Control systems for internal combustion engines

Abstract

A vehicle (10) is provided. The vehicle (10) includes an internal combustion engine (22) having a combustion chamber (64), a crankshaft (58), an intake manifold (302), a manifold absolute pressure (MAP) sensor (308) for detecting pressure in the intake manifold (302), and a crank angle sensor (328) for detecting an angular position of the crankshaft (58). The vehicle (10) also includes a control system (300) configured to control the engine (22). The control system (300) includes an electronic control unit (ECU) (310) that is in electronic communication with a spark plug (318), a MAP sensor (308), and a crank angle sensor (328). The ECU (310) is configured to receive an output from each of the MAP sensor (308) and the crank angle sensor (328) to determine a rotation direction of the crankshaft (58) based on the output from each of the MAP sensor (308) and the crank angle sensor (328).

Description

Technical Field

[0001] The present invention relates to an internal combustion engine, and more particularly to a control system for an internal combustion engine. Background Art

[0002] In order to improve the efficiency and emissions-related performance of internal combustion engines, direct injection systems have evolved. By injecting fuel directly into the combustion chamber or intake manifold of an internal combustion engine, many advantages can be achieved. One of these advantages is the ability to run the engine with a substoichiometric mixture.

[0003] In various types of engines, for example in single cylinder internal combustion engines, the ignition system is controlled by a control unit. The control unit controls the movement of the crankshaft and the ignition of the ignition system. Thus, the control unit controls the movement of the crankshaft and the ignition of the ignition system so that the ignition system ignites during the forward rotation of the crankshaft, i.e. when the piston moves from TDC to BDC. The control unit also ensures that the ignition from the ignition system is resisted during the reverse rotation of the crankshaft, i.e. when the piston moves from BDC to TDC.

[0004] However, in certain types of engines, for example where the control unit controls the ignition system and a separate controller such as an ISG ACG controller controls the movement of the crankshaft, it is often difficult to ensure that ignition from the ignition system is resisted during reverse rotation of the crankshaft. Summary of the invention

[0005] In one aspect of the present invention, a vehicle is provided. The vehicle includes an internal combustion engine and a control system. The internal combustion engine includes a combustion chamber defined by a cylinder head and a crankcase. The internal combustion engine also has a crankshaft disposed in the crankcase. The internal combustion engine also includes a spark plug disposed in the combustion chamber for igniting the charge therein. The internal combustion engine includes an intake manifold and an exhaust manifold fluidically coupled to the combustion chamber. The internal combustion engine also includes a rotary electric machine configured to act as a starter motor for rotating a crankshaft of the internal combustion engine when the engine is started. The internal combustion engine includes a manifold absolute pressure sensor disposed in the intake manifold. The MAP sensor is configured to detect the pressure in the intake manifold. The internal combustion engine also includes a crank angle sensor provided with an ISG. The crank angle sensor is configured to detect the angular position of the crankshaft of the internal combustion engine and the engine speed. The control system is configured to control the internal combustion engine. The control system includes an electronic control unit that electronically communicates with the MAP sensor and the crank angle sensor. The electronic control unit is configured to receive an output from each of the MAP sensor and the crank angle sensor to determine a rotational direction of the crankshaft based on the output from each of the MAP sensor and the crank angle sensor.

[0006] In one embodiment, the electronic control unit is further configured to selectively allow and limit the firing of the spark plug in response to the determination of the rotational direction of the crankshaft. In one embodiment, the rotary electric machine is mounted on the crankshaft and includes at least one reference tooth and a plurality of teeth, wherein the at least one reference tooth indicates a predetermined position on the crankshaft and the plurality of teeth are angularly positioned along the circumference of the rotary electric machine. Each of the plurality of teeth from the reference tooth indicates a predetermined angular position of the crankshaft.

[0007] In one embodiment, the reference teeth have a predetermined profile or are in the form of missing teeth. In one embodiment, the MAP sensor generates a voltage signal in response to the sensed pressure in the intake manifold, and the crank angle sensor generates a voltage signal indicative of the crank angle position. The voltage signals generated by the MAP sensor and the crank angle sensor are transmitted to the electronic control unit.

[0008] In one embodiment, if the voltage generated by the MAP sensor at a predetermined time of the PIP signal is above a predetermined threshold stored in the electronic control unit, the crankshaft rotates in a first rotational direction (D1). In one embodiment, the crank angle sensor generates a surface ignition sensing (PIP) signal indicative of the angular position of the crankshaft.

