Claims:1. A system for improving efficiency of power source of a vehicle comprising:
a power source or a prime mover for providing required power to drive the vehicle;
a control unit in connection with the power source or prime mover; wherein said control unit comprises
a desired acceleration calculation module;
a corrective load index calculation module; and
a torque calculation module
wherein; the desired acceleration calculation module is configured to calculate desired acceleration for the vehicle based on received current vehicle speed or acceleration and current acceleration pedal positions (APP) using an ideal map data;
-the corrective load index module is configured to calculate corrective load index based on at least predetermined mass and a drive force acting on the vehicle; and to calculate corrected desired acceleration based on the corrective load index and the desired acceleration; and
-the torque calculation module is configured to calculate the desired prime mover torque using the corrected desired acceleration calculated by the corrective load index module; and
-the control unit is further configured to control acceleration of the vehicle by controlling the power source or the prime mover for delivering the desired prime mover torque to optimise the distance travelled.

2. The system for improving efficiency of power source of the vehicle as claimed in claim 1 wherein; the control unit is configured to control acceleration of the vehicle by controlling the torque delivered by the prime mover while the accelerator pedal opening (APP) is within a pre-defined optimum range.

3. The system for improving efficiency of power source of the vehicle as claimed in claim 1 wherein; the corrective load index module configured to calculate corrected desired acceleration by multiplying the desired acceleration with a multiplication factor wherein; the multiplication factor for each corrective load index is determined and stored in a corrective index lookup table.

4. The system for improving efficiency of power source of the vehicle as claimed in claim 3 wherein; the multiplication factor for each corrective load index is determined by
driving the vehicle at different load and road gradients and measuring vehicle acceleration at different acceleration pedal openings and speed levels;
calculating corrective load index is for different measured vehicle accelerations; and comparing the measured load index with the desired acceleration of ideal map data to determine multiplication factor for each corrective load index.

5. The system for improving efficiency of power source of the vehicle as claimed in claim 1 wherein; the control unit comprises an acceleration control unit stored with predefined maximum and minimum prime mover torque and predefined mass; and further configured
to receive value of at least one vehicle parameter including accelerator pedal position (APP); brake pedal position, current vehicle speed and/or acceleration;
to process the received values for calculating the desired prime mover torque based on corrected desired acceleration; and
to control the power source or the prime mover for delivering the calculated torque.

6. The system for improving efficiency of power source of the vehicle as claimed in claim 1 wherein; the acceleration control unit comprises a feedback controller configured to
identify error between the current vehicle acceleration and the corrected desired vehicle acceleration in a continuous close loop;
calculate the corrective output torque to be delivered by the power source or the prime mover; and
combine said corrective output torque with the torque calculated by torque calculation module to provide final desired torque, which is delivered by the power source or the prime mover to reduce the error between corrected desired acceleration and actual vehicle acceleration.

7. The system for improving efficiency of power source of the vehicle as claimed in claim 1 wherein; the ideal map data stored in the control unit comprises values of optimum vehicle acceleration against different percentages of accelerator pedal opening for plurality of vehicle acceleration levels wherein; said values are derived by driving a vehicle at different acceleration levels with different APP values by keeping at least one parameter constant including a load acting on vehicle, road gradient and riding style of vehicle.

8. The system for improving efficiency of power source of the vehicle as claimed in claim 1 wherein; the control unit controls the torque produced by the prime mover either by
controlling the electric power supplied by the power source to the prime mover including controlling of voltage/current; or by
adjusting the gear ratio of a transmission system of vehicle; or by both
wherein; the amount of electric power to be supplied to the prime mover and gear ratio to be adjusted for the desired prime mover torque is calculated by the control unit.

9. The system for improving efficiency of power source of the vehicle as claimed in claim 2 wherein; the control unit is configured to not control the acceleration of the vehicle or control the acceleration of the vehicle purely based on the ideal map data if the accelerator pedal opening is not within said pre-defined optimum range.

10. The system for improving efficiency of power source of the vehicle as claimed in claim 1 wherein; said control unit is configured to provide at least a visual and/or auditory indication means to alert the driver on suboptimal drive behaviour based on the ideal map data.

11. The system for improving efficiency of power source of the vehicle as claimed in claim 10 wherein; the indication means indicate that the acceleration pedal opening is not within said pre-defined optimum range wherein; the indication means is configured to indicate at least three different conditions of accelerator pedal opening comprising; acceleration pedal opening is well within pre-defined optimum range, the acceleration pedal opening is about to go beyond or below the pre-defined optimum range and the accelerator pedal opening is not within pre-defined optimum range.

