Device and method for evaluating a fill level of a coolant in a coolant container

Abstract

The invention proposes a device for evaluating a fill level of a coolant in a coolant container, in particular in a vehicle, wherein the device comprises a sensor designed to output a sensor signal, wherein the sensor signal has a first value when the sensor is in contact with the coolant and has a second value when the sensor is not in contact with the coolant, wherein the first value differs from the second value, wherein the device comprises a processing unit designed to receive the sensor signal and to determine a frequency with which the sensor signal has the second value, wherein the processing unit is furthermore designed to output an evaluation of the fill level of the coolant on the basis of the determined frequency of the second value.

Description

[0001] Device and method for evaluating a fill level of a coolant in a coolant tank

[0002] Description

[0003] The present invention relates to a device for detecting the fill level of a coolant in a coolant tank, in particular a coolant tank in a vehicle, according to the preamble of patent claim 1. Furthermore, the present invention relates to a method for detecting the fill level of a coolant in a coolant tank according to the preamble of patent claim 9.

[0004] In various technical systems, especially in vehicles, cooling circuits with coolant are used to cool various components. These include, for example, high-voltage storage units or combustion engines. The cooling circuits used typically have a coolant reservoir.

[0005] If the coolant reservoir is leaking and causing coolant to leak, or if the cooling circuit is losing coolant elsewhere, the coolant level in the reservoir may drop. If the coolant level drops, cooling can no longer be guaranteed, which in the worst case could lead to failure of the cooled components or at least damage to these components. With a high-voltage storage system, there is also the risk that the coolant (in this case, water) could leak from the coolant reservoir or cooling circuit into the high-voltage storage system, causing an undesirable chemical reaction that could, for example, produce oxyhydrogen.

[0006] In order to detect such a leak in the coolant tank or the entire cooling circuit, it is known to monitor the fill level of the coolant tank and to issue a warning if the level falls below a predefined minimum coolant level.

[0007] Until now, simple fill level sensors have been used for this purpose, e.g. for a coolant expansion tank, which measure a voltage value via two pins. If a critical threshold is undershot, the measured voltage changes significantly, so that evaluation electronics with a certain degree of damping (e.g. to compensate for fluctuations in the fill level caused by sloshing of the liquid) trigger an alarm. However, these simple 2-pin sensors can only detect when a threshold has been exceeded or not reached, but not how far the fill level is from the threshold. Furthermore, more complex measuring systems are known which measure the fill level not only by means of threshold monitoring, but also measure the fill level continuously, e.g. via the movement of a float. However, these more complex measuring systems are expensive.

[0008] The present invention is therefore based on the object of providing a favorable possibility to monitor the fill level of a coolant in a coolant tank more accurately.

[0009] This object is achieved by a device for detecting the fill level of a coolant in a coolant tank according to patent claim 1 and a method for detecting the fill level of a coolant in a coolant tank according to patent claim 9.

[0010] The device is particularly intended for evaluating a fill level of a coolant in a coolant tank in a vehicle.

[0011] The coolant can be any coolant that can be used in a vehicle. For example, the coolant can be a coolant in a cooling circuit for cooling an internal combustion engine or for cooling a high-voltage battery in a vehicle. The coolant tank in which the coolant is located can be a coolant tank used in such cooling circuits, for example a coolant expansion tank. The coolant can move in the coolant tank due to movements, e.g. of the vehicle. The fill level of the coolant can therefore change on the one hand due to an actual decrease in the coolant (in this case permanently) and on the other hand due to such movements (in this case only temporarily).

[0012] The device therefore has a sensor configured to output a sensor signal that has a first value when the sensor is in contact with the coolant and a second value when the sensor is not in contact with the coolant. The first value and the second value differ from each other. The sensor can be any sensor, e.g., a 2-pin sensor or 2-wire sensor, that outputs different values ​​when in contact with the coolant or when not in contact with it.

[0013] For example, the sensor can be like a switch that closes upon contact with the coolant and therefore has a low resistance, and that is open when there is no contact with the coolant and therefore has a high resistance. The sensor can therefore output a low voltage as the first value in the first case and a significantly higher voltage as the second value in the second case.