[0009] In one embodiment, the rotation direction of the crankshaft is determined by the electronic control unit based on a voltage signal of the MAP sensor at a predetermined angular position of the crankshaft. In one embodiment, the predetermined angular position of the crankshaft is a first tooth of the plurality of teeth that is located after a reference tooth. In one embodiment, if the voltage generated by the MAP sensor at the predetermined angular position of the crankshaft is higher than a predetermined threshold value stored in the electronic control unit, the crankshaft rotates in a first rotation direction (D1).

[0010] In one embodiment, if the voltage generated by the MAP sensor at a predetermined angular position of the crankshaft is lower than a predetermined threshold value stored in the electronic control unit, the crankshaft rotates in a second rotational direction (D2). In one embodiment, the first rotational direction (D1) is a reverse direction and the second rotational direction (D2) is a forward direction. In one embodiment, the rotating electrical machine is an integrated starter generator (ISG). In one embodiment, the crank angle sensor is a pulse coil. In one embodiment, the crank angle sensor is a Hall effect sensor. In one embodiment, the electronic control unit (ECU) does not allow the spark plug to be fired until it determines the rotational direction of the crankshaft.

[0011] In one embodiment, the rotation direction of the crankshaft is determined by the electronic control unit based on a first voltage signal of the MAP sensor at a first predetermined angular position of the crankshaft and a second voltage signal of the MAP sensor at a second predetermined angular position of the crankshaft.

[0012] In one embodiment, if a first voltage generated by the MAP sensor at a first predetermined angular position of the crankshaft and a second voltage generated by the MAP sensor at a second predetermined angular position of the crankshaft are higher than a predetermined threshold value stored in an electronic control unit, the crankshaft rotates in a first rotational direction (D1); and if the first voltage generated by the MAP sensor at the first predetermined angular position of the crankshaft and the second voltage generated by the MAP sensor at the second predetermined angular position of the crankshaft are lower than a predetermined threshold value stored in the electronic control unit, the crankshaft rotates in a second rotational direction.

[0013] In another aspect of the present invention, a method for controlling an internal combustion engine by a control system is provided. The method includes sensing air pressure in an intake manifold via a manifold absolute pressure (MAP) sensor; generating a MAP voltage signal representing the sensed air pressure; sensing an angular position of a crankshaft of the internal combustion engine via a crank angle sensor; generating a voltage signal representing the angular position of the crankshaft; and determining, by an electronic control device, a rotation direction of the crankshaft based on the MAP voltage signal generated at a predetermined position of the crankshaft.

[0014] In one embodiment, the electronic control unit controls the spark of the spark plug based on the determined rotational direction of the crankshaft. In one embodiment, the crankshaft rotates in a first rotational direction (D1) if a voltage generated by the MAP sensor at a predetermined angular position of the crankshaft is higher than a predetermined threshold value stored in the electronic control unit, wherein the electronic control unit limits the spark of the spark plug when the first rotational direction (D1) of the crankshaft is determined to rotate.

[0015] In one embodiment, the crankshaft rotates in a second rotational direction (D2) if a voltage generated by the MAP sensor at a predetermined angular position of the crankshaft is higher than a predetermined threshold stored in the electronic control unit, wherein the electronic control unit enables sparking of the spark plug when the crankshaft is determined to rotate in the first rotational direction (D2). BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention itself, as well as other features and advantages noted, will become apparent from the following detailed description considered in conjunction with the accompanying drawings. One or more embodiments of the invention will now be described by way of example only, wherein like reference numerals represent like elements, and in the accompanying drawings:

[0017] Figure 1 shows a side view of an exemplary two-wheeled vehicle according to an embodiment of the present invention;

[0018] Figure 2 A perspective view of a frame of an exemplary two-wheeled vehicle showing an embodiment of the present invention;

[0019] Figure 3A schematic diagram showing a control system and an internal combustion engine of a vehicle according to an embodiment of the present invention;

[0020] Figure 4 shows a parameter diagram of an internal combustion engine according to an embodiment of the present invention;

[0021] Figure 5 shows a parameter diagram of an internal combustion engine according to an embodiment of the present invention;

[0022] Figure 6 A method for controlling an internal combustion engine by a control system according to an embodiment of the present invention is shown;

[0023] Unless specifically noted, the drawings referred to in this specification should not be understood as being drawn to scale and such drawings are merely schematic in nature. DETAILED DESCRIPTION

[0024] Although the invention is susceptible to various modifications and alternative forms, embodiments of the invention have been shown by way of example in the accompanying drawings and will be described herein below. However, it should be understood that the invention is not intended to limit the invention to the particular form disclosed, but on the contrary, the invention will cover all modifications, equivalents and substitutes falling within the spirit and scope of the invention.

[0025] The terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a configuration, structure, or method that includes a list of components or steps includes not only those components or steps, but may include other components or steps not expressly listed or inherent to such configuration, structure, or method. In other words, without further constraints, one or more elements in a system or device beginning with "includes" does not exclude the presence of other or additional elements in the system or device.

