EP3546308B1 - Method for operating a control device, motor vehicle and computer program - Google Patents

Description

The invention relates to a method for operating a control device of a motor vehicle, the control device being designed for fully automatic guidance of the motor vehicle by evaluating driving situation data including environment data from at least one environment sensor of the motor vehicle, which are fed to the control device. The invention also relates to a motor vehicle and a computer program.

Motor vehicles with vehicle systems which allow completely automatic guidance of the motor vehicle, and therefore autonomous operation of the motor vehicle, have already been proposed in the prior art. Input situations from different information sources are merged within a control unit of the vehicle system in order to evaluate input data, which in particular include driving situation data describing the current driving situation, to determine control signals describing driving interventions to corresponding actuators of the motor vehicle. From the control unit, which controls the operation of the motor vehicle completely automatically, that is to say autonomously, control signals are sent to actuators that perform driving interventions, for example a motor, a steering device and the like.

Environment data, which are supplied by various environment sensors of the motor vehicle, represent a significant portion of the driving situation data. Such environment sensors can include, for example, radar sensors, lidar sensors, ultrasonic sensors and, in particular, cameras, the image data of which, as environmental data, can usually be evaluated by various image processing algorithms and converted into useful information describing the driving situation. Due to the high quality and thus the amount of image data of modern cameras, it is known to use high-speed data connections and high-speed interfaces to the control device in order to be able to transmit the large amount of image data generated to the control device quickly, so that the image data in the contained information describing the driving situation can be reacted to as quickly as possible. The control devices themselves have a mostly rather small-sized buffer memory in which driving situation data from at least one previous time step can also be held, in particular also with regard to tracking changes in the driving situation.

Documenting accidents is an essential task in fully automated motor vehicles. After the motor vehicle is operated autonomously, the occupants usually do not focus on the driving situation, so that further evidence is necessary, especially when clarifying the question of guilt in the event of an accident. In order to ensure this, it has already been proposed in the prior art, in the event of a detected accident, in particular a detected collision of the motor vehicle with an object, which can happen for example via a crash sensor, at least partially to save the current driving situation data for later evaluation, in particular with regard to the image data of at least one camera of the motor vehicle. In this case, for example, the content of the aforementioned “buffer memory” can be “frozen” when a collision is detected by means of a collision sensor (crash sensor). Refinements are also known in which the loss of power that occurs in the event of a collision within the control device means that the last content of the buffer memory is retained for later evaluation.

However, this can lead to the problem that the driving situation data stored at this point in time are not sufficient for the To adequately reconstruct the course of the accident or to clarify a question of guilt. This means that the data available may be too small for the purposes required by law, for example. This applies in particular if the sensor system or the power supply within the motor vehicle fails due to the collision and therefore only driving situation data from the immediate time of the accident are available.

DE 100 29 401 A1 relates to a method for event-related storage of vehicle system data, an interface to a vehicle system bus being used. Vehicle system bus data present on the vehicle system bus can be stored in a memory upon receipt of a storage command via the vehicle system bus. In particular, driver command data and boundary condition data are recorded. The storage event can be a recognized vehicle accident. Such an approach also only reacts when an accident has occurred and has the further disadvantage that the vehicle system bus is often significantly too slow, which means that further delays occur which can lead to no data at all being transferred in the event of a power failure or the like in an accident the driver's operating activities can be saved more.

DE 10 2004 045 813 A1 relates to a system and a method for predictive detection of an accident risk situation. In particular, it is sensed in the blind spot of the motor vehicle in order to be able to detect data relating to a potential accident object. At least one suitable occupant protection measure can be activated as a function of the data recorded by the blind spot sensor device. In particular, the probability of a side accident can be estimated in different ways using suitable algorithms. Other possibilities for increasing the safety of vehicle occupants, in particular the driver, who monitor for collisions, have also already been proposed.

EP 0 891 903 A2 relates to an automatic emergency braking function, which is intended to give the driver a high degree of decision-making authority when avoiding obstacles, without foregoing the advantages of a collision limitation system that supports the driver in the event of an actual collision situation. Accordingly, provision is made to give the driver of the vehicle the opportunity for as long as possible to avoid the collision by taking actions himself, such as braking and / or steering operations. Only when a collision can clearly no longer be avoided due to the physical driving conditions resulting from the driving state of the vehicle and the collision constellation, is the vehicle braked before the collision by an automatically triggered and preferably strongest possible deceleration This minimizes the consequences of accidents for the driver and vehicle. The environmental data or sensor signals supplied by the detection device there can be stored in a memory device, in particular also image signals from a camera device.

