Vibration detection device for aircraft

Abstract

To detect vibrations of a rotor blade.SOLUTION: A vibration detection device 70 for an aircraft includes: a difference calculation part 72 that calculates a difference between a target value and an actual value of an angle of a spoiler 12; a threshold determination part 74 that determines whether or not an absolute value of the difference is a threshold or above; and a vibration determination part 82 that determines that vibrations are generated in the spoiler 12 when the absolute value of the difference is the threshold or above.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to an aircraft vibration detection device, an aircraft vibration detection method, and an aircraft vibration detection program.

Background Art

[0002] On the main wing of an aircraft disclosed in Patent Document 1, a spoiler which is a movable wing is attached. The spoiler is driven by an actuator. The actuator is controlled by a controller. The controller outputs a control signal to the actuator in response to a signal from above according to an operation of a control lever by a pilot or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a technique such as Patent Document 1, due to a failure of a circuit in the controller or the like, an inappropriate control signal may be output from the controller to the actuator. In this case, while the target value of the angle of the movable wing commanded to the controller from above is constant, the actual angle of the movable wing may alternately repeat exceeding and falling below the target value, that is, vibration of the movable wing may occur. Further, in addition to a failure of a circuit in the controller, the target value of the angle of the movable wing itself may be an inappropriate value, and vibration may occur in the movable wing when trying to control the actuator to compensate for the difference between the inappropriate target value and the actual angle of the movable wing. From the viewpoint of more reliably controlling the movable wing, it is preferable to be able to detect such vibration of the movable wing.

[0005] This invention has been made in view of such circumstances, and its object is to detect vibration of a movable wing.

Means for Solving the Problems

[0006] A vibration detection device for aircraft that solves the above problems is applied to an aircraft in which a rotor blade is driven by an actuator, and comprises a difference calculation unit that calculates the difference between a target value of the angle of the rotor blade and a measured value of the angle of the rotor blade, a threshold determination unit that determines whether the absolute value of the difference is greater than or equal to a threshold, and a vibration determination unit that determines that vibration is occurring in the rotor blade if the absolute value of the difference is greater than or equal to the threshold.

[0007] If vibration occurs in the rotor blade, the measured angle of the rotor blade will be above or below the target value. Therefore, if the difference exceeds the threshold, there is a high probability that vibration is occurring in the rotor blade. Accordingly, as in the configuration described above, vibration in the rotor blade can be detected by comparing the absolute value of the difference with the threshold.

[0008] The above-described vibration detection device for aircraft may include a count calculation unit that calculates the number of times the absolute value of the difference exceeds the threshold. In the above-described aircraft vibration detection device, the vibration determination unit may determine that vibration is occurring in the rotor blade when the absolute value of the difference exceeds the threshold a specified number of times.

[0009] The above-described aircraft vibration detection device may include an elapsed time determination unit that measures the elapsed time since the absolute value of the difference exceeded the threshold. In the above-described aircraft vibration detection device, the vibration determination unit may determine that vibration is occurring in the control surface if the absolute value of the difference exceeds the threshold value once, and then the absolute value of the difference exceeds the threshold value a specified number of times within the determination period.

[0010] In the above-described aircraft vibration detection device, the vibration determination unit may determine that the vibration of the control surface has subsided if, after the absolute value of the difference exceeds the threshold once, the number of times the absolute value of the difference exceeds the threshold within the determination period is less than the specified number of times.

[0011] The above-described aircraft vibration detection device may have a stop signal output unit that outputs a stop signal to stop the actuator from driving the rotor blade when it is determined that vibration is occurring in the rotor blade.

[0012] The above-described vibration detection device for aircraft includes a control operation determination unit that determines whether the time change of the target value corresponds to the operation of the aircraft's control stick, and the vibration determination unit does not need to determine that vibration is occurring in the control surface if the time change of the target value corresponds to the operation of the control stick.

[0013] A vibration detection method for aircraft that solves the above problems is applied to an aircraft in which a rotor blade is driven by an actuator, and comprises a difference calculation process that calculates the difference between a target value of the angle of the rotor blade and a measured value of the angle of the rotor blade, a threshold determination process that determines whether the absolute value of the difference is greater than or equal to a threshold, and a vibration determination process that determines that vibration is occurring in the rotor blade if the absolute value of the difference is greater than or equal to the threshold.

[0014] If vibration is occurring in the rotor blade, the measured angle of the rotor blade will be above or below the target value. Therefore, if the difference exceeds the threshold, there is a high probability that vibration is occurring in the rotor blade. Accordingly, by comparing the absolute value of the difference with the threshold, as in the method described above, it is possible to detect that vibration is occurring in the rotor blade.

[0015] The vibration detection program for aircraft, designed to solve the above problems, is applied to an aircraft in which the control surfaces are driven by actuators, and causes a computer to perform a difference calculation process that calculates the difference between a target value for the angle of the control surface and the measured value for the angle of the control surface, a threshold determination process that determines whether the absolute value of the difference is greater than or equal to a threshold, and a vibration determination process that determines that vibration is occurring in the control surface if the absolute value of the difference is greater than or equal to the threshold.

[0016] When vibration occurs in the moving blade, the measured value of the angle of the moving blade exceeds or falls below the target value. From this, when the difference exceeds the threshold value, there is a high possibility that vibration has occurred in the moving blade. Therefore, by comparing the absolute value of the difference with the threshold value as in the above program, it is possible to detect that vibration has occurred in the moving blade.

Advantages of the Invention

[0017] According to the present invention, vibration of the moving blade can be detected.

Brief Description of the Drawings

[0018] [Figure 1] Schematic diagram of the configuration related to the drive of the spoiler. [Figure 2] Flowchart showing the processing procedure of the flight operation determination process. [Figure 3] Flowchart showing the processing procedure of the positive side vibration detection process. [Figure 4] Flowchart showing the processing procedure of the negative side vibration detection process. [Figure 5] Time chart showing an example of the time change of the difference. [Figure 6] Time chart showing an example of the time change of the difference. [Figure 7] Block diagram showing the outline of the vibration detection process and the flight operation determination process. [Figure 8] Figure showing an example in which minute fluctuations are included in the time change of the difference.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, an embodiment of an aircraft vibration detection device applied to an aircraft will be described with reference to the drawings. First, the schematic configuration of the spoiler and the actuator will be described. As shown in FIG. 1, a spoiler 12 is attached to the wing 11 of the aircraft 10. The spoiler 12 is located behind the center of the wing 11 in the longitudinal direction of the aircraft 10. Although a plurality of spoilers 12 are provided, only one is shown in FIG. 1. The plurality of spoilers 12 are arranged side by side in the lateral direction of the aircraft 10. Hereinafter, any one of the plurality of spoilers 12 will be described.

[0020] The spoiler 12 is connected to the wing 11 via a rotating shaft 14. The spoiler 12 is rotatable with respect to the wing 11 about the rotating shaft 14 as the center of rotation. The spoiler 12 rotates between a retracted position arranged substantially parallel to the wing 11 and an inclined position inclined upward with respect to the wing 11.

[0021] An actuator 30 for driving the operation of the spoiler 12 is attached to the spoiler 12. The actuator 30 is an electro-hydraulic type. The actuator 30 has a cylindrical cylinder 32. The inside of the cylinder 32 is a fluid chamber 32A to which hydraulic oil is supplied and discharged. A rod-shaped rod 34 is arranged coaxially with the cylinder 32 in the fluid chamber 32A. A piston 36 projects radially outward from the tip of the rod 34 on one side in the central axis direction. The piston 36 divides the fluid chamber 32A into two parts. When the hydraulic pressure of the fluid chamber 32A acts on the piston 36, the rod 34 reciprocates in the central axis direction thereof. A part of the rod 34 on the other side in the central axis direction projects from the cylinder 32. The tip of the rod 34 on the other side in the central axis direction is a substantially annular mounting portion 38. The mounting portion 38 is attached to the spoiler 12.

[0022] A position detector 39 for detecting the position of the rod 34 with respect to the cylinder 32 is attached to the cylinder 32. The position of the rod 34 is defined as the separation distance between a predetermined reference position and the end of the rod 34 on one side in the central axis direction thereof. The predetermined reference position is the end of the cylinder 32 on one side in the central axis direction thereof. The position detector 39 detects a measured separation distance R1 which is the measured value of the above separation distance.

[0023] A manifold 31, which contains a hydraulic circuit for hydraulic fluid, is fixed to the outer surface of the cylinder 32. The hydraulic circuit includes hydraulic control valves, etc., for switching the flow path of the hydraulic circuit. The hydraulic fluid of the hydraulic circuit is supplied to and discharged from the inside of the cylinder 32.

[0024] Next, the control configuration of the actuator 30 will be described. The aircraft 10 is equipped with a central control unit 50 that comprehensively controls the operation of various parts of the aircraft 10. The central control unit 50 may be configured as one or more processors that execute various processes according to a computer program (software). Alternatively, the central control unit 50 may be configured as a circuit including one or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs), or a combination thereof, that execute at least some of the various processes. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0025] The control unit 50 receives input from the control input P1 of the control stick 17 located in the cockpit of the aircraft 10. The control unit 50 calculates a target value P2 for the angle of the spoiler 12 (hereinafter referred to as the target angle) according to the control input P1 of the control stick 17, and outputs a signal related to this target angle P2.

[0026] The aircraft 10 is equipped with an actuator control device 60 that controls the actuator 30. The actuator control device 60 may be configured as one or more processors that execute various processes according to a computer program (software). Alternatively, the actuator control device 60 may be configured as a circuit including one or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs), or a combination thereof, that execute at least some of the various processes. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0027] The actuator control device 60 receives a signal regarding the measured separation distance R1 of the rod 34 detected by the position detector 39. The actuator control device 60 also receives a signal regarding the target angle P2 of the spoiler 12 output by the overall control device 50.

