TECHNICAL FIELD
[0001] The present subject matter relates generally to a motor vehicle and more particularly to a fuel level indicator system for the motor vehicles.
BACKGROUND
[0002] Generally, in a motor vehicle with a prime drive source as an internal combustion (IC) engine, petrol or gasoline is used as fuel for driving the IC engine. An air-fuel mixture is combusted in the IC engine for generating a desired power or torque output. A fuel tank mounted to the motor vehicle holds fuel and supplies to the IC engine through a carburetor or the like. The fuel tank has a limited capacity and the fuel has to be refilled when it reaches a low value.
BRIEF DESCRIPTION OF DRAWINGS
[0003] The detailed description of a fuel indicator system and a method
thereof of the present subject matter is described with reference to the
accompanying figures. Same numbers are used throughout the drawings to
reference like features and components.
[0004] Fig. 1 illustrates a right side view of an exemplary saddle ride type
vehicle, in accordance with an embodiment of present subject matter.
[0005] Fig. 2 (a) illustrates a left side perspective view of an exemplary fuel
tank assembly, in accordance with an embodiment of the present subject matter.
[0006] Fig. 2 (b) depicts a left side view of a float assembly, in accordance
with an embodiment of the present subject matter.
[0007] Fig. 3 (a) depicts a left side cross-sectional view of a fuel tank
assembly, in accordance with an embodiment of the present subject matter.
[0008] Fig. 3 (b) depicts a front cross-sectional view of the fuel tank assembly
depicted in Fig. 3 (a).

[0009] Fig, 4 (aa) depicts a front view of a fuel tank assembly tilted towards
right side, in accordance with an embodiment of the present subject matter.
[00010] Fig. 4 (ab) depicts the fuel tank assembly of Fig, 4 (aa).
[00011] Fig. 4 (b) depicts a front view of a fuel tank assembly tilted towards
left side.
[00012] Fig. 5 (a) depicts a tilt sensor, in accordance with another
embodiment of the present matter.
[00013] Fig. 5 (ba) depicts the tilt in a fuel tank assembly with reduced fuel
level.
[00014] Fig. 5 (bb) depicts the tilt sensor in a fuel tank assembly with
increased fuel level.
[00015] Fig. 5 (be) depicts the sensor in a fuel tank assembly with no change
in fuel level, and the fuel tank assembly is tilted to the left side.
[00016] Fig. 6 illustrates a fuel indicator system, in accordance with an
embodiment of the present subject matter.
[00017] Fig. 7 depicts a flow chart for fuel level indication method for
working with the fuel indicator depicted in Fig. 6, in accordance with another
embodiment of the present subject matter.
DETAILED DESCRIPTION
[00018] Generally, in a motor vehicle an IC engine acts as a primary drive source. The IC engine is cranked by using a kick-start mechanism or an electric start mechanism. Generally, a fuel tank is mounted to the frame assembly of the vehicle. A cap is provided for filling fuel into the fuel tank. The fuel tank may be covered by fuel tank cover. Generally, the fuel level in the fuel tank is not visible directly. A fuel indicator is provided on the vehicle. The user relies on the fuel indicator for knowing the status of fuel volume in the fuel tank. Depending on the fuel level indicated, the user estimates the distance that can be covered with

available fuel and plans for refill accordingly. Therefore, the fuel indicator must be foolproof. Further, the fuel indicator should be effectively functional even after repetitive use. For example, in case of resistive track based moving contact sensor, a moving contact is used along with a resistive track. Wear out of the resistive track occurs after repetitive use. Further, reaction of the resistive track / moving contact surface with the fuel leads to error in output. Deposition of oil or dirt on the surface of resistive track / moving contact effects the functioning. As the fuel level sensor is installed in a fuel tank, which is a closed fuel tank, maintenance of the sensor is a complex task.
[00019] Especially in a two-wheeled vehicle, when the user checks for the fuel before starting a journey, the vehicle parked on a side stand or for vehicles with more than two wheels i.e., a three wheeler, when the road is slant or uneven, then the fuel level observed by the user is not true value. When the vehicle is tilted, all the fuel gets accumulated on one side of the tank due to gravity. The fuel level sensor gives a higher or lower fuel level when the vehicle is tilted. The lack of tilt compensation leads to providing incorrect fuel value to the user. For actual fuel level indication, the vehicle tilt must be considered during indication for accuracy.
[00020] Hence, an objective of the present subject matter is to provide a foolproof fuel level indicator system for a vehicle. The fuel level indicator system includes a float assembly. According to one aspect of the present subject matter, the fuel level indicator system provides fuel level by compensating for any error occurred due to tilt of vehicle. According to another aspect, the fuel indicator is more reliable. Yet another aspect is, the fuel level indicator works efficiently with fuel tanks having either regular or irregular geometric shape. Further, the fuel indicator system is capable of identifying tilt of the vehicle by considering

