Claims:
1. A method for monitoring a fuel level in a fuel tank (20) of a vehicle, the method comprising:
receiving, by a control unit (50) of the vehicle, temperature of fuel in the fuel tank (20) and ambient temperature from one or more sensors (30) associated with the control unit (50);
comparing, by the control unit (50), the temperature of the fuel in the fuel tank (20) and the ambient temperature with a pre-stored data; and
determining, by the control unit (50), the fuel level in the fuel tank (20) based on the comparison.

2. The method as claimed in claim 1, wherein the temperature of the fuel in the fuel tank (20) is determined by the one or more sensors (30) disposed downstream of the fuel tank (20).

3. The method as claimed in claim 1, wherein the ambient temperature is determined by the one or more sensors (30) provisioned at one or more locations in the vehicle.

4. The method as claimed in claim 1, wherein the comparison by the control unit (50) includes mapping the temperature of the fuel in the fuel tank (20) and the ambient temperature, with the pre-stored data stored in a memory unit (40) associated with the control unit (50).

5. The method as claimed in claim 1, wherein the pre-stored data comprises fuel level data in the fuel tank (20) corresponding to a plurality of temperatures of the fuel in the fuel tank (20), and a plurality of ambient temperatures.

6. The method as claimed in claim 5, wherein the pre-stored data is generated by trials performed at a plurality of operating conditions, and wherein the plurality of operating conditions include different levels of the fuel in the fuel tank (20), and a plurality of vehicle ambient conditions.

7. The method as claimed in claim 1, comprises:
reducing, by the control unit (50), a fuel supply to an engine (10) of the vehicle, when the fuel level in the fuel tank (20) drops below a first threshold level; and
stopping, by the control unit (50), the fuel supply to the engine (10) when the fuel level in the fuel tank (20) drops below a second threshold level,
wherein, the first threshold level of the fuel is higher than the second threshold level of the fuel.

8. A system (100) for monitoring a fuel level in a fuel tank (20) of a vehicle, the system (100) comprising:
one or more sensors (30), each configured to determine at least one of temperature of fuel in the fuel tank (20) and ambient temperature; and
a control unit (50), communicatively coupled to the one or more sensors (30), wherein the control unit (50) is configured to:
receive, the temperature of the fuel in the fuel tank (20) and the ambient temperature from the one or more sensors (30);
compare, the temperature of the fuel in the fuel tank (20) and the ambient temperature with a pre-stored data; and
determine, the fuel level in the fuel tank (20) based on the comparison.

9. The system as claimed in claim 8 comprises a memory unit (40) communicatively coupled to the control unit (50), wherein the memory unit (40) stores the pre-stored data.

10. The system as claimed in claim 8, wherein the one or more sensors (30) are provisioned downstream of the fuel tank (20), and at one or more locations (110) in the vehicle.

11. The system as claimed in claim 8, wherein the control unit (50) is configured to:
reduce fuel supply to an engine (10) of the vehicle, when the fuel level in the fuel tank (20) drops below a first threshold level; and
stop the fuel supply to the engine (10) when the fuel level in the fuel tank (20) drops below a second threshold level, wherein,
the first threshold level of the fuel is higher than the second threshold level of the fuel.

12. A vehicle comprising a system (100) for monitoring a fuel level in a fuel tank (20) as claimed in claim 8.
, Description:TECHNICAL FIELD

[001] Present disclosure generally relates to the field of automobiles. Particularly, but not exclusively, the present disclosure relates to fuel level monitoring in a fuel tank of a vehicle. Further, embodiments of the present disclosure disclose a method and a system for monitoring the fuel level in the fuel tank using fuel temperature and ambient temperature conditions.

BACKGROUND OF THE DISCLOSURE

[002] Internal Combustion (IC) engines are power plants of the vehicles which convert chemical energy of the fuel into heat and again into mechanical work. IC engines with injection type fuel supply systems are popular these days owing to a number of reasons like regulation of flow or metering, timing control, improved efficiency of combustion, proper atomization, mixing and so on. Typically, in vehicles like passenger vehicles and commercial vehicles, an IC engine is provided with an in-line fuel injection system having a number of injectors, which inject pressurized fuel into the combustion chambers they are associated with. A fuel injection system includes low-pressure side components and high-pressure side components. Low pressure side components include fuel tank, one or more fuel pumps and fuel filters, with optional coolers/heaters to regulate the fuel temperatures. High pressure side components, on the other hand, include high pressure pump, injectors, nozzles, accumulators, metering unit and nozzle needle actuators.

