Recording and providing data in a vehicle

Abstract

The invention relates to a method for recording and providing data in a vehicle. In this method, sensor data is continuously acquired by the vehicle's sensors and stored in a ring buffer. Furthermore, driving events are defined, and each of these driving events is assigned an event period (T1, T2) extending from a first time (t1, t3) before the occurrence of the driving event to a second time (t2, t4) after the occurrence of the driving event. When one of the driving events occurs, the sensor data stored in the ring buffer that was acquired during the event period (T1, T2) assigned to the driving event are stored in a permanent memory (P). All sensor data stored in the ring buffer that was acquired during an overlap period in which several event periods (T1, T2) overlap are stored only once in the permanent memory (P).Data stored in permanent storage (P) is made available to data users.

Description

The invention relates to a method for recording and providing data in a vehicle.Many vehicles today have a plurality of sensors that acquire sensor data. The sensor data can relate to an environment of the vehicle and / or an operating state of the vehicle. Sensors that acquire sensor data relating to an environment of a vehicle are, for example, cameras, lidar sensors, radar sensors, and ultrasonic sensors. Sensors that detect an operating state of a vehicle are, for example, rotational speed sensors, speed sensors, and acceleration sensors.More particularly, the invention relates to a method for recording and providing data in a self-driving vehicle. A self-driving vehicle is also referred to as an autonomous vehicle. Such a vehicle is understood to mean a vehicle that can drive and control without a human driver. In order to be able to drive and control itself with the required traffic safety, a self-driving vehicle has a particularly large number of sensors and therefore requires the acquisition, storage and processing of a particularly large number of sensor data. The acquisition of specific sensor data is often prescribed by legal regulations, on the one hand, in order to check the traffic safety of the self-driving vehicle. On the other hand, the sensor data are required and used by computer programs that train, check and / or correct the driving behavior of the self-driving vehicle if necessary. The driving behavior of the self-driving vehicle comprises, for example, driving maneuvers which are carried out by the self-driving vehicle in response to traffic situations. These traffic situations and the reaction of the self-driving vehicle are detected and evaluated in particular by the sensor data.It is an object of the invention to provide an improved method for recording and providing data in a vehicle.The object is achieved according to the invention by a method for recording and providing data in a vehicle, whereinsensor data are continuously detected by sensors of the vehicle,storing the acquired sensor data in a ring buffer,defining driving events and associating each of said driving events with an event time period extending from a first time prior to the occurrence of said driving event to a second time after the occurrence of said driving event; and,when one of the driving events occurs, the sensor data stored in the ring buffer, which were acquired during the event period associated with the driving event, are stored in a permanent memory, whereinall sensor data stored in the ring buffer, which were acquired during an overlap period in which a plurality of event periods overlap, are stored in the permanent memory only oncereferencing metadata corresponding to the stored data; andproviding data users with data stored in the permanent memory.In the method according to the invention, sensor data recorded by sensors of a vehicle are thus initially stored in a ring buffer. The circular buffer, which is also referred to as a circular buffer, refers to a memory area having a fixed memory size, in which the sensor data are temporarily stored. The sensor data are stored in the ring buffer, for example, according to the so-called FIFO principle (FIFO: abbreviation for First In-First Out). In this principle, in the case that the storage space in the ring buffer is not sufficient for storing newly acquired sensor data, the oldest sensor data stored in the ring buffer are overwritten by the newly acquired sensor data. The most recently acquired sensor data are thus always stored in the ring buffer.Further, driving events are defined and each driving event is associated with an event period that extends from a first time prior to the occurrence of the driving event to a second time after the occurrence of the driving event. For example, the definition of a driving event comprises a change in a driving speed of the vehicle and / or a change in the driving direction of the vehicle. A driving event can be, for example, a hard braking of the vehicle or a change in the direction of travel when the vehicle turns at a road intersection or when a lane changes. The event period associated with a driving event associates the driving event with sensor data captured during the event period. This makes it possible, for example, to analyze whether and how the driving event is associated with events in a surrounding environment of the vehicle and how the vehicle responds to these events.When a driving event occurs, the sensor data acquired during an event period is stored in permanent memory because they are overwritten earlier or later in the circular buffer. The permanent memory is a non-volatile memory