orientation(s) change of the tilt sensor and by referring to a lookup table provided by the manufacturer.
[00021] In an embodiment, a float assembly comprises a float arm with a tilt sensor mounted to it. Any variation in fuel level is reflected on the float arm of the float arm assembly. The tilt sensor capable of providing a variation in at least two orientations, is provided.
[00022] In an embodiment, variation in a first direction of tilt sensor represents a variation in the fuel level/volume. A variation in a second orientation enables identification of any tilt of the vehicle by the fuel indicator system. A variation in the first direction along a plane formed by a first axis and a third axis indicates a variation in fuel level/volume, and a variation in second orientation along a plane formed by the second axis and the third axis indicates a change in tilt. In an embodiment, an indicator control unit of the fuel indicator system compensates for error occurred due to tilt and calculates actual fuel value by compensating for variation in fuel value from an observed fuel value. Further, the calculated actual fuel level is indicated to the user on an indicator provided on instrument cluster. [00023] In an embodiment, the tilt sensor is mounted to a float arm of a float assembly. Further, the float assembly can be mounted to any surface inside the fuel tank assembly. A support member of the float assembly is fastened to a surface of a fuel tank of the fuel tank assembly.
[00024] In an embodiment, a fuel indicator system is installed on a fuel tank assembly with an irregular shape. An indicator control unit (ICU) fetches data from tilt sensor regarding change in one or more orientation(s). The ICU calculates for any compensation required due to a variation in one or more orientations. In an embodiment, a lookup table is provided with values for variation in one or more orientations, an observed fuel value and a corresponding actual fuel value. The ICU sends the actual fuel value for displaying in a display unit.

[00025] In another embodiment, the variation in orientation may also be used for identifying any abnormality such as a vehicle fall down or crash, or roll-over thereby cutting-off engine ignition or for sensing abnormality such a s vibration. [00026] The aforesaid and other advantages of the present subject matter would be described in greater detail in conjunction with the figures in the following description.
[00027] Fig. 1 illustrates a right side view of an exemplary saddle ride type vehicle, in accordance with an embodiment of present subject matter. Fig. 1 depicts a saddle ride type motorcycle 100. The motorcycle 100 has a frame assembly 105, which acts as the skeleton for the motorcycle 100. The frame assembly 105 includes a head tube (not shown), a main tube (not shown) and a down tube (not shown). A swing arm 110 is swingably connected to a pivotal point. A rear wheel 115 is rotatably supported by the swing arm. 110. One or more rear suspension(s) 120 connect the swing arm to the frame assembly. A seat assembly 125 is mounted to the frame assembly. A fuel tank cover 130 comprising of fuel tank assembly (not shown) is disposed at an anterior portion of seat assembly 125. An engine assembly 135 is mounted in the anterior portion of the frame assembly.
[00028] The engine assembly 135 includes an internal combustion, a kick-start mechanism, a transmission mechanism for transferring the power to the rear wheel 115, an air-fuel supply mechanism for the IC engine includes a carburetor or the like and an exhaust mechanism. A steering assembly 140 includes a handle bar assembly 145, one or more front forks 140A and a front wheel 140B. The handle bar assembly 145 includes a handle bar, an instrument cluster, handle grips and one or more levers. The vehicle 100 has various electrical loads including a headlamp 150, a tail lamp 155, and a starter motor (not shown). A front fender 160 covers at least a portion of the front wheel 145. A rear fender

