The present disclosure relates, in general, to Hybrid Control Unit (HCU) of an automatic hybrid vehicle.
[0002] In particular, the present disclosure relates to a Hybrid Control Unit and a method for minimizing or improving instantaneous engine Fuel consumption in an automatic hybrid electric vehicle during acceleration.
BACKGROUND
[0003] Background description includes information that may be useful in understanding the present subject matter.
[0004] In today's world, one of the major topics of the day is the unknown future of energy, threat of depletion of fossil fuels, and alternative sources of energy. Energy is a commodity that is devoured by the entire world. However, it is also something that, in many senses, cannot be restored. Take, for instance, gasoline. Today's society is extremely dependent on the role of the automobile as a means of transportation. In addition, with the exponential growth of our dependency on automobile, the use of gasoline has increased along with its wastage.
[0005] Generally, there is a technology of reducing fuel consumption in an automobile, i.e., hybrid vehicle that involves combination of an electric motor and a battery pack with an internal combustion engine to increase fuel efficiency over traditional automobiles. In the hybrid electric vehicles (except plug-in hybrid electric vehicles) the battery pack is of smaller size as compared to battery electric vehicles as the stored energy in the battery pack can be used to assist the engine to run the vehicle and to minimize the fuel consumption. In addition, hybrid vehicles use energy from the battery to enhance dynamic performance, convert kinetic energy into electric energy using regenerative braking, and store the converted

energy in the battery pack to reduce fuel consumption. When a driver requests acceleration, in order to realize a necessary desired torque, there are methods such as supplying the torque by engine or supplying the torque by electric motor or jointly by engine and motor; and by optimizing gear ratio selection.
[0006] As shown in fig. 1, the hybrid vehicle comprises a hybrid control unit (HCU) 100 which is coupled with Engine Control Unit (ECU) 300, Transmission Control Unit (TCU) 200, and a Motor Control Unit (MCU) 400. The hybrid control unit (HCU) 100 communicatively coupled with other control units and provide inputs for operation.
[0007] Technical objective of the present subject matter is to achieve improvement in fuel efficiency or fuel consumption in hybrid vehicle.
[0008] Existing technologies as explained in US9827979B2 where hybrid controller is provided to operate the engine by the controller unit at its most efficient point. But actual point of minimum fuel consumption can be different from the efficient point.
[0009] Therefore, there is a need to provide system and a method for minimizing instantaneous engine fuel consumption in the automatic hybrid electric vehicle during acceleration.
OBJECTS OF THE DISCLOSURE
[0010] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below.
[0011] A general object of the present disclosure is to provide a method and a system for determining lowest fuel consumption point at any instant during acceleration of the automatic hybrid vehicle.

[0012] An object of the present disclosure is to provide a method and a system to determine a target point with lowest/minimum fuel consumption at any instance during drive cycle of the vehicle.
[0013] These and other objects and advantages of the present disclosure will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY
[0014] This summary is provided to introduce concepts related to a method and a system for determining lowest fuel consumption point at any instant during acceleration of the automatic hybrid vehicle. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0015] The present disclosure relates to a hybrid Control Unit (HCU) for improving/minimizing instantaneous engine fuel consumption of an automatic hybrid vehicle. The automatic hybrid vehicle comprising an internal combustion engine controlled by Engine Control Unit (ECU), a battery device/pack controlled by a battery controller and an electric motor where the electric motor is configured to apply torque to power transmission path where the electric motor is controlled by a Motor Control Unit (MCU), and a Transmission control unit (TCU) configured to control engagement of desired gear in transmission system. The hybrid control unit (HCU) has a processor and a memory to achieve the technical objective. The HCU comprising a driver demand torque determining unit configured to determine, from a driver demand torque map, a driver demand torque based on accelerator pedal pressed condition as driver input. A gear range determining unit is configured to determine, based on vehicle traction map, working gear range for the determined driver demand torque. A torque range determining unit is configured to determine torque range of the engine, based on

