Detection method for detecting speed sensing abnormality of internal combustion engine and apparatus for detecting speed sensing abnormality

Abstract

The present invention relates to a detection method for detecting a short-term speed sensing abnormality of an internal combustion engine. The detection method comprises the following steps: executing sensor health check, detecting engine speed deviation, and executing torque deviation check; and identifying whether the detected engine speed deviation involves a short-term speed sensing anomaly based on the sensor health check and the torque deviation check. Furthermore, an apparatus adapted to perform the detection method according to the present invention may be provided, comprising a control unit configured to perform the detection method according to the present invention.

Description

Technical Field

[0001] The present invention relates to a detection method for detecting short-term or sudden speed sensing anomalies in an internal combustion engine, in particular for a stationary gas engine. Furthermore, the present invention relates to an associated device for detecting speed sensing anomalies of an internal combustion engine according to the detection method disclosed herein. Background Art

[0002] Internal combustion engines, especially stationary gas engines, may be subject to various abnormal combustion phenomena that may lead to degradation and / or reduced performance of the engine. Such abnormal combustion phenomena may be caused by various reasons, such as improper gas-air / fuel-air mixture in the combustion chamber, damaged valves, improperly adjusted valve clearance, engine or intake air temperature that is too low, spark plug temperature that is too low, improperly adjusted spark ignition timing, and more.

[0003] Abnormal combustion can lead in particular to engine knock or surface ignition in the combustion chamber. Both phenomena can lead to engine damage or a significant reduction in engine performance. In order to prevent such phenomena, appropriate measures must be taken to reliably prevent these phenomena.

[0004] Since any abnormal combustion will affect the engine speed, engine speed sensing is often used as one of the key measures to detect abnormal combustion phenomena. Specifically, speed sensing is used to detect abnormal speed deviations to which the engine may react, and the control system is configured to receive the speed signal and initiate appropriate measures to offset the speed deviation. Therefore, it is particularly important that speed sensing is reliable and that potential sensing failures are detected in this way, otherwise the engine control system may react to significant speed deviations and may thereby degrade engine performance and / or cause engine or component damage.

[0005] In the prior art, the monitoring of engine speed is mainly used to detect the continuous fault of the engine, that is, the long-term component and / or sensor failure. However, there is no method disclosed in the prior art that can detect the short-term or sudden fault of the speed sensor.

[0006] However, preventing improper combustion phenomena due to short-term or sudden engine speed sensing anomalies may be critical to engine performance and / or to preventing damaging effects on the engine. It is therefore desirable to reliably detect short-term speed sensing anomalies in order to prevent any disadvantages caused thereby. A particular challenge here is the distinction between actual (physical) speed anomalies and apparent speed anomalies. Summary of the invention

[0007] Starting from the prior art, the object of the present invention is to provide a method and a device which are designed to reliably detect short-term speed anomalies of an internal combustion engine.

[0008] The object is solved by a detection method for detecting short-term speed anomalies of an internal combustion engine having the features of claim 1 and by a device for detecting such short-term speed anomalies having the features of claim 12. Preferred embodiments are set forth in the description, the drawings and the dependent claims.

[0009] Therefore, a detection method for detecting short-term speed anomalies of an internal combustion engine is proposed, the method comprising the following steps: performing a sensor health check; detecting an engine speed deviation; performing a torque deviation check; and identifying whether the detected engine speed deviation involves a short-term speed sensing anomaly based on the sensor health check and the torque deviation check.

[0010] Furthermore, a device adapted to implement the method according to the invention may be provided, the device comprising a control unit configured to perform the steps according to the detection method. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0012] Figure 1 A flow chart of a detection method for detecting short-term speed anomaly according to the present invention is schematically shown;

[0013] Figure 2 An exemplary case of two different engine speed signals monitored over time is shown;

[0014] Figure 3 shows a mathematical model of key parameters as a function of engine torque and pre-calibrated bands of key parameter values ​​according to one embodiment;

[0015] Figure 4 A flow chart of an algorithm according to an embodiment is shown, the algorithm being configured to perform the detection method according to the present invention. DETAILED DESCRIPTION

[0016] Hereinafter, the present invention will be explained in more detail with reference to the accompanying drawings. In the accompanying drawings, the same elements are represented by the same reference numerals, and in order to avoid repetition, repeated description thereof may be omitted.

