JP7457527B2 - aircraft - Google Patents

Description

The present invention relates to an aircraft.

Conventionally, techniques for avoiding lightning strikes by emitting ions have been studied. For example, Patent Document 1 describes a lightning strike prevention device that causes corona discharge and releases ions attached to fog from the ground to form an ion cloud to avoid direct lightning strikes on the ground.

Japanese Unexamined Patent Publication No. 4-071197

Lightning strikes can occur not only on ground facilities but also on aircraft. Aircraft are electrical conductors, and when the electric field in the space beneath a thundercloud concentrates on the aircraft, lightning strikes often occur when the aircraft is the trigger. Therefore, there is a need for the development of technology that suppresses lightning strikes on aircraft.

For example, it is possible to predict the appearance position of thunderclouds and derive a flight path that can avoid the thunderclouds. However, it is difficult to accurately predict the location of a lightning strike triggered by an aircraft, and if thunderclouds suddenly appear on the flight path, there is a risk that the aircraft will be affected by the lightning strike.

In view of these problems, the present invention aims to provide an aircraft that can suppress the effects of lightning strikes.

In order to solve the above problems, the aircraft of the present invention includes a cloud position acquisition unit that acquires the position of a cloud, and an electric field when passing near the cloud based on the acquired cloud position and flight path. An electric field direction estimation unit that estimates the direction; an attitude derivation unit that derives a target aircraft attitude that reduces the possibility of lightning strikes based on the estimated electric field direction; The aircraft includes a route derivation unit that derives a flight path anew, and an attitude control unit that controls the attitude of the aircraft so that it assumes the derived target aircraft attitude when passing near clouds.

The attitude derivation unit derives a plurality of target aircraft postures in time series according to changes in the positional relationship between the aircraft and clouds, and the route derivation unit derives a flight path so as to maintain a plurality of target aircraft postures. Good too.

The present invention makes it possible to reduce the effects of lightning strikes.

FIG. 1 is a schematic perspective view of an aircraft. FIG. 2 is a diagram showing the state of charge polarization in an aircraft. FIG. 3 is a functional block diagram for explaining the control system of the aircraft. FIG. 4 is a flowchart showing the flow of lightning strike avoidance processing. FIG. 5 is an explanatory diagram for explaining the electric field intensity distribution. FIG. 6 is a table in which electric field intensity distributions and electric field directions are associated with each other. FIG. 7 is an explanatory diagram for explaining the protruding plane. FIG. 8 is an explanatory diagram for explaining the target aircraft attitude. FIG. 9 is an explanatory diagram for explaining attitude control processing. FIG. 10 is another functional block diagram for explaining the control system of the aircraft. FIG. 11 is a flowchart showing the flow of lightning strike avoidance route control processing. FIG. 12 is an explanatory diagram for explaining the electric field direction. FIG. 13 is an explanatory diagram for explaining the flight path. FIG. 14 is an explanatory diagram for explaining the flight path.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely illustrative to facilitate understanding of the invention, and do not limit the invention unless otherwise specified. In this specification and the drawings, elements with substantially the same functions and configurations are given the same reference numerals to omit redundant explanation, and elements not directly related to the present invention are omitted from illustration. do.

FIG. 1 is a schematic perspective view of an aircraft 1. FIG. As shown in FIG. 1, the aircraft 1 includes a fuselage 10, a main wing 12, a horizontal stabilizer 14, a vertical stabilizer 16, a flight control device 18, an attitude sensor 20, an electric field sensor 22, and a flight mechanism 24. Be prepared. Here, a passenger plane is illustrated as the aircraft 1, but various machines that fly in the atmosphere can be employed.

The fuselage 10 is provided to extend in a roll axis direction connecting the nose side and the aft side of the aircraft 1. The main wing 12, horizontal stabilizer 14, and vertical stabilizer 16 are fixed to the fuselage 10 and contribute to stable flight of the aircraft 1.

The flight control device 18 is composed of a semiconductor integrated circuit including a central processing unit (CPU), a ROM in which programs and the like are stored, and a RAM as a work area. The flight control device 18 receives operational input from a pilot operating the aircraft 1 and controls the flight mechanism 24 to maintain the flight of the aircraft 1.

