DESC:TECHNICAL FIELD
[0001] The present subject matter relates generally to a vehicle and more particularly to an engine management system for a vehicle.
BACKGROUND
[0002] Manufacturers have been trying to reduce fuel consumption of internal combustion engines. However, much of the effort was focused on fuel efficiency of the engines itself. Consequently, many manufacturers use smaller engines with forced air injection and fuel injection. Conventionally, research is also focused on technologies that aid in efficient and reduced consumption of fuel, to effectively reduce pollution and global warming. But even after almost half a century of efforts, the most efficient internal combustion engines that only use a single type of fuel and lose about 65% - 80% of the fuel energy as heat upon combustion.
[0003] Some known arts disclose about multi cylinder engines which are configured to switch ‘OFF’ one or more cylinders, while the vehicle cruise at low speeds, particularly when high performance is not required. Some other known arts disclose recommended ideal range of engine speed and vehicle speed to achieve the highest possible fuel economy. One of the most effective and easiest ways of conserving fuel include switching ‘OFF’ the engine, while waiting at a traffic stop, or similar short duration stops.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments. The same numbers are used throughout the drawings to reference like features and components.
[0005] Figure 1 illustrates a side perspective view of a single cylinder internal combustion engine, according to an embodiment of the present subject matter.
[0006] Figure 2a illustrates a side perspective view of a portion of the engine without a crankcase assembly, according to an embodiment of the present subject matter.
[0007] Figure 2b shows the internal construction as shown in cut section view of camshaft assembly inside a cylinder head of an engine.
[0008] Figure 3 illustrates a block diagram of an engine management system (EMS) of an internal combustion engine, in accordance with at least an embodiment of the present subject matter.
[0009] Figure 4a illustrates is a block diagram representing the process implemented by the engine management system, in a single cylinder engine, in accordance with an embodiment of the present subject matter.
[00010] Figure 4b illustrates a flow chart representing the process, which is implemented by the engine management system, in a single cylinder engine, in accordance with an embodiment of the present subject matter.
[00011] Figure 5a illustrates is a block diagram representing the process implemented by the engine management system, in a multi cylinder engine, in accordance with an embodiment of the present subject matter.
[00012] Figure 5b illustrates a flow chart representing the process, which is implemented by the engine management system, in a multi cylinder engine, in accordance with an embodiment of the present subject matter.
DETAILED DESCRIPTION
[00013] As a means of saving fuel, riders are often encouraged to turn ‘OFF’ the engine of the vehicle, temporarily during traffic stops or waiting for a passenger. This has been a conventional practice, that has been followed by riders all around the globe. To generalize this practice the modern vehicles now come equipped with special sensors. These sensors can detect the idling time of a vehicle, especially when the vehicle idles for more than a threshold time. Some of these vehicles give reminders to the riders to switch ‘OFF’ the engine when the vehicle has been idling for a prolonged time. Some other vehicles include an vehicle control unit (VCU) which is capable of automatically switching ‘OFF’ of the engine of the vehicle, once the vehicle idle time is more than the threshold time.
[00014] Such automatic switching ‘OFF’ of engine, once the vehicle’s idle time crosses the threshold time, is commonly known as an Integrated Start – Stop system, or the ISS system. Mostly the vehicles having the ISS system, also include a manual switch integrated with the instrument cluster or placed in proximity of the instrument cluster. This switch enables the rider to manually choose the activation and deactivation of the ISS system in the vehicle. Some other vehicles also include an indication system, for example, an indicator lamp, to indicate the rider about the activation status of the ISS system.
[00015] The automatic start-stop function in modern automobiles is a vital instrument in improving the fuel economy of the vehicle. It saves fuel costs for the owner/rider. Further, the ISS system also ensures reduction in overall pollution produced by the vehicle, by switching the vehicle ‘OFF’ when the vehicle is not in use.
[00016] Some known arts suggest, actuation of the ISS start involving inputs from the rider. Such inputs often include one or more changes of state of one or more movable parts of the vehicle, e.g., the throttle, the clutch pedal / lever and the gear shifter. For brevity, hence forth the clutch actuating mechanism is a lever as available in two-wheeler vehicles, as opposed to a pedal which is more commonly found in four wheelers. The manufacturers often provide a combination of changes of states in one or more of these movable parts. The most used combination is that of a change in state of the clutch lever and a change in state of the throttle. However, this often results in false start of the vehicle, as it is common for drivers to fiddle with the movable parts while stopping for a small duration of time.
[00017] Most automobiles achieve ISS start-stop function by automatically switching ‘OFF’ the ignition, when a set of predetermined stop conditions are satisfied. After the stop, the vehicle can be restarted by following simpler steps, rather than repeating the initial starting procedure of the vehicle. This is because restarting the vehicle by repeating a lengthy process of starting can potentially discourage the driver/owner from having the ISS system installed in their vehicle, in the first place.
[00018] Moreover, the method of switching ‘OFF’ the ignition of the engine, every time the rider/driver uses the ISS stop, is detrimental to the fuel economy of the vehicle. This is because, even after the ignition is switched ‘OFF’, the fuel injection takes some to completely stop its function, resulting into accumulation of small amount of fuel inside the combustion chamber of the engine. Therefore, the remaining fuel stays unburnt in the combustion chamber. However, when the vehicle is restarted, fresh fuel is injected into the combustion chamber, resulting in accumulation of more than required fuel, especially during the first few compression and power strokes of the engine. This results in emission of unburnt hydrocarbons as the fuel accumulated from the previous cycle does not burn completely.
[00019] Thereby, some known arts disclose actuation of the ISS start without involving the switching ‘ON’ of the ignition of the vehicle. Such known arts further disclose that the ignition of the vehicle is only switched ‘ON’ while the vehicle is started by the rider for the first time. Later the vehicle does not require switching ‘OFF’ the ignition, when every time the rider/driver stops using the ISS stop function. This is because the system switches ‘OFF’ the internal combustion engine when the vehicle stops at a stop light or during stop and go traffic where the vehicle would normally idle for a minimum of three to five seconds. The engine is then automatically restarted when the driver is ready to proceed. Further the VCU determines an appropriate time to switch ‘OFF’ the engine based on data from various sensors 410.
