DESC:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)

TITLE OF THE INVENTION
“MEASUREMENT OF FUEL LEVELS IN A FUEL TANK OF A VEHICLE”
APPLICANT:
Name Nationality Address
Mahindra & Mahindra Limited Indian Mahindra & Mahindra Ltd.,
MRV, Mahindra World City (MWC),
Plot No. 41/1, Anjur Post, Chengalpattu,
Kanchipuram District – 603204 (TN) INDIA

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:-

TECHNICAL FIELD
The embodiments herein relate to vehicles and, more particularly, to measurement of fuel levels in a fuel tank of a vehicle.

BACKGROUND
Fuel gauge is an important component of any vehicle, as the fuel gauge displays amount of available fuel in the fuel tank. This is helpful for the driver, as the fuel level indication helps him plan re-fuelling intervals, so that the vehicle will not run out of fuel during a trip.
Currently, fuel float sensors are being used for the purpose of fuel level measurement. The fuel float sensors measures fuel level using a 'float'. As the fuel level decreases, the 'float' falls, thereby increasing resistance of a potentiometer it is connected to. The increased resistance causes an indicator to change position, indicating fuel level in the tank.
Though the float sensor based mechanism is accurate to certain extent, it is prone to errors, mainly when the vehicle is travelling or stationary on an uneven or a sloped surface; thereby providing erroneous reading to the driver. The fuel float sensors which are currently being used in the market are not capable of identifying errors in the reading, and automatically making adjustments so as to provide accurate fuel level reading.

BRIEF DESCRIPTION OF THE FIGURES
The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:
FIG. 1 illustrates a block diagram of an fuel level measurement system, as disclosed in the embodiments herein;
FIGS. 2a and 2b illustrate example implementation of the fuel level measurement system, as disclosed in the embodiments herein; and
FIG. 3 is a flowchart depicting the process of measuring fuel levels in a fuel tank in a vehicle, as disclosed in the embodiments herein.

