WO2008060996A2 - Hard landing detection - Google Patents
Hard landing detection Download PDFInfo
- Publication number
- WO2008060996A2 WO2008060996A2 PCT/US2007/084236 US2007084236W WO2008060996A2 WO 2008060996 A2 WO2008060996 A2 WO 2008060996A2 US 2007084236 W US2007084236 W US 2007084236W WO 2008060996 A2 WO2008060996 A2 WO 2008060996A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- aircraft
- heuristic algorithm
- recited
- loads
- estimate
- Prior art date
Links
- 238000001514 detection method Methods 0.000 title description 7
- 238000000034 method Methods 0.000 claims abstract description 37
- 238000007689 inspection Methods 0.000 claims abstract description 34
- 238000012360 testing method Methods 0.000 claims abstract description 11
- 238000012423 maintenance Methods 0.000 claims description 24
- 230000001133 acceleration Effects 0.000 claims description 17
- 238000013528 artificial neural network Methods 0.000 claims description 6
- 238000004088 simulation Methods 0.000 claims description 5
- 238000012549 training Methods 0.000 claims description 4
- 238000012545 processing Methods 0.000 claims 1
- 238000005259 measurement Methods 0.000 abstract description 3
- 230000005484 gravity Effects 0.000 description 8
- 230000001939 inductive effect Effects 0.000 description 4
- 238000013459 approach Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 230000008439 repair process Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000010200 validation analysis Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
- G05B13/02—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
- G05B13/0265—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric the criterion being a learning criterion
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B23/00—Testing or monitoring of control systems or parts thereof
- G05B23/02—Electric testing or monitoring
- G05B23/0205—Electric testing or monitoring by means of a monitoring system capable of detecting and responding to faults
- G05B23/0218—Electric testing or monitoring by means of a monitoring system capable of detecting and responding to faults characterised by the fault detection method dealing with either existing or incipient faults
- G05B23/0224—Process history based detection method, e.g. whereby history implies the availability of large amounts of data
- G05B23/024—Quantitative history assessment, e.g. mathematical relationships between available data; Functions therefor; Principal component analysis [PCA]; Partial least square [PLS]; Statistical classifiers, e.g. Bayesian networks, linear regression or correlation analysis; Neural networks
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- B64D45/00—Aircraft indicators or protectors not otherwise provided for
- B64D2045/008—Devices for detecting or indicating hard landing
Definitions
- the present invention relates generally to aircraft maintenance and, more particularly, to a method and system for detecting hard or heavy aircraft landings .
- Hard or heavy landings are significant high load events that may adversely impact airframe structural integrity. Such landings may result in damage that affects the ability of the aircraft to fly safely. When this happens, repairs must be performed prior to flying the aircraft again. An inspection must be performed when there is a hard landing, so as to determine if such repairs are needed.
- a heuristic algorithm may be used to estimate the severity of at least one load, generally a plurality of loads, experienced by an aircraft during landing.
- the heuristic algorithm may use at least one flight parameter to facilitate estimation of the loads (s).
- the heuristic algorithm may use a plurality of flight parameters, such as pitch angle, roll angle, roll rate, center of gravity (CG) vertical speed, vertical acceleration, airspeed, pilot seat acceleration, and air/ground indication to facilitate the estimation of the loads.
- flight parameters such as pitch angle, roll angle, roll rate, center of gravity (CG) vertical speed, vertical acceleration, airspeed, pilot seat acceleration, and air/ground indication to facilitate the estimation of the loads.
- CG center of gravity
- information from at least one sensor may be used to facilitate estimation of the load(s) .
- information from strain gauges and/or accelerometers may be used by the heuristic algorithm to facilitate the estimation of the load(s) .
- the heuristic algorithm may be trained using results from an analytical ground loads simulation.
- the heuristic algorithm may be validated using flight test data.
- the heuristic algorithm may update itself using strains that are measured during operation of the aircraft.
- the heuristic algorithm may be based upon neural networks, such as probabilistic neural networks trained with Bayesian regularization techniques. Sampled flight parameters and sensor data prior to and during the landing event may be processed by the heuristic algorithm to estimate the loads induced on the aircraft.
- Fig. 1 shows a high level overview of a hard landing detection system of the present invention in accordance with an exemplary embodiment of the present invention
- Fig. 2 shows a flow chart illustrating a method for detecting hard landings in accordance with an exemplary embodiment of the present invention
- Fig. 3 shows a block diagram of a system for detecting hard landings in accordance with an exemplary embodiment of the present invention.
- an example of an embodiment of the present invention comprises methods and systems for detecting hard or heavy landings by using primarily kinematic information (i.e., displacement, velocity, accelerations, etc.).
- kinematic information i.e., displacement, velocity, accelerations, etc.
- One or more embodiments of the present invention may also use measured values based on instrumentation to further enhance accuracy.
- One or more embodiments of the present invention comprises a hard landing detection method and system that provides information that aides substantially the maintenance process.
- a heuristic algorithm may use relevant aircraft flight parameters, as well as information from additional sensors, to predict pertinent loads critical to evaluation of damage due to a hard landing. By providing accurate and reliable load information, this system may significantly reduce the number of hours that an airplane is grounded for inspection due to a hard landing.
- a heuristic algorithm uses multiple airplane parameters to predict load information.
