Method and computer program product for monitoring the bleed air supply system of an aircraft

Abstract

The present invention relates to a method and a computer program product for monitoring an air bleed supply system of an aircraft. For the method, there is provided: at least one sensor (20-22) for monitoring the state of the air bleed supply system (10) by sensor data; at least one operating state monitor (5) for detecting the operating state of the aircraft (1) other than the air bleed supply system (10) using at least one operating state value; and at least two independent monitoring modules (30) for evaluating the state of at least a part of the air bleed supply system (10), and for each monitoring module (30), providing a separate monitoring function as well as separate activation parameters and deactivation parameters based on the sensor data of at least one sensor and at least one operating state value.

Description

Technical Field

[0001] The present invention relates to a method and a computer program product for monitoring the bleed air supply system of an aircraft. Background Art

[0002] In an aircraft, especially a commercial aircraft, compressed air is discharged from the turbocompressor of an engine to be able to generate or maintain a desired pressure in the pressurized cabin or pneumatic system of the aircraft. The engine can be a jet engine, a propeller turbine or an auxiliary power unit (APU). Commonly, each engine of the aircraft is also equipped with a separate bleed air supply system etc., which also ensures redundancy.

[0003] Bleed air is taken from the engine through the bleed air supply system and supplied to a plurality of consuming devices. In this case, in addition to the bleed air that is severely compressed and thus heated, air that is significantly colder and less compressed is usually taken from another location of the engine so that the bleed air heated during compression can be cooled to a desired temperature in a heat exchanger.

[0004] The bleed air supply system basically has a plurality of actuators, especially controllable or self-regulating valves, pressure and temperature sensors or sensors, and may have a control unit that can actuate the actuators according to the determined pressure and temperature values and possibly external control signals. It is also possible to dispense with the control unit, where only pneumatic regulation of the individual actuators can be implemented. In both cases, in addition to maintaining the desired operating pressure, the temperature of the compressed air supplied to the plurality of consuming devices can in principle also be regulated.

[0005] Due to many mechanical components, the bleed air supply system has a low level of reliability, especially in the case of only pneumatic regulation. In case of a failure, for safety reasons, the bleed air supply system will in principle be cut off, even if frequent failures may sometimes cause significant interference to the operation of the aircraft (especially a commercial aircraft).

[0006] In order to be able to identify failures of the bleed air supply system during flight, the values determined by the pressure sensors and temperature sensors of the bleed air supply system can be monitored, where in the prior art, usually only a check against a predetermined threshold is carried out. If the measured value exceeds the threshold in such a system, the entire bleed air supply system is deactivated as a precautionary measure.

[0007] Although this monitoring of the bleed air supply system can identify possible failures in the bleed air supply system and deactivate the system if necessary, the monitoring devices known from the prior art do not provide detailed information items about the possible causes of the failures of the bleed air supply system in the fault message, such that the faults usually require complex troubleshooting and repair measures.

[0008] Deactivating the bleed air supply system in the event of a malfunction has the additional disadvantage that when one system is deactivated, the other bleed air supply systems of the aircraft must additionally supply the bleed air of the deactivated bleed air supply system, which increases the wear and the risk of failure of the other bleed air supply systems.

[0009] A method for diagnosing malfunctions of a bleed air supply system is described in document US 9,555,903 B2, in which various sensors arranged on the bleed air supply system are read out and the deviation of the corresponding sensor data from a comparison value is checked. The comparison value can be a fixed predetermined value, a parameter determined from the operating parameters of the engine and the associated bleed air supply system, a (mean) value determined in the past for the bleed air supply system in question or an average value determined in the past for all bleed air supply systems of the construction series.

[0010] Here, the interpretation of possible deviations can be carried out in particular by flight phase, thus, for example, separately for the take-off, climb, descent and cruise flight phases. In individual cases, the determined deviation of the sensor value from the comparison value in a predetermined flight phase can then be assigned to a specific malfunction of the bleed air supply system. Conversely, for example, an excessively low pressure during the climb or cruise flight phase cannot actually be assigned uniquely to one component or at least can only be assigned uniquely to a small group of components. At least in part of the fault message, there is no actual limitation of the possibly faulty components of the bleed air supply system, even in the method according to US 9,555,903 B2, whereby troubleshooting is very complex in such a fault situation. Summary of the Invention

[0011] The object of the present invention is to provide a method and a computer program product for monitoring the bleed air supply system of an aircraft, which are improved with respect to the prior art, for example, such that a more accurate error diagnosis is possible with regard to the time point at which an error occurs and / or the identification of the component in which the error occurs.