12. The system for improving efficiency of power source of the vehicle as claimed in claim 5 wherein; the control unit is configured to indicate the desired torque of prime mover or power source is within predefined maximum and minimum torque that is delivered by the prime mover or the power source.

13. The system for improving efficiency of power source of the vehicle as claimed in claim 5 wherein; the control unit is configured to control the acceleration of the vehicle only if brake is not applied or if the desired prime mover torque is within the range of maximum and minimum torque that is delivered by the prime mover or power source.

14. The system for improving efficiency of power source of the vehicle as claimed in claim 12 wherein; the control unit is configured
to instruct the prime mover or power source to deliver the maximum torque, if the desired prime mover torque is greater than maximum torque that is delivered by the prime mover or power source; and
to instruct the prime mover or power source to deliver the minimum torque, if the desired prime mover torque is less than the minimum torque that is delivered by the prime mover or power source.

15. The system for improving efficiency of power source of the vehicle as claimed in any one of the claim above wherein; the control unit of a vehicle is any controller within vehicle including vehicle control unit (VCU) or Engine Control Unit (ECU) or Engine Management System (EMS) or provided as a separate external unit.

16. The system for improving efficiency of power source of the vehicle as claimed in any one of the claim above wherein; the vehicle is an electric or hybrid or fuel operated vehicle including two-wheeled, three wheeled and four-wheeled vehicle wherein; the prime mover is an electric motor or engine or both.

17. The system for improving efficiency of power source of the vehicle as claimed in claim 16 wherein; the vehicle is a fuel-operated vehicle and the power source or prime mover is a fuel-operated engine wherein; the control unit is configured to control the torque generated by engine through controlling quantity of fuel/ airflow supplied to engine or by adjusting a gear ratio or by both.

18. A method of improving efficiency of power source of the vehicle comprising steps of:
receiving values of current vehicle acceleration and accelerator pedal position (APP) by a control unit;
determining desired acceleration for the vehicle based on the received current vehicle acceleration and the received accelerator pedal position (APP) using an ideal map data;
calculating corrective load index based on a drive force and based on a predefined mass acting on the vehicle;
determining corrected desired acceleration for the vehicle based on corrective load index and the desired acceleration;
calculating the torque required to be produced by a prime mover or power source to achieve the corrected desired acceleration; and
controlling power produced by the prime mover or power source to deliver the calculated torque.
, Description:The invention comprises an improvement in, or a modification of, the invention claimed in the specification of the main patent applied for “SYSTEM FOR IMPROVING VEHICLE PERFORMANCE” having application number 201921029382 filed on 22-Jul-2019.

FIELD OF INVENTION:
The present invention relates to a system for improving the performance of vehicle and more particularly relates to improving efficiency of the power source in terms of mileage or travel distance of a vehicle for a given amount of fuel or battery charge.

BACKGROUND OF INVENTION:
Vehicle performance in terms of Mileage is an important factor in vehicle which is a maximum distance travelled by a vehicle for a given amount of fuel or battery charge. Higher is a mileage, longer the distance travelled by the vehicle without refuelling or recharging battery, lower is a running cost of the vehicle. Hence mileage of the vehicle is an important factor for any vehicle, higher the mileage it is better in terms of fuel efficiency and against frequent refilling/recharging.

Every manufacturer tries to improve the vehicle mileage through various means. In case of fuel operated vehicles the mileage is maximised through various design changes related to engine and its associated components such as valve timing, ignition timing, twin spark, Controlling fuel rate, Electronic carburettor, etc. Electronically controlled systems are also available with utilizes various sensors to sense number of vehicle parameters and controls the fuelling rate of the vehicle in order to maximise the mileage of the vehicle.

Similarly, in case of electric vehicles (EV) as well efforts are being made to maximise the mileage of the vehicle that is possible in a single charge of battery. This will help in reducing the frequent charging required for EV, which is one of the major concern currently. One of the prior art system work based on state of charge (SOC) of the battery, internal resistance, temperature within battery to determine battery efficiency which is further used to operate the vehicle in economic speed mileage. One of the disadvantage in SOC based system is that it results in different drive feel of the vehicle as SOC of the vehicle drops. Similarly, few prior art system calculates motor efficiency along with or without battery efficiency and determines the economic speed zone for driving a vehicle. However, these systems do not actively control the vehicle speed to ensure economic driving. Further, such systems are very costly.

