DE102008005896B4 - Method and warning device for warning of an insufficient filling level for a motor vehicle - Google Patents

Abstract

Method for warning of an insufficient fill level of a first fluid (1) in a first container (3) for a motor vehicle (10), wherein a fill level of the first fluid (1) in the first container (3) is measured, and wherein the motor vehicle (10) the first fluid (1) and a second fluid (2) are consumed during operation of the motor vehicle (10), characterized in that a corrected fill level is calculated by using a correction value (K) to determine the fill level of the first fluid (1 ) is corrected in the first container (3), that the warning is provided when the corrected fill level is below a threshold value (S), and that the correction value (K) depends on a fill level (FS) of the second fluid (2) in a second container (4) or depending on a circumstance that the second fluid (2) is refilled, or the threshold value (S) is selected depending on the fill level (FS) of the second fluid (2) in the second container (4) or is selected depending on the fact that the second fluid (2) is refilled.

Description

The present invention relates to a method for providing a warning of a too low filling level, in particular an oil level, for a motor vehicle and a correspondingly designed warning device.

The US 2002/0177960 A1 describes a method for measuring an engine oil level of a vehicle. The engine oil level is measured while the vehicle is being refueled.

The DE 101 41 520 A1 describes an oil level measurement for a vehicle, which is carried out under certain conditions. One of these conditions is that the vehicle is refueled.

The DE 196 17 987 A1 discloses the checking of an oil level for a vehicle, which is carried out when a signal from a fuel level sensor indicates a positive change in level.

The DE 10 2006 030 677 A1 describes the display of a fill level signal in a vehicle. A second fill level signal, which indicates that a second liquid level falls below a second threshold, is only displayed if a first fill level sensor does not determine that a first liquid level has fallen below a first threshold.

According to the prior art, for example, the oil level in an engine of a motor vehicle is automatically checked periodically or continuously. As soon as the detected oil level has fallen below a predetermined threshold, a warning is issued by the engine control unit and instrument cluster due to the low level. If necessary, this warning is delayed until the next ignition change in order not to unsettle the driver of the motor vehicle while driving. The warning is determined by the engine control unit and displayed by the instrument cluster. In principle, it is also possible for other control devices or electronic components to detect the warning.

Since, for example, an oil level that is too low must be remedied as quickly as possible (by topping up the engine oil), it is particularly annoying if the warning about the oil level being too low occurs, for example, when there is no shop anywhere, such as a gas station which engine oil could be purchased.

It is therefore the object of the present invention to at least reduce the probability of occurrence of the problem described above according to the prior art.

This object is achieved according to the invention by a method for warning of a filling level that is too low according to claim 1, by a warning device against a filling level that is too low according to claim 14 and by a motor vehicle according to claim 18. The dependent claims define advantageous and preferred embodiments of the present invention.

Within the scope of the present invention, a method is provided for generating a warning about a too low fill level of a first fluid (i.e. gas or liquid) in a first container for a motor vehicle. In this case, the first fluid but also a second fluid (in particular liquid or gaseous fuel) is consumed during operation of the motor vehicle, and a fill level of the first fluid in the first container is automatically measured. Starting from the fill level of the first fluid, a corrected fill level of the first fluid is calculated by correcting the fill level of the first fluid using a correction value. The correction value can be deducted from the fill level of the first fluid. It is also possible for the fill level of the first fluid to be multiplied by the correction value or for the fill level of the first fluid to be divided by the correction value in order to calculate the corrected fill level. The warning is generated when the corrected fill level is below a predetermined threshold value. Either the correction value or the predetermined threshold value is selected depending on a fill level of the second fluid or depending on a circumstance that the second fluid is being refilled. In other words, the warning that the fill level of the first fluid is too low is generated depending on the fill level of the second fluid or depending on the fact that the second fluid is being refilled, i.e. if it can be seen that a gas station is about to be approached or that Gas station has already arrived.

It should be pointed out here that the present invention covers all embodiments in which the fill level of the first fluid is corrected with the correction value, although in principle it is irrelevant whether this is done by subtraction (or addition with a negative correction value), Multiplication or division occurs because the correction value can be adapted, for example, from one form of calculation, subtraction, to another form of calculation (addition, subtraction, multiplication or division). Unless otherwise stated below, this will be done the correction of the fill level of the first fluid via subtraction with the correction value.

This makes it possible according to the invention to generate the warning about the low level of the first fluid, in particular engine oil, if possible when the second fluid is refueled or when it is detected via the level of the second fluid that the second fluid needs to be refueled soon . If the second fluid is, for example, a fuel or a fuel, e.g. gasoline or diesel, for the motor vehicle, it can be achieved according to the invention that the probability of the warning of an oil level being too low occurs more frequently when the motor vehicle is in motion is already at a gas station or if it is foreseeable that the motor vehicle will soon drive into a gas station. This offers the advantage that the driver of the motor vehicle can buy engine oil when purchasing the fuel, so that he virtually never or at least rarely has to drive to a gas station just to refill engine oil or transmission oil.

