SYSTEMS AND METHODS FOR ADAPTIVE CONTROL OF ENGINE KNOCK

Abstract

In one instance, an engine system is disclosed herein, comprising an engine (14) with multiple engine cylinders (20); and a control unit (80) serving to control a respective ignition timing for each engine cylinder (20) of the multiple engine cylinders (20); detecting an increase in the knock intensity of the engine (14); after detecting the increase in the knock intensity of the engine (14), comparing the knock intensity of the engine (14) with a knock intensity threshold (32); if the knock intensity of the engine (14) is greater than the knock intensity threshold (32), delaying the respective ignition timing for each engine cylinder (20) of the multiple engine cylinders (20) by the same amount; and if the knock intensity of the engine (14) is less than the knock intensity threshold (32), delaying a first ignition timing of a first engine cylinder (20) by a first amount independent of a second ignition timing of a second engine cylinder (20).

Description

Technical field

[0001] The present disclosure relates generally to internal combustion engines and in particular to methods and systems for adaptive control of knocking in an internal combustion engine. State of the art

[0002] An internal combustion engine (ICE) contains one or more engine cylinders. Each engine cylinder is connected to an assembly of components, such as an intake valve, an exhaust valve, a spark plug, and a piston, that work together to complete an engine cycle. The engine cycle may include one or more steps (e.g., strokes) to take in and / or burn a fuel (e.g., a gaseous fuel such as natural gas), to provide torque to a drivetrain, and to expel exhaust gases. The operation of the components and / or the execution of the engine cycle may be carefully coordinated to ensure that the internal combustion engine operates safely and efficiently.

[0003] For example, the engine cycle can include four strokes: 1) an intake stroke, in which the piston moves towards the bottom of a combustion chamber formed by the engine cylinder, allowing air to enter the combustion chamber; 2) a compression stroke, in which the piston moves towards the top of the combustion chamber, compressing the contents of the combustion chamber; 3) a power stroke, in which the fuel in the combustion chamber is ignited, and the combustion of the fuel pushes the piston back towards the bottom of the combustion chamber; 4) and an exhaust stroke, in which the piston moves back towards the bottom of the combustion chamber, expelling the exhaust gases produced by the combustion of the fuel.To generate torque as efficiently as possible, the fuel in the combustion chamber is ignited by the spark plug just before the piston reaches the top of the chamber. This creates a flame front that grows in a controlled manner and eventually burns almost all of the fuel in the combustion chamber. However, if sufficient heat and / or pressure acts on the fuel in the combustion chamber that is not consumed by the flame front, it can detonate and / or burn uncontrollably, a phenomenon known as knocking. Knocking can damage the engine and / or cause it to stall.

[0004] An ignition system for spark-ignition internal combustion engines is disclosed in US Patent 4,243,007 (the "007 Patent") by Ehrhardt et al. The system described in "007 Patent" detects knocking in an engine and retards the ignition timing of individual engine cylinders in response to the detected knocking. Patent '007 does not disclose any methods or systems that involve comparing the knock intensity of an engine with a knock threshold intensity and adjusting the ignition timing of a plurality of engine cylinders of the engine, collectively or individually, based on the comparison of the engine's knock intensity with the knock threshold intensity.

[0005] The methods and systems of this disclosure can solve one or more of the problems mentioned above and / or other problems in this field. However, the scope of the protection afforded by this disclosure is defined by the accompanying claims and not by the ability to solve a specific problem. Summary

[0006] In one aspect, an engine system comprises an engine comprising multiple engine cylinders; and a control unit that is actuated to control a respective ignition timing for each of the multiple engine cylinders; to detect an increase in the engine's knock intensity; after detecting the increase in the engine's knock intensity, to compare the engine's knock intensity with the knock intensity threshold; if the engine's knock intensity is greater than the knock intensity threshold, to retard the respective ignition timing for each of the multiple engine cylinders by the same amount; and if the engine's knock intensity is less than the knock intensity threshold, to retard the first ignition timing of a first of the multiple engine cylinders by a first amount independent of a second ignition timing of a second of the multiple engine cylinders.

[0007] In another aspect, an engine control unit comprises a processor and memory that stores instructions which cause the processor to: detect an increase in an engine's knock intensity; after detecting the increase in the engine's knock intensity, compare the engine's knock intensity to a knock threshold intensity; if the engine's knock intensity is greater than the knock threshold intensity, retard the ignition timing for each of the multiple engine cylinders contained in the engine by a first amount; and, if the engine's knock intensity is less than the knock threshold, retard the first ignition timing of one of the multiple engines by a second amount that is less than the first amount.

[0008] In another aspect, a method for controlling an engine comprises detecting an increase in the engine's knocking intensity; and collectively retarding the ignition timing of each engine cylinder of a plurality of engine cylinders contained in the engine, wherein a first ignition timing of a first engine cylinder of the plurality of engine cylinders is retarded by a first amount, and a second ignition timing of a second engine cylinder of the plurality of engine cylinders is retarded by a second amount that differs from the first amount. Brief description of the drawings

[0009] The accompanying drawings, which form part of this description, illustrate various exemplary embodiments and, together with the description, serve to explain the principles of the disclosed embodiments. Fig. Figure 1 shows a schematic diagram of an exemplary engine, which includes an exemplary variety of engine cylinders; Fig. Figure 2 shows a block diagram of an example engine control unit; Fig. Figure 3 shows a diagram illustrating an exemplary operation of an exemplary plurality of spark plugs contained in a corresponding plurality of engine cylinders; and Fig. Figure 4 shows a flowchart of a procedure for controlling an engine system. Detailed description

[0010] Both the preceding general description and the following detailed description serve only for illustration and explanation and do not limit the claimed features. As used herein, the terms "comprises," "comprising," "with," "including," or other variations thereof are intended to denote non-exclusive inclusion, such that a process, method, article, or device comprising a list of elements may include not only those elements but also other elements not expressly listed or inherent in such process, method, article, or device. Furthermore, relative terms such as "about," "essentially," "generally," and "approximately" are used in this disclosure to indicate a possible deviation of ±10% of the stated value.In this revelation, the term “based on” or any other variation thereof is to include, for example, “partially based on”, “at least partially based on”, and “fully based on”.

