Methods and devices for combustion diagnosis and control of internal combustion engines using acceleration sensors

Abstract

Device comprising: a filter circuit (144) configured to filter vibration data within a predetermined combustion period of the machine, wherein the vibration data represent a vibration of an internal combustion engine (110), the vibration data comprising voltage signals; a PCP determination circuit (146) which is functionally and communicatively connected to the filter circuit (144) and is configured to determine a cylinder peak pressure (PCP) of a combustion cycle of the internal combustion engine (110) on the basis of the filtered vibration data, wherein the PCP corresponds to a maximum of absolute values ​​of the voltage signals or a difference between the maximum and a minimum of the absolute values ​​of the voltage signals; an LPP determination circuit (148) which is functionally and communicatively connected to the filter circuit (144) and configured to determine a location of the cylinder peak pressure (LPP) of the combustion cycle of the internal combustion engine (110) based on the filtered vibration data, wherein the PCP and the LPP represent a functional property of the combustion cycle; and an ignition timing circuit which is functionally and communicatively connected to the PCP determination circuit and the LPP determination circuit, wherein the ignition timing circuit is configured to modify an ignition timing of the internal combustion engine on the basis of the determined PCP and the determined LPP.

Description

BACKGROUND

[0001] The present disclosure relates to the diagnosis and control of internal combustion engines. In particular, the present disclosure relates to the diagnosis and control of internal combustion engines using signals from acceleration sensors attached to the engines.

[0002] Emissions regulations for internal combustion engines have become significantly stricter in recent years. Consumers and authorities are increasingly demanding improved fuel efficiency in vehicles while simultaneously reducing pollutant emissions. During the operation of an internal combustion engine, combustion data can provide crucial information for diagnosing and controlling engine parameters, thereby improving engine performance and reducing toxic exhaust emissions. However, conventional pressure sensors installed inside the cylinder, used to capture data on combustion characteristics, are difficult and costly to integrate into combustion chambers. Furthermore, cylinder-mounted pressure sensors can be damaged by the high temperatures and pressures encountered during typical engine operation.Therefore, an inexpensive yet durable technology is desired for the diagnosis and control of machines.

[0003] US Patent 8,396,649 B2 discloses a method in which the cylinder pressure is reconstructed from a vibration signal. The resulting cylinder pressure can be used to control engine operation. SUMMARY

[0004] The invention is defined in the independent claims. Preferred embodiments are the subject of the dependent claims.

[0005] One embodiment relates to a device. The device includes a filter circuit configured to filter vibration data within a predetermined combustion period of the machine. The vibration data indicates vibration of an internal combustion engine. The device also includes a peak cylinder pressure (PCP) determination circuit, which is functionally and communicatively connected to the filter circuit and configured to determine the PCP of a combustion cycle of the internal combustion engine based on the filtered vibration data. Furthermore, the device includes a location of peak cylinder pressure (LPP) determination circuit, which is functionally and communicatively connected to the filter circuit and configured to determine the LPP of the combustion cycle of the internal combustion engine based on the filtered vibration data. The PCP and the LPP indicate a functional characteristic of the combustion cycle.The device further comprises an ignition timing circuit that is functionally and communicatively connected to the PCP determination circuit and the LPP determination circuit. The ignition timing circuit is configured to modify the ignition timing of the internal combustion engine based on the determined PCP and the determined LPP.

[0006] The ignition timing circuit can be designed to modify the ignition timing of the internal combustion engine in order to prevent partial ignitions, misfires, or overpressure in the internal combustion engine.

[0007] The predetermined combustion period of the machine can encompass a crank angle range between approximately -100 degrees and approximately 100 degrees.

[0008] The filter circuit can include a low-pass filter, with a cutoff frequency of the low-pass filter in a range of about 100 Hz to about 800 Hz.

[0009] The vibration data may contain voltage signals, and the PCP may correspond to a maximum of absolute values ​​of the voltage signals or a difference between the maximum and a minimum of the absolute values ​​of the voltage signals, and the LPP may correspond to a crank angle position corresponding to a peak value of the filtered vibration data.

[0010] The device may further include a PCP control circuit which is functionally and communicatively connected to the PCP determination circuit and is configured to determine a first ignition timing offset to a base ignition timing based on the PCP determined by the PCP determination circuit.

[0011] The device may further include an LPP control circuit which is functionally and communicatively connected to the LPP determination circuit and is configured to determine a second ignition timing offset to the base ignition timing based on the LPP determined by the LPP determination circuit.

[0012] Another embodiment relates to a system comprising an internal combustion engine, a vibration sensor, and a control device. The vibration sensor is communicatively connected to the internal combustion engine and configured to detect vibration data representing vibration of the engine. The control device is communicatively connected to the vibration sensor and configured to filter the vibration data within a predetermined combustion period of the engine, determine a peak cylinder pressure (PCP) of a combustion cycle of the internal combustion engine based on the filtered vibration data, determine a location of the peak cylinder pressure (LPP) of the combustion cycle of the internal combustion engine based on the filtered vibration data, wherein the PCP and the LPP represent a functional property of the combustion cycle, and modify an ignition timing of the internal combustion engine based on the determined PCP and the determined LPP.

