Vehicle, driver assistance system and method for processing fault conditions

Abstract

The invention relates to a vehicle (10), to a driver assistance system, and to a method for handling a fault situation of a vehicle (10) having a high-voltage on-board electrical system (1) and a low-voltage on-board electrical system (2). The method comprises the following steps: automatically determining a fault of the vehicle (10); automatically determining that the energy conversion from the HV on-board electrical system (1) to the low-voltage on-board electrical system (2) is unsuccessful; automatically determining a state of charge of an energy store (3) of the low-voltage on-board electrical system (2); the criticality of the vehicle condition is automatically determined; and based on the aforementioned information, automatically deciding whether and if so, which measures are to be taken or to be suggested for securing the vehicle safety and / or the occupant safety.

Description

Technical Field

[0001] The present invention relates to a vehicle, a driver assistance system, and a method for handling fault situations in an electrically driven vehicle. In particular, the present invention relates to measures for shutting down electrical consumers in the event of a fault, so that the reduced energy resources of the low-voltage onboard electrical system in a hybrid vehicle can be used as effectively as possible for safety protection in the event of a fault. Background Art

[0002] The electrification of personal transportation is currently progressing rapidly. In addition to high-voltage onboard electrical systems (voltages above 60V or 80V DC), low-voltage onboard electrical systems, typically 12V or 24V, are generally maintained. Appropriate energy storage devices (accumulators, batteries) are available to supply energy for use in the respective onboard electrical systems and to support / buffer the respective onboard electrical systems. With increasing electrification and the shift in electrical energy content toward the high-voltage onboard electrical system, smaller energy storage devices are being installed in the low-voltage onboard electrical system area. This is particularly true for weight and efficiency reasons, as, for example, starting the internal combustion engine is no longer necessary (if it is not present), or the internal combustion engine has lower power and requires less energy to start, or the high-voltage onboard electrical system is used to start the internal combustion engine. In the event of a vehicle failure while the high-voltage onboard electrical system or the 48V onboard electrical system remains intact, the ability to convert energy from the high-voltage onboard electrical system to the low-voltage onboard electrical system ensures sufficient energy for vehicle safety (primarily for warning and exterior lighting). The situation is different if only the 12V storage device carries the load and must independently power the warning and exterior lighting. In this case, the vehicle's safety in the event of a fault is significantly reduced. In particular, vehicles known from the prior art do not take appropriate measures to ensure sufficiently long-term availability of the warning and exterior lighting. Summary of the Invention

[0003] According to the present invention, the aforementioned object is achieved by a method for handling fault situations in an electrically driven vehicle having a high-voltage onboard electrical system and a low-voltage onboard electrical system. Within the scope of this disclosure, the term "fault" is understood to mean a vehicle state in which, due to a technical defect or unavailability of energy, the functions necessary for propulsion are not available, and energy transfer between the high-voltage onboard electrical system and the low-voltage onboard electrical system is prevented. In other words, the vehicle cannot or should not be moved in the event of a fault. Causes of a "fault" can include other electrical problems, such as a dead traction battery, a defective converter, a defective cable to the low-voltage onboard electrical system, etc., as well as traditional fault situations (tire failure, motor damage, etc.).

[0004] According to the present invention, the fault is automatically detected in a first step. This can be accomplished using suitable sensors in the vehicle. However, a fault in the sense of the present invention differs from an "accident" at least in that the fault itself does not automatically trigger an airbag or an emergency call. In other words, the external influence (if any) is so minimal that there is no (initially) direct health risk to the occupants of the vehicle.

