Method for monitoring components in a combustion chamber of a turbine engine

Abstract

A method for monitoring an ignition system of a turbine engine of an aircraft, the ignition system comprising a combustion chamber equipped with a spark plug and an ignition housing, the turbine engine comprising an accelerometer and an acoustic sensor, the method being characterized by the following steps: - acquiring (E2, E3, E6, E7) acceleration data and acoustic data representing a breakdown noise of the spark plug based on signals generated by the accelerometer and the acoustic sensor, - detecting (E4, E8) the time of a breakdown peak based on the acceleration data and the acoustic data, - correlating (E9) the time of the breakdown peak detected based on the acceleration data with the time of the breakdown peak detected based on the acoustic data, and - establishing (E10, E12) a diagnosis of the health of the ignition housing and a diagnosis of the spark plug based on the correlation result.

Description

Technical Field

[0001] The present invention relates to monitoring the health state of components of an aircraft turbine engine. More particularly, the present invention relates to monitoring the health state of components of an aircraft turbine engine. Background Art

[0002] The ignition system of a turbine engine comprises at least one combustion chamber in which one or more spark plugs are mounted to ignite the fuel jet injected into the combustion chamber. The spark plugs are activated by an ignition actuator box, which is itself controlled by an electronic unit or computer, which is usually responsible for regulation.

[0003] The starting of an aircraft's turbine engines is carried out according to predetermined rules that are specific to each engine. The starting of the engines causes a series of steps characterized by vibration and acoustic phenomena.

[0004] The spark plug is used to ignite the combustion chamber by generating a spark, hereinafter referred to as a breakdown spark. This spark is generated between two electrodes. During each breakdown, particles are detached from the electrodes, which gradually causes wear.

[0005] During operation, the spark plug is exposed to flames, which can cause corrosion and coking deposits on these electrodes. In addition, fine particles circulating in the fuel flow can also cause erosion.

[0006] As a result, the spark plug loses efficiency over time until it no longer generates enough energy to ensure ignition, which can cause delays to planned flights. To avoid this, the spark plugs are replaced preventively based on a fixed operating time.

[0007] Spark plug wear is not the only cause of misfire. There may also be a fault in the ignition actuator box. Therefore, investigation work must be carried out to diagnose the cause of misfire.

[0008] Has multiple goals:

[0009] Avoid ignition failures related to spark plug wear,

[0010] In the case of misfire, identify whether the ignition exciter box is faulty or the spark plug is worn.

[0011] Avoid premature spark plug replacement by determining the optimal replacement time.

[0012] During the breakdown phase, the air / fuel mixture injected into the spark plug ignites the combustion chamber. The resulting flame produces a characteristic low-frequency noise that enables the detection of combustion chamber ignition.

[0013] Ringing noise is an acoustic phenomenon that is more or less noticeable in all engines. It occurs at low frequencies, such as 290 Hz, and is a source of customer dissatisfaction (regardless of regulations). This phenomenon is identified as combustion instability within the combustion chamber. It is more likely to occur when the combustion chamber temperature is low (equal to the external temperature). Studying the ringing noise can reveal cracks in the combustion chamber or the presence of fouling and coking.

[0014] Various methods are known for determining the health of an igniter in a gas turbine engine.

[0015] According to one example, a dynamic pressure sensor responsive to acoustic frequencies captures the sound produced by the igniter during the ignition process. The spectral characteristics of the captured signal are then analyzed to identify spectral characteristics that can be used to relate a spectral model to an igniter state or condition.

[0016] According to another example, monitoring of the health of an igniter of a gas turbine engine is based on counting the number of sparks generated.

[0017] It is also possible to calculate the wear of the igniter of the turbine engine based on the ignition time and the pressure in the combustion chamber.

[0018] It is also possible to detect current pulses in a shielding layer surrounding the power supply cable of the igniter in order to deduce from these current pulses a signal indicating the presence of a spark in the igniter.

[0019] Monitoring the health of each of the spark plugs in the ignition system and the energizing circuit may be performed by detecting abnormal conditions in the waveform of the system used to generate the spark.