165 covers at least a portion of the rear wheel 115. The frame assembly is covered by plurality of panels 170. An instrument cluster 175 is mounted to the handle bar assembly, for displaying various vehicle related information including speed, rotation per minute of engine, side stand indicator.
[00029] Fig. 2 (a) illustrates a left side perspective view of an exemplary fuel tank assembly 200, in accordance with an embodiment of the present subject matter. Fig. 2 (b) depicts a float assembly 200, in accordance with an aforesaid embodiment of the present subject matter. The fuel tank assembly 200 comprises a . fuel tank body 210, which is having a cuboid shape, with an opening (not shown), which is preferably in an upper portion of the fuel tank body 210. A lid (not shown) is provided for securing the opening of the fuel tank. Fuel is filled through the opening. The fuel tank body 210 is mounted to a frame assembly of the vehicle by using one or more bracket(s) 220. The fuel tank body 210 may be covered by a fuel tank cover.
[00030] The float assembly 250 is formed by a float 255 connected to a first end of a float arm 260 and a second end of the float arm 260 is operably connected to a support member 265. The float 255 is made of material with density less than density of liquid/fuel, which is used. The float arm 260 length is chosen such that it enables movement of the float arm 260 in the fuel tank body 210. The second end of the float arm 260 is connected to the support member 265 through a pivot or a hinge assembly, which is mounted to a surface of the fuel tank body 210. The fuel tank assembly 200 depicted in Fig. 1, which is in the shape of a cuboid, with a fuel tank body 210 having length L, width W and height H. In a preferred embodiment, an accelerometer 270 is mounted to the float arm 260 and the support member 265 is mounted to a surface of the fuel tank body 210, which in a top portion of the fuel tank body 210. In a preferred embodiment, the

accelerometer 270 is mounted .to the flat arm at a top portion. The support member 265 is mounted to the surface of the fuel tank by one or more fastener(s). [00031] The float arm 260 is operably connected to the support member 265 by using a hinge assembly (not shown), which enables the float arm to rotate in a first direction along a vertical plane passing through X-axis. The float 255 is made of a low-density material that enables it to float on the fuel. A change in the volume of the fuel, would either push the float 255 up or push the float 255 down in the first direction. The movement of the float 255 in first direction thereby changes the orientation of the float arm 260 in the first direction. [00032] Fig. 3 (a) depicts a cross-sectional view of a fuel tank assembly 300, in accordance with another embodiment of the present subject matter. The cross-section of the fuel tank assembly 300 is taken along the longitudinal direction of the vehicle, which is along length L of the fuel tank 310. A float assembly 250is mounted is positioned in a rear half of a fuel tank 310. A hinge assembly (not shown) enables rotation of the float member 255along with the float arm 260in the first direction XZ, which is along a plane formed by X-axis and Z-axis. The float arm is having a length R, which is also the radius of the arc with a reference point at the support member 265. L is length of the fuel tank, F is actual fuel level in the fuel tank, and E is the empty level in the fuel tank 310. The sum of empty level E and fuel level F will be equal to height H of the fuel tank 310. The volume of fuel tank is obtained by the product of length L, width W and actual fuel level F. In a preferred embodiment, the fuel level F indicated the fuel volume in the fuel tank 300.
[00033] Fig. 3 (b) depicts another cross-sectional view of the fuel tank assembly, which is taken along the width W of the fuel tank assembly 300. The float assembly 250may be positioned on any surface of the fuel tank 310. In a preferred embodiment, the float assembly 250is mounted to an inner portion of the top

surface through a support member 265. The float assembly 250is positioned at a distance of D from the mid-point of the width W. A first angle 0 represents the angle between the float arm 260and the X-axis, which is variation along the first direction XZ. The tilt sensor 270provides change of orientation in the first . direction XZ. For example, an accelerometer or gyro meter or the like may be used as tilt sensor 270. The tilt sensor 270, which is substantially parallel to the longitudinal direction of the vehicle. The output of the tilt sensor 270maybe voltage or current variation corresponding to the variation orientations. The empty . level E is obtained from using a right-angled triangle formed by empty level E, float arm length R, the top surface of the fuel tank 310 and the first angle 8 being angle formed between a horizontal plane and the float arm 260.
empty level (E) =R sin (9) actual fuel level (F) =H - E
[00034] Therefore, the actual fuel level F in the fuel tank assembly 300 is the difference between the empty level E and the height H of the fuel tank 310. Therefore, the volume of the fuel is obtained by the product of length L, width W and actual fuel level F. The sensor 270provides the variation in the first direction XZ in X-axis, which is the first angle 9.
[00035] Fig. 4 (aa) depicts a front view of a fuel tank assembly 400 tilted towards right side, in accordance with an embodiment of the present subject matter. The tilt is in a second directionYZ, which is along a plane formed by Y-axis and Z-axis, which is substantially parallel to the lateral direction of the fuel tank 410. A second angle a with respect to the Y-axis, which is due to variation in a second orientation. Generally, such a tilt occurs when the vehicle, especially two-wheelers, are parked on side stand. Due to the tilt in second angle a, the actual fuel level F inside the fuel tank 410 will be shifted to the right side of the fuel tank 410 and the observed fuel level F'. A variation in fuel level due to tilting