The attitude sensor 20 is composed of, for example, an IMU (Inertial Measurement Unit), and detects the attitude of the aircraft 1. There are multiple electric field sensors 22 (four in this case), which are provided at different positions on the upper outer surface of the aircraft 1 (for example, the nose, tail, and ends of the main wings 12 as shown in FIG. 1). The electric field sensors 22 detect the electric field strength at the locations where they are installed. Here, each of the four electric field sensors 22 is installed on the surface of the aircraft and detects the electric field strength at that position, but the electric field sensors 22 and the positions at which the electric field strength is detected do not necessarily have to correspond one-to-one.

The flight mechanism 24 is composed of fixed wings such as the main wings 12, horizontal stabilizer 14, and vertical stabilizer 16, and an internal combustion engine (e.g., a jet engine or a reciprocating engine) that obtains propulsive force, and maintains the aircraft suspended in the atmosphere by generating lift around the wings using the propulsive force. However, the mechanism that generates lift is not limited to this, and it is also possible to obtain lift or propulsive force using rotatable rotating wings (rotors). The flight mechanism 24 can also control the aircraft attitude, flight direction (yaw angle), altitude, and flight speed by adjusting the nose angle (pitch angle), bank angle (roll angle), and internal combustion engine output through the elevators and ailerons.

FIG. 2 is a diagram showing the state of charge polarization of the aircraft 1. In FIG. 2, "+" indicates a positive charge, and "-" indicates a negative charge. In FIG. 2, the aircraft 1 is flying near the bottom of a cloud CL that is negatively charged. Due to the influence of the electric field (electrostatic induction) due to the negative charge of the cloud CL, the upper side of the aircraft 1 is polarized to the positive polarity side, and the lower side is polarized to the negative polarity side.

Note that the cloud CL may be charged to the positive electrode side. Further, the aircraft 1 may be sandwiched between a negatively charged cloud CL and a positively charged cloud CL. Therefore, the charge polarization of the aircraft 1 is not necessarily in the state shown in FIG. 2.

In the example of Figure 2, cloud CL is located to the right of directly above aircraft 1, so the positive charges are polarized toward the upper side of aircraft 1 and are biased toward the right end of the main wing 12. Meanwhile, negative charges are polarized toward the lower side of aircraft 1 and are biased toward the lower side of the left end of the main wing 12. Therefore, a strong electric field generated at the site of concentrated positive charges causes insulation breakdown in the air, and charges leak out from streamers into the air in the form of leaders. Furthermore, charges that can no longer be held by cloud CL may move toward the site where the positive charges are biased, and the leader from cloud CL may connect with the leader extending from the aircraft and discharge. In this way, lightning may strike aircraft 1.

In order to avoid such lightning strikes, it is effective to predict the appearance position of the cloud CL using the aircraft 1 or ground equipment and to derive a flight path that can avoid the cloud CL itself. However, the appearance of the cloud CL is irregular and susceptible to the influence of the season and temperature, and furthermore, it is difficult to accurately predict the location where a lightning strike triggered by the aircraft 1 will occur. For example, it is easy to predict the location of a cumulonimbus cloud that can cause a lightning strike in the summer, but it is difficult to predict the location of a streaky cloud that can occur in the winter.

Therefore, even if the flight route is intended to avoid lightning strikes, if a cloud CL suddenly appears on the flight route, there is a risk that the aircraft will be affected by the lightning strike in the vicinity of the cloud CL. Here, the influence of lightning is suppressed by controlling the attitude of the aircraft 1.

Here, the bias of positive charges and negative charges in the aircraft 1 mainly depends on the direction of the electric field around the aircraft 1 (hereinafter simply referred to as the electric field direction). That is, an electric field having a predetermined direction is generated in the atmosphere by the cloud CL, and when the aircraft 1 flies in the electric field, positive charges and negative charges are biased as shown in FIG. Therefore, in this embodiment, the direction of the electric field is estimated, and the body posture of the aircraft 1 is displaced to a body posture that minimizes the influence of the electric field. suppress. The specific process will be explained below.

(Lightning avoidance attitude control process)
FIG. 3 is a functional block diagram for explaining the control system of the aircraft 1. The flight control device 18 also functions as an electric field direction estimation section 50, an attitude derivation section 52, and an attitude control section 54 in cooperation with the program. Further, such a functional unit obtains detection results from the attitude sensor 20 and the electric field sensor 22 and controls the flight mechanism 24. Here, the configuration necessary for avoiding lightning strikes, which is the purpose of this embodiment, will be explained, and the explanation of configurations that are not related to this embodiment will be omitted.