[0028] The actuator control device 60 has an operating amount calculation unit 62 that calculates the operating amount R3 of the rod 34. The operating amount calculation unit 62 acquires the target angle P2 of the spoiler 12 and converts this target angle P2 into a target distance R2, which is the target distance of the rod 34 from the reference position. The operating amount calculation unit 62 also acquires the measured distance R1 of the rod 34 and calculates the operating amount R3 of the rod 34 so as to compensate for the difference between the measured distance R1 and the target distance R2. Specifically, the operating amount calculation unit 62 calculates the operating amount R3 of the rod 34 by multiplying the difference between the measured distance R1 and the target distance R2 by a predetermined gain. The operating amount calculation unit 62 then outputs a signal related to the operating amount R3 of the rod 34. The signal related to the operating amount R3 of the rod 34 is, in effect, the operating amount R3 of the rod 34 converted into an electrical signal for driving the hydraulic control valve of the manifold 31.

[0029] The circuit constituting the operation amount calculation unit 62 is connected to the hydraulic control valve of the manifold 31 via a communication line 61. An actuator connection switch 63 is provided along this communication line 61 to switch the communication line 61 between an connected state and an disconnected state. When this actuator connection switch 63 is in the connected state, a signal related to the operation amount R3 of the rod 34 is input to the hydraulic control valve. On the other hand, when this actuator connection switch 63 is in the disconnected state, the input of the above signal to the hydraulic control valve is cut off. When the input of the above signal to the hydraulic control valve is cut off, the actuator 30 is set to operate to return the spoiler 12 to the retracted position.

[0030] As will be explained in detail later, a malfunction in the circuit of the control amount calculation unit 62 may cause the control amount R3 of the rod 34 to be calculated as an inappropriate value, resulting in the measured separation distance R1 of the rod 34 repeatedly exceeding or falling below the target separation distance R2. Similarly, a malfunction in the circuit of the overall control device 50 may cause the target angle P2 of the spoiler 12 to be calculated as an inappropriate value, resulting in the measured separation distance R1 of the rod 34 repeatedly exceeding or falling below the target separation distance R2. This alternating pattern causes the actual angle of the spoiler 12 to repeatedly exceed or fall below the target angle P2, i.e., it leads to vibration of the spoiler 12. Part of the actuator control device 60 functions as an aircraft vibration detection device 70 to detect such vibration of the spoiler 12.

[0031] The aircraft vibration detection device 70 is capable of performing a vibration detection process W1 to detect vibrations of the spoiler 12. As shown in Figures 1 and 7, the aircraft vibration detection device 70 has a difference calculation unit 72 that performs a difference calculation process M1, which is one of the processes in the vibration detection process W1. The difference calculation unit 72 calculates the difference between the target angle P2 of the spoiler 12 and the measured angle of the spoiler 12. In essence, the difference calculation unit 72 calculates the difference Z between the target separation distance R2 of the rod 34 and the measured separation distance R1 (Z = R1 - R2). That is, in this embodiment, the difference calculation unit 72 treats the target separation distance R2 of the rod 34 as the target angle P2 of the spoiler 12, and treats the measured separation distance R1 of the rod 34 as the measured angle of the spoiler 12. Furthermore, when the measured separation distance R1 alternately exceeds and falls below the target separation distance R2, the difference Z shows a time change that increases or decreases around zero, as shown in Figure 5. The vibration detection process W1 has two types: a positive vibration detection process W1A that detects the vibration of the spoiler 12 by utilizing the time change characteristics while the difference Z is increasing, and a negative vibration detection process W1B that detects the vibration of the spoiler 12 by utilizing the time change characteristics while the difference Z is decreasing. Here, when trying to determine the magnitude of the amplitude in a time change that increases or decreases relative to a reference value, if the reference value itself changes, it becomes difficult to determine the first threshold K1 and the second threshold K2, described later, for determining the magnitude of the amplitude. In this respect, the difference Z shows a time change centered on zero. With such a time change, it is possible to uniformly determine the first threshold K1 and the second threshold K2 for determining the magnitude of the amplitude, which is preferable.

[0032] The aircraft vibration detection device 70 has a threshold determination unit 74 that performs a threshold determination process M2, which is one of the processes in the vibration detection process W1. In the first threshold determination process M2A, which is the threshold determination process M2 of the positive vibration detection process W1A, the threshold determination unit 74 determines whether the difference Z is greater than or equal to the first threshold K1. The threshold determination unit 74 continuously acquires the difference Z and continues to perform the above determination. The first threshold K1 is a positive value. As shown in Figure 8, the difference Z may fluctuate above or below the first threshold K1 due to the influence of noise, etc. Therefore, the threshold determination unit 74 excludes such fluctuating components and determines whether the difference Z has become greater than or equal to the first threshold K1. That is, once the threshold determination unit 74 determines that the difference Z is greater than or equal to the first threshold K1, it does not determine whether the difference Z is greater than or equal to the first threshold K1 until the difference Z decreases to zero or less in the time change of the difference Z. After the threshold determination unit 74 determines that the difference Z is greater than or equal to the first threshold K1, if the difference Z decreases to zero or less, it resumes determining whether the difference Z is greater than or equal to the first threshold K1.

[0033] As shown in Figures 1 and 7, the threshold determination unit 74 determines whether the difference Z is less than or equal to the second threshold K2 in the second threshold determination process M2B, which is the threshold determination process M2 of the negative vibration detection process W1B. The threshold determination unit 74 continuously acquires the difference Z and continues to perform the above determination. The second threshold K2 is a negative value that has the same absolute value as the first threshold K1. Once the threshold determination unit 74 determines that the difference Z is less than or equal to the second threshold K2, it does not determine whether the difference Z is less than or equal to the second threshold K2 until the difference Z increases to zero or more in the time change of the difference Z. After the threshold determination unit 74 determines that the difference Z is less than or equal to the second threshold K2, if the difference Z increases to zero or more, it resumes determining whether the difference Z is less than or equal to the second threshold K2.

[0034] The threshold determination unit 74 stores a first threshold K1 and a second threshold K2 in advance. The first threshold K1 is determined by experimentation or simulation as the minimum amplitude that the time change of difference Z can take under the condition that the circuit of the manipulated variable calculation unit 62 or the circuit of the control unit 50 has failed. The first threshold K1 is, for example, a value corresponding to 1 degree as the angle of the spoiler 12. The amplitude is half the difference between the upper peak where the difference Z changes from increasing to decreasing and the lower peak where the difference Z changes from decreasing to increasing in the time change of difference Z.

[0035] The aircraft vibration detection device 70 has an elapsed time determination unit 76 that performs an elapsed time determination process M3, which is one of the processes in the vibration detection process W1. In the elapsed time determination process M3A of the positive vibration detection process W1A, the elapsed time determination unit 76 measures the elapsed time since the difference Z increased to a first threshold K1. Specifically, the elapsed time determination unit 76 measures the first elapsed time TS1 from when the difference Z increased to the first threshold K1 until the difference Z increased to the first threshold K1 again. The elapsed time determination unit 76 then determines whether the first elapsed time TS1 is within a specified elapsed time range SD. Furthermore, in relation to the condition that the difference Z decreases to zero or less between the time it is determined that the difference Z is greater than or equal to the first threshold K1 and the time it is determined that the difference Z is greater than or equal to the first threshold K1 again, the elapsed time determination unit 76 determines whether the first elapsed time TS1 is within the specified elapsed time range SD, on the condition that the difference Z becomes zero or less between the time it increases to the first threshold K1 and the time it increases to the first threshold K1 again.

[0036] Furthermore, in the elapsed time determination process M3B of the negative vibration detection process W1B, the elapsed time unit 76 measures the elapsed time since the difference Z decreased to the second threshold K2. Specifically, the elapsed time determination unit 76 measures the second elapsed time TS2 from the time the difference Z decreased to the second threshold K2 until the difference Z decreased to the second threshold K2 again. The elapsed time determination unit 76 then determines whether the second elapsed time TS2 is within the specified elapsed time range SD. In relation to the condition that the difference Z increases to zero or more between the time the difference Z is determined to be less than or equal to the second threshold K2 and the time the difference Z is determined to be less than or equal to the second threshold K2 again, the elapsed time determination unit 76 determines whether the second elapsed time TS2 is within the specified elapsed time range SD, on the condition that the difference Z is zero or more between the time the difference Z decreased to the second threshold K2 and the time the difference Z decreased to the second threshold K2 again.

[0037] The elapsed time determination unit 76 stores in advance a predetermined elapsed time range SD, which is defined as a range from a lower limit time to an upper limit time. The lower limit time of the predetermined elapsed time range SD is determined by experimentation or simulation as the minimum period that the time change of difference Z can take under circumstances where the circuits of the manipulated variable calculation unit 62 or the control unit 50 have failed. For example, the lower limit time of the predetermined elapsed time range SD is 0.01 seconds. The upper limit time of the predetermined elapsed time range SD is determined by experimentation or simulation as the maximum period that the time change of difference Z can take under circumstances where the circuits of the manipulated variable calculation unit 62 or the control unit 50 have failed. For example, the upper limit time of the predetermined elapsed time range SD is 0.05 seconds. Note that the period refers to the time interval between adjacent upper peaks in the time change of difference Z.