Mileage of any vehicle depends upon various factors such as road condition, load, riding style and system efficiency. Road condition, riding style and load on the vehicle are variable factors and cannot be maintained constant which affect vehicle efficiency. The roads with high gradient reduces the mileage of the vehicle. Similarly, higher load and rough riding style has negative impact on the mileage of the vehicle. Hence, even though various methods are used for maximizing the mileage of the vehicle, due to these variable factors none of the method is very effective to maximise the mileage. Most of the prior art systems do not consider the variation caused by these variable factors and hence they are not very effective.

Few prior art systems which actively control the vehicle speed are very complex and costly as these system deploy too many sensors and considers multiple parameters including parameters of battery and motor. For example, few prior arts considers the variable factors such as load on acting on vehicle using load sensor for actively monitoring the load acting on the vehicle. However, the overall cost increases due to use of load sensor as well the complexity increases due to additional input required to implement control strategy.
Hence, there is a need to provide an effective vehicle mileage improving system, which can effectively consider the variable factors while being less complex and less costly.

Therefore, an objective of the present invention is to provide an effective system for improving vehicle mileage, which is less complex and less costly.

Yet another objective of the present invention is to provide a system for improving vehicle mileage, which effectively consider the variable factors including load acting on the vehicle while being less complex and less costly.

SUMMARY OF INVENTION:
With the above mentioned objects in view, the present invention provides a system for improving efficiency of power source of a vehicle comprising:
a prime mover or a power source to drive the vehicle;
a control unit in connection with the prime mover or power source; wherein the control unit comprises
a desired acceleration calculation module;
a corrective load index calculation module; and
a torque calculation module
wherein; the desired acceleration calculation module is configured to calculate desired acceleration for the vehicle based on received current vehicle speed or acceleration and current acceleration pedal positions (APP) using an ideal map data;
- the corrective load index calculation module is configured to calculate corrective load index based on a predetermined mass and based on a drive force acting on the vehicle; and to calculate corrected desired acceleration based on the corrective load index and the desired acceleration; and
-the torque calculation module is configured to calculate a desired prime mover torque using the corrected desired acceleration calculated by the corrective load index module; and
-the control unit is further configured to control acceleration of the vehicle by controlling the power source/ prime mover for delivering the desired prime mover torque to optimise the distance travelled.
According to preferred embodiment of present invention the control unit is configured to control acceleration of the vehicle by controlling the torque delivered by the power source/ prime mover while the accelerator pedal position (APP) is within a pre-defined optimum range.

The control unit is configured to provide at least a visual and/or auditory indication to alert the driver on suboptimal drive behaviour based on the ideal map data.

According to one of the embodiment of present invention, wherein; the control unit is configured to control the power delivered by the power source/ prime mover to control acceleration of the vehicle wherein; the control unit is configured to control the acceleration of the vehicle within a pre-defined optimum range of accelerator pedal position (APP).

The control unit of a vehicle may be any controller within vehicle including vehicle control unit (VCU), Engine Control Unit (ECU), Engine Management System (EMS) or any other suitable controller within vehicle. Alternatively, the controller may be provided as a separate external unit.

The control unit comprises an acceleration control unit is stored with predefined maximum and minimum prime mover torque and predefined mass; configured to receive value of at least one vehicle parameter including percent of accelerator pedal position (APP); brake pedal position, current vehicle speed/ acceleration. The average load acting on the vehicle is predetermined and fed into the control unit. For example, the average weight may be vehicle weight plus driver and one passenger weight. The acceleration control unit further configured to process the received values to calculate the desired prime mover torque using an ideal map data. The prime mover delivers the calculated torque as per received signal from acceleration control unit in order to achieve ideal desired acceleration.

The acceleration control unit comprises a memory stored with values of ideal map data and further comprises various modules including a desired acceleration lookup module, corrective load index calculation module and a torque calculation module

The corrective load index calculation module is configured to calculate load index on the vehicle by dividing total drive force acting on the vehicle by a constant predetermined mass wherein; the total drive force is calculated by considering at least one of the parameter including torque produced by the prime mover, transmission efficiency, rolling resistance of vehicle, drag force etc. The predetermined mass is considered as driver plus one passenger. The corrective load index module is configured to determine a multiplication factor allocated for corrective load index and further configured to determine corrected desired acceleration by multiplying the desired acceleration with the multiplication factor to compute corrected desired acceleration. The multiplication factor corresponding to the range of corrective load index is predetermined and stored in the corrective load index module.