[0017] The present invention generally relates to a detection method for detecting short-term speed anomalies of an internal combustion engine. In particular, the present invention relates to a method for identifying whether a detected speed deviation involves a speed sensing anomaly, such as a sensor fault - to which the engine control system should not react - or involves an actual physical speed deviation - to which the engine control system should react. In other words, the present invention provides a verification method for short-term speed sensing anomalies.

[0018] In more detail, the detection method according to the invention is characterized in that a sensor health check is performed in order to ensure the correct function of the associated sensor and thus exclude sensor failure as the cause of an apparent speed sensing anomaly. In addition, a torque deviation check is performed to check whether the detected speed deviation (after the sensor health check has been passed) actually affects the power output / torque of the engine. Depending on whether the torque is affected, the speed sensing anomaly can be verified or not.

[0019] exist Figure 1 , a flow chart of a detection method for detecting a short-term speed sensing abnormality of an internal combustion engine according to the present invention is shown. The detection method comprises the following steps: performing S1 a sensor health check; detecting S2 an engine speed deviation; performing S3 a torque deviation check; and identifying S4 whether the speed deviation detected involves a short-term speed sensing abnormality based on the sensor health check and the torque deviation check.

[0020] In the case of a stationary gas engine, the engine can be started while monitoring the operating state of the engine, and it can be determined in which state the engine is running before starting the detection method according to the present invention. Once the engine reaches a mature operating state, from which power can be output, the detection method according to the present invention can be started.

[0021] It may be determined whether the stationary gas engine is operating in an island mode or in a grid parallel mode.The detection method according to the invention may be adapted to process relevant signals associated with sensors used in the speed anomaly detection method in a specific operating mode.

[0022] In step S1 a sensor health check is performed. In the context of the present invention, a sensor health check is understood as a functional test of one or more sensors. According to the present invention, these sensors may include any sensors relevant for the detection and / or verification of speed sensing anomalies.

[0023] The sensor health check may be performed continuously during engine operation. Thus, sensor functionality may be continuously monitored during engine operation so that a potential failure of any sensor may be detected at any time. The term continuous monitoring includes situations where monitoring is performed cyclically in synchronization with the CPU cycle and / or sensor output cycle or multiples thereof.

[0024] Alternatively, the sensor health check may be performed periodically. For example, the sensor health check may be performed at the beginning of the detection method according to the present invention and then be repeated continuously at certain time intervals.

[0025] Sensors checked during a sensor health check may include an engine speed sensor. The engine speed may be measured, for example, using a pick-off sensor on the crankshaft or cam of the engine.

[0026] In addition, the sensors checked may include sensors that measure the output power and / or torque of the engine. For example, the output power of a stationary gas engine connected to the grid can be measured by calculating the power from a current transformer and / or a voltage transformer of a generator connected to the internal combustion engine.

[0027] Other sensors checked during the sensor health check may include sensors indicating intake manifold pressure, intake manifold temperature, or intake manifold density. Intake manifold pressure and intake manifold temperature are measures of the pressure and temperature of the gas-air or fuel-air mixture present in the intake manifold. Intake manifold density can be derived from intake manifold temperature and pressure. Pressure and temperature can be determined by pressure sensors and thermocouple sensors, respectively.

[0028] Furthermore, a sensor indicating the emission level of the engine may be included. The emission level may be determined by a lambda sensor.

[0029] In the event of a non-functional sensor, the system cannot ensure normal engine operation and thus abnormal combustion phenomena may occur. According to one embodiment, if the sensor health check fails due to one or more non-functional sensors, a protective action may be activated to prevent engine damage and / or engine performance degradation.

[0030] Protective actions may include preventing engine knock and / or activating surge protection. Exemplary means for protection may include retarding the engine's ignition timing to a safe level, isolating the engine from the load and / or cutting off the fuel / gas supply to the engine.