[0020] FR 2 968 143 relates to monitoring the ignition robustness of spark plugs subjected to electromagnetic attack. This monitoring is based on the analysis of the optical radiation emitted by the spark plug. Summary of the Invention

[0021] The present invention aims to solve the problems of the prior art by providing a method for monitoring an ignition system of an aircraft turbine engine, the ignition system comprising at least one combustion chamber, at least one spark plug located in the at least one combustion chamber, and an ignition actuator box for activating the at least one spark plug, the turbine engine comprising at least one accelerometer and at least one acoustic sensor, the method being characterized in that the method comprises the following steps:

[0022] - acquiring acceleration data and acoustic data representative of a breakdown noise of at least one spark plug based on signals generated by at least one accelerometer and at least one acoustic sensor,

[0023] - detecting a time of a breakdown peak of at least one spark plug based on the acceleration data, and detecting a time of a breakdown peak of at least one spark plug based on acoustic data representing a breakdown noise of at least one spark plug,

[0024] - correlating a time of a breakdown peak of at least one spark plug detected based on the acceleration data with a time of a breakdown peak of at least one spark plug detected based on acoustic data representing a breakdown noise of the at least one spark plug, and

[0025] - establishing a diagnosis of the health of the ignition actuator box and a diagnosis of the at least one spark plug as a function of the results of the associated steps.

[0026] Through the present invention, vibration data and acoustic data are correlated to improve the monitoring of the spark plugs and ignition actuator box, as well as to improve the monitoring of the startability of the engine.

[0027] The invention makes it possible to avoid ignition faults associated with wear of the spark plug.

[0028] In the event of a misfire, the present invention makes it possible to distinguish between a malfunction of the ignition actuator box and wear of the spark plug.

[0029] The invention also makes it possible to avoid premature replacement of the spark plugs by determining the optimal replacement time.

[0030] According to a preferred feature, the step of acquiring acceleration data and acoustic data comprises extracting a breakdown signal from the signals generated by the at least one accelerometer and the at least one acoustic sensor, and low-pass filtering the signal resulting from the extraction.

[0031] Preferably, sensors are used which are dedicated to other functions and which are already present in the turbine engine.

[0032] According to a preferred feature, the monitoring method further comprises the step of predicting the service life of the ignition actuator cartridge based on the result of the correlating step and a damage model of the ignition actuator cartridge.

[0033] According to a preferred feature, the monitoring method further comprises the step of predicting the service life of at least one spark plug based on the result of the correlating step and a damage model of at least one spark plug.

[0034] According to a preferred feature, the monitoring method further comprises the following steps:

[0035] -A test is conducted to verify that the combustion chamber temperature is equal to the external ambient temperature and in the event of an affirmative answer,

[0036] - extracting a signal corresponding to the ignition from a signal generated by at least one acoustic sensor,

[0037] - applying a bandpass filter to the extracted signal, the frequency band of the filter corresponding to the frequency of the ringing phenomenon,

[0038] - comparing the acoustic energy of the filtered signal with energies from a reference database to detect the presence of a ringing noise, and if a ringing noise is detected,

[0039] - Establish diagnostics of the health of the combustion chamber.

[0040] These features allow the combustion chamber to be monitored.

[0041] According to a preferred feature, the monitoring method further comprises the step of establishing a prognosis of the health of the combustion chamber.

[0042] The present invention also relates to a device for monitoring the ignition system of a turbine engine of an aircraft, the ignition system comprising at least one combustion chamber, at least one spark plug located in the at least one combustion chamber, an ignition exciter box for stimulating the at least one spark plug, the turbine engine comprising at least one accelerometer and at least one acoustic sensor, the device being characterized in that the device comprises a data processing unit capable of performing the following steps: acquiring acceleration data and acoustic data representing a breakdown noise of at least one spark plug based on signals generated by the at least one accelerometer and the at least one acoustic sensor; detecting the time of a breakdown peak of at least one spark plug based on the acceleration data, and detecting the time of a breakdown peak of at least one spark plug based on the acoustic data representing the breakdown noise of the at least one spark plug; correlating the time of the breakdown peak of at least one spark plug detected based on the acceleration data with the time of the breakdown peak of at least one spark plug detected based on the acoustic data representing the breakdown noise of the at least one spark plug; and establishing a diagnosis of the health status of the ignition exciter box and a diagnosis of at least one spark plug based on the results of the correlating steps.

