Description:Technical Field
[0001] The present invention generally relates to automated start – stop procedures in vehicles. More specifically, it relates to such start – stop procedures being modified to reduce hydrocarbon emission and to prevent false starts.

Background
[0002] As a means of saving fuel, drivers are often encouraged to turn off their engines temporarily during traffic stops. This has been a long practice that is being followed by drivers all around the world. Modern vehicles come equipped with sensors that can detect when the vehicle has been idling for more than a threshold time after having been driven greater than a threshold distance. Some of these vehicles give reminders to the driver to switch off the engine when the vehicle has been idling for a prolonged time, and some vehicles have Electronic control units which can turn off the vehicle by itself.
[0003] This system is commonly known as an Integrated Start – Stop system, or the ISS system. The ISS system typically has a switch that the driver can manually turn on or turn off. This switch either activates or deactivates the ISS system in the vehicle. Typically, there is also a lamp on the vehicle’s dashboard indicating to the driver whether the ISS system is currently activated or not.
[0004] This improves the fuel economy of the vehicle by turning off the engine automatically when the engine has been idling for a pre-determined time. Typically, to restart the engine, the driver does not have to go through the starting procedure, but rather there is some procedure, on detecting which the control unit automatically restarts the engine. Most of the time, this procedure involves opening the throttle in combination with the clutch and gear levers being at a certain position. But sometimes, if the vehicle has been turned off for too long, the control unit considers that the vehicle has come to a permanent stop, following which, normal start procedures have to be followed to restart the engine.
[0005] There are however instances where a false ISS start has occurred due to the driver mistakenly initiating the start procedure. This is a problem due to the very nature of the start procedure itself, the throttle handle on a motorcycle is made to be rotated, or a throttle pedal on a car is supposed pressed, and drivers sometimes instinctively do these actions without realising that they are going through the ISS start procedure.
[0006] Engineers have been trying to reduce fuel consumption of internal combustion engines. Much of the effort was focused on fuel efficiency of the engines itself. Many manufacturers tried by fitting smaller engines with forced air injection and fuel injection. Research was also focused on the fuel itself so that it can be used more efficiently. All this was done in an effort to 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 lose about 65% - 80% of the energy in the fuel as heat upon combustion, and cannot be converted to useful work, moving the vehicle.
[0007] User awareness was thus sought to be raised, and drivers were educated to save fuel wherever possible. There are engines which can switch off some of their cylinders while cruising at low speeds, when high performance is not required. Manufacturers recommend to the drivers what is the ideal range of engine speed and vehicle speed to achieve the highest possible fuel economy. One of the effective and easiest ways to save fuel was observed to be turning off the engines while waiting at a traffic stop, or other such short duration stops. Manufacturers insisted on drivers following this practice, and hence automated this process. The vehicle’s engine would switch off automatically when stopped for a short duration of time, and then turn on when required as well.
[0008] The automatic start – stop function in modern automobiles is a vital instrument of fuel saving. It saves fuel costs for the owner / driver. Most automobiles achieve this by automatically switching off the ignition when a set of predetermined stop conditions are satisfied. Subsequent to the stop, the vehicle has to be started when the driver needs to. Starting the vehicle again by going through the ignition could potentially discourage the driver / owner from having this system installed in their vehicle in the first place. Thus, the automated start has to be actuated without involving the ignition procedure that the driver has to go through while starting the vehicle for the first time.
[0009] This usually works with inputs from the driver. 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 considered to be a lever as available in two wheeler vehicles, as opposed to a pedal which is more commonly found in four wheelers. The OEM often provides a combination of changes of states in one or more of these movable parts. The most commonly used combination is that of a change in state of the clutch lever and a change in state of the throttle. This often results in false starts as it is common for drivers to fiddle with the movable parts while stopped for a small duration of time. This invention seeks to provide a solution to the above mentioned problem.
[00010] Moreover, the method of switching off the ignition of the engine is detrimental to the fuel economy of the vehicle as well. Since the ignition is being switched off, some fuel remains in the combustion chamber that is left unburnt as the ignition has been switched off, but the fuel injection hasn’t. therefore, the remaining fuel stays unburnt in the chamber. Fuel injection completely stops only when the engine has come to a complete stop. Once the vehicle gets restarted, fresh fuel is injected into the chamber, resulting on too much fuel during the first few compression and power strokes of the engine. This results in more fuel being burnt in the chamber than is required, resulting in a thicker smoke being exhausted during those first few strokes. This not only affects the fuel economy of the vehicle, but also causes more air pollution. This present invention also seeks to provide a solution to the above mentioned problem.
[00011] There are mainly two types of powertrain arrangements in modern vehicles with an internal combustion engine. The powertrain itself includes the engine and a gearbox. The gearbox and the engine are connected to each other with a clutch plate. The clutch plate can be engaged or disengaged. Engaging the clutch plate implies that the power from the engine is being transferred to the gearbox, and through the gearbox to the driven wheels of the vehicle. Disengaging the clutchplate implies that the power from the engine is not being transferred to the gearbox, and the wheels are not being driven by the power from the engine. There are generally two types of powertrains. The first type is that with an automatic gearbox, and the second type is that with a manual gearbox. In the first type, the control of the clutch plate is not with the driver of the vehicle, and the clutch operation as well as the gear selection is done automatically. Some automatic gearboxes use a system which is known as the continuously variable transmission, which eliminates the need of a clutch plate altogether. Whereas, in the second type, that is the manual transmission, the driver is provided with a clutch lever and a gear shifter to disengage the clutch and change gears when he/she feels necessary. Hence, this invention primarily applies to vehicles with a manual transmission system.
[00012] A prior art disclosed in this subject matter discusses detecting the throttle input along with an input from the clutch lever while determining whether predetermined automatic start conditions are fulfilled. This requires determining inputs from at least two different movable parts and hence creates a more complex system than required. Another prior art disclosed in this subject matter discusses the input from the clutch pedal only in determining whether the driver requires the vehicle to be started. This is implemented by using a potentiometer type switch which determines whether the clutch pedal is pressed beyond one or more threshold levels, which then determines whether the preconditions for the automatic start are being fulfilled. This increases the cost of the system to be implemented as because the sensors being used in this prior art are costly. Hence, neither of these solutions may be implemented in vehicles without incurring a risk of false starts or increasing the cost of the system.