[0026] For a better understanding of the present invention, reference will now be made to the embodiments shown in the drawings and the following description, and in the following drawings, like reference numerals are used to identify like parts throughout the various views.

[0027] In one aspect of the present invention, a control system for an internal combustion engine is shown. The internal combustion engine includes at least one combustion chamber, an intake manifold communicating with the combustion chamber, a fuel injector for injecting fuel directly into the combustion chamber, and at least one spark plug positioned on the combustion chamber for igniting the charge therein. The control system includes a MAP sensor disposed on the intake manifold, the MAP sensor configured to measure the intake manifold pressure; a crank angle sensor configured to determine the position of a crankshaft of the internal combustion engine; a control module adapted to receive an output of each of the MAP sensor and the crank angle sensor to determine a reverse rotation of the crankshaft; and an ignition system interacting with the control module and the spark plug, wherein the control system limits ignition of the spark plug by the ignition system during reverse rotation of the crankshaft.

[0028] However, although the present invention is described in the context of a vehicle, the control system and internal combustion engine and aspects and features thereof can also be used with other types of vehicles. The terms "vehicle", "two-wheeled vehicle" and "motorcycle" have been used interchangeably throughout the specification. The term "vehicle" includes vehicles such as motorcycles, scooters, bicycles, mopeds, scooter-type vehicles, all-terrain vehicles (ATVs), etc.

[0029] The terms “front / forward”, “back / backward / rearward / backwards”, “up / upward / top”, “down / lower / lower / downward, bottom”, “left / to the left”, and “right / rightward” used in this document indicate the directions seen by the vehicle driver when sitting astride, and these directions are represented by the arrows Fr, Rr, U, Lr, L, R in the accompanying drawings.

[0030] Reference Figure 1 , showing a vehicle (10) according to an embodiment of the present invention. The vehicle (10) referred to herein is implemented as a two-wheeled motorcycle. Alternatively, without limiting the scope of the present invention, the vehicle (10) may be implemented as any other riding type vehicle, such as a scooter, a tricycle, an all-terrain vehicle (ATV), etc.

[0031] The vehicle (10) includes one or more main body parts such as a frame (12), a handlebar (14), a front wheel (16), a seat (18), a rear wheel (20), an internal combustion engine (22), a headlight (24), and a fuel tank (26). The frame (12) supports the internal combustion engine (22) (hereinafter also referred to as the engine (22)) located in the middle part of the vehicle (10). In the example shown, the engine (22) provides the necessary power required to drive the rear wheel (20) of the vehicle (10). Alternatively, without limiting the scope of the present invention, the engine (22) can provide the necessary power to drive the front wheel (16), or to drive the front wheel (16) and the rear wheel (20) at the same time. The rear wheel (20) is connected to the engine (22) through a transmission mechanism (not numbered).

[0032] The frame (12) supports a seat (18) extending from a mid-section of the vehicle (10) toward a rear section (28). The seat (18) provides a seat for a driver and / or passenger of the vehicle (10). The fuel tank (26) provides the necessary fuel to the engine (22) to generate power within the vehicle (10).

[0033] like Figure 2 As shown, the frame (12) of the vehicle (10) includes a front tube (30), a main frame (32) and a lower frame (34). The main frame (32) extends downward and rearward from the rear portion of the front tube (30) to form a relatively gentle slope in a side view. The lower frame (34) extends downward and rearward in a manner of branching to the left and right, respectively, to form a relatively steep slope in a side view. The frame (12) includes a pair of lower frames (36). The pair of lower frames (36) are bent to extend rearward from the lower end of the lower frame (34).

[0034] In addition, the frame (12) includes a pair of intermediate frames (38). The pair of intermediate frames (38) extend downward and rearward from the main frame crossbar (40). The frame (12) includes a mounting bracket (42) coupled to the front side of the lower portion of the pair of intermediate frames (38). In addition, the frame (12) also includes a pair of sub-frame members (50). In one embodiment, the pair of sub-frame members (50) are implemented as a pair of seat frames, which are arranged behind the upper ends of the pair of corresponding intermediate frames (38). The frame (12) also supports the engine (22).

