DE102018215786A1 - Method and battery sensor for monitoring a circuit in a vehicle - Google Patents

Abstract

The invention relates to a method for monitoring a circuit (32) in a vehicle (10), the circuit (32) having a vehicle battery (12), a battery sensor (26) and at least one consumer (22, 24) which are electrically controlled Connections (30) are electrically connected to one another, the battery sensor (26) having at least one detection device (38, 44, 60) for detecting a battery parameter of the vehicle battery (12) and for outputting a battery value dependent on the battery parameters, and an evaluation circuit (42) for evaluating the battery values and for outputting battery signals. The method has the following steps: - detecting the at least one battery parameter with the at least one detection device (38, 44, 60) and outputting the battery values, - comparing the battery values with at least one limit value (70, 72) stored in the evaluation circuit (42) , 74), the limit value corresponding to a critical value of the battery parameter for the vehicle battery (12), the battery sensor (26), the at least one consumer (22, 24) and / or the at least one electrical connection (30), and- The evaluation circuit (42) generates a warning signal when at least one limit value is reached or exceeded. The invention further relates to a battery sensor for carrying out this method.

Description

The invention relates to a method for monitoring a circuit in a vehicle, the circuit having a vehicle battery, a battery sensor and at least one consumer, which are electrically connected to one another via electrical connections. The invention further relates to a battery sensor for performing such a method.

Battery sensors are used in vehicles to obtain information about the state of the battery, for example the state of charge of the battery. The battery parameters to be recorded are, for example, the battery voltage, the battery current and the temperature of the battery. In particular, the battery voltage and the battery current have to be recorded permanently in order, for example, to be able to make an exact statement about the state of charge of the battery.

The battery sensor is usually arranged in a circuit with the vehicle battery and at least one consumer of the vehicle, so that the entire current flow of the vehicle battery takes place via the battery sensor and is therefore monitored by the battery sensor. The vehicle battery, the battery sensor and the consumers of the vehicle are interconnected via electrical connections, in particular via cables.

In order to ensure permissible operation of the vehicle, reliable functioning of the circuit and the components of the circuit, that is to say the vehicle battery, the battery sensor, the consumers and the electrical connection, must be ensured. This includes the function and the contacting of the individual consumers as well as the battery sensor. In addition, this also includes the electrical connections, in particular cables, and their contacting with the other components of the electrical circuit. Monitoring or diagnosing the circuit has so far been very complex. For example, monitoring the circuit requires additional current contacts and sensors, since, for example, a faulty current flow can only be detected by measuring in parallel via a second electrical connection.

The object of the invention is to provide a method for monitoring a circuit in a vehicle, which enables simple detection of fault states or a prediction of possible fault states of the circuit. Another object of the invention is to provide a sensor for such a method.

• - Erfassen des zumindest einen Batterieparameters mit der zumindest einen Erfassungseinrichtung und Ausgabe der Batteriewerte an die Auswerteschaltung
• - Vergleich des zumindest einen Batteriewertes mit zumindest einem in der Auswerteschaltung gespeicherten Referenzwert durch die Auswerteschaltung, wobei der Referenzwert zu einem kritischen Wert des Batterieparameters für die Fahrzeugbatterie, den Batteriesensor, den zumindest einen Verbraucher und/oder die zumindest eine elektrische Verbindung korrespondiert, und
• - Erzeugen zumindest eines Warnsignals durch die Auswerteschaltung, wenn der Batteriewert mit zumindest einem Referenzwert übereinstimmt oder diesen überschreitet.

To achieve the object, a method for monitoring a circuit in a vehicle is provided, the circuit having a vehicle battery, a battery sensor and at least one consumer which are electrically connected to one another via electrical connections, the battery sensor having at least one detection device for detecting a battery parameter Vehicle battery and for outputting a battery value dependent on the battery parameters and an evaluation circuit for evaluating the battery values and for outputting battery signals. The process has the following steps:

• - Detection of the at least one battery parameter with the at least one detection device and output of the battery values to the evaluation circuit
• - Comparison of the at least one battery value with at least one reference value stored in the evaluation circuit by the evaluation circuit, the reference value corresponding to a critical value of the battery parameter for the vehicle battery, the battery sensor, the at least one consumer and / or the at least one electrical connection, and
• - Generating at least one warning signal by the evaluation circuit if the battery value agrees with or exceeds at least one reference value.

According to the invention, a critical value for a battery parameter, which is detected by the battery sensor, is defined for at least one component of the circuit, that is to say the vehicle battery, a consumer, the battery sensor or an electrical connection. The critical value can be defined, for example, in such a way that reliable operation of the component of the circuit is ensured as long as the battery parameter does not exceed this critical value. If the critical value is exceeded, further measures may be necessary to continue to ensure the reliable operation of the component. These measures can represent, for example, a check, a shortening of test intervals, a repair, a calibration or an exchange of the respective component.

