Fault monitoring method and system for servo displacement sensors used in aircraft control surfaces

Abstract

This invention relates to a fault monitoring method and system for servo displacement sensors on aircraft control surfaces. The method first compares the actuator displacement sensors on the same control surface. When a discrepancy is found in the comparison for a particular control surface, it indicates that the value of a sensor on that control surface is abnormal. Then, feedback values ​​from two other actuator displacement sensors on symmetrical control surfaces are introduced for a comprehensive judgment.

Description

Technical Field

[0001] This invention belongs to the field of flight control for civil transport aircraft, and particularly relates to a fault monitoring method and system for servo displacement sensors used on aircraft control surfaces. Background Technology

[0002] Civil aircraft typically use movable control surfaces such as ailerons, elevators, and rudders to control the aircraft, performing maneuvers such as roll, pitch, and yaw. In the flight control system, two or more control surfaces are usually used to control the main control surfaces such as ailerons, elevators, and rudders. When a servo displacement sensor malfunctions and becomes disengaged, the flight control system must identify the fault and handle it accordingly.

[0003] Generally, actuators use linear displacement sensors (LVDTs) to measure the position of the control surfaces. The LVDT calculates the displacement proportionality coefficient R based on the output voltages Va and Vb of its two secondary coils: R = (Va - Vb) / (Va + Vb). The linear displacement is then calculated based on the proportionality coefficient, gain, and offset. In the control surface displacement calculation, the gain and offset are constant values, and the linear displacement value is mainly affected by the outputs of Va and Vb. The sum of the secondary coil output voltages Va and Vb is generally within the normal range. However, when a short circuit or open circuit occurs due to electrical interfaces, wiring, or coil factors, the sum of the LVDT voltages Va and Vb will exceed the normal range, or the LVDT may mechanically disconnect, leading to erroneous measurements.

[0004] Therefore, multiple position sensors are generally required on the control surface. When a single position sensor fails to connect, the fault is identified by comparison and voting to prevent incorrect control surface position from being introduced into the closed-loop control.

[0005] Typical control surface position sensor configurations include:

[0006] 1. Two actuators are installed on a single main control surface. Each actuator has a displacement sensor. The system compares the feedback from the displacement sensors of the two actuators on the same control surface. If the difference is large, it can determine that a sensor has disconnected, but it cannot determine which sensor has disconnected. Therefore, when dealing with the fault, both actuators must be disconnected to avoid the fault causing abnormal movement of the control surface.

[0007] The disadvantage of this configuration is that if a sensor on any one actuator fails to disconnect, the source of the failure cannot be determined. In order to prevent abnormal movement of the control surface, two actuators must be disconnected, resulting in the loss of control of a single control surface, which has a significant impact on the aircraft's attitude and the pilot's handling of the aircraft.

[0008] 2. Each main control surface is equipped with three actuators, each with a displacement sensor. The system compares the feedback from the displacement sensors of the three actuators on the same control surface. If a sensor fails, a vote is taken to determine which sensor has the largest difference from the others. The actuator containing the faulty sensor is then deactivated to prevent the fault from affecting the control surface. After the faulty actuator is deactivated, the remaining two actuators can still control the control surface normally.

[0009] This solution can accurately identify faulty actuators, but the redundancy of this triple redundancy configuration is too high. Each additional actuator will increase weight, cost, cables, hydraulic lines and installation structure. Generally, only the rudder on an aircraft is controlled by three actuators, while the ailerons and elevators generally use two actuators per control surface.

[0010] 3. Each main control surface is equipped with two actuators, each with a displacement sensor. An additional control surface displacement sensor is installed on the control surface. The system compares the feedback from the two actuator displacement sensors on the same control surface with the control surface displacement sensor. If one sensor fails, a vote is taken to determine which sensor has a larger difference from the others. The actuator containing the faulty sensor is then deactivated to prevent the fault from affecting the control surface. After the faulty actuator is deactivated, the remaining actuators can still control the control surface normally.

[0011] This solution can accurately identify faulty actuators and has been applied to many aircraft models. However, adding a control surface displacement sensor will still increase weight, cost, cabling, and installation structure.

[0012] In summary, existing flight control systems generally utilize displacement sensor data from different servos on a single control surface, or add an additional independent displacement sensor to determine displacement sensor disconnection faults. However, this also faces problems such as difficulty in identifying the source of the fault and increased weight and cost.