[00020] Some other known arts suggest cutting ‘OFF’ the fuel supply or stopping the fuel injection by the ISS system upon certain conditions being met. However, often it is seen that the ISS stop causes the stopping of the fuel injection abruptly, again resulting into accumulation of small amount of fuel inside the combustion chamber of the engine. Therefore, the remaining fuel stays unburnt in the combustion chamber. However, when the vehicle is restarted, fresh fuel is injected into the combustion chamber, resulting in accumulation of more than required fuel, especially during the first few compression and power strokes of the engine. This results in emission of unburnt hydrocarbons as the fuel accumulated from the previous cycle does not burn completely.
[00021] Such accumulated fuel does not only affect the fuel economy of the vehicle, but also causes emission of the unburnt hydrocarbons resulting into air pollution. This present invention seeks to provide a solution to the above-mentioned problem.
[00022] Furthermore, addressing the problem of accumulated fuel, is more complicated if the engine being used is a multi-cylinder engine. This is because during the ISS stop the position of the pistons in the multi-cylinder engine is not monitored. Further, since the multi-cylinder engine uses synchronous sparking in the combustion chamber of each of the multi-cylinder. Thereby, when the ISS stop is performed, and the functioning of the engine is stopped abruptly, the last position of the pistons in each cylinder remains unknown. Thereby, upon using the ISS start to start the engine of the vehicle, the regular synchronous sparking is performed irrespective of the last position of the pistons. Such regular synchronous sparking leads to delayed starting of the engine, which is not desirable.
[00023] For instance, if the multi-cylinder engine includes four cylinders and as per the regular synchronous sparking the first sparking during the first stroke is configured to occur in the second cylinder and the fourth cylinder. However, when the ISS stop is used the functioning of the engine is stopped abruptly; leaving the last position of the piston in the first cylinder and the third cylinder near the Top dead center (TDC) of the combustion chamber. The positioning of the piston near the TDC of the combustion chamber signifies, the engine being in compression stroke. As during the compression stroke, fuel is accumulated within the combustion chamber, thereby some fuel from the last stroke remains accumulated in the combustion chambers of the first cylinder and the third cylinder. Therefore, there arises a need of the first sparking in the first cylinder and the third cylinder, once the functioning of the engine is restored, using the ISS start.
[00024] However, once the functioning of the engine is restored, due to the pre-configured regular synchronous sparking the first sparking during the first stroke occurs in the second cylinder and the fourth cylinder., Subsequently the second sparking occurs in the first cylinder and the third cylinder, causing a delay in the starting of the engine. This present invention seeks to also provide a solution to the above-mentioned problem.
[00025] Therefore, there is a need of improving fuel economy, startability of the engine and at the same time reducing hydrocarbon emission during automatic start of a vehicle after an automatic stop of the vehicle.
[00026] Hence, there is a need of addressing the above circumstances and problems of the known arts.
[00027] The present subject matter has been devised in view of the above circumstances as well as solving other problems of the known art.
[00028] The present subject matter discloses about an engine management system for a vehicle. The engine management system comprises of a vehicle control unit, a processor, a transceiver, a sensor unit, a piston position detection unit, a cylinder selection unit, an estimation unit, and an injector unit.
[00029] The engine management system is configured to enable a start-stop system of the vehicle, subsequent to achieving the pre-determined integrated start-stop conditions.
[00030] As per an aspect of the present subject matter, the pre-determined integrated start-stop (ISS) conditions include vehicle being in idling state for more than a pre-defined time period, wherein the pre-defined time period ranges between 5 seconds and 30 seconds.
[00031] Further, the present subject matter discloses about the engine management system which is capable to determining the position of at least one piston of at least one cylinder of the engine by means of one or more sensors.
[00032] As per an aspect of the present subject matter, the one or more sensors include at least one of a crankshaft position sensor and a crank angle sensor being disposed near a crankshaft. The at least one of a crankshaft position sensor and a crank angle sensor senses the position of the crankshaft. The data from the at least one of a crankshaft position sensor and a crank angle sensor is received by the sensor unit. Based on the data received from the at least one of a crankshaft position sensor and a crank angle sensor, the sensor unit in conjunction with the piston position detection unit estimates the position of said at least one piston of cylinders of the engine.
[00033] Further, the engine management system can estimate the residual fuel within the at least one cylinder of the engine and determining the required fuel within the at least one cylinder of the engine. The required fuel is the fuel required for complete combustion of the fuel in the combustion chamber for the first few strokes, when the functioning of the engine is restored using ISS start function.
[00034] As per an aspect of the present subject matter, one or more cam lobe sensors sense the opening and closing of an inlet valve and an exhaust valve and share the data with the sensor unit. The estimation unit in conjunction with the sensor unit estimates the residual fuel in a combustion chamber of the at least one of the cylinders of the engine.
[00035] As per another aspect of the present subject matter, the determination of the injection of the fuel required within a combustion chamber of the engine is deduced by deducting the estimated residual fuel from a pre-defined fuel injected within a combustion chamber of at least one of the cylinders of the engine.
[00036] Further, the engine management system is also configured to perform sparking by means of a spark plug, within the at least one cylinder of the engine, subsequent to completion of injection of the required fuel within the at least one cylinder of the engine.
[00037] Exemplary embodiments detailing features regarding the aforesaid and other advantages of the present subject matter will be described hereunder with reference to the accompanying drawings. Various aspects of different embodiments of the present invention will become discernible from the following description set out hereunder. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof. Further, it is to be noted that terms “upper”, “down”, “right”, “left”, “front”, “forward”, “rearward”, “downward”, “upward”, “top”, “bottom”, “exterior”, “interior” and like terms are used herein based on the illustrated state or in a standing state of the two wheeled straddle type vehicles with a user riding thereon. Furthermore, arrows wherever provided in the top right corner of figure(s) in the drawings depicts direction with respect to the vehicle, wherein an arrow F denotes front direction, an arrow R indicates rear direction, an arrow Up denotes upward direction, an arrow Dw denotes downward direction, an arrow RH denotes right side, and an arrow LH denotes left side. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[00038] Figure 1 illustrates a side perspective view of a single cylinder internal combustion engine 100, according to an embodiment of the present subject matter. The internal combustion engine 100, herein called as an engine 100, includes a cylinder block 102 supported by a crankcase assembly 101 of the engine 100. The cylinder block 102 defines a cylinder portion at which a piston can perform reciprocating motion. A cylinder head 103 is mounted to the cylinder block 102 and the cylinder head 103 acts as one end of the cylinder portion. The cylinder block 102 is provided with cooling fins 106 and the cylinder head 103 may be provided with the cooling fins 106.
