A state monitoring system and method for an aircraft engine ignition device

Abstract

The present invention discloses a state monitoring system and method for an aircraft engine ignition device, comprising a signal sampling module, a signal processing module and a signal conversion circuit, wherein the signal conversion circuit is used to convert a sampled electrical signal into a passive resistance signal, and monitor the operating state of the ignition device through the resistance value change of the resistance signal. The signal sampling module comprises an input end sampling unit, an output end sampling unit and a plurality of auxiliary signal sampling units, the signal conversion circuit comprises a plurality of relays S1 to Sn arranged in sequence from front to back, two resistors with different resistance values ​​are arranged between adjacent relays, the input end sampling unit, the output end sampling unit and the plurality of auxiliary signal sampling units are respectively connected to different relays through the signal processing module, so as to realize that different electrical signals respectively control the on and off of different relays, so that the resistors between the plurality of relays are connected in series to form a resistance network.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft engine point detection, and in particular relates to a state monitoring system and method for an aircraft engine ignition device. Background Art

[0002] With the continuous changes in aircraft requirements and the continuous improvement of performance, aircraft systems are becoming more and more complex, making it difficult to quickly and accurately locate faults. Therefore, automatic fault diagnosis is required for aircraft systems. Automatic fault diagnosis is a technology that automatically determines whether a fault exists and determines the fault location. It mainly includes two steps: state monitoring and fault diagnosis. The ignition device is the main component of the aircraft engine electric ignition system, which converts the DC or AC power on the aircraft into high-voltage pulse electricity. As part of the aircraft system, the ignition device also needs to realize automatic fault diagnosis.

[0003] Currently, few ignition devices have the function of automatic fault diagnosis. Some ignition devices with this function usually use sensors and single-chip microcomputers to perform status monitoring and fault diagnosis respectively. However, the ignition device itself has a single function and a simple circuit. Using sensors and single-chip microcomputers to add automatic fault diagnosis functions will be distracting and even affect the realization of the main functions of the ignition device, reducing the reliability of the ignition device, which is not worth the loss.

[0004] The ideal state is that the ignition device can realize status monitoring and feed back its own status signal to the upper-level system for fault diagnosis. Installing sensors at key locations to collect signals and monitor the operating status of the ignition device is an effective method of status monitoring. However, considering the operating temperature range and internal high-voltage insulation requirements of the ignition device itself, the available sensors are very limited. Some available sensors will increase the weight and volume of the ignition device, and are generally expensive, making it difficult to meet the requirements of low cost, lightweight, and miniaturization of the ignition device.

[0005] In summary, the existing state monitoring methods for aircraft engine ignition devices have the problem of difficulty in selecting sensors and increasing the weight and volume of the ignition device. Therefore, it is necessary to invent a lightweight and efficient state monitoring solution for the ignition device to meet the comprehensive requirements of the ignition device itself, such as high voltage, wide temperature range, light weight, and small volume. Summary of the invention

[0006] The purpose of the present invention is to provide a system and method for monitoring the state of an aircraft engine ignition device, aiming to solve the above-mentioned problems.

[0007] The present invention is mainly achieved through the following technical solutions:

[0008] A state monitoring system for an aircraft engine ignition device comprises a signal sampling module, a signal processing module and a signal conversion circuit, wherein the signal conversion circuit is used to convert a sampled electrical signal into a passive resistance signal, and monitor the operating state of the ignition device through the resistance value change of the resistance signal;

[0009] The signal sampling module includes an input sampling unit, an output sampling unit and a plurality of auxiliary signal sampling units, wherein the input sampling unit and the output sampling unit are used to sample the power input end and the high voltage output end of the ignition device respectively;

[0010] The signal conversion circuit includes a plurality of relays S1 to Sn arranged sequentially from front to back, two resistors with different resistance values ​​are arranged between adjacent relays, and one end of the two resistors is respectively connected to the normally open end and the normally closed end of the relay on one side, and the other ends of the two resistors are respectively connected to the common end of the relay on the other side;

[0011] The input sampling unit, the output sampling unit and the plurality of auxiliary signal sampling units are respectively connected to different relays through the signal processing module, so that different electrical signals can respectively control the on and off of different relays, so that the resistors between the plurality of relays are connected in series to form a resistor network.