Furthermore, a limit value for a battery parameter is defined at which this critical value for the component of the circuit is reached or is to be expected. If the battery sensor determines a battery value that corresponds to or exceeds the limit value, it is assumed that the critical value of the battery parameter for the corresponding component is also reached or exceeded. A warning signal is then generated. The warning signal can Evaluation circuit are provided and / or output, in particular at an output of the evaluation circuit, for example for output to a controller.

The battery sensor is therefore not only used for recording battery parameters and for assessing the state of the battery, but is now also used for monitoring or for early detection and prediction of errors in the entire circuit and its components. No additional sensors or circuits are required to monitor the circuit.

The monitoring of the circuit or the prediction of possible fault states also has the advantage in principle that the components of the circuit can be dimensioned better. Up to now, components, in particular electrical connections and electrical contacting, have been designed in such a way that a reliable function of the components is ensured even in the event of an overload, since fault detection is very complex. With the method described above, an error state or an impending or probable error state can be recognized or predicted indirectly, that is to say not by detecting the load applied to the respective component, but rather by detecting the battery parameters via the battery sensor. Appropriate measures can then be taken to avoid or correct the fault condition.

Such a fault condition can consist, for example, of the existing or impending failure or a malfunction of the component.

The warning signal can indicate, for example, a necessary check or calibration of the circuit or one of its components.

In order to ensure the reliable operation of the circuit, a test cycle for the circuit, the vehicle battery, the battery sensor, the at least one consumer and / or at least one electrical connection can be carried out, for example, after the warning signal has been generated. The test cycle can be carried out, for example, by the component itself, for example if it has devices for checking, for example in the case of a battery sensor. Alternatively, the check can be carried out by additional components of the circuit or by additional devices to be connected.

The critical value can, for example, also characterize a value of the battery parameter that can lead to a faulty function of a component of the electricity price. For example, high currents or high voltages in measuring devices can lead to a decrease in the accuracy of the measuring device, so that calibration or calibration of the measuring device is necessary. In the case of battery sensors in particular, a high degree of accuracy is required over the measurement period, so that rapid detection, testing and correction of possible inaccuracies in the measurement process are required. After the warning signal has been output, the battery sensor, in particular the at least one detection device, can also be calibrated, for example. The battery sensors usually have devices for self-diagnosis and / or calibration of the detection devices, which is carried out at defined, for example regular, intervals. The warning signal can be used to carry out an unscheduled calibration or self-diagnosis in order to increase the measuring accuracy of the battery sensor.

The limit value can be, for example, a maximum value for at least one battery parameter, and if this maximum value is exceeded, a component of the electricity price can be influenced or malfunction.

The components of the circuit can also be influenced by prolonged exposure to a high parameter, the maximum value of which is fundamentally not problematic for the components of the circuit. For example, a high current applied over a longer period of time can lead to undesired heating of individual components of the electricity price. The limit value can therefore also be a time profile of at least one battery parameter.

For example, the limit value can also represent the repeated occurrence of a specific limit value. This means that the number of events in which the limit value is exceeded is determined via a counter and, when a critical number is reached, a warning signal is generated and, for example, provided or output.

Several limit values for a battery parameter can also be stored in the evaluation circuit, the limit values differing over time and / or in the maximum value. For example, different limit values can be stored for the different components of the circuit, wherein several different limit values can also be stored for one component of the circuit in order to be able to detect different load scenarios.

In particular, depending on the limit value reached by the evaluation circuit a component-dependent warning signal can also be generated, so that the warning signal can be used to identify which of the components should be checked, calibrated and / or exchanged.

Depending on the at least one limit value, which corresponds to or is exceeded by the battery values, an error signal can be output, a test cycle can be triggered and / or a calibration method can be triggered. I.e. If different limit values are reached, various measures are recommended or carried out. For example, a check of the components or a new calibration may be sufficient when a low limit value is reached. When a second, higher limit value is reached, the replacement of a component of the circuit, for example, may be recommended or necessary. Different warning signals can be used to differentiate between reaching the various limit values and thus differentiating the required measures.

The battery sensor can also have a plurality of detection devices for detecting at least one battery parameter, in each case at least one limit value corresponding to a battery parameter is stored in the evaluation circuit and for each of the battery parameters the battery values are compared with the at least one corresponding limit value and a warning signal is generated if the battery values match or exceed the limit values. In particular, limit values for combinations of different battery parameters can also be defined, so that a more accurate determination of possible fault conditions can take place. For example, the predicted occurrence of a critical value of the battery parameter for a component of the circuit can be checked for plausibility via a critical value of a further battery parameter.