[0014] In order to achieve more precise monitoring of the fill level than in previous systems, which goes beyond simply detecting when a threshold value is exceeded or undershot, the device has a processing unit which is designed to receive the sensor signal and to determine a frequency with which the sensor signal has the second value, i.e. the value when there is no contact between the sensor and the coolant.

[0015] If the coolant level changes, especially if it drops to a level where the sensor is no longer in contact with the coolant, the sensor signal will display the second value. If the coolant level is at a height around the sensor position, movements of the coolant reservoir and thus movements of the coolant can cause the level to fluctuate, causing the coolant to come into contact with the sensor more or less frequently. In this case, the first and second values ​​can alternate.

[0016] Previous systems only determined whether and for how long a threshold was exceeded. While this allowed for one-off, short-term threshold violations to be ignored, the previous systems did not allow for a more precise determination of the fill level.

[0017] In contrast, the present device enables a more accurate assessment of the fill level, as the processing unit detects how frequently the second value of the sensor signal occurs and thus how often the sensor is not in contact with the coolant. This information can be used by the processing unit to assess the coolant level in the coolant reservoir and output this assessment. At the same time, a very simple sensor can be used that only provides an indication of contact or non-contact with the lubricant.

[0018] The processing unit can output the assessment to a user, e.g., a driver or passenger of the vehicle, e.g., via a screen. Alternatively, the processing unit can also forward the information or assessment to other units or devices in the vehicle, which in turn can use this information to perform or initiate further actions. This could, for example, involve stopping the vehicle or throttling the engine, or similar actions to prevent damage to the elements being cooled.

[0019] According to one embodiment, the processing unit is configured to determine the frequency with which the sensor signal has the second value over a predefined period of time. This ensures that not only a short-term dry state of the sensor is detected, but rather that several such events occur over a specific period of time, which are indicated by the sensor outputting the second value. The more frequently the sensor outputs the second value within the predefined period of time, the more likely it is that the sensor is dry and thus that the coolant level is at a critical level, as explained below.

[0020] Furthermore, in addition to the frequency of the second value, the processing unit can also consider the duration of the second value. For example, if the second value occurs more frequently and for longer periods, this can also indicate a high probability that a critical coolant level has been reached.

[0021] Furthermore, the processing unit can be configured to calculate a gradient based on an increase in the frequency of the second value over the predefined period. This gradient can then be used to determine the time remaining until the critical fill level is reached. If this time is below a defined threshold (e.g., two weeks), the processing unit issues a corresponding warning.

[0022] According to a further embodiment, the evaluation of the coolant level includes a statement regarding a sufficient level, an insufficient level, or an insufficient level. At a sufficient level, there is enough coolant in the coolant reservoir to ensure proper operation. Furthermore, at a sufficient level, it can be assumed that there is no leak in the coolant reservoir or the cooling circuit, which would cause the level to decrease.

[0023] If the fill level is insufficient, there is still enough coolant in the coolant reservoir to ensure proper operation, but in this case, the level has already dropped so low that it should be topped up. Furthermore, if the fill level is insufficient, there is a risk that proper operation will no longer be possible in the near future and that other cooled components may be damaged. Additionally, an insufficient fill level may indicate a leak in the coolant reservoir or the cooling circuit, which should therefore be investigated and checked.

[0024] If the level is insufficient, there may still be coolant in the coolant reservoir, but this has already reached a critical level, meaning proper operation may no longer be guaranteed. In this case, you can check for a leak in the coolant reservoir or the cooling circuit. Appropriate measures should be taken, such as refilling the coolant reservoir or possibly stopping the vehicle.

[0025] According to a further embodiment, the processing unit is configured to determine whether the frequency of the second value exceeds a first threshold or a second threshold. In particular, the first threshold may correspond to a pre-warning threshold, and the second threshold may correspond to a critical threshold. The first threshold corresponds to a lower frequency of occurrence of the second value than the second threshold. The pre-warning threshold may, as described above, correspond to an insufficient fill level, which may, for example, be an indication of a loss of coolant. The critical threshold may correspond to an insufficient fill level.

[0026] According to a further embodiment, the processing unit is designed to determine, based on the determined frequency, a probability with which the fill level of the coolant corresponds to the pre-warning threshold and / or the critical threshold.

