Flight body, control methods and procedures

Abstract

An aircraft includes a control unit configured to set a horizontal ground speed based on wind information, including information about wind direction and wind speed.

Description

Technical Field

[0001] This disclosure relates to flight bodies, control methods, and procedures. Background Technology

[0002] Recently, unmanned autonomous aerial vehicles (UAVs) or drones (hereinafter appropriately referred to as drones) have been used in various situations, such as various types of photography, observation, disaster relief, etc. Consequently, various control methods for drones have been proposed (for example, see PTL 1).

[0003] [List of Citations]

[0004] [Patent Literature]

[0005] [PTL 1]

[0006] JP 2018-52341A Summary of the Invention

[0007] [Technical Issues]

[0008] Generally, the landing attitude of a drone is affected by wind, making it prone to instability. Therefore, it is necessary to control the drone's attitude so that it can land stably even when affected by wind.

[0009] This disclosure was designed in view of the above circumstances, and the purpose of this disclosure is to provide a flight body, control method, and procedure that can be controlled to land in a stable attitude even when the flight body is affected by wind.

[0010] [Solution to the problem]

[0011] This disclosure includes, for example, an aircraft including a control unit configured to set a horizontal ground speed based on wind information including information about wind direction and wind speed.

[0012] This disclosure relates to, for example, a control method in an aircraft, including setting a horizontal ground speed by a control unit based on wind information, including information about wind direction and wind speed.

[0013] This disclosure is, for example, a program that enables a computer to execute control methods in an aircraft, including setting a horizontal ground speed by a control unit based on wind information including information about wind direction and wind speed. Attached Figure Description

[0014] [ Figure 1 ]

[0015] Figure 1 These are the figures that will be referenced when describing the issues to be considered in the embodiments.

[0016] [ Figure 2 ]

[0017] Figure 2 These are the figures that will be referenced when describing the issues to be considered in the embodiments.

[0018] [ Figure 3 ]

[0019] Figure 3 These are figures referenced when describing an overview of an embodiment.

[0020] [ Figure 4 ]

[0021] Figure 4 These are figures referenced when describing an overview of an embodiment.

[0022] [ Figure 5 ]

[0023] Figure 5 These are figures referenced when describing an overview of an embodiment.

[0024] [ Figure 6 ]

[0025] Figure 6 A to Figure 6 C in the figure is the one that will be referenced when describing an example of a wind information estimation method.

[0026] [ Figure 7 ]

[0027] Figure 7 This is a block diagram illustrating an example configuration of a drone according to the first embodiment.

[0028] [ Figure 8 ]

[0029] Figure 8 This is a flowchart illustrating the processing flow performed in a drone according to the first embodiment.

[0030] [ Figure 9 ]

[0031] Figure 9 This is a block diagram illustrating an example configuration of a drone according to the second embodiment.

[0032] [ Figure 10 ]

[0033] Figure 10 This is a flowchart illustrating the processing flow performed in a drone according to the second embodiment.

[0034] [ Figure 11 ]

[0035] Figure 11This is a flowchart illustrating the processing flow performed in a drone according to a third embodiment.

[0036] [ Figure 12 ]

[0037] Figure 12 This is a block diagram illustrating an example configuration of a drone according to the fourth embodiment.

[0038] [ Figure 13 ]

[0039] Figure 13 This is a flowchart illustrating the processing flow performed in a drone according to the fourth embodiment. Detailed Implementation

[0040] In the following description, embodiments of the present disclosure will be described with reference to the accompanying drawings. The description will proceed in the following order.

[0041] <Issues to be considered in the embodiments>

[0042] <Overview of the Implementation>

[0043] <First Embodiment>

[0044] <Second Embodiment>

[0045] <Third Embodiment>

[0046] <Fourth Embodiment>

[0047] <Modification Example>

[0048] The embodiments described below are preferred specific examples of this disclosure, and the content of this disclosure is not limited to these embodiments.

[0049] <Issues to be considered in the embodiments>

[0050] First, to facilitate understanding of this disclosure, reference will be made to Figure 1 and Figure 2 The issues to be considered in the embodiments are described.

[0051] Figure 1 This is a schematic diagram illustrating the landing of drone 1. Figure 1 In the example shown, the wind blows from left to right relative to Drone 1 in the figure. For a stable landing of Drone 1, it is desirable that the horizontal ground velocity of Drone 1 becomes 0 or close to 0 upon landing. When making Drone 1 descend vertically, imagine a method that makes Drone 1 fly at the same speed as the wind in the opposite direction of the wind, such that the horizontal ground velocity near the ground surface becomes 0. When this control is executed, the attitude of Drone 1 tilts towards the windward side ( Figure 1(The states are indicated by reference numerals A1 and A2 in the attached diagram). Then, the side of the UAV 1 fuselage closest to the ground experiences a considerable ground effect upon approaching the ground surface, resulting in the generation of a rotational torque ( Figure 1 (The state indicated by reference numeral A3 in the attached figure). Due to the generation of rotational torque, attitude control of UAV 1 becomes difficult. Furthermore, since UAV 1 lands at an angle, it may tip over upon landing. Figure 1 (The state indicated by reference numeral A4 in the attached figure).