[0043] According to a preferred feature, the data processing unit is further capable of performing the following steps: verifying whether the combustion chamber temperature is equal to the external ambient temperature, and in case of a positive response, extracting a signal corresponding to the ignition based on the signal generated by at least one acoustic sensor; applying a bandpass filter to the extracted signal, the frequency band of the filter corresponding to the frequency of the ringing phenomenon; comparing the acoustic energy of the filtered signal with the energy from a reference database to detect whether a ringing noise is present, and establishing a diagnosis of the health status of the combustion chamber if a ringing noise is detected.

[0044] The invention also relates to an ignition system for an aircraft turbine engine, comprising the above-mentioned device.

[0045] The device and the ignition system have advantages similar to those described above.

[0046] In a particular embodiment, the steps of the method according to the present invention are implemented by computer program instructions.

[0047] Therefore, the present invention is also directed to a computer program on an information support medium, capable of being implemented in a computer, comprising instructions suitable for implementing the steps of the above-described method.

[0048] The program may use any programming language, and may be in the form of source code, object code, or a code intermediate between source code and object code (such as in a partially compiled form), or in any other desired form.

[0049] The present invention is also directed to an information support medium readable by a computer and comprising computer program instructions adapted to implement the steps of the above-mentioned method.

[0050] The information support medium may be any unit or device capable of storing a program. For example, the support medium may include a storage medium (such as a ROM, for example a CD-ROM or a ROM of a microelectronic circuit) or a magnetic recording medium (such as a disk or hard disk).

[0051] Furthermore, the information support medium may be a transmissible support medium such as an electrical or optical signal, which may be transferred via an electrical or optical cable, by radio or by other means.The program according to the invention may in particular be downloaded via a network of the Internet type.

[0052] Alternatively, the information support medium may be an integrated circuit embodying the program, which circuit is suitable for executing or for executing the method according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Other characteristics and advantages will emerge on reading the following description of a preferred embodiment given as a non-limiting example with reference to the accompanying drawings, in which:

[0054] [ Figure 1 ] shows a device for monitoring an ignition system of a turbine engine of an aircraft according to an embodiment of the invention;

[0055] [ Figure 2 ] shows a data processing unit included in the device of the previous figure according to an embodiment of the present invention;

[0056] [ Figure 3 ] shows a method for monitoring an ignition system of a turbine engine of an aircraft according to an embodiment of the invention;

[0057] [ Figure 4 ] shows an embodiment of the present invention according to the present invention from the Figure 1the signal of the acoustic sensor in the device;

[0058] [ Figure 5 ] shows a method for monitoring the health of a combustion chamber according to an embodiment of the present invention.

[0059] Identical, similar or equivalent components in different figures are provided with the same reference numerals to facilitate transition from one figure to another.

[0060] The various components shown in the drawings are not necessarily shown to uniform scale to make the drawings easier to read.

[0061] The various possibilities (alternatives and embodiments) are to be understood as not being mutually exclusive and as being combinable. DETAILED DESCRIPTION

[0062] according to Figure 1 In the preferred embodiment shown, a device for monitoring the ignition system of an aircraft turbine engine is provided in a turbine engine M, comprising at least one combustion chamber 1 in which one or more spark plugs 2 are installed to ensure ignition of the air and fuel mixture injected into the combustion chamber. The one or more spark plugs 2 are activated by an ignition actuator box 3, which is configured to transmit a breakdown pulse to the one or more spark plugs 2 upon receiving an ignition command provided by a circuit 4 for regulating ignition.

[0063] Only the elements useful for understanding the present invention are described and shown.

[0064] Furthermore, the turbine engine M is equipped with one or more vibration sensors 5 (usually two accelerometers) in order to ensure redundancy. These accelerometers are positioned and used primarily to sense the imbalance of the fan of the turbine engine.

[0065] The first accelerometer is typically located at the front of the turbine engine, while the second accelerometer is located at the rear of the turbine engine, often on the casing to facilitate access during maintenance. The turbine engine's fan is attached to a low-pressure shaft (BP), which passes through the entire turbine engine, and low-pressure imbalances manifest themselves in the various bearings that guide this shaft (at least one bearing at the front and at least one bearing at the rear). The exact location of the accelerometers varies from engine to engine.