[0012] This object is achieved by the method and the computer program product presented below.

[0013] Accordingly, the present invention relates to a method for monitoring a bleed air supply system of an aircraft, the bleed air supply system having: at least one sensor for state monitoring of the bleed air supply system based on sensor data; at least one operating state monitor for detecting the operating state of the aircraft other than the bleed air supply system via at least one operating state value; and at least two independent monitoring modules for evaluating the state of at least a part of the bleed air supply system based on a monitoring function, wherein for each monitoring module, a separate monitoring function and separate activation and deactivation parameters are provided based on the sensor data of at least one sensor and at least one operating state value, the method having the following steps:

[0014] - Detect the state of the bleed air supply system via sensor data and detect the operating state of the aircraft via the at least one operating state value;

[0015] - Activate the monitoring module when the sensor data and the at least one operating state value satisfy the activation parameters of the monitoring module;

[0016] - Monitor the state of at least a part of the bleed air supply system by the activated monitoring module based on its monitoring function; and

[0017] - Deactivate the activated monitoring module when the sensor data and the at least one operating state value satisfy the deactivation parameters.

[0018] Furthermore, the present invention relates to a computer program product or a collection of computer program products, including program parts, which are designed to execute the method according to the present invention when loaded into a computer or computers networked with each other.

[0019] The method according to the present invention is based on the one hand on sensor data provided by at least one sensor, and the sensor data is suitable for state monitoring of the bleed air supply system at least in the area of the respective sensor. Generally, a plurality of sensors (such as pressure sensors and temperature sensors) are arranged to be distributed on the bleed air system to detect the respective variables at different points of the system. It is also possible to provide a transducer, by using which the current position of the actuator of the bleed air supply system can be detected.

[0020] On the other hand, at least one operating state value is considered, which provides an item of information about the operating state of the aircraft rather than an item of information about the bleed air supply system. The operating state value is a technical variable, which reflects the state of the technical device of the aircraft (such as the landing gear position or the thrust lever position), the operating value of the technical device (such as the pressure inside the engine), or the state value of the aircraft or the surrounding environment (such as the internal pressure or the external temperature in the aircraft cabin). The at least one operating state value, but usually a large number of operating state values, are provided by an operating state monitor, which can also be, for example, an on-board computer or an electronic monitoring system of the aircraft.

[0021] Of course, the operating state values and sensor data for the state monitoring of the bleed air supply system can be detected and / or determined by a single system of the aircraft and provided to the method according to the present invention as a unified set of input variables. However, even in this case, the input variables can be logically divided into sensor data for the state monitoring of the bleed air supply system and operating state values of the aircraft other than the bleed air supply system.

[0022] The method according to the invention is distinguished by providing at least two independent monitoring modules for evaluating the state of at least a part of the bleed air supply system, wherein for each monitoring module a separate monitoring function as well as separate activation parameters and deactivation parameters are provided based on the sensor data of at least one sensor and at least one operating state value. Thus, the monitoring modules can be activated and deactivated completely independently of each other to also monitor the state of the bleed air supply system or a part thereof independently of each other. The latter is ensured in particular by the respective monitoring functions, which, in contrast to homogeneous redundancy, are in no case identical.

[0023] When activated, the monitoring module can monitor the state of the entire bleed air supply system or only a part thereof by means of its monitoring function based on all the sensor data or at least those sensor data that are relevant to the part of the bleed air supply system that is designed to monitor its module or its monitoring function.

[0024] This is because the invention has recognized that on the one hand the bleed air supply system is a very complex system and its overall monitoring is usually difficult, but on the other hand the bleed air supply system can usually be divided into subsystems, and the respective states of these subsystems and the resulting individual functions of the subsystems can be monitored well independently of each other. Thus, a common bleed air supply system can usually be divided into some subsystems or parts, such as a pressure regulating valve (PRV), a high-pressure valve (HPV), and a temperature regulating system that may include a supply air valve. Here, the valve subsystem can usually be monitored, for example, by appropriately arranged pressure sensors and valve position sensors, while temperature sensors and possibly valve position sensors for the supply air valve can be provided for the cooling system.

