Procedure and system

Abstract

The present invention relates to a method for monitoring the fill level of a medium in a device of an aircraft comprising the steps: - Determining the fill level of the medium in the device, in particular in a memory of the device; - Determining the fill level from the determined fill level using a correction model.

Description

[0001] The present invention relates to a method for monitoring the fill level of a medium in a device of an aircraft.

[0002] It is known that a hydraulic component, such as an actuator or damper, of an aircraft has its own closed circuit for the hydraulic fluid and can thus be operated.

[0003] Due to temperature fluctuations, extension and retraction movements, and leaks, a storage device or reservoir is required in the hydraulic component's circuit to ensure safe and continuous operation of the hydraulic component.

[0004] The accumulator usually has an optical display and / or sensors, such as a differential transformer (LVDT), which can display and / or measure the current level of hydraulic fluid in the accumulator.

[0005] Fluctuations in the fluid level within the reservoir due to temperature and the position of the hydraulic component make reliable monitoring of the fill level—that is, the actual amount of hydraulic fluid in the reservoir or circuit—difficult, if not impossible, and certainly preclude reliable trend and / or predictive monitoring. Only after a stabilization phase, particularly with regard to temperature and the position of the hydraulic component, which typically lasts about three hours, can comparable fill levels be determined that reliably allow conclusions to be drawn about the fill level of the hydraulic fluid in the circuit. For example, a reliable determination of the fill level of the hydraulic fluid in the circuit for a hydraulic component of an aircraft can therefore only be achieved after a steady-state flight duration, i.e., a cruise of the aircraft, of approximately three hours.

[0006] A stabilization phase lasting approximately three hours makes it difficult or impossible to reliably determine the fill level of the hydraulic fluid in the circuit for shorter periods.

[0007] The large temperature fluctuations of hydraulic components in aircraft, which range from approximately -54°C to approximately +50°C during aircraft operation, are a major cause of this long stabilization phase. During a short flight, for example, of less than an hour, or during a short turnaround time of less than an hour, this stabilization phase is not yet complete. Therefore, the fluid level measured during such a short flight or turnaround cannot be used to reliably determine the fill level of the hydraulic fluid in the circuit.

[0008] In the diagram in Fig. 5. The altitude H is plotted on the ordinate and the flight time FZ on the abscissa.

[0009] The line in the diagram shows the altitude H of an aircraft. The point shown on the left side of the line in the diagram marks the time after three hours of steady-state cruising flight at altitude H, at which the fill level of the hydraulic fluid in the circuit can be reliably determined from the level of hydraulic fluid in the reservoir.

[0010] The point shown on the line to the right in the diagram marks the time after three hours on the ground at which a reliable determination of the fill level of the hydraulic fluid in the circuit can be made from the fill level of the hydraulic fluid in the accumulator.

[0011] Against this background, the present invention aims to provide a method for monitoring the fill level of a medium in a device of an aircraft that is improved compared to the prior art.

[0012] This problem is solved by the method with the features of independent claim 1. Advantageous embodiments of the invention are the subject of the dependent claims.

[0013] According to the invention, the method comprises the following steps: - Determining the fill level of the medium in the device, in particular in a memory of the device; - Determining the fill level from the determined fill level using a correction model.

[0014] The fill level can refer to the amount of medium in the device, a filling of the medium in the device and / or a filling relative to a desired filling.

[0015] The method is preferably a computer-implemented method.

[0016] The fill level is preferably determined by measurement and the fill degree is preferably determined by calculation.

[0017] Preferably, it is provided that the determination of the fill level is carried out several times during a period of an operating cycle, in particular a flight, of the device and / or the aircraft and / or that an average fill level for the operating cycle or a part of the operating cycle is determined from several or all determined fill levels, in particular by forming the arithmetic mean.

[0018] Preferably, it is provided that, in particular during an operating cycle, especially a flight, of the device and / or the aircraft, several averaged fill levels determined in previous operating cycles are compared with each other and / or a trend line is determined from several averaged fill levels determined in previous operating cycles.