To achieve the object, a battery sensor, in particular for a vehicle battery, is also provided, with at least one detection device for battery values of a battery parameter, and with at least one evaluation circuit for evaluating the battery values and for outputting battery signals. The evaluation circuit is designed to compare the battery values with at least one reference value stored in the evaluation circuit, the reference value corresponding to a critical value of the battery parameter for the vehicle battery, the battery sensor, the at least one consumer and / or the at least one electrical connection. Furthermore, the evaluation circuit is designed to generate a warning signal when at least one reference value is reached or exceeded.

In particular, the evaluation circuit can be designed to provide and / or output the warning signal, in particular at a signal output.

After generation, the warning signal can be provided within the battery sensor if the warning signal is processed within the battery sensor, for example at the start of a test cycle or a calibration. The warning signal can optionally or additionally be output at an external output of the battery sensor, for example in order to inform the vehicle operator of the warning signal via a vehicle controller, to carry out test cycles for other components of the circuit or to carry out other measures of the vehicle.

The detection device can each comprise a voltage detection device, a current detection device and / or a temperature detection device.

• 1 eine schematische Darstellung eines Fahrzeugs mit einem Stromkreis;
• 2 eine schematische Darstellung eines Batteriesensors; und
• 3 ein Ablaufdiagramm eines Verfahrens zur Überwachung eines Stromkreises mit dem Batteriesensor aus 2.

Further advantages and features result from the following description in connection with the attached symbol. In this show:

• 1 a schematic representation of a vehicle with a circuit;
• 2nd a schematic representation of a battery sensor; and
• 3rd a flowchart of a method for monitoring a circuit with the battery sensor 2nd .

In 1 is a vehicle 10th shown. The vehicle 10th has an engine compartment 12th in which a drive unit 14 is provided. There is also a vehicle battery 16 with two battery poles 18th , 20th provided with multiple electrical consumers 22 , 24th is electrically connected. The electrical consumers 22 , 24th can be any electrical or electronic components of the vehicle 10th be, for example, an air conditioning system, driver assistance systems or parts of the drive unit 14 . In particular, the drive unit 14 also be an electrical consumer with the vehicle battery 16 is electrically connected.

On the vehicle battery 16 , especially at the battery pole 18th is also a battery sensor 26 intended. The battery sensor 26 captures at least one, preferably several, battery values in order to make statements about the battery status, in particular about the charge status of the vehicle battery 16 to be able to meet. The battery sensor 26 can with a control unit 28 of the vehicle connected to the signals from the battery sensor 26 evaluates.

The battery sensor 26 , the consumers 22 , 24th as well as the vehicle battery 16 are interconnected via electrical connections 30th connected and form together with these electrical connections 30th a circuit 32 . the electrical connections 30th can be formed, for example, by cables or parts of the vehicle body.

In 2nd is an embodiment of a battery sensor 26 shown. At a first connection 34 of the battery sensor 26 is an electrical connection 30th provided that about consumers 22 , 24th with a battery pole 18th the vehicle battery 16 connected is. The second connection 36 is formed by a pole clamp over which the battery sensor 26 with the second battery pole 20th is electrically connected.

The battery sensor shown here 26 is designed to record the battery voltage, the battery current and the battery temperature.

A voltage detection device is used to measure the battery voltage 38 provided that with the first connector 30th or the first battery pole 18th connected is. The voltage detection device 38 is via an analog-digital converter with an evaluation circuit 42 of the battery sensor 26 connected.

Furthermore, there is a current detection device 44 to record the load current 46 between the first battery pole 18th and the second battery terminal 20th intended. The current detection device has one in the path of the load current 46 arranged measuring resistor 48 with a known electrical resistance.

The measuring resistor is preferably 48 Made of a material that has a low temperature dependency and a low aging drift of the electrical resistance, for example from a copper-nickel-manganese alloy.

The current detection device 44 also has a voltage measuring device 50 on that with contact points 52 , 54 before and after the measuring resistor 48 is contacted so that there is a voltage drop in the load current 46 via the measuring resistor 48 can capture. The current detection device 44 also has an amplifier 56 as well as an analog-to-digital converter 58 on the one with the evaluation circuit 42 connected is.

From that with the voltage measuring device 50 detected voltage drop across the measuring resistor 48 and the known electrical resistance of the measuring resistor 48 can about the ohmic law over the measuring resistance 48 flowing current, i.e. the load current 46 , be determined.