[0031] By retarding the ignition timing, normal combustion of the engine can be ensured in exchange for a slight reduction in engine efficiency. Decoupling the engine from the load ensures that the engine can run freely, thus preventing any component damage caused by connecting the engine to the load during abnormal combustion phenomena. In addition, it can also be used as surge protection when the engine is separated from the grid. By cutting off the gas or fuel supply to the engine, any abnormal combustion is immediately suppressed, thus preventing component damage to the engine.

[0032] See also Figure 1 , in step S2 an engine speed deviation detection is performed. According to the present invention, any means for detecting an engine speed deviation is included here. The engine speed is monitored by measuring the speed over time.

[0033] In the most general sense, a speed deviation according to the invention may be considered to be any deviation of the engine speed from a predetermined value or a predetermined range of values. Deviations may be detected by software configured to record changes in the engine speed signal from the relevant sensor over time and to generate a signal if the measured engine speed deviates from a predetermined value or a predetermined range of values.

[0034] According to one embodiment, a speed deviation is detected if the monitored engine speed exceeds or falls below a predetermined steady-state band condition and / or if the rate of change of the engine speed exceeds a predetermined threshold.

[0035] refer to Figure 2 The steady-state band condition may be more clearly understood where an exemplary measurement 2 of the engine speed is shown as a function of time. The bandwidth 23 of the steady-state band condition may be defined by an upper boundary 21 and a lower boundary 22 of the engine speed. In one embodiment, the upper boundary 21 and the lower boundary 22 may be arranged symmetrically around the target speed value 20, such as Figure 2 As shown. Alternatively, the upper boundary 21 and the lower boundary 22 may also be arranged asymmetrically around the target value 20. The target speed value 20 may be constant. Typically, the steady-state band condition defines a range of engine speed values ​​around the target speed value 20 within which the engine speed is considered to be consistent with normal engine operation and therefore no abnormal combustion phenomena can be expected.

[0036] The engine speed change rates of the first engine speed signal 24 and the second engine speed signal 25 are shown by straight dashed lines 240 and 250, respectively. In addition, a predetermined threshold change rate 260 is shown by another dashed line. Lines 240 and 250 are characterized by being tangent to the speed signal at the point of maximum change rate, i.e., the point at which the slope of lines 240 and 250 reaches its maximum value. Therefore, lines 240 and 250 show the rate of change of the engine speed at the points where these lines are tangent to the first and second speed signals 24 and 25, respectively. The predetermined threshold change rate 260 refers to a predetermined value of the rate of change, above which the engine operation can be considered abnormal.

[0037] According to one embodiment, a speed deviation may be detected if either of two conditions are met. Thus, a speed deviation may be detected when the engine speed exceeds or falls below a predetermined steady-state bandwidth 23 but the rate of change of the engine speed does not exceed a predetermined threshold rate of change 260. Accordingly, a speed deviation may be detected when the engine speed does not exceed or fall below a predetermined steady-state bandwidth 23 but the rate of change of the engine speed exceeds a predetermined threshold rate of change 260.

[0038] According to another preferred embodiment, a speed deviation can be detected only when two conditions are met at the same time. Therefore, a speed deviation can be detected only when the monitored engine speed exceeds or falls below the bandwidth 23 of the predetermined steady-state band condition and the rate of change of the engine speed exceeds the predetermined threshold rate of change 260.

[0039] exist Figure 2 In the example shown, the first speed signal 24 exceeds the steady state band condition 23 at certain time intervals. However, the rate of change 240 of the first engine speed signal 24 does not exceed the predetermined threshold rate of change 260. Therefore, speed deviations may or may not be detected depending on the embodiment.

[0040] On the other hand, the second speed signal 25 exceeds the steady-state band condition 23 and also exhibits a rate of change 250 that exceeds a predetermined threshold rate of change 260. Thus, for the second speed signal 25, for any of the disclosed embodiments, a speed deviation will be detected.

[0041] In the next step S3 according to the invention, a torque deviation check is performed to verify whether the engine speed deviation detected in the previous step relates to an actual true speed deviation of the engine or whether the detected speed deviation is ultimately a speed sensing anomaly / speed sensor failure.