DETAILED DESCRIPTION OF EMBODIMENTS
The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The embodiments herein disclose a system and method for automatic measurement of fuel levels in a fuel tank in a vehicle. Referring now to the drawings, and more particularly to FIGS. 1 through 3, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
Embodiments herein disclose a method and system for measuring fuel present in a fuel tank of a vehicle, using a plurality of pressure sensors, an accelerometer, a gyroscope, and so on. Embodiments herein measure the weight of the fuel present in the fuel tank and determining the amount of fuel present in the vehicle at the current instant by comparing the measured weight against a reference weight of fuel when the fuel tank is at maximum capacity.
FIG. 1 illustrates a system for determining fuel present in a fuel tank of a vehicle. The fuel level measurement system 100 comprises of a fuel tank 101 and a pressure sensor 2 105. The fuel tank 101 further comprises of a fuel float 102, an accelerometer 103, a pressure sensor 1 104, and a fuel level measurement module 106. The accelerometer 103 can be integrated with the fuel float 102. The accelerometer 103 can comprise of a gyroscope, such as a 3-axis gyroscope. The accelerometer 103 can measure the movement of the fuel float 102, such as the movement of the vehicle when on uneven surfaces such as uneven roads, bridges, and so on. The accelerometer 103 can determine the angle of incline with respect to the vehicle. The accelerometer 103 can measure changes in the angle of the fuel tank 101 with respect to a reference position.
The pressure sensors 104 and 105 can be at least one of a barometer, strain gauge, or any other sensor configured for measuring pressure. The pressure sensors 104 and 105 can measure pressure internal to and external to the fuel tank 101, respectively. The pressure sensor 1 104 can measure the pressure exerted by the contents of the fuel tank, such as the fuel, atmosphere, and so on. The cosine component of the weight of the fuel present in the fuel tank exerts pressure on the pressure sensor 1 104, which is measured by the pressure sensor 1 104. The pressure sensor 2 105 can measure the atmospheric pressure outside the fuel tank 101. The pressure sensor 2 105 can measure the atmospheric pressure outside the fuel tank 101, in a suitable format such as Pa (Pascals), hPa (Hundred Pascals, hectopascals), and so on.
The fuel level measurement module 106 can be located within the fuel tank 101, the fuel pump or any other equivalent means. The fuel level measurement module 106 can be located remotely from the fuel tank 101. The fuel level measurement module 106 can be a dedicated module. The fuel level measurement module 106 can be a module present in the vehicle (such as an ECU (Electronic Control Unit)) configured to determine the fuel levels.
The measurements by the accelerometer 103, the pressure sensor 1 104 and the pressure sensor 2 105 are provided to the fuel level measurement module 106. The fuel level measurement module 106 can determine the pressure exerted by the fuel by determining the difference between the pressure values provided by the pressure sensors 104 and 105. The fuel level measurement module 106 can determine the weight of the fuel present in the fuel tank, as the cosine component of the weight of the fuel present in the fuel tank exerts pressure on the pressure sensor 1 104. The fuel level measurement module 106 can factor the angle of the vehicle as provided by the accelerometer 103 to determine the actual weight of the fuel. This is because in case the vehicle is at an angle, the entire fuel may not exert pressure on the pressure sensor 1 104. The fuel level measurement 106 can compare the weight of the fuel to a pre-defined weight of fuel when the fuel tank 101 is at full capacity. Based on the comparison, the fuel level measurement module 106 can determine a percentage of fuel present in the fuel tank 101. The fuel level measurement module 106 can provide the determined fuel present in the fuel tank 101 to other vehicle systems, wherein the vehicle systems can display the determined fuel to a user of the vehicle using a suitable means such as the dashboard, infotainment system, a user device, or any other device/system/component that can use and/or display the fuel levels.
FIGS. 2a and 2b illustrate an example implementation of the fuel level measurement system. For the purpose of understanding working of the fuel level measurement system 100, fuel level is measured when slope = 0 (scenario 1), when slope = 45 (scenario 2), and when slope = 30 degrees (scenario 3). Please note that the amount of fuel left in the fuel tank is same in both scenarios, and the end result of measurement in both scenarios indicates accuracy with which the correction is done by the fuel level measurement system 100 while measuring fuel level.
Static values with respect to the fuel tank 100 considered in this scenario are:
Base area = 0.4 m2
Total height = 0.27m (0.243 is allowed limit)
Full tank weight of fuel, w_t= 60kg (maximum capacity is 70L)
Scenario 1: When slope = 0, parallel to ground and fuel tank contains 35L of fuel
The angle from accelerometer = 0 degree
Atmospheric Pressure from pressure sensor 2 105, Patm = 1050 hPa
Barometer Pressure inside Fuel Tank, Pfa =1057.40 hPa
Fuel Pressure, Pf = Pfa - Patm
= 7.40hPa
Weight of the Fuel, w_f= Base Area x Pf
= 7.40hPa x 0.4 m2
= 296 N
= 30.234 kgwt.
Percentage Fuel Level = w_f/w_t *100
= 30.234/60*100
= 50.39
Scenario 2: When slope = 45, hill ascent and fuel tank contains 35L of fuel
The angle from accelerometer = 45 degree
Atmospheric Pressure, Patm = 1050 hPa
Barometer Pressure inside Fuel Tank, Pfa = 1055.23 hPa
Fuel Pressure, Pf = Pfa - Patm
= 5.23 hPa
Weight of the Fuel, w_f = (Base Area * Pf)/cos?45
= (0.4 * 5.23 * 100)/cos?45
= 295.8 N
= 30.214 kgwt.
Percentage Fuel Level = w_f/w_t *100
= 30.214/60*100
= 50.35
Scenario 3:
When slope = 30, hill descent and fuel tank 35L
The angle from accelerometer = 30 degree
Atmospheric Pressure, Patm = 1050 hPa
Barometer Pressure inside Fuel Tank, Pfa =1056.40 hPa
Fuel Pressure, Pf = Pfa - Patm
= 6.40 hPa
Weight of the Fuel, W_f = Base Area x Pf
= (0.4 * 6.4 * 100)/cos?30
= 295.65 N
= 30.199 kgwt.
Percentage Fuel Level = w_f/w_t *100
= 30.199/60*100
= 50.331 %.
As given in the above mentioned scenarios, the fuel level measurement system 100 measures the fuel level accurately, regardless of the slope.
FIG. 3 is a flowchart depicting the process of measuring fuel levels in a fuel tank in a vehicle. The accelerometer 103 determines (301) the angle of incline with respect to the vehicle (if any), as depicted in FIG. 2. The accelerometer 103 measures the angle of the fuel tank 101 with respect to a reference position. The pressure sensor 1 104 measures (302) the pressure inside the fuel tank. The pressure sensor 2 105 measures (303) the atmospheric pressure outside the fuel tank 101. The pressure sensor 2 105 measures the atmospheric pressure outside the fuel tank 101, in a suitable format such as Pa (Pascals), hPa (Hundred Pascals, hectopascals), and so on. The fuel level measurement module 106 determines (304) the pressure exerted by the fuel by determining the difference between the pressure values provided by the pressure sensors 104 and 105. The fuel level measurement module 106 determines (305) the weight of the fuel present in the fuel tank, as product of the base area of the fuel tank 101 and the fuel pressure divided by the cosine of the angle (as provided by the accelerometer 103). The fuel level measurement 106 determines (306) the fuel in the fuel tank 101 in terms of percentage using the weight of the fuel and the pre-defined weight of fuel when the fuel tank 101 is at full capacity. The various actions in method 300 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 3 may be omitted.
The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and performing network management functions to control the network elements. The network elements shown in Fig. 1 include blocks which can be at least one of a hardware device, or a combination of hardware device and software module.
The embodiments disclosed herein specify a system for fuel level measurement in vehicles. The mechanism allows automatic measurement of fuel levels in a fuel tank, providing a system thereof. Therefore, it is understood that the scope of protection is extended to such a system and by extension, to a computer readable means having a message therein, said computer readable means containing a program code for implementation of one or more steps of the method, when the program runs on a server or mobile device or any suitable programmable device. The method is implemented in a preferred embodiment using the system together with a software program written in, for ex. Very high speed integrated circuit Hardware Description Language (VHDL), another programming language, or implemented by one or more VHDL or several software modules being executed on at least one hardware device. The hardware device can be any kind of device which can be programmed including, for ex. any kind of a computer like a server or a personal computer, or the like, or any combination thereof, for ex. one processor and two FPGAs. The device may also include means which could be for ex. hardware means like an ASIC or a combination of hardware and software means, an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein. Thus, the means are at least one hardware means or at least one hardware-cum-software means. The method embodiments described herein could be implemented in pure hardware or partly in hardware and partly in software. Alternatively, the embodiment may be implemented on different hardware devices, for ex. using a plurality of CPUs.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the claims as described herein.

