MXPA05013351A - Cam sensor elimination in compression-ignition engines - Google Patents

Abstract

A method for controlling start of a compression ignition engine (10) having a plurality of cylinders without a cam sensor is provided. The method comprises providing a respective fuel delivery assembly (30) for each cylinder. In one embodiment the method further comprises retrieving (from memory a set of fuel delivery assembly firing rules and then processing the firing rules so that a firing signal is delivered to each fuel delivery assembly on every crank revolution during a cranking mode of operation. The fuel delivery assembly is arranged to be responsive to any firing signal received during an injection window leading to the top position along the longitudinal axis so as to supply fuel to each cylinder during that injection window. The fuel delivery assembly is further arranged to be insensitive to any firing signal received during an exhaust stroke so that no fuel is delivered to each cylinder during that exhaust stroke.

Description

ELIMINATION OF THE CAM SENSOR IN COMPRESSION IGNITION ENGINES BACKGROUND OF THE INVENTION The invention relates in general to the control of compression ignition engines, and more particularly to the removal of the cam sensor in four time compression ignition engines having cylinders with large displacement volumes, such as engines of type locomotives and marine. Although several techniques for the removal of cam sensors have been provided in the context of relatively small engines. Ignition by spark, these types of techniques are not believed to be suitable for the unique designs of larger compression ignition engines, such as diesel engines. For example, the displacement of a single cylinder for a large sixteen cylinder locomotive diesel engine can be in the order of 1 1 liters while the displacement of a single cylinder for a typical diesel engine of a truck can be in the order of only 2 liters per cylinder. Therefore a single cylinder for a large locomotive engine can easily be five times larger than the large truck diesel engine. In addition, a typical truck engine has 6 or 8 cylinders as opposed to 12 or 16 for a typical locomotive engine, so each cylinder contributes a small portion of the total energy. This usually results in very different design limitations since high injection pressure levels (in the order of 1 0-20 kps i) are required in conjunction with much higher volume fuel flow rate ranges (100-1). 600mm3 / time) to effect proper combustion in the largest locomotive engine. Other differences also impact the type of fuel injection system which can be used in larger compression ignition engines. For example, locomotive engines are typically designed to maintain regulator stability eg. provide a relatively constant speed output to provide a constant power generating source for large fraction motors used to move the wheels. Also, large locomotive engines encounter radical load changes due to the change of large auxiliary loads such as compressor loads, fan loads, and "hotel" energy loads (an alternator for the generation of 1 10V to 60Hz) for applications in passenger trains. Handling such loads or shutting down such loads can result in load changes in the order of 500 horsepower in any case. Another generally unique design consideration for such large engines is low engine speeds (RPM) and reduced air movement in the chamber. Smaller motors typically operate at engine speeds of several thousand RPM's. However, large locomotive engines typically operate between 0-1050 RPM. The range at which the pistons move generally impacts the speed of air intake and / or swirling. Lower RPM usually results in slower air intake. With cylinders of smaller volume, sufficient movement of air in the chamber to allow proper atomization of the fuel to the air mixture typically occurs during motor impulse. However, larger cylinders typically have a much smaller air movement in the cylinder resulting in a more stagnant volume of trapped air. This generally requires that a higher fuel injection pressure be applied to overcome the compression within the cylinder and penetrate the trapped air volume in a sufficiently atomized state, such that the intake will result in a homogeneous stoichiometric combustion of the air / fuel mixture. . In a conventional locomotive engine design, a crankshaft sensor synchronizes an engine drive unit (EGU) to the crankshaft. A cam sensor, however, determines at what respective time the motor is, that is, without the cam sensor, the EGU would not be able to determine the difference between a compression time and an escape time. Once the cam position is known, the EGU typically does not need additional data from the cam due to the detection of crankshaft information, the EGU is able to maintain the proper sensor of the cam. In fact, one can not simply start the engine of the locomotive without the cam sensor. In view of the issues discussed above, it would be desirable to provide control techniques that would allow a reliable supply of controlled ignition of the ignition engine by compression of the locomotive even in the absence of the cam sensor since in fact, the cam sensor is a single point of failure in the locomotive. Another reliable improvement resulting from the removal of the cam sensor would be the elimination of the loss of synchronization in the EGU due to noisy pulses from the cam. It would be more desirable to lower the manufacturing costs of the engine if the cam sensor could be eliminated, one could even eliminate the machining finish on the cam sensor cover and the timing wheel. In addition, the wiring and circuits of the EGU that process the signal from the cam sensor could be eliminated. Additionally, the removal of the cam sensor would result in a simpler manufacturing process without requiring time consuming and error-prone cam sensor offset actions.