[0019] Preferably, a warning is generated if a deviation of two or more averaged fill levels is detected that is greater than or equal to a limit value, and / or if it is detected that one or more of the averaged fill levels are less than or equal to a limit value, and / or if it is detected that the trend line is less than or equal to a limit value.

[0020] Preferably, the warning is transmitted to a unit separate from the aircraft, in particular before an alarm triggered by the warning is issued on the aircraft and / or an alarm triggered by the warning is issued on the aircraft.

[0021] Preferably, a prediction is made, in particular using artificial intelligence and / or a mathematical method, about a time and / or period of time at or during which there will be a deviation of two or more averaged fill levels that is greater than or equal to a limit value, and / or at or during which one or more of the averaged fill levels will be less than or equal to a limit value, and / or at or during which the trend line will be less than or equal to a limit value.

[0022] Preferably, the correction model establishes a relationship between the determined fill level and the fill degree to be determined from the determined fill level, taking into account the operating conditions of the device and / or the aircraft.

[0023] Preferably, the operating conditions include an ambient temperature of the device and / or the aircraft, an altitude of the device and / or the aircraft, a status of the device and / or the aircraft and / or a position of the device, in particular relative to the aircraft, wherein the operating conditions are in each case determined in particular by the aircraft and / or may originate from a source separate from the aircraft.

[0024] The operating conditions can either be data determined by the aircraft itself or can come from third-party sources such as weather data.

[0025] Preferably, the procedure is carried out entirely by means of the aircraft, or the determination of the fill level is carried out on a unit separate from the aircraft, e.g. a server.

[0026] Preferably, the medium is an operating fluid, in particular hydraulic fluid, and the device is a hydraulic component, in particular an actuator or damper.

[0027] Preferably, the procedure is carried out for several devices of an aircraft and / or for several devices distributed across several aircraft forming an aircraft fleet.

[0028] Preferably, it is provided that, in particular during an operating cycle, especially a flight, of the device and / or the aircraft, several determined fill levels from several similar and / or different devices of an aircraft and / or several averaged fill levels from several similar and / or different devices determined in previous operating cycles are compared with each other and / or a trend line is determined from several averaged fill levels from several similar and / or different devices determined in previous operating cycles.

[0029] Preferably, it is provided that if a deviation of two or more averaged fill levels is detected that is greater than or equal to a limit value for one of the devices, and / or if it is determined that one or more of the averaged fill levels for one of the devices is less than or equal to a limit value, and / or if it is determined that the trend line for one of the devices is less than or equal to a limit value, a display, in particular in a cockpit of the aircraft, and / or a message is issued that makes this device identifiable, e.g. by displaying the position of the device in the aircraft.

[0030] The deviation can be observed between average fill levels for a single device or between average fill levels of multiple devices. For example, it may be determined that one device has a lower fill level than another.

[0031] Identical devices include, for example, two dampers, especially those of the same design. Dissimilar devices include, for example, an actuator and a damper, or two dampers or actuators of different designs.

[0032] The invention also relates to a system with means for carrying out a method according to the invention.

[0033] Preferably, the means are components of an aircraft, in particular an airplane, and / or distributed across an aircraft fleet, in particular an airplane fleet.

[0034] Within the scope of this invention, monitoring can also be referred to as surveillance.

[0035] Preferably, the level and / or fill level of a medium in a hydraulic actuator or damper is monitored.

[0036] The storage device can also be called a reservoir. The medium can be hydraulic oil.

[0037] Preferably, the fill level of a medium is monitored in a hydraulic actuator or damper with its own reservoir for the medium. The device can be a moving damper.

[0038] Preferably, health monitoring of the fill level and / or fill degree of a medium is carried out in a memory of a device for an aircraft and / or in multiple memories of devices distributed across aircraft of an aircraft fleet during ongoing flight operations, with aircraft data being transmitted to the ground regardless of the flight duration.