- the parameters may include sources that describe an internal distribution of forces or strains in materials or structures of the aircraft.
- the algorithm may be trained using results from an analytical ground-loads simulation.
- the algorithm may be validated using flight-test data.
- strains are measured during operation of the aircraft, then the algorithm may update itself as the aircraft ages .
- One or more embodiments of the present invention may facilitate condition based maintenance.
- at least some aircraft maintenance procedures that are presently mandatory and periodic may be based upon need and thus only performed when necessary. This may be accomplished without compromising the safety of the aircraft.
- Variations of the algorithm described herein may be used to predict in-flight loads which would serve as a detailed load history for the airframe. The load history may then be used to alter the inspection and maintenance intervals resulting in increased revenues.
- the heuristic algorithm may be based on derivatives of known mathematical theories.
- the heuristic algorithm may be based on neural networks or probabilistic neural networks trained with Bayesian regularization.
- the proposed hard landing detection system may be used to provide accurate and reliable load information for use in evaluating need and/or level of inspection that is required due to a hard landing event. In this manner, wasteful and unnecessary inspections may be avoided. Further, the scope of some inspections may be reduced to only those items and tests that are actually needed. Thus, both costs and downtime are desirably reduced while safety is maintained.
- One or more embodiments of the present invention may further aid the maintenance process.
- the decision to proceed with an appropriate maintenance procedure may be made with enhanced accuracy. Cost savings may be realized by reducing the number of false call inspections resulting from improperly classified landings .
- the load estimation algorithm determines approximate loads experienced by selected aircraft structures as a result of load producing events, such as landings. Flight parameter data and optionally sensor information may be recorded during such events.
- the load estimation algorithm may be executed either immediately following the event or at a later time.
- the load estimation algorithm may be executed either on board the aircraft or at a location or facility that is remote with respect to the aircraft.
- flight parameters examples include, but are not limited to, pitch angle, roll angle, roll rate, center of gravity (CG) vertical speed, center of gravity (CG) vertical acceleration, airspeed, pilot seat acceleration, and air/ground indication.
- sensor information examples include, but are not limited to, strains and accelerations measured at key locations on the aircraft, e.g., on the landing gear, fuselage, nacelle struts, and on other key structural elements affected by hard landings.
- the flight parameters and sensor readings may be recorded with appropriate sample rates so as to accurately resolve the values of parameters that occurred prior to and during landing. It is worthwhile to note that this is generally the only operation that is necessarily performed in real time. Subsequent operations may generally occur off line, e.g., at another time and/or location.
- the sampled flight parameters and sensor data may be processed to determine their initial and peak values. This reduced set of sampled data may be used as the input to the load estimation algorithm.
- heuristic models are used for load estimation.
- a heuristic model such as one using artificial neural networks, may be used to model the complicated phenomena associated with load determination involving multiple inputs and outputs.
- the heuristic model may be configured so as to act much like a high order nonlinear curve fitting algorithm, such as by relating flight parameters and sensor data to load information.
- the heuristic model may be created and/or trained by providing examples of inputs and outputs .
- Training data sets may be created analytically, e.g., using a numerical simulation, or may be created experimentally, e.g., using flight test data. Training data sets may be created by a combination of both analytical and experimental methods .
- Some of the advantages of the use of a heuristic model are the ability to model considerably nonlinear phenomena with a fairly compact and efficient set of computations and the automatic handling of the model validation process (which may be extremely challenging, time consuming and costly) .
- Using analytically developed training sets reduces the amount of data required from flight tests, and using judiciously chosen flight test data both validates and increases the accuracy of the algorithm.
- Estimated stresses, strains, and/or loads may be used in a variety of ways. For example, all estimated loads may be compared to their threshold values . When one or more of the loads exceeds or approaches its respective threshold value, this would indicate a hard landing and thus the need for inspection.
- This data may be used in a binary sense such that no actual load information is presented to maintenance personnel. Thus, just a yes or no answer is provided so as to indicate whether or not the aircraft experienced a hard landing. In this manner, the need for an inspection may be determined.
- Load information for many locations on an aircraft may be provided. Thus, better information is available to guide maintenance personnel in both the need for an inspection and regarding what aircraft components are to be inspected.
- One or more embodiments of the present invention may be implemented completely or partially in software, such as via the use of a general purpose computer.
- One or more embodiments of the present invention may be implemented in hardware, such as via the use of one or more custom processors.
- One or more embodiments of the present invention provide a method and system for detecting hard landings that is cost effective, accurate (i.e., provides minimal false positive and zero false negative hard landing indications), and reliable
- Flight parameters and/or sensor data 12 are determined and recorded. For example, pitch angle, roll angle, roll rate, center of gravity (CG) vertical speed, center of gravity (CG) vertical acceleration, airspeed, pilot seat acceleration, and air/ground indication may be determined and recorded.
- CG center of gravity
- CG center of gravity
- the heuristic load estimation algorithm (also referred to as a load prediction algorithm) 13 receives at least one, generally a plurality, of inputs. These inputs may comprise flight data and/or sensor data, as described above. These inputs are processed according to an algorithm that has been determined to reliably provide adequately accurate structural load information as outputs. For example, at its simplest the algorithm may comprise one or more lookup tables that correlate flight data and/or sensor data to loads.
- a heuristic algorithm may generally be trained so as to provide properly known outputs when given corresponding inputs.