[0013] The vibration sensor can be an acceleration sensor attached to the internal combustion engine.

[0014] The accelerometer may include a knock sensor.

[0015] The acceleration sensor can be attached to a cylinder head or a head bolt of the internal combustion engine.

[0016] The vibration data can be filtered using a low-pass filter.

[0017] The cutoff frequency of the low-pass filter can be in a range from about 100 Hz to about 800 Hz.

[0018] The internal combustion engine can be a single-cylinder or a multi-cylinder engine.

[0019] The predetermined combustion period of the machine can encompass a crank angle range between approximately -100 degrees and approximately 100 degrees.

[0020] The vibration data may contain voltage signals; the PCP may correspond to a maximum of absolute values ​​of the voltage signals or a difference between the maximum and a minimum of the absolute values ​​of the voltage signals; and the LPP may correspond to a crank angle position corresponding to a peak value of the filtered vibration data.

[0021] The control device can further be configured to determine a first ignition timing offset to a base ignition timing based on the determined PCP, and to modify the base ignition timing with the first ignition timing offset.

[0022] The control device can further be configured to determine a second ignition timing offset to the base ignition timing based on the determined LPP, and to modify the base ignition timing with the second ignition timing offset.

[0023] Another embodiment relates to a method that includes filtering the vibration data within a predetermined combustion period of the engine. The vibration data indicates vibration of an internal combustion engine. The method further includes determining a peak cylinder pressure (PCP) of a combustion cycle of the internal combustion engine based on the filtered vibration data and determining a location of the peak cylinder pressure (LPP) of the combustion cycle of the internal combustion engine based on the filtered vibration data. The PCP and the LPP indicate a functional characteristic of the combustion cycle. The method further includes modifying an ignition timing of the internal combustion engine based on the determined PCP and the determined LPP.

[0024] The predetermined combustion period of the machine can encompass a crank angle range between approximately -100 degrees and approximately 100 degrees.

[0025] Filtering the vibration data can include filtering the vibration data using a low-pass filter, and the cutoff frequency of the low-pass filter can be in a range of about 100 Hz to about 800 kHz.

[0026] The vibration data may contain voltage signals; the PCP may correspond to a maximum of absolute values ​​of the voltage signals or a difference between the maximum and a minimum of the absolute values ​​of the voltage signals; and the LPP may correspond to a crank angle position corresponding to a peak value of the filtered vibration data.

[0027] The procedure may further include determining a first ignition timing offset from a base ignition timing based on the determined PCP, and modifying the base ignition timing with the first ignition timing offset.

[0028] The procedure may further include determining a second ignition timing offset to the base ignition timing based on the determined LPP, and modifying the base ignition timing with the second ignition timing offset.

[0029] These and other characteristics, as well as the organization and nature of its operation, can be found in the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic diagram of a system for diagnosing and controlling an internal combustion engine according to an exemplary embodiment. Fig. Figure 2 is a flowchart of a method for diagnosing and controlling an internal combustion engine according to an exemplary embodiment. Fig. 3 is a representation showing the correlation between the data obtained using the method of Fig. 2 processed vibration data and the signals from the cylinder internal pressure sensor for an identical machine. Fig. Figure 4 is a representation showing the correlation between the cylinder peak pressure (PCP) of combustion, as derived from the vibration data, using the method of Fig. 2 determined, and the PCP, as determined from the data recorded by the cylinder internal pressure sensor, shows for a single-cylinder engine. Fig. Figure 5 is a representation showing the correlation between the location of the cylinder peak pressure (LPP) of combustion, as derived from the vibration data using the method of Fig. 2 determined, and the LPP, as determined from the data recorded by the cylinder internal pressure sensor, shows for a single-cylinder engine. Fig. Figure 6 is a representation showing the correlation between the PCP of combustion, as derived from the vibration data, using the method of Fig. 2 determined, and the PCP, as determined from the data recorded by the cylinder internal pressure sensor, shows for a multi-cylinder machine. Fig. Figure 7 is a representation showing the correlation between the LPP of combustion, as derived from the vibration data using the method of Fig. 2 determined, and the LPP, as determined from the data recorded by the cylinder internal pressure sensor, shows for a multi-cylinder machine. Fig. Figures 8(a)-8(d) are representations that show the results of the machine control based on the data obtained from a vibration sensor using the method of Fig. 2 and show the results of the machine control based on the signals from the cylinder internal pressure sensor. DETAILED DESCRIPTION

[0030] For the purpose of a better understanding of the principles of the disclosure, reference is now made to the embodiments shown in the drawings, and certain terms are used for their description. It is understood, however, that this is not intended to limit the scope of protection of the invention; any changes and further modifications of the embodiments shown, and all further applications of the principles of the disclosure as described herein, which may normally be apparent to those skilled in the art of disclosure, are included herein.