[0035] like Figure 3As shown, a system (300) for controlling an engine (22) is shown, which is also referred to as a control system (300). The engine (22), also interchangeably referred to as an "internal combustion engine (22)", includes a crankcase (52), a cylinder (54) connected to the crankcase (52), and a head portion (56) (also referred to as a cylinder head (56)) connected to the crankcase (52). In an alternative embodiment of the present disclosure, the internal combustion engine (22) includes a plurality of cylinders, such as cylinder (54), which are positioned in a straight line or at a certain angle relative to each other. The crankcase (52) contains a crankshaft (58), which is connected to a connecting rod (60). The connecting rod (60) is connected to a piston (62) contained in the cylinder (54). The piston (62) is configured to move within the cylinder (54), thereby causing the crankshaft (58) to rotate. Thus, the piston (62) moves between its TDC (top dead center) position and BDC (bottom dead center) position to rotate the crankshaft (58) along its axis of rotation (not shown). Alternatively, where the internal combustion engine (22) includes a plurality of cylinders, there may be a plurality of pistons, such as the piston (62), which reciprocate within the corresponding plurality of cylinders and are connected to the crankshaft (58).

[0036] In one embodiment, an internal combustion engine (22) includes an intake portion (302) and an exhaust portion (304) mounted on a cylinder (54). Specifically, the intake portion (302), also referred to as an "intake manifold (302)", and the exhaust portion (304), also referred to as an "exhaust manifold (304)", are connected to a top portion of the cylinder (54), i.e., a head portion (56). The intake manifold (302) and the exhaust manifold (304) are fluidly coupled to a combustion chamber (64).

[0037] like Figure 3 As shown, the internal combustion engine (22) further includes a butterfly valve (306), a MAP sensor (308), a fuel injector (312) and an intake valve (314). The intake portion (302) defines a passage extending to the cylinder (54) of the internal combustion engine (22). The passage defined by the intake portion (302) enters the combustion chamber (64) via the intake valve (314). The butterfly valve (306) is positioned in the intake portion (302). The butterfly valve (306) allows and restricts the entry of air through its open position and closed position. Therefore, the butterfly valve (306) allows air to enter in the open position and restricts air to enter in the closed position. In the example shown, the control system (300) includes an electronic control unit (ECU) (310). In another example, the internal combustion engine (22) includes an electronic control unit (ECU) (310) and is electronically and electrically connected to the control system (300) of the vehicle (100) without any limitation.

[0038] A MAP sensor (308), also referred to as a "manifold absolute pressure sensor (308)", is positioned on a passage defined by the intake portion (302). The MAP sensor (308) is electrically coupled to the ECU (310). In one embodiment, the MAP sensor (308) includes a probe (not numbered) positioned within the intake portion (302), a sensor voltage output connector (not numbered) extending from the probe to the ECU (310), a ground connector (not numbered) extending from the probe to the ECU (310), and a power connector (not numbered) extending from the probe to the ECU (310).

[0039] The MAP sensor (308) generates a voltage signal in response to the pressure sensed within the intake manifold (302). More specifically, the probe of the MAP sensor (308) is adapted to measure the pressure within the intake portion (302) and provide a corresponding output to the ECU (310). In one embodiment, the probe of the MAP sensor (308) is adapted to measure the pressure within the intake portion (302) and provide a corresponding voltage output to the ECU (310). A fuel injector (312) positioned adjacent to the MAP sensor (308) is connected to a fuel pump (not shown) and a fuel filter (316). The fuel injector (312) supplies fuel from the fuel pump and the fuel filter (316) to the intake portion (302) under the command of the ECU (310). Thus, the fuel injector (312) interacts with the ECU (310). The intake valve (314) is positioned upstream of the fuel injector (312), and so is the butterfly valve (306). The intake valve (314) selectively opens to the combustion chamber (64). When the intake valve (314) is open, intake air from the butterfly valve (308) and the fuel injector (312) is allowed to enter the combustion chamber (64). Likewise, when the intake valve (314) is closed, intake air from the butterfly valve (308) and the fuel injector (312) is not allowed to enter the combustion chamber (64).

[0040] As will be apparent to one skilled in the art, when intake air, also referred to as a "charge," is admitted into the combustion chamber (64), and when an ignition system (319) controlled by a controller or ECU (310) causes a spark plug (318) to generate a spark, the charge is ignited in the combustion chamber (64). The charge in the combustion chamber (64) is ignited, causing the piston to move rearwardly, and subsequently the combusted gases are exhausted from the combustion chamber (64) via an exhaust valve (320) positioned in an exhaust portion (304) of the internal combustion engine (22). In one embodiment, an O2 sensor (not numbered) is disposed on the exhaust portion (304), adjacent to the exhaust valve (320).

