JP2009281263A - Failure diagnosis method for internal combustion engine of aircraft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To meet a demand for failure diagnosis with high accuracy in view of safety, in a failure diagnosis of a control system of an aircraft engine. <P>SOLUTION: An internal combustion engine of an aircraft has three or more of sensors and a control system. In the internal combustion engine, a failure diagnosis method includes: a step of determining correlation for each pair of sensors about output values of three or more of sensors; a step of determining whether or not any one of the sensors is abnormal based on the result of the correlation determination; and a step of determining a failure of a control system if the number of sensors that determined as abnormalities is larger than a predetermined value, or determining that any one of the sensors is in failure when the number of sensors that determined as abnormalities is smaller than the predetermined value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a failure diagnosis method for an aircraft internal combustion engine.

  Examples of the control system for the engine include a system for controlling the operation of the engine, a cooling system, a lubrication system, and an exhaust system. A number of sensors are used in these engine control systems, and based on the sensor information, a diagnosis is made as to whether or not the sensors and these engine control systems are faulty.

For example, Patent Document 1 discloses a control device that determines an abnormality of a lubrication system based on hydraulic pressure information from a hydraulic pressure sensor provided in a lubricating oil supply passage downstream of the hydraulic regulator. Further, Patent Document 2 discloses an abnormality detection device that compares the information from the water temperature sensor with a reference value to determine a thermostat failure (cooling system) or a water temperature sensor failure.
Japanese Patent Publication No. 7-84843 Japanese Patent Laid-Open No. 11-173149

  In Patent Document 1 and Cited Document 2, failure determination is performed based on information from one sensor, and there is a risk of erroneous determination. As for failure diagnosis of an aircraft engine control system, failure diagnosis with higher accuracy is required from the viewpoint of safety. Therefore, a method capable of diagnosing a failure with good accuracy is desired.

  According to an aspect of the present invention, in an aircraft internal combustion engine including three or more sensors and a control system, a correlation between two sensor sets is determined for output values of three or more sensors, and a correlation result is obtained. Based on the above, it is determined whether any of the sensors is abnormal. If the number of sensors determined to be abnormal is greater than a predetermined value, it is determined that the control system has failed. If the number of sensors determined to be abnormal is less than a predetermined value, it is determined that one of the sensors has failed.

  According to this aspect, since the failure of the sensor is determined based on the correlation, the failure diagnosis can be performed with better accuracy. Further, it is possible to obtain an advantage that it is possible to determine whether a failure is caused by the cooling system or the sensor.

  According to one embodiment of the present invention, if the number of abnormal output values of the sensor is one, it is determined that the sensor has failed.

  According to another aspect of the present invention, in an aircraft internal combustion engine having three or more sensors and a control system, it is respectively determined whether the output values of the three or more sensors fall within a predetermined range for each sensor. As a result of the comparison, if there are a plurality of sensors whose output values do not fall within a predetermined range, it is determined that the system has failed. If one sensor does not fall within the predetermined range, it is determined that the sensor has failed.

  According to this aspect, since the failure of the sensor is determined based on the value that each sensor can take, failure diagnosis can be performed with better accuracy. In addition, there is an advantage that it is possible to make a failure diagnosis judgment as to whether the failure is in the cooling system or the sensor.

  According to one embodiment of the present invention, the control system for the internal combustion engine is at least one of a cooling system and a lubrication system.

  According to one embodiment of the present invention, when the control system is a cooling system, the three or more sensors are a water temperature sensor for an internal combustion engine, a tank pressure sensor for a cooling water tank, and an oil temperature sensor for an oil cooler.

  Next, embodiments of the present invention will be described with reference to the drawings. In the second and subsequent embodiments, only the configuration different from that of the first embodiment will be described, and the same components will be denoted by the same reference numerals, and description thereof will be simplified or omitted.

(First embodiment)
FIG. 1 is an overall configuration diagram of a failure diagnosis system 1 for a cooling system that is a control system for an internal combustion engine (hereinafter referred to as an engine) 2 according to a first embodiment of the present invention. The failure diagnosis system 1 of the present embodiment diagnoses failure of the cooling system and the sensor based on the correlation between the output values of the sensors attached to the engine and the cooling system.