[0012] In order to better implement the present invention, further, the output end sampling unit uses a current transformer T1 to sample the pulse electricity, and the high-voltage output line of the ignition device passes through the transformer coil as the primary of the current transformer T1, and the number of coil windings is the number of secondary turns of the current transformer.

[0013] In order to better implement the present invention, further, the signal processing module connected to the output end sampling unit includes resistors R6, R7, capacitors C2, C3, C4, transistors Q1, Q2 and diodes D3 to D7;

[0014] The base of the transistor Q1 is connected to the cathode of the diodes D3 and D4, the emitter is connected to the resistor R7, the capacitor C3, and the anode of the diodes D4 and D5, and the collector is connected to the cathode of the diodes D5 and D7, the capacitor C4, and the voltage VCC.

[0015] The base of the transistor Q2 is respectively connected to the cathode of the diode D6 and the resistor R7, the emitter is respectively connected to the anode of the diode D6 and the ground, the collector is respectively connected to the anode of the diode D7, the capacitor C4 and the relay S2, and the capacitor C4 is connected in parallel with the diode D7; one end of the capacitors C2 and C3 is grounded, and one end of the capacitor C4 is connected to the relay S2; the current transformer T1 is respectively connected to the resistor R6 and the capacitor C2 to realize charging filtering; the resistor R7 is respectively connected to the capacitor C3 and the anode of the diode D5, and the anode of the diode D3 is respectively connected to the capacitor C2 and the resistor R6.

[0016] In order to better implement the present invention, further, the input sampling unit adopts resistor series voltage division sampling.

[0017] In order to better implement the present invention, further, the input end sampling unit includes a rectifier D1 and a resistor R1, and the signal processing module connected to the input end sampling unit includes a capacitor C1 for filtering and a diode D2 for voltage stabilization; the rectifier D1 is connected to the resistor R1, and the resistor R1 is respectively connected to the capacitor C1, the diode D2 and the relay S1, and the other ends of the capacitor C1 and the diode D2 are respectively grounded.

[0018] The present invention is mainly achieved through the following technical solutions:

[0019] A method for monitoring the state of an aircraft engine ignition device is based on the above-mentioned aircraft engine ignition device state monitoring system and comprises the following steps:

[0020] Step S1: signal acquisition: based on the signal sampling module, the power input end and the high voltage output end of the ignition device are respectively sampled for electrical signals;

[0021] Step S2: signal processing: performing stabilization processing on the signals collected in step S1 based on the signal processing module;

[0022] Step S3: signal conversion: based on the signal conversion circuit, the different active electrical signals processed in step S2 are used to control the on and off of different relays respectively, and the on and off of the relays are controlled to connect different resistors to the resistor network, so that multiple active electrical signals are converted into a passive resistor signal;

[0023] Step S5: Signal feedback and judgment: Measure the resistance value between the two pins of the ignition device to determine whether the working state of the ignition device is normal.

[0024] In order to better implement the present invention, further, in the step S1, for the power input end, a resistor series voltage division sampling is adopted; for the high voltage output end, a current transformer connected in series in the circuit is adopted to sample the pulse electricity.

[0025] In order to better implement the present invention, further, in the step S2, the voltage signal collected from the power input end is stabilized and filtered; the electrical signal collected from the high voltage output end is processed and a continuous and stable signal is output:

[0026] When the current transformer T1 senses a discontinuous electrical signal, the resistor R6 and the capacitor C2 are used to charge and filter the electrical signal, and then the electrical signal passes through the diode D3 to turn on the transistor Q1 for a short time;

[0027] When T1 has no induction signal, capacitor C2 discharges through R6, causing transistor Q1 to be turned on for a very short time, and voltage VCC turns Q2 on and charges capacitor C3; when Q1 is turned off, capacitor C3 discharges and continues to turn on transistor Q2 until T1 generates an induction signal again; during the conduction period of Q2, VCC is filtered by capacitor C4 to generate a continuous and stable electrical signal at both ends.

[0028] In order to better implement the present invention, further, in the step S1, the electrical signals of other key parts are sampled by multiple auxiliary signal sampling units to further determine the fault location inside the ignition device. The electrical signals of other key parts include any one or more of the signals of thyristor part temperature, transformer secondary voltage, energy storage capacitor voltage, and discharge tube secondary voltage.