[0041] like Figure 3As shown, the internal combustion engine (22) further includes a rotating electric machine (322). In one example, the rotating electric machine can be an integrated starter generator (ISG) (322). In one example, the integrated starter generator (322) can be an ISG ACG. Specifically, the integrated starter generator (322) is connected to the crankshaft (58) of the internal combustion engine (22). The integrated starter generator (322) communicates with the ISG controller (324). The ISG controller (324) is suitable for operating the integrated starter generator (322), that is, suitable for enabling the integrated starter generator (322) to function interchangeably as a starter or a generator. It may be obvious to those skilled in the art that when operating as a generator, the integrated starter generator (322) receives power from the crankshaft (58) of the internal combustion engine (22) and generates electrical energy. On the other hand, when operating as a starter, the integrated starter generator (322) provides rotational motion to the crankshaft (58) to promote combustion in the combustion chamber (64) of the internal combustion engine (22).

[0042] The internal combustion engine (22) further includes a pulse wheel (not shown) having a plurality of teeth (326) (hereinafter alternatively referred to as PIP (326)). In the example shown, the pulse wheel (326) having a plurality of teeth is disposed on the ISG (322). In another example, the pulse wheel having a plurality of teeth (326) is disposed on the crankshaft (58), without limiting the scope of the present invention. In one example, the plurality of teeth (326) of the integrated starter generator (322) are implemented as a predetermined number of metal protrusions disposed in an equidistant manner on the outer peripheral surface of the integrated starter generator (322). The plurality of teeth (326) are angularly equidistantly spaced along the periphery of the pulse wheel. The pulse wheel includes missing teeth in an area where the angular separation between the plurality of teeth (326) is large. In an alternative embodiment, the missing teeth are implemented as reference teeth. The missing teeth represent a predetermined position on the crankshaft (58), and each tooth of the plurality of teeth (326) positioned starting from the missing teeth represents various predetermined angular positions of the crankshaft (58). In one example, the number of predefined metal protrusions on the outer circumferential surface of the integrated starter generator (322) is "18-1". Therefore, in such an embodiment, there are 17 teeth followed by gaps, i.e., missing teeth. In another example, the number of predefined metal protrusions on the outer circumferential surface of the integrated starter generator (322) is "22-1". Therefore, in such an embodiment, there are 21 teeth followed by gaps, i.e., missing teeth. The internal combustion engine (22) also includes a sensor (328) for measuring the position of the crankshaft (58). In one embodiment, the sensor (328) for measuring the position of the crankshaft (58) can be a crank angle sensor.

[0043] In one embodiment, a sensor (328) for measuring the position of the crankshaft (58) is positioned on the outer peripheral surface of the integrated starter generator (322). The sensor (328) is positioned on the outer peripheral surface of the integrated starter generator (322) so that the sensor (328) can sense and generate a pulse accordingly each time a pip passes near it. Similarly, no pulse is generated each time a gap passes near the sensor (328). Therefore, in an embodiment where the number of predetermined metal protrusions on the outer peripheral surface of the integrated starter generator (322) is "18-1", during the movement of the integrated starter (322), the sensor (328) generates 17 pulses for each full rotation of the integrated starter generator (322), followed by a gap. In this context, it can be noted that the sensor (328) is configured to generate pulses regardless of the rotation direction of the integrated starter generator (322), whether in the first rotation direction (D1) or in the second rotation direction (D2). In the example shown, the first rotation direction (D1) is the reverse direction and the second rotation direction (D2) is the forward direction. In the example shown, the forward and reverse directions may be clockwise or counterclockwise, depending on requirements and the configuration of the engine.

[0044] The sensor (328) is electrically coupled to the ECU (310). Due to the coupling of the sensor (328) to the ECU (310), the measurement of the pulses and the absence of pulses are transmitted to the ECU (310). In one embodiment, the sensor (328) for measuring the position of the crankshaft (58) of the engine (22) may be a pulse coil. Alternatively, the sensor (328) for measuring the position of the crankshaft (58) of the engine (22) may be a HAL effect sensor, also referred to as a HAL sensor.

[0045] like Figure 3 As shown, the control system (300) includes a MAP sensor (308), a crank angle sensor (328), and an ECU (310) in communication with each of the MAP sensor (308) and the crank angle sensor (328). Therefore, the ECU (310), also referred to as the control module (310), is configured to receive input related to the pressure at the intake portion (302) as measured by the MAP sensor (308). Likewise, the control module (310) is configured to receive input related to the angular position of the crankshaft (58) as measured by the crank angle sensor (328). The MAP sensor (308) generates a voltage signal in response to the sensed pressure within the intake manifold (302), and the crank angle sensor (58) generates a surface ignition sensing (PIP) signal indicative of the angular position of the crankshaft. The voltage signal and the PIP signal generated by the MAP sensor (308) are transmitted to the electronic control unit (310).