of the fuel tank assembly 400 by an angle a is AF, which is the difference between actual fuel level F andobserved fuel levelF'. The tilt sensor 270'mounted tothe float arm 260provides the variation of second angle a along Y-axis. [00036] Fig. 4 (ab) depicts another perspective view of the fuel tank assembly 400 depicted in Fig. 4 (aa). The variation in fuel level AF is determined by considering triangle (Aabc) formed by a first side D, which is the distance of mounting point of support member 265form middle of the fuel tank along the width W, a second side AF, which is the variation in fuel level and a third side, which is a hypotenuse adjoining the ends of the first side D and the second side AF. The second angle between the first side and the third side is a. The variation in fuel level AF, which is an error,is calculated by,
AF = D tan (a)
[00037] The actual fuel level F is obtained by compensating for the error due to tilt by second angle a, which is obtained by subtracting AF from the observed fuel value F'.
F = F'-AF
[00038] Fig. 4 (b) depicts a front view of a fuel tank assembly tilted towards left side. The tilt angle would be negative in tliis case and the observed fuel value will be decreased by AF. The fuel value will be obtained by adding AF to the observed fuel value F'.
F = F' + AF
[00039] The tilt sensor 270 of the float assembly 250, is communicatively coupled to the indicator control unit. The indicator control unit is adapted to receive data from the tilt sensor 270 and calculate respective variation in fuel level AF, which is the error duel to tilting. Further, the actual level is calculated and communicated to the user through audio or visual indicator including a display.

■-1
[00040] Fig. 5 (a) depicts the accelerometer 270as an exemplary tilt sensor, in accordance with an embodiment of the present matter. The first direction XZ is along a plane formed by X-axis and Z-axis, and the second orientation YZ is along a plane formed by Y-axis and Z-axis. The accelerometer 270is mounted to a float arm such that if there is any variation in the fuel level then the float arm is rotated in the first orientation. A tilt in a lateral direction of the vehicle is reflected by variation of the accelerometer angle in a second orientation. The tilt sensor 270detects the variation of the angle in any of the first direction XZ and/or second direction YZ. Fig. 5 (ba) depicts the tilt sensor 270in the fuel tank assembly with reduced fuel level. Variation in fuel level that is indicated by variation in the first direction XZ by a first angle 9, which is from X to X' and by an angle p, which is form Z to Z\ Fig. 5 (bb) depicts the tilt sensor 270in a fuel tank assembly with increased fuel level. Variation in fuel level that is indicated by variation in the first direction XZ by a first angle 6, which is from X to X" and by an angle p, which is form Z to Z". Fig. 5 (be) depicts the tilt sensor 270in a fuel tank assembly with no change in fuel level and to the left side. Variation in fuel level that is indicated by variation in the second orientation YZ by an angle a, which is from Y to Y'" and by an angle p, which is form Z to Z"[00041] In the aforementioned embodiment, calculation of actual fuel level is obtained by using aforesaid equations since the fuel tank has a regular geometrical shape.
[00042] In a case when the fuel tank of the fuel tank assembly is of irregular shape, for such fuel tank assembly equation development gets complicated, therefore a look-up table based tilt compensation and fuel level and fuel volume estimation can be used. The look-up table is developed by noting the behavior of tilt sensor output for different fuel volumes from empty to full condition in a reference tank level or in three dimensional model level at various tilt conditions

on both left and right sides. The lookup table comprises observed fuel value F', variation of orientation in the first orientation, and second orientation YZ corresponding to change in angle in X-axis, Y-axis and Z-axis, if any, and the corresponding actual fuel level F. Further, the look-up table is capable of providing the readings of fuel volume by compensating for tilt of the vehicle. Furthermore, a look-up maybe also used for a fuel tank assembly with a regular geometric shape.
[00043] Fig. 6 illustrates a fuel indicator system 600, in accordance with an embodiment of the present subject matter. A tilt sensor 270detects any variation in a first direction XZ and a second orientation. A gyro meter is another example for tilt sensor. The variation of fuel level is reflected by variation in a first direction XZ and the tilt of vehicle is identified by variation in second orientation. An output from the tilt sensor 270 may be analog or digital output. The output from tilt sensor 270is fed to a signal conditioning unit 620A. The signal conditioning unit 620A enables regulation or enhancement of the output from the tilt sensor 270. An analog to digital converter (ADC) may be used as signal conditioning unit 620A for analog tilt sensor or a digital tilt sensor. A microcontroller 620B calculates the tilt compensation required for finding.out actual fuel value F. A display unit 630 depicts the actual fuel level in the fuel tank assembly through a display driver 620C. The signal conditioning unit 620A, the microcontroller 620B and the display driver 620C may be integrated in an indicator control unit (ICU) 610.
[00044] Fig. 7 depicts a flow chart 700 for fuel level indication method for working with the fuel indication depicted in Fig. 6, in accordance with an embodiment of the present subject matter. At step 710, the user turns ON an ignition key thereby the on-board auxiliary power source of the vehicle initializes the ICU 610 and other modules including display unit 630. At step 720, the ICU