  The cooling system is a water-cooling type cooling system composed of a radiator 3, a thermostat 4, a water pump 6, a cooling water tank 7, and the like in order to keep the operating temperature of the engine 2 within an appropriate range. The cooling system circulates the cooling water by the water pump 6, and when the cooling water reaches a high temperature state, the cooling water is sent to the radiator 3 by the thermostat 4 to lower the temperature of the cooling water and is used again for cooling the internal combustion engine.

  An electronic control unit (hereinafter referred to as “ECU”) 9 is a computer including a central processing unit (CPU), a memory having a read only memory (ROM) and a random access memory (RAM). The ROM can store a computer program for realizing various controls of the aircraft and data (including a map) necessary for executing the program. The ROM includes a non-volatile memory such as an EPROM. The RAM is provided with a work area for calculation by the CPU. The ECU 9 receives a signal from each part of the aircraft and performs an operation according to data and a program stored in the memory to generate a control signal for controlling each part of the aircraft.

  The thermostat 4 is provided with a water temperature (Tw) sensor 5 to detect the water temperature of the cooling water in the thermostat 4. The cooling water tank 7 is provided with a tank pressure (Pw) sensor 8 for detecting the pressure in the cooling water tank. Furthermore, an oil temperature (Toc) sensor is provided in an oil cooler (not shown) provided in the lubrication system, and detects the oil temperature of the engine oil in the oil cooler. The output values of these sensors are sent to the ECU 9.

  The ECU 9 diagnoses a failure of the cooling system in accordance with programs and data (including a map) stored in the memory in accordance with input signals from the various sensors, and displays the diagnosis result on the monitor 10.

  FIG. 2 is a functional block diagram of the ECU 9 of the failure diagnosis system 1 for the cooling system of the present embodiment. Processing by each functional block is executed at a predetermined control cycle. For example, it may be executed based on a pulse (TDC signal) generated by a cam angle sensor (not shown) at the top dead center at the start of the intake stroke of each cylinder.

  The correlation determination unit 21 determines the collapse of the correlation based on the output value of each sensor during driving. First, the output value of each sensor during operation is detected, the output value of a predetermined sensor among the sensors is estimated using the output values of the other remaining sensors, and the estimated value of the predetermined sensor is obtained. The difference between the two sets of the output value of the predetermined sensor and the estimated value of the sensor is obtained, and each difference is compared with a predetermined value to determine whether the correlation between the sensors during operation is broken. .

If it demonstrates based on this embodiment, in the correlation determination part 21, the output value of the above-mentioned Tw sensor 5, Pw sensor 8, and Toc sensor will be first acquired at the time of the driving | operation of the engine 2, respectively. Next, an estimated value Tw _Pw of the Tw sensor is obtained from the output value of the Pw sensor 8, and an estimated value Tw _Toc of the Tw sensor is obtained from the output value of the Toc sensor. As a result, as shown in the following equation, a difference is obtained for each of the two sets of the output value Tw of the Tw sensor 5 and the estimated values Tw _Pw and Tw _Toc of the Tw sensor, and it is determined whether or not they are within a predetermined value range.

| Tw-Tw _Pw | <10 ° C
| Tw−Tw _Toc | <10 ° C. (1)
| Tw _Pw -Tw _Toc | <10 ° C
Here, in Equation (1), the predetermined value is 10 ° C., but the predetermined value is not limited to this, and different values may be set for each.

  The sensor abnormality determination unit 22 determines which of the Tw sensor 5, the Pw sensor 8, and the Toc sensor is abnormal from the determination result of the correlation determination unit 21.

  The failure determination unit 23 determines that the cooling system has failed when the number of sensors determined to be abnormal by the sensor abnormality determination unit 22 is greater than a predetermined value, and the number of sensors determined to be abnormal is less than the predetermined value. In this case, it is determined that any of the above-described sensors has failed.

  According to this aspect, since the failure of the sensor is determined based on the correlation, the failure diagnosis can be performed with better accuracy. Further, it is possible to determine whether the cooling system is malfunctioning or the sensor is malfunctioning.

