Method for determining an amount of a fluid in a container of a vehicle

Abstract

Method for determining an amount of a fluid in a container of a vehicle The invention relates to a method for determining an amount of a fluid in a container of a vehicle, the method comprising the following steps: - obtaining at least one previous injection flow rate value (F1) - determining an injection-based consumed volume value (Vinj1) of the fluid in the container during this previous period of time (T1); - obtaining a level value (h1end) of the fluid in the container at the end of this previous period of time (T1); - determining a level-based consumed volume value (Vlev1) of the fluid in the container during this previous period of time (T1), - determining a difference value (d1= Vinj1– Vlev1) - determining an injector deviation value (P1) for the previous period of time (T1); - obtaining one current injection flow rate value (F2) of the fluid in the injector system during a current period of time (T2); - determining an injection-based consumed volume value (Vinj2) of the fluid in the container during this current period of time (T2); - determining a corrected consumed volume value (Vcor2) of the fluid in the container during this current period of time (T2).

Description

Method for determining an amount of a fluid in a container of a vehicle

[0001] The invention relates to fluid gauging in a vehicle. In particular, it relates to the determination of an amount of urea in a container in a vehicle.

[0002] It is required, in particular by regulations and standards regarding On-Board Diagnostics (“OBD”) in a vehicle, to provide an accurate amount of the volume of urea contained in the vehicle. It is notably an important issue to warn the driver about the need to refill the container of urea when necessary.

[0003] To this effect, it is known from the state of the art to measure a urea level in a container by a fluid level sensor, such as an ultrasonic float sensor, positioned in the container. However, when the vehicle meets slopes of the road or accelerates and decelerates, it creates what is called a “slosh effect”, such that the measured level of urea in the container changes abruptly and is too inaccurate to compute the correct volume of the urea contained in the container.

[0004] Another solution of the state of the art is based on an injector system of the urea. Such an injector system in the vehicle injects the urea out of the container into the selective catalytic reduction system of the vehicle. The injector system includes an injector controller that provides, to an onboard processing unit of the vehicle, data such as the flow rate value of the urea injected at a current time. Based on this flow rate value, the volume value of the fluid contained in the container can be calculated. However, it has been determined that the injection flow rate value provided by the injection system is inaccurate. This inaccuracy depends on the injector device, it evolves over time in an unpredictable manner and is a result of a complex variety of parameters.

[0005] This issue is extendable to any fluid contained in a container of a vehicle, such as water or fuel.

[0006] JP2004316491 teaches a method to compute a remaining fuel level.

[0007] It is an object of the present invention to improve the accuracy of the determined volume of a fluid in a container of a vehicle.

[0008] In order to achieve this object, there is provided a method for determining an amount of a fluid in a container of a vehicle, the container being connected to an injector system, the method comprising the following steps:

[0009] - obtaining, from the injector system, at least one previous injection flow rate value of the fluid in the injector system during at least one previous period of time;

[0010] - determining, based on the obtained previous injection flow rate value of the previous period of time, an injection-based consumed volume value of the fluid in the container during this previous period of time;

[0011] - obtaining a level value of the fluid in the container at the end of this previous period of time;

[0012] - determining, based on the obtained level value at the end of the previous period of time, a level-based consumed volume value of the fluid in the container during this previous period of time;

[0013] - determining, for this previous period of time, a difference value, between the injection-based consumed volume value and the level-based consumed volume value;

[0014] - determining, based on the determined difference value, an injector deviation value for the previous period of time;

[0015] wherein the method further comprises the steps of:

[0016] - obtaining, from the injector system, at least one current injection flow rate value of the fluid in the injector system during a current period of time;

[0017] - determining, based on the obtained current injection flow rate value of the current period of time, an injection-based consumed volume value of the fluid in the container during this current period of time;

[0018] - determining, based on the injection-based consumed value of the current period of time and the injector deviation value of the previous period of time, a corrected consumed volume value of the fluid in the container during this current period of time.