DE 10 2013 212 092 A1 relates to a method and a device for operating a pedestrian protection device of a vehicle. A type of collision object is to be determined, and with regard to the data of the environment sensors that describe this collision object, a freeze state can be established when a threshold value for the impact probability is exceeded, in order to have data about the collision object in any case.

DE 10 2016 222 219 A1 relates to a driver assistance system for a motor vehicle in which the vehicle's geographic positions, which have an increased probability of triggering a collision avoidance system, are stored in a self-learning manner in order to take into account the stored vehicle position in preparation for a hazard warning or emergency braking when the spatial environment is driven again. Further data can also be saved with the vehicle position.

DE 10 2015 218 762 A1 discloses a method and apparatus for accident data storage for a vehicle. It is proposed there, in the event of an imminent vehicle accident being detected, not only to give accident-relevant vehicle data to an interface to an in-vehicle storage device for storing the accident-relevant vehicle data, but also to an interface to a transmission device for transmitting the accident-relevant vehicle data to at least one external storage device for Saving the vehicle data relevant to the accident. It can thus be achieved that no information can be lost which could be important for reconstructing the accident.

DE10231558 discloses the automatic triggering of a deceleration of a vehicle, with data from an environment sensor system with which the vehicle is equipped and data describing the vehicle's own movement being read in to determine a current hazard potential, which is compared with a threshold value or a triggering threshold to trigger a preparation of a braking system or a braking.

The invention is based on the object of specifying a possibility for better documentation of accidents in a fully automatically operated motor vehicle.

To achieve this object, the features of claim 1 are provided according to the invention in a method of the type mentioned at the beginning.

The invention therefore proposes to provide a dedicated, additional storage means within the control unit itself and also to generate a trigger signal within the control unit itself by evaluating driving situation data, which indicates a very likely impending collision accident of the motor vehicle in order to continuously read at least part of the current environment data to store this storage means, so that an excellent basis is created for evaluating the occurrence of the accident at a later point in time, for example with regard to a question of guilt and / or a possibly occurring error in the fully automatic driving of the motor vehicle. Included the storage means is preferably used in addition to a smaller, continuously used buffer memory of the control device, so that even larger amounts of data, as can be expected from image data from a camera, for example, can be held within the storage means over the longer period of time. Especially with regard to modern environment sensors, the quality of which is constantly increasing, that of Data volume received by these environment sensors per time step, so that only an insufficient part of the environment data could be kept within a buffer memory. The present invention makes particular use of the fact that, on the one hand, it has already been proposed in the prior art to determine collision probabilities from driving situation data, and on the other hand, the corresponding driving situation data are already available within the control unit, which also controls the fully automatic guidance of the motor vehicle , so that a collision probability can also be determined here, which can be used to trigger a trigger signal, which therefore allows environment data (and preferably also further driving situation data and / or operating data of the motor vehicle) to be started before a collision occurs Record documentation within the control unit. An additional documentation period is thus gained.

Because both the determination of the probability of a collision and the generation of the trigger signal take place within the control unit itself and the storage means is also provided within the control unit itself, there is no need to use a slow vehicle bus, which would cause a significant delay in the recording of the surrounding data . Rather, it is possible to react extremely quickly to an impending accident within the control device and to record and maintain at least some of the surrounding data, in particular image data from a camera, in an extended manner.

In this context it is also of particular advantage if a storage means is used that allows fast access times. An SSD and / or eMMC can therefore preferably be used as the storage means, so that the documentation data useful for documentation, in particular the part of the surrounding data, can be saved as quickly as possible in the event of an impending accident. This, together with the fact that the trigger signal is an internal signal of the control unit, ensures maximum utilization of the available time Saving at least the part of the environment data and possibly further documentation data.

In summary, before the collision, at least part of the environment data is started to be stored in a storage means provided within the control device, so that documentation of the collision that begins earlier is just as possible as a provision of a larger amount of information to document the collision.

As already mentioned, it is particularly expedient within the scope of the present invention if the part of the environment data to be stored when the threshold value is exceeded by the collision probability is selected to include at least image data from a camera as the environment sensor. The part of the surroundings data to be stored can preferably also include radar data from a radar sensor as an surroundings sensor, since radar data can also provide particularly useful information when analyzing an accident, in particular on the relative speeds and / or distances. With regard to the camera in particular, it is also advantageous if the environment data, in particular the part of the environment data to be stored, is at least partially transmitted to the control device via a high-speed interface.

