DESC:TECHNICAL FIELD
[0001] The present subject matter relates generally to an on-board center of gravity determination system and more particularly to an on-board center of gravity determination system of a single track two wheeled vehicle.
BACKGROUND

10 [0002] Conventionally, a two wheeled vehicle has a driving wheel and a driven wheel. The driving wheel is a wheel that transmits force, and aids in transforming torque generated by a power source, into tractive force. Further the tractive force from the tires of the two wheeled vehicle is transferred to the road, causing the two wheeled vehicle to move. Usually, the two wheels of the
15 two wheeled vehicle are arranged in tandem, i.e. one behind the other. Such two wheeled vehicles are either pedal powered vehicles, such as a bicycle, or motor-powered vehicles, such as a motorcycle or a scooter type vehicle.
[0003] Usually, two-wheeled vehicles stay upright while moving forward due to a physical property known as conservation of angular momentum in the
20 wheels. Ideally, the direction of the angular momentum vector lies along the axis of rotation, that is the axle of the wheel of the two wheeled vehicle. Thereby, if no external torque is applied, the axle of the wheels will remain horizontal, and as a result, the entire two wheeled vehicle remains vertical. Therefore, when such a vehicle turns, if the turning speed is too high, or the
25 turning radius is too small, the vehicle may tilt excessively under the action of centrifugal force.
[0004] Different types of two wheeled vehicles have different dynamics and these play a key role in determining how a two wheeled vehicle performs in given conditions. For example, the two wheeled vehicle having a longer
30 wheelbase provides more vehicle stability as compared to vehicles having shorter wheelbase.

5 BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to
10 limit the scope of the invention to these particular embodiments. The same numbers are used throughout the drawings to reference like features and components.
[0006] Figure 1 illustrates a block diagram showing brief overview for an on- board center of gravity determination system of a two-wheeled vehicle, in
15 accordance with an embodiment of the present subject matter.
[0001] Figure 2 illustrates a block diagram showing detailed overview for an on-board center of gravity determination system of a two-wheeled vehicle, in accordance with an embodiment of the present subject matter.
[0002] Figure 3 illustrates a flow diagram showing detailed overview for an
20 on-board center of gravity determination system of a two-wheeled vehicle, in accordance with an embodiment of the present subject matter.
[0003] Figure 4A to Figure 4B illustrates schematic diagrams depicting the parameters involved in estimation of the real time position of the center of gravity for a two-wheeled vehicle in a three-dimensional space, using the on-
25 board center of gravity determination system in accordance with an embodiment of the present subject matter.
DETAILED DESCRIPTION

[0004] The Center of Gravity of a vehicle is a critical parameter, affecting not only the vehicle dynamics but also the stability of the vehicle. The influence
30 of the center of gravity is more strongly felt in single track two wheeled vehicles. A single-track vehicle, which leaves a single ground track, as it moves forward, usually have little or no lateral stability when being stationary.

5 However, required stability is developed upon the movement of the single- track vehicle, making the center of gravity of the single-track two-wheeled vehicle, a crucial factor affecting the dynamics and stability of the vehicle.
[0005] In single-track two wheeled vehicles, herein interchangeably called as ‘the two wheeled vehicle’ for brevity, the center of gravity of the vehicle is
10 strongly affected by the center of gravity of the rider. This is because, as compared to vehicles having more than two vehicles, herein interchangeably called as ‘multi-wheeled vehicle’ for brevity, the two wheeled vehicles are smaller vehicle. Any movement or action of the rider majorly affects and changes the center of gravity of the two wheeled vehicle from time to time.
15 Therefore, the center of gravity is strongly influenced in small vehicles by the rider's center of gravity, which can constantly change due to the rider's movements and actions. Further, the two-wheeled vehicles have larger ratios of the weight of the rider to the weight of the vehicle compared to multi- wheeled vehicles, which makes the rider's movements even more significant.
20 [0007] Further, the two wheeled vehicle is capable of having have three- dimensional motion, i.e longitudinal motion, lateral motion and rotational motion. For example: the two wheeled vehicle has a longitudinal motion, when the two-wheeler is accelerating or decelerating, the two wheeled vehicle experiences longitudinal motion. This is because the wheels are rotating and
25 causing the two wheeled vehicle to move forward or backward. Similarly, for lateral motion, when the two-wheeler takes a turn or changes direction, the two wheeled vehicle experiences lateral motion. This is because the wheels are turned, and the two wheeled vehicle moves in a sideways direction.
[0008] Similarly, for rotational motion, when the two-wheeler is balanced on
30 the two wheels and the rider turns the handlebar, the two wheeled vehicle experiences rotational motion. This is because the wheels are rotating in opposite directions, causing the two wheeled vehicle to turn. In addition to

5 these, the two-wheeler can also experience other types of motion such as vertical motion when going over bumps or jumps, and oscillatory motion when encountering uneven terrain.

[0006] Thereby, the dynamics and the center of gravity of the vehicle, in two wheeled vehicles is dependent on three-dimensional motion of the vehicle. For
10 instance, if the rider is cornering the two wheeled vehicle, he is leaning as well as controlling the steering the vehicle at the same time. Vehicle leaning is induced by the method known as counter steering, which is a technique used to induce leaning, where the rider momentarily steers the handlebars in the direction opposite of the desired turn. Thereby, during leaning the vehicle is
15 moving forward as well as making an angle with the ground. Particularly during leaning the vehicle is moving almost in a three-dimensional plane. Thereby, leaning also becomes a deciding factor in determining center of gravity of two wheeled vehicles.
[0007] However, the dynamics and center of gravity of multi-wheeled vehicles,
20 for example a four wheeled vehicle, are largely dependent on two-dimensional motion, i.e lateral and longitudinal motion, because of the weight of the multi- wheeled vehicle along with the occupants, at any point of time, being balanced on at least one parallel set of wheels. Thereby, the dynamics and the center of gravity of the vehicle, in multi-wheeled vehicles is largely dependent on two-
25 dimensional motion of the vehicle while two-wheeled vehicles are more sensitive to third-dimensional motion, making it more complex to determine the real-time center of gravity position, which is different from the dynamics of the two wheeled vehicles.
[0008] Further, since the two wheeled vehicle is more sensitive to the third
30 dimensional motion, the chances of interference of the third dimensional motion with the dynamics and center of gravity of the vehicle is more.

