Device and method for monitoring a traction battery of an electric or hybrid vehicle

Abstract

The invention relates to a device (1) for monitoring a traction battery (2) of an electric or hybrid vehicle, wherein the device (1) comprises at least one measuring unit (4) and an evaluation and control unit (8), wherein the evaluation and control unit (8) is configured to detect or determine at least one parameter of the traction battery (2) and / or of battery cells (3) of the traction battery (2) from the data of the at least one measuring unit (4), wherein the at least one parameter is compared with at least one threshold value, wherein the device (1) comprises at least one transmitting unit (9, 10), wherein the evaluation and control unit (8) is configured such that, if the at least one threshold value is exceeded, at least data of the parameter are transmitted to the at least one transmitting unit (9, 10), wherein the transmitting unit (9, 10) is configured such thatat least the transmitted data of the parameter to an external storage device (16), as well as a method.

Description

[0001] The invention relates to a device and a method for monitoring a traction battery of an electric or hybrid vehicle.

[0002] Traction batteries typically consist of numerous battery cells connected in series and, if necessary, in parallel. Due to the cell technology used, monitoring is essential. For example, internal resistance increases at low temperatures, reducing the available current and decreasing efficiency. Conversely, the battery cells must not overheat, as this could lead to cell failure and trigger a chain reaction with neighboring cells. One method is to directly measure the battery cell temperature using temperature sensors or to estimate it based on temperature values ​​(e.g., the ambient temperature). The evaluation and control unit can then adjust the system to maintain the battery cells within a desired temperature range and, if necessary, generate warnings.

[0003] In specific vehicle condition situations, such as after an accident, the sequence of events is usually reconstructed retrospectively. All environmental data and indicators that directly or indirectly influence the driving and vehicle conditions are helpful in this process. In the case of vehicle accidents, these can include, in particular, driving condition parameters such as vehicle speed, lateral acceleration, and yaw rate. From 2024, the recording of this data in temporal relation to an accident situation will be mandatory (event-related data storage; UN Regulation No. 160; EU Regulation No. 2019 / 2144).

[0004] For this purpose, in-vehicle storage units have already been proposed, which are arranged in a crash-proof housing and are often referred to as a black box.

[0005] An additional option is described in US 8,160,764 B2. This proposes that a vehicle involved in an accident collect data from other nearby vehicles. This collected data, along with time and location information, is then transmitted via a cellular connection to a responsible agency (police or traffic control center) so that they can respond quickly to the accident. If a cellular or satellite connection is not possible, the data can also be transmitted to a traffic infrastructure using an alternative transmission method, from where it is then forwarded to the responsible agency.

[0006] From DE 10 2010 001 006 A1 a method is known for providing at least one piece of information about an accident in which at least two vehicles are involved, in which the accident is registered by at least one sensor of at least one of the vehicles involved and transmitted to another vehicle, which can also be done by means of C2C communication.

[0007] From DE 10 2010 028 996 A1 a method for configuring a control unit of a vehicle is known.

[0008] From DE 10 2020 214 180 A1, a method for determining a state variable of an electrical energy storage device using a state model based on at least one curve of at least one operating variable is known, comprising the following steps: - Recording the at least one curve of the at least one operating parameter that characterizes the operation of the electrical energy storage device, with a predetermined normal recording frequency, whereby the recording frequency is increased in the event of a fault.

[0009] From US patent 2019 / 0 036 178 A1, a device for monitoring a traction battery of an electric or hybrid vehicle is known, wherein the device comprises at least one measuring unit and an evaluation and control unit, the evaluation and control unit being configured to acquire or determine at least one parameter of the traction battery and / or battery cells of the traction battery from the data of the at least one measuring unit. The at least one parameter is compared with at least one threshold value. It is further disclosed therein that the parameters are transmitted to an external storage device.

[0010] The invention addresses the technical problem of creating a device for monitoring the traction battery of an electric or hybrid vehicle that can provide more meaningful data in specific vehicle situations. A further technical problem is the provision of a suitable method.

[0011] The solution to the technical problem is achieved by a device having the features of claim 1 and a method having the features of claim 8. Further advantageous embodiments of the invention are set forth in the dependent claims.

[0012] The device for monitoring a traction battery of an electric or hybrid vehicle comprises at least one measuring unit and an evaluation and control unit, wherein the evaluation and control unit is configured to acquire or determine at least one parameter of the traction battery and / or battery cells of the traction battery from the data of the at least one measuring unit, wherein the at least one parameter is compared with at least one threshold value. The device further comprises at least one transmitting unit. The evaluation and control unit is configured such that, if the at least one threshold value is exceeded, at least data of the parameter are transmitted to the at least one transmitting unit, wherein the transmitting unit is configured to send at least the transmitted data of the parameter to an external storage device.Furthermore, the evaluation and control unit is designed to adjust a measurement cycle (i.e., how frequently the measured values ​​are recorded) of the at least one measuring unit and / or a transmission cycle to the at least one transmitting unit (i.e., how frequently the transmitting unit receives data) depending on whether at least one further threshold value of at least one parameter is exceeded or depending on whether a hazardous situation is classified based on the parameters.