[0019] Thus, for a determined previous period of time, a quantity of a fluid, as determined by the flow rate value provided by the injector system, is compared to a quantity of the same fluid measured by a level sensor. The difference is deduced, which then allows, in the current time, to correct the quantity of fluid as determined by the flow rate value. In other terms, the method allows to learn the deviation between the volume obtained through the injector system and the volume obtained by a level sensor, during one or a plurality of previous period of time, in order to correct the volume value obtained through the injector system in a current period of time.

[0020] Hereafter follow other optional features taken alone or in combination.

[0021] Preferably, the method further comprises the steps of:

[0022] - obtaining a level value of the fluid in the container at the end of the current period of time;

[0023] - determining, based on the level value of the fluid at the end of the current period of time, a level-based consumed volume value of the fluid from the container during the current period of time,

[0024] - determining, for the current period of time, a difference value between the level-based consumed volume value of the current period of time and the corrected consumed volume value of the current period of time,

[0025] - determining, based on at least one injector deviation value of a previous period of time and on the difference value of the current period of time, an injector deviation value of the current period of time.

[0026] Thus, at each period of time, the level-based value of the period of time is compared to the corrected consumed volume value, which is the current injection-based value corrected based on the injector deviation computed thanks to previous periods of times. This comparison allows to compute an updated injector deviation value. This new injector deviation value will in turn help correcting the next injection-based value of the next period of time. To sum-up, each period of time allows to compute an updated injector deviation value, which itself allows to correct the next injection-based value, which then allows to compute a next updated injector deviation value, etc. As a result, the accuracy of the corrected value improves over time.

[0027] Advantageously, the method comprises, for determining the injector deviation value of the current period of time, computing a moving average value based on at least one of the injector deviation values of a previous period of time and on the difference value of the current period of time.

[0028] The moving average calculation allows to associate a weight to each injector deviation value, corresponding to respective periods of time, depending on different criterion, for example depending on time, the most recent computed deviation value being for example more important in the calculation. In particular, computing the updated injector deviation value is based on the exponential moving average calculation. The moving average value then evolves at each period of time in an accurate manner.

[0029] Preferably, each period of time starts from a refill event wherein the container is completed and ends when a successive and distinct refill event in the container is detected.

[0030] Thus, a period of time matches a cycle between two refill events. Starting from a full container and ending as the container is empty. This allows to take into account the maximal amount of data in order to compute a deviation value as accurate as possible.

[0031] Advantageously, the method further comprises the following steps, with the level value being obtained from raw level values:

[0032] - applying a smoothing filter to raw level values obtained over a period of time, in a manner to smooth the evolution of these values during the period of time, in order to obtain a filtered level value at the end of the period of time;

[0033] - computing the other steps based on the filtered level value.

[0034] Thus, the level value that is measured is then filtered, in order to diminish the “slosh effect” of the fluid in the container. The filtered value is then taken into account to compute the difference. This improves the accuracy of the injector deviation value.

[0035] Preferably, the method further comprises the following steps, after the end of a period of time and before the step of determining an injector deviation value of this period of time:

[0036] - determining a remaining volume value of fluid in the container based on at least one of the consumed volume values;

[0037] - comparing the remaining volume value to predetermined minimal and maximal values;

[0038] - comparing at least one of the consumed volume values to a threshold value;

[0039] - determining the state, frozen, intermediate or liquid, of the fluid in the container;

[0040] wherein the step of determining an injector deviation value of this period of time only takes place when at least one, preferably all, of the following conditions are met:

[0041] - the fluid is only in liquid state;

[0042] - the remaining volume is between the minimal and maximal values;

[0043] - the consumed volume value is above the threshold value.

[0044] Thus, the method comprises enabling conditions: the difference between the volume at the beginning of the period of time and the end of this period must be sufficient, the remaining volume must be low enough, but not too low, in order to be relevant, and the fluid must be in liquid state. These conditions allow the deviation value to be appropriate. Thus, between two refill events, when the full period of time between these two refill events does not match one of the conditions, it is possible to extract a period of time from the full period of time, wherein all the conditions are met.