5 Accurately determining the center of gravity position in two-wheeled vehicles is critical for developing better vehicle control systems, but it is challenging due to the added third-dimensional motion and changing parameters. For instance, chances of toppling in two wheeled vehicles are more as compared in a multi-wheeled vehicle, because of the extra stability provided by at least a
10 set of parallelly placed wheels. Some of such changing parameters include changes in the motion of the vehicle, acceleration and deacceleration of the vehicle, turning speed, leaning of the vehicle, driving style, and weight of the occupants of the vehicle. Thereby, in two wheeled vehicles the added third dimensional motion adds complexity in determining the real time center of
15 gravity of the vehicle.

[0009] Further accurate and precise real-time determination of the center of gravity position for two wheeled vehicles becomes critical for vehicular functions related to dynamics and control of the two wheeled vehicle. Determining the precise position of center of gravity of the two wheeled
20 vehicle, helps in the development of better vehicle control systems.

[00010] Additionally certain sensors are sensitive to their mounting position on the vehicle and are to be mounted on areas where the center of gravity of the vehicle lies. However, in absence of being mounted near center of gravity area, faulty data may be reproduced by such sensors and, the data captured may not
25 reflect the exact dynamics of the vehicle. In such scenarios, determining the center of gravity position as well as shift in position of the center of gravity helps in providing corrections to this data, thereby providing the actual dynamics of the vehicle.
[00011] Several attempts have been made to determine the center of gravity of
30 vehicles, particularly in multi-wheeled vehicles. Some known arts disclose about determining the height of the center of gravity for multi-wheeled vehicles, such as cars, taking in consideration the vehicular loads measured on

5 at least one sprung axle. However, such parameters fail to precisely determine the center of gravity of single track two wheeled vehicles. This is because the lean angle of two wheeled vehicles strongly affects the center of gravity, as compared to the height of the center of gravity and wheel load dynamics. The lean angle of a two-wheeled vehicle strongly affects the center of gravity (CG)
10 of the two wheeled vehicle because it determines the position of the CG relative to the wheels, which in turn affects the stability and handling of the vehicle. This is because, the center of gravity (CG) of the two-wheeled vehicle is located above the ground and can be affected by the rider's position on the bike and the weight distribution of the vehicle. When the two wheeled vehicle
15 is in upright position, the CG is directly above the contact patch of the two wheels, making it easier to maintain balance. However, when the bike is leaned over, the CG shifts to one side of the vehicle, and this makes it harder to maintain balance. Further, the wheel load dynamics of the two-wheeled vehicle are also affected by the lean angle. When the bike is leaned over, the load on
20 the inside wheel increases, while the load on the outside wheel decreases. This can cause the inside wheel to lose traction, making it more difficult to control the bike. Moreover, the height of the CG also affects the stability of the two wheeled vehicle, however, it is less significant than the lean angle. This is because the height of the CG remains constant regardless of the lean angle,
25 whereas the position of the CG relative to the wheel’s changes with the lean angle. Overall, the lean angle of the two-wheeled vehicle is a critical factor in determining the stability and handling of the bike. A rider must be skilled in managing the bike's lean angle to maintain balance, control, and maneuverability.
30 [00012] Some other known arts disclose about determining the height of the center of gravity of four wheeled vehicles, considering longitudinal and lateral dynamics of the four wheeled vehicle. Some other known arts disclose about

5 determining center of gravity of two wheeled vehicles having wheels arranged parallel to each other. In addition, both the wheels are independently powered by providing a differential torque to each wheel. Thus, the vehicle dynamics considered for such parallel wheeled vehicles substantially differs from single track two wheeled vehicles which makes it impossible to correspondingly
10 apply for a two-wheeled vehicle.

[00013] Some other known arts disclose about determining the height of the center of gravity of multi wheeled vehicles using the natural frequency value for the vehicle roll, and the static gain values associated to a group of values relating to the roll angle and lateral acceleration of the multi wheeled vehicle.
15 However, such known arts do not disclose about determining the center of gravity position in the horizontal plane, i.e. longitudinal and lateral position of two wheeled vehicles. In addition, the multi wheeled vehicles disclosed in such known arts are majorly vehicles like tractors, trailers, trucks, and passenger cars. Thereby because of the difference in vehicle dynamics between the single
20 track two wheeled vehicle and such multi wheeled vehicles, the methodology adapted to determine the height of the center of gravity cannot be applied to single track two wheeled vehicles.
[00014] Some other known arts aim at solving the problem of developing a vehicle control device capable of accurately calculating the height of the center
25 of gravity of a vehicle when the front axle and the rear axle of the vehicle are vibrating in the same phase. In such known arts the vehicle considered are multi-wheeled vehicle. Further in such known arts only the longitudinal position and height of the center of gravity of the vehicle is calculated. However, such known art does not consider complexity caused due to overall
30 three-dimensional motion of two wheeled vehicles.