[0013] This offers several advantages. For example, when determining the cause of an accident due to a failure or malfunction of the traction battery, the data immediately before the accident may not be particularly informative if stored in a black box. Furthermore, in accidents where the traction battery is the cause or is affected, there is the possibility of a vehicle fire, which would prevent or hinder the evaluation of data from an internal vehicle black box. The invention addresses this by proactively transmitting data of at least one parameter to the external storage device via the transmitter unit when at least one threshold value is exceeded, ensuring that this data is available for evaluation even in the event of a vehicle fire.Furthermore, the threshold setting and data transmission can be designed to prevent critical driving or vehicle conditions. This prevention can be achieved through external intervention, such as relocating the vehicle to a non-critical location, or through internal vehicle responses, such as controlling energy consumption or output. The external storage device could be, for example, a cloud service or a server belonging to an OEM or government agency. This also provides more data, thus improving root cause analysis. Data transmission can be periodic, for example, sending parameter data every 10 seconds. The transmission cycle can also be adjusted.For example, if another threshold is exceeded, the time interval between two data transmissions can be shortened.

[0014] In another embodiment, the at least one transmitting unit is configured as a mobile communication interface and / or as a CAR2X interface. Preferably, both transmitting units are present. It can be provided that transmission always occurs in parallel (redundantly) via both transmitting units. Preferably, however, transmission normally takes place via the mobile communication interface, switching to the CAR2X interface if network coverage is lacking. The data can then be transmitted to an infrastructure (e.g., a Road Side Unit, or RSU) and from there to the external storage device. Alternatively or additionally, the data can also be transmitted to other vehicles, which then forward the data (e.g., to other vehicles or an RSU). The other vehicles are thus used as intermediate storage or relay stations.

[0015] In another embodiment, the data is transmitted in encrypted form from the sending unit, so that it is only accessible to authorized persons. Alternatively or additionally, the data can also be compressed.

[0016] In another embodiment, the at least one transmitting unit is designed to send authentication information with the data, so that the external storage device and / or the infrastructure and / or the other vehicles know that the data comes from a trusted source.

[0017] In a further embodiment, a plurality of measuring units are provided, wherein the measuring units are configured to detect or determine parameters for recording or determining the temperature and / or pressure of the battery cells and / or the voltage of the battery cells and / or the current of the traction battery. Particularly in the event of a subsequent vehicle fire, the temporal development of the temperature is of special importance in order to determine the cause.

[0018] In a further embodiment, the at least one transmitting unit is configured to send additional vehicle status data to the external storage device, in addition to the traction battery parameters. This additional vehicle status data includes, for example, acceleration values ​​of a vehicle body, which may be relevant for troubleshooting. For instance, high vertical acceleration could be the cause of mechanical damage to the traction battery. Furthermore, data from other units, such as drive, brake, and / or steering units, can also be transmitted.

[0019] In a further embodiment, the device has at least one internal storage unit, wherein the device is designed such that data of the at least one parameter are stored in the internal storage unit when at least one threshold value is exceeded.

[0020] With regard to the procedural design of the invention, full reference is made to the preceding statements concerning the device.

[0021] The invention is explained in more detail below with reference to a preferred embodiment. The single figure shows a schematic block diagram of a device for monitoring a traction battery of an electric or hybrid vehicle.

[0022] In the Fig.Figure 1 is a highly schematic block diagram of a device 1 for monitoring a traction battery 2. The traction battery 2 has a plurality of battery cells 3 connected in series. The device 1 has a plurality of measuring units 4, which are configured, for example, as current sensors 5, temperature sensors 6, and voltage sensors 7. The temperature sensors 6 and voltage sensors 7 can each be assigned to a battery cell 3, although for clarity, this is only shown for the uppermost battery cell 3. Furthermore, the device 1 has an evaluation and control unit 8, which is implemented, for example, in a battery management control unit. The device 1 also has two transmitter units 9 and 10, the first transmitter unit 9 being configured as a mobile communication interface and the second transmitter unit 10 being configured as a CAR2X interface.The evaluation and control unit 8 is connected to the two transmitter units 9 and 10 via a bus system 11. The device also includes cell controllers 12, which are connected to the evaluation and control unit 8 via another bus system 13. Further vehicle control units 14 and an internal storage unit 15 are connected to the bus system 11. An external storage device 16 and an infrastructure 17, which may consist of a large number of roadside units, are also provided. The infrastructure 17 is connected to the external storage device 16 via a network 18. The network 18 can, for example, be a wired network.

[0023] The cell controllers 12 are assigned to groups of battery cells 3 and read the data from the assigned measuring units 4, transmitting this data, possibly already processed, to the evaluation and control unit 8. The evaluation and control unit 8 then evaluates the data and transmits availability data to a drive control unit (not shown). Furthermore, the evaluation and control unit 8 may initiate cell balancing to compensate for voltage differences between the battery cells 3.