[0045] The invention has also as its object a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the steps of the method described above.

[0046] The invention has also as its object a computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the steps of the method described above.

[0047] The invention has also as its object a data processing system comprising means for carrying out the steps of the method described above.

[0048] The invention has also as its object a system for determining an amount of a fluid in a container of a vehicle, comprising:

[0049] - a container for a fluid,

[0050] - a gauging device for measuring a level of the fluid in the container,

[0051] - an injector controller providing an injection flow rate of the fluid injected out of the container,

[0052] - the data processing system described above.

[0053] Preferably, in the system, the fluid is one of the following:

[0054] - aqueous solution, in particular urea, water or cleaner,

[0055] - hydrogen,

[0056] - fuel.

[0057] More preferably, in the system, the fluid is water, urea or fuel.

[0058] Thus, regarding the aqueous solution, in a preferred embodiment, the aqueous solution is a urea or ammonia solution also known as “urea” (e.g. for SCR systems). In another embodiment, the aqueous solution is water or water with an electrical conductivity close to zero also known as “demineralized water” (e.g. for water injection systems). In another embodiment, the aqueous solution is a cleaning solution also known as “cleaner” (e.g. for cleaning windshield or LiDAR systems). In another embodiment, an amount of methanol is added to the aqueous solution to lower its freezing point.

[0059] The invention has also as its object a vehicle comprising the system described above.Brief description of the figures

[0060] The invention will be better understood on reading the following description, which is given only by way of example and is made with reference to the attached drawings in which:

[0061] schematically illustrates a system according to an embodiment of the invention;

[0062] schematically illustrates a vehicle according to an embodiment of the invention;

[0063] schematically illustrates a method according to an implementation of the invention;

[0064] is a graphic illustrating an implementation of the method ofover time.Detailed description

[0065] The system 1 for determining an amount of a fluid in a container of a vehicle is illustrated on. It allows to implement the steps of the method 100 that will be described below. Only the components necessary to the understanding of the invention are schematically illustrated. It will clearly appear to the skilled person that other components are implicit.

[0066] This system 1 for determining an amount of a fluid in a container of a vehicle includes a container 5. This container 5 contains urea 7, i.e., a urea solution. For the skilled person, what is called “urea” could also be an ammonia solution. The container 5 also includes an ultrasonic float sensor or an analogic level sensor 9. This sensor 9 allows to measure a level of the urea 7 in the container 5, i.e., a vertical distance between the bottom of the container 5 and the surface of the urea 7 in the container. This sensor 9 contains processing means able to determine a current level value, such as h1end and h2end, of the urea in the container 5, at any current time. Alternatively, this sensor 9 could by any other gauging device allow determining a level value of urea in the container 5.

[0067] The system 1 for determining an amount of a fluid in a container of a vehicle also includes an injector system 11. This injector system allows to inject urea out of the container into a selective catalytic reduction system 13 that is not part of the invention. The injector system 11 contains processing means, such as an injector controller, able to determine a flow rate value of the urea, such as F1and F2, injected at any current time into the selective catalytic system 13.

[0068] Finally, the system 1 for determining an amount of a fluid in a container of a vehicle also includes a data processing system 15 comprising means for carrying out the steps of the method 100 described above. These means are conventional processing means such as a processing unit, a database, a memory. In particular, the data processing system 15 contains a computer-readable storage medium 17 comprising instructions which, when executed by a computer, cause the computer to carry out the steps of the method 100 described above. The term controller refers to any controller or processing unit. More concretely, the storage medium 17 contains a computer program 19 comprising instructions which, when the program is executed by a computer, cause the computer to carry out the steps of the method 100 described above. The program computer may also refer to several computer programs, forming a software.