[00039] A piston (not shown) performs the reciprocating motion in the cylinder portion due to force imparted to it by the combustion of air-fuel mixture. This reciprocating motion is converted and transferred to a rotary motion of a crankshaft 110 through a connecting rod (not shown). Further, a cylinder head-cover 104 is mounted to the cylinder head 103. The crankcase assembly 101 rotatably supports the crankshaft 110. Further, an electric machine like a magneto assembly 111 or an integrated starter generator is mounted to the crankshaft 110. The magneto assembly 211 is configured to rotate along with the crankshaft 110 to generate power which recharges a battery (not shown).
[00040] The cylinder head 103 includes an intake port 105 and an exhaust port (not shown) that are provided on a first face and a second face of the cylinder head 103. In the present embodiment, the first face is an upward facing side and the second face is a downward facing side thereof. Further, the cylinder head 103 supports a camshaft assembly (not shown) that is capable of operating intake valve(s) and exhaust valve(s) of the engine 100.
[00041] Typically, the transmission assembly of the engine 100 includes a spring-loaded multiplate friction clutch assembly 107 fixedly attached to the left-hand portion of the crankshaft 110 using plurality of fastening means. The clutch assembly 107 ensures that the power transmission from the engine 100 is engaged and disengaged to one or more rear wheel (not shown) of a vehicle based on rotational speed of the internal combustion engine 100.
[00042] Figure 2a illustrates a side perspective view of a portion of the engine 100 without a crankcase assembly 101 (shown in Figure 1), according to an embodiment of the present subject matter. The present illustration illustrates a cylinder block 102, a cylinder head 103 and a cylinder head cover 104. The cylinder block 102 and the cylinder head 103 are mated along a plane XX’ (shown by dotted line).
[00043] The cylinder head 103 comprises a valve train arrangement to control opening and closing of intake and exhaust valves disposed at the intake port 105 (shown in Figure 1) and one or more exhaust ports (not shown), thereby controlling intake of air-fuel mixture and outlet of exhaust gases. The camshaft assembly (not shown) is rotatably mounted to the cylinder head 103. A cam chain (not shown) operably connects the crankshaft 110 and camshaft assembly.
[00044] Usually, in spark ignition engines 100, the cylinder block 102 along with the cylinder head 103 is configured as a combustion chamber (not shown), to facilitate ignition of the fuel and air mixture. The cylinder block 102 is configured to facilitate reciprocating movement of the piston (not shown). The piston is housed inside the cylinder bore 108 of the cylinder block 102 along with a cam chain or a timing chain and a cylinder liner (not shown). The piston is connected to the crankshaft 110 (shown in Figure 1) on one end, through a connecting rod (not shown).
[00045] Generally, the engines 100 are either single cylinder engines or multi cylinder engines. Both the single cylinder engine or multi cylinder engine can be either two-stroke or four-stroke engines. The two-stroke engines typically have a single piston (not shown) and a crankcase assembly 101. In such engines, the crankcase assembly 101 is used for the gas exchange. The two-stroke engines also have a spark plug 109 (shown in Figure 2a) and the intake port 105 (shown in Figure 1) as well as an exhaust port. A crucial difference between the two stroke and the four-stroke engine lies in the presence of a transfer port in the two-stroke engine.
[00046] The two-stroke engine completes a power cycle with two strokes (up and down movements) of the piston during only one crankshaft 110 revolution. In the first stroke cycle, a first fuel air mixture is drawn via the intake port 105. Therefore, the fuel air mixture is added to the existing mixture in the crankcase assembly 101. At the same time the mixture is compressed in the combustion chamber and ignited by the spark plug 109, which further initiates the second cycle. During the second cycle, the hot air expands and pushes the piston downwards increasing the volume of the combustion chamber resulting in the release of hot burned gases from the exhaust port of the ongoing cycle. Because of the downward motion of the piston, a fresh air fuel mixture which was sucked in during the compression of the previous cycle is now forced into the combustion chamber via a transfer port. At the same time the fresh air fuel mixture scavenges out the remains of the burned gases from the previous combustion cycle via an opened exhaust port.
[00047] In a four-stroke engine, the power is produced in the engine by a four-stroke process. Firstly, during the movement of the piston towards the bottom dead centre of the internal combustion engine 100 from a top dead centre, a vacuum is created in the combustion chamber. Due to the created vacuum, the air fuel mixture is sucked in via the intake valve (s), filling the combustion chamber with a fresh charge enriched with oxygen and hydrocarbons. Secondly, the intake valve closes, and the piston moves upward towards the top dead centre results in gradual compression of the air fuel mixture. This compression stroke develops a pressure within and increases the in-cylinder temperature making the air fuel mixture ready for combustion.
[00048] While the compression stroke is in progress, and the piston is few crank degrees behind the top dead centre, an approximate of 25000 V of energy stepped up by the ignition coil (not shown), is transferred to the spark plug 109 generating a spark across its electrodes, which further ignites the compressed charge. Further, the burned charge followed by a flame front travel all along the combustion volume and reaches the last unburned charge molecule, resulting in complete combustion by igniting the whole mixture. Furthermore, during the expansion stroke, due to the burning of the air fuel mixture, the pressure of the combustion chamber increases which results in the movement of the piston from the top dead centre to the bottom dead centre. Lastly, in the exhaust stroke, i.e., the fourth stroke, the piston moves from the bottom dead centre to the top dead centre, pushes the burned exhaust gases out of the combustion chamber via the exhaust port.