FIG. 4 is a flowchart showing the flow of lightning strike avoidance attitude control processing. Here, the lightning strike avoidance attitude control process is executed in response to an interrupt signal every predetermined period of time. In the lightning strike avoidance attitude control process, the electric field direction estimation unit 50 estimates the electric field direction around the aircraft 1 based on the detection result of the electric field sensor 22 (S100). Next, the attitude deriving unit 52 derives a target aircraft attitude that lowers the possibility of being struck by lightning based on the estimated electric field direction (S102). Subsequently, the attitude control unit 54 performs attitude control of the aircraft 1 so as to achieve the derived target aircraft attitude (S104). Each process will be explained in detail below.

(Electric field direction estimation process S100)
FIG. 5 is an explanatory diagram for explaining the electric field strength distribution. First, the electric field direction estimating unit 50 acquires the electric field strength on the upper side of the fuselage from a plurality of (here, four) electric field sensors 22. Then, the electric field strength at each position of the plurality of electric field sensors 22 is represented as a bar graph 60 in FIG. 5. Note that FIG. 5 shows the electric field strength above the body, that is, the electric field strength corresponding to positive charges. Here, the electric field strength at the right end of the main wing 12 near the cloud CL becomes high, while the electric field strength at the left end of the main wing 12 becomes low. Further, the electric field strength at the nose and the tail, which correspond to the intermediate position of the main wing 12, is an intermediate value between the right end portion and the left end portion of the main wing 12.

6 is a table in which the electric field strength distribution and the electric field direction are associated. Here, the electric field strength distribution at each position of the electric field sensors 22 when an electric field is applied to the aircraft with a unit electric field strength in each electric field direction is obtained in advance and tabulated. When the electric field direction estimation unit 50 acquires the electric field strength at each position of the electric field sensors 22, it identifies the electric field strength distribution in which the ratio of the electric field strengths is equal from the above table. For example, it is assumed that the ratio of the electric field strengths of the electric field sensors 22 is equal to A:B:C:D in FIG. 6. In other words, the electric field strengths of the electric field sensors 22 are A, B, C, D multiplied by a predetermined value. The electric field direction estimation unit 50 extracts the electric field directions E and F corresponding to A, B, C, and D in FIG. 6, and sets the electric field directions E and F as the current electric field directions 62 indicated by the white arrows in FIG. 5. In this way, the electric field direction estimation unit 50 can estimate the electric field direction around the aircraft 1.

Although an example is given here in which four electric field sensors 22 are used, the direction of the electric field can also be specified by arranging the three electric field sensors 22 unbalancedly instead of symmetrically. Furthermore, if it is sufficient to specify the direction of the electric field around one axis, the pitch axis or the roll axis, two electric field sensors 22 are sufficient.

(Posture derivation process S102)
In the example of FIG. 5, it can be seen that the electric field strength corresponding to positive charges increases from the upper left side to the upper right side of the main wing 12 of the aircraft 1. In other words, it can be said that positive charges are biased towards the upper right side of the aircraft 1. In this case, when the aircraft 1 flies near the left side of the negatively charged cloud CL, lightning strikes are likely to occur near the right end of the main wing 12 of the aircraft 1. On the other hand, the electric field strength corresponding to negative charges increases from the lower right side to the lower left side of the main wing 12 of the aircraft 1, and the negative charges are biased towards the lower left side of the aircraft 1. In this case, when the aircraft 1 flies near the right side of the positively charged cloud CL, lightning strikes are likely to occur near the left end of the main wing 12 of the aircraft 1.

Therefore, based on the estimated electric field direction, the attitude derivation unit 52 determines a target aircraft attitude with less bias in positive charges and negative charges, that is, a target aircraft attitude that can smooth out the bias in electric field strength and lower the possibility of being struck by lightning. Derive the posture.

First, the attitude derivation unit 52 derives a plane formed based on the protrusion of the aircraft 1 (hereinafter referred to as the protrusion plane).

FIG. 7 is an explanatory diagram for explaining the protruding plane. Here, the vertically upward protruding parts of the aircraft 1 include a vertically upper part 66a of the cockpit located in front of the fuselage 10, a vertically upper part 66b of the vertical tail 16, a right end 66c of the main wing 12, and a left end 66d of the main wing 12. and is set.

The posture deriving section 52 forms a plane located vertically above all of the set protrusions 66a, 66b, 66c, and 66d. Specifically, the attitude deriving unit 52 includes a connection 68 between the vertical upper part 66a of the cockpit and the vertical upper part 66b of the vertical tail 16, and the distance from the right end 66c of the main wing 12 and the left end 66d of the main wing 12 is An equal plane is set as the protruding plane 70.