[0029] The beneficial effects of the present invention are as follows:

[0030] The present invention samples the electrical signals of the power input terminal, high-voltage output terminal or other key parts of the ignition device respectively, and the multiple electrical signals obtained by sampling are converted into a passive resistance signal through signal processing. The upper-level system controller determines the operating status of the ignition device by monitoring the resistance value of this signal. The present invention realizes quantitative monitoring of the status of the ignition device and improves the reliability and accuracy of detection. The present invention can effectively solve the technical problems that the existing status monitoring methods are difficult to select sensors that do not affect the ignition function and the sensor detection will suddenly increase the weight and volume. The present invention can efficiently and reliably realize the status monitoring of the ignition device of the aircraft or engine system, reduce the time and labor cost of maintenance, and the resistance value passively fed back by the ignition device will not affect the aircraft or engine system.

[0031] Secondly, the state monitoring circuit of the present invention is isolated from the main circuit, and whether the monitoring circuit works or not does not affect the realization of the main functions of the ignition device, meeting the reliability and safety requirements of the ignition device. The state monitoring circuit designed by the present invention does not contain special components, and can use common components such as resistors, capacitors, inductors, diodes, triodes, relays, etc., which has low cost and meets the low cost requirements of the ignition device. The state monitoring circuit of the present invention can simultaneously meet the requirements of the ignition device in terms of temperature height, volume weight, electromagnetic compatibility, etc., and has high practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a principle block diagram of the state monitoring system of the aircraft engine ignition device of the present invention;

[0033] Figure 2 A schematic diagram of a high voltage pulse signal output by an ignition device;

[0034] Figure 3 A circuit diagram of a signal processing module connected to an output terminal sampling unit;

[0035] Figure 4 is a schematic diagram of a resistance network consisting of relays and resistors;

[0036] Figure 5 The present invention is a circuit diagram of a state monitoring system for an aircraft engine ignition device. DETAILED DESCRIPTION

[0037] Embodiment 1:

[0038] A condition monitoring system for an aircraft engine ignition device, such as Figure 1 As shown, the power input terminal and the high-voltage output terminal of the ignition main circuit are sampled respectively, and then processed and converted into resistance signals through signal processing and signal conversion and sent to the controller. The controller determines the overall operating status of the ignition device according to the size of the resistance.

[0039] Specifically, the status monitoring system includes a signal sampling module, a signal processing module and a signal conversion circuit. The different signals output by the signal sampling module are processed by the signal processing module and connected to different relays in the signal conversion circuit to realize different active electrical signals to control the on and off of different relays respectively, so that the resistors between several relays are connected in series to form a resistor network, and the overall operating status of the ignition device is judged according to the size of the resistance of the signal conversion circuit.

[0040] Preferably, if Figure 4As shown, the signal conversion circuit includes a number of relays S1 to Sn arranged in sequence from front to back, two resistors with different resistance values ​​are arranged between adjacent relays, and one end of the two resistors is respectively connected to the normally open end and the normally closed end of the relay on one side, and the other end of the two resistors is respectively connected to the common end of the relay on the other side. Preferably, the signal conversion circuit is connected to a resistor network of four electrical signals, and relays S1 to S4 and resistors R1 to R8 are correspondingly arranged. When the ignition device is not powered, the relay is in a normally closed state, and the resistance of the resistor network is R1+R3+R6+R8; when the ignition device is powered and working normally, the state of each relay may be different according to the requirements of the monitoring parameters; assuming that all relays are normally closed and disconnected, and normally open and connected, indicating that the ignition device is working normally, the resistance of the resistor network is R2+R4+R5+R7. Other different resistance values ​​can be used to characterize whether there are electrical signals at different positions of the ignition device, thereby judging whether the working state of the ignition device is normal.

[0041] Specifically, the signal sampling module includes an input sampling unit, an output sampling unit and a plurality of auxiliary signal sampling units, wherein the number of the auxiliary signal sampling units may be 0. The auxiliary signal sampling unit is used to sample electrical signals of other key parts, and further determine the faulty parts inside the ignition device, such as the temperature of the thyristor part, the secondary voltage of the transformer, the voltage of the energy storage capacitor, the secondary voltage of the discharge tube, and the like. The sampling method may adopt the above-mentioned resistance series voltage division sampling, mutual inductor sampling, sensor sampling or other sampling methods according to the characteristics of the signal. For example, if a fault occurs and the ignition device is replaced as a whole, the system does not need to know which part of the ignition device is faulty, and the redundant functions will increase more weight and volume, so whether other key parts collect signals can be determined according to specific needs.