in which the sensor data are permanently stored and data users are provided, inter alia for regulatory purposes, e.g. accident examinations or adhesion questions. In this case, all sensor data stored in the ring buffer, which were captured during an overlap period in which a plurality of event periods overlap, are stored in the permanent memory only once. Thus, for example, if a second event period begins during a first event period and ends after the first event period, the sensor data that were acquired from the beginning of the first event period to the end of the second event period are stored in the permanent memory. The same applies if more than two event periods overlap. In this way, a very large amount of storage space can be saved in the permanent memory compared, for example, with a storage in which a separate storage block is provided for each driving event, in which storage block the sensor data acquired during the event period assigned to the driving event are stored.In one embodiment of the method according to the invention, the vehicle is a self-driving vehicle. As stated above, a self-driving vehicle requires the acquisition, storage, and processing of a lot of sensor data. Therefore, the efficient storage of the sensor data in the permanent memory according to the invention has a particularly advantageous effect in a self-driving vehicle.In a further embodiment of the method according to the invention, the sensor data comprise environment data relating to an environment of the vehicle and / or vehicle data relating to an operating state of the vehicle. The environmental data are detected, for example, by cameras, lidar sensors, radar sensors and / or ultrasonic sensors. The vehicle data are detected, for example, by rotational speed sensors, speed sensors and / or acceleration sensors.In a further embodiment of the method according to the invention, metadata are assigned to each driving event that has occurred, said metadata referencing a memory area in the permanent memory, in which the sensor data that were acquired during the event period assigned to the driving event that has occurred are stored.The aforementioned specific embodiment of the method according to the present invention makes it possible to assign sensor data stored in the permanent memory to a driving event that has occurred by the metadata assigned to the driving event. This is important because, according to the invention, not every driving event is assigned a separate memory block for sensor data in the permanent memory, in which memory block the sensor data acquired during the event period assigned to the driving event are stored, but instead, in the case of overlapping event periods, sensor data are stored in the permanent memory, which sensor data were acquired during the entire period that comprises all these overlapping event periods. The metadata associate a driving event with the storage area in the permanent storage, on which the sensor data acquired during the event period associated with the driving event are stored.In a further embodiment of the method according to the invention, the metadata are stored in the permanent memory. This allows a data user to access the metadata and the sensor data via the same storage medium, namely the permanent storage.In a further embodiment of the method according to the invention, the metadata assigned to a driving event that has occurred comprise event properties characterizing the driving event that has occurred. In particular, the metadata assigned to a driving event that has occurred comprise, for example, a time of the occurrence of the driving event. Further, the metadata associated with a driving event that occurred includes, for example, a time of the end of the driving event.In a further embodiment of the method according to the invention, at least one data user profile is defined which specifies which sensor data stored in the permanent memory may be provided to a data user of this data user profile.The data user profile thus defines an access authorisation to which sensor data stored in the permanent memory a data user of this data user profile is allowed to access. For example, for an authority that has to be granted access to specific sensor data on the basis of legal regulations, for example in order to examine accident causes, a different data user profile is defined than for a manufacturer of software used in the vehicle, the aim of which is to train and optimize this software.In a further embodiment of the method according to the invention, each data user profile defines a cryptographic data encryption method for encrypting the sensor data provided to a data user of this data user profile. Accordingly, a further embodiment of the method according to the invention provides that sensor data stored in the permanent memory is provided to a data user of a data user profile in encrypted form using the data encryption method defined in the data user profile.The aforementioned embodiment of the method according to the invention aims at data security of the sensor data stored in the permanent memory. Since different data user profiles have different access permissions for sensor data stored in the permanent memory, in this embodiment of the method according to the invention a cryptographic data encryption method for encrypting the sensor data provided to a data user of this data user profile is also assigned to a data user profile. In this way, for example, data users that may use sensor data of a higher security level may provide this sensor data with a stronger encryption than data users that may