Method for monitoring an on-board network of a motor vehicle

Abstract

The invention relates to a method for monitoring a motor vehicle's onboard network, a safety-relevant consumer and possibly further consumers being supplied by an energy store, an onboard network model being provided which represents the safety-relevant consumer and the corresponding lines with associated line resistances and the connection to the energy store, the method comprising: providing a current profile or a power profile which would be necessary for a determined operation of the motor vehicle with the participation of the safety-relevant consumer, including the basic load of the further consumers; determining a predicted characteristic variable of the energy store using the current profile or the power profile; determining a predicted characteristic variable of the safety-relevant consumer using the current profile or the power profile, the associated line resistances and the predicted characteristic of the energy store, it being assumed that the safety-relevant consumer is loaded with the current profile or the power profile; analyzing the predicted characteristic variable of the safety-relevant consumer.

Description

Technical Field

[0001] This invention relates to a method for monitoring a vehicle-mounted network (Bordnetz) of a motor vehicle according to the present invention. Background Technology

[0002] A method for monitoring a motor vehicle with automated driving functions and an apparatus for performing the method are known from WO 2018 / 077658 A1. Here, at least one characteristic parameter of an energy storage device is predicted based on at least one load characteristic, and the predicted characteristic parameter of the energy storage device is used to enable, prevent, deactivate, or influence an operating mode and / or automated driving function associated with that load characteristic.

[0003] A method for monitoring energy supply in a motor vehicle is known from DE 102018212369 A1, wherein, in a sub-vehicle network, at least one energy storage device supplies energy to a plurality of electrical appliances, preferably safety-related. At least one measurement parameter of the energy storage device and / or at least one electrical appliance is detected, wherein at least one wiring harness model representing the sub-vehicle network is set. A parameter estimator is set that estimates at least one characteristic parameter of the wiring harness model using the measurement parameter.

[0004] A method for operating an electric vehicle is known from DE 102018219222 A1. Here, the charging strategy for the battery is derived based on a mechanical trajectory that represents the torque curve of the vehicle's future operation.

[0005] A method for monitoring in-vehicle networks in motor vehicles is known from DE 102018212770 A1. Here, simulations are used to examine which safe stopping scenario is available under the current battery state and in-vehicle network state. Furthermore, corresponding measures in the in-vehicle network are proposed, and an analysis of the direct impact of these measures on the availability of various scenarios is obtained. Summary of the Invention

[0006] This invention is based on the objective of further improving usability, particularly in the case of in-vehicle networks with high security requirements, such as in relation to automated driving functions. This objective is achieved through a method for monitoring in-vehicle networks of motor vehicles according to the invention.

[0007] In contrast, the method according to the invention has the following advantages: potential faults leading to undervoltage at safety-related electrical appliances are eliminated. The availability of the on-board energy network is improved because the individual thresholds of various components (e.g., the maximum resistance of the lines) can be reduced to a uniform threshold. Various operations, especially driving operations, are satisfied in terms of performance technology. Therefore, faults caused by undervoltage at safety-related electrical appliances are eliminated. Furthermore, the components of the on-board energy network (e.g., energy storage devices) can be made smaller because the corresponding prediction of characteristic parameters of safety-related electrical appliances can be achieved more accurately and targetedly.

[0008] In a suitable extended scheme, if the predicted characteristic parameters are below the limit value, the activation of an operation is rejected, and / or operation matching is performed, and / or corresponding information regarding the executability of the operation is generated. This allows for the exclusion of dangerous operations, or in other words, only those operations that are not of concern are permitted. This increases vehicle availability.

[0009] In a suitable extension scheme, the following steps are set: receiving current characteristics (Stromprofil) or power characteristics (Leistungsprofil) queried by the vehicle control device for a corresponding operation; processing the queried current characteristics into current or power characteristics to be provided by the energy storage device and / or into current or power characteristics for each line used to power safety-related electrical appliances involved in the operation. Therefore, the operation of specific electrical appliances installed in the corresponding in-vehicle network, queried by the vehicle control device, can be accurately converted into the corresponding current characteristics. A unified interface between the vehicle control device and the in-vehicle network monitoring device can be defined.

[0010] In a suitable extension scheme, at least one model of a safety-related electrical appliance is established, and the current or power characteristics of the safety-related appliance are estimated, particularly under different operating conditions, using this model. This allows for particularly simple consideration of different situations using the corresponding current characteristics, further increasing flexibility.