[0025] Therefore, it can be advantageous if the provided monitoring modules are designed to evaluate the state of a part of the bleed air supply system, because the state of the bleed air supply system is not evaluated by an additionally provided monitoring module. Thus, the monitoring function of the first-mentioned monitoring module can be specifically customized only for the part of the bleed air supply system that is not monitored by another monitoring module. Thus, a plurality of monitoring modules customized for specific parts of the bleed air supply system can be provided, which can in principle operate in parallel with each other to ensure the monitoring of the entire bleed air supply system. Here, the parts monitored by the respective monitoring modules can also partially overlap.

[0026] Since the individual monitoring modules do not monitor the overall complexity of the bleed air supply system, but only a part of the bleed air supply system in each case, the complexity of the corresponding monitoring functions is accordingly usually lower. This in turn has a positive effect on the reliability of the monitoring of the bleed air supply system as a whole, and in particular enables the accurate indication of possible faults in a faulty subsystem or even worn or faulty system components. This is because in the case of a fault being detected by a monitoring module that only monitors a part of the bleed air supply system, it is usually assumed that a fault has occurred in the corresponding monitored part of the bleed air supply system, which facilitates subsequent fault repair.

[0027] Providing at least two monitoring modules (usually significantly more), each of which can be individually activated and deactivated based on appropriate criteria related not only to sensor data but also to operating state values, provides a further advantage.

[0028] In the activation and deactivation of the monitoring modules, in addition to sensor data, the operating state values of the aircraft are also taken into account, ensuring that the monitoring modules are only activated when their monitoring functions are designed to be suitable for the actual operating state of the aircraft or the state of the bleed air supply system that can be read from the sensor data. However, the activation and deactivation of each monitoring module can be defined individually, so that for example, multiple monitoring modules are provided to monitor a specific part of the bleed air supply system, and these monitoring modules are activated due to different activation parameters and deactivation parameters in different operating states. It should be noted here that due to the combination of the sensor data of at least one sensor and at least one operating state value, the individual monitoring modules can be activated in a state-related manner, the level of detail of which has exceeded the division of flight phases known in the prior art at the beginning. Of course, the more sensors and / or operating state values are taken into account during activation and / or deactivation, the more applicable this is.

[0029] Obviously, it is possible and usually also desirable to combine the two aforementioned advantages of the multiple monitoring modules provided. Therefore, preferably, at least three monitoring modules are provided, one monitoring module being designed to evaluate the state of a part of the bleed air supply system, another monitoring module not evaluating the state of this part of the bleed air supply system, and two of the monitoring modules being designed to monitor the state of at least partially overlapping parts of the bleed air supply system, but having different activation parameters and deactivation parameters. The number of monitoring modules can be arbitrarily extended, so as to achieve any desired monitoring function for the bleed air supply system or any part thereof in any state of the bleed air supply system and / or the aircraft.

[0030] It is again noted that since the monitoring module according to the invention or its monitoring function may focus on a specific part of the bleed air supply system of an aircraft including the bleed air supply system and / or a specific operating state of the entire system, a monitoring function with an understandable complexity can be achieved. Thus, compared to the single complex monitoring function attempted in the prior art for the entire bleed air supply system and all operating states, this is generally significantly more reliable.

[0031] The deactivation parameter of the monitoring module can in principle correspond to its activation parameter, whereby the monitoring module is activated when a specific state defined by the activation parameter is reached and deactivated again only when leaving this state. Thus, it can be ensured that the monitoring module is actually only operative in the operating modes of the aircraft and the bleed air supply system for which its monitoring function is designed.

[0032] The activation parameter of the monitoring module can include a delay parameter in order to activate the monitoring module only after a predetermined time after the activation parameter is satisfied. In this case, after the activation parameter based on sensor data and at least one operating state value is satisfied, the monitoring module is not activated immediately, but only after the time predetermined by the delay parameter has elapsed. Due to this time delay of activation, transient effects in the case of a change in the operating mode of the aircraft and / or the bleed air supply system that in principle causes the activation of the monitoring module can be excluded from the monitoring by this monitoring module alone to avoid, for example, false fault messages. Since transient effects can be excluded from the monitoring by the monitoring module, the monitoring function of such a monitoring module does not have to take transient effects into account, and thus a low complexity of the monitoring function can generally be achieved.