[00049] Thereby, all strokes occur or are driven by the reciprocating movement of the piston along with opening and closing of one or more inlet valve and one or more exhaust valve (not shown). As the piston compresses the fuel and air mixture and contacts the spark generated by a spark plug 109 disposed on the cylinder head 103; the mixture is combusted, and exhaust gases are pushed out of the combustion chamber.
[00050] Figure 2b shows the internal construction as shown in cut section view of camshaft assembly inside a cylinder head 103 of an engine 100. As illustrated, the engine 100 has the cylinder head 103, the cylinder block 102, the camshaft (not shown), a rocker arm (not shown), the intake valve (not shown) disposed at the intake port 105 (shown in Figure 1), the exhaust valve (not shown) disposed at the exhaust port (not shown), a connecting rod (not shown) with a smaller end and a bigger end, and a crank-web (not shown). The connecting rod smaller end is connected to the piston at one end and to the crank-web at the other end through its bigger end. During combustion, the piston is pushed downwards, the smaller end is pushed downwards, it provides a rotator motion to the crank web, and hence, the connecting rod bigger end along with the crank web rotates. The rotation of the crank web provides the synchronized rotation to the camshaft through a cam chain (not shown). The camshaft is equipped with two cam lobes, i.e. a camshaft first lobe 114 and a camshaft second lobe 113. Usually, a camshaft inner 115 is rigidly attached to the inner race of the bearing 112, 117. The outer race of the bearings 112, 117 is fixed with an interference fit or rigidly fixed to the cylinder head 103 portion thereby allowing the camshaft along with the camshaft first lobe 114 and the camshaft second lobe 113 to rotate on a camshaft axis. The camshaft first lobe 114 operates the inlet valve and the camshaft second lobe 113 operates the exhaust valve. The camshaft first lobe 114 and the camshaft second lobe 113 are joined to the camshaft outer 54.
[00051] The profile of the camshaft first lobe 114 and the camshaft second lobe 113 defines the opening and closing of the inlet and exhaust valves. The rocker arm moves on its axis, and degree of movement is being decided by the profile of the cam of the camshaft. Depending upon the movement of the rocker arm, the intake valve stem and exhaust valve movement is controlled thus it may close or open the passage of inlet and exhaust. Thereby, the opening and closing of intake and exhaust valves is controlled through plurality of lobes on the outer periphery of the camshaft.
[00052] Figure 3 illustrates a block diagram of an engine management system (EMS) 400 of an internal combustion engine 100, in accordance with at least an embodiment of the present subject matter. The engine management system 400 is configured to control the operation of an engine 100 of the vehicle. In an embodiment the engine management system 400 comprises of a vehicle control unit (VCU) 409, a processor 401, a transceiver 403, and a plurality of units (404, 405, 406, 407, 408). The processor 401 may be communicatively coupled to the memory 402, the transceiver 403, and the plurality of units (404, 405, 406, 407, 408).
[00053] The VCU 409 also called as a vehicle control unit (VCU) is used for controlling the amount of fuel, duration of fuel injection, amount of air, and receiving temperature of engine, temperature of air intake etc. from various sensors 410. More specifically, the engine 100 temperature sensor senses the temperature of the internal combustion engine 100, and an intake air sensor senses the temperature of ambient air. These parameters are used by VCU 409 for the EFI system for functioning of the engine 100. Usually, the VCU 409 with the help of various sensors 410 such as intake air temperature sensor, the engine temperature sensor etc. monitors the air fuel ratio for the combustion of the engine 100.
[00054] The processor 401 may include suitable logic, circuitry, interfaces, and/or code that may be configured to execute a set of instructions stored in the memory 402. The processor 401 may be implemented based on several processor technologies known in the art. The processor 401 may work in coordination with the transceiver 403, the plurality of units involved (404, 405, 406, 407, 408), and process the received data
[00055] The memory 402 may include suitable logic, circuitry, interfaces, and/or code that may be configured to store the set of instructions, which are executed by the processor 401.
[00056] The transceiver 403 may include suitable logic, circuitry, interfaces, and/or code that may be configured to receive the information from the plurality of units. The transceiver 403 may further be configured to transmit information to the VCU 409. The transceiver 403 may implement one or more known technologies to support wired or wireless communication with the VCU 409. The transceiver 403 may communicate via wireless communication with networks, such as the Internet, an Intranet and/or a wireless network, such as a cellular telephone network, a wireless local area network (LAN) and/or a metropolitan area network (MAN).
[00057] The processor 401, the memory 402, the transceiver 403, and the plurality of units (404, 405, 406, 407, 408) may be communicatively coupled to the VCU 409. The plurality of units (404, 405, 406, 407, 408) includes a sensor unit 404, a piston position detection unit 405, a cylinder selection unit 406, an estimation unit 407, and an injector unit 408.
[00058] The sensor unit 104 processes the data received from the plurality of the sensors 410. The Piston position detection unit 405 in conjunction with the sensor unit 104, detects the position of the piston in each cylinder of the internal combustion engine 100. The cylinder selection unit 406, works in conjunction with the piston position detection unit 405. Based on the position of the piston, the cylinder selection unit 406 selects the one or more optimum cylinder of the multi-cylinder engine 100, in accordance with an embodiment of the present subject matter.
[00059] The Estimation unit 407 in conjunction with the sensor unit 404, estimates the amount of existing fuel in the one or more optimum cylinder. Further the estimation unit 407, estimates the amount of required fuel to be injected in the earlier identified one or more optimum cylinder. The required fuel is the fuel required for complete combustion of the fuel in the combustion chamber for the first few strokes, when the functioning of the engine is restored using ISS start function.
[00060] The Injection unit 408 works in conjunction with the estimation unit 407. Based on the estimated amount of required fuel to be injected in the one or more optimum cylinder, the injector unit 408, guides the injector of the one or more optimum cylinder to inject the fuel in the combustion chamber of the one or more optimum cylinder.