[0038] The aircraft vibration detection device 70 has a count calculation unit 78 that performs a count calculation process M4, which is one of the processes in the vibration detection process W1. In the count calculation process M4A of the positive vibration detection process W1A, the count calculation unit 78 calculates a first count C1, which is the number of times it is determined that the difference Z has increased to a first threshold K1 during a period in which the condition that the first elapsed time TS1 is within a specified elapsed time range SD is continuously met. This first count C1 is the number of times it is determined that the difference Z has increased to the first threshold K1, with a state in between where the difference Z has decreased to zero or less. In addition, in the count calculation process M4B of the negative vibration detection process W1B, the count calculation unit 78 calculates a second count C2, which is the number of times it is determined that the difference Z has decreased to a second threshold K2 during a period in which the condition that the second elapsed time TS2 is within a specified elapsed time range SD is continuously met. This second count C2 is the number of times it is determined that the difference Z has decreased to the second threshold K2, with a state in between where the difference Z has increased to zero or greater.

[0039] The aircraft vibration detection device 70 has a vibration determination unit 82 that performs a vibration determination process M5, which is one of the processes in the vibration detection process W1. The vibration determination unit 82 determines whether or not vibration is occurring in the spoiler 12. In the vibration determination process M5A of the positive vibration detection process W1A, the vibration determination unit 82 determines that vibration is occurring in the spoiler 12 on the condition that the first count C1 is equal to or greater than a specified count CD. As described above, the first count C1 is calculated on the premise that the first elapsed time TS1 is within the specified elapsed time range SD, so one of the conditions for the vibration determination unit 82 to determine that vibration is occurring in the spoiler 12 is that the first elapsed time TS1 is within the specified elapsed time range SD. Also, since the first count C1 is the number of times it is determined that the difference Z has increased to the first threshold K1, one of the conditions for the vibration determination unit 82 to determine that vibration is occurring in the spoiler 12 is that the difference Z has increased to or greater than the first threshold K1.

[0040] As described above, the vibration determination unit 82 determines that vibration is occurring in the spoiler 12 when the first count C1 is equal to or greater than the specified count CD. This can be rephrased based on the definition of the first count C1. That is, the vibration determination unit 82 determines that vibration is occurring in the spoiler 12 when, after the difference Z increases once to the first threshold K1, the number of times the difference Z increases to the first threshold K1, including the one that triggered the start of the determination period J, is equal to or greater than the specified count CD. The above determination period J is the value obtained by multiplying the specified count CD by the upper limit time of the specified elapsed time range SD. In other words, the determination period J is predetermined. As described above, the elapsed time determination unit 76 measures the first elapsed time TS1 each time the difference Z increases to the first threshold K1. In this way, the elapsed time determination unit 76 indirectly measures the series of elapsed times from when the difference Z increases once to the first threshold K1 until the determination period J has elapsed. The vibration detection unit 82 takes this elapsed time into consideration when determining whether or not the spoiler 12 is vibrating.

[0041] In the vibration determination process M5B of the negative vibration detection process W1B, the vibration determination unit 82 determines that vibration is occurring in the spoiler 12 on the condition that the second count C2 is equal to or greater than the specified count CD. In the definition of calculating the second count C2, one of the conditions for the vibration determination unit 82 to determine that vibration is occurring in the spoiler 12 is that the second elapsed time TS2 is within the specified elapsed time range SD. Another condition for the vibration determination unit 82 to determine that vibration is occurring in the spoiler 12 is that the difference Z decreases to or less than the second threshold K2.

[0042] As described above, the vibration determination unit 82 determines that vibration is occurring in the spoiler 12 when the second count C2 is equal to or greater than the specified count CD. This can be rephrased based on the definition of the second count C2. That is, the vibration determination unit 82 determines that vibration is occurring in the spoiler 12 when, after the difference Z decreases to the second threshold K2 once, the number of times the difference Z decreases to the second threshold K2, including the one time that triggered the start of the determination period J, is equal to or greater than the specified count CD. The determination period J has already been explained. As described above, the elapsed time determination unit 76 measures the second elapsed time TS2 each time the difference Z decreases to the second threshold K2. In this way, the elapsed time determination unit 76 indirectly measures the series of elapsed times from when the difference Z decreases to the second threshold K2 once until the determination period J has elapsed. The vibration determination unit 82 then takes this elapsed time into consideration when determining whether or not there is vibration in the spoiler 12.

[0043] The vibration determination unit 82 stores a predetermined number of cycles CD in advance. The predetermined number of cycles CD is determined through experiments and simulations as the number of cycles at which it can be considered certain that continuous vibration is occurring in the spoiler 12 due to a failure in the circuit of the manipulated variable calculation unit 62 or the circuit of the overall control device 50. The predetermined number of cycles CD is, for example, 10 times.

[0044] The aircraft vibration detection device 70 has a stop signal output unit 84 that performs a stop signal output process M6, which is one of the processes in the vibration detection process W1. In the stop signal output process M6, the stop signal output unit 84 outputs a stop signal to stop the actuator 30 from driving the spoiler 12 when it is determined that vibration is occurring in the spoiler 12. Specifically, as a stop signal, the stop signal output unit 84 outputs a shut-off signal Q to the actuator connection switch 63, which switches the actuator connection switch 63 to the shut-off state.

[0045] The aircraft vibration detection device 70 has a control operation determination unit 88 that performs a control operation determination process W2 in parallel with the vibration detection process W1. In this case, the target angle P2 of the spoiler 12 may be changed by operating the control stick 17 to intentionally cause the spoiler 12 to vibrate. In such situations, it is necessary to exclude the vibration of the spoiler 12 from the detection of the occurrence of vibration of the spoiler 12. Therefore, the control operation determination unit 88 determines whether the time change of the target angle P2 is a change corresponding to the operation of the control stick 17. If the control operation determination unit 88 determines that the time change of the target angle P2 is a change corresponding to the operation of the control stick 17, it turns on a prohibition flag F to prevent it from determining that vibration is occurring in the spoiler 12.

[0046] Specifically, the control operation determination unit 88 performs a rate of change calculation process N1 to calculate the rate of change of the target angle P2 per unit time (hereinafter referred to as the target value rate of change) ΔP2. The control operation determination unit 88 also performs a positive rate of change determination process N2 to determine whether the first condition is met, which is that the target value rate of change ΔP2 is equal to or greater than the first rate of change L1 while the target angle P2 is increasing. The control operation determination unit 88 also performs a negative rate of change determination process N3 to determine whether the second condition is met, which is that the target value rate of change ΔP2 is equal to or less than the second rate of change L2 while the target angle P2 is decreasing after the first condition has been met and the target angle P2 has changed from increasing to decreasing. The second rate of change L2 is a negative value with the same absolute value as the first rate of change L1. Furthermore, assuming that the second condition is met, the control operation determination unit 88 performs a change rate continuation determination process N4 to determine whether the third condition is met, which is the elapsed time for determination TM, the time elapsed from the moment the first condition is met to the moment the first condition is met again, and whether or not the prescribed time for determination TMD is less than or equal to the third condition. The control operation determination unit 88 determines that the time change of the target angle P2 is in response to the operation of the control stick 17 during the period in which the third condition is continuously met, and turns on a prohibition flag F to prohibit vibration detection of the spoiler 12 during that time. The process of turning on the prohibition flag F is a mask process N5. As described later, when the prohibition flag F is on, the determination of whether the difference Z is greater than or equal to the first threshold K1, and the determination of whether the difference Z is less than or equal to the second threshold K2 are not performed.

[0047] The control operation determination unit 88 stores a first rate of change L1 and a second rate of change L2 in advance. The first rate of change L1 is, for example, the minimum value of the target value change rate ΔP2 that the time change of the target angle P2 can take when the control stick 17 is being operated, and is determined by experimentation or simulation as the minimum value of the target value change rate ΔP2 when the target angle P2 is increasing. The control operation determination unit 88 also stores a predetermined determination time TMD in advance. The predetermined determination time TMD is the same as the upper limit of the predetermined elapsed time range SD.

[0048] Next, the specific processing procedures for vibration detection process W1 and control operation determination process W2 will be explained. In control operation determination process W2, the prohibition flag F is set to on or off. Then, in vibration detection process W1, it is determined whether or not vibration of the spoiler 12 can be detected based on the on or off status of this prohibition flag F. Therefore, below, control operation determination process W2 will be explained first, and then vibration detection process W1 will be explained.

[0049] The control operation determination unit 88 performs the control operation determination process W2 under the following settings. As described below, in the control operation determination process W2, the control operation determination unit 88 repeatedly acquires the target angle P2 of the spoiler 12 input from the control unit 50. The control operation determination unit 88 is configured to hold the most recently acquired target angle P2 and the target angle P2 acquired at the previous timing. The control operation determination unit 88 is also configured to acquire the target angle P2 at a predetermined acquisition time interval ΔT.

[0050] As shown in Figure 2, when the piloting operation determination unit 88 starts the piloting operation determination process W2, it executes the process in step S110. In step S110, the piloting operation determination unit 88 sets the prohibition flag F to OFF. After this, the piloting operation determination unit 88 proceeds to step S115.

[0051] In step S115, the control operation determination unit 88 waits for a predetermined acquisition time interval ΔT to elapse since the previous acquisition of the target angle P2 before acquiring a new target angle P2. Once the new target angle P2 is acquired, the control operation determination unit 88 proceeds to step S120.