[0013] Therefore, there is a need for systems and methods that can improve upon the deficiencies in existing technologies. Summary of the Invention

[0014] This summary is provided to introduce, in a simplified form, some concepts that will be further described in the following detailed description section. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

[0015] To address the shortcomings of existing technologies, this invention utilizes the symmetrical characteristics of aircraft control of ailerons and elevators, integrating signals from all displacement sensors on the symmetrical control surfaces to monitor and handle displacement sensor disconnection faults. In this invention, by comprehensively utilizing commands from the symmetrical control surfaces and feedback from position sensors, a hierarchical voting system is used to determine the source of a position sensor disconnection fault without adding additional position sensors. This allows for accurate fault location and isolation while avoiding additional weight, cost, cabling, and installation structures, thereby improving the availability of control surface control and minimizing its impact on pilot maneuvering.

[0016] Specifically, in one embodiment of the present invention, a method for monitoring and handling actuator failures on symmetrical control surfaces of an aircraft is provided, the method comprising:

[0017] Two actuators are arranged on symmetrical control surfaces, and a displacement sensor is arranged for each actuator.

[0018] The displacement sensor values ​​of the two actuators on each control surface are compared to determine whether the control surface is working properly. If the difference between the control surface position feedback values ​​is greater than a first monitoring threshold, it is determined that the control surface has an actuator malfunction.

[0019] Determine the average position feedback value of the displacement sensors of the two actuators on the symmetrical control surface of the control surface;

[0020] Each of the control surface position feedback values ​​is compared with the average control surface position feedback value, wherein a comparison result greater than a second monitoring threshold indicates that the actuator corresponding to that control surface position feedback value has malfunctioned; and

[0021] Disconnect the rudder circuit of the faulty actuator.

[0022] In one embodiment of the present invention, the first monitoring threshold and the second monitoring threshold are determined based on the control accuracy of the control surface position and the difference between the maximum force conflict angle of the control surface, and the result of the comparison is the absolute value of the difference between the control surface position feedback value and the average value of the control surface position feedback.

[0023] In this embodiment of the invention, when the rudder surface is in a stable static state, the range of the rudder surface position feedback value is between the rudder surface command position minus the rudder surface position control accuracy and the rudder surface command position plus the rudder surface position control accuracy, and the first monitoring threshold is determined to be the sum of the maximum force conflict angle difference of the rudder surface and twice the rudder surface position control accuracy under the strictest error accumulation.

[0024] In this embodiment of the invention, when the rudder surface is in motion, the range of the rudder surface position feedback value is between the rudder surface position minus the rudder surface position control accuracy and the rudder surface position plus the rudder surface position control accuracy, and the first monitoring threshold is determined to be the sum of the maximum force conflict angle difference of the rudder surface and twice the rudder surface position control accuracy under the strictest error accumulation.

[0025] In this embodiment of the invention, when the rudder surface is in a stable static state, the range of the average rudder surface position feedback value is between the rudder surface command position minus the rudder surface position control accuracy and the rudder surface command position plus the rudder surface position control accuracy, and the second monitoring threshold is determined to be the sum of the maximum force conflict angle difference of the rudder surface and four times the rudder surface position control accuracy under the strictest error accumulation.

[0026] In this embodiment of the invention, when the rudder surface is in motion, the range of the rudder surface position feedback value is between the average rudder surface position feedback value minus twice the rudder surface position control accuracy and the average rudder surface position feedback value plus twice the rudder surface position control accuracy, and the second monitoring threshold is determined to be the sum of the maximum force conflict angle difference of the rudder surface and four times the rudder surface position control accuracy under the strictest error accumulation.

[0027] In this embodiment of the invention, the accuracy of the rudder position control is based on at least the following factors: the accuracy of the displacement sensor; the installation clearance; and the accuracy of the digital-to-analog conversion.

[0028] In this embodiment of the invention, the maximum force dispute angle is the ratio of the actuator output force to the torsional stiffness of the control surface, and the absolute value of the angle difference of the maximum force dispute angle is greater than twice the control surface position control accuracy.

[0029] In one embodiment of the present invention, the control surface includes an aileron control surface and an elevator control surface.