[0069] This system 1 for determining an amount of a fluid in a container of a vehicle is integrated on a conventional vehicle 3 illustrated on. In particular, the data processing system 15 is integrated into the On-Board-Diagnostic unit, unillustrated, already positioned in the vehicle 3 and allowing to control all of the On-board diagnostic proceedings.

[0070] We will now describe, in reference to figures 1, 3 and 4, the steps of method 100, implemented by the system 1 for determining an amount of a urea in the container 5 of a vehicle 3.

[0071] The method 100 is implemented over time. Values are calculated at the end of each distinct period of time. As illustrated inwith T1, T2and T3, each period of time starts from a refill event wherein the container 5 is completed and ends when a successive and distinct refill event in the container 5 is detected. In the following, T1is considered as a previous period of time and T2is considered as a current period of time. T3 is, for now, a future period of time.

[0072] In, curve 21 relates to the injection-based volume values computed by the data processing system 15 on the basis of the flow rate values provided by the injector controller of the injector system 11. Curve 22 relates to the level-based volume values computed by the data processing system 15 on the basis of the level values provided by the level sensor 9.

[0073] Step 101 is obtaining, from the injector system 11, at least one previous injection flow rate value F1of the urea 7 in the injector system 11 during the previous period of time T1.

[0074] Step 102 is determining, based on the obtained previous injection flow rate value F1of the previous period of time T1, an injection-based consumed volume value Vinj1of the urea 7 in the container 5 during this previous period of time T1. In other terms, the data processing system 15 converts the injection flow rate value F1during the period of time T1into an injection-based volume value Vinj1representing the volume of urea 7 injected to the selective catalytic system 13 during the period of time T1. Indeed, by knowing the flow rate value at any moment during this period and the length of this period, it is possible to deduce the injected volume. Alternatively, this injection-based volume may be deduced even if the flow rate value varies during the period T1, if the data processing system 15 obtains this flow rate value at any moment of the period.

[0075] Step 103 is obtaining a raw level value of the urea 7 in the container 5 at the end of this previous period of time T1.

[0076] Step 104 is applying a smoothing filter to raw level values obtained over the period of time T1in a manner to smooth the evolution of these values during the period of time T1, in order to obtain a filtered level value h1end at the end of the period of time T1. In other terms, the value h1end is a filtered value based on the raw value at the end of the period of time T1and based on all of the raw values of the period of time T1. This aims to smooth the slosh effect of the urea 7 in the container 5 when the vehicle 3 meets slopes, accelerates, or decelerates.

[0077] Alternatively, this smoothing step does not take place.

[0078] In the following, we will consider that it takes place and that all the level values are filtered values.

[0079] Step 105 is determining, based on the obtained level value h1end at the end of the previous period of time T1, a level-based consumed volume value Vlev1of the urea 7 in the container 5 during this previous period of time T1. Thus, the data processing system 15 converts the level value h1end into a level-based volume value Vlev1, while considering the dimensions of the container 5.

[0080] Step 106 is determining, for this previous period of time T1, a difference value d1= Vinj1– Vlev1, between the injection-based consumed volume value Vinj1and the level-based consumed volume value Vlev1.

[0081] Step 107 is determining, based on the determined difference value d1, an injector deviation value P1for the previous period of time T1. The injector deviation value P1is a percentage value of the injection-based consumed volume value Vinj1. This injector deviation value P1reflects an inaccuracy of the injector system 11.

[0082] Step 108 is obtaining, from the injector system 11, at least one current injection flow rate value F2of the urea 7 in the injector system 11 during a current period of time T2.

[0083] Step 109 is determining, based on the obtained current injection flow rate value F2of the current period of time T2, an injection-based consumed volume value Vinj2of the urea 7 in the container 5 during this current period of time T2. In other terms, the data processing system 15 converts the injection flow rate value F2during the period of time T2into an injection-based volume value Vinj2representing the volume of urea 7 injected during the period of time T2. Indeed, by knowing the flow rate value at any moment during this period and the length of this period T2, it is possible to deduce the injected volume. Alternatively, this injection-based volume may be deduced even if the flow rate value varies during the period T2, if the data processing system 15 obtains this flow rate value at any moment of the period.

