DE102017005969A1 - Fuel level indicator system of a motor vehicle, motor vehicle and method for displaying a fuel level of a motor vehicle - Google Patents

Abstract

What is described is a fuel level indicating system (4) of a motor vehicle (2) having at least one level sensor (8) disposed in a motor vehicle tank (6), a level indicator (12) and a controller (10) connected to the level sensor (8) and the level indicator (12) is connected, the controller (10) for converting an input signal of the level sensor (8) into a control signal for the level indicator (12) on the basis of an algorithm (28) stored in the controller (10), wherein the controller (10) comprises a computing unit (20) and a memory (22), wherein the algorithm (28) provides that when a threshold value (Vs) is exceeded, a control signal indicating a full vehicle tank (6) is sent to the fill level indicator (12). the memory (22) has a memory area (26) for storing a plurality of maximum values (M1 - M4) of the level sensor (8), wherein the algorithm (28) by the Reche A motor vehicle (2) and a method for displaying a fuel level of a motor vehicle (2) are further described in accordance with the stored maximum values (M1 - M4).

Description

In the present case, a fuel level indicator system of a motor vehicle, a motor vehicle and a method for displaying a fuel level of a motor vehicle are described.

Automotive vehicles with internal combustion engines have fuel tanks for storing the fuel to be burned. Fuel is a consumable that needs regular replenishment. To inform a driver of a motor vehicle on the current level of the fuel tank level indicators are provided in all motor vehicles.

The level indicators couple in simpler versions of motor vehicles directly with a level sensor, which is located in the fuel tank. The level sensor outputs an electrical signal correlated to the position of a float in the fuel tank. The level indicator converts this signal into a pointer reading.

More advanced systems have a controller located between the level sensor and the level gauge that interprets the signals output from the level sensor and passes corresponding signals to the level indicator.

Drivers of motor vehicles expect that the level indicator after refueling of their motor vehicle as a level "full" displays. For this reason, in the more advanced systems, thresholds are defined above which "full" is displayed, for example at a level greater than 92% of the maximum level of the motor vehicle. The corresponding values are specified by the factory control in production.

Tank systems of motor vehicles and level sensors are subject to tolerances. Fuel tanks of various motor vehicles of the same type may have different capacity volumes. In addition, different level sensors can output slightly different electrical signals, for example voltage values, at the same filling level of a fuel tank.

In case of deviations in the margins of the permissible tolerances of filling volumes or electrical signals or an unfavorable combination of the corresponding tolerances, it may happen that the level indicator does not indicate "full" despite a sufficiently full fuel tank. This can lead to irritation in the driver and may cause complaints from customers.

Systems are known which, for example with several fuel sensors in a fuel tank, try to increase the measurement accuracy. However, these systems are expensive and expensive.

Thus, the task, fuel level display system of a motor vehicle, motor vehicle and methods for displaying a fuel level of a motor vehicle of the type mentioned in such a way that a more accurate level indicator under all tolerance conditions without significant increase in costs is possible.

The object is achieved by a fuel level indicator system of a motor vehicle according to claim 1, a motor vehicle according to the independent claim 5 and by a method for displaying a fuel level of a motor vehicle according to the independent claim 6. Further developments and concretizations are the subject of the dependent claims.

The fuel level indicating system of a motor vehicle described herein includes at least one level sensor disposed in an automotive tank, a level indicator, and a controller connected to the level sensor and the level indicator, the controller for converting an input signal of the level sensor into a control signal for the level indicator is provided on the basis of an algorithm stored in the controller, the controller having an arithmetic unit and a memory, wherein the algorithm provides that when a threshold value is exceeded a full vehicle tank indicating control signal is sendable to the level indicator, the memory having a Memory area for storing a plurality of maximum values of the level sensor, wherein the algorithm is adaptable by the arithmetic unit in dependence on the stored maximum values.