[0030] In another embodiment of the present invention, a system for monitoring and handling actuator failures on symmetrical control surfaces of an aircraft is provided, wherein two actuators are arranged on each symmetrical control surface of the aircraft, and each actuator has a displacement sensor, the system comprising:

[0031] The first-level monitoring device is configured to compare the control surface position feedback values ​​of the displacement sensors of two actuators on each control surface to determine whether the control surface is working properly, wherein if the difference between the control surface position feedback values ​​is greater than a first monitoring threshold, it is determined that the control surface has an actuator malfunction.

[0032] The second-level monitoring device is configured as follows:

[0033] Determine the average position feedback value of the displacement sensors of the two actuators on the symmetrical control surface of the control surface; and

[0034] Each of the control surface position feedback values ​​is compared with the average control surface position feedback value, wherein a comparison result greater than a second monitoring threshold indicates that the actuator corresponding to that control surface position feedback value has malfunctioned; and

[0035] A fault isolation device configured to disconnect the rudder circuit of a faulty actuator.

[0036] In one embodiment of the present invention, the first-layer monitoring device and the second-layer monitoring device are further configured to determine the first monitoring threshold and the second monitoring threshold based on the control surface position control accuracy and the difference in the maximum force dispute angle of the control surface.

[0037] In one embodiment of the present invention, the first-layer monitoring device is further configured to:

[0038] When the control surface is in a stable static state, the range of the control surface position feedback value is determined to be between the control surface command position minus the control surface position control accuracy and the control surface command position plus the control surface position control accuracy. Furthermore, under the most stringent error accumulation condition, the first monitoring threshold is determined to be the sum of the maximum force conflict angle difference of the control surface and twice the control surface position control accuracy; and

[0039] When the control surface is in motion, the range of the control surface position feedback value is determined to be between the control surface position minus the control surface position control accuracy and the control surface position plus the control surface position control accuracy. Furthermore, under the most stringent error accumulation, the first monitoring threshold is determined to be the sum of the maximum force conflict angle difference of the control surface and twice the control surface position control accuracy.

[0040] In one embodiment of the present invention, the second-layer monitoring device is further configured to:

[0041] When the control surface is in a stable static state, the range of the average control surface position feedback value is determined to be between the control surface command position minus the control surface position control accuracy and the control surface command position plus the control surface position control accuracy. Furthermore, under the most stringent error accumulation condition, the second monitoring threshold is determined to be the sum of the maximum force conflict angle difference of the control surface and four times the control surface position control accuracy; and

[0042] When the control surface is in motion, the range of the control surface position feedback value is determined to be between the average control surface position feedback value minus twice the control surface position control accuracy and the average control surface position feedback value plus twice the control surface position control accuracy. Furthermore, under the most stringent error accumulation, the second monitoring threshold is determined to be the sum of the maximum force conflict angle difference of the control surface and four times the control surface position control accuracy.

[0043] Other aspects, features, and embodiments of the invention will become apparent to those skilled in the art after reading the following description of specific exemplary embodiments of the invention in conjunction with the accompanying drawings. Although features of the invention may be discussed below with reference to certain embodiments and drawings, all embodiments of the invention may include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed having certain advantageous features, one or more of such features may also be used according to the various embodiments of the invention discussed herein. Similarly, although exemplary embodiments may be discussed below as embodiments of devices, systems, or methods, it should be understood that such exemplary embodiments may be implemented in various devices, systems, and methods. Attached Figure Description

[0044] To gain a more detailed understanding of the features described above in this disclosure, reference can be made to a more specific description of the above-briefly summarized aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only certain typical aspects of this disclosure and should not be considered as limiting its scope, as other equivalent aspects are permissible in this description.

[0045] Figure 1 A logic diagram of a fault diagnosis process for a single-sided control surface actuator according to an embodiment of the present invention is shown.

[0046] Figure 2 A block diagram of a system according to the invention for monitoring and handling actuator failures on symmetrical control surfaces of an aircraft is shown.

[0047] Figure 3 This is a flowchart of a method for monitoring and handling actuator failures on symmetrical control surfaces of an aircraft, according to an embodiment of the present invention. Detailed Implementation

[0048] The various embodiments will now be described in more detail with reference to the accompanying drawings, which form part of this invention and illustrate specific exemplary embodiments. However, the embodiments may be implemented in many different forms and should not be construed as limiting the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of these embodiments to those skilled in the art. The embodiments may be implemented as methods, systems, or devices. Therefore, these embodiments may be implemented in hardware, entirely in software, or in a combination of software and hardware aspects. Therefore, the following detailed description is not intended to be limiting.