Summary of the Invention
[00013] Hence, the present invention proposes a method for reducing hydrocarbon emission during automatic start of a vehicle after an automatic stop, comprising, an automatic stop procedure and an automatic start procedure, the automatic stop procedure comprising: determining said engine being in an idling condition, determining all of one or more predetermined conditions for automatic stop being satisfied, determining all of one or more sensors not communicatively transmitting erroneous data, and configuring a controller to actuate a fuel injector to stop fuel injection in said engine; and, the automatic start procedure comprising: determining whether a previous power unit stop being an automatic stop, determining a start sequence being input by a driver of said vehicle being valid, and configuring a controller to initiate automatic start of said vehicle when said valid start sequence being input, wherein, the automatic start being initiated by the controller upon determining one or more change of state in a clutch lever of the vehicle by a state sensor (switch), the state sensor being a first of said one or more sensors.
[00014] Further, the present invention also proposes a method for automatically starting a vehicle after an automatic stop comprising: determining whether a previous power unit stop being an automatic stop, determining a gear position and a clutch lever position, determining whether a start sequence being input by a driver of the vehicle, wherein, determination of whether a start sequence being input comprises: determining one or more change of state in the clutch lever of said vehicle by a state sensor (switch), the one or more change of state of said clutch lever being communicatively transmitted to a control unit by the state sensor, and the control unit determining whether the start sequence being valid, wherein, the automatic engine start being initiated upon determining the start sequence being valid.
[00015] This summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described below, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
[00016] In an aspect, a method for automatically starting a vehicle after an automatic stop is disclosed. The method comprises: determining, by an engine management system (EMS) controller, a previous power unit stop being an automatic stop; determining, by the EMS controller, a gear position and a clutch lever position; determining, by the EMS controller (101), a clutch start sequence being input by a driver of said vehicle (305).
[00017] In an embodiment, determining a clutch start sequence being input includes: receiving, by the EMS controller, one or more change of state of said clutch lever from said state sensor; determining, by the EMS controller, one or more change of state in a clutch lever of said vehicle based on inputs received from a state sensor (switch), wherein said one or more change of state in a clutch lever being a start sequence; determining, by the EMS controller, said start sequence being valid; initiating, by the EMS controller, automatic engine start when said clutch start sequence being valid.
[00018] In an embodiment, determination of whether a previous power unit stop being an automatic stop comprises said control unit being configured to retrieve data from a memory unit within said control unit, said data being processed by said control unit to determine whether a previous power unit stop being an automatic stop.
[00019] In an embodiment, the state sensor being a switch configured to determine said state of said clutch lever.
[00020] In an embodiment, said one or more change of state in said clutch lever being at least two changes in state of said clutch lever, wherein, said change of state being a force being applied on said lever, resulting in said lever being in one of a pressed state and a released state.
[00021] In an embodiment, said pressed state of said clutch lever corresponding to a clutch plate disengaging a power unit and a transmission unit of said vehicle, and said released state of said clutch lever corresponding to said clutch plate engaging a power unit and a transmission unit of said vehicle.
[00022] In an embodiment, said method being initiated upon first determining an automatic start-stop switch being actuated to activate an automatic start stop system, said method not being initiated upon said automatic start stop switch not being actuated.
[00023] In an embodiment, determining said gear position includes determining said gear being in one of a neutral position and a non-neutral position.
[00024] In an embodiment, said clutch start sequence comprising a sequence of two or more movements of said clutch lever, said control unit determining said validity of said start sequence by considering said change of state in said clutch lever and said gear together, and said valid start sequence being a predetermined sequence of change of state in said clutch lever movements with respect to a refence initial gear and clutch position.
[00025] In an embodiment, wherein said gear position being determined, and a determination of said start sequence being input includes: determination that a first movement of said start sequence being actuated in said clutch lever; determination that an at least second movement of said start sequence being actuated in said clutch lever; wherein, determination of an at most third movement in said start sequence, said third movement being required in one or more said start sequences.
[00026] In an embodiment, said start sequence being a first start sequence, wherein said gear position being determined to be neutral, and said clutch lever being in said released state, said first start sequence includes: a first change of state of said clutch lever, said change being to said pressed state from said released state; and a second change of state of said clutch lever, said change being to said released state from said pressed state.
[00027] In an embodiment, said start sequence being a second start sequence, wherein said gear position being determined to be neutral, and said clutch lever being in said pressed state, said second start sequence includes: a first change of state of said clutch lever, said change being to said released state from said pressed state; and a second change of state of said clutch lever (406), said change being to said pressed state from said released state.
[00028] In an embodiment, said start sequence being a third start sequence, wherein said gear position being determined to be non-neutral, and said clutch lever being in said released state, said third start sequence includes: a first change of state of said clutch lever, said change being to said pressed state from said released state; a second change of state of said clutch lever, said change being to said released state from said pressed state; and a third change of state of said clutch lever, said change being to said pressed state from said released state.
[00029] In an embodiment, said start sequence being a fourth start sequence, wherein said gear position being determined to be non-neutral, and said clutch lever being in said pressed state, said fourth start sequence includes: a first change of state of said clutch lever, said change being to said released state from said pressed state; a second change of state of said clutch lever, said change being to said pressed state from said released state.
[00030] In an embodiment, a method for reducing hydrocarbon emission during the automatic start of a vehicle after an automatic stop is further disclosed. An automatic stop procedure comprises: determining, by the EMS controller, the engine being in an idling condition; determining, by the EMS controller, all of one or more predetermined conditions for automatic stop being satisfied; determining, by the EMS controller (101), all of one or more sensors not communicatively transmitting erroneous data (205); and, actuating, by the EMS controller (101), a fuel injector to stop fuel injection (206) in said engine.