Since the algorithm can be adapted as a function of the stored maximum values, an independent calibration of the fuel level indicating system can take place during operation of the motor vehicle, so that the display accuracy of the fuel level indicating system is increased in the course of operation of the motor vehicle. The stored maximum values of the level sensor can be used for the calibration, since they represent a good measure of the limits of the output value range.

The fuel level indicating system may also include a plurality of level sensors to achieve an increase in display precision.

In a first further embodiment, it may be provided that the algorithm has an allocation table, wherein the controller is set up to change the allocation table as a function of the stored maximum values. This can be done by replacing a previously stored threshold value for displaying a full fuel tank with a new threshold value calculated on the basis of the maximum values. In addition, it is possible to calibrate the entire allocation table based on the new threshold value.

In an alternative embodiment it can be provided that the algorithm has a calculation rule in which parameters of the calculation rule are modified on the basis of the calculated new threshold value, for example by preceding a scaling multiplier.

In a further refinement that goes beyond that, provision can be made for the assignment table to be stored in the memory. The memory can be designed as a readable and writable memory, so that the arithmetic unit can overwrite the allocation table when a new threshold value is calculated.

In another further embodiment, it can be provided that the arithmetic unit is set up to store a value transmitted by the filling level sensor as a maximum value in the memory, if the maximum value represents a local maximum of a fill-time curve and if the maximum value lies within a predetermined value range around the Threshold is.

The level-time history indicates the change in level over time. The level changes with consumption of the fuel by the motor vehicle and when filling the fuel tank during refueling, for example at a gas station. As soon as the motor vehicle leaves the filling station, the fuel level in the fuel tank drops again. The arithmetic unit may be configured to store the level-time history and to identify a local maximum by time derivative. Alternatively, the arithmetic unit can be set up to respectively store a highest fill level value and to overwrite a previous highest fill level value in a buffer as soon as a new maximum is reached. The system can store the maximum value as soon as falling levels are registered by fuel consumption. The system may be sufficiently sluggishly programmed to eliminate any deviations from the position of the motor vehicle or from dynamic forces on the fuel.

By specifying a range of values around the current threshold value, it is possible to erroneously store maximum values which do not correspond to a fully fueled fuel tank. Such a situation may occur when the driver of the respective motor vehicle does not fill up the fuel tank completely, but only add a certain amount of fuel that is insufficient to fill up the motor vehicle. Due to the value range around the current threshold value, it is also possible to detect situations in which the fuel tank has a lower than the average filling volume. For example, the range of values may begin 10% below the current threshold and be open at the top.

A first independent article relates to a motor vehicle with a fuel level indicator system of the aforementioned type.

Another independent object relates to a method for displaying a fuel level of a motor vehicle, wherein a level sensor measures a level of a motor vehicle tank and forwards the measured value to a controller, wherein the controller converts the measured value by means of an algorithm into a control signal of a level indicator, which provides algorithm, in that, when a threshold value is exceeded, a full motor vehicle tank of the control signal is sent to the level indicator, wherein a plurality of maximum values of the level sensor are stored, wherein the controller adjusts the threshold based on the stored maximum values.

The plurality of maximum values may be, for example, three or more. The actual number may vary depending on the particular embodiment and may be adaptable under some circumstances.

In a first further embodiment, the threshold value calculated is a percentage of an average of the stored maximum values. Averaging is a simple operation that does not require much processing power and is also suitable for the purpose here.

In another further embodiment, provision can be made for a maximum value to be stored if a local maximum of a fill-time-time curve is present and lies within a predetermined value range around the threshold value.

The level-time history indicates the change in level over time. The level changes when the fuel is consumed by the fuel Motor vehicle and when filling the fuel tank during refueling, for example, at a gas station. As soon as the motor vehicle leaves the filling station, the fuel level in the fuel tank drops again. The arithmetic unit may be configured to store the level-time history and to identify a local maximum by time derivative. Alternatively, the arithmetic unit can be set up to respectively store a highest fill level value and to overwrite a previous highest fill level value in a buffer as soon as a new maximum is reached. The system can store the maximum value as soon as falling levels are registered by fuel consumption. The system may be sufficiently sluggishly programmed to eliminate any deviations from the position of the motor vehicle or from dynamic forces on the fuel.