BRIEF DESCRIPTION OF THE INVENTION Generally, the present invention meets the foregoing needs by providing in an exemplary embodiment a method for controlling ignition of a compression ignition engine having a plurality of cylinders. Each cylinder includes a respective piston reciprocally movable between the respective positions, upper and lower, along a longitudinal axis of the cylinder. The method comprises the provision of a respective fuel supply assembly for each cylinder.

The method further comprises recovering from memory a set of ignition rules of the fuel supply assembly and then processing the ignition rules so that a firing signal is supplied to each fuel supply assembly at each revolution of the crankshaft during a of crankshaft operation. The fuel supply assembly is arranged to be responsive to any ignition signal received during an injection window by guiding the upper position along the longitudinal axis to supply fuel to each cylinder during that injection window. The fuel supply assembly is further arranged to be insensitive to any ignition signal received outside the injection window so that fuel is not supplied outside the injection window. The present invention further satisfies the foregoing needs by the provision in another embodiment of a method for ignition control of a compression ignition engine having a plurality of cylinders. Each cylinder includes a respective reciprocally movable piston between the upper and lower positions, respectively, along a longitudinal axis of the cylinder. The method comprises allowing the supply of a respective fuel supply assembly for each cylinder. The method also allows recovering from memory a set of regias of ignition of the assembly of fuel supply. The ignition rules are processed so that an ignition signal is supplied to each fuel supply assembly at each of the crankshaft revolutions relative to an assumed cam position. Reprocessing the ignition rules every n revolutions of the engine so that the ignition signal is supplied to each fuel supply assembly relative to a cam position approximately 1 80 degrees relative to the assumed original cam position, n corresponds to a whole number positive greater than 1. The present invention further satisfies the foregoing needs by supplying in yet another embodiment a method for controlling ignition of a compression ignition engine having a plurality of cylinders grouped in at least two sets of cylinders. Each cylinder includes a respective reciprocally movable piston between the upper and lower positions, respectively, along a longitudinal axis of the cylinder. The method allows the supply of a respective fuel supply assembly for each cylinder. The method also allows memory recovery of a set of ignition rules for the fuel supply assembly. The method further allows the processing of the ignition rules so that a firing signal is supplied to each fuel supply assembly in one of the two sets of cylinders in each other revolution of the crankshaft relative to an assumed cam position and for the processing of the ignition rules so that one signal is supplied to each fuel supply assembly in the other of the two sets of cylinders in each other revolution of the crankshaft relative to a cam position approximately 180 degrees relative to the cam position assumed .

DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of an exemplary diesel-style engine of locomotive that can benefit from the cam removal techniques of the present invention. Figure 2 is a partial sectional view of an energy assembly in units controlled by a processor including the control algorithms illustrated below in the context of Figures 3-5. Figure 3 is a flow chart of an exemplary embodiment for ignition control of a compression ignition engine having a plurality of cylinders without the use of a cam sensor. Figure 4 is a flow diagram of another exemplary embodiment for ignition control of a compression ignition engine without the use of a cam sensor. Figure 5 is a flow chart of yet another exemplary embodiment for ignition control of a compression ignition engine having a plurality of cylinders without the use of a cam sensor. Figure 6 is a simplified block diagram of a processor that can be used for ignition control of a compression ignition engine without the use of a cam sensor.

Before any embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of having other modalities and of being practiced or carried out in different ways. It should also be understood that the phraseology and terminology used herein is for the purpose of description and should not be considered as limiting.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 generally represents an exemplified diesel ignition engine by compression 1 0 which employs an electronic fuel control system according to an embodiment of the invention. The engine 10 can be any relatively large diesel engine, such as the diesel engine models FDL-12, FDL-16, according to the manufacture of General Electric Company, in Grove City, PA. Such an engine may include a turbocharger 12 and a series of unified power or fuel injection assemblies 14. For example, a 12-cylinder engine has 12 power assemblies while a 16-cylinder engine has 16 power assemblies. The motor 1 0 further includes an air intake manifold 16, a fuel supply line 18 for supplying fuel to each of the power assemblies 14, a water intake manifold 20 used to cool the engine, a fuel pump lubricating oil 22 and a water pump 24, like all known in the art.