  In the present embodiment, three sensors are used. However, the present invention is not limited to this, and three or more sensors may be used. Although the Pw sensor 8 is used, for example, a water temperature sensor that detects the water temperature of the cooling water in the tank and a water level sensor that detects the water surface height of the cooling water in the tank may be used.

  Next, a failure diagnosis flow of the cooling system of the present embodiment will be described with reference to FIG. The process shown in the flow is executed by the ECU 9, and more specifically, is realized by the functional blocks shown in FIG. The control cycle of the flow is synchronized with, for example, a TDC signal as described above.

In step S31, a process for determining the collapse of the correlation is executed. FIG. 4 is a diagram in which the output 41 of the Toc sensor, the output 42 of the Tw sensor 5 and the output 43 of the Pw sensor 8 are shown on the vertical axis and the time is shown on the horizontal axis during engine operation. FIG. 4A is a diagram showing the output of each sensor when the engine 2 is operating normally. Based on FIG. 4A, functions Tw _Pw = f1 (Pw) and Tw _Toc = f2 (Toc) of the estimated value of Tw are obtained. Here, Pw is an output value of the Pw sensor 8, and Toc is an output value of the Toc sensor.

The output values of each sensor during operation are obtained, the estimated values Tw _Pw and Tw _Toc of Tw are calculated using the above-mentioned functions, and the output values of each sensor are calculated using the above-described equation (1). Next, it is determined whether the correlation during driving is broken.

In step 32, when the correlation is not broken in the result of the determination in step 31, it is determined that the cooling system is normal (step 33). For example, when the output of each sensor during driving is shown in FIG. 4A, the correlation between the Toc sensor output 41 and the Tw sensor output 42 (hereinafter referred to as 41-42 correlation, and the correlation is in the same format. ) Is determined not to collapse because | Tw−Tw _Toc | falls within the range of 10 ° C. The 41-43 correlation does not collapse because | Tw _Pw −Tw _Toc | falls within the range of 10 ° C., and the 42-43 correlation collapses because | Tw−Tw _Pw | falls within the range of 10 ° C. Otherwise, it is determined. Thus, since the correlations are not broken, it is determined that the cooling system is normal, and the failure diagnosis is terminated. On the other hand, if there is a correlation failure in the determination result of step 31 in step 32, the sensor abnormality is determined in the next step (step 34).

In step 34, the number of sensors determined to be abnormal based on the correlation determination result in step 31 is determined. For example, in the case of FIG. 4B, after the line 44, if the 41-42 correlation is broken because | Tw-Tw _Toc | is out of the range of 10 ° C., the 41-43 correlation becomes | Tw. _{Since Pw−} Tw _Toc | is out of the range of 10 ° C., it is determined that it is broken. As a result, the 41-42 correlation and the 41-42 correlation are broken, and the 42-43 correlation is not broken. Therefore, it is understood that one sensor (Toc sensor) is abnormal.

For example, in the case of FIG. 4C, after the line 44, if the 41-42 correlation is broken because | Tw-Tw _Toc | is out of the range of 10 ° C., the 42-43 correlation is | Since Tw−Tw _Pw | is out of the range of 10 ° C., it is determined that it has collapsed. Accordingly, the 41-42 correlation and the 42-43 correlation are broken, and the 41-43 correlation is not broken, so that it is understood that one sensor (Tw sensor) is abnormal.

Further, for example, in the case of FIG. 4D, after the line 44, if the 41-42 correlation is broken because | Tw-Tw _Toc | is out of the range of 10 ° C., the 41-43 correlation is | If Tw _Pw −Tw _Toc | falls outside the range of 10 ° C., the 42-43 correlation is judged to be broken because | Tw−Tw _Pw | falls outside the range of 10 ° C., respectively. As a result, since all the correlations are broken, it is understood that two or more sensors are abnormal.

  In step 35, the number of abnormal sensors in step 34 is compared with a predetermined value. In the present embodiment, the predetermined value is 2. The predetermined value can be an appropriate value according to the number of sensors used for failure diagnosis. If the number of abnormal sensors is 2 or more as shown in FIG. 4D, it is determined that the cooling system is out of order (step 36), and the fault diagnosis is terminated. If the number of abnormal sensors is less than 2 as shown in FIGS. 4B and 4C, it is determined that the sensors are out of order (step 39), and the fault diagnosis is terminated.