[0011] Fig. Figure 1 shows a schematic diagram of an exemplary engine system 10, which includes an internal combustion engine 14 with multiple engine cylinders 20, a fuel source 30, and an electronic control module 80. The engine system 10 can be configured to adjust the ignition timing of each engine cylinder 20 contained in the engine 14, either collectively or individually, in response to the detection of a change in the knock intensity of the engine 14.

[0012] While the engine system 10 in Fig. Where Figure 1 is shown with six engine cylinders 20, it is understood that the engine system 10 can contain any number of engine cylinders 20, e.g., one engine cylinder 20, two engine cylinders 20, four engine cylinders 20, six engine cylinders 20, eight engine cylinders 20, twelve engine cylinders 20, etc. As mentioned above, each engine cylinder 20 contained in the engine system 10 can contain an assembly of components or otherwise be functionally connected to one that work together to burn fuel according to an engine cycle, e.g., a four-stroke engine cycle described above. The fuel can be supplied to the engine 14 from a fuel source 30, e.g., a fuel tank and / or a local fuel source, such as a natural gas pipeline. The fuel can enter the engine 14 of the engine system 10 in any suitable manner, e.g., by port fuel injection, gas injection, or direct injection.

[0013] The engine system 10 may include a spark plug 22, which serves to ignite the fuel contained in an engine cylinder 20, for example, the fuel in a combustion chamber formed by the engine cylinder 20. The spark plug 22 can be actuated to ignite the fuel contained in the engine cylinder 20 at a precisely defined and / or controlled time relative to the operation of one or more other components of the assembly, such as a piston located in the engine cylinder 20, in order to generate torque most efficiently. The timing of the spark plug 22 may be referred to as the ignition timing of the engine cylinder 20 and may be measured in terms of the crank angle, for example, the angle of rotation of a crankshaft of the engine system 10, measured from the position at which a piston of the engine system 10 is located at its highest point or top dead center (TDC), for example, the TDC of the compression stroke.The ignition timing of the engine cylinder 20 can be determined or controlled by an engine control unit 80, for example by generating commands for the spark plug 22, e.g. ignition timing control commands 85 (. Fig. 2) For example, for a four-stroke engine cycle involving 720 degrees of crank angle, the engine control unit 80 can generate and transmit ignition timing control commands 85 to each spark plug 22 contained in the engine 14 to ignite fuel contained in the engine cylinders 20 at an ignition time shortly before the power stroke, for example between 5 and 40 degrees before a crank angle of 360 degrees.

[0014] As mentioned above, the engine system 10 may additionally or alternatively include a fuel injection device (not shown) that injects fuel from a fuel source 30 into the engine 14, for example, into an engine cylinder 20. For example, each engine cylinder 20 may be functionally connected to a separate and corresponding fuel injection device contained within the engine 14. The fuel injection device can be actuated to inject fuel into the engine 14 at a precisely defined and / or controlled time relative to the operation of one or more other components of the assembly, such as a piston located within the engine cylinder 20, in order to generate torque most efficiently.The timing of the fuel injection device can be referred to as the injection timing or start of injection (SOI) of the fuel injection device or of an engine cylinder 20 functionally connected to the fuel injection device and can be measured in crank angles. The injection timing of the fuel injection device can be determined or controlled by the engine control unit 80, for example, by generating commands for the fuel injection device. For example, for a four-stroke engine cycle comprising 720 degrees of crank angle, the engine control unit 80 can generate and transmit commands to each fuel injection device contained in the engine 14 to inject fuel into the engine 14 at an injection timing at the beginning of the intake stroke, for example, 360 degrees before top dead center.

[0015] The engine system 10 may further include one or more sensors that detect, measure, recognize, and / or estimate one or more properties of the engine cylinder 20 or other components of the engine 14. For example, the engine 14 may include a knock sensor 24, which serves to detect or measure the knocking intensity of the engine 14, as described in more detail below. For example, the knock sensor 24 may be a piezoelectric sensor, which serves to detect knocking in the form of vibrations within the engine cylinder 20. Or, for example, the knock sensor 24 may be a pressure sensor, e.g., an internal cylinder pressure sensor (ICPS), which measures the pressure within the engine cylinder 20.

[0016] Fig. Figure 2 shows a block diagram of an exemplary engine control unit 80, e.g., an electronic control module (ECM). The engine control unit 80 may include a memory 81, a processor 82, or any other means for performing a task according to the present disclosure. The memory 81 may store data and / or software that enables the processor 82 to perform various functions. In particular, the memory 81 and / or the processor 82 may enable the engine control unit 80 to perform any of the adaptive ignition timing functions described herein. Numerous commercially available microprocessors can be configured to perform the functions of the engine control unit 80. Various other known circuits may be connected to the engine control unit 80, including signal conditioning circuits, communication circuits, and / or other suitable circuits.