[003] Due to the presence of low-pressure and high-pressure components, and also due to fluctuating pressure and temperature conditions of the fuel, a fuel injection system may face a number of complications within the flow paths. Other important factors are the flow rate and quantity of the fuel present in the fuel tank. Pumps present in the fuel injection system may suffer from undesirable phenomena such as dry running, cavitation, insufficient priming and so on. Dry running occurs when there is insufficient fuel in the fuel tank required to keep the pump operating in an uninterrupted manner. Lack of fuel results in inadequate lubrication of pump elements, thereby heating up these elements. This could result in thermal stresses and eventual failure of the elements, eliciting high replacement costs to users or Original Equipment Manufacturers (OEMs). Injectors starving from lack of fuel may also face similar adverse effects during operation.

[004] Inadequate fuel level in the fuel tank may also give rise to a phenomenon called cavitation, where vapour bubbles are formed due to cold boiling of the fuel. In other words, cavitation is phenomenon of formation of vapour bubbles when pressure of liquidus fuel falls below its vapour pressure, and thereafter, upon entering a high-pressure zone, these vapour bubbles collapse giving rise to high impact pressure and/or shock waves which may cause cavities or pits on adjacent metallic surfaces of the pump.

[005] Korean Patent Publication KR101297698 discloses an arrangement in which a fuel filter is located upstream of the fuel pump to minimize cavitation. This arrangement, however, has limitation with respect to entry of minute impurities present in the fuel when fuel is delivered by the fuel pump into the fuel injectors, which is undesired.

[006] The present disclosure is directed to overcome one or more limitations stated above or other such limitations associated with the prior art.

SUMMARY OF THE DISCLOSURE

[007] One or more shortcomings of conventional systems are overcome, and additional advantages are provided through the method and the system as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered as a part of the claimed disclosure.

[008] In one non-limiting embodiment of the disclosure, a method for monitoring fuel level in a fuel tank of a vehicle is disclosed. The method includes receiving, by a control unit of the vehicle, temperature of the fuel in the fuel tank and ambient temperature from one or more sensors associated with the control unit. Then, the control unit compares the temperature of the fuel in the fuel tank and the ambient temperature with a pre-stored data, and determine fuel level in the fuel tank based on the comparison.

[009] In an embodiment of the disclosure, the temperature of the fuel in the fuel tank is determined by the one or more sensors disposed downstream of the fuel tank. Further, the ambient temperature is determined by the one or more sensors provisioned at one or more locations in the vehicle.

[010] In an embodiment of the disclosure, the comparison by the control unit includes mapping the temperature of the fuel in the fuel tank and the ambient temperature with the pre-stored data in a memory unit associated with the control unit. The pre-stored data comprises fuel level data in the fuel tank corresponding to a plurality of temperatures of the fuel in the fuel tank, and a plurality of ambient temperatures. Further, the pre-stored data is generated by trials performed at a plurality of operating conditions, and wherein the plurality of operating conditions include different levels of the fuel in the fuel tank, and a plurality of vehicle ambient conditions.

[011] In an embodiment of the disclosure, the method further includes reducing, by the control unit, a fuel supply to an engine, when the fuel level in the fuel tank drops below a first threshold level. Then, the control unit stops the fuel supply to the engine when the fuel level in the fuel tank drops below a second threshold level, where the first threshold level of the fuel is higher than the second threshold level of the fuel

[012] In another non-limiting embodiment of the disclosure, a system for monitoring fuel level in a fuel tank of a vehicle is disclosed. The system comprises one or more sensors, each configured to determine at least one of temperature of a fuel in the fuel tank and ambient temperature. Further, the system comprises a control unit communicatively coupled to the one or more sensors. The control unit is configured to receive the temperature of the fuel in the fuel tank and the ambient temperature from the one or more sensors. Then, the control unit compares the temperature of the fuel in the fuel tank and the ambient temperature with a pre-stored data, and determines the fuel level in the fuel tank based on the comparison.