[0052] In step S120, the piloting operation determination unit 88 determines whether the target value change rate ΔP2 is greater than or equal to the first change rate L1. Specifically, the piloting operation determination unit 88 calculates the target value change rate ΔP2 by dividing the value obtained by subtracting the previous target angle P2 from the latest target angle P2 obtained in step S115 by the acquisition time interval ΔT. This process is the change rate calculation process N1. Note that if the piloting operation determination process W2 is performed for the first time after the aircraft 10 has started operation, the previous target angle P2 is set to zero. If the target value change rate ΔP2 is less than the first change rate L1 (step S120: NO), the piloting operation determination unit 88 executes the process in step S115 again. The piloting operation determination unit 88 repeats the processes in steps S115 and S120 until the target value change rate ΔP2 is greater than or equal to the first change rate L1. This iterative process involves monitoring the time change of the target angle P2 and waiting until the rate of change of the target value ΔP2 becomes equal to or greater than the first rate of change L1. When the control operation determination unit 88 determines that the rate of change of the target value ΔP2 is equal to or greater than the first rate of change L1 (step S120: YES), it proceeds to step S125. In this case, the first condition described above is met. That is, the process in step S120 is a positive rate of change determination process N2 that determines whether or not the first condition described above is met.

[0053] In step S125, the control operation determination unit 88 resets the elapsed time TM for determination and then starts measuring the elapsed time TM for determination. After this, the control operation determination unit 88 proceeds to step S130.

[0054] In step S130, the control operation determination unit 88 determines whether the elapsed time TM for determination is less than or equal to the specified time TMD for determination. If the elapsed time TM for determination is less than or equal to the specified time TMD for determination (step S130: YES), the control operation determination unit 88 proceeds to step S135. Then, in step S135, the control operation determination unit 88 waits for a predetermined acquisition time interval ΔT to elapse since the previous acquisition of the target angle P2 and acquires a new target angle P2. Once the new target angle P2 is acquired, the control operation determination unit 88 proceeds to step S140. In step S140, the control operation determination unit 88 calculates a new target value change rate ΔP2 in the same manner as in step S120 and determines whether the target value change rate ΔP2 is less than or equal to the second change rate L2. If the target value change rate ΔP2 is greater than the second change rate L2 (step S140: NO), the control operation determination unit 88 returns to step S130.

[0055] The piloting operation determination unit 88 repeats the processes of steps S130, S135, and S140 until the elapsed time TM for determination exceeds the specified time TMD for determination. If the elapsed time TM for determination exceeds the specified time TMD for determination without the rate of change ΔP2 of the target value becoming less than or equal to the second rate of change L2 (step S140: NO), the piloting operation determination unit 88 terminates the series of processes of the piloting operation determination process W2. In this case, the piloting operation determination unit 88 executes the process of step S110 again.

[0056] On the other hand, if the control operation determination unit 88 determines in step S140 that the rate of change of the target value ΔP2 becomes less than or equal to the second rate of change L2 before the elapsed time for determination TM exceeds the prescribed time for determination TMD (step S140: YES), it proceeds to step S145. In this case, the second condition described above is met. That is, the process in step S140 is a negative rate of change determination process N3 that determines whether or not the second condition described above is met.

[0057] In step S145, the control operation determination unit 88 waits for a predetermined acquisition time interval ΔT to elapse since the previous acquisition of the target angle P2 before acquiring a new target angle P2. Once the new target angle P2 is acquired, the control operation determination unit 88 proceeds to step S150. In step S150, the control operation determination unit 88 determines, in the same manner as in step S120, whether the target value change rate ΔP2 is greater than or equal to the first change rate L1. If the target value change rate ΔP2 is less than the first change rate L1 (step S150: NO), the control operation determination unit 88 proceeds to step S155.

[0058] In step S155, the control operation determination unit 88 determines whether the elapsed time TM for determination is less than or equal to the specified time TMD for determination. If the elapsed time TM for determination is less than or equal to the specified time TMD for determination (step S155: YES), the control operation determination unit 88 returns to the process in step S145.

[0059] The piloting operation determination unit 88 repeats the processes of steps S145, S150, and S155 until the elapsed time TM for determination exceeds the specified time TMD for determination. If the elapsed time TM for determination exceeds the specified time TMD for determination without the rate of change ΔP2 of the target value becoming equal to or greater than the first rate of change L1 (step S150: NO), the piloting operation determination unit 88 terminates the series of processes of the piloting operation determination process W2. In this case, the piloting operation determination unit 88 executes the process of step S110 again.

[0060] On the other hand, if the control operation determination unit 88 determines in step S150 that the rate of change of the target value ΔP2 becomes equal to or greater than the first rate of change L1 before the elapsed time for determination TM exceeds the prescribed time for determination TMD (step S150: YES), it proceeds to step S160. In this case, the third condition is met. The process from step S115 to step S155 is a rate of change continuation determination process N4 that determines whether or not the third condition is met.

[0061] In step S160, the control operation determination unit 88 determines that the time change of the target angle P2 is a change corresponding to the operation of the control stick 17, and sets the prohibition flag F to ON. This process is masking process N5. Then, the control operation determination unit 88 returns to the process of step S125. After this, the control operation determination unit 88 repeats the process from step S125 onward. In the subsequent processes, if the third condition continues to be met, the prohibition flag F remains ON. When the third condition is no longer met, the prohibition flag F is turned OFF.

[0062] Next, the processing procedure for vibration detection process W1 will be explained. As described above, vibration detection process W1 has two types: positive vibration detection process W1A and negative vibration detection process W1B. These positive vibration detection process W1A and negative vibration detection process W1B are performed in parallel. When either the positive vibration detection process W1A or the negative vibration detection process W1B detects vibration of the spoiler 12, the other process is terminated.

[0063] The aircraft vibration detection device 70 performs positive vibration detection processing W1A and negative vibration detection processing W1B under the following settings. As described below, the difference calculation unit 72 repeatedly calculates the difference Z between the measured separation distance R1 of the rod 34 and the target separation distance R2 in positive vibration detection processing W1A and negative vibration detection processing W1B. The difference calculation unit 72 is set to hold the latest difference Z it calculates and the previous difference Z which was calculated at the previous timing. The difference calculation unit 72 is also set to calculate the difference Z at predetermined calculation time intervals.

[0064] Now, let's explain the processing procedure for the positive vibration detection process W1A. As shown in Figure 3, first, the count calculation unit 78 executes the process in step S210. In step S210, the count calculation unit 78 resets the first count C1 to zero. After this, the count calculation unit 78 proceeds to step S215. The process in step S210 is the count calculation process M4A.

[0065] In step S215, the difference calculation unit 72 waits for a predetermined calculation time interval to elapse since the previous difference Z calculation, and then calculates the difference Z between the measured separation distance R1 of the rod 34 and the target separation distance R2. Specifically, the difference calculation unit 72 obtains the latest target angle P2 of the spoiler 12 input from the control unit 50, and converts this target angle P2 into the target separation distance R2 of the rod 34. The difference calculation unit 72 also obtains the latest measured separation distance R1 input from the position detector 39. Then, the difference calculation unit 72 calculates the difference Z by subtracting the target separation distance R2 from the measured separation distance R1. After this, the difference calculation unit 72 proceeds to step S220. The process in step S215 is the difference calculation process M1.

[0066] In step S220, the threshold determination unit 74 determines whether the latest difference Z is greater than or equal to the first threshold K1, and whether the previous difference Z was less than the first threshold K1. If the previous difference Z was less than the first threshold K1, and the latest difference Z is greater than or equal to the first threshold K1, then the difference Z reached the first threshold K1 during the increase of the difference Z over time. In other words, the determination in step S220 is a process to detect that the difference Z has increased and reached the first threshold K1. In making this determination, first the threshold determination unit 74 obtains the latest difference Z and the previous difference Z calculated by the difference calculation unit 72. Then, the threshold determination unit 74 compares the latest difference Z with the first threshold K1, and further compares the previous difference Z with the first threshold K1. The threshold determination unit 74 returns to step S215 if at least one of the following conditions is not met (step S220: NO): the latest difference Z is greater than or equal to the first threshold K1, and the previous difference Z was less than the first threshold K1. The threshold determination unit 74 and the difference calculation unit 72 repeat the processes of steps S215 and S220 until the latest difference Z is greater than or equal to the first threshold K1, and the previous difference Z is less than the first threshold K1. This repeated process monitors the time change of the difference Z and waits until the difference Z increases and reaches the first threshold K1. The threshold determination unit 74 proceeds to step S225 if the latest difference Z is greater than or equal to the first threshold K1, and the previous difference Z is less than the first threshold K1 (step S220: YES). The process in step S220 is the first threshold determination process M2A.

[0067] In step S225, the count calculation unit 78 determines whether the prohibition flag F is off or not. If the prohibition flag F is on (step S225: NO), the count calculation unit 78 terminates the series of processes of the positive vibration detection process W1A. In this case, the count calculation unit 78 executes the process of step S210 again. That is, the first count C1 is reset. In this way, if the prohibition flag F is on, it is not determined that vibration is occurring in the spoiler 12. As described above, the situation in which the prohibition flag F is on is a situation in which the target angle P2 of the spoiler 12 is changing in response to the operation of the control stick 17.

[0068] On the other hand, in step S225, if the prohibition flag F is off (step S225: YES), the count calculation unit 78 proceeds to step S230. In step S230, the elapsed time determination unit 76 resets the first elapsed time TS1 and then starts measuring the first elapsed time TS1. After this, the elapsed time determination unit 76 proceeds to step S235.

[0069] In step S235, the count calculation unit 78 updates the first count C1. Specifically, it calculates the new first count C1 by adding 1 to the current first count C1. After this, the count calculation unit 78 proceeds to step S240. The process in step S235 is the count calculation process M4A.

[0070] In step S240, the vibration determination unit 82 determines whether the first count C1 is equal to or greater than the specified count CD. If the first count C1 is equal to or greater than the specified count CD (step S240: YES), the vibration determination unit 82 proceeds to step S245 and determines that vibration is occurring in the spoiler 12. That is, the vibration determination unit 82 detects vibration in the spoiler 12. The processing in steps S240 and S245 is the vibration determination process M5A. After this, the vibration determination unit 82 proceeds to step S250. Then, in step S250, the stop signal output unit 84 outputs a stop signal, which is a cutoff signal Q, to the actuator connection switch 63. As a result, the actuator connection switch 63 switches to the cutoff state. After executing the process in step S250, the stop signal output unit 84 terminates the series of processes of the positive side vibration detection process W1A. That is, in this case, the process does not return to step S210. The process in step S250 described above is the stop signal output process M6.