[0017] The engine control unit 80 can comprise one or more modules that operate by receiving measured inputs and generating commands and / or other signals to control the operation of the engine 10. For example, the engine control unit 80 can include a knock management module 83 (e.g., commands stored in a memory 81) that serves to receive sensor data 25 from one or more sensors (e.g., a knock sensor 24) located in an engine cylinder 20 of the engine 10 and, based on the sensor data 25, to generate ignition timing control commands 85 that can be transmitted to a spark plug 22 of the engine cylinder 20 to control the spark plug 22 to ignite the fuel contained in the engine cylinder 20 at a specific ignition time, as described above, e.g., to reduce and / or optimize a knock intensity of the engine 10, as described in more detail below. The motor control unit 80 can also include a calibration module 84 (e.g.The knock management module 83 includes instructions stored in a memory 81, which serves to receive sensor data 25 from one or more sensors (e.g., knock sensor 24) of the engine system 10 and to generate a calibration factor for the engine cylinder 20 based on the sensor data 25. The knock management module 83 can use the calibration factor generated by the calibration module 84 for the engine cylinder 20 when it generates ignition timing control commands 85 for the engine cylinder 20. Industrial applicability

[0018] The systems, devices, and methods disclosed herein can be used in any machine that uses an engine 14, for example, an internal combustion engine (ICE). In particular, the systems, devices, and methods disclosed herein can be used in any machine where it is desirable to adjust the ignition timing or injection timing of an engine cylinder 20 of an engine 14 that can accept different types or qualities of fuel.

[0019] As mentioned above, knocking can occur when fuel contained in engine cylinder 20 that is not consumed by a flame front ignited by a spark plug 22 in engine cylinder 20 is subjected to sufficient heat and / or pressure. Different types or grades of fuel can exhibit different detonation resistances. For example, for a gaseous fuel such as natural gas, the detonation resistance of the fuel can be measured by its methane number (MN). Or, for example, for a liquid fuel such as unleaded gasoline or diesel, the detonation resistance of the fuel can be measured by its octane number or cetane number. With the methane number scale, the higher the value for a given fuel, the more resistant that fuel is to detonation.The cetane number scale states: the higher the value for a particular fuel, the less resistant that fuel is to detonation.

[0020] The earlier the ignition timing of an engine cylinder 20, the more likely it is that knocking will occur within the engine cylinder 20, for example, because the fuel contained in the engine cylinder 20 has more time and / or opportunities to detonate after the spark plug 22 fires. Therefore, an engine cylinder 20 of an engine 14 designed to operate with a fuel with a higher probability of knocking may have a comparatively retarded ignition timing than an engine cylinder 20 of an engine 14 designed to operate with a fuel with a lower probability of knocking, in order to reduce, for example, the time and / or opportunities that the fuel contained in the engine cylinder 20 has to detonate.

[0021] While retarding the ignition timing can be helpful in preventing knocking, the more the ignition timing of engine cylinder 20 of engine 14 is retarded, the worse the fuel efficiency of engine 14 becomes and / or the higher the exhaust gas temperature of engine 14 tends to rise. This can increase the operating costs of engine 14 and / or impair the performance of an exhaust aftertreatment system coupled to engine 14.

[0022] As mentioned above, an engine can receive 14 different types or qualities of fuel, which may have different detonation resistances. If the ignition timing of an engine cylinder 20, contained within the engine 14, has been set to a specific crankshaft angle that is optimal for a fuel with a particular detonation resistance, and the engine 14 subsequently receives a fuel with a different detonation resistance, the engine 14 or its performance may be negatively affected.As described in more detail below, the engine control unit 80 can be used to dynamically adjust the respective ignition timings of a plurality of spark plugs 22 contained in an engine system 10, either collectively or individually, when an engine 14 contained in the engine system 10 receives different types or qualities of fuel, for example by using a knock management module 83 and / or a calibration module 84 to improve the efficiency, reliability and / or safety of the engine 14.

[0023] Fig. Figure 3 shows a diagram illustrating an exemplary operation of an exemplary plurality of spark plugs 22 contained in a corresponding plurality of engine cylinders 20 of an engine 14. In this example, the engine 14 comprises six engine cylinders 20 and is operated according to a four-stroke engine cycle, as described above. In the diagram of Fig. Figure 3 shows the respective ignition timing 26A-26F for each of the six engine cylinders 20 over time (e.g., measured in engine cycles). The ignition timings 26A-26F are measured in degrees of the crankshaft angle before top dead center. For example, at time t7, the ignition timing 26F of the first engine cylinder 20 of the six engine cylinders 20 is retarded relative to the ignition timing 26A of the second engine cylinder 20 of the six engine cylinders 20.

[0024] In the diagram in Fig. Figure 3 also represents the percentage 31 of a relatively MN-poor fuel B that is blended with a relatively MN-rich fuel A that is supplied to the engine 14. Fig. Figure 3 also shows the respective knock intensity for each of the six engine cylinders 20, both plotted against time (e.g., over different cycles of the four-stroke engine cycle of engine 14). For example, between time zero (e.g., where the X-axis intersects the Y-axis) and time t1, the percentage 31 of fuel B blended with fuel A is P1%, and the respective knock intensities of the six engine cylinders 20 fluctuate slightly around an average knock intensity value of approximately k1. After time t1, the proportion 31 of fuel B blended with fuel A increases sharply to approximately P5%, causing a significant decrease in the detonation resistance of the fuel mixture. Shortly thereafter, around time t2, the respective knock intensities of the six engine cylinders 20 consequently fluctuate more, with some approaching intensity value k2.