[0052] Therefore, such as Figure 2 As shown, it is envisioned that the drone 1 will descend vertically ( Figure 2 (The states indicated by reference numerals A5 and A6 in the attached diagram) and with the fuselage leveled when the UAV 1 is close to the ground surface. Figure 2 The control of the state (represented by reference numeral A7 in the attached figure) is as follows. However, when the attitude of the UAV 1 changes significantly near the ground surface, the attitude of the UAV 1 is prone to instability. Furthermore, the UAV 1 sways in the wind according to its attitude changes, thus making landing unstable because the UAV 1 maintains a horizontal ground speed. Based on the above description, embodiments of this disclosure implement control for enabling the UAV 1 to land in a stable state.

[0053] <Overview of the Implementation>

[0054] The following will describe an overview of embodiments of the present disclosure. Common aspects of the embodiments will also be described in this description.

[0055] [Overview of the Implementation]

[0056] Figure 3 This is a diagram used to describe an overview of an embodiment. Assume that drone 1 lands on... Figure 3 The landing point LP is shown. The landing point LP can be a preset coordinate location or a location indicated by coordinates from a suitable ground device (hereinafter appropriately referred to as a ground station). A transition point PA is set at an appropriate location in space, such as... Figure 3 As shown in the diagram, the transition point PA is a point located above the landing point LP and is the point from which the drone begins its landing operation. The drone 1, located at a position in space (above the transition point PA), determines its landing location. For example, the drone 1 may determine its landing location autonomously based on commands from the remote controller, completion of a given task, depletion of remaining battery capacity, malfunction of sensors included in the drone 1, or the occurrence of a communication failure.

[0057] Upon landing, UAV 1 acquires wind information. This wind information includes information about the winds affecting the UAV's flight, including wind direction and speed. This wind information can be acquired through sensors included in UAV 1 or transmitted to UAV 1 from a ground station.

[0058] UAV 1 determines its landing approach sequence and grounding sequence. The landing approach sequence is determined from UAV 1's current position ( Figure 3 The control performed on UAV 1 from the current point PB to the transition point PA is described. A specific example of a landing approach sequence is information representing the temporal position of UAV 1 from the current point PB to the transition point PA and the velocity of UAV 1 at each position. Here, for a stable landing of UAV 1, it is desired that the horizontal ground velocity at landing is approximately 0. Approximately 0 means that the horizontal ground velocity is 0 or sufficiently close to 0 for UAV 1 to land safely. Therefore, at the transition point PA, control is performed in the landing approach sequence to pre-assign a horizontal ground velocity to UAV 1 so that the horizontal ground velocity of UAV 1 becomes approximately 0 at the landing point LP. Specifically, the control includes the rotational speed of multiple motors in the UAV, so that the horizontal ground velocity of the UAV becomes the set horizontal ground velocity. The trajectory of UAV 1 from the current point PB to the transition point PA and the horizontal ground velocity at each position are calculated, such that a predetermined horizontal ground velocity is assigned at the transition point PA, and the operation of UAV 1 is appropriately controlled based on the calculation results.

[0059] The grounding sequence is the control exercised on UAV 1 from transition point PA to landing point LP. When UAV 1 detects that it has passed transition point PA, it is controlled according to the grounding sequence. The grounding sequence is, for example, information representing the temporal sequence of positions before landing and the vertical velocity at each position. Simultaneously, the grounding sequence defines the control or horizontal ground velocity at each position to keep UAV 1 level. UAV 1 descends towards landing point LP by being controlled based on the grounding sequence, as... Figure 3 As shown in the diagram, since the horizontal ground velocity becomes approximately 0 when the drone 1 lands with its fuselage already horizontal, it is possible to suppress the tilt of the drone 1 and enable the drone 1 to land in a stable attitude.

[0060] [Common Aspects in the Examples]

[0061] (Transition Height)

[0062] Next, common aspects of the embodiments will be described. First, the transition altitude H will be described as the altitude from the landing point LP to the transition point PA. Meanwhile, the coordinates of the landing point LP are represented by (x, y, 0), and the coordinates of the transition point PA are represented by (x', y', H) (see [link to documentation]). Figure 4 ).

[0063] When the transition altitude is H, the descent speed of UAV 1 is v. z (t), the time from the transition point is t, and the landing time is t. t The descent velocity of UAV 1 at the transition point PA (hereinafter appropriately referred to as the descent velocity during the transition) is vz (0)=v zH And the descent speed of UAV 1 during landing (hereinafter appropriately referred to as the descent speed during landing) is v z (t t ) = v z0 (refer to Figure 4 This relationship is represented by the following mathematical formula 1.

[0064] [Mathematical Formula 1]

[0065]

[0066] In particular, when the descent rate decreases at a constant rate, the integral mentioned above is solved analytically and expressed by the following mathematical formula 2.