[013] In an embodiment of the disclosure, the system comprises a memory unit communicatively coupled to the control unit, wherein the memory unit stores the pre-stored data.

[014] In an embodiment of the disclosure, the one or more sensors are provisioned downstream of the fuel tank and at one or more locations in the vehicle.

[015] In an embodiment of the disclosure, the control unit is further configured to reduce a fuel supply to an engine when the fuel level in the fuel tank drops below a first threshold level, and stop the fuel supply to the engine when the fuel level in the fuel tank drops below a second threshold level. The first threshold level of the fuel is higher than the second threshold level of the fuel.

[016] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

[017] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

[018] The novel features and characteristics of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of an embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:

[019] FIG. 1 illustrates a schematic view of a system for monitoring fuel in a fuel tank in a vehicle, in accordance with an embodiment of the present disclosure;

[020] FIG. 2 illustrates a schematic view of the system of FIG. 1 with an arrangement to determine fuel pressure in the rail, in accordance with an embodiment of the present disclosure;

[021] FIG. 3 is a graphical illustration of variations of engine torque, fuel temperature and fuel level in the fuel tank, in accordance with an embodiment of the present disclosure, and

[022] FIG. 4 is a flowchart illustrating the method by which fuel level in the fuel tank is monitored, in accordance with an embodiment of the present disclosure.

[023] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the systems and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

[024] While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

[025] It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify various features of the mechanism or the system, without departing from the scope of the disclosure. Therefore, such modifications are considered to be part of the disclosure. Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skilled in the art having benefit of the description herein. Also, the system of the present disclosure may be employed in variety of vehicles such as passenger vehicles, commercial vehicles having different specifications. However, the engine and other components associated with the engine are not illustrated in the drawings of the disclosure for the purpose of simplicity.

[026] The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a mechanism or a system that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such a system, a method, or an assembly, or a device. In other words, one or more elements in the system or the device or the method proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or the device or the method.

[027] Embodiments of the present disclosure disclose a method and a system for monitoring fuel level in a fuel tank of a vehicle. The method is aimed at alleviating the limitations associated with conventional fuel injection systems which are integral with the engines in the vehicles. A conventional fuel injection system includes a low-pressure side for drawing the fuel from the fuel tank, and a high-pressure side for directing the fuel into the fuel injectors, which thereafter inject incoming fuel into engine cylinders. The fuel injectors may be in fluid communication with a common passageway known as “rail”, which secures the fuel injectors relative to the combustion chambers of the engine.
[028] Conventional fuel injection systems face difficulties with respect to fluctuations in fuel pressure, leading to cavitation. Cavitation is inevitable in pressure pumps, however, may be minimized to significant extent by ensuring proper supply of fuel, and maintenance of fuel lines, pump elements, pressure regulators, valves and associated components. Another drawback associated with the pumps is the dry-run condition due to insufficient fuel supply. This may be due to blockage in the fuel flow lines or inconsistent frequency of fuel top-up in the fuel tanks. Malfunctioning of pumps due to one or more reasons stated above may lead to misfiring, sudden fluctuation in engine power, clicking or whining noise during engine idling, or sudden ceasing of the engine, which are undesirable.

[029] Accordingly, the present disclosure discloses a method by which fuel level in the fuel tank is monitored during engine operation on a continuous basis without a need for separate fuel level sensor or an input from existing fuel level sensor. The method involves recording temperature value of the fuel in the fuel tank and ambient temperature by one or more sensors, which is further fed to a control unit associated with the fuel supply and monitoring system of the vehicle. The control unit then compares the received data values i.e., fuel temperature data and ambient temperature data with data values pre-stored in a memory unit. The memory unit may be communicatively coupled to the control unit. Based on the comparison, the fuel level in the fuel tank may be ascertained.

[030] In an embodiment, the one or more sensors may be provisioned downstream of the fuel tank and at one or more locations in the vehicle. In the first scenario, the one or more sensors detect the temperature of the fuel flowing out of the fuel tank and inputs the detected temperature value to the control unit and/or the memory unit. In the second scenario, the one or more sensors may be disposed at any location in the vehicle, including, but not limited to vicinity of the engine and vehicle body where ambient conditions, like ambient temperature, may be determined. The one or more sensors detect ambient temperature conditions within the vehicle body, and sends the detected ambient temperature values to the control unit and/or the memory unit.