[0066] Vibration sensor 5 is connected to a data processing unit 6 on the aircraft to provide it with acceleration signals. Alternatively, data processing unit 6 may or may not be integrated into control circuit 4. Data processing unit 6 is responsible for determining the vibration level based on the signals it receives. This vibration level is transmitted to the cockpit for display on the instrument panel. This provides the pilot with the information necessary to perform engine balancing.

[0067] The accelerometer 5 may also be used to perform wear monitoring of engine components, such as bearings.

[0068] The turbine engine M is also equipped with an acoustic sensor 7, such as a microphone. The acoustic sensor 7 is positioned around the gas generator, behind the structure to protect it from particles or dust. The acoustic sensor 7 is connected to a data processing unit 6 to provide acoustic signals. These signals can be used to monitor rotating elements (such as turbine and compressor blades), as well as the power transmission (gear) and combustion chamber.

[0069] The turbine engine M is also provided with other sensors, in particular a pressure sensor 9 , a temperature sensor 10 , a rotational speed sensor 11 and a sensor 12 of the position of the variable geometry. These sensors are also connected to the data processing unit 6 .

[0070] The signals transmitted by the vibration sensor 5, the acoustic sensor 7, and the sensors 9 to 12 are acquired by a data processing unit 6. Preferably, this acquisition is performed at high frequency. The data processing unit 6 includes a digital computing component (a processor or an FPGA) and a memory for processing the measured signals, typically processing the signals, recording and transmitting the information (communication functions).

[0071] When the aircraft is on the ground, all or part of the processing described below may be performed on the ground by a computer 8 suitably connected to the data processing unit 6 .

[0072] Figure 2 An embodiment of a data processing unit 6 is shown.

[0073] The data processing unit 6 has a general structure of a computer and particularly comprises a processor 100 for executing a computer program for implementing the method according to the present invention, a memory 101 , an input interface 102 and an output interface 103 .

[0074] These various elements are typically connected via a bus 105 .

[0075] The input interface 102 is connected to the vibration sensor 5 and the acoustic sensor 7 and is intended to receive measured values.

[0076] The processor 100 executes the processes disclosed below. The processes are executed in the form of code instructions of a computer program stored by the memory 101 before being executed by the processor 100.

[0077] The memory 101 stores measured values, reference values ​​and established diagnoses.The memory 101 may be divided into different parts to separate instructions, reference values ​​and measured values.

[0078] The output interface 103 is connected to at least one of the FADEC of the engine, another electronic system on the aircraft, and a system external to the aircraft to communicate the established diagnostics.

[0079] Figure 3 An embodiment of a method for monitoring the ignition system of an aircraft turbine engine, in particular a spark plug 2 and an ignition actuator box 3, is shown. The method comprises steps E1 to E12 implemented in a data processing unit 6 or, alternatively, partly in the data processing unit 6 and partly in a computer 8. These steps are implemented when the spark plug is controlled to break down.

[0080] First, steps E1 to E4 implemented to process the vibration signal are described.

[0081] Step E1 is to obtain the signal transmitted by the vibration sensor 5 .

[0082] The next step E2 consists in extracting the breakdown signal from the signal acquired in the previous step. To this end, the acquired signal is limited to the time periods during which the spark plug 2 is controlled to break down. These time periods are determined by the fact that they correspond to the following time periods:

[0083] - During the entire period during which the spark plugs must break down, the computer for engine regulation sends a command to the ignition exciter box 3. This command consists in selecting the spark plug or plugs to be broken down;

[0084] - The ignition exciter box 3 generates an electrical signal that is periodically sent to the spark plug or selected spark plugs in order to cause the spark plug to break down.

[0085] The following step E3 is to carry out low-pass filtering on the signal generated by the previous step. In fact, the breakdown of the spark plug will produce low-frequency vibrations, so the high frequencies are eliminated from the processed signal.

[0086] Low-pass filtering can involve undersampling the signal using an anti-folding filter before applying the low-pass filter. This is equivalent to connecting multiple low-pass filters in series. This avoids introducing distortion when the acquisition of the signal delivered by the vibration sensor is performed at a high frequency (e.g., tens of kHz).

[0087] According to one alternative, wavelet filtering may be used, either a standard wavelet (such as Daubechies) or a specific wavelet based on the shape of the spark plug breakdown sensed by the vibration sensor.