- the heuristic algorithm may be trained using known inputs and outputs derived from experiments using instrumented aircraft.
- the heuristic algorithm may be trained using results from an analytical ground-loads simulation.
- the heuristic algorithm may be validated using flight test data.
- the heuristic algorithm may optionally update itself using strains that are measured during operation of the aircraft. Estimated or predicted stresses, strains and/or loads 14 are provided by the load estimation program 13. This information may be used, such as by another algorithm, to determine what, if any, inspections and/or maintenance procedures (such as replacement and/or testing of parts) is necessary. Thus, maintenance information 15, such as hard landing indication, damage information, inspection information, and/or stress and strain information is provided to maintenance personnel. In this manner, unnecessary inspections and/or maintenance are mitigated and necessary inspections and/or maintenance are enhanced.
- Flight parameter data is provided when there is a potential high load event, such as a hard landing, as indicated in block 21.
- sensor data such as from accelerometers , velocity sensors, inclinometers and/or strain gauges are also provided.
- Initial and peak values for the flight parameters and/or sensor data are determined, as indicated in block 22.
- the values of such parameters are generally the most indicative of the peak values of loads experienced by aircraft structures.
- the initial and peak values are processed using a heuristic algorithm as indicated in block 23.
- the heuristic algorithm estimates or predicts the peak loads experienced during the high load event.
- Any inspections and/or maintenance procedures that are determined to be necessary as a result of the loads experienced by the aircraft are performed, as indicated in block 24.
- Use of the present invention tends to provide a better indication of the need for such inspections and maintenance procedures, as compared to the subjective determination of a hard landing by a pilot.
- vertical acceleration of the aircraft center of gravity (CG) alone may be used to determine when a hard landing has occurred.
- Vertical CG acceleration may be derived from flight parameters.
- the maximum CG acceleration experienced during landing may be used by the heuristic load estimation algorithm to estimate the loads experienced by the aircraft.
- the load estimation program may use prior flight data to estimate such loads (such as wherein an instrumented aircraft was subjected to various vertical accelerations during test landings and strains were measured on aircraft structures to determine the loads experienced thereby) . When loads are greater than a predetermined threshold, then inspections and/or maintenance procedures are indicated.
- the aircraft parameter sources may include sources of information such as pitch angle, roll angle, roll rate, center of gravity (CG) vertical speed, center of gravity (CG) vertical acceleration, airspeed, pilot seat acceleration, and air/ground indication.
- the sensors may include accelerometers and strain gauges.
- Sensor pre-processor 32 determines the initial and peak values of the aircraft parameters and/or sensor readings. These values are provided to heuristic processor 33. As those skilled in the art will appreciate, the initial and peak values of such data tend to be more representative of potential excessive loads than do other portions of such data. Heuristic processor 33 uses a heuristic algorithm, as discussed above, to estimate loads, such as loads on key or safety critical aircraft structures. The loads are provided to inspection and maintenance processor 34. Inspection and maintenance processor 34 provides inspection and/or maintenance instructions to an output device 35, such as a monitor or printer. The inspection and/or maintenance instructions may be used by maintenance personnel to perform any inspections and/or maintenance procedures that are required as a result of a hard landing or other load inducing event.
- references to an aircraft herein is by way of example only and not by way of limitation. Those skilled in the art will appreciate that the methods and systems disclosed herein are likewise applicable to a large variety of other items including non-vehicles (such as buildings, oil rigs, and bridges) and vehicles (such as automobiles, ships, submarines, satellites, and spacecraft) .
- non-vehicles such as buildings, oil rigs, and bridges
- vehicles such as automobiles, ships, submarines, satellites, and spacecraft
- Hard landings are described herein as examples of load inducing events.
- One or more embodiments of the present invention may be used to detect when other types of load inducing events have induced loads that exceed a threshold. For example, high load events caused by gusts during flight.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Artificial Intelligence (AREA)
- Automation & Control Theory (AREA)
- Evolutionary Computation (AREA)
- General Physics & Mathematics (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Software Systems (AREA)
- Medical Informatics (AREA)
- Health & Medical Sciences (AREA)
- Mathematical Physics (AREA)
- Traffic Control Systems (AREA)
- Testing Of Balance (AREA)
Abstract
A method and system for detecting a hard landing or other high load event of an aircraft are disclosed. A heuristic algorithm may be used to estimate loads experienced by the aircraft during landing. The heuristic algorithm may use flight parameters and/or measured sensor information to estimate the loads. The heuristic algorithm may be trained by means of analytical loads predictions and/or test measurements. The heuristic algorithm may be updated during operation. This invention may potentially reduce the number of unnecessary structural inspections, and may also limit the scope of any such required inspections
Description
HARD LANDING DETECTION
TECHNICAL FIELD The present invention relates generally to aircraft maintenance and, more particularly, to a method and system for detecting hard or heavy aircraft landings .
BACKGROUND
Hard or heavy landings are significant high load events that may adversely impact airframe structural integrity. Such landings may result in damage that affects the ability of the aircraft to fly safely. When this happens, repairs must be performed prior to flying the aircraft again. An inspection must be performed when there is a hard landing, so as to determine if such repairs are needed.
However, the inspection process that is required to assess the potential for damage due to a suspected hard landing event is undesirably time consuming. Further, the inspection process frequently results in a finding of no damage. Studies have shown that up to 90% of pilot initiated hard landing inspections resulted in no finding of damage.