The threshold value can expediently be selected in a range from 40 to 70%, in particular as 50%. A value of 50% has proven to be useful when using conventional algorithms for determining the collision speed, as they are known in the prior art, in order to obtain both a suitably dimensioned period of time before the actual collision, but not to do so often to generate the trigger signal, thus covering too many cases of false alarms that are not followed by an actual accident.

According to the invention, it is provided that when the trigger signal is received, at least a part of the memory space stored in an earlier period of time is available in the case of a free storage space in the storage means which falls below a limit value Environment data are deleted. In this way, sufficient or, in particular, all of the free storage space of the storage means is available and can be used for relevant data.

In such a refinement, in particular, previously stored environmental data can also be deleted, for example if, without the occurrence of an actual accident, after the threshold value has been exceeded by the collision probability, at least part of the environmental data was stored for a period of time until the further threshold value or the further threshold value was undershot again . It should also be noted that the same threshold value can be used for both activation and deactivation; If necessary, a slightly lower value than the threshold value for generating the trigger signal can be selected as an additional threshold value in order to avoid saving for short periods of time that is then immediately aborted and in any case to achieve continuous recording over a significant period of time, even if there is no accident. For example, 50% can be selected as the threshold value for generating the trigger signal, and 40% as the further threshold value.

It should be pointed out that the evaluation of the collision probability after the collision has occurred, which can be detected, for example, by a collision sensor of the motor vehicle, can expediently be terminated if electrical energy is still present within the control device. In such a case, provision can be made, for example, to store at least part of the environment data in the storage means for a predetermined period of time after the occurrence of the collision or to end the period of storage in the storage means as soon as the collision occurs.

To determine the probability of a collision, a wide variety of calculation methods or algorithms that have already been proposed in the prior art with regard to safety systems can be used, which do not need to be explained in more detail here. In particular, can It can be provided that, in order to determine the probability of a collision, a prediction of the behavior of road users described by the driving situation data, including their own motor vehicle, is carried out. Known approaches, especially in security systems, use forecast algorithms to determine how likely a collision is in a forecast period.

In addition to the method, the invention also relates to a motor vehicle having a vehicle system for fully automatic guidance of the motor vehicle with a control device designed to carry out the method according to the invention and at least one environment sensor. All statements relating to the method according to the invention can be applied analogously to the motor vehicle according to the invention, with which the advantages already mentioned can therefore also be obtained.

A computer program according to the invention can, for example, be loaded directly into a memory of a control unit of a motor vehicle and has program means to execute the steps of a method according to the invention when the computer program is executed in the control unit of the motor vehicle. The computer program can be stored on an electronically readable data carrier, which therefore includes electronically readable control information stored thereon, which record at least one computer program according to the invention and are designed in such a way that they carry out a method according to the invention when the data carrier is used in a control unit of a motor vehicle.

Fig. 1

eine Prinzipskizze eines erfindungsgemäßen Kraftfahrzeugs, und

Fig. 2

den Aufbau eines Steuergeräts eines Kraftfahrzeugs gemäß Fig. 1.

Further advantages and details of the present invention emerge from the exemplary embodiments described below and on the basis of the drawings. Show:

Fig. 1

a schematic diagram of a motor vehicle according to the invention, and

Fig. 2

the structure of a control unit of a motor vehicle according to Fig. 1 .

Fig. 1 shows a schematic diagram of a motor vehicle 1 according to the invention, which has a vehicle system 2 with a control unit 3 designed for completely automatic guidance of the motor vehicle. In order to perform its fully automatic vehicle guidance function, which is known in principle, the control unit 3 receives as driving situation data in addition to operating data of the motor vehicle 1 environment data from environment sensors of the motor vehicle 1, cameras 4 and radar sensors 5 being shown here by way of example. A high-speed data connection with a corresponding high-speed interface on the control device 3 is used in order to have them quickly and reliably available within the control device 3, particularly in the case of larger amounts of data, such as the image data from the camera 4.

The driving situation data are evaluated in the control unit 3 in order to generate control signals describing driving interventions for corresponding actuators of the motor vehicle 1, a motor 6, a braking device 7 and a steering system 8 being shown here only by way of example.