The multiplication factor for each corrective load index is determined by driving the vehicle at different load and road gradients and measuring vehicle acceleration at different acceleration pedal openings and speed levels; calculating corrective load index is for different measured vehicle accelerations; and comparing the measured load index with the desired acceleration of ideal map data to determine multiplication factor for each corrective load index.

The acceleration control unit is further provided with a feedback controller configured to compare the current vehicle acceleration with the corrected desired acceleration in a continuous close loop and initiate a corrective action in order to minimise any error there between. Based on any error identified, the feedback control module calculates the torque required to reduce the error between corrected desired and actual/ current vehicle acceleration. The torque calculated by the feedback controller and the torque calculation module are combined to provide corrected desired torque, which is delivered by the prime mover.

The ideal map data stored in acceleration control unit is having values of various vehicle acceleration levels against different percentages of accelerator pedal position. The ideal map data is developed by driving a vehicle at different acceleration levels with different APP values. At least one parameter is kept constant while collecting the data for example, a constant load is considered to be acting on vehicle, preferably load of driver plus three passengers, no sharp upward or downward road gradient and ideal riding style of vehicle etc. An optimum range of accelerator pedal position (APP) is pre-defined in the control unit. The optimum range of APP is range of percentage of accelerator pedal position in which maximum vehicle mileage may be obtained. The acceleration pedal position corresponds to opening of the acceleration pedal, which indicates the amount of desired power or torque required by the rider to drive the vehicle. The optimum range of APP is derived by driving the vehicle at different acceleration levels with different APP values under above-mentioned ideal condition and observing the mileage of the vehicle at each condition. Similarly, the multiplication factor for each corresponding corrective load index is determined through similar experimentation explained herein above. The multiplication factor represents the percent of desired acceleration applicable considering the load acting on the vehicle.

The control unit is configured to control the acceleration of the vehicle only if brake is not applied or if the desired prime mover torque is within the range of maximum and minimum torque that can be delivered by the prime mover. According to one of the embodiment, the vehicle may be an electric or hybrid vehicle and the prime mover is an electric motor powered by the power source as a battery in the form of energy source. According to another aspect of the present invention, the vehicle may also be a fuel-operated vehicle and the power source/ prime mover is a fuel-operated engine, for ex IC engine. In case of battery as power source; the power/ current supplied by battery is adjusted in order to control the torque generation, whereas in case of fuel-operated power source, quantity of fuel/ airflow is suitably adjusted. In addition to above, gear ratio may also be adjusted in order to generate the required torque. If the total desired prime mover torque is greater than maximum torque that can be delivered by prime mover then the maximum torque is delivered by the prime mover or if the total prime mover torque is less than the minimum torque that can be delivered by prime mover then the minimum torque is delivered by the prime mover.

The control unit is configured to control acceleration of the vehicle purely on the basis of the ideal map data if the accelerator pedal position is not within the pre-defined optimum range i.e. without applying any controlling strategy. Alternatively, the acceleration is not controlled if the accelerator pedal position is not within the pre-defined optimum range.

The vehicle is provided with indication means to indicate that the acceleration pedal position is not within the pre-defined optimum range. Preferably, the indication means is a visual indication provided on a dashboard of the vehicle in the form of light. The indication means comprises at least three different ways of indication to indicate three different conditions of accelerator pedal position comprising; acceleration pedal position is well within pre-defined optimum range, the acceleration pedal position is about to go beyond or below the pre-defined optimum range and the accelerator pedal position is not within pre-defined optimum range. The indication means is also configured to indicate whether desired power is within pre-set threshold limit of power that is delivered by the prime mover. The indication means may be additionally equipped with an audio alarm to indicate different conditions of APP.

In another aspect of present invention, the present system may be applied to any electric, hybrid or fuel operated vehicle including two-wheeled, three wheeled and four-wheeled vehicle wherein; the prime mover which may be an electric motor or engine produces controlled torque according to pre-stored control strategy which controls the acceleration of the vehicle thereby helping in improving mileage of the vehicle. Therefore, the present invention is also applicable to any vehicle including two-wheeled, three-wheeled or four-wheeled vehicle.

A method of improving vehicle performance comprising steps of receiving values of current vehicle acceleration and accelerator pedal position by a control unit; comparing the received current vehicle acceleration with the received accelerator pedal position to identify desired acceleration using an ideal map data; calculating corrective load index based on predetermined mass and drive force; determine corrected desired acceleration for vehicle based on corrective load index and desired acceleration; calculating the torque required to be produced by a prime mover/ power source to achieve the corrected desired acceleration; and controlling power produced by the prime mover or power source in order to deliver the calculated torque.