Although pilots attempt to be realistic about the need for inspections, the fact that people's lives are at stake creates a strong bias in favor of safety. The results of performing unnecessary inspections include undesirably increased labor costs and lost revenues due to the down time of the aircraft.
In view of the foregoing, there is a need for a method and system for detecting hard aircraft landings that is not subject to human bias and thus provides a more realistic indication of
the severity of the landing and the consequent need for inspection.
SUMMARY
Systems and methods are disclosed herein for the detection of load inducing events in structures, such as hard landings of aircraft. For example, a heuristic algorithm may be used to estimate the severity of at least one load, generally a plurality of loads, experienced by an aircraft during landing.
More particularly, the heuristic algorithm may use at least one flight parameter to facilitate estimation of the loads (s).
Generally, the heuristic algorithm may use a plurality of flight parameters, such as pitch angle, roll angle, roll rate, center of gravity (CG) vertical speed, vertical acceleration, airspeed, pilot seat acceleration, and air/ground indication to facilitate the estimation of the loads.
Further, information from at least one sensor may be used to facilitate estimation of the load(s) . For example, information from strain gauges and/or accelerometers may be used by the heuristic algorithm to facilitate the estimation of the load(s) .
The heuristic algorithm may be trained using results from an analytical ground loads simulation. The heuristic algorithm may be validated using flight test data. The heuristic algorithm may update itself using strains that are measured during operation of the aircraft.
The heuristic algorithm may be based upon neural networks, such as probabilistic neural networks trained with Bayesian regularization techniques. Sampled flight parameters and sensor data prior to and during the landing event may be processed by
the heuristic algorithm to estimate the loads induced on the aircraft.
The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the present invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 shows a high level overview of a hard landing detection system of the present invention in accordance with an exemplary embodiment of the present invention;
Fig. 2 shows a flow chart illustrating a method for detecting hard landings in accordance with an exemplary embodiment of the present invention; and
Fig. 3 shows a block diagram of a system for detecting hard landings in accordance with an exemplary embodiment of the present invention.
Embodiments of the present invention and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures.
DETAILED DESCRIPTION
According to contemporary practice, an attempt to fully characterize the loads applied to an aircraft during landing is performed by instrumenting the landing gear of the aircraft so as to obtain force measurements (e.g., via strain gauges) . While this approach may be adequate in theory, the practical implementation of this technique presents logistical roadblocks, undesirably high costs, and reliability issues.
By way of contrast, an example of an embodiment of the present invention comprises methods and systems for detecting hard or heavy landings by using primarily kinematic information (i.e., displacement, velocity, accelerations, etc.). Thus, the need to instrument the aircraft is mitigated and costs are correspondingly decreased. One or more embodiments of the present invention may also use measured values based on instrumentation to further enhance accuracy.
One or more embodiments of the present invention comprises a hard landing detection method and system that provides information that aides substantially the maintenance process. A heuristic algorithm may use relevant aircraft flight parameters, as well as information from additional sensors, to predict pertinent loads critical to evaluation of damage due to a hard landing. By providing accurate and reliable load information, this system may significantly reduce the number of hours that an airplane is grounded for inspection due to a hard landing.
According to an example of an embodiment of the present invention, a heuristic algorithm uses multiple airplane parameters to predict load information. The parameters may include sources that describe an internal distribution of forces or strains in materials or structures of the aircraft. The algorithm may be trained using results from an analytical ground-loads simulation. The algorithm may be validated using flight-test data. In addition, if strains are measured during
operation of the aircraft, then the algorithm may update itself as the aircraft ages .
One or more embodiments of the present invention may facilitate condition based maintenance. Thus, at least some aircraft maintenance procedures that are presently mandatory and periodic may be based upon need and thus only performed when necessary. This may be accomplished without compromising the safety of the aircraft. Variations of the algorithm described herein may be used to predict in-flight loads which would serve as a detailed load history for the airframe. The load history may then be used to alter the inspection and maintenance intervals resulting in increased revenues.
The heuristic algorithm may be based on derivatives of known mathematical theories. For example, the heuristic algorithm may be based on neural networks or probabilistic neural networks trained with Bayesian regularization.
The proposed hard landing detection system may be used to provide accurate and reliable load information for use in evaluating need and/or level of inspection that is required due to a hard landing event. In this manner, wasteful and unnecessary inspections may be avoided. Further, the scope of some inspections may be reduced to only those items and tests that are actually needed. Thus, both costs and downtime are desirably reduced while safety is maintained.
One or more embodiments of the present invention, such as the system as a whole, may further aid the maintenance process. By providing a more accurate estimation of loads developed during the landing event, the decision to proceed with an appropriate maintenance procedure may be made with enhanced accuracy. Cost savings may be realized by reducing the number
of false call inspections resulting from improperly classified landings .
The load estimation algorithm determines approximate loads experienced by selected aircraft structures as a result of load producing events, such as landings. Flight parameter data and optionally sensor information may be recorded during such events. The load estimation algorithm may be executed either immediately following the event or at a later time. The load estimation algorithm may be executed either on board the aircraft or at a location or facility that is remote with respect to the aircraft.