[0046] Now refer to Figure 4 and Figure 5 , these graphs show the output value from the MAP sensor (308) and the output value from the crank angle sensor (328). The output of the MAP sensor (308) is directly proportional to the absolute pressure of the intake manifold (302). Therefore, the output of the MAP sensor (308) represents the absolute pressure of the intake manifold (302). Figure 4 and Figure 5 As shown, MAP sensor output line (330) represents the MAP sensor voltage. When the vehicle (10) is started and running, the pressure at the intake manifold (302) changes, and accordingly the output of the MAP sensor (308) also changes as indicated by the MAP sensor output line (330).

[0047] The control module (310) interacts with the MAP sensor (308) to receive its output to determine when the voltage, and therefore the pressure, at the intake manifold (302) is above a predetermined threshold. In another embodiment, the control module (310) is adapted to determine when the pressure of the intake manifold is below a predetermined threshold. In yet another embodiment, the control module (310) is adapted to determine when the pressure of the intake manifold falls within a predetermined threshold range. In one example, the control module (310) is adapted to determine that the voltage corresponding to the pressure of the intake manifold (302) is above 2.77 volts.

[0048] The output of the crank angle sensor (328) is in the form of pulses and is represented by the crank angle sensor pulse line (332). Figure 4 and Figure 5As shown. When the vehicle (10) is started and running, the position of the crankshaft (58) changes, and the crank angle sensor (328) senses each time a pip passes near it and generates a pulse accordingly. Similarly, no pulse is generated each time a gap passes near the sensor (328). The control module (310) also interacts with the crank angle sensor (328) to receive its output. Based on the output of the crank angle sensor (328) and the MAP sensor (308), the control module (310) determines the rotation direction of the crankshaft (58). More specifically, the rotation direction of the crankshaft (58) is determined by the electronic control unit (310) based on the voltage signal generated by the MAP sensor (308) at any predetermined time related to the PIP signal indicating the angular position of the crank angle sensor (328). The control module (310) determines that the crankshaft (58) rotates in a first rotational direction (D1) if the voltage generated by the MAP sensor (308) at a predetermined time of the PIP signal is above a predetermined threshold stored in the electronic control unit (310). The control module (310) determines that the crankshaft (58) rotates in a second rotational direction (D2) if the voltage generated by the MAP sensor (308) at a predetermined time of the PIP signal is below a predetermined threshold stored in the electronic control unit (310). The predetermined time of the PIP signal is selected from any one of predetermined angular positions of the crankshaft (58), wherein the angular position of the crankshaft (58) is represented by a plurality of teeth (326).

[0049] In one embodiment, based on the output of the crank angle sensor (328) and the MAP sensor (308), the control module (310) determines the reverse rotation of the crankshaft (58). The control module (310) also interacts with the injection system and is adapted to limit the ignition system (319) from firing the spark plug (318) during the reverse rotation of the crankshaft (58).

[0050] In one embodiment, the control module (310) determines that the rotation direction of the crankshaft (58) is a forward direction when the output of the MAP sensor (308) is above a predetermined threshold and senses a gap in the output pulse of the crank angle sensor (328). For example, when the control module (310) senses that the output of the MAP sensor (308) is above approximately 2.77 volts and the crank angle sensor (328) senses the first pulse after the gap, the control module (310) determines that the crankshaft (58) is rotating in a reverse direction. In other examples, the control module (310) makes the following determination: if the ADC value @ first Pip < a reference voltage (e.g., 2.5 V), the engine (22) is rotating in a forward direction, and if the ADC value @ first Pip > the reference voltage, the engine (22) is rotating in a reverse direction.

[0051] Reference Figure 6, depicting a method (400) of controlling an internal combustion engine by a control system (300). In step 402, a MAP sensor (308) senses air pressure within an intake manifold (322). In step 404, the MAP sensor (308) generates a MAP voltage signal (330) representative of the sensed air pressure. In step 406, a crank angle sensor (328) senses an angular position of a crankshaft (58). In step 408, the crank angle sensor (328) generates a surface ignition sensing signal (332) representative of the angular position of the crankshaft (58). In step 410, the ECU (310) determines a rotational direction of the crankshaft (58) based on the MAP voltage signal (330) and the surface ignition sensing signal (322) generated at a predetermined time.

[0052] The electronic control unit (310) controls the spark of the spark plug (318) based on the determined rotation of the crankshaft (58). If the voltage generated by the MAP sensor (308) at a predetermined time of the PIP signal (332) is higher than a predetermined threshold stored in the electronic control unit (310), the crankshaft rotates in a first rotation direction (D1), wherein when the first rotation direction (D1) of the crankshaft is determined to rotate, the electronic control unit (310) limits the spark of the spark plug (318). If the voltage generated by the MAP sensor (308) at a predetermined time of the PIP signal (332) is lower than a predetermined threshold stored in the electronic control unit (310), the crankshaft (58) rotates in a second rotation direction (D2). When the second rotation direction (D2) of the crankshaft (58) is determined to rotate, the electronic control unit (310) allows the spark of the spark plug (318).