The battery temperature is measured using a temperature detection device 60 that detects a first temperature sensor 62 and a second temperature sensor 64 having. The first temperature sensor 62 is on a circuit board 57 arranged on which the evaluation circuit 42 as well as the analog-digital converter 40 and 58 are provided. The second temperature sensor 64 can for example at the measuring resistor 48 or the vehicle battery 16 be provided. Via a switch 66 is optionally the first temperature sensor 62 or the second temperature sensor 64 with an analog-digital converter 68 connectable to the evaluation circuit 42 connected is.

The battery sensor 26 is also used to monitor the vehicle battery 16 also for monitoring the entire circuit 32 used. The monitoring preferably includes the prediction and the detection of critical or possibly or probable critical states. For example, high currents and / or high voltages, in particular also when these are present over a longer period of time, can damage or weaken various components of the circuit 32 to lead. The purpose of monitoring the circuit is to overstress individual components of the circuit 32 recognized or predicted so that they can be checked, repaired and / or replaced in good time.

In the evaluation circuit 42 are in limits 70 , 72 , 74 stored for the battery parameters, that is to say for the battery voltage, the battery current and / or the battery temperature. The limits 70 , 72 , 74 correspond to critical values of the respective battery parameter for the battery sensor 26 that at least one consumer 22 , 24th and / or the electrical connections 30th . This means that when the battery parameter reaches the limit, it is up to the battery sensor 26 , on the consumer 22 , 24th or on the electrical connection 30th a value of the battery parameter that could be critical for them.

In this context, a critical value can be defined such that the respective component of the circuit functions reliably 32 is ensured if the battery parameter does not exceed this value. If the critical value is exceeded, for example, a higher probability of a malfunction or an incorrect function of the respective component cannot be ruled out, so that further measures to ensure the function of the circuit may be necessary. The measures can represent the performance of a functional test, the shortening of test intervals, a calibration, a repair or an exchange of the respective component.

In the case of a battery sensor, for example, when a critical value of a battery parameter on the battery sensor is reached or exceeded 26 that are outside the intended measuring range of the battery sensor 26 are below the measurement inaccuracies of the battery sensor 26 come so that a calibration of the battery sensor 26 is required. Act on the electrical connections 30th If the currents are too high, the resulting high temperatures can lead to premature material fatigue or screw connections. If these are recognized or predicted in good time, the electrical connections can be made 30th checked and, for example, contact points renewed or electrical connections exchanged.

The limits 70 , 72 , 74 can represent maximum values of one or more battery parameters. Alternatively, the limit values 70 , 72 , 74 also represent time profiles of one or more other parameters. For example, the application of a high current over a long period of time can lead to strong heating of individual components, for example an electrical connection. For example, the limit 70 , 72 , 74 also consist of a repeated occurrence of a maximum value, the evaluation circuit 42 in this case has a counter for the occurrence of the respective limit value.

In particular, several different limit values can be set for a battery parameter 70 , 72 , 74 in the evaluation circuit 42 be saved

For monitoring the circuit 32 first the battery parameters with the battery sensor 26 , so the voltage detection device 38 , the current detection devices 44 and the temperature detection devices 60 recorded and the recorded battery values to the evaluation circuit 42 spent ( 3rd ).

The evaluation circuit 42 processes the battery values of the battery parameters and sends battery signals to the control unit 28 out.

Furthermore, the battery values with those in the evaluation circuit 42 stored limit values 70 , 72 , 74 compared. One of the battery values of a battery parameter corresponds to one for this battery parameter in the evaluation circuit 42 stored limit 70 , 72 , 74 or exceeds this, a warning signal from the evaluation circuit 42 generated and provided or output.

The warning signal can, for example, within the evaluation circuit 42 are processed. For example, the limit corresponds 70 , 72 , 74 that is reached or exceeded, a critical value of the battery parameter for the battery sensor 26 or a detection device 38 , 44 , 60 of the battery sensor 26 . After issuing the warning signal, the battery sensor can then be self-diagnosed 26 or a recalibration of the battery sensor 26 be performed.

Optionally or additionally, the warning signal can be output at an output, for example to the control unit 28 . The warning signal can be from the control unit 28 be communicated to a vehicle operator, for example optically, acoustically or in another way. The vehicle operator can then take appropriate measures to complete the circuit 32 or individual components of the circuit 32 to check, repair or replace.

Alternatively, the control unit 28 self-diagnosis or recalibration of individual components of the circuit 32 cause.

The warning signal can preferably be used to output information for which of the components of the circuit 32 a critical value of the battery parameter has been reached, especially if different limit values 70 , 72 , 74 for different components of the circuit 32 in the evaluation circuit 42 are saved. A test of the components of the circuit 32 can be restricted to the components loaded by the corresponding battery parameters.