[00015] Since the above-mentioned known arts does not consider complexity caused due to overall three dimensional motion of two wheeled vehicles and

5 overall difference in dynamics of a two wheeled vehicle and two and three wheeled vehicles, the above mentioned methods cannot be applied in determining accurate and precise real-time determination of the center of gravity of single track two wheeled vehicles.
[00016] Hence, there is a need for addressing the above circumstances and
10 problems of the known arts.
[00017] The present subject matter has been devised in view of the above circumstances as well as solving other problems of the known art.
[00018] The present subject matter discloses about an on-board center of gravity determination system which provides information about the real-time position
15 of the vehicle center of gravity in a three-dimensional space, with respect to a single track two wheeled vehicle.
[00019] As per an aspect of the present embodiment, the determined the real- time position of the vehicle center of gravity in the three-dimensional space, may be used in vehicle dynamics, stability, and control applications.
20 [00020] Exemplary embodiments detailing features regarding the aforesaid and other advantages of the present subject matter will be described hereunder with reference to the accompanying drawings. Various aspects of different embodiments of the present invention will become discernible from the following description set out hereunder. Rather, the following description
25 provides a convenient illustration for implementing exemplary embodiments of the invention. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein
30 reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof. Further, it is to be noted that terms “upper”, “down”, “right”, “left”, “front”,

5 “forward”, “rearward”, “downward”, “upward”, “top”, “bottom”, “exterior”, “interior” and like terms are used herein based on the illustrated state or in a standing state of the two wheeled straddle type vehicles with a user riding thereon. Furthermore, arrows wherever provided in the top right corner of figure(s) in the drawings depicts direction with respect to the vehicle, wherein
10 an arrow F denotes front direction, an arrow R indicates rear direction, an arrow Up denotes upward direction, an arrow Dw denotes downward direction, an arrow RH denotes right side, and an arrow LH denotes left side. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
15 [00021] Figure 1 illustrates a block diagram showing brief overview for an on- board center of gravity determination system 10 of a two-wheeled vehicle 20 , herein referred as a vehicle 20 for brevity (shown in Figure 4A), in accordance with an embodiment of the present subject matter. The on-board center of gravity determination system 10 includes a plurality of sensors 108. The
20 plurality of sensors 108 include one or more vehicle weight sensor 100, one or more suspension displacement sensor 101, one or more pitch angle measurement sensor 102, and one or more tire deformation sensor 103. The plurality of sensors 108 are placed throughout the vehicle 20 at optimum locations. The plurality of sensors 108 provides the required inputs to an
25 Electronic Control Unit (ECU) 106,.
[00022] Based on the inputs provided by the plurality of sensors 108, the on- board center of gravity determination system 10 aids in providing as an output through an output system 107, a precise and accurate measurement of the real time center of gravity position of the vehicular system in a three-dimensional
30 space. The output includes determination of the real time center of gravity position of the vehicular system, for a longitudinal position (X co-ordinate) 107a, for a lateral position (Y co-ordinate) 107b, and for a vertical position,

5 particularly determining the height of the center of gravity (Z co-ordinate)
107c.
[00023] Herein the real time center of gravity position of the vehicular system includes the real time center of gravity position of the vehicle 20 along with the real time center of gravity position of the rider.
10 [00024] The plurality of sensors 108 used to acquire the inputs for the on-board center of gravity determination system 10 may be of different types. For instance, for calculating the vehicle 20 weight, different types of vehicle weight sensors 100 may be used. However, it needs to be considered that the weight of the vehicle 20 does not change often, except in exceptional
15 conditions. Such exceptional conditions include load due to the amount of fuel present in the fuel tank. The weight of the vehicle 20 can be measured by taking a sum of the initial weight of the vehicle 20 (without any fuel) and the load due to the total amount of fuel present in the fuel tank at any given time. Thereby, the on-board center of gravity determination system 10 can account for
20 changes in vehicle 20 weight due to fuel load and can also determine the real- time center of gravity position of the rider along with the vehicle.
[00025] Further, such vehicle weight sensors may be used to evaluate the initial weight of the vehicle 20 which is used to calculate the center of gravity of the two wheeled vehicle 20 in unloaded condition.
25 [00026] Thereby, the vehicle weight data 100a corresponds to a sum of a prestored data of an initial weight of the vehicle 20, without fuel, prestored within the electronic control unit 106, and real time data of weight of total amount of fuel present in a fuel tank of the vehicle 20 sensed by a vehicle weight sensor 100.
30 [00027] Further, since the two wheeled vehicle’s 20 chassis is connected to both front and rear wheels through the suspension system, which further consists of spring and damper majorly. The suspension displacement sensor 101 provide suspension displacement data 101a of the vehicle’s 20 attitude relative to an

5 underlying road. Herein, the suspension deflection mainly arises from the relative vehicle attitude and the vertical displacement of the vehicle 20 center of gravity. Hence, if the vehicle 20 geometric is known beforehand, the suspension displacement can be related to the following vehicle dynamics.
[00028] The vehicle pitch angle 102a (shown in Figure 2) is one of the important
10 state variables of vehicle dynamic control system. From determining the vehicle pitch angle 102a one can draw conclusions concerning course of road and loading state of the vehicle 20. The pitch angle measurement sensor 102 aids in determining the real time vehicle pitch angle 102a when the vehicle 20 is in motion. Thereby, the pitch angle data 102a corresponds to sensing of
15 heave motion of the vehicle 20 and determining pitch angle of the vehicle 20. [00029] Further, once the two wheeled vehicle 20 is leaned for turning, a slight but significant deformation on the crown area of the tire is formed, due to the increased load near the crown area of the tire. Thereby with leaning the overall radius of the tire decreases for the time the vehicle 20 is leaned. The decreased
20 radius of the tire further decreases the overall tire crown radius. The Tire deformation sensor 103 determines the amount of compression of tire at the contact patch of the vehicle 20 with the road.
[00030] Figure 2 illustrates a block diagram showing detailed overview for an on-board center of gravity determination system 10 of a two-wheeled vehicle
25 20 (shown in Figure 4A), in accordance with an embodiment of the present subject matter. The on-board center of gravity determination system 10 comprises of receiving sensor data from a plurality of sensors 108, including sensors such one or more vehicle weight sensor 100, one or more suspension displacement sensor 101, one or more pitch angle measurement sensor 102,
30 and one or more tire deformation sensor 103.
[00031] The plurality of sensors 108 comprises of sensing data related to at least one of a vehicle weight data 100a, a suspension displacement data 101a, a tire deformation data 103a, and a pitch angle data 102a.