  Preferably, step 37 may be performed, and when there is one abnormality sensor, it is specified that the sensor has failed (step 38), and the failure diagnosis is terminated. In the case of FIG. 4B, it is specified that the Toc sensor has failed, and in the case of FIG. 4C, the Tw sensor has failed.

(Second Embodiment)
FIG. 5 is a functional block diagram of the ECU 9 of the failure diagnosis system 1 for the cooling system according to the second embodiment of the present invention. The failure diagnosis system 1 of the present embodiment is for diagnosing a failure in the cooling system and the sensor by comparing output values of sensors attached to the engine and the cooling system with predetermined values. The failure diagnosis system 1 for the cooling system is as shown in FIG.

  The sensor value determination unit 51 determines whether the output value of the sensor falls within a predetermined range that is determined in advance for each sensor, and determines that the sensor that exceeds the predetermined range is abnormal. For example, the predetermined range is a range between the minimum value and the maximum value of the output of each sensor when the engine 2 is operating normally as a value that each sensor can take.

  The failure determination unit 52 determines that the cooling system has failed when the number of sensors determined to be abnormal by the sensor value determination unit 51 is two or more, and when the number of sensors determined as abnormal is one. It is determined that the sensor has failed.

  According to this aspect, since the failure of the sensor is determined based on the value that each sensor can take, failure diagnosis can be performed with better accuracy. Further, it is possible to make a failure diagnosis determination as to whether the cooling system system is faulty or the sensor is faulty. As in the first embodiment, this may be performed using another sensor.

  Next, a failure diagnosis flow of the cooling system of the present embodiment will be described with reference to FIG.

  In step S61, a process for determining whether each sensor value falls within a predetermined range is executed. FIG. 7 is a diagram in which the output 41 of the Toc sensor, the output 42 of the Tw sensor 5 and the output 43 of the Pw sensor 8 are shown on the vertical axis and the time is shown on the horizontal axis, as in FIG. is there. FIG. 7A is a diagram showing the output of each sensor when the engine 2 is operating normally. According to this figure, the predetermined range is the minimum and maximum value width 46 of the Toc sensor output, the minimum and maximum value width 45 of the Tw sensor output, and the minimum and maximum value width of the Pw sensor output. 47.

  In step 62, when there is no sensor determined to be abnormal in step 61, it is determined that the cooling system is normal (step 63). For example, when the output of each sensor during operation is shown in FIG. 7A, the cooling system is normal because the Toc sensor output 41, the Tw sensor output 42, and the Pw sensor output 43 are within a predetermined range. Is determined and the fault diagnosis is terminated. On the other hand, if there is a sensor determined to be abnormal in step 61, the process proceeds to the next step (step 64).

  If there is one sensor determined to be abnormal in step 64, it is specified that the sensor is faulty (step 65), and the fault diagnosis is terminated. For example, when the output of each sensor during operation is FIG. 7B, it is determined that the Toc sensor output 41 is out of a predetermined range after the line 44 and the Toc sensor is abnormal, and the Toc sensor fails. Identified. On the other hand, when the number of sensors determined to be abnormal in step 64 is not one, it is determined that the cooling system has failed (step 66), and the failure diagnosis is terminated. For example, when the output of each sensor during operation is shown in FIG. 7C, the Toc sensor output 41, the Tw sensor output 42, and the Pw sensor output 43 are out of a predetermined range after the line 44, and three sensors ( Since it is determined that the Toc sensor, the Tw sensor, and the Pw sensor are abnormal, it is determined that the cooling system is malfunctioning (step 66).

(Third embodiment)
FIG. 8 is an overall configuration diagram of the failure diagnosis system 1 of the lubrication system that is the control system of the engine 2 according to the third embodiment of the present invention. The failure diagnosis system 1 of the present embodiment diagnoses a failure of the lubrication system and the sensor based on the correlation between the output value of the sensor attached to the engine and the lubrication system and the hydraulic pressure setting information.