[0088] The next step E4 is to detect a breakdown peak in the filtered signal. This is for example detected by a change in the sign of the derivative of the signal or by detection of the peak as a local extrema by exceeding a threshold.

[0089] According to one alternative, the filtered signal may be superimposed on the original signal to find the peak of the original signal corresponding to the breakdown of the spark plug.

[0090] The results of step E4 are the number of breakdown peaks, the respective amplitudes of the breakdown peaks, the respective times of occurrence of the breakdown peaks and the time between two consecutive breakdowns.

[0091] The method involves steps E5 to E8 carried out simultaneously with steps E1 to E4 in order to process the acoustic signal.

[0092] Step E5 is to acquire the signal transmitted by the acoustic sensor 7 .

[0093] The next step E6 is to extract the breakdown signal from the signal obtained in the previous step. Similar to step E2, the signal is limited to the time period during which the spark plug 2 is controlled to break down.

[0094] The following step E7 is to perform low-pass filtering on the signal generated by the previous step. In fact, the breakdown of the spark plug will produce low-frequency noise, so the high frequencies are eliminated from the processed signal.

[0095] The next step E8 is to detect breakdown peaks in the filtered signal. This is done, for example, by detecting a peak as a local extremum, by changing the sign of the signal's derivative or by exceeding a threshold. The result of step E8 is the number of breakdown peaks, their respective amplitudes, their respective times of occurrence, and the time between two consecutive breakdowns.

[0096] Steps E4 to E8 are followed by step E9 which is a comparison of the results of step E4 and step E8.

[0097] This comparison involves correlating the time of occurrence of the breakdown peak from the acceleration signal with the time of occurrence of the breakdown peak from the acoustic signal. When these times of occurrence correspond, the time of occurrence of the breakdown peak thus determined is verified to be reliable. The time of occurrence of the breakdown peak in the acceleration signal and the acoustic signal corresponds to the time of breakdown of the spark plug.

[0098] Step E9 is followed by a step E10 in which the times of occurrence of the breakdown peaks in the acceleration signal and the acoustic signal are used to:

[0099] - Diagnose the health of the ignition actuator box,

[0100] - Predicting the service life of the ignition actuator box by using a damage model of the ignition actuator box that takes into account the environment, previous data and cross-validation with other engines.

[0101] Steps E8 and E9 are followed by step E11 of extracting the acoustic power indicator associated with each breakdown peak verified in step E9. The acoustic power indicator of a peak is determined based on the time of occurrence of the peak and the amplitude of the peak.

[0102] Step E11 is followed by step E12 in which the sound power indicator of the peak value is used to:

[0103] - Diagnose the health of the spark plugs,

[0104] - Predicting spark plug life by using a spark plug wear model that takes into account the environment, legacy data, and cross-validation with other engines,

[0105] - Check the replacement of spark plugs,

[0106] - estimate the quality of maintenance operations,

[0107] -Detect manufacturing defects in newly installed spark plugs.

[0108] Spark plug damage is directly related to the number of breakdowns leading to particle and component detachment, and the components that mitigate this damage (temperature, flow rate).

[0109] The peak acoustic power level depends on spark plug damage. Two average acoustic breakdown levels can be defined: one before ignition in the combustion chamber and one after. In practice, the breakdown emits more noise before ignition than after. This also enables monitoring or adjustment of the combustion chamber's ignition. Furthermore, within a certain speed range and depending on temperature conditions, fuel injection into the combustion chamber is interrupted by a "micro-cutoff" logic. During the micro-cutoff, spark plug breakdown is also interrupted, which can be confirmed by an acoustic sensor. Figure 4 This phenomenon is shown.

[0110] Figure 4 The signal from the acoustic sensor at the time of breakdown of the spark plug is shown.

[0111] The breakdown starts at time t1. Between time t1 and time t2, the acoustic breakdown level (expressed in dB / Hz) is high, which corresponds to the time interval before ignition of the combustion chamber.

[0112] Between time t2 and the end of the breakdown, time t4, the acoustic breakdown level is low.

[0113] Around time t3, between time t2 and time t4, no acoustic signal is noted, corresponding to no breakdown due to the micro-cutoff.