[0011] In a suitable extended solution, the current or power characteristics are determined based on the state of the appliance. Therefore, it is particularly possible to first consider the current basic load of appliances unrelated to safety when assessing and determining operation, and then take countermeasures only at a later time if necessary. Accuracy is increased. Load shutdown may be avoided.

[0012] In a suitable extension scheme, for a given operation, a fixed-defined current or power characteristic is stored. The energy storage device is then predictably loaded with the current or power characteristic based on this fixed-defined characteristic. This simplifies or accelerates the calculation by eliminating the need for other components to provide data.

[0013] In a suitable extended configuration, the model receives sensor data, particularly from the vehicle control unit. This allows for further improvement in accuracy when using the model.

[0014] In a suitable extension scheme, the on-board network model receives line resistance, particularly from wiring harness diagnostics. This further improves the accuracy of the layout by also considering the aging effects in updated line resistance.

[0015] In one suitable extension scheme, a power divider is installed through which safety-related electrical appliances are protected, and this power divider is connected to an energy storage device. Within this power divider, all relevant data for monitoring the vehicle network can be collected, as special protection for safety-related electrical appliances is ultimately implemented there using particularly accurate predictions.

[0016] In one suitable extension configuration, the power divider includes at least one switching device for separating an on-board network branch with safety-related appliances from another on-board network branch that supplies power to safety-independent appliances. This switching device can suppress any negative impact from other on-board network branches on the power supply to safety-related appliances, thereby improving the availability of those appliances.

[0017] In a suitable extended scheme, voltage is used as a predicted characteristic parameter for safety-related electrical appliances. Therefore, potential functional limitations can be predicted particularly easily, and these limitations can also be readily obtained via an onboard network model.

[0018] Further preferred embodiments and extensions that meet the objectives can be derived from the specification. Attached Figure Description

[0019] The attached diagram shows:

[0020] Figure 1 Showing the vehicle network,

[0021] Figure 2 A simplified model of the vehicular network is shown.

[0022] Figure 3The structure of the functional chain is shown.

[0023] Figure 4 This demonstrates the different operations of the vehicle.

[0024] Figure 5 A first embodiment for monitoring in-vehicle networks is shown.

[0025] Figure 6 A second embodiment for monitoring in-vehicle networks is shown.

[0026] Figure 7 This illustrates a third embodiment for monitoring in-vehicle networks. Detailed Implementation

[0027] The invention is illustrated schematically based on embodiments and described in detail below with reference to the accompanying drawings.

[0028] Figure 1 A possible topology of an energy supply system comprising an in-vehicle network 10 is shown. This network includes an energy storage device 12 (particularly a battery 12 with associated sensors 14, preferably battery sensors) and a number of electrical appliances 16, particularly safety-related, which are protected or controlled by a power distributor 18. The electrical appliances 16 refer to special appliances with high requirements or high protection needs, generally referred to as safety-related appliances 16. Examples include electric steering and / or braking systems as components that must be powered in any case to ensure vehicle steering and / or braking in the event of a failure. For this purpose, the corresponding characteristic parameters of the relevant electrical appliance 16 are individually detected, and the corresponding switch 15 is activated to protect the relevant electrical appliance 16 if it deviates from a tolerable value.

[0029] Energy storage device 12 is also connected at one connection terminal (terminal KL30_1) of power divider 18. Sensor 14 is capable of detecting electrical characteristic parameters, such as voltage Ub at energy storage device 12 and / or current Ib through energy storage device 12 and / or temperature Tb of energy storage device 12. Sensor 14 can determine, for example, the state of charge (SOC) of energy storage device 12 or other characteristic parameters of energy storage device 12 from the determined electrical characteristic parameters Ub, Ib, and Tb. Optionally, an additional power supply branch for at least one other appliance 25 is also provided at the other connection terminal (KL30_1) of power divider 18—where energy storage device 12 is also connected. Optional appliance 25 can be protected by fuse 23. Another appliance 25 can also be provided, which can also be protected by fuse 23. These electrical appliances 25 involve appliances that should still be supplied with energy by the energy storage device 12 even when the switching device 19 in the power distributor 18 is open or closed; that is, preferably, appliances 25 that are safety-critical or critical in terms of the generation of interference related to power supply safety. Therefore, a safety-related or safety-critical on-board network path is optionally connected at the connection terminal KL30_1.