[0033] The deactivation parameter of the monitoring module may also include a duration parameter to deactivate the monitoring module after a predetermined duration has elapsed after the monitoring module is activated. This deactivation can occur independently of the deactivation based on sensor data and at least one operating state value. By deactivating the monitoring module via the duration parameter, the monitoring module can be used to monitor a predetermined change in the operating mode of the aircraft and / or the bleed air supply system in a time-ordered restricted manner, where the end of transient changes in the sensor data and / or at least one operating state value may not be readable from the sensor data or at least one operating state value itself.

[0034] It is preferred if the monitoring module or its monitoring function is designed to compare the detected sensor data with historical sensor data recorded during a previous activation of the monitoring module. By comparison with the corresponding historical data, changes in the monitored part of the bleed air supply system can be determined, which may indicate a possible fault in the monitored part of the bleed air supply system. Based on the activation parameters and deactivation parameters of the monitoring module, it is ensured that the comparison of the sensor data only takes place on historical sensor data that was recorded in the state of the aircraft and the bleed air supply system for which the monitoring module is designed.

[0035] It is preferred if the monitoring module or its monitoring function is designed to determine the minimum value, maximum value, average value and / or variance value of the sensor data of at least one sensor or other set of values during the activation period between activation and subsequent deactivation. During subsequent monitoring actions, the monitoring module can take into account the corresponding values to identify possible faults. Thus, for example, a change in sensor data that has increased sharply relative to historical values may indicate a (forthcoming) fault in the part of the bleed air supply system monitored by the monitoring module or in the entire bleed air supply system.

[0036] It is preferred if at least one monitoring module is designed to monitor at least a part of the sensor, i.e., to monitor the sensor functionally. Incorrect sensor data can be identified by the corresponding monitoring module, otherwise the incorrect sensor data might be interpreted by other monitoring modules as an indication of a fault in the part of the bleed air supply system monitored by these monitoring modules.

[0037] The monitoring module can be arranged directly on the aircraft. However, it is preferably arranged outside the aircraft, where the sensor data and at least one operating state value are transmitted from the aircraft to the external monitoring module. A continuous transmission of the data discussed for real-time monitoring by the monitoring module can be provided. However, it is also possible to record the mentioned data on the aircraft and transmit it to the monitoring module with a time delay. For example, after each landing, the data recorded during the previous flight can be transmitted to the monitoring module. The data recorded on the aircraft can also be read out in a wired manner during maintenance or copied in the form of a removable storage medium.

[0038] Regardless of whether the monitoring module is arranged on the aircraft or outside the aircraft, the monitoring modules for real-time monitoring are preferably designed to output a warning if the monitoring function of the monitoring module identifies a fault. The corresponding monitoring module can also be designed to deactivate the bleed air supply system in the case of a fault classified as severe by the monitoring function if another redundant bleed air system remains ensuring the bleed air supply.

[0039] Alternatively or additionally, the monitoring module is designed to perform a prediction method and output a warning if necessary. In the prediction method, the change over time of the sensor data of the part of the bleed air supply system monitored by the monitoring module is observed, which in itself may not indicate an immediate fault, but may indicate that a fault is about to occur immediately. If this is established accordingly, a warning can be output. Then, the affected part of the bleed air supply system can be prevented before an actual fault occurs due to the failure of the bleed air supply system. The prediction method is particularly suitable for the evaluation of the time delay of the recorded sensor data.

[0040] At least one operating state value preferably may include an item of information about the operating state of a bleed air consuming device, such as an air temperature control and cabin pressure regulation system. The position of a shut-off valve in a pneumatic system (e.g., in order to divide the pneumatic system into separate zones) can also be described by one or more operating state values. Alternatively or additionally, the operating state value may include an item of information about the state of the landing gear, about the output pressure of the high-pressure compressor of an engine, or about the ambient temperature.

[0041] However, the operating state values incorporated in the activation and deactivation of the monitoring module for monitoring a specific bleed air supply system according to the invention may also include the operating state of another bleed air supply system of the aircraft. Thus, for example, in a monitoring module provided for the bleed air supply system of a main engine, an item of information about the operating state of the bleed air supply system of an auxiliary power unit (APU) or another engine can be considered in the activation parameters and the deactivation parameters.