[0042] Preferably, if Figure 5 As shown, the input sampling unit and the output sampling unit are connected to relay S1 and relay S2 respectively through the signal processing module, and the two electrical signals of the power input end and the high-voltage output end are converted into a passive resistance signal. The system can judge whether the overall operating status of the ignition device is normal or faulty based on this.

[0043] The output sampling unit uses a current transformer T1 to sample the pulse electricity. Figure 3 and Figure 5 As shown, the current transformer is an inductor with a coil wound on a magnetic ring, and the high-voltage output line of the ignition device passes through the transformer coil as the primary of the current transformer. The signal processing module connected to the output end sampling unit includes resistors R6, R7, capacitors C2, C3, C4, transistors Q1, Q2 and diodes D3 to D7.

[0044] The base of the transistor Q1 is connected to the cathode of the diodes D3 and D4 respectively, the emitter is connected to the resistor R7, the capacitor C3, and the anode of the diodes D4 and D5 respectively, and the collector is connected to the cathode of the diodes D5 and D7, the capacitor C4, and the voltage VCC respectively; the base of the transistor Q2 is connected to the cathode of the diode D6 and the resistor R7 respectively, the emitter is connected to the anode of the diode D6 and the ground respectively, the collector is connected to the anode of the diode D7, the capacitor C4, and the relay S2 respectively, and the capacitor C4 is connected in parallel with the diode D7; one end of the capacitors C2 and C3 is grounded, and one end of the capacitor C4 is connected to the relay S2; the current transformer T1 is connected to the resistor R6 and the capacitor C2 respectively, for realizing charging filtering; the resistor R7 is connected to the capacitor C3 and the anode of the diode D5 respectively, and the anode of the diode D3 is connected to the capacitor C2 and the resistor R6 respectively.

[0045] During use of the present invention, when the current transformer T1 induces a discontinuous electric signal, the resistor R6 and the capacitor C2 are used to charge and filter the electric signal, and then the electric signal passes through the diode D3 to turn on the transistor Q1 for a short time; when T1 has no induced signal, the capacitor C2 discharges through R6 to turn on the transistor Q1 for a very short time, and the voltage VCC turns on Q2 and charges the capacitor C3; when Q1 is cut off, the capacitor C3 discharges and continues to turn on the transistor Q2 until T1 generates an induced signal again; during the conduction period of Q2, VCC is filtered by the capacitor C4 to generate a continuous and stable electric signal at both ends thereof.

[0046] The input sampling unit adopts resistor series voltage division sampling, and the input sampling unit includes a rectifier D1 and a resistor R1. The signal processing module connected to the input sampling unit includes a capacitor C1 for filtering and a diode D2 for voltage stabilization; the rectifier D1 is connected to the resistor R1, and the resistor R1 is respectively connected to the capacitor C1, the diode D2 and the relay S1, and the other ends of the capacitor C1 and the diode D2 are respectively grounded.

[0047] The state monitoring circuit of the present invention is isolated from the main circuit, and whether the monitoring circuit works or not does not affect the realization of the main functions of the ignition device, thereby meeting the reliability and safety requirements of the ignition device. The state monitoring circuit designed by the present invention does not contain special components, and can use common components such as resistors, capacitors, inductors, diodes, triodes, relays, etc., which has low cost and meets the low cost requirements of the ignition device. The state monitoring circuit of the present invention can simultaneously meet the requirements of the ignition device in terms of temperature height, volume weight, electromagnetic compatibility, etc., and has high practicality.

[0048] Embodiment 2:

[0049] A method for monitoring the state of an aircraft engine ignition device is provided based on the state monitoring system for the aircraft engine ignition device described in Example 1. Taking a certain type of aircraft engine low-voltage AC input energy storage ignition device as an example, the method specifically includes the following steps:

[0050] Step 1: Sampling the electrical signal at the input end. Figure 5 As shown, the power input end of the ignition device is 115V / 400Hz AC, which is first rectified by rectifier D1 and then passed through resistor R1 and relay S1 coil resistance R S1 The sampling circuit composed of voltage division sampling.