[0049] The steps in each flowchart can be performed by hardware (e.g., processor, engine, memory, circuitry), software (e.g., operating system, application, driver, machine / processor executable instructions), or a combination thereof. As will be understood by those skilled in the art, the methods involved in each embodiment may include more or fewer steps than shown.

[0050] This invention proposes a method and system for monitoring the disconnection fault of displacement sensors in symmetrical control surfaces of large aircraft servos. Large aircraft typically employ a symmetrical layout for their elevators and ailerons. In flight control, the control commands for the left and right elevators are identical, meaning the deflection angles of the left and right elevator surfaces should be consistent during normal operation. Similarly, the control commands for the left and right ailerons have the same amplitude but opposite directions; that is, one aileron deflects upwards and the other downwards, with the same amplitude. Each symmetrical control surface usually has two actuators, and each actuator has one displacement sensor, providing control surface position feedback for all four actuators.

[0051] For symmetrical control surfaces like elevators, the actuator displacement sensors on the same control surface are first compared. If a discrepancy is found on a certain control surface, it indicates an anomaly in the value of a sensor on that surface. However, the source of the fault cannot be determined solely by the values ​​of two sensors on a single control surface. Therefore, the position feedback from the other two actuator displacement sensors on the symmetrical control surfaces is introduced for a comprehensive judgment.

[0052] The various aspects of the present invention will now be described in detail.

[0053] Figure 1 A logic diagram of a fault diagnosis process for a single-sided control surface actuator according to an embodiment of the present invention is shown.

[0054] In one embodiment of the present invention, the monitoring and handling of single-sided control surface actuator failures is achieved through the following method: A flight control computer reads the LVDT values ​​of each actuator, calculates the control surface angle, and sets up a monitor in the flight control computer to compare the LVDT values ​​of two actuators on a single control surface. When the difference between the two LVDT values ​​on the same control surface exceeds the monitoring threshold, it indicates a problem with the LVDT of a certain actuator. At this time, feedback from the LVDT values ​​of two actuators on the symmetrical control surface is introduced. By comparing the LVDT values ​​of four actuators, the malfunctioning actuator's LVDT is identified. Then, the flight control computer disconnects the control loop of that actuator, while the other actuator on the same control surface continues to operate normally. This... Figure 1 The logic diagram shown is explained in detail in Figure 1 middle:

[0055] R1 and R2 are the control surface position feedback of the two actuators on one side of the control surface;

[0056] L1 and L2 are the control surface position feedback of the two actuators on the symmetrical control surface;

[0057] L aver It is the average value of the control surface position feedback of the two actuators on the symmetrical control surface;

[0058] a cmd For the control surface command position;

[0059] Δ represents the control accuracy of the control surface position (considering factors such as LVDT accuracy, installation clearance, and digital-to-analog conversion accuracy), and the value of Δ is positive;

[0060] a Force The maximum force conflict angle difference of the control surface is given by: Maximum force conflict angle = Actuator output force / Control surface torsional stiffness. Considering that the commands on both sides of the actuator are the same during normal operation, to ensure that the control surface force conflict threshold is not falsely triggered, |a Force |>2Δ.

[0061] When operating normally, the position feedback of each control surface actuator (R1, R2, L1, L2) should be within [a] cmd -Δ, a cmd Within the range of +Δ].

[0062] As an example, not a limitation, assuming a force conflict occurs on the right-hand control surface, then under the most stringent error accumulation,

[0063] |R1-R2|>a Force +2Δ. The symmetrical sides L1 and L2 should still be in [a] cmd -Δ, a cmd Within the range of +Δ], R1 and R2 are affected by aerodynamic forces because the output capacity of the faulty actuator and the active actuator are the same.

[0064] 1) Scenario 1: The control surface is in a stable static state. cmd hour.

[0065] When a single actuator fails, the faulty actuator will drive the control surface in a direction deviating from its current position due to sensor feedback errors. The normal actuator will stabilize the control surface at its current position according to the angle command.

[0066] First-level monitoring: The faulty actuator drives in a direction deviating from the current control surface position, and the two actuators will generate control surface force conflict. When the first-level monitoring threshold |R1-R2|>A is reached, A=a Force +2Δ (the threshold needs to consider accuracy based on actual force disputes), then the first-level monitoring can determine that there is an actuator fault on the right-side control surface. If the first-level monitoring threshold 'a' is not reached... Force +2Δ indicates that the right-side control surface is functioning normally.