the engine torque curve from the ECU and torque range of the motor, based on a motor torque curve, from the MCU for each of the determined gear from the determined working range of gears. A mass fuel flow consumption determining unit is configured to: determine battery state of charge (SOC) level from the battery controller; determine, based on an engine fuel consumption map, mass fuel flow consumption for torque range in assist condition and in engine load shift condition for each determined gear from the determined working range of gears when the battery SOC level is more than a predefined minimum threshold battery SOC level value (Th); and determine, based on the engine fuel consumption map, mass fuel flow consumption for torque range in engine load shift condition for each determined gear from the determined working range of gears when the battery SOC level is less than a predefined minimum threshold battery SOC level value (Th). A target input values determining unit is configured to determine lowest mass fuel flow consumption point from the determined range of the mass fuel flow consumption. Upon determining the lower mass fuel flow consumption point, the hybrid control unit has a communication unit which is configured to communicate a target gear corresponding to the determined lowest mass fuel flow consumption point to the Transmission Control Unit (TCU); communicate a target engine torque corresponding to the determined lowest mass fuel flow consumption point to the Engine Control Unit (ECU); and communicate a target motor torque corresponding to the determined lowest mass fuel flow consumption point to the Motor Control Unit (MCU).
[0016] In an aspect, the assist condition is a condition where the electric motor assists the engine to achieve the driver demand torque, the assist condition is defined as X-Y = A where X is driver demand torque from pedal map, Y is Motor torque from the motor torque map, and A is torque that is to be generated by the engine.
[0017] In an aspect, the engine load shift condition is a condition where the engine generates torque to charge the battery and fulfil the driver demand torque, the load condition is defined as X+Y = L where X is driver demand torque from

the pedal map, Y is Motor generation torque from the motor torque map, and L is torque that is to be generated by the engine.
[0018] In an aspect, the determined lowest mass fuel flow consumption point is target for the engine operation.
[0019] In another embodiment of the present subject matter, a method for minimizing instantaneous engine fuel consumption of an automatic hybrid vehicle is disclosed. The method comprises steps of determining, from a driver demand torque map, a driver demand torque based on accelerator pedal pressed condition as driver input; determining, based on traction map, working gear range for the determined driver demand torque; determining torque range of the engine, based on the engine torque curve from the ECU and torque range of the electric motor, based on a motor torque curve, from the MCU for each of the determined gear from the determined working range of gears. The method further comprises determining, based on an engine fuel consumption map, mass fuel flow consumption for torque range in assist condition and in load shift condition for each determined gear from the determined working range of gears when the battery SOC level is more than a predefined minimum threshold battery SOC level value (Th); and determining, based on the engine fuel consumption map, mass fuel flow consumption for torque range in load shift condition for each determined gear from the determined working range of gears when the battery SOC level is less than a predefined minimum threshold battery SOC level value (Th). Upon determining lowest mass fuel flow consumption point from the determined range of the mass fuel flow consumption, the method comprises a step to communicate a target gear corresponding to the determined lowest mass fuel flow consumption point to the Transmission Control Unit (TCU); communicate a target engine torque corresponding to the determined lowest mass fuel flow consumption point to the Engine Control Unit (ECU); and communicate a target motor torque corresponding to the determined lowest mass fuel flow consumption point to the Motor Control Unit (MCU).

[0020] In an aspect, the assist condition is a condition where the electric motor assists the engine to achieve the driver demand torque, the assist condition is defined as X-Y = A where X is driver demand torque from pedal map, Y is Motor torque from the motor torque map, and A is torque that is to be generated by the engine.
[0021] In an aspect, the load shift condition is a condition where the engine generates torque to charge the battery and fulfil the driver demand torque, the load condition is defined as X+Y = L where X is driver demand torque from pedal map, Y is Motor torque from the motor torque map, and L is torque that is to be generated by the engine.
[0022] In an aspect, the determined lowest mass fuel flow consumption point is target fuel flow consumption point for the engine operation.
[0023] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which numerals represent like components.
[0024] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[0025] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and with reference to the accompanying figures, in which:
[0027] Fig. 1 illustrates block diagram of control units provided in an automatic Hybrid vehicle connected to each other through CAN bus as known;
[0028] Fig. 2 illustrates a block diagram of Hybrid Control Unit receiving inputs and determining target values for operating the engine, in accordance with an embodiment of the present disclosure;
[0029] Fig. 3 illustrates block diagram of Hybrid Control Unit (HCU) in the automatic hybrid vehicle, in accordance with an embodiment of the present disclosure;
[0030] Fig. 4a illustrates traction map of the automatic hybrid vehicle, in accordance with an embodiment of the present disclosure;
[0031] Fig. 4b illustrates fuel consumption map of the automatic hybrid vehicle, in accordance with an embodiment of the present disclosure;
[0032] Fig. 5 illustrates method for determine the lowest fuel consumption point, in accordance with an embodiment of the present disclosure.
[0033] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in a computer-

readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.
DETAILED DESCRIPTION
[0034] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
[0035] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0036] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[0037] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example,

two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0038] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Definitions:
[0039] Vehicle Traction Force Map: A vehicle traction force map or curve, represents the maximum force available at wheels in different gears to generate motion in a vehicle. It also includes resistive force curve. The motion of vehicle is only possible when vehicle traction force is greater than total resistive forces.
[0040] Pedal Map: Pedal maps are one of the main factors which allow to match an engine's output to a driver's requirements. For a given pedal position and a given engine speed, engine torque demand is generated by the driver. It is this demand that gets fed to the engine side of the ECU and motor side of MCU to deliver the required amount of torque in a hybrid vehicle.
[0041] Motor Torque map: The motor torque curve is a plot showing its torque capacity versus the speed.
[0042] Driveline Efficiency map: The driveline efficiency is the cumulative efficiency of all drivetrain components which are delivering the engine power to the wheels. The higher the efficiency of the drivetrain, the lower the fuel consumption of the vehicle

[0043] Fuel Consumption map: Fuel consumption map represents contours of constant Fuel Consumption areas on engine torque-speed maps to show torque-speed combinations at which the engine will operate most efficiently.
[0044] Engine Control Unit (ECU): ECU is a controller which controls functionality of the internal combustion engine.
[0045] Motor Control Unit (MCU): MCU is a controller which is coupled with an electric motor to control functionality of the electric motor. Based on inputs, the MCU instruct the electric motor to generate requested torque.
[0046] Transmission Control Unit (TCU): TCU is a controller which is coupled with the other controllers of the vehicle to receive inputs to change the gear engagement in the gear transmission.
[0047] Battery Management System (BMS): BMS is a controller which is coupled with the battery pack to determine health, state of charge, and all other functions associated with the battery.
[0048] The present subject matter discloses an automatic hybrid vehicle that is in driving mode means accelerator pedal is pressed and no braking is applied. With the present subject matter, driver torque demand at any instant is required to be satisfied by a combination of the engine torque and the motor torque. When Battery charge level is greater than minimum level of allowed battery charge capacity, possible gears in which the driver demand can be satisfied is checked and for each possible gear, entire torque range of engine alone, motor assist, and engine load shift functions are calculated for determining point of minimum fuel consumption for the engine. At any given instant, point of minimum fuel consumption becomes target point for engine operation.
[0049] FIG. 1 illustrates block diagram of the automatic hybrid vehicle having the Hybrid control unit (HCU) 100. The hybrid vehicle comprises a hybrid control unit (HCU) 100 which is communicatively coupled with the TCU 200, ECU 300,