[0084] Step 110 is determining, based on the injection-based consumed value Vinj2of the current period of time T2and the injector deviation value P1of the previous period of time T1, a corrected consumed volume value Vcor2of the urea 7 in container 5 during this current period of time T2. The corrected consumed volume value Vcor2is the result of the injection-based consumed value Vinj2to which is added or deduced a percentage corresponding to the injector deviation value P1.

[0085] Alternatively, other calculation methods could be performed by the skilled person.

[0086] Step 111 is obtaining a level value h2endof the urea 7 in container 5 at the end of the current period of time T2. This smoothing step in this time period T2to obtain h2end, can be performed in the same as it was to obtain h1end. Step 112 is determining, based on the level value h2endof the urea 7 at the end of the current period of time T2, a level-based consumed volume value Vlev2of the urea 7 from container 5 during the current period of time T2. Thus, the data processing system 15 converts the level value h2endinto a level-based volume value Vlev2, by considering the dimensions of container 5.

[0087] Step 113 is determining, for the current period of time T2, a difference value d2= Vlev2- Vcor2between the level-based consumed volume value Vlev2of the current period of time T2and the corrected consumed volume value Vcor2of the current period of time T2.

[0088] Step 114 is determining, based on the injector deviation value P1of a previous period of time T1and on the difference value d2of the current period of time, an injector deviation value P2of the current period of time T2. To determine the injector deviation value P2of the current period of time T2, the data processing system 15 computes a moving average value based on the injector deviation value P1of the previous period of time T1and on the difference value d2of the current period of time T2.

[0089] In statistics, a moving average (also called “rolling average” or “running average”) is a calculation to analyze data points by creating a series of averages of different selections of the full data set. It is also called a moving mean (“known as “MM”) or rolling mean and is a type of finite impulse response filter. A moving average filter is sometimes called a boxcar filter, especially when followed by decimation. Given a series of numbers and a fixed subset size, the first element of the moving average is obtained by taking the average of the initial fixed subset of the number series. Then the subset is modified by "shifting forward"; that is, excluding the first number of the series and including the next value in the subset.

[0090] In a preferred implementation of the invention, the calculation performed to associate the weights and compute the injector deviation value P2is the exponential moving average (also known as “EMA”). It is a first-order infinite impulse response filter that applies weighting factors which decrease exponentially. The weighting for each older datum decreases exponentially, never reaching zero. This formulation is according to Hunter (1986).

[0091] In particular, P1being a percentage based on the difference d1related to the previous period of time T1, the data processing system 15 also computes a percentage based on the difference d2which is related to the current period of time T2. Then, the data processing system 15 associates to each of these percentages a weight, in order to compute the injector deviation value P2, the weight being higher for the percentage related to the current period of time T2, than for P1, which is related to the previous period of time T1. Alternatively, other calculations method could be performed by the skilled person to compute the injector deviation value P2related to the current period of time T2based on the injector deviation value P1related to the previous period of time T1and on the difference d2related to the current period of time T2.

[0092] The steps described above repeat for the future period of time T3when this period T3 becomes the current period of time.

[0093] Thus, a corrected Volume value Vcor3, based on an injection-base volume Value Vinj3and on P2, and a level-based volume value Vlev3, are calculated the same way for the current period T3as for the previous period of time T1and T2. The difference d3between these two values is computed in order to obtain a percentage of deviation. The injector deviation value P3is calculated based on this percentage and on the previous injector deviation values P1and P2, by using the exponential moving average method. Thus, the weight associated to the percentage of deviation related to the current period T3is higher than the weight associated to P2, itself being higher than the weight associated to P1.

[0094] It is advantageous that the method is performed over many periods of time. The injector deviation value is thus updated period of time after period of time.

[0095] The more period of time there are, the more accurate becomes the injector deviation value. As a result, the corrected Volume values also become more accurate.