[0051] Specifically, the voltage of 115V / 400Hz AC after rectification by D1 is about 162V. Since the rated working voltage of the selected relay coil is 12V, the coil resistance R S1 =850Ω, to ensure that the current is sufficient to drive the relay, the current of the sampling circuit [162 / (R1+R S1 )] must be greater than the relay drive current 12V / 850Ω≈0.01412A, then R1+R S1 <11475Ω, to ensure sufficient drive current while minimizing the power consumption of the monitoring circuit, select R1+R S1 =10kΩ, the drive current is about 0.0162A. Since the maximum voltage of the relay coil is 16V, R is directly selected here. S1 As a sampling resistor, 162×(850 / 10k) =13.77V can meet the voltage requirements. If the current or voltage is difficult to meet the requirements, you can use R S1 Other resistors are connected in series or in parallel. Since R1 = 9150Ω, its power is I 2 *R=0.0162*0.0162*9150≈2.4W, so a 3W resistor can be selected. The operating temperature, temperature coefficient and accuracy of the resistor should also be considered to select the type of resistor.

[0052] Step 2: Sampling of electrical signals at the output end. Figure 2 As shown, the output end of the ignition device is a high-voltage pulse signal with a pulse amplitude of about 17 kV, a pulse width of about 270 us, and a pulse period of about 0.47 s. The current transformer T1 is used to sample the pulse electricity.

[0053] Here, we mainly need to consider the number of turns of the coil and the selection of the magnetic ring. When selecting the magnetic ring, we should consider the operating temperature of the ignition device and the requirements of the subsequent circuit, and select the iron-nickel-molybdenum magnetic ring with good temperature stability and low loss. Specifically, through repeated principle tests, it is determined that when the number of turns of the transformer coil is 20, it can meet the requirements of the subsequent circuit to generate a continuous and stable electrical signal.

[0054] Step 3: Signal processing.

[0055] like Figure 5 As shown, the voltage signal collected by the resistor series voltage division sampling can be directly used to control the relay S1 after being stabilized by the voltage stabilizing diode D2 and filtered by the capacitor C1. Specifically, the selection of the diode D2 takes into account the coil voltage of the relay S1, and selects a silicon diode with a reverse stabilizing voltage of 12V, a reverse current of 0.03A, a power of 1.5W, and a temperature range of -55℃~125℃. C1 selects a ceramic capacitor with a capacitance of 100nF, a withstand voltage of 50V, and a suitable temperature coefficient for filtering.

[0056] like Figure 5 As shown, the discontinuous pulse induction electrical signal collected by the current transformer T1 needs to be converted into a continuous and stable signal using a signal processing module to control the relay S2. Specifically, when the ignition device works at a spark frequency of about 2Hz, the current transformer T1 senses and generates a discontinuous electrical signal. The electrical signal is charged and filtered through the resistor R6 and the capacitor C2. R6 is a charging and discharging resistor with a resistance of 5.6Ω and a power of 3W. Its resistance value can be adjusted to control the capacitor to maintain the voltage and charging time. When selecting the resistor, its accuracy and temperature coefficient also need to be considered. C2 is a ceramic capacitor with a capacitance of 2.2nF and a withstand voltage of 250V. The electrical signal generated by the current transformer T1 passes through the diode D3 to turn on the transistor Q1 for a short time. When there is no T1 induction signal, C2 discharges through R6 and maintains a certain voltage at both ends for a short time, and continues to turn on the transistor Q1. Since C2 is a small capacitor, the discharge time is short. When the voltage at both ends of C2 is less than the turn-on voltage of the transistor Q1, Q1 is cut off, so the turn-on time of Q1 is extremely short. During the conduction period of Q1, VCC turns on Q2 and charges capacitor C3. The capacity of capacitor C3 is 47uF, the voltage across the capacitor is about 10V-12V, and the charging time is nanoseconds. The conduction time of Q1 is enough for it to charge and maintain the voltage across the two ends to keep Q2 on during the next T1 induction signal generation period. When Q1 is turned off, capacitor C3 discharges and continues to turn on transistor Q2 until T1 generates an induction signal again. During the conduction period of Q2, VCC generates a continuous and stable electrical signal at its two ends after filtering through capacitor C4.