the MCU 400, BMS 800 and brake control unit 700 through a Controller Area Network (CAN) bus communication line of the vehicle.
[0050] The automatic hybrid vehicle comprising an internal combustion engine coupled with the Engine Control Unit (ECU) 300 which is main source of power generation, a battery device coupled with a battery controller and an electric motor where the electric motor is configured to apply additional/secondary torque to power transmission path. The electric motor is controlled by a Motor Control Unit (MCU) 400 which controls the rotation of the electric motor based on the state of charge of the battery pack. A gear transmission system has a Transmission control unit (TCU) 200 to control engagement of gears in transmission system upon receiving instructions from the HCU 100.
[0051] Fig. 3 illustrates components of the HCU 100, in accordance with some embodiments of the present disclosure. The HCU 100 can work as a central system to communicate with a plurality of electronic components and other controllers as shown in fig. 1. Present specification does not provide detailed explanation about the ECU, TCU, BMS, brake control unit, and MCU as a person skilled in the art would know about the functioning and the components of these controllers. The HCU 100 includes a processor(s) 102, an interface(s) 104, and a memory 106.
[0052] The processor(s) 102 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, logic circuitries, and/or any devices that manipulate data based on operational instructions.
[0053] Among other capabilities, the one or more processor(s) 102 are configured to fetch and execute computer-readable instructions and one or more routines stored in the memory 106. The memory 106 may store one or more computer-readable instructions or routines or maps which may be fetched and executed to determine lowest/minimum fuel consumption point for the engine.

The memory 106 may include any non-transitory storage device including, for example, volatile memory such as RAM, or non-volatile memory such as EPROM, flash memory, and the like.
[0054] The interface(s) 104 may include a variety of interfaces, for example, interfaces for data input and output devices referred to as I/O devices, storage devices, and the like. The interface(s) 104 may facilitate communication of the HCU 100, specifically, the communication unit 120 (as explained below) with various other controllers, such as ECU 300, TCU 200, MCU 400, receive driver input from the pedal. The interface(s) 104 may also provide a communication pathway for one or more components of the HCU 100. Examples of such components include, but are not limited to, processing unit(s) 108 and data 122.
[0055] The processing unit(s) 108 may be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the processing unit(s) 108. In examples described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the processing unit(s) 108 may be processor-executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the processing unit(s) 108 may include a processing resource (for example, one or more processors), to execute such instructions. In the present examples, the machine-readable storage medium may store instructions that, when executed by the processing resource, implement the processing unit(s) 108. In such examples, the HCU 100 may include the machine-readable storage medium storing the instructions and the processing resource to execute the instructions or the machine-readable storage medium may be separate but accessible to the HCU 100 and the processing resource. In other examples, the processing unit(s) 108 may be implemented as electronic circuitry to perform the functions.
[0056] In an aspect, the processing unit(s) 108 may include gear range determining unit 112, torque range determining unit 114, mass fuel flow

consumption determining unit 116, and a communication unit 120. The processing unit(s) 108 may include other unit(s) which may implement functionalities that supplement applications or functions performed by the HCU 100 or the processing unit(s) 108. As shown in fig. 3, a Driver Demand Torque (DDT) determining unit 110 and a target input value determining unit 118 provided as an input to the HCU 100. In an embodiment, these can be provided as part of the HCU 100 and coupled with other processing units to provide input for functioning of the processing units to achieve objective as defined.
[0057] Further, the data 122 may include data that is either stored or generated as a result of functionalities implemented by any of the components of the processing unit(s) 108. In some aspects, the data 122 may be stored in the memory 106 in the form of various data structures. Additionally, the data 122 can be organized using data models, such as relational or hierarchical data models. The data 122 may store data, including temporary data and temporary files, generated by the processing unit(s) 108 for performing the various functions of the HCU 100.
[0058] In the present subject matter, the data 122 may store a pedal map, traction map, engine torque map, motor torque map, fuel consumption map. The maps may be stored in the form of tables or lookup tables having values for each instant corresponding to the parameters. The stored predefined maps provide real¬time assistance in computation to the units of the processing unit(s) 108 to perform the action to determine the lowest/minimum fuel consumption point during acceleration of the vehicle at any instant.
[0059] The HCU 100 is coupled with a plurality of controllers for to-fro communication. The HCU 100 is also coupled with accelerator pedal and brake pedal to receive driver instructions in the form of acceleration, de-acceleration, and brake. Referring to fig. 2 and 3 together for better understanding of flow of information and working of the present subject matter, the HCU 100 coupled with