[0039] Preferably, monitoring is carried out in aircraft for devices that are temporarily and / or permanently self-sufficient and have a storage tank with level measurement for operating fluids such as oil or other liquids.

[0040] Preferably, additional operational data or conditions of the device, the aircraft, and / or the environment are used for monitoring, such as temperature, altitude, device position, and / or device and / or aircraft status. This operational data or these conditions can be either data collected by the aircraft itself or obtained from third-party sources, such as weather data.

[0041] Preferably, a trend monitor, in particular a stabilized one, of the fill level and / or fill degree of a medium in a device is provided over a period of time and / or over one or more flights.

[0042] Preferably, a trend monitor, particularly a stabilized one, is provided, which operates or is based on comparisons to other and / or identical devices on the same aircraft.

[0043] Preferably, the trend monitor has a mean value for temperature compensation that has been adjusted by a correction factor or a correction model, and which has been determined on the test bench and is supported by characteristic curves.

[0044] Preferably, a monitor that does not require time-based temperature stabilization for the device is provided.

[0045] Preferably, data is sent from the aircraft to one or more on-ground servers, where it is stored and processed.

[0046] Preferably, a monitor is provided that evaluates fill levels and / or fill grades for an aircraft fleet, e.g., an airline or a worldwide aircraft fleet.

[0047] Preferably, a prediction of when a limit value will be reached or exceeded is made in terms of time, such as days or based on flight cycles. The prediction can be linear, dynamic, and / or machine learning.

[0048] Preferably, a warning is sent via a server to an airline or the device manufacturer when a limit value is exceeded and / or fallen below, before an alarm is sounded on the aircraft.

[0049] Preferably, the position of the defective device in the aircraft is displayed, especially if several devices are installed in the aircraft.

[0050] It should be noted here that the terms "a" and "an" do not necessarily refer to exactly one of the elements, although this is a possible interpretation, but can also denote a plurality of elements. Likewise, the use of the plural also includes the presence of the element in question in the singular, and conversely, the singular also includes several of the elements in question. Furthermore, all features of the invention described herein can be combined with one another or claimed separately from one another as desired.

[0051] Further advantages, features, and effects of the present invention will become apparent from the following description of preferred embodiments with reference to the figures, in which identical or similar components are designated by the same reference numerals. These figures show: Fig. 1: a diagram showing the times at which the fill level can be determined according to an embodiment of a method according to the invention. Fig. 2: a diagram showing the fill level in an embodiment of a device and an ambient temperature as well as a temperature of the device over a period of time. Fig. 3: three diagrams, each showing the height of an embodiment of a device and the fill level and fill degree of a medium in the device over a flight time. Fig. 4: a diagram showing several averaged fill levels of a medium of an embodiment of a device and a trend line of these averaged fill levels over time. Fig. 5: a diagram showing times at which the fill level can be determined according to a method known from the prior art.

[0052] In this embodiment, an aircraft has a device in the form of a hydraulic actuator or damper, which includes a hydraulic fluid reservoir arranged in its hydraulic circuit. The actuator or damper is part of a landing flap system.

[0053] In the diagram in Fig. 1. The altitude H of the aircraft is plotted on the ordinate and the flight time FZ on the abscissa.

[0054] The line in the diagram indicates the altitude H of the aircraft or device. The points shown on the line in the diagram mark the times at which the fill level of the hydraulic fluid in the hydraulic circuit can be reliably determined from the fill level of the hydraulic fluid in the accumulator using a method according to the invention.

[0055] The hydraulic fluid level in the reservoir is measured periodically throughout the entire flight at a sampling rate of, for example, 1 Hz. This results in a time series of fluid levels, spaced one second apart.

[0056] Additional operating conditions, such as the aircraft's outside temperature, altitude, and position (i.e., the extension and retraction position of the actuator or damper), are also recorded at the same sampling rate.

[0057] For example, temperature curves or the "thermal inertia" of the actuator or damper are available from laboratory tests and are used as input for the correction model.