CLAIMS
We claim:
A system for determining fuel present in a fuel tank located in a vehicle, the system comprising an accelerometer, a first pressure sensor located in the fuel tank, and a second pressure sensor located outside the fuel tank.
The system, as claimed in claim 1, wherein the accelerometer comprises of a gyroscope.
The system, as claimed in claim 1, wherein the accelerometer is integrated with a fuel float present in the fuel tank.
The system, as claimed in claim 1, wherein the system is configured for determining fuel pressure by a fuel level measurement module as a difference in pressures measured by the first pressure sensor and the second pressure sensor;
determining weight of fuel present in the fuel tank by the fuel level measurement module as product of base area of the fuel tank and the determined fuel pressure divided by cosine of angle measured by the accelerometer; and
determining the fuel present in the fuel tank by the fuel level measurement module.
The system, as claimed in claim 4, wherein the fuel level measurement module is configured for determining the fuel present in the fuel tank as a percentage of full capacity of the fuel tank.
A vehicle comprising a system for determining fuel present in a fuel tank located in a vehicle, the system comprising an accelerometer, a first pressure sensor located in the fuel tank, and a second pressure sensor located outside the fuel tank.
The vehicle, as claimed in claim 6, wherein the accelerometer comprises of a gyroscope.
The vehicle, as claimed in claim 6, wherein the accelerometer is integrated with a fuel float present in the fuel tank.
The vehicle, as claimed in claim 6, wherein the system is configured for determining fuel pressure by a fuel level measurement module as a difference in pressures measured by the first pressure sensor and the second pressure sensor;
determining weight of fuel present in the fuel tank by the fuel level measurement module as product of base area of the fuel tank and the determined fuel pressure divided by cosine of angle measured by the accelerometer; and
determining the fuel present in the fuel tank by the fuel level measurement module.
The vehicle, as claimed in claim 9, wherein the fuel level measurement module is configured for determining fuel present in the fuel tank as a percentage of full capacity of the fuel tank.
A method for determining fuel level in a fuel tank located in a vehicle, the method comprising;
determining fuel pressure by a fuel level measurement module as a difference in pressures measured by a first pressure sensor located in the fuel tank and a second pressure sensor located outside the fuel tank;
determining weight of fuel present in the fuel tank by the fuel level measurement module as product of base area of the fuel tank and the determined fuel pressure divided by cosine of angle measured by an accelerometer; and
determining the fuel present in the fuel tank by the fuel level measurement module.
The method, as claimed in claim 11, wherein the method further comprises determining the fuel present in the fuel tank as a percentage of full capacity of the fuel tank.