5 [00032] Figure 3 illustrates a flow diagram showing detailed overview for an on-board center of gravity determination system 10 of a two-wheeled vehicle 20 (shown in Figure 4A), in accordance with an embodiment of the present subject matter.
[00033] As per an aspect of the present embodiment, the process starts 201,
10 when a set of pre-stored data is stored within the ECU 106 and determined 202 by the on-board center of gravity determination system 10. The set of pre- stored data herein includes data regarding the actual weight of the vehicle 20 without fuel; the actual weight of the vehicle 20 along with the full capacity of fuel the vehicle 20 can store; the center of gravity of the vehicle 20 in X Y Z
15 co-ordinates in stationary position; the original dimensions of the tires used in the vehicle 20, the suspension angle of the vehicle 20 when the vehicle 20 is unloaded and in stationary position; the suspension displacement when the vehicle 20 is unloaded and in stationary position; the pitch angle of the vehicle 20 when the vehicle 20 is unloaded and in stationary position; and the amount
20 of tire deformation when the vehicle 20 is unloaded and in stationary position. [00034] By means of the plurality of sensors 108 (as discussed under Figure 1), the on-board center of gravity determination system 10 receives the data 203 with respect to vehicle from the plurality of sensors 108. The plurality of sensors 108 includes one or more vehicle weight sensor 100, one or more
25 suspension displacement sensor 101, one or more pitch angle measurement sensor 102, and one or more tire deformation sensor 103.
[00035] Apart from the plurality of sensors 108, the on-board center of gravity determination system 10 includes the ECU 106 having a filter and a data smoothening module 106a, and a processor 104.
30 [00036] In an embodiment, the filter and data smoothening module 106a is a combination of both hardware filter modules as well as software filter modules. Hardware filters include filters such as high pass filters, medium pass filters or low pass filters. Software filters includes filters such as moving average filter,

5 digital filters such as IR or FIR filters, or the like. The filter and data smoothening module 106a aids in filtering received signals from the plurality of sensors 108 and reproducing refined version of sensor signals. Particularly with help of the filter and smoothening module 106a, received sensor signals are filtered, and the noise associated with the sensor signals is removed.
10 [00037] Along with it, the data smoothness feature of the filter and data smoothening module 106a, aids in making the sensor signals to have algorithm compatible data with respect to the on-board center of gravity determination system 10. Once the noise is removed and the sensor signals are filtered, the filtered signals are received by the processor 104 of the ECU 106 by using the
15 on-board center of gravity determination system 10. The processor 104 of the ECU 106 calculates the real time longitudinal, lateral and vertical positions of the vehicular system center of gravity position on X, Y and Z coordinates, positions of the center of gravity of the vehicular system.
[00038] Thereby the sensor signals from the plurality of sensors 108 are received
20 203 by the filter and smoothening module 106a of the ECU 106 in form of data. Once the noise is removed and the sensor signal data is made compatible with the algorithm associated with the on-board center of gravity determination system 10; the processor 201 of the ECU 106 calculates the real time vehicular system center of gravity position on X, Y and Z co-ordinates.
25 [00039] The filtered data received from the plurality of sensors 108, such as suspension displacement data 101a and the tire deformation data 103a, are used together by the processor 104, to determine (205, 206) the real time suspension spring force 105 and the real time suspension damper force 109. To evaluate 207 the total force exerted on the suspension system, the calculated
30 real time suspension spring force 105 and the suspension damper force 109 are added together. The suspension spring force 105 and the suspension damper force 109 acting on the vehicle 20 together constitute total force 110 acting on the vehicle 20.

5 [00040] Further, the processor 104 of the electronic control unit 106, being capable of determining real time fractional weight supported by individual suspension systems 208 for a rear wheel of the vehicle 20, by using data related to at least one of the suspension spring forces 105 and the suspension damper force 109 acting on the vehicle 20, and a pre stored data and real time vehicle
10 weight data 100a.
[00041] Further the processor 104 of the electronic control unit 106 being capable of determining real time fractional weight supported by individual suspension systems 208 for a front wheel of the vehicle 20, by using data related to at least one of the real time fractional weight supported by individual
15 suspension systems 208 for the rear wheel of the vehicle 20 and pre-stored vehicular dimensions in the electronic control unit 106. Herein the real time fractional weight supported by individual suspension systems for the front wheel is determined by the determined the real time fractional weight supported by individual suspension systems 208 for the rear wheel and the pre-
20 stored vehicular dimensions.
[00042] Further, the real time fractional weight supported by individual suspension systems 208 for the front wheel of the vehicle 20, and the real time fractional weight supported by individual suspension systems 208 for the rear wheel of the vehicle 20, together constitute total fractional weight of the
25 vehicle 20. The processor 104 of the electronic control unit 106 being capable of determining whether the two wheeled vehicle 20 being disposed in one of a horizontal plane and a plane inclined to said horizontal plane of the vehicle 20 by using a total fractional weight of the vehicle 20 and total force 110 acting on the vehicle 20.
30 [00043] Further, the pitch angle measurement sensor 102, is one individual sensor component of Inertial measurement unit (IMU) (IMU made of multiple sensors along with pitch angle sensor) and senses the heave motion of the