Here, the protruding plane 70 has been described as a plane located vertically above all of the protruding portions 66a, 66b, 66c, and 66d, but it is sufficient for the protruding plane 70 to be formed based on the protruding portions 66a, 66b, 66c, and 66d of the aircraft 1. For example, the approximate plane of the protruding portions 66a, 66b, 66c, and 66d may be used as the protruding plane 70.

Furthermore, here, the protrusion plane 70 is derived assuming that the protrusions 66a, 66b, 66c, and 66d have the same shape, but the charge density may differ depending on the shape of the protrusions 66a, 66b, 66c, and 66d. be. For example, if the shapes of the protrusions 66a, 66b, 66c, and 66d are sharp, or if the corners are acute, charges will be concentrated (the electric field strength will be high), making it easy to cause lightning strikes.On the other hand, if the shapes are flat or If the surface is spherical and the corners are obtuse, the charges will be dispersed (the electric field strength will be lower) and lightning will be less likely to occur. Therefore, the attitude deriving unit 52 determines not only the positions of the protrusions 66a, 66b, 66c, and 66d but also their shapes. The protruding plane 70 may be derived by being offset.

Further, here, since the cloud CL is located vertically above the aircraft 1, an example has been described in which the vertically upward protruding portion of the aircraft 1 is raised to form the protruding plane 70. However, the target protrusion may be changed depending on the position of the cloud CL. For example, if the cloud CL is located vertically below, a vertically downward protrusion of the aircraft 1, for example, the abdomen of the fuselage 10, may be targeted.

Next, the attitude deriving unit 52 derives a target aircraft attitude such that the protruding plane 70 intersects perpendicularly to the electric field direction 62 estimated by the electric field direction estimating unit 50. At this time, the attitude deriving unit 52 may decompose the electric field direction 62 into a pitch axis and a roll axis.

FIG. 8 is an explanatory diagram for explaining the target aircraft attitude. For example, in the example of FIG. 8, the attitude deriving unit 52 derives a target aircraft attitude 72 in which the angle around the pitch axis (pitch angle) is inclined by α° so as to be perpendicular to the electric field direction 62. The attitude deriving unit 52 also derives a target aircraft attitude 72 in which the angle around the roll axis (roll angle) is inclined by β° so as to be perpendicular to the electric field direction 62. Here, the purpose is to equalize the electric field strength at the protrusion by setting the body posture of the aircraft 1 to a target body posture 72 in which the protrusion plane 70 and the electric field direction 62 perpendicularly intersect.

However, such target aircraft attitude 72 is derived within a range that allows stable flight to continue (for example, pitch angle -30° to +30°, roll angle -30° to +30°) and within a range where the flight path does not change significantly. be done. Therefore, if it is determined that the target aircraft attitude 72 that intersects perpendicularly to the electric field direction impedes stable flight or requires a significant change in the flight path, the attitude derivation unit 52 limit to the range where stable flight can continue and the flight path will not change significantly.

Further, although an example has been described here in which the attitude deriving unit 52 derives the target aircraft attitude 72 from the electric field intensity distribution at one point in time, the present invention is not limited to such a case. For example, the target aircraft attitude 72 may be derived based on the time change of the electric field strength distribution, which changes from moment to moment, by, for example, PID control or the like.

(Attitude control processing S104)
The attitude control unit 54 performs attitude control of the aircraft 1 so as to achieve the target aircraft attitude 72 derived by the attitude derivation unit 52. Specifically, the attitude control unit 54 first notifies (warns) the pilot that the target aircraft attitude 72 derived by the attitude derivation unit 52 will be achieved. Then, when the pilot allows the target aircraft attitude 72 to be achieved, the attitude control unit 54 inputs the target aircraft attitude 72 as an operation input. In this way, the pilot is no longer confused by sudden changes in the aircraft's attitude.

Further, the attitude control unit 54 may notify the pilot of the target aircraft attitude 72 itself derived by the attitude derivation unit 52 through a display device or the like. In this case, the pilot visually recognizes the target aircraft attitude 72 and manually controls the aircraft attitude of the aircraft 1. In this way, the aircraft can be placed in a posture that reduces the possibility of being struck by lightning, with the pilot being aware of it.