[0067] Second-level monitoring: Introducing symmetrical side control surface position feedback for comparison.

[0068] Because the symmetrical sides L1 and L2 are in [a cmd -Δ, a cmd Within the range of +Δ], therefore L aver In [a cmd -Δ, a cmd Within the range of +Δ].

[0069] As an example, not a limitation, assuming the malfunction is in actuator R2, and the three normally functioning actuators on both sides have the same command, then the position feedback range of R1 is [a cmd -Δ, a cmd Within the range of +Δ].

[0070] The position feedback R2 of the faulty actuator must satisfy R2-R1>a according to the first-level monitor. Force +2Δ.

[0071] Then, under the most stringent error accumulation condition, R²-(a) cmd +Δ)>a Force +2Δ, i.e., R2-a cmd >a Force +3Δ, due to L aver In [a cmd -Δ, a cmd Within the range of +Δ], then R2-L aver >a Force +4Δ, the second-level monitoring threshold B = a Force +4Δ, R2-L aver >B, considering that the angle has two directions, positive and negative, then |R²-L aver|>B(In fact, the average value of the control surface position feedback value of each actuator on the single control surface where the actuator failure occurs and the control surface position feedback value of the two actuators on the symmetrical control surface is L) aver Compare, such as Figure 1 As shown), at this time, the faulty actuator (i.e., the actuator corresponding to the rudder position feedback R2) can be monitored through the above logic circuit.

[0072] 2) Scenario 2: The rudder surface position is a ini rudder command a cmd The control surfaces are in motion.

[0073] First-level monitoring: The faulty actuator drives in a direction deviating from the current control surface position, and the two actuators will generate control surface force conflict. When the first-level monitoring threshold |R1-R2|>A is reached (assuming the actuator on the right control surface fails), A=a Force +2Δ (the threshold needs to consider accuracy issues based on actual force disputes), then the first layer of monitoring can determine that there is an actuator failure on the control surface of that side.

[0074] Second-level monitoring: Introducing left-side rudder surface position feedback for comparison.

[0075] Assuming the malfunction is in actuator R2, the position feedback of R1, although related to a... cmd There is no specific relationship, but the R1 actuator is symmetrically designed with the L1 and L2 actuators, and their airspeed, aerodynamic forces, control commands, and actuator performance are consistent. L is defined as... aver Let R1 be the average value of the control surface position feedback from the two actuators on the symmetrical control surface. Then, under the most stringent error accumulation condition, R1 should be within [L]. aver -2Δ, L aver Within the range of +2Δ].

[0076] The position feedback of the faulty actuator is R2. According to the first-level monitor, R2-R1>a must be satisfied. Force +2Δ.

[0077] Then, under the most stringent error accumulation condition, R²-(L) aver +2Δ)>a Force +2Δ, i.e., R²-L aver >a Force +4Δ, the second-level monitor threshold B = a Force +4Δ, R2-L aver >B.

[0078] Considering that the angle has two directions, positive and negative, then |R²-L aver |>B, at this time the faulty actuator (i.e., the actuator corresponding to the control surface position feedback R2) can be monitored through the above logic circuit.

[0079] Combining Case 1 and Case 2 above, by using two layers of logic judgment and introducing symmetrical actuator position feedback information, it is possible to identify a large deviation in the position feedback of a certain actuator on a single control surface and cut off the corresponding actuator control circuit.

[0080] To ensure system robustness, it is necessary to prevent the monitor from triggering erroneously under certain interference conditions. When designing the monitor's amplitude threshold, first calculate the normal range value under the most stringent error accumulation, considering LVDT accuracy, installation gaps, and analog-to-digital conversion accuracy. Then, add a certain percentage of margin (such as...) to this value. Figure 1 The maximum force difference angle between the rudder surfaces in the middle is a Force After that, it serves as the amplitude threshold for the voltage and sum value monitor; once the monitor detects that the sum value voltage exceeds the amplitude threshold and the duration exceeds the set time threshold, it will trigger the monitor.

[0081] After the system detects the fault, it generally needs to latch the fault and invalidate the LVDT feedback. If the LVDT is an internal LVDT of the actuator, the corresponding actuator needs to be set to bypass / damped mode.