5 vehicle 20. The collected data from the pitch angle measurement sensor 102 is the pitch angle data 102a of the vehicle.
[00044] After the pitch angle data 102a is determined, the ECU 106, determines whether the vehicle is disposed in a horizontal plane or in a plane inclined to the horizontal plane 209. With the help of the information regarding the real
10 time plane of the vehicle 20 along with the determined fractional weight 111 that is supported by individual suspension, the three-dimensional location of the center of gravity 210 is determined in the three-dimensional center of gravity coordinate (X, Y, Z) 114 by the ECU 106. However, if the vehicle 20 runs on a horizontal plane with a constant velocity, the two-dimensional center
15 of gravity location is calculated in two-dimensional center of gravity coordinate (X, Z) 113.
[00045] In an embodiment, the present subject matter includes a method of on- board determining of center of gravity for the vehicle 20, comprising: receiving data related to at least one real time physical parameter from a plurality of
20 sensors 108 located throughout the vehicle 20; processing data received from the plurality of sensors 108 by a processor 104 of an electronic control unit 106; and determining real time longitudinal position in a X coordinate 107a, real time lateral position in Y coordinate 107b, and real time vertical position in a Z coordinate 107c of the center of gravity of the vehicle 20, by processing
25 data received from the plurality of sensors 108.
[00046] Figure 4A to Figure 4B illustrates schematic diagrams depicting the parameters involved in estimation of the real time position of the center of gravity for a two-wheeled vehicle in a three-dimensional space, using the on- board center of gravity determination system 10 in accordance with an
30 embodiment of the present subject matter. Figure 4A to Figure 4B depicts the parameters involved in estimation of the real time position of the center of gravity for a two-wheeled vehicle in a three-dimensional space, using the on- board center of gravity determination system 10, from a side view of the

5 vehicle 20, particularly when the vehicle is moving uphill in a forward direction.
[00047] The proposed vehicle system (rider and vehicle) center of gravity determination method is derived and dependent on the vehicle dynamics of a single track two wheeled vehicle. Herein, as the vehicle moves, there is a
10 constant change in the parameters related to the vehicle’s 20 dynamics, such as the vehicle weight, the suspension displacement, the vertical tire deformation, and the vehicle pitch angle. In addition, an important parameter affecting the two-wheeler dynamics is its center of gravity position, which is determined using one or more of above stated vehicle dynamics parameters.
15 [00048] In accordance, with an embodiment of the present subject matter, the below mentioned calculations are performed within the ECU 106, where the inputs to the system, provided by the plurality of sensors (100-105) are processed by a processor 104 of the ECU 106 to determine the center of gravity position for the vehicle system in a three-dimensional space.
20 [00049] The chassis of the vehicle 20 is connected to the front and rear wheels of the vehicle 20 through the suspension system, and the suspension system consists of spring and damper majorly. Thereby the weight of vehicle system is evaluated using the suspension displacement sensor 101 and the tire deformation sensor 103. Herein for instance, a long stroke sensor can be used
25 as suspension displacement sensor 101. The data collected from the suspension displacement sensor 101 and the tire deformation sensor 103 are suspension displacement data 101a and the amount of compression of tire at the contact patch named as tire deformation data 103a respectively. These data are used together to evaluate the suspension spring force 105 and suspension damper
30 force 109.
[00050] As an embodiment, the suspension spring force includes the front suspension spring force and the rear suspension spring force.

5 The Rear suspension spring force is denoted by ??????????.and the front suspension spring force is denoted by ????????.; and
Thereby the ECU 106 using the on-board center of gravity determination
system 10 determines ??????????., and ???????? in the following manner:
??????????[Front suspension spring force] = ???? ????????? - ??????? + ??????(???????? - ??????)3,
?????? ??????
10 ????????[Rear suspension spring force] = ???? (?? - ?? ) + ??????(?? - ?? )3,
[00051] As an embodiment, the suspension damper force includes the front suspension damper force and the rear suspension damper force. The Rear suspension spring force is denoted by ??????????.and the front suspension spring force is denoted by ????????.; and
15 Thereby the ECU 106 using the on-board center of gravity determination
system 10 determines ??????????, and ????????in the following manner:

?????????? = ???? ?????????? - ??????

? + ???????????????? - ??????

sgn?????????? - ???????,

???????? = ???? (??

- ??

) + ?????????

- ??

sgn(??

- ?? ),

[00052] Here, the linear spring constant for the front wheel suspension is
20 denoted as ???? . And the non-linear spring constant for the front wheel suspension is denoted as ??????. Further the linear damping coefficient for front wheel suspension is denoted by ???? , and the non-linear damping coefficient for the front wheel suspension is denoted as ??????.
[00053] The inear spring constant for rear wheel suspension is denoted as ???? ;
25 and the Non-linear spring constant for rear wheel suspension is denoted as ??????.
[00054] The Linear damping coefficient for rear wheel suspension is denoted as
???? ; and the nonlinear damping coefficient for rear wheel suspension is denoted as ??????.
[00055] The front unsprung mass displacement/ front tire deformation is denoted
30 as ????????; and the front sprung mass displacement/ front suspension displacement

5 is denoted as ????????. The rear unsprung mass displacement/ rear tire deformation is denoted as ??????; and the rear sprung mass displacement/rear suspension displacement is denoted as ????.
[00056] As per the present embodiment, in order to determine the total force exerted on the suspension system, the suspension spring force 105 and the
10 suspension damper force 109 are summed up together and the total force is evaluated 110. Further on based of the pre stored and real time vehicle weight data 100a and the evaluated total force 110, the fractional weight supported by individual suspension systems of front wheel and rear wheel 111. In accordance with the present embodiment, the calculations performed by the
15 ECU 106 using the on-board center of gravity determination system 10 is mentioned below:
?????? = ????(????????, ????????, ????), [fraction of weight supported by front wheel suspension system]
???? = ????(????????, ????????, ????), [fraction of weight supported by Rear wheel
20 suspension system]
Here, Ms indicates the sprung mass/ chassis of the vehicle system.
[00057] Further, using the real time pitch angle data 102a, the ECU 106 evaluates the whether the two wheeled vehicle 20 being disposed in one of a horizontal plane and a plane inclined to the horizontal plane of the vehicle 112,
25 i.e., the information whether the vehicle 20 is in horizontal plane or at an angle.
???????????? = ????(??????, ????, ????), [Vehicle plane evaluation]
[00058] During the evaluation of real time plane, i.e. whether the two wheeled vehicle 20 being disposed in one of a horizontal plane and a plane inclined to the horizontal plane of the vehicle 112, the fractional weight that is supported
30 by front wheel suspension (??????), the fractional weight that is supported by rear wheel suspension (????) and the pitch angle (????) is used.