An intercooler 26 connected to the turbo charger 12 facilitates the cooling of the charged turbo air before it enters a respective combustion chamber within one of the power assemblies 14. The engine can be of the Vee-style type or an in-line type, also known in the field. Figure 2 represents one of the plurality of energy assemblies 14 including a cylinder 28 and a corresponding fuel supply assembly generally indicated at 30 for supplying fuel to the combustion chamber within the cylinder 28. Each assembled energy assembly 14 it may further include an exhaust cam shaft of the air valve 32 for moving a plurality of spring-deflected air valves generally indicated at 34. The exhaust cam shaft of the valve 32 is connected to the valve pusher 36 through of the valve escape valve 38. The exhaust cam shaft of the air valve 32 is connected to a valve pusher 36 and is actuated as is known in the art. Each unified power assembly 14 further includes a cylinder cover 40 that is insertable into a perforated opening (not shown) in the engine block 1 0. The unified power assembly 14 includes a cylinder sleeve or model for housing the cylinder 28 and associated components. For a typical engine 10, such as that which can be used in locomotive applications, an exemplary range of injection pressure is between approximately 15-20 k. . i. A range of fuel supply flow volume, exemplifying is between approximately 1 00-1600mm3 / time. An exemplary range of displacement per cylinder can be from about 5.5 liters to about 1 1 liters. It will be appreciated that the present invention is not limited to the exemplary ranges described above. The fuel supply assembly 30 includes a fuel injection mechanism 42 connected to a high-pressure injection line 44 which is fluidly connected to a fuel pressure generating unit 46 such as a fuel pump. This configuration is known as a pump line nozzle configuration. The fuel pressure generating unit 46 produces pressure through the activation of the fuel pusher 48 which is driven by a lobe on the engine's camshaft dedicated to the fuel supply action. The fuel supply assembly 30 includes an electronic signal line 50 for receiving electronic signals from an electronic controller, as will be described later. The electronic signal line 50 supplies a control signal to an electronically controlled valve 52 that forms part of the fuel supply assembly 30. The unified power assembly 14 derives its name from the factor that each cylinder and the accompanying components (or assembly) of energy) can be removed from the motor individually to facilitate maintenance. Consequently, the entire motor does not need to be removed or replaced to facilitate the repair of the cylinder or any of its associated components. It will be appreciated that the system and techniques of the present invention are not limited to unified energy assemblies. Figure 3 illustrates a flow diagram of an exemplary method incorporating an aspect of the present invention. The method allows controlling the ignition of a compression ignition engine having a plurality of cylinders without the use of a cam sensor. Each cylinder includes a respective reciprocally movable piston between the respective upper and lower positions, eg. , upper dead center (TDC) lower dead center (BDC), along a longitudinal axis of the cylinder. As demonstrated above, subsequent to the start stage 100, step 102 allows the supply of a fuel supply assembly, e.g. , fuel supply assembly 30 (figure 2) for each cylinder. Step 104 allows memory recovery of a set of ignition rules of the fuel supply assembly. Step 1 06 allows the process of the recovered ignition rules to supply an ignition signal to each fuel supply assembly for each revolution of the crankshaft during a crankshaft operation mode. It will be appreciated by those skilled in the art that standard engine ignition techniques that rely on the cam sensor information would generally provide an ignition signal during each other revolution of the crankshaft during the crankshaft operation mode instead of supplying the signal of ignition for each revolution of the crankshaft. Step 108 allows the arrangement of the fuel supply assembly to be responsive to any ignition signal received during a TDC compression time to supply fuel to each cylinder during an injection window, which is determined by the increase in the lobe of the fuel cam. For example, if the profile of the cam lobe is increasing, then the fuel pusher 48 (figure 1) will be activated and, in cooperation with the ignition signal which drives the solenoid that opens the high pressure line, then the supply of fuel inside the cylinder will occur. It will be appreciated that the fuel supply within the injection window is not limited to fuel supply only within the compression time, since the supply usually continues up to the energy time. For example, we can start the injection at 5 degrees before TDC and continue up to 25 degrees after TDC. Stage 1 10 allows the arrangement of the fuel supply assembly to be insensitive to any ignition signal received outside the injection window so that no fuel is supplied to the cylinder outside the injection window. For example, if the profile of the cam lobe does not continue to increase, then the fuel pusher 48 (Fig. 1) will not be driven to supply any fuel and, even the presence of the ignition signal would not result in the fuel supply within the cylinder since the fuel pusher in this case would not have been driven by the fuel cam lobe. In this way, this mode takes advantage of the dual interrelation described above for the supply of fuel within the cylinders: 1) fuel pusher drive and 2) presence of ignition signal. If either of the two actions does not occur, then the fuel supply does not happen. It will be appreciated that the foregoing interrelation comprises an electromechanical interrelation constructed in an exemplary embodiment and does not need to be implemented via software code. The actions described above allow during the crankshaft operation mode to trigger one or more solenoids in the fuel supply assembly as if each TDC cylinder corresponded to the compression time. This results in firing the cylinder if in fact the cylinder is in TDC of the compression time, however, the fuel supply assembly will not inject fuel if the cylinder is in TDC of the exhaust time since in the latter case a cam of The fuel pump will not move upwards, and thus no fuel flow will develop and the cylinder will not be fired even in the presence of an ignition signal. This mode allows the engine to be started with all the cylinders and could be continued indefinitely. In the event that there may be a concern with respect to increased wear on the injector pump valve if each crankshaft revolution is receiving a start signal, then the following optional steps can be used to synchronize the motor.