[0031] With general reference to the figures, the various systems, methods, and devices described herein relate to the diagnosis and control of an internal combustion engine using data obtained from a vibration sensor (e.g., an accelerometer) mounted on the engine. The combustion data, which represent combustion characteristics such as peak cylinder pressure (PCP) and peak cylinder pressure location (LPP), can provide important information for diagnosing the engine's operation. The term "peak cylinder pressure" or "PCP" refers to the maximum pressure in the engine cylinder during engine operation. The term "peak cylinder pressure location" or "LPP" refers to the crankshaft angle position corresponding to the peak cylinder pressure. Normal combustion has a region of LPP slightly to the right of zero (0) degrees of crankshaft angle (e.g., top dead center).When a misfire occurs, the low-pressure peak (LPP) is located at top dead center (TDC). In the case of partial combustion, for example, the pressure peak value is shifted significantly to the right of TDC. By determining the LPP, the combustion process can be diagnosed.

[0032] PCP and LPP can also be used as a basis for machine control. For example, PCP and LPP can be used, either alone or in combination, to control the ignition timing (also known as "sparking timing"), ignition angle, or spark angle. The term "ignition timing" refers to the crank angle position at which a spark is generated in the combustion chamber of the machine. Setting the correct ignition timing is crucial for the machine's operation. For example, the ignition timing can affect machine lifespan, fuel consumption, and machine performance. Sparks occurring too early or too late in the machine cycle can cause excessive vibration or even damage to the machine. Compared to the scheme of determining PCP and LPP using cylinder pressure sensors, the embodiments disclosed herein can utilize a vibration sensor mounted on the machine (e.g., a vibration sensor).An accelerometer can be used to acquire combustion data and determine combustion characteristics (e.g., PCP and LPP) from this data. Since the accelerometer is located outside the combustion chamber, no structural modifications to the machine are required. Furthermore, the accelerometer does not need to withstand very high pressures and temperatures; therefore, the vibration sensor can be relatively inexpensive and have a longer lifespan than a sensor located inside a combustion chamber.

[0033] With reference to Fig. Figure 1 shows a schematic diagram of a system 100 for diagnosing and controlling an internal combustion engine according to an exemplary embodiment. The system 100 comprises an internal combustion engine 110, a vibration sensor 120, and an electronic control unit (EC) 130. The internal combustion engine 110 can be a single-cylinder or a multi-cylinder engine. The vibration sensor 120 can be an accelerometer or another type of sensor capable of measuring, detecting, or sensing vibrations of the engine 110 or of components of the engine 110, such as a cylinder head or block. For example, in some embodiments, the vibration sensor 120 is a knock sensor. The vibration sensor 120 can be mounted on the engine 110 to monitor vibrations and obtain real-time information about the cylinder pressure of the engine 110.In some embodiments, the vibration sensor 120 is attached to the head of the machine 110.

[0034] For example, the vibration sensor 120 can be mounted on a cylinder head bolt of a single-cylinder machine. In some embodiments, the vibration sensor 120 can be mounted on a cylinder head bolt of a multi-cylinder machine. In multi-cylinder machines, several vibration sensors can be mounted on the machine, and each vibration sensor can be mounted on a specific cylinder of the machine. In some embodiments, one vibration sensor can be used for more than one cylinder of the machine. In some embodiments, more than one acceleration sensor can be mounted on a single cylinder of the machine. The vibration sensor 120 can be a commercially available knock sensor for detecting machine knock or any suitable type of acceleration sensor.

[0035] The EC 130 can be connected to both the machine 110 and the vibration sensor 120. The EC 130 can include a signal processor 140 and an ignition control unit 150. It is understood that the EC 130 can include various other diagnostic and control systems not shown in the present figure. Communication between and among the components of the system 100 can take place via any number of wired or wireless connections. For example, a wired connection can be a serial cable, a fiber optic cable, a CAT5 cable, or any other type of wired connection. A wireless connection can include the internet, Wi-Fi (WLAN), cellular devices, radio, etc. In one embodiment, a Controller Area Network (CAN) bus provides the means for exchanging signals, information, and / or data. The CAN bus can have any number of wired and wireless connections.Although the signal processor 140 and the ignition control 150 are shown as separate components in the figure, they can be combined into a single component. The EC 130 can be implemented as a general-purpose processor, an application-specific integrated circuit (ASIC), one or more field-programmable gate arrays (FPGAs), a digital signal processor (DSP), a group of processor components, or other suitable electronic processing components. The EC 130 can include one or more memory devices (e.g., RAM, ROM, flash memory, hard disk storage, etc.) that store data and / or instructions to facilitate the various processes described herein. The one or more memory devices can include database components, object code components, script components, or any other type of information structures to support the various activities and information structures described herein.