  The lubrication system includes an oil pan 81, an oil pump 83, a regulator 84 and a check valve 88, an oil cooler 85, an oil filter 86, a differential pressure sensor 87, and the like. In the lubrication system, the engine oil in the oil pan 81 is sucked up by the oil pump 83, cooled by the oil cooler 85, filtered by the oil filter 86, sent to each part of the engine 2, and returned to the oil pan 81. repeat. The regulator 84 controls the pressure of the engine oil based on the regulator set pressure information (Preg) sent from the EUC 9.

  The oil pump 83 is provided with a hydraulic pressure (Pop) sensor 82 and detects the discharge pressure of the oil pump 83. The oil filter 86 is provided with a differential pressure (dPo) sensor 87, which detects the differential pressure of the engine oil when it is input to the oil filter 86 and when it is output. The output values of these sensors are sent to the ECU 9.

  A functional block diagram of the ECU 9 of the failure diagnosis system 1 of the lubrication system of the present embodiment is shown in FIG. The correlation determination unit 21 determines the collapse of the correlation based on the output value of each sensor during operation and the value of Preg. First, the output value of each sensor during operation is detected, the output value of a predetermined sensor among the sensors is estimated using the output value of the other remaining sensors and the value of Preg, and the estimated value of the predetermined sensor is calculated. Ask for each. The difference between the two sets of the output value of the predetermined sensor and the estimated value of the sensor is obtained, and each difference is compared with a predetermined value to determine whether the correlation between the sensors during operation is broken. .

If it demonstrates based on this embodiment, in the correlation determination part 21, the output value of the above-mentioned Pop sensor 82 and the dPo sensor 87 will each be acquired first at the time of driving | operation of the engine 2. Next, the estimated value Pop _dPo of the Pop sensor is obtained from the output value of the dPo sensor 87, and the estimated value Pop Preg of the Pop sensor is obtained from the value of _Preg . As a result, as shown in the following equation, a difference is obtained for each of the two sets of the output value Pop of the Pop sensor 82 and the estimated values Pop _dPo and Pop _Preg of the Pop sensor, and it is determined whether or not they are within a predetermined value range.

| Pop-Pop _dPo | <100KPa
| Pop-Pop _Preg | <100 KPa (2)
| Pop _dPo -Pop _Preg | <100 KPa
Here, in Equation (2), the predetermined value is 100 KPa, but the predetermined value is not limited to this, and different values may be set for each.

  The sensor abnormality determination unit 22 determines whether one of the Pop sensor 82 and the dPo sensor 87 is abnormal from the determination result of the correlation determination unit 21.

  The failure determination unit 23 determines that the lubrication system has failed when the number of sensors determined to be abnormal by the sensor abnormality determination unit 22 is greater than a predetermined value, and the number of sensors determined to be abnormal is less than the predetermined value. In this case, it is determined that any of the above-described sensors has failed.

  According to this embodiment, since a sensor failure is determined based on the correlation, failure diagnosis can be performed with better accuracy. Further, it is possible to make a failure diagnosis judgment as to whether the lubrication system is malfunctioning or the sensor is malfunctioning.

  Although three sensors are used in the present embodiment, the present invention is not limited to this, and three or more sensors may be used. Further, although the dPo sensor 87 is used, for example, a pressure sensor for detecting the pressure of the engine oil may be used on the outlet side of the oil filter 86.

Next, a failure diagnosis flow of the lubrication system according to the present embodiment will be described with reference to FIG. In step S31, a process for determining the collapse of the correlation is executed. FIG. 9 is a diagram in which the output 92 of the Pop sensor 82 and the output 93 of the dPo sensor 87 during operation of the engine are shown on the vertical axis, and the time is shown on the horizontal axis. Reference numeral 91 denotes regulator set pressure information (Preg). FIG. 9A is a diagram showing the output and Preg of each sensor when the engine 2 is operating normally. Based on FIG. 9A, functions Pop _dPo = f3 (dPo) and Pop _Preg = f4 (Preg) of the estimated value of the Pop sensor are obtained, respectively. Here, dPo is the output value of the dPo sensor 87, and Preg is the value of Preg.