[0027] The closer the fill level is to the critical threshold, the more frequently the sensor signal will show the second value. The more frequently the second value is present, the higher the probability that the pre-warning threshold has been reached.

[0028] If the second value occurs more frequently, the probability that the critical threshold has already been reached is even higher. Any number of gradations can be defined between the sufficient fill level and the prewarning threshold or the critical threshold. Furthermore, the probability can be set depending on the application. If the device is to issue an early warning, the processing unit can set a high probability of the prewarning threshold based on a low frequency of the second value. If, on the other hand, the device is to issue a late warning, the processing unit can set a high probability based on a high frequency of the second value. The same applies to the critical threshold.

[0029] According to a further embodiment, the device has one or more further sensors for determining the acceleration of the vehicle, wherein the processing unit is designed to take the acceleration of the vehicle into account when evaluating the fill level of the coolant.

[0030] In this way, in addition to the fluctuations in the coolant detected by the sensor through changing values ​​of the sensor signal, the fluctuations in the fill level that occur, for example, in a vehicle while driving due to lateral and longitudinal acceleration forces can also be exploited. As already described above, the closer the fill level is to the critical threshold, the more frequently the sensor signal will exhibit the second value. Since in this embodiment the processing unit also has access to data from the acceleration sensors in the vehicle, the processing unit can determine a model for the actual fill level based on this acceleration information and the sensor signal. The processing unit can use, for example, machine learning algorithms or neural networks to create the model.

[0031] For example, the processing unit can determine the probability of reaching the pre-warning threshold based on the following rules:

[0032] 1 ) The more often the sensor signal has the second value, the higher the probability that the pre-warning threshold is reached;

[0033] 2) The lower the accelerations at which the second value occurs, the higher the probability that the pre-warning threshold is reached.

[0034] According to a further embodiment, the device has one or more additional sensors for determining the inclination of the vehicle. The inclination of the vehicle, and thus of the coolant reservoir, can also influence the contact of the sensor with the coolant and thus the sensor signal. According to this embodiment, the processing unit can therefore be configured to take the inclination of the vehicle into account when assessing the coolant level. This can preferably be done in combination with the acceleration.

[0035] According to a further embodiment, the processing unit is designed to take into account information relating to the shape of the coolant tank and / or the position of the sensor in the coolant tank when assessing the coolant level. Depending on the shape of the coolant tank and / or the position of the sensor in the coolant tank, the sensor can be in contact with the coolant or not in the event of different fluctuations in the fill level. In particular, if the sensor is arranged asymmetrically, in the event of corresponding movements or positions of the vehicle, caused e.g. by lateral and / or longitudinal acceleration forces or by an inclination of the vehicle, the sensor can still be in contact with the coolant even though a critical threshold or pre-warning threshold has already been reached, or it can no longer be in contact with the coolant even though the fill level is sufficient. By assessing the fill level based both on the sensor signal and / or the input signal.The frequency of the second value of the sensor signal as well as other information such as the position of the sensor, the acceleration of the vehicle and / or the inclination of the vehicle enable an accurate and comprehensive assessment of the fill level.

[0036] According to a further aspect, a method for assessing a coolant level in a coolant tank, in particular in a vehicle, is proposed. The method comprises the following steps: outputting a sensor signal from a sensor, wherein the sensor signal has a first value when the sensor is in contact with the coolant and has a second value when the sensor is not in contact with the coolant, wherein the first value differs from the second value, receiving the sensor signal, determining a frequency with which the sensor signal has the second value, and outputting an assessment of the coolant level based on the determined frequency of the second value. The embodiments and features described for the proposed device apply accordingly to the proposed method.

[0037] Furthermore, a computer program product is proposed which has a program code which is designed to cause the method as explained above to be carried out on a computer.

[0038] A computer program product, such as a computer program means, can be provided or delivered, for example, as a storage medium, such as a memory card, USB stick, CD-ROM, DVD, or in the form of a downloadable file from a server in a network. This can be done, for example, in a wireless communications network by transmitting a corresponding file with the computer program product or the computer program means.