[0036] The signal processor 140 can receive vibration data from the vibration sensor 120. The signal processor 140 can include a filter circuit 144, a PCP determination circuit 146, and an LPP determination circuit 148. Optionally, the signal processor 140 can include a time window circuit 142. In some embodiments, the vibration signals include voltage signals. To accurately detect a pressure peak value in a cylinder, a portion of the vibration data can be considered according to the combustion process in the cylinder. The time window circuit 142 can determine the vibration data that fall within a time window encompassing the combustion process in the machine 110. In some embodiments, the time window includes a case where the crank reaches top dead center (i.e., 0 degrees crank angle). For example, the time window includes a crank angle range from -100 degrees to 100 degrees.The determination can be implemented by masking the vibration data for an entire firing cycle except within the time window. The crank angle can be monitored by a crank position sensor. In some embodiments, the time window circuit 142 can include a circuit configured to determine the signals from the accelerometer within the time window. In some embodiments, the time window circuit 142 can include instructions stored in a machine-readable medium. In some embodiments, the time window circuit 142 can include any combination of machine-readable content and circuitry.

[0037] To determine information about the combustion process from the vibration data within the specified time window, the filter circuit 144 can filter the vibration data to isolate a low-frequency range and generate filtered vibration data. The cutoff frequencies of the low-pass filter 144 generally depend on the design and combustion characteristics of the machine used and can therefore vary for different machines. The cutoff frequencies of the low-pass filter 144 can be determined experimentally during a setup phase after the vibration sensor 120 has been attached to the machine 110. In some embodiments, the cutoff frequencies are approximately a few hundred Hz, for example, approximately 100 Hz to 800 Hz. In some embodiments, the cutoff frequencies are approximately 200 Hz to 700 Hz. In some embodiments, the cutoff frequencies are approximately 300 Hz to 500 Hz.In some embodiments, the filter circuit 144 is implemented as a hardware filter comprising capacitors, resistors, and other circuitry to isolate low-frequency components from the vibration signals. In some embodiments, the filter circuit 144 is implemented in the form of machine-readable instructions stored in a machine-readable medium. For example, Fourier transform algorithms or zero-voltage low-pass filters can be used to isolate the low-frequency components of the vibration signals. In some embodiments, the filter circuit 144 can comprise any combination of machine-readable content and circuitry.

[0038] The PCP determination circuit 146 can determine the cylinder peak pressure from the filtered vibration signals. In some embodiments, the vibration signals are voltage signals. The cylinder peak pressure can correspond to the maximum of the absolute voltage value or to the difference between the maximum and minimum absolute voltage values. With the vibration signals on some machines (e.g., QSK60 SCE), the signals are inverted to detect the peak value because the voltage at the peak is negative. With the vibration signals on other machines (e.g., HH 16), the signals are not inverted because the voltage at the peak is positive. In some embodiments, the PCP determination circuit 146 includes a circuit configured to determine the cylinder peak pressure. In some embodiments, the PCP determination circuit 146 has instructions stored in a machine-readable medium.In some embodiments, the PCP determination circuit 146 can comprise any combination of machine-readable content and circuitry. The LPP determination circuit 148 determines the location of the cylinder peak pressure (i.e., the crank angle position corresponding to the cylinder peak pressure). The crank angle position can be monitored by a crank position sensor or a camshaft position sensor and correlated with the signals from the accelerometer. It is understood that the signal processor 140 can comprise any number of circuits for performing the functions described herein. For example, the activities of multiple modules can be combined into a single module, as additional modules with further functionalities can be included, etc.

[0039] The combustion characteristics determined by the signal processor 140 (e.g., PCP and LPP) can be used for real-time control of the ignition timing of the machine 110 to prevent or correct combustion anomalies (e.g., misfires or partial combustion). The combustion characteristics determined by the signal processor 140 (e.g., PCP and LPP) can also be used to control the ignition timing of the machine 110 to direct combustion to a target LPP or PCP. Therefore, the machine can operate with lower emissions or improved fuel efficiency. The ignition controller 150 can include a PCP control circuit 152 and an LPP control circuit 154. The ignition controller 150 sets a base ignition timing (i.e., ignition angle) of θ0. In some embodiments, the base ignition angle is in a range of 10 degrees to 30 degrees. For example, in some embodiments, the base ignition angle is 20 degrees.The PCP control circuit 152 determines a first ignition timing offset based on the PCP determined by the PCP determination circuit 146. For example, in some embodiments, if the PCP is greater than a predetermined value, the ignition timing can be retarded by the control device, since the larger PCP means that the current ignition timing is too early. In some embodiments, if the PCP is less than a predetermined value, the ignition timing can be advanced by the control device, since the smaller PCP means that the current ignition timing is too far retarded. The LPP control circuit 154 determines a second ignition timing offset based on the LPP determined by the LPP determination circuit 148. For example, in some embodiments, if the LPP is earlier than a predetermined value, the ignition timing can be retarded by the control device.If the LPP (Low Power Point) is later than a predetermined value, the ignition timing can be advanced by the control device. It is understood that the signal processor 140 can have any number of modules for performing the functions described herein. For example, the activities of multiple modules can be combined into a single module, as further modules with additional functionalities can be included, etc.