[0096] This method 100 can be based on any period of time situated between two refill events.

[0097] However, in a preferred implementation of the invention, only the periods of time that meet specific criteria are selected to compute the injector deviation values. Thus, considering for example the period T3, after the end of the period of time T3and before the step of determining an injector deviation value P3of this period of time T3, the following steps are performed.

[0098] Step 115 is determining a remaining volume value of urea 7 in the container 5 based on the corrected consumed volume value V3cor. It could also be based on the injection-based volume value V3injor the level-based volume value V3lev.

[0099] Step 116 is comparing the remaining volume value to predetermined minimal and maximal values. These values are chosen by a skilled person.

[0100] Step 117 is comparing the corrected volume value V3corto a threshold value. This threshold value is chosen by a skilled person.

[0101] Step 118 is determining the state, frozen, intermediate or liquid, of the urea in the container.

[0102] Based on steps 115 to 118, the step of determining an injector deviation value P3of this period of time T3only takes place when at least one, preferably all, of the following conditions are met:

[0103] - the urea is only in liquid state;

[0104] - the remaining volume is between the minimal and maximal values;

[0105] - the consumed volume value V3coris above the threshold value.

[0106] These conditions ensure that the injector deviation value P3will be accurate. Indeed, if not enough urea has been injected, or if it remains too little urea in the container, or if the urea is not liquid, the values measured and computed could be irrelevant as the behavior of the injector system and of the level sensor would not be accurate.

[0107] The invention is not limited to the embodiments presented and other embodiments will appear clearly to those skilled in the art.

[0108] In particular, it is possible to implement this method to other types of fluid, in particular to another type of aqueous solution, such as water or water with an electrical conductivity close to zero, also known as “demineralized water” (e.g. for water injection systems), or to a cleaning solution also known as “cleaner” (e.g. for cleaning windshield or LiDAR systems).

[0109] It is possible to add an amount of methanol to the aqueous solution to lower its freezing point.Numerals

[0110] 1: System for determining an amount of a fluid in a container of a vehicle,3: Vehicle5: Container

[0111] 7: urea

[0112] 9: gauging device

[0113] 11: injector system

[0114] 13: selective catalytic reduction system

[0115] 15: data processing system

[0116] 17: storage medium

[0117] 19: computer program

[0118] 21: curve related to the injection-based volume values

[0119] 22: curve related to the level-based volume values

[0120] P1, P2, P3:injector deviationvalues

[0121] T1, T2, T3: Periods of time

[0122] F1, F2, F3: flow rate values

[0123] Vinj1, Vinj2, Vinj3: injection-based volume values

[0124] Vlev1, Vlev2, Vlev3: level-based volume values

[0125] Vcor2, Vcor3: corrected volume values

[0126] d1, d2: differences between injected or corrected volume values and level-based volume values.