Since a change in the correction value corresponds to a corresponding change in the threshold value, the correction value is then chosen in particular to be equal to 0 (or equal to 1 when multiplying or dividing with the correction value) (i.e. the corrected fill level then corresponds to the fill level measured for the first fluid in the first container) if the threshold value is selected depending on the fill level of the second fluid or depending on the fact that the second fluid is being refilled. For the same reason, in particular the threshold value is not changed by the method according to the invention if the correction value is selected depending on the fill level of the second fluid or depending on the fact that the second fluid is refilled.

• • Ein Zustand Z_1, welcher vorliegt, wenn erfasst wird, dass das zweite Fluid in dem zweiten Behälter nachgefüllt wird. Wenn es sich bei dem zweiten Fluid um ein Brennmittel für das Kraftfahrzeug handelt, kann dieser Zustand beispielsweise über einen Sensor am Tankdeckel erfasst werden, welcher aktiviert wird, wenn der Tankdeckel geöffnet wird.
• • Ein Zustand Z₂, welcher vorliegt, wenn eine Nachfüllerinnerung bezüglich des zweiten Fluids ausgegeben wird. Wenn es sich bei dem zweiten Fluid um ein Brennmittel für das Kraftfahrzeug handelt, entspricht diese Nachfüllerinnerung einer in nahezu allen Kraftfahrzeugen vorhandenen Anzeige, dass das Brennmittel zur Neige geht, welche meist im Bereich einer Tankfüllstandsanzeige des Kraftfahrzeugs vorhanden ist.
• • Ein Zustand Z₃, welcher vorliegt, wenn der Füllstand des zweiten Fluids in dem zweiten Behälter unterhalb eines vorbestimmten Schwellenwerts liegt. Wenn es sich bei dem zweiten Fluid um ein Brennmittel für das Kraftfahrzeug handelt, wird die Warnung dann erzeugt, wenn das Brennmittel im Tank des Kraftfahrzeugs zur Neige geht, also davon auszugehen ist, dass demnächst eine Tankstelle angesteuert wird.

In an embodiment according to the invention, the warning is generated when one of the following states Z ₁ to Z ₃ is detected:

• • A state Z _1, which exists when it is detected that the second fluid is being refilled in the second container. If the second fluid is a fuel for the motor vehicle, this state can be detected, for example, via a sensor on the tank cap, which is activated when the tank cap is opened.
• • A state Z ₂ which exists when a refill reminder regarding the second fluid is issued. If the second fluid is a fuel for the motor vehicle, this refill reminder corresponds to an indication present in almost all motor vehicles that the fuel is running low, which is usually present in the area of a fuel level indicator of the motor vehicle.
• • A state Z ₃ , which exists when the fill level of the second fluid in the second container is below a predetermined threshold value. If the second fluid is a fuel for the motor vehicle, the warning is generated when the fuel in the tank of the motor vehicle is running low, i.e. it can be assumed that a gas station will soon be visited.

The embodiment according to the invention described here is not to be understood in such a way that the warning that the fill level of the first fluid is too low is always or unconditionally generated when one of the aforementioned states is present. Instead, the correction value and/or the predetermined threshold value, which the corrected fill level of the first fluid must fall below in order for the warning to be generated, is changed in such a way that the warning is issued when it is to be expected that the first fluid in the first Container falls below a critical value within a period of time in which the motor vehicle, for example, uses a full tank of its fuel.

In other words, the previously stated states describe a situation in which it can be assumed that the motor vehicle is already at a gas station or that the motor vehicle will soon head to a gas station. In this case, the warning that the fill level of the first fluid is too low is issued when it can be assumed that the fill level of the first fluid falls below a critical value before the motor vehicle drives to a gas station again.

According to a further embodiment, which is referred to below as the first embodiment, the predetermined threshold value S becomes periodic or continuous depending on a threshold variable S ₀ , a threshold security Si, a maximum fill level FS _max of the second fluid in the second container and depending on the second Level FS is calculated by the following equation 1. The threshold variable S ₀ is a volume of the first fluid that the motor vehicle consumes according to an average consumption of the first fluid in a period of time or during a trip in which the motor vehicle also consumes a complete volume of the second container of the second fluid. If the first fluid is engine oil and the second fluid is fuel means for the motor vehicle, the threshold variable S corresponds to a volume of engine oil that is consumed on average when the motor vehicle consumes a tank of its fuel. In other words, the threshold variable S ₀ corresponds to an oil consumption of one tank filling. $$S=S_0\times \left(1-\frac{FS}{F{S}_{max}}\right)+Si$$

The threshold security S _i corresponds to the predetermined threshold value with regard to engine oil without the present method according to the invention. In other words, the warning of a filling level that is too low is generated without the present method according to the invention when the oil level is below the threshold safety value Si.