the acceleration pedal of the automatic hybrid vehicle to receive driver input for acceleration.
[0060] In operation, when the driver presses the acceleration pedal to demand the torque from the engine. The driver demand torque determining unit 110 of the HCU 100 is configured to determine driver demand torque based on the accelerator pedal pressed condition and consider the pedal input as driver input 501 (as shown in fig. 2). The driver demand torque determining unit 110 maps the percentage of pedal pressed condition with a pre-defined driver demand torque map 502 or pedal map 502 to determine the demanded torque at that instant.
[0061] The gear range determining unit 112 is configured to determine working gear range for the determined driver demand torque based on vehicle traction map 503.
[0062] The torque range determining unit 114 is configured to determine torque range of the engine for each of the determined probable gear from the determined working gear range, based on the traction map 503 from the engine torque curve of ECU 300 and Motor torque curve of MCU 400. Similarly, torque range of the electric motor (it can be interchangeably referred as motor), based on a motor torque map 504 from the MCU 400 for each of the determined gear from the determined working range of gears.
[0063] The mass fuel flow consumption determining unit 116 is configured to check battery state of charge (SOC) level 505 from the battery controller. The mass fuel flow consumption determining unit 116 is configured to determine, based on an engine fuel consumption map 506, mass fuel flow consumption for calculated torque range, when engine gets assist from motor and in engine load shift condition for each of the determined gear from the determined working range of gears when the battery SOC level 505 is more than a predefined minimum threshold battery SOC level value 'Th'. The predefined minimum threshold battery SOC level value 'Th' is considered to improve health of the battery and to improve life of the battery.

[0064] Further, the mass fuel flow consumption determining unit 116 is determine, based on the engine fuel consumption map 506, mass fuel flow consumption for torque range in engine load shift condition for each determined gear from the determined working range of gears when the battery SOC level 505 is less than a predefined minimum threshold battery SOC level value (Th).
[0065] The assist condition is a condition where the electric motor assists the engine to achieve the driver demand torque. The assist condition may be defined as X-Y = A where X is driver demand torque from the pedal map, Y is Motor torque from the motor torque map, and A is torque that is to be generated by the engine. In the assist condition, a portion of the required torque is being given by the electric motor. The engine is to generate less torque from the determined driver torque.
[0066] The engine load shift condition is a condition where the engine generates torque to charge the battery and fulfil the driver demand torque both at the same instant. The load condition is defined as X+Y = L where X is driver demand torque from the pedal map, Y is Motor torque from the motor torque map, and L is torque that is to be generated by the engine. The engine generates more torque as compared to the determined driver demanded torque where the extra torque is being supplied to charge the battery pack.
[0067] The target input values determining unit 118 is configured to determine lowest mass fuel flow consumption point from the determined range of the mass fuel flow consumption for each of the gear. The communication unit 120 is configured to communicate a target gear corresponding to the determined lowest mass fuel flow consumption point to the Transmission Control Unit (TCU) 200 for shifting the gear to the target gear and to run the vehicle at the target gear.
[0068] The target input values determining unit 118 is configured to communicate a target engine torque corresponding to the determined lowest mass fuel flow consumption point to the Engine Control Unit (ECU) 300 to run the engine at the target engine torque.

[0069] The target input values determining unit 118 is configured to communicate a target motor torque corresponding to the determined lowest mass fuel flow consumption point to the Motor Control Unit (MCU) 400 to run the electric motor at the target motor torque.
[0070] Exemplary illustration:
[0071] In the present example, hypothetical values are considered to explain the working and flow of the present subject matter.
[0072] Based on the acceleration pedal press condition where the driver presses 30% of acceleration pedal to achieve velocity of 50 Kmph and the driver demand torque determining unit 110 determine that demanded torque is 350 Nm at wheels. The gear range determining unit 112 determine that only Gear Gl, Gear G2, and Gear G3 are probable gears which can achieve desired vehicle speed at defined accelerator pedal pressing. Further, it is determined that in gear Gl engine requires torque of 25 Nm at 30% acceleration pedal pressed condition, in gear G2 engine requires torque of 35 Nm at 30% acceleration pedal pressed condition, and in gear G3 engine require torque of 45 Nm at 30% acceleration pedal pressed condition. The electric motor torque capacity is ±10Nm in gear Gl, ±15 Nm in gear G2, ±20 Nm in gear G3.
[0073] Further, the battery SOC level is 50% and threshold value 'Th' of the battery SOC level is 20%. When the battery SOC level is more than predefined threshold value which is true in the present example, the mass fuel flow consumption determining unit 116 determines mass fuel flow consumption for torque range in assist condition and in engine load shift condition for each of the determined gear from the determined working range of gears.