[0039] Further possible implementations of the invention also include combinations of features or embodiments described above or below with respect to the exemplary embodiments not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

[0040] Further advantages and advantageous embodiments are set forth in the description, the drawings, and the claims. In particular, the combinations of features set forth in the description and the drawings are purely exemplary, so the features may also be present individually or in other combinations.

[0041] The invention will be described in more detail below with reference to exemplary embodiments illustrated in the drawings. The exemplary embodiments and the combinations shown in the exemplary embodiments are purely exemplary and are not intended to define the scope of the invention. This scope is defined solely by the appended claims.

[0042] Shown are: Fig. 1: a schematic block diagram of a device for evaluating a level of a coolant; and

[0043] Fig. 2: a schematic view of a vehicle with the device from Fig. 1.

[0044] Fig. 1 shows a device 1 for evaluating a fill level F1, F2, F3 of a coolant 4 in a coolant tank 2. The device can be used in particular in a vehicle 20, as shown in Fig. 2.

[0045] The coolant 4 in the coolant reservoir 2 can be monitored by a sensor 6. The sensor 6 is preferably arranged such that it is in contact with the coolant 4 when the fill level F1 of the coolant 4 is sufficient, and is not in contact with the coolant 4 when the fill level F3 is insufficient. In a fill level F2, in which there is still sufficient coolant 4 but a pre-warning threshold has already been reached, the sensor 6 will sometimes be in contact with the coolant 4 and sometimes not, depending on movements of the coolant 4, which may be caused by movements of the vehicle 20.

[0046] This alternating contact of sensor 6 with coolant 4 is detected because sensor 6 outputs a sensor signal 8 that has a first value when sensor 6 is in contact with coolant 4 and a second value when sensor 6 is not in contact with the coolant (4). The first value and the second value are different; for example, the first value may be a low voltage and the second value a high voltage.

[0047] In order to evaluate the fill level F1, F2, F3 of the coolant 4 based on the sensor signal 8, the device 1 has a processing unit 10. The processing unit 10 can, for example, be part of a control or computing system of the vehicle 20.

[0048] The processing unit 10 receives the sensor signal 8 and determines a frequency with which the sensor signal 8 has the second value. Based on the determined frequency of the second value, the processing unit 10 can then output an evaluation of the fill level F1, F2, F3 of the coolant 4 (12).

[0049] Preferably, in addition to the sensor signal 8, the processing unit 10 receives further sensor signals from sensors 14-1, ... 14-n. These sensors 14-1, ... 14-n can be various sensors, for example of the vehicle, which contain information about a longitudinal and / or lateral acceleration, inclination, or tilt angle of the vehicle 20. This information can additionally be used to evaluate the fill level F1, F2, F3.

[0050] The processing unit 10 can further receive information 18 regarding the position of the sensor 6 in the coolant reservoir 4, the position of the coolant reservoir 4 in the vehicle 2, the shape of the coolant reservoir 4, or the like. This information 18 can be retrieved, for example, from a database 16, which can be part of the vehicle 20 or implemented on a server.

[0051] The processing unit 10 is designed in particular to evaluate whether the fill level of the coolant 4 is at a sufficient fill level F1, a fill level F2 which corresponds to a pre-warning threshold, or a critical fill level F3.

[0052] For this purpose, the processing unit 10 determines, as described above, the frequency with which the sensor signal 8 assumes the second value. In contrast to previous systems, which only determined whether the sensor 6 exceeds or falls below a threshold value, the processing unit 10 can also detect fluctuations / movements of the coolant 4 by determining the frequency of the second value and take them into account when assessing the fill level. In the case of strong fluctuations or movements, if the fill level has actually already reached the pre-warning threshold F2, the second value will occur more frequently than if the fill level is still sufficient (F1). However, if the critical threshold F3 has already been reached, the second value of the sensor signal 8 will occur even more frequently.

[0053] If the sensor 8 is mounted asymmetrically, e.g. on the left side of the container 2, as shown by way of example in Fig. 1, the sensor 6 may be dry due to the corresponding fluctuation in the coolant 4 when the vehicle 20 turns right, even though the fill level F1 is sufficient. In contrast, for example, the sensor 6 may be in contact with the coolant 4 when the vehicle 20 turns left, even though the fill level has already reached the pre-warning threshold F2. Therefore, if the processing unit 10 receives not only the sensor signal 8 but also further additional information from sensors 14, 14-1 ... 14-n, the evaluation of the fill level F1, F2, F3 can be further improved.