[0030] The power divider 18 can determine corresponding characteristic parameters, such as the voltage Uv and current Iv of the appliance 16. Furthermore, the power divider 18 can also determine corresponding characteristic parameters of the energy storage device 12, such as voltage Ub and / or current Ib and / or temperature Tb. For this purpose, the power divider 18 includes corresponding sensing devices. The power divider 18 also has corresponding processing devices, such as a microcontroller 13 for storing or analyzing the detected parameters. The microcontroller 13 can also control the switching device (high-current circuit breaker) of the corresponding switch 15 or switching device 19. Alternatively, the analysis and processing can also be performed in other control devices.

[0031] Electrical appliances 16 powered by power distributor 18 may include, for example, vehicle functions related to safety (e.g., braking, steering, etc.), especially those with high protection requirements. Typically, safety-related electrical appliances 16, 25 involve those particularly worthy of protection, such as those necessary to maintain certain emergency functions. In addition to the described functions (e.g., steering and braking), functions that should remain functional if possible after an accident may also be involved, such as restraint systems, closing systems for opening and closing doors, emergency call systems for making electronic emergency calls, sunroof functions, lighting, etc.

[0032] The basic vehicle network 10 has a lower voltage level U1 than the high-voltage vehicle network 20, for example, it may involve a 14V vehicle network. A DC-DC voltage converter 22 is arranged between the basic vehicle network 10 and the high-voltage vehicle network 20. The high-voltage vehicle network 20 includes, for example, an energy storage device 24 (e.g., a high-voltage battery, possibly with an integrated battery management system), a load 26 (e.g., a comfort appliance, such as an air conditioning unit supplied at a higher voltage level), and a motor 28. In this case, a voltage level U2 higher than the voltage level U1 of the basic vehicle network 10 is understood as high voltage. Thus, for example, a 48V vehicle network may be involved. Alternatively, especially in vehicles with electric drive units, even higher voltage levels may be involved. Alternatively, the high-voltage vehicle network 20 may be completely eliminated.

[0033] Another branch or sub-vehicle network is arranged between the connection terminal (KL30_0) of the power divider 18 and the DC-DC voltage converter 22 to supply additional electrical appliances 17. The respective electrical appliances 17 are protected via corresponding fuses 23, as exemplarily shown. These electrical appliances 17 typically involve comfort appliances or appliances unrelated to safety. Comfort appliances 17 and fuses 23 can be grouped into main groups and subgroups according to the application. This involves electrical appliances 17 that are not characterized by high safety relevance (e.g., appliance 25) or high protection requirements (e.g., appliance 16). The reaction of these appliances 17 to safety-related appliances 25 or 16 can be prevented by isolating faults via an open switch device 19. Therefore, the switch device 19 is arranged between the appliance 17 and the safety-related appliance 25 and / or the appliance 16 with high protection requirements.

[0034] At least one or more, particularly safety-related channels or vehicle network branches 10', can be connected to the high-voltage vehicle network 20 via another DC-DC voltage converter 22'. The safety-related channels may each have an additional electronic power divider 18'. Alternatively, the additional power divider 18' can also be directly connected to the same connection terminal KL30_0 as the power divider 18, without the need for another DC-DC voltage converter 22'. The additional electronic power divider 18' can be used for the protection, control, and safe and reliable shutdown of safety-related appliances 16' or electronic energy network distribution. These appliances 16' can be redundantly configured such that they are powered via other safety-related branches of the vehicle network 10. Furthermore, the additional electronic power divider 18' is capable of detecting the current flowing through the appliances or the applied voltage. This briefly described, optional embodiment can be configured for highly available designs, for example, for autonomous driving, to enhance safety. Additional energy storage devices 12' with additional sensors 14' can also be provided in the additional vehicle network branches.

[0035] For example, in this embodiment, a battery or accumulator is described as a possible energy storage device 12, 24. However, alternatively, other energy storage devices suitable for this task, such as inductive or capacitive devices, fuel cells, capacitors, etc., can be used in the same way.