[031] Both fuel temperature and ambient temperature values are mapped with data values pre-stored in the memory unit. In an embodiment, the mapping may be performed by mapping tools such as machine learning tools, AI tools, programming tools structured using set of instructions and the like. The fuel temperature and the ambient temperature values (source data) are mediated onto the data values pre-stored (target data) in the memory unit. The pre-stored data may be generated on the basis of trials conducted previously in different operating conditions of the engine and vehicle ambient conditions, for example, different fuel levels, and temperatures of the vehicle corresponding to ambient environmental conditions.

[032] The method further encompasses engine output management steps on the basis of fuel level in the fuel tank. The control unit, being communicatively coupled to the engine, reduces fuel supply to the engine gradually in proportion to reduction of quantity of the fuel in the fuel tank. The gradual reduction of fuel supply to the engine begins when the fuel level drops below a first threshold level in the tank and continues until the fuel level reaches a second threshold level. In an embodiment, gradual reduction of fuel supply to engine reduces power produced by the engine, and the control unit also provide signals to an engine management system to reduce the torque of the engine. As soon as the fuel level drops below the second threshold level, the engine fuel supply is stopped or cut-off (i.e., the engine is brought to halt), which indicates inadequate fuel in the tank needed to operate the engine. Thus, the driver is alerted of subsiding fuel level in the tank, and prompted for re-fueling of the tank to restore normal engine operation.

[033] The following paragraphs describe the present disclosure with reference to FIGS.1 to 4. In the figures, the same element or elements which have similar functions are indicated by the same reference signs.

[034] FIG. 1 portrays a schematic of the system (100) for monitoring fuel level in the fuel tank (20) in a vehicle. The system (100) includes an engine (10), which generates mechanical power by combustion of the fuel to propel the vehicle (not shown). The engine (100) may include, but not limited to a gasoline engine, diesel engine, hybrid engine, Natural Gas engine, Bio-fuel engine and the like, which uses a liquidus or a gaseous fuel. The fuel required to run the engine (100) is stored in a fuel tank (20) of different capacities depending on the type of vehicle. The fuel tank (20) has a downstream fuel filter (70) intended to filter out impurities from the fuel. The filter (70) may be in the form of a permeable membrane or a strainer which is permeable to the flow of fuel through it, while entraining or trapping the foreign constituents. In an embodiment, the fuel filter (70) may be present at any point in the fuel pathway between the fuel tank (20) and the injectors (60B) in the system (100) to trap or filter out foreign constituents.

[035] As shown in FIG. 1, the filtered fuel coming out of the filter (70) is drawn by a pump (80) under suction pressure. In an embodiment, the pump (80) such as a feed pump or a low-pressure side pump may be provided between the filter (70) and the fuel tank (20). The arrangement of pump (80) with respect to the filter (70) as shown in FIG. 1 should not be considered as the only possible arrangement, and is in no way limiting the scope of the embodiments of the present disclosure. The pump (80) delivers the fuel into the rail (60A), which secures one or more fuel injectors (60B) (not shown explicitly). In an embodiment, the pump (80) is an in-line fuel injector pump. In FIG. 1, fuel injector(s) (60A) and the rail (60B) are shown as an integrated component, and should not be in any way construed as a limitation, as both these components may be assembled with each other in the fuel injection system.

[036] Further, as shown in FIG. 1, the injectors (60B) may be fluidly coupled to the fuel tank (20) via an overflow or a leak-off-line (60C), so that the residual or unused fuel present in the injector head (not shown) may flow back to the fuel tank (20) via the line (60C). In an embodiment, the overflow or leak-off line (60C) is a conduit or a pipe which carries un-injected or residual fuel present in the fuel injector (60B), with the un-injected or residual fuel being at a higher temperature than the temperature of the fuel at any other line in the system (100). The high temperature of the fuel flowing through the line (60C) may be attributed to reasons including, but not limited to, proximity of the fuel injectors (60B) to the combustion chambers (not shown) of the engine (10), increase of pressure by an in-line injector pump (80) or a compressor (not shown), higher compression ratios and so on. In an embodiment, the pump (80) and/or the rail-injector component (60A, 60B) may include one or more sensors disposed downstream to detect fuel characteristics like fuel pressure, temperature, flow rate and so on. In another embodiment, the temperature data, pressure data or flow rate data of the fuel (30) flowing from the pump (80) and/or the rail-injector component (60A, 60B), is detected by the one or more sensors. The detected data is fed or input to the control unit (50).