[0042] The computer program product according to the invention is explained with reference to the above statements. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will now be described by way of example based on advantageous embodiments with reference to the accompanying drawings. In the drawings:

[0044] Figure 1 An aircraft designed to perform the method according to the invention is shown;

[0045] Figure 2 Is shown Figure 1 A detailed illustration of the bleed air supply system of the aircraft; and

[0046] Figure 3 Is shown Figure 1 A schematic diagram of an aircraft designed to perform the method according to the invention. DETAILED DESCRIPTION

[0047] Figure 1 An aircraft 1 is schematically shown, which is designed to monitor a bleed air supply system 10 of the aircraft 1 according to the invention.

[0048] Aircraft 1 has two engines 2, each of which is equipped with a bleed air supply system 10 including different sensors 20 - 22. The bleed air supply system 10 and the sensors 20 - 22 will be explained in more detail below based on Figure 2 and Figure 3 explained in more detail.

[0049] The sensors 20 - 22 are connected to a communication unit 4 via an aircraft internal data bus 3. Using this data bus, the sensor data of the sensors 20 - 22 is sent to a ground station 6. An operating status monitor 5 provides operating status values that are also sent to the ground station 6 and is also connected to the aircraft internal data bus 3 and thus to the communication unit 4.

[0050] At the ground station 6, a plurality of monitoring modules 30 are arranged. The functions of these monitoring modules will be explained in more detail below in connection with Figure 3 explained in more detail. Fault messages or other information items can also be sent via the ground station 6 to an on - board computer that is the operating status monitor 5 of the aircraft 1, and this on - board computer displays these information items to the pilot in the cockpit.

[0051] Figure 2 The bleed air supply system 10 of the engine 2 is shown in more detail structurally, while Figure 3 including a schematic functional diagram of the bleed air supply system 10.

[0052] The bleed air supply system 10 has two extraction points 11, 12 located in the region of the compressor stage of the engine 2. One extraction point 11 is arranged in the region of the output of the high - pressure compressor of the engine 2, while the other extraction point 12 is arranged in a region of the engine 2 with a lower pressure. Additionally, another extraction point 13 is arranged in the region of the engine fan 2'. Ambient air can flow into the engine 2 via this extraction point, and this ambient air is not or hardly compressed. In Figure 2 for clarity, the extraction point 13 is not shown, but only the supply line 13' that is only assembled to this extraction point 13 is shown.

[0053] The extraction point 11 in the output region of the high - pressure compressor of the engine 2 is assigned a first control valve 14 (high - pressure valve), and the output of this first control valve is connected to the extraction point 12. The output point 12 and the output of the first control valve 14 are connected to another control valve 15 (pressure regulating valve). From there, the bleed air reaches a consumption device or enters a compressed air supply network (not shown) through a heat exchanger 16.

[0054] The heat exchanger 16 can be supplied with cooler ambient air via the supply line 13' to cool the bleed air heated due to compression. A control valve 17 is provided in the supply line 13' for regulating the cooling air flow and thus the cooling.

[0055] The control valves 14, 15, 17 can be self-regulating valves or valves actively controlled by a control unit (not shown).

[0056] The bleed air supply system 10 is equipped with an array of sensors 20 - 22, where measured values of the state of the bleed air supply system 10 can be read. Thus, looking in the flow direction of the bleed air, the pressure sensors 20, 21 are arranged immediately upstream and immediately downstream of the pressure regulating valve 15, while the temperature sensor 22 is provided downstream of the heat exchanger 16.

[0057] The sensor data detected by the sensors 20 - 22 is sent via the data bus 3 to the communication unit 4, and from there it is wirelessly sent together with the operating state values from the operating state monitor 5 to the ground station 6.

[0058] In the ground station 6, a plurality of monitoring modules 30 independent of each other are arranged, and the received sensor data and operating state values are supplied to each monitoring module. In Figure 3 it, four monitoring modules 30 are shown by way of example, but any number of monitoring modules 30 is possible.

[0059] Each monitoring module 30 has activation parameters and deactivation parameters, and the received sensor data and operating state values satisfy the activation parameters and deactivation parameters to correspondingly cause the activation or deactivation of the affected monitoring module 30. In addition, each monitoring module 30 includes a monitoring function, by means of which the received sensor data can be monitored for possible faults or failures of the bleed air supply system 10. If a fault occurs, the monitoring module 30 can assign a corresponding fault message.