It will be appreciated, however, that if the increased wear of the injector valve is not a factor, then the following steps are not necessary. Step 1 12 allows determining if the engine has reached a predefined engine condition, such as engine RPM ranging from about 200 to about 250 RPM. If the engine has reached predefined engine RPMs, then step 1 14 allows the processing of a new set of ignition rules so that the ignition signal is supplied to each fuel supply mbly during each other revolution of the relative crankshaft. an med cam position. If the engine has not reached the predefined speed of the engine, then the method repeatedly continues to step 106. Step 1 16, achieved through a connection node A, allows the monitoring of one or more operational parameters of the engine indicative of the level of engine performance, eg. , engine speed, acceleration, etc. As indicated in decision block 1 1 8, if the level of the motor performance drops, then step 120 allows the change of the med cam position by approximately 1 80 degrees, prior to the return of step 122. Conversely, if the performance level of the motor rises, then the method proceeds to return to step 122. This will indicate that the med cam position corresponds to the current position of the cam. An additional synchronization of the motor will be maintained upon detecting a signal indicative of the position of the crankshaft teeth, as will be readily understood by one of ordinary skill in the art. Figure 4 illustrates a flow chart of an exemplary method including another aspect of the present invention. The method allows ignition control of a compression ignition engine having a plurality of cylinders without the use of a cam sensor. Each cylinder includes a respective reciprocally movable piston between the respective upper and lower positions, eg. , upper dead center (TDC) and lower dead center (BDC), along the longitudinal axis of the cylinder. As mentioned above, subsequent to the ignition stage 200, the stage 202 allows the supply of a fuel supply mbly, e.g. , fuel supply mbly 30 (figure 2) for each cylinder. Step 204 allows memory recovery of a set of ignition rules of the fuel supply mbly. Step 206 allows processing of the retrieved ignition rules to supply an ignition signal to each fuel supply mbly in every other revolution of the crankshaft relative to an med cam position. Step 208 allows reprocessing of the ignition rules every n revolutions so that the timing signal of the ignition signal is changed approximately 180 degrees relative to the med cam position. Step 21 0 allows the determination of whether the engine has reached a predefined engine condition, such as engine RPM ranging from about 200 to about 250 RPM. If the engine has reached predefined engine RPM, then the method continues to step 212 reached through connection node B. If the engine has not reached the predefined engine speed, then the method repeatedly continues to step 206. stage 212 allows the monitoring of one or more of the engine operational parameters of the engine performance level, e.g. , engine speed, acceleration, etc. As indicated in decision block 214, if the performance level of the motor decreases, then step 216 allows changing the med cam position by approximately 180 degrees, prior to returning to step 220. Conversely, if the level of engine performance ascends, then the method proceeds to return to step 220. As suggested above, this last described mode will attempt to start the engine correctly for n revolutions, then turn it on incorrectly for n revolutions and could give the operator the impression that the engine is not working properly. It is believed that proper operator training will avoid this case. In addition, n should be chosen to allow enough time for the engine to accelerate to the speed of decision. Also, the decision speed must be far enough away from the speed of the crankshaft to ensure that the engine has indeed reached this speed by your own energy In an exemplary implementation n can be equal to one. That is, one would assume the cam position (eg, either by responding to a compression time or the escape time) and attempt to start the engine based on the assumed position. If the engine does not turn on, one would change the assumption to the other position and try to start the engine based on this other position. It is contemplated to make use of sensors commonly available in locomotive engines indicative of the probability of correctly performing an appropriate ignition cycle the first time. That is, increase the probability that the cam position assumed corresponds to the current condition of the motor, eg. , either in a compression time or in an escape time. For example, one could use a manifold pressure sensor to sense the characteristic manifold pressure during rotation that would indicate which engine cycle is on. It will be appreciated that any other convenient sensor for the measurement of characteristics indicative of the probability of being in a compression time or in an escape time could equally be used effectively. Another technique that can be used to improve the probability of correctly doing a firing cycle the first time may be for the