_Obtain the output value of each sensor during operation, calculate Pop estimated values Pop _dPo and Pop _Preg using the above-mentioned functions, and use the above-mentioned equation (2) for each of the two sets of output values of each sensor Next, it is determined whether the correlation during driving is broken.

In step 32, when the correlation is not lost in the determination result in step 31, it is determined that the lubrication system is normal (step 33). For example, when the output of each sensor during operation is FIG. 9A, it is determined that the 91-92 correlation has not collapsed since | Pop-Pop _Preg | is in the range of 100 KPa. The 91-93 correlation does not collapse because | Pop _dPo -Pop _Preg | falls within the range of 100 KPa, and the 92-93 correlation does not collapse because | Pop-Pop _dPo | falls within the range of 100 KPa. Each is judged. Thus, since the correlations are not broken, it is determined that the lubrication system is normal, and the failure diagnosis is terminated. On the other hand, if there is a correlation failure in the determination result of step 31 in step 32, the sensor abnormality is determined in the next step (step 34).

In step 34, the number of sensors determined to be abnormal based on the correlation determination result in step 31 is determined. For example, in the case of FIG. 9B, after the line 94, if the 91-93 correlation is broken because | Pop _dPo -Pop _Preg | is out of the range of 100 KPa, the 92-93 correlation becomes | Pop- Since Pop _dPo | is out of the range of 100 KPa, it is determined that it has collapsed. As a result, the 91-93 correlation and the 92-93 correlation are broken, and the 91-92 correlation is not broken. Therefore, it is understood that one sensor (Pop sensor) is abnormal.

For example, in the case of FIG. 9C, after the line 94, if the 91-92 correlation is broken because | Pop-Pop _Preg | is out of the range of 100 KPa, the 91-93 correlation is | Pop. If -Pop _dPo | is out of the range of 100 KPa and is broken, the 92-93 correlation is determined to be broken because | Pop-Pop _dPo | is out of the range of 100 KPa. From this, since all the correlations are broken, it can be seen that the two sensors are abnormal.

  In step 35, the number of abnormal sensors in step 34 is compared with a predetermined value. In the present embodiment, the predetermined value is 2. The predetermined value can be an appropriate value according to the number of sensors used for failure diagnosis. If the number of abnormal sensors is 2 or more as shown in FIG. 9C, it is determined that the lubrication system is out of order (step 36), and the fault diagnosis is terminated. If the number of abnormal sensors is less than 2 as shown in FIG. 9B, it is determined that the sensors are out of order (step 39), and the fault diagnosis is terminated. Preferably, step 37 may be performed as described above.

(Fourth embodiment)
A functional block diagram of the ECU 9 of the failure diagnosis system 1 of the lubrication system according to the fourth embodiment of the present invention is shown in FIG. The failure diagnosis system 1 according to the present embodiment diagnoses a failure in the lubrication system and the sensor by comparing output values of sensors attached to the engine and the lubrication system with predetermined values. The failure diagnosis system 1 of the lubrication system is as shown in FIG.

  The sensor value determination unit 51 determines whether the output value of the sensor falls within a predetermined range that is determined in advance for each sensor, and determines that the sensor that exceeds the predetermined range is abnormal. For example, the predetermined range is a range of 10% before and after the output value of each sensor when the engine 2 is operating normally as a value that each sensor can take.

  The failure determination unit 52 determines that the lubrication system has failed when the number of sensors determined as abnormal by the sensor value determination unit 51 is 2 or more, and when the number of sensors determined as abnormal is one. It is determined that the sensor has failed.

  According to this aspect, since the failure of the sensor is determined based on the value that each sensor can take, failure diagnosis can be performed with better accuracy. Further, it is possible to make a failure diagnosis judgment as to whether the lubrication system is malfunctioning or the sensor is malfunctioning. As in the third embodiment, this may be performed using another sensor.

  Next, a failure diagnosis flow of the lubrication system according to the present embodiment will be described with reference to FIG. In step S61, a process for determining whether each sensor value falls within a predetermined range is executed. FIG. 10 shows the Pop sensor output 92, the dPo sensor output 93 and the regulator set pressure information (Preg) 91 on the vertical axis, and the time on the horizontal axis, as in FIG. FIG. FIG. 10A is a diagram showing the output of each sensor when the engine 2 is operating normally. According to this figure, the predetermined range is a width 95 of a value 10% before and after the output 92 of the Pop sensor and a width 96 of a value 10% before and after the output 93 of the dPo sensor.