use sensor data of a lower security level. For example, an authority is granted access to specific sensor data with a cryptographically weaker encryption than a software manufacturer for software used in the vehicle.In a further embodiment of the method according to the invention, in the event that event periods of a plurality of driving events overlap, a data user is permitted to retrieve from the permanent memory sensor data relating to one of these driving events which were recorded during a period which comprises and increases the event period associated with the driving event.The aforementioned specific embodiment of the method according to the present invention uses the fact that, according to the present invention, sensor data that were acquired during overlapping event periods of multiple driving events are not stored in the permanent memory independently of one another. This allows an event period actually assigned to the driving event to extend beyond this event period. As a result, the driving event can be examined more accurately, if necessary, by analyzing a time period that increases the event time period actually assigned to the driving event.In a further embodiment of the method according to the invention, at least one driving event is defined for which the acquisition of sensor data is legally prescribed.The aforementioned specific embodiment of the method according to the present invention takes into account that, in particular for self-driving vehicles, the acquisition of sensor data for specific driving events may be legally prescribed.Embodiments of the invention are explained in more detail below with reference to drawings. The following are shown: FIG. 1 shows a flow diagram of an embodiment of the method according to the invention, FIG. 2 shows a diagram for storing sensor data in a permanent memory.FIG. 1 (FIG. 1 ) shows a flow diagram 100 of an embodiment of the method according to the invention, having method steps 101 to 107 for recording and providing data in a vehicle. The vehicle can be, in particular, a self-driving vehicle.In a first method step 101, driving events are defined and each of these driving events is assigned an event period which extends from a first point in time before the occurrence of the driving event to a second point in time after the occurrence of the driving event. A driving event comprises, for example, a change in a driving speed of the vehicle and / or a change in the direction of travel of the vehicle. For example, a driving event can be a hard braking of the vehicle or a change in the direction of travel when the vehicle turns at a road intersection or when a lane changes. In particular, driving events can be defined for which the storage of sensor data, which are detected by sensors of the vehicle, is legally prescribed.For example, a driving event is assigned an event period which begins 30 s before the occurrence of the driving event and ends 5 s after the end of the driving event.In a second method step 102, sensor data are continuously acquired by sensors of the vehicle. The sensor data includes environment data relating to an environment of the vehicle and vehicle data relating to an operating state of the vehicle. The environmental data are captured, for example, by at least one camera, at least one lidar sensor, at least one radar sensor and / or at least one ultrasonic sensor of the vehicle. The vehicle data are recorded, for example, by at least one rotational speed sensor, at least one speed sensor and / or at least one acceleration sensor.In a third method step 103, the acquired sensor data are stored in a ring buffer arranged in the vehicle. The circular buffer is a storage area with a fixed storage size in which the acquired sensor data are temporarily stored. The sensor data are stored in the ring buffer according to the FIFO principle, in which, in the case that the storage space in the ring buffer is not sufficient for storing newly acquired sensor data, the oldest sensor data stored in the ring buffer are overwritten by the newly acquired sensor data. The most recently acquired sensor data are thus always stored in the ring buffer.In a fourth method step 104, it is checked whether one of the driving events defined in the first method step 101 has occurred. When one of these driving events has occurred, the sensor data stored in the circular buffer during the event period associated with this driving event is stored in a permanent memory located in the vehicle. In this case, all sensor data stored in the ring buffer, which were captured during an overlap period in which a plurality of event periods overlap, are stored in the permanent memory only once. The permanent memory is a non-volatile memory in which the sensor data are permanently stored. The permanent storage device can either belong to the same module as the ring buffer or can be a stand-alone module.The event period associated with a driving event associates the driving event with the sensor data captured during the event period. This sensor data is stored in the permanent memory because it is overwritten in the ring buffer and lost without storage in the permanent memory. This makes it possible, for example, to analyze whether and how the driving event is associated with events in a surrounding environment of the vehicle and how the vehicle has reacted to these events.FIG. 2 (FIG. 2 ) shows, by way of example, a diagram for storing sensor data in the permanent memory of the vehicle. The permanent storage is only schematically shown here and is denoted by the reference symbol P.In FIG. 2, two event periods