To detect a collision actually taking place, the motor vehicle 1 can furthermore also comprise crash sensors 9 embodied as acceleration sensors, for example. These also supply their corresponding sensor data to the control unit 3.

3 shows the structure of the control device 3 in more detail. At least some of the environment data, in particular the environment data of the cameras 4, are received via a high-speed interface 10. The control device 3 also has further interfaces, for example to a vehicle bus system and / or for other direct connections.

In a computing device 12 of the control device 3, which can include one or more processors, a guide unit 13 is used to complete the automatic guidance operation of the motor vehicle 3 is realized. In addition to this or integrated into it, the computing device 12 also realizes a collision documentation unit 14. Driving situation data that are evaluated by the computing device 12 are temporarily stored in a buffer memory 15 of the control device 3. In addition to the buffer memory 15, the control device 3, however, also has a memory means 16 which is larger than the buffer memory 15 in terms of memory space, in this case an SSD, in which documentation data relating to an accident of the motor vehicle 1 can be recorded.

For this purpose, the collision documentation unit 14 further evaluates the driving situation data in order to determine a collision probability of the motor vehicle 1 with a foreign object. If this probability of collision exceeds a threshold value, in this case 50%, an internal trigger signal is generated in the control unit 3, which ensures that a defined part of the environment data, together with other defined driving situation data and / or operating data of the motor vehicle 1, is continuously stored in the storage means from now on 16 is stored, whereby this can also be at least partially deleted first if the trigger signal is received, in particular if documentation data is still stored on it that originates from a driving situation in which there was a high probability of a collision but no accident occurred. The defined, to be stored part of the environment data in the present case includes at least the image data of the cameras 4 and the radar data of the radar sensors 5. The period for which such current documentation data are stored in the storage means 16 can be measured on the one hand until the collision probability is below the or another threshold value, here 40% falls. If, however, a collision actually occurs, which can be determined by the collision sensors 9, the occurrence of the collision can also mark the end of the storage; However, it is also conceivable, in particular if the power supply of the control device 3 is maintained, to store further documentation data including at least the defined part of the environment data in the storage means 16 for a predetermined period of time beyond the time of the collision.

In this way, documentation data is stored in a high-quality evaluation and analysis of the amount received before a collision occurs. The documentation data can be read out and analyzed at a later point in time.

It should also be pointed out that the probability of a collision, which is determined here, can also be used for other purposes, for example in a safety system which is also implemented by the control device 3 and which preconditions the occupant restraint or the like.

Claims (7)

1. Method for operating a control device (3) of a motor vehicle (1), wherein the control device (3) is configured for fully automatic guidance of the motor vehicle (1), in which driving situation data, comprising environment data of at least one environment sensor of the motor vehicle (1), which are supplied to the control device (3) are evaluated, wherein a collision probability for the occurrence of a collision with a foreign object is determined in the control device (3) by further evaluation of the driving situation data, wherein, if a threshold value for the collision probability is exceeded, a trigger signal is generated, the presence of which initiates continuous storage of at least part of the current environment data in a storage means (16) of the control device (3) in a period of time until at least the occurrence of the collision and/or until the collision probability falls below the and/or a further threshold value, so that it can be retrieved at a later time, wherein at least part of the environment data stored in an earlier period of time is deleted when the trigger signal is received if the free memory space of the storage means (16) is below a limit value.
2. Method according to claim 1,
   characterised in that
   when the threshold value of the collision probability is exceeded the part of the environment data that is to be stored is selected to comprise at least image data from a camera (4) as an environment sensor and/or the environment data are at least partially transmitted via a high-speed interface (10) to the control device (3).
3. Method according to claim 1 or 2,
   characterised in that
   the storage means (16) is used in addition to a smaller-dimensioned, continuously used buffer memory (15) of the control device (3).
4. Method according to any one of the preceding claims,
   characterised in that
   the threshold value is selected to be in a range of 40 to 70%.
5. Method according to any one of the preceding claims,
   characterised in that
   in order to determine the collision probability, a prediction is made of the behaviour of road users described by the driving situation data, including the motor vehicle (1) itself.
6. Motor vehicle (1), having a vehicle system (2) for fully automatic guidance of the motor vehicle (1) comprising a control device (3) configured to carry out a method according to any one of the preceding claims and at least one environment sensor.
7. Computer program which carries out the steps of a method according to any one of claims 1 to 5 when it is executed on a control device (3) of a motor vehicle (1) according to claim 6.

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