[00061] Figure 4a illustrates is a block diagram 200 representing the process implemented by the engine management system 400 (shown in Figure 3), in a single cylinder engine 100, in accordance with an embodiment of the present subject matter. Figure 4b illustrates a flow chart 209 representing the process which is implemented by the engine management system 400 (shown in Figure 1), in a single cylinder engine 100, in accordance with an embodiment of the present subject matter.
[00062] According to the present subject matter, the rider is required to manually select 201 the ISS feature provided on the vehicle. In an embodiment, such manual selection of the ISS feature is done by means of selecting an option of ISS feature on the instrument cluster of the vehicle. Further the VCU 409 (shown in Figure 3) in conjunction with the sensor unit 404 (shown in Figure 3), determines whether the pre-determined integrated start-stop conditions are met. Herein, the pre-determined integrated start-stop conditions include idling of the engine 100 of the vehicle 202 for more than a pre-defined time. The pre-defined time can range between 5 seconds and 30 seconds. Once it is ascertained by the VCU 409, that the vehicle is in idling state for more than the pre-defined time, the functioning of the engine 100 is stopped, bringing the vehicle to a halt. Thereby, the process starts 210 when the VCU 409 of the vehicle checks weather the ISS stop conditions are met and the vehicle is stopped using ISS stop 211. If No ‘a’, i.e. if the ISS stop conditions are not met and the vehicle does not stop. The VCU 409 waits until the ISS Stop conditions are met and the functioning of the engine stops 212. Once the functioning of the engine stops using ISS stop, i.e. Yes ‘b’, the process moves to the next step.
[00063] In an embodiment, at least one crankshaft position sensor or at least a crank angle sensor are disposed near the crankshaft 110 of the single cylinder engine 100. The at least one crankshaft position sensor or at least one crank angle sensor senses the position of the crank in its rotation. The sensor unit 404 receives the data from the at least one crankshaft position sensor or at least one crank angle sensor and shares the data with the piston position detection unit 405. The piston position detection unit 405 aid in estimating the position of the piston of the cylinder of the engine 100.
[00064] The VCU 409 based on data received by the piston position detection unit 405, checks whether the position of the piston in the single cylinder engine 100 is determined 213. If the position of the piston is determined 204, i.e. Yes ‘b’, the process moves to the next step. Else, i.e. No ‘a’, the VCU 409 waits until the position of the piston is determined 214.
[00065] Once the position of the piston is determined 204, based on the vicinity of the piston from the TDC, the estimation unit 407 estimates the residual fuel left out unburnt in the combustion chamber of the cylinder. The position of the piston from the TDC, aid in determining the last stroke in which the engine 100 was, when the functioning of the engine 100 was stopped abruptly while using the ISS stop.
[00066] As described under Figure 2a, the profile of the camshaft first lobe 114 and the camshaft second lobe 113 defines the opening and closing of the inlet and exhaust valves. Thereby, as an embodiment, the cam lobe sensors (not shown) are disposed on the camshaft first lobe 114 and the camshaft second lobe 113, to sense the opening and closing of the inlet and exhaust valves. The sensor unit 404 receives the data regarding the opening and closing of the inlet and exhaust valves from the cam lobe sensors.
[00067] Based on the opening and closing of the inlet valve, and the pre-determined amount of fuel injected by the injector within each opening and closing of the inlet valve, the estimation unit 407 in conjunction with the sensor unit 404, estimates the residual fuel in the combustion chamber of the cylinder. Further, the VCU 409 checks whether the residual fuel is determined 215. If yes ‘b’, the VCU 409 determines the injection of the required fuel within the combustion chamber 206.
[00068] The determination of the injection of the required fuel within the combustion chamber of the engine 206 is done by deducting the estimated residual fuel from the pre-defined fuel normally injected within the combustion chamber in between opening and closing of the inlet valve.
[00069] The VCU 409 checks whether the amount of the fuel to be injected is determined 217 by the estimation unit 407. If No ‘a’, the VCU 409 waits 218 until the fuel to be injected is determined by the estimation unit 407. If Yes ‘b’, i.e. once the fuel to be injected is estimated by the estimation unit 407, the injector unit 408 sends signal to the injector of the engine 100, to inject the estimated fuel, once the functioning of the engine 100 is restored by means of the ISS system 207. Once the functioning of the engine 100 is restored and the estimated fuel is injected, an approximate of 25000 V of energy stepped up by the ignition coil (not shown), is transferred to the spark plug 109, generating a spark across its electrodes 208, 219, which further ignites the compressed charge.
[00070] Since the estimated residual fuel is taken into consideration while injecting the required fuel, better fuel economy is obtained. This is because the present subject matter ensures zero wastage of the fuel, particularly zero wastage of the residual fuel already present in the combustion chamber of the one or more optimum cylinder, from the last abrupt stopping of the functioning of the engine 100.
[00071] Furthermore, the present subject matter also ensures reduced emission of the fuel. This is because overall emission of the unburnt hydrocarbons are curbed, especially the unburnt hydrocarbons produced because of the unburnt residual fuel already present in the combustion chamber of the one or more optimum cylinder, from the last abrupt stopping of the functioning of the engine 100.
[00072] In many vehicles cranking, i.e. turning the crankshaft 110 in order to start the engine 100, is done till the state of charge of the battery is reduced to a predetermined minimum voltage. However, it is seen that if customer is continuously cranking the vehicle unsuccessfully by using a first feature, vehicular machinery damage, reduction of battery life and fuel wastage is caused. Herein, the first feature, for e.g. IDSS mode, enables multiple cranking in the same ignition key cycle. In an embodiment, the unsuccessful cranking of the engine 100, based on the engine 100 speed is identified. The unsuccessful cranking indicates the engine 100 is failing to reach a first pre-defined engine speed within a first pre-defined time required for cranking. The first pre-defined engine speed ranges in between 100rpm and 700rpm, and the first pre-defined time required for cranking ranges in between 0.5 seconds and 4 seconds.