FIG. 9 is an explanatory diagram for explaining attitude control processing. Then, according to the input target aircraft attitude 72, the attitude control unit 54 tilts the nose vertically upward by a pitch angle α° and tilts the bank angle by a roll angle β°, as shown in FIG. At this time, the attitude control unit 54 targets the target aircraft attitude 72 and controls the aircraft attitude by feeding back the detection result of the attitude sensor 20.

In addition, after the aircraft attitude reaches the target aircraft attitude 72, the flight control device 18 again acquires the electric field strengths of the multiple electric field sensors 22. If the deviation in the electric field strength exceeds a predetermined range, the process from the electric field direction estimation process S100 may be executed again.

The attitude control unit 54 may adjust the rate of change of the aircraft attitude rather than immediately controlling it to the target aircraft attitude 72. For example, the target aircraft attitude 72 input by a first-order lag filter may be changed with a predetermined time constant. In this way, the safety of the pilot and passengers can be ensured even if the aircraft attitude is suddenly changed due to the appearance of clouds CL.

Further, here, the electric field direction is estimated using the table of FIG. 6 in which the electric field intensity distribution and the electric field direction are associated with each other, but the attitude of the aircraft 1 may be controlled without estimating the electric field direction. For example, a plurality of electric field sensors 22 are arranged symmetrically with respect to the aircraft body (for example, at the right end of the main wing 12 and at the left end of the main wing 12), and the attitude control unit 54 controls the two symmetrically arranged electric field sensors. The attitude of the aircraft 1 may be controlled so that the detection results (electric field strengths) of the sensors 22 are equal.

The configuration described above makes it possible to equalize the distribution of electric field strength corresponding to each positive charge and negative charge, and to place the aircraft 1 in an attitude that reduces the possibility of a lightning strike, thereby making it possible to suppress the effects of lightning strikes.

In the embodiment described above, when a cloud CL appears on the flight path, the attitude of the aircraft 1 is controlled in an area near the cloud CL where there is a high possibility of an aircraft-triggered lightning strike, thereby preventing a lightning strike. The impact was suppressed. However, depending on the flight situation, there is a possibility that the aircraft may not be able to take the desired attitude, or that the aircraft may deviate from the desired flight path due to abrupt control of the aircraft attitude. Therefore, when passing near the cloud CL (specifically, an area near the cloud CL that is likely to cause a lightning strike), it is possible to control the attitude of the aircraft 1 to a position that has a low possibility of being struck by lightning. By deriving flight paths, the effects of lightning strikes can be suppressed. The specific process will be explained below.

(Lightning avoidance route control processing)
FIG. 10 is another functional block diagram for explaining the control system of the aircraft 1. In cooperation with the program, the flight control device 18 functions as a cloud position acquisition section 56 and a route derivation section 58 in addition to the electric field direction estimation section 50, attitude derivation section 52, and attitude control section 54 described above. Note that the attitude deriving unit 52 and the attitude control unit 54 already explained in the above embodiment have substantially the same functions, so a detailed explanation will be omitted, and here, the electric field direction estimating unit 50 and the cloud position The acquisition section 56 and route derivation section 58 will be mainly explained.

FIG. 11 is a flowchart showing the flow of lightning strike avoidance route control processing. Here, the lightning strike avoidance route control process is executed in response to an interrupt signal every predetermined period of time. In the lightning strike avoidance route control process, the cloud position acquisition unit 56 acquires the position of the cloud CL (S200). Next, the electric field direction estimating unit 50 estimates the electric field direction when passing near the cloud CL, based on the acquired position and flight path of the cloud CL (S202). Next, the attitude deriving unit 52 derives a target aircraft attitude that lowers the possibility of being struck by lightning based on the estimated electric field direction (S204). Subsequently, the route deriving unit 58 derives a flight path anew so that the derived target aircraft attitude can be maintained in the vicinity of the cloud CL (S206). Next, the attitude control unit 54 controls the attitude of the aircraft 1 so that it has the derived target aircraft attitude when passing near the cloud CL (S208). Each process will be explained in detail below.

(Cloud position acquisition process S200)
The cloud position acquisition unit 56 acquires the position of the cloud CL, particularly the position of the cloud CL near the flight path. The position of the cloud CL is specified by various means. For example, (1) the prediction information of the cloud CL may be acquired from outside, (2) it may be acquired from the preceding aircraft 1, etc.