[0067] [Mathematical Formula 2]

[0068] H = 1 / 2(v) z Hv z0 )·t t

[0069] The descent speed during landing is set to a speed no higher than the safe landing speed for the drone. If the descent speed during landing is set to 0 or very close to 0, the drone may fail to land under conditions of large positional error; therefore, the descent speed during landing is set within the range where the drone can land safely. The descent speed during landing can be set according to the fuselage specifications. Furthermore, the transition altitude can be set based on an approximate indication of the fuselage size (e.g., approximately a few times the fuselage diameter). In this case, a height set as the transition altitude H can be used. As an example, the descent speed v at the transition point is adjusted approximately. z H and time t t To calculate the transition height H.

[0070] (Horizontal ground speed)

[0071] Next, the horizontal ground velocity will be described. When the mass of UAV 1 is M and its gravitational acceleration is g, the rotor thrust of UAV 1 can be calculated from (Mg + F). v ) indicates (reference) Figure 5 Additionally, horizontal force

[0072]

[0073] This is based on the horizontal component of the wind pressure received in the horizontal direction.

[0074]

[0075] This is the horizontal ground velocity vector of UAV 1. Furthermore,

[0076]

[0077] It is the wind vector in the horizontal direction.

[0078] Horizontal ground velocity vector of UAV 1

[0079]

[0080] It is represented by the following differential equation derived from the equation of motion.

[0081]

[0082] If at grounding time t t The horizontal ground speed of UAV 1 is 0 and By solving the equations mentioned above under the given conditions, we can obtain the horizontal ground velocity of UAV 1 at the transition point PA.

[0083]

[0084] Although

[0085]

[0086] The equations mentioned above need to be explicit, but they can be approximated using the following mathematical formula 3.

[0087] [Mathematical Formula 3]

[0088]

[0089] K1 and K2 are the primary and secondary constants of the wind pressure applied to UAV 1. K1 and K2 can be obtained in advance through experiments, simulations, etc. When only the component of the velocity of UAV 1 that is parallel to the wind is taken, the equation expressed by the following mathematical formula 4 is obtained.

[0090] [Mathematical Formula 4]

[0091]

[0092] If we numerically or analytically solve the mathematical formula 4 mentioned above by approximating K2 to K2 = 0, then we can obtain the horizontal ground velocity of UAV 1 required at the transition point PA.

[0093]

[0094] According to each embodiment, this horizontal ground speed is set by a control unit included in the UAV. Simultaneously, when determining the horizontal ground speed of UAV 1, the horizontal coordinates (x', y') of the transition point PA are determined by performing integration on the horizontal ground speed, etc. These coordinates are then combined with the transition height H determined as described above to determine the coordinates (x', y', H) of the transition point PA.

[0095] (Wind Information Estimation Method)

[0096] Next, the wind information estimation method will be described. In this description, an example of wind information acquisition by a UAV 1 (multi-rotor aircraft) is presented.

[0097] As a method for estimating wind information, UAV 1 maintains a horizontal position and its airspeed is set to 0, such as... Figure 6 The diagram in section A illustrates this. Due to the ground speed of the fuselage at that time...

[0098]

[0099] Become equal to wind vector

[0100]

[0101] Therefore, this value is set to wind information.

[0102] As another method for estimating wind information, wind vectors

[0103]

[0104] The airspeed is estimated from the speedometer or fuselage attitude installed in the UAV 1.

[0105]

[0106] Mid-vector minus the fuselage's ground velocity

[0107]

[0108] To estimate (see Figure 6 (B) The estimation result is set as wind information.

[0109] When the uncertainty in the ground velocity estimate is high, UAV 1 flies along the atmospheric return-to-origin route (reference). Figure 6 (C) and estimate wind direction and speed based on the difference between airspeed at the starting and ending points. Therefore, it is possible to offset the uncertainty of airspeed estimates.

[0110] In addition to the methods described above, wind information can also be estimated based on changes in position from Simultaneous Localization and Mapping (SLAM) performed in UAV 1, as well as the attitude and motor output of UAV 1. Furthermore, wind information can be estimated based on the difference between the GPS position of UAV 1 and its attitude and motor output. Wind information can be estimated or measured by a ground station (as an external device) or another UAV. The measured wind information can then be transmitted from the ground station to UAV 1 and acquired by a wind information acquisition unit. Alternatively, wind information can be input by a user through a user interface (UI), and the input wind information can be transmitted to UAV 1.

[0111] <First Embodiment>

[0112] [Example of drone internal configuration]

[0113] Figure 7 This is a block diagram illustrating an example of the internal configuration of a drone (hereinafter appropriately referred to as drone 1A) according to a first embodiment. For example, drone 1A includes a control unit 101, a fuselage control unit 102, a sensor unit 103, a fuselage information acquisition unit 104, a wind information acquisition unit 105, and a communication unit 106. The control unit 101 includes a flight status management unit 101A, a flight planner 101B, a landing planner 101C, and an attitude planner 101D as functional blocks.