[0025] In this example, each of the six engine cylinders 20 includes a knock sensor 24, which serves to detect and / or measure the knock intensity of the engine cylinder 20 over time. Through a communicative coupling between the knock sensor 24 and the engine control unit 80, the knock intensities of the six engine cylinders 20 are transmitted to the engine control unit 80 as sensor data 25. The engine control unit 80 can then use the sensor data 25 to generate ignition timing commands 85 for the six engine cylinders 20. In this way, the respective ignition timings of the six engine cylinders 20 can be adjusted to changes in the conditions of the engine 14, such as changes in the type or quality of the fuel supplied to the engine 14.

[0026] For example, as in Fig. As shown in Figure 3, when the knock intensity of the engine 14 (i.e., the individual, combined, or average respective knock intensities of the six engine cylinders 20) increases around time t2 due to the increase in the proportion of fuel B blended with fuel A, the engine control unit 80 can detect the increase in the knock intensity of the engine 14 using the sensor data 25 generated by the knock sensors 24 contained in the six engine cylinders 20. In response to the detection of the increase in the knock intensity of the engine 14, the engine control unit 80 generates ignition timing control commands 85 to retard the respective ignition timings 26A-26F of the six engine cylinders 20. As shown in Figure 3, the engine control unit 80 generates ignition timing control commands 85 to retard the respective ignition timings 26A-26F of the six engine cylinders 20. Fig. As shown in Figure 3, the engine control unit 80 can reduce the knocking intensity of the engine 14 by delaying the respective ignition timing of the six engine cylinders 20.

[0027] In response to the detection of an increase in knock intensity of an engine 14, which includes several engine cylinders 20 (e.g. the six engine cylinders 20 of the in Fig. (As in the example shown in Figure 3), the engine control unit 80 can retard the respective ignition timings of the multiple engine cylinders 20 collectively and / or individually, for example, by using the knock management module 83. For example, after detecting the increase in the knock intensity of the engine 14, the engine control unit 80 can compare the knock intensity of the engine 14 with a knock intensity threshold 32. If the knock intensity of the engine 14 is greater than the knock intensity threshold 32, the engine control unit 80 can retard the respective ignition timings of the multiple engine cylinders 20 collectively (e.g., globally). As described in more detail below, the engine control unit 80 can retard the respective ignition timings of the multiple engine cylinders 20 collectively by retarding the respective ignition timings of the multiple engine cylinders 20 simultaneously, by the same amount, and / or to the same degree.

[0028] Or, if the knock intensity of the engine 14 is less than the knock intensity threshold 32, the engine control unit 80 can retard the respective ignition timings of the multiple engine cylinders 20 individually. As described in more detail below, the engine control unit 80 can retard the respective ignition timings of the multiple engine cylinders 20 individually by retarding the respective ignition timings of the multiple engine cylinders 20 at different times, by different amounts, and / or to different degrees. When the engine control unit 80 retards the respective ignition timings of a plurality of engine cylinders 20 individually, the engine control unit 80 can retard the ignition timing of a single engine cylinder 20 independently of the ignition timing of any other engine cylinder 20.

[0029] The engine control unit 80 (e.g., via the knock management module 83) can compare the knock intensity of the engine 14 with the knock intensity threshold 32 in various ways. For example, when comparing the knock intensity of the engine 14 with the knock intensity threshold 32, the engine control unit 80 can determine a knock intensity value and compare this value with the knock intensity threshold 32. Or, for example, when comparing the knock intensity of the engine 14 with the knock intensity threshold 32, the engine control unit 80 can determine a rate of change of the knock intensity and compare this rate of change with the rate of change of the knock intensity threshold.Or, for example, when comparing the knock intensity of the engine 14 with the knock intensity threshold 32, the engine control unit 80 can determine a knock intensity value and compare this knock intensity value with a moving or rolling average of the knock intensity of the engine 14. However, the engine control unit 80 can also compare the knock intensity of the engine 14, or the increase in the knock intensity of the engine 14, with a knock intensity threshold 32 in any other suitable way.

[0030] In the Fig. In the example shown in Figure 3, the increase in the knock intensity of engine 14 at time t2 is determined by the engine control unit 80 to be greater than the knock intensity threshold 32. As a reaction, the engine control unit 80 retards the respective ignition timings 26A-26F of the six engine cylinders 20 simultaneously. As shown in Figure 3, the engine control unit 80 retards the respective ignition timings 26A-26F of the six engine cylinders 20 simultaneously. Fig. As shown in Figure 3, when retarding the respective ignition timings 26A-26F of a plurality of engine cylinders 20 together, the engine control unit 80 can retard the respective ignition timings of the plurality of engine cylinders 20 simultaneously, although the amount or degree by which the respective ignition timing of an individual engine cylinder 20 of the plurality of engine cylinders 20 is retarded may be based on factors specific to the individual engine cylinder 20, such as a calibration factor determined for the individual engine cylinder 20, as described in more detail below. However, the engine control unit 80 can retard the respective ignition timings of a plurality of engine cylinders 20 together in various ways. For example, when retarding the respective ignition timings of a plurality of engine cylinders 20 together, the engine control unit 80 can retard the respective ignition timings of the plurality of engine cylinders 20 simultaneously and / or by the same amount (e.g.,delay by the same degree of crank angle) or to the same degree (e.g., to the same crank angle).