controller to remember the last ignition cycle based on the position of the engine when it was last running, as can be noticed by the position of the motor sensor. In practice, this technique can be somewhat difficult to implement since the resolution of the typical position of the engine will tend to decrease while the engine descends to a stop. Figure 5 illustrates a flow diagram of an exemplified method including yet another aspect of the present invention. The method allows ignition control of a compression ignition engine having a plurality of cylinders without the use of a cam sensor. Each cylinder includes a respective reciprocally movable piston between the respective upper and lower positions, eg. , upper dead center (TDC) and lower dead center (BDC), along the longitudinal axis of the cylinder. As mentioned above, subsequent to ignition stage 300, step 302 allows the supply of a fuel supply assembly for each cylinder. Step 304 allows memory recovery of a set of ignition rules of the fuel supply assembly. Step 306 allows the grouping of a plurality of cylinders into at least two different sets of cylinders. For example, in a 16-cylinder engine made by two banks of eight cylinders, then each cylinder in a bank would comprise a group of cylinders and each cylinder in the other bank would comprise the second group of cylinders. It will be appreciated that another grouping of sets is possible. For example, the 8 front cylinders could be one set and the 8 back cylinders could be another. All the even cylinders could be in one set, the odd cylinders in the other. Step 308 allows processing of the retrieved ignition rules to supply an ignition signal to each fuel supply assembly in one of the two sets of cylinders in each other revolution of the crankshaft relative to an assumed cam position. Step 310 allows processing of the retrieved ignition rules to supply a signal to each fuel supply assembly in the other of the two sets of cylinders in each other revolution of the crankshaft about 1 80 degrees relative to the assumed cam position. It will be appreciated that in this exemplary modalityHalf of the cylinders will receive an ignition signal during the ignition window and will produce power. The other half of the cylinders will receive the signal during the exhaust / intake time and no fuel will be supplied. Step 312, achieved through a connection node C, allows the determination of whether the engine has reached the predefined engine condition, such as engine RPM ranging from about 200 to about 250 RPM. If the motor has not reached the predefined motor speed, then the method continues to step 308 achieved through a connection node D. If the motor has reached the predefined motor RPM, then step 314 allows the monitoring of one or more engine operational parameters indicative of engine performance level, eg. , engine speed, acceleration, etc. As indicated in decision block 316, if the performance level of the motor decreases, then step 31 8 allows the change of an assumed cam position of approximately 180 degrees, prior to returning to step 322. I nversely, if the level of performance of the motor ascends, then step 320 allows to continue maintaining an ignition signal relative to the assumed cam position prior to returning to step 322. It is believed that the last technique described can offer advantages in a exemplary mode since it does not require any change of wiring to an existing engine control design and it is further believed that this mode best handles dry injector conditions. Figure 6 illustrates an exemplary processor 400 configured to turn on a large compression ignition motor without information from the cam sensor. A memory 402 is used to store the various ignition rules supplied respectively to each fuel supply assembly 30, as mentioned in the context of Figures 3 to 5. As suggested above, once a good orientation of the cam has been determined, a signal from the crankshaft teeth together with signals indicative of various environmental and / or operational conditions, eg. , ambient temperature, barometric pressure, engine RPM, acceleration, etc. , are used to determine any desired time and fuel value requirements to efficiently control the operation of the engine in a manner well understood by those skilled in the art. A sensor 404, such as manifold pressure sensor, can be used to sense an indication of the motor that can indicate the probability of making a correct assumption for the cam position the first time a firing signal is supplied. For example, manifold pressure may vary depending on whether the engine is in a compression time or an escape time. It should be understood that the specific embodiment of the invention shown and described herein is exemplary only. Numerous variations, changes, substitutions and equivalents will now occur to those skilled in the art without departing from the spirit and scope of the present invention. In accordance with the foregoing, it is proposed that all subject matter described herein and shown in the accompanying drawings be considered as illustrative only and not in a limiting sense and that the scope of the invention be determined solely by the appended claims.