[0058] In Fig. 2. On the abscissa, the time in seconds is plotted, on the left ordinate, the ambient temperature T_U in °C, on the middle ordinate, the level FS of the hydraulic fluid in the accumulator in mm, and on the right ordinate, the temperature of the actuator or damper T_D in °C.

[0059] During a flight, the temperatures T_U and T_D as well as the fill level FS decrease.

[0060] The left vertical line in the diagram marks the time after a stationary flight duration, i.e., a cruise of the aircraft, of one hour, and the right vertical line in the diagram marks the time after a stationary flight duration, i.e., a cruise of the aircraft, of three hours.

[0061] As the diagram shows, the fill level FS reached an almost steady value of approximately 26 mm after about three hours in this example. Therefore, according to the state of the art, the correct fill level can be reliably determined.

[0062] For each determined fill level in the time series, a fill level is calculated using the correction model, which includes the recorded operating conditions, in particular the insertion and retraction position of the actuator or damper, and the temperature curves.

[0063] The fill level can therefore be determined using the time grid of the sampling rate.

[0064] In other words, the fill level is corrected using the correction model. A corrected fill level is thus determined.

[0065] The fill level is corrected in relation to the insertion and retraction position of the actuator or damper.

[0066] The fill level is corrected in relation to the thermal expansion of the hydraulic fluid.

[0067] The fill level is determined by correcting the fill level using a correction model. The correction model can include or consist of a single correction factor, i.e., be in the form of a characteristic curve, and / or it can be a multifactorial model, i.e., be in the form of a characteristic map.

[0068] After one hour of cruising, the fill level FS is approximately 31 mm, the ambient temperature T_U is approximately -40 °C, and the temperature of the actuator or damper T_D is approximately -30 °C. According to the correction model, under these operating conditions, the fill level is the same as that which, according to the state of the art, results from a fill level of approximately 26 mm under steady-state conditions. The corrected fill level is therefore 26 mm.

[0069] Therefore, when determining the fill level, the fill level can be determined directly from the current fill level, or first a corrected fill level can be determined from which the fill level is then calculated.

[0070] In Fig. In the diagrams, the flight time FZ is plotted on the abscissa and the altitude H on the ordinate of the upper diagram, the fill level FS on the ordinate of the middle diagram and the degree of filling FG, i.e. the corrected fill level, on the ordinate of the lower diagram.

[0071] During flight, the aircraft gains altitude, while the temperature drops from approximately +20°C to approximately -50°C, as shown in the diagram above. Fig. 3 emerges.

[0072] The fill level, i.e., the currently measured fill level in the storage tank, fluctuates, as can be seen from the middle diagram. Fig. 3. During climb and descent, the landing flaps are moved between their positions 1 and 3, which significantly changes the position of the actuator or damper, causing the fill level to fluctuate considerably, as shown by the two large fluctuations in the middle diagram. Fig. 3 emerges.

[0073] The fill level or the corrected fill level is ideally a horizontal line, as shown in the diagram below. Fig. 3 emerges because the amount of hydraulic fluid in the hydraulic circuit ideally remains constant.

[0074] Slight variations in the fill level are inevitable. Therefore, the average fill level is calculated by averaging the fill levels determined during a flight.

[0075] In Fig. In figure 4, the abscissa represents time Z and the ordinate represents the average fill level FG_G.

[0076] The individual points in the diagram represent average fill levels for flights F1, F2, etc.

[0077] A trend line T can be drawn using these averaged fill levels.

[0078] The average fill level determined during each flight is compared with the average fill level determined during the previous flight, and a deviation A is calculated. If this deviation A is greater than or equal to a limit value, a leak can be inferred and / or a warning can be issued.

[0079] If the average occupancy level decreases permanently over several flights, as can occur, for example, when the trend line falls below a level indicated by the dashed line in Fig. If the limit value GW shown in section 4 can be determined, this can indicate a leak in the actuator or damper and / or a warning for a low fill level.