[0031] In the Fig. In the example shown, the proportion 31 of fuel B blended with fuel A, after rising to approximately P5% around time t1, stabilizes at P4% between times t2 and t3, then gradually decreases and stabilizes again at approximately P2% between times t4 and t5, then rises sharply and stabilizes again at P3% between times t5 and t8. In this example, the knock intensity of engine 14 increases when the proportion 31 of fuel B blended with fuel A rises to P3%, but does not exceed the knock intensity threshold 32. In response to the detection of the increase in engine 14's knock intensity and the finding that the increase is less than the knock intensity threshold 32, the engine control unit 80 retards the respective ignition timings 26A-26F of the six engine cylinders 20 individually. As in Fig. As shown in Figure 3, the engine control unit 80 can, when individually retarding the respective ignition timings of a plurality of engine cylinders 20, retard the ignition timing of a single engine cylinder 20 of the plurality of engine cylinders 20 independently of any other ignition timing of any other engine cylinder 20 of the plurality of engine cylinders 20. When individually retarding the respective ignition timings of a plurality of engine cylinders 20, the engine control unit 80 can retard the respective ignition timings of the plurality of engine cylinders 20 at different times and / or by different amounts or to different degrees.

[0032] When individually delaying the respective ignition timing of a large number of engine cylinders 20, the engine control unit 80 can delay the ignition timing of a single engine cylinder 20 based on sensor data 25 generated for the individual engine cylinder 20.

[0033] For example, if simultaneously a first knock sensor 24 for a first engine cylinder 20 detects a first increase in knock intensity within the first engine cylinder 20 and a second knock sensor 24 for a second engine cylinder 20 detects a second increase in knock intensity within the second engine cylinder 20 that is less than the first increase in knock intensity within the first engine cylinder 20, the engine control unit 80 can retard a first ignition timing of the first engine cylinder 20 by a first amount or by a first degree and retard a second ignition timing of the second engine cylinder 20 by a second amount that is less than the first amount, or by a second degree that is earlier than the first degree.Or, for example, if the respective ignition timings of a multitude of engine cylinders 20 are retarded individually, the amount by which the engine control unit 80 retards the ignition timing of an individual engine cylinder 20 can be based on a value of the knock intensity within that individual engine cylinder 20. For example, if the respective ignition timings of a multitude of engine cylinders 20 are retarded, the engine control unit 80 can determine a first value of the knock intensity detected in a first engine cylinder 20 and a second value of the knock intensity detected in a second engine cylinder 20, which is smaller than the first value. In this example, because the first value is larger than the second value, the engine control unit 80 can retard the first ignition timing of the first engine cylinder 20 more than the second ignition timing of the second engine cylinder 20.

[0034] A desired balance can be achieved between retarding the ignition timing of engine cylinder 20 of an engine 14 to reduce knocking and advancing the ignition timing of engine cylinder 20 to improve fuel efficiency and / or reduce the exhaust gas temperature of the engine 14. For this purpose, the engine control unit 80 can be operated to search for a target knock intensity value 33 for an engine 14, for example, for each engine cylinder 20 of a plurality of engine cylinders 20 contained in the engine 14. To this end, the engine control unit 80 can compare the target knock intensity value 33 with an average knock intensity of a plurality of engine cylinders 20 and / or with individual knock intensity values ​​of individual engine cylinders 20 of the plurality of engine cylinders 20.If the target knock intensity value 33 is exceeded, the engine control unit 80 can retard the respective ignition timings of one or more of the multiple engine cylinders 20, and if the target knock intensity value 33 is not exceeded, the engine control unit 80 can advance the respective ignition timings of one or more of the multiple engine cylinders 20.

[0035] For example, as in Fig. As shown in Figure 3, a target knock intensity value 33 for engine 14 has been set to a knock intensity value of k1. Between time t3 and time t6, the target knock intensity value 33 is not exceeded by the average knock intensity of the six engine cylinders 20. Since the target knock intensity value 33 is not exceeded by the average knock intensity of the six engine cylinders 20, the engine control unit 80 advances the respective ignition timings of the six engine cylinders 20 incrementally. In some embodiments, when advancing the ignition timing of engine cylinder 20, the ignition timing of engine cylinder 20 can be advanced by an incremental and / or predetermined amount during each successive cycle of the four-stroke engine cycle.In some embodiments, the amount by which the engine control unit 80 advances the ignition timing of an individual engine cylinder 20 may be based on factors specific to that individual engine cylinder 20, such as a calibration factor determined for that individual engine cylinder 20, as described in more detail below.

[0036] After time t6, the average knock intensity of the six engine cylinders 20 begins to exceed the target knock intensity value 33 in response to the increasing percentage 31 of fuel B mixed with fuel A, which stabilizes at approximately P3%. As a result, the engine control unit 80 individually retards the respective ignition timings 26A-26F of the six engine cylinders 20 when the knock intensity within a particular engine cylinder 20 exceeds the target knock intensity value 33. After retarding the ignition timing of engine cylinder 20, the engine control unit 80 advances the ignition timing of engine cylinder 20 incrementally, as described above, until the knock intensity within engine cylinder 20 again exceeds the target knock intensity value 33 or until an upper limit for the ignition timing is reached.If the upper limit for the ignition timing is not reached, the delay and advancement of the ignition timing of engine cylinder 20 by the engine control unit 80 can lead to a characteristic interruption of the ignition timing of engine cylinder 20, as shown in . Fig. 3 shown.