[0036] Figure 2 A simplified vehicular network model 30 is shown. This vehicular network model, for example, consists of two (i=2) safety-related electrical appliances (16i) 16.1 and 16.2, which are powered by a power divider 18, as also... Figure 1 As shown in more detail in the diagram. Current I1 flows through one appliance 16.1, and another current I2 flows through another appliance 16.2. A first voltage U1 drops at appliance 16.1, and another voltage U2 drops at appliance 16.2. Resistors R11 and R12 represent the harness resistance in a branch of appliance 16.1, and resistors R21 and R22 represent the harness resistance or line resistance in a branch of appliance 16.2. Energy storage device 12 with voltage Ub feeds power divider 18 with current I3. Resistors R31 and R32, also provided in a branch of energy storage device 12, represent the associated harness resistance or line resistance of that branch. Appliance 17, not explicitly shown in the vehicle network model 30, also loads energy storage device 12 via a base load (state 40) and thus also contributes to the determination of the predicted output voltage Up_b. The determination of the predicted voltage Up_b can be performed, for example, by sensor 14, which may include a model of energy storage device 12. Figure 3Typically, a block 32 is provided for monitoring the energy storage 12. This block calculates the predicted output voltage Up_b and, for example, passes the minimum output voltage Ubmin to the vehicle network model 30 or to the monitoring device 34, in which the vehicle network model 30 is implemented.

[0037] To predict the terminal voltage Ui at the corresponding safety-related appliance 16i, three factors are crucial. The predicted or assumed power characteristics Lp or Lpges, in the form of current characteristics, consist of both the current characteristics Lpi of appliance 16i and the current characteristics of the basic load of appliance 17, where appliance 16i is required for driving operation, and appliance 17 must be safety-independent, such as a computer used in highly automated driving (for which undervoltage is critical, and the computer operates independently of driving conditions and with approximately the same current), seat heating devices, etc. All the predicted power characteristics Lpges of all, especially those of the appliance 16i required for the corresponding operation, together with the basic load 40 of the safety-independent appliance 17, are converted into the predicted current characteristics Ib_p50 that energy storage 12 must provide. The predicted current characteristics Ib_p of energy storage 12 are used to predict the voltage Ub_p of energy storage 12. The predicted voltage Ub_p of the energy storage device 12 is provided, for example, to a monitoring device 32 or a sensor 14, which for this purpose accesses, for example, a model of the energy storage device 12. The minimum predicted voltage Ub_min of the energy storage device 12 is calculated and compared with a limit value, below which a critical state of the vehicle network 10 is assumed.

[0038] Based on the appliance type (ohmic, power-related, voltage-related) of appliances 16 and 17, the overall current characteristic of the entire safety-related appliance 16 is converted into the individual current characteristics 70i (Ix) of each safety-related appliance 16i. These are then added together using a node-based method.

[0039] The resistance Rx of the corresponding line or branch must be known. This resistance can be assumed to be a constant value or determined, for example, through harness diagnostics 36 or a harness model. The voltage drop (Rx*Ix) on the line can be determined using the predicted minimum voltage Ubmin, resistance Rx, and corresponding current characteristic Ix 70i at energy storage 12. Here, the basic load 40 of the non-safety-related appliance 17 in another branch of the vehicle network model with relevant resistance is also considered, if necessary.

[0040] By means of the vehicle network model 30, under a defined load (which occurs under a defined operation to bring the vehicle to a safe stop), the corresponding current Ii or Ix through the involved lines or the voltage drop Ui at the corresponding appliance 16i can be predicted according to the following formula:

[0041]

[0042] Wherein, Ui is the voltage at the corresponding, especially safety-related, electrical appliances 16i and 17.

[0043] Ubatt is the voltage (or Ub_p) at energy storage device 12.

[0044] Rx is the line resistance involved.

[0045] Ix is the predicted current through the lines involved.

[0046] Thus, the voltage U1 at appliance 16.1 (e.g., steering mechanism) is obtained by the following formula:

[0047] U1 = Ubatt - I3 * (R31 + R32) - I1 * (R11 + R12)

[0048] Crucially, it is essential to combine diagnostics of the energy storage device 12, wiring harness diagnostics, or the determination of relevant parameters of the vehicle network model 30, as well as the prediction or determination of the power or current characteristics 64 Ix of the safety-related electrical appliances 16. If the electrical appliance 16 will receive the predicted or queried current characteristic 64 by the vehicle control unit 60, the diagnostics of the energy storage device 12 provide the predicted terminal voltage Ub_p of the energy storage device 12 as an output parameter. The wiring harness diagnostics determine the corresponding wiring harness resistance or line resistance Rx. This function can create predictions about the future power or current characteristics 64. The future power or current characteristics 64 depend on the corresponding required driving operations (e.g., full braking, two-lane change, etc.), the vehicle's surrounding environment (e.g., weather, route), and the activated electrical appliances 16, 17 (e.g., seat heating, infotainment, computers for highly automated driving, etc., in the form of a base load 40). For example, if an undervoltage (Ui < Umin) is predicted at the safety-related electrical appliance 16, measures 44 can be taken accordingly. Its effectiveness can be re-examined in terms of its adequacy by means of the predicted power or current characteristics 64 (which may have changed due to the measures taken), as already described.