BRIEF DESCRIPTION OF THE DRAWINGS
The vehicle of the present invention may be more fully understood from the following description of preferred embodiments thereof, made with reference to the accompanying drawings in which:

FIG. 1 illustrates the block diagram of acceleration control unit according the preferred embodiment of present invention;

FIG. 2 illustrates a flow diagram of various steps involved in control strategy according to the preferred embodiment of present invention;

FIG. 3 illustrates a block diagram of acceleration control unit with its sub-modules according to the preferred embodiment of present invention; and

FIG. 4 illustrates a flow chart describing a major steps involved in controlling acceleration by the acceleration control unit according to the preferred embodiment of present invention.

DETAIL DESCRIPTION OF INVENTION
A preferred embodiment will now be described in detail with reference to the accompanying drawings. The preferred embodiment does not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.

Referring now to FIG. 1, illustrating an acceleration control unit 101, which is a part of control unit of vehicle. The control unit of a vehicle may be any controller within vehicle including vehicle control unit (VCU), Engine Control Unit (ECU), Engine Management System (EMS) or any other suitable controller within vehicle. The acceleration control unit 101 is a microprocessor device in communication with various vehicle components to receive plurality of inputs including but not limiting to vehicle speed/ acceleration sensor 150 to receive running vehicle speed/ acceleration, accelerator pedal position (APP) sensor 110 to receive accelerator pedal position, maximum and minimum prime mover torque value (130, 140), brake pedal position sensor 120 to identify brake position and a predefined load or mass acting on the vehicle 160 etc. The acceleration control unit 101 is configured to process the received input as per pre-determined control strategy to provide an output command, which is a best-desired prime mover torque to be delivered. The acceleration control unit 101 is in connection with the prime mover 170 for delivering the output command of calculated torque and the prime mover 170 is configured to receive the output command and deliver the calculated torque. Therefore, the prime mover torque is controlled in order to control the acceleration of the vehicle, which helps to obtain maximum vehicle mileage. The control strategy, which is used by the acceleration control unit 101, is further explained herein below with the help of drawings.

Acceleration of vehicle depends on various factors such as road condition i.e. upward or downward gradient, load on the vehicle, present vehicle speed, riding style, accelerator pedal position etc. All these parameters are variable parameters and changes according to running condition. In order to determine ideal desired acceleration values and minimise the effect of these variable parameters, certain conditions may be assumed constant for example, according to one of the embodiment of the present invention a constant load/ mass is considered on the vehicle for example average load/ mass of driver plus three passengers is considered. Similarly, the road condition is considered to be a normal driving road without much upward or downward gradient. Further, the riding style is assumed to be ideal. Thereby the vehicle acceleration is independent of the vehicle loading condition, riding style and gradient condition of the road. Under such ideal conditions a data is collected of vehicle acceleration against various values of percentage of accelerator pedal position. The ideal data is collected by driving the vehicle at different acceleration levels and plotting the graph of different acceleration levels against time, which gives a graph for acceleration. The mileage obtained by the vehicle at each accelerator pedal position (APP) and acceleration level is observed and accordingly, the best desired acceleration for vehicle is determined for each APP value and vehicle acceleration level in order to obtain best mileage for vehicle. The required optimum torque at each acceleration level is derived therefrom. This forms the ideal map data from which a desired acceleration lookup table is generated using known mathematical methods and vehicle dynamics equation. The control strategy is based on an ideal map data. This data is stored in the control unit of the vehicle. The above strategy helps in collecting the data in minimum number of sensors and with less complexity, which helps in reducing cost.