[037] The control unit (50) present in the system (100) is communicatively interfaced with the one or more sensors (30), as depicted in FIG. 1. In an embodiment, the control unit (50) is an Electronic Control Unit (ECU) associated with Engine Management system (EMS) and/or fuel supply and management unit in the vehicle. The control unit (50) in the system (100) receives temperature data of the fuel in the fuel tank (20), and ambient temperature data recorded by the one or more sensors (30). As illustrated in FIG. 1, the one or more sensors (30) may be provisioned at one or more locations in vehicle. In an embodiment, the one or more locations include, but not limited to engine compartment and vehicle body. The one or more sensors (30) detect ambient temperature conditions of the vehicle which may vary with engine (10) operating conditions (engine speed, power, load etc.) and external environmental conditions. The ambient temperature signal detected by the one or more sensors (30) is fed to the control unit (50). In an embodiment, the control unit (50) may receive air temperature as an input signal from the air supply unit (90) of the vehicle.

[038] Additionally, the one or more sensors (30) may be thermally coupled with the fuel tank (20) or disposed downstream of the fuel tank (20) to detect the fuel temperature present in the tank (20). We may consider two different cases with respect to temperature detection of the fuel relative to the fuel level in the tank (20).

[039] Case – I: In this case, fuel level in the tank (20) is adequate enough to keep the engine (10) operate normally. At any instant of time and at a given ambient temperature, the fuel temperature in the tank (20) is a function of fuel level present in the fuel tank (20). Now, due to presence of adequate fuel in the fuel tank (20), the incoming residual or un-injected fuel from the fuel injectors (60B), which is at a higher temperature, will not influence or elevate the overall temperature of the fuel in the fuel tank (20). In other words, mixing of high temperature fuel returning from the injectors (60B) to the fuel tank (20) with the fuel already present in the fuel tank (20) will not result in significant temperature rise of the net fuel in the fuel tank (20).

[040] Case – II: In this case, the fuel level in the fuel tank (20) is low to sustain normal engine (10) operation. The incoming residual or un-injected fuel from the injectors (60B) mixes with the low-level fuel in the tank (20), due to which there is elevation in overall temperature of the fuel in the tank (20). This elevated temperature or fluctuation in temperature is recorded by the one or more sensors (30) disposed downstream of the tank (20). The recorded temperature value is fed to the control unit (50). The control unit (50) then compares the received data values i.e., fuel temperature data and ambient temperature data with the data pre-stored in the memory unit (40). In an embodiment, comparison of the fuel temperature and the ambient temperature with the pre-stored data in the memory unit (40) is by mapping the data values, including but not limited to look-up table mapping, indexing and the like. Based on the comparison, the fuel level in the fuel tank (20) may be ascertained.

[041] In an embodiment, the pre-stored data in the memory unit (40) may be generated through a series of simulations, considering different fuel temperature values and ambient condition values corresponding to different fuel levels in the fuel tank (20). In an alternate embodiment, the pre-stored data may be generated using trials or runs performed at various ambient conditions, fuel temperatures in the tank (20) and fuel levels in the tank (20). The pre-stored data may also be derived from prediction models, numerical models such as interpolation and extrapolation of data values, experiments etc., for a series of ambient temperature values, fuel temperature values and fuel levels in the fuel tank (20). In another embodiment, the temperature of the fuel flowing out of the fuel injectors (60B) may also be detected and used as an additional input for the comparison.