[0114] Control unit 101 provides overall control of UAV 1A. Flight status management unit 101A manages the flight status of UAV 1A and switches between control according to flight planner 101B and landing planner 101C depending on the flight status. Flight planner 101B generates a flight path plan for UAV 1A. The flight path plan defines the time sequence of positions that UAV 1A will pass through and the speed at those positions. The flight path plan can be preset or set by flight planner 101B according to tasks assigned to UAV 1A, etc. Flight planner 101B outputs the flight path plan to attitude planner 101D.

[0115] Landing planner 101C generates an approach route plan and a landing route plan. The approach route plan defines the temporal positions from the current position of UAV 1A to the transition point PA and the velocities at those positions. Furthermore, the landing route plan according to this embodiment defines the attitude, temporal positions, and vertical velocities from the transition point PA to the landing point LP. Landing planner 101C outputs the approach route plan and the landing route plan to attitude planner 101D.

[0116] The attitude planner 101D generates fuselage control information based on the flight path plan applied from the flight planner 101B and the approach and touchdown path plans applied from the landing planner 101C. The attitude planner 101D generates fuselage control information, for example, for a UAV 1A, to enable the UAV 1A to reach positions and velocities (specifically, ground velocities in all directions) defined in the flight path plan. The attitude planner 101D determines fuselage control information, including attitude, vertical acceleration, etc., based on the flight path plan, taking into account differences in fuselage position and velocity.

[0117] Additionally, the attitude planner 101D generates, for example, fuselage control information for the UAV 1A, to enable the UAV 1A to reach the positions and velocities (specifically, ground velocities in all directions) defined in the approach route plan. Furthermore, the attitude planner 101D generates, for example, fuselage control information for the UAV 1A to reach the positions, vertical velocities, and attitudes defined in the grounding route plan. The attitude planner 101D outputs the fuselage control information to the fuselage control unit 102. Simultaneously, the attitude planner 101D generates, for example, fuselage control information to control the attitude of the UAV 1A to achieve the attitude assigned according to the grounding route plan, without needing to correct the horizontal position and horizontal velocity of the UAV 1A's fuselage according to the grounding route plan.

[0118] The fuselage control unit 102 performs control in response to fuselage control information supplied from the attitude planner 101D. The fuselage control unit 102 controls the rotational speed of the motors included in the UAV 1A, so that the UAV 1A has an attitude and speed according to the fuselage control information.

[0119] The sensor unit 103 is named collectively after the multiple sensors used to acquire airframe information of the UAV 1A (e.g., the current position, speed, attitude, etc. of the UAV 1A). The sensors constituting the sensor unit 103 may include GPS, SLAM sensors, accelerometers, gyroscopes, atmospheric pressure sensors, etc.

[0120] The fuselage information acquisition unit 104 appropriately converts the sensing data input from the sensor unit 103 from analog data into digital data. Then, the fuselage information acquisition unit 104 outputs the converted digital sensing data to the control unit 101.

[0121] The wind information acquisition unit 105 acquires wind information and outputs the acquired wind information to the control unit 101. Since a specific example of the wind information estimation method has already been described, a repeated description is omitted.

[0122] The communication unit 106 allows the UAV 1A to communicate with other devices. The communication unit 106 includes modulation / demodulation circuitry, etc., according to a communication method. The communication unit 106 performs, for example, communication with a ground station GS. According to this communication, for example, wind information transmitted from the ground station GS is received by the communication unit 106. The communication unit 106 outputs the received wind information to the control unit 101.

[0123] [Processing Flow]

[0124] Figure 8 This is a flowchart illustrating the processing flow performed in the UAV 1A according to the first embodiment.

[0125] In step ST101, the flight status management unit 101A determines landing. As described above, the flight status management unit 101A determines landing based on instructions from the remote controller, completion of a designated task, reduction of remaining battery capacity, malfunction of sensors included in the UAV 1, or occurrence of communication failure. Although not shown, the UAV 1A plans its flight based on the flight route according to the flight planner 101B prior to step ST101. Then, processing proceeds to step ST102.

[0126] In step ST102, the flight status management unit 101A switches the planner from flight planner 101B to landing planner 101C. Furthermore, the flight status management unit 101A applies the coordinates of landing point LP to the landing planner 101C. Then, the process proceeds to step ST103.

[0127] In step ST103, the landing planner 101C acquires wind information. This wind information can be estimated by the UAV 1A or transmitted from the ground station GS. The landing planner 101C then generates a touchdown route plan based on the acquired wind information. Specifically, the landing planner 101C sets the horizontal ground speed of the UAV 1A based on the acquired wind information and determines the position of the transition point PA based on the horizontal ground speed. The specific method for setting the horizontal ground speed has been described above. Furthermore, the landing planner 101C generates a touchdown route plan that includes the attitude at the transition point PA (horizontal in this example), the temporal sequence of positions from the transition point PA to the landing point LP, the vertical acceleration at these positions, etc. Processing then proceeds to step ST104.

[0128] In step ST104, the landing planner 101C generates an approach route plan from the current position to the transition point PA, such that the position of the transition point PA and the speed of the UAV 1A at the transition point PA correspond to the horizontal ground speed determined in step ST103. Then, the process proceeds to step ST105.