[0071] On the other hand, in step S240, if the vibration determination unit 82 determines that the first count C1 is less than the specified count CD (step S240: NO), it proceeds to step S270. In step S270, the elapsed time determination unit 76 determines whether the first elapsed time TS1 is less than or equal to the upper limit of the specified elapsed time range SD. If the elapsed time determination unit 76 determines that the first elapsed time TS1 is less than or equal to the upper limit of the specified elapsed time range SD (step S270: YES), it proceeds to step S275.

[0072] In this case, in step S275, the difference calculation unit 72 waits for a predetermined calculation time interval to elapse since the previous calculation of difference Z, and then calculates a new difference Z. That is, the difference calculation unit 72 calculates difference Z using the same process as in step S215, and proceeds to step S280. Then, in step S280, the threshold determination unit 74 determines whether the latest difference Z is less than or equal to zero, and whether the previous difference Z was greater than zero. Here, if the previous difference Z was greater than zero, and the latest difference Z is less than or equal to zero, then it means that the difference Z reached zero during the decrease of difference Z in the time change of difference Z. This determination is a process to confirm that the difference Z has decreased to less than or equal to zero between the time it is determined that the difference Z is greater than or equal to the first threshold K1 and the time it is determined that the difference Z is greater than or equal to the first threshold K1 again. If the determination in step S280 is NO, the threshold determination unit 74 returns to the process in step S270.

[0073] The elapsed time determination unit 76, the difference calculation unit 72, and the threshold determination unit 74 repeat the processes of steps S270, S275, and S280 until the first elapsed time TS1 exceeds the upper limit of the specified elapsed time range SD. If the elapsed time determination unit 76 determines that the first elapsed time TS1 exceeds the upper limit of the specified elapsed time range SD without the difference Z decreasing to zero (step S280: NO) (step S270: NO), it terminates the series of processes of the positive vibration detection process W1A. In this case, the count calculation unit 78 executes the process of step S210 again.

[0074] On the other hand, if the threshold determination unit 74 determines in step S280 that the difference Z decreases to zero before the first elapsed time TS1 exceeds the upper limit of the specified elapsed time range SD (step S270: YES, step S280: YES), it proceeds to step S285.

[0075] In this case, in step S285, the difference calculation unit 72 waits for a predetermined calculation time interval to elapse since the previous calculation of difference Z, and then calculates a new difference Z. That is, the difference calculation unit 72 calculates difference Z by the same process as in step S215, and proceeds to step S290. Then, in step S290, the threshold determination unit 74 performs the same process as in step S220. That is, it makes a determination to detect whether the difference Z has reached the first threshold K1 during the increase of difference Z in the time change of difference Z. If the determination in step S290 is NO, the threshold determination unit 74 proceeds to step S295.

[0076] In step S295, the elapsed time determination unit 76 determines whether the first elapsed time TS1 is less than or equal to the upper limit of the specified elapsed time range SD. If the first elapsed time TS1 is less than or equal to the upper limit of the specified elapsed time range SD (step S295: YES), the elapsed time determination unit 76 returns to the process in step S285.

[0077] The elapsed time determination unit 76, the difference calculation unit 72, and the threshold determination unit 74 repeat the processes of steps S285, S290, and S295 until the first elapsed time TS1 exceeds the upper limit of the specified elapsed time range SD. If the elapsed time determination unit 76 determines that the first elapsed time TS1 exceeds the upper limit of the specified elapsed time range SD without the difference Z increasing to the first threshold K1 (step S290: NO) (step S295: NO), it terminates the series of processes of the positive vibration detection process W1A. In this case, the count calculation unit 78 executes the process of step S210 again.

[0078] On the other hand, if the elapsed time determination unit 76 determines that the difference Z increases to the first threshold K1 before the first elapsed time TS1 exceeds the upper limit of the specified elapsed time range SD (step S290: YES, step S295: YES), it proceeds to step S300.

[0079] In step S300, the elapsed time determination unit 76 determines whether the first elapsed time TS1 is equal to or greater than the lower limit of the specified elapsed time range SD. If the first elapsed time TS1 is less than the lower limit of the specified elapsed time range SD (step S300: NO), the elapsed time determination unit 76 terminates the series of processes of the positive vibration detection process W1A. In this case, the count calculation unit 78 executes the process of step S210 again. The situation in which the determination in step S300 is NO is that the time variation of the difference Z is shorter than the variation period caused by a failure in the circuit of the manipulated variable calculation unit 62 or the circuit of the control unit 50.

[0080] On the other hand, in step S300, the elapsed time determination unit 76 returns to the process of step S225 if the first elapsed time TS1 is greater than or equal to the lower limit of the specified elapsed time range SD (step S300: YES). By executing the processes of steps S295 and S300, it is determined whether or not the first elapsed time TS1 is within the specified elapsed time range SD. These processes S295 and S300 constitute the elapsed time determination process M3A. Since the determination in step S280 is performed before executing steps S295 and S300, the elapsed time determination unit 76 determines whether or not the first elapsed time TS1 is within the specified elapsed time range SD, provided that the difference Z is zero or less between the time the difference Z increases to the first threshold K1 and the time the difference Z increases to the first threshold K1 again.

[0081] Now, when the process returns to step S225, if the prohibition flag F is off (step S225: YES), the measurement of the first elapsed time TS1 is started again by the process in step S230, and the first count C1 is updated by the process in step S235. After this, the difference Z increases to the first threshold K1 within the specified elapsed time range SD (steps S290: YES, S295: YES, S300: YES), and this is repeated, increasing the first count C1. When the first count C1 exceeds the specified count CD (step S240: YES), the vibration of the spoiler 12 is detected in step S245 as described above.

[0082] Next, the processing procedure for the negative vibration detection process W1B will be explained. The negative vibration detection process W1B is a modification of the positive vibration detection process W1A, which previously captured the time-varying characteristics while the difference Z was increasing, to a process that captures the time-varying characteristics while the difference Z was decreasing. The basic processing flow is the same as that of the positive vibration detection process W1A. Therefore, the contents of the negative vibration detection process W1B will be explained briefly.

[0083] As shown in Figure 4, first in step S310, the count calculation unit 78 resets the second count C2 to zero. This process is the count calculation process M4B. After this, in step S315, the difference calculation unit 72 calculates the difference Z between the measured separation distance R1 of the rod 34 and the target separation distance R2. This process is the difference calculation process M1. After this, in step S320, the threshold determination unit 74 determines whether the latest difference Z is less than or equal to the second threshold K2, and whether the previous difference Z was greater than the second threshold K2. Here, if the previous difference Z was greater than the second threshold K2, and the latest difference Z is less than or equal to the second threshold K2, then in the time change of difference Z, the difference Z reached the second threshold K2 while the difference Z was decreasing. In other words, the determination in step S320 is a process to detect that the difference Z has decreased and reached the second threshold K2. The threshold determination unit 74 monitors the time change of the difference Z and waits until the difference Z decreases to the second threshold K2. When the difference Z decreases to the second threshold K2 (step S320: YES), the process proceeds to step S325. The process in step S320 is the second threshold determination process M2B.

[0084] In step S325, the count calculation unit 78 determines whether the prohibition flag F is on or off. If the prohibition flag F is on (step S325: NO), the series of processes for negative vibration detection W1B are terminated. If the prohibition flag F is off (step S325: YES), the process proceeds to step S330. Then, in step S330, the elapsed time determination unit 76 resets the second elapsed time TS2 and starts measuring the second elapsed time TS2.

[0085] Next, in step S335, the count calculation unit 78 updates the second count C2. This process is the count calculation process M4B. In the following step S340, the vibration determination unit 82 determines whether the second count C2 is equal to or greater than the specified count CD. If the second count C2 is equal to or greater than the specified count CD (step S340: YES), the process proceeds to step S345 to detect vibration of the spoiler 12. When vibration of the spoiler 12 is detected, in step S350 the stop signal output unit 84 outputs a cutoff signal Q. The processes in steps S340 and S345 are the vibration determination process M5B. The process in step S350 is the stop signal output process M6.

[0086] On the other hand, in step S340, if the vibration determination unit 82 determines that the second count C2 is less than the specified count CD (step S340: NO), it proceeds to step S370. In step S370, the elapsed time determination unit 76 determines whether the second elapsed time TS2 is less than or equal to the upper limit of the specified elapsed time range SD. If the elapsed time determination unit 76 determines that the second elapsed time TS2 is less than or equal to the upper limit of the specified elapsed time range SD (step S370: YES), it proceeds to step S375.

[0087] In step S375, the difference calculation unit 72 calculates the difference Z. After this, in step S380, the threshold determination unit 74 determines whether the latest difference Z is greater than or equal to zero and whether the previous difference Z was less than zero. If the previous difference Z was less than zero and the latest difference Z is greater than or equal to zero, then the difference Z reached zero during the increase of the difference Z over time. This determination is a process to confirm that the difference Z has increased to zero or greater between the time it is determined that the difference Z is less than or equal to the second threshold K2 and the time it is determined that the difference Z is less than or equal to the second threshold K2. If the determination in step S380 is NO, the threshold determination unit 74 returns to the process in step S370.