[0005] In the second step, it is detected that the energy conversion from the high-voltage onboard electrical system to the low-voltage onboard electrical system was unsuccessful. In other words, it can be automatically determined that the low-voltage onboard electrical system cannot be supported by the energy resources available in the high-voltage onboard electrical system. This may be because no high-voltage energy source is available or the conversion or transfer of high-voltage energy to the low-voltage onboard electrical system cannot be performed. In other words, the long-term (optical) safety of the vehicle is compromised due to the low capacity of the energy storage device in the low-voltage onboard electrical system. In the third step, the state of charge of the energy storage device in the low-voltage onboard electrical system is then automatically determined. For example, it can be determined that the energy storage device is in a predetermined good state of charge and ensures relatively long-term safety of the vehicle. In a further step, a certain criticality of the vehicle situation is automatically determined. Criticality can also be understood as a dangerous state of the vehicle or a dangerous state caused by the vehicle or its occupants. For example, the potential danger in the emergency lane of a highway is greater than in a parking lot or in a home garage. A crime rate determined for the vehicle's location can also be automatically determined and taken into account in determining the criticality of the vehicle situation. Alternatively or additionally, weather conditions (intense heat / solar radiation, storms, etc.) may also contribute to or lead to a critical level. Based on all of this information, the present invention automatically determines whether, and if so, which measures are to be automatically taken or automatically recommended for the safety of the vehicle and / or its occupants. Taking measures can also be understood as initiating these measures. Recommending measures, on the other hand, results in a notification to the vehicle user (e.g., the driver), who can then independently initiate the introduction of these measures. In particular, this can be indicated to the user via a prompt on the screen, and upon accepting the prompt, the recommended measures can be initiated using a predetermined button panel. Consequently, despite reduced energy availability, the safety of the vehicle can still be ensured, depending on the situation.

[0006] The dependent claims present preferred further developments of the present invention. The criticality can take into account various parameters of the vehicle's condition. To this end, in addition to the vehicle's own system values, external conditions such as traffic volume, date and season, lighting and visibility conditions, and regional risks (such as crime, landslide risk, rockfall risk, etc.) based on satellite positioning (geolocation) can also be inferred. In particular, digital map material can be used to estimate the location of the fault and assess its criticality. However, the criticality can also take into account conditions within the passenger compartment. For example, elderly, infirm, or very young passengers may be present in the vehicle's interior and lead to an increased criticality level. In particular, in cases where external or inherent conditions can be considered a hazard to the occupants, the criticality can be increased due to the detected occupants. For example, occupants can be determined using cameras, pressure sensor mats for seat occupancy detection, interior temperature, and the like. Vitality sensors and (non-contact) temperature sensors, which are sometimes proposed in the prior art for detecting body temperature, can be used to draw further conclusions about the occupants' criticality.

[0007] The high-voltage onboard electrical system can have a voltage of at least 60 V, preferably at least 400 V or even 800 V, while the low-voltage onboard electrical system can have a voltage of 6 V to 20 V, but at most 48 V. The aforementioned voltages particularly relate to a DC onboard electrical system or respectively to individual DC onboard electrical systems.

[0008] A vehicle may have a traction engine that, in the event of a fault, is no longer operational or should no longer be operational. In particular, the traction engine may no longer be able to support the low-voltage onboard electrical system by switching to fossil fuels. According to the present invention, measures are therefore initiated or recommended to adjust the safety protection of the vehicle or its occupants in a graded manner and according to the respective availability level of electrical or electrochemical resources.

[0009] The low-voltage onboard electrical system can be supplied with energy by means of an energy store, wherein the electrochemical energy store has a capacity of no more than 50 ampere hours, preferably a smaller capacity of 10 ampere hours or more.

[0010] The criticality of the vehicle situation can be determined using sensors for satellite-based positioning in conjunction with digital road maps. Road areas or road categories can be used here, which represent the speed, width, and avoidance options of the flowing traffic in the digital map material and are therefore used for information about the criticality of the geographically specific vehicle situation.

[0011] If the energy stored in the low-voltage onboard electrical system is further depleted, a decrease in the state of charge and / or an increase in the criticality of the vehicle's situation can be automatically detected (particularly by sensors). In response, a decision can be automatically taken or suggested to the user to implement additional measures to protect the vehicle and / or the safety of the occupants. For example, to conserve energy resources, a decision can be made to switch off the interior lighting, interior air conditioning, entertainment functions, or even (separately) the exterior lighting. This reduces the signaling effect of the safety measures, but the maximum duration of the exterior lighting (even if it is also reduced) can be extended.