[00031] In an embodiment, said predetermined conditions for automatic stop include: a vehicle speed being less than a predetermined value of said vehicle speed; a throttle actuation level being less that a predetermined value of said throttle actuation level; and, an engine speed being less than a predetermined value of said engine speed.
[00032] In an embodiment, stopping said fuel injection while an ignition pulse being active combusts any remaining fuel in a combustion chamber of said engine for achieving reduced hydrocarbon emission during a subsequent automatic start.
[00033] In an embodiment, determining a start sequence being input by a driver of said vehicle being valid comprises determining a gear position and an initial clutch position, wherein, said determining one or more change of state in a clutch lever of said vehicle.
[00034] In an embodiment, said start sequence being said one or more change of state in said clutch lever, corresponding to said determined gear position, and said determined initial clutch position.
[00035] In an aspect, a system for implementing one of a method to actuate an automatic stop and a method to actuate an automatic start is disclosed. The system comprising an EMS controller, a plurality of sensors, and a plurality of actuators, the EMS controller is configured to: determine a previous power unit stop being an automatic stop; determine a gear position and a clutch lever position; determine a clutch start sequence being input by a driver of said vehicle.
[00036] In an embodiment, said plurality of sensors comprising, a throttle position sensor, a manifold pressure sensor, an intake air temperature sensor, an engine temperature sensor, a crank position sensor, a lambda sensor, a clutch sensor, and a gear sensor.
[00037] In an embodiment, said plurality of actuators comprises a fuel injector, an idle air control valve, a canister purge valve, an ignition coil, a secondary air injection valve, and a lambda sensor heater.
[00038] In an embodiment, said controller being configured to communicatively receive a plurality of data from said sensors.
[00039] In an embodiment, said controller being configured to one of enable and disable said actuators.
[00040] In an embodiment, determining said gear position includes determining said gear being in one of a neutral position and a non-neutral position.
[00041] In an embodiment, said clutch start sequence comprising a sequence of two or more movements of said clutch lever, wherein, said control unit is configured to determine said validity of said start sequence by considering said change of state in said clutch lever and said gear together; and said valid start sequence being a predetermined sequence of change of state in said clutch lever movements with respect to a refence initial gear and clutch position.
[00042] In an embodiment, said gear position being determined, and a determination of said start sequence being input includes: determination that a first movement of said start sequence being actuated in said clutch lever; determination that an at least second movement of said start sequence being actuated in said clutch lever; determination of an at most third movement in said start sequence, said third movement being required in one or more said start sequences.
[00043] In an embodiment, said clutch sensor being configured to delineate the state of a clutch lever, said state of clutch lever being one of a pressed state and a released state.
[00044] In an embodiment, said gear sensor being configured to delineate the state of a gear, said state of gear being one of a neutral state and a non-neutral state.
Brief Description of Drawings
[00045] The details in the following paragraphs are described with reference to an embodiment of the present invention along with the accompanying diagrams and flow charts. The inventive concepts are explained through the same, and the same reference numerals are used throughout the drawings and flowcharts to reference similar features and components.
[00046] Figure 1 is a representative schematic block diagram representing the system level components in the present invention.
[00047] Figure 2 is a flow diagram representing the process which is implemented by the system depicted in figure 1 to actuate the ISS stop procedure.
[00048] Figure 3 is a flow diagram representing the process which is implemented by the system depicted in figure 1 to actuate the ISS start procedure.
[00049] Figure 4 is a flow diagram representing the process which is implemented by the system depicted in figure 1 to determine the gear position and the clutch status.
[00050] Figure 5(a) is a flow diagram representing the process which is implemented by the system depicted in figure 1 in order to determine a first start sequence.
[00051] Figure 5(b) is a flow diagram representing the process which is implemented by the system depicted in figure 1 in order to determine a second start sequence.
[00052] Figure 5(c) is a flow diagram representing the process which is implemented by the system depicted in figure 1 in order to determine a third start sequence.
[00053] Figure 5(d) is a flow diagram representing the process which is implemented by the system depicted in figure 1 in order to determine a fourth start sequence.
[00054] Figure 6 is a functional flow diagram representing the process depicted in figure 3, which is implemented by the system depicted in figure 1 to actuate the ISS start procedure.
[00055] Figure 7 is a chart depicting the result of the process described in figure 2 being implemented.
[00056] Figure 8 is a chart depicting the process depicted in figure 5(a) being implemented.
[00057] Figure 9 is a chart depicting the process depicted in figure 5(b) being implemented.
[00058] Figure 10 is a chart depicting the process depicted in figure 5(c) being implemented.
[00059] Figure 11 is a chart depicting the process depicted in figure 5(d) being implemented.
[00060] Figure 12 is a chart depicting the process depicted in figures 2 resulting in less hydrocarbon emission when the process depicted in figure 3 is implemented.

Detailed Description
[00061] Various features and embodiments of the present invention here will be discernible from the following description thereof, set out hereunder.
[00062] The present embodiments are described in the following paragraphs with the help of accompanying exemplary diagrams and figures.
[00063] Figure 1 exemplarily illustrates a system level block diagram (100) of the sensors, actuators and the controller (101) for controlling the automatic start and automatic stop system. As per the present invention, a vehicle is equipped with one or more sensors including a throttle position sensor (102), a manifold pressure sensor (103), an intake air temperature sensor (104), an engine temperature sensor (105), a crank position sensor (106), a lambda sensor (107), and a clutch lever state sensor (not shown). Also, as per the present invention, a vehicle is equipped with one or more actuators including an injector (112), an idle air control valve (113), a canister purge valve (114), an ignition coil (115), an electronic secondary air injection valve (116) and a lambda Sensor heater (117).
[00064] Figure 2 is an exemplary flow diagram representing the automatic stop method (200) being implemented by the system shown in figure 1. A switch is provided to the driver on the vehicle dashboard / control panel which allows him / her to switch the automatic start - stop on or off as per his requirements. This automatic start – stop switch is also known as the integrated start – stop (ISS) switch, as has been noted in the figures.
[00065] At 201, the system makes a determination whether the automatic start – stop switch is on or off. The system proceeds to the next step only when the automatic start – stop switch is determined to be On.