[0088] The elapsed time determination unit 76, the difference calculation unit 72, and the threshold determination unit 74 repeat the processes of steps S370, S375, and S380 until the second elapsed time TS2 exceeds the upper limit of the specified elapsed time range SD. If the elapsed time determination unit 76 determines that the second elapsed time TS2 exceeds the upper limit of the specified elapsed time range SD without the difference Z increasing to zero (step S380: NO) (step S370: NO), it terminates the series of processes of the negative vibration detection process W1B. In this case, the count calculation unit 78 executes the process of step S310 again.

[0089] On the other hand, if the threshold determination unit 74 determines in step S380 that the difference Z increases to zero before the second elapsed time TS2 exceeds the upper limit of the specified elapsed time range SD (step S370: YES, step S380: YES), it proceeds to step S385.

[0090] In step S385, the difference calculation unit 72 calculates the difference Z, and in the following step S390, the threshold determination unit 74 determines whether the difference Z has decreased to the second threshold K2 by the same process as in step S320. If the determination in step S390 is NO, the threshold determination unit 74 proceeds to step S395.

[0091] In step S395, the elapsed time determination unit 76 determines whether the second elapsed time TS2 is less than or equal to the upper limit of the specified elapsed time range SD. If the second elapsed time TS2 is less than or equal to the upper limit of the specified elapsed time range SD (step S395: YES), the elapsed time determination unit 76 returns to the process in step S385.

[0092] The elapsed time determination unit 76, the difference calculation unit 72, and the threshold determination unit 74 repeat the processes of steps S385, S390, and S395 until the second elapsed time TS2 exceeds the upper limit of the specified elapsed time range SD. If the elapsed time determination unit 76 determines that the second elapsed time TS2 exceeds the upper limit of the specified elapsed time range SD without the difference Z decreasing to the second threshold K2 (step S390: NO), then the series of processes of the negative vibration detection process W1B is terminated.

[0093] On the other hand, if the elapsed time determination unit 76 determines that the difference Z has decreased to the second threshold K2 before the second elapsed time TS2 exceeds the upper limit of the specified elapsed time range SD (step 390: YES, step S395: YES), it proceeds to step S400. In step S400, the elapsed time determination unit 76 determines whether the second elapsed time TS2 is greater than or equal to the lower limit of the specified elapsed time range SD. If the second elapsed time TS2 is less than the lower limit of the specified elapsed time range SD (step S400: NO), the elapsed time determination unit 76 terminates the series of processes of the negative vibration detection process W1B. On the other hand, in step S400, if the second elapsed time TS2 is greater than or equal to the lower limit of the specified elapsed time range SD (step S400: YES), the elapsed time determination unit 76 returns to the process in step S325. The processes in S395 and S400 are the elapsed time determination process M3B.

[0094] Next, the operation of this embodiment will be described. (1) Factors causing vibration of spoiler 12 (1-a) Circuit failure of the manipulated variable calculation unit 62 A malfunction in the circuit of the manipulated amount calculation unit 62 may cause the gain value used to calculate the manipulated amount R3 of the rod 34 to become larger than its intended value. When the gain is large, the manipulated amount R3 of the rod 34 is amplified. In this case, for example, while the target separation distance R2 of the rod 34 is constant, the measured separation distance R1 may exceed or fall below the target separation distance R2. Specifically, when the measured separation distance R1 and the target separation distance R2 are compared in the calculation of the manipulated amount R3 of the rod 34, if the measured separation distance R1 is larger than the target separation distance R2, the manipulated amount R3 of the rod 34 is determined to reduce the measured separation distance R1 toward the target separation distance R2. However, if the manipulated amount R3 is amplified due to an inappropriate gain, the rod 34 may move to a position beyond the target separation distance R2. In other words, as a result of controlling the actuator 30 with the amplified manipulated variable R3, the measured separation distance R1 becomes smaller than the target separation distance R2.

[0095] When the measured distance R1 becomes smaller than the target distance R2, the manipulation amount R3 of the rod 34 is determined in order to increase the measured distance R1 toward the target distance R2. However, if the manipulation amount R3 is amplified due to an inappropriate gain, the rod 34 will move beyond the target distance R2. In other words, as a result of controlling the actuator 30 with the amplified manipulation amount R3, the measured distance R1 becomes larger than the target distance R2. This repetition causes the measured distance R1 to repeatedly exceed or fall below the target distance R2. As a result, vibration occurs in the spoiler 12. Furthermore, as the measured distance R1 exceeds or falls below the target distance R2, the difference Z between the measured distance R1 and the target distance R2 shows a time variation that increases or decreases around zero, as shown in Figure 5.

[0096] (1-b) Circuit failure of the control unit 50 A malfunction in the control unit 50's circuitry can cause the target angle P2 of the spoiler 12 to repeatedly increase or decrease. In this case, the target separation distance R2 of the rod 34 will repeatedly increase or decrease, and the measured separation distance R1 will increase or decrease accordingly. This will cause vibration in the spoiler 12. Even in such cases, the difference Z between the measured separation distance R1 and the target separation distance R2 will show a time variation that increases or decreases around zero. This is because the measured separation distance R1 used to calculate the difference Z is essentially a value that reflects the target separation distance R2 at the previous timing relative to the latest target separation distance R2. For example, if the latest target separation distance R2 is larger than the previous target separation distance R2, the measured separation distance R1 is smaller than the latest target separation distance R2 because it corresponds to the previous target separation distance R2. Therefore, the difference Z will be a negative value. Conversely, if the latest target separation distance R2 is smaller than the previous target separation distance R2, the difference Z will be a positive value. Therefore, as the target separation distance R2 increases or decreases repeatedly, the difference Z will also increase or decrease repeatedly.

[0097] (2) Vibration detection of spoiler 12 by vibration detection process W1 (2-a) An example in which vibration occurs in the spoiler 12 due to a malfunction in various circuits. As a first example, we will explain a case in which continuous vibration occurs in the spoiler 12 due to a malfunction in the circuit of the manipulated variable calculation unit 62 or the circuit of the overall control device 50.

[0098] In the positive vibration detection process W1A, as shown in Figure 5, when the difference Z reaches the first threshold K1 at time A1 while the difference Z is increasing (step S220: YES), the first count C1 becomes 1 (step S235). After this, at time A2, which is more than the lower limit of the specified elapsed time range SD from time A1 but before the upper limit of the specified elapsed time range SD from time A1 has elapsed (step S295: YES, step S300: YES), when the difference Z reaches the first threshold K1 again while the difference Z is increasing (step S290: YES), the first count C1 becomes 2 (step S235). After this, the increase of the difference Z to the first threshold K1 within the specified elapsed time range SD is repeated in the same manner, and the first count C1 increases. Then, at time A3 following time A2, when the difference Z increases to the first threshold K1 and the first count C1 reaches the specified count CD (step S240: YES), it is determined that vibration is occurring in the spoiler 12 (step S245). The actuator connection switch 63 is then switched to the off state. Similar to the positive vibration detection process W1A, in the negative vibration detection process W1B, the second count C2 increases each time the difference Z reaches the second threshold K2 while the difference Z is decreasing.

[0099] (2-b) An example in which the vibration of spoiler 12 subsides without continuing. As a second example, we will explain the case where the vibration of spoiler 12 converges without continuing. As shown in Figure 6, the difference Z repeatedly increases to the first threshold K1 within the specified elapsed time range SD, and at time B1, the first count C1 reaches an arbitrary count CN which is less than the specified count CD. In this second example, even at time B2, when the upper limit of the specified elapsed time range SD has elapsed from time B1, the difference Z does not increase to the first threshold K1. In this case, the determination in step S290 does not determine that the difference Z has reached the first threshold K1 (step S290: NO), and the first elapsed time TS1 from time B1 exceeds the above upper limit (step S295: NO). Consequently, the positive vibration detection process W1A is terminated, and the first count C1 is reset (step S210). In addition, in the negative vibration detection process W1B, the second count C2 is also reset before reaching the specified count CD.

[0100] Next, the effects of this embodiment will be described. (1) The vibration of the spoiler 12 corresponds to the measured separation distance R1 being greater than or less than the target separation distance R2. Therefore, by setting a first threshold K1 and a second threshold K2 and detecting when the difference Z becomes greater than or equal to the first threshold K1 or less than or equal to the second threshold K2, the vibration of the spoiler 12 can be detected.

[0101] (2) When the spoiler 12 vibrates due to a failure in the circuit of the manipulated variable calculation unit 62 or the circuit of the control unit 50, the vibration occurs on a specific time scale. Therefore, a specified elapsed time range SD is set as the time corresponding to that time scale, and the fluctuation of the difference Z that occurs within the specified elapsed time range SD is identified. As a result, vibration can be detected only when the vibration of the spoiler 12 is caused by a failure in the above-mentioned circuits. This prevents the detection of vibration even when the spoiler 12 is operating regardless of a failure in the above-mentioned circuits.

[0102] (3) If vibration of the spoiler 12 is detected, the actuator 30 will be stopped and the use of the spoiler 12 will be discontinued. However, the differential Z may increase or decrease accidentally even if there is no malfunction in the circuit of the operating amount calculation unit 62 or the circuit of the overall control device 50. If such an accidental increase or decrease in the differential Z is interpreted as the occurrence of vibration of the spoiler 12 and vibration detection is performed, the use of the spoiler 12 will be discontinued even though the above-mentioned circuits are not malfunctioning.

[0103] In this regard, by counting the first count C1 and the second count C2, it is determined that vibration is occurring in the spoiler 12 only when a continuous fluctuation in the differential Z is confirmed, thus excluding accidental fluctuations in the differential Z from vibration detection. Therefore, it is possible to prevent the spoiler 12 from being discontinued even if the various circuits are not malfunctioning.