[0012] In particular, it can also be determined that assistance is approaching. This can be automatically communicated to the vehicle, for example. For example, a notified breakdown service can send a message to the vehicle (e.g., a telemetry unit), in response to which an expected arrival time can be determined. The expected arrival time can in turn be used to determine whether the criticality of the vehicle's condition will persist for an extended period, and therefore to maintain increased energy consumption for the best possible safety or occupant protection measures or occupant entertainment measures, which must be disabled for precautionary reasons if the arrival time of the breakdown service is unknown.

[0013] Below are some examples of measures that can be used to conserve energy resources in the low-voltage onboard electrical system in the event of a fault. For example, a notification can be issued to the user of the vehicle, in response to which the user can initiate measures to conserve energy resources. In addition, automatic shutdown of a first group of electrical consumers can be recommended or automatically executed. Alternatively or additionally, shutdown of other groups of electrical consumers can also be recommended or automatically performed. For example, an emergency call (not yet dialed) can also be recommended or automatically established to inform rescue forces of a critical or reduced energy level (which may have increased in the meantime). Alternatively or additionally, the shutdown of a predetermined area of ​​the vehicle's exterior lighting can be automatically switched off or recommended.

[0014] Therefore, once the strategy for operating the onboard electrical system according to the present invention switches to emergency mode, energy consumption can be reduced in stages, depending on the state of charge (SOC). To this end, individual consumers or groups of consumers can be separated from the energy supply in a time-determined manner within a predetermined group of consumers. In particular, it is possible to communicate to the user which consumers are no longer available and for what reason. In particular, it is possible to communicate how long the safety measures for the vehicle can still be maintained or how long they can be extended by corresponding shutdowns. This increases user acceptance of the proposed measures.

[0015] In particular, when a predefined charge level threshold is reached, a prioritized emergency call or “breakdown call” can be sent to the service provider. This communicates the increased criticality and allows the handling of the own vehicle to be prioritized.

[0016] In particular, when a predefined criticality level is reached, another service provider (rescue forces, etc.) can also be automatically called or the user can be advised to establish contact with the other service provider.

[0017] According to a second aspect of the present invention, a driver assistance system is provided, which can implement the aforementioned method steps. The driver assistance system includes a data input and an evaluation unit, whereby the driver assistance system is configured to automatically determine a vehicle fault using the data input. In other words, it is determined in the vehicle's onboard electrical system that the vehicle cannot or should not proceed any further. Furthermore, it is automatically determined using the data input that the conversion of energy stored in the high-voltage onboard electrical system into energy in the low-voltage onboard electrical system is no longer successful (e.g., because it is no longer possible or for other reasons). Furthermore, the driver assistance system is configured to automatically determine the state of charge of the energy storage device of the low-voltage onboard electrical system and the criticality of the vehicle's situation (e.g., based on the vehicle's geographic location) using the data input, and to automatically decide, based on this information, whether and, if so, which measures to take (if necessary, automatically) or to recommend (automatically) to a user for vehicle safety and / or occupant safety. In this way, the driver assistance system according to the present invention is configured to clearly and appropriately implement the features, combinations of features, and the resulting advantages of the method according to the present invention, so that reference is made to the above description to avoid repetition.

[0018] According to a third aspect of the present invention, a vehicle is provided, which can be designed as a car, a truck, a motorcycle, an air vehicle, and / or a water vehicle. The vehicle comprises a driver assistance system according to the second aspect of the invention, resulting in the same features, feature combinations, and advantages for the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Further details, advantages and features of the present invention can be gathered from the following description of exemplary embodiments based on the accompanying drawings. In the drawings:

[0020] Figure 1 shows a fault situation of a vehicle designed according to the invention, which has an embodiment of a driver assistance system designed according to the invention;

[0021] Figure 2A schematic diagram shows a group of consumers according to an exemplary embodiment of the present invention, which can be automatically switched off individually and, in particular, over time.