[0060] A part of the monitoring module 30 can also be designed to perform a prediction method, in which the change of the sensor data over time is used to evaluate the impending fault. If it is recognized that a fault is impending, a corresponding communication occurs so that the bleed air supply system 10 can be repaired as much as possible before the fault actually occurs.

[0061] The bleed air supply system 10 is logically divided into a plurality of partially overlapping parts 31 - 33, where the monitoring module 30 is largely only designed to monitor a corresponding part of the bleed air supply system 10 in each case. However, of course, a plurality of monitoring modules 30 can be provided for different parts of the bleed air supply system 10, and these monitoring modules are all effective due to different activation parameters and deactivation parameters in different operating states of the bleed air supply system 10 and / or the aircraft 1. Of course, it is also possible for the overlap to be monitored by two different monitoring modules 30.

[0062] The final monitoring by separate monitoring modules independent of each other is explained below based on an example of a possible monitoring module:

[0063] During flight, the pressure regulation carried out by the pressure regulating valve 15 meets different requirements, each of which requires different monitoring actions.

[0064] During the acceleration phase when the aircraft 1 takes off, usually all compressed air consuming devices are closed, so that in this phase, in principle, no bleed air is taken from the engine 2 through the bleed air supply system 10, thus providing maximum power for thrust generation. Thereby, the dominant pressure in the compressed air supply network when the compressed air consuming devices and the bleed air supply system 10 are deactivated should remain constant in this operating state and should generally correspond to the setpoint pressure of the compressed air supply network.

[0065] The monitoring function of the monitoring module 30 for this specific operating state of the aircraft 1 alone can be supported by the sensor data of the pressure sensor 21 downstream of the pressure regulating valve 20, which in principle depicts the dominant pressure in the compressed air supply network. An increase in the measured pressure observed in this operating state indicates a malfunction of the pressure regulating valve 20. As an alternative way to determine the pressure curve during the operating state under discussion, the average and maximum pressure values of this operating state can also be determined and compared with historical values, which were determined in the same operating state in the past or predefined as a fixed value. Excessive deviation indicates a malfunction and generates a corresponding fault message. The increase in the observed average pressure value over time can be used for the prediction of possible malfunctions.

[0066] Different sensor data and operating state values are used to determine the operating state under discussion and thus activate the associated monitoring module. For the activation of the monitoring module, the pressure detected via the pressure sensor 21 must therefore be within an allowable range near the setpoint pressure of the compressed air supply network, and the corresponding sensor data is used for this purpose. The information items that all compressed air consuming devices are deactivated, the bleed air supply system 10 is activated and the high-pressure compressor output pressure of the engine 2 is greater than a predetermined threshold are used as operating parameters. The co-occurrence of the mentioned individual technical operating parameters indicates the takeoff acceleration phase under discussion or the corresponding operating state of the aircraft 1.

[0067] If one of the above activation parameters is no longer met, the monitoring module 30 under discussion is deactivated. The deactivation parameters thus correspond to the activation parameters.

[0068] As a result of the above statements, the described monitoring module 30 is thus designed to monitor only the part of the bleed air supply system 10 that is provided for pressure regulation only during the takeoff acceleration phase of the aircraft. The monitoring function of the monitoring module 30 is quite simple and thus very robust and reliable. Only the fault message of this monitoring module 30 indicates a problem with the pressure regulating valve 15.

[0069] When the operating status value indicates that the landing gear of the aircraft 1 is no longer compressed (and thus no longer has ground contact), at least a part of the compressed air consumption device is activated, and the output pressure of the high-pressure compressor of the engine 2 is greater than a predetermined threshold, another monitoring module 30 that monitors the part of the bleed air supply system 10 responsible for pressure regulation is also designed to be activated. The data of the sensor 21 is considered to be the sensor data that must be greater than a predetermined threshold, and by this predetermined threshold, it is indicated that the bleed air supply system 10 is operative or substantially connected to the compressed air supply network.