610 fetches data from the tilt sensor 270. The signal conditioning unit 620A of the ICU 620 fetches data from the tilt sensor 270with regard to the tilt sensor angle in all the orientation(s) i.e., a first direction XZ and a,second orientation. At step 730, the microcontroller 620B looks-up in a lookup table for observed fuel value F\ variation of orientation in the first orientation, and second orientation, if any, and the corresponding actual fuel level F. The microcontroller of the ICU 620B calculates for actual fuel by compensating any tilt of the vehicle in the second orientation. In an embodiment, at step 730, equations are used for calculation of actual fuel level by considering the tilt in the first direction XZ and the second orientation. Further, at step 740, the calculated fuel level is sent to a display unit 630 through a display driver 620C. At step 740, the ICU 610 checks for a status of the ignition switch and if the switch is ON, then sequence from step 710 is repeated till the ignition switch status if OPT.
[00045] It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. Many modifications and variations of the present subject matter are possible in the light of above disclosure. Therefore, within the scope of claims of the present subject matter, the present disclosure may be practiced other than as specifically described.

I/We claim:
1. A float assembly (250) employed to a fuel tank assembly (200, 300, 400)
mounted to a vehicle (100), said float assembly (250) comprising:
a float arm (260) having one end mounted to a fuel tank body (210, 310, 410) of the fuel tank assembly (200); and
a float member (255) connected to another end of said float arm (260),
wherein
said float arm (260) is pivotable in a first direction (XZ) in response to change in fuel level, and a tilt sensor (270) mounted to said float arm (260) is adapted to identify change in orientation (9, a) of said float arm (260) in one. or more directions (XZ, YZ) including said first direction (XZ).
2. A fuel indicator system (600). for a vehicle (100) a fuel tank assembly (200,
300, 400), said system (600) comprising:
a float arm (260) mounted to a fuel tank body (210, 310, 410) of the fuel tank assembly (200); and
a float member (255) connected to said float arm (260),
wherein
said float arm (260) is pivotable in a first direction (XZ) in response to change in fuel level, and a tilt sensor (270) mounted to said float arm (260) is adapted to.identify change in orientation (8, a) of said float arm (270) in one or more directions (XZ, YZ) including said first direction (XZ); and

an indicator control unit (610) communicatively connected to said tilt sensor (270), and said indicator control unit (610) is adapted to calculate an actual fuel level (F) by identifying an observed fuel level (F') from orientation of said float arm (270) in said first direction (XZ) and compensating error (AF) from said observed fuel level (F') due to identified change in orientation(a) of float arm (270) in one or more direction(s) (XZ, YZ) excluding said first direction (XZ).
3. The fuel indicator system (600) of claim 2, wherein the float member (255) is made of a material having density less than density of fluid for which the level is indicated.
4. The fuel indicator system (600) of claim 2, wherein said first direction (XZ) is substantially parallel to the longitudinal axis of the vehicle (100) and said second direction (YZ) is substantially parallel to a lateral direction (YZ) of the vehicle (100).
5. The fuel indicator system (600) of claim 2, wherein said indicator control unit (610) communicatively coupled to a fuel indicator (630) to indicate said actual fuel (F) and said fuel indicator (630) is a display unit (630).
6. The fuel indicator system (600) of claim 2, wherein said tilt sensor (270) includes a gyro meter.
7. The fuel level indicator system (600) of claim 2, wherein said indicator control unit (610) calculates said error (AF) from change in orientation (a) provided by said tilt sensor (270).
8. The fuel level indicator system (600) of claim 2, wherein said indicator

control unit (610) calculates said error (AF) and said actual fuel level (F) from change in orientation (0, a) provided by said tilt sensor (270).
9. The fuel level indicator system (600) of claims 2 or 8, wherein sad indicator unit (610) is provided with a lookup table to identify said actual fuel (F) from said change in orientation (9, a).
10. The fuel level indicator system (600) of claim 2, wherein said vehicle (100) includes a two-wheeled vehicle (100) and three-wheeled vehicle.