T 1, T 2 are shown by way of example. A first event period T 1 associated with a first driving event extends from a time t 1 to a time t 2 of a time t. A second event period T 2 associated with a second driving event extends from a time t 3 to a time t 4. In the example shown in FIG. 2, the event periods T 1, T 2 overlap between the times t 3 and t 2. According to the invention, the sensor data acquired between the points in time t 3 and t 2 are stored only once in the permanent memory P, that is to say the sensor data acquired between the points in time t 1 and t 4 are stored only simply in the permanent memory P.In other words, the sensor data acquired during the event period T 1 and the sensor data acquired during the event period T 2 are therefore not stored in mutually independent memory areas of the permanent memory P, but rather the sensor data acquired between the times t 3 and t 2 are stored in the same memory area of the permanent memory P.In a fifth method step 105, metadata are assigned to each driving event that has occurred, said metadata referencing a memory area S 1, S 2 in the permanent memory P, in which the sensor data that were acquired during the event period T 1, T 2 assigned to the driving event that has occurred are stored. In the example shown in FIG. 2, the metadata of the first driving event references a first storage area S 1 in which the sensor data acquired during the event period T 1 associated with the first driving event is stored. The metadata of the second driving event references a second storage area S 2 in which the sensor data acquired during the event period T 2 associated with the second driving event are stored. Each of these memory areas S 1, S 2 is referenced, for example, by memory addresses which are stored in the metadata. However, it is essential that the memory areas S 1, S 2 have a non-empty intersection set in which those sensor data are stored which were acquired between the times t 3 and t 2 between which the event periods T 1, T 2 overlap.The metadata are also stored in the permanent memory P. In the example shown in FIG. 2, the metadata for the first driving event is stored in a storage area M 1 of the permanent storage P, and the metadata for the second driving event is stored in a storage area M 2 of the permanent storage P.Referencing the storage area S 1, S 2 of the permanent storage P, in which the sensor data acquired during an event period T 1, T 2 assigned to an occurred driving event are stored, by the metadata assigned to the occurred driving event enables the assignment of sensor data stored in the permanent storage P to an occurred driving event. This is important because, according to the invention, a separate memory block for sensor data is not assigned to each driving event, but rather, in the case of overlapping event periods T 1, T 2, sensor data are stored in the permanent memory P, which sensor data were acquired during the entire period that comprises all these overlapping event periods. The metadata associate a driving event with the storage locations in the permanent storage P at which the associated sensor data are stored.The metadata associated with a driving event that occurred further includes event characteristics characterizing the driving event that occurred. For example, the metadata associated with a driving event that occurred includes a time of the occurrence of the driving event and a time of the end of the driving event.In addition, the metadata includes cryptographic keys for encrypting the sensor data.In a further embodiment of the invention, the metadata of successive driving events form a blockchain. This means that each block automatically contains the metadata of the preceding driving event that were stored in the permanent memory P. Moreover, each metadata block contains the so-called hash or fingerprint of the previous metadata block ("#"), and provides a new hash as a reference for the metadata block of a subsequent driving event.In a sixth method step 106, different data user profiles are defined. Each data user profile specifies which sensor data stored in the permanent memory P may be provided to a data user of this data user profile. Furthermore, each data user profile defines a cryptographic data encryption method for encrypting the sensor data provided to a data user of this data user profile.A data user profile thus defines an access authorisation to which sensor data stored in the permanent memory P a data user of this data user profile is allowed to access. In addition, the data user profile defines a data encryption method with which sensor data is provided encrypted to a data user of the data user profile.The data user profiles are adapted to the requirements of the respective data users. On the one hand, in particular for a self-driving vehicle, for example, the registration and storage of sensor data for specific driving events may be legally prescribed, for example, in order to examine the circumstances of a traffic accident in which the vehicle was involved. Therefore, a corresponding data user profile for "official" data users can be defined, which is adapted to these legal regulations. On the other hand, sensor data associated with a driving event may be useful to software manufacturers who develop and optimize software for the vehicle. Therefore, a data user profile for a software manufacturer can also be defined. The data user profile for a software manufacturer will usually differ from the data user profile for official data users, since the data usage by the software manufacturer is directed, for example, to training and