Gear Engine Motor torque Assist Fuel Lowest Fuel
torque based range based Engine consumption consumption
on traction on Motor Torque range point
map torque map range

(Assist and Load shift)
Gl 25 Nm ±10 Nm 15-35 Nm 1.7-2.1 kg/h 0.91
G2 35 Nm ±15 Nm 20-50 Nm 1.6-2.0 kg/h 0.94
G3 45 Nm ±20 Nm 25-65 Nm 1.8-2.4 kg/h 0.96
[0074] From the above determined data, the target input values determining unit 118 determine that Gear G2 with Engine torque 20 Nm and the electric motor torque 15 Nm with the lowest mass fuel flow consumption point, i.e., 1.6 kg/h is selected as target values for operating the transmission unit at gear G2, target value for engine torque is 20 Nm, and target value for the electric motor torque is 15 Nm.
[0075] In second scenario, where battery SOC level is below the threshold value, the HCU 100 determine a lowest fuel consumption point in Engine Load shift condition where engine generates a torque which can fulfil the driver demand and simultaneously can charge the battery at lowest fuel consumption point.
[0076] For example, the target input values determining unit 118 determine that Gear G2 with Engine torque 50 Nm with the lowest mass fuel flow consumption point, i.e., 2.0 kg/h is selected as target values for operating the transmission unit at gear G2, target value for engine torque is 50 Nm, and where extra 15 Nm is transferred to charge the battery pack.
[0077] Fig. 4a illustrates vehicle traction map for traction force available at wheels in different gears to generate motion in a vehicle. It also includes vehicle driving resistance force curve. The motion of vehicle is only possible when vehicle traction force is greater than total resistive forces. In this invention, this

map is used to check that in which all transmission gears, the desired vehicle speed can be achieved.
[0078] Fig. 4b illustrate fuel flow consumption map which represents contours of constant Fuel Consumption areas on engine torque-speed maps to show torque-speed combinations at which the engine will operate most efficiently. This map is used here to calculate actual fuel mass flow(Kg/h) taking into account specific fuel consumption (g/KWh) and engine power(KW).
[0079] FIG. 2 illustrates a method 600 of determining the lowest fuel flow consumption point to minimize instantaneous engine Fuel consumption in a hybrid electric vehicle during acceleration at any instant. The order in which the method 600 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any appropriate order to carry out the method 600 or an alternative method. Additionally, individual blocks may be deleted from the method 600 without departing from the scope of the subject matter described herein.
[0080] At block 601, the method 600 includes determining, from a driver demand torque map 502, a driver demand torque based on accelerator pedal pressed condition as driver input 501.
[0081] At block 603, the method 600 includes determining, based on traction map 503, working gear range for the determined driver demand torque.
[0082] At block 605, the method 600 includes determining torque range of the engine, based on the traction map 503 from the ECU 300 and torque range of the electric motor, based on a motor torque map 504, from the MCU 400 for each of the determined gear from the determined working range of gears.
[0083] At block 609, the method 600 includes determining, based on an engine fuel consumption map 506, mass fuel flow consumption for torque range in assist condition and in engine load shift condition for each determined gear from the determined working range of gears when the battery SOC level 505 is