[0024] If, for example, the evaluation and control unit 8 detects that the temperature of a battery cell 3 exceeds a threshold (e.g., >40°C), the evaluation and control unit 8 can, for example, inform the drive control unit that less power should be drawn from the traction battery 2 in order to thermally stabilize battery cell 3. At the same time, exceeding the threshold acts as a trigger, causing the evaluation and control unit 8 to transmit data on the parameters of the traction battery 2 and the battery cells 3 (i.e., temperature, voltage, and current) to the transmitter units 9 and 10. The transmitter unit 9 then transmits the data wirelessly via the cellular interface to the external storage device 16, where the data is stored. Preferably, the data is encrypted and compressed. This process is repeated cyclically as long as the threshold is exceeded. If a further threshold is then exceeded (e.g.,If the temperature exceeds 60°C, the cycle time can be adjusted. The measurement cycles and intervals can also be adjusted. Should a total failure occur (e.g., the traction battery catches fire), all relevant measurement data for later reconstruction of the fault cause are securely stored in the external storage device 16, even if the internal storage unit 15 also burns out. In cases where the transmitter unit 9 cannot transmit the data (e.g., due to a dead zone or lack of network coverage), the system switches to the second transmitter unit 10, which then transmits the data to the infrastructure 17 and / or other vehicles via an alternative, short-range communication method. For this purpose, the second transmitter unit 10 uses, for example, a WLAN and / or Bluetooth connection. This ensures high availability for data transmission.It can also be provided that the transmitter unit 9 or another control unit has data about network coverage, so that the switchover from the first transmitter unit 9 to the second transmitter unit 10 can take place in advance, i.e., before the vehicle enters a dead zone. This prevents a data transmission that has already started from suddenly breaking down in a dead zone and then having to be repeated via the second transmitter unit 10. Reference symbol list 1 Device 2 traction batteries 3 battery cells 4 Unit of measurement 5 Current sensor 6 Temperature sensor 7 Voltage sensor 8 Evaluation and control unit 9 first transmitting unit 10 second transmitting unit 11 Bus system 12 cell controllers 13 Bus system 14 Vehicle control unit 15 internal storage units 16 external storage devices 17 Infrastructure 18 Network

Claims

[1] Device (1) for monitoring a traction battery (2) of an electric or hybrid vehicle, wherein the device (1) comprises at least one measuring unit (4) and an evaluation and control unit (8), wherein the evaluation and control unit (8) is configured to detect or determine at least one parameter of the traction battery (2) and / or of battery cells (3) of the traction battery (2) from the data of the at least one measuring unit (4), wherein the at least one parameter is compared with at least one threshold value, wherein the device (1) comprises at least one transmitting unit (9, 10), wherein the evaluation and control unit (8) is configured such that, if the at least one threshold value is exceeded, at least data of the parameter are transmitted to the at least one transmitting unit (9, 10), wherein the transmitting unit (9, 10) is configuredat least the transmitted data of the parameter to an external storage device (16), wherein the evaluation and control unit (8) is designed to adapt a measurement cycle of the at least one measuring unit (4) and / or a transmission cycle to the at least one transmitting unit (9, 10) depending on the exceedance of at least one further threshold value of at least one parameter or depending on a classification of a hazardous situation based on the parameters. [2] Device according to claim 1, characterized by , that at least one transmitting unit (9, 10) is designed as a mobile communication interface and / or as a CAR2X interface. [3] Device according to claim 1 or 2, characterized by , that the at least one transmitting unit (9, 10) is designed in such a way that the data is encrypted. [4] Device according to any of the preceding claims, characterized by, that the at least one transmitting unit (9, 10) is designed to send authentication information with the data. [5] Device according to any of the preceding claims, characterized by , that a plurality of measuring units (4) are provided, wherein the measuring units (4) are designed to detect or determine parameters for detecting or determining a temperature of the battery cells (3) and / or a pressure of the battery cells (3) and / or a voltage of the battery cells (3) or a current of the traction battery (2). [6] Device according to any of the preceding claims, characterized by , that the at least one transmitting unit (9, 10) is designed to send additional vehicle status data to the external storage device (16) in addition to the parameters of the traction battery (2). [7] Device according to any of the preceding claims, characterized bythat the device (1) has at least one internal storage unit (15), wherein the device (1) is designed such that data of the at least one parameter are stored in the internal storage unit (15) when at least one threshold value is exceeded. [8] Method for monitoring a traction battery (2) of an electric or hybrid vehicle, using at least one measuring unit (4) and an evaluation and control unit (8), wherein the evaluation and control unit (8) detects or determines at least one parameter of the traction battery (2) and / or of battery cells (3) of the traction battery (2) from the data of the at least one measuring unit (4), wherein the at least one parameter is compared with at least one threshold value, wherein, if the at least one threshold value is exceeded, the evaluation and control unit (8) transmits at least data of the parameter to at least one transmitting unit (9, 10), which sends at least the transmitted data of the parameter to an external storage device (16),wherein the evaluation and control unit (8) adapts a measurement cycle of the at least one measuring unit (4) and / or a transmission cycle to the at least one transmitting unit (9, 10) depending on whether a further threshold value of at least one parameter is exceeded or depending on whether a hazardous situation is classified based on the parameters. [9] Method according to claim 8, characterized by that the data is sent via a mobile communication interface and / or a CAR2X interface.

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