[0057] Step 4: Signal conversion, through relays S1, S2 and resistors R2 to R5, four resistors with different resistance values ​​form a resistor network, and convert two active electrical signals into a passive resistance signal. The electrical signal at the power input end controls the on and off of relay S1, and the normally open terminal of relay S1 is connected to resistor R2 and the normally closed terminal is connected to resistor R3; the electrical signal at the high-voltage output end controls the on and off of relay S2, and the normally open terminal of relay S2 is connected to resistor R5 and the normally closed terminal is connected to resistor R4. Preferably, since the resistance value of the monitoring resistor OUT-R is required to be between 10Ω and 500Ω, in order to avoid overlap of the feedback resistance signal or misjudgment due to small differences, the resistance value of the resistance network is set as wide as possible, so resistor R2 is set to 300Ω, resistors R3 and R4 are set to 100Ω, and resistor R5 is set to 200Ω.

[0058] Depending on the presence or absence of electrical signals at the power input and high-voltage output, there are four states of OUT-R resistance values:

[0059] ① There is no electrical signal at both the input and output ends, that is, the power does not enter the ignition device, the ignition device does not work, relays S1 and S2 are in the normally closed state, and the monitoring resistor OUT-R = R3 + R4 = 200Ω;

[0060] ② There is an electrical signal at the input end, but no electrical signal at the output end, that is, the power has entered the ignition device, the ignition device fails and does not work, the relay S1 is in the normally open state, S2 is in the normally closed state, and the monitoring resistor OUT-R = R2 + R4 = 400Ω;

[0061] ③ There is no electrical signal at the input end, but there is an electrical signal at the output end, that is, the power has entered the ignition device but the input monitoring circuit is faulty, the ignition device works normally, the relay S1 is in the normally closed state, S2 is in the normally open state, and the monitoring resistor OUT-R = R3 + R5 = 300Ω;

[0062] ④ There are electrical signals at both the input and output ends, that is, the power enters the ignition device, the ignition device works normally, relays S1 and S2 are in the normally open state, and the monitoring resistor OUT-R = R2 + R5 = 500Ω.

[0063] Taking into account the accuracy of the resistor and the temperature drift at high and low temperatures, the error of OUT-R is set to ±10Ω.

[0064] Step 5: Signal feedback and judgment. Since the input electrical signal and the output electrical signal are converted into a resistance signal, the controller only needs to measure the resistance value between the two pins of the ignition device to monitor the operating status of the ignition device. A resistance value of 200Ω±10Ω indicates that the ignition device is not powered on, 300Ω±10Ω indicates that the main circuit of the ignition device is working normally but the input monitoring circuit is faulty, 400Ω±10Ω indicates that the main circuit of the ignition device is faulty and not working or the output monitoring circuit is faulty, and 500Ω±10Ω indicates that the ignition device is working normally. Different resistance values ​​are used to characterize different operating states of the ignition device, thereby judging whether the ignition device is working normally.

[0065] Compared with sensors that are difficult to select, have a large increase in volume and weight, and are expensive, the present invention can safely and reliably implement the status monitoring function by slightly increasing the volume and weight, reducing the time and labor cost of maintenance. For this embodiment, the volume is increased by about 15cm 3 , accounting for 1.5% of the total volume of the ignition device, and the weight increases by about 30g, accounting for 2.3% of the total weight of the ignition device, which effectively solves the technical problems that it is difficult to select sensors for existing status monitoring methods and sensor detection will suddenly increase weight and volume. The present invention can efficiently and reliably realize the status monitoring of the ignition device of the aircraft or engine system, reduce the time and labor cost of maintenance, and the resistance value of the passive feedback of the ignition device will not affect the aircraft or engine system.