[00066] At 202, the system makes a determination of whether the engine is in an idling state. The idling state of an engine can be determined by various means, such as measuring the rotational speed of the crankshaft for a predetermined amount of time, or measuring the position of the throttle for a predetermined amount of time. In an embodiment of the present invention, if the rotational speed of the crankshaft measured over a predetermined amount of time is found not to cross a maximum threshold, the engine is determined to be idling.
[00067] In another embodiment of the present invention, if the throttle position is found to be below a threshold over a predetermined amount of time, the engine is determined to be idling. The system proceeds to the next step of the method only upon determination that the engine is in idling condition as per the conditions of step 202.
[00068] At 203, the system determined the gear and clutch status of the vehicle. The gear status is measured by the system as whether the vehicle is in a neutral gear position or a non-neutral gear position. The clutch status of the vehicle is determined by whether the clutch plate is engaged or disengaged. In an embodiment of the present invention, this determination is made by a clutch lever state sensor. When the clutch lever is actuated, the clutch plate is disengaged, and when the clutch lever is in a relaxed state, the clutch plate is engaged.
[00069] As per an embodiment of the present invention, the gear at a neutral position is a suitable condition for engine idling. As per another embodiment of the present invention, actuating the clutch lever while the gear is at a non-neutral position is also a suitable condition for engine idling.
[00070] At 204, the system (100) makes a determination as to whether all conditions for an automatic stop are being satisfied. In an embodiment of the present invention, an engine being in an idling state for a predetermined amount of time is a condition for an automatic stop. In another embodiment of the present invention, the gear being in a neutral position while the engine is idling is a second condition of an automatic stop.
[00071] In another embodiment, the clutch lever being actuated while the gear is in a non-neutral position during an engine idling state is also a second condition for an automatic stop. In another embodiment of the present invention, the conditions mentioned herein are the conditions for an automatic stop in a vehicle.
[00072] In another embodiment of the present invention, there is at least another condition (not shown in the figure) for an automatic stop. In an embodiment of the present invention, the automatic stop will be actuated only if all the predetermined conditions are satisfied for the same. In another embodiment, the ISS stop may be actuated if a set of predetermined conditions are satisfied while the other conditions are in an undetermined state.
[00073] At 205, the system (100) makes a determination that all the sensors being employed by the system (100) are accurately conducting a set of measurements as said sensors have been configured to do. In an embodiment, it is also determined that the sensors are communicating a set of data within a predetermined level of accuracy. In an embodiment, if such a determination is made that none of the sensors are communicatively transmitting data erroneously, the automatic stop is activated.
[00074] At 206, the automatic stop has been actuated. In an embodiment of the present invention, upon the determination that automatic stop to be actuated, the engine management system controller (100) of the system (100) is configured to stop the actuation of the fuel injector (112) till determined otherwise.
[00075] At 207, ISS stop is achieved.
[00076] In an embodiment of the present invention, stopping the actuation of the fuel injector (112) disables the fuel from the fuel storage tank of the vehicle to be injected into the combustion chamber of the engine of the vehicle. As a result, in the absence of fuel in the chamber, combustion does not take place when the chamber is ignited at the predetermined point with respect to the piston moving towards Top Dead Centre (TDC) in the Compression stoke of the engine, As a result, the crankshaft stops rotating after a certain point of time under its own inertia, and thus the engine comes to a complete stop.
[00077] Figure 3 is an exemplary representing the automatic start method (300) being implemented by the system (100) shown in figure 1. A switch is provided to the driver on the vehicle dashboard / control panel which allows him / her to switch the automatic start - stop on or off as per his / her requirements.
[00078] At 301, the system makes a determination whether the automatic start – stop switch is on or off. The system proceeds to the next step only when the automatic start – stop switch is determined to be On.
[00079] At 302, the system determines whether the engine of the vehicle is in off condition. In order to start the engine automatically, first it has to be determined whether the engine is running or not. The system proceeds to the next step of the process only when it has been determined that the engine is in an off state.
[00080] At 303, the system (100) makes a determination whether the previous stop for the engine was an automatic stop (207). In an embodiment of the present invention, the system is configured to actuate automatic start of the engine only when the previous stop was an automatic stop actuated by the system (100). As per an embodiment, this is configured as such so as to avoid any false starts from being actuated when the vehicle is not required to be started.
[00081] At 304, the system determines the clutch and gear status of the vehicle. As per an embodiment of the present invention, the driver communicates to the system (100) through a sequence of predetermined input commands that the automatic stop has to be actuated. As per an embodiment of the present invention, the sequence of predetermined input commands are changes of state of the clutch lever.
[00082] As per another embodiment of the present invention, the sequence of predetermined input commands varies as per the initial state of the clutch lever and the initial position of the gear. Therefore, as per the present embodiment, it is necessary to determine an initial reference state of the clutch lever and the initial reference position of the gear of the vehicle.
[00083] At 305, the system determines whether the sequence of predetermined input commands have been input by the driver. As per an embodiment of the present invention, the sequence of predetermined input commands are at least two changes to the state of the clutch lever from an initial reference position recorded at 304.
[00084] At 306, the system (100) makes a determination that all the sensors being employed by the system (100) are accurately conducting a set of measurements as said sensors have been configured to do. In an embodiment, it is also determined that the sensors are communicating a set of data within a predetermined level of accuracy. In an embodiment, if such a determination is made that none of the sensors are communicatively transmitting data erroneously, the automatic start is activated.
[00085] At 307, the conditions for automatic start are met, and automatic start is achieved.
[00086] In an embodiment of the present invention, achieving the automatic start state entails enabling a integrated starter generator to rotate the crankshaft of the power unit of the vehicle, enabling the ignition coil (115) to be configured to generate ignition sparks in the combustion chamber of the power unit of the vehicle, and enabling the fuel injector (112) to deliver fuel to the combustion chamber at a specified instant between the combustion stroke and the power stroke of the power unit. As a result, the crankshaft starts rotating due to the power delivered by the power unit, and the integrated starter generator is then configured to work as a generator, generating electricity from the rotating motion of the crankshaft of the power unit. Thus, the engine is started.