5 [00059] At the time of only pitching, the entire weight of the vehicle 20 system is distributed non-uniformly among two wheel’s suspensions. But the added weight becomes the actual weight of the vehicle 20. Thereby, when the vehicle 20 leans, the added weight will not be equal to the actual weight of the vehicle 20, but less than actual weight.
10 [00060] Once the summation of two fractional weight is not equal to the actual weight, the algorithm of the ECU 106 using the on-board center of gravity determination system 10, starts interpreting the vehicle 20 at lean position and initiate to capture real time Y coordinate of the center of gravity of the vehicle 20.
15 [00061] With the help of the information regarding the plane of the motorcycle along with the fractional weight that is supported by individual suspension, the three-dimensional location of the center of gravity is determined in three- dimensional coordinate (X,Y,Z) is evaluated 114.
(????, ??, ??) = ??(????, ????, ????????????).
20 [00062] However, if the vehicle 20 runs on horizontal plane with constant velocity, the two-dimensional location of the center of gravity is determined in two-dimensional coordinate (X,Z) 113.
(????, ??) = ??(????, ????)
[00063] The calculations are performed within the ECU 106 of the vehicle 20.
25 The method helps to ensure the stability and safety of the two-wheeled vehicle
20 during operation.
[00064] The present subject matter ensures that the on-board center of gravity determination system is sensitive to the third dimensional motion of small and less stable vehicles, such as a two wheeled vehicle. Because of being sensitive
30 to the third dimensional motion, the present claimed on-board center of gravity determination system is capable of determining the chances of interference of the third dimensional motion with the dynamics and center of gravity of the

5 vehicle. Thereby, the present claimed invention is capable of determining accurate and precise real-time determination of the center of gravity position for two wheeled vehicles.
[00065] Further, because of the estimation of the accurate and precise real-time determination of the center of gravity position for two wheeled vehicles, the
10 present claimed subject matter aids in development of better vehicle control systems.
[00066] Further, since the present claimed on-board center of gravity determination system is sensitive to the third dimensional motion of small and less stable vehicles, the mounting location of sensors on the vehicle, does not
15 produce faulty data or effect the estimation of the accurate and precise real- time determination of the center of gravity position.
[00067] The present subject matter discloses about the on-board center of gravity determination system, which uses minimum number of sensors to precisely calculate the vehicle's real-time center of gravity position. Because
20 of a smaller number of inputs required, the present disclosed system can process the required data at a fast pace and deliver the output with respect to the real-time center of gravity position of the vehicle in no time.
[00068] Moreover, since minimum number of sensors are required to calculate the real-time center of gravity position of a vehicle, the present disclosed on-
25 board center of gravity determination system becomes an ideal and cost- effective solution for small vehicles, like two-wheeled vehicles.
[00069] Further, the present disclosed on-board center of gravity determination system can aid in providing a precise and accurate measurement of the vehicle's real-time center of gravity position in three-dimensional space. This
30 can help riders maintain better control of the vehicle, especially during sudden maneuvers or in adverse road conditions.
[00070] Further, the present disclosed on-board center of gravity determination system can also aid in optimizing the fuel efficiency of the vehicle by providing

5 information on the vehicle's weight distribution. This information can be used by the vehicle's engine management system to optimize fuel consumption and reduce emissions. By optimizing the fuel efficiency of the vehicle, the system can help reduce operating costs and environmental impact.
[00071] Further, knowing the vehicle's center of gravity position, can aid in
10 improving the vehicle's overall performance, especially during cornering and braking. By providing real-time information on the vehicle's weight distribution, the system can aid in optimizing the suspension and braking systems to improve handling and stability. This can result in a more enjoyable and safer riding experience for the rider.
15 [00072] Moreover, by providing real-time information on the vehicle's weight distribution, the on-board center of gravity determination system can aid in detecting and diagnosing potential issues with the suspension, braking, and other systems. This can help in preventing more serious problems from developing and reducing maintenance costs over the lifetime of the vehicle.
20 [00073] Further, the present disclosed, on-board center of gravity determination system can also aid in optimizing the suspension and other systems to reduce stress on the tires and other components. By reducing stress on these components, the system can help extend their lifespan and reduce replacement costs.
25 [00074] 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.

30

5
10: On-board center of gravity determination system
20: Vehicle

100: vehicle weight sensor

LIST OF REFERENCE NUMERAL
111: Fractional weight determination 112: Vehicle plane determination
30 113: Two-dimensional center of gravity co- ordinates

10 101: suspension displacement sensor 102: pitch angle measurement sensor 103: tire deformation sensor
104: processor

105: suspension spring force

15 106: electronic control unit 107: Output system
107a: X coordinate 107b: Y coordinate 107c: Z coordinate
20 106a: filter and data smoothening module 100a: vehicle weight data
101a: suspension displacement data 102a: pitch angle data
103a: vertical tire deformation data

25 108: plurality of sensors

109: Suspension damper force

110: Total force acting on the vehicle

114: Three-dimensional center of gravity co- ordinates
202: pre stored data determination

35 203: Receive sensors data such as suspension displacement, pitch angle, tire deformation in vertical direction
204: Evaluate actual spring force along the direction of suspension
40 205: Calculate damper force exerted on a wheel
206: Calculate spring force exerted on a wheel
207: Evaluate the total force exerted on the
45 rear wheel through the suspension

208: Determine the fraction of weight that is being supported by rear suspension
209: Determine the plane of the vehicle

210: Determine the three-dimensional
50 location of center of gravity

Fksf: Front suspension spring force

Fksr: Rear suspension spring force Fbsf: Front suspension damper force Fbsr: Rear suspension damper force
???? : linear damping coefficient for front
5 wheel suspension