[0022] Figure 3 a flow chart showing the steps embodying an embodiment of a method for handling a fault condition of a vehicle according to the present invention; and

[0023] Figure 4 A schematic diagram of a low-voltage onboard electrical system with a plurality of individually switchable electrical consumers is shown. DETAILED DESCRIPTION

[0024] Figure 1 The diagram shows a situation in which a passenger car, in the form of an electrically driven vehicle 10, is traveling in the emergency lane of a highway 20. Vehicle 10 has a tire failure, so a user 7 is traveling upstream or against the direction of travel with a warning triangle to ensure safety at the location of the failure. The high-voltage energy storage 5, which normally supplies electrical energy to the traction engine 4, is still largely operational. The DC / DC converter 21 is also largely operational to convert the electrical energy present in the high-voltage onboard electrical system 1 to the voltage level of the low-voltage onboard electrical system 2. However, a line interruption 22 means that the energy stored in the energy storage 3 of the low-voltage onboard electrical system 2 is no longer sufficient for operating the exterior lighting 23. Consequently, a child 26 left in vehicle 10 can no longer enjoy the air conditioning of the interior of vehicle 10 for an extended period. Therefore, the data output 8 of the electronic control unit 9 prompts the sensor antenna 6 to notify the transmitting antenna mast 19 that vehicle 10, at its current position (determined using geostationary satellites 18), urgently requires assistance from the breakdown service. Information about the status and criticality of the situation of vehicle 10 can be communicated to the nearest location of a car club, for example, via the Internet via the transmitting antenna mast 19 , so that help can arrive in time before other comfort features of vehicle 10 reduce the protection of the vehicle's occupants.

[0025] Figure 2 A schematic diagram shows low-voltage consumers 11, which are divided into groups 12, 13, 14, 15, 16, and 17. Groups 12 through 17 are assigned different priority categories and can be prioritized differently, particularly depending on the current external temperature, ambient light intensity, or the vehicle. For example, when the external temperature is cold, the vehicle's air conditioning may be completely unimportant, while the heating function is very important for the safety of the vehicle's occupants. On the other hand, exterior lighting is significantly less important for ensuring vehicle safety during the day than at night. Therefore, the order in which groups 12 through 17 are switched off can be varied depending on these circumstances.

[0026] Figure 3 The following illustrates the steps of an exemplary embodiment of a method for handling a vehicle fault according to the present invention. In step 100, a vehicle fault is automatically determined. To this end, the vehicle's electronic control unit can challenge or deny the vehicle's drive-ready state. In step 200, it is then automatically determined that energy stored in the high-voltage onboard electrical system cannot be converted into low-voltage energy. For example, an energy converter (e.g., a DC / DC converter) may be defective. In step 300, the state of charge of the energy storage device of the low-voltage onboard electrical system is automatically determined. This may include, for example, measuring the voltage of the energy storage device. In step 400, the criticality of the vehicle's condition is then automatically determined. Based on all of the aforementioned information, a decision is automatically made in step 500 regarding whether and, if so, which measures should be taken to protect the vehicle and / or its occupants' safety, and if so, which measures should be taken or automatically recommended to the user. In other words, a decision is made regarding which electrical consumers should be shut down or continue to be used to ensure the safety of the vehicle or its occupants, taking into account the actual fault condition. Thus, in step 600, a message is output to the vehicle user: in step 700, a first group of consumers is switched off; in step 800, another group of consumers is also switched off (after a predetermined time period); in step 900, an emergency call is automatically initiated; and finally, in step 1000, a predetermined area of ​​the vehicle's exterior lighting is switched off. This can particularly involve an area of ​​the exterior lighting that faces away from the nearest approaching traffic. For example, a rearview camera and / or a front camera can be used to determine the direction from which vehicles are most densely passing the stationary vehicle, and only the area of ​​the exterior lighting facing these vehicles continues to operate, while all other consumers are switched off.