Equation 1 stated above ensures that the lower the fill level of the second fluid in the second container, the greater the predetermined threshold value. Conversely, the predetermined threshold value with which the fill level of the first fluid is compared in order to generate the warning depending on this comparison when the fill level is below the predetermined threshold value is smaller, the greater the fill level of the second fluid in the second container . This advantageously ensures that the probability of occurrence of the warning that the fill level of the first fluid is too low is greater, the lower the fill level of the second fluid in the second container.

$$S>S_0\times \left(1-\frac{FS}{x\times F{S}_{\text{max}}}\right)+Si$$

$$S\ge Si$$

$$0<x<1$$

In another embodiment according to the invention, which is referred to here as the second embodiment, the predetermined threshold value S is periodically or continuously degressive in turn depending on the threshold variable S ₀ , the threshold security Si, the maximum fill level FS _max of the second fluid in the second container and depending on the second fill level FS is set in such a way that the following equations 2 to 5 are adhered to. $$S\le S_0\times \left(1-\frac{FS}{F{S}_{\text{Max}}}\right)+Si,$$

$$S>S_0\times \left(1-\frac{FS}{x\times F{S}_{\text{Max}}}\right)+Si$$

$$S\ge Si$$

$$0<x<1$$

Equation 2 corresponds to equation 1 except for the comparison operator. This ensures that the predetermined threshold value according to this second embodiment is at least not larger, but is generally smaller than the predetermined threshold value according to the first embodiment. Equation 4 ensures that the predetermined threshold according to the present invention is never smaller than the threshold security. In addition, equations 3 and 5 provide a further lower limit for the predetermined threshold value according to the invention, where x is better in the range 0.2 <x <0.5. Equations 3 and 5 in particular ensure that the lower the fill level of the second fluid, the closer the predetermined threshold value in this embodiment is to the predetermined threshold value of the first embodiment. In other words, the degressive adjustment of the predetermined threshold value according to the second embodiment discussed here ensures that the probability of occurrence of the warning for low fill levels of the second fluid is in a similar range as in the first embodiment and that the probability of occurrence of the warning for higher ones Fill levels of the second fluid are advantageously lower than in the first embodiment.

Furthermore, it is possible to increase the predetermined threshold value by a threshold value offset if one of the previously executed states Z ₁ to Z ₃ is present.

By increasing the predetermined threshold value by a threshold value offset, the probability of occurrence of the warning is increased if one of the corresponding states Z ₁ to Z ₃ is present. In other words, the threshold value offset ensures that the warning about the low level of the first fluid occurs almost exclusively when the motor vehicle is being refueled or when the motor vehicle is about to be refueled.

In addition, it is possible for the threshold value offset to be determined in such a way that the threshold value offset corresponds to a consumption of the first fluid, e.g. oil consumption, for a distance that can be covered with a refueled volume of the second fluid. This is particularly advantageous if the predetermined threshold value is then corrected with the threshold value offset when it has been detected that the motor vehicle is currently being refueled.

According to a third embodiment of the invention, the correction value K is periodically or continuously dependent on a correction value maximum K _max , the maximum fill level FS _max of the second fluid and the second fill level FS is calculated by the following equation 6. The correction value maximum K _max is set such that K _max corresponds to a volume of the first fluid which is consumed in an operating period (ie a period in which the motor vehicle is in operation) in which a tank content of the second fluid is also consumed . If the first fluid is engine oil and the second fluid is the fuel for the motor vehicle, the correction value maximum K _max corresponds to a volume of engine oil that is consumed on average when the motor vehicle consumes a tank of its fuel. $$K=K_{\text{Max}}\times \left(1-\frac{FS}{F{S}_{\text{Max}}}\right)$$

The equation 6 given above ensures that the correction value is greater the lower the fill level of the second fluid in the second container. Conversely, the larger the fill level of the second fluid in the second container, the smaller the correction value is. This advantageously ensures that the probability of occurrence of the warning of a too low fill level of the first fluid is greater the lower the fill level of the second fluid in the second container, i.e. the higher the probability that the motor vehicle will soon visit a gas station .