[0129] In step ST105, the landing planner 101C provides the approach route plan to the attitude planner 101D. Then, the process proceeds to step ST106.

[0130] In step ST106, the attitude planner 101D generates fuselage control information based on the approach route plan prior to the transition point PA. According to the fuselage control unit 102, which operates based on the generated fuselage control information, the UAV 1A moves to the position defined in the approach route plan. Additionally, according to the fuselage control unit 102, which operates based on the generated fuselage control information, the motors of the UAV 1A rotate to reach the speed defined in the approach route plan. Then, processing proceeds to step ST107.

[0131] In step ST107, it is determined that the fuselage altitude has reached the transition point PA. For example, the flight status management unit 101A determines that the fuselage altitude of the UAV 1A has reached the transition point PA based on sensing data input from the sensor unit 103. The flight status management unit 101A notifies the landing planner 101C that the fuselage altitude of the UAV 1A has reached the transition point PA. Upon receiving the notification, the landing planner 101C provides the grounding route plan generated in step ST103 to the attitude planner 101D. Then, the process proceeds to step ST108.

[0132] In step ST108, the attitude planner 101D generates fuselage control information based on the grounding route plan. In this example, the grounding route plan includes information on the attitude level and information about vertical acceleration. Therefore, having received the grounding route plan, the attitude planner 101D generates fuselage control information, including vertical velocity, to maintain the attitude level of the UAV 1A after passing the transition point PA. The attitude planner 101D then outputs the generated fuselage control information to the fuselage control unit 102. Based on the fuselage control unit 102 operating according to the fuselage control information, the UAV 1A descends at a predefined speed while maintaining its attitude level. Then, processing proceeds to step ST109.

[0133] In step ST109, the landing planner 101C instructs the attitude planner 101D to put the propellers of the UAV 1A into an idle state while simultaneously checking the landing of the UAV 1A. The attitude planner 101D generates fuselage control information based on this instruction. The attitude planner 101D outputs the generated fuselage control information to the fuselage control unit 102. Based on the fuselage control unit 102 operating according to the fuselage control information, the propellers of the UAV 1A enter an idle state. An idle state refers to the state in which the propellers of the UAV 1A rotate at a predetermined rotational speed or a lower rotational speed (a speed at which the fuselage of the UAV 1A does not increase). When the propellers of the UAV 1A enter an idle state, the user can confirm that the UAV 1A has not been damaged. However, the propellers of the UAV 1A can stop instead of entering an idle state.

[0134] According to the first embodiment described above, the horizontal ground velocity is pre-assigned to the UAV 1A at the transition point PA, such that the horizontal ground velocity at landing becomes 0 or approximately 0. Furthermore, after the transition point PA, the attitude of the UAV 1A is controlled to be horizontal. Therefore, the UAV 1A can land stably.

[0135] <Second Embodiment>

[0136] Next, a second embodiment will be described. In the description of the second embodiment, the same reference numerals are assigned to components that are the same as or similar to those described above, and repeated descriptions will be omitted as appropriate. Unless otherwise mentioned, the matters described in the first embodiment can be applied to the second embodiment.

[0137] Figure 9 This is a block diagram illustrating a configuration example of a drone (hereinafter appropriately referred to as drone 1B) according to a second embodiment. Drone 1B differs from drone 1A in that drone 1B does not include a wind information acquisition unit 105 and the control unit 101 includes a wind measurement planner 101E in its configuration.

[0138] The wind measurement planner 101E generates a route plan for acquiring wind information. The wind measurement planner 101E outputs the generated route plan to the attitude planner 101D. The attitude planner 101D generates fuselage control information to cause the UAV 1B to move along the route plan provided by the wind measurement planner 101E or to change the speed of the UAV 1B to the speed according to the route plan. The attitude planner 101D outputs the generated fuselage control information to the fuselage control unit 102. The fuselage control unit 102, operating based on the fuselage control information, implements the route plan generated by the wind measurement planner 101E.

[0139] Figure 10This is a flowchart illustrating the processing flow performed in the UAV 1B. In step ST101, the flight status management unit 101A determines the landing as in the first embodiment. Then, the process proceeds to step ST201.

[0140] In step ST201, the flight status management unit 101A switches the planner from flight planner 101B to wind measurement planner 101E. Then, the process proceeds to step ST202.

[0141] In step ST202, the wind measurement planner 101E measures the wind and generates a route plan for acquiring wind information. The route plan for acquiring wind information includes, for example, information defining the time-sequential positions of the UAV 1B, its attitude, and velocity at those positions. Processing then proceeds to step ST203.

[0142] In step ST203, the wind measurement planner 101E sends the resulting route plan to the attitude planner 101D. Then, processing proceeds to step ST204.

[0143] In step ST204, the attitude planner 101D generates fuselage control information for implementing the route plan devised by the wind measurement planner 101E, specifically the flight position, attitude at the flight position, and velocity. The attitude planner 101D then sends the fuselage control information to the fuselage control unit 102. The UAV 1B flies according to the fuselage control unit 102, which operates based on the fuselage control information. Processing then proceeds to step ST205.