[00087] Figure 4 is an exemplary flow diagram representing the sequence of predetermined input commands (304) being input by the driver by actuating the clutch lever according to an embodiment of the present invention.
[00088] 303 is a precursor to this step in the process where a determination is made whether a previous stop was an automatic stop as represented in figure 2. The following step 304 determines the clutch and gear status of the vehicle. This determination is made so as to determine an initial reference state with respect to which, the sequence of predetermined input commands (304) can be delineated. As per an embodiment of the present invention, two or more distinct changes of state in the clutch lever are required to delineate the clutch start sequence being input.
[00089] At 404, a determination is made whether a first movement in the clutch start sequence is performed. In an embodiment, the first movement is a single change of state of the clutch lever from the initial reference state determined at 303.
[00090] At 406, a determination is made whether a second movement in the clutch start sequence is performed. In an embodiment, the second movement is a single change of state of the clutch lever from the final state of the clutch lever in 404.
[00091] At 408, a determination is made whether a third movement in the clutch start sequence is performed. In an embodiment of the present invention, the third movement is a single change of state of the clutch lever from the final state of the clutch lever at 406.
[00092] At 305, a determination is made by the system (100) whether the two or more changes of state of the clutch lever (404, 406, 408) with respect to the initial reference state of the clutch lever constitute a valid sequence of predetermined input commands for an automatic start to be actuated by the system (100).
[00093] In an embodiment of the present invention, at least two distinct changes of state of the clutch lever with respect to the initial reference state (404, 406) are required to determine a valid sequence of predetermined input commands for an automatic start.
[00094] As per another embodiment of the present invention, at least three distinct changes of state of the clutch lever with respect to the initial reference state (404, 406, 408) are required to determined a valid sequence of predetermined input commands for an automatic start.
[00095] Figure 5(a) is an exemplary flow chart representing a first valid sequence of predetermined inputs (501) as shown in figure 4.
[00096] 303 is a precursor to this step in the process where a determination is made whether a previous stop was an automatic stop as represented in figure 2. The following step 304 determines the clutch and gear status of the vehicle. This determination is made so as to determine an initial reference state with respect to which, the sequence of predetermined input commands (304) can be delineated. As per an embodiment of the present invention, two distinct changes of state in the clutch lever are required to delineate the clutch start sequence being input.
[00097] At 404(a), step 304 has been executed by the system (100) and it is determined that the initial reference state is that the gear is at a neutral position and the clutch is in an engaged state, i.e., the clutch lever is in a released state.
[00098] At 406(a), 404 and 406 are implemented by the system. A determination is made that while the gear is at a neutral state and the initial reference state of the clutch lever is being in a released state, the clutch lever is pressed (the clutch is disengaged) as a first movement in the clutch start sequence (404), and subsequently, the clutch lever is released (the clutch is engaged) as a second movement in the clutch start sequence (406).
[00099] According to an embodiment of the present invention, this is a first valid sequence of predetermined inputs (501) for enabling an automatic start.
[000100] At 305, the system (100) has determined that the sequence of predetermined input commands at 406(a) is valid.
[000101] Figure 5(b) is an exemplary flow chart representing a second valid sequence of predetermined inputs (502) as shown in figure 4.
[000102] 303 is a precursor to this step in the process where a determination is made whether a previous stop was an automatic stop as represented in figure 2. The following step 304 determines the clutch and gear status of the vehicle. This determination is made so as to determine an initial reference state with respect to which, the sequence of predetermined input commands (304) can be delineated. As per an embodiment of the present invention, two distinct changes of state in the clutch lever are required to delineate the clutch start sequence being input.
[000103] At 404(b), step 304 has been executed by the system (100) and it is determined that the initial reference state is that the gear is at a neutral position and the clutch is in an disengaged state, i.e., the clutch lever is in a pressed state.
[000104] At 406(b), 404 and 406 are implemented by the system. A determination is made that while the gear is at a neutral state and the initial reference state of the clutch lever is being in a pressed state, the clutch lever is released (the clutch is engaged) as a first movement in the clutch start sequence (404), and subsequently, the clutch lever is pressed (the clutch is disengaged) as a second movement in the clutch start sequence (406).
[000105] According to an embodiment of the present invention, this is a second valid sequence of predetermined inputs (502) for enabling an automatic start.
[000106] At 305, the system (100) has determined that the sequence of predetermined input commands at 406(a) is valid.
[000107] Figure 5(c) is an exemplary flow chart representing a third valid sequence of predetermined inputs (503) as shown in figure 4.
[000108] 303 is a precursor to this step in the process where a determination is made whether a previous stop was an automatic stop as represented in figure 2. The following step 304 determines the clutch and gear status of the vehicle. This determination is made so as to determine an initial reference state with respect to which, the sequence of predetermined input commands (304) can be delineated. As per an embodiment of the present invention, three distinct changes of state in the clutch lever are required to delineate the clutch start sequence being input.
[000109] At 404(c), step 304 has been executed by the system (100) and it is determined that the initial reference state is that the gear is at a non-neutral position and the clutch is in an engaged state, i.e., the clutch lever is in a released state.
[000110] At 406(c), 404, 406 and 408 are implemented by the system. A determination is made that while the gear is at a non-neutral state and the initial reference state of the clutch lever is being in a released state, the clutch lever is pressed (the clutch is disengaged) as a first movement in the clutch start sequence (404), and subsequently, the clutch lever is released (the clutch is engaged) as a second movement in the clutch start sequence (406), and subsequently, the clutch lever is pressed (the clutch is disengaged) as a third movement in the clutch start sequence (408).
[000111] According to an embodiment of the present invention, this is a third valid sequence of predetermined inputs (503) for enabling an automatic start.
[000112] At 305, the system (100) has determined that the sequence of predetermined input commands at 406(c) is valid.
[000113] Figure 5(d) is an exemplary flow chart representing a fourth valid sequence of predetermined inputs (504) as shown in figure 4.