[0070] The activation parameter also includes a delay parameter of 60 seconds. Since the activation parameter includes the activation status of the compressed air consumption device, after the technical activation parameter is satisfied, due to the usually sudden activation of the consumption device, in principle, transient pressure changes occur in the compressed air supply network, which are not considered by the monitoring module 30. Because the delay parameter is provided, the monitoring module 30 actually takes over the monitoring only after the transient pressure changes in question have subsided.

[0071] If one of the above activation parameters is no longer satisfied, the monitoring module 30 in question is deactivated. Therefore, the deactivation parameter initially corresponds to the activation parameter. Additionally, as another deactivation parameter, a duration parameter is also provided, according to which the monitoring module 30 is deactivated 600 seconds after it is activated, even if all the activation parameters are still satisfied at this time point.

[0072] The monitoring function of the monitoring module 30 can be based on the change of sensor data. An overly sudden pressure change and / or a significant change in pressure indicate a malfunction in the pressure regulation of the bleed air supply system 10. This change can also be evaluated during the process of a prediction method, where an increase in the change indicates, for example, that the pressure regulating valve 15 is about to malfunction.

[0073] Another monitoring module 30 is designed to monitor the part of the bleed air supply system 10 that regulates the high-pressure bleed air supply, and thus especially the high-pressure valve 31. The monitoring module 30 is specifically operative during the takeoff acceleration phase or the corresponding operating status of the aircraft 1. For this purpose, the activation parameters and deactivation parameters of this monitoring module 30 correspond to the parameters of the monitoring module 30 for monitoring only the pressure regulating valve 15 during this takeoff acceleration phase: the pressure detected via the pressure sensor 20 must be within an allowable range near the setpoint pressure of the compressed air supply network, all compressed air consumption devices must be deactivated, the bleed air supply system 10 must be activated, and the output pressure of the high-pressure compressor of the engine 2 must be greater than a predetermined threshold. The deactivation is carried out using the corresponding deactivation parameter, and thus when one of the activation parameters is no longer satisfied.

[0074] If it is determined by the monitoring function that the pressure recorded by the pressure sensor 20 is greater than a threshold value or deviates upwards from the historical average value of this pressure sensor 20 in the operation phase under discussion by more than a predetermined difference, a fault is reported. In this case, the high-pressure valve 14 is faulty. Within the scope of the prediction method, the curve of the average value of the take-off acceleration in regularly repeated operating states can be determined, which can indicate an impending defect of the high-pressure valve 14.

[0075] Another monitoring module 30 is designed to monitor those parts of the bleed air supply system 10 that regulate the high-pressure bleed air supply and the pressure finally supplied to the pressure supply network. The monitoring module 30 is activated when the operating state value indicates that the landing gear of the aircraft 1 is compressed (and thus in contact with the ground), the compressed air consumption device is deactivated, and the high-pressure compressor output pressure of the engine 2 is within a predetermined range. The data of the sensor 21 is considered as sensor data, and this sensor data must be greater than a predetermined threshold value, indicating that the bleed air supply system 10 is operational or substantially connected to the compressed air supply network.

[0076] In addition, the monitoring module 30 has a delay parameter of 10 seconds as an activation parameter and a duration parameter of 600 seconds as part of the deactivation parameter. These time-related parameters are explained with reference to the above statements.

[0077] The monitoring function of the monitoring module 30 is based on the sensor data of the pressure sensors 20, 21, and checks their changes and substantially synchronized values. Excessive changes or excessive deviations in the pressure value curve indicate problems with at least one of the two control valves 14, 15 or their activation.

[0078] Another monitoring module 30 is used to monitor the sensors 20 - 22. The monitoring module 30 is activated when the operating state value indicates an altitude greater than 6000 m, the high-pressure compressor output pressure of the engine 2 is within a predetermined range, at least some of the compressed air consumption devices are activated, and the difference between the measured values from the two sensors 20 or 21 is constant. The monitoring module 30 is deactivated when one of the above activation parameters is no longer met or the activation state of the compressed air consumption device or the difference between the measured values of the two sensors 20 or 21 changes.

[0079] The activation parameters basically indicate a constant system state, such that in this phase, for possible drifts, it can be checked whether the sensors 20 - 22 that are not used for activation are constant. As long as the basic operating state of the compressed air system does not change (which is ensured by the deactivation parameter), the difference in the sensor data of the sensors 20 - 22 under discussion should also not change. If a change in the measured value is determined in the sensor data, this indicates a problem with the affected sensors 20 - 22.