more than a predefined minimum threshold battery SOC level value (Th) at block 607.
[0084] At block 611, the method 600 includes determining, based on the engine fuel consumption map 506, mass fuel flow consumption for torque range in engine load shift condition for each determined gear from the determined working range of gears when the battery SOC level 505 is less than a predefined minimum threshold battery SOC level value (Th) at block 607.
[0085] At block 613, the method 600 includes determining lowest mass fuel flow consumption point from the determined range of the mass fuel flow consumption.
[0086] At block 617, the method 600 includes communicating a target gear corresponding to the determined lowest mass fuel flow consumption point to the Transmission Control Unit (TCU) 200 to run the vehicle at the target gear.
[0087] At block 617, the method 600 includes communicating a target engine torque corresponding to the determined lowest mass fuel flow consumption point to the Engine Control Unit (ECU) 300 to run/operate the engine at the target engine torque.
[0088] At block 617, the method 600 includes communicating a target motor torque corresponding to the determined lowest mass fuel flow consumption point to the Motor Control Unit (MCU) 400 to operate the electric motor at the target motor torque.
[0089] Technical advantages:
[0090] When Battery charge level is greater than minimum level of allowed battery charge capacity, the HCU determine the target gear, target engine torque, and target motor torque to satisfy the driver demand in the assist condition and the engine load shift condition at lowest/minimum fuel consumption point. At any given instant, point of minimum fuel consumption point becomes the target point for engine operation.

[0091] If Battery charge level is lower than minimum level of allowed battery charge capacity, the engine runs in engine load shift condition till battery reaches a pre-defined SOC level.
[0092] With the implementation of the present subject matter, the automatic hybrid vehicle is operated at minimum instantaneous fuel flow consumption point (fuel consumption point) during acceleration at any instant.
[0093] The above description does not provide specific details of the manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art can choose suitable manufacturing and design details.
[0094] It should be understood, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, as apparent from the discussion herein, it is appreciated that throughout the description, discussions utilizing terms such as "receiving," or "setting," or "transmitting," or the like, refer to the action and processes of an electronic control unit, or similar electronic device, that manipulates and transforms data represented as physical (electronic) quantities within the control unit's registers and memories into other data similarly represented as physical quantities within the control unit memories or registers or other such information storage, transmission or display devices.
[0095] Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by

those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0096] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
[0097] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants and others.

We claim:

1. A hybrid Control Unit (HCU) (100) for improving instantaneous engine
fuel consumption of an automatic hybrid vehicle, where the automatic hybrid vehicle comprising an internal combustion engine coupled with an Engine Control Unit (ECU) (300), a battery device coupled with a battery controller and an electric motor where the electric motor is configured to apply torque to power transmission path where the electric motor is controlled by a Motor Control Unit (MCU) (400), and a Transmission control unit (TCU) (200) to control engagement of gears in transmission;
the hybrid control unit (HCU) (100) having a processor (102) and a memory (106), the HCU (100) comprising:
a driver demand torque determining unit (110) configured to determine, from a driver demand torque map (502), a driver demand torque based on accelerator pedal pressed condition as driver input (501);
a gear range determining unit (112) configured to determine, based on traction map (503), working gear range for the determined driver demand torque;
a torque range determining unit (114) configured to determine torque range of the engine, based on the traction map (503) from the ECU (300) and torque range of the motor, based on a motor torque map (504), from the MCU (400) for each of the determined gear from the determined working range of gears;
a mass fuel flow consumption determining unit (116) configured to:
determine battery state of charge (SOC) level (505) from the battery controller;
determine, based on an engine fuel consumption map (506), mass fuel flow consumption for torque range in assist condition and in engine load shift condition for each

determined gear from the determined working range of gears when the battery SOC level (505) is more than a predefined minimum threshold battery SOC level value (Th);
determine, based on the engine fuel consumption map (506), mass fuel flow consumption for torque range in engine load shift condition for each determined gear from the determined working range of gears when the battery SOC level (505) is less than a predefined minimum threshold battery SOC level value (Th); a target input values determining unit (118) configured to determine lowest mass fuel flow consumption point from the determined range of the mass fuel flow consumption; a communication unit (120) configured to:
communicate a target gear corresponding to the determined lowest mass fuel flow consumption point to the Transmission Control Unit (TCU) (200);
communicate a target engine torque corresponding to the determined lowest mass fuel flow consumption point to the Engine Control Unit (ECU) (300);
communicate a target motor torque corresponding to
the determined lowest mass fuel flow consumption point to
the Motor Control Unit (MCU) (400).
2. The hybrid Control Unit (HCU) (100) as claimed in claim 1, wherein the
assist condition is a condition where the electric motor assists the engine to
achieve the driver demand torque, the assist condition is defined as
X-Y = A where X is driver demand torque from the pedal map, Y is Motor torque from the motor torque map, and A is torque that is to be generated by the engine.