[000114] 303 is a precursor to this step in the process where a determination is made whether a previous stop was an automatic stop as represented in figure 2. The following step 304 determines the clutch and gear status of the vehicle. This determination is made so as to determine an initial reference state with respect to which, the sequence of predetermined input commands (304) can be delineated. As per an embodiment of the present invention, two distinct changes of state in the clutch lever are required to delineate the clutch start sequence being input.
[000115] At 404(d), step 304 has been executed by the system (100) and it is determined that the initial reference state is that the gear is at a non-neutral position and the clutch is in an disengaged state, i.e., the clutch lever is in a pressed state.
[000116] At 406(d), 404 and 406 are implemented by the system. A determination is made that while the gear is at a non-neutral state and the initial reference state of the clutch lever is being in a pressed state, the clutch lever is released (the clutch is engaged) as a first movement in the clutch start sequence (404), and subsequently, the clutch lever is pressed (the clutch is disengaged) as a second movement in the clutch start sequence (406).
[000117] According to an embodiment of the present invention, this is a fourth valid sequence of predetermined inputs (504) for enabling an automatic start.
[000118] At 305, the system (100) has determined that the sequence of predetermined input commands at 406(d) is valid.
[000119] Figure 6 is an exemplary functional flow diagram representing the automatic start process (600) as it is being implemented by the system (100). As per an embodiment of the present invention, the process described herein is implemented by the system one or more times in a given interval of time.
[000120] The process starts at 601. At 602, the system (100) determines whether the previous stop was an automatic stop (303). If it is determined by the system (100) that the previous stop was not an automatic stop, the process ends. If it is determined that the previous stop was an automatic stop, the system (100) proceeds to 603.
[000121] At 604, it has been determined at 603 that the vehicle is in neutral gear position. Here, a further determination is made by the system (100) as to the position of the clutch for the initial reference state of the clutch. The clutch of the transmission of the vehicle is at one of two states, engaged and disengaged. The clutch being at an engaged state implies that the clutch lever is at a released state, and the clutch being at a disengaged state means that the clutch lever is at a pressed state.
[000122] Similarly, at 605, it has been determined at 603 that the vehicle is in a non-neutral gear position. Here, a further determination is made by the system (100) as to the position of the clutch for the initial reference state of the clutch. The clutch of the transmission of the vehicle is at one of two states, engaged and disengaged. The clutch being at an engaged state implies that the clutch lever is at a released state, and the clutch being at a disengaged state means that the clutch lever is at a pressed state.
[000123] At 606 (a), it has been determined that the clutch is engaged following the determination made in 604, and the method in 501 is implemented by the system to enable an automatic start. While the gear is at a neutral state and the initial reference state of the clutch lever is being in a released state, the clutch lever is pressed (the clutch is disengaged) as a first movement in the clutch start sequence (404), and subsequently, the clutch lever is released (the clutch is engaged) as a second movement in the clutch start sequence (406). According to an embodiment of the present invention, this is a first valid clutch start sequence of predetermined inputs (501) for enabling an automatic start.
[000124] At 606 (b), it has been determined that the clutch is disengaged following the determination made in 604, and the method in 502 is implemented by the system to enable an automatic start. While the gear is at a neutral state and the initial reference state of the clutch lever is being in a pressed state, the clutch lever is released (the clutch is engaged) as a first movement in the clutch start sequence (404), and subsequently, the clutch lever is pressed (the clutch is disengaged) as a second movement in the clutch start sequence (406). According to an embodiment of the present invention, this is a second valid sequence of predetermined inputs (502) for enabling an automatic start.
[000125] At 606 (c), it has been determined that the clutch is engaged following the determination made in 605, and the method in 503 is implemented by the system to enable an automatic start. While the gear is at a non-neutral state and the initial reference state of the clutch lever is being in a released state, the clutch lever is pressed (the clutch is disengaged) as a first movement in the clutch start sequence (404), and subsequently, the clutch lever is released (the clutch is engaged) as a second movement in the clutch start sequence (406), and subsequently, the clutch lever is pressed (the clutch is disengaged) as a third movement in the clutch start sequence (408). According to an embodiment of the present invention, this is a third valid sequence of predetermined inputs (503) for enabling an automatic start.
[000126] At 606 (d), it has been determined that the clutch is disengaged following the determination made in 605, and the method in 504 is implemented by the system to enable an automatic start. While the gear is at a non-neutral state and the initial reference state of the clutch lever is being in a pressed state, the clutch lever is released (the clutch is engaged) as a first movement in the clutch start sequence (404), and subsequently, the clutch lever is pressed (the clutch is disengaged) as a second movement in the clutch start sequence (406). According to an embodiment of the present invention, this is a fourth valid sequence of predetermined inputs (504) for enabling an automatic start.
[000127] Once the automatic start has been enabled following the determination of the clutch start sequence, the system ends (607).
[000128] Figure 7 is an exemplary graphical representation of the method 200 for an automatic stop being implemented by the system. This representation is according to an embodiment of the current invention, wherein the automatic stop is actuated by disabling the fuel injection of the vehicle. This results in no combustion of fuel when the piston of the power unit is at TDC between the combustion and power strokes in the power unit. For the purpose of representation, the operation of the power unit is shown between two instances of time, t0 and t2. At an instant t1 between t0 and t2, the fuel injection is disabled by the system when the conditions for automatic stop are met as per 200. At the instant t1, the fuel injection is disabled, while the ignition remains enabled. Because no fuel is being delivered to the combustion chamber, the engine stops. This is represented by the gradual decrease in the engine speed between t1 and t2.
[000129] Figure 8 is an exemplary graphical representation of the method (300, 400, 501) for an automatic start being implemented by the system. This representation is according to an embodiment of the present invention. According to this embodiment, a first clutch start sequence is being input by the driver of the vehicle. Also according to this embodiment, the gear is at a neutral position. While the clutch lever is in a pressed state, the clutch is disengaged, and while the clutch lever is in a released state, the clutch is engaged. Also, according to the present embodiment, the previous stop of the vehicle has been an automatic stop. At the instant t3, the clutch state is changed from engaged to disengaged, that is, the clutch lever pressed from a reference released state. At the instant t4, the clutch state is changed from disengaged to engaged, that is, the clutch lever is released from a previous pressed state. Following the two states of change in the clutch lever, the automatic start of the power unit is enabled, as is shown in the graphical representation of the engine speed which is shown to increase from an idle state.