In embodiments in which the fill level of the first fluid is multiplied by the correction value or divided by the correction value, equation (6) must be adjusted accordingly.

$$K\ge K_{\text{max}}\times \left(1-\frac{FS}{x\times F{S}_{\text{max}}}\right)$$

$$K\ge 0$$

$$0<x<1$$

In a fourth embodiment according to the invention, the correction value K is periodically or continuously degressively set again depending on the correction value maximum K _max , the maximum fill level FS _max of the second fluid and the second fill level FS in such a way that the following equations 7-10 are adhered to. $$K\le K_{\text{Max}}\times \left(1-\frac{FS}{F{S}_{\text{Max}}}\right)$$

$$K\ge K_{\text{Max}}\times \left(1-\frac{FS}{x\times F{S}_{\text{Max}}}\right)$$

$$K\ge 0$$

$$0<x<1$$

Equation 7 corresponds to equation 6 except for the comparison operator. This ensures that the correction value according to this fourth embodiment is at least not larger, but is generally smaller than the correction value according to the third embodiment. Equation 9 ensures that the correction value according to the present invention is never less than 0. In addition, equations 8 and 10 provide a further lower limit for the correction value, whereby x is better in the range 0.2 < x < 0.5. Equations 8 and 10 in particular ensure that the lower the fill level of the second fluid, the closer the correction value in this embodiment is to the correction value of the third embodiment. In other words, the degressive adjustment of the correction value according to the fourth embodiment discussed here ensures that the probability of occurrence of the warning for low fill levels of the second fluid is in a similar range as in the third embodiment, but that the probability of occurrence of the warning for higher ones Fill levels of the second fluid are advantageously lower than in the third embodiment.

In a similar manner to the predetermined threshold value, it is possible to increase the correction value by a correction value offset if one of the previously executed states Z ₁ to Z ₃ is present.

By increasing the correction value by a correction value offset, the probability of the warning occurring is increased if one of the corresponding states Z ₁ to Z ₃ is present. In other words, the correction value offset ensures that the warning about the low level of the first fluid occurs almost exclusively when the motor vehicle is being refueled or when the motor vehicle is about to be refueled.

In addition, it is possible for the correction value offset to be determined in such a way that the correction value offset corresponds to a consumption of the first fluid, e.g. oil consumption, for a route that can be covered with a currently refueled volume of the second fluid. This is particularly advantageous if the fill level of the first fluid is corrected with the correction value offset when it has been detected that the motor vehicle is being refueled.

Within the scope of the present invention, a warning device is also provided in order to generate the warning that the fill level of the first fluid in the first container is too low. The warning device comprises a first level meter, with which the level of the first fluid in the first container is detected, and a second level meter, with which the level of the second fluid in the second container is recorded. The warning device is designed in such a way that the warning device calculates the corrected fill level in that the warning device subtracts the correction value from the fill level of the first fluid measured by the first fill level meter. The warning device generates the warning when the warning device detects that the corrected fill level is below the predetermined threshold value. In addition, the warning device comprises a detection device, which is designed such that the detection device detects when the second fluid is refilled. The warning device determines the predetermined threshold value or the correction value depending on the fill level of the second fluid or depending on whether the detection device has detected that the second fluid is being refilled.

The advantages of the warning device according to the invention essentially correspond to the advantages of the method according to the invention, which have been discussed in detail in advance, which is why repetition is omitted here.

Within the scope of the present invention, a motor vehicle with a warning device according to the invention is also provided.

The present invention combines the warning of a too low fill level of the first fluid, for example an insufficient oil level, with the fill level of a second fluid, in particular the fill level of a fuel, so that the warning of a too low fill level of the first fluid increasingly or progressively accumulated with low fill levels of the second fluids, so that advantageously the first fluid and the second fluid can be supplemented at the same time. This increases customer satisfaction, simplifies maintenance of the motor vehicle and avoids uncertainty for the driver of the motor vehicle due to a warning that the oil level is too low, for example, being activated at the wrong time. This in particular prevents the driver of the motor vehicle from receiving a warning that the oil level is too low when he has just refueled. This is particularly annoying if the driver drove onto a motorway shortly after refueling, meaning he has to travel a longer distance even if he wants to drive back to the petrol station. This is exactly what is advantageously avoided by the present invention.

The present invention is used in particular in motor vehicles that consume engine oil and fuel during their operation in order to refill the engine oil and fuel, if possible, with just one stop at a gas station. However, the present invention is of course not limited to this preferred area of application, but can also be used if the second fluid is, for example, an operating medium (e.g. an aqueous urea solution) for a catalytic converter of the motor vehicle. In addition, the present invention can also be used on ships, aircraft or rail-bound vehicles.

• In 1 ist schematisch ein erfindungsgemäßes Kraftfahrzeug mit einer erfindungsgemäßen Warnvorrichtung dargestellt.
• In 2 ist ein möglicher Kurvenverlauf für einen linearen Schwellenwertverlauf und für einen degressiven Schwellenwertverlauf dargestellt.
• In 3 ist ein möglicher Kurvenverlauf für einen linearen Korrekturwertverlauf und für einen degressiven Korrekturwertverlauf dargestellt.
• In 4 ist ein beispielhafter Verlauf des Ölstands und eines korrigierten Ölstand bei einer linearen Korrektur dargestellt.
• In 5 ist ein beispielhafter Verlauf eines Ölstands und eines korrigierten Ölstands bei einer degressiven Korrektur dargestellt.
• In 6 ist ein beispielhafter Verlauf eines Ölstands und eines mit einem Offset korrigierten Ölstands dargestellt.
• In 7 ist ein beispielhafter Verlauf eines Ölstands und eines mit einem Offset korrigierten und zusätzlich degressiv korrigierten Ölstands dargestellt.