(1) Ground equipment can identify the appearance position of cloud CL predicted through weather radar or the like. Furthermore, the position of the cloud CL at a predetermined time in the future can also be estimated based on the position of the cloud CL, the wind direction, and the wind speed in the vicinity thereof. The cloud position acquisition unit 56 acquires, as the prediction information of the cloud CL, the position of the cloud CL near the flight route estimated by the ground equipment when passing through each flight route, for example. Further, the cloud position acquisition unit 56 can acquire the size, type, and amount of charge of the cloud CL in addition to the position of the cloud CL.

(2) Furthermore, as described above, in the aircraft 1, the electric field direction estimation unit 50 can estimate the electric field direction around the aircraft 1 based on the detection result of the electric field sensor 22. Therefore, the other preceding aircraft 1 temporarily holds the estimated electric field direction. Then, the cloud position acquisition unit 56 acquires the electric field direction in the flight path of the own aircraft 1 from other aircraft 1 flying in advance. In this way, the cloud position acquisition unit 56 can acquire the electric field direction, which is information equivalent to the position of the cloud CL.

(Electric field direction estimation process S202)
FIG. 12 is an explanatory diagram for explaining the electric field direction. Here, for convenience of explanation, the electric field direction around the roll axis of the aircraft 1 will be explained, but it goes without saying that the electric field direction around the pitch axis can be similarly derived.

(1) When the cloud position acquisition unit 56 acquires the position of the cloud CL, the electric field direction estimation unit 50 estimates the electric field (electric field lines) in the vicinity of the cloud CL based on the position, size, type, and charge amount of the cloud CL, as shown by the solid arrows in Figure 12.

Then, the electric field direction estimating unit 50 identifies the positional relationship between the cloud CL and the aircraft 1 based on the flight path of the own aircraft 1. For example, assume that the aircraft 1 is scheduled to fly toward the back of FIG. 12 from the position shown in FIG. 12 with respect to the cloud CL. Then, the aircraft 1 will pass through the lower right side of the cloud CL, as shown in FIG. 12. Next, the electric field direction estimating unit 50 identifies the direction of the lines of electric force near the aircraft 1, here the roll angle β°, and sets the roll angle β° as the electric field direction.

(2) When the cloud position acquisition unit 56 acquires the electric field direction on the flight path, the electric field direction estimation unit 50 uses the electric field direction as is. In this way, the electric field direction estimation unit 50 can estimate the electric field direction around the aircraft 1 when passing near the cloud CL.

(Posture derivation process S204)
The attitude deriving unit 52 derives a target aircraft attitude that reduces the possibility of lightning strikes based on the estimated electric field direction. The procedure for deriving such a target aircraft attitude has already been explained using FIG. 5 in the embodiment described above, so the explanation thereof will be omitted here.

(Route derivation processing S206)
The route deriving unit 58 re-derives a flight path so that the target aircraft attitude derived by the attitude deriving unit 52 can be maintained in the vicinity of the cloud CL.

FIG. 13 is an explanatory diagram for explaining the flight path. Here, it is assumed that the aircraft 1 lands on the runway RW. That is, the destination of the aircraft 1 is the runway RW. For example, assume that the aircraft 1 is scheduled to fly along a flight path 80 shown by a broken line in FIG. However, based on the position of the cloud CL acquired by the cloud position acquisition unit 56, it is assumed that the aircraft 1 is predicted to pass near the cloud CL before landing on the runway RW. Then, when the aircraft 1 passes near the cloud CL, the electric field of the cloud CL causes bias in positive charges and negative charges, which may cause a lightning strike triggered by the aircraft 1.

Therefore, as described above, the electric field direction estimating unit 50 estimates the electric field direction when passing near the cloud CL, based on the acquired position of the cloud CL and the flight path. Then, the attitude deriving unit 52 derives a target aircraft attitude that reduces the possibility of being struck by lightning based on the estimated electric field direction. Here, it is assumed that an attitude in which the roll axis is rotated by a predetermined angle (counterclockwise with the nose forward) is derived as the target aircraft attitude.

The route derivation unit 58 again derives a flight path 81 shown by a solid line in FIG. 13 so that the derived target aircraft attitude can be maintained in the vicinity of the cloud CL. Here, since the aircraft 1 turns for a predetermined period according to the target aircraft attitude (counterclockwise with the nose forward), the route derivation unit 58 derives a flight path 81 on the left side from the original flight path 80.

Furthermore, if the aircraft 1 were to fly along a flight path 81D shown by a dashed line in FIG. In this state, the left end of the main wing 12 faces in the direction of the electric field caused by the cloud CL. In this case, there is a higher possibility that the aircraft 1 will be struck by lightning than on the original flight path 80. Therefore, it is preferable that the route derivation unit 58 derives the flight route 81 on the left side from the original flight route 80.