[0037] The effect of adjusting the ignition timing of one engine cylinder 20 can differ from the effect of the same adjustment of the ignition timing of another engine cylinder 20 for various reasons. For example, differences in geometry, wear, position, etc., between a first engine cylinder 20 and a second engine cylinder 20 can cause a retardation of the ignition timing of the first engine cylinder 20 to produce a more effective reduction in knocking than the same retardation of the ignition timing of the second engine cylinder 20, or cause an advancement of the ignition timing of the second engine cylinder 20 to produce more knocking than the same advancement of the ignition timing of the first engine cylinder 20.As mentioned above, the amount by which the ignition timing of an individual engine cylinder 20 is delayed or advanced by the engine control unit 80 can be based on factors specific to that individual engine cylinder 20.

[0038] For example, the engine control unit 80 (e.g., via the calibration module 84) can identify, determine, or generate a calibration factor for a single engine cylinder 20. In some embodiments, a calibration factor for a single engine cylinder 20 can be determined during one or more end-of-line (EOL) tests performed on the engine 14 before it is put into field operation. In some embodiments, a calibration factor for a single engine cylinder 20 can be determined during the operation of the engine 14.For example, the engine control unit 80 can be operated to analyze sensor data 25 generated over time by a knock sensor 24 located in an engine cylinder 20 in order to determine how effective a retardation of the ignition timing of engine cylinder 20 is in reducing knocking, and to generate a calibration factor for engine cylinder 20 accordingly. Additionally or alternatively, the engine control unit 80 can be operated to analyze sensor data 25 generated over time by a knock sensor 24 located in an engine cylinder 20 in order to determine how likely or to what extent an advancement of the ignition timing of engine cylinder 20 will lead to knocking within engine cylinder 20, and to generate a calibration factor for engine cylinder 20 accordingly.In some embodiments, an engine cylinder 20 can be given an initial calibration factor determined during one or more EOL tests performed prior to field use of the engine cylinder 20, and the calibration factor for the engine cylinder 20 can be periodically updated during field use of the engine cylinder 20, for example, based on sensor data 25 generated by a knock sensor 24 included in the engine cylinder 20.

[0039] A calibration factor specified or generated for an engine cylinder 20 can be a scaling factor and / or refer to a standard or default calibration value. In some embodiments, for example, the default calibration value for each engine cylinder 20 can be 0%, and an individual engine cylinder 20 can be assigned a positive or negative calibration factor relative to the default calibration value of 0%, for example, +5% or -5%. For example, in response to the detection of an increase in the knock intensity of an engine 14 that exceeds a knock intensity threshold 32, as described above, the engine control unit 80 can determine that the respective ignition timings of all engine cylinders 20 contained in the engine 14 should be retarded by a crank angle.In this example, the engine control unit 80 then identifies a specific engine cylinder 20 contained in the engine 14 and assigned a calibration factor of +5%, and instead of delaying the ignition timing of the specific engine cylinder 20 by one degree of crank angle, the engine control unit 80 delays the ignition timing of the specific engine cylinder by 1.05 degrees of crank angle according to the calibration factor of +5% specified for the specific engine cylinder 20.

[0040] In some embodiments, the engine control unit 80 can determine and / or output a value indicating the detonation resistance (e.g., a methane number or an octane number) of a fuel supplied to the engine 14, at least partially based on an increase in the knock intensity of an engine 10 detected by the engine control unit 80. For example, the engine control unit 80 may contain data relating a specific methane number to an expected knock intensity at a particular ignition timing. In this example, if, using this data, the engine control unit 80 detects a knock intensity of an engine 14 that is greater than the expected knock intensity at the particular ignition timing, the engine control unit 80 may determine a methane number of the fuel supplied to the engine 14, e.g.,relative to the determined methane number, the engine control unit 80 can then output the determined methane number of the fuel supplied to the engine 14, for example to a control interface (e.g. a display) of a vehicle in which the engine system 10 is installed.

[0041] Fig. Figure 4 shows a flowchart of a procedure 100 for controlling an engine system 10, which may include an engine 14 with multiple cylinders 20 and the engine control unit 80. The procedure 100 can be performed repeatedly during the operation of the engine system 10 to adjust commands (e.g., ignition timing commands 85) generated and / or issued by the engine control unit 80 in response to changing engine conditions (e.g., different types or qualities of fuel supplied to the engine 14). Although the steps of the procedure 100 are shown and explained in a specific sequence, it is understood that all steps of the procedure 100 can be performed in any suitable order or simultaneously.

[0042] As in Fig. As shown in Figure 4, the procedure 100 can begin with a step 102 in which the engine control unit 80 detects an increase in the knocking intensity of the engine 14 of the engine system 10. For example, the engine 14, as described above, can include multiple engine cylinders 20, and each of the multiple engine cylinders 20 can include a knock sensor 24 for detecting knocking within the engine cylinder 20. Sensor data 25 generated by the knock sensors 24 can be supplied to the engine control unit 80, and the engine control unit 80 can be operated to detect an increase in the knocking intensity of the engine using the sensor data 25. As mentioned above, a knock sensor 24 can be a piezoelectric sensor or a pressure sensor (e.g., an intra-cylinder pressure sensor or ICPS).

[0043] As in Fig. As shown in Figure 4, after detecting the increase in the knock intensity of the engine 14, the method 100 can proceed to a step 104 in which the engine control unit 80 compares the knock intensity of the engine 14 with a knock intensity threshold 32. In some embodiments, the knock intensity threshold 32 is a standard, default, or predetermined value. In some embodiments, the knock intensity threshold 32 is updated throughout the operation of the engine 14 and may be based, at least in part, on a sliding or moving average of the knock intensities detected within the engine 14 (e.g., within one or more engine cylinders 20 contained in the engine 14). As explained above, if the knock intensity of the engine 14 is greater than the knock intensity threshold 32, the engine control unit 80 can collectively retard the respective ignition timings of each engine cylinder 20 contained in the multiple engine cylinders 20.Or if the knock intensity of the engine 14 is lower than the knock intensity threshold 32, the engine control unit 80 can delay the respective ignition times of the several engine cylinders 20 on an individual engine cylinder-by-engine cylinder basis.