[0082] The cross-comparison threshold for LVDT calculation of skewness values ​​in the monitoring device is generally determined based on factors such as the difference in rudder surface torsion angle under the most severe conditions and the maximum force contention of the actuator.

[0083] Figure 2 A block diagram of a system 200 according to the invention for monitoring and handling actuator malfunctions on symmetrical control surfaces of an aircraft is shown. In one embodiment of the invention, two actuators are arranged on each symmetrical control surface of the aircraft, and each actuator has a displacement sensor.

[0084] like Figure 2 As shown, the system 200 for monitoring and handling actuator failures on the symmetrical control surfaces of an aircraft includes a first-level monitoring device 202, a second-level monitoring device 204, and a fault isolation device 206.

[0085] In one embodiment of the invention, the first-layer monitoring device 202 may be configured to compare the control surface position feedback values ​​of the displacement sensors of the two actuators on each control surface to determine whether the control surface is functioning properly (in... Figure 1 In this case, it is determined whether |R1-R2| is greater than A, where A = a. Force +2Δ), where if the difference between the two control surface position feedback values ​​is greater than the first monitoring threshold, it is determined that the control surface has an actuator fault.

[0086] In another embodiment of the present invention, the first-layer monitoring device 202 may be further configured to: when the control surface is in a stable static state, determine the range of the control surface position feedback value as between the control surface command position minus the control surface position control accuracy and the control surface command position plus the control surface position control accuracy (in the case of...). Figure 1 In, that is, [a cmd -Δ, a cmd +Δ]), and under the most stringent error accumulation, the first monitoring threshold is determined as the sum of the maximum force dispute angle difference of the control surface and twice the position control accuracy of the control surface (in Figure 1 In the middle, that is, the first monitoring threshold A = a Force +2Δ); and when the rudder surface is in motion, the range of the rudder surface position feedback value is determined to be between the rudder surface position minus the rudder surface position control accuracy and the rudder surface position plus the rudder surface position control accuracy, and under the strictest error accumulation, the first monitoring threshold is determined to be the sum of the maximum force conflict angle difference of the rudder surface and twice the rudder surface position control accuracy.

[0087] In one embodiment of the present invention, the second-layer monitoring device 204 may be configured to determine the average value (L) of the displacement sensors of the two actuators on the symmetrical control surface of the faulty control surface. aver ), and compare each of the control surface position feedback values ​​of the two actuators on the faulty control surface with the average control surface position feedback value (in Figure 1 In, that is, |R1-L aver |、|R2-L aver |), if the result of the comparison is greater than the second monitoring threshold (|R1-L) aver |or|R2-L aver |>B, Second monitoring threshold B=a Force If +4Δ), it indicates that the actuator corresponding to the control surface position feedback value (the actuator corresponding to R1 or R2) has failed.

[0088] In another embodiment of the present invention, the second-layer monitoring device 204 may be further configured to: when the control surface is in a stable static state, determine the range of the average control surface position feedback value as between the control surface command position minus the control surface position control accuracy and the control surface command position plus the control surface position control accuracy (in the case of...). Figure 1 In, that is, L aver In [a cmd -Δ, a cmd Within the range of +Δ], and under the most stringent error accumulation, the second monitoring threshold is determined as the sum of the maximum force conflict angle difference of the control surface and four times the position control accuracy of the control surface (i.e., the second monitoring threshold B = a). Force+4Δ); and when the control surface is in motion, the range of the control surface position feedback value is determined to be between the average control surface position feedback value minus twice the control surface position control accuracy and the average control surface position feedback value plus twice the control surface position control accuracy (within Figure 1 In the middle, that is, R1 and R2 are in [L aver -2Δ, L aver Within the range of +2Δ], and under the strictest error accumulation, the second monitoring threshold is determined as the sum of the maximum force dispute angle difference of the control surface and four times the position control accuracy of the control surface.

[0089] As those skilled in the art will understand, in addition to the most stringent error accumulation method, any other suitable error accumulation method may be used in this invention, and any other suitable margin may be superimposed in addition to the maximum force conflict angle difference of the control surface. This invention is not limited to any specific error accumulation method and any specific margin or specific margin ratio.