[0104] (4) In some cases, the spoiler 12 may be intentionally vibrated by operating the control stick 17. If such intentional vibrations are included in the vibration detection, it may lead to a situation where the use of the spoiler 12 is discontinued when it is necessary to use it.

[0105] Therefore, if the time change of the target angle P2 of the spoiler 12 is determined to be a change corresponding to the operation of the control stick 17, the first count C1 and the second count C2 are reset so that vibration of the spoiler 12 is not detected. Consequently, intentional vibration of the spoiler 12 will not be detected as vibration due to a malfunction in various circuits, and the use of the spoiler 12 will not be discontinued.

[0106] (5) When vibration of the spoiler 12 is detected, a cutoff signal Q is output to the actuator connection switch 63. This stops the actuator 30 from driving the spoiler 12. This prevents the vibration of the spoiler 12 from continuing.

[0107] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically. • Either the positive vibration detection process W1A or the negative vibration detection process W1B may be executed, and the other may be omitted. In other words, the vibration of the spoiler 12 may be detected using only one of the time-varying characteristics during the increase of the difference Z or the time-varying characteristics during the decrease of the difference Z.

[0108] A duration determination unit 89 may be provided to determine whether the first duration during which the difference Z increases to a first threshold K1 and the state in which the difference Z remains at or above the first threshold K1 is greater than or equal to a specified duration. The elapsed time determination unit 76 may then determine, on the condition that the first duration is greater than or equal to the specified duration, whether the first elapsed time TS1, based on the start timing of the first duration, is within the specified elapsed time range SD. The specified duration is preferably, for example, smaller than the lower limit of the specified elapsed time range SD. Here, the difference Z may momentarily exceed the first threshold K1 due to the influence of noise, etc. When determining the first elapsed time TS1 on the condition that the first duration is greater than or equal to the specified duration as described above, the determination of the first elapsed time TS1 is performed on the premise that there are no momentary fluctuations, and therefore the determination of the first elapsed time TS1 can be performed appropriately.

[0109] The duration determination unit 89 in the above modification example may determine whether the second duration during which the difference Z decreases to the second threshold K2 and the state in which the difference Z remains below the second threshold K2 continues is equal to or greater than the specified duration. The elapsed time determination unit 76 may then determine, on the condition that the second duration is equal to or greater than the specified duration, whether the second elapsed time TS2, based on the start timing of the second duration, is within the specified elapsed time range SD. When determining the second elapsed time TS2 on the condition that the second duration is equal to or greater than the specified duration, the determination of the second elapsed time TS2 is performed on the premise that no instantaneous fluctuations are occurring, thus enabling an appropriate determination of the second elapsed time TS2.

[0110] In the above embodiment, the threshold determination unit 74 was required to have the difference Z decrease to zero or less between the time it was determined that the difference Z was greater than or equal to the first threshold K1 and the time it was determined that the difference Z was greater than or equal to the first threshold K1 again. However, this condition may be abolished. In this case, for example, the duration determination unit 89 can be provided as in the above modified example to remove the influence of noise.

[0111] Similar to the above modification example, the condition that the difference Z increases to zero or greater between the time it is determined that the difference Z is less than or equal to the second threshold K2 and the next time it is determined that the difference Z is less than or equal to the second threshold K2 may be abolished.

[0112] The elapsed time determination unit 76 may determine whether the first elapsed time TS1 is within the specified elapsed time range SD, on the condition that the difference Z increases to the first threshold K1, then changes from increasing to decreasing, and then decreases to the second threshold K2.

[0113] Similar to the above modification example, the elapsed time determination unit 76 may determine whether the second elapsed time TS2 is within the specified elapsed time range SD, on the condition that the difference Z decreases to the second threshold K2, then changes from decreasing to increasing, and then increases to the first threshold K1.

[0114] The vibration determination unit 82 may determine that vibration is occurring in the spoiler 12 once it has determined that the first elapsed time TS1 is within the specified elapsed time range SD, regardless of whether the state of the first elapsed time TS1 remaining within the specified elapsed time range SD continues. In this case, the calculation of the first count C1 by the count calculation unit 78 can be omitted. However, at the stage when it has been determined that the first elapsed time TS1 is within the specified elapsed time range SD, it is possible that only an accidental fluctuation in the difference Z has been detected. Therefore, when it is determined that vibration is occurring in the spoiler 12 once it has been determined that the first elapsed time TS1 is within the specified elapsed time range SD, instead of immediately outputting a stop signal after that determination, an inspection process may be performed on the circuits of the manipulated variable calculation unit 62 and the control unit 50 to check for any malfunctions. If a malfunction is detected, a stop signal may be output.

[0115] Similar to the above modification example, the vibration determination unit 82 may determine that vibration is occurring in the spoiler 12 once it has determined that the second elapsed time TS2 is within the specified elapsed time range SD.

[0116] The vibration determination unit 82 may detect vibration of the spoiler 12 without using the first elapsed time TS1. For example, regardless of the magnitude of the first elapsed time TS1, the vibration determination unit 82 may determine that vibration is occurring in the spoiler 12 if the number of times the difference Z increases to the first threshold K1 within the determination period J after the difference Z has increased to the first threshold K1 once reaches a predetermined number of times CD or more. In this case, the elapsed time determination unit 76 starts measuring the elapsed time when the difference Z increases to the first threshold K1, and then continues measuring the elapsed time without resetting the measurement when the difference Z next increases to the first threshold K1. The elapsed time determination unit 76 then determines whether or not this elapsed time has reached the determination period J. The count calculation unit 78 calculates the number of times the difference Z increases to the first threshold K1 until the above elapsed time reaches the determination period J. The vibration determination unit 82 determines whether or not vibration is occurring in the spoiler 12 by referring to the determination result of the elapsed time determination unit 76 and the calculation result of the count calculation unit 78. When this configuration is adopted, the determination period J and the specified number of counts CD should be predetermined to appropriate values ​​that indicate vibration is occurring in the spoiler 12. As described in this modified example, the elapsed time determination unit 76 and the count calculation unit 78 function effectively in grasping the persistence of the variation in difference Z.

[0117] From the same perspective as the above modification example, the vibration determination unit 82 may determine that vibration is occurring in the spoiler 12 if, regardless of the magnitude of the second elapsed time TS2, the number of times the difference Z decreases to the second threshold K2 within the determination period J after the difference Z decreases to the second threshold K2 once is equal to or greater than a specified number CD.

[0118] As described in the above modification example, the judgment period J and specified number of counts CD related to the detection of vibration of the spoiler 12 are not limited to those described in the above embodiment. The judgment period J and specified number of counts CD should be set to appropriate values ​​depending on the method of vibration detection.

[0119] Regarding the number of times the difference Z increases to the first threshold K1 within the judgment period J after it has increased to the first threshold K1 once, the one instance that triggered the start of the judgment period J may be excluded. Then, if the number of instances excluding the triggering instance exceeds a specified number CD, it may be determined that vibration is occurring in the spoiler 12.

[0120] The vibration determination unit 82 may determine that the vibration of the spoiler 12 has subsided if, after the difference Z has increased to the first threshold K1 once, the number of times the difference Z has increased to the first threshold K1 within the determination period J is less than a specified number CD. To realize this embodiment, as in the above modified example, the elapsed time determination unit 76 can continuously measure the elapsed time from the timing when the difference Z has increased to the first threshold K1. By adopting such a configuration, it is possible to understand that the vibration of the spoiler 12 has subsided after it has flapped around once. From a similar viewpoint, the vibration determination unit 82 may determine that the vibration of the spoiler 12 has subsided if, after the difference Z has decreased to the second threshold K2 once, the number of times the difference Z has decreased to the second threshold K2 within the determination period J is less than a specified number CD.

[0121] The vibration determination unit 82 may determine that vibration is occurring in the spoiler 12 when the number of times the difference Z increases to the first threshold K1 during the operation of the aircraft 10 reaches a specified number of times CD, without specifying the determination period J as described above. In this case as well, the specified number of times CD can be predetermined to an appropriate value. From a similar viewpoint, without specifying the determination period J, the unit may determine that vibration is occurring in the spoiler 12 when the number of times the difference Z decreases to the second threshold K2 during the operation of the aircraft 10 reaches a specified number of times CD.

[0122] Regardless of whether a judgment period J is defined, it may be determined that the spoiler 12 is vibrating when the sum of the number of times the difference Z increases to the first threshold K1 and the number of times the difference Z decreases to the second threshold K2 reaches a specified number CD. In this case, the specified number CD should be adjusted to an appropriate value. Similarly, it may be determined that the vibration of the spoiler 12 has converged when the sum of the number of times the difference Z increases to the first threshold K1 and the number of times the difference Z decreases to the second threshold K2 does not reach a specified number CD.

[0123] If the difference Z increases to the first threshold K1 at least once, it may be determined that vibration is occurring in the spoiler 12 at that stage. Similarly, if the difference Z decreases to the second threshold K2 at least once, it may be determined that vibration is occurring in the spoiler 12 at that stage. In these cases, the elapsed time determination unit 76 and the count calculation unit 78 can be omitted.

[0124] The absolute values ​​of the first threshold K1 and the second threshold K2 may be different. Furthermore, not only the first threshold K1 but also the second threshold K2 may be a positive value. Moreover, both the first threshold K1 and the second threshold K2 may be negative values. The first threshold K1 and the second threshold K2 should be values ​​appropriate for detecting vibrations of the spoiler 12.

[0125] The difference Z does not necessarily represent a time change that increases or decreases around zero. The first threshold K1 and the second threshold K2 should be determined according to the range of values ​​represented by the difference Z. The vibration of the spoiler 12 may be detected while changing the first threshold K1 and the second threshold K2 each time according to the target angle P2.