[0044] For example, if the knock intensity of the engine 14 is greater than the knock intensity threshold 32, the engine control unit 80 can simultaneously retard the respective ignition timings of the multiple engine cylinders 20 as described above. When retarding the respective ignition timings of a plurality of engine cylinders 20, the amount or degree by which the ignition timing of an individual engine cylinder 20 of the plurality of engine cylinders 20 is retarded can be based on a calibration factor specific to that individual engine cylinder 20, or the amount or degree by which the ignition timing of each engine cylinder 20 is retarded can be predetermined and / or the same.

[0045] If the knock intensity of the engine 14 is less than the knock intensity threshold 32, the engine control unit 80 can individually retard the respective ignition timings of the multiple engine cylinders 20. When individually retarding the respective ignition timings of a plurality of engine cylinders 20, the engine control unit 80 can retard the ignition timing of a specific engine cylinder 20 if the knock intensity within that specific engine cylinder 20 exceeds a target knock intensity 33. When individually retarding the respective ignition timings of a plurality of engine cylinders 20, the engine control unit 80 can retard the ignition timing of a specific engine cylinder 20 independently of the ignition timing of any other engine cylinder 20.For example, the engine control unit 80 can retard the ignition timing of a particular engine cylinder 20 to a different time, by a different amount, or to a different extent than the ignition timing of another engine cylinder 20. When individually retarding the respective ignition timings of a plurality of engine cylinders 20, the amount or degree by which the ignition timing of an individual engine cylinder 20 is retarded can be based on a calibration factor specific to that individual engine cylinder 20, as described above, or the amount or degree by which the ignition timing of the individual engine cylinder 20 is retarded can be predetermined.

[0046] As in Fig. As shown in Figure 4, the procedure 100 can proceed after comparing the knock intensity of the engine with the knock intensity threshold 32 with a step 106 in which the engine control unit 80 delays a first ignition timing of a first engine cylinder 20 of the several engine cylinders 20 by a first amount, and a step 108 in which the engine control unit 80 delays a second ignition timing of a second engine cylinder 20 of the several engine cylinders 20 by a second amount that is smaller than the first amount.

[0047] For example, as described above, if the knock intensity of the engine 14 is greater than the knock intensity threshold 32, even though the first and second amounts are different, the first and second ignition timings can be retarded together during the same cycle of a four-stroke engine cycle. The first amount can be based on a first calibration factor identified or generated for the first engine cylinder 20, and the second amount can be based on a second calibration factor identified or generated for the second engine cylinder 20, as described above.Or, for example, if the knock intensity of the engine 14 is greater than the knock intensity threshold 32, the engine control unit 80 can retard the first ignition timing and the second ignition timing together to the same crank angle, even though the first amount and the second amount are different, because the first ignition timing was previously further ahead of the second ignition timing.

[0048] Or, for example, if the knock intensity of the engine 14 is less than the knock intensity threshold 32, the engine control unit 80 can individually retard the first ignition timing and the second ignition timing by different amounts and to different crank angles or at different times, as described above. The first amount can be based on a first calibration factor identified or generated for the first engine cylinder 20, and the second amount can be based on a second calibration factor identified or generated for the second engine cylinder 20, as described above.

[0049] As in Fig.As shown in Figure 4, the process 100 can be continued with a step 110 in which the engine control unit 80 advances the first or second ignition timing until a target knock intensity 33 is reached or until an upper limit for the first or second ignition timing is reached. As described above, the engine control unit 80 can advance the first or second ignition timing by an incremental and / or predetermined amount during each successive cycle of the four-stroke engine cycle. The amount by which the engine control unit 80 advances the first or second ignition timing can be based on a first calibration factor identified or generated for the first engine cylinder 20, or on a second calibration factor identified or generated for the second engine cylinder 20.

[0050] By collectively and individually adjusting the ignition timing of a large number of engine cylinders 20 contained in an engine 14, the engine control unit 80 can quickly and precisely adapt the operation of the engine 14 to different fuel types and qualities, thus enabling the engine 14 to reduce wear due to knocking and avoid knock-induced shutdowns. By setting a target knock intensity value 33 and advancing the respective ignition timing of a large number of engine cylinders 20 contained in an engine 14, the engine control unit 80 can improve the fuel efficiency of the engine 14 and prevent the exhaust gas temperature of the engine 14 from becoming undesirably high.By using sensor data 25 generated by pressure sensors arranged in each engine cylinder 20 of a plurality of engine cylinders 20 contained in an engine 14, the engine control unit 80 can reliably detect and measure knocking in each engine cylinder 20.