By specifying a range of values around the current threshold value, it is possible to erroneously store maximum values which do not correspond to a fully fueled fuel tank. Such a situation may occur when the driver of the respective motor vehicle does not fill up the fuel tank completely, but only add a certain amount of fuel that is insufficient to fill up the motor vehicle. Due to the value range around the current threshold value, it is also possible to detect situations in which the fuel tank has a lower than the average filling volume. For example, the range of values may begin 10% below the current threshold and be open at the top.

In another further embodiment, the algorithm can have an allocation table, wherein the allocation table is changed as a function of the stored maximum values.

Alternatively, the algorithm may be configured as a calculation rule, which is calibrated by adapting parameters of the calculation rule. This can be done for example by a scaling factor in the calculation rule.

In a further refinement going beyond this, an adaptation of the threshold value can only be made when a certain number of maximum values have been stored. For example, this display may be at three or higher. This ensures that there is a sufficiently large selection of maximum values before the threshold value is adjusted.

Another independent object relates to a device for displaying a fuel level of a motor vehicle, wherein a level sensor is provided for measuring a level of a motor vehicle tank, wherein means are provided for forwarding the measured value to a controller, wherein the controller is adapted to the measured value using an algorithm to convert to a fill level control signal, the algorithm configured to transmit, when a threshold value is exceeded, a full vehicle tank of the control signal to the level gauge, wherein memory means are provided for storing a plurality of maximum levels of the level sensor, the controller being arranged thereto to adjust the threshold based on the stored maximum values.

A first further embodiment provides that the controller is set up to calculate as a threshold a percentage of an average of the stored maximum values.

Another further embodiment provides that the controller is set up to store a maximum value if it represents a local maximum of a filling level-time curve and lies within a predetermined value range around the threshold value.

An additional further embodiment provides that the algorithm has an allocation table, wherein the control is set up to change the allocation table as a function of the stored maximum values.

Another further embodiment provides that the controller is set up to make an adjustment of the threshold only when a certain number of maximum values are stored.

• 1 ein Kraftfahrzeug mit einem Kraftstofffüllstandsanzeigesystem;
• 2 ein Kraftstofffüllstandsanzeigesystem;
• 3 ein Füllstands-Zeit-Diagramm sowie
• 4 ein Ablaufdiagramm des Verfahrens.

Further features and details will become apparent from the following description, in which - where appropriate, with reference to the drawings - at least one embodiment is described in detail. Described and / or illustrated features form the subject matter, or independently of the claims, either alone or in any meaningful combination, and in particular may additionally be the subject of one or more separate applications. The same, similar and / or functionally identical parts are provided with the same reference numerals. Here are shown schematically:

• 1 a motor vehicle with a fuel level indicator system;
• 2 a fuel level indicating system;
• 3 a level-time diagram as well
• 4 a flowchart of the method.

1 shows a motor vehicle 2 with a fuel level indicator system 4 (dashed framed).

The fuel level indicator system 4 is used to measure and display the level of a motor vehicle tank 6 , In the motor vehicle tanks 6 a level sensor emerges 8th on The level sensor 8th is with a controller 10 connected, in turn, with a level indicator 12 communicates. The level indicator 12 is in an interior of the motor vehicle 2 arranged such that it is for a driver of the motor vehicle 2 is visible.

The task of the controller 10 it is the sensor signals of the level sensor 8th to interpret and in control signal for the level indicator 12 convert.

Motor vehicle tank 6 and level sensor 8th are tolerant components. In various motor vehicles, the motor vehicle tanks may have different filling volumes and the level sensors produce different signals.

2 shows the fuel level indicator system 4 with more details.

The level sensor 8th has a dip tube 14 in which a swimmer 16 which is on a in the motor vehicle tank 6 stored fuel 18 swims. The swimmer 16 is also a sensor connected to the controller 10 connected is.