[0054] In summary, the device described here enables an assessment of the coolant level in a coolant tank that is significantly more comprehensive and accurate than previous systems. Furthermore, the device described is capable of taking into account and compensating for movements and fluctuations in the coolant during the assessment.

[0055] Reference symbol

[0056] 1 device

[0057] 2 coolant tanks

[0058] 4 Coolant

[0059] 6 Sensor

[0060] 8 Sensor signal

[0061] 10 processing unit

[0062] 12 Output signal

[0063] 14, 14-1 , 14-2 Accelerometers, inclination sensors

[0064] 16 Database

[0065] 18 further information

[0066] F1 sufficient fill level

[0067] F2 insufficient fill level (pre-warning threshold)

[0068] F3 insufficient fill level (critical threshold)

Claims

Device and method for evaluating a fill level of a coolant in a coolant tank Claims:

1. Device (1) for evaluating a fill level (F1, F2, F3) of a coolant (4) in a coolant tank (2), in particular in a vehicle (20), wherein the device (1) has a sensor (6) which is designed to output a sensor signal (8), wherein the sensor signal (8) has a first value when the sensor (6) is in contact with the coolant (4) and has a second value when the sensor (6) is not in contact with the coolant (4), wherein the first value differs from the second value, characterized in that the device (1) has a processing unit (10) which is designed to receive the sensor signal (8) and to determine a frequency with which the sensor signal (8) has the second value, wherein the processing unit (10) is further designed to output an evaluation of the fill level (F1, F2, F3) of the coolant (4) based on the determined frequency of the second value.

2. Device according to claim 1, wherein the processing unit (10) is designed to determine the frequency with which the sensor signal (8) has the second value over a predefined period of time.

3. Device according to claim 1 or 2, wherein the evaluation of the fill level (F1, F2, F3) of the coolant (4) comprises a statement about a sufficient fill level (F1), an insufficient fill level (F2) or an insufficient fill level (F3).

4. Device according to one of the preceding claims, wherein the processing unit (10) is designed to determine whether the frequency of the second value exceeds a first threshold or a second threshold.

5. Device according to claim 4, wherein the first threshold value corresponds to a pre-warning threshold (F2) and wherein the second threshold value corresponds to a critical threshold (F3).

6. Device according to one of the preceding claims, wherein the processing unit (10) is designed to determine, based on the determined frequency, a probability with which the fill level (F1, F2, F3) of the coolant (4) corresponds to the pre-warning threshold (F2) and / or the critical threshold (F3).

7. Device according to one of the preceding claims, wherein the device (1) has one or more further sensors (14, 14-1, 14-n) for determining the acceleration of the vehicle (20), and wherein the processing unit (10) is designed to take the acceleration of the vehicle (20) into account when evaluating the fill level (F1, F2, F3) of the coolant (4).

8. Device according to one of the preceding claims, wherein the device (1) has one or more further sensors (14, 14-1, 14-n) for determining an inclination of the vehicle (20), and wherein the processing unit (10) is designed to take the inclination of the vehicle (20) into account when evaluating the fill level (F1, F2, F3) of the coolant (4).

9. Device according to one of the preceding claims, wherein the processing unit (10) is designed to take into account information relating to the shape of the coolant tank (2) and / or the position of the sensor (6) in the coolant tank when evaluating the fill level (F1, F2, F3) of the coolant (4).

10. Method for evaluating a fill level (F1, F2, F3) of a coolant (4) in a coolant tank (2), in particular in a vehicle (20), the method comprising outputting a sensor signal (8) from a sensor (6), wherein the sensor signal (8) has a first value when the sensor (6) is in contact with the coolant (4) and has a second value when the sensor (6) is not in contact with the coolant (4), the first value being different from the second value, characterized in that the method comprises the following steps: receiving the sensor signal (8), determining a frequency with which the sensor signal (8) has the second value, and outputting an assessment of the fill level (F1, F2, F3) of the coolant (4) based on the determined frequency of the second value.

Images