The present invention will be explained in detail below using embodiments according to the invention with reference to the drawing.

• In 1 A motor vehicle according to the invention is shown schematically with a warning device according to the invention.
• In 2 A possible curve shape is shown for a linear threshold value curve and for a degressive threshold value curve.
• In 3 A possible curve shape is shown for a linear correction value curve and for a degressive correction value curve.
• In 4 an exemplary course of the oil level and a corrected oil level is shown with a linear correction.
• In 5 an exemplary course of an oil level and a corrected oil level with a degressive correction is shown.
• In 6 An example of an oil level and an oil level corrected with an offset is shown.
• In 7 An example of an oil level and an oil level corrected with an offset and additionally degressively corrected is shown.

1 schematically represents a motor vehicle according to the invention, which comprises a first container 3 with engine oil 1, a second container 4 with fuel 2 and a warning device 8 according to the invention. The warning device 8 in turn comprises a first level gauge 5, with which a fill level of the engine oil 1 within the first container 3 is measured, and a second fill level gauge 6, with which a fill level of the fuel 2 in the second container 4 is measured. In addition, the device 8 includes a detection device 7, with which, for example, by means of a sensor on the tank cap (not shown), it is detected when the motor vehicle 10 is refueled (i.e. fuel 2 is refilled into the second container 4) or with which it is detected that a re-anchoring reminder signal has been generated elsewhere. The warning device 8 determines whether the fuel level 1 is filled Motor vehicle 10 will soon drive to a gas station, and via the detection device 7, the warning device 8 determines whether the motor vehicle is currently at a gas station or the driver has been informed of the need for fuel. Depending on the fill level of the engine oil 1 and depending on whether the motor vehicle 10 will soon be heading to a gas station or is already at a gas station, the warning device 8 activates a warning lamp 9 of the warning device 8, which is in a dashboard (not shown) of the motor vehicle 10 is arranged and signals to the driver that engine oil 1 needs to be refilled at the current or soon intended stop at the gas station. The warning device 8 is designed according to the invention in such a way that it does not activate the warning lamp 9 only if the warning device 8, based on an average consumption of the engine oil 1, can assume with a relatively high degree of certainty that the engine oil 1 is in the first container 3 a period of time or on a route in which the motor vehicle consumes a full tank of fuel (a complete volume of the second container 4) will not fall below a critical level.

2 represents, by way of example, a course of the predetermined threshold value S depending on the fill level FS of the fuel 2. The line designated by reference number 14 shows a linear course of the threshold value and the line designated by reference number 19 shows a degressive threshold value. When the tank 4 of the motor vehicle 10 is full, the predetermined threshold value corresponds to a threshold security Si, which is to be equated to the normal threshold value, which, when fallen below, is activated by the fill level of the engine oil 1 according to the prior art or without the present invention, a warning lamp, to signal to the driver of the motor vehicle that the level of engine oil 1 has fallen below a critical value. The further the fuel level moves away from the maximum possible level, ie the emptier the tank of the motor vehicle 10 becomes, the more the predetermined threshold value increases. The increase is linear according to curve 14 and degressive or progressive according to curve 19 depending on the viewing angle. This ensures that the predetermined threshold value S according to the degressive curve 19 is never greater than the predetermined threshold value S according to the linear curve 14. In addition to the lower limit Si, a further lower limit is drawn with a line 28, which must not fall below the degressive curve 19, which falls steadily as the fill level FS increases. The lower limit Si and the lower barrier 28 ensure that the degressive curve 19 must run closer to the linear curve 14, the emptier the tank 4 is, and the higher the probability that the driver of the motor vehicle will soon have one Heads for gas station. Since the higher the predetermined threshold value, the higher the probability that the oil level will slip below the predetermined threshold value, the emptier the tank 4 is, the more likely it is that the warning lamp 9 of the warning device 8 will be activated. The course of the linear curve 14 is in particular somewhat steeper than a course with which engine oil 1 is consumed on average by the motor vehicle 10 depending on the consumption of fuel 2

In 3 is a similar course as in 2 for the correction value K depending on the fill level FS in the tank 4 of the motor vehicle 10. The correction value K, which is subtracted from the oil level measured by the first level gauge 5, has the value 0 when the tank 4 is full and increases to the value K _max , the lower the fill level of the fuel 2 in the tank 4 is Motor vehicle 10 is. A curve 26 shows a linear course of the correction value K, and a curve 27 shows a degressive course of the correction value K. It is ensured that the correction value K according to the degressive course 27 is always smaller than the correction value K according to the linear course, but each is greater than 0 and greater than a value specified by another auxiliary line 29. This is similar to the predetermined threshold value S 2 ensures that the correction value K according to the degressive curve 27 is closer to the correction value K according to the linear curve 26, the less fuel 2 is in the tank 4. This leads to the same advantages as when discussing the predetermined threshold 2 has been carried out.