The control 10 has an arithmetic unit 20 as well as a memory 22 on. The memory 22 is with the arithmetic unit 20 connected. The memory 22 is a rewriteable memory. In the store 22 is an assignment table 24 provided, the specific input values of the level sensor 8th linked to control signals. The assignment table 24 is factory in the store 22 stored. That is, in different motor vehicles of identical type with identical configuration is always the same allocation table 24 provided with the same values.

The assignment table 24 can by the arithmetic unit 20 be overwritten.

Furthermore, there is a memory area 26 for storing several maximum values of the level sensor 8th intended. In the present case, three memory locations are occupied.

The control 10 is set up based on the memory area 26 stored maximum values to calculate a new threshold, from the level indicator 12 a control signal is to be transmitted which is an indication of a full fuel tank 6 conditionally.

One in the arithmetic unit 20 charged and from the arithmetic unit 20 executed algorithm 28 serves to implement the necessary operations. The algorithm 28 on the one hand uses the assignment table 24 for controlling the level indicator 12 On the other hand, it also serves to calibrate the allocation table 24 provided this by the in the memory area 26 stored maximum values is conditional. Such a calculation is only performed if in the memory area 26 at least three maximum values are stored. In other embodiments, other minimum conditions may be set from which calibration occurs.

The calibration can be done depending on the specific embodiment in that the allocation table 24 is overwritten with new values or that a factor is calculated on the allocation table 24 is applicable. The factor can also be stored 22 be filed.

Another task of the algorithm 28 it is the signals of the level sensor 8th to monitor for maximum values. If a new maximum value is found, it will be in the corresponding memory area 26 stored on a free space. If all memory locations are occupied, older measured values can be overwritten, which causes aging or wear-related changes in the sensor signals of the level sensor 8th can be compensated.

3 shows a level-time diagram.

The time is shown on an X-axis of the level-time diagram, and the respective filling volume of the fuel tank on a Y-axis 6 at the given time. A concrete level-time curve K moves between low and high levels. The steep rising branches represent refueling operations, the gently sloping areas represent the consumption of fuel 18 , in between, the local maxima arise M1 to M4 ,

At the beginning, the motor vehicle 2 up to a local maximum M1 refueled. After a certain amount of fuel 18 was consumed, becomes the motor vehicle 2 refueled, this time up to another local maximum M2 , This process repeats several times and generates more local maxima M3 . M4 , All local maxima are below a maximum theoretical filling volume Vmax the motor vehicle tank 6 ,

The arithmetic unit 20 can the local maxima M1 to M4 by time derivative of the level-time curve K identify. The first derivative of K is in the range of local maxima M1 to M4 equal to 0, the second derivative negative in this range. Thus, local maxima can be distinguished from areas in which the motor vehicle 2 stops and consumes no fuel.

Local maxima are only in the memory area 26 stored if within a range of values B around a threshold vs lying around. The range of values B is bounded at the bottom and open at the top. Through the lower limit Vmin refueling operations are excluded in which the motor vehicle tank 6 not completely refueled. The lower limit Vmin can be a certain percentage of a threshold vs from which the level indicator 12 Should show "full". The threshold vs may be 92%, for example.

4 shows a flowchart of the method.

In a first step, a level of the motor vehicle tank 6 measured. Monitoring after a maximum checks whether there is a local maximum. If this is not the case, the system returns to level measurement. If this is the case, it is further checked whether the local maximum at or above the lower limit Vmin lies. If this is not the case, the system returns to level measurement.

In a next step will be a number N from in the storage area 26 stored maximum values M1 - M4 checked. Is the number N below a threshold, here 3 , the measured level is looked up in the allocation table, as further detailed in the next paragraph. Is the number N above the limit of 3 , the threshold becomes vs adapted and rewritten an assignment table. In other embodiments, the threshold may be chosen differently, eg 5.