[0126] • Instead of using the actual value of difference Z, the absolute value of difference Z may be used to detect vibrations of the spoiler 12. Furthermore, if the actual value of difference Z is used for determining vibrations of the spoiler 12, as shown in the above embodiment, dual vibration detection becomes possible, such as positive vibration detection process W1A and negative vibration detection process W1B.

[0127] The configuration for preventing the vibration determination unit 82 from detecting the vibration of the spoiler 12 when the control operation determination unit 88 determines that the time change of the target angle P2 corresponds to the operation of the control stick 17 is not limited to the example of the above embodiment. For example, if the prohibition flag F is on, the execution of the positive vibration detection process or the negative vibration detection process may be canceled.

[0128] The method for determining whether the time change of the target angle P2 corresponds to the operation of the control stick 17 is not limited to the example of the above embodiment. For example, the number of times the third condition is met consecutively may be calculated, and the prohibition flag F may be turned on when that number exceeds the number of judgments.

[0129] The first rate of change L1 and the second rate of change L2 should be values ​​suitable for determining the operation of the control stick 17. For example, the absolute values ​​of the first rate of change L1 and the second rate of change L2 may be different. After the first condition is met, it may be determined whether the second condition is met after confirming that the time change of the target angle P2 has reached a peak where it changes from increasing to decreasing. Alternatively, after the second condition is met, it may be determined whether the first condition is met after confirming that the time change of the target angle P2 has reached a peak where it changes from decreasing to increasing. The peak where the target angle P2 changes from increasing to decreasing, or the peak where the target angle P2 changes from decreasing to increasing, can be determined, for example, by the target value change rate ΔP2 becoming zero. Note that the term "peak" here does not include peaks associated with minute fluctuations, but refers to the peak that defines the amplitude in the time change of the target angle P2. According to the above embodiment, it is possible to determine whether the time change of the target angle P2 corresponds to the operation of the control stick 17 while eliminating the influence of noise as shown in Figure 8.

[0130] It is not essential to determine whether the time change of the target angle P2 corresponds to the operation of the control stick 17. If this determination is omitted, for example, the change in difference Z when the control stick 17 is being operated can be used to detect the vibration of the spoiler 12 by appropriately adjusting the prescribed elapsed time range SD.

[0131] The difference calculation unit 72 may calculate the difference Z by subtracting the measured separation distance R1 from the target separation distance R2 of the rod 34. The difference calculation unit 72 may calculate the difference Z between the measured value of the spoiler 12 angle and the target value. In this case, for example, a sensor that measures the rotational position can be provided on the rotation axis 14 of the spoiler 12 to detect the measured value of the spoiler 12 angle. Alternatively, the first threshold K1 and the second threshold K2 can be changed according to the angle of the spoiler 12.

[0132] The reference position for determining the position of the rod 34 relative to the cylinder 32 is not limited to the examples of the above embodiments. The reference position may be, for example, the center of the cylinder 32 in the direction of its central axis.

[0133] The actuator 30 is not limited to an electrohydraulic type. The actuator 30 may also be an electromechanical type in which a rod is driven by a motor. The control surface subject to vibration detection is not limited to the spoiler 12. The control surface subject to vibration detection may also be, for example, a flap.

[0134] The stop signal is not limited to the cutoff signal Q. The stop signal can be any signal that stops the actuator from driving the rotor blade. For example, if the rotor blade to be detected is a flap and the actuator that drives the flap is electrohydraulic, the stop signal may be configured as a signal that switches the hydraulic circuit to a fluid circuit mode in which the hydraulic fluid can freely move between the two fluid chambers 32A divided within the cylinder 32. In this fluid circuit mode, the actuator operates passively in accordance with the movement of the flap.

[0135] It is not mandatory to output a stop signal when vibration is detected in the object being detected. The pilot should take appropriate action as needed after detecting vibration. The aircraft vibration detection device 70 may be configured as a separate control device from the actuator control device 60. In this case, the aircraft vibration detection device 70 may be configured as one or more processors that execute various processes according to a computer program (software). The aircraft vibration detection device 70 may also be configured as a circuit including one or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs), or a combination thereof, that execute at least some of the various processes. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0136] The aircraft vibration detection device 70 may be configured as part of the overall control device 50. Each functional unit constituting the aircraft vibration detection device 70 may be provided in a separate control device. As long as signals can be exchanged between these separate control devices, there will be no problem in performing positive vibration detection processing or negative vibration detection processing.

[0137] The technical concepts that can be derived from the above embodiments and modifications are described below. (i) The vibration detection device for an aircraft according to claim 1, comprising: (i) the difference indicates an increase or decrease over time, the difference calculated by the difference calculation unit continuously acquires the difference and continuously determines whether the difference is greater than or equal to a first threshold, or whether the difference is less than or equal to a second threshold which is less than the first threshold; and the elapsed time determination unit determines whether the first elapsed time from when the difference increases to the first threshold until the difference increases to the first threshold again, or the second elapsed time from when the difference decreases to the second threshold until the difference decreases to the second threshold again, and the vibration determination unit determines that vibration is occurring in the rotor blade when the first elapsed time is within the specified elapsed time range, or when the second elapsed time is within the specified elapsed time range.

[0138] (b) The aircraft vibration detection device according to (a) above, comprising a duration determination unit that determines whether the first duration, in which the difference increases to the first threshold and the state in which the difference remains at or above the first threshold continues, or the second duration, in which the difference decreases to the second threshold and the state in which the difference remains at or below the second threshold continues, is at or above a specified duration, wherein the elapsed time determination unit determines whether the first elapsed time, based on the start timing of the first duration, is within the specified elapsed time range if the first duration is at or above the specified duration, and whether the second elapsed time, based on the start timing of the second duration, is within the specified elapsed time range if the second duration is at or above the specified duration.

[0139] (h) The aircraft vibration detection device according to (a) or (b) above, having a count calculation unit that calculates a first count which is the number of times the difference is determined to have increased to the first threshold during a period in which the condition that the first elapsed time is within the specified elapsed time range is continuously met, or a second count which is the number of times the difference is determined to have decreased to the second threshold during a period in which the condition that the second elapsed time is within the specified elapsed time range is continuously met, wherein the vibration determination unit determines that vibration is occurring in the rotor blade when the first count or the second count is equal to or greater than a specified number. [Explanation of Symbols]

[0140] 10...Aircraft, 17...Control stick, 30...Actuator, 70...Vibration detection device for aircraft, 72...Difference calculation unit, 74...Threshold determination unit, 76...Elapsed time determination unit, 78...Count calculation unit, 82...Vibration determination unit, 84...Stop signal output unit, 88...Control operation determination unit, 89...Duration determination unit.

Claims

1. The present invention is applied to an aircraft in which a moving surface is driven by an actuator, a difference calculation unit that calculates a difference between a target value of the angle of the rotor blade and an actual measured value of the angle of the rotor blade; a threshold determination unit that determines whether the absolute value of the difference is equal to or greater than a threshold; a vibration determination unit that determines that vibration is occurring in the rotor blade when the absolute value of the difference is equal to or greater than the threshold value; Vibration detection device for aircraft.

2. a count calculation unit that calculates the number of times the absolute value of the difference exceeds the threshold value; 2. The aircraft vibration detection device according to claim 1.

3. The vibration determination unit The number of times calculated by the number of times calculation unit is Specified number of times It became more than If the vibration is detected, it is determined that the rotor blade is vibrating. Claim Section 2 The aircraft vibration detection device according to claim 1.

4. an elapsed time determination unit that measures the elapsed time since the absolute value of the difference exceeded the threshold value; 4. The aircraft vibration detection device according to claim 1.

5. The vibration determination unit determines whether the absolute value of the difference exceeds the threshold value once. When the elapsed time determination unit detects that During the judgment period The number of times calculated by the number of times calculation unit is The specified number of times It became more than If the vibration is detected, it is determined that the rotor blade is vibrating. Citing claim 3 5. The aircraft vibration detection device according to claim 4.

6. The vibration determination unit, after the absolute value of the difference exceeds the threshold value once, The elapsed time measured by the elapsed time determination unit The aforementioned judgment period Even when the number of times calculated by the number of times calculation unit reaches If the number of times does not reach the specified number of times, it is determined that the vibration of the rotor blade has converged.

6. The aircraft vibration detection device according to claim 5.

7. The vibration determination unit It is determined that vibration is occurring in the rotor blade. death a stop signal output unit that outputs a stop signal for stopping the driving of the rotor blade by the actuator when the 7. The aircraft vibration detection device according to claim 1.

8. a control operation determination unit that determines whether the change over time of the target value corresponds to an operation of a control stick of the aircraft; The vibration determination unit does not determine that vibration is occurring in the moving surface when the change over time of the target value corresponds to the operation of the control stick.

8. The aircraft vibration detection device according to claim 1.

9. The present invention is applied to an aircraft in which a moving surface is driven by an actuator, a difference calculation process for calculating a difference between a target value of the angle of the rotor blade and an actual measured value of the angle of the rotor blade; a threshold determination process for determining whether the absolute value of the difference is equal to or greater than a threshold; a vibration determination process for determining that vibration is occurring in the rotor blade when the absolute value of the difference is equal to or greater than the threshold value; Vibration detection method for aircraft.

10. The present invention is applied to an aircraft in which a moving surface is driven by an actuator, a difference calculation process for calculating a difference between a target value of the angle of the rotor blade and an actual measured value of the angle of the rotor blade; a threshold determination process for determining whether the absolute value of the difference is equal to or greater than a threshold; and causing the computer to execute a vibration determination process of determining that vibration is occurring in the rotor blade when the absolute value of the difference is equal to or greater than the threshold value. Vibration detection program for aircraft.

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