[0090] In one embodiment of the invention, the fault isolation device 206 may be configured to disconnect the rudder circuit of the faulty actuator. In another embodiment of the invention, after the fault is detected, the fault isolation device 206 is generally configured to latch the fault and disable the displacement sensor feedback of the faulty actuator. If the displacement sensor is an internal displacement sensor of the actuator, the corresponding actuator is set to bypass / damping mode.

[0091] Figure 3 This is a flowchart of a method 300 for monitoring and handling actuator failures on symmetrical control surfaces of an aircraft, according to an embodiment of the present invention.

[0092] like Figure 3 As shown, method 300 begins at step 302, where two actuators are arranged on symmetrical rudder surfaces and a displacement sensor is arranged for each actuator.

[0093] Next, method 300 continues to step 304, comparing the control surface position feedback values ​​of the displacement sensors of the two actuators on each control surface to determine whether the control surface is working properly. If the difference between these control surface position feedback values ​​is greater than a first monitoring threshold, it is determined that the control surface has an actuator malfunction. In one embodiment of the invention, the first monitoring threshold is determined based on the control surface position control accuracy and the maximum force dispute angle difference of the control surface. In this embodiment, when the control surface is in a stable static state, the range of the control surface position feedback value is between the control surface command position minus the control surface position control accuracy and the control surface command position plus the control surface position control accuracy. Furthermore, the first monitoring threshold, under the most stringent error accumulation, is determined to be the sum of the maximum force dispute angle difference of the control surface and twice the control surface position control accuracy. When the control surface is in motion, the range of the control surface position feedback value is between the control surface position minus the control surface position control accuracy and the control surface position plus the control surface position control accuracy. Furthermore, the first monitoring threshold, under the most stringent error accumulation, is determined to be the sum of the maximum force dispute angle difference of the control surface and twice the control surface position control accuracy. In another embodiment of the invention, the control surface position control accuracy is based on at least the following factors: displacement sensor accuracy; installation clearance; and digital-to-analog conversion calculation accuracy, and the maximum force dispute angle is the ratio of the actuator output force to the torsional stiffness of the control surface, and the absolute value of the angle difference of the maximum force dispute angle is greater than twice the control surface position control accuracy.

[0094] Subsequently, method 300 continues to step 306, determining the average rudder surface position feedback value of the displacement sensors of the two actuators on the symmetrical rudder surface of the faulty rudder surface. In one embodiment of the invention, the range of the average rudder surface position feedback value is determined to be between the rudder surface command position minus the rudder surface position control accuracy and the rudder surface command position plus the rudder surface position control accuracy.

[0095] Then, method 300 continues to step 308, comparing each of these control surface position feedback values ​​with the average control surface position feedback value, wherein the result of the comparison is greater than a second monitoring threshold indicating that the actuator corresponding to the control surface position feedback value has failed. In one embodiment of the invention, the second monitoring threshold is determined based on the control surface position control accuracy and the difference between the maximum force dispute angle of the control surface, and the result of the comparison is the absolute value of the difference between the control surface position feedback value of each actuator on the failed control surface and the average control surface position feedback value. In another embodiment of the present invention, when the rudder surface is in a stable static state, the range of the average rudder surface position feedback value is between the rudder surface command position minus the rudder surface position control accuracy and the rudder surface command position plus the rudder surface position control accuracy. Furthermore, the second monitoring threshold is determined under the most stringent error accumulation as the sum of the maximum force conflict angle difference of the rudder surface and four times the rudder surface position control accuracy. When the rudder surface is in motion, the range of the rudder surface position feedback value is between the average rudder surface position feedback value minus twice the rudder surface position control accuracy and the average rudder surface position feedback value plus twice the rudder surface position control accuracy. Furthermore, the second monitoring threshold is determined under the most stringent error accumulation as the sum of the maximum force conflict angle difference of the rudder surface and four times the rudder surface position control accuracy.

[0096] Finally, method 300 proceeds to step 310, disconnecting the rudder circuit of the faulty actuator.

[0097] After step 310, method 300 ends.

[0098] In summary, this invention proposes a method and system for monitoring and handling faults in aircraft servo displacement sensors for symmetrical control surfaces of flight control. By comprehensively utilizing the commands of the symmetrical control surfaces and the feedback from the position sensors, and without adding additional position sensors, the fault source of the position sensor is disconnected through hierarchical voting. This allows for accurate fault location and isolation while avoiding additional weight, cost, cabling, and installation structures, thereby improving the availability of control surface control and preventing any impact on pilot operation.