[042] Now reference is made to FIG. 2 which illustrates the system (200) for monitoring fuel level in the fuel tank (20). When the comparison of fuel temperature data and ambient temperature data with the pre-stored data is complete, the next step is to provide a feedback to the driver indicating different fuel levels in the tank (20), and its influences on engine (10) operation. The control unit (50), being communicatively coupled to the engine (10), reduces fuel supply to the engine gradually in proportion to reduction of quantity of the fuel in the fuel tank (20). The reduction of fuel level in the tank (20) is in turn predicted proportionately based on temperature variation of the fuel in the tank (20), in accordance with Case – II discussed above. With continuous monitoring of decreasing fuel levels in the fuel tank (20), the control unit (50) prompts the fuel supply system to subside the fuel feed or fuel injection into the engine (10). This gradual reduction in fuel supply results in gradual reduction of engine output. Further, gradual reduction of engine (10) output begins when the fuel level drops below a first threshold level in the tank (20). In an embodiment, gradual reduction of fuel supply to engine reduces power produced by the engine, and the control unit (50) also provides signals to the engine management system [not shown] to reduce the torque of the engine. Specifically, when the fuel level in the tank (20) is below the first threshold level, the output of the engine (10) is proportional to the fuel level in the tank (20) at a given instant of time. This proportional engine output reduction continues until the fuel level reaches a second threshold level in the tank (20). As soon as the fuel level drops below the second threshold level, fuel supply to the engine (10) is stopped or cut-off (the engine is brought to halt), which indicates insufficiency of the fuel in the tank (20) required to operate the engine (10) normally. Thus, driver is alerted of subsiding fuel level in the tank (20) in the form of varying engine (10) output, and prompted for re-fueling of the tank (20) to restore normal engine operation. In an embodiment, the engine output may be in the form of engine torque. Variation of engine output (torque) as a function of measured fuel temperature and predicted fuel level is graphically depicted in FIG. 3.
[043] Further, as it can be seen in FIG. 2, the system (200) may include a sensor (30) in communication with a Fuel Injection System (FIS), comprising a fuel pump (65A), a rail (65B) and fuel injectors (65C). The sensor (30) associated with FIS detects fluctuation of fuel parameters in the rail (65B), such as fuel pressure variation inside the rail (65B). When the fuel is restored in the tank (20) to sufficient extent, the sensor (45) detects variations in the pressure of the fuel flowing inside the rail (65B) once the fuel is pumped from the tank (20). The detected pressure is input to the control unit (50), and the control unit (50) compares the received pressure value with pressure data pre-stored in the memory unit (40). If the input pressure value maps onto the pre-stored pressure data, the control unit (50) prompts the engine (10) to restore engine’s normal operation. Restoration of engine (10) operation may occur in one of the following forms: a) restoration of engine (10) output to normal value when the engine (10) is operating at “gradual fuel supply reduction mode” corresponding to a fuel level between the first threshold level and the second threshold level in the tank (20); or b) Restart of the engine (10) when the engine (20) is retarded (or halted) in the previous cycle due to drop of fuel level below the second threshold level in the fuel tank (20).

[044] Now reference is made to FIG. 4 which illustrates an operational embodiment of the present disclosure. The embodiment discloses a method by which fuel level in the fuel tank (20) is monitored on a continuous basis during engine (10) operation. The sequence of operation is depicted using a flowchart (400). This involves receiving temperature data of the fuel in the fuel tank (20) and ambient temperature data recorded by one or more sensors (30) by a control unit (50) in the first step (401). The one or more sensors (30) may be provisioned downstream of the fuel tank (20) and at one or more locations in the vehicle. In the first case, the one or more sensors (30) detect the temperature of the fuel flowing out of the fuel tank (20) and inputs the detected temperature value to the control unit (50). The one or more sensors (30) may be located at any location in the vehicle, including, but not limited to engine compartment or the vehicle body. The control unit (50) then compares the received data values i.e., fuel temperature data and ambient temperature data with data pre-stored in a memory unit (40), as shown in step (402). Based on the comparison, the fuel level in the fuel tank may be ascertained in step (403).

[045] The method further encompasses engine output management steps based on the fuel level in the fuel tank (20). The control unit (50), being communicatively coupled to the engine (10), reduces the engine output gradually in proportion to reduction of quantity of the fuel in the fuel tank (20), as shown in step 405, which in turn influences temperature fluctuations in the tank (20). If the fuel level in the tank (20) is above the first threshold level, engine (10) operates normally. The gradual reduction of engine output begins when the fuel level drops below a first threshold level in the tank (20), and continues until the fuel level reaches a second threshold level. When the fuel level drops below the second threshold level, as shown in step 408, the engine fuel supply is stopped or cut-off (i.e., the engine is brought to halt), which indicates insufficiency of the fuel in the tank (20) needed to operate the engine. If the fuel level in the tank (20) is still above the second threshold level but below the first threshold level, step 405 continues until the fuel level drops below the second threshold level. Thus, the driver is alerted of subsiding fuel level in the tank (20), and prompted for re-fueling of the tank (20) to restore normal engine (10) operation.