[0040] With reference to Fig. Figure 2 shows a flowchart of a method 200 for diagnosing and controlling an operating parameter of an internal combustion engine according to an exemplary embodiment. In certain embodiments, the method 200 is implemented using EC 130 described herein. For example, the method 200 can be executed in the form of machine-readable instructions that can be executed by the signal processor 140 and the ignition control unit 150. In step 202, vibration data is received. The vibration data can be received from a vibration sensor mounted on a single-cylinder engine or from vibration sensors mounted on a multi-cylinder engine. The vibration sensor or sensors can be commercially available knock sensors for detecting engine knock or can be accelerometers configured to detect engine vibrations.

[0041] In step 204, time window data is extracted from the received accelerometer data by, for example, the time window circuit 142. Fig. 1. The time window circuit 142 can determine the vibration data that fall within a time window encompassing the combustion process in the machine 110. In some embodiments, the time window includes a case where the crank reaches top dead center (i.e., 0 degrees crank angle). In one embodiment, the time window encompasses a crank angle range from -100 degrees to 100 degrees. The determination can be implemented by masking the vibration data for an entire combustion cycle except within the time window. The crank angle can be monitored by a crank position sensor.

[0042] In step 206, the time window data or the vibration data are processed by, for example, the filter circuit 144. Fig. 1. A low-frequency range is filtered to produce filtered signals. The cutoff frequencies of the low-pass filter 144 generally depend on the design and combustion characteristics of the machine used and can therefore differ for different machines. The cutoff frequencies of the low-pass filter 144 can be determined experimentally during a setup phase after the accelerometer 120 has been attached to the machine 110. In some embodiments, the cutoff frequencies are approximately a few hundred Hz, for example, approximately 100 Hz to 800 kHz. In some embodiments, the cutoff frequencies are approximately 200 Hz to 700 Hz. In some embodiments, the cutoff frequencies are approximately 300 Hz to 500 Hz.

[0043] In step 208, the PCP and the LPP are determined from the filtered data by, for example, the PCP determination circuit 146 and the LPP determination circuit 148. Fig. 1. In some embodiments, the vibration signals include voltage signals. In some embodiments, the PCP corresponds to the maximum of the absolute voltage value or the difference between the maximum and minimum absolute voltage values. For the accelerometer signals on some machines (e.g., QSK60 SCE), the signals are inverted to detect the peak value, since the voltage at the peak is negative. For the accelerometer signals on other machines (e.g., HH 16), the signals are not inverted, since the voltage at the peak is positive. The LPP determination circuit 148 determines the LPP (i.e., the crank angle position corresponding to the PCP). The crank angle position can be monitored by a crank position sensor or a crank angle velocity sensor and correlated with the accelerometer signals.

[0044] In step 210, an ignition timing (or ignition angle) is set based on the specified LPP and PCP by, for example, the ignition control unit 150. Fig. 1. Controlled. In some embodiments, the ignition control 150 includes the PCP control circuit 152 and the LPP control circuit 154. The ignition control 150 sets a basic ignition timing (i.e., ignition angle) of θ0. In some embodiments, the basic ignition angle is in a range of 10 degrees to 30 degrees (e.g., 20 degrees). The PCP control circuit 152 determines a first ignition timing offset based on the PCP determined by the PCP determination circuit 146. For example, if the PCP is greater than a predetermined value, the ignition timing should be retarded. If the PCP is less than a predetermined value, the ignition timing should be advanced. The LPP control circuit 154 determines a second ignition timing offset based on the LPP determined by the LPP determination circuit 148. For example, if the LPP (Low Power Point) occurs earlier than a predetermined value, the ignition timing should be delayed.If the LPP (Low Power Point) occurs later than a predetermined value, the ignition timing should be moved forward.

[0045] It is understood that the schematic flowchart described above is generally implemented as a logical flowchart. As such, the sequence shown and the marked steps represent representative implementations. Other steps, sequences, and procedures are conceivable that are equivalent in function, logic, or effects to one or more steps or substeps of the procedures depicted in the schematic diagrams.

[0046] Fig. Figure 3 shows a representation of the correlation between using the method of Fig. 2 processed vibration data and data from a cylinder pressure sensor for the same machine. For testing purposes, an accelerometer was attached to a machine that also has a cylinder pressure sensor. The signals generated by the pressure sensor and the accelerometer were compared for various crank angles, as shown in Fig. Figure 3 shows that the representation confirms the existence of a significant correlation between the two signals.