[0080] Any additional monitoring module 30 with a separate monitoring function and activation and deactivation parameters can be provided. However, as has been shown by the above examples of several possible monitoring modules 30, different monitoring modules 30 can be designed to monitor the status of different (but possibly partially overlapping) parts of the bleed air supply system 10. Monitoring modules 30 designed to monitor the same part of the bleed air supply system 10 can have distinct activation and deactivation parameters such that they are substantially operative in different operating states of the aircraft 1.

[0081] Here, overlap is also possible without problems since a part of the bleed air supply system 10 is monitored simultaneously by multiple monitoring modules 30.

[0082] The results of the monitoring module 30 can be directly incorporated into the operation of the monitored bleed air supply system 10 such that, for example, a warning is output to the pilot and / or the bleed air supply system 10, the bleed air supply system is immediately deactivated if the bleed air supply is ensured in another way, or it is used for the maintenance of the bleed air supply system 10 to enable the performance of the target service.

Claims

1. A method for monitoring a bleed air supply system (10) of an aircraft (1), the bleed air supply system having: - at least one sensor (20 - 22) for condition monitoring of the bleed air supply system (10) based on sensor data; - at least one operating condition monitor (5) for detecting an operating condition of the aircraft (1) other than the bleed air supply system (10) via at least one operating condition value; and - at least two independent monitoring modules (30) for evaluating the condition of at least a part of the bleed air supply system (10), wherein for each of the monitoring modules (30), a separate monitoring function, as well as separate activation parameters and deactivation parameters, are provided based on sensor data of at least one sensor and at least one operating condition value, The method comprises the following steps: - detecting the condition of the bleed air supply system (10) via the sensor data and detecting the operating condition of the aircraft (1) via the at least one operating condition value; - activating a monitoring module (30) when the sensor data and the at least one operating condition value satisfy the activation parameters of the monitoring module; - monitoring the condition of the bleed air supply system (10) by means of the monitoring function of the activated monitoring module (30); and - deactivating the activated monitoring module (30) when the sensor data and at least one operating condition value satisfy the deactivation parameters of the monitoring module, wherein the monitoring module (30) is configured to perform a prediction method in which the change of sensor data over time is used to evaluate an impending failure.

2. The method according to claim 1, characterized in that, One of the plurality of monitoring modules (30) is designed to evaluate the condition of a part of the bleed air supply system (10), the condition of which part is not evaluated by another monitoring module (30).

3. The method according to claim 2, wherein At least three of the monitoring modules (30) are provided, and the other two of these monitoring modules (30) are designed to perform condition monitoring of at least partially overlapping parts of the bleed air supply system (10) but have distinct activation parameters and deactivation parameters.

4. The method according to any one of claims 1 to 3, characterized in that, The deactivation parameters of a monitoring module (30) correspond to the activation parameters of that monitoring module.

5. The method according to any one of claims 1 to 3, characterized in that The activation parameters of a monitoring module (30) include a delay parameter to activate the monitoring module (30) only after a predetermined time after the activation parameters are satisfied.

6. The method according to any one of claims 1 to 3, characterized in that, The deactivation parameters of a monitoring module (30) include a duration parameter to deactivate the monitoring module after a predetermined duration after the monitoring module (30) is activated.

7. The method according to any one of claims 1 to 3, characterized in that, One monitoring module (30) is designed to compare the detected sensor data with historical sensor data recorded during the previous activation of that monitoring module (30).

8. The method according to any one of claims 1 to 3, characterized in that One monitoring module (30) is designed to determine the minimum value, maximum value, average value, and / or variance value of the sensor data of at least one sensor (20 - 22) during the activation period between activation and subsequent deactivation.

9. The method according to any one of claims 1 to 3, characterized in that One monitoring module (30) is designed to monitor at least a part of the sensors (20 - 22).

10. The method according to any one of claims 1 to 3, characterized in that, The monitoring module (30) is designed to perform an output warning.

11. The method according to any one of claims 1 to 3, characterized in that, The at least one operating state value includes information items regarding the operating state of the bleed air consumption device, the state of the landing gear, the output pressure of the high-pressure compressor of the engine, and / or the ambient temperature.

12. A computer program product, comprising program portions designed to perform the method according to any one of claims 1 to 11 when loaded into a computer or into computers networked with each other.

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