Examples of flight parameters that may be used by the load estimation algorithm include, but are not limited to, pitch angle, roll angle, roll rate, center of gravity (CG) vertical speed, center of gravity (CG) vertical acceleration, airspeed, pilot seat acceleration, and air/ground indication. Examples of sensor information that may be used by the load estimation algorithm include, but are not limited to, strains and accelerations measured at key locations on the aircraft, e.g., on the landing gear, fuselage, nacelle struts, and on other key structural elements affected by hard landings.
In order to maintain desired fidelity, the flight parameters and sensor readings may be recorded with appropriate sample rates so as to accurately resolve the values of parameters that occurred prior to and during landing. It is worthwhile to note that this is generally the only operation that is necessarily performed in real time. Subsequent operations may generally occur off line, e.g., at another time and/or location.
The sampled flight parameters and sensor data may be processed to determine their initial and peak values. This
reduced set of sampled data may be used as the input to the load estimation algorithm.
According to one or more embodiments of the present invention, heuristic models are used for load estimation. A heuristic model, such as one using artificial neural networks, may be used to model the complicated phenomena associated with load determination involving multiple inputs and outputs. The heuristic model may be configured so as to act much like a high order nonlinear curve fitting algorithm, such as by relating flight parameters and sensor data to load information.
The heuristic model may be created and/or trained by providing examples of inputs and outputs . Training data sets may be created analytically, e.g., using a numerical simulation, or may be created experimentally, e.g., using flight test data. Training data sets may be created by a combination of both analytical and experimental methods .
Some of the advantages of the use of a heuristic model (as compared to a finite element model, for example) are the ability to model considerably nonlinear phenomena with a fairly compact and efficient set of computations and the automatic handling of the model validation process (which may be extremely challenging, time consuming and costly) . Using analytically developed training sets reduces the amount of data required from flight tests, and using judiciously chosen flight test data both validates and increases the accuracy of the algorithm.
Estimated stresses, strains, and/or loads may be used in a variety of ways. For example, all estimated loads may be compared to their threshold values . When one or more of the loads exceeds or approaches its respective threshold value, this would indicate a hard landing and thus the need for inspection.
This data may be used in a binary sense such that no actual load
information is presented to maintenance personnel. Thus, just a yes or no answer is provided so as to indicate whether or not the aircraft experienced a hard landing. In this manner, the need for an inspection may be determined.
Conversely, detailed information describing loads at a variety of locations around the aircraft may be presented to guide the inspection process. In this manner, some additional details regarding what needs to be inspected and how the inspection is to be performed may be provided.
Load information for many locations on an aircraft (not just the landing gear) may be provided. Thus, better information is available to guide maintenance personnel in both the need for an inspection and regarding what aircraft components are to be inspected.
Using flight parameters reduces the dependence upon strain sensors which have been shown to be less reliable than desired when used to monitor landing gear strains. Thus, reliability is enhanced and the performance of unnecessary inspection is made less likely. The large number of variables involved in a landing event are evaluated in a combined sense that facilitates classification of the landing as either acceptable or hard.
One or more embodiments of the present invention may be implemented completely or partially in software, such as via the use of a general purpose computer. One or more embodiments of the present invention may be implemented in hardware, such as via the use of one or more custom processors.
One or more embodiments of the present invention provide a method and system for detecting hard landings that is cost effective, accurate (i.e., provides minimal false positive and zero false negative hard landing indications), and reliable
(i.e., does not solely rely upon measurements from transducers
that are non-redundant and/or susceptible to damage) . In this manner, less reliance need be placed upon the subjective opinion of the pilot and less downtime of the aircraft is likely to result.
Referring now to Figure 1, a high level overview of an example of an embodiment of a hard landing detection system of the present invention is shown. An aircraft 10 lands upon a surface, typically a runway 11. Flight parameters and/or sensor data 12 are determined and recorded. For example, pitch angle, roll angle, roll rate, center of gravity (CG) vertical speed, center of gravity (CG) vertical acceleration, airspeed, pilot seat acceleration, and air/ground indication may be determined and recorded.
The heuristic load estimation algorithm (also referred to as a load prediction algorithm) 13 receives at least one, generally a plurality, of inputs. These inputs may comprise flight data and/or sensor data, as described above. These inputs are processed according to an algorithm that has been determined to reliably provide adequately accurate structural load information as outputs. For example, at its simplest the algorithm may comprise one or more lookup tables that correlate flight data and/or sensor data to loads.
As those skilled in the art will appreciate, a heuristic algorithm may generally be trained so as to provide properly known outputs when given corresponding inputs. For example, the heuristic algorithm may be trained using known inputs and outputs derived from experiments using instrumented aircraft. Alternatively, the heuristic algorithm may be trained using results from an analytical ground-loads simulation. The heuristic algorithm may be validated using flight test data.
The heuristic algorithm may optionally update itself using strains that are measured during operation of the aircraft.
Estimated or predicted stresses, strains and/or loads 14 are provided by the load estimation program 13. This information may be used, such as by another algorithm, to determine what, if any, inspections and/or maintenance procedures (such as replacement and/or testing of parts) is necessary. Thus, maintenance information 15, such as hard landing indication, damage information, inspection information, and/or stress and strain information is provided to maintenance personnel. In this manner, unnecessary inspections and/or maintenance are mitigated and necessary inspections and/or maintenance are enhanced.