Here, in order to facilitate understanding, an example has been given in which the route deriving unit 58 derives the flight route 81 based on the electric field direction when passing near the cloud CL, but this is not limited to such a case. The route deriving unit 58 may derive the flight path 81 by taking into consideration not only the direction of the electric field but also the strength of the electric field. In this case, the route deriving unit 58 first preferentially avoids the route where the electric field strength is high, and as a result, the route derivation unit 58 first avoids the route where the electric field strength is high, and as a result, the route derivation unit 58 performs the estimated Based on the direction of the electric field, a target aircraft attitude that can reduce the possibility of lightning strikes is derived.

When the aircraft 1 lands on the runway RW, the route deriving unit 58 calculates not only the electric field direction and electric field strength, but also the approach position, approach angle, minimum turning radius, and amount of residual combustion required for approaching the runway RW. A flight path 81 is derived by taking into account the flight distance and altitude that can be flown. Since the technology that reflects the parameters required for entering the runway RW is an existing technology, detailed explanation thereof will be omitted here.

(Attitude control processing S208)
While flying along the newly derived flight path 81, the attitude control unit 54 performs attitude control of the aircraft 1 so as to have the derived target aircraft attitude at the timing when the aircraft 1 passes near the cloud CL. Such attitude control of the aircraft 1 has already been explained using FIG. 9 in the above embodiment, so the explanation thereof will be omitted here.

By doing this, even if a cloud CL exists on the flight path 81, when passing near the cloud CL, the electric field strength distribution corresponding to each positive charge and negative charge is made uniform, and the airframe of the aircraft 1 is Since the attitude of the aircraft can be set to a position where the possibility of being struck by lightning is low, it is possible to suppress the effects of lightning while ensuring the safety of the pilot and passengers.

Note that the flight path is often longer than the width of the cloud CL. That is, the planned flight path 80 may include a plurality of clouds CL. In this embodiment, even if the flight path 80 includes a plurality of clouds CL, the influence of lightning can be appropriately suppressed.

FIG. 14 is an explanatory diagram for explaining the flight path. Here, it is also assumed that the aircraft 1 lands on the runway RW. For example, assume that the aircraft 1 is scheduled to fly along a flight path 80 shown by a broken line in FIG. However, based on the positions of the clouds CL acquired by the cloud position acquisition unit 56, it is assumed that the aircraft 1 is predicted to pass near a plurality of clouds CL before landing on the runway RW.

Here, the attitude deriving unit 52 derives a plurality of target aircraft postures in time series according to changes in the positional relationship between the aircraft 1 and the plurality of clouds CL, and the route deriving unit 58 maintains a plurality of target aircraft postures. Determine the flight path so that the aircraft can fly while keeping the aircraft on course.

Specifically, the attitude derivation unit 52 derives a target aircraft attitude that lowers the possibility of being struck by lightning, based on the estimated electric field direction (or electric field direction and electric field strength) for the cloud CL1 near the runway RW. Here, it is assumed that the derived target aircraft attitude is an attitude in which the roll axis is rotated by a predetermined angle (the nose is rotated forward and counterclockwise). The route derivation unit 58 derives a flight route 81 shown by a solid line in FIG. 14 so that the aircraft 1 can fly while maintaining the derived target aircraft attitude in the vicinity of the cloud CL1.

Next, the attitude deriving unit 52 derives a target attitude of the aircraft that reduces the possibility of being struck by lightning, based on the estimated electric field direction, for the cloud CL2 that the cloud CL2 will pass through in order to fly on the flight path 81. Here, it is assumed that the derived target aircraft posture is a posture that keeps the roll axis horizontal. The route derivation unit 58 derives a flight path 82 shown by a dashed line in FIG. 14 so that the aircraft 1 can fly while maintaining the derived target aircraft attitude in the vicinity of the cloud CL2.

Subsequently, the attitude deriving unit 52 derives a target aircraft attitude that lowers the possibility of being struck by lightning, based on the estimated electric field direction, for the cloud CL3 that the cloud CL3 will pass through in order to fly on the flight path 82. Here, it is assumed that the derived target aircraft attitude is an attitude in which the roll axis is rotated by a predetermined angle (the nose is rotated forward and clockwise). The route derivation unit 58 derives a flight route 83 shown by a two-dot chain line in FIG. 14 so that the aircraft 1 can fly while maintaining the derived target aircraft attitude in the vicinity of the cloud CL3.