In the 4 to 7 a course of the oil level 11 over a route 12 is shown. It can be seen that the oil level 15 drops gradually as the distance 12 increases. The stages in the course 15 are due to the fact that the oil level 15 is only calculated, for example, every 100 km. The points at which the motor vehicle 10 is (completely) refueled are marked with a reference number 16. It can be seen that neither the oil level measured by the first level gauge 5 nor the oil level corrected with the linearly increasing correction value 26 at the second refueling stop is below the critical oil level 13, which is indicated by the threshold security Si, so that neither before nor at that second refueling stop, the warning lamp 9 is activated by the warning device 8.

In contrast, the oil level corrected by the linearly increasing correction value is already below the warning threshold 13 at a point marked with the reference number 17, so that the warning lamp 9 is activated by the warning device 8 at this point in time. It can be seen that the uncorrected oil level at the third refueling 16 is not yet below the warning threshold 13, so that without the present invention, a driver of a motor vehicle according to the prior art does not receive a warning at the third refueling 16 that the oil level is about to fall below the warning threshold 13 will fall. In other words, a driver of the motor vehicle 10 will normally refill engine oil 1 at the third refueling stop 16 because he has been warned by the present invention via the warning lamp 9, while a driver who drives a motor vehicle according to the prior art will only do so briefly After leaving the gas station, he is informed that his oil level has now fallen below a critical level.

In 5 is a similar course of the oil level 11 over the route 12 as in 4 shown, whereby the oil level is corrected by a progressive or degressive correction value. Despite this progressive correction value (the correction value is progressively larger the empty tank is or degressively smaller the fuller the tank is), the corrected oil level at the second refueling stop 16 is not yet below the warning threshold 13, so that even at the in 5 shown course 27 of the oil level, the warning lamp 9 is not activated before or during the second refueling stop 16. However, the oil level corrected by the progressive correction value 27 falls below the warning threshold 13 at point 17, so that the warning lamp 9 is activated at this point in time. You can see when comparing the course of the oil level 4 with the course of the oil level 15 according to the 5 that the warning lamp is activated later with the progressive course of the correction value 27 than with the linear course of the correction value 26 4 . This has the advantageous effect that the warning about the oil level being too low occurs closer to the time of the third refueling 16. Like with that 4 The oil level, which was not corrected according to the invention, only falls below the warning threshold 13 at point 18 after the third refueling.

In 6 is like in the 4 and 5 the course of the oil level 15 over the route 12 is shown. At the with 6 In the embodiment shown, the oil level measured by the first level gauge 5 is corrected by an offset or offset 21 when the detection device 7 detects that the motor vehicle 10 is being refueled or when the detection device 7 detects that the fill level of the fuel 2 in the tank 4 falls below a predetermined level Threshold value has fallen, so that a re-anchoring reminder signal has been activated (eg by a corresponding lamp in the dashboard of the motor vehicle 10). The warning device 8 is designed in such a way that it activates the warning lamp 9 when the oil level corrected by the offset 21 has fallen below the warning threshold 13. It can be seen that this is not yet the case with the second occurrence of the refueling event or the refueling reminder. However, the oil level corrected by the offset 21 is below the warning threshold 13 on the third occurrence of the refueling event or the refueling reminder, so that the warning lamp 9 is activated by the warning device 8 at a point marked with the reference number 22. It can be seen that a motor vehicle according to the state of the art does not receive any indication of a critical fill level of the engine oil 1 on the third occurrence of the refueling event or the refueling reminder, but rather this indication only appears a short time later (i.e. after leaving the gas station). Reference numeral 23 takes place.

In 7 a course of the oil level 11 is again shown over the route 12, with an embodiment according to the invention being shown graphically, in which the measured oil level is corrected both with a progressive correction value (which results in the curve 27) and with an offset 21 . The measured oil level is corrected at any time with a progressive correction value, so that the curve 27 results (again, the empty the tank 4, the greater the correction value). In addition, the corrected oil level is additionally corrected with an offset 21 when the detection device 7 detects either a refueling event or a refueling reminder signal. In 7 At point 24 (third occurrence of the refueling event or refueling reminder), no oil level warning 9 is activated despite the corrected oil level applied with the offset 21. It is only on the fourth occurrence of the refueling event or the refueling reminder that the warning lamp 9 is activated by reducing the oil level corrected with the progressive correction value with the offset 21, since the corrected oil level has fallen below the warning threshold 13. Without the fourth occurrence of the refueling event or the refueling reminder, the oil level corrected by the progressive correction value would only fall below the warning threshold 13 at point 30, so that the warning lamp 9 is then activated according to the invention.