Claims

Method (100) for determining an amount of a fluid (7) in a container (5) of a vehicle (3), the container (5) being connected to an injector system (11), the method (100) comprising the following steps:- obtaining (101), from the injector system (11), at least one previous injection flow rate value (F1) of the fluid in the injector system during at least one previous period of time (T1);- determining (102), based on the obtained previous injection flow rate value (F1) of the previous period of time (T1), an injection-based consumed volume value (Vinj1) of the fluid in the container (5) during this previous period of time (T1);- obtaining (103) a level value (h1end) of the fluid (7) in the container (5) at the end of this previous period of time (T1);- determining (105), based on the obtained level value (h1end) at the end of the previous period of time (T1), a level-based consumed volume value (Vlev1) of the fluid in the container (5) during this previous period of time (T1);- determining (106), for this previous period of time (T1), a difference value (d1= Vinj1– Vlev1), between the injection-based consumed volume value (Vinj1) and the level-based consumed volume value (Vlev1);- determining (107), based on the determined difference value (d1), an injector deviation value (P1) for the previous period of time (T1);characterized in that the method (100) further comprises the steps of:- obtaining (108), from the injector system (11), at least one current injection flow rate value (F2) of the fluid (7) in the injector system during a current period of time (T2);- determining (109), based on the obtained current injection flow rate value (F2) of the current period of time (T2), an injection-based consumed volume value (Vinj2) of the fluid (7) in the container during this current period of time (T2);- determining (110), based on the injection-based consumed value (Vinj2) of the current period of time (T2) and the injector deviation value (P1) of the previous period of time (T1), a corrected consumed volume value (Vcor2) of the fluid (7) in the container (5) during this current period of time (T2).The method (100) according to claim 1, further comprising the steps of:- obtaining (111) a level value (h2end) of the fluid (7) in the container (5) at the end of the current period of time (T2);- determining (112), based on the level value (h2end) of the fluid at the end of the current period of time (T2), a level-based consumed volume value (Vlev2) of the fluid (7) from the container (5) during the current period of time (T2),- determining (113), for the current period of time (T2), a difference value (d2= Vlev2- Vcor2) between the level-based consumed volume value (Vlev2) of the current period of time (T2) and the corrected consumed volume value (Vcor2) of the current period of time (T2),- determining (114), based on at least one injector deviation value (P1) of a previous period (T1) of time and on the difference value (d2) of the current period of time (T2), an injector deviation value (P2) of the current period of time (T2).Method (100) according to the preceding claim, comprising, for determining the injector deviation value (P2) of the current period of time (T2), computing a moving average value based on at least one of the injector deviation values (P1, P2) of a previous period of time (T1) and on the difference value (d2) of the current period of time (T2).The method (100) according to any one of the preceding claims, wherein each period of time (T1, T2) starts from a refill event wherein the container is completed and ends when a successive and distinct refill event in the container is detected.The method (100) according to any one of the preceding claims, further comprising the following steps, with the level value (h1end, h2end) being obtained from raw level values:- applying (104) a smoothing filter to raw level values obtained over a period of time (T1, T2), in a manner to smooth the evolution of these values during the period of time (T1, T2), in order to obtain a filtered level value (h1end, h2end) at the end of the period of time (T1, T2);- computing the other steps based on the filtered level value (h1end, h2end).The method (100) according to any one of the preceding claims, further comprising the following steps, after the end of a period of time (T1, T2) and before the step of determining an injector deviation value (P1, P2) of this period of time (T1, T2):- determining (115) a remaining volume value of fluid (7) in the container (5) based on at least one of the consumed volume values;- comparing (116) the remaining volume value to predetermined minimal and maximal values;- comparing (117) at least one of the consumed volume values (Vlevi, Vinji) to a threshold value;- determining (118) the state, frozen, intermediate or liquid, of the fluid (7) in the container (5);wherein the step of determining an injector deviation value (P1, P2) of this period of time (T1, T2) only takes place when at least one, preferably all, of the following conditions are met:- the fluid (7) is only in liquid state;- the remaining volume (Vremain) is between the minimal (Vmin) and maximal (Vmax) values;- the consumed volume value (Vlevi, Vinji) is above the threshold value.A computer program (19) comprising instructions which, when the program is executed by a computer, cause the computer to carry out the steps of the method (100) of any one of the preceding claims.A computer-readable storage medium (17) comprising instructions which, when executed by a computer, cause the computer to carry out the steps of the method (100) of any one of claims 1 to 6.A data processing system (15) comprising means for carrying out the steps of the method (100) of any one of the preceding claims.System (1) for determining an amount of a fluid in a container of a vehicle,comprising:- a container (5) for a fluid (7),- a gauging device (9) for measuring a level of the fluid (7) in the container (5),- an injector controller providing an injection flow rate (F1, F2) of the fluid injected out of the container,- the data processing system (15) according to the preceding claim.System (1) according to the preceding claim, wherein the fluid is one of the following:- aqueous solution, in particular urea, water or cleaner,- hydrogen,- fuel.Vehicle (3) comprising the system (1) according to claim 10 or 11.

Images