[0144] In step ST205, the wind measurement planner 101E estimates the wind information, for example, based on the difference between the route plan used to obtain wind information and the actual location of the UAV 1B, using a known method.

[0145] Following the processing in step ST205, the processing related to steps ST102 to ST109 is performed. Since the details of the processing related to steps ST102 to ST109 have already been described, repeated descriptions will be omitted.

[0146] According to the second embodiment described above, the UAV 1B can autonomously generate a route plan for acquiring wind information and acquire wind information based on the route plan.

[0147] <Third Embodiment>

[0148] Next, a third embodiment will be described. In the description of the third embodiment, the same reference numerals are assigned to components that are the same as or similar to those described above, and repeated descriptions will be omitted as appropriate. Furthermore, unless otherwise mentioned, the content described in the first and second embodiments can be applied to the second embodiment.

[0149] The same configuration as that of UAV 1A described in the first embodiment can be applied as the configuration of UAV 1C according to the third embodiment (hereinafter appropriately referred to as UAV 1C). Although the attitude (horizontal) after the transition point PA is provided as the grounding path plan in the first embodiment, the third embodiment differs from the first embodiment in that the horizontal ground velocity from the transition point PA to the landing point LP is provided as the grounding path plan.

[0150] Figure 11 This is a flowchart illustrating the processing flow performed in the UAV 1C. Details of the processing related to steps ST101 to ST104 have already been described, so repeated descriptions will be omitted. Meanwhile, the grounding route plan generated in step ST103 of this embodiment defines the horizontal ground velocity at the transition point PA and the horizontal ground velocity at each location from the transition point PA to the landing point LP.

[0151] In step ST301, following step ST104, the landing planner 101C integrates the grounding route plan and the approach route plan. Then, processing proceeds to step ST301.

[0152] In step ST302, the landing planner 101C provides the integrated route plan to the attitude planner 101D. Then, the process proceeds to step ST303.

[0153] In step ST303, the attitude planner 101D generates fuselage control information to implement the route plan provided to it by the landing planner 101C. The attitude planner 101D then outputs the generated fuselage control information to the fuselage control unit 102. Based on the operation of the fuselage control unit 102 in response to the fuselage control information, the UAV 1C reaches a position, attitude at those positions, and horizontal ground velocity according to the route plan integrated by the landing planner 101C. Processing then proceeds to step ST109. The details of step ST109 have already been described, so a repeated description will be omitted.

[0154] As described above, according to the third embodiment, by assigning the horizontal ground speed from the transition point PA to the landing point LP to the UAV 1C, the UAV 1C can land in a stable attitude.

[0155] <Fourth Embodiment>

[0156] Next, a fourth embodiment will be described. In the description of the fourth embodiment, the same reference numerals are assigned to components that are the same as or similar to those described above, and repeated descriptions will be omitted as appropriate. Unless otherwise mentioned, the matters described in the first to third embodiments can be applied to the fourth embodiment.

[0157] Figure 12This is a block diagram illustrating a configuration example of a drone (hereinafter appropriately referred to as drone 1D) according to a fourth embodiment. Drone 1D differs from drone 1A in that it includes a go-around planner 101F. The go-around planner 101F is a planner that stops the landing and allows the drone 1D to ascend to a safe altitude if the attitude and horizontal ground speed of drone 1D do not fall within permissible ranges during landing.

[0158] Figure 13 This is a flowchart illustrating the processing flow performed in UAV 1D. Details of the processes related to steps ST101 to ST104 and ST301 to ST303 have already been described, therefore repeated descriptions will be omitted. After the processing in step ST303, the process proceeds to step ST401.

[0159] In step ST401, it is determined whether the fuselage of the UAV 1D is above the transition point PA; specifically, whether the height of the UAV 1D's fuselage changes to the transition point PA or lower. For example, this determination is performed by the flight status management unit 101A based on sensing data acquired by the sensor unit 103. When the fuselage of the UAV 1D is not above the transition point PA, the process returns to step ST303. When the fuselage of the UAV 1D is not above the transition point PA, the process proceeds to step ST402.

[0160] In step ST402, it is determined whether the UAV 1D has been grounded. For example, this determination is performed by the flight status management unit 101A based on sensing data acquired by the sensor unit 103. When the flight status management unit 101A determines that the UAV 1D has been grounded, the process proceeds to step ST403.

[0161] In step ST403, the flight status management unit 101A notifies the landing planner 101C that the fuselage of the UAV 1D has touched down. Upon receiving the notification, the landing planner 101C instructs the attitude planner 101D to put the propellers of the UAV 1A into an idle state. Based on this instruction, the attitude planner 101D generates fuselage control information. The attitude planner 101D outputs the generated fuselage control information to the fuselage control unit 102. According to the fuselage control unit 102 operating based on the fuselage control information, the propellers of the UAV 1A enter an idle state. As described above, the idle state refers to the state in which the propellers of the UAV 1A rotate at a predetermined rotational speed or a lower rotational speed (a rotational speed at which the fuselage of the UAV 1A does not increase).