Referring now to Figure 2, a flow chart shows the method of detecting hard landings according to an exemplary embodiment of the present invention. Flight parameter data is provided when there is a potential high load event, such as a hard landing, as indicated in block 21. Optionally, sensor data (such as from accelerometers , velocity sensors, inclinometers and/or strain gauges) are also provided.
Initial and peak values for the flight parameters and/or sensor data are determined, as indicated in block 22. As those skilled in the art will appreciate, the values of such parameters are generally the most indicative of the peak values of loads experienced by aircraft structures.
The initial and peak values are processed using a heuristic algorithm as indicated in block 23. The heuristic algorithm estimates or predicts the peak loads experienced during the high load event.
Any inspections and/or maintenance procedures that are determined to be necessary as a result of the loads experienced by the aircraft are performed, as indicated in block 24. Use of the present invention tends to provide a better indication of
the need for such inspections and maintenance procedures, as compared to the subjective determination of a hard landing by a pilot.
As a simplified example of an embodiment of the present invention, vertical acceleration of the aircraft center of gravity (CG) alone may be used to determine when a hard landing has occurred. Vertical CG acceleration may be derived from flight parameters. The maximum CG acceleration experienced during landing may be used by the heuristic load estimation algorithm to estimate the loads experienced by the aircraft. For example, the load estimation program may use prior flight data to estimate such loads (such as wherein an instrumented aircraft was subjected to various vertical accelerations during test landings and strains were measured on aircraft structures to determine the loads experienced thereby) . When loads are greater than a predetermined threshold, then inspections and/or maintenance procedures are indicated.
Referring now to Figure 3, a plurality of aircraft parameter sources and sensors 31 provide aircraft parameters and sensor readings to sensor pre-processor 32. The aircraft parameter sources may include sources of information such as pitch angle, roll angle, roll rate, center of gravity (CG) vertical speed, center of gravity (CG) vertical acceleration, airspeed, pilot seat acceleration, and air/ground indication. The sensors may include accelerometers and strain gauges.
Sensor pre-processor 32 determines the initial and peak values of the aircraft parameters and/or sensor readings. These values are provided to heuristic processor 33. As those skilled in the art will appreciate, the initial and peak values of such data tend to be more representative of potential excessive loads than do other portions of such data.
Heuristic processor 33 uses a heuristic algorithm, as discussed above, to estimate loads, such as loads on key or safety critical aircraft structures. The loads are provided to inspection and maintenance processor 34. Inspection and maintenance processor 34 provides inspection and/or maintenance instructions to an output device 35, such as a monitor or printer. The inspection and/or maintenance instructions may be used by maintenance personnel to perform any inspections and/or maintenance procedures that are required as a result of a hard landing or other load inducing event.
Reference to an aircraft herein is by way of example only and not by way of limitation. Those skilled in the art will appreciate that the methods and systems disclosed herein are likewise applicable to a large variety of other items including non-vehicles (such as buildings, oil rigs, and bridges) and vehicles (such as automobiles, ships, submarines, satellites, and spacecraft) .
Hard landings are described herein as examples of load inducing events. One or more embodiments of the present invention may be used to detect when other types of load inducing events have induced loads that exceed a threshold. For example, high load events caused by gusts during flight.
Embodiments described above illustrate but do not limit the invention. It should also be understood that numerous modifications and variations are possible in accordance with the principles of the present invention. Accordingly, the scope of the invention is defined only by the following claims.
Claims
1. A method for detecting a high load event of an aircraft, the method comprising using a heuristic algorithm to estimate at least one load experienced by the aircraft during the event .
2. The method as recited in claim 1, wherein the heuristic algorithm uses at least one flight parameter to facilitate estimation of the loads (s) .
3. The method as recited in claim 1, wherein the heuristic algorithm uses information from at least one sensor to facilitate estimation of the load(s) .
4. The method as recited in claim 1, wherein the heuristic algorithm uses information from at least one kinematic source to estimate the load(s) .
5. The method as recited in claim 1, wherein the heuristic algorithm uses information from at least one kinematic source to estimate a plurality of loads, the kinematic source (s) comprising at least one source that provides information that is representative of an internal distribution of forces in at least one structural element of the aircraft.
6. The method as recited in claim 1, wherein the heuristic algorithm uses information comprising at least one of pitch angle, roll angle, roll rate, vertical speed, vertical acceleration, airspeed, pilot seat acceleration, and air/ground indication to detect a hard landing event.
7. The method as recited in claim 1, wherein the heuristic algorithm uses information comprising at least one of strains and accelerations measured at key locations on the aircraft.
8. The method as recited in claim 1, wherein the heuristic algorithm is trained using results from an analytical loads simulation.
9. The method as recited in claim 1, wherein the heuristic algorithm is validated using test data.
10. The method as recited in claim 1, wherein the heuristic algorithm updates itself using sensors that are measured during operation of the aircraft.
11. The method as recited in claim 1, wherein the heuristic algorithm utilizes probabilistic neural networks.
12. The method as recited in claim 1, wherein the heuristic algorithm utilizes Bayesian regularization for training.
13. The method as recited in claim 1, wherein sampled flight parameters and sensor data are processed to estimate their initial and peak values and the heuristic algorithm uses these values to estimate the loads.