Date: 29th January 2016 Signature:
Dr.Kalyan Chakravarthy

ABSTRACT
Disclosed herein are a method and a system for measuring fuel levels in a fuel tank in a vehicle. The system comprises of a plurality of pressure sensors and an accelerometer. The pressure sensors determine the fuel pressure and the accelerometer determines the angle of the fuel tank with respect to a reference position. The system determines the fuel weight as the product of the fuel pressure and the base area of the fuel tank divided by the cosine of the angle of the fuel tank. The system determines the fuel in the fuel tank as a percentage of the total weight of the fuel.

FIG. 3

,CLAIMS:CLAIMS
We claim:
1. A system for determining fuel present in a fuel tank located in a vehicle, the system comprising an accelerometer, a first pressure sensor located in the fuel tank, and a second pressure sensor located outside the fuel tank.
2. The system, as claimed in claim 1, wherein the accelerometer comprises of a gyroscope.
3. The system, as claimed in claim 1, wherein the accelerometer is integrated with a fuel float present in the fuel tank.
4. The system, as claimed in claim 1, wherein the system is configured for determining fuel pressure by a fuel level measurement module as a difference in pressures measured by the first pressure sensor and the second pressure sensor;
determining weight of fuel present in the fuel tank by the fuel level measurement module as product of base area of the fuel tank and the determined fuel pressure divided by cosine of angle measured by the accelerometer; and
determining the fuel present in the fuel tank by the fuel level measurement module.
5. The system, as claimed in claim 4, wherein the fuel level measurement module is configured for determining the fuel present in the fuel tank as a percentage of full capacity of the fuel tank.
6. A vehicle comprising a system for determining fuel present in a fuel tank located in a vehicle, the system comprising an accelerometer, a first pressure sensor located in the fuel tank, and a second pressure sensor located outside the fuel tank.
7. The vehicle, as claimed in claim 6, wherein the accelerometer comprises of a gyroscope.
8. The vehicle, as claimed in claim 6, wherein the accelerometer is integrated with a fuel float present in the fuel tank.
9. The vehicle, as claimed in claim 6, wherein the system is configured for determining fuel pressure by a fuel level measurement module as a difference in pressures measured by the first pressure sensor and the second pressure sensor;
determining weight of fuel present in the fuel tank by the fuel level measurement module as product of base area of the fuel tank and the determined fuel pressure divided by cosine of angle measured by the accelerometer; and
determining the fuel present in the fuel tank by the fuel level measurement module.
10. The vehicle, as claimed in claim 9, wherein the fuel level measurement module is configured for determining fuel present in the fuel tank as a percentage of full capacity of the fuel tank.
11. A method for determining fuel level in a fuel tank located in a vehicle, the method comprising;
determining fuel pressure by a fuel level measurement module as a difference in pressures measured by a first pressure sensor located in the fuel tank and a second pressure sensor located outside the fuel tank;
determining weight of fuel present in the fuel tank by the fuel level measurement module as product of base area of the fuel tank and the determined fuel pressure divided by cosine of angle measured by an accelerometer; and
determining the fuel present in the fuel tank by the fuel level measurement module.
12. The method, as claimed in claim 11, wherein the method further comprises determining the fuel present in the fuel tank as a percentage of full capacity of the fuel tank.