[0099] The embodiments of the present invention have been described above with reference to block diagrams and / or operational descriptions of methods, systems, and computer program products according to embodiments of the present invention. The functions / actions indicated in the blocks may appear in a different order than shown in any flowchart. For example, depending on the functions / actions involved, two blocks shown consecutively may actually be executed substantially simultaneously, or these blocks may sometimes be executed in reverse order.

[0100] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for monitoring and handling actuator failures on symmetrical control surfaces of an aircraft, the method comprising: Two actuators are arranged on symmetrical control surfaces, and a displacement sensor is arranged for each actuator. The displacement sensor values ​​of the two actuators on each control surface are compared to determine whether the control surface is working properly. If the difference between the control surface position feedback values ​​is greater than a first monitoring threshold, it is determined that the control surface has an actuator malfunction. Determine the average position feedback value of the displacement sensors of the two actuators on the symmetrical control surface of the control surface; Each of the control surface position feedback values ​​is compared with the average control surface position feedback value, wherein if the result of the comparison is greater than a second monitoring threshold, it indicates that the actuator corresponding to the control surface position feedback value has malfunctioned. as well as Disconnect the rudder circuit of the faulty actuator.

2. The method of claim 1, wherein the first monitoring threshold and the second monitoring threshold are determined based on the control surface position control accuracy and the difference between the maximum force conflict angle of the control surface, and the result of the comparison is the absolute value of the difference between the control surface position feedback value and the average value of the control surface position feedback.

3. The method of claim 2, wherein when the control surface is in a stable static state, the range of the control surface position feedback value is between the control surface command position minus the control surface position control accuracy and the control surface command position plus the control surface position control accuracy, and the first monitoring threshold is determined under the strictest error accumulation as the sum of the maximum force conflict angle difference of the control surface and twice the control surface position control accuracy.

4. The method of claim 2, wherein when the control surface is in motion, the range of the control surface position feedback value is between the control surface position minus the control surface position control accuracy and the control surface position plus the control surface position control accuracy, and the first monitoring threshold is determined under the strictest error accumulation as the sum of the maximum force conflict angle difference of the control surface and twice the control surface position control accuracy.

5. The method of claim 2, wherein when the control surface is in a stable static state, the range of the average value of the control surface position feedback is between the control surface command position minus the control surface position control accuracy and the control surface command position plus the control surface position control accuracy, and the second monitoring threshold is determined under the strictest error accumulation as the sum of four times the maximum force conflict angle difference of the control surface and the control surface position control accuracy.

6. The method of claim 2, wherein when the control surface is in motion, the range of the control surface position feedback value is between the average control surface position feedback value minus twice the control surface position control accuracy and the average control surface position feedback value plus twice the control surface position control accuracy, and the second monitoring threshold is determined under the strictest error accumulation as the sum of the maximum force conflict angle difference of the control surface and four times the control surface position control accuracy.

7. The method of claim 2, wherein the control surface position control accuracy is based at least on the following factors: displacement sensor accuracy; installation clearance; and digital-to-analog conversion accuracy.

8. The method of claim 2, wherein the maximum force dispute angle is the ratio of the actuator output force to the torsional stiffness of the control surface, and the absolute value of the difference in the maximum force dispute angle of the control surface is greater than twice the control surface position control accuracy.

9. The method of claim 1, wherein the control surfaces include aileron control surfaces and elevator control surfaces.

10. A system for monitoring and handling actuator failures on symmetrical control surfaces of an aircraft, wherein two actuators are arranged on each symmetrical control surface and each actuator has a displacement sensor, the system comprising: The first-level monitoring device is configured to compare the control surface position feedback values ​​of the displacement sensors of two actuators on each control surface to determine whether the control surface is working properly, wherein if the difference between the control surface position feedback values ​​is greater than a first monitoring threshold, it is determined that the control surface has an actuator malfunction. The second-level monitoring device is configured as follows: Determine the average position feedback value of the displacement sensors of the two actuators on the symmetrical control surface of the control surface; as well as Each of the control surface position feedback values ​​is compared with the average control surface position feedback value, wherein if the result of the comparison is greater than a second monitoring threshold, it indicates that the actuator corresponding to the control surface position feedback value has malfunctioned. as well as A fault isolation device, configured to disconnect the rudder circuit of a faulty actuator.

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