[0080] Fig.Figure 5 illustrates a prior art method and is described above.

Claims

[1] Method for monitoring the fill level of a medium in a device of an aircraft, characterized by the steps: - Determining the fill level of the medium in the device, in particular in a memory of the device; - Determining the fill level from the determined fill level using a correction model. [2] Method according to claim 1, characterized by , that the determination of the fill level is carried out multiple times during a period of an operating cycle, in particular a flight, of the device and / or the aircraft and / or that an average fill level for the operating cycle or a part of the operating cycle is determined from several or all determined fill levels, in particular by forming the arithmetic mean. [3] Method according to claim 1 or 2, characterized by, that, in particular during an operating cycle, especially a flight, of the device and / or the aircraft, several averaged fill levels determined in previous operating cycles are compared with each other and / or a trend line is determined from several averaged fill levels determined in previous operating cycles. [4] Method according to claim 3, characterized by , that if a deviation of two or more averaged fill levels is detected that is greater than or equal to a limit value and / or if it is detected that one or more of the averaged fill levels are less than or equal to a limit value and / or if it is detected that the trend line is less than or equal to a limit value, a warning will be generated. [5] Method according to claim 4, characterized bythat the warning is transmitted to a unit separate from the aircraft, in particular before an alarm triggered by the warning is issued on the aircraft and / or an alarm triggered by the warning is issued on the aircraft. [6] Method according to any one of the preceding claims, characterized by , that a prediction, in particular using artificial intelligence and / or a mathematical method, is made about a point in time and / or period of time at or in which there will be a deviation of two or more averaged fill levels that is greater than or equal to a threshold, and / or at or in which one or more of the averaged fill levels will be less than or equal to a threshold, and / or at or in which the trend line will be less than or equal to a threshold. [7] Method according to any one of the preceding claims, characterized bythat the correction model establishes a relationship between the determined fill level and the fill level to be determined from the determined fill level, taking into account the operating conditions of the device and / or the aircraft. [8] Method according to claim 7, characterized by , that the operating conditions include an ambient temperature of the device and / or the aircraft, an altitude of the device and / or the aircraft, a status of the device and / or the aircraft and / or a position of the device, in particular relative to the aircraft, wherein the operating conditions in each case were determined in particular by the aircraft and / or may originate from a source separate from the aircraft. [9] Method according to any one of the preceding claims, characterized bythat the procedure is carried out entirely by means of the aircraft or that the determination of the fill level is carried out on a unit separate from the aircraft, e.g. a server. [10] Method according to any one of the preceding claims, characterized by that the medium is an operating fluid, in particular hydraulic fluid, and the device is a hydraulic component, in particular an actuator or damper. [11] Method according to any one of the preceding claims, characterized by , that the procedure is carried out for multiple devices of an aircraft and / or for multiple devices distributed across multiple aircraft that form an aircraft fleet. [12] Method according to claim 11, characterized by, that in particular during an operating cycle, especially a flight, of the device and / or the aircraft, several determined fill levels from several similar and / or different devices of an aircraft and / or several averaged fill levels determined in previous operating cycles from several similar and / or different devices are compared with each other and / or a trend line is determined from several averaged fill levels determined in previous operating cycles from several similar and / or different devices. [13] Method according to claim 11 or 12, characterized by, that if a deviation of two or more averaged fill levels is detected which is greater than or equal to a limit value for one of the devices and / or if it is determined that one or more of the averaged fill levels for one of the devices is less than or equal to a limit value and / or if it is determined that the trend line for one of the devices is less than or equal to a limit value, an indication, in particular in a cockpit of the aircraft, and / or a message is issued which makes this device identifiable, e.g. by indicating the position of the device in the aircraft. [14] System comprising means for carrying out a method according to any of the preceding claims. [15] System according to claim 14, characterized by that the funds are components of an aircraft, in particular an airplane, and / or distributed across an aircraft fleet, in particular an airplane fleet.

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