[0162] When it is determined in step ST402 that the UAV 1D is not grounded, the process proceeds to step ST404.

[0163] In step ST404, it is determined whether the tilt angle and horizontal ground speed of the UAV 1D fall within the allowable range. For example, this determination is performed by the flight status management unit 101A based on sensing data acquired by the sensor unit 103. Specifically, the flight status management unit 101A determines whether the tilt angle is a threshold or less, and if so, determines that the tilt angle falls within the allowable range. Furthermore, the flight status management unit 101A determines whether the difference between the current horizontal ground speed and the horizontal ground speed defined in the route plan is a threshold or less, and if so, determines that the current horizontal ground speed falls within the allowable range.

[0164] If it is determined that the tilt angle and horizontal ground speed of UAV 1D are within the allowable range, then the process returns to step ST303. If it is determined that the tilt angle and horizontal ground speed of UAV 1D are not within the allowable range, then the process proceeds to step ST405.

[0165] In step ST405, the flight status management unit 101A switches the planner from the landing planner 101C to the go-around planner 101F. Because the fuselage tilt and horizontal ground speed of the UAV 1D are not within the allowable range, the go-around planner 101F executes control to stop the landing. Specifically, the go-around planner 101F generates a route plan to allow the UAV 1D to ascend to a safe altitude. The go-around planner 101F outputs the generated route plan to the attitude planner 101D. Then, processing proceeds to step ST406.

[0166] In step ST406, the attitude planner 101D generates fuselage control information to implement the route plan provided by the go-around planner 101F. Then, the attitude planner 101D outputs the generated fuselage control information to the fuselage control unit 102. Based on the fuselage control unit 102, which controls the rotational speed of motors, etc., according to the fuselage control information, the UAV 1D ascends to a safe altitude. Then, processing proceeds to step ST407.

[0167] In step ST407, the UAV 1D, having ascended to a safe altitude, enters a standby state. The flight status management unit 101A of the UAV 1D performs control, for example, to restart the landing sequence (e.g., the processing of steps ST101 to ST104 above, and the processing of steps ST301 and ST302) to land the UAV 1D again. The UAV 1D may wait for instructions from the user.

[0168] Meanwhile, although this embodiment determines whether the tilt angle and horizontal ground speed of the UAV 1D fall within the allowable range, it is possible to determine whether either the tilt angle or the horizontal ground speed falls within the allowable range, or whether other parameters fall within the allowable range.

[0169] According to the fourth embodiment described above, when the tilt angle and horizontal ground speed of the drone differ from the plan, the drone 1D can ascend to a safe altitude. Therefore, when the drone 1D performs a landing operation in an inappropriate attitude, it can prevent the drone 1D from failing to land.

[0170] <Modification Example>

[0171] While the embodiments of this disclosure have been described in detail above, the content of this disclosure is not limited to the above embodiments, and various modifications can be made based on the technical spirit of this disclosure. Examples of modifications will be described below.

[0172] While each embodiment has been described with regard to convenience of description as a configuration of the control unit including multiple planners, this disclosure is not limited thereto. For example, the flight planner and landing planner may be configured as a single functional block.

[0173] Known control methods for drones can be applied to the drone in each embodiment.

[0174] This disclosure can also be implemented by devices, methods, programs, systems, etc. For example, by allowing programs with the functions described in the above embodiments to be downloadable and allowing devices without the functions described in the embodiments to download and install programs, the controls described in the embodiments can be executed in the device. This disclosure can also be implemented by a server that distributes programs. Furthermore, this disclosure can also be implemented as a tool for easily creating flight plans described in the embodiments. The items described in each embodiment and modified example can be appropriately combined.

[0175] It should be noted that the beneficial effects described herein are not necessarily limiting, and any beneficial effects described in this disclosure can be achieved. Furthermore, the interpretation of this disclosure should not be limited to the exemplified beneficial effects.

[0176] This disclosure can also be implemented using the following configurations. (1)

[0178] An aircraft includes a control unit configured to set a horizontal ground speed based on wind information, including information about wind direction and wind speed. (2)

[0180] According to the flight body described in (1), the wind information includes information about the wind that affects the flight of the flight body. (3)

[0182] The flying body according to (1) or (2), wherein the flying body includes a plurality of motors, and

[0183] The control unit controls the rotation speed of the multiple motors to achieve a set horizontal ground speed. (4)

[0185] The flying body according to any one of (1) to (3) wherein the horizontal ground speed set by the control unit becomes approximately 0 at the landing point. (5)

[0187] The flying body according to any one of (1) to (4) wherein the control unit controls the rotational speed of the motor to become the set horizontal ground speed at a point positioned above the landing point. (6)

[0189] According to the flight body described in (5), the control unit controls the attitude to become approximately horizontal at a point positioned above the landing point. (7)

[0191] According to the flight body described in (5) or (6), the point located above the landing point is the point where the landing operation begins. (8)

[0193] According to the aircraft described in (7), during the event from the start of the landing operation to the landing point, when at least one of the fuselage tilt and the horizontal ground speed exceeds the allowable range, the control unit performs control to raise the fuselage. (9)