optimizing driving functions of the vehicle, while the official data usage is directed, for example, to the traffic safety of the vehicle.In a seventh method step 107, data users are provided with the sensor data stored in the permanent memory P. The data user profile of the respective data user is taken into account in this case. Thus, only those sensor data are provided to a data user, the provision of which allows the data user profile thereof for the data user.In addition, this sensor data is provided to the data user in encrypted form using the cryptographic data encryption method defined in its data user profile. The sensor data is accessed via the metadata.For example, official data users are given the possibility of accessing the metadata via a public cryptographic key. However, the access to the sensor data stored in the permanent memory P is limited in accordance with the data user profile for official data users. For example, access to sensor data is restricted, which were recorded during event periods T 1, T 2 of specific driving events for which the storage of sensor data is legally prescribed. Furthermore, for official data users, for example, access to specific data transmitted via a CAN bus of the vehicle (CAN: abbreviation for Controller Area Network) and / or to data from a lidar sensor of the vehicle can be restricted insofar as the provision of this data for official data users is not prescribed.A software manufacturer, on the other hand, is given the possibility, for example, of accessing the metadata via a private cryptographic key, which enables him to access all sensor data stored in the permanent memory P. This allows the software manufacturer, for example, to analyze interactions of the vehicle with events in an environment of the vehicle and, in particular, reactions of the vehicle to events in an environment of the vehicle and to check the functions of the software used in the vehicle and, if necessary, to correct or optimize them. This is advantageous in particular for a self-driving vehicle, since a self-driving vehicle requires particularly high-quality and stable software for operating the vehicle.List of reference characters100 Flow diagram 101 to 107 Method step t Time t 1 to t 4 Time M 1, M 2, S 1, S 2 Memory area P Permanent memory T 1, T 2 Event period

Claims

Method for recording and providing data in a vehicle, wherein - sensor data are acquired continuously by sensors of the vehicle, - the acquired sensor data are stored in a ring buffer, - driving events are defined and each of these driving events is assigned an event period (T1, T2) which extends from a first point in time (t1, t3) before the occurrence of the driving event to a second point in time (t2, t4) after the occurrence of the driving event, and - when one of the driving events occurs, the sensor data stored in the ring buffer, which were acquired during the event period (T1, T2) assigned to the driving event, are stored in a permanent memory (P), wherein - all sensor data stored in the ring buffer, which are stored during an overlap period in which a plurality of event periods (T1, T2) overlap, In the case of the permanent storage device, data stored in the permanent storage device (P) are provided to data users.The method of claim 1, wherein the vehicle is a self-propelled vehicle.Method according to Claim 1 or 2, wherein the sensor data comprise environment data relating to an environment of the vehicle and / or vehicle data relating to an operating state of the vehicle.Method according to one of the preceding claims, wherein each driving event that has occurred is assigned metadata which references a storage area (S1, S2) in the permanent memory (P), in which the sensor data which were acquired during the event period (T1, T2) assigned to the driving event that has occurred are stored.The method of claim 4, wherein the metadata is stored in the permanent storage (P).The method of claim 4 or 5, wherein the metadata associated with a driving event that occurred comprises event characteristics characterizing the driving event that occurred.The method of any of claims 4 to 6, wherein the metadata associated with an occurred driving event comprises a time of the occurrence and / or the end of the driving event.The method of any of claims 4 to 7, wherein the metadata portion of successive driving events comprises a blockchain.Method according to one of the preceding claims, wherein at least one data user profile is defined which specifies which sensor data stored in the permanent memory (P) are allowed to be provided to a data user of this data user profile.The method of claim 9, wherein each data user profile defines a cryptographic data encryption method for encrypting the sensor data provided to a data user of that data user profile.Method according to claim 10, wherein sensor data stored in the permanent memory (P) is provided to a data user of a data user profile in encrypted form using the data encryption method defined in the data user profile.Method according to one of the preceding claims, wherein, in the event that event periods (T1, T2) of a plurality of driving events overlap, a data user is permitted to retrieve from the permanent memory (P) sensor data relating to one of these driving events which were recorded during a period which comprises and increases the event period (T1, T2) associated with the driving event.Method according to one of the preceding claims, wherein at least one driving event is defined for which the acquisition of sensor data is legally prescribed.

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