In order to obtain a higher mileage for vehicle, acceleration of vehicle is controlled. Acceleration is governed by torque generated by prime mover. For each APP desired acceleration value is derived from ideal map data from which desired prime mover torque is calculated by acceleration control unit and sent to prime mover. The acceleration control unit is configured to control the acceleration of the vehicle according to the values stored in the ideal map data. Vehicle mileage is calculated at each acceleration level. An optimum range of accelerator pedal position (APP) is pre-defined in the control unit. The optimum range of APP is range of percentage of accelerator pedal position in which maximum vehicle mileage may be obtained. The optimum range of APP is derived by driving the vehicle at different speed/ acceleration levels with different APP values under above-mentioned ideal condition and observing the mileage of the vehicle at each condition. Therefore, whenever the accelerator pedal position/ opening is within the optimum range then vehicle acceleration is governed according to the proposed control strategy and in rest of the conditions the vehicle is run purely based on ideal map data. For example, the vehicle mileage is observed to be maximum between 20% to 80% accelerator pedal position then this is pre-defined as optimum range. Therefore, as far as the percentage of accelerator pedal position is within 20% to 80% the prime mover torque is governed by the acceleration control unit 101, rest in other conditions the vehicle is run according to the ideal map data or by the actual values and not controlled . For example, at initial pick up from rest when vehicle acceleration is lesser or in case of overtaking other vehicle, higher acceleration is required. In such scenarios APP value generally does not stay with the optimum range of 20% to 80%, the vehicle is run directly according to ideal map data, and no other control strategy is applied. Magnitude of a torque is always less than or equal to ideal torque map values.

As illustrated in FIG. 2 illustrating flowchart illustrating various checks to be done the control unit before applying the control strategy. Specifically in certain scenarios, the control strategy is reset. For example, when the brake is applied the vehicle speed starts reducing in such scenarios the vehicle is run according to actual values or according to ideal map data. Similarly, in case the desired vehicle torque is greater than maximum torque that can be delivered by the prime mover or less than minimum torque that can be delivered by the prime mover, then the vehicle is run according to actual values or ideal map data. Therefore, all these conditions are verified and the vehicle is controlled only if vehicle brake is not applied and the desired more torque is between the minimum and maximum values of torque that can be delivered by prime mover.

Referring to FIG. 3 illustrating block diagram of various control sub-modules as a part of acceleration control module 101. Upon receiving plurality of inputs as explained above, a desired acceleration lookup module 310 determines the desired acceleration after referring to ideal map data based on received parameters including vehicle speed and/or acceleration and Accelerator Pedal position (APP). The desired acceleration is predetermined in the ideal map data, which is derived based on ideal driving condition keeping variable parameters as constant or ideal as explained herein above. However; practically the variable parameters like road gradient and load/ mass acting on the vehicle may not be constant or ideal always. Therefore, in order to account for these variable parameters a corrective load index is determined by a corrective load index module based on current drive force on the vehicle and a predefined load/mass acting on the vehicle. A constant average mass is considered for this purpose preferably as mass/ load of driver plus one passenger acting on the vehicle. The corrective load index provides a multiplication factor for further correcting the desired acceleration considering effect of reduced load and road gradient and helps in further tuning of desired acceleration. The desired acceleration is multiplied by the multiplication factor to obtain corrected desired acceleration. The calculation of corrective load index is explained herein below in subsequent paras. Once the corrected desired Acceleration is determined, a torque calculation module 330 calculates the desired torque required to be produced by the prime mover in order to achieve the corrected desired acceleration. A feedback controller 340 monitor and compare the actual acceleration with corrected desired ideal acceleration and generates a corrective action in order to minimise any error there between in a continuous loop till the error becomes zero. The feedback controller 340 provides output command as a corrective output torque. Final desired prime mover torque is calculated at torque calculating module 350, which is sum of torque calculated by torque calculation module 330 and feedback controller 340. The prime mover is operated to deliver the calculated torque. The torque calculation is explained herein below in subsequent paras.

According to one of the embodiment of present invention; the corrective load index calculation method is explained herein below. The load acting on the vehicle is determined according to following equation, the load itself is a combined effect of mass or gradient.
M dV/dt=[(T×G×eff)/r-A-BV^2-Mg sin?(?)]
Wherein,
A= Rolling resistance acting on the vehicle [N]
B= Quadratic coefficient of drag force [N/kmph2]
V= Vehicle velocity [kmph]
M= Vehicle Mass [kg]
?= Road gradient [%]
g= Acceleration due to gravity [m/s2] (9.81)
T = Motor torque (Nm)
G = Gear ratio of the transmission
Eff = efficiency of the powertrain / transmission.
Rearranging the above equation and assuming constant mass of vehicle (e.g. Driver+1 passenger condition as 527 kg). The vehicle curb weight is already considered and added into the above mass. The average mass considered may vary based on vehicle type, size, capacity etc.
(dV/dt+g sin?(?)) =((T×G×eff)/r-A-BV^2)÷M
Wherein the term (dV/dt+g sin?(?) )= a^' ? a^'is a corrective load index acting on the vehicle, in m/s2. The term ((T×G×eff)/r-A-BV^2) represents net drive force acting on the vehicle.
The negative values of the corrective load index calculated above are neglected and the desired acceleration calculated by the desired acceleration calculation module is directly considered for torque calculation.