[00073] Further the number of unsuccessful cranking of the engine 100 beyond a predetermined number of times is determined. And ultimately, the Integrated Start Stop feature is disabled upon determination of number of unsuccessful cranking of the engine 100 beyond the predetermined number of times. Herein, the predetermined number of times of unsuccessful cranking ranges in between 5 to 8 times. Thereby, the automatic ISS feature of the vehicle is disabled, if the number of unsuccessful cranking by an Integrated Start Stop Controller (ISG Controller) is more than a predetermined value. Herein, the counting of the unsuccessful crank by ISG controller is termed as a Failed start counter value. The usage of failed start counter value to determine disabling of the ISS feature and the IDSS mode of the vehicle ensures reduced machine damage, reduction in battery drainage, and reduction in the fuel wastage.
[00074] Figure 5a illustrates is a block diagram 300 representing the process implemented by the engine management system 400 (shown in Figure 3), in a multi cylinder engine 100, in accordance with an embodiment of the present subject matter. Figure 5b illustrates a flow chart 309 representing the process which is implemented by the engine management system 400 (shown in Figure 1), in a multi cylinder engine 100, in accordance with an embodiment of the present subject matter.
[00075] According to the present subject matter, the rider is required to manually select the ISS feature provided on the vehicle 301. In an embodiment, such manual selection of the ISS feature is done by means of selecting an option of ISS feature on the instrument cluster of the vehicle. Further the VCU 409 (shown in Figure 3) in conjunction with the sensor unit 404 (shown in Figure 3), determines whether the engine 100 of the vehicle is in idling state for more than a pre-defined time 302. The pre-defined time 302 can range between 5 seconds and 30 seconds. Once it is ascertained by the VCU 409, that the vehicle is in idling state for more than the pre-defined time, the functioning of the engine 100 is stopped using ISS stop 303, halting the vehicle. Thereby, the process starts 310 when the VCU 409 of the vehicle checks weather the ISS stop conditions are met and the functioning of the engine 100 is stopped using the ISS stop 311. If No ‘a’, i.e. if the ISS stop conditions are not met and the functioning of the engine 100 does not stop. The VCU 409 waits until the ISS Stop conditions are met and the functioning of the engine 100 stops 312. Once the functioning of the engine stops using ISS stop, i.e. Yes ‘b’, the process moves to the next step.
[00076] The VCU 409 based on data received by the piston position detection unit 405, checks whether the position of piston of each cylinder of the engine 100 is determined 313. If the position of the piston of each cylinder of the engine 100 is determined 304, i.e. Yes ‘b’, the process moves to the next step. Else, i.e. No ‘a’, the VCU 409 waits until the position of the piston of each cylinder of the engine 100 is determined 314.
[00077] In an embodiment, at least one crankshaft position sensor or at least a crank angle sensor are disposed near the crankshaft 110 of the multicylinder engine 100. The at least one crankshaft position sensor or at least one crank angle sensor senses the position of the crank in its rotation. The sensor unit 404 receives the data from the at least one crankshaft position sensor or at least one crank angle sensor and shares the data with the piston position detection unit 405. The piston position detection unit 405 aid in estimating the position of each cylinder of the engine 100.
[00078] Once the position of the piston of each cylinder of the engine 100 is estimated, the VCU 409 identifies the at least one cylinder having the piston near the TDC of the combustion chamber, as a one or more ‘optimum cylinder’ 304. It is to be noted, that usually in a multi-cylinder engine 100, at any point of time the pistons of at least two cylinders are near the TDC and the pistons of at least two cylinders are away from the TDC. Herein the identification of the one or more optimum cylinder 304, is based on the position of the piston being near the TDC, signifies that the one or more optimum cylinder 304 was in the compression stroke when the functioning of the engine 100 was abruptly stopped using the ISS stop function. Thereby, due to abrupt stopping of the functioning of the engine, the unburnt fuel remained accumulated in the combustion chamber of the one or more cylinders near the TDC. Once the position of the piston within the one or more optimum cylinder is determined 304, the estimation unit 407 estimates the residual left out unburnt fuel in the combustion chamber of the optimum cylinder 305.
[00079] As described under Figure 2a, the profile of the camshaft first lobe 114 and the camshaft second lobe 113 defines the opening and closing of the inlet and exhaust valves. Thereby, as an embodiment, the cam lobe sensors (not shown) are disposed on the camshaft first lobe 114 and the camshaft second lobe 113, to sense the opening and closing of the inlet and exhaust valves. The estimation unit 407 receives the data regarding the opening and closing of the inlet and exhaust valves from the cam lobe sensors. Based on the opening and closing of the inlet valve, and the pre-determined amount of fuel injected by the injector within each opening and closing of the inlet valve, the estimation unit 407 in conjunction with the sensor unit 404, estimates the residual fuel in the combustion chamber of the cylinder 305. Thereby, the VCU 409 checks whether the amount of the residual fuel is determined 318 within the one or more optimum cylinder. If yes ‘b’, the VCU 409 determines the injection of the required fuel within the combustion chamber 307.
[00080] The determination of the injection of the required fuel within the combustion chamber of the engine 206 is done by deducting the estimated residual fuel from the pre-defined fuel normally injected within the combustion chamber in between opening and closing of the inlet valve.
[00081] Since the estimated residual fuel is taken into consideration while injecting the required fuel, better fuel economy is obtained. This is because the present subject matter ensures zero wastage of the fuel, particularly zero wastage of the residual fuel already present in the combustion chamber of the one or more optimum cylinder, from the last abrupt stopping of the functioning of the engine 100.
[00082] Furthermore, the present subject matter also ensures reduced emission of the fuel. This is because overall emission of the unburnt hydrocarbons are curbed, especially the unburnt hydrocarbons produced because of the unburnt residual fuel already present in the combustion chamber of the one or more optimum cylinder, from the last abrupt stopping of the functioning of the engine 100.
[00083] The VCU 409 checks 319 whether the amount of the fuel to be injected is estimated by the estimation unit 407. If No ‘a’, the VCU 409 waits 320 until the fuel to be injected is determined by the estimation unit 407. If Yes ‘b’, i.e. once the fuel to be injected is estimated by the estimation unit 407, the injector unit 408 sends signal to the injector of the engine 100, to inject the estimated fuel once the vehicle is started by means of ISS system 308, 321.