[000130] Figure 9 is an exemplary graphical representation of the method (300, 400, 502) for an automatic start being implemented by the system. This representation is according to an embodiment of the present invention. According to this embodiment, a second clutch start sequence is being input by the driver of the vehicle. Also, according to this embodiment, the gear is at a neutral position. While the clutch lever is in a pressed state, the clutch is disengaged, and while the clutch lever is in a released state, the clutch is engaged. Also, according to the present embodiment, the previous stop of the vehicle has been an automatic stop. At the instant t5, the clutch state is changed from disengaged to engaged, that is, the clutch lever is released from a reference pressed state. At the instant t4, the clutch state is changed from engaged to disengaged, that is, the clutch lever is pressed from a previous released state. Following the two states of change in the clutch lever, the automatic start of the power unit is enabled, as is shown in the graphical representation of the engine speed which is shown to increase from an idle state.
[000131] Figure 10 is an exemplary graphical representation of the method (300, 400, 503) for an automatic start being implemented by the system. This representation is according to an embodiment of the present invention. According to this embodiment, a third clutch start sequence is being input by the driver of the vehicle. Also, according to this embodiment, the gear is at a non-neutral position. While the clutch lever is in a pressed state, the clutch is disengaged, and while the clutch lever is in a released state, the clutch is engaged. Also, according to the present embodiment, the previous stop of the vehicle has been an automatic stop. According to the present embodiment, at the instant t7, the gear is changed to a non-neutral position from a reference neutral position. Also, At the instant t7, the clutch state is changed from engaged to disengaged, that is, the clutch lever pressed from a reference released state. At the instant t8, the clutch state is changed from disengaged to engaged, that is, the clutch lever is released from a previous pressed state. At the instant t9, the clutch state is changed from engaged to disengaged, that is, the clutch lever pressed from a reference released state. Following the three states of change in the clutch lever, the automatic start of the power unit is enabled, as is shown in the graphical representation of the engine speed which is shown to increase from an idle state.
[000132] Figure 11 is an exemplary graphical representation of the method (300, 400, 504) for an automatic start being implemented by the system. This representation is according to an embodiment of the present invention. According to this embodiment, a fourth clutch start sequence is being input by the driver of the vehicle. Also, according to this embodiment, the gear is at a non-neutral position. While the clutch lever is in a pressed state, the clutch is disengaged, and while the clutch lever is in a released state, the clutch is engaged. Also, according to the present embodiment, the previous stop of the vehicle has been an automatic stop. According to the present embodiment, at the instant t10, the gear is changed to a non-neutral position from a reference neutral position. At the instant t11, the clutch state is changed from disengaged to engaged, that is, the clutch lever is released from a reference pressed state. At the instant t12, the clutch state is changed from engaged to disengaged, that is, the clutch lever is pressed from a previous released state. Following the two states of change in the clutch lever, the automatic start of the power unit is enabled, as is shown in the graphical representation of the engine speed which is shown to increase from an idle state.
[000133] Figure 12 is an exemplary graphical representation of the advantages of the present invention in decline of hydrocarbon emissions as a result of the present method being implemented. the values on the x axis represent time, whereas the values on the y axis represents the hydrocarbons being emitted by the power unit, measured in parts per million. The dashed line with circular markers represents the conventional methods being used at the moment. The results of the current method of implementing an automatic start stop system are shown in the graph with a continuous line with square markers. Clearly the emissions as a result of the current method being implemented are lower than the existing methods.
[000134] In light of the above-mentioned advantages and the technical advancements provided by the disclosed method and system, the claimed steps as discussed above are not routine, conventional, or well understood in the art, as the claimed steps enable the above-mentioned solutions to the existing problems in conventional technologies. Further, the claimed steps clearly bring an improvement in the functioning of the system itself as the claimed steps provide a technical solution to a technical problem.
, C , Claims:We Claim:
1. A method for automatically starting a vehicle (300) after an automatic stop (207), said method comprising the steps:
determining, by an engine management system (EMS) controller (101), a previous power unit stop being an automatic stop (303),
determining, by the EMS controller (101), a gear position and a clutch lever position (304),
determining, by the EMS controller (101), a clutch start sequence being input by a driver of said vehicle (305),
2. The method as claimed in claim 1, wherein determining a clutch start sequence being input includes:
receiving, by the EMS controller (101), one or more change of state of said clutch lever from said state sensor
determining, by the EMS controller (101), one or more change of state in a clutch lever (404, 406, 408) of said vehicle based on inputs received from a state sensor (switch), wherein said one or more change of state in a clutch lever (404, 406, 408) being a start sequence,
determining, by the EMS controller (101), said start sequence being valid (501, 502, 503, 504),
initiating, by the EMS controller (101), automatic engine start when said clutch start sequence being valid (307).
3. The method as claimed in claim 1, wherein determination of whether a previous power unit stop being an automatic stop (303) comprises said control unit being configured to retrieve data from a memory unit within said control unit (101), said data being processed by said control unit to determine whether a previous power unit stop being an automatic stop.
4. The method as claimed in claim 1, wherein said state sensor being a switch configured to determine said state of said clutch lever.
5. The method as claimed in claim 1, wherein said one or more change of state in said clutch lever (404, 406, 408) being at least two changes in state of said clutch lever (404, 406), wherein, said change of state being a force being applied on said lever, resulting in said lever being in one of a pressed state and a released state.
6. The method as claimed in claim 4, wherein said pressed state of said clutch lever corresponding to a clutch plate disengaging a power unit and a transmission unit of said vehicle, and said released state of said clutch lever corresponding to said clutch plate engaging a power unit and a transmission unit of said vehicle.