As previously mentioned, the measured fill level in the allocation table is looked up for output. If the measured level is below the threshold value vs , the current level is displayed on the level indicator 12 displayed. Is the measured level at or above the threshold? vs , "full" is displayed.

Although the subject matter has been further illustrated and explained in detail by way of embodiments, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art. It is therefore clear that a multitude of possible variations exists. It is also to be understood that exemplary embodiments are only examples that are not to be construed in any way as limiting the scope, applicability, or configuration of the invention. Rather, the foregoing description and description of the figures enable one skilled in the art to practice the exemplary embodiments, and those of skill in the knowledge of the disclosed inventive concept may make various changes, for example, to the operation or arrangement of particular elements recited in an exemplary embodiment, without Protected area, which is defined by the claims and their legal equivalents, such as further explanation in the description.

LIST OF REFERENCE NUMBERS

2

motor vehicle

4

Fuel level indicator system

6

Motor vehicle tank

8th

level sensor

10

control

12

level indicator

14

dip tube

16

swimmer

18

fuel

20

computer unit

22

Storage

24

allocation table

26

storage area

28

algorithm

B

value range

K

Level-time curve

M1 - M4

local maximum

N

Number of maximum values stored in the memory area

Vmax

maximum value

Vmin

lower limit

vs

threshold

Claims (10)

Fuel level indicating system of a motor vehicle (2) with at least one level sensor (8) disposed in an automotive tank (6), a level indicator (12) and a controller (10) connected to the level sensor (8) and the level indicator (12), the controller (10) for conversion an input signal of the level sensor (8) is provided in a control signal for the level indicator (12) on the basis of an algorithm (28) stored in the controller (10), the controller (10) comprising a computing unit (20) and a memory (22 ), wherein the algorithm (28) provides that when a threshold value (Vs) is exceeded, a control signal indicating a full motor vehicle tank (6) can be sent to the level indicator (12), the memory (22) having a memory area (26) for storage of a plurality of maximum values (M1-M4) of the filling level sensor (8), wherein the algorithm (28) can be adapted by the calculating unit (20) as a function of the stored maximum values (M1-M4). Fuel level indicator system according to Claim 1 wherein the algorithm (28) comprises an allocation table (24), wherein the controller (10) is adapted to change the allocation table (24) in dependence on the stored maximum values (M1 - M4). Fuel level indicator system according to Claim 2 , wherein the allocation table (24) is stored in the memory (22). Fuel level reading system according to one of the preceding claims, wherein the arithmetic unit (20) is adapted to store a value transmitted by the level sensor (8) as the maximum value (M1 - M4) in the memory (22), if the maximum value (M1 - M4) is a local maximum represents a level-time history and when the maximum value (M1 - M4) is within a predetermined value range (B) by the threshold value (Vs). Motor vehicle with a fuel level indicator system (4) according to one of the preceding claims. Method for displaying a fuel level of a motor vehicle (2), wherein a level sensor (8) measures a level of a motor vehicle tank (6) and forwards the measured value to a controller (10), the controller (10) using an algorithm (28) the algorithm (28) provides that when a threshold value (Vs) is exceeded, a control signal indicating a full vehicle tank (6) is sent to the level indicator (12), a plurality of maximum values ( M1 - M4) of the level sensor (8) are stored, wherein the controller (10) adjusts the threshold value (Vs) based on the stored maximum values (M1 - M4). Method according to Claim 6 , where as threshold (Vs) a percentage of an average of the stored maximum values (M1 - M4) is calculated. Method according to Claim 6 or 7 in which a maximum value (M1-M4) is stored if it represents a local maximum (M1-M4) of a fill-time curve and lies within a predetermined value range (B) about the threshold value (Vs). Method according to one of Claims 6 to 8th wherein the algorithm (28) comprises an allocation table (24), wherein the allocation table (24) is changed in dependence on the stored maximum values (M1 - M4). Method according to one of Claims 6 to 9 , wherein an adjustment of the threshold value (Vs) is made only when a certain number of maximum values (M1 - M4) are stored.

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