[0051] Although the systems and methods disclosed herein are often described as reducing and / or controlling knocking within an engine 14 by collectively and / or individually adjusting the ignition timing of a plurality of engine cylinders 20 contained in the engine 14, it is understood and acknowledged that the systems and methods disclosed herein may alternatively or additionally be capable of reducing and / or controlling knocking within an engine 14 by collectively and / or individually adjusting the injection timing of a plurality of engine cylinders 20 contained in the engine 14. For example, an engine control unit 80, in response to the detection of an increase in the knock intensity of an engine 14 comprising multiple engine cylinders 20, may compare the knock intensity of the engine 14 with a knock intensity threshold 32, as described above.If the knock intensity of the engine 14 is greater than the knock intensity threshold 32, the engine control unit 80 can retard the respective injection timings of each engine cylinder 20 contained in the multiple engine cylinders 20 collectively, similar to how the engine control unit 80 can retard the respective ignition timings of each engine cylinder 20 contained in the multiple engine cylinders 20 collectively, as described above. Or, for example, if the knock intensity of the engine 14 is less than the knock intensity threshold 32, the engine control unit 80 can retard the respective injection timings of the multiple engine cylinders 20 individually, cylinder by cylinder, similar to how the engine control unit 80 can retard the respective ignition timings of each engine cylinder 20 contained in the multiple engine cylinders 20 individually, cylinder by cylinder, as described above.Similar to the way in which the engine control unit 80 can delay the respective ignition timings of the engine cylinders 20 together or individually as described above, the engine control unit 80, regardless of whether it delays the respective injection timings of the engine cylinders 20 together or individually, can delay a first injection timing of a first engine cylinder 20 of the multiple engine cylinders 20 by a first amount and delay a second injection timing of a second engine cylinder 20 of the multiple engine cylinders 20 by a second amount that differs from the first amount.After jointly or individually delaying the respective injection timings of the engine cylinders 20, the engine control unit 80 can advance the respective injection timings of one or more engine cylinders 20 contained in the multiple engine cylinders 20 until a target knock intensity 33 is reached or until an upper limit for the respective injection timings of the one or more engine cylinders 20 is reached.To reduce and / or control knocking in an engine 14, the engine control unit 80 can adjust either the respective ignition timings of a plurality of engine cylinders 20 contained in the engine 14 and / or the respective injection timings of the plurality of engine cylinders 20 contained in the engine 14, collectively and / or individually, so that the engine control unit 80 is able to reduce and / or control knocking in an engine 14 that is operated with different types of fuel, for example a dual-fuel engine or an engine that is operated with hybrid fuel mixtures.

[0052] Those skilled in the art will recognize that various modifications and variations of the disclosed method and system can be made without departing from the scope of the disclosure. Other embodiments of the method and system are apparent to those skilled in the art from a review of the patent specification and from the practical application of the device and system disclosed herein. It is intended that the patent specification and the examples given are to be considered merely illustrative, with the true scope of the disclosure being defined by the following claims and their equivalents. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 4,243,007

[0004]

Claims

[1] Engine system, comprising: an engine (14) comprising several engine cylinders (20); and a control unit (80) that is capable of: to control a specific ignition timing for each engine cylinder (20) of the multiple engine cylinders (20); Detecting an increase in engine knock intensity (14); after detecting the increase in engine knock intensity (14), comparing the engine knock intensity (14) with a knock intensity threshold (32); If the knock intensity of the engine (14) is greater than the knock intensity threshold (32), delay the respective ignition timing for each of the multiple engine cylinders (20) by the same amount; and if the knock intensity of the engine (14) is less than the knock intensity threshold (32), delay a first ignition timing of a first engine cylinder (20) of the multiple engine cylinders (20) by a first amount independent of a second ignition timing of a second engine cylinder (20) of the multiple engine cylinders (20). [2] Motor system according to claim 1, wherein the control unit (80) is further operable to: Determining a calibration factor for the first engine cylinder (20); and If the knock intensity of the engine (14) is less than the knock intensity threshold (32), delay the first ignition timing of the first engine cylinder (20) by the first amount, which is based at least partially on the calibration factor. [3] Engine system according to claim 2, wherein the control unit (80) further operates such that, when the knock intensity of the engine (14) is greater than the knock intensity threshold (32), it delays the respective ignition timing for each engine cylinder (20) of the multiple engine cylinders (20) by a predetermined amount. [4] Engine system according to one of the preceding claims, wherein the increase in the knocking intensity of the engine (14) is detected by a pressure sensor (24). [5] Motor system according to claim 4, wherein the pressure sensor (24) is arranged inside the first motor cylinder (20). [6] Motor system according to claim 1, wherein the control unit (80) is further operable to: Determining a value for the engine knock intensity (14); and If the knock intensity of the engine (14) is less than the knock intensity threshold (32), delay the first ignition timing of the first engine cylinder (20) by the first amount which is based at least partially on the value of the knock intensity of the engine (14). [7] Engine system according to claim 1, wherein the control unit (80) further operates such that, when the knock intensity of the engine (14) is less than the knock intensity threshold (32), it delays a second ignition timing of a second engine cylinder (20) of the multiple engine cylinders (20) by a second amount which differs from the first amount. [8] Motor system according to claim 7, wherein: the detection of the increase in engine knock intensity (14) further includes the detection of a first increase in knock intensity within the first engine cylinder (20) and a second increase in knock intensity within the second engine cylinder (20); and the control unit (80) is further effective in delaying the first ignition timing by the first amount and the second ignition timing by the second amount, based at least partially on the first increase in knock intensity and the second increase in knock intensity, respectively. [9] Engine system according to claim 8, wherein the first increase in knock intensity is detected by a first pressure sensor (24) arranged inside the first engine cylinder (20), and the second increase in knock intensity is detected by a second pressure sensor (24) arranged inside the second engine cylinder (20). [10] Engine system according to claim 1, wherein the control unit (80) further operates such that, when the knock intensity of the engine (14) is less than the knock intensity threshold (32), after delaying the first ignition timing of the first engine cylinder (20) by the first amount, it advances the first ignition timing until a target knock intensity of the engine (14) is reached.

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