DE102018202230A1 - Data recorder for a vehicle and corresponding device for a vehicle - Google Patents

Abstract

The invention relates to a data recorder (1) for a vehicle, comprising a memory device (10) which comprises an evaluation and control unit (12) and a ring memory (14), wherein the evaluation and control unit (12) continuously records accident-relevant data in the ring memory (14) stores which are suitable for reconstructing an accident, the oldest data in the ring memory (14) being overwritten by the newest data, and a device for a vehicle for providing at least one safety function and / or at least one vehicle function, in particular an automated one Driving function, which includes such a data recorder (1). In this case, the vehicle comprises at least one autonomous driving function, which at least partially assumes an actual driving task, wherein the evaluation and control unit (12) stores the time and geolocation of the assumption of the actual driving task by the at least one driving function in the ring memory (14) which can be rewritten as non-volatile Memory (NVRAM) is executed, the memory cells receive their power-free memory state without power supply.

Description

The present invention is also an apparatus for a vehicle for providing at least one safety function and / or at least one vehicle function, in particular an automated driving function, which includes such a data recorder includes.

In today's airbag control units, a data recorder is already partially available. This has the task, for example, in the event of an accident to record data to reconstruct the accident. Usually in a ring memory continuously accident-relevant data, such as. Acceleration values, saved. In order to be able to evaluate data in the event of an accident before the actual accident event, the oldest data in the ring buffer are always replaced by the latest data. If an accident occurs, the entire contents of the ring buffer are stored in a retentive memory and can be read out if necessary.

From the DE 199 39 468 A1 For example, a method for controlling a recording of an accident data recorder in motor vehicles and an accident data recorder are known. Here, a vehicle environment is detected in the direction of travel of the motor vehicle with a video sensor and provided as a video signal in the accident data recorder. In the method, it is provided that the video signal in the accident data recorder is analyzed and evaluated in accordance with a predeterminable scheme, and the evaluation signal is fed into a predefinable map which serves to establish a period of recording of the accident data record. It is further provided that the accident data recorder consists of at least one signal processing unit with a data processor for analyzing a provided video signal and at least one signal storage component with a storage medium for storing an analysis program and for storing data. In addition, the accident data recorder may also include an interface to an in-vehicle data network, so that the acquisition of data, such as vehicle speed, acceleration or the like, is possible. Since a power supply via the vehicle power network is often no longer possible after an accident, the accident data recorder can be assigned a independent of the vehicle power supply power supply.

Disclosure of the invention

The data recorder for a vehicle having the features of independent claim 1 has the advantage that time and geolocation of the acquisition of the actual driving task by the at least one automatic driving function can be stored in the ring memory. In connection with the accident-relevant data in the ring buffer, the accident can be reconstructed afterwards. Furthermore, the storage of the time and the geolocation in the acquisition of the actual driving task by the at least one automatic driving function for the defense against product liability claims will be relevant.

The core of the invention is the use of new storage media, which belong to the nonvolatile random access memory (NVRAM) class. They are characterized by the fact that they retain their current memory state when the supply voltage is lost. Embodiments of such nonvolatile rewritable memories advantageously combine multiple requirements for storage technologies to be used in the environment of a data recorder for automated vehicles. On the one hand, the technology offers the property of storing data remanently much faster than previously known. This means that the ring buffer can be implemented directly as a non-volatile memory, since the previous limitation by number of possible write cycles and the maximum write speed of known retentive memory cells almost eliminated. In addition, the data is stored permanently permanently if the power supply is lost. This is done by virtue of the fact that the payload in the memory cell is stored retentively during the writing process, for example by changing the phase state of the memory material. Since only data for a predetermined period of time after loss of power must be buffered, if post-crash data are of interest, an existing backup battery can then be dimensioned correspondingly smaller or completely eliminated, so that costs can be saved.

Embodiments of the present invention provide a data recorder for a vehicle having a memory device comprising an evaluation and control unit and a ring buffer. The evaluation and control unit continuously stores accident-relevant data in the ring memory, which are suitable for reconstructing an accident, whereby the oldest data in the ring memory is overwritten by the newest data. Here, the vehicle comprises at least one autonomous driving function, which at least partially assumes an actual driving task, wherein the evaluation and control unit stores the time and geolocation of the assumption of the actual driving task by the at least one driving function in the ring memory, which is designed as nonvolatile rewritable memory (NVRAM), receive its memory cells without power supply their bistable memory state.