The explanations also apply to level determination and level monitoring of a container with aqueous urea solution, which is used in SCR systems (“Selective Catalytic Reduction”) for NO _X exhaust gas aftertreatment is preferably used in diesel engines.

REFERENCE SYMBOL LIST

1

Engine oil

2

fuel

3, 4

container

5.6

Level gauge

7

Detection device

8th

Warning device

9

Warning lamp (low oil level)

10

motor vehicle

S

Threshold

Si

Security

S0

Threshold variable

K

Correction value

Kmax

maximum correction value

FS

level

FSmax

maximum filling level

11

oil level

12

Driving distance

13

Warning threshold

14

linear threshold curve

15

oil level

16

Tank event

17

Oil level warning (with correction)

18

Oil level warning (without correction)

19

degressive threshold value progression

20

Refueling event or refueling reminder signal

21

Oil level corrected by offset

22

Oil level warning (by offset)

23

Oil level warning (without offset)

24

progressive correction and offset

25

Oil level warning (through progressive correction and offset)

26

linear correction value curve

27

degressive correction value curve

28.29

Guideline

30

Oil level warning through progressive correction

Claims (18)

Method for warning of an insufficient fill level of a first fluid (1) in a first container (3) for a motor vehicle (10), wherein a fill level of the first fluid (1) in the first container (3) is measured, and wherein the Motor vehicle (10) consumes the first fluid (1) and a second fluid (2) during operation of the motor vehicle (10), characterized in that a corrected fill level is calculated by using a correction value (K) to determine the fill level of the first fluid ( 1) is corrected in the first container (3), that the warning is provided when the corrected fill level is below a threshold value (S), and that the correction value (K) depends on a fill level (FS) of the second fluid (2) in a second container (4) or depending on a circumstance that the second fluid (2) is being refilled, or the threshold value (S) is selected depending on the fill level (FS) of the second fluid (2) in the second container (4 ) or depending on the fact that the second fluid (2) is refilled, is selected. Procedure according to Claim 1 , characterized in that the corrected fill level is calculated by subtracting the correction value (K) from the fill level of the first fluid (1) in the first container (3), such that the correction value (K) is equal to 0 when the threshold value ( S) is selected depending on the fill level (FS) of the second fluid (2), and that the threshold value (S) is not changed by the method if the correction value (K) depends on the fill level (FS) of the second fluid (2 ) is selected. Procedure according to Claim 1 or 2 , characterized in that the warning is provided when at least one condition is detected, which is selected from a group of conditions comprising • a condition which is present when it is detected that the second fluid (2) is in the second container (4 ) is refilled, • a state which exists when a refill reminder is issued regarding the second fluid (2), and • a state which exists when it is detected that the fill level (FS) of the second fluid (2) in the second container (4) is below a predetermined further threshold value. Procedure according to one of the Claims 1 - 3 , characterized in that the threshold value S depends on a threshold variable S ₀ , a threshold security Si, a maximum fill level FS _max of the second fluid (2) in the second container (4) and the second fill level FS is adjusted as follows: $$S=S_0\times \left(1-\frac{FS}{F{S}_{\text{Max}}}\right)+Si,$$

where S ₀ corresponds to an average consumption during operation of the motor vehicle (10) to a volume of the first fluid (1) which is consumed in an operating period in which a volume of the second container (4) is also consumed by the second fluid (2). is consumed. Procedure according to one of the Claims 1 - 3 , characterized in that the threshold value S is adjusted depending on a threshold value variable S ₀ , a threshold value security Si, a maximum fill level max. FS of the second fluid (2) in the second container (4) and the second fill level FS in such a way that the following equations be respected: $$S\le S_0\times \left(1-\frac{FS}{F{S}_{\text{Max}}}\right)+Si,$$

$$S>S_0\times \left(1-\frac{FS}{x\times F{S}_{\text{Max}}}\right)+Si$$

$$S\ge Si$$

$$0<x<1$$

where S ₀ corresponds to an average consumption during operation of the motor vehicle (10) to a volume of the first fluid (1) which is consumed in an operating period in which a volume of the second container (4) is also consumed by the second fluid (2). is consumed. Procedure according to one of the Claims 1 - 5 , characterized in that the threshold value (S) is increased by a threshold value offset when at least one state is detected, which is selected from a group of states comprising • a state which is present when it is detected that the second fluid (2) in the second container (4) is refilled, • a state which exists when a refill reminder is issued regarding the second fluid (2), and • a state which exists when it is detected that the fill level (FS) of the second Fluid (2) in the second container (4) is below a predetermined threshold value. Procedure according to Claim 6 , characterized in that the threshold value offset corresponds to a volume of the first fluid (1) which is required for a route which can be covered with a refueled volume of the second fluid. Procedure according to one of the Claims 1 - 3 , characterized in that the corrected fill level is calculated by subtracting the correction value from the fill level of the first fluid (1) in the first container (3), and that the correction value K depends on a correction value maximum K _max , a maximum fill level FS _max of the second fluid (2) in the second container (4) and the second fill level FS is adjusted as follows: $$K=K_{\text{Max}}\times \left(1-\frac{FS}{F{S}_{\text{Max}}}\right),$$