[0066] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A state monitoring system for an aircraft engine ignition device, characterized in that: It includes a signal sampling module, a signal processing module and a signal conversion circuit, wherein the signal conversion circuit is used to convert the sampled electrical signal into a passive resistance signal, and monitor the operating state of the ignition device through the resistance value change of the resistance signal; The signal sampling module includes an input sampling unit, an output sampling unit and a plurality of auxiliary signal sampling units, wherein the input sampling unit and the output sampling unit are used to sample the power input end and the high voltage output end of the ignition device respectively; The signal conversion circuit includes a plurality of relays S1 to Sn arranged sequentially from front to back, two resistors with different resistance values ​​are arranged between adjacent relays, and one end of the two resistors is respectively connected to the normally open end and the normally closed end of the relay on one side, and the other ends of the two resistors are respectively connected to the common end of the relay on the other side; The input sampling unit, the output sampling unit and the plurality of auxiliary signal sampling units are respectively connected to different relays through the signal processing module, so that different electrical signals can respectively control the on and off of different relays, so that the resistors between the plurality of relays are connected in series to form a resistor network; The output sampling unit uses a current transformer T1 to sample the pulse electricity. The high-voltage output line of the ignition device passes through the transformer coil as the primary of the current transformer T1, and the number of coil windings is the number of secondary turns of the current transformer. The signal processing module connected to the output sampling unit includes resistors R6 and R7, capacitors C2, C3 and C4, transistors Q1 and Q2, and diodes D3 to D7; The base of the transistor Q1 is connected to the cathode of the diodes D3 and D4, the emitter is connected to the resistor R7, the capacitor C3, and the anode of the diodes D4 and D5, and the collector is connected to the cathode of the diodes D5 and D7, the capacitor C4, and the voltage VCC. The base of the transistor Q2 is respectively connected to the cathode of the diode D6 and the resistor R7, the emitter is respectively connected to the anode of the diode D6 and the ground, the collector is respectively connected to the anode of the diode D7, the capacitor C4 and the relay S2, and the capacitor C4 is connected in parallel with the diode D7; one end of the capacitors C2 and C3 is grounded, and one end of the capacitor C4 is connected to the relay S2; the current transformer T1 is respectively connected to the resistor R6 and the capacitor C2 to realize charging filtering; the resistor R7 is respectively connected to the capacitor C3 and the anode of the diode D5, and the anode of the diode D3 is respectively connected to the capacitor C2 and the resistor R6.

2. The state monitoring system of an aircraft engine ignition device according to claim 1, characterized in that: The input sampling unit adopts resistor series voltage division sampling.

3. The state monitoring system of an aircraft engine ignition device according to claim 2, characterized in that: The input sampling unit includes a rectifier D1 and a resistor R1, and the signal processing module connected to the input sampling unit includes a capacitor C1 for filtering and a diode D2 for voltage stabilization; the rectifier D1 is connected to the resistor R1, and the resistor R1 is respectively connected to the capacitor C1, the diode D2 and the relay S1, and the other ends of the capacitor C1 and the diode D2 are respectively grounded.

4. A method for monitoring the state of an aircraft engine ignition device, based on the aircraft engine ignition device state monitoring system according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step S1: signal acquisition: based on the signal sampling module, the power input end and the high voltage output end of the ignition device are respectively sampled for electrical signals; Step S2: signal processing: performing stabilization processing on the signals collected in step S1 based on the signal processing module; Step S3: signal conversion: based on the signal conversion circuit, the different active electrical signals processed in step S2 are used to control the on and off of different relays respectively, and the on and off of the relays are controlled to connect different resistors to the resistor network, so that multiple active electrical signals are converted into a passive resistor signal; Step S5: Signal feedback and judgment: Measure the resistance value between the two pins of the ignition device to determine whether the working state of the ignition device is normal.

5. The method for monitoring the state of an aircraft engine ignition device according to claim 4, characterized in that: In the step S1, for the power input end, a resistor series voltage division sampling is adopted; for the high voltage output end, a current transformer connected in series in the circuit is adopted to sample the pulse electricity.

6. The method for monitoring the state of an aircraft engine ignition device according to claim 5, characterized in that: In step S2, the voltage signal collected from the power input terminal is stabilized and filtered; Process the electrical signal collected from the high voltage output end and output a continuous and stable signal: When the current transformer T1 senses a discontinuous electrical signal, the resistor R6 and the capacitor C2 are used to charge and filter the electrical signal, and then the electrical signal passes through the diode D3 to turn on the transistor Q1 for a short time; When T1 has no induction signal, capacitor C2 discharges through R6, causing transistor Q1 to be turned on for a very short time, and voltage VCC turns Q2 on and charges capacitor C3; when Q1 is turned off, capacitor C3 discharges and continues to turn on transistor Q2 until T1 generates an induction signal again; during the conduction period of Q2, VCC is filtered by capacitor C4 to generate a continuous and stable electrical signal at both ends.

7. The method for monitoring the state of an aircraft engine ignition device according to claim 6, characterized in that: In the step S1, the electrical signals of other key parts are sampled by multiple auxiliary signal sampling units to further determine the fault location inside the ignition device. The electrical signals of other key parts include any one or more of the signals of thyristor part temperature, transformer secondary voltage, energy storage capacitor voltage, and discharge tube secondary voltage.

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