Here, as described above, the derivation of the target aircraft attitude and the derivation of the flight path are repeated by calculating backwards (in reverse chronological order) from the target position. Note that for airspaces where clouds CL do not exist, it is possible to derive, for example, a flight route with the shortest flight distance or the lowest fuel consumption according to existing technology. In this way, even when a plurality of clouds CL are included in the flight path, the attitude of the aircraft 1 can be set to a body attitude with a low possibility of being struck by lightning, so it is possible to suppress the effects of lightning strikes. .

Note that here, we have explained an example in which the direction of the electric field near the aircraft 1 is derived for each of multiple clouds CL, but when the cloud CL is large and the electric field (lines of electric force) changes depending on the flight path, In this case, it is also possible to deal with it by regarding it as a plurality of clouds CL.

However, if priority is given to adopting a target aircraft attitude that reduces the possibility of lightning strikes, and a safe flight path is strictly derived, other factors, such as flight distance and fuel consumption, may be affected. Therefore, for example, the target aircraft attitude may be adjusted to the extent that the flight path does not affect the flight distance to the destination or the fuel consumption. For example, the attitude deriving unit 52 may correct the target aircraft attitude so that it becomes close to the shortest flight route, and the route deriving unit 58 may derive the flight route using the corrected target aircraft attitude.

In addition, the above-described embodiment allows the attitude of the aircraft 1 to be maintained at the target aircraft attitude when passing near the cloud CL. However, the state of the electric field may change depending on the state of the cloud CL. In that case, as described above, the electric field direction may be derived in real time by the electric field sensor 22, and the attitude of the aircraft 1 may be controlled in accordance with the change in the electric field direction.

With the configuration described above, it is possible to equalize the electric field strength distribution corresponding to positive charges and negative charges, and to derive a flight path that makes the aircraft 1's attitude less likely to be struck by lightning. This makes it possible to suppress the effects of lightning strikes while ensuring the safety of people.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these embodiments. It is clear that those skilled in the art can come up with various changes and modifications within the scope of the claims, and it is understood that these naturally fall within the technical scope of the present invention. be done.

For example, in the embodiment described above, four or more electric field sensors 22 are provided in the aircraft 1, and the electric field direction estimation unit 50 estimates the electric field direction around the aircraft 1 based on the detection results of the electric field sensors 22. I listed and explained. However, the present invention is not limited to this case, and one electric field sensor 22 may be provided on the upper side and the lower side of the body 10. In this case, the electric field direction estimation unit 50 estimates the electric field direction around the aircraft 1 based on the detection results of the two electric field sensors 22.

Also provided are programs for causing a computer to function as the flight control device 18, and storage media such as computer-readable flexible disks, magneto-optical disks, ROMs, CDs, DVDs, and BDs on which the programs are recorded. Here, the program refers to data processing means written in any language or writing method.

In addition, in the above-described embodiment, an example was given in which all of the functional units are mounted on the aircraft 1, but some or all of the functional units may be operated in ground equipment, and the flight of the aircraft 1 may be controlled using the results.

Note that the steps of the lightning avoidance attitude control process and the lightning avoidance path control process in this specification do not necessarily need to be processed in chronological order according to the order described in the flowchart, and may include parallel or subroutine processing.

REFERENCE SIGNS LIST 1 Aircraft 18 Flight control device 20 Attitude sensor 22 Electric field sensor 50 Electric field direction estimation unit 52 Attitude derivation unit 54 Attitude control unit 56 Cloud position acquisition unit 58 Route derivation unit 62 Electric field direction

Claims (2)

a cloud position acquisition unit that acquires the position of the cloud;
an electric field direction estimation unit that estimates an electric field direction when passing near the cloud based on the acquired cloud position and flight path;
an attitude derivation unit that derives a target aircraft attitude that reduces the possibility of lightning strikes based on the estimated electric field direction;
a route deriving unit that re-derives a flight path in the cloud so that the derived target aircraft attitude can be maintained;
an attitude control unit that controls the attitude of the aircraft so that the aircraft has the derived target aircraft attitude when passing near the cloud;
An aircraft equipped with The attitude deriving unit derives a plurality of target aircraft postures in time series according to changes in the positional relationship between the aircraft and the clouds,
The aircraft according to claim 1, wherein the route derivation unit derives the flight route so that a plurality of the target aircraft postures can be maintained.

Images