[0049] Figure 3A schematic overview of the components that work together to monitor the electrical appliance 16 related to safety is shown. The monitoring device 32 of the energy storage device 12 receives or includes parameters 46 of the energy storage device 12, such as those used for modeling the energy storage device 12. Furthermore, the monitoring device 32 receives, for example, corresponding practical parameters of the energy storage device 12, such as voltage Ub and / or current Ib and / or temperature Tb. These practical parameters can be provided, for example, by the sensor 14, particularly the battery sensor. Additionally, the monitoring device 32 receives information about discharge 48 or power characteristics Lpges (e.g., by the corresponding current characteristics in a typical scenario) and / or current characteristics 50, such as the maximum current at which the energy storage device 12 is predictably loaded. The monitoring device 32 of the energy storage device 12, when using a suitable model of the energy storage device 12, determines characteristic parameters of the energy storage device 12, such as the predicted minimum voltage Ub_min, which can be predictably set under the corresponding load at the energy storage device 12. These characteristic, predicted parameters Ub_min, along with the wiring harness resistance Rx of different electrical appliances 16, 17 and status information 40 (e.g., basic load and / or information about which electrical appliances 16, 17 are active, thereby enabling the determination of the basic load), reach the monitoring device 34 of the vehicle network 10. The monitoring device 34 then determines the input parameters 42 for the vehicle control device 60 and / or the measures to be taken 44.

[0050] exist Figure 4 The diagram illustrates that although the vehicle is configured for planned operation 52, this operation cannot be performed as planned due to critical limits in the relevant safety-related electrical appliances 16. The monitoring device 34 can then, for example, induce the shutdown 53 of at least one basic load or safety-independent electrical appliance 17 as a measure 44. This could result in the planned operation 52 actually being performed, although the basic load is off, but while adhering to the permissible voltage limits of the safety-related electrical appliances 16 (in the form of operation 55 after the basic load is off). Alternatively, the planned operation 52 can be performed in a slightly modified manner and method (e.g., by gentler steering, which would result in lower energy demand and thus potentially lead to adherence to the permissible limits of the safety-related electrical appliances 16) as a matched operation 57. Alternatively, the planned operation 52 can be implemented as a modified operation 56. For example, in this embodiment, instead of avoiding the obstacle (the originally planned operation 52), braking should be initiated promptly (the modified operation 56). Here, the energy demand or related, inquired current characteristics 64 of the modified operation 56 are selected such that they comply with the permissible limits (especially voltage limits) of the electrical appliance 16 (e.g., the braking system in this case) related to safety.

[0051] according to Figure 5 The embodiments described are particularly applicable to automation levels 3 or higher (as defined in SAE J3016). Here, the vehicle control unit 60 creates a current characteristic 64 based on the planned driving operation 52 and the associated trajectory. This current characteristic 64 (initially only queried by the vehicle control unit 60) is a prediction of the future load for the various electrical appliances 16, 17. The monitoring unit 34 includes a conversion unit 68 that provides the various current characteristics 70 Ix (e.g., the corresponding maximum current for the corresponding branch) of each line or branch in the vehicle network to the vehicle network model 30. The vehicle network model 30 is also part of the monitoring unit 34. It includes the minimum voltage Ub_min of the energy storage as an input parameter, but either by means of the sensor 14 itself or by means of the prediction of the minimum voltage Ub_min of the energy storage, as predicted within the framework of the simulation using the model of the energy storage 12 and the corresponding load characteristics. In addition, the vehicle network model 30 receives the corresponding harness resistance Rx. From this, the voltage drop on the line can be calculated, possibly also taking into account the basic load of the electrical appliances 17, which are not related to safety. The vehicle network model 30, using the provided parameters, particularly the expected minimum voltage Ub_min of the energy storage 12 and the corresponding current characteristics 70 of the corresponding lines, determines the minimum characteristic parameter or appliance voltage Ui_min for the corresponding safety-related appliance 16i. These terminal voltages Ui at different appliances 16i are analyzed and processed in block 62. Here, depending on the available possibilities, one or more measures 44 can be taken or corresponding information 66 regarding the feasibility of operation 52 can be reported back to the vehicle control unit 60. Subsequently, the vehicle control unit 60 can query the modified current characteristics 64 based on the modified trajectory in the vehicle control unit 60 or the matched operation 54 or modified operation 56 relative to the planned operation 52. Therefore, this function is implemented only when the query (the queried load characteristic 64) is made by the vehicle control unit 60. If necessary, multiple iterative loops are required with the aid of the vehicle control unit 60.