[0053] During use of a vehicle (10) having a control system (300), when an ignition request for the engine (22) is registered, such as when a rider turns an ignition key, the control system (300) begins receiving intake manifold (302) pressure values ​​from the MAP sensor (308). During this time, the ISG controller (324) causes the ISG to rotate the crankshaft (58). For example, when the piston (62) is in a BDC (bottom dead center) position, the ISG rotates the crankshaft (58) to move the piston from the BDC position to the TDC (top dead center) position. In another example, when the piston (62) is in any position other than TDC, the ISG rotates the crankshaft (58) to move the piston from the BDC position to the TDC (top dead center) position.

[0054] During such movement of the crankshaft (58), the crankshaft position sensor (328) measures pulses generated, for example, as the pip passes near the pulse sensor. A control module (310) of the control system (300) receives outputs from the MAP sensor (308) and the crank angle sensor (328) and determines that the engine (22) is rotating in a forward motion when the value from the MAP sensor (308) at the first pip is less than a threshold voltage. Similarly, when the value from the MAP sensor (308) at the first pip is greater than the threshold voltage, the control module (310) determines that the engine (22) is rotating in a reverse motion. In addition, when the control module (310) determines that the engine is rotating in a reverse motion, the control module (310) restricts ignition of the engine (22) by the ignition system (319). Otherwise, when the control module (310) determines that the engine is rotating in a forward motion, the control module (310) allows ignition of the spark plug (318) by the ignition system (319).

[0055] In view of the above, the present invention provides a system that can prevent the ignition of the ignition system (319) when the engine (22) rotates in reverse motion. By preventing the ignition of the ignition system (319), when the engine (22) rotates in reverse motion, the present invention reduces fuel waste while also ensuring that there is no undesirable damage to the various components of the engine (22). In addition, the present invention provides a system that determines the rotation direction of the engine (22) based solely on the pressure of the intake manifold (302) and the position of the crankshaft (). Therefore, the present invention, in its embodiment, assists in determining the rotation direction of the engine (22), when the ISG controller (324) is used to initially rotate the crankshaft, the ISG controller is decoupled from the ECU (310) that controls the ignition of the engine (22).

[0056] Although a few embodiments of the present invention are described above, it should be understood that the present invention is not limited to the above embodiments and that appropriate modifications can be made thereto within the spirit and scope of the present invention.

[0057] Although considerable emphasis has been placed herein on the specific features of the present invention, it should be understood that various modifications may be made without departing from the principles of the present invention, and that many modifications may be made in the preferred embodiments. These and other modifications having the nature of the present invention or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, and it should be clearly understood that the above illustrative matters are to be interpreted only as illustrations of the present invention and not as limitations.

Claims

1. A vehicle (10), comprising: An internal combustion engine (22), the internal combustion engine comprising: a combustion chamber (64) defined by the cylinder head (56) and the crankcase (52); a crankshaft (58) rotatably supported by the crankcase (52); and a spark plug (318) for igniting the charge; an intake manifold (302) and an exhaust manifold (304) fluidly coupled to the combustion chamber (64); a rotating electric machine (322) configured to rotate the crankshaft (58) when the engine is started; a manifold absolute pressure (MAP) sensor (308) disposed in the intake manifold (302), wherein the MAP sensor (308) is configured to detect pressure in the intake manifold (302) and generate a MAP voltage signal in response to the pressure sensed in the intake manifold (302); and a crank angle sensor (328) configured to detect an angular position and a rotational speed of the crankshaft (58) of the internal combustion engine (22) and to generate a surface ignition sensing (PIP) signal indicative of the angular position of the crankshaft (58); and A control system (300), the control system being configured to control the internal combustion engine (22), wherein the control system (300) comprises: An electronic control unit (310) in electronic communication with the MAP sensor (308) and the crank angle sensor (328), wherein the electronic control unit (310) is configured to: Receiving outputs of the MAP sensor (308) and the crank angle sensor (328); determining a rotational direction of the crankshaft (58) based on a MAP voltage signal (330) and the surface ignition sensing (PIP) signal generated at a predetermined time; and Firing of the spark plug (318) is selectively enabled and limited in response to a determination of a rotational direction of the crankshaft (58).

2. The vehicle (10) according to claim 1, characterized in that The rotating motor (322) is mounted on the crankshaft (58) and includes at least one reference tooth and a plurality of teeth (326), wherein the at least one reference tooth indicates a predetermined position on the crankshaft (58), the plurality of teeth (326) are positioned along the circumferential angle of the rotating motor (322), and each of the plurality of teeth (326) from the reference tooth indicates a predetermined angular position of the crankshaft (58).