??????: non-linear spring constant for the front wheel suspension
???? : linear spring constant for the front wheel suspension
10 ??????: non-linear spring constant for rear wheel suspension
???? : linear damping coefficient for rear wheel suspension
???? : linear damping coefficient for rear
15 wheel suspension

??????: lLinear damping coefficient for rear wheel suspension

????????: front unsprung mass displacement/ front tire deformation
20 ??????: front sprung mass displacement/ front suspension displacement
??????: rear unsprung mass displacement/ rear tire deformation
????: rear sprung mass displacement/rear
25 suspension displacement

??????: fraction of weight supported by front wheel suspension system
????: fraction of weight supported by rear wheel suspension system
30 ????????????: Vehicle plane evaluation

????: pitch angle

,CLAIMS:I/We Claim:

1. An electronic control unit (106) for a two wheeled vehicle (20), comprising:
said electronic control unit (106) being configured to receive and process at least one real time physical parameter of said two wheeled vehicle (20), and said electronic
5 control unit (106) being configured to store at least one pre-stored physical parameter of said two wheeled vehicle (20),
wherein said electronic control unit (106) being configured to determine a total force acting on said two wheeled vehicle (20), by using one of said at least one real time physical parameter of said two wheeled vehicle (20) and said at least one
10 pre-stored physical parameter of said two wheeled vehicle (20);
wherein said electronic control unit (106) being configured to determine a total fractional weight of said two wheeled vehicle (20) by using said at least one pre-stored physical parameter of said two wheeled vehicle (20) and said at least one real time physical parameter of said two wheeled vehicle (20);
15 wherein said electronic control unit (106) being configured to determine whether said two wheeled vehicle (20) being disposed in one of a horizontal plane and a plane inclined to said horizontal plane of said two wheeled vehicle (20), by using said total fractional weight of said two wheeled vehicle (20) and said total force (110) acting on said two wheeled vehicle (20).
20 2. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 1, wherein said electronic control unit (106) comprises at least one processor (104), said at least one processor (104) being configured to receive and process said at least one real time physical parameter of said two wheeled vehicle (20), and said at least one processor
(104) being configured to store at least one pre-stored physical parameter of said two
25 wheeled vehicle (20).
3. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 1, wherein said electronic control unit (106) being configured to determine a three- dimensional location of a center of gravity (114) of said two wheeled vehicle (20), in real time longitudinal position in a X coordinate (107a), real time lateral position in a Y
30 coordinate (107b), and real time vertical position in a Z coordinate (107c) based on at least one of said whether said two wheeled vehicle (20) being disposed in one of a

horizontal plane and a plane inclined to said horizontal plane of said two wheeled vehicle
(20) and a pitch angle (102a) of said two wheeled vehicle (20).
4. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 1, wherein said at least one real time physical parameter of said two wheeled vehicle (20)
5 being configured to be detected by means of a plurality of sensors (108), wherein said plurality of sensors (108) being distributed throughout said two wheeled vehicle (20).
5. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 4, wherein said plurality of sensors (108) being at least one of one or more vehicle weight sensor (100), one or more suspension displacement sensor (101), one or more pitch angle
10 measurement sensor (102), and one or more tire deformation sensor (103).
6. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 1, wherein said at least one real time physical parameter includes at least one of a vehicle weight (100a), a suspension displacement (101a), a tire deformation (103a), and said pitch angle (102a).
15 7. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 1, wherein said at least one pre-stored physical parameter comprises of one of an actual weight of said two wheeled vehicle (20) without fuel; an actual weight of said two wheeled vehicle (20) with full capacity of fuel; a center of gravity of said two wheeled vehicle (20) in stationary position in X co-ordinate, Y co-ordinate, and Z co-ordinate; an
20 original dimensions of tires (20); a suspension angle and suspension displacement of said two wheeled vehicle (20) in an unloaded position and stationary position; a pitch angle of said two wheeled vehicle (20) in an unloaded and in stationary position; and a tire deformation of said two wheeled vehicle (20) in unloaded and stationary position.
8. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 1,
25 wherein said electronic control unit (106) being communicatively connected to an output system (107) for transmitting real time position of center of gravity of said two wheeled vehicle (20) in a three-dimensional space to one or more systems and devices.
9. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 6, wherein said vehicle weight (100a) corresponds to a sum of a prestored data of an initial
30 weight of said two wheeled vehicle (20) without fuel, and real time weight of total amount

of fuel present in a fuel tank of said two wheeled vehicle (20), wherein said real time weight of total amount of fuel present in said fuel tank of said two wheeled vehicle (20) being detected by a vehicle weight sensor (100).
10. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 6,
5 wherein said suspension displacement (101a) corresponds to said two wheeled vehicles’
(20) attitude relative to an underlying road, wherein said two wheeled vehicles’ (20) attitude relative to said underlying road being detected by one or more suspension displacement sensor (101).
11. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 6,
10 wherein said tire deformation (103a) corresponds to amount of compression of at least one tire of said two wheeled vehicle (20), wherein said compression of at least one tire of said two wheeled vehicle (20) being sensed by one or more tire deformation sensor (103).
12. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 6, wherein said pitch angle (102a) corresponds to detection of heave motion of said two
15 wheeled vehicle (20) and estimation of pitch angle of said two wheeled vehicle (20), by means of one or more pitch angle measurement sensor (102).
13. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 1, wherein said total force acting on said two wheeled vehicle (20), being a sum of a suspension spring force (105) and a suspension damper force (109) acting on said two
20 wheeled vehicle (20).
14. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 13, wherein at least one of said suspension spring force (105) and said suspension damper force (109) acting on said two wheeled vehicle (20), being determined by using detected at least one of a tire deformation (103a) and a suspension displacement (101a).
25 15. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 1, wherein said total fractional weight of said two wheeled vehicle (20) being determined by using a real time fractional weight supported by an individual suspension system (208) for a front wheel of said two wheeled vehicle (20), and a real time fractional weight supported by an individual suspension system (208) for a rear wheel of said two wheeled
30 vehicle (20).

16. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 15, wherein said real time fractional weight supported by individual suspension systems (208) for said rear wheel of said two wheeled vehicle (20), being determined by using at least one of a suspension spring force (105) and a suspension damper force (109) acting on
5 said two wheeled vehicle (20), and a pre stored data and real time vehicle weight data (100a).
17. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 16, wherein said real time fractional weight supported by an individual suspension system
(208) for said front wheel of said two wheeled vehicle (20) being determined by using at
10 least one of said real time fractional weight supported by individual suspension systems
(208) for said rear wheel of said two wheeled vehicle (20) and a pre-stored vehicular dimensions in said electronic control unit (106).
18. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 16, wherein said at least one of a suspension spring force (105) and said suspension damper
15 force (109) acting on said two wheeled vehicle (20), being determined by using at least one of a tire deformation (103a) and a suspension displacement (101a) of said two wheeled vehicle (20).
19. The on-board center of gravity determination system (10) for a two wheeled vehicle (20) as claimed in claim 18, wherein said suspension spring force (105) and said suspension
20 damper force (109) acting on said two wheeled vehicle (20) together constitute a total force (110) acting on said two wheeled vehicle (20).
20. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 1, wherein said electronic control unit (106) being capable of determining the two- dimensional center of gravity (113) in real time longitudinal position in a X coordinate
25 (107a), and real time vertical position in a Z coordinate (107c), by using said total fractional weight of said two wheeled vehicle (20).
21. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 1, wherein said electronic control unit (106) comprises of a filter and data smoothening module (106a), enabling filtering of noise from said received data detected by a plurality
30 of sensors (108) of said two wheeled vehicle (20).

22. The electronic control unit (106) for a two wheeled vehicle (20) as claimed in claim 21, wherein said filter and data smoothening module (106a) being one of a hardware and a software filter.
23. A system for a two wheeled vehicle (20) comprising:
5 an electronic control unit (106), said electronic control unit (106) comprising:
said electronic control unit (106) being configured to receive and process at least one real time physical parameter of said two wheeled vehicle (20), and said at least one processor (104) being configured to store at least one pre-stored physical parameter of said two wheeled vehicle (20),
10 wherein said electronic control unit (106) being configured to determine a total force acting on said two wheeled vehicle (20), by using at least one of said at least one real time physical parameter of said two-wheeled vehicle (20), and said at least one pre-stored physical parameter of said two- wheeled vehicle (20);
15 wherein said electronic control unit (106) being configured to determine a total fractional weight of said two wheeled vehicle (20) by using at least one of said at least one real time physical parameter of said two- wheeled vehicle (20), and said at least one pre-stored physical parameter of said two-wheeled vehicle (20);
20 wherein said electronic control unit (106) being configured to determine whether said two wheeled vehicle (20) being disposed in one of a horizontal plane and a plane inclined to said horizontal plane of said two wheeled vehicle (20) by using said total fractional weight of said two wheeled vehicle (20) and said total force (110) acting on said two wheeled vehicle (20);
25 and
wherein said electronic control unit (106) being configured to determine a three-dimensional location of a center of gravity (114) of said two wheeled vehicle (20), in real time longitudinal position in a X coordinate (107a), real time lateral position in a Y coordinate (107b), and real time
30 vertical position in a Z coordinate (107c) based on at least one of said whether

said two wheeled vehicle (20) being disposed in one of a horizontal plane and a plane inclined to said horizontal plane of said two wheeled vehicle (20) and a pitch angle (102a) of said two wheeled vehicle (20).
24. The system for the two-wheeled vehicle (20), as claimed in claim 22, wherein said
5 electronic control unit (106) comprises at least one processor (104), said at least one processor (104) being configured to receive and process at least one real time physical parameter of said two wheeled vehicle (20), and said at least one processor (104) being configured to store at least one pre-stored physical parameter of said two wheeled vehicle (20).
10 25. A method for determining the three-dimensional location of the center of gravity of a two-wheeled vehicle (20), said method comprising:
receiving and processing at least one real time physical parameter of the two- wheeled vehicle (20) by an electronic control unit (106);
storing at least one pre-stored physical parameter of said two-wheeled vehicle (20)
15 in said electronic control unit (106);
determining a total force acting on said two-wheeled vehicle (20) by using at least one of said at least one real time physical parameter of said two-wheeled vehicle (20), and said at least one pre-stored physical parameter of said two-wheeled vehicle (20);
determining a total fractional weight of said two-wheeled vehicle (20) by using at
20 least one of said at least one real time physical parameter of said two-wheeled vehicle (20), and said at least one pre-stored physical parameter of said two-wheeled vehicle (20);
determining the real-time plane of said two-wheeled vehicle (20) by using said total fractional weight of the two-wheeled vehicle (20) and said total force acting on said
25 two-wheeled vehicle (20);
determining a three-dimensional location of the center of gravity (114) of said two- wheeled vehicle (20) in a real-time longitudinal position in an X coordinate (107a), real-time lateral position in a Y coordinate (107b), and real-time vertical position in a Z coordinate (107c) based on at least one of said real-time plane of said two-wheeled
30 vehicle (20) and a pitch angle (102a) of said two-wheeled vehicle (20).

26. The method for determining the three-dimensional location of the center of gravity of a two-wheeled vehicle (20), as claimed in claim 24, wherein said electronic control unit
(106) comprises at least one processor (104), said at least one processor (104) being configured to receive and process at least one physical parameter of said two wheeled
5 vehicle (20), and said at least one processor (104) being configured to store at least one pre-stored physical parameter of said two wheeled vehicle (20).
27. The method for determining the three-dimensional location of the center of gravity of a two-wheeled vehicle (20), as claimed in claim 25, wherein said method, comprising at least one real time physical parameter of said two-wheeled vehicle (20) being detected by
10 means of a plurality of sensors (108) distributed throughout said two-wheeled vehicle (20).