3. The hybrid Control Unit (HCU) (100) as claimed in claim 1, wherein the
load shift condition is a condition where the engine generates torque to
charge the battery and fulfil the driver demand torque, the load condition
is defined as
X+Y = L where X is driver demand torque from the pedal map, Y is Motor torque from the motor torque map, and L is torque that is to be generated by the engine.
4. The hybrid Control Unit (HCU) (100) as claimed in claim 1, wherein the determined lowest mass fuel flow consumption point is target for the engine operation.
5. The hybrid Control Unit (HCU) (100) as claimed in claim 1, wherein the vehicle traction map stores information about transmission gears and corresponding traction force available at wheels in all gears.
6. The hybrid Control Unit (HCU) (100) as claimed in claim 1, wherein the pedal map stores information of percentage of accelerator pedal pressed, desired vehicle speed and corresponding driver desired torque value.
7. The hybrid Control Unit (HCU) (100) as claimed in claim 1, wherein the engine fuel map stores information about engine torque and engine speed corresponding fuel consumption.
8. A method (600) for minimizing instantaneous engine fuel consumption of
an automatic hybrid vehicle, where the automatic hybrid vehicle comprising an internal combustion engine coupled with an Engine Control Unit (ECU) (300), a battery device coupled with a battery controller and an electric motor where the electric motor is configured to apply torque to power transmission path where the electric motor is controlled by a Motor Control Unit (MCU) (400), and a Transmission control unit (TCU) (200) to control engagement of gears in transmission;
the method (600) comprising:

determining (601), from a driver demand torque map (502), a driver demand torque based on accelerator pedal pressed condition as driver input (501);
determining (603), based on traction map (503), working gear range for the determined driver demand torque;
determining (605) torque range of the engine, based on the traction map (503) from the ECU (300) and torque range of the electric motor, based on a motor torque map (504), from the MCU (400) for each of the determined gear from the determined working range of gears;
determining (609), based on an engine fuel consumption map (506), mass fuel flow consumption for torque range in assist condition and in load condition for each determined gear from the determined working range of gears when the battery SOC level (505) is more than a predefined minimum threshold battery SOC level value (Th);
determining (611), based on the engine fuel consumption map (506), mass fuel flow consumption for torque range in engine load shift condition for each determined gear from the determined working range of gears when the battery SOC level (505) is less than a predefined minimum threshold battery SOC level value (Th);
determining (613) lowest mass fuel flow consumption point from the determined range of the mass fuel flow consumption; and
communicating (617) a target gear corresponding to the determined lowest mass fuel flow consumption point to the Transmission Control Unit (TCU) (200);
communicating (617) a target engine torque corresponding to the determined lowest mass fuel flow consumption point to the Engine Control Unit (ECU) (300);

communicating (617) a target motor torque corresponding to the determined lowest mass fuel flow consumption point to the Motor Control Unit (MCU) (400).
9. The method (600) as claimed in claim 8, wherein the assist condition is a
condition where the electric motor assists the engine to achieve the driver
demand torque, the assist condition is defined as
X-Y = A where X is driver demand torque from pedal map, Y is Motor torque from the motor torque map, and A is torque that is to be generated by the engine.
10. The method (600) as claimed in claim 1, wherein the load condition is a
condition where the engine generates torque to charge the battery and
fulfil the driver demand torque, the load condition is defined as
X+Y = L where X is driver demand torque from the pedal map, Y is Motor torque from the motor torque map, and L is torque that is to be generated by the engine.
11. The method (600) as claimed in claim 1, wherein the determined lowest
mass fuel flow consumption point is target fuel flow consumption point
for the engine operation.