3. The vehicle (10) according to claim 2, characterized in that The reference teeth have a predetermined profile or are in the form of missing teeth.

4. The vehicle (10) according to claim 2, characterized in that The crank angle sensor (328) generates a voltage signal indicative of the angular position of the crankshaft (58), and the voltage signals generated by the MAP sensor (308) and the crank angle sensor (328) are transmitted to the electronic control unit (310).

5. The vehicle (10) according to claim 4, characterized in that The rotation direction of the crankshaft (58) is determined by an electronic control unit (310) based on a MAP voltage signal of the MAP sensor (308) at a predetermined angular position of the crankshaft (58).

6. The vehicle (10) according to claim 5, characterized in that The predetermined angular position of the crankshaft (58) is a first tooth of the plurality of teeth (326) that is located after the reference tooth.

7. The vehicle (10) according to claim 5, characterized in that If the voltage generated by the MAP sensor (308) at the predetermined angular position of the crankshaft (58) is higher than a predetermined threshold value stored in the electronic control unit (310), the crankshaft (58) rotates in a first rotational direction (D1).

8. The vehicle (10) according to claim 5, characterized in that If the voltage generated by the MAP sensor (308) at the predetermined angular position of the crankshaft (58) is lower than a predetermined threshold value stored in the electronic control unit (310), the crankshaft (58) rotates in a second rotational direction (D2).

9. The vehicle (10) according to any one of claims 5, 7 and 8, characterized in that The first rotation direction (D1) is a reverse direction, and the second rotation direction (D2) is a forward direction.

10. The vehicle (10) according to claim 1, characterized in that The rotating electrical machine (322) is an integrated starter generator (ISG).

11. The vehicle (10) according to claim 1, characterized in that The crank angle sensor (328) is a pulse coil.

12. The vehicle (10) according to claim 1, characterized in that The crank angle sensor (328) is a Hall effect sensor.

13. The vehicle (10) according to claim 1, characterized in that The electronic control unit (310) does not allow the spark plug (318) to fire until it determines the direction of rotation of the crankshaft (58).

14. The vehicle (10) according to claim 4, characterized in that The rotation direction of the crankshaft (58) is determined by the electronic control unit (310) based on a first voltage signal of the MAP sensor (308) at a first predetermined angular position of the crankshaft (58) and a second voltage signal of the MAP sensor (308) at a second predetermined angular position of the crankshaft (58).

15. The vehicle (10) according to claim 14, characterized in that If a first voltage signal generated by the MAP sensor (308) at the first predetermined angular position of the crankshaft (58) and a second voltage signal generated by the MAP sensor (308) at the second predetermined angular position of the crankshaft (58) are higher than a predetermined threshold value stored in the electronic control unit (310), the crankshaft (58) rotates in a first rotational direction (D1); and if a first voltage signal generated by the MAP sensor (308) at the first predetermined angular position of the crankshaft (58) and a second voltage signal generated by the MAP sensor (308) at the second predetermined angular position of the crankshaft (58) are lower than a predetermined threshold value stored in the electronic control unit (310), the crankshaft (58) rotates in a second rotational direction (D2).

16. A method (400) of controlling an internal combustion engine (22) by means of a control system (300), wherein: The method (400) comprises: Sensing air pressure in the intake manifold (302) via a manifold absolute pressure (MAP) sensor (308); generating a MAP voltage signal representative of the sensed air pressure ( 330 ); sensing the angular position of a crankshaft (58) of the internal combustion engine (22) via a crank angle sensor (328); generating a voltage signal (332) representative of the angular position of the crankshaft (58); determining the rotation direction of the crankshaft (58) by an electronic control unit (310) at a predetermined position of the crankshaft based on a MAP voltage signal (330) generated at a predetermined time; and Sparking of a spark plug (318) is controlled based on the determined rotational direction of the crankshaft (58).

17. The method (400) of claim 16, characterized in that If a voltage generated by the MAP sensor (308) at a predetermined position of the crankshaft (58) is higher than a predetermined threshold value stored in the electronic control unit (310), the crankshaft (58) rotates in a first rotational direction (D1), wherein when it is determined that the crankshaft (58) rotates in the first rotational direction (D1), the electronic control unit (310) limits the spark of the spark plug (318).

18. The method (400) of claim 16, characterized in that If a voltage generated by the MAP sensor (308) at a predetermined position of the crankshaft (58) is lower than a predetermined threshold value stored in the electronic control unit (310), the crankshaft (58) rotates in a second rotational direction (D2), wherein the electronic control unit (310) allows sparking of the spark plug (318) when it is determined that the crankshaft (58) rotates in the second rotational direction (D2).

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