[0047] With reference to Fig. Figure 4 shows a graph of the relationship between the PCPs derived from the vibration data using the method of Fig. The graph shows a good agreement between the two sets of PCPs, determined from the data collected by the cylinder pressure sensor for a single-cylinder engine.

[0048] Fig. Figure 5 shows a representation of the correlation between the vibration data obtained using the method of Fig. The graph shows two sets of LPPs determined by the LPPs themselves and the LPPs determined from the data acquired by the cylinder pressure sensor for a single-cylinder engine. The graph demonstrates good agreement between the two sets of LPPs.

[0049] Fig. Figure 6 shows a representation of the correlation between the vibration data obtained using the method of Fig. The graph shows two sets of PCPs: one set determined by the cylinder pressure sensor and the other determined from the data acquired by the cylinder pressure sensor for a multi-cylinder engine. The graph demonstrates good agreement between the two sets of PCPs.

[0050] Fig. Figure 7 shows a representation of the correlation between the vibration data obtained using the method of Fig. The graph shows two sets of LPPs: one determined by the LPP itself and the other determined from the data acquired by the cylinder pressure sensor for a multi-cylinder engine. The graph demonstrates good agreement between the two sets of LPPs.

[0051] Fig. 8, Fig. Figures 8(a) to 8(d) show results of machine control based on the vibration sensor readings using the method of Fig. 2. Data obtained and results of the machine control based on signals from the cylinder internal pressure sensor. In particular, it shows Fig. 8(a) the results of the specific fuel consumption (BSFC), which is a measure of the fuel efficiency of a machine. Fig. 8(b) shows the results of the NO x -Emission. Fig. Figure 8(c) shows the results of the coefficient of variation of the effective mean pressure (GIMEP), which is the average pressure on a piston during one working stroke of its cycle. Fig. Figure 8(d) shows the results of the fuel consumption quantity, which is also a measure of the fuel efficiency of a machine. As in Fig. As shown in section 8, similar results were obtained for machine control based on signals from an accelerometer using the method of Fig. 2 and obtained based on the signals from the cylinder pressure sensor.

[0052] It should be noted that the term "example", as used here to describe different embodiments, is intended to indicate that such embodiments are possible examples, representations and / or illustrations of possible embodiments (and that such a term is not necessarily intended to imply that such embodiments are exceptional or outstanding examples).

[0053] Exemplary and non-limiting elements of the circuit implementation are sensors (e.g.the sensors 140), which provide a value specified herein, sensors which provide a value which is a precursor to a value specified herein, data link and / or network hardware including communication chips, oscillating crystals, communication links, cables, twisted pair wiring, coaxial wiring, shielded wiring, transmitters, receivers and / or transceivers, logic circuits, hard-wired logic circuits, reconfigurable logic circuits in a specified non-transient state which are structured according to the module specification, any actuator including at least one electrical, hydraulic or pneumatic actuator, solenoid, operational amplifier, analog control elements (springs, filters, integrators, adders, dividers, gain elements) and / or digital control elements.

[0054] The schematic flowcharts and schematic process diagrams described above are generally designed as logical flowcharts. As such, the sequence shown and the marked steps represent representative implementations. Other steps, sequences, and processes are conceivable that are equivalent in function, logic, or effects to one or more steps or substeps of the processes depicted in the schematic diagrams.

[0055] Furthermore, the format and symbols used are intended to explain the logical steps of the schematic diagrams and are not meant to restrict the scope of protection of the procedures illustrated by the diagrams. Although various arrow and line types may be used in the schematic diagrams, they are not intended to restrict the scope of protection of the corresponding procedures. In fact, some arrows or other connections may be used simply to indicate the logical sequence of a procedure. For example, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of a depicted procedure. Furthermore, the sequence in which a particular procedure is executed may or may not exactly match the sequence of the corresponding steps shown.It should also be noted that each block of the block diagrams and / or flowcharts, and each combination of blocks in the block diagrams and / or flowcharts, can be implemented by special-purpose hardware-based systems that perform the specified functions or operations, or by special-purpose hardware and program code combinations.

[0056] Many of the functional units described in this specification have been designated as modules to further emphasize their implementation independence. For example, a module may be implemented as a hardware circuit containing user-defined VLSI circuits or general-purpose circuits, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware units such as field-programmable general-purpose circuits, programmable logic circuits, programmable logic units, or the like.

[0057] Modules can also be implemented in a machine-readable medium for execution by various types of processors. An identified module of executable code can, for example, contain one or more physical or logical blocks of computer instructions, which may be organized as objects, processes, procedures, or functions. However, the executable files of an identified module need not be physically located together; they can contain fundamentally different instructions stored in different locations. When logically linked, these instructions constitute the module and achieve its stated purpose.