[00084] Once functioning of the engine 100 is restored and the estimated fuel is injected, asynchronous sparking is initiated when, an approximate of 25000 V of energy stepped up by the ignition coil (not shown), is transferred to the spark plug 109 generating a spark across its electrodes 308, 321. The asynchronous sparking further ignites the compressed charge.
[00085] Herein, the asynchronous sparking, refers to initiation of sparking in the identified one or more optimum cylinder of the multi-cylinder engine 100.
[00086] For instance, if the multi-cylinder engine 100 includes four cylinders and as per the regular synchronous sparking the first sparking during the first stroke is configured to occur in the second cylinder and the fourth cylinder. However, when the ISS stop is used the functioning of the engine 100 is stopped abruptly, leaving the last position of the piston in the first cylinder and the third cylinder near the TDC of the combustion chamber. The positioning of the piston near the TDC of the combustion chamber signifies, the engine being in compression stroke. As during the compression stroke, fuel is accumulated within the combustion chamber, thereby some fuel from the last stroke remains accumulated in the combustion chambers of the first cylinder and the third cylinder.
[00087] As per an embodiment of the present subject matter, asynchronous sparking is initiated in the one or more optimum cylinder. In this instance, the one or more optimum cylinder is the first cylinder and the third cylinder. Thereby upon the determination of the first cylinder and the third cylinder as one or more optimum cylinder, the first sparking occurs in the identified one or more optimum cylinder, rather than in the second cylinder and the fourth cylinder. Subsequently the second sparking occurs in the second cylinder and the fourth cylinder.
[00088] Thereby, because of the initiation of the first sparking in the identified one or more optimum cylinder, the delay in the starting of the engine 100 is avoided. Such avoidance of startability issues ensures a comfortable and hassle-free ride for the rider.
[00089] Many modifications and variations of the present subject matter are possible in the light of above disclosure. Therefore, within the scope of claims of the present subject matter, the present disclosure may be practiced other than as specifically described.

LIST OF REFERENCE NUMERAL


100: engine
101: crankcase assembly
102: cylinder block
103: cylinder head
104: cylinder head cover
105: intake port
106: cooling fins
107: clutch assembly
108: cylinder bore
109: spark plug
110: crankshaft
111: magneto assembly
XX’: plane
112: bearings
113: camshaft second lobe
114: camshaft first lobe
115: camshaft inner
117: bearings
400: engine management system
401: Processor
402: Memory
403: Transceiver
404: Sensor unit
405: Piston position detection unit
406: Cylinder selection unit
407: Estimation unit
408: Injection unit
409: VCU
410: Sensor
200, 300: Block diagram
201, 301: Manual selection of the ISS feature
a: No
b: Yes
202, 302: Determination of idling state of a vehicle for more than a predefined time period
203, 303: Determination of ISS stop
204: Determination of the position of the piston of the engine
304: Identification of the optimum cylinder based on positioning of the piston
305: Estimation of the residual fuel within the optimum cylinder
205: Estimation of the residual fuel within the engine
306: Determination of the injection of the fuel required within the optimum cylinder
206: Determination of the injection of the fuel required within the engine
207, 307: Injection of the required fuel
308: Performing asynchronous sparking within the optimum cylinder to crank and start the Engine
208: Performing sparking within the optimum cylinder to crank and start the Engine
209, 309: Flow chart
210, 310: Start
211, 311: Check if the vehicle is stopped using ISS Stop
212, 312: Wait until ISS conditions are met
213, 313: Check if the position of the piston determined
214, 314: Wait until the position of the piston determined
215, 318: Check if the residual fuel determined
315: Check if the optimum cylinder identified
316: Wait until the optimum cylinder identified
216, 317: Wait until the residual fuel is determined
217, 319: Check if the amount of the fuel to be injected determined
218, 320: Wait until the estimation of the fuel to be injected is determined
219, 321: The fuel mixture injected and the sparking within the engine initiated to start the engine
220, 322: Stop

,CLAIMS:We Claim:
1. An engine management system (400) for a vehicle, wherein
said engine management system (400) being configured to enable a start-stop system of said vehicle (201, 301), subsequent to achieving the pre-determined integrated start-stop conditions (202, 302);
wherein said engine management system (400) being capable to determining the position of at least one piston of at least one cylinder (204, 304) of said engine (100) by means of one or more sensors (410);
wherein said engine management system (400) being capable of estimating the residual fuel (205,305) within said at least one cylinder of said engine (100), and determining the required fuel (206, 306) within said at least one cylinder of said engine (100);
wherein said engine management system (400) being configured to perform sparking by means of a spark plug (109), within said at least one cylinder (208, 308) of said engine (100), subsequent to completion of injection of the required fuel (207, 307) within said at least one cylinder of said engine (100).
2. The engine management system (400) for a vehicle as claimed in claim 1, wherein said engine management system (400) comprises of a vehicle control unit (409), a processor (401), a transceiver (403), a sensor unit (404), a piston position detection unit (405), a cylinder selection unit (406), an estimation unit (407), and an injector unit (408).
3. The engine management system (400) for a vehicle as claimed in claim 1, wherein said pre-determined integrated start-stop (ISS) conditions include vehicle being in idling state for more than a pre-defined time period, wherein said pre-defined time period ranges between 5 seconds and 30 seconds.
4. The engine management system (400) for a vehicle as claimed in claim 1, wherein said one or more sensors (410) includes at least one of a crankshaft position sensor and a crank angle sensor being disposed near a crankshaft (110), wherein said at least one of a crankshaft position sensor and a crank angle sensor senses the position of the crankshaft.
5. The engine management system (400) for a vehicle as claimed in claim 1 or claim 4, wherein the data from said at least one of a crankshaft position sensor and a crank angle sensor being received by a sensor unit (404), wherein on the basis of said data received from said at least one of a crankshaft position sensor and a crank angle sensor, said sensor unit (404) in conjunction with a piston position detection unit (405) estimates the position of said at least one piston of cylinders of said engine (100).