[0027] Figure 4 An exemplary topology of a low-voltage onboard electrical system 2 in an embodiment of a vehicle according to the present invention is shown. A low-voltage battery 3 supplies power to a battery management control unit 24, which provides a 12 V DC voltage to a busbar. Electrical consumers 11, organized into groups 12, 13, and 14, are connected to the busbar. Furthermore, an external starting point 25 and the low-voltage input of a voltage converter 21 are connected to the busbar. The battery management control unit 24 can individually and as needed shut down electrical consumers 12, 13, and 14 via switches to conserve energy resources of the low-voltage battery 3. Reference Signs List

[0028] 1 High voltage onboard power grid

[0029] 2Low voltage onboard power grid

[0030] 3Electric energy storage

[0031] 4 traction machine

[0032] 5 Traction energy storage

[0033] 6 antennas

[0034] 7 users

[0035] 8Data output unit

[0036] 9 Electronic control unit

[0037] 10. Transportation

[0038] 11 Electrical equipment

[0039] 12 to 17 electrical equipment groups

[0040] 18 satellites

[0041] 19 Transmitting antenna mast

[0042] 20 Highway

[0043] 21 Energy Converter

[0044] 22 Line interruption department

[0045] 23Exterior lighting fixtures

[0046] 24 battery management control device

[0047] 25 external starting basis points

[0048] 26 children

[0049] 100 to 1000 method steps

[0050] S switch

Claims

1. A method for handling a fault situation of a vehicle (10) having a high voltage (hereinafter referred to as "HV") on-board electrical system (1) and a low voltage on-board electrical system (2), the method comprising the following steps: · Automatically determine (100) a malfunction of a vehicle (10); Automatic determination (200): Energy conversion from the HV onboard electrical system (1) to the low-voltage onboard electrical system (2) was unsuccessful; Automatically determining (300) a state of charge of an energy storage device (3) of a low-voltage onboard electrical system (2); · automatically determining (400) the criticality of the vehicle condition; and based on the foregoing information: Automatically decide (500) whether and, if so, which measures are to be taken or recommended for protecting the safety of the vehicle and / or protecting the safety of the occupants.

2. A method according to any one of the preceding claims, wherein: The HV onboard electrical system (1) has a voltage of at least 400V, in particular 800V, and the low-voltage onboard electrical system (2) has a voltage of 12V to 48V.

3. A method according to any one of the preceding claims, wherein: Due to the fault, the vehicle (10) can no longer participate in road traffic or can no longer participate in road traffic safely, in particular the airbag or the automatic voice link is not triggered and in particular the traction machine (4) can no longer be operated.

4. A method according to any one of the preceding claims, wherein: The low-voltage onboard electrical system (2) is supplied with power by means of an energy storage device (3), which has a capacity of 10 Ah to 50 Ah.

5. A method according to any one of the preceding claims, wherein: The criticality of the vehicle's situation is determined using a sensor (6) for satellite-based positioning in conjunction with a digital road map.

6. A method according to any one of the preceding claims, wherein: The fault is characterized by: an error in a system related to the travel or driving of the vehicle (10), and / or Tire defects, and / or failure of the fuel supply and / or traction energy supply, Errors in the cooling system, Errors in the connection system, in particular short circuits or line interruptions, Software errors.

7. The method according to any one of the preceding claims, further comprising: - Determine a decrease in charge state and / or an increase in criticality and in response thereto: - Decide on measures to be taken to protect the safety of the vehicle and / or the safety of its occupants.

8. A method according to any one of the preceding claims, wherein: The measures include one or more of the following: - outputting (600) a message to a user (7) of the vehicle (10); - shutting down (700) the first group (12) of electrical equipment (11); - switching off (800) the first group (12) and the further group (13) of electrical consumers; - Initiate (900) or propose emergency call establishment; - Switching off (1000) a predetermined area of ​​an exterior lighting device (23) of a vehicle (10).

9. Driver assistance systems, including: - Data entry department, and - an evaluation unit (9), wherein the driver assistance system is configured to use the data input: Automatically determine a malfunction of a vehicle (10); Automatic determination: energy conversion from the HV onboard electrical system (1) to the low-voltage onboard electrical system (2) was unsuccessful; Automatic determination of the state of charge of the energy storage device (3) of the low-voltage onboard electrical system (2), Automatically determine the criticality of the vehicle condition; and based on the foregoing information: Automatically decide whether and, if so, what measures to take to protect the safety of the vehicle and / or the safety of its occupants. 10 . The driver assistance system according to claim 9 , which is configured to carry out the method according to claim 1 .

11. A vehicle comprising a driver assistance system according to claim 9 or 10.

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