In particular, several limit values can also be used 70 , 72 , 74 for a battery parameter in the evaluation circuit 42 be saved. Depending on which of the limit values has been reached, various warning signals can be generated. For example, when a low limit is reached 70 , 72 , 74 only a test or recalibration may be required. When a second, higher limit value is reached 70 , 72 , 74 an exchange of the corresponding component may be recommended. By using various warning signals, the vehicle operator can be informed of any measures that are already required.

Reference list

10th

vehicle

12th

Engine compartment

14

Drive unit

16

Vehicle battery

18th

first battery pole

20th

second battery pole

22

consumer

24th

consumer

26

Battery sensor

28

control

30th

electrical connection

32

Circuit

34

first connection

36

second connection

38

Voltage detection device

40

Analog-to-digital converter

42

Evaluation circuit

44

Current detection device

46

Load current

48

Measuring resistor

50

Voltage measuring device

52

Contact point

54

Contact point

56

amplifier

58

Analog-to-digital converter

60

Temperature detection device

57

Circuit board

62

first temperature sensor

64

second temperature sensor

66

switch

68

Analog-to-digital converter

70

limit

72

limit

74

limit

Claims (10)

Method for monitoring a circuit (32) in a vehicle (10), the circuit (32) having a vehicle battery (12), a battery sensor (26) and at least one consumer (22, 24), which are connected via electrical connections (30) are electrically connected to one another, the battery sensor (26) having at least one detection device (38, 44, 60) for detecting a battery parameter of the vehicle battery (12) and for outputting a battery value dependent on the battery parameter, and an evaluation circuit (42) for evaluating the battery values and for outputting battery signals, with the following steps: - Detecting the at least one battery parameter with the at least one detection device (38, 44, 60) and outputting the battery values to the evaluation circuit (42), - Comparison of the at least one battery value with at least one limit value (70, 72, 74) stored in the evaluation circuit (42) by the evaluation circuit (42), the limit value being a critical value of the battery parameter for the vehicle battery (12), the battery sensor ( 26), which corresponds to the at least one consumer (22, 24) and / or the at least one electrical connection (30), and - Generating a warning signal by the evaluation circuit (42) when at least one limit value is reached or exceeded. Procedure according to Claim 1 , characterized in that after generating the warning signal, a test cycle for the vehicle battery (12), the battery sensor (26), at least one consumer (22, 24) and / or the at least one electrical connection (30) is carried out. Method according to one of claims 1 and 2, characterized in that after generating the warning signal, a calibration of the battery sensor (26), in particular of the at least one detection device (38, 44, 60), is carried out. Method according to one of the preceding claims, characterized in that the limit value is a maximum value of at least one battery value. Method according to one of the preceding claims, characterized in that the limit value is a time profile of at least one battery value. Method according to one of Claims 4 and 5, characterized in that a plurality of limit values (70, 72, 74) for a battery value are stored in the evaluation circuit (42), the limit values differing over time and or in the maximum value. Procedure according to Claim 6 , characterized , characterized in that, depending on the at least one limit value (70, 72, 74) which corresponds to or is exceeded by the battery values, an output of an error signal, a triggering of a test cycle and / or a calibration procedure is triggered. Method according to one of the preceding claims, characterized in that the battery sensor (26) has a plurality of detection devices (38, 44, 60) for detection of at least one battery parameter in each case, wherein in the evaluation circuit (42) in each case at least one limit value corresponding to a battery parameter ( 70, 72, 74) and for each of the battery parameters the battery values are compared with the at least one corresponding limit value (70, 72, 74) and a warning signal is generated if the battery values with the limit values (70, 72, 74) match or exceed them. Battery sensor (26), in particular for a vehicle battery (12), with at least one detection device (38, 44, 60) for battery values of a battery parameter, and with at least one evaluation circuit (42) for evaluating the battery values and for outputting battery signals, characterized in that that the evaluation circuit (42) is designed to compare the battery values with at least one limit value (70, 72, 74) stored in the evaluation circuit, the limit value (70, 72, 74) becoming a critical value of the battery parameter for the vehicle battery (12) , the battery sensor (26), which corresponds to at least one consumer (22, 24) and / or the at least one electrical connection (30), and that the evaluation circuit (42) is designed to generate a warning signal if at least one limit value (70, 72, 74) is reached or exceeded. Battery sensor after Claim 9 , characterized in that the detection device (38, 44, 60) comprises a voltage detection device (38), a current detection device (44) and / or a temperature detection device (60).

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