Only positive values of corrective load index are further considered for torque calculation.

a^'?(0,+inf)
A multiplication factor?????is determined from the a load index lookup table; wherein the multiplication factor ????is predefined for each specific range of corrective load index
(a^'), as illustrated in the following example.

a^' 0 0.25 1 0.5 2.5
? 1 0.95 0.85 0.7 0.5

The multiplication factor (???is considered as 1 for corrective load index value (a^'), as zero or negative. For all the positive values the multiplication factor is pre-determined considering maximum mileage is obtained with minimum acceleration/ torque requirement.

The corrected desired acceleration is then recomputed as follows:
A’ = A* ???wherein A= desired acceleration determined from the ideal map data.
Where,
??= multiplication factor from corrective index lookup table

With the help of above manipulation of desired acceleration, control unit lowers down the value of the desired torque if the loading condition of the vehicle is already too high (more people are seating in the vehicle) OR if the vehicle is climbing the gradient. Since the desired torque/ prime mover torque is less, it results in the low power consumption of the vehicle. Thereby improving the mileage. Further, the variable factors like mass/ load acting vehicle, road gradient are being considered in the above equation and the corrected desired acceleration is being calculated accordingly. Therefore, the system do not need any additional sensors like load sensor, road gradient sensor etc. which helps in reducing complexity as well as cost.

According to one of the embodiment of present invention, the methodology to establish a relationship of corrective load index? (a?^') to the multiplication factor (?? is determined using following experiments. The vehicle is driven with constant minimum load (Preferably load of Driver+ One passenger) with different constant road gradients applied (For example 5%, 15% etc.). Preferably, ideal driving condition is considered for this experiment (for example: ideal driving style with minimum or no sudden acceleration/deceleration and with minimum or no abrupt braking). The measured acceleration values are noted down at different speeds and different acceleration pedal openings (APP). The same experiment is repeated under different load conditions & different road gradient values and the acceleration is measured. The effect of change in load, gravity and road gradient is studied from this experiment. In order to consider the effect of change in load and road gradient, above calculated values of acceleration are co-related with the values of ideal acceleration stored in ideal map data. This helps in further correcting the ideal acceleration values by considering the effect of change in load and road gradient. For this purpose, a corrective load index ? (a?^') is calculated for each experimental value. As load acting on vehicle and road gradient are known, load index may be easily calculated from above defined equation. The corrective load index ? (a?^') is then compared against the desired acceleration (A) stored in ideal map data and a multiplication factor (???is determined for each corrective load index ? (a?^').

Prime-mover desired torque calculation is done by torque calculation module as follows. The desired torque is calculated by following formula.
T_desired=(Mass*A’+F_r+0.5*b*V^2 )*r
In above formula, “A’” is corrected desired acceleration determined by the corrective load index module as explained herein above, “F_r” is rolling resistance in newton for assumed mass. “b” is aerodynamic drag loss coefficient which is also assumed to be constant and “v” is a present vehicle speed. “r” is a rolling radius of wheel. Once the desired torque is calculated, actual torque required to be produced by prime mover is calculated by,
Prime Mover?_Torque1?=T_desired/(Gear_ratio )
Wherein, the Prime Mover?_Torque1? is torque required to overcome the vehicle drag losses and gear ratio is of the power train of vehicle.

During lightly loaded condition of the vehicle, the desired torque computation might be very high & the speed might overshoot. Similarly, during heavily loaded condition of the vehicle the desired acceleration might not be achieved at all. For the above reason the feedback controller 340 is added. The feedback controller 340 compares the present vehicle acceleration against the desired vehicle acceleration & calculates the prime mover torque2 required to reduce the error between the above quantities. The function and components of feedback controller is explained in applicant’s another patent application having application number 201621039983 dated 23rd November 2016 the contents of which are brought herein by reference.

The final torque is calculated as
Total desired prime mover Torque = prime mover_Torque1 + prime mover_Torque2.
Based on this calculated torque the control unit gives appropriate command to the prime mover in order to generate the required torque. In case of electric motor as prime mover the power/ current supplied by the power source as battery is adjusted such that prime mover generates the required torque, whereas in case of fuel operated prime movers, quantity of fuel/ airflow is suitably adjusted. In addition to above, gear ratio may also be adjusted in order to generate the required torque. If the total desired prime mover torque is greater than maximum torque that can be delivered by prime mover then the maximum torque is delivered by the prime mover or if the total prime mover torque is less than the minimum torque that can be delivered by prime mover then the minimum torque is delivered by the prime mover.