7. The method as claimed in claim 4, wherein said method being initiated upon first determining an automatic start-stop switch being actuated to activate an automatic start stop system, said method not being initiated upon said automatic start stop switch not being actuated.
8. The method as claimed in 1, determining said gear position (304) includes determining said gear being in one of a neutral position and a non-neutral position.
9. The method as claimed in claim 7, wherein, said clutch start sequence comprising a sequence of two or more movements of said clutch lever, wherein,
said control unit (101) determining said validity of said start sequence by considering said change of state in said clutch lever and said gear together, and
said valid start sequence being a predetermined sequence of change of state in said clutch lever movements with respect to a refence initial gear and clutch position.
10. The method as claimed in claim 8, wherein said gear position being determined, and a determination of said start sequence being input includes:
determination that a first movement of said start sequence being actuated in said clutch lever,
determination that an at least second movement of said start sequence being actuated in said clutch lever,
wherein,
determination of an at most third movement in said start sequence, said third movement being required in one or more said start sequences.
11. The method as claimed in claim 9 , wherein said start sequence being a first start sequence, wherein said gear position being determined to be neutral, and said clutch lever being in said released state, said first start sequence includes:
a first change of state of said clutch lever (404), said change being to said pressed state from said released state, and
a second change of state of said clutch lever (406), said change being to said released state from said pressed state.
12. The method as claimed in claim 9, wherein said start sequence being a second start sequence, wherein said gear position being determined to be neutral, and said clutch lever being in said pressed state, said second start sequence includes:
a first change of state of said clutch lever (404), said change being to said released state from said pressed state, and
a second change of state of said clutch lever (406), said change being to said pressed state from said released state.
13. The method as claimed in claim 9, wherein said start sequence being a third start sequence, wherein said gear position being determined to be non-neutral, and said clutch lever being in said released state, said third start sequence includes:
a first change of state of said clutch lever (404), said change being to said pressed state from said released state,
a second change of state of said clutch lever (406), said change being to said released state from said pressed state, and
a third change of state of said clutch lever (408), said change being to said pressed state from said released state.
14. The method as claimed in claim 9, wherein said start sequence being a fourth start sequence, wherein said gear position being determined to be non-neutral, and said clutch lever being in said pressed state, said fourth start sequence includes:
a first change of state of said clutch lever (404), said change being to said released state from said pressed state,
a second change of state of said clutch lever (406), said change being to said pressed state from said released state.
15. The method as claimed in claim 1, further including a method for reducing hydrocarbon emission during the automatic start of a vehicle after an automatic stop, wherein, an automatic stop (200) procedure comprising:
determining, by the EMS controller (101), the engine being in an idling condition (202),
determining, by the EMS controller (101), all of one or more predetermined conditions for automatic stop being satisfied (204),
determining, by the EMS controller (101), all of one or more sensors not communicatively transmitting erroneous data (205), and
actuating, by the EMS controller (101), a fuel injector to stop fuel injection (206) in said engine.
16. The method as claimed in claim 14, wherein said predetermined conditions for automatic stop (207) include:
a vehicle speed being less than a predetermined value of said vehicle speed,
a throttle actuation level being less that a predetermined value of said throttle actuation level, and
an engine speed being less than a predetermined value of said engine speed.
17. The method as claimed in claim 14, wherein stopping said fuel injection while an ignition pulse being active combusts any remaining fuel in a combustion chamber of said engine for achieving reduced hydrocarbon emission during a subsequent automatic start.
18. The method as claimed in claim 14, wherein determining a start sequence being input by a driver of said vehicle being valid comprises determining a gear position and an initial clutch position, wherein, said determining one or more change of state in a clutch lever of said vehicle.
19. The method as claimed in claim 17, wherein said start sequence being said one or more change of state in said clutch lever, corresponding to said determined gear position, and said determined initial clutch position.
20. A system (100) for implementing one of a method (200) to actuate an automatic stop (207) and a method (300) to actuate an automatic start (307), said system comprising an EMS controller (101), a plurality of sensors, and a plurality of actuators, the EMS controller (101) is configured to:
determine a previous power unit stop being an automatic stop (303),
determine a gear position and a clutch lever position (304),
determine a clutch start sequence being input by a driver of said vehicle (305).
21. The system (100) as claimed in claim 20, wherein said plurality of sensors comprising, a throttle position sensor (102), a manifold pressure sensor (103), an intake air temperature sensor (104), an engine temperature sensor (105), a crank position sensor (106), a lambda sensor (107), a clutch sensor, and a gear sensor.
22. The system (100) as claimed in claim 20, wherein said plurality of actuators comprises a fuel injector (112), an idle air control valve (113), a canister purge valve (114), an ignition coil (115), a secondary air injection valve (116), and a lambda sensor heater (117).
23. The system (100) as claimed in claim 20, wherein said controller (101) being configured to communicatively receive a plurality of data from said sensors.
24. The system (100) as claimed in claim 20, wherein said controller (101) being configured to one of enable and disable said actuators.
25. The system (100) as claimed in claim 20, wherein determining said gear position (304) includes determining said gear being in one of a neutral position and a non-neutral position.
26. The system (100) as claimed in claim 20, wherein said clutch start sequence comprising a sequence of two or more movements of said clutch lever, wherein,
said control unit (101) is configured to determine said validity of said start sequence by considering said change of state in said clutch lever and said gear together, and
said valid start sequence being a predetermined sequence of change of state in said clutch lever movements with respect to a refence initial gear and clutch position.
27. The system (100) as claimed in claim 20, wherein said gear position being determined, and a determination of said start sequence being input includes:
determination that a first movement of said start sequence being actuated in said clutch lever,
determination that an at least second movement of said start sequence being actuated in said clutch lever,
wherein,
determination of an at most third movement in said start sequence, said third movement being required in one or more said start sequences.
28. The system (100) as claimed in claim 20, wherein said clutch sensor being configured to delineate the state of a clutch lever, said state of clutch lever being one of a pressed state and a released state.
29. The system (100) as claimed in claim 20, wherein said gear sensor being configured to delineate the state of a gear, said state of gear being one of a neutral state and a non-neutral state.