[0195] The flying body according to any one of (5) to (8), wherein the point located above the landing point is determined at least based on the horizontal ground velocity. (10)

[0197] The flying body according to any one of (1) to (9) includes a wind information acquisition unit configured to acquire wind information. (11)

[0199] According to the flight body described in (10), the flight body includes a sensor unit, and

[0200] The wind information acquisition unit calculates and acquires wind information based on the difference between the sensing data obtained by the sensor unit and the motor output. (12)

[0202] According to the flight body described in (10), the wind information acquisition unit acquires wind information from an external device. (13)

[0204] A control method for an aircraft includes setting a horizontal ground speed by a control unit based on wind information, including information about wind direction and wind speed. (14)

[0206] A program that enables a computer to execute a control method in an aircraft, the control method comprising setting a horizontal ground speed by a control unit based on wind information including information about wind direction and wind speed.

[0207] [List of reference numerals]

[0208] 1A, 1B, 1C, 1D UAVs

[0209] 101 Control Unit

[0210] 101A Flight Status Management Unit

[0211] 101B Flight Planner

[0212] 101C Landing Planner

[0213] 101D Attitude Planner

[0214] 102 Airframe Control Unit

[0215] 103 Sensor Unit

[0216] 105 Wind Information Acquisition Unit

[0217] 106 Communication Units

Claims

1. An aircraft comprising a control unit configured to generate a touchdown route plan based on wind information including information about wind direction and wind speed, set a horizontal ground velocity greater than 0, and determine the position of a transition point positioned above a landing point based on the horizontal ground velocity, the touchdown route plan including horizontal attitude at the transition point, temporal positions from the transition point to the landing point, and vertical accelerations at these temporal positions. The control unit generates an approach route plan from the current position of the aircraft to the transition point, such that the horizontal velocity of the aircraft at the transition point becomes the horizontal ground velocity. The approach route plan includes the time sequence positions from the current position to the transition point and the horizontal and vertical ground velocities at these time sequence positions. The control unit controls the aircraft based on the approach route plan and the grounding route plan, and controls the attitude to keep the aircraft's attitude approximately horizontal during landing from the transition point to the landing point, which is the point where the landing operation begins.

2. The flying body according to claim 1, wherein the wind information includes information about the wind affecting the flight of the flying body.

3. The flying body according to claim 1, wherein the flying body comprises a plurality of motors, and The control unit controls the rotation speed of the multiple motors to achieve a set horizontal ground speed.

4. The aircraft according to claim 1, wherein the horizontal ground speed set by the control unit becomes approximately 0 at the landing point.

5. The flying body according to claim 1, wherein, During the event from the start of the landing operation to the landing point, if at least one of the fuselage tilt and horizontal ground speed exceeds the permissible range, the control unit executes control to raise the fuselage.

6. The aircraft according to claim 1, comprising a wind information acquisition unit configured to acquire wind information.

7. The flying body according to claim 6, comprising a sensor unit, The wind information acquisition unit calculates and acquires wind information based on the difference between the sensing data obtained by the sensor unit and the motor output.

8. The aircraft according to claim 6, wherein the wind information acquisition unit acquires wind information from an external device.

9. A control method for an aircraft, comprising generating a touchdown route plan by a control unit based on wind information including information about wind direction and wind speed, setting a horizontal ground velocity greater than 0 and determining the position of a transition point positioned above a landing point based on the horizontal ground velocity, the touchdown route plan including horizontal attitude at the transition point, temporal positions from the transition point to the landing point, and vertical accelerations at these temporal positions. The method further includes: The control unit generates an approach route plan from the current position of the aircraft to the transition point, such that the horizontal velocity of the aircraft at the transition point becomes the horizontal ground velocity. The approach route plan includes the time sequence positions from the current position to the transition point and the horizontal and vertical ground velocities at these time sequence positions. The control unit controls the flight body based on the approach route plan and the grounding route plan, and controls the attitude to keep the flight body approximately horizontal during landing from the transition point to the landing point, which is the point where the landing operation begins.

10. A computer program product storing instructions, which, when executed, cause a computer to perform a control method in an aircraft, the control method comprising generating a touchdown route plan by a control unit based on wind information including information about wind direction and wind speed, setting a horizontal ground velocity greater than 0 and determining, based on the horizontal ground velocity, the position of a transition point positioned above a landing point, the touchdown route plan including horizontal attitude at the transition point, temporal positions from the transition point to the landing point, and vertical accelerations at these temporal positions. The method further includes: The control unit generates an approach route plan from the current position of the aircraft to the transition point, such that the horizontal velocity of the aircraft at the transition point becomes the horizontal ground velocity. The approach route plan includes the time sequence positions from the current position to the transition point and the horizontal and vertical ground velocities at these time sequence positions. The control unit controls the flight body based on the approach route plan and the grounding route plan, and controls the attitude to keep the flight body approximately horizontal during landing from the transition point to the landing point, which is the point where the landing operation begins.

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