14. A system for detecting a high load event of an aircraft, the system comprising:
a sensor pre-processor configured to receive aircraft parameters and to determine initial and peak values thereof; and
a load estimation processor configured to use a heuristic algorithm to estimate loads on aircraft structure from the aircraft parameter initial and peak values.
15. The system as recited in claim 14, wherein the sensor pre-processor is configured to determine the initial and peak values of sensor readings and the load estimation processor is configured to use the heuristic algorithm to estimate loads on aircraft structures using both aircraft parameter and measured sensor readings .
16. The system as recited in claim 14, further comprising a processor for processing the loads so as to determine what aircraft structural elements require inspection and/or maintenance.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07845005.3A EP2092401B1 (en) | 2006-11-10 | 2007-11-09 | Hard landing detection |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/558,815 | 2006-11-10 | ||
US11/558,815 US20080114506A1 (en) | 2006-11-10 | 2006-11-10 | Hard landing detection |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2008060996A2 true WO2008060996A2 (en) | 2008-05-22 |
WO2008060996A3 WO2008060996A3 (en) | 2008-07-24 |
Family
ID=39327260
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2007/084236 WO2008060996A2 (en) | 2006-11-10 | 2007-11-09 | Hard landing detection |
Country Status (3)
Country | Link |
---|---|
US (1) | US20080114506A1 (en) |
EP (1) | EP2092401B1 (en) |
WO (1) | WO2008060996A2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2481488A (en) * | 2010-06-21 | 2011-12-28 | Boeing Co | Integrated aeroelasticity measurement for vehicle health management |
CN102901531A (en) * | 2011-07-27 | 2013-01-30 | 中国国际航空股份有限公司 | Plane landing quality detection method |
CN104648690A (en) * | 2014-11-24 | 2015-05-27 | 中国运载火箭技术研究院 | Whole aircraft drop simulation predication and testing method |
CN106707792A (en) * | 2016-11-18 | 2017-05-24 | 中航飞机起落架有限责任公司 | Multifunctional undercarriage integration test control device and method |
Families Citing this family (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB0704878D0 (en) * | 2007-03-14 | 2007-04-18 | Trw Ltd | Aircraft landing gear monitoring apparatus |
FR2931553B1 (en) * | 2008-05-22 | 2010-10-29 | Airbus France | ESTIMATING A CHARGING CRITERION SUBJECTED BY A STRUCTURAL COMPONENT OF AN AIRCRAFT AND ASSISTING THE DETECTION OF A "HARD" DRAWING THROUGH SUCH A CRITERION |
EP2331928A1 (en) * | 2008-09-19 | 2011-06-15 | Valorbec Société En Commandite, Représentée Par Gestion Valeo S.E.C | Hard-landing occurrence determination system and method for aircraft |
US8761970B2 (en) * | 2008-10-21 | 2014-06-24 | The Boeing Company | Alternative method to determine the air mass state of an aircraft and to validate and augment the primary method |
US8886402B1 (en) * | 2010-04-22 | 2014-11-11 | Armorworks Enterprises LLC | Actively variable shock absorbing strut and system |
US20110276217A1 (en) | 2010-05-10 | 2011-11-10 | The Boeing Company | Hard Landing Report Based on Sink Rate Algorithm |
US8655619B1 (en) * | 2010-07-27 | 2014-02-18 | Raytheon Company | System, method, and software for estimating a peak acceleration of an optical system |
US10131419B2 (en) | 2010-10-15 | 2018-11-20 | Goodrich Corporation | Systems and methods for detecting landing gear ground loads |
GB2480124B8 (en) * | 2011-03-17 | 2013-09-25 | Messier Dowty Ltd | Method and system for determining friction coefficient u for an aircraft landing event. |
US8862377B2 (en) * | 2011-03-31 | 2014-10-14 | Sikorsky Aircraft Corporation | Method and system for detecting forces on aircraft |
US8554396B2 (en) * | 2012-01-03 | 2013-10-08 | Honeywell International Inc. | Systems and methods for issuing a hard landing warning and providing maintenance advisories for hard landing incidents |
US8972310B2 (en) * | 2012-03-12 | 2015-03-03 | The Boeing Company | Method for identifying structural deformation |
CN104614992B (en) * | 2015-01-04 | 2017-02-22 | 哈尔滨工程大学 | System for simulating actual spot landing behavior of pilot |
US10984338B2 (en) | 2015-05-28 | 2021-04-20 | Raytheon Technologies Corporation | Dynamically updated predictive modeling to predict operational outcomes of interest |
CN105069187B (en) * | 2015-07-15 | 2018-06-26 | 北京航空航天大学 | A kind of landing Forecasting Methodology again based on winged ginseng Panel Data Model |
ES2773653T3 (en) * | 2015-10-23 | 2020-07-14 | Safran Landing Systems Uk Ltd | Aircraft landing gear assembly including a condition and usage monitoring method and system (HUMS) |
US20170283085A1 (en) | 2016-04-04 | 2017-10-05 | The Boeing Company | On-board structural load assessment of an aircraft during flight events |
US10017263B2 (en) | 2016-04-11 | 2018-07-10 | Sikorsky Aircraft Corporation | Model based contact predictor |
CN105905314A (en) * | 2016-05-31 | 2016-08-31 | 中国航空工业集团公司西安飞机设计研究所 | Intelligent monitoring method for airplane heavy landing |