In case, the driver wants full acceleration for example during over taking then the driver may open the accelerator pedal fully. When the APP goes above 80% the acceleration is controlled according to ideal map data or according to the actual values.

When driver demand power is more than threshold 1 or accelerator pedal position is greater than the threshold 2, then tell-tale indication, which is nominally green colour in drive mode, is made to made solid amber colour. Similarly, when driver demand power is more than threshold 3 or accelerator pedal position is greater than threshold 4, then tell-tale indication, which is nominally green in drive mode, is made to blink in amber colour. Green signal indicates that the vehicle is being driven in an economic zone as per control strategy while green signal is turned into amber as soon as vehicle acceleration/ desired power is noticed to be going beyond economic zone. When the acceleration is not within economic zone the light is turned to blink into amber colour. The vehicle acceleration is controlled up to some percent of APP for example 80% as the driver goes beyond 80% the acceleration is controlled according to ideal map data or according to the actual values. However; this condition can impact the overall mileage of the vehicle hence indication is provided to indicate this situation to driver.

This concept is now explain with the help of an example herein below. According to an ideal map data an economic zone/ optimum range is defined for a vehicle, which is from 20% to 80% of APP. Therefore, vehicle acceleration is control in order to force the vehicle to be driven in economic zone in order to get maximum mileage. However, during initial or highly accelerated condition APP may not be within the economic zone defined above. In such scenario, vehicle acceleration is controlled as per ideal map data. In order to indicate this situation to the driver a green light is turned to a solid amber colour as the vehicle starts appropriating an upper threshold level of 80% APP. For example APP with 60% to 80%. As soon as the vehicle exceeds to upper threshold of 80% the indication, starts blinking with amber colour. It may additionally be provided with audible alarm. Indication helps driver to identify situations wherein the vehicle is not driven according to the control strategy.

According to another embodiment of present invention the threshold level is not only limited to APP but also power delivered by prime mover. For giving a visual indication the power provided to the prime mover is considered rather than only torque. Power is derived from torque and RPM produced by prime mover shaft. If the power is above threshold level then the lights starts operating to indicate risk.
Referring to FIG. 4 illustrating a flow chart of major steps involved in controlling the acceleration of the vehicle, which are performed by the acceleration control unit, when the APP valve is within pre-set optimum limit. At step 405, the acceleration control unit receives various parameters including APP, brake pedal position, Current Speed/ acceleration etc. The acceleration control unit further calculates the desired acceleration based on current APP value and current vehicle speed/ acceleration using ideal map data at step 410. The corrective load index is determined by the corrective load index module as explained herein above, to determine corrected desired acceleration at step 415. Desired torque is calculated based on corrected desired acceleration as explained herein above at step 420 and the prime mover is controlled to deliver the calculated desired torque. Once the desired torque is delivered by the prime mover, a current vehicle acceleration is received/ obtained by the acceleration control unit at step 425. The received acceleration of the vehicle is then compared with the target corrected desired acceleration at step 430. If any error is identified there between, then a feedback torque is calculated by a feedback control module at step 440. The feedback torque is then combined with the previously calculated desired torque to calculate the final desired motor torque at step 445, which is further delivered by the prime mover. The acceleration control unit then again calculates the error between target vs current acceleration and repeat the above steps until the error between actual acceleration and target corrected desired acceleration becomes zero. Above methodology is applicable only when the APP is within predefine optimum range. Once the APP goes outside the optimum range, the vehicle acceleration or torque is equal to the actual value or equal to the ideal values of map data. Additionally, the predefined conditions are also checked before controlling the acceleration as explained above with reference to FIG.2.

In another aspect of present invention, the present system may be applied to any electric, hybrid or fuel operated vehicle wherein the prime mover or power source, which may be an electric motor or engine, produces controlled torque according to pre-stored control strategy, which controls the acceleration of the vehicle thereby helping in improving mileage of the vehicle. Therefore, the present invention is also applicable to any vehicle including two-wheeled, three-wheeled or four-wheeled vehicle including electric or hybrid vehicles.

Although the invention has been described with regard to its embodiments, specific embodiments, and various examples, which constitute the best mode presently known to the inventors, it should be understood that various changes and modifications as would be obvious to one having the ordinary skill in this art may be made without departing from the scope of the invention. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. All changes that come with meaning and range of equivalency of the claims are to be embraced within their scope.