[0052] Now, according to Figure 6 In this embodiment, fixed-defined current characteristics 72 are stored in the monitoring device 34. These fixed-defined current characteristics 72 correspond to fixed-defined operation 52 under worst-case conditions (e.g., full braking). Using these current characteristics 72, the voltage Ui at the safety-related appliance 16i can now be predicted. This is essentially consistent with... Figure 5The implementation proceeds in a consistent manner. Again, the conversion device 68 is used to convert the fixed-defined current characteristic 72 into a current characteristic 70 Ix for each line or into a current characteristic 50 for the energy storage device 12, again according to the corresponding state 40 of the appliances 16, 17. If necessary, this can be repeated for each fixed-defined current characteristic 72 and the relevant voltage Ui at the corresponding safety-related appliance 16i can be predicted. Now, the analysis and processing device 62 provides feedback or information 66 regarding the feasibility of operation (which driving operations 52 are feasible) to the vehicle control device 60 for each fixed-defined current characteristic 72. In the analysis and processing device 62, for example, the corresponding voltage Ui at the safety-related appliance 16i can be compared with a determined limit value for the corresponding appliance 16i, and countermeasures can be triggered, for example, if the voltage is below the minimum. For example, braking operation may become critical due to the increased line resistance Rx of the braking system. Therefore, the worst-case driving operation is hindered due to its corresponding current characteristic. Measures 44 are taken without considering the vehicle control device 60. This function is executed cyclically so that the output always matches the current state of the vehicle network 10. As a result, the determination operation 52 of the vehicle control unit 60 is blocked, so that the trajectory can only be generated by the permitted operation.

[0053] according to Figure 7 The embodiment is characterized in that the monitoring device 34 includes a model 76 of a safety-related electrical appliance 16. For example, it stores a model 76.1 for a steering system, a model 76.2 for a braking system, and a model 76.3 for an electronic stability program. The model 76 is equipped with sensor data 74 from the vehicle control unit 60. Thus, for different possible driving operations in different environmental conditions, the maximum current is calculated as an example of the current characteristic 64i. In an alternative simplification, the model 76 can be replaced by a corresponding lookup table. As previously described in the embodiments, the corresponding voltage Ui at the relevant electrical appliance 16i can be calculated. Subsequently, the vehicle control unit 60 is notified which driving operations 84 or which related parameters of the driving operation can be invoked. Additionally, feedback in the form of result 80 is returned from the analysis processing unit 62 to the model 76. The model 76 also forwards the hypothetical driving operation 78 or the hypothetical current characteristic 64i of the electrical appliance 16i to the analysis processing unit 62. Furthermore, the model 76 can observe and recalculate the voltage Ui at the electrical appliance 16 by means of the matched current characteristic of the electrical appliance 16. This change ensures that possible operation 52 or possible load characteristics are always delivered.

[0054] With the aid of load characteristics 84 (driving operation and torque characteristics of each component), the framework conditions for trajectory planning (as can be implemented in vehicle control unit 60) are pre-given by analysis and processing unit 62. Thus, a trajectory can be generated corresponding to the on-board network state. Here, the trajectory is only allowed to be generated within the given framework conditions, as pre-given by analysis and processing unit 62 and passed to vehicle control unit 60. Vehicle control unit 60 can test possible future environmental parameters by manipulating sensor data 74. Therefore, feedback is continuously provided to vehicle control unit 60 regarding which driving operations 52 are possible. As an additional measure, for example, the vehicle speed can be reduced and / or the automated driving function can be terminated, as notified via signal 82. This measure is then implemented in vehicle control unit 60 if necessary.