Claims (1)

1. CLAIMS 1. A method for controlling ignition of a compression ignition engine (10) without a cam sensor, the engine having a plurality of cylinders (28), each cylinder including a respective piston reciprocally movable between the positions, upper and lower, respective, along a longitudinal axis of the cylinder, the method comprises: providing (202) a respective fuel supply assembly for each cylinder; recovering (204) from a memory (402) a set of ignition rules for the fuel supply assembly; processing (202) the ignition rules so that an ignition signal is supplied to each fuel supply assembly relative to an assumed cam position; and monitoring (212) at least one operational parameter of the motor so that if the operational performance of the motor rises, then the assumed cam position is maintained and in the event that the operational performance of the motor decreases, then the assumed cam position is changed by approximately 180 degrees. The method according to claim 1, characterized in that the ignition signal is supplied in each other revolution of the crankshaft relative to the assumed cam position. 3. The method according to claim 2 further comprises reprocessing (208) the ignition rules every n revolutions of the engine so that the ignition signal is supplied to each fuel supply assembly relative to a cam position approximately 180 relative degrees to the assumed cam position, n corresponding to a positive integer. The method according to claim 1 further comprising, in the case of an unsuccessful engine ignition, arranging the ignition signal to be supplied to each fuel supply assembly relative to a cam position approximately 180 degrees relative to the position of assumed cam (216). The method according to claim 4, characterized in that the operational parameter of the motor is selected from the group consisting of the motor speed, acceleration, motor output power. 6. A method for controlling ignition of a compression ignition engine without a cam sensor, the engine having a plurality of cylinders grouped in at least two sets of cylinders, each cylinder including a respective reciprocally movable piston between the positions, upper and lower, respectively along a longitudinal axis of the cylinder, the method comprising: providing (302) a respective fuel supply assembly for each cylinder; recovering (304) from the memory a set of ignition rules for the fuel supply assembly; processing (308) the ignition rules so that an ignition signal is supplied to each fuel supply assembly in one of the two sets of cylinders every other revolution of the crankshaft relative to an assumed cam position; and processing (310) the ignition rules so that one signal is supplied to each fuel supply assembly in the other two sets of cylinders in each other revolution of the crankshaft relative to a cam position approximately 180 degrees relative to the position of cam assumed. The method according to claim 6 further comprising the monitoring of one or more operational parameters of the engine so that if the operational performance of the engine increases, then the assumed cam position is maintained. The method according to claim 6 further comprising detecting one or more operational parameters of the motor so that if the operational performance of the motor decreases, then the assumed cam position is changed by approximately 180 degrees. 9. A system for controlling the ignition of a compression ignition engine (10) without a cam sensor, the engine having a plurality of cylinders (28), each cylinder including a respective piston reciprocally movable between the positions, upper and lower , respective along a longitudinal axis of the cylinder, the system comprising: a respective fuel supply assembly (30) for each cylinder; a memory (402) comprising a set of ignition rules of the fuel supply assembly; a processor (400) configured to process the ignition rules so that an ignition signal is supplied to each fuel supply assembly relative to an assumed cam position; and at least one sensor for monitoring at least one operational parameter of the motor so that if the operational performance of the motor rises, then the assumed cam position is maintained, and in the case that the operational performance of the motor decreases, then the position of assumed cam is changed by approximately 180 degrees. The system according to claim 9, characterized in that the processor is further configured to reprocess the ignition rules every n revolutions of the engine so that the ignition signal is supplied to each fuel supply assembly relative to a cam position of approximately 180 degrees relative to the assumed cam position, n corresponds to a positive integer. The system according to claim 9, characterized in that in the case of an unsuccessful ignition of the engine, the processor is configured to cause the ignition signal to be supplied to each fuel supply assembly relative to an approximately cam position. 180 degrees relative to the assumed cam position.