In addition, a device for a vehicle for providing at least one safety function and / or at least one vehicle function, in particular at least one autonomous driving function, which at least partially assumes an actual driving task, proposed with such a data recorder.

In the present case, the evaluation and control unit can be understood to mean an electrical assembly which processes or evaluates detected sensor signals. The evaluation and control unit may have at least one interface, which may be formed in hardware and / or software. In the case of a hardware-based configuration, the interfaces can be part of a so-called system ASIC, for example, which contains a wide variety of functions of the evaluation and control unit. However, it is also possible that the interfaces are their own integrated circuits or at least partially consist of discrete components. In a software training, the interfaces may be software modules that are present, for example, on a microcontroller in addition to other software modules. Also of advantage is a computer program product with program code which is stored on a machine-readable carrier such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out the evaluation when the program is executed by the evaluation and control unit.

By the provisions and refinements recited in the dependent claims are advantageous improvements of the independent claim 1 data recorder for a vehicle and specified in the independent claim 8 device for a vehicle to provide at least one safety function and / or at least one vehicle function, in particular an automated driving function , possible.

It is particularly advantageous that the accident-relevant data comprise vehicle surroundings data and / or vehicle condition data which provides at least one vehicle sensor system. In the present case, the vehicle sensor system is understood to mean an assembly which comprises at least one sensor element which directly or indirectly detects a physical variable or a change in a physical variable and preferably converts it into an electrical sensor signal. The vehicle sensor system can include, for example, pressure-sensitive sensor elements which determine an impact area on the vehicle, and / or acceleration sensor elements which detect acceleration-relevant information of the vehicle, and / or sensor elements which determine objects and / or obstacles and / or other crash-relevant vehicle surroundings data and are available for evaluation put. Such sensor elements may for example be based on video and / or radar and / or lidar and / or PMD and / or ultrasound technologies. In addition, signals and information of an existing ABS sensor system and the variables derived in the control unit provided can also be evaluated. Based on the acceleration-relevant information and / or variables determined therefrom, it is possible, for example, to estimate a vehicle movement and a vehicle position in three-dimensional space, wherein the currently estimated vehicle position in the room can be evaluated for rollover detection and evaluated as a normal driving state or as a rollover. For position determination and satellite signals, such as GPS signals can be received and evaluated.

In an advantageous embodiment of the data recorder of the memory device, a buffer battery can be assigned, which supplies the evaluation and control unit and the ring memory for performing a memory functionality for a predetermined period of time after failure of a supply voltage with energy. As a result, accident-relevant data can be advantageously stored even after an accident and taken into account in the subsequent evaluation. The backup battery may be arranged in the memory device, for example. In addition, it is possible that the backup battery also supplies other devices of the device for providing at least one safety function and / or at least one vehicle function for a predetermined period of time after the supply voltage has failed. Therefore, the backup battery can also be arranged at a different mounting location than in the storage device.

In a further advantageous embodiment of the data recorder, the ring buffer can be designed as a nonvolatile rewritable phase change memory (PCRAM: Phase-Change Random Access Memory) whose operating principle is based on a phase change of a used memory material. The memory material used can be in amorphous phase, which represents a high electrical resistance and a reset state, or in crystalline phase, which has a low electrical resistance and a set State represents. By appropriate current pulses, the memory material can be switched between the two phase states.

Alternatively, the ring buffer can be embodied as a ferroelectric rewritable memory (FeRAM: Ferroelectric Random Access Memory) whose operating principle is based on the ferroelectric properties of a storage material used. The ferroelectric memory material has a permanent electrical polarization even without an external electric field. The storage principle of the FeRAMS is based on the fact that this polarization can be switched by an external electric field in another direction.

In addition, the ring buffer can alternatively be designed as a magnetoresistive rewritable memory (MRAM) (magnetoresistive random access memory), whose operating principle is based on magnetic properties of a storage material used. The magnetoresistive memory material changes its electrical resistance under the influence of magnetic fields, so that the information can be stored with magnetic charge carriers.