  In step 62, if there is no sensor determined to be abnormal in step 61, it is determined that the lubrication system is normal (step 63). For example, when the output of each sensor during operation is shown in FIG. 10A, the Pop sensor output 92 is in the predetermined range 95 and the dPo sensor output 93 is in the predetermined range 96, so the lubrication system is normal. It is determined that the failure diagnosis is finished. On the other hand, if there is a sensor determined to be abnormal in step 61, the process proceeds to the next step (step 64).

  If there is one sensor determined to be abnormal in step 64, it is determined that the sensor is faulty (step 65), and the fault diagnosis is terminated. For example, if the output of each sensor during operation is shown in FIG. 10B, the dPo sensor output 93 is determined to be out of the predetermined range 96 after line 94, and one sensor (dPo sensor) fails. It is determined that On the other hand, if the number of sensors determined to be abnormal in step 64 is not one, it is determined that the lubrication system has failed (step 66), and the failure diagnosis is terminated. For example, when the output of each sensor during operation is shown in FIG. 10C, the Pop sensor output 92 and the dPo sensor output 93 are out of a predetermined range after the line 94, and two sensors (Pop sensor, dPo sensor) Is determined to be abnormal, and it is determined that the lubrication system has failed.

  The specific embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and includes other configurations that can achieve the object of the present invention.

The figure which shows schematically the internal combustion engine for aircrafts, and the failure diagnosis system of its control system according to 1st and 2nd embodiment of this invention. The functional block diagram of the failure diagnosis system according to 1st and 3rd embodiment of this invention. 7 is a flowchart of a fault diagnosis process according to the first and third embodiments. The figure showing the relationship of the output of a sensor according to 1st Embodiment of this invention. The functional block diagram of the failure diagnosis system according to 2nd and 4th embodiment of this invention. 7 is a flowchart of a fault diagnosis process according to the second and fourth embodiments. The figure showing the relationship of the output of a sensor according to 2nd Embodiment of this invention. The figure showing roughly the failure diagnosis system of the internal-combustion engine for airplanes, and its control system according to the 3rd and 4th embodiment of the present invention. The figure showing the relationship between the output of a sensor and the setting pressure information of a regulator according to 3rd Embodiment of this invention. The figure showing the relationship between the output of a sensor and setting information according to 4th Embodiment of this invention.

Explanation of symbols

2 Engine (Internal combustion engine)
5 Water temperature sensor (sensor)
8 Tank pressure sensor (sensor)
9 ECU
82 Oil pressure sensor (sensor)
87 Differential pressure sensor

Claims (5)

In an aircraft internal combustion engine comprising three or more sensors and a control system,
Determining a correlation for each set of two sensors for the output values of the three or more sensors;
Determining whether one of the sensors is abnormal based on the correlation result; and
If the number of sensors determined to be abnormal is greater than a predetermined value, it is determined that the control system has failed, and if the number of sensors determined to be abnormal is less than a predetermined value, one of the sensors Determining that is faulty;
A failure diagnosis method including:   The fault diagnosis method according to claim 1, further comprising a step of determining that the sensor is faulty when the number of abnormal output values of the sensor is one. In an aircraft internal combustion engine comprising three or more sensors and a control system,
Determining whether the output values of the three or more sensors fall within a predetermined range for each sensor;
As a result of the comparison, when there are a plurality of sensors whose output values do not fall within the predetermined range, it is determined that the system has failed, and when there is one sensor that does not fall within the predetermined range. Determining that the sensor is faulty;
A failure diagnosis method including:   The fault diagnosis method according to claim 1, wherein the control system of the internal combustion engine is at least one of a cooling system and a lubrication system.   When the control system is a cooling system, the three or more sensors are a water temperature sensor of the internal combustion engine, a tank pressure sensor of a cooling water tank, and an oil temperature sensor of an oil cooler. The failure diagnosis method described.

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