[0058] In fact, a module of computer-readable program code can be a single instruction, or it can consist of many instructions, evenly distributed across several different code sections, across different programs, and across multiple storage devices. Likewise, operational data can be identified and illustrated within modules and can be expressed in any suitable form and organized within any suitable type of data structure. The operational data can be collected as a single data set or distributed across various locations, including different storage devices, and can exist, at least in part, primarily as electronic signals on a system or network.If a module or parts of a module are implemented in a machine-readable (or computer-readable) medium, the computer-readable program code can be stored in and / or transferred to one or more computer-readable media.

[0059] The computer-readable medium can be a tangible, computer-readable storage medium that stores the computer-readable program code. The computer-readable storage medium can be, for example (but is not limited to), a system, device, or apparatus based on electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor technology, or any suitable combination thereof.

[0060] More specific examples of a computer-readable medium may, but are not limited to, a portable computer disk, a hard disk, a RAM module, a ROM memory, a wipeable programmable read-only memory (EPROM or flash memory), a portable read-only CD-ROM, a versatile digital disc (DVD), an optical storage device, a magnetic storage device, a holographic storage device, a micromechanical storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium can be any tangible medium capable of containing or storing computer-readable program code for use by or in conjunction with an instruction execution system, device, or apparatus.

[0061] The computer-readable medium can also be a computer-readable signaling medium. A computer-readable signaling medium can include a propagated data signal containing computer-readable program code, for example, on baseband or as part of a carrier wave. Such a propagated signal can take any of a variety of different forms, including, but not limited to, electrical, electromagnetic, magnetic, optical, or any suitable combination thereof. A computer-readable signaling medium can be any computer-readable medium other than a computer-readable storage medium that can communicate, propagate, or transport computer-readable program code for use by or in conjunction with an instruction execution system, device, or apparatus.A computer-readable program code embedded in a computer-readable signaling medium may be transmitted using any suitable medium, including (but not limited to) wireless, wired, fiber optic cable, radio frequency (RF) or the like, or any suitable combination thereof.

[0062] In one embodiment, the computer-readable medium can comprise a combination of one or more computer-readable storage media and one or more computer-readable signal media. For example, computer-readable program code can be transmitted both as an electromagnetic signal through a fiber optic cable for execution by a processor and stored in a RAM memory device for execution by the processor.

[0063] A computer-readable program code for executing operations for aspects of the present invention can be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, Smalltalk, C++, or the like, and conventional procedural programming languages ​​such as the programming language "C" or similar programming languages. The computer-readable program code can run entirely on the user's computer, partially on the user's computer, as a computer-readable stand-alone package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server.

[0064] The program code may also be stored in a computer-readable medium capable of controlling a computer, other programmable data processing equipment, or other devices to operate in a particular manner, such that the instructions stored in the computer-readable medium produce a manufactured item including instructions that implement the function or corresponding operation specified in the schematic flowcharts and / or the block or blocks of the schematic block diagrams.

[0065] No element of the claims herein shall be construed in accordance with the provisions of 35 USC § 112, sixth paragraph, unless the element is expressly named using the phrase “means for”.

[0066] Accordingly, the present disclosure may be implemented in other specific forms without departing from its spirit or essential characteristics. The described embodiments are in every respect to be regarded as merely illustrative and not as limiting. The scope of protection of the disclosure is therefore specified by the accompanying claims and not by the foregoing description; all modifications that fall within the meaning and scope of equivalence of the claims are to be understood as included therein.