An embodiment of the invention is illustrated in the drawing and will be explained in more detail in the following description. In the drawing, like reference numerals designate components that perform the same or analog functions.

list of figures

• 1 shows a schematic block diagram of an embodiment of a data recorder according to the invention for a vehicle.

Embodiments of the invention

How out 1 can be seen includes the illustrated embodiment of a data recorder according to the invention 1 for a vehicle, a storage device 10 which an evaluation and control unit 12 and a ring buffer 14 includes. The evaluation and control unit 12 continuously stores accident-relevant data in the ring buffer 14 which are suitable to reconstruct an accident, the oldest data in the ring memory 14 be overwritten by the latest data. Here, the vehicle comprises at least one autonomous driving function, which at least partially assumes an actual driving task, wherein the evaluation and control unit 12 Time and geolocation of the assumption of the actual driving task by the at least one driving function in the ring memory 14 which is implemented as a non-volatile rewritable memory NVRAM whose memory cells receive their bistable memory state without power supply.

In the illustrated exemplary embodiment, the accident-relevant data comprise vehicle surroundings data and / or vehicle condition data, which include at least one vehicle sensor system 3 provides.

The ring buffer 14 is executed in the illustrated embodiment as a rewritable phase change memory PCRAM whose operating principle is based on a phase change of a memory material used. In alternative embodiments, not shown, the ring memory 14 as a ferroelectric rewritable memory (FeRAM) whose operating principle is based on the ferroelectric properties of a storage material used, or as a magnetoresistive rewritable memory (MRAM) are performed, the operating principle based on magnetic properties of a memory material used.

In addition, the storage device may 10 a buffer battery are assigned, which the evaluation and control unit 12 and the ring buffer 14 to run a memory functionality for a predetermined period of time after failure of a supply voltage supplied with energy. As a result, even after an accident data can still be recorded and stored.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19939468 A1 [0003]

Claims (9)

Data recorder (1) for a vehicle, comprising a memory device (10) which comprises an evaluation and control unit (12) and a ring memory (14), wherein the evaluation and control unit (12) continuously stores accident-relevant data in the ring memory (14) which are suitable to reconstruct an accident, wherein the oldest data in the ring memory (14) are overwritten by the latest data, characterized in that the vehicle comprises at least one autonomous driving function, which at least partially assumes an actual driving task, wherein the evaluation and Control unit (12) stores the time and geolocation of the assumption of the actual driving task by the at least one driving function in the ring memory (14), which is designed as a non-volatile rewritable memory (NVRAM), receive its memory cells without power supply their bistable memory state. Data recorder (1) to Claim 1 , characterized in that the accident-relevant data comprises vehicle surroundings data and / or vehicle condition data, which provides at least one vehicle sensor system (3). Data recorder (1) to Claim 1 or 2 , characterized in that the memory device (10) is associated with a backup battery, which supplies the evaluation and control unit (12) and the ring memory (14) for carrying out a memory functionality for a predetermined period of time after failure of a supply voltage. Data recorder (1) to Claim 3 , characterized in that the storage device (10) comprises the backup battery. Data recorder (1) according to one of Claims 1 to 4 , characterized in that the ring memory (14) is designed as a rewritable phase change memory (PCRAM) whose operating principle is based on a phase change of a storage material used. Data recorder (1) according to one of Claims 1 to 4 , characterized in that the ring memory (14) is designed as a ferroelectric rewritable memory (FeRAM) whose operating principle is based on ferroelectric properties of a memory material used. Data recorder (1) according to one of Claims 1 to 4 , characterized in that the ring memory (14) is designed as a magnetoresistive rewritable memory (MRAM) whose operating principle is based on magnetic properties of a storage material used. Device for a vehicle for providing at least one safety function and / or at least one vehicle function, in particular an automated driving function, which at least partially assumes an actual driving task, characterized by a data recorder (1), which according to at least one of Claims 1 to 7 is executed. Device after Claim 8 wherein the device comprises the backup battery, wherein the backup battery also supplies power to other devices of the device after failure of the supply voltage for a predetermined period of time.

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