[0114] Based on the results of previous flights and those measured during the current flight, the damage model evaluation can include calculating the flow rate of the air jet in the combustion chamber during the breakdown. The air jet is estimated using a thermodynamic model based on the engine's rotational speed, the position of the variable geometry, the pressures and temperatures measured at the fan and compressor (and optionally the booster, if available), and the sound level associated with each peak. This model depends on the engine.

[0115] The method includes using a damage model that is based on the number of breakdowns per spark plug, temperature measured near the combustion chamber, pressure measured near the combustion chamber, humidity that can be retrieved from a METAR type weather bulletin, calculated flow rate, injected fuel flow, current injected by the ignition exciter box when current is measurable, and the time spent at various temperatures and various flow rates when the spark plug does not breakdown.

[0116] Figure 5 An embodiment of a method for monitoring the health of a combustion chamber based on signals delivered by an acoustic sensor 7 is shown. The method comprises steps E20 to E26 implemented in the data processing unit 6 or, alternatively, partly in the data processing unit 6 and partly in the computer 8. These steps are executed simultaneously with the steps described above when the spark plug is controlled to break down.

[0117] Monitoring the health of the combustion chamber is performed by studying the ringing phenomenon. At startup, when the temperature of the combustion chamber initially equals the external ambient temperature, combustion instability can cause ringing noises, which can be annoying for the user. The principle used is as follows:

[0118] - Damage to the combustion chamber (such as cracks) will produce abnormal resonance and abnormally strong ringing noise,

[0119] - Fouling or coking of the combustion chamber can produce a dampening of the jingling noise, resulting in abnormally low sound levels.

[0120] Step E20 is to acquire the signal delivered by the acoustic sensor 7. This step is identical to step E5 described above.

[0121] Step E21 is to perform a test to verify whether the circuit 4 for regulating ignition indicates the combustion chamber temperature T EGT Equal to the external ambient temperature T 环境(ambiante) .

[0122] If the response is positive, then steps E20 and E21 are followed by step E22 , which consists in extracting a signal corresponding to ignition based on the acoustic signal acquired in step E20 . This step is identical to step E6 described above.

[0123] The next step E23 consists in applying a bandpass filter to the signal extracted in the previous step. The frequency band of the filter is chosen to correspond to the frequencies of the expected ringing phenomena.

[0124] The following step E24 consists in comparing the acoustic energy of the filtered signal with energies from a reference database. The reference database comprises data previously obtained, for example on the same engine and / or on engines of the same type.

[0125] This comparison is a spectral correlation, or a difference in power spectral density (PSD), which allows for the determination of energy differences. This difference is monitored over time, and as long as the engine is healthy, the observed dispersion must be solely due to environmental factors. The result of this comparison is a detection of the presence of a ringing noise.

[0126] If a ringing phenomenon is detected, step E24 is followed by step E25 of establishing a diagnosis of the health of the combustion chamber.

[0127] If the detected ringing phenomenon is less intense than the reference database, that is, has a lower amplitude, it is diagnosed as combustion chamber fouling or combustion chamber coking. If the detected ringing phenomenon is more intense than the reference database, that is, has a higher amplitude, and resonance is detected, it is diagnosed as a crack in the combustion chamber.

[0128] Following step 24, step E26 is again used to generate a prediction of the health of the combustion chamber. This prediction identifies sudden changes in the trend of the ringing phenomenon over time. This allows for the foreseeing of future fouling or cracks in the combustion chamber.

Claims

1. A method for monitoring an ignition system of a turbine engine (M) of an aircraft, said ignition system comprising at least one combustion chamber (1), at least one spark plug (2) located in said at least one combustion chamber, an ignition exciter box (3) for activating said at least one spark plug, said turbine engine comprising at least one accelerometer (5) and at least one acoustic sensor (7), said method comprising the following steps: - acquiring (E2, E3, E6, E7) acceleration data and acoustic data representative of a breakdown noise of said at least one spark plug based on the signals generated by said at least one accelerometer and said at least one acoustic sensor, - detecting (E4, E8) the time of a breakdown peak of said at least one spark plug based on said acceleration data, and detecting the time of a breakdown peak of said at least one spark plug based on said acoustic data representing a breakdown noise of said at least one spark plug, - correlating the time of the breakdown peak of the at least one spark plug detected based on the acceleration data with the time of the breakdown peak of the at least one spark plug detected based on the acoustic data representing the breakdown noise of the at least one spark plug (E9), and - establishing ( E10 , E12 ) a diagnosis of the health of the ignition actuator box and of the at least one spark plug as a function of the results of the associated steps.

