a second braking (S2) with a second braking force (B2) if a second set of conditions is fulfilled, wherein: the second braking force (B2) is greater than the first braking force (B1); the first set of conditions comprises: the first data (11) comprises no information about the opponent vehicle (2); the collision probability is equal to or greater than a first limit value; and the second set of conditions includes: the first data (11) includes a position, a direction, and a speed of the opposing vehicle (2); the collision probability is equal to or greater than a second threshold.Method (1) according to Claim 1, further comprising: a step of generating an environment model (14) of the ego vehicle (1) which comprises a description of the position, direction and speed of the ego vehicle (1) and of the opposing vehicle (2) and of their respective uncertainties, wherein the collision probability (15) is determined as a function of the environment model (14).Method (1) according to Claim 2, wherein the environment model further comprises: information about a lane of the ego vehicle (1) and / or of the opponent vehicle (2); and / or map information which describes a topography of an environment of the ego vehicle (1) and / or of the opponent vehicle (2); and / or information about a right of priority of the ego vehicle (1) and / or of the opponent vehicle (2).Method (1) according to one of the preceding claims, wherein the first data (11) further comprise: an acceleration of the opposing vehicle (2); and / or a yaw rate of the opposing vehicle (2); and / or a vehicle type of the opposing vehicle (2); and / or dimensions of the opposing vehicle (2); and / or a past trajectory of the opposing vehicle (2); and / or a planned trajectory of the opposing vehicle (2).Method (1) according to one of the preceding claims, wherein the second data (12) further comprise: an acceleration of the opposing vehicle (2); and / or a braking force of the opposing vehicle (2); and / or a steering angle of the opposing vehicle (2); and / or a yaw rate of the opposing vehicle (2); and / or a vehicle type of the opposing vehicle (2); and / or dimensions of the opposing vehicle (2); and / or a past trajectory of the opposing vehicle (2); and / or a planned trajectory of the opposing vehicle (2).Method (1) according to one of the preceding claims, wherein the third data (13) further comprise: an acceleration of the ego vehicle; and / or a braking force of the ego vehicle; and / or a steering angle of the ego vehicle; and / or a yaw rate of the ego vehicle; and / or a vehicle type of the ego vehicle; and / or dimensions of the ego vehicle; and / or a past trajectory of the ego vehicle; and / or a planned trajectory of the ego vehicle.Method (1) according to one of the preceding claims, wherein the first braking force (B1) causes a deceleration of the ego vehicle (1) of at most 4 ms -2 ; and / or the second braking force (B2) causes a maximum deceleration of the ego vehicle (1).Method (1) according to one of the preceding claims, wherein the first braking (S1) is initiated at a point in time at which a calculated remaining time period until collision falls below a maximum value. At the same time, the time of the brake introduction should take place as late as possible, so that unnecessarily early braking is avoided.Method (1) according to one of the preceding claims, wherein the first set of conditions further comprises detecting an obstacle that prevents the opposing vehicle (2) from being detected by means of the first data (11).The method (1) according to any one of the preceding claims, further comprising: acquiring information about a right of priority of the ego vehicle (1) and the opponent vehicle (2), wherein the first set of conditions further comprises: the ego vehicle (1) is to pay attention to a right of priority of the opponent vehicle (2).An apparatus for performing braking in an ego vehicle, comprising: a first means for acquiring first data (11) from sensors on board the ego vehicle (1) configured to detect an environment of the ego vehicle (1); a second means for acquiring second data (12) via vehicle communication, V2X, via an opponent vehicle (2), the second data (12) comprising a position, a direction and a speed of the opponent vehicle (2); a third means for acquiring third data (13) comprising a position, a direction and a speed of the ego vehicle (1); a controller for determining a probability of collision (15) between the ego vehicle (1) and the opponent vehicle (2) depending on the first data (11), second data (12) and third data (13), wherein the controller is configured to: perform a first braking (S1) with a first braking force (B1) when a first set of conditions is satisfied; and perform a second braking (S2) with a second braking force (B2) when a second set of conditions is satisfied, wherein: the second braking force (B2) is greater than the first braking force (B1); the first set of conditions comprises: the first data (11) does not comprise any information about the opponent vehicle (2); the probability of collision is equal to or greater than a first threshold; and the second set of conditions includes: the first data (11) includes a position, a direction, and a speed of the opposing vehicle (2); the collision probability is equal to or greater than a second threshold.

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