[046] The method and the resulting system by which fuel level in the fuel tank (20) is monitored based on variations in ambient temperature conditions and fuel temperatures in the fuel tank (20), in accordance with some embodiments, has several advantages. One advantage is that the system can be easily integrated with vehicle fuel supply systems where direct detection or measurement of fuel level in the fuel tank (20) is not possible. Another advantage of having the system in a vehicle is that the vehicle is not brought to halt all of a sudden due to miscalculation or misapproximation of very low fuel level in the fuel tank (20). This is possible by continuous feedback provided by the system to the driver when fuel levels start dropping below the first threshold level, during which engine output also drops proportionally with the fuel level drop. There is also an advantage with respect to prevention of dry running of fuel pump using the system and method disclosed in the present disclosure. The adverse effects of cavitation, air block, etc., may be avoided, thereby minimizing the replacement and maintenance costs associated with the vehicle.

[047] In an embodiment of the disclosure, the control unit (50) (like an ECU) may be a centralized control unit, or a dedicated control unit associated with the fuel system of the engine. The control unit may be implemented by any computing systems that is utilized to implement the features of the present disclosure. The control unit may be comprised of a processing unit. The processing unit may comprise at least one data processor for executing program components for executing user- or system-generated requests. The processing unit may be a specialized processing unit such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc. The processing unit may include a microprocessor, such as AMD Athlon, Duron or Opteron, ARM’s application, embedded or secure processors, IBM PowerPC, Intel’s Core, Itanium, Xeon, Celeron or other line of processors, etc. The processing unit may be implemented using a mainframe, distributed processor, multi-core, parallel, grid, or other architectures. Some embodiments may utilize embedded technologies like application-specific integrated circuits (ASICs), digital signal processors (DSPs), Field Programmable Gate Arrays (FPGAs), etc.

[048] In some embodiments, the ECU may be disposed in communication with one or more memory devices (e.g., RAM, ROM etc.) via a storage interface. The storage interface may connect to memory devices including, without limitation, memory drives, removable disc drives, etc., employing connection protocols such as serial advanced technology attachment (SATA), integrated drive electronics (IDE), IEEE-1394, universal serial bus (USB), fiber channel, small computing system interface (SCSI), etc. The memory drives may further include a drum, magnetic disc drive, magneto-optical drive, optical drive, redundant array of independent discs (RAID), solid-state memory devices, solid-state drives, etc.

[049] Furthermore, one or more computer-readable storage media may be utilized in implementing embodiments consistent with the present disclosure. A computer-readable storage medium refers to any type of physical memory on which information or data readable by a processor may be stored. Thus, a computer-readable storage medium may store instructions for execution by one or more processors, including instructions for causing the processor(s) to perform steps or stages consistent with the embodiments described herein. The term “computer-readable medium” should be understood to include tangible items and exclude carrier waves and transient signals, i.e., are non-transitory. Examples include random access memory (RAM), read-only memory (ROM), volatile memory, non-volatile memory, hard drives, CD ROMs, DVDs, flash drives, disks, and any other known physical storage media.

[050] It is to be understood that a person of ordinary skill in the art may develop a mechanism or a system of similar configuration without deviating from the scope of the present disclosure. Such modifications and variations may be made without departing from the scope of the present invention. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents.

Equivalents:

[051] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

[052] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system (108) having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system (108) having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope being indicated by the following claims.

Reference Numerals:

System 100, 200
Engine 10
Fuel tank 20
One or more sensors 30
Memory Unit 40
Pressure sensor 45
Control Unit 50
Fuel rail 60A, 65B
Injectors 60B, 65C
Overflow or leak-off line 60C
Filter 70
Fuel Pump 65A, 80
Air supply unit 90
Air flow sensor 90A
Locations in the vehicle 110
Fuel Injection System FIS
Method steps 400-408