Claims

[1] Device comprising: a filter circuit (144) configured to filter vibration data within a predetermined combustion period of the machine, wherein the vibration data represent a vibration of an internal combustion engine (110), wherein the vibration data comprise voltage signals; a PCP determination circuit (146) which is functionally and communicatively connected to the filter circuit (144) and is configured to determine a cylinder peak pressure (PCP) of a combustion cycle of the internal combustion engine (110) on the basis of the filtered vibration data, wherein the PCP corresponds to a maximum of absolute values ​​of the voltage signals or a difference between the maximum and a minimum of the absolute values ​​of the voltage signals; an LPP determination circuit (148) which is functionally and communicatively connected to the filter circuit (144) and configured to determine a location of the cylinder peak pressure (LPP) of the combustion cycle of the internal combustion engine (110) based on the filtered vibration data, wherein the PCP and the LPP represent a functional property of the combustion cycle; and an ignition timing circuit which is functionally and communicatively connected to the PCP determination circuit and the LPP determination circuit, wherein the ignition timing circuit is configured to modify an ignition timing of the internal combustion engine on the basis of the determined PCP and the determined LPP. [2] Device according to claim 1, wherein the ignition timing circuit is configured to modify the ignition timing of the internal combustion engine (110) in order to prevent partial ignitions, misfires or overpressure in the internal combustion engine (110). [3] Device according to claim 1 or claim 2, wherein the previously determined combustion period of the machine includes a range of the crank angle from about -100 degrees to about 100 degrees. [4] Device according to a preceding claim, wherein the filter circuit (144) comprises a low-pass filter, and wherein a cutoff frequency of the low-pass filter is in a range of about 100 Hz to about 800 Hz. [5] Device according to a preceding claim, wherein the LPP corresponds to a crank angle position corresponding to a peak value of the filtered vibration data. [6] Device according to any of the preceding claims, further comprising: a PCP control circuit (152) which is functionally and communicatively connected and configured to the PCP determination circuit (146) to determine a first ignition timing offset to a base ignition timing on the basis of the PCP determined by the PCP determination circuit (146). [7] Device according to any of the preceding claims, further comprising: an LPP control circuit (154) which is functionally and communicatively connected and configured to the LPP determination circuit (146) to determine a second ignition timing offset to the base ignition timing on the basis of the LPP determined by the LPP determination circuit (146). [8] System (100), comprising: a vibration sensor (120) which is communicatively connected to an internal combustion engine (110) and configured to acquire vibration data representing a vibration of the internal combustion engine (110), wherein the vibration data comprise voltage signals; and a control device (130) which is communicatively connected to the vibration sensor (120), wherein the control device (130) is configured as follows: to filter the vibration data within a predetermined combustion period of the machine; to determine a cylinder peak pressure (PCP) of a combustion cycle of the internal combustion engine (110) based on the filtered vibration data, wherein the PCP corresponds to a maximum of absolute values ​​of the voltage signals or a difference between the maximum and a minimum of the absolute values ​​of the voltage signals; to determine a location of the cylinder peak pressure (LPP) of the combustion cycle of the internal combustion engine (110) based on the filtered vibration data, wherein the PCP and the LPP represent a functional property of the combustion cycle; and to modify the ignition timing of the internal combustion engine (110) based on the determined PCP and the determined LPP. [9] System (100) according to claim 8, wherein the vibration sensor (120) is an acceleration sensor attached to the internal combustion engine (110). [10] System (100) according to claim 8 or claim 9, wherein the acceleration sensor includes a knock sensor. [11] System (100) according to one of claims 8 to 10, wherein the acceleration sensor is attached to a cylinder head or a head bolt of the internal combustion engine (110). [12] System (100) according to any one of claims 8 to 11, wherein the vibration data are filtered using a low-pass filter. [13] System (100) according to claim 12, wherein a cutoff frequency of the low-pass filter is in a range of about 100 Hz to about 800 Hz. [14] System (100) according to any one of claims 8 to 13, wherein the internal combustion engine (110) is a single-cylinder or a multi-cylinder engine. [15] System (100) according to any one of claims 8 to 14, wherein the previously determined combustion period of the machine includes a range of the crank angle from about -100 degrees to about 100 degrees. [16] System (100) according to any one of claims 8 to 15, wherein the LPP corresponds to a crank angle position corresponding to a peak value of the filtered vibration data. [17] System (100) according to one of claims 8 to 16, wherein the control device (130) is further configured as follows: to determine a first ignition timing offset from a base ignition timing based on the determined PCP; and to modify the base ignition timing with the first ignition timing offset. [18] System (100) according to any one of claims 8 to 17, wherein the control device (130) is further configured as follows: to determine a second ignition timing offset to the base ignition timing based on the determined LPP; and to modify the base ignition timing with the second ignition timing offset. [19] Procedures, including: Filtering vibration data within a predetermined combustion period of the machine, wherein the vibration data represent a vibration of an internal combustion engine (110), wherein the vibration data include voltage signals; Determining a cylinder peak pressure (PCP) of a combustion cycle of the internal combustion engine (110) based on the filtered vibration data, wherein the PCP corresponds to a maximum of absolute values ​​of the voltage signals or a difference between the maximum and a minimum of the absolute values ​​of the voltage signals; Determining a location of the cylinder peak pressure (LPP) of the combustion cycle of the internal combustion engine (110) based on the filtered vibration data, wherein the PCP and the LPP represent a functional property of the combustion cycle; and Modifying the ignition timing of the internal combustion engine (110) based on the determined PCP and the determined LPP. [20] Method according to claim 19, wherein the previously determined combustion period of the machine includes a range of the crank angle from about -100 degrees to about 100 degrees. [21] Method according to claim 19 or claim 20, wherein the filtering of the vibration data comprises filtering the vibration data using a low-pass filter, and wherein a cutoff frequency of the low-pass filter is in a range of about 100 Hz to about 800 kHz. [22] Method according to one of claims 19 to 21, wherein the LPP corresponds to a crank angle position corresponding to a peak value of the filtered vibration data. [23] Method according to any one of claims 19 to 22, further comprising: Determining a first ignition timing offset from a base ignition timing based on the determined PCP; and Modifying the base ignition timing with the first ignition timing offset. [24] Method according to any one of claims 19 to 23, further comprising: Determining a second ignition timing offset to the base ignition timing based on the determined LPP; and Modifying the base ignition timing with the second ignition timing offset.

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