2. Method for monitoring the ignition system of a turbine engine (M) of an aircraft according to claim 1, wherein: The step of acquiring said acceleration data and said acoustic data comprises extracting (E2, E6) a breakdown signal from the signals generated by said at least one accelerometer and said at least one acoustic sensor, and low-pass filtering (E3, E7) the signal resulting from said extraction.

3. The method for monitoring the ignition system of a turbine engine (M) of an aircraft according to claim 1 or 2, further comprising the following steps: The useful life of the ignition actuator box is predicted ( E10 ) based on the result of the correlating step and a damage model of the ignition actuator box.

4. The method for monitoring the ignition system of a turbine engine (M) of an aircraft according to claim 1 or 2, further comprising the following steps: The service life of the at least one spark plug is predicted (E12) based on the result of the correlating step and the damage model of the at least one spark plug.

5. The method for monitoring the ignition system of a turbine engine (M) of an aircraft according to claim 1 or 2, further comprising the following steps: - Perform a test (E21) to verify that the temperature of the combustion chamber is equal to the external ambient temperature and, in the event of an affirmative answer, - extracting (E22) a signal corresponding to an ignition based on the signal generated by said at least one acoustic sensor, - applying ( E23 ) a bandpass filter to the extracted signal, the frequency band of said bandpass filter corresponding to the frequency of the ringing phenomenon, - comparing (E24) the acoustic energy of the filtered signal with the energy from a reference database to detect the presence of a ringing noise and, if a ringing noise is detected, - establishing (E25) a diagnosis of the health of said combustion chamber.

6. The method for monitoring the ignition system of a turbine engine (M) of an aircraft according to claim 5 , further comprising the steps of: A prediction of the health of the combustion chamber is established (E26).

7. A device for monitoring an ignition system of a turbine engine (M) of an aircraft, said ignition system comprising at least one combustion chamber (1), at least one spark plug (2) located in said at least one combustion chamber, an ignition exciter box (3) for exciting said at least one spark plug, said turbine engine comprising at least one accelerometer (5) and at least one acoustic sensor (7), said device being characterized in that it comprises a data processing unit (6) capable of performing the following steps: acquiring acceleration data and data representative of the at least one spark plug based on signals generated by said at least one accelerometer and said at least one acoustic sensor Acoustic data of breakdown noise; detecting a time of a breakdown peak of the at least one spark plug based on the acceleration data, and detecting a time of a breakdown peak of the at least one spark plug based on the acoustic data representing the breakdown noise of the at least one spark plug; correlating the time of the breakdown peak of the at least one spark plug detected based on the acceleration data with the time of the breakdown peak of the at least one spark plug detected based on the acoustic data representing the breakdown noise of the at least one spark plug; and establishing a diagnosis of the health status of the ignition exciter box and a diagnosis of the at least one spark plug based on the results of the correlating step.

8. Device for monitoring the ignition system of a turbine engine (M) of an aircraft according to claim 7, wherein The data processing unit (6) is also capable of performing the following steps: verifying whether the temperature of the combustion chamber (1) is equal to the external ambient temperature and, in the case of a positive response, extracting a signal corresponding to ignition based on the signal generated by the at least one acoustic sensor; A bandpass filter is applied to the extracted signal, the frequency band of the bandpass filter corresponding to the frequency of the ringing phenomenon; the acoustic energy of the filtered signal is compared with the energy from a reference database to detect whether the ringing noise is present, and in the event that the ringing noise is detected, a diagnosis of the health of the combustion chamber is established.

9. Ignition system for a turbine engine (M) of an aircraft, characterized in that The ignition system comprises a device according to claim 7 or 8 for monitoring an ignition system of a turbine engine (M) of an aircraft.

10. Computer program product comprising instructions executable by a computer for performing the steps of the method for monitoring an ignition system of a turbine engine (M) of an aircraft according to any one of claims 1 to 6.

11. A computer-readable information support medium on which a computer program is recorded, the computer program comprising instructions for executing the steps of the method for monitoring an ignition system of a turbine engine (M) of an aircraft according to any one of claims 1 to 6.

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