where K _max corresponds to an average consumption during operation of the motor vehicle to a volume of the first fluid (1) which is consumed in an operating period in which a volume of the second container (4) is also consumed by the second fluid (2). Procedure according to one of the Claims 1 - 3 , characterized in that the corrected fill level is calculated by subtracting the correction value from the fill level of the first fluid (1) in the first container (3), and that the correction value K depends on a correction value maximum K _max ,, a maximum fill level FS _max of the second fluid (2) in the second container (4) and the second fill level FS is adjusted in such a way that the following equations are adhered to: $$K\le K_{\text{Max}}\times \left(1-\frac{FS}{F{S}_{\text{Max}}}\right),$$

$$K\ge K_{\text{Max}}\times \left(1-\frac{FS}{x\times F{S}_{\text{Max}}}\right)$$

$$K\ge \mathrm{0,}$$

$$0<x<1$$

where K _max corresponds to an average consumption during operation of the motor vehicle (10) to a volume of the first fluid (1) which is consumed in an operating period in which a volume of the second container (4) is also consumed by the second fluid (2) is consumed. Procedure according to one of the Claims 1 - 3 , 8th or 9 , characterized in that the correction value (K) is increased by a correction value offset when at least one state is detected, which is selected from a group of states comprising • a state which is present when it is detected that the second fluid (2) is being refilled in the second container (4), • a state which is present when a refill reminder regarding the second Fluid (2) is dispensed, and • a state which exists when it is detected that the fill level (FS) of the second fluid (2) in the second container (4) is below a predetermined threshold value. Procedure according to Claim 10 , characterized in that the correction value offset corresponds to a volume of the first fluid (1) which is required for a route which can be covered with a refueled volume of the second fluid (2). Method according to one of the preceding claims, characterized in that the first fluid is gear oil (1) in an engine of the motor vehicle (10) and/or an aqueous urea solution for NO _X exhaust aftertreatment of an engine of the motor vehicle (10). Method according to one of the preceding claims, characterized in that the second fluid is a fuel (2) for an engine of the motor vehicle (10) or an operating fluid for a catalytic converter of the motor vehicle (10). Warning device of an insufficient fill level of a first fluid (1) in a first container (3) for a motor vehicle (10), the warning device (8) comprising a first fill level meter (5), which indicates a fill level of the first fluid (1). the first container (3), the warning device (8) comprising a second level meter (6) which measures a level (FS) of a second fluid (2) in a second container (4), and wherein the motor vehicle (10) the first fluid (1) and the second fluid (2) are consumed during operation of the motor vehicle (10), characterized in that the warning device (8) is designed such that • the warning device (8) calculates a corrected fill level by the Warning device (8) corrects the fill level of the first fluid (1) by means of a correction value (K), • the warning device (8) provides the warning when the warning device (8) detects that the corrected fill level is below a threshold value (S), and • the warning device (8) sets the threshold value (S) depending on a fill level (FS) of the second fluid (2) or depending on the fact that a detection device (7) of the warning device (8) detects that the second fluid (2) has been refilled is selected, or selects the correction value (K) depending on the fill level (FS) of the second fluid (2) or depending on the fact that the detection device (7) detects that the second fluid (2) is being refilled. Warning device after Claim 14 , characterized in that the warning device (8) is designed such that the warning device (8) calculates the corrected fill level by the warning device (8) taking the correction value (K) from the fill level of the first fluid (1) in the first container ( 3) deducts that the correction value (K) is equal to 0 if the threshold value (S) is selected depending on the fill level (FS) of the second fluid (2), and that the threshold value (S) of the warning device (8) is not is changed when the correction value (K) is selected depending on the fill level (FS) of the second fluid (2). Warning device after Claim 14 or 15 , characterized in that the warning device (8) provides the warning • when the detection device (7) detects that the second fluid (2) in the second container (4) is being refilled, or • when the warning device (8) issues a refill reminder regarding the second fluid (2), or • when the second level meter (6) detects that the level (FS) of the second fluid (2) in the second container (4) is below a predetermined threshold value. Warning device according to one of the Claims 14 - 16 , characterized in that the warning device (8) for carrying out the method according to one of the Claims 1 - 13 is designed. Motor vehicle with a warning device according to one of the Claims 14 - 17 .

Images