[0042] In the most general sense, the torque deviation check includes any means suitable for testing whether the torque of the engine complies with the speed deviation detected in the preceding steps. If the speed deviation refers to a real, physical speed deviation, then a substantial effect on the engine torque, and hence a torque deviation, is expected. In the case where the speed deviation is only evident due to a speed sensing anomaly, no substantial torque deviation is expected.

[0043] According to one embodiment, the torque deviation check may be performed by comparing one or more measured key parameters representing the engine torque with a pre-calibrated band of values ​​for the key parameters. Thus, the comparison is performed by monitoring the key parameters as a function of time in order to check for any changes in the engine torque and comparing these changes with an acceptable band of values ​​within which normal engine operation is considered. The comparison is performed for a specific engine torque that corresponds to the engine speed target value 20 for the current operation of the engine. Thus, the pre-calibrated band of key parameter values ​​may be given as a function of the engine torque and / or the engine output power.

[0044] In general, key parameters refer to almost any engine-specific and / or combustion-related parameter that is characterized by being directly or indirectly indicative of engine torque and which can be measured in or near the combustion engine via appropriate sensors. It should be noted that although engine speed directly represents engine torque, it is generally not included in the key parameters. This is because engine speed refers to the parameter that should be tested for potential sensed anomalies according to the present invention. Therefore, the key parameter representing engine torque can generally be any suitable parameter other than engine speed. However, as long as the torque deviation check measures engine speed via an engine speed sensor that is different from the engine speed measured during the speed deviation detection in step S2, the engine speed can still be used as a key parameter.

[0045] A precalibrated band of values ​​for a key parameter refers to predetermined values ​​for the key parameter, wherein the bandwidth may be selected so as to include even the most severe cases of torque variations during normal engine operation. Defining the bandwidth in this manner avoids torque deviation checks that result in false positive detections of torque deviations. Thus, when the measured key parameter falls within the precalibrated band of values, the torque deviation check may indicate normal engine operation, and when the measured key parameter does not fall within the precalibrated band of values, may indicate abnormal combustion.

[0046] Typically, according to an embodiment, the torque deviation check is considered to have passed if the measured key parameter falls within the pre-calibrated band of key parameter values, and the torque deviation check is considered to have failed if the measured key parameter deviates from the pre-calibrated band of key parameter values. Passing the torque deviation check means that the speed deviation detected in step S2 is only apparent, and thus refers to a speed sensing anomaly. On the other hand, failing the torque deviation check means that the speed deviation detected in step S2 is real, and thus does not involve a speed sensing anomaly.

[0047] According to some embodiments, the key parameter indicative of the engine torque is given by a suitable power output signal of the engine, engine speed, intake manifold pressure, intake manifold temperature, intake manifold density and / or emission levels of the engine.

[0048] Each of these key parameters may be given as a function of engine torque and / or power. According to an embodiment, the key parameter indicative of engine torque is given as a function of engine torque and / or engine power via a 2D lookup table and / or an appropriate mathematical model, wherein the 2D lookup table and the mathematical model are configured to define a pre-calibrated band of values ​​for the key parameter in which the measured key parameter is considered to be indicative of normal engine operation.

[0049] See also Figure 3 The torque deviation check according to the embodiment can be more clearly understood. Figure 3In the upper figure of FIG. , an exemplary mathematical model of key parameters as a function of engine torque is shown. Here, the functional dependence is given by a mathematical model curve 30, around which the upper boundary 31 and the lower boundary 32 as a function of engine torque are included. It should be noted that Figure 3 The specific functional correlation shown in is for illustrative purposes of torque deviation checking only and may not necessarily refer to actual actual correlation. The upper and lower boundaries 31 and 32 define a bandwidth 33 of a precalibrated band of key parameter values ​​within which engine operation for a specific engine torque is considered normal.

[0050] According to an embodiment, the engine torque 34 corresponding to the engine speed target value 20 for the assumed engine operation is used to determine the corresponding key parameter value 35 from the mathematical model curve 30. Then, a bandwidth 33 can be defined within which the key parameters are assumed for the current engine speed target value 20 / engine torque 34 if normal engine operation is considered.