CN106384169B (en) * | 2016-09-22 | 2018-02-06 | 合肥工业大学 | A kind of satellite task planing method based on meta-heuristic algorithms |
EP3336485B1 (en) | 2016-12-15 | 2020-09-23 | Safran Landing Systems UK Limited | Aircraft assembly including deflection sensor |
LU101181B1 (en) * | 2019-04-12 | 2020-10-12 | Compredict Gmbh | Method for determining a load forecast for a component of a motor vehicle |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3712122A (en) * | 1971-02-08 | 1973-01-23 | Electro Dev Corp | Aircraft hard landing indicator |
US4751443A (en) * | 1986-07-22 | 1988-06-14 | Honeywell Inc. | Servo simulator |
US5050070A (en) * | 1988-02-29 | 1991-09-17 | Convex Computer Corporation | Multi-processor computer system having self-allocating processors |
US6317658B1 (en) * | 1997-10-15 | 2001-11-13 | The Boeing Company | Neurocomputing control distribution system |
US6125333A (en) * | 1997-11-06 | 2000-09-26 | Northrop Grumman Corporation | Building block approach for fatigue spectra generation |
DE10048826B4 (en) * | 2000-09-29 | 2012-03-01 | Robert Bosch Gmbh | Method and device for detecting age-related changes in technical systems such as electric motors |
US20040176887A1 (en) * | 2003-03-04 | 2004-09-09 | Arinc Incorporated | Aircraft condition analysis and management system |
US20060004499A1 (en) * | 2004-06-30 | 2006-01-05 | Angela Trego | Structural health management architecture using sensor technology |
CA2487704A1 (en) * | 2004-11-18 | 2006-05-18 | R. Kyle Schmidt | Method and system for health monitoring of aircraft landing gear |
-
2006
- 2006-11-10 US US11/558,815 patent/US20080114506A1/en not_active Abandoned
-
2007
- 2007-11-09 WO PCT/US2007/084236 patent/WO2008060996A2/en active Application Filing
- 2007-11-09 EP EP07845005.3A patent/EP2092401B1/en active Active
Non-Patent Citations (1)
Title |
---|
None |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2481488A (en) * | 2010-06-21 | 2011-12-28 | Boeing Co | Integrated aeroelasticity measurement for vehicle health management |
CN102901531A (en) * | 2011-07-27 | 2013-01-30 | 中国国际航空股份有限公司 | Plane landing quality detection method |
JP2013028339A (en) * | 2011-07-27 | 2013-02-07 | Air China Ltd | Method for detecting landing quality of aircraft |
EP2557542A3 (en) * | 2011-07-27 | 2013-06-12 | Air China Limited | A method for detecting the landing quality of an aircraft |
CN102901531B (en) * | 2011-07-27 | 2015-08-12 | 中国国际航空股份有限公司 | A kind of detection method of aircraft landing quality |
TWI548565B (en) * | 2011-07-27 | 2016-09-11 | 中國國際航空股份有限公司 | Method for detecting the landing quality of an aircraft |
CN104648690A (en) * | 2014-11-24 | 2015-05-27 | 中国运载火箭技术研究院 | Whole aircraft drop simulation predication and testing method |
CN106707792A (en) * | 2016-11-18 | 2017-05-24 | 中航飞机起落架有限责任公司 | Multifunctional undercarriage integration test control device and method |
Also Published As
Publication number | Publication date |
---|---|
EP2092401B1 (en) | 2019-03-27 |
EP2092401A2 (en) | 2009-08-26 |
WO2008060996A3 (en) | 2008-07-24 |
US20080114506A1 (en) | 2008-05-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2092401B1 (en) | Hard landing detection | |
EP3229187B1 (en) | On-board structural load assessment of an aircraft during flight events | |
US10891406B2 (en) | Prediction methods and systems for structural repair during heavy maintenance of aircraft | |
CN102037421B (en) | Assistant method for auxiliary detection of so-called ''hard'' landing of aircraft | |
US10501152B2 (en) | Structural monitoring system of the hull of a ship integrated with a navigation decision support system | |
CN106428617B (en) | Integrated system and method for vehicle management and monitoring | |
US20060004499A1 (en) | Structural health management architecture using sensor technology | |
EP2686243B1 (en) | Method and system for determining friction coefficient for an aircraft landing event | |
Farrar et al. | An introduction to damage prognosis | |
CA2865181A1 (en) | Methods and systems for aircraft health and trend monitoring | |
EP2957883A2 (en) | Method for prognostics of an aircraft structure based on structural testing | |
EP3721197B1 (en) | Estimating fatigue damage in a structure | |
Kordonsky et al. | Choice of the best time scale for system reliability analysis | |
Knezevic | Quality of maintenance: Mirce Mechanics axiom | |
Walker et al. | Design for continuing structural integrity | |
Gunther | Loads monitoring and HUMS | |
Spaulding | Design for Fatigue | |
Azzam et al. | A route for qualifying/certifying an affordable structural prognostic health management (SPHM) system | |
CN117612415A (en) | Landing safety assessment method and system based on flight data | |
Boller | Business potential of structural health monitoring in aeronautics | |
Swift | First Diamond: ‘Damage tolerance’for the structural honeymoon |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 07845005 Country of ref document: EP Kind code of ref document: A2 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2007845005 Country of ref document: EP |