[0055] Particularly advantageously, the described monitoring device 34 is implemented in the load divider 18. This is therefore highly advantageous because all relevant parameters, as described, are present in the load divider 18. This is particularly advantageous for the possible comparison of predicted and actual characteristic parameters.

Claims

1. A method for monitoring an in-vehicle network of a motor vehicle, wherein, At least one safety-related electrical appliance (16) is powered by an energy storage device (12), wherein at least one vehicle network model (30) is provided, the at least one vehicle network model representing the safety-related electrical appliance (16) and the corresponding wiring, wherein the wiring has an associated line resistance (Rx) and a connection to the energy storage device (12), the method comprising the steps of: providing current or power characteristics (64, 72) that are at least predictably necessary for a given operation (52) of the motor vehicle with the participation of the safety-related electrical appliance (16); in order to make The predicted characteristic parameter (Ub_min) of the energy storage device (12) is obtained using the current characteristic or the power characteristic (64, 72); the predicted characteristic parameter (Ui) of the safety-related appliance (16) is obtained using the following current characteristic (Ix) or power characteristic, the line resistance (Rx) and the predicted characteristic parameter (Ub_min) of the energy storage device (12): the safety-related appliance (16) is predictably loaded with the current characteristic or the power characteristic; the predicted characteristic parameter (Ui) of the safety-related appliance (16) is analyzed and processed.

2. The method according to claim 1, characterized in that, If the predicted feature parameter (Ui) is below the limit value, the activation of the operation (52) is rejected, and / or the operation (52) is matched, and / or the corresponding information (68) regarding the executability of the operation (52) is generated.

3. The method according to any one of the preceding claims, characterized in that, The following additional steps are provided: receiving current or power characteristics (64) queried by the vehicle control unit (60) for the corresponding operation (52), processing the queried current or power characteristics (64) into current or power characteristics to be provided by the energy storage (12) and / or processing them into current characteristics (Ix) or power characteristics for each of the following lines: lines that supply power to safety-related electrical appliances (16) involved in the operation (52).

4. The method according to claim 1 or 2, characterized in that, Set up at least one model (76) of the safety-related electrical appliance (16) and estimate the current characteristics or power characteristics (64) of the safety-related electrical appliance (16) through the at least one model.

5. The method according to claim 1 or 2, characterized in that, Other electrical appliances (17) are also powered by the energy storage device (12).

6. The method according to claim 5, characterized in that, The current or power characteristics (64, 72) include the basic load of at least one of the other electrical appliances (17).

7. The method according to claim 1 or 2, characterized in that, The current characteristic or power characteristic (64) is obtained based on the state (40) of the electrical appliances (16, 17).

8. The method according to claim 1 or 2, characterized in that, For a given operation (52), a fixed current characteristic or power characteristic (72) is stored, wherein the corresponding current characteristic or power characteristic (72) is fixedly defined according to the driving operation, and the energy storage (12) and the circuit are predictably loaded with the current characteristic or power characteristic.

9. The method according to claim 4, characterized in that, The sensor data (74) is transmitted to the model (76).

10. The method according to claim 1 or 2, characterized in that, The vehicle network model (30) receives the line resistance (Rx).

11. The method according to claim 1 or 2, characterized in that, A power distributor (18) is provided, through which the safety-related electrical appliance (16) is protected, and the power distributor is connected to the energy storage device (12).

12. The method according to claim 11, characterized in that, The power divider (18) includes at least one switching device (19) for separating the on-board network branch having the safety-related appliance (16) from another on-board network branch that supplies power to the safety-independent appliance (17).

13. The method according to claim 1 or 2, characterized in that, Voltage is used as a predicted characteristic parameter (Ui) for the safety-related electrical appliance (16).

14. The method according to claim 1 or 2, characterized in that, Take action based on the predicted characteristic parameter (Ui) (44).

15. The method according to claim 4, characterized in that, The current or power characteristics (64) of the safety-related electrical appliance (16) under different operating conditions (52) are estimated by the at least one model (76).

16. The method according to claim 9, characterized in that, The sensor data (74) is transmitted from the vehicle control unit (60) to the model (76).

17. The method according to claim 10, characterized in that, The vehicle network model (30) receives the line resistance (Rx) from the wiring harness diagnostics (36).

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