[0051] exist Figure 3 In the lower figure of FIG. 3 , an exemplary monitored key parameter signal 36 is shown as a function of time. Here, a bandwidth 33 of pre-calibrated key parameter values ​​having an upper boundary 31 and a lower boundary 32 is located around a key parameter value 35 determined from the mathematical model curve 30. In the example shown, the key parameter signal 36 does not deviate from the pre-calibrated band of key parameter values ​​because it falls within the bandwidth 33. Thus, in the example, the torque deviation check passes because no substantial torque deviation is detected.

[0052] According to another embodiment, a detected engine speed deviation is identified as a speed sensing anomaly if the sensor health check passes and the torque deviation check fails, whereas an engine speed sensing anomaly is not identified if the sensor health check fails and / or the torque deviation check passes.

[0053] Thus, if the speed deviation detection indicates a deviating speed signal, a speed sensing anomaly may be detected only if the torque deviation check indicates a non-deviating engine torque.

[0054] Similar to the case of sensor health check failure, in the case of identifying engine speed sensing abnormality, a protective action is activated to prevent engine damage and / or engine performance degradation. The protective action is given by the same action discussed in the corresponding embodiment above.

[0055] The protection action when a speed sensing anomaly is identified is to prevent the engine from reacting to an apparent speed deviation. If the protection action is not initiated in this case, the engine will attempt to counteract an unreal speed deviation, which may result in a severe reduction in engine performance and / or engine / component damage.

[0056] According to the present invention, an apparatus for detecting a short-term speed anomaly of an internal combustion engine is disclosed. The apparatus includes a control unit configured to perform a sensor health check, detect an engine speed deviation, perform a torque deviation check, and identify whether the detected engine speed deviation involves a short-term speed sensing anomaly based on the sensor health check and the torque deviation check.

[0057] According to a particularly preferred embodiment, the control unit can be configured to execute Figure 4 Algorithm 4.

[0058] Algorithm 4 may be initiated after the engine reaches a mature operating state in which power output is possible. Then, step S40 is entered to check whether the sensor health check passes. For example, a sensor health check may be performed on the engine speed sensor and the intake manifold pressure sensor. Only if both sensors pass the sensor health check, the algorithm may proceed to the next step S41. If one or more sensors fail the sensor health check due to a fault, Algorithm 4 may proceed directly to step S44, where a protection action according to some embodiments of the present invention may be activated.

[0059] Typically, the algorithm may decide that even if not all sensors pass the sensor health check, the algorithm may still proceed to step S41. This may be the case if those sensors that pass the sensor health check are suitable for implementing the required sequential steps of the detection method according to the invention.

[0060] For example, if another sensor indicating engine torque, such as an intake manifold temperature sensor, is included next to the engine speed sensor and the intake manifold pressure sensor, and only the intake manifold pressure sensor or the intake manifold temperature sensor fails the sensor health check while the other sensors pass, the algorithm may still proceed to the next step S41 instead of S44 because the remaining sensors are still suitable for performing the engine speed deviation check and the torque deviation check.

[0061] In step S41, Algorithm 4 checks whether an engine speed deviation is detected. The control unit thus performs the steps of detecting an engine speed deviation according to the corresponding embodiment disclosed herein. In the case that no engine speed deviation is detected, Algorithm 4 may start from above and thus proceed to step S40. In the case that an engine speed deviation is detected, step S42 is entered to perform a torque deviation check.

[0062] Therefore, in step S42, algorithm 4 checks whether the engine torque complies with the speed deviation detected in the aforementioned step S41. For example, the engine torque deviation can be performed by monitoring the intake manifold pressure as a function of time and checking whether it is within the expected range of values ​​given by the pre-calibration band of key parameter values. If the torque deviation check fails, i.e. a torque deviation has been detected, algorithm 4 proceeds to start executing step S40. If the torque deviation check passes, i.e. no torque deviation is detected, algorithm 4 proceeds to the next steps S43 and S44.

[0063] In steps S43 and S44, speed sensing abnormalities are detected and thus protection actions according to some embodiments of the present invention will be activated.

[0064] It is obvious to those skilled in the art that these embodiments and projects only depict examples of multiple possibilities. Therefore, the embodiments shown here should not be understood as forming limitations of these features and configurations. Any possible combination and configuration of the described features can be selected according to the scope of the present invention.

[0065] Industrial Applicability

[0066] The detection method for detecting short term speed sensing anomalies of the present invention is suitable for use in an internal combustion engine having a speed sensor and a sensor for measuring a parameter indicative of engine torque. The invention is particularly designed to benefit stationary gas engines designed to be connected to an electrical grid for generating electricity. The detection method for detecting short term speed anomalies is generally intended to provide a reliable method for detecting short term speed sensing anomalies which may be harmful to the engine if not reliably detected.

[0067] In order to solve this problem, a detection method for short-term engine speed detection abnormality is provided, comprising the following steps: performing a sensor health check, detecting an engine speed deviation, performing a torque deviation check, and identifying whether the detected engine speed deviation involves a short-term speed sensing abnormality based on the sensor health check and the torque deviation check. In addition, a device suitable for implementing the method according to the present invention may be provided, the device comprising a control unit configured to perform the steps according to the detection method.

[0068] In the following, various advantageous effects according to the present invention and according to preferred embodiments are disclosed. These advantages relate to a method of detecting short-term engine speed sensing anomalies and a related device according to the present invention.

[0069] Performing a sensor health check and a torque deviation check in accordance with the present invention provides a fast and reliable method for verifying engine speed deviations detected by an associated speed sensor. The sensor health check ensures that any sensor used in the detection method according to the present invention is fully functional and therefore prevents false positive detections of, for example, speed deviations or torque deviations, which could cause the engine to attempt to correct itself for no reason. Together with the verification method in the form of a torque deviation check in accordance with the present invention, a method is provided for detecting whether a short-term speed deviation due to a sensor fault (i.e., involving a speed sensing anomaly) is real or apparent. This is very advantageous because a short-term speed sensing anomaly, if not identified as such, could result in a strong reaction of the engine attempting to correct itself. By means of the present invention, such damage and / or performance degradation effects due to unidentified speed sensing anomalies are prevented.

[0070] According to a preferred embodiment, the sensor health check includes functional tests of various sensors, such as an engine speed sensor, a sensor indicating engine power and / or engine torque, a sensor indicating intake manifold pressure, intake manifold temperature, intake manifold density and / or a sensor indicating engine emission levels. Using a plurality of these sensors may be advantageous, because in the event that one of the sensors fails the sensor health check, the detection method according to the present invention may still be implemented with one or more of the remaining sensors.

[0071] According to another embodiment, when a sensor health check fails, a protective action may be activated. In this way, potential engine damage and / or performance degradation may be prevented.

[0072] According to a particularly preferred embodiment, a speed deviation is detected if the monitored engine speed exceeds / falls below a predetermined steady-state band condition defined around the engine speed target value, and if the rate of change of the engine speed exceeds a predetermined threshold rate of change of the engine speed. By limiting the engine speed deviation to be detected only when these two conditions are met, false positive engine speed deviation detections can be avoided. Therefore, performing engine speed deviation detection in this way makes the detection method according to the invention more reliable.

[0073] According to a preferred embodiment, the torque deviation check can be performed by monitoring one or more key parameters indicating the engine torque at a specific engine torque corresponding to a target value of the engine speed over time, and testing whether the monitored key parameters exceed / fall below a pre-calibrated band of key parameter values ​​at the specific engine torque. By means of embodiments, the detection method, in particular the torque deviation check, can be implemented based on quantitative conditions defining whether the torque is deviated. Therefore, the detection method according to the present embodiment provides an accurate and reliable method of verifying short-term speed sensing anomalies.

[0074] The key parameter representing the engine torque may be given by a suitable output power signal of the engine, engine speed, intake manifold pressure, intake manifold temperature, intake manifold density and / or emission levels of the engine. These specific parameters refer to standard measurements for internal combustion engines, in particular stationary gas engines. The use of these specific parameters may therefore be advantageous, since no additional sensors need to be added to the engine, since these sensors are mostly already included in existing engines.

[0075] In another preferred embodiment, the pre-calibrated band of key parameter values ​​is configured so that even the most severe key parameter variations are still considered to be indicative of normal engine operation. In other words, the bandwidth of the pre-calibrated key parameter values ​​is selected to be relatively wide, thereby avoiding false positive detections in the torque deviation check. Otherwise, a torque deviation of the engine reaction may be detected, although the engine is operating normally and does not need correction.

[0076] According to another preferred embodiment, when the detected engine speed deviation is identified as a speed sensing anomaly, a surge and / or knock protection action is performed. In particular, the surge and / or knock protection action can be performed by retarding the ignition timing of the engine to a safe level, isolating the engine from the load and / or cutting off the fuel / gas supply to the engine. Any of these measures ensures a safe way to prevent any engine damage that may be caused by a speed sensing anomaly.

Claims

1. A method for detecting a short-term speed sensing anomaly of an internal combustion engine, comprising the following steps: -Perform sensor health check; -Detect engine speed deviation; -Perform a torque deviation check; - identifying whether the detected engine speed deviation involves a short-term speed sensing anomaly based on the sensor health check and the torque deviation check.

2. The detection method according to claim 1, wherein: The sensor health check includes a functional test of at least an engine speed sensor, a sensor indicating engine power and / or engine torque, a sensor indicating intake manifold pressure, intake manifold temperature, intake manifold density and / or a sensor indicating the emission level of the engine.

3. The detection method according to claim 2, wherein: In the event that the sensor health check (S1) fails due to one or more of the sensors being non-functional, a protective action is activated to prevent engine damage and / or engine performance degradation.

4. The detection method according to any one of the preceding claims, wherein A speed deviation is detected if the monitored engine speed exceeds / falls below the bandwidth of a predetermined steady-state band condition defined around an engine speed target value over time and / or if a rate of change of the engine speed exceeds a predetermined threshold rate of change of the engine speed.

5. The detection method according to any one of the preceding claims, wherein: The torque deviation check is performed by monitoring one or more key parameters indicative of the engine torque at a specific engine torque corresponding to the engine speed target value over time, and testing whether the monitored key parameter exceeds / is below a pre-calibrated band of key parameter values ​​at the specific engine torque, wherein the torque deviation check is deemed passed if the monitored key parameter is within the pre-calibrated band of key parameter values, and deemed failed if it is not.

6. The detection method according to claim 5, wherein: The key parameter indicative of the engine torque is given by a suitable power output signal of the engine, the engine speed, intake manifold pressure, intake manifold temperature, intake manifold density and / or emission levels of the engine.

7. The detection method according to claim 5 or 6, wherein: The key parameter indicative of the engine torque is given as a function of engine torque and / or engine power via a 2D lookup table and / or a suitable mathematical model, wherein the 2D lookup table and the mathematical model are configured to define the precalibrated band of values ​​for the key parameter such that even the most severe variations are included while still ensuring normal engine operation.

8. The detection method according to any one of the preceding claims, wherein If the sensor health check passes and the torque deviation check fails, the detected engine speed deviation is identified as a speed sensing anomaly, whereas if the sensor health check fails and / or the torque deviation check passes, no engine speed sensing anomaly is identified.

9. The detection method according to claim 8, wherein: In the case where an engine speed sensing anomaly is identified, the protective action is activated to prevent engine damage and / or engine performance degradation.

10. The detection method according to claim 3 or 9, wherein: The protection action includes surge and / or knock protection action.

11. The detection method according to claim 11, wherein: The surge and / or knock protection actions are performed by retarding the ignition timing of the engine to a safe level, isolating the engine from a load and / or cutting off the fuel / gas supply to the engine.

12. An apparatus for detecting a short-term speed anomaly of an internal combustion engine, comprising a control unit configured to perform the following steps: -Perform sensor health check; -Detect engine speed deviation; -Perform a torque deviation check; - identifying whether the detected engine speed deviation involves a short-term speed sensing anomaly based on the sensor health check and the torque deviation check.

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