6. The engine management system (400) for a vehicle as claimed in claim 1 or claim 5, wherein upon estimation of positioning of said at least one piston in the vicinity of the Top Dead Centre of a combustion chamber of said at least one cylinder, an estimation unit (407) estimates the residual fuel present in said combustion chamber of said at least one cylinder.
7. The engine management system (400) for a vehicle as claimed in claim 1 or claim 2, wherein one or more cam lobe sensors sense the opening and closing of an inlet valve and an exhaust valve and share the data with said sensor unit (404), wherein said estimation unit (407) in conjunction with said sensor unit (404) estimates the residual fuel in a combustion chamber of said at least one of the cylinders of said engine (100).
8. The engine management system (400) for a vehicle as claimed in claim 1 or claim 7, wherein determination of the injection of the fuel required within a combustion chamber of said engine (206) being deduced by deducting said estimated residual fuel from a pre-defined fuel injected within a combustion chamber of at least one of the cylinders of said engine (100).
9. The engine management system (400) for a vehicle as claimed in claim 1 or claim 7, wherein said engine (100) being one of a single cylinder engine (100) and a multi-cylinder engine (100).
10. The engine management system (400) for a vehicle as claimed in claim 6, wherein said at least one cylinder having at least one piston in the vicinity of the Top Dead Centre of a combustion chamber being at least one optimum cylinder.
11. The engine management system (400) for a vehicle as claimed in claim 1 or claim 10, wherein said engine management system (100) being capable of initiating sparking through said spark plug (109), within one or more optimum cylinder, subsequent to injection of the required fuel within said one or more optimum cylinder.
12. A method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle, wherein the method comprising:
determining enablement of a start-stop system of said vehicle (201), subsequent to achieving the pre-determined integrated start-stop conditions (202);
determining position of a piston (204) of a cylinder (204) of said engine (100) by means of one or more sensors (410);
estimating residual fuel (205) within said cylinder of said engine (100);
determining the amount of required fuel to be injected (206) within said cylinder of said engine (100) based on the estimated residual fuel;
injecting the determined amount of required fuel (207) within said cylinder of said engine (100); and
performing sparking within a combustion chamber (208) of said cylinder of said engine (100) to start said engine (100) of said vehicle.
13. A method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle, wherein the method comprising:
determining enablement of a start-stop system of said vehicle (301), subsequent to achieving the pre-determined integrated start-stop conditions (302);
determining position of each of the pistons from the plurality of cylinders (313) using one or more sensors (410);
identifying one or more optimum cylinder (304) from the plurality of cylinders based on the determined position of the piston in each of the plurality of cylinders,
wherein said piston position in the identified said one or more optimum cylinder, being in vicinity of the top dead center of the combustion chamber of said one or more optimum cylinder;
estimating residual fuel (305) within said one or more optimum cylinder;
determining, the amount of required fuel to be injected (306) within said one or more optimum cylinder based on the estimated residual fuel;
injecting the determined amount of required fuel (307) within said one or more optimum cylinder of said engine (100); and
performing sparking within one or more combustion chamber (308) of said one or more optimum cylinder of said engine (100) to start said engine (100) of said vehicle.
14. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 13, wherein said one or more optimum cylinder being on an intake stroke at the time of idling stop.
15. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 12, wherein said engine (100) being a single cylinder engine.
16. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 13, wherein said engine (100) being a multi-cylinder engine.
17. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 12 or claim 13, wherein said engine management system (100) comprises of a vehicle control unit (409), a processor (401), a transceiver (403), a sensor unit (404), a piston position detection unit (405), a cylinder selection unit (406), an estimation unit (407), and an injector unit (408).
18. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 12 or claim 13, said pre-determined integrated start-stop (ISS) conditions include vehicle being in idling state for more than a pre-defined time period, wherein said pre-defined time period ranges between 5 seconds and 30 seconds.
19. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 12 or claim 13, wherein said one or more sensors (410) includes at least one of a crankshaft position sensor and a crank angle sensor being disposed near a crankshaft (110), wherein said at least one of a crankshaft position sensor and a crank angle sensor senses the position of said crankshaft.
20. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 12 or claim 13 or claim 19, wherein the data from said at least one of a crankshaft position sensor and a crank angle sensor being received by a sensor unit (404), wherein on the basis of said data received from said at least one of a crankshaft position sensor and said at least one of a crank angle sensor, said sensor unit (404) in conjunction with a piston position detection unit (405) estimates the position of said at least one piston of at least one cylinder from a plurality of cylinders of said engine (100).
21. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 12 or claim 13 or claim 14, wherein one or more cam lobe sensors sense the opening and closing of an inlet valve and an exhaust valve and share the data with said sensor unit (404), wherein said estimation unit (407) in conjunction with said sensor unit (404) estimates the residual fuel in a combustion chamber of said at least one of the cylinders from said plurality of cylinders of said engine (100).
22. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 12 or claim 13 or claim 21, wherein determination of the injection of the fuel required within a combustion chamber of said engine (206) being deduced by deducting said estimated residual fuel from a pre-defined fuel injected within said one or more combustion chamber of at least one of the cylinders from a plurality of cylinders of said engine (100).
23. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 12 or claim 13, wherein the method includes:
cranking of said engine (100) based on received one of an engine start signal and an Integrated Start Stop signal for a pre-defined time;
identification of unsuccessful cranking of said engine (100), based on said engine (100) speed, wherein
said unsuccessful cranking indicates said engine (100) failing to reach a first pre-defined engine speed within a first pre-defined time required for cranking;
determination of number of unsuccessful cranking of said engine (100) beyond a predetermined number of times; and
disabling of the Integrated Start Stop feature upon determination of number of unsuccessful cranking of said engine (100) beyond said predetermined number of times.
24. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 23, wherein said first pre-defined engine speed ranges in between 100rpm and 700rpm.
25. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 23, wherein said first pre-defined time required for cranking ranges in between 0.5 seconds and 4 seconds.
26. The method of operating an engine (100) of a vehicle by an engine management system (400) of said vehicle as claimed in claim 